Salimi M.,Tarbiat Modares University |
Mozdarani H.,Tarbiat Modares University |
Majidzadeh K.,Breast Diseases Research Center
Medical Oncology | Year: 2012
ATM protein kinase plays a critical role in maintaining genome integrity by activating a biochemical chain reaction that in turn leads to cell cycle checkpoint activation and repair of DNA damage. Cyclin D1 acts in regulating the G1 phase of the cell cycle. Experimental and clinical studies suggest them to be involved in transformation and tumour progression. To elucidate the role of ATM and cyclin D1 expression in sporadic breast cancer, we investigated the possible link between their RNA expression levels in ductal carcinoma and normal adjacent versus normal breast tissues measured by Taqman realtime PCR in 119 breast tissues. Results showed that cyclin D1 over-expressed in 51.4% of breast tumours, whereas ATM expression was down regulated in 55% of breast tumours compared to both normal adjacent and normal controls (P ≤ 0.01). Cyclin D1 expression in adjacent normal and normal tissues was not significantly differed, whereas ATM expression in normal adjacent was lower than normal control (P ≤ 0.01). Over-expression of cyclin D1 correlated with ER+ and/or PR+ (oestrogen/progesterone receptor) status, whereas it mostly under-expressed in HER2+ (human epidermal growth factor 2) tumours. ATM under-expression was more observed in triple-negative tumours (ER -, PR- and HER2-). Our results indicated that reduced expression of the ATM and aberrant cyclin D1 expressions may contribute to the development and/or malignant progression of breast carcinomas also the latter could be involved in the regulation of hormone sensitivity associated with ER and PR. © Springer Science+Business Media, LLC 2011.