Cholesterol Drug May Protect Mesothelioma Patients from Radiation

A new study suggests that the cholesterol-lowering drug pravastatin could one-day be used to help protect mesothelioma patients from the damaging side effects of radiotherapy.

According to Japanese researchers, mice with malignant mesothelioma who were given pravastatin (Pravachol) in drinking water prior to receiving radiation experienced less damage to healthy cells in their lungs and intestines.

The results suggest that pravastatin might make radiotherapy safer and more effective for people with pleural or peritoneal mesothelioma and other cancers.

How Does Pravastatin Work?

Like other statin drugs, pravastatin is designed to lower the level of low-density lipoprotein (LDL) or “bad” cholesterol in the blood while increasing levels of “good” cholesterol or high-density lipoprotein (HDL).

Marketed under the brand name Pravachol, pravastatin is used to help prevent heart attacks and strokes in high risk patients but it has also been reported to have therapeutic applications in a range of inflammatory conditions.

Radiotherapy and Mesothelioma

Radiotherapy is one of treatments doctors utilize to treat mesothelioma and many other cancers. In conjunction with chemotherapy and surgery, radiotherapy may extend survival by disrupting the DNA of cancer cells, making it harder for them to replicate and grow out of control.

Side effects occur when radiation is absorbed by healthy tissues. In people with mesothelioma, the location and irregular shape of their tumors often makes it difficult to irradiate them without also irradiating some of the surrounding healthy tissue in the lungs or abdomen.

When the DNA of these normal cells is sufficiently damaged, the results can be life-threatening.

Protecting Mesothelioma Patients from Side Effects

In their new study, on the radioprotective effects of pravastatin, researchers at Hyogo College of Medicine treated two groups of lab mice with ionizing radiation.

One group received 30 mg of pravastatin per kg of body weight 24 hours before treatment and again 4 hours before treatment. The second group of mice was not pretreated.

“The pravastatin group showed significantly lower apoptotic indices in all examined parts of the intestine and tended to show reduced apoptosis [cell death] in the lung,” writes radiologist and lead investigator Hiroshi Doi.

Just as importantly, the team found no difference in responsiveness of mesothelioma tumors in the treated and untreated mice, suggesting that pravastatin will not interfere with the effectiveness of radiotherapy in mesothelioma patients.

The authors conclude that pravastatin may “increase the therapeutic index of radiotherapy”, making it possible to treat mesothelioma with fewer serious side effects.

Statins and Mesothelioma

Several previous studies have also highlighted the potential benefits of using statin drugs in mesothelioma treatment. A 2014 study in the International Journal of Oncology suggested that the drug simvastatin may boost the effectiveness of pemetrexed (Alimta) in mesothelioma treatment.

Another Japanese study conducted in 2013 found that combining two statin drugs with gamma-tocotrienol triggered apoptosis in mesothelioma cells.

Source:

Doi, H, et al “Pravastatin reduces radiation-induced damage in normal tissues”, May 2017, Experimental and Therapeutic Medicine, pp. 1765-1772