Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0345904 (liver cancer)
 15,188 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Chlorination of drinking water results in the generation of low levels of numerous chlorinated hydrocarbons due to the reaction of chlorine with naturally occurring organic compounds in the water. Concern has been raised about the safety of these chlorinated contaminants as several of them, most notably chloroform (trichloromethane), have been shown to be carcinogenic in long-term rodent bioassays and weak correlations between trihalomethane levels in drinking water and an increased risk of bladder and colorectal cancer in humans have been found. Chloroform and carbon tetrachloride induce liver cancer in rats and mice only at doses where significant hepatotoxicity is observed and have been classed as non-genotoxic carcinogens. We have investigated the ability of chloroform, carbon tetrachloride and 1,1,1-trichloroethane to induce deletions via intrachromosomal recombination in the yeast Saccharomyces cerevisiae. Chloroform and carbon tetrachloride induced this genotoxic recombination event at similar doses, 1,1,1-Trichloroethane gave only a weak response in the DEL recombination assay and only at the highest dose. We further show that chloroform and carbon tetrachloride, but not trichloroethane, induced oxidative free radical species in our yeast strain. The free radical scavenger N-acetylcysteine reduced chloroform-induced toxicity and recombination, and both chloroform and carbon tetrachloride were able to oxidize the free radical-sensitive reporter compound dichlorofluorescein diacetate in vivo. The implications of these findings to the carcinogenic activities of the three compounds are discussed.
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PMID:Chloroform and carbon tetrachloride induce intrachromosomal recombination and oxidative free radicals in Saccharomyces cerevisiae. 954 52

Inhibition of the natural immune system may be involved in the liver cancer caused by some non-genotoxic chemicals when they are administered at high doses to certain strains of animals. Previous studies have shown that some chlorinated solvents inhibit liver natural immune function in rodents. In this preliminary study, the effects of in vitro exposure to three commonly used chlorinated solvents were determined on three tumoricidal activities expressed by isolated human liver immune cells-natural killer (NK), natural cytotoxic (NC) and natural P815 killer (NPK) (Wright and Stacey, 1991) cell activities. The NK, NC and NPK cell activities of immune cells isolated from three human livers were 115, 45 and 53 lytic units (LU(20%)/10(6) effector cells), respectively. In vitro exposure to trichloroethylene (TRI) inhibited all three natural immune activities, and the ranking of sensitivity was NPK NC NK. Tetrachloroethylene (TET) inhibited NC and NPK cell activities, but had little effect on NK cell activity. 1,1,1-Trichloroethane (TCE) had little or no effect on the three tumoricidal activities examined. Overall, these data show clear similarities to the results obtained in vitro using cells from experimental animals.
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PMID:Effects of chlorinated solvents on the natural lymphocytotoxic activities of human liver immune cells. 2069 67