m6A modification of RNA in cervical cancer: role and clinical perspectives

ABSTRACT

N6-methyladenosine (m6A) is widely recognized as the predominant form of RNA modification in higher organisms, with the capability to finely regulate RNA metabolism, thereby influencing a series of crucial physiological and pathological processes. These processes include regulation of gene expression, cell proliferation, invasion and metastasis, cell cycle control, programmed cell death, interactions within the tumour microenvironment, energy metabolism, and immune regulation. With advancing research into the mechanisms of RNA methylation, the pivotal role of m6A modification in the pathophysiology of reproductive system tumours, particularly cervical cancer, has been progressively unveiled. This discovery has opened new research avenues and presented significant potential for the diagnosis, prognostic evaluation, and treatment of diseases. This review delves deeply into the biological functions of m6A modification and its mechanisms of action in the onset and progression of cervical cancer. Furthermore, it explores the prospects of m6A modification in the precision diagnosis and treatment of cervical cancer, aiming to provide new perspectives and a theoretical basis for innovative and advanced treatment strategies for cervical cancer.

1. Introduction

Cervical cancer (CC) is identified by the International Agency for Research on Cancer (IARC), a division of the World Health Organization, as the fourth leading cause of death among women globally. In 2022, it accounted for approximately 661,021 new cases and 348,189 deaths worldwide [1]. The primary treatment methods include surgical interventions, radiotherapy, chemotherapy, and more recently, emerging targeted therapies and immunotherapies. Despite the diversity of treatment options, the prognosis for advanced cervical cancer remains poor, with recurrent issues of drug resistance and relapse. Moreover, significant inter-individual variability in treatment responses highlights a critical gap in effective personalized therapeutic strategies.

The m6A modification, a pervasive epigenetic modification across various RNA molecules, plays a crucial role in RNA metabolism. It influences RNA splicing, nuclear export, localization, translation, and degradation, serving as a significant modality for regulating gene expression [2]. The m6A modification is enriched in the 3’ untranslated region (3’UTR) adjacent to the RNA termination codon, with a predominant RRACH sequence motif (where R stands for G or A, and H denotes A, C, or U) [3,4]. Research demonstrates the multifaceted roles of m6A modifications, occurring not solely within mRNA but also within distinctive motifs of noncoding RNAs (ncRNAs) – circular RNA (circRNA), long noncoding RNA (lncRNA), micro RNA (miRNA) and et al. [5]. Analogous to DNA and histone methylation, the m6A modification is characterized by its reversible and dynamic nature, modulated predominantly by the enzymatic activities of ‘writers’, ‘erasers’, and ‘readers [6]’. The roles and categorization of m6A enzymes in RNA metabolism are detailed in Table 1.

Table 1.

An overview of m6A enzymes: classification and functions in RNA metabolism.

Type	Enzyme	Function	References
Writers	METTL3/METTL14	The catalytic subunit of m6A methyltransferase complex, forms stable heterosomes	[7,8]
		which has methyltransferase activity and forms stable heterosomes forms stable heterosomes
	METTL16	Catalyzes m6A modification of U6 snRNA, snRNA, and other lncRNAs	[9]
	WTAP	Ensures that METTL3-METTL14 heterodimer is located on the nuclear spot and promotes catalytic activity	[10]
	RBM15/RBM15B	Facilitate the binding of the m6A complex and its recruitment to a specific RNA site	[11]
	ZC3H13	Promotes methyltransferase complex RNA binding	[12]
	VIRMA/KIAA1429	Bind WTAP, ZC3H13, and HAKAI together to provide binding sites for METTL3 and METTL14	[13]
Erasers	FTO	mRNA, lncRNA or other ncRNA demethylase	[14]
	ALKBH5	mRNA, lncRNA or other ncRNA demethylase	[15]
	ALKBH3	tRNAs demethylase	[16]
Readers	YTHDF1/2/3	YTHDF1 enhances mRNA translation	[17–19]
		YTHDF2 promotes mRNA degradation
		YTHDF3 interacts with YTHDF1 and YTHDF2 to enhance translation and degradation
	YTHDC1/2	YTHDC1 promotes SRSF3 or inhibits SRSF10 regulatory splicing, and interacts with NXF1× to promote nucleation	[20,21]
		YTHDC2 is a helicase that regulates mRNA translation or degradation
	HNRNPA2/B1	Regulate mRNA splicing or miRNA maturation	[22]
	HNRNPC/HNRNPG	Binding and controlling the processing of nascent RNA	[23]
	IGF2BP1/2/3	Safeguard mRNA transcripts against degradation and regulates alternative splicing of mRNA	[24]
	eIF3H	Initiates protein synthesis via a cap-independent mechanism	[25]

Methyltransferase complexes (MTC), known as ‘writers’, mediate RNA methylation. This complex primarily includes methyltransferase-like 3 (METTL3) [7], methyltransferase-like 14 (METTL14) [8], and Wilms tumour 1-associated protein (WTAP) [10]. METTL3, serving as the primary catalytic component, and METTL14, which acts more as a regulatory and RNA-binding scaffold, work synergistically to enhance methylation efficiency when co-localized within nuclear speckles [26]. WTAP aids in their localization and function within these nuclear structures. Additional components like zinc finger CCCH-type containing 13 (ZC3H13), RNA-binding motif proteins 15 (RBM15) and 15B (RBM15B), along with methyltransferase-like 16 (METTL16) and KIAA1429, extend the functionality of MTCs. ZC3H13 enhances the complex’s efficiency via its interaction with WTAP [12]. RBM15 and RBM15B, lacking catalytic activity, guide METTL3 and WTAP to specific RNA sites, ensuring precise m6A placement [11]. METTL16 specifically methylates U6 spliceosomal small nuclear RNA (snRNA), impacting S-Adenosyl Methionine (SAM) homoeostasis, while KIAA1429 directs the MTC to targeted RNA regions for methylation [9,13].

