Genotype and phenotype of glutathione-s-transferase in patients with head and neck carcinoma☆
Oral presentation: annual meeting of the AAO-HNS Foundation in San Diego, September 2002
Abstract
Objective
Association of glutathione-S-transferase M1 (GSTM1) polymorphisms and cancer has been demonstrated. Possible underlying mechanisms and genotype-phenotype correlations are not adequately investigated. The aim of this study was to investigate the influence of the GSTM1-null-genotype on the level of GSTM enzyme concentration and on the enzyme activity of GST in patients with head and neck cancer (HNC).
Methods
We investigated in 83 patients and 91 healthy controls the GSTM1 polymorphisms, GSTM1 protein concentration, GSTM1 protein in tumor tissues, and total GST enzyme activity.
Results
Total GST enzyme activity was significantly lower in patients with HNC (208 ± 9 μmol/min*l) than in controls (264 ± 11 μmol/min*l, P< 0.0001) but did not depend on GSTM1-genotype (P = 0.1). GSTM protein concentration in null-genotype patients (3.6 ± 2.5 μg/mL, mean ± SE) was significantly lower than in GSTM1 allele carriers (26.7 ± 9.6 μg/ml, P< 0.0001); GSTM protein expression did not depend on GSTM1-genotype (P> 0.5).
Conclusion
GST enzyme activity in patients with HNC is suppressed, indicating impaired detoxification capacity of tobacco-smoke-related carcinogens. This suppression is not correlated with the GSTM1-genotype.
aDepartment of Otorhinolaryngology, University of Ulm, Ulm, Germany (Drs Konig-Greger, Riechelmann, and Gronau)
bInstitute of Clinical Chemistry, University of Ulm, Ulm, Germany (Dr Wittich)
Reprint requests: Silke Gronau, MD, Department of Otorhinolaryngology, University of Ulm, Prittwitzstr 43, 89075 Ulm, Germany
ABSTRACT