Another tumor repressing microRNA controls angiogenesis - and recovers tissue!

As mentioned previously in the section discussing Down's syndrome and its effects on tumor growth the suppression of angiogenesis proofs to be a rather powerful tool in cancer medicine. Fast growing tumorous tissue is in the need of sophisticated supply hence inhibiting growth of new blood vessels through inhibiting division of endothelial cells and thus starving the tumor is a strikingly functional strategy. Here I want to point out a new microRNA investigated by the team around Stefanie Dimmeler and recently made public in Science (http://www.sciencemag.org/cgi/content/abstract/324/5935/1710) being capable of controling angiogenesis. The role of miR-92a in angiogenesis has so far been unclear but the team could demonstrate now that overexpression of miR-92a suppresses angiogenesis. Different approaches can take advantage of this finding. One has already been mentioned above (and in my post concerning therapeutic potentials of miR-26a). It would appear plausible to slow down tumor growth by overexpressing inhibitory microRNA. Another approach, and this has actually been done in this work, is doing exactly the opposite. It has been observed that during ischemic injuries miR-92a expression is significantly increased. Applying antisense RNA against miR-92a, a so called antagomir, leads to neovascularization and reduction in toe necrosis. At least in a murine model. Yet hope rises to functionally recover ischemic tissue through application of an antagomir. Potential molecular targets of were also identified and the action of miR-92a might not be limited to endothelial cells.

I think these findings might add some new features to the already wide-ranging applications of microRNA in developing future therapeutic strategies.