How Vitamin D Dampens Melanoma Aggression

According to a new study from University of Leeds scientists, vitamin D alters a signaling pathway in melanoma cells, making them less aggressive. The study’s findings, published yesterday in Cancer Research, could ultimately lead to new ways of treating melanoma.

The researchers looked at the activity of the gene that makes the vitamin D receptor (VDR) in numerous human melanoma tumors. The activity of the VDR gene was cross-referenced with other patient characteristics, such as the thickness of their tumor and how fast their tumor grew. The team also wanted to see if the amounts of VDR in human melanoma cells were associated with genetic changes that happen when tumors become more aggressive, so they used mice to check whether VDR levels changed the cancer’s ability to spread.

According to their results, human tumors with low levels of the VDR gene grew faster and had less activity in genes controlling pathways that help the immune system fight cancer cells. Additionally, tumors with lower VDR levels also had a higher activity of genes linked to cancer growth and spread, especially those controlling the Wnt/β-catenin signaling pathway.

In mice, increasing the amount of VDR on the melanoma cell surfaces reduced activity of the Wnt/β-catenin pathway and slowed the melanoma cells’ growth. Under these conditions, the cancer was also less likely to spread to the lungs.

“What’s really intriguing is that we can now see how vitamin D might help the immune system fight cancer. We know when the Wnt/β-catenin pathway is active in melanoma, it can dampen down the immune response, causing fewer immune cells to reach the inside of the tumor, where they could potentially fight the cancer better,” says senior author Julia Newton-Bishop. “Although vitamin D on its own won’t treat cancer, we could take insights from the way it works to boost the effects of immunotherapy, which uses the immune system to find and attack cancer cells.”