Effects of oral squamous cell carcinoma-derived TGF-beta1 on CD26/DPPIV expression in T cells.
BACKGROUND
Enzymatic activity levels of serum CD26/dipeptidylpeptidase (DPP) IV in oral cancer patients are lower than those in healthy subjects. However, the mechanism for this decrease is not yet fully understood.


METHODS
The influence of malignant cell-derived cytokines on cell surface CD26/DPPIV expression in human T cells was analyzed using an oral squamous cell carcinoma (SCC) cell line, KB, and peripheral blood T cells.


RESULTS
Tumor growth factor (TGF)-beta1 in KB-conditioned medium (KBCM) down-regulated CD26/DPPIV expression in T cells, which was responsible for the decreased DPPIV activities in the cultured supernatant. Expression p27kip in T cells was maintained in addition to G1 arrest when cultured with KBCM but was abolished by inclusion of anti-TGF-beta1 antibody.


CONCLUSIONS
SCC-derived TGF-beta1 down-regulates CD26/DPPIV expression in T cells, resulting in decreased serum CD26/DPPIV activity in oral cancer patients.
Uematsu
Takashi
T
Department of Oral and Maxillofacial Surgery, Matsumoto Dental University School of Dentistry, Nagano, Japan. uematsu@po.mdu.ac.jp
Tanaka
Hitoshi
H
Yamaoka
Minoru
M
Furusawa
Kiyofumi
K
D002294:Carcinoma, Squamous Cell / Q000378:metabolism*; D002453:Cell Cycle; D002846:Chromatography, Affinity; D018920:Coculture Techniques; D017077:Culture Media, Conditioned; D018819:Dipeptidyl Peptidase 4 / Q000096:biosynthesis*; D015536:Down-Regulation; D006801:Humans; D007624:KB Cells; D008213:Lymphocyte Activation; D011480:Protease Inhibitors / Q000032:analysis / Q000378:metabolism; D013601:T-Lymphocytes / Q000201:enzymology* / Q000276:immunology; D016212:Transforming Growth Factor beta / Q000032:analysis / Q000378:metabolism / Q000502:physiology*; D053773:Transforming Growth Factor beta1
D017077:Culture Media, Conditioned; D011480:Protease Inhibitors; C508960:TGFB1 protein, human; D016212:Transforming Growth Factor beta; D053773:Transforming Growth Factor beta1; D018819:Dipeptidyl Peptidase 4