Novel Methods for Molecular Analysis of Colorectal Polyps

DESCRIPTION (provided by applicant): Colorectal cancer (CRC) is the second leading cause of cancer-related death in the United States. Considerable evidence has shown that cancer fatalities can be dramatically reduced through early detection and removal of premalignant adenomatous polyps by colonoscopy. However, as the demand for colonoscopy keeps increasing, capacity constraints pose a formidable challenge to population-based screening. An attractive strategy for dealing with this problem is to extend the interval between surveillance colonoscopies for certain individuals by stratifying patient risk on the basis of molecular fingerprinting of polyps. However, at present there are no suitable techniques for scanning DNA extracted from micro-dissected polyps for mutations in key CRC-associated genes. Such a technique would also provide a valuable research tool for studying the molecular basis of CRC tumorigenesis. The Phase I project will evaluate two novel, low-cost, high throughput techniques for scanning of mutations in key CRC-associated genes including the APC, K-Ras and P53 genes from polyp DNA. A newly developed ELISA-based protein truncation test (ELISA-PTT) will be utilized to detect chain truncating mutations in the APC gene. A second related approach, MASS Spectrometry of In Vitro Expressed PROtein (MASSIVE-PRO) goes beyond ELISA-PTT by enabling high sensitivity detection of both truncating and non-chain truncating (missense) mutations in the P53 and K-Ras genes. Evaluation of these techniques will be performed on DNA extracted from a repository of polyp tissue using full DNA sequencing to validate the accuracy of the results. In Phase II, a combination of these optimized mutation detection techniques will be applied to analyze polyps from patients who have had an initial polypectomy and follow-up surveillance colonoscopy. Dr. Paul C. Schroy, Director of Clinical Research at Boston Medical Center and Dr. Faye Eggerding, Director of Molecular Oncology at the Huntington Medical Research Institute (HMRI), Pasadena, CA will serve as consultants and participate in the study by providing either polyp tissue or DNA extracted from micro-dissected polyps for analysis. Dr. Daniel Normolle, Research Assistant Professor in the Department of Radiation Oncology at University of Michigan Medical Center will assist in statistical analysis of data. Considerable evidence has shown that colorectal cancer (CRC) fatalities can be dramatically reduced through early detection and removal of polyps by colonoscopy. This project is aimed to develop novel low-cost, high throughput technology to obtain the molecular fingerprint of polyps by scanning key CRC-associated genes. This will aid in determining the future risk of patients to develop CRC and the need for follow-up surveillance thereby conserving limited resources for colonoscopy screening.