Expression of O6-Alkylguanine-DNA Alkyltransferase in Normal and Malignant Bladder Tissue of Egyptian Patients

Bladder tumour tissues and corresponding uninvolved mucosa (normal tissue) of Egyptian bladder cancer patients were assessed for O6-alkylguanine-DNA-alkyltransferase (MGMT) activity by functional assay of tissue extracts (36 paired samples), and distribution by immunofluorescence (IF) microscopy of fixed material (24 paired samples). MGMT varied widely from 42–253 fmoles/mg protein and from 3.2–40 fmoles/μg DNA in normal and 58–468 fmoles/mg protein and 2.5–49.5 fmoles/mg protein, in the tumour tissues; only one tumour had undetectable activity. Pairwise comparison of MGMT activity in tumour and adjacent normal tissue showed no significant difference based on DNA content but was 1.75-fold higher in tumour (P