PSCA表达及其单抗对PC-3M细胞生长与凋亡影响的观察

目的：观察前列腺干细胞抗原（prostate stem cell antigen，PscA）在人雄激素非依赖性前列腺癌PC-3M细胞的表达状况以及PSCA特异性单克隆抗体（PSCA—mAb）对PC-3M细胞生长和凋亡的影响。方法：采用细胞免疫化学方法检测PSCA在PC-3M的表达；以O～1．0／tg／mL浓度的PSCA—mAb作用PC-3M细胞0～96h，采用细胞生长曲线、四甲基噻唑氮蓝（methyl thiazolyl tetrazolium，MTT）法、琼脂糖凝胶电泳和流式细胞术（flow cytometry，FCM）分析P＆3M细胞生长及凋亡的变化。结果：PSCA在PC-3M细胞膜和细胞质呈阳性表达；0．1／μg／mLPSCA—mAb作用时的细胞生长抑制率为（11．3±2．2）％，0．2／μg／mL为（27．5±3．4）％，0．4／μg／mL为（39．4±5．8）％，0．6μg／mL为（47．7±7．4）％，0．8μg／mL为（69．3±8．2）％，l.0〉g／mL为（70．8±9．3）％，细胞凋亡率为0．1／μg／mL为（8．7±1．4）％，0．2μg／mL为（12．3±2．8）％，0．4μg／mL为（21．6±3．2）％，0．6〉g／mL为（33．6±4．9）％，0．8g／mL为（41．4土5．8）％，1．0μg／mL为（42．3土6．1）％，均显著高于相应对照组细胞生长抑制率和凋亡率，P均〈0．01；PSCA-mAb作用PC-3M细胞24h的生长抑制率为（47．8士6．4）％，48h为（59．4±7．3）％，72h为（70．3±7．9）％，96h为（71．1±9．0）％，细胞凋亡率24h为（33．6±4．3）％，48h为（36．3±5．1）％，72h为（42．7±5．7）％，96h为（43．4±6．3）％，均高于相应的对照组细胞生长抑制率和凋亡率，P均〈O．01。MTT及FCM分析结果表明，PSCA-mAb在0．6μg／mL作用72h时，细胞生长抑审l率为（71．5±6．2）％，凋亡率为（44．4±5．5）％，均达到最大。结论：PSCA在人雄激素非依赖性前列腺癌PC-3M细胞呈阳性表达；PSCA-mAb能够时间一剂量依赖性地抑制PC一3M生长和诱导其凋亡。

Prostate stem cell antigen expression and effects of PSCA-mAb on growth and apoptosis of prostate cancer PC-3M cells

OBJECTIVE： To determine the expression status of prostate stem cell antigen（PSCA） in human androgen independent cancer PC-3M cells and the effects of PSCA specific mAb on growth and apoptosis of PC-3M cells in vitro. METHODS：PC-3M cells were cultured in vitro routinely and PSCA expression was examined by immunocytochemistry. PC-3M cells were treated by 0 -- 1. 0 μg/mL PSCA-mAb for 0 -- 96 h. Cell growth inhibition was analyzed using cell growth curve and MTT. Apoptotic cells were detected by DNA fragmentation analyse on agarose gel electrophoresis and confirmed by flow cytometric analysis. RESULTS： PSCA positive staining was found in membrane and cytoplasm of PC-3M cells by cytoimmunochemistry. When PC-3M cells were treated by PSCA-mAb at 0.1,0. 2,0. 4,0. 6,0. 8 and 1.0 μg/mL,the cell growth inhibition rates -（11.3±2.2）%, （27.5±3.4）%, （39.4±5.8）%, （47. 7±7. 4）%, （69.3±8. 2）%, （70.8±9.3）%] and the cell apoptosis rates F（8.7±91.4）%,（12.3±2.8） ,（21. 6±3. 2）%,（33. 6±4. 9）%,（41. 4±5.8） %, （42.3±6.1）%1 were significantly higher than those of the control cells,respectively （P〈0.01 for each）. PC-3M cells were also found having the significantly higher cell growth inhibition rates E （47.8 ±6.4） %, （59.4 ±7.3） %, （70.3±7.9） %, （71.1±F 9.0） %1 and cell apoptosis rates （33.6±4.3） %, （36.3-9 5.1） %, （42.7±9 5.7） %, （43.4±6.3） % than those of the control cells when treated by PSCA-mAb at 24,48,72 and 96 h,respectively （P〈0.01） for each）. MTT and flow cytometry analysis showed that PC-3M cells had the maximum growth inhibition rate of （71.5±6.2） % and the max imum apoptosis rate of （44.4± 5.5）% at 0.6 PSCA-mAb for 72 h. CONCLUSION：The results demonstrate that PSCA as a new cell surface marker is expressed in human prostate cancer PC-3M cells,and that PSCA-mAb can inhibit cell growth and induce cell apoptosis of PC-3M cells in a dose-and time-dependent manner.