METALLOTHIONEIN-II AND FERRITIN-H MESSENGER-RNA LEVELS ARE INCREASED IN ARSENITE-EXPOSED HELA-CELLS

Arsenite is extremely toxic and, though non-mutagenic, is a carcinogen . To determine the effects of arsenite on changes in cell physiology, we searched for genes in HeLa cells whose mRNAs are more abundant afte r cellular exposure to arsenite. A cDNA subtraction was performed betw een cDNA synthesized from HeLa cells grown in the absence and presence of 5 mu M sodium arsenite. Isolation and sequencing of three clones t hat showed a higher hybridization signal to RNA from arsenite-exposed cells, versus unexposed cells, revealed that two of the cDNAs coded fo r human ferritin H chain and the other coded for metallothionein-II. T hese results suggest the possibility that arsenite exposure may lead t o increased levels of oxygen radicals, which augmented metallothionein and ferritin can act to detoxify. (C) 1994 Academic Press, Inc.