Expression of TA1, a rat oncofetal cDNA with homology to transport-associated genes, in carbon-tetrachloride-induced liver injury

TA1, a novel rat oncofetal cDNA, is the predicted homolog of the human lymphocyte activation gene E16. The encoded peptides share high homology with transport-associated and uncharacterized sequences in distant species, suggesting an important and conserved function in cellular homeostasis. Moderate steady-state levels of TA1 RNA were induced following acute and chronic CCl4-mediated liver injury. TA1 expression was either greatly reduced or absent in livers of animals receiving injury-protective doses of vitamin E in conjunction with CCl4. In contrast to the in vivo data, acute in vitro exposure of hepatocytes to CCl4 did not induce TA1 RNA. Our resulls indicate that TA1 is spatially and temporally associated with liver injury in vivo and may play an adaptive role in the hepatic response to environmental toxicants.