Down-regulation of the miRNA master regulators Drosha and Dicer is associated with specific subgroups of breast cancer

作者：Dedes Konstantin J; Natrajan Rachael; Lambros Maryou B; Geyer Felipe C; Angeles Lopez Garcia Maria; Savage Kay; Jones Robin L^*; Reis Filho Jorge S

来源：European Journal of Cancer, 2011, 47(1): 138-150.

DOI：10.1016/j.ejca.2010.08.007

• Breast cancer
• Drosha
• Dicer
• miRNA
• Survival
• qRT-PCR
• Basal-like
• Triple-negative

Down-regulation of Drosha and Dicer has been suggested to be of prognostic value in some cancers. The aims of our study were to investigate the down-regulation of Drosha and Dicer in breast cancers and its associations with clinicopathological features, molecular subtypes and outcome. Drosha and Dicer expression was assessed with real-time RT-PCR in 245 patients with breast cancer receiving adjuvant anthracycline-based chemotherapy and compared to expression levels of normal breast tissue. Drosha down-regulation was observed in 18% of cases and was associated with high grade, high Ki-67, lack of Bcl2 expression, HER2 over-expression and gene amplification and TOPO2A gene amplification. Dicer down-regulation was found in 46% of cases and was associated with lack of expression of ER, PR and Bcl2 and with high grade, high Ki-67, triple-negative and basal-like phenotypes. Drosha and Dicer were concurrently down-regulated in 15% of cases and significantly associated with high grade and high Ki-67 index. No significant associations between down-regulation of Drosha and/or Dicer and outcome were observed. Our results suggest that down-regulation of Drosha and/or Dicer is not robustly associated with the outcome of breast cancer patients treated with adjuvant anthracycline-based chemotherapy but preferentially observed in distinct subgroups of breast cancer.

• 出版日期2011-1