Targeting the Interleukin-8 Signaling Pathway in Colorectal Cancer
Colorectal cancer (CRC), commonly called colon cancer, is a cancer of the colon or rectum. Although colon cancer is highly treatable, the National Cancer Institute of Canada (NCIC) acknowledges it as the third most common cancer and the second most common cause of cancer-related deaths among Canadians. Scientific studies have shown that colon cancer is caused, in part, by the overproduction of a molecule called Interleukin-8 (IL-8), which is released from the surface of tumor cells. Once generated, IL-8 binds to specialized proteins, called CXCR2 receptors, on the surface of nearby cancer cells. Binding of IL-8 to CXCR2 produces signals within tumor cells that activate molecules called transcription factors. The activation of various transcription factors, including NF-kB and AP-1, via the Akt and MAPK signaling pathways, ultimately causes the growth and survival of colon cancer cells. Hence, reducing the expression of IL-8 by cancer cells may have therapeutic implications for patients suffering from colon cancer. Although various treatment methods have been developed to inhibit the production of IL-8, most techniques pose a safety risk to patients because they may interact with the human immune system in unpredictable ways. This review suggests that the safest treatment method to target IL-8 is the use of nano-particles, specifically quantum dots (QDs), to transport small interfering RNA (siRNA) into colon cancer cells. Once delivered, siRNA can silence IL-8 expression, reducing the risk of cancerous growth.