Cancer stem cells, a new therapeutic approach for treating colon cancer

Researchers at Princess Margaret Cancer Centre have made remarkable progress in the treatment of colon cancer. It seems that disabling the gene that promotes self- renewal of tumor cells may stop not only  tumor growth but also relapses and resistance to treatment. This new approach for treating cancer had promising results and researchers hope that this will translate into humans too.

Colorectal cancer is the third most common form of cancer in men and the second in women. In terms of mortality rate, colon cancer is the fourth place after lung, stomach and liver cancer. Among the causes that lead to the development of colon cancer, diet plays an important: it seems that the consumption of red meat, fat and alcohol are among the risk factors. Also, studies have shown that an unhealthy lifestyle, obesity, lack of physical activity predispose to colon cancer. In terms of treatment, although in recent years there have been many advances in the field, however, the 5-year survival does not exceed 60 %.

Principal investigator Dr. John Dick said this is the first step in applying the principles of stem cell biology to control cancer development and the first step towards a long-term cure. Dr. Dick is a Senior Scientist at University Health Network ‘s Princess Margaret Cancer Centre and McEwen Centre for Regenerative Medicine, and a Professor in the Department of Molecular Genetics, University of Toronto. It should be noted that Dr. Dick initiated the cancer stem cells field in 1994 when he identified leukemic stem cells. Also, Dr. Dick was the first to isolate stem cells from the blood in the purest form and paved the way for their clinical use.

To see that targeting stem cells can indeed provide healing, researchers replicated human colon cancer cells in mice. In this way, the researchers found that BMI -1 gene is responsible for the cycle of self- renewal, survival and proliferation; it appears that this gene is a key regulator of colon cancer stem cells. Based on these findings, the researchers created a small molecule to inhibit gene BMI -1. Dr. Dick explained by the inhibition of BMI -1 gene, stem cells were unable to self-renew which altered tumor growth. Lead author Dr. Antonija Kreso said that inhibiting this regulator of self – renewal is an effective approach to control tumor growth. She also said the study provides strong evidence that self- renewal is an important therapeutic target in cancer treatment.