The expression of glutamate cysteine ligase (GCL) subunit in human non-small cell lung cancer xenografts

530 Glutamatae cysteine ligase (GCL) is a key enzyme in glutathione (GSH) synthesis, and is thought to play a significant role in intracellular detoxification of anticancer drugs, especially of cisplatin (CDDP). The GCL is composed of a modifier subunit (GCLM) and a catalytic subunit (GCLC). It was unclear whether a subunit is an effective molecular target to relieve CDDP-resistance. We examined the gene expression of GCLM and GCLC in thirty-nine xenografts of human non-small cell lung cancer by real time-PCR assay. Drug sensitivity to CDDP was evaluated in the nine xenografts by the in vivo drug sensitivity test. There was association between the expression of GCLM and GCLC mRNA in each xenograft (Fisher’s test, p