Erasers, or m6A demethylases, reverse the methylation of RNA by removing m6A modifications. The fat mass and obesity-associated protein (FTO) was the first such enzyme discovered [14]. AlkB homolog 5 (ALKBH5) and FTO belong to the nonheme Fe II/α-ketoglutarate (α-KG)-dependent dioxygenase AlkB family. They catalyse the oxidation of m6A to N6-hydroxymethyl adenosine (hm6A), which is further processed to N6-formyl adenosine (f6A), and eventually converted back to adenosine (A) [15,27]. FTO operates both in the nucleus and cytoplasm, whereas ALKBH5’s activity is primarily nuclear. Unlike FTO, which requires several steps to demethylate m6A, ALKBH5 can directly convert m6A to adenosine, streamlining the demethylation process [15,28]. Recent discoveries have also highlighted ALKBH3 as another m6A demethylase, expanding the family of enzymes that modulate RNA function and gene expression through methylation dynamics [16].

m6A can be recognized by readers, enabling their binding and subsequent involvement in downstream processes such as translation, mRNA degradation, and nucleation acceleration. The YTHDF family, known for its role in RNA biology, comprises YTHDF1/2/3 and YTHDC1/2 [17]. YTHDF2 was the first m6A reader characterized and is known for its binding to m6A sites through its C-terminal domain while interacting with the CCR4-NOT transcription complex, thereby facilitating the targeted mRNA degradation within processing bodies (P-bodies) [18]. Conversely, YTHDF1 preferentially targets m6A sites proximal to stop codons to enhance translation by promoting the assembly of the ribosomal initiation complex [29]. YTHDF3 collaborates with YTHDF2, augmenting its functions to either accelerate mRNA decay or enhance translation, contingent upon the cellular context [19]. YTHDC1 facilitates the inclusion of exons in specific mRNA transcripts by recruiting SRSF3 for pre-mRNA splicing while concurrently impeding the binding of SRSF10 near m6A sites [20]. Additionally, YTHDC2 enhances the translation efficiency and reduces RNA stability through interactions with the meiosis-specific coiled-coil domain and 5’-3’ exoribonuclease 1 [21].The heterogeneous nuclear ribonucleoprotein (HNRNP) family, including HNRNPA2/B1, also recognizes m6A modifications. HNRNPA2/B1 facilitates the maturation of primary microRNA transcripts by interacting with components of the microRNA processing machinery such as Drosha ribonuclease III and DiGeorge syndrome critical region 8 [22]. Additionally, HNRNPC and HNRNPG manipulate mRNA splicing and stability through an m6A-dependent regulatory mechanism termed the ‘m6A switch’. [23]. Insulin-like growth factor 2 mRNA-binding proteins (IGF2BPs), encompassing IGF2BP1/2/3, detect m6A modifications and enhance mRNA stability and translational output in an m6A-dependent manner [24]. In the 5’ UTRs of transcripts, m6A facilitates the recruitment of the eukaryotic initiation factor 3 (eIF3), triggering the assembly of the 43S ribosomal pre-initiation complex and enabling cap-independent translation [30]. Moreover, cytoplasmic METTL3 specifically recruits eIF3H to boost cap-dependent translation on selected mRNA subsets [25]. Regulation of m6A modification and its role in RNA metabolism is shown in Figure 1.

Figure 1.

Potential mechanism of action of m6A. The MTC, denoted colloquially as the ‘writer’, assumes responsibility for the methylation of RNA. Its constituents encompass METTL3, METTL14, WTAP, ZC3H13, RBM15/15B, and KIAA1429. FTO and ALKBH3/5 function as ‘erasers’, by demethylating m6A-modified RNA. Readers encompass the YTHDF1/2/3, YTHDC1/2, eIF3H, IGF2BP1/2/3, and HNRNP genealogies. m6A methylation can be discerned by molecular entities, herein referred to as ‘readers’, thereby engaging in subsequent cellular processes, including RNA splicing, nucleation, translation, and degradation. a. the molecular chemical structure of m6A. b. the role of m6A in coding RNA. c. the role of m6A in non-coding RNA.

Research indicates that m6A modifications, by regulating the expression of oncogenes and tumour suppressor genes, play a significant role in the onset and progression of cervical cancer. Moreover, m6A modifications also influence cancer-related signalling pathways, thereby modulating cellular processes such as proliferation, invasion, and metastasis. Aberrations in m6A modifications are closely associated with tumour aggressiveness, drug resistance, and patient prognosis, positioning them as a focal point of biomedical research. Particularly in cervical cancer, which has a high incidence rate, a thorough investigation into the mechanisms of m6A action not only deepens our understanding of the molecular pathology of the disease but also may guide the development of novel diagnostic and therapeutic strategies. This review summarizes the regulatory roles of m6A in cervical cancer and its impact on RNA metabolism, aiming to provide a scientific basis for the development of new biomarkers and treatment methods based on epigenetics. The roles of m6A ‘writers’, ‘erasers’, and ‘readers’ in cervical cancer are shown in Tables 2–4.

Table 2.

Roles of m6A ‘writers’ in cervical cancer.

m6A regulators	Molecular mechanism	Target genes	Role in cancer	Biological Functions	References
METTL3, METTL14	mRNA translation	DARS	Oncogene	Autophagy	[31]
	mRNA degradation	DIRAS1	Suppressor	Progression	[32]
METTL3	mRNA stability	HK2	Oncogene	Glycolysis (Warburg effect)	[33]
	mRNA stability	RAB2B, ACIN1, CTSL	Oncogene	proliferation, metastasis, and invasion	[34–36]
	mRNA degradation	RAGE	Oncogene	Chemosensitivity and apoptosis	[37]
	miRNA maturation	miR-193b	Suppressor	Cell cycle progression	[38]
	LncRNA stability	FOXD2-AS1	Oncogene	Proliferation and metastasis	[39]
	mRNA translation	CDC25B	Oncogene	Cell cycle progression and proliferation	[40]
	mRNA degradation	NR4A1	Suppressor	Progression	[41]
	circRNA degradation	circRNF13	Oncogene	Radiosensitivity	[42]
	Not Given	KRAS	Oncogene	Ferroptosis	[43]
METTL14	Not Given	Akt/mTOR	Oncogene	Cell cycle progression	[44]
	mRNA stability	CYP1B1	Oncogene	Proliferation, migration, and invasion	[45]
	mRNA translation	LDHA	Oncogene	Glycolysis and immune escape	[46]
	mRNA stability	FTH1	Oncogene	Ferroptosis	[47]
ZC3H13	mRNA stability	CENPK	Oncogene	Chemoresistance	[48]
	Not Given	CKAP2	Oncogene	Proliferation, migration, and invasion	[49]
WTAP	mRNA stability	Not Given	Not Given	Tumorigenesis	[50]
RBM15	Not Given	STAT, JAK	Oncogene	Proliferation, migration, and invasion	[51]
	mRNA translation	OTUB2	Oncogene	Tumorigenesis	[52]
	Not Given	Myc	Oncogene	Autophagy	[53]

Table 3.

