锌对前列腺癌细胞PC-3M凋亡的影响

目的:探讨锌对前列腺癌细胞PC-3M凋亡的影响。方法:分别选用不同浓度ZnSO₄•7H₂O（终浓度分别为6.25、15、25、50、100、150、200、250及300 μmol•L^-1）作用于PC-3M细胞24 h，用MTT法筛选对PC-3M细胞增殖抑制的有效浓度，利用吖啶橙/溴化乙锭染色、DNA ladder及流式细胞术检测PC-3M细胞凋亡情况。结果:MTT显示，锌的浓度在250 μmol•L^-1时, PC-3M细胞存活率显著低于对照组（P<0.01）。Zn²⁺浓度达250 μmol•L^-1时，相差显微镜下细胞形态变化明显，细胞变长，并伸出较长的突起，细胞分裂相明显减少，细胞数量较对照组明显减少。吖啶橙/溴化乙锭染色显示，对照组细胞形态为规则的圆形，细胞膜光滑无皱缩和发泡，呈现均匀的绿色，偶可见橙色细胞(自然凋亡细胞)；Zn²⁺（250 μmol•L^-1）作用后，相差显微镜下可观察到较多早期凋亡细胞，细胞多为圆形，但细胞膜较对照组粗糙，细胞呈绿色，细胞核中有鲜绿色的斑点；也可观察到较多的晚期凋亡细胞，细胞形状不规则，细胞膜粗糙，有较多突起，被吖啶橙染成橙色，细胞中有鲜亮的橙色斑点。DNA ladder可见梯形条带出现；流式细胞术显示亚二倍体峰的出现，细胞凋亡率为13.3%。上述各项指标均显示PC-3M细胞的凋亡水平明显高于对照组（P<0.05）。结论：高Zn²⁺可以抑制前列腺癌细胞生长并诱导前列腺癌细胞凋亡。

Effects of zinc on apoptosis of prostate cancer cells

Objective To investigate the effects of zinc on apoptosis of prostate cancer cells(PC-3M). Methods The cell proliferation was determined by MTT assay treated with different concentrations of ZnSO_4·7H_2O (end concentrations were 6.25,15,25,50,100,150,200,250,and 300 μmol·L~ -1 ,respectively), the cell morphological changes after exposed to zinc for 24 h was observed under phase-contrast microscope, the apoptosis was detected by AO/EB assay, the cell cycle and apoptotic peak were detected by flow cytometry, DNA fragmentation was observed by agarose gel electrophoresis(AGE).Results PC-3M cells proliferation rate was obviously changed after exposed to different levels of zinc for 24 h. Zinc(250 μmol·L~ -1 ) inhibited proliferation of PC-3M cells (P<0.01). Compared with control cells, the changes of morphological characteristics of PC-3M cells were found,including shrank and floated,decreased refraction in the cells exposed to zinc (250 μmol·L~ -1 ) for 24 h. The confocal microscopy showed the changes of cells through AO/EB staining.The cellular membrane was integrity but vacuolization of the cytoplasm,chromatin was flavo-green, nuclear condensed, nuclear side collection, caryolysis, nuclear fragmented. The flow cytometry showed the hypodip-loid peak in G_0/G_1 phase after exposed to zinc (250 μmol·L~ -1 )for 24 h. It had visible DNA fragmentation by AGE. Conclusion Zinc with high concentrationcan inhibit human prostate cancer cell growth and induce apoptosis of human prostate cancer cells.