Researchers identify cell pathway in colon cancer

In a study to be published in the Proceedings of the National Academy of Sciences, {PNAS Online Edition Feb. 20-23, 2007} led by Zhenghe John Wang, Ph.D., Assistant Professor, Department of Genetics at Case Western Reserve University School of Medicine and Case Comprehensive Cancer Center, researchers have identified a cell pathway which plays a critical role in the development of colon cancer. This pathway may also play a role in the development of lung and stomach cancers.

Investigators say they have identified STAT3 {signal transducer and activator of transcription 3}, as a target regulated by PTPRT {Receptor Protein tyrosine phosphatase T}, which was previously identified to be mutated in colon, lung and stomach cancer patients.

“The role of protein tyrosine phosphatase in cancer is still an under-explored area. Our study shows that receptor protein tyrosine phosphatase T regulates an important signaling pathway that is critical in cancer development. This identification will allow new approaches to pharmacological designs and facilitate alternative approaches for cancer treatment”, said Wang.

With over 52,000 deaths each year, colon and rectal cancer is the second leading cause of cancer death in the United States. Colon and rectal cancers begin in the digestive system and may start in a variety of different areas of the GI tract which take years to progress. Both colon and rectal cancer have many commonalities and for that are commonly referred as ‘colorectal cancer’. Most cancers begin as polyps—a growth of tissue into the center of the colon or rectum and when typed as “adenoma”, can become cancerous. The mortality rates have been declining, this in part due to earlier screenings, awareness of symptoms, removing polyps and improved treatments through advances in research discoveries.

“The finding that STAT3 is important for the growth of colon cancer is highly novel, and provides new impetus to the development of drugs that will target this molecule”, said Dr. Sanford Markowitz, Ingalls Professor of Cancer Genetics at Case Western Reserve University School of Medicine and Investigator in The Howard Hughes Medical Institute, Case Medical Center.

The study also included collaboration with Bert Vogelstein, Victor Velculescu and Kenneth Kinzler of The Johns Hopkins Kimmel Cancer Center and a team led by Roberto Polakiewicz at Cell Signaling Technology Incorporation.