硒化合物诱导高危型HPV亚型宫颈癌细胞凋亡

目的探讨二氧化硒(SeO_2)对高危型HPV亚型宫颈癌细胞凋亡的诱导作用及其分子途径。方法不同浓度SeO_2分别作用于高危型HPV亚型宫颈癌细胞He La(HPV18+)和Caski(HPV16+)24 h,光学显微镜下观察细胞形态;四甲基偶氮唑蓝(MTT)比色法检测细胞增殖及活力;流式细胞计量术(FCM)检测细胞凋亡率;Western blot测定细胞内caspase-3和p53蛋白表达;Stem-loop实时定量PCR检测凋亡相关miRNA LET-7a表达。结果 SeO_2作用后宫颈癌细胞变圆、皱缩;SeO_2呈量效依赖关系抑制宫颈癌细胞增殖,其中He La细胞在7.5~30μmol/L组抑制作用显著;Caski细胞在SeO_2低浓度组即有显著抑制作用(P0.05)。宫颈癌细胞凋亡率亦随SeO_2浓度升高而升高,在Caski细胞上升更加明显。SeO_2可明显上调宫颈癌细胞系中caspase-3与p53蛋白水平,在He La细胞中二者均于7.5μmol/L处达到峰值。Caski细胞从7.5μmol/L组开始凋亡蛋白表达量显著性升高(P0.05)。SeO_2还可显著上调两细胞系实验组细胞LET-7a表达水平,且均在7.5μmol/L处出现峰值。结论 SeO_2通过上调高危型HPV亚型宫颈癌细胞中凋亡相关蛋白p53蛋白及miRNA LET-7a的表达,经caspase-3途径诱导细胞凋亡。对于SeO_2诱导宫颈癌细胞凋亡,HPV16+型较HPV18+型宫颈癌细胞更为敏感。

Selenium compound induces apoptosis of cervical carcinoma cells of high risk HPV subtypes

Objective To investigate the inducing effects and related pathways of selenium dioxide ( SeO2 ) on the apoptosis in 2 human cervical carcinoma cell lines of high risk HPV subtypes .Methods HeLa (HPV-18-positive) and Caski (HPV-16-positive) cells were incubated with different concentrations of SeO 2 for 24 h respectively.Mor-phological changes of HeLa and Caski cells were observed under inverted optical microscope ;cell proliferation and activity were examined by MTT assay;flow cytometry was employed to detect the cell apoptosis;the expressions of apoptosis-related proteins caspase-3 and p53 in cervical carcinoma cell lines were determined by Western blot analysis;the effects of SeO 2 on apoptosis-related miRNA LET-7a expression was detected by stem-loop reverse tran-scription-polymerase chain reaction (RT-PCR).Results Cell morphology was obviously changed in vitro.Cells be-came rounded and shrunken .SeO2 markedly inhibited cell proliferation and viability in a dose-dependent manner in both cell lines; In HeLa cells the inhibitory effects induced by 7.5-30 μmol/L of SeO 2 were significant ( P<0.05);The inhibitory effects on Caski were statistical significant (P<0.05) even with low concentrations of SeO 2. The apoptosis induced by SeO 2 increased dose-dependently in cervical carcinoma cell lines , which were higher in Caski.SeO2 up-regulated the apoptosis-related proteins in cervical carcinoma cell lines .The expressions of caspase-3 and p53 in HeLa cells both significantly increased as compared with control group (P<0.05), and peaked at the concentration of 7.5 μmol/L.Treated with higher concentrations ( 7.5-30 μmol/L ) of SeO 2 , the expression on Caski cells increased significantly ( P<0.05 ) .SeO 2 induced of expression of apoptosis-related miRNA LET-7a both in HeLa cells and Caski cells with statistical meanings ( P<0.05 );the effects reached its peak at the concentration of 7.5 μmol/L bothly.Conclusions SeO2 shows anti-tumor properties via apoptosis pathway by up-regulating the expressions of apoptosis-related proteins caspase-3, the mechanisms of can be potentially explained by p 53 and LET-7a in cervical cancer cell lines.The apoptosis-inducing effect of SeO2 is more sensitive in HPV16+cell line compared with HPV18+cell line.