Table 1.

Overview on available studies of cold atmospheric plasma (CAP) in gynaecologic cancer cell lines.

Cell Line Origin	Cell Line/s	Main Effects of CAP on Cell Lines Observed in the Studies	Ref.
Cervix	HeLa SiHa HFB	° Reduced viability of cells after plasma treatment in a dose-dependent manner ° Selective inhibition of proliferation in cancer cells compared to HFB ° Higher inhibition effect in the case of SiHa cells in comparison to Hela cells ° Significant increase of cells in subG0 phase cell and vice versa: reduction of populations in S phase and G2/M phase in a cell-type-specific manner ° Identification of caspase-3, -8 and -9 activation as an important mechanism underlying apoptosis in plasma-treated cells	[12]
Cervix	HeLa HFB detroit551	° Induction of HeLa cell apoptosis by facilitating an accumulation of intracellular reactive oxygen and nitrogen species (RONS) in a dose-dependent manner by both dielectric barrier discharge (DBD) plasma and nitric oxide-plasma activated water (NO-PAW) ° Higher selectivity of NO-PAW at given conditions	[62]
Cervix	HeLa	° Inhibited proliferation and induced cell death in an exposure time-dependent manner ° Significant suppression of the migration and invasion ° Reduced activity and expression of the matrix metalloproteinase (MMP)-9 enzyme ° Decreased phosphorylation level of both ERK1/2 and JNK, but not p38 MAPK	[63]
Cervix	CaSki DoTc2-4510 SiHa C-33-A	° Time- and energy-dependent effects of the treatment on cell proliferation ° Higher sensitivity of cervical cancer cells to plasma treatment in comparison to non-cancerous cervical tissue cells ° Decreased metabolic activity in cancer cells lines when compared to NCCT	[64]
Cervix	CaSki	° Distance and flow rate-dependent effect of CAP on tumour cell viability ° Dose-dependent induction of tumour cell death by CAP treatment	[65]
Cervix	HeLa	° Augmented number of early apoptotic cells, late apoptotic cells, but rarely necrotic cells by treatment with N2 and air plasma jets ° Induced apoptotic cell death in a dose-dependent manner ° Increased level of ROS and consequently, induction of apoptosis ° Induction of the mitochondria membrane depolarisation, causing increased mitochondrial transmembrane permeability and release of proapoptotic factors ° Blocking of ROS mediated plasma-induced apoptosis by D-mannitol, sodium pyruvate, carboxyl-PTIO or N-acetyl-cysteine ° Generation of different types and compositions of ROS by different plasma sources	[66]
Cervix	HeLa	° After controlled application of plasma with the precision of tens of nanometres observed killing of plasma-treated cells, neighbouring cells were not affected significantly ° Induction of morphological changes as well as indicators of apoptosis in treated cells ° Crucial role of ROS in cancer cell death induction	[67]
Cervix	HeLa	° Induction of cellular lipid membrane collapse by atmospheric-pressure plasma ° Alteration of electrical conductivity of the cells and induction of lipid oxidation by ROS	[68]
Cervix	SiHa + healthy human cervical tissue cells from cervical conus	° Immediate and persisting decrease in CC cell growth and cell viability associated with significant plasma-dependent effects on lipid structures	[69]
Endometrium	AMEC HEC50	° Reduction of cell viability and induction of cell death by PAM ° Increased autophagic cell death ° Inactivation of the mTOR pathway by PAM ° G2/M-phase arrest in all PAM concentrations ° Induction of intracellular ROS accumulation	[70]
Endometrium	HEC-1 HEC-108	° Reduction of cells containing high levels of aldehyde dehydrogenase (ALDH) - a marker of cancer-initiating cells (CICs) ° Synergistic effect of combined treatment with cisplatin, especially at lower doses ° Combination of plasma and cisplatin treatment is effective both in ALDH high and low cells	[71]
Endometrium	HEC-1 GCIY	° Reduction of cell viability ° Reduction of the number of cells with high aldehyde dehydrogenase (ALDH) production	[72]
Ovary	OVCAR-3 SKOV-3 TOV-21G TOV-112D	° Variation of anti-proliferative efficacy of CAP dependent on treatment duration as well as on the OC cell line used ° Decreased motility, invasion, and metastasis potential ° Culture medium treated with plasma before addition mediates the CAP effect on the cells, however, this effect depends on the cell medium composition	[73]
Ovary	SKOV-3 OV-90 HOSE	° Selective anticancer activity of plasma-activated Ringer’s Lactate solution (PA-RL) containing reactive oxygen and nitrogen species (RONS)	[74]
Ovary	TOV21G ES-2 SKOV3 NOS2 OHFC HPMC	° Decreased viability of CCC cell line after plasma-activated medium treatment ° Induction of morphological changes in EOC cell lines treated with PAM ° Anti-tumour effects mediated by produced ROS ° Selective anti-proliferative effect on cancer cells without causing adverse reactions in normal cells	[75]
