Over 95% of the cells displayed chromosomal aberrations typical for metastatic breast cancers, and amplifications at the CCND1 locus were validated by qPCR.
Treatment of breast cancer cells with inhibitors of cyclin D1 and CDK4/6 (Flavopiridol/PD0332991), currently in clinical trials, mimicked the effects observed with siRNA treatment.
Cyclin D1 gene amplification and chromosome 11 aneusomy were investigated using fluorescence in situ hybridization whereas cyclin D1, PgR, HER-2, Bcl2, p53, and Ki-67 expressions were analyzed by immunohistochemistry in 121 stage I or II breast cancer patients uniformly treated with cyclophosphamide/metotrexate/5-fluorouracil-based chemotherapy.