No abstract

Accumulating data have shown the involvement of microRNAs in cancerous processes as either oncogenes or tumor suppressor genes. Here, we established miR-30a as a tumor suppressor gene in breast cancer development and metastasis. Ectopic expression of miR-30a in breast cancer cell lines resulted in the suppression of cell growth and metastasis in vitro. Consistently, the xenograft mouse model also unveiled the suppressive effects of miR-30a on tumor growth and distal pulmonary metastasis. With dual luciferase reporter assay, we revealed that miR-30a could bind to the 3'-untranslated region of metadherin (MTDH) gene, thus exerting inhibitory effect on MTDH. Furthermore, we demonstrated that silence of MTDH could recapitulate the effects of miR-30a overexpression, while overexpression of MTDH could partially abrogate miR-30a-mediated suppression. Of significance, expression level of miR-30a was found to be significantly lower in primary breast cancer tissues than in the paired normal tissues. Further evaluation verified that miR-30a was negatively correlated with the extent of lymph node and lung metastasis in patients with breast cancer. Taken together, our findings indicated miR-30a inhibits breast cancer proliferation and metastasis by directly targeting MTDH, and miR-30a can serve as a prognostic marker for breast cancer. Manipulation of miR-30a may provide a promising therapeutic strategy for breast cancer treatment.

In the past decade, stimuli-responsive drug delivery vehicles based on surface-functionalized mesoporous silica nanoparticles have attracted intense interest as a new type of drug carrier.

Traditional Chinese medicine, a rich source of potent cancer chemopreventive agents, is attracting increasing attention worldwide. Recently, the anticancer activity of Trametes robiniophila Murr. (Huaier) has been widely investigated. However, the mechanisms are not yet fully understood. This study aimed to elucidate the inhibitory effect of Huaier extract on angiogenesis and tumor growth. Incubation with Huaier extract inhibited the proliferation of human umbilical vein endothelial cells (HUVECs) and mouse mammary tumor cells (4T1). In addition, treatment with Huaier extract decreased the motility and tube formation of HUVECs in a dose-dependent manner in vitro. As determined by western blot analysis, Huaier extract dose-dependently decreased the levels of phosphorylated extracellular signal-regulated kinase (ERK), transcription factor p65, c-Jun N-terminal kinase (JNK), signal transducer and activator of transcription 3 (STAT3) and the expression of vascular endothelial growth factor (VEGF). In ex vivo experiments, new vessel growth was suppressed as shown by chick embryo chorioallantoic membrane (CAM) and rat aortic ring assays in the presence of Huaier extract. To further evaluate the inhibitory effect, 4T1 cells were injected subcutaneously into BALB/c mice. The administration of Huaier extract suppressed tumor volume, decreased microvessel density and induced apoptosis. These data suggest that Huaier extract may serve as a potent anti-angiogenic and antitumor agent.