STGC3 inhibits xenograft tumor growth of nasopharyngeal carcinoma cells by altering the expression of proteins associated with apoptosis

• Main Authors: Qing-chao Qiu, Bo Hu, Xiu-pei He, Qiao Luo, Guo-hua Tang, Zhi-feng Long, Zhu-chu Chen, Xiu-sheng He
• Format: Article
• Language: English
• Published: Sociedade Brasileira de Genética 2012-01-01
• Series: Genetics and Molecular Biology
• Subjects: CNE2 cell line; nasopharyngeal carcinoma; nude mouse; STGC3; Tet-on; two-dimensional electrophoresis
• Online Access: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1415-47572012000100002
• ISSN: 1415-4757; 1678-4685

STGC3 is a potential tumor suppressor that inhibits the growth of the nasopharyngeal carcinoma cell line CNE2; the expression of this protein is reduced in nasopharyngeal carcinoma compared with normal nasopharyngeal tissue. In this study, we investigated the tumor-suppressing activity of STGC3 in nude mice injected subcutaneously with Tet/pTRE-STGC3/CNE2 cells. STGC3 expression was induced by the intraperitoneal injection of doxycycline (Dox). The volume mean of Tet/pTRE-STGC3/CNE2+Dox xenografts was smaller than that of Tet/pTRE/CNE2+Dox xenografts. In addition, Tet/pTRE-STGC3/CNE2+Dox xenografts showed an increase in the percentage of apoptotic cells, a decrease in Bcl-2 protein expression and an increase in Bax protein expression. A proteomic approach was used to assess the protein expression profile associated with STGC3-mediated apoptosis. Western blotting confirmed the differential up-regulation of prohibitin seen in proteomic analysis. These results indicate that overexpression of STGC3 inhibits xenograft growth in nude mice by enhancing apoptotic cell death through altered expression of apoptosis-related proteins such as Bcl-2, Bax and prohibitin. These data contribute to our understanding of the function of STGC3 in human nasopharyngeal carcinoma and provide new clues for investigating other STGC3-associated tumors.