Simvastatin enhances myocardial angiogenesis induced by vascular endothelial growth factor gene transfer

Immunomodulatory effect of statins on Regulatory T Lymphocytes in human colorectal cancer is determined by the stage of disease

Colorectal cancer (CRC) is a public health problem worldwide and in Jordan. Statins are cholesterol lowering agents. Beyond their effects, statins use has been reported to reduced risk of several malignances, including CRC. This study aimed to assess the effect of statins on CRC by studying cellular infiltration of Regulatory T Lymphocytes (Tregs) into CRC tissues and their effect on Transforming growth factor beta 1 (TGF-β₁) level and on angiogenesis. Fourty seven specimens (25 statins users vs. 22 non-users) were used. Immunohistochemistry was performed to study Tregs infiltration using their marker, fork head transcription factor, and angiogenesis using CD31 as a marker. TGF-β₁ levels were measured using ELISA. Results revealed that statins use was associated with more Tregs infiltration, less angiogenesis but no difference in TGF-β₁ content in tumor tissue. When results were further stratified according to stage of disease, more Tregs infiltration was significantly noticed in advanced disease but not in early disease. In addition, more angiogenesis inhibition was noticed in early disease but not in advanced disease. Same stage-dependence wasn’t noticed with TGF-β₁ expression. In early disease, reduction of angiogenesis mediated by statins might lead to reduction of tumor aggressiveness. On the other hand, Tregs infiltration into tumor mediated by statins might reduce cancer aggressiveness in advanced disease. These results suggest that statins might be used in the treatment of CRC.

Impact of Enhanced Production of Endogenous Heme Oxygenase-1 by Pitavastatin on Survival and Functional Activities of Bone Marrow-derived Mesenchymal Stem Cells

Although mesenchymal stem cells (MSCs) have a therapeutic potential for the repair of tissue injuries, their poor viability in damaged tissue limits their effectiveness. Statins can induce an increased production of heme oxygenase-1 (HO-1), which may prevent this detrimental effect in MSCs. We investigated the protective effect of statin-induced overexpression of HO-1 by examining changes in gene expression and function in MSCs after pitavastatin treatment. The relative expression of the HO-1 and endothelial nitric oxide synthase genes in MSCs was significantly increased after treatment with pitavastatin (MSCs). Immunocytological analysis showed that MSCs also stained with phospho-Akt. After exposure to oxidative stress, MSCs showed increased resistance to induced cell death compared with control MSCs. Under serum starvation conditions, MSCs treated with 1 μM pitavastatin showed enhanced cell proliferation and a marked increase in vascular endothelial growth factor production compared with control MSCs. Interestingly, MSCs showed enhanced tube formation under both normoxia and hypoxia. These results demonstrate that pitavastatin can enhance endogenous HO-1 expression in MSCs, which may protect the cells into the environment of oxidative stress with partial activation of endothelial nitric oxide synthase and Akt phosphorylation.

The effects of simvastatin on angiogenesis: studied by an original model of atherosclerosis and acute myocardial infarction in rabbit

Statins have shown pleiotropic effects, many of them independent of their impact on lipids. Angiogenesis can be beneficial in the acute myocardial infarction to improve circulation. However, it also can be harmful due to worsening of atherosclerosis. Here, we established a new minimal invasive rabbit model to study ischemic myocardium and atherosclerosis together to mimic clinical scenario. We demonstrated that simvastatin has the effect of pro-angiogenesis and further improve cardiac function in ischemic myocardium, as well as the effect of anti-angiogenesis to improve atherosclerosis in aorta vessels.

Anti-angiogenic and anti-inflammatory effects of statins: relevance to anti-cancer therapy

Angiogenesis is indispensable for the growth of solid tumors and angiogenic factors are also involved in the progression of hematological malignancies. Targeting the formation of blood vessels is therefore regarded as a promising strategy in cancer therapy. Interestingly, besides demonstration of some beneficial effects of novel anti-angiogenic compounds, recent data on the activity of already available drugs point to their potential application in anti-angiogenic therapy. Among these are the statins, the inhibitors of 3-hydroxy-3-methylglutaryl-coenzyme A reductase. Statins are very efficient in the treatment of hypercholesterolemia in cardiovascular disorders; however, their effects are pleiotropic and some are not directly related to the inhibition of cholesterol synthesis. Some reports particularly highlight the pro-angiogenic effects of statins, which are caused by low, nanomolar concentrations and are regarded as beneficial for the treatment of cardiovascular diseases. On the other hand, the anti-angiogenic activities, observed at micromolar concentrations of statins, may be of special significance for cancer therapy. Those effects are caused by the inhibition of both proliferation and migration and induction of apoptosis in endothelial cells. Moreover, the statin-mediated inhibition of vascular endothelial growth factor synthesis, the major angiogenic mediator, may contribute to the attenuation of angiogenesis. It has been suggested that the anti-cancer effect of statins can be potentially exploited for the cancer therapy. However, several clinical trials aimed at the inhibition of tumor growth by treatment with very high doses of statins did not provide conclusive data. Herein, the reasons for those outcomes are discussed and the rationale for further studies is presented.