Rm. Rawal et al., Assessment of glutathione-S-transferase and glutathione reductase in patients with squamous-cell carcinoma of buccal mucosa, INT J CANC, 83(6), 1999, pp. 727-731
Serum and tumor cytosolic levels of glutathione-S-transferase (GST) and glu
tathione-reductase (GR) activity were determined spectrophotometrical ly. T
he levels were correlated with clinicopathological criteria and a tobacco-a
ssociated protein band (T band) found in serum. The results showed signific
antly decreased mean serum GST levels (p < 0.02) in cancer patients as comp
ared with controls. However, mean serum GR levels were significantly higher
in patients than in controls (p < 0.01). T-band-positive patients showed l
ow GST and low GR activity as compared with T-band-negative patients. Tumor
cytosolic-enzyme levels of GST and GR activity were significantly higher (
P < 0.0003 and p < 0.0001, respectively) than in corresponding adjacent non
cancerous mucosa. Tumour cytosolic GST and GR activity showed significant a
ssociation with clinicopathologic criteria, e.g., stage, histologic grade a
nd nodal involvement. T-band-negative patients showed significantly higher
levels of GST (p < 0.0001) than did T-band-positive patients. Low levels of
cytosolic GST may be associated with increased susceptibility towards carc
inogen-induced damage. The results suggest that the presence of T band in t
he sera may be associated with a high-risk phenotype due to decreased detox
ification ability. (C) 1999 Wiley-Liss, Inc.