Roles of m6A ‘erasers’ in cervical cancer.

m6A regulators	Molecular mechanism	Target genes	Role in cancer	Biological Functions	References
FTO	mRNA translation	β-catenin	Oncogene	Chemo-radiotherapy resistance	[66]
	mRNA translation	E2F1, Myc	Oncogene	Proliferation and migration	[67]
	LncRNA stability	HOXC13-AS	Oncogene	Proliferation, migration, and EMT	[68]
	mRNA translation	HK2	Oncogene	Inhibits tumorigenesis and invasion	[69]
	Not Given	BMP4	Oncogene	Proliferation, migration, and invasion	[70]
ALKBH5	circRNA stability	circCCDC134	Oncogene	Proliferation and migration	[71]
	mRNA translation	MMP2, MMP9	Oncogene	Proliferation and metastasis	[72]
	mRNA stability	PAK5	Oncogene	Tumorigenesis and invasion	[73]
	mRNA stability	SIRT3	Oncogene	Inhibits lipid metabolism and tumorigenesis	[74]
FTO, ALKBH5	mRNA degradation	DIRAS1	Suppressor	Inhibits progression	[32]

Table 4.

Roles of m6A ‘readers’ in cervical cancer.

m6A regulators	Molecular mechanism	Target genes	Role in cancer	Biological Functions	References
YTHDF1	mRNA translation	RANBP2	Oncogene	Proliferation and invasion	[54]
YTHDF2	mRNA degradation	CARMN	Suppressor	Progression	[55]
YTHDF3	mRNA translation	RAD51D	Oncogene	Radioresistance	[56]
	mRNA translation	LRP6	Oncogene	Lipid metabolism	[57]
IGF2BP1	mRNA stability	TRIM11	Oncogene	Proliferation, migration, and invasion	[58]
	mRNA stability	SYVN1	Suppressor	EMT	[59]
IGF2BP2	mRNA stability	FOXM1	Oncogene	Tumorigenesis	[60]
	mRNA translation	Myc	Oncogene	Glycolysis, proliferation, and metastasis	[61]
IGF2BP3	LncRNA stability	KCNMB2-AS1	Oncogene	Inhibits apoptosis	[62]
	mRNA stability	GLS, GLUD1	Oncogene	Immune escape	[63]
	Not Given	SCD	Oncogene	Lipid metabolism	[64]
YTHDF1, IGF2BP3	mRNA translation	PDK4	Oncogene	Glycolysis	[65]

2. m6A regulates gene expression in cervical cancer

m6A modification exhibits aberrant patterns across various cancer types and is closely associated with patient prognosis. In cervical cancer, m6A regulatory factors can function as either oncogenic promoters or tumour suppressors. The role of m6A in tumorigenesis and progression is primarily mediated through the regulation of oncogene and tumour suppressor gene expression. When m6A regulators act as oncogenic promoters, they facilitate tumour progression by upregulating oncogenes or downregulating tumour suppressor genes. Conversely, when functioning as tumour suppressors, m6A regulators inhibit tumour growth by repressing oncogene expression or enhancing the expression of tumour suppressor genes. This dual regulatory mechanism positions m6A as a critical target in cancer research and therapy, with its role in cervical cancer progression illustrated in Figure 2.

Figure 2.

The significance of m6A modification in CC. The molecular mechanism is mainly the fine-tuning of cancer-related gene expression. Specifically, m6A modification can upregulate oncogenes and downregulate tumour suppressor genes, thereby facilitating the onset and progression of cervical cancer. In specific instances, m6A modification may also impede cancer progression via the downregulation of oncogenes and the promotion of tumour suppressor gene expression.

2.1. m6A regulators function as tumour promoters

In the context of oncogenes, m6A modification may enhance RNA stability and translation efficiency, reducing degradation and consequently leading to the overexpression of oncogenic proteins. In the development of cervical cancer, m6A modification significantly regulates the expression and function of oncogenes through various mechanisms. Specifically, METTL3 enhances the mRNA stability of cervical cancer-related genes such as ACIN1, CTSL, and RAB2B through interactions with IGF2BP family proteins [34–36]. Simultaneously, YTHDF1 regulates the translation of RANBP2 dependent on m6A modification, while ALKBH5 enhances the stability of PAK5 mRNA through its demethylation activity, thus promoting the progression of cervical cancer [54,73]. Additionally, CKAP2 m6A modification mediated by ZC3H13 also plays a significant role in the development of cervical cancer [49]. Ji et al. [39] demonstrated that METTL3 enhances the m6A methylation of lncRNA FOXD2-AS1, which increases its mRNA stability and accelerates the progression of cervical cancer by inhibiting the expression of p21. Additionally, m6A modifications of E2F1 and Myc transcripts significantly influence tumour development, promoting cell proliferation, migration, and invasion [67]. Further research by Zhang et al. revealed that METTL14-mediated m6A methylation of TRIM11 and IGF2BP1 activates the AKT signalling pathway, enhancing the invasiveness of cervical cancer cells [58]. Concurrently, the knockout of RBM15 reduces the expression of proteins involved in the JAK-STAT pathway, effectively inhibiting tumour formation [51]. In the pathological progression of cervical cancer, ncRNAs play a crucial role. piRNA-14633, through the METTL14/CYP1B1 pathway, and piRNA-17458, mediated by WTAP-induced m6A methylation, play decisive roles in the development of cervical cancer [45,50]. A newly identified m6A-modified circular RNA, circARHGAP12, is upregulated and enhances the stability of FOXM1 mRNA through interactions with IGF2BP2 and FOXM1 mRNA, further promoting the progression of cervical cancer [60].

