title: STGC3 inhibits xenograft tumor growth of nasopharyngeal carcinoma cells by altering the expression of proteins associated with apoptosis.
abstract: 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.
authors.affiliation: Cancer Research Institute, University of South China, Hengyang, China.
authors.forename: Qing-Chao
authors.initials: QC
authors.lastname: Qiu
authors.forename: Bo
authors.initials: B
authors.lastname: Hu
authors.forename: Xiu-Pei
authors.initials: XP
authors.lastname: He
authors.forename: Qiao
authors.initials: Q
authors.lastname: Luo
authors.forename: Guo-Hua
authors.initials: GH
authors.lastname: Tang
authors.forename: Zhi-Feng
authors.initials: ZF
authors.lastname: Long
authors.forename: Zhu-Chu
authors.initials: ZC
authors.lastname: Chen
authors.forename: Xiu-Sheng
authors.initials: XS
authors.lastname: He