SBIR-STTR Award

Approximately one in 200 individuals in the general population are afflicted with hereditary nonpolyposis colorectal cancer (HNPCC). Mutations in four genes, all encoding proteins involved in DNA mismatch repair, have been correlated with HNPCC. The molecular characterization of these genes is the first step toward development of genetic tests for HNPCC. Since early detection of colon cancers is correlated with patient prognosis, screening of individuals with a family history of colon cancer will certainly be indicated when an accurate, reliable test is available. While it is currently possible to rt-PCR amplify each of the genes implicated in HNPCC, it will frequently not be clear whether an observed altered DNA sequence for an individual represents a mutation impairing function of the DNA mismatch repair protein or merely a polymorphism. The Phase I research of this SBIR grant will develop functional genetic tests for human DNA mismatch repair protein activity. The protein encoded by each of the four wild type human genes (rt-PCR amplified from non-HNPCC individuals) will be used to develop an assay capable of quantitating the activity of the DNA mismatch repair protein. This quantitative assay will be developed into a functional genetic test during Phase II which, in conjunction with DNA sequence analysis of the genes, is expected to constitute an unambiguous presymptomatic test for HNPCC.Proposed commercial application:Hereditary colorectal cancer affects one in 200 individuals in the western world. Since early cancer detection correlates with patient prognosis, a reliable genetic test for this common cancer should reduce HNPCC morbidity. Effective screening programs, furthermore, should reduce HNPCC related health care costs.National Cancer Institute (NCI)

It has long been understood that cancer cells have lost normal cellular growth control. Recent research has demonstrated a correlation between specific defects in cell cycle regulation and a variety of cancers. During Phase I of this SBIR grant, BitTech, Inc. developed in vivo phenotypic screens for cyclin/cyclin dependent kinase (cyclin/CDK) function. Cyclin/CDKs are the key regulators of eukaryotic cell cycle control, and three reporter genes were placed under control of a promoter which is regulated by a specific cyclin/CDK. Phase I research further demonstrated the feasibility of using the BitTech core technology for measuring effects on cyclins, CDKs or CDK inhibitor proteins (CKIs). During Phase II, the core technology will be further developed for use in targeted screening programs. Cell lines will be generated in which human cell cycle regulatory proteins, which are known to be mutant or aberrantly regulated in specific cancers, are incorporated as the molecular targets in the phenotypic screens. The test material for these high throughput screens may be expressed cDNA from various cell types, existing chemical libraries, new combinatorial libraries or products of rational design programs. Because these compounds will be discovered in screens which are highly specific for proteins which are mutant or aberrantly regulated in cancer cells, they (or analogues developed from the lead compound) are expected to exhibit improved efficacy and reduced side effects for the patients, compared to currently available therapies. PROPOSED COMMERCIAL APPLICATION Current cancer therapies are frequently ineffective and have significant side effects for the patient. The in vivo screens for cyclin/CDK function are targeted to the key cell cycle regulatory proteins which are defective in certain cancers. Therefore, therapeutic compounds discovered with this technology are expected to exhibit improved efficiency and reduced side effects for the patient. Such therapies will decrease cancer-associated morbidity and health care costs.

Thesaurus Terms:
biotechnology, cell cycle protein, drug screening /evaluation, enzyme activity, method development, protein kinase antineoplastic, bioassay, cell growth regulation, cell line, cyclin, fungal genetics, gene deletion mutation, genetic regulation, phenotype, protein structure /function, reporter gene Saccharomyces cerevisiae, molecular cloning