Conversely, for tumour suppressor genes, m6A modification may accelerate RNA degradation, impairing stability and translation efficiency, thereby diminishing the expression of tumour-suppressive proteins and weakening their regulatory role in cell growth and differentiation. NR4A1, recognized as a tumour suppressor, inhibits cancer progression through multiple mechanisms, including suppression of the AKT signalling pathway. After m6A modification by METTL3, NR4A1 mRNA is recognized by the m6A ‘reader’ protein YTHDF2, which accelerates its degradation, reducing both its stability and expression levels in cells. This subsequently lifts the inhibition on the AKT signalling pathway, promoting the growth and survival of tumour cells [41]. CARMN, a tumour suppressor gene with significant differences in m6A modification, is also regulated by YTHDF2. The recognition of its m6A modification leads to the degradation of CARMN mRNA, further exacerbating tumour development [55]. Additionally, DIRAS1, a potential tumour suppressor, has demonstrated its functionality in vitro, where the knockout of the DIRAS1 gene significantly enhances the proliferation, growth, migration, and invasion of C33A and SiHa cervical cancer cells. METTL3 and METTL14, by increasing m6A modification of DIRAS1, decrease its expression, thereby affecting the proliferative and migratory capabilities of cervical cancer cells, underscoring the critical role of m6A modification in regulating the expression of tumour suppressor genes [32].

2.2. m6A regulators function as tumour suppressors

m6A modification regulates the expression and function of oncogenes and tumour suppressor genes through a series of complex molecular mechanisms, playing a crucial role in cancer biology. For oncogenes, m6A modification promotes rapid degradation of their mRNA, reducing the stability and translation efficiency of oncogene mRNA, thereby effectively suppressing their expression and exerting an anti-tumour effect. CXCL1 may modulate the tumour microenvironment by regulating inflammatory responses and cellular signalling pathways, thereby significantly influencing the sensitivity of cervical cancer cells to radiotherapy. METTL3 enhances the levels of m6A modifications in circRNF13, promoting the degradation of its mRNA, while YTHDF2 specifically recognizes these m6A sites to enhance the radiotherapy responsiveness of cervical cancer cells [42]. Additionally, RAGE, a molecule closely associated with inflammation and cancer progression, is highly expressed in various tumours and correlates with poor cancer prognoses. Overexpression of METTL3 substantially reduces RAGE expression, not only inhibiting the proliferation and survival of cervical cancer cells but also enhancing their sensitivity to the chemotherapeutic drug cisplatin [37]. Concurrently, overexpression of FTO elevates the levels of HK2 precursor mRNA in the nucleus and reduces the levels of mature HK2 mRNA in the cytoplasm, thus inhibiting the maturation and translation of HK2 mRNA and effectively exerting its antitumor effects [69].

Conversely, for tumour suppressor genes, m6A modification may enhance the stability and translation efficiency of their mRNA, decreasing their degradation, thus increasing protein levels and enhancing the cells’ anti-cancer capabilities. In recent research, Wang et al. [32] explored how the demethylases FTO and ALKBH5 enhance the stability and increase the expression of DIRAS1 protein by removing m6A modifications from DIRAS1 mRNA, thereby exerting an anticancer effect. These findings underscore the pivotal role of m6A modifications in regulating the expression of the tumour suppressor gene DIRAS1 in cervical cancer treatment, highlighting the significance of m6A modifications in tumour biology and their potential as therapeutic targets. The discovery of this epigenetic regulatory mechanism provides a solid theoretical foundation and experimental support for the precise modulation of tumour suppressor gene activity and the development of new cancer treatment strategies. However, research on the role of m6A modification in suppressing cervical cancer is still in its early stages, and more studies are needed in the future to fully understand its specific mechanisms.

3. m6A regulates cell proliferation, metastasis, and invasion in cervical cancer

m6A modulates the expression of key genes involved in cell cycle processes, directly impacting the proliferative capacity of tumour cells. Furthermore, m6A regulates molecules interacting with the extracellular matrix, proteins affecting cell adhesion, and key signalling pathways involved in cell migration and invasion. Through these mechanisms, m6A significantly promotes epithelial-mesenchymal transition (EMT) in cancer cells, thereby enhancing their migratory and invasive capabilities. Knockdown of METTL14 can inhibit the PI3K/Akt/mTOR signalling pathway, subsequently reducing the phosphorylation levels of Akt and mTOR, and inducing cell cycle arrest, which significantly suppresses the proliferation and invasion of cervical cancer cells [44]. Additionally, RBM15-mediated m6A modification leads to the upregulation of OTUB2, thereby enhancing malignant behaviours in cervical cancer cells through the AKT/mTOR signalling pathway [52]. CCND1, a key protein regulating the cell cycle process, has its expression increased through the downregulation of miR-193b by METTL3, thereby promoting cell cycle progression and cellular proliferation [38]. Moreover, the expression of CDC25B enhances the activity of the CDK1/cyclin B complex, a crucial step in driving the transition from the G2 to the M phase. The m6A modification mediated by METTL3 increases the translation efficiency of CDC25B mRNA, a process recognized by YTHDF1, not only accelerating the progression of the cervical cancer cell cycle but also enhancing tumour growth both in vitro and in vivo [40]. FTO reduces the m6A modification level of HOXC13-AS, enhancing its stability and further promoting EMT in cervical cancer through the activation of the Wnt/β-catenin signalling pathway [68]. Concurrently, the m6A modification of circCCDC134 mediated by ALKBH5 enhances the transcriptional activity of HIF1A, thereby facilitating the metastasis of cervical cancer [71]. Additionally, MALAT1 indirectly increases the expression levels of matrix metalloproteinases (MMP2 and MMP9) by regulating the expression of ALKBH5, thus enhancing the migratory and invasive capabilities of cervical cancer cells [72]. LRRC75A-AS1 competitively binds to the IGF2BP1 protein, destabilizing SYVN1 mRNA, which in turn inhibits the ubiquitination degradation of NLRP3 mediated by SYVN1 and activates the IL-1β/Smad2/3 signalling pathway, promoting EMT in cervical cancer [59]. Lastly, FTO plays a crucial role in the proliferation, colony formation, migration, and invasion of cervical cancer cells by regulating the BMP4/Hippo/YAP1/TAZ signalling pathway [70].

