OVEREXPRESSION OF GLUTATHIONE-S-TRANSFERASE-PI MESSENGER-RNA AND ITS RELATIONSHIP TO GENE AMPLIFICATION IN HEAD AND NECK SQUAMOUS-CELL CARCINOMA

Human glutathione S-transferase pi has been known to be a good marker for several tumor types because of the high frequency with which it is overexpressed. In order to determine whether GST pi is useful as an i ndicator for head and neck cancers, expression of GST pi was investiga ted by Northern analysis. Overexpression of mRNA was detected in 9 of 36 primary head and neck squamous cell carcinomas. To examine the rela tionship between overexpression and amplification of GST pi gene, Sout hern analysis was performed on all samples. Only 3 of the 36 tumors sh owed amplification GST pi genes, indicating that gene amplification ma y not play a key role in GST pi mRNA overexpression in these cancers.