All Publications


  • Downregulation of NPM-ALK by siRNA causes anaplastic large cell lymphoma cell growth inhibition and augments the anti cancer effects of chemotherapy in vitro CANCER INVESTIGATION Hsu, F. Y., Zhao, Y., Anderson, W. F., Johnston, P. B. 2007; 25 (4): 240-248

    Abstract

    The fusion protein, nucleophosmin-anaplastic lymphoma kinase (NPM-ALK), results from the chromosome translocation t(2;5)(p23;q25) and is present in 50-70 percent of anaplastic large-cell lymphomas (ALCLs). NPM-ALK is a constitutively activated kinase that transforms cells through stimulating several mitogenic signaling pathways. To examine if the NPM-ALK is a potential therapeutic target in ALCL, we used siRNA to specifically downregulate the expression of the NPM-ALK in ALCL cell lines. In this report, we demonstrated viability loss in t(2;5)-positive ALCL cell lines, SUDHL-1 and Karpas 299 cells, but not in lymphoma cell lines without the chromosome translocation, Jurkat and Granta 519 cells. Further study demonstrated that the downregulation of NPM-ALK resulted in decreased cell proliferation and increased cell apoptosis. When used in combination with chemotherapeutic agents, such as doxorubicin, the inhibition of the NPM-ALK augments the chemosensitivity of the tumor cells. These results revealed the importance of continuous expression of NPM-ALK in maintaining the growth of ALCL cells. Our data also suggested that the repression of the fusion gene might be a potential novel therapeutic strategy for NPM-ALK positive ALCLs.

    View details for DOI 10.1080/07357900701206372

    View details for Web of Science ID 000247781900004

    View details for PubMedID 17612934

  • The expression of CD30 in anaplastic large cell lymphoma is regulated by nucleophosmin-anaplastic lymphoma kinase-mediated JunB level in a cell type-specific manner CANCER RESEARCH Hsu, F. Y., Johnston, P. B., Burke, K. A., Zhao, Y. 2006; 66 (18): 9002-9008

    Abstract

    Chromosomal translocation t(2;5) and the resulting fusion protein nucleophosmin-anaplastic lymphoma kinase (NPM-ALK) are detected in 50% to 70% of anaplastic large cell lymphoma (ALCL), which is a T/null cell non-Hodgkin's lymphoma showing anaplastic morphology with cell surface expression of CD30. Because aberrant CD30 expression was also observed in the T-cell lymphoma derived from lineage-specific NPM-ALK transgenic mice, we tested the hypothesis that there might be a functional relationship between the two neoplastic-related proteins: NPM-ALK and CD30. In this study, we used the RNA interference method to modulate NPM-ALK protein expression in ALCL-derived, t(2;5)-positive Karpas 299 cells. We observed decreased CD30 expression when NPM-ALK was repressed. Further analysis suggested that JunB functioned as the mediator of NPM-ALK-derived CD30 transcriptional regulation. The NPM-ALK-repressed cells, which had low CD30 expression, were characterized with lower cell proliferation compared with cells in the control group, suggesting that altered CD30 expression may correlate to NPM-ALK-mediated tumor cell growth inhibition. Combination of NPM-ALK repression and CD30 ligand leads to significantly increased tumor cell growth inhibition compared with one method alone, suggesting its potential application for ALCL-specific cancer treatment.

    View details for DOI 10.1158/0008-5472.CAN-05-4101

    View details for Web of Science ID 000240650300014

    View details for PubMedID 16982741