4. m6A regulates cell death in cervical cancer

Cell death refers to the irreversible termination of cellular activity following a series of biological processes under specific physiological or pathological conditions. In cervical cancer, the mechanisms of cell death are multifaceted, potentially inhibiting tumour initiation and progression through pathways such as apoptosis and ferroptosis. Conversely, these mechanisms can also contribute to tumour progression and therapeutic resistance by enhancing autophagy, evading ferroptosis, suppressing apoptosis, and enabling immune evasion. Thus, a comprehensive understanding of the distinct forms of cell death and their roles in cancer is crucial for the development of novel anticancer strategies and the improvement of current therapeutic outcomes.

4.1. m6A and apoptosis

Apoptosis, a form of programmed cell death, typically functions to eliminate abnormal cells in normal tissues, thereby preventing the formation of potential cancer cells. However, in cervical cancer, apoptotic signalling pathways are frequently suppressed, allowing cancer cells to evade natural cell death processes and continue to survive and proliferate. METTL14 knockdown alters the expression of apoptosis-related proteins, with upregulation of pro-apoptotic proteins Bax, Bim, and activated Caspase 9, and downregulation of the anti-apoptotic protein Bcl-2 [44]. Zhang et al. [62] identified KCNMB2-AS1 as a lncRNA closely associated with cervical cancer, which is stabilized by m6A modification. Knockdown of KCNMB2-AS1 significantly induced apoptosis and inhibited the proliferation of cervical cancer cells. These findings suggest that m6A modification stabilizes KCNMB2-AS1, thereby inhibiting apoptosis and promoting cancer cell survival and tumour progression in cervical cancer.

4.2. m6A and ferroptosis

Ferroptosis is an iron-dependent form of cell death characterized by lipid peroxidation. In certain contexts, ferroptosis serves as an antitumor mechanism, inhibiting tumour growth by inducing cancer cell death. Drugs that induce ferroptosis are considered a novel anticancer strategy, particularly for cancers resistant to conventional therapies, as they can effectively eliminate cancer cells through this pathway. Ferritin heavy chain 1 (FTH1) is a key regulator of iron metabolism, and its expression is significantly elevated in cervical cancer. Sorafenib, a multi-targeted anticancer agent, has been widely shown to inhibit cervical cancer progression by inducing ferroptosis. Li et al. [47] found that METTL14 enhances m6A modification of FTH1 mRNA, reducing its stability and thereby downregulating FTH1 protein expression. This mechanism amplifies the ferroptotic effect induced by sorafenib, effectively suppressing cervical cancer progression. Additionally, the study revealed that METTL14-mediated downregulation of FTH1 also inhibits the activation of the PI3K/Akt signalling pathway, thereby increasing the sensitivity of cancer cells to ferroptosis. KRAS has been identified as a gene susceptible to ferroptosis inhibition via m6A modification. Further research by Gong et al. [43] indicated that METTL3 is involved in the m6A modification of KRAS, with miR-30c-5p promoting ferroptosis by inhibiting the METTL3/KRAS axis, thus suppressing cervical cancer cell proliferation and migration. However, cancer cells can evade ferroptosis by modulating their antioxidant systems, allowing them to survive in adverse microenvironments. Currently, research on how m6A modification promotes cervical cancer progression by evading ferroptosis is still in its early stages, and extensive studies are needed to elucidate the underlying mechanisms.

4.3. m6A and autophagy

Autophagy is a process of cellular self-degradation that occurs under stress conditions and typically aids in cell survival. Although autophagy can, in certain circumstances, lead to cell death, it more commonly serves as a protective mechanism in cancer. By maintaining energy supply and clearing damaged organelles in environments of nutrient deprivation or oxidative stress, autophagy enhances the survival of cancer cells, thereby promoting tumour progression and drug resistance. Research by Shen et al. [31] demonstrated that METTL3 and METTL14 increase the stability of DARS mRNA, promoting DARS protein translation, which in turn activates the HIF1α/DARS-AS1/DARS pathway and induces protective autophagy. This mechanism enhances the survival of cervical cancer cells under hypoxic conditions and drives tumour progression. Additionally, Nie et al.‘s [53] study revealed that HPV-E6 inhibits the degradation of RBM15 protein during autophagy, leading to its accumulation within the cell. This accumulation subsequently increases the m6A modification of c-myc mRNA, resulting in elevated c-myc protein expression and the promotion of cervical cancer cell proliferation.

5. m6A influences the tumour microenvironment in cervical cancer

The tumour microenvironment (TME) refers to the localized milieu surrounding tumour cells, encompassing not only the cancerous cells themselves but also a diverse array of non-tumour cells, such as immune cells, fibroblasts, endothelial cells, along with the extracellular matrix, blood vessels, lymphatics, signalling molecules, and metabolic byproducts. This complex ecosystem not only provides essential nutrients and survival signals to tumour cells but also plays a crucial role in facilitating immune evasion by suppressing immune responses. In cervical cancer, m6A modification influences the dynamic modulation of the TME through multiple mechanisms, thereby impacting tumour initiation, progression, and response to therapy.

5.1. m6A and immune infiltration

In oncology, immune infiltration refers to the migration of various immune cells – including T cells, B cells, natural killer cells, and macrophages – into tumour tissues where they perform immune surveillance and exert antitumor effects. Particularly in cervical cancer, high levels of immune cell infiltration, notably effector T cells, correlate with enhanced antitumor activity and improved prognosis. Research has demonstrated that variations in the clustering of m6A regulatory factors significantly affect immune cell infiltration in cervical cancer [75,76]. Jia et al. [77] analysed the TCGA-CC database and identified two m6A-related lncRNA clustering patterns. Tumours with a high m6A lncRNA score are characterized by significant infiltration of active CD8+ T cells, CD56dim natural killer cells, and monocytes, while tumours with a low m6A lncRNA score are predominantly infiltrated by immunosuppressive cells such as Th2 and Tregs, alongside higher expressions of the immunosuppressive factors IL-10 and TGF-β1. These patterns exhibit independent prognostic value for overall survival, progression-free survival, and disease-specific survival in cervical cancer patients, and may influence the effectiveness of immunotherapy.

