Table 1.

Role of miRNAs via targeting EGFR or its downstream signaling in modulating lung cancer cell behavior in preclinical models and clinical specimens.

Type of miRNA	Proposed Mechanism of Action in Lung Cancer	Preclinical and Clinical Studies	Methodology	Reference
Oncosuppressor miRNAs
miR-27a	-Regulation of MET and EGFR axis	A549, H1299, and CALU-1 NSCLC cell lines	qRT-PCR Western blot Luciferase reporter assay	[52]
miR-133a	-Suppressing EGFR, p-ERK, and p-AKT -Augmenting caspase-3 protein expression -Inducing apoptosis; repressing cell growth	Human NSCLC tissues and adjacent normal lung tissue H358 human NSCLC cell line transfected with miR-133a mimics	qRT-PCR Immunohistochemistry (IHC)	[64,65,66]
miR-25-3p	-Prognostic biomarker in NSCLC by regulating TGFβ and EGFR signaling	miRNA regression model supported by target prediction databases	Multiple linear regression based on expression levels	[8]
miR-128b	-Regulating the expression of EGFR	Human NSCLC and adjacent normal lung tissue samples	qRT-PCR Semi-quantitative RT-PCR IHC analysis	[49]
miR-134	-Repressing EGFR-related signaling pathways -Inhibiting NSCLC cell proliferation by promoting apoptosis and/or cell cycle arrest	NSCLC cell lines (A549, H1299, H520, and H1975)	qRT-PCR MTT assay Flow cytometry Luciferase reporter assay RNAi and rescue experiments A549 xenograft in nude mice	[36]
miR-34a	-Suppressing tumor growth and metastasis and promoting cell apoptosis -Targeting many cellular pathways, including cell proliferation, erlotinib resistance, and EGFR-inhibited pathways	Human NSCLC and adjacent normal lung tissue samples A549 (EGFR-wild type), SPC-A1 and HCC827 (EGFR-mutated) cell lines lung carcinoma xenograft mouse model	qRT-PCR Cell proliferation assay Cell transwell assay Luciferase reporter assay Western blot analysis xenograft assay IHC analysis	[20,57]
miR-542-5p	-Associated with EGFR, vascular invasion, advanced TNM stage, lymphatic metastasis, and patients’ poor prognosis	Human NSCLC and adjacent normal lung tissue samples	qRT-PCR	[67]
miR-146a-5p	-Targeted EGFR and NF-κB signaling -Decreasing cellular expression and release of CCL2, a chemokine	A549 cells	RNA-Seq Gene ontology analysis qRT-PCR	[68]
miR-183 miR-210 miR-34c	-Correlated with lymphovascular invasion -Independently associated with T stage -High expression exhibited poor overall survival in the exon 19 mutated EGFR group -All 3 miRNAs were related to poor tumor differentiation	Human mutated LADC and adjacent normal lung tissue samples	Microarray analysis qRT-PCR	[25]
miR-125b	-Predicting EGFR mutational status and gefitinib-sensitivity -Associated with disease-free survival and overall survival	Human NSCLC and adjacent normal lung tissue samples and plasma gefitinib-sensitive PC9, and gefitinib-resistant A549 and H1299 human lung ADC cells	MicroRNA array Genotyping of EGFR mutational status	[69]
miR-30a-5p	-Suppressing cell proliferation, migration, invasion, and EMT	Human NSCLC and adjacent normal lung tissue samples lung carcinoma xenograft mouse model	CCK-8 and clonogenic assays Wound healing, migration and invasion assays	[70]
miR-145	-Inhibiting EGFR expression -Improving the sensitivity to erlotinib -Cell proliferation and survival -Inhibition of cell growth in the EGFR mutant lung adenocarcinoma -Induced cell arrest of G1/S cycle phase	NSCLC cell line A549	qRT-PCR Trypan blue and MTT assays ELISA cell death assay Combination effect analysis	[71]
miR-200a	-Downregulating EGFR and c-Met levels and inhibited invasion, migration, and gefitinib resistance	lung cancer cell lines H3255 (L858R EGFR allele), H1975 (L858R/T790M mutations in EGFR), and HCC827	qRT-PCR Luciferase assays Western Blot Wound-Healing Assay Cell Invasion Assay MTS assay and BrdU incorporation assay	[1]
miR-125a-5p	-Downregulating EGFR mRNA expression -Inhibiting cell proliferation and triggered apoptosis -Augmenting the erlotinib’s cytotoxic effect reduced cellular proliferation and enhanced its apoptotic effect	A549 lung cancer cells	qRT-PCR Trypan blue assays MTT assay Combination index (Chou-Talalay) ELISA cell death assay kit	[72]
