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Altered regulation of extrinsic apoptosis pathway in HCV‐infected HCC cells enhances susceptibility to mapatumumab‐induced apoptosis
Author(s) -
Zhang Xiaozhen,
Frank Astrid C.,
Gille Christine M.,
Daucher Marybeth,
Kabat Juraj,
Becker Steven,
Lempicki Richard A.,
Cortez Karoll J.,
Polis Michael A.,
Subramanian G. Mani,
Kottilil Shyam
Publication year - 2009
Publication title -
hepatology research
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.123
H-Index - 75
eISSN - 1872-034X
pISSN - 1386-6346
DOI - 10.1111/j.1872-034x.2009.00568.x
Subject(s) - apoptosis , cancer research , biology , microbiology and biotechnology , intrinsic apoptosis , virology , programmed cell death , caspase , genetics
Background: Hepatitis C virus (HCV)‐infected patients, including those co‐infected with human immunodeficiency virus (HIV), are at increased risk of developing hepatocellular carcinoma (HCC). We evaluated the ability of agonistic human monoclonal antibodies to tumor necrosis factor‐related apoptosis inducing ligand (TRAIL) receptors, mapatumumab and lexatumumab, respectively, to induce TRAIL‐receptor mediated apoptosis (TRMA) in HCC (HCV‐infected and ‐uninfected) cells and in peripheral blood cells (HIV‐infected and ‐uninfected). Methods: Susceptibility to antibody‐mediated TRMA was measured by caspase 3/7 activity and by confocal microscopy. Surface expression of receptors on HCV‐uninfected and ‐infected Huh7.5 cells was measured by flow cytometry and confocal microscopy. Inhibitor of Apoptosis Protein (IAP) RNA levels were quantified by RT‐PCR. DNA Microarray was performed using RNA isolated from Huh7.5 cells (HCV‐infected and uninfected) using Affymetrix U133A chips. Results: Mapatumumab preferentially induces TRMA of HCV‐infected Huh7.5 cells by binding to TRAIL‐R1. Higher basal expression of TRAIL‐R2 compared to that of TRAIL‐R1 on HCV‐uninfected Huh7.5 cells were observed. Lexatumumab induces TRMA of both HCV‐infected and ‐uninfected cells by binding to TRAIL‐R2. IFN‐α has minimal effect on mapatumumab‐ and lexatumumab‐induced TRMA. HCV infection of Huh7.5 cells up‐regulates TRAIL‐R1 expression and X‐linked Inhibitor of apoptosis protein and survivin gene expression. Neither antibody had a pro‐apoptotic effect on PBMCs from patients with HIV infection ex vivo . Conclusion: Both mapatumumab and lexatumumab are excellent candidates for therapy of HCC. HCV infection of Huh7.5 cells selectively up‐regulates TRAIL‐R1 receptor, associated with increased susceptibility to mapatumumab‐mediated TRMA. HCV infection up‐regulated IAP genes, offering promise for future combination therapy using TRAIL agonists and IAP inhibitors.