Colon cancer can be resistant to treatment, and is prone to relapse. This can be for a number of reasons, but one important reason is related to stem cells.
Colon Cancer, Relapse, and Stem Cells
Researchers at the Ecole Polytechnique Fédérale de Lausanne looked for ways to improve outcomes for colon cancer. After chemotherapy kills off most of the cancer cells, a few surviving stem cells can remain after treatment, and still contain the cancerous mutation, which can lead to a relapse.
In their experiments with mice that had colon cancer, the retinoid treatment stopped tumor progression and normalized the tissue.
In their study, the looked at a protein call HOXA5, which oversees stem cells to regulate their identity and function. They found HOXA5 in the gut plays a role restricting stem cells and the cells that create them. They also found that the cancerous stem cells was able to block the HOXA5, allowing the cancerous mutations to grow and spread unchecked.
Retinoids stopped tumor progression
Understanding how retinoids in vitamin A have been able to induce differentiation of skin stem cells, these scientists were able to re-activate the HOXA5. In their experiments with mice that had colon cancer, the retinoid treatment stopped tumor progression and normalized the tissue. The HOXA5 eliminated the colon cancer stem cells, which is the primary cause of relapse in colon cancer. Even more promising, is that they were able to replicate these results in actual patients.
Retinoid treatment is well-tolerated, with little-to-no side effects, and can be a promising addition to colon cancer treatment or a preventative treatment for high-risk patients.