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Background/Aims: Breast cancer (BC) is the most common cancer in women worldwide. Despite great advancements in cancer therapy in recent years, surgery and chemotherapy are still the mainstays of BC treatment. However, cancer cells usually develop mechanisms to evade cell death induced by chemotherapy. Thus, strategies are needed to reverse the chemoresistance of cancer cells. Methods: We established cisplatin-resistant BC models in MDA-MB-231 and MCF-7 BC cell lines through long-term exposure to cisplatin. Quantitative reverse transcription PCR was used to examine the expression of microRNA (miR)-100. MTT cell viability assays were performed to determine cell viability. Regulation of hematopoietic cell-specific protein 1-associated protein X-l (HAX-1) targeted by miR-100 was confirmed by western blotting and luciferase reporter assays. The mitochondrial membrane potential and apoptosis were measured by flow cytometry. Release of cytochrome c from the mitochondria into the cytoplasm, HAX-1 expression, and activation of caspase-9 and caspase-3 were detected by western blotting. Results: A clear decrease in miR-100 expression was observed in cisplatin-resistant MDA-MB-231 and MCF-7 cells (MDA-MB-231/R and MCF-7/R). Overexpression of miR-100 increased the sensitivity of MDA-MB-231/R and MCF-7/R cells to cisplatin treatment and promoted cisplatin-induced mitochondrial apoptosis by targeting HAX-1 gene. Conclusions: MiR-100 targeted HAX-1 to increase the chemosensitivity of BC by mediating the mitochondrial apoptosis pathway.

Background: The present study was designed to observe the infection of human cytomegalovirus (HCMV) to human vascular smooth muscle cells (VSMCs), and the effect of viral infection on lipid metabolism in VSMCs. Methods: The cytopathic effects were observed by inverted microscopy and viral infection were examined by electron microscopy and RT-PCR. The lipid metabolism related gene profiling of VSMCs after HCMV infection was assayed by cDNA assay and the abnormal expression of genes were validated by quantitative RT-PCR. The content of cholesterol in VSMCs after HCMV infection was assayed by cholesterol detection kit. Results: VSMCs showed obvious cytopathic effects after HCMV infection. Intact viral particles could be detected in VSMCs using electron microscope. By use of RT-PCR technology, IE gene of HCMV could be amplified from VSMCs. The expression of cell lipid metabolism related gene profiling showed obvious disorders. The expression levels of HMG-CoA synthase and HMG-CoA reductase after infection increased significantly. The cellular cholesterol content (µmol/106 cells) was significantly higher than that of mock infected group at 72h post infection. Conclusion: HCMV can infect VSMCs and the infection can affect cellular lipid metabolism related gene expression, which get involved in the occurrence and development of atherosclerosis (AS).

Background/Aims: The previous study in our lab showed that Nodal molecule on bronchial epithelial cells (BECs) was modulated by all kinds of lung microbes. The present study was designed to determine the effects of Nodal on proliferation of BECs and BECs-induced differentiation of T-helper (Th) cells. The epigenetic mechanisms of Nodal expression following treatments of different lung microbes were also identified. Methods: Real-time polymerization chain reaction (PCR) and western blot were used to determine the expression of Nodal. Flow cytometry was used to observe the effects of proliferation of BECs and subsequent BECs-induced differentiation of Th cells. Methylation levels of CpG islands in Nodal promoters were also analyzed by time of flight mass spectrometry. Results: The results showed that Nodal promoted proliferation of BECs and BECs-induced differentiation of Th cell from Th1 to Th2 and Th17. Nodal promoter showed a hyper-methylation in normal BECs. Through methylation modification in the promoter, P. aeruginosa or A.baumanni inhibited the expression of Nodal while RSV promoted the expression of Nodal. Conclusions: Our data showed that Nodal promoted Th2 and Th17 differentiation and inhibited Th1 differentiation which may cause imbalance of airway microenvironment. P. aeruginosa or A.baumanni may be hopeful for the treatment of airway hyperresponsveness by inhibition Nodal expression through DNA methylation modification in the promoter.