International Journal of Cancer Research1811-97271811-9735Academic Journals Inc.10.3923/ijcr.2005.16.20FouladdelShamileh Zahra Motahari AziziEbrahim 1200511In the present study, the protein expression of cyclin D1 wasdetermined in human breast cancer T47D cells and its TAM-resistant subline (T47D/TAMR-6 cells). The resistant subline was established in vitro following stepwise increase in TAM concentration in the culture medium of parent cells. Immunocytochemical method was used to determine the expression of cyclin D1 in both parent and resistant cells. The slow growing T47D/TAMR-6 cells showed lower level of expression of cyclin D1 protein compare to parent T47D cells. Expression of cyclin D1 protein was significantly decreased in both cell types following exposure to TAM (1 μM). Therefore, it can be suggested that TAM can regulate the expression of cyclin D1 protein that affects the cell proliferation. In conclusion, determination of protein expression of cyclin D1 in tumor samples of patients would be helpful in tumor prognosis and prediction of outcome of chemo-hormonal therapy of breast cancer.]]>Pestell, R.G., C. Albanese, A.T. Reutens, J.E. Segall, R.J. Lee and A. Arnold,199920501534Sherr, C.J.,199627416721677Sherr, C.J. and J.M. Roberts,19991315011512Weinberg, R.A.,199581323330Lukas, J., J. Bartkova and J. Bartek,19961669176925Zwijsen, R.M.L., R. Klompmaker, E.B.H.G.M. Wientjens, P.M.P. Kristel, B. van der Burg and R.J.A.M. Michalides,19961625542560Kenny, F.S., R. Hui, E.A. Musgrove, J.M. Gee and R.W. Blamey et al.,1999520692076Shtutman, M., J. Zhurinsky, I. Simcha, C. Albanese, M.D. Amico, R. Pestell and A. Ben-Ze'ev,19999655225527Wang, T.C., R.D. Cardiff, L. Zukerberg, E. Lees, A. Arnold and E.V. Schmidt,1994369669671Yu, Q., Y. Geng and P. Sicinski,200141110171021Ganter, B., S.L. Fu and J.S. Lipsick,199817255268Inoue, K. and C.J. Sherr,19981815901600McMahon, C., T. Suthiphongchai, J. DiRenzo and M.E. Ewen,19999653825387Reutens, A.T., M. Fu, G. Watanabe, C. Albanese and M.J. McPhaul et al.,200115797811Neuman, E., M.H. Ladha, N. Lin, T.M. Upton and S.J. Miller et al.,19971753385347Zwijsen, R.M.L., E. Wientjens, R. Klompmaker, J. van der Sman, R. Bernards and R.J.A.M. Michalides,199788405415Gajdos, C. and V.C. Jordan,20022272281Chan, S.,200229129133Chew, H.K.,200217137149Clemons, M., S. Danson and A. Howell,200228165180Jordan, V.C.,199890967971Favoni, R.E. and A. Cupis,199819406415Jordan, C.,200224316Katzenellenbogen, B.S.,199654287293Spyratos, F., P.M. Martin, K. Hacene, S. Romain and M. Brunet et al.,19928412661272Swain, S.M., M.E. Lippman, E.F. Egan, J.C. Drake, S.M. Steinberg and C.J. Allegra,19897890899Johnston, S.R.,19978911930Katzenellenbogen, B.S., M.M. Montano, K. Ekena, M.E. Herman, E.M. McInerney and L. William,1997442338Levenson, A.S. and V.C. Jordan,19993516281639Hamilton, A. and M. Piccart,199910377384Braun, M.,20024213217