[Biological implication of PTEN gene expression in human gastric cancer and related molecular mechanisms].
OBJECTIVE
To study the role of PTEN gene involved in the biological behavior of human gastric carcinoma cells and underlying molecular mechanisms.


METHODS
Gastric carcinoma cell line, SGC7901, was transfected with plasmid PBP-PTEN and stable high PTEN expression clones were selected by Western blot and cell immunohistochemistry screening. Cell proliferation rate and apoptosis index of transfected cells were investigated by growth curve analysis, colony-formation assay and flow cytometry (FCM). Expressions of vascular endothelial growth factor (VEGF), matrix metalloprotease-2 (MMP-2) and MMP-9 proteins in cell culture supernatant and cytoplasm were determined by ELISA, gelatin zymogram, Western blot and cell immunohistochemistry.


RESULTS
Stable clone with high level expression of PTEN was successfully established (PTEN-SGC7901). Cell doubling time of PTEN-SGC7901 was longer than that of the control cells (P < 0.05). The size and colony-forming efficiency of PTEN-SGC7901 cells deceased compared with those of the control. The relative colony-inhibition efficiency of PTEN-SGC7901 to SGC7901 (naïve untransfected) and PBP-SGC7901 (control vector transfected) cells were 69.8% and 64.8%, respectively. PTEN-SGC7901 clone had more cells at G1 phase (P < 0.05) compared with that of the control. However, the apoptosis index did not show significant differences among the three groups (P > 0.05). There were significantly less VEGF and MMP-9 protein expressions in the PTEN-SGC7901 culture supernatant and cytoplasm (P < 0.05). In contrast, the MMP-2 expression among three cell groups had no significant difference (P > 0.05).


CONCLUSIONS
PTEN expression suppresses the growth and proliferation of gastric carcinoma cell SGC7901, possibly through an inhibition of the expressions of VEGF and MMP-9.
He
Rong-fang
RF
Department of Pathology, Xiangya Medical School, Central South University, Changsha 410078, China.
Hu
Zhong-liang
ZL
Wen
Ji-fang
JF
D017209:Apoptosis; D002453:Cell Cycle; D045744:Cell Line, Tumor; D049109:Cell Proliferation; D015972:Gene Expression Regulation, Neoplastic; D006801:Humans; D020778:Matrix Metalloproteinase 2 / Q000378:metabolism; D020780:Matrix Metalloproteinase 9 / Q000378:metabolism*; D051059:PTEN Phosphohydrolase / Q000235:genetics / Q000378:metabolism*; D010957:Plasmids; D013274:Stomach Neoplasms / Q000378:metabolism* / Q000473:pathology; D014162:Transfection; D042461:Vascular Endothelial Growth Factor A / Q000378:metabolism*
C467484:VEGFA protein, human; D042461:Vascular Endothelial Growth Factor A; D051059:PTEN Phosphohydrolase; C494929:PTEN protein, human; C522361:MMP2 protein, human; D020778:Matrix Metalloproteinase 2; D020780:Matrix Metalloproteinase 9