Energy-Boosting Supplement May Increase Risk of Prostate Cancer Recurrence

Certain prostate cancer treatments can be extremely effective, but in some patients, cancer cells can become resistant to therapy. Prior research has shown that stem cells inside cancer cells are resistant to radiotherapy treatment and, until now, the reason was unclear.

In a new study published in Oncotarget, researchers found that a standard hormone supplement given to prostate cancer patients following radiotherapy, could potentially increase cancer recurrence.

The hormone, glucocorticoid, is often administered in tablet form to help boost energy levels after patients have undergone radiotherapy.

For the study, researchers used cancer cells obtained from prostate cancer patients, which showed that SMARC proteins located inside stem cells help keep the core of the cancer alive. But most surprisingly, it was found that cancer cells treated with the glucocorticoid hormone became more resistant to cancer treatment.

“This was a really unexpected result of our investigation, so we took a slightly different direction in order to find out why these stem cells would become more resistant to cancer treatment,” said lead researcher Norman Maitland.

Normally, MicroRNAs that respond to changes in the body are present in all normal cells and can be regulated by hormones, but are kept at very low levels in cancer stem cells. However, researchers found that any increase in MicroRNAs impacted the levels of SMARCs in the stem cells.

“When more glucocorticoid hormones are ingested, the levels of MicroRNAs decrease even further, resulting in an increase in SMARCs,” Maitland said. “These SMARC proteins wind up chromosomes inside the cancer cells to make them resistant to treatment. Hormone injections to counter the energy-sapping effects of radiotherapy and chemotherapy have been a standard part of aftercare for 15 years or more, so we were surprised to find that the treatment was actually to the detriment of radiotherapy.”

Researchers sought to determine what would happen if they blocked the natural levels of glucocorticoids. They found that there was an increase in the number of MicroRNAs and the expected decrease in the levels of SMARCs.

This suggests the possibility that the same radiotherapy dose could kill more cancer stem cells.

“We now need to move into clinical trials to see whether blocking, rather than boosting, the glucocorticoid in patients could bolster the success rate of radiotherapy,” Maitland said. “It would ultimately mean that the patient is more tired after treatment, but there are other non-hormone treatments that could be used to improve energy levels that would not interfere with how we now believe stem cells to behave in cancer.”