Prostate cancer: how statins reduce the risk of an aggressive tumor

Statins, drugs from the lipid-lowering family, are prescribed to millions of patients. This treatment is mainly used to lower their blood cholesterol levels, as well as to prevent diabetes.

Several previous studies performed in the laboratory on human cells have shown that this drug can also help fight certain forms of cancer. New research by American researchers from Johns Hopkins Medicine (Baltimore, USA) describes how statins can reduce the risk of an aggressive form of prostate cancer.

“There have been epidemiological indications that people who take statins long term have less aggressive cancers and that statins can kill cancer cells in the laboratory, but our research was not originally designed to investigate the possible biological causes of these observations,” said Peter Devreotes, professor of cell biology and biological chemistry at Johns Hopkins University School of Medicine.

Statins considered most effective in fighting cancer

The results of this new research were published on February 12 in the journal Proceedings of the National Academy of Sciences. The study is based on the examination of approximately 2,500 drugs approved by the United States Food and Drug Administration (FDA), in order to determine which were most likely to interrupt the progression of genetically modified cancer cells via the action of mutation of a cancer gene called PTEN.

Of the thousands of drugs, statins, and in particular pitavastatin, have emerged as the most effective in killing cancer. Most other drugs either had no effect or killed normal cells and modified cells at the same rate. Equal concentrations of pitavastatin caused almost all of the artificial cells to die, but very few of the normal cells, the study summary says.

The scientists then looked at the molecular pathways that statins were likely to affect. For example, statins are known to block an enzyme in the liver that makes cholesterol, but the drug also causes the creation of a small molecule called geranylgeranyl pyrophosphate (GGPP) that is responsible for connecting cell proteins to cell membranes.

Cancer cells stop feeding on statins

When researchers added pitavastatin and GGPPs to human cancer cells with PTEN mutations, they found that GGPPs prevented the killing effects of statins and the cancer cells survived, suggesting that GGPPs may be a key ingredient for cancer cell survival.

The third phase of the experiment consisted of observing under a microscope the cells designed to lack the enzyme that makes GGPPs. The researchers found that the cells stopped moving and feeding, which had the effect of stopping their progression.

Peter Devreotes and his team plan to continue research into the effects of statins in people with cancer as well as compounds that may block the action of GGPPs.