Fig 1.
Reactivation of GFP expression in HeLa TI cells by TSA.
A. GFP expression in HeLa TI cells depending on the treatment. Cells treated with TSA (0.25 μM and 0.06 μM) and DMSO (0.1%) were analyzed with phase-contrast and fluorescent microscopy and flow cytometry. B. Time-response effect of TSA; FACS. C. Dose-response effect of TSA; FACS. The values are expressed as the means ± SD; “*” indicates the level of significance to vehicle (p <0.05).
Fig 2.
Epigenetic modulators used in the study.
HDACis–histone deacetylase inhibitors, DNMTis–DNA-methyltransferase inhibitors, HMTis–histone methyltransferase inhibitors, BETis–bromodomains and extraterminal motif inhibitors, and KDMi–a lysine demethylase inhibitor.
Fig 3.
Reactivation of silenced GFP expression in HeLa TI cells.
A. After treatment with epigenetic modulators. B. After treatment with combinations of CBL0137, TSA and 5-azaC. C. After treatment with combinations of UNC with CBL0137, TSA and 5-azaC. GFP-positive cells were counted with flow cytometry. Data normalized to vehicle. The values are expressed as the means ± SD; “*” indicates the level of significance to vehicle (p <0.05); “#” indicates the level of significance to 1st agent (p <0.05) and “ǂ” indicates the level of significance to 2nd agent (p <0.05).
Fig 4.
Reactivation of silenced GFP in HeLa TI cells by combinations of epigenetic modulators.
A. JQ-35 with CBL0137, TSA and 5-azaC. B. JQ-1 with CBL0137, TSA and 5-azaC. C. Tazemetostat with CBL0137, TSA and 5-azaC. GFP-positive cells were counted with flow cytometry. Data normalized to vehicle. The values are expressed as the means ± SD; “*” indicates the level of significance to vehicle (p <0.05); “#” indicates the level of significance to 1st agent (p <0.05) and “ǂ” indicates the level of significance to 2nd agent (p <0.05).
Fig 5.
Metabolic competence of HeLa TI cells.
A. Metabolism of procarcinogen benzo[a]pyrene by HeLa TI cells; Shpol’skii method. B. Level of DNA damage in HeLa TI cells after carcinogen and procarcinogen treatment; Comet assay. C. Activity of different CYP450 isoform genes in HeLa TI cells after treatment with microsomal oxygenase inductors, qRT-PCR (results are presented as the fold change (2 −ΔCT) in the level of the expression, which was normalized to that of the RPL27 gene). The values are expressed as the means ± SD, and “*” indicates the level of significance (p <0.05).
Table 1.
mRNA induction of CYP isoforms in HeLa TI cells.
Fig 6.
A, B. Effects of the S9 mixture and its components on GFP reactivation in HeLa TI cells. C. Effects of procarcinogens from the N-nitrosamine class on GFP reactivation in HeLa TI cells. GFP-positive cells were counted with flow cytometry. Data normalized to vehicle. D. Analysis of the sensitivity of HeLa TI and CaSki cells to the demethylating agents. E. Effects of nitrosamines NDMA and NDPhA on DNA methylation. The values are expressed as the means ± SD, and “*” indicates the level of significance (p <0.05).