Effects of trichostatin A on FHIT and WWOX genes expression, cell growth inhibition and apoptosis induction in hepatocellular carcinoma WCH 17 cell line

Previously, we evaluated the effect of trichostatin A (TSA) on the expression of DNA methyltransferase 1 (DNMT1) in Hepatocellular Carcinoma (HCC). Fragile histidine triad (FHIT) and WW domain-containing oxidoreductase (WWOX) are two of the most common down-regulated genes in many cancers located on chromosome 3p14.2 and 16q23.3-24.1 respectively. The aim of the current study was to assess the effect of TSA on these genes expression, cell growth, and apoptosis in HCC WCH 17 cell. The cells were seeded and treated with TSA at different times. Then, MTT assay, flow cytometry, and qRT-PCR were achieved to determine viability, apoptosis and gene expression respectively. Cell growth was significantly inhibited, 92 to 36% after 24 h, 86 to 28% after 48 h, and 78 to 24% after 72 h. The results of flow cytometry confirmed that TSA increased apoptosis compared to the control group, the apoptosis percentage increased to 12%, 16%, and 18% in comparison to control groups (2%). Significant up-regulation of the genes was observed in all treated groups. We concluded that re-expression of silenced WWOX and FHIT genes could be achieved by TSA resulting in cell growth inhibition and apoptosis induction in WCH 17 cell.

既往本课题组已评估曲古抑菌素A（trichostatin A, TSA）对肝细胞癌（Hepatocellular Carcinoma, HCC）细胞中DNA甲基转移酶1（DNA methyltransferase 1, DNMT1）表达的影响。脆性组氨酸三联体（Fragile histidine triad, FHIT）与含WW结构域的氧化还原酶（WW domain-containing oxidoreductase, WWOX）是多种恶性肿瘤中最常见的两种下调基因，二者分别定位于染色体3p14.2与16q23.3-24.1区域。本研究旨在评估TSA对HCC WCH 17细胞中上述基因表达、细胞增殖及细胞凋亡的影响。将细胞接种后，采用TSA进行不同时长的处理。随后分别通过MTT实验（MTT assay）、流式细胞术（flow cytometry）与实时定量反转录PCR（qRT-PCR）检测细胞活力、细胞凋亡水平及基因表达情况。细胞增殖受到显著抑制：处理24小时后抑制率区间为92%~36%，48小时后为86%~28%，72小时后为78%~24%。流式细胞术结果证实，与对照组相比，TSA处理可诱导细胞凋亡：对照组凋亡率为2%，而TSA处理组的凋亡率分别升至12%、16%与18%。所有TSA处理组中，目标基因均出现显著上调表达。本研究结论表明，TSA可重新激活沉默的WWOX与FHIT基因，进而抑制WCH 17细胞的增殖并诱导其凋亡。