title: RhoBTB2 gene in breast cancer is silenced by promoter methylation.
abstract: Mutation analysis in breast cancer has failed to explain the inactivation of RhoBTB2, a candidate breast cancer tumor suppressor gene on chromosome 8p. Some breast cancer-related genes in this region become inactivated by hypermethylation, and hypermethylation of RhoBTB2 abrogates its expression in bladder cancers. The aim of the present study was to determine whether RhoBTB2 was silenced by methylation in breast cancer. Nested methylation-speciﬁc PCR (nMSP) and quantitative reverse transcription PCR were used to analyze the methylation status and mRNA levels of RhoBTB2 in 50 paired breast cancer and normal tissues and the results were correlated with clinicopathological characteristics. Promoter methylation and the downregulation of RhoBTB2 mRNA was observed in tumor tissues (P<0.001). mRNA levels were decreased in samples with methylation (χ² = 15.751, P<0.001). RhoBTB2 methylation was observed preferentially in progesterone receptor (PR)-negative samples (P<0.05). The results demonstrated that aberrant methylation of RhoBTB2 may be responsible for the suppression of RhoBTB2 mRNA expression in breast cancer, a significant event during the genesis of breast cancer that correlated with PR status.
authors.affiliation: Department of Oncology, Graduate School of Education, Fujian Medical University, Fuzhou, Fujian, P.R. China.
authors.forename: Weiwei
authors.initials: W
authors.lastname: Tang
authors.affiliation: Department of Oncology, Graduate School of Education, Fujian Medical University, Fuzhou, Fujian, P.R. China.
authors.forename: Chuan
authors.initials: C
authors.lastname: Wang
authors.affiliation: Department of Galactophore Surgery, Affiliated Union Hospital, Fujian Medical University, Fuzhou, Fujian, P.R. China.
authors.forename: Fangmeng
authors.initials: F
authors.lastname: Fu
authors.affiliation: Department of Oncology, Graduate School of Education, Fujian Medical University, Fuzhou, Fujian, P.R. China.
authors.forename: Qiang
authors.initials: Q
authors.lastname: Chen
mesh_terms: D000328:Adult; D000368:Aged; D001943:Breast Neoplasms / Q000235:genetics* / Q000473:pathology; D019175:DNA Methylation / Q000235:genetics*; D005260:Female; D019204:GTP-Binding Proteins / Q000096:biosynthesis* / Q000235:genetics; D015972:Gene Expression Regulation, Neoplastic; D020868:Gene Silencing; D006801:Humans; D008875:Middle Aged; D011379:Prognosis; D011401:Promoter Regions, Genetic; D012333:RNA, Messenger / Q000235:genetics; D011980:Receptors, Progesterone / Q000235:genetics; D025521:Tumor Suppressor Proteins / Q000096:biosynthesis* / Q000235:genetics
chemical_list: C497336:RHOBTB2 protein, human; D012333:RNA, Messenger; D011980:Receptors, Progesterone; D025521:Tumor Suppressor Proteins; D019204:GTP-Binding Proteins