MicroRNA let-7g alleviates atherosclerosis via the targeting of LOX-1 in vitro and in vivo
INTERNATIONAL JOURNAL OF MOLECULAR MEDICINE
Authors: Liu, Mingxin; Tao, Guizhou; Liu, Qifeng; Liu, Kun; Yang, Xinchun
Abstract
Atherosclerosis is a chronic arterial disease and the leading cause of stroke and myocardial infarction. Micro RNAs (miRNAs or miRs) have been reported to act as essential modulators during the progression of atherosclerosis. Although miR-let-7g has been demonstrated to contribute to maintaining endothelial function and vascular homeostasis, it is not known whether miR-let-7g exerts a therapeutic effect on experimental atherosclerosis. The aim of this study was to investigate the effects of miR-let-7g on atherosclerosis in vivo and in vitro and to explore its underlying mechanisms. Data from our study showed that exogenous lectin-like oxidized low-density lipoprotein receptor-1 (LOX-1 or OLR1) overexpression resulted in the significant promotion of proliferation and migration of human aortic smooth muscle cells (ASMCs), whereas such changes induced by LOX-1 were obviously suppressed by transfection of miR-let-7g. We later confirmed that LOX-1 is a potential target of miR-let-7g, and miR-let-7g markedly inhibited LOX-1 expression in ASMCs by directly binding to the 3 untranslated region of LOX-1. Furthermore, in a hyperlipidemic apolipoprotein E knockout (ApoE(-/-)) mouse model, intravenous delivery of miR-let-7g mimics obviously attenuated high-fat diet-induced neointima formation and atherosclerotic lesions, accompanied by the significant downregulation of LOX-1, which was consistent with the effect of miR-let-7g on ASMCs. Taken together, our data revealed that miR-let-7g exhibits anti-atherosclerotic activity, at least partially by targeting the LOX-1 signaling pathway. This study suggests that miR-let-7g may be a therapeutic candidate for treating atherosclerosis, and provides novel insight into miRNA-based therapy for this disease.
OLR1 Promotes Pancreatic Cancer Metastasis via Increased c-Myc Expression and Transcription of HMGA2
MOLECULAR CANCER RESEARCH
Authors: Yang, Gang; Xiong, Guangbing; Feng, Mengyu; Zhao, Fangyu; Qiu, Jiangdong; Liu, Yueze; Cao, Zhe; Wang, Huanyu; Yang, Jinshou; You, Lei; Zheng, Lianfang; Zhang, Taiping; Zhao, Yupei
Abstract
Pancreatic cancer is one of the most lethal human malignancies, partly because of its propensity for metastasis. However, the mechanisms of metastasis in pancreatic cancer remain unclear. Oxidized low-density lipoprotein receptor 1 (OLR1), a lectin-like scavenger receptor that recognizes several ligands, such as oxidized low-density lipoprotein, was previously reported in cardiovascular and metabolic diseases. The role and mechanism of OLR1 in pancreatic cancer is unclear. In this study, we found that OLR1 expression was significantly higher in pancreatic cancer tissues than that in adjacent normal tissues and closely associated with reduced overall survival. OLR1 promoted proliferation and metastasis of pancreatic cancer cells in vitro and in vivo. Mechanistically, OLR1 increased HMGA2 transcription by upregulating c-Myc expression to promote the metastasis of pancreatic cancer cells. In addition, patients with pancreatic cancer with high expression of OLR1-c-Myc-HMGA2 axis showed worse prognosis compared with patients with low expression of OLR1-c-Myc-HMGA2 axis. Implications: Our findings suggested that the OLR1-c-MycHMGA2 axis promotes metastasis of pancreatic cancer cells and may serve as potential therapeutic targets and prognosis markers for patients with pancreatic cancer.