Differential gene expression assessed by cDNA microarray analysis in breast cancer tissue under tamoxifen treatment
del Carmen Garcia Molina Wolgien, M.; da Silva, I.D.C.G.; Villanova, F.E.; Yumi Otsuka, A.; Borra, R.C.; Lima Reis, L.F.; Carvalho, A.F.; Baracat, E.C.; Gebrim, L.H.
European Journal of Gynaecological Oncology 26(5): 501-504
2005
ISSN/ISBN: 0392-2936 PMID: 16285565 Document Number: 587607
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.