The overall objective of this research project is to understand the mechanism by which chromium(VI) compounds affect gene expression. The approaches we plan to use in attacking this problem are: (1) examine the ability of chromium(IV) to differentially affect gene expression in rats and chick embryos, two well-characterized, yet developmentally different, in vivo systems; (2) compare the effects of chromium(IV) on different types of genes, i.e., constitutive genes, tissue-specific genes, inducible genes, and quiescent genes; and (3) determine possible mutations in genes affected by chromium(IV). The long-range objective of this research project is to understand the mechanism by which chromium(IV) compounds act as carcinogens. We plan to test the hypothesis that chromium(IV) - induced DNA damage will adversely affect the expression of genes containing repetitive sequences and inducible genes.
The specific aims of the proposed research are: (1) Determination of the effects of chromium(IV) - induced DNA damage in rat liver and kidney and in chick embryo liver and blood cells on the steady-state mRNA levels (using liquid hybridization) and rate of transcription (using nuclear """"""""run-off"""""""" transcription) of specific genes in vivo. The genes which will be examined are: a. constitutive inducible genes - chick delta-aminolevulinate synthase, rat and chick cytochromes P-450, rat and chick metallothioneins, and rat glutathione S - transferases (contain repetitive sequences); b. constitutive noninducible gene - chick transferrin (contains repetitive sequences); c. oncongenes - rat ras, chick myc; and d. constitutive noninducible gene - rat and chick actin. (2) Determination of possible chromium(IV) - induced mutations in specific genes in vivo using amplification and hybridization mismatch analysis.

Agency
National Institute of Health (NIH)
Institute
National Cancer Institute (NCI)
Type
Research Project (R01)
Project #
5R01CA045735-02
Application #
3188980
Study Section
Chemical Pathology Study Section (CPA)
Project Start
1987-07-01
Project End
1990-06-30
Budget Start
1988-07-01
Budget End
1989-06-30
Support Year
2
Fiscal Year
1988
Total Cost
Indirect Cost
Name
Dartmouth College
Department
Type
Schools of Arts and Sciences
DUNS #
041027822
City
Hanover
State
NH
Country
United States
Zip Code
03755
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