GSTP1

GSTP1, or glutathione S-transferase Pi 1, is a cytosolic enzyme in the pi class of the glutathione S-transferase (GST) family. It is encoded by the GSTP1 gene, located on chromosome 11q13, and is widely expressed in many tissues, including liver, lung, kidney, and prostate.

GSTP1 functions as a homodimer and catalyzes the conjugation of glutathione (GSH) to a broad range of electrophilic compounds, facilitating their detoxification and elimination. It participates in the metabolism of environmental carcinogens, products of oxidative stress, and certain chemotherapeutic agents, thereby contributing to cellular defense and, in some contexts, to drug resistance.

Genetic variation includes the Ile105Val (rs1695) polymorphism, which alters catalytic efficiency and substrate preference, with studies examining links to cancer risk and treatment response. In addition, promoter hypermethylation of GSTP1 is observed in several cancers—most notably in prostate cancer—leading to reduced or silenced expression.

Clinical relevance: GSTP1 status can influence pharmacokinetics and the effectiveness of GSTP1-targeting strategies. Inhibitors of GSTP1 have been investigated to modulate drug resistance and to reactivate tumor suppressor pathways in cancer models, though routine clinical use is not established. The gene remains a focus in pharmacogenomics and cancer epidemiology due to its role in detoxification and potential impact on therapy outcomes.