5.2. m6A and immune escape

Immune escape is a phenomenon wherein tumour cells evade the surveillance and attack of the immune system, thereby sustaining their survival and proliferation. This involves the expression of immunosuppressive molecules, reduction in antigen presentation, modification of immune cell functionalities, and manipulation of related signalling pathways. PD-1, a crucial immune checkpoint molecule, when overexpressed, aids tumour cells in evading clearance by the immune system. Wang et al. [46] demonstrated that METTL14, by activating the AMPK pathway, promotes the polarization of macrophages towards the M2 phenotype, which is conducive to tumour growth and immunosuppression. This polarization enhances the expression of PD-1, further strengthening the immune escape capabilities of tumour cells. Additionally, Zhou et al. [63] revealed that IGF2BP3 enhances the mRNA stability of GLS and GLUD1 through m6A modification, impacting the differentiation of Treg cells and thereby exacerbating immune escape. The elucidation of these mechanisms provides crucial targets for the development of targeted cancer therapies.

5.3. m6A and tumour metabolic reprogramming

The Warburg effect delineates a metabolic phenomenon where tumour cells, even under oxygen-sufficient conditions, prefer glycolysis over oxidative phosphorylation for energy production. This mechanism enables cancer cells to efficiently utilize glucose for rapid lactate production, thereby supporting swift proliferation. m6A modifications regulate the stability and translational efficiency of specific mRNAs, thus affecting the expression and activity of pivotal enzymes in glycolysis, enhancing the Warburg effect, and consequently impacting tumour cell growth, survival, and spread. Li et al. [65] have found that YTHDF1 and IGF2BP3 promote the expression of PDK4 by binding to its mRNA. Wang et al.‘s [33] studies indicate that METTL3 targets the 3’UTR of HK2 mRNA and recruits the m6A reader protein YTHDF1 to augment HK2 stability, thereby enhancing its expression. Furthermore, Hu et al. [61] have demonstrated that HPV E6/E7 proteins, by modulating the activity of IGF2BP2, affect the m6A modification of Myc mRNA, which consequently promotes the expression of critical glycolytic enzymes such as HK2, PFKM, PDK1, GLUT1, and LDHA. Recent studies elucidate that glycolysis not only supports cancer cell proliferation but may also modify the metabolic products within the tumour microenvironment (such as lactate accumulation), influencing immune cell functionality and fostering tumour immune escape [46].

Lipid metabolism serves as a critical source of energy and biosynthetic needs for tumour cells. m6A modifications regulate the activity of key enzymes in lipid metabolism, closely associating with tumour cell proliferation, migration, invasion, and apoptosis, thereby significantly influencing tumour behaviour. Notably, IGF2BP3 enhances the stability of SCD mRNA via m6A modification, promoting the expression of SCD, a pivotal enzyme that converts saturated fatty acids into unsaturated fatty acids, thus regulating tumour growth and spread [64]. Upregulation of YTHDF3, through m6A modification, enhances the activity of LRP6, further increasing the expression of FASN and ACC1, activating lipid metabolism. This mechanism not only augments the synthesis of lipid droplets and the release of fatty acids but also triggers the LRP6-YAP-VEGF-C signalling axis, promoting lymph angiogenesis and lymph node metastasis [57]. Additionally, ALKBH5 catalyses the demethylation of SIRT3 through an m6A-IGF2BP1 dependent pathway, downregulating ACC1 to alter lipid metabolism, thereby inhibiting the growth of cervical squamous cell carcinoma and hindering tumour development [74].

6. m6A influences treatment resistance in cervical cancer

The m6A modification is closely associated with the reactivity and resistance of cancer therapies, exhibiting its multifaceted and complex role in the resistance to cervical cancer treatment through mechanisms of DNA damage repair and the modulation of cancer stem cell functions. This underscores the potential for developing novel anticancer strategies that target m6A regulatory mechanisms, particularly in overcoming limitations of traditional treatments and enhancing therapeutic efficacy. YTHDF3 enhances the translation of the DNA repair protein RAD51D by relying on m6A modifications, thereby regulating the role of HNF1α in the resistance of cervical cancer to radiotherapy [56]. Concurrently, FTO significantly upregulates the expression of β-catenin through its demethylase activity and further modulates the activity of the core DNA repair factor ERCC1 [66]. This regulatory mechanism is crucial for activating downstream signalling pathways that affect cell survival and repair during treatment, thereby significantly enhancing the cell’s ability to repair DNA damage induced by chemotherapy and radiotherapy. This plays a critical role in the development of resistance to chemoradiotherapy. Cancer stem cells (CSCs), characterized by their self-renewal capabilities, play a pivotal role in driving tumour growth and recurrence. The m6A modification is critically involved in maintaining the self-renewal and differentiation potential of these cells. Specifically, ZC3H13 regulates the expression of hallmark stem cell genes such as CENPK, sustaining the characteristics of CSCs and enabling cervical cancer cells to better adapt and resist the effects of chemotherapy [48]. Moreover, m6A modifications influence the differentiation of CSCs by modulating cell fate-determining signalling pathways, such as the Wnt/β-catenin pathway and the ubiquitination of p53, thereby complicating treatment.

7. Clinical potentials of m6A components in cervical cancer

With advancements in screening technologies and optimization of treatment methods, the overall incidence of cervical cancer has gradually declined. However, patients in advanced stages, those with positive lymph nodes, or those with affected surgical margins continue to face a high risk of recurrence. For these patients, the recurrence rate exceeds 50% following conventional treatment, and the five-year survival rate post-relapse remains low, ranging between 30% and 60%. m6A modification has been identified as a promising biomarker in various cancers. In cervical cancer, it exhibits distinct expression patterns and regulatory mechanisms, significantly impacting the biological behaviours of tumour cells and providing a novel mechanistic basis for the development of new diagnostic and therapeutic strategies. Furthermore, the level of m6A modification is closely associated with the prognosis of cervical cancer patients, holding potential as a biomarker for assessing disease progression and treatment response. As research into the biological functions of m6A continues, its application in the treatment of cervical cancer appears promising, potentially leading to the development of targeted therapeutics based on m6A modification mechanisms, offering more precise treatment options for patients.

