Despite the extensive work being performed to understand cancer and carcinogenic properties of chemicals and other agents, there are still gaps in our ability to efficiently identify carcinogens, and elucidate their mode(s) of action. The current state of assays designed to examine mutation and carcinogenic mechanisms are especially limited by their high costs and low throughput capacities. This laboratory has developed a gene mutation assay that is based on the endogenous Pig-a gene. The Pig-a gene product is essential for the biosynthesis of glycosyl phosphatidylinositol (GPI) anchors. Mutations giving rise to nonfunctional GPI anchors prevent certain proteins from being expressed on the cell surface, and this represents a phenotype that can be measured by flow cytometry. The work proposed herein will extend our development efforts by creating a suite of assays that represent a platform for studying a key mode of carcinogenic action, mutation. By devising Pig-a based methods that examine cells in culture, laboratory rodents, and human subjects, a truly comprehensive bridging biomarker will be realized. The bridging capabilities and high throughput nature of the proposed mutation assessment tools will contribute significantly to important areas of research that include academic, regulatory, and industrial settings.
The ability to efficiently and comprehensively study mutation, a key pathway of carcinogenesis, is critical for gaining insight into this complex disease, and for elucidating carcinogens'mode of action. We will develop a suite of complementary assays based on an endogenous reporter gene, Pig-a. An important feature of these assays will be their compatibility with high throughput, automated scoring methods, and their ability to bridge between cells in culture, whole animals models, and humans.
|Bemis, Jeffrey C; Avlasevich, Svetlana L; Labash, Carson et al. (2018) Glycosylphosphatidylinositol (GPI) anchored protein deficiency serves as a reliable reporter of Pig-a gene Mutation: Support from an in vitro assay based on L5178Y/Tk+/- cells and the CD90.2 antigen. Environ Mol Mutagen 59:18-29|
|Long, Alexandra S; Wills, John W; Krolak, Dorothy et al. (2018) Benchmark dose analyses of multiple genetic toxicity endpoints permit robust, cross-tissue comparisons of MutaMouse responses to orally delivered benzo[a]pyrene. Arch Toxicol 92:967-982|
|Avlasevich, Svetlana L; Labash, Carson; Torous, Dorothea K et al. (2018) In vivo pig-a and micronucleus study of the prototypical aneugen vinblastine sulfate. Environ Mol Mutagen 59:30-37|
|Bemis, Jeffrey C; Wills, John W; Bryce, Steven M et al. (2016) Comparison of in vitro and in vivo clastogenic potency based on benchmark dose analysis of flow cytometric micronucleus data. Mutagenesis 31:277-85|
|Wickliffe, Jeffrey K; Dertinger, Stephen D; Torous, Dorothea K et al. (2016) Diet-induced obesity increases the frequency of Pig-a mutant erythrocytes in male C57BL/6J mice. Environ Mol Mutagen 57:668-677|
|Labash, Carson; Carlson, Kristine; Avlasevich, Svetlana L et al. (2015) Induction of Pig-a mutant erythrocytes in male and female rats exposed to 1,3-propane sultone, ethyl carbamate, or thiotepa. Mutat Res Genet Toxicol Environ Mutagen 782:24-9|
|Labash, Carson; Avlasevich, Svetlana L; Carlson, Kristine et al. (2015) Comparison of male versus female responses in the Pig-a mutation assay. Mutagenesis 30:349-57|
|Dertinger, Stephen D; Phonethepswath, Souk; Avlasevich, Svetlana L et al. (2014) Pig-a gene mutation and micronucleated reticulocyte induction in rats exposed to tumorigenic doses of the leukemogenic agents chlorambucil, thiotepa, melphalan, and 1,3-propane sultone. Environ Mol Mutagen 55:299-308|
|Avlasevich, Svetlana L; Phonethepswath, Souk; Labash, Carson et al. (2014) Diethylnitrosamine genotoxicity evaluated in sprague dawley rats using pig-a mutation and reticulocyte micronucleus assays. Environ Mol Mutagen 55:400-6|
|Dertinger, Stephen D; Avlasevich, Svetlana L; Torous, Dorothea K et al. (2014) Persistence of cisplatin-induced mutagenicity in hematopoietic stem cells: implications for secondary cancer risk following chemotherapy. Toxicol Sci 140:307-14|