Hexavalent chromium (Cr(VI)) compounds are well-established human lung carcinogens. Solubility plays an important role in their carcinogenicity with the particulate Cr(VI) compounds being the most carcinogenic. Epidemiology and animal studies suggest that zinc chromate is the most potent particulate Cr(VI) compound; however, there are few comparative data to support these observations. The purpose of this study was to compare the genotoxicity of zinc chromate with two other particulate Cr(VI) compounds, barium chromate and lead chromate, and one soluble Cr(VI) compound, sodium chromate. The clastogenic effects of barium chromate and zinc chromate were similar, but lead chromate induced significantly less damage. The levels of DNA damage measured by gamma-H2A.X foci formation were similar for the three particulate chromium compounds. Corrected for chromium uptake differences, we found that zinc chromate and barium chromate were the most cytotoxic, and lead chromate and sodium chromate were less cytotoxic. Zinc chromate was more clastogenic than all other chromium compounds, and lead chromate was the least clastogenic. There was no significant difference between any of the compounds for the induction of DNA double strand breaks. All together, these data suggest that the difference in the carcinogenic potency of zinc chromate over the other chromium compounds is not due solely to a difference in chromium ion uptake and that the zinc cation may in fact have an important role in its carcinogenicity.
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http://dx.doi.org/10.1021/tx900363j | DOI Listing |
J Hazard Mater
December 2024
Wise Laboratory for Environmental and Genetic Toxicology, Department of Pharmacology and Toxicology, University of Louisville, 500 S Preston Street, Building 55A, Room 1422, Louisville, KY 40292, United States. Electronic address:
Hexavalent chromium [Cr(VI)] is a human lung carcinogen with widespread exposure. How Cr(VI) causes cancer is poorly understood, but chromosome instability plays a central role. Inhibition of DNA repair pathways leads to chromosome instability; however, despite the importance of these pathways in the mechanism of Cr(VI)-induced lung carcinogenesis, there are no data considering in-depth analysis on the transcriptional changes of genes involved in them.
View Article and Find Full Text PDFChemosphere
February 2025
Wise Laboratory of Environmental and Genetic Toxicology, University of Louisville, Louisville, KY 40202, USA; Department of Pharmacology and Toxicology, University of Louisville, Louisville, KY 40202, USA. Electronic address:
Lung cancer is an important human health concern because of its high mortality rate, with many cases caused by environmental chemicals other than tobacco. Particulate hexavalent chromium [Cr(VI)] is a well-established human lung carcinogen, but how Cr(VI) induces lung cancer is poorly understood. Chromosome instability, a hallmark of lung cancer, is considered a major driving factor in Cr(VI)-induced lung cancer.
View Article and Find Full Text PDFToxicol Sci
September 2024
Wise Laboratory of Environmental and Genetic Toxicology, Department of Pharmacology and Toxicology, University of Louisville, Louisville, KY 40292, United States.
Hexavalent chromium [Cr(VI)] is an established human lung carcinogen, but the carcinogenesis mechanism is poorly understood. Chromosome instability, a hallmark of lung cancer, is considered a major driver of Cr(VI)-induced lung cancer. Unrepaired DNA double-strand breaks are the underlying cause, and homologous recombination repair is the primary mechanism preventing Cr(VI)-induced DNA breaks from causing chromosome instability.
View Article and Find Full Text PDFToxicol Appl Pharmacol
April 2024
Wise Laboratory of Environmental and Genetic Toxicology, Department of Pharmacology and Toxicology, University of Louisville, 500 S Preston St, Rm, 1422 Louisville, KY, USA.
Hexavalent chromium [Cr(VI)] is considered a major environmental health concern and lung carcinogen. However, the exact mechanism by which Cr(VI) causes lung cancer in humans remains unclear. Since several reports have demonstrated a role for inflammation in Cr(VI) toxicity, the present study aimed to apply transcriptomics to examine the global mRNA expression in human lung fibroblasts after acute (24 h) or prolonged (72 and 120 h) exposure to 0.
View Article and Find Full Text PDFInt J Mol Sci
December 2023
Wise Laboratory for Environmental and Genetic Toxicology, University of Louisville, 500 S Preston Street, Building 55A, Room 1422, Louisville, KY 40292, USA.
Hexavalent chromium [Cr(VI)] is a known human lung carcinogen with widespread exposure in environmental and occupational settings. Despite well-known cancer risks, the molecular mechanisms of Cr(VI)-induced carcinogenesis are not well understood, but a major driver of Cr(VI) carcinogenesis is chromosome instability. Previously, we reported Cr(VI) induced numerical chromosome instability, premature centriole disengagement, centrosome amplification, premature centromere division, and spindle assembly checkpoint bypass.
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