Ovary	NOS2 NOS3 NOS2TR NOS2CR NOS3TR NOS3CR	° Decreased viability of ovarian cancer cells treated with PAM in plasma activation time-dependent manner ° Treatment with PAM decreased proliferation rate of paclitaxel and cisplatin-resistant cells derived from parental cell lines ° Addition of ROS scavenger into activated medium decreases anticancer activity, the addition of ROS scavenger inhibitor re-established anticancer activity, thus this point on the crucial role of ROS in an anti-tumour mechanism	[76]
Ovary	K2 K2R100 TOV-21G ES-2	° An anti-tumour effect of PAM on acquired chemo-resistant OC cells ° An anti-tumour effect of aqueous plasma against clear-cell carcinoma, which is natively chemo-refractory OC ° PAM has a selective cytotoxic effect on OC cells	[77]
Ovary	SKOV3 HRA	° Effective killing of ovarian cancer cells lines by the plasma, while plasma-treated fibroblast cells were not damaged ° Plasma treatment induces apoptosis ° The exposure time of treatment affects the proliferation rate	[78]
Ovary	OVCAR-3 NOS2 TOV21G ES-2	° Negative impact of cell density on PAM-induced proliferation inhibition rate ° Selective, cell line dependent sensitivity to PAM ° Dependence of PAM effect on the proportion of ROS and the cell number ° Sensitivity to PAM affected by morphological characteristics of the cells ° TGF-β induced epithelial-mesenchymal morphological transition sensitised cancer cells to PAM	[11]
Ovary	ES2 SKOV3 WI-38 HPMCs	° Inhibition of cell viability of ovarian cancer cells depends on the cell type, cell number, and plasma-activated medium (PAM) dilution ratio ° PAM mediated suppression of cell migration, invasion, and adhesion ° PAM-induced down-regulation of matrix metalloproteinase-9 (MMP-9) prevents cell plantation in co-culture with human peritoneal mesothelial cells ° Inhibition of anti-metastatic effect of PAM by the ROS scavenger	[157]
Breast	MCF-7	° CAP inhibitory effect on the cell proliferation is mediated by miR-19a-3p (miR-19a, oncomiR) ° CAP induces hypermethylation at the promoter CpG sites and subsequent downregulation of miR-19a ° CAP recovers production of ABCA1 and PTEN which are targets of miR-19a	[38]
Breast	MCF-7 MCF-7/TamR	° CAP induces restoration of sensitivity to tamoxifen (Tam) in Tam-resistant cells ° Increase of ROS levels in CAP-treated cells ° Inhibition of the proliferation and promotion of the apoptosis in MCF-7/TamR ° Oppositely altered expression of 20 genes involved in Tam resistance in TamR cells and CAP-treated TamR cells ° MX1 and HOXC6 mediated the restoration of sensitivity against Tam	[39]
Breast	MSC MDA-MB-231	° Synergistic inhibition of breast cancer cell growth after treatment with the combination of CAP and drug (5FU) loaded core-shell nanoparticles ° Induction of down-regulation of metastasis-related genes (VEGF, MTDH, MMP9, and MMP2) ° Facilitation of the uptake of drug-loaded nanoparticles	[40]
Breast	MCF7 MCF10A MTT	° Reduction of the viability of breast cancer cells ° Significantly lower CAP-induced damage on normal cells ° Enhanced reduction of cancer cells viability after addition of 5% oxygen to the helium plasma	[41]
Breast	metastatic BrCa cells MSC	° CAP-induced selective ablation of metastatic BrCa cells in vitro without damaging healthy MSC ° Inhibition of the migration and invasion of BrCa cells after CAP treatment ° Different BrCa cell and MSC responses under varied CAP conditions	[42]
Breast	MCF-7	° Induction of apoptosis in cultured human breast cancer cells ° Significant portion of CAP-treated cells exhibits apoptotic fragmentation, with only limited necrosis	[43]
Breast	MDA-MB-231 MCF-7 HMEC	° ROS in a liquid phase is generated via plasma irradiation of gas, producing the reactive species (electrons, ions, and radicals) and these species dissolve into the liquid phase and/or react with water ° Irradiation time, distance to the liquid surface and voltage affects OH radical generation in the extracellular culture medium	[44]
Breast	MDAMB231 MDAMB468 MCF7 MCF10A	° Induction of apoptosis, inhibition of the proliferation and migration of triple-negative breast cancers (TNBC) after PAM treatment ° Significant increase of H2O2 concentration in the media after CAP treatment ° PAM selectively inhibits the activity of JNK and NF-κB in TNBC cells	[55]
Breast	4T1	° Inhibition of cell migration after both plasma and doxorubicin treatment, assessed by wound healing assay	[56]
Breast	MCF-7 MCF-7/TxR	° Restoration of sensitivity to paclitaxel in resistant cells ° Identification of altered expression of multiple drug resistance-related genes ° DAGLA and CEACAM1 were essential for the acquisition of resistance and the recovery of sensitivity	[158]