title: Effect of CD26/dipeptidyl peptidase IV on Jurkat sensitivity to G2/M arrest induced by topoisomerase II inhibitors.
abstract: CD26/dipeptidyl peptidase IV (DPPIV) is a surface antigen with multiple functions, including a role in T-cell activation and the development of certain human cancers. We previously demonstrated that CD26/DPPIV enhanced sensitivity of Jurkat cells to doxorubicin. We now show that expression of CD26/DPPIV enhanced sensitivity of CD26 Jurkat transfectants to G(2)-M arrest mediated by the antineoplastic agent etoposide. The increased sensitivity to etoposide-induced G(2)-M arrest was associated with disruption of cell cycle-related events, including hyperphosphorylation of p34(cdc2) kinase, change in cdc25C expression and phosphorylation, and alteration in cyclin B1 expression. CD26/DPPIV-associated enhancement of doxorubicin and etoposide-induced G(2)-M arrest was also observed in serum-free media, suggesting an effect of CD26 on cell-derived processes rather than serum-derived factors. Importantly, our work elucidated a potential mechanism for the enhanced susceptibility of CD26-expressing Jurkat cells to the topoisomerase II inhibitors by demonstrating that CD26/DPPIV surface expression was associated with increased topoisomerase II alpha levels and enhanced enzyme activity. Besides being the first to show a functional association between the multifaceted molecule CD26 and the key cellular protein topoisomerase II alpha, our studies provide additional evidence of a potential role for CD26 in the treatment of selected malignancies.
authors.affiliation: Department of Lymphoma/Myeloma, MD Anderson Cancer Center, Houston, TX 77030, USA.
authors.forename: U
authors.initials: U
authors.lastname: Aytac
authors.forename: K
authors.initials: K
authors.lastname: Sato
authors.forename: T
authors.initials: T
authors.lastname: Yamochi
authors.forename: T
authors.initials: T
authors.lastname: Yamochi
authors.forename: K
authors.initials: K
authors.lastname: Ohnuma
authors.forename: G B
authors.initials: GB
authors.lastname: Mills
authors.forename: C
authors.initials: C
authors.lastname: Morimoto
authors.forename: N H
authors.initials: NH
authors.lastname: Dang
mesh_terms: D000951:Antigens, Neoplasm; D000972:Antineoplastic Agents, Phytogenic / Q000494:pharmacology; D016203:CDC2 Protein Kinase / Q000378:metabolism; D018797:Cell Cycle Proteins / Q000378:metabolism; D019926:Cyclin B / Q000378:metabolism; D056744:Cyclin B1; D004250:DNA Topoisomerases, Type II / Q000378:metabolism; D004268:DNA-Binding Proteins; D018819:Dipeptidyl Peptidase 4 / Q000378:metabolism*; D004347:Drug Interactions; D004791:Enzyme Inhibitors / Q000494:pharmacology*; D005047:Etoposide / Q000494:pharmacology*; D016195:G2 Phase / Q000187:drug effects*; D006801:Humans; D019169:Jurkat Cells; D008938:Mitosis / Q000187:drug effects*; D059005:Topoisomerase II Inhibitors; D014162:Transfection; D020687:cdc25 Phosphatases / Q000378:metabolism
chemical_list: D000951:Antigens, Neoplasm; D000972:Antineoplastic Agents, Phytogenic; C534699:CCNB1 protein, human; D018797:Cell Cycle Proteins; D019926:Cyclin B; D056744:Cyclin B1; D004268:DNA-Binding Proteins; D004791:Enzyme Inhibitors; D059005:Topoisomerase II Inhibitors; D005047:Etoposide; D016203:CDC2 Protein Kinase; C517009:CDC25C protein, human; D020687:cdc25 Phosphatases; D018819:Dipeptidyl Peptidase 4; D004250:DNA Topoisomerases, Type II