A Vaccine for Colon Cancer

As a University of Pittsburgh graduate, I was excited to read in the spring issue of Pitt Magazine about a promising advance in cancer prevention research at my alma mater. Immunologist Olivera Finn and her research team at Pitt have been studying potential cancer prevention methods since 1991, and they have announced a breakthrough in their research of a colon cancer vaccine.¹

Finn’s group studies cancer-associated antigens (abnormal proteins produced by tumors) and the immune system response to these proteins. They discovered the tumor antigen MUC1 glycoprotein by studying T-cells that attack pancreatic cancer. Healthy MUC1 protects cells by trapping pathogens and also contributes to cell signaling functions, but abnormal arrangements of sugar molecules in MUC1 can cause the protein to malfunction, leading to replication and stimulation of abnormal cells forming tumors.¹

The vaccine Finn’s team has developed includes synthetic abnormal MUC1 molecules which stimulate the immune system’s production of tumor-specific antibodies and T-cells that attach to only the abnormal MUC1 in cancerous cells. It also includes, among other components, a substance derived from viruses that stimulates antibody production. This vaccine has begun human clinical trials in patients with advanced colon polyps, a precursor to colon cancer. 44% of patients showed a strong immune response, which is greater than responses previously observed in patients who already had colon cancer. Patients who did not respond were shown to have immune system function that was already compromised by the polyps. These results suggest that vaccines have a higher likelihood of being effective if administered early in cancer development.¹

Although further clinical trials must be completed in order to test whether the vaccine does actually prevent cancer and to evaluate the duration of its effectiveness, the results so far look promising. Abnormal MUC1 is expressed on various types of tumors, so this vaccine could possibly be shown to prevent other forms of cancer as well. Finn’s team’s research into the mechanisms of normal and abnormal MUC1 behavior may apply to other tumor antigens, which could contribute to additional methods of vaccine development in the future.¹ While there is still much to be learned in the field of cancer research, this is an exciting new development for cancer prevention.

-KB

Image credit: AJ Cann @ Flikr

¹ Templeton, David. “Vaccine Advantage,” Pitt Magazine, Spring 2013, p. 28-29.