title: Cyclin-dependent kinase inhibitor seliciclib shows in vitro activity in diffuse large B-cell lymphomas.
abstract: Despite recent improvements in treatment, a significant fraction of patients with diffuse large B-cell lymphoma (DLBCL) still fail therapy. Therefore, new therapeutic modalities are needed to advance the cure rate. Seliciclib (CYC202, R-roscovitine) is a purine analog developed as an inhibitor of CDK2/cyclin E CDK7/cyclin H and CDK9/cyclin T. Seliciclib has been shown to be active in B-cell neoplasms, such as mantle cell lymphoma, chronic lymphocytic leukemia and in multiple myeloma in vitro. The aim of this study was to assess the in vitro activity of seliciclib in DLBCL. The anti-proliferative activity of seliciclib was tested in nine human DLBCL cell lines and six DLBCL primary cell cultures. The effects of seliciclib on the cell cycle and on apoptosis, as well as on transcription-related proteins were assessed. The cell viability of all DLBCL cell lines and primary cells was reduced by seliciclib treatment. The IC50 for the cell lines ranged from 13 - 36 microm. The effect of seliciclib was independent of the genetic aberrations characterizing the cell lines. After seliciclib exposure cells accumulated in G2/M or in G1 phase, with most of the cells showing signs of apoptosis. Despite the clear cytotoxic effect and induction of apoptosis, this study could not identify a unique mechanism of action. The in vitro data suggest that seliciclib is an active agent in DLBCL. Its efficacy is apparently independent of the underlying chromosomal translocations characteristic of DLBCL. The drug might represent a new therapeutic agent in this lymphoma sub-type.
authors.affiliation: Laboratory of Experimental Oncology, Oncology Institute of Southern Switzerland (IOSI), Bellinzona, Switzerland.
authors.forename: Katia
authors.initials: K
authors.lastname: Lacrima
authors.forename: Andrea
authors.initials: A
authors.lastname: Rinaldi
authors.forename: Sara
authors.initials: S
authors.lastname: Vignati
authors.forename: Vittoria
authors.initials: V
authors.lastname: Martin
authors.forename: Maria Grazia
authors.initials: MG
authors.lastname: Tibiletti
authors.forename: Gianluca
authors.initials: G
authors.lastname: Gaidano
authors.forename: Carlo V
authors.initials: CV
authors.lastname: Catapano
authors.forename: Francesco
authors.initials: F
authors.lastname: Bertoni
mesh_terms: D000368:Aged; D017209:Apoptosis / Q000187:drug effects; D002453:Cell Cycle / Q000187:drug effects; D049109:Cell Proliferation / Q000187:drug effects; D002470:Cell Survival / Q000187:drug effects; D004353:Drug Evaluation, Preclinical; D005260:Female; D006801:Humans; D016393:Lymphoma, B-Cell / Q000188:drug therapy* / Q000378:metabolism / Q000473:pathology; D016403:Lymphoma, Large B-Cell, Diffuse / Q000188:drug therapy* / Q000378:metabolism / Q000473:pathology; D008297:Male; D008875:Middle Aged; D047428:Protein Kinase Inhibitors / Q000627:therapeutic use*; D011687:Purines / Q000627:therapeutic use*; D000077546:Roscovitine; D014157:Transcription Factors / Q000378:metabolism; D014407:Tumor Cells, Cultured
chemical_list: D047428:Protein Kinase Inhibitors; D011687:Purines; D014157:Transcription Factors; D000077546:Roscovitine