miR-379 Regulates Cyclin B1 Expression and Is Decreased in Breast Cancer

Abstract

MicroRNAs are small non-coding RNA molecules that control gene expression post-transcriptionally, and are known to be altered in many diseases including breast cancer. The aim of this study was to determine the relevance of miR-379 in breast cancer. miR-379 expression was quantified in clinical samples including tissues from breast cancer patients (n=103), healthy controls (n=30) and patients with benign breast disease (n=35). The level of miR-379 and its putative target Cyclin B1 were investigated on all breast tissue specimens by RQ-PCR. Potential relationships with gene expression and patient clinicopathological details were also determined. The effect of miR-379 on Cyclin B1 protein expression and function was investigated using western blot, immunohistochemistry and proliferation assays respectively. Finally, the levels of circulating miR-379 were determined in whole blood from patients with breast cancer (n=40) and healthy controls (n=34). The level of miR-379 expression was significantly decreased in breast cancer (Mean(SEM) 1.9 (0.09) Log10 Relative Quantity (RQ)) compared to normal breast tissues (2.6 (0.16) Log10 RQ, p<0.01). miR-379 was also found to decrease significantly with increasing tumour stage. A significant negative correlation was determined between miR-379 and Cyclin B1 (r=-0.31, p<0.001). Functional assays revealed reduced proliferation (p<0.05) and decreased Cyclin B1 protein levels following transfection of breast cancer cells with miR-379. Circulating miR-379 was not significantly dysregulated in patients with breast cancer compared to healthy controls (p=0.42). This data presents miR-379 as a novel regulator of Cyclin B1 expression, with significant loss of the miRNA observed in breast tumours.

RETRACTED: MicroRNA‐379 suppresses osteosarcoma progression by targeting PDK1

“…For instance, Khan et al . demonstrated that the expression of miR‐379 was significantly reduced in breast cancer, in which this miRNA significantly inhibited cell proliferation by repressing cyclin B1 expression 34. Haenisch et al .…”

Favorable modulation of benign breast tissue and serum risk biomarkers is associated with >10 % weight loss in postmenopausal women

“…Sufficient tissue was available for pre-post reverse phase proteomics analysis for 18 subjects The most significant changes were reduction in the proliferation associated proteins cyclin B1 (p=0.001) and phosphorylated retinoblastoma protein (p=0.005) [48-50], as well as ribosomal protein S6 (p=0.004), which is correlated with mTOR signaling [51]. All are thought to be important in development of breast cancer [49-51].…”

miR-379 Inhibits Cell Proliferation, Invasion, and Migration of Vascular Smooth Muscle Cells by Targeting Insulin-Like Factor-1

“…One study found that miR-379 levels are lower in circulating blood from patients with atherosclerotic coronary artery disease 18. In cancer studies, miR-379 was found to inhibit breast cancer cell proliferation by regulating cyclin B1 expression;21 Yamamoto reported that miR-379 inhibited cell growth of malignant pleural mesothelioma by targeting interleukin 18 23. In addition, miR-379 also exhibited a tumor-suppressive function in liver cancer 22.…”

“…miR-379 has also been found to inhibit cell growth in certain types of cancers including breast cancer, malignant mesothelioma, and liver cancer 212223. In this study, we investigated the functional role of miR-379 in the growth of VSMCs.…”