Expression Of Dicer And Drosha And Its Correlation With ER, PR And HER-2in Breast Cancer

1PurposeBreast cancer has been considered as the most common cancer in women. The incidence of it accounts for almost10%in all systemic tumors. Better understanding of the mechanism of genesis and procession of breast cancer will greatly contribute to the optimal treatment of the disease. The expression levels of ER, PR and HER-2can reflect the invasion and prognosis in breast carcinoma to some extent. Analysis of the expression levels of these critical targets will provide vital information towards clinical diagnosis and treatment. Furthermore, investigation of the relationship between these targets and various clinical parameters could also lead to discovery of novel targets. Recent advances in miRNAs have indicated that miRNA is implicated in development of many types of human cancers. Specifically, in human breast cancer cells, dysregulation of expression levels of certain miRNA has been shown to be involved in breast cancer development. Therefore, these miRNA can be new targets for breast cancer diagnosis and treatment. Two RNase-â…¢ members, Dicer and Drosha, play important roles in miRNA maturation, as well as tumorigenesis.In this study, we compare the expression levels of Dicer and Drosha and further analysis the correlation of them with the clinicopathological features to reveal their functions in development and invasion of breast cancer.2Materials and MethodsTissue samples came from49patients who underwent radical surgery for primary breast cancer at the Breast Diseases Center. Tumor tissues and paired adjacent normal tissues were obtained from49breast cancer patients by surgery.The expression of Dicer and Drosha was detected by real-time PCR (RT-PCR). ER,PR and HER-2products were detected immunohistochmically and through FISH in a series of breast neoplasms. The correlation of Dicer and Drosha expression with the clinicopathological features was analyzed.All analysis was performed by using SPSS software (v11.0). P<0.05was regarded as the statistical criterion.3Results1. Decreased expression was observed in53.1%(Dicer),51.0%(Drosha) and77.6%(Dicer plus Drosha) in breast cancer tissues (P<0.05).2.The expression level of Dicer showed positive correlation with that of Drosha (P<0.05).3.The decreased expression rate in ER(+) was46.7%(Dicer) and50%(Drosha).The decreased expression rate in PR(+) was67.3%(Dicer) and48.5%(Drosha). The decreased expression rate in HER-2(+) was57.1%(Dicer) and35.7%(Drosha).The expression level of Dicer or Drosha was not related to those of ER, PR or HER-2(P>0.05).4.The expression level of Dicer or Drosha was not related to age (P=0.882), tumor volume (P=0.376), histological type (P=0.702), histological grade(P=1.0), N statu(P=0.904) or cancer subtype(P=0.866).4Conclusions1. Dicer and Drosha are frequently down-regulated in breast cancer tissues, indicating their involvement in the genesis of breast cancer.2. The expression level of Dicer showed positive correlation with that of Drosha3. The expression levels of Dicer and Dorsha have no correlation to the expression levels of ER, PR and HER-2in breast caner.4. The expression levels of Dicer and Dorsha have no correlation to age, tumor volume, histological type, histological grade, N statu or cancer subtype in breast cancer.