7.1. m6A for diagnosis of cervical cancer

Significant differences in the expression of m6A regulatory factors have been observed between cervical cancer tissues and their corresponding non-tumour tissues. Through bioinformatics methods, key m6A markers associated with cervical cancer have been identified, suggesting their potential as tools for early diagnosis. Lu et al. performed a comprehensive analysis of m6A-related gene expression in cervical cancer and normal cervical tissues using the TCGA, GTEx, and GSE52903 databases. The differential expression analysis indicated significant variations in the expression levels of several genes associated with m6A modification, including METTL14, METTL16, ZC3H13, YTHDC1, and YTHDC2, between cervical cancer and normal tissues [78].By integrating expression data of m6A regulatory factors from cervical cancer patients, a diagnostic model based on machine learning has been developed. These models are capable of comprehensively analysing complex patterns of biomarkers, thereby providing more effective methods for the accurate diagnosis of cervical cancer. Wang et al. [79] selected 33 m6A regulatory factors and conducted copy number variation (CNV) analysis across TCGA-CESC, GSE63514, and GSE6791 datasets. They discovered consistent upregulation of HNRNPA2B1, YTHDF2, RBM15, and NSUN2 in tumour tissues. The study utilized 70% of the GSE63514 dataset as a training set, with the remaining portion serving as a validation set. Random Forest (RF) and Support Vector Machine (SVM) models were employed to construct and validate the diagnostic model. In the cervical cancer diagnostic model, the ROC curves for the RF and SVM models demonstrated high precision (AUC values of 0.946 and 0.982, respectively), confirming the effectiveness of the models.

7.2. m6A for evaluation of cervical cancer prognosis

The expression levels of m6A regulatory factors are closely associated with overall survival (OS) and disease-free survival (DFS) in cancer patients. Ni et al. [80] discovered that the level of METTL3 serves as an independent prognostic factor for patient survival, specifically manifested as DFS (HR = 3.157, p = 0.022) and OS (HR = 3.271, p = 0.012). In patients with advanced cervical cancer (stages II-IV), the level of METTL3 has a more pronounced impact on DFS (HR = 6.725, p = 0.010) and OS (HR = 5.140, p = 0.021). These findings suggest that the expression levels of m6A regulatory factors can serve as important indicators for predicting patient survival outcomes. Condic et al. [81] revealed that high protein expression levels of METTL14, WTAP, KIAA1429, ALKBH5, HNRNPC, YTHDC1, and YTHDF3 were significantly associated with shorter OS (p < 0.05). Based on the expression data of m6A regulatory factors, researchers have developed various m6A risk scoring systems that accurately stratify cancer patients by risk. The m6A scoring models effectively differentiate between high-risk and low-risk patients, assisting clinicians in more accurately assessing patient survival prognoses [82]. Wu et al. [83] constructed a prognostic risk assessment model using six m6A regulatory factors: YTHDC2, YTHDC1, ALKBH5, ZC3H13, RBM, and YTHDF1. The findings indicate that the OS of patients in the high-risk group was significantly lower than that in the low-risk group, with the model achieving an AUC of 0.718. Chen et al. [84] developed and validated a five-gene prognostic model based on m6A-related genes, including IGF2BP1, IGF2BP2, HNRNPA2B1, YTHDF1, and RBM15. The study results indicated that the OS rate in the high-risk group was significantly lower than that in the low-risk group, with statistically significant differences. In the TCGA training cohort, the model’s AUC values for 1-, 3-, and 5-year survival were 0.819, 0.861, and 0.849, respectively, demonstrating high specificity and sensitivity. Similarly, in the GSE44001 validation cohort, the AUC values for 1-, 3-, and 5-year survival were 0.708, 0.737, and 0.718, respectively, further confirming the model’s reliability. These models provide crucial evidence for the formulation of personalized treatment plans.

7.3. m6A for monitoring the response to cervical cancer therapy

The reversibility of m6A modification makes it a valuable indicator for dynamically monitoring cancer treatment responses. By regularly assessing changes in m6A regulatory factors in tumour tissues or circulating tumour cells, the effectiveness of treatment can be evaluated in real-time.

Studies have shown that the status of m6A modification significantly influences the sensitivity of cancer cells to various therapeutic interventions. In certain cancer types, higher levels of m6A modification may confer greater chemoresistance to tumour cells, whereas in other cases, the regulation of m6A modification may enhance the responsiveness of cancer cells to treatment. For instance, the FTO gene enhances resistance to chemotherapy and radiotherapy by regulating β-catenin expression [66]. Additionally, YTHDF3 induces radioresistance in cervical cancer cells by interfering with the HIF1α/YTHDF3/RAD51D pathway [56]. Conversely, the METTL3/YTHDF2 axis promotes the accelerated degradation of circRNF13, thereby increasing the radiosensitivity of cervical cancer cells [42]. Further research has found that enhanced METTL3 expression leads to the downregulation of RAGE expression, ultimately improving the sensitivity of the SiHa-DDP cell line to cisplatin treatment [37]. Lu et al. [78] demonstrated that patients with different m6A risk scores exhibit significant differences in the half-maximal inhibitory concentration (IC50) of various chemotherapy drugs and small-molecule anticancer agents, such as KIN001.135, Akt inhibitors, and rapamycin (p < 0.001). Therefore, assessing the status of m6A modification can not only help predict patients’ responses to treatment regimens but also optimize therapeutic strategies, thereby improving treatment outcomes.

Immune checkpoint therapy is an innovative targeted treatment strategy that selectively targets programmed cell death protein 1 (PD-1) or its ligand PD-L1 [85], thereby activating the adaptive immune system to eliminate cancer cells. In tumours lacking YTHDF1, the increase in CD8+ T cells and NK cells enhances tumour antigen cross-presentation and promotes CD8+ T cell activation [86]. The depletion of METTL14 or METTL3 impairs T cell differentiation and proliferation, reducing their sensitivity to interleukin-7 (IL-7) [87]. Additionally, ALKBH5 enhances the efficacy of immunotherapy across various malignancies by modulating lactate levels and tumour-infiltrating immune cells [88]. The downregulation of GATA16, YTHDF1, or ZC3H13 has been shown to increase PD-L1 expression [76]. m6A modification also indirectly influences tumour progression and treatment response by regulating the interactions between immune cells and stromal cells within the tumour microenvironment. Targeting m6A regulatory factors holds the potential to remodel the TME, enhance the effectiveness of immunotherapy, and reduce immune evasion, thereby improving overall treatment success rates. Jia et al. [77] revealed that different m6A lncRNA clustering patterns exhibit distinct characteristics within the TME, consequently affecting patients’ responses to immune checkpoint inhibitors (ICIs). Recent study has shown that patients with higher m6AlncRNAscores exhibit a more significant response to immune checkpoint inhibitors, such as anti-CTLA-4 therapy, suggesting that these patients may be more likely to benefit from immunotherapy [89]. These findings suggest that m6A risk scores could serve as a critical indicator for predicting patients’ responses to specific therapeutic agents.

