Randomized controlled trials for preventing cardiovascular disease indicated that statins had provocative and unexpected benefits for reducing colorectal cancer and melanoma. These findings have led to the intensive study of statins in cancer prevention, including recent, large population-based studies showing statin-associated reductions in overall, colorectal and prostate cancer. Understanding the complex cellular effects (for example, on angiogenesis and inflammation) and the underlying molecular mechanisms of statins (for example, 3-hydroxy-3-methylglutaryl coenzyme-A (HMG-CoA) reductase-dependent processes that involve geranylgeranylation of Rho proteins, and HMG-CoA-independent processes that involve lymphocyte-function-associated antigen 1) will advance the development of molecularly targeted agents for preventing cancer. This understanding might also help the development of drugs for other ageing-related diseases with interrelated molecular pathways.

Statins and cancer prevention

Multiple functions of p21 in cell cycle, apoptosis and transcriptional regulation after DNA damage.

The mevalonate (MVA) pathway is an essential metabolic pathway that is affected by many oncogenic signalling pathways. This Review discusses the opportunity to immediately target the MVA pathway in cancer with agents approved for other therapeutic uses, such as statins.

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The interplay between cell signalling and the mevalonate pathway in cancer

http://www.oncoveterinaria.com.ar/contenidos/archivos/file/Julio/STATINSreview.pdf

Effects of statins and farnesyltransferase inhibitors on the development and progression of cancer

MYC is a potential target for many cancers but is not amenable to existing pharmacologic approaches. Inhibition of 3-hydroxy-3-methylglutaryl-coenzyme A reductase (HMG-CoA reductase) by statins has shown potential efficacy against a number of cancers. Here, we show that inhibition of HMG-CoA reductase by atorvastatin (AT) blocks both MYC phosphorylation and activation, suppressing tumor initiation and growth in vivo in a transgenic model of MYC-induced hepatocellular carcinoma (HCC) as well as in human HCC-derived cell lines. To confirm specificity, we show that the antitumor effects of AT are blocked by cotreatment with the HMG-CoA reductase product mevalonate. Moreover, by using a novel molecular imaging sensor, we confirm that inhibition of HMG-CoA reductase blocks MYC phosphorylation in vivo. Importantly, the introduction of phosphorylation mutants of MYC at Ser62 or Thr58 into tumors blocks their sensitivity to inhibition of HMG-CoA reductase. Finally, we show that inhibition of HMG-CoA reductase suppresses MYC phosphorylation through Rac GTPase. Therefore, HMG-CoA reductase is a critical regulator of MYC phosphorylation, activation, and tumorigenic properties. The inhibition of HMG-CoA reductase may be a useful target for the treatment of MYC-associated HCC as well as other tumors.

https://cancerres.aacrjournals.org/content/canres/71/6/2286.full.pdf

MYC Phosphorylation, Activation, and Tumorigenic Potential in Hepatocellular Carcinoma Are Regulated by HMG-CoA Reductase

We earlier showed that lovastatin potentiated the chemopreventive effects of sulindac against colon neoplasia in a rodent model and augments apoptosis induced by 5-FU and cisplatin in human colon cancer cells. In the present study, we investigated effects of lovastatin in spontaneously immortalized rat intestinal epithelial cells, IEC-18 and their K-ras transformed clones. Lovastatin induced morphologic changes (cell rounding and detachment) and apoptosis that were not influenced by K-ras mutations, but were prevented by geranylgeranyl-pyrophosphate or by mevalonate. Clostridium difficile toxin B, which directly inactivates rho, induced similar morphologic changes and apoptosis. Cycloheximide prevented these effects of lovastatin, but not C. difficile toxin B. Lovastatin decreased the amounts of membrane bound rhoA and rhoB. Cycloheximide and geranylgeranyl-pyrophosphate prevented lovastatin induced morphologic changes and apoptosis but did not inhibit lovastatin-induced changes in membrane translocation of rho. Our data suggest that lovastatin induces morphologic changes and apoptosis by inhibiting geranylgeranylation of small GTPases of the rho family and thereby inactivating them. Restoration of membrane translocation of rho is not necessary for preventing lovastatin-induced morphologic changes or apoptosis.

Aleksander S. Feoktistov

Papers

Mechanism of lovastatin-induced apoptosis in intestinal epithelial cells.