Reduced expression of dipeptidyl peptidase (DPP) IV in peripheral blood T lymphocytes of oral cancer patients.
To investigate the mechanism of decrease of serum DPP IV activity in oral cancer patients, we analyzed the expression of DPP IV in peripheral blood T lymphocytes of oral cancer patients and healthy subjects. Consequently, serum DPP IV activity was found to correlate significantly with the number of peripheral blood lymphocytes (PBL), T lymphocytes and CD26 (identified as DPP IV)+ T lymphocytes in healthy subjects, and the number of PBL and CD26+ T lymphocytes in cancer patients. However, the numbers of PBL and T lymphocytes were significantly less in cancer patients than in healthy subjects. Although the number of CD26+ T lymphocytes was somewhat greater in cancer patients than in healthy subjects, serum DPP IV activity was significantly lower in cancer patients. DPP IV activity and amount of CD26 in T lymphocyte plasma membranes were much less in cancer patients than in healthy subjects. These findings suggest that a decrease in the number of T lymphocytes and the small amount of DPP IV in their plasma membrane may contribute to the decrease of serum DPP IV activity in cancer patients.
Uematsu
T
T
Oral and Maxillofacial Surgery Department II, Matsumoto Dental College, Japan.
Urade
M
M
Yamaoka
M
M
Yoshioka
W
W
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000954:Antigens, Surface / Q000032:analysis / Q000097:blood / Q000235:genetics; D015153:Blotting, Western; D002462:Cell Membrane / Q000276:immunology; D018819:Dipeptidyl Peptidase 4 / Q000032:analysis / Q000097:blood* / Q000235:genetics; D005260:Female; D005434:Flow Cytometry; D015972:Gene Expression Regulation, Neoplastic; D006801:Humans; D018655:Lymphocyte Count; D008297:Male; D008875:Middle Aged; D009062:Mouth Neoplasms / Q000097:blood* / Q000235:genetics / Q000473:pathology; D013601:T-Lymphocytes / Q000145:classification / Q000276:immunology* / Q000473:pathology
D000954:Antigens, Surface; D018819:Dipeptidyl Peptidase 4