8. Current status and future perspectives

As a critical component of post-transcriptional RNA processing in humans, m6A modification is closely associated with the development and progression of various diseases, particularly in the field of oncology. Through the precise regulation of key gene expression during tumorigenesis, m6A modification plays a pivotal role in shaping the malignant phenotype of cervical cancer. Abnormal expression of m6A-related proteins may serve as a prognostic biomarker, indicating poor outcomes, and it also opens new avenues for early diagnosis and targeted therapy in CC. Although current research has begun to uncover the complex roles of m6A modification in carcinogenesis and cancer treatment, many scientific questions remain to be explored. Further in-depth studies are required to fully understand the functions of m6A in cervical cancer and its potential clinical applications.

Numerous studies have revealed the paradoxical roles of m6A modification in tumours, showing its potential both to promote tumorigenesis and to inhibit tumour growth [33,37,68,69,71,74]. The diversity displayed by m6A regulatory factors across different cancer types and within individual tumours reflects the significant impact of tumour heterogeneity. This variability in function may stem from the specific regulation of downstream molecules and signalling pathways by m6A-modified regulators, leading to different biological outcomes. Particularly in cervical cancer, the study of RNA epigenetic modifications faces substantial challenges, primarily due to significant discrepancies in the expression patterns and functions of different m6A regulators. The inconsistency of these research findings underscores the complexity of m6A-related regulatory factors in CC research, suggesting that current scientific understanding may only scratch the surface of this intricate phenomenon. Thus, there is an urgent need to conduct further empirical research to thoroughly investigate the specific biological functions and precise molecular mechanisms of these regulators in cervical cancer, aiming to lay a solid foundation for future clinical applications.

Furthermore, research centred around m6A has predominantly focused on the fundamental molecular aspects, yet key questions such as the strategic targeting of downstream effectors, precise modulation of m6A regulatory pathways, and reversal of chemotherapy resistance in tumour tissues remain unresolved. This uncertainty casts a shadow over the translational potential of these findings in clinical practice. Additionally, reliance on big data analyses from public databases like GEO and TCGA, though supportive of oncological m6A mechanism studies, also highlights existing research gaps, indicating an urgent need for further studies to bridge the clinical application divide. Despite the potential anti-cancer effects demonstrated by inhibitors targeting m6A modifying enzymes across various cancer types, exploring more effective pharmacological interventions and developing innovative therapeutic strategies related to m6A remain critical avenues for future research.

In the investigation of m6A modifications, various distinctive methodologies are employed. Spot hybridization, a cost-effective and straightforward technique, is suitable for the semi-quantitative assessment of m6A modifications [90]. Liquid chromatography-tandem mass spectrometry/mass spectrometry (LC-MS/MS) offers high-precision quantitative analysis, capable of accurately identifying and measuring the m6A methylation status within mRNA transcripts [91]. Methylated RNA immunoprecipitation sequencing (MeRIP-seq) can detect m6A modifications across the transcriptome, although it lacks single-nucleotide resolution [92]. m6A individual-nucleotide-resolution cross-linking and immunoprecipitation (miCLIP) provides precise m6A site localization at the mononucleotide level, exhibiting high technical accuracy [93]. Deamination adjacent to RNA modification sequencing (DART-seq), a probe-free technique, identifies m6A sites by inducing C-to-U deamination through editing enzymes [94]. While these methods each have their strengths in detecting m6A modifications, they also present limitations such as resolution constraints, technical complexity, and cost issues. Future research necessitates the development of more precise, cost-effective technologies with simplified protocols to advance m6A research in cancer diagnostics and therapeutics.

Epigenetic modifications of ncRNAs may play a role in the oncogenic and drug resistance mechanisms within cervical cancer. Current research predominantly focuses on m6A modifications of mRNA molecules, with limited exploration into m6A modifications of ncRNAs. A thorough investigation into how m6A modifications affect the biogenesis, cellular localization, and functional dynamics of ncRNAs could significantly advance our understanding of the potential carcinogenic mechanisms in cervical cancer. Furthermore, such studies could provide novel perspectives for developing therapeutic strategies.

9. Conclusion

m6A modification plays a crucial role in the onset and progression of cervical cancer. By precisely regulating key pathways and gene expression associated with tumorigenesis, m6A significantly affects the proliferation, invasion, migration, and drug resistance of cervical cancer cells. Particularly, the role of m6A in RNA stability and post-transcriptional regulation underscores its potential as a biomarker and therapeutic target. Future research should explore in depth the detailed mechanisms of m6A modification in cervical cancer and identify key m6A regulatory factors, providing essential biological insights for the development of new diagnostic and therapeutic strategies. This article comprehensively reviews the current advancements in m6A methylation modification research related to cervical cancer, providing a solid theoretical foundation and clear directional guidance for future research in this field.

Funding Statement

The author(s) reported there is no funding associated with the work featured in this article.

Disclosure statement

No potential conflict of interest was reported by the author(s).

Author contributions

All authors contributed to the study conception and design. Literature collection were performed by Yajuan Gao and Qi Guo. Yajuan Gao drafted the manuscript. Qi Guo revised and finalized the review. Liming Yu provided supervision.

CrediT statements

Yajuan Gao: Writing-Original draft, Conceptualization, Visualization, Writing-Review & Editing, Resources, Supervision

Qi Guo: Conceptualization, Visualization, Writing-Review & Editing

Liming Yu: Conceptualization, Visualization, Writing-Review & Editing, Supervision

Ethical approval

This manuscript is a review article and does not involve a research protocol requiring approval by the relevant institutional review board or ethics committee.

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We affirm that: All images and tables included in the manuscript are original works created by the authors of this study (). These charts have been developed specifically for this research and have not been published or submitted elsewhere in any form.

Supplementary material

Supplemental data for this article can be accessed online at https://doi.org/10.1080/15476286.2024.2408707