title: Differential gene expression assessed by cDNA microarray analysis in breast cancer tissue under tamoxifen treatment.
abstract: Our purpose was to identify tamoxifen (TAM) responsive genes after 30 days of TAM treatment in tumor tissues obtained from women with breast cancer using microarray expression analysis. In our study, we identified 12 candidates to be considered as tamoxifen-modulated genes. Among them, we selected two candidates the TEGT BI-1 (testis enhanced gene transcript Bax Inhibitor-1) and the CD63 gene in order to further confirm their differential expression under tamoxifen effects. We observed that both were down-regulated in tumor tissues of patients during TAM treatment. TEGT is able to inhibit the expression of Bax, which is known to promote apoptosis. On the other hand, CD63 encodes a cell membrane protein and it seems to be involved in mechanisms of platelet activation, cell adhesion and cell motility. We therefore hypothesize that TAM would be able to modulate tumor growth by down-regulating genes involved in mechanisms such as cell cycle control, tumor invasion and metastasis.
authors.affiliation: Department of Gynecology, Federal University of São Paulo, Paulista School of Medicinel, Brazil.
authors.forename: M
authors.initials: M
authors.lastname: del Carmen Garcia Molina Wolgien
authors.forename: I D C G
authors.initials: ID
authors.lastname: da Silva
authors.forename: F E
authors.initials: FE
authors.lastname: Villanova
authors.forename: A
authors.initials: A
authors.lastname: Yumi Otsuka
authors.forename: R C
authors.initials: RC
authors.lastname: Borra
authors.forename: L F
authors.initials: LF
authors.lastname: Lima Reis
authors.forename: A F
authors.initials: AF
authors.lastname: Carvalho
authors.forename: E C
authors.initials: EC
authors.lastname: Baracat
authors.forename: L H
authors.initials: LH
authors.lastname: Gebrim
mesh_terms: D001943:Breast Neoplasms / Q000188:drug therapy / Q000235:genetics* / Q000473:pathology / Q000601:surgery; D018270:Carcinoma, Ductal, Breast / Q000188:drug therapy / Q000235:genetics* / Q000473:pathology / Q000601:surgery; D004965:Estrogen Antagonists / Q000494:pharmacology* / Q000627:therapeutic use; D005260:Female; D015972:Gene Expression Regulation, Neoplastic / Q000187:drug effects*; D006801:Humans; D046228:Microarray Analysis; D020411:Oligonucleotide Array Sequence Analysis; D011518:Proto-Oncogene Proteins / Q000096:biosynthesis / Q000235:genetics; D020133:Reverse Transcriptase Polymerase Chain Reaction; D013629:Tamoxifen / Q000494:pharmacology* / Q000627:therapeutic use
chemical_list: D004965:Estrogen Antagonists; D011518:Proto-Oncogene Proteins; D013629:Tamoxifen