The glutathione S-transferases (alpha, mu, and pi), a family of Phase II detoxication enzymes, play a critical role in protecting the colon mucosa by catalyzing the conjugation of dietary carcinogens with glutathione. We investigated the efficacy of using the glutathione S-transferase (GST) activity of blood lymphocytes and GST-mu expression as biomarkers of risk for colorectal cancer. GST acti...

Background: Normal tissue toxicity continues to remain as a major challenge for radiation oncologists for delivering the total dose to the tumour cells in cancer patients. Cellular, molecular and plasma based early biomarkers to predict the overreactions and non-overreactions of normal tissue toxicity before the initiation of radiotherapy can be valuable for personalised treatment. The aim of t...

Background: The most frequently mutated tumor suppressor gene found in human cancer is p53. In a normal situation, p53 is activated upon the induction of DNA damage to either arrest the cell cycle or to induce apoptosis. However, when mutated, p53 is no longer able to properly accomplish these functions. The aim of this study was to investigate the expression of p53 gene in cases of skin cancer...

Glutathione S-transferases (GSTs) are a family of soluble enzymes of detoxification that use reduced glutathione in conjugation and reduction reactions. Toxic electrophiles are substrates for the GSTs. GST is expressed at high levels in different tissues such as the testis. Among the different GSTs present in the testis, GST is specifically expressed in Leydig and Sertoli cells known to be unde...

Nonenzymatic and glutathione S-transferase (GST) catalyzed glutathione (GSH) conjugation has been postulated as a mechanism by which alkylating cytostatic drugs can be inactivated intracellularly. In this study, we describe studies on the glutathione-dependent biotransformation of thiotepa (tris(1-aziridinyl)phosphine sulfide), a trifunctional alkylating agent. 31P NMR studies showed that thiot...

Concomitant gastric stromal tumor (GST) and gastric cancer (GC) is uncommon; even more uncommon is a concomitant GST and early stage GC (EGC). Tumor resection by endoscopic submucosal dissection (ESD) for concomitant GST and EGC has not been reported. We sought to define the clinical importance of detection of concomitant GST and EGC during the first esophagogastroduodenoscopy (EGD), and compar...

Glutathione S-transferase (GST) and multidrug resistance-associated proteins (MRPs) play major roles in drug resistance in melanoma. In this study, we investigated caffeic acid phenethyl ester (CAPE) as a selective GST inhibitor in the presence of tyrosinase, which is abundant in melanoma cells. Tyrosinase bioactivates CAPE to an o-quinone, which reacts with glutathione to form CAPE-SG conjugat...

GST family genes have a critical role in xenobiotic metabolism and drug resistance. Among the GST family the GST-μ, GST-π, GST-α and GST-θ are the most abundant classes and have a major role in the carcinogen detoxification process. Nevertheless the activity of these enzymes may differ due to polymorphisms which ultimately results in interindividual susceptibility to cancer development. In this...