Posted on Sep 13, 2011, 6 a.m.
Spanish researchers confirm that a lack of vitamin D increases the aggressiveness of colon cancer.
Previous studies have indicated that Vitamin D exerts a protective effect against various types of cancer and Vitamin D3 (or cholecalciferol) and some of its derivatives have been shown to inhibit colon cancer. Researchers at the Vall d'Hebron Institute of Oncology (VHIO; Spain), in collaboration with the Alberto Sols Institute of Biomedical Research (CSIC-UAB; Spain), have confirmed the pivotal role of vitamin D, specifically its receptor (VDR), in slowing down the action of a key protein in the carcinogenic transformation process of colon cancer cells. This protein, known as beta-catenin, which is normally found in intestinal epithelial cells where it facilitates their cohesion, builds up in large quantities in other areas of the cells when the tumor transformation begins. As a result of these changes, the protein is retained in the cell nucleus, where it facilitate the carcinogenic process, and this is the point at which vitamin D intervenes, or rather, the vitamin D receptor (VDR). The researchers then analyzed the effect of the VDR on human colon cancer cell cultures and observed that the concentration of the altered protein, beta-catenin, increased in cells without the VDR. These findings were repeated in the three types of colon cancer cells studied, and confirmed the results observed in the mice. In two-thirds of advanced colon cancer tumors there was a lack of VDR in the cancer cells, suggesting that this loss may contribute to speeding up the growth of the tumor.
Maria Jesus Larriba, Paloma Ordonez-Moran, Irene Chicote, Genesis Martin-Fernandez, Isabel Puig, Alberto Munoz, Hector G. Palmer. “Vitamin D Receptor Deficiency Enhances Wnt/[beta]-Catenin Signaling and Tumor Burden in Colon Cancer .” PLoS One, 15 Aug 2011.