目的： 采用RNA干涉技术沉默液泡型ATP酶c亚基ATP6V0C的表达，探索ATP6V0C在前列腺癌侵袭中的分子作用机制，并研究其与LASS2/TMSG1的关系。方法与结果： ATP6V0C在高转移潜能人前列腺癌细胞系（PC-3M-1E8和PC-3M）中的表达明显高于低转移潜能人前列腺癌细胞系（PC-3M-2B4和PC-3）， 选择ATP6V0C表达量最高的PC-3M-1E8细胞进行基因沉默实验，发现ATP6V0C的siRNA转染PC-3M-1E8后，其基质金属蛋白酶2（matrix metalloprotein-2，MMP-2）和基质金属蛋白酶9(MMP-9)蛋白的表达量及MMP-2的分泌量均无明显变化，但上清液中MMP-9的活性明显减弱，与空白对照组及阴性对照组相比，差异有统计学意义（P<0.05)；干扰组细胞外氢离子浓度及液泡型ATPase的活性明显降低（P<0.05)；细胞划痕修复实验及transwell体外侵袭实验结果显示ATP6V0C siRNA干扰组细胞的体外迁移及侵袭能力明显减弱（P<0.05)。PC-3M-1E8细胞转染ATP6V0C siRNA后，LASS2/TMSG1的表达明显减弱（P<0.05)。免疫荧光双重染色结果显示ATP6V0C蛋白与LASS2/TMSG1共定位于胞浆和胞膜，干扰组共定位信号与对照组相比明显减弱。结论： 特异性siRNA沉默ATP6V0C能抑制人前列腺癌细胞的迁移和侵袭能力，其机制与ATP6V0C沉默后抑制V-ATPase的活性，使细胞外氢离子浓度降低，抑制MMP-9的激活，从而影响细胞外基质的降解和重塑有关。靶向siRNA干扰ATP6V0C的表达后，可能通过反馈调节机制抑制LASS2/TMSG1的表达，但其具体分子机制尚待进一步研究。

Objective： Vacuolar ATPase (V-ATPase) was found within the membranes and internal organelles of a vast array of eukaryotic cells, and was related to various kinds of highly metastatic tumors. LASS2/TMSG1 gene was a novel tumor metastasis suppressor gene cloned from human prostate cancer cell line PC--3M in 1999 by our laboratory. It was found out that protein encoded by LASS2/TMSG1 could interact with the c subunit of V-ATPase (ATP6V0C). In this study, To use RNA interference to suppress the expression of ATP6V0C and try to further investigate the molecular mechanism of ATP6V0C in tumor metastasis and its relationship with LASS2/TMSG1 gene. Methods and Results: The expression level of ATP6V0C mRNA and protein in high metastatic potential prostate cancer cell lines (PC-3M-1E8 and PC-3M) was significantly higher than that in low metastatic potential prostate cancer cell lines (PC-3M-2B4 and PC-3), the expression level in PC-3M-1E8 being the highest. Follow-up tests selected PC-3M-1E8 cells for gene silencing. The expression and secretion of MMP-2 and the expression of MMP-9 in ATP6V0C siRNA transfected PC-3M-1E8 cells displayed no obvious change, but the activity of secreted MMP-9 was abated noticeably compared with the controls (P<0.05). Extracellular hydrogen ion concentration and V-ATPase activity in interference group were both reduced significantly compared with the controls (P<0.05). The migration and invasion capacity of ATP6V0C siRNA interfered cells in vitro were diminished significantly compared with the controls (P<0.05). Furthermore, a dramatic reduction of LASS2/TMSG1 mRNA and protein level after transfection of siRNA in PC-3M-1E8 cells was discovered (P<0.05). Confocal immunofluorescence showed a vast co-localization of ATP6V0C protein and LASS2/TMSG1 protein in plasma and membrane. The co-localization signals of control group were much stronger than those of interference group. Conclusion: Specific siRNA silencing of ATP6V0C gene inhi-bits the invasion of human prostate cancer cells in vitro by mechanism of inhibiting V-ATPase activity and then reducing the extracellular hydrogen ion concentration, inhibiting MMP-9 activation and affecting ECM degradation and reconstruction. Meanwhile, ATP6V0C and LASS2/TMSG1 have interaction and it is likely that ATP6V0C functions as a feedback regulator of LASS2/TMSG1.