A study published in the journal Drug Metabolism and Disposition found that calcitriol and calcipotriol, two active forms of vitamin D, have the ability to block a mechanism that enables cancer cells to become drug-resistant. The mechanism involved is a drug transporter protein called multidrug resistance-associated protein 1 (MRP1). This protein resides in the cell walls and ejects cancer drugs out of the cell. According to the researchers, these two forms of vitamin D actively target cancer cells that have too much MRP1 and destroy them.
"Several epidemiologic and preclinical studies show the positive effect of vitamin D in reducing cancer risk and progression, but we are the first to discover its interaction with drug transporter protein and its ability to selectively kill drug-resistant cancer cells," said senior author Surtaj Hussain Iram.
These drug transport proteins take the helm in processes that distribute, absorb and expel drugs from the body. Cancer cells that develop resistance to chemotherapy drugs can overproduce these transport proteins, which then causes chemoresistance. The way calcitriol and calcipotriol kill chemoresistant cancer cells is an example of "collateral sensitivity," which refers to the ability of compounds to kill multidrug-resistant cells but not the parent cells. According to Iram, these compounds do not attack "naive cancer cells," or cells that have yet to develop chemoresistance. Once the cell becomes drug-resistant however, it becomes fair game for the two. (Related: Taking vitamin D supplements for multiple years found to help those with cancer live LONGER.)
For their study, Iram and his colleagues from the South Dakota State University aimed to target the "Achilles' heel" of these resistant cells by exploiting their fitness cost. The researchers used cultured cancer cells to test eight compounds that previous research established as being able to react to MRP1. Of the eight they tested, only calcitriol and calcipotriol were able to block the transport function of MRP1. Iram claims that their findings can help pave the way for treatments of many other diseases. This is because MRP1 does not only reduce the effectiveness of cancer cells. It also weakens the effect of various other medicines like drugs, antivirals, anti-inflammatories and antidepressants.
Once the researchers get a handle on these proteins, patients will be able to take less medication to get the exact same effect.
Vitamin D is an essential nutrient, meaning that it cannot be synthesized by the body and must be gained from an external source. However, vitamin D deficiency is a rampant health concern worldwide, with research claiming that it affects almost 50 percent of the world's population. Below you can find a few ways you can give your vitamin D levels a quick boost.
It is an unfortunate reality that people do not get enough vitamin D. With that said, boosting your vitamin D intake not only keeps your body healthy, it could also prevent cancer cells from becoming resistant to treatment. Learn more about the power of vitamin D at Nutrients.news.