摘要目的 探讨LASS2/TMSG1基因沉默对人前列腺癌细胞增殖、侵袭和转移能力的影响及其分子作用机制.方法 建立稳定表达LASS2/TMSG1-shRNA的低转移潜能人前列腺癌PC-3M-2B4细胞系,然后采用四甲基偶氮唑蓝(MTT)掺入实验、软琼脂集落形成实验、流式细胞术、Matrigel穿膜侵袭实验和裸鼠体内成瘤实验研究LASS2/TMSG1的细胞生物学功能;采用Western blot法、明胶酶谱法检测基质金属蛋白酶2和9(MMP-2和MMP-9)的表达、分泌及活性;并采用V-ATPase活性检测试剂盒检测细胞内V-ATPase活性,以及采用BCECF H+敏感荧光探针检测细胞外H+浓度以研究LASS2/TMSG1抑制前列腺癌转移的分子作用机制.结果 转染LASS2/TMSG1-shRNA后,PC-3M-2B4细胞的增殖能力、锚定不依赖生长能力及体外侵袭能力明显提高(P＜0.05),而细胞凋亡率明显下降(P＜0.01),但对细胞周期无影响(P＞0.05);LASS2/TMSG1基因沉默组移植瘤的体积、质量及淋巴结转移率(5/6)和核增殖指数(0.53±0.05)明显大于空白对照组(0/6,0.13 ±0.02)和无关阴性对照组(1/6,0.10 ±0.03;P＜0.05);LASS2/TMSG1基因沉默组的V-ATPase酶活性(P＜0.01)及细胞外H+浓度明显升高(P＜0.01),而MMP-2及MMP-9的表达量和分泌量无明显变化(P＞0.05),但分泌的MMP-2和MMP-9活性增加(P＜0.05).结论 特异性shRNA沉默LASS2/TMSG1基因能促进人前列腺癌细胞增殖、侵袭和转移能力,其机制可能是沉默LASS2/TMSG1基因后激活液泡型ATPase,从而使细胞外H+浓度升高,进而激活MMP-2和MMP-9有关,提示LASS2/TMSG1基因是一种新的肿瘤转移抑制基因.

abstractsObjective To explore the effects of LASS2/TMSG1 silencing on the growth,invasion and metastasis of prostate carcinoma cells and to investigate the related molecular mechanisms.Methods LASS2/TMSG1 expression of human prostate carcinoma cell line with low metastatic potentiality (PC-3M-2B4 cells) was knocked down using DNA vector-based small interfering RNA (shRNA),followed by evaluations of tumor cell invasion and metastasis.Results A stable PC-3M-2B4 cell line with expression of LASS2/TMSG1-shRNA was successfully established.MTT assay showed PC-3M-2B4 cells exhibited a strong proliferation after transfection of LASS2/TMSG1-shRNA.LASS2/TMSG1-shRNA transfected clones demonstrated an increased clonogenicity by soft agar colony formation assay and a significant increase of tumor cell invasion by matrigel invasion study.Flow cytometry showed that after LASS2/TMSG1 gene silencing,the apoptotic rate of PC-3M-2B4 cell significantly decreased (P ＜ 0.01) without significant cell cycle change (P ＞ 0.05).Eight weeks after implantation into subcutaneous tissues in BAL B/c (nu +) mice,the size and weight of sh-LASS2/TMSG1 xenografts were significantly larger than those of the control group (P ＜ 0.05).Nuclear proliferation index of the subcutaneous tumor was also higher in the LASS2/ TMSG1 shRNA group than those in the control group.Lymph node metastasis was observed in 5 of 6 mice of LASS2/TMSG1 shRNA group and only 1 of 6 of the control group.V-ATPase activity,activities of secreted MMP-2 and MMP-9 and extracellular hydrogen ion concentration were significantly increased in LASS2/ TMSG1-shRNA group compared with the control group (P ＜ 0.05).Conclusion Silencing of LASS2/ TMSG1 promotes the growth,invasion and metastasis of prostate cancer cells through up-regulation of V-ATPase activity,indicating that LASS2/TMSG1 is a tumor metastasis suppressor gene.