Studies of glutathione S-transferase P1 gene.

Glutathione S-transferase P1-1 (GSTP1-1) is expressed at a different level in tumor cell and drug resistant neoplastic cell, It is suggested that GSTP1-1 can serve as a marker for malignant transformation and drug resistance, On the study upstream regulatory sequence of rat glutathione S-transferase P1 (rGSTP1) gene, it is found that two enchancing elements named GPE I and GPE II are located in -2.5 kb, -2.2 kb respectively. A silencer locates at -400 bp. Both of GPE I and silencer bind at least three kinds of transacting factors. Although any enhancer or silencer has not been found in human glutathione S-transferase P1 (hGSTP1) gene so far, but insulin and retinoic acid (RA) responsive sequences have been identified, The regulatory mechanism of hGSTP1 gene in tumor cells and antidrug tumor cells is different from normal cells.