Expression of glutathione-S-transferase-π in human tumours

Expression of glutathione-S-transferase-π (GST-π) gene was quantitatively analysed on various human tumours (renal cell, colorectal, head and neck, ovarian carcinomas, soft tissue sarcomas; non-Hodgkin lymphomas) and on the corresponding normal tissues when available (kidney, colorectum and head and neck). GST-π mRNA expression level was found to be significantly higher in tumours (P<0.01) than in the normal counterparts (mainly 7.3-, 3.5- and 3.0-fold in colorectal, head and neck, and renal carcinomas, respectively). Most tumours displayed a significant relationship between higher GST-π expression level and poor differentiation grade of tumour cells, thus suggesting a relationship between GST-π activity, neoplastic transformation and cellular differentiation grade. The high requirement of GST-π activity neoplastic cells displayed was not singularly related to cellular replication rate. Finally, GST-π gene expression levels were not affected by chemotherapeutic treatments.