title: Sexual dimorphism of STGC3 tumor suppressor function in nasopharyngeal  carcinoma CNE2 cells.
abstract: STGC3 is a potential tumor suppressor in nasopharyngeal carcinoma. We previously found that CNE2 cells that re-expressed STGC3 formed smaller tumors in female mice than in male mice. Here, we investigated the sexual dimorphism of STGC3 as a tumor-suppressor in female and male nude mice injected subcutaneously with pcDNA3.1(+)-STGC3/CNE2 cells. ER-α was positively expressed in vitro in the CNE2 cells. The pcDNA3.1(+)-STGC3/CNE2 cell growth rate decreased after treatment with β-estradiol in vitro. There were significant differences in tumor size or mass between pcDNA3.1(+)-STGC3/CNE2 and control cases (P < 0.05), but there were significant differences in tumor size between female and male nude mice in the STGC3 transfection groups, and the pcDNA3.1(+)-STGC3/CNE2 tumor growth rate in the female nude mice was the lowest in all cases (P < 0.05). There were no significant differences between female and male nude mice in control groups. Furthermore, a greater number of cells were blocked in the G(0)/G(1) phase in pcDNA3.1(+)-STGC3/ CNE2 tumor xenografts in the female mice. Protemic analysis found 9 differentially expressed proteins in the pcDNA3.1-STGC3/CNE2 xenograft tissues in females and males. A heat shock 70 protein 8 isoform 2 variant was identified as a down-regulated protein associated with cell cycle control and its downstream factor cyclin D1 was also decreased in STGC3-repressed xenografts in female mice. The data above suggest that STGC3 and its associated proteins play an important role in nasopharyngeal carcinoma gender differences.
authors.affiliation: Cancer Research Institute, University of South China, Hengyang, Hunan, China.
authors.forename: Q
authors.initials: Q
authors.lastname: Qiu
authors.forename: B
authors.initials: B
authors.lastname: Hu
authors.forename: Z C
authors.initials: ZC
authors.lastname: Chen
authors.forename: X S
authors.initials: XS
authors.lastname: He
mesh_terms: D000818:Animals; D002277:Carcinoma / Q000378:metabolism / Q000473:pathology*; D045744:Cell Line, Tumor; D019938:Cyclin D1 / Q000378:metabolism; D004958:Estradiol / Q000502:physiology; D047628:Estrogen Receptor alpha / Q000378:metabolism; D005260:Female; D016147:Genes, Tumor Suppressor; D050883:HSC70 Heat-Shock Proteins / Q000378:metabolism; D006801:Humans; D008297:Male; D051379:Mice; D008807:Mice, Inbred BALB C; D008819:Mice, Nude; D000077274:Nasopharyngeal Carcinoma; D009303:Nasopharyngeal Neoplasms / Q000378:metabolism / Q000473:pathology*; D009368:Neoplasm Transplantation; D011506:Proteins / Q000235:genetics* / Q000378:metabolism / Q000502:physiology; D016192:Resting Phase, Cell Cycle; D012727:Sex Characteristics; D012737:Sex Factors; D059467:Transcriptome; D047368:Tumor Burden
chemical_list: C530104:CCND1 protein, human; C506487:ESR1 protein, human; D047628:Estrogen Receptor alpha; D050883:HSC70 Heat-Shock Proteins; C494371:HSPA8 protein, human; D011506:Proteins; C502770:STGC3 protein, human; D019938:Cyclin D1; D004958:Estradiol