[LASS2/TMSG1 gene silencing promotes the invasiveness and metastatic of human prostatic carcinoma cells through increase in vacuolar ATPase activity].
OBJECTIVE
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).


CONCLUSIONS
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.
Department of Pathology, Peking University Health Science Center, Beijing 100191, China.
Xiaoyan
X
Xu
Department of Pathology, Peking University Health Science Center, Beijing 100191, China.
Jiangfeng
J
You
Department of Pathology, Peking University Health Science Center, Beijing 100191, China. E-mail:peifei@bjmu.edu.cn.
Fei
F
Pei
D000818:Animals; D017209:Apoptosis; D002453:Cell Cycle; D045744:Cell Line, Tumor; D020868:Gene Silencing; D006801:Humans; D006863:Hydrogen-Ion Concentration; D008207:Lymphatic Metastasis; D008297:Male; D020778:Matrix Metalloproteinase 2 / Q000378:metabolism; D020780:Matrix Metalloproteinase 9 / Q000378:metabolism; D008565:Membrane Proteins / Q000235:genetics* / Q000378:metabolism; D051379:Mice; D008807:Mice, Inbred BALB C; D008819:Mice, Nude; D009361:Neoplasm Invasiveness; D009368:Neoplasm Transplantation; D011471:Prostatic Neoplasms / Q000235:genetics* / Q000378:metabolism / Q000473:pathology*; D034741:RNA, Small Interfering / Q000235:genetics; D051049:Sphingosine N-Acyltransferase / Q000235:genetics* / Q000378:metabolism; D014162:Transfection; D047368:Tumor Burden; D025521:Tumor Suppressor Proteins / Q000235:genetics* / Q000378:metabolism; D015854:Up-Regulation; D025262:Vacuolar Proton-Translocating ATPases / Q000378:metabolism*
D008565:Membrane Proteins; D034741:RNA, Small Interfering; D025521:Tumor Suppressor Proteins; C438311:CERS2 protein, human; D051049:Sphingosine N-Acyltransferase; D020778:Matrix Metalloproteinase 2; D020780:Matrix Metalloproteinase 9; D025262:Vacuolar Proton-Translocating ATPases