These tools will no longer be maintained as of December 31, 2024. Archived website can be found here. PubMed4Hh GitHub repository can be found here. Contact NLM Customer Service if you have questions.


PUBMED FOR HANDHELDS

Search MEDLINE/PubMed


  • Title: Protein kinase C-delta is commonly expressed in multiple myeloma cells and its downregulation by rottlerin causes apoptosis.
    Author: Ni H, Ergin M, Tibudan SS, Denning MF, Izban KF, Alkan S.
    Journal: Br J Haematol; 2003 Jun; 121(6):849-56. PubMed ID: 12786795.
    Abstract:
    The growth and proliferation of multiple myeloma (MM) cells are influenced by various cytokines produced by bone marrow stromal cells. As cytokine interaction between malignant plasma cells and neighbouring stromal cells is important in the pathogenesis of MM, the understanding of intracellular signalling events elicited by this interaction is of central importance. Recent reports have shown that protein kinase C (PKC) is directly involved in modulating apoptosis in different cells types, including those of haematopoietic neoplasms. In the present study, we analysed the expression patterns of PKC isoforms in the myeloma cell lines U266, RPMI-8226 and K620. This analysis demonstrated common expression of PKC-delta, PKC-iota, PKC- micro and PKC-zeta in all three myeloma cell lines. PKC-delta expression in plasma cells from 11 patients with MM was also shown by immunohistochemistry, utilizing a monoclonal mouse anti-human PKC-delta antibody. U266 cells treated with the broad PKC inhibitor safingol (l-threo-dihydrosphingosine) or the PKC-delta-specific inhibitor rottlerin (3'-[(8-Cinnamoyl-5,7-dihydroxy-2,2-dimethyl-2H-1-benzopyran-6-yl)methyl]-2',4',6'-trihydroxy-5'-methylacetophenone) showed decreased PKC-delta in the particulate fraction and resulted in significant apoptosis. Primary myeloma cells also showed apoptosis after treatment with the PKC inhibitors, as detected by both flow cytometric and morphological evaluation. Our results indicate that PKC-delta is commonly expressed in myeloma cells and plays an important role in plasma cell survival.
    [Abstract] [Full Text] [Related] [New Search]