miR-30a-5p	-Targeting EGFR and IGF-1R signaling pathways -Regulating PI3K/AKT signaling pathway -Promoting cell apoptosis, impeding cell migration and invasion properties, and reducing gefitinib resistance	Gefitinib-resistant NSCLC cell lines, H460 and H1975	Western Blot Annexin V-FITC Apoptosis Detection Kit CytoSelect™ Cell Invasion Assay Kit Wound healing assay	[15,73]
let-7b	-Targeting many cellular pathways, including cell proliferation, and EGFR-inhibited pathways -Potentiation of erlotinib anti-proliferative activity	NSCLC cells bearing clinically relevant mutations in KRAS and TP53 (H358, H23, H441, Calu-6) or NRAS and TP53 (H1299)	qRT-PCR Sulforhodamine B (SRB) assays	[20,49]
miR-200c-3p	-Increasing sensitivity to EGFR-TKIs in EGFR mutant NSCLC by modifying the EMT process	EGFR-mutant NSCLC and adjacent normal lung tissue EGFR TKI-sensitive cell lines- PC9 and HCC287, and gefitinib-resistant PC9/gef cells that harbor a deletion in exon 19 of EGFR	MicroRNA array qRT-PCR Western Blot Migration assay Cytotoxicity and apoptosis assays	[74]
miR-762	-Gefitinib resistance and poor prognosis of post-chemotherapy -IL-6 signaling-induced miR-762 upregulation improved cell survival and retained NSCLC cells’ resistance to gefitinib	NSCLC Cell lines with EGFR mutations PC-9 (E746-A750 del) NCI-H820 (E746-E749 del) NCI-H1650 (E746-A750 del) NCI-H1975 (L858R) A549, NCI-H2170, NCI-H1993, NCI-H2126, NCI-H1299, NCI-H1648, NCI-H1703 and NCI-H2347 (WT) lung carcinoma xenograft mouse model	qRT-PCR Cytotoxicity In vivo chemosensitivity Luciferase reporter assay	[75]
miR-126	-Suppression of Akt and ERK activation -Suppressing cell growth; inhibited cell proliferation -Enhanced gefitinib-induced cytotoxicity	NCI-H460 (H460) and A549 cells lung carcinoma xenograft mouse model	qRT-PCR Growth inhibition assay Western Blot	[19]
miR-138-5p	-Increasing the sensitivity to gefitinib	Human NSCLC and adjacent normal lung tissue samples NSCLC cell lines PC9 and H1975	qRT-PCR Luciferase assays Western Blot IHC	[76]
Oncogenic miRNAs
miR-147b	-Inducing tolerant-state to osimertinib in both EGFR-mutated and osimertinib-tolerant lung cancer cells -Suppressing succinate dehydrogenase and VHL that linked to the pseudohypoxia and TCA pathways	EGFR-wild type cell lines H358, H460, A549, H1299, and H69 (ATCC) EGFR-mutant cell lines H1650, H1975, HCC827, HCC827GR, PC9, PC9ER, and H3255 Patient-derived Xenograft Tumor Specimens	MicroRNA array Colony Formation Assay High-Throughput Sequencing Western Blot H&E Staining and Immunofluorescence. Targeted Mass Spectrometry.	[77]
miR-21	-Reinforcing the aberrant regulation linked to lung carcinogenesis in never-smokers -More dramatic expression changes in EGFR-mutated patient mutations as opposed to EGFR wild-type cases -A strong association between p-EGFR and miR-21 levels and the suppression of miR-21 by the EGFR-TKI AG1478	-Data set -NSCLC patients with EGFR 19 deletion -Another cohort with EGFR 19 deletion mutations, who had dramatically different responses to EGFR-TKI (for miRNA expression validation)	Gene expression data (target scan database) qRT-PCR	[78,79,80]
Oncogenic/Oncosuppressor miRNAs
miR-29b	-Targeting TNFAIP3/A20 (NF-κB negative regulator) -miR-29b–refractory isoform of TNFAIP3 restored NF-κB and extrinsic apoptosis -confers sensitivity to intrinsic apoptosis induced by cisplatin exposure.	mutated KRASG12V Cells	Microarray analysis Mechanistic investigations	[41]
miR-7	-Enhanced phosphorylation of c-Myc and EGFR in EGFR mutant (L858R), (CL1-5 cells), promoting miR-7 expression -EGFR prompts miR-7 expression via Ras/ERK/Myc pathway -Reducing the ERF level; inducing cell growth and tumor formation; raising the mortality rate -Repressing cell proliferation, tumorigenicity; tempting cell apoptosis -Downregulating EGFR and RAF-1 expression	EGFR-silenced cells EGFR mutant (L858R) CL1-5 cells.	MiRNA microarray analysis qRT-PCR	[81,82]