Antibiotics Show Promise in Cancer Treatment

Researchers have pinpointed various drugs typically used to treat diseases such as heart failure, cardiac arrhythmia, and infections that could also be beneficial in treating cancers.

A team including researchers from Temple University School of Medicine, the University of Montreal, and the University of Pennsylvania screened more than 1,100 FDA-approved drugs, ultimately choosing 14 that they deemed to be most promising in terms of potential use as part of cancer treatment. The investigators chose drugs that reactivate tumor suppressor genes through an epigenetic mechanism, which the authors note are highly deregulated in cancer cells, and control gene expression by targeting intracellular calcium levels. The drugs selected for validation were primarily cardiac glycosides and antibiotics, and were chosen using a cellular model created in the laboratory of study co-author Jean-Pierre Issa, MD, a professor at Temple University’s School of Medicine.
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In terms of managing or co-managing patients who already have cancer, “it’s important to always keep in mind the potential interactions between advice and drugs prescribed for non-cancer indications and the therapies prescribed for cancer treatment,” says Issa. “These interactions are hard to predict, and can be good in some cases and bad in others.”

For example, the findings from this study suggest that some non-cancer drugs such as cardiac glycosides “may be good therapies for cancer, especially in combination with anti-cancer drugs,” says Issa, adding that “we are testing this concept in clinical trials.”

However, Issa continues, “other interactions may be bad. For example, multi-vitamins and antioxidants can compromise the efficacy of cancer treatments in some cases.”

With regard to patients who do not have cancer, “it goes without saying that chronic exposure to medications can have unexpected effects, both good and bad.”

In this case, chronic cardiac glycoside exposure may have cancer-preventive properties, says Issa, noting that previous studies suggest as much.

“But one can also imagine many situations where the reverse is true. These studies illustrate the need for research on the effects of long-term drug and vitamin exposures; effects that are sometimes missed in relatively short-term clinical trials.”

This particular study shows that “some approved drugs have a promising future in terms of drug repositioning as anti-cancer drugs targeting epigenetic aberrations in cancer,” adds Noel Raynal, MSc, PhD, a professor in the department of pharmacology at the University of Montreal, and another study co-author.

While noting that further studies are needed to fully understand their mechanism of action, and to discover new drug combinations, Raynal says “it is likely that, in the near future, primary care practitioners will use old drugs at different doses for new indications such as cancer.”

—Mark McGraw

Reference:

Zhang H, Raynal N, et al. A phenotypic screen to identify novel potential epigenetic anticancer drugs from natural compounds. Cancer Research. 2016.