Elsevier

Human Pathology

Volume 32, Issue 3, March 2001, Pages 250-256
Human Pathology

Original Contributions
Expression of Fas and Fas-related molecules in human hepatocellular carcinoma*,**

https://doi.org/10.1053/hupa.2001.22769Get rights and content

Abstract

Many tumor cells, including hepatocellular carcinoma (HCC), express both Fas and its ligand on their surfaces, and it has remained a mystery why such cells do not spontaneously become apoptotic. In the current study, we analyzed the alterations of Fas structure and the expression of Fas and Fas ligand (FasL) and of Fas pathway inhibitors, including soluble Fas (sFas), Fas-associated phosphatase-1 (FAP-1), and bcl-2, in 50 cases of human HCC. Monoallelic loss of the Fas gene, as determined by loss of heterozygosity with intragenic polymorphisms, was observed in 5 of the 34 informative cases (15%), but none of the 50 cases showed Fas gene mutation. Expression of Fas and FasL was detected in 44 (88%) and 50 (100%) cases, respectively. sFas messenger RNA, as analyzed by in situ reverse-transcription polymerase chain reaction was expressed in 42 of the 50 cases (84%), and FAP-1 expression was observed in 40 of the 50 cases (80%). In contrast, none of the 50 cases showed bcl-2 expression. Our results showed that the majority of the HCCs (88%) coexpressed a death receptor, Fas and its cognate ligand, FasL, but all HCCs showed one or more alterations of the Fas pathway molecules known to inhibit Fas-mediated apoptosis. These findings suggest that the expression of sFas and FAP-1 and, in part, loss of Fas expression, rather than Fas gene alteration or bcl-2 expression, may be involved in the Fas resistance of HCC in vivo and that these mechanisms may play important roles in the pathogenesis of human HCC. HUM PATHOL 32:250-256. Copyright © 2001 by W.B. Saunders Company

Section snippets

Tissue samples

Tumor samples from 50 patients undergoing hepatic resection at the Inje University Paik Hospital from 1992 to 1997 were randomly collected. Formalin-fixed, paraffin-embedded tissues from these samples were used in immunohistochemistry, in situ reverse-transcription polymerase chain reaction (in situ RT-PCR), and single-strand conformation polymorphism (SSCP) analysis. The diagnosis of each tumor was confirmed by 3 independent pathologists. The clinical data of the HCCs are summarized in Table 1.

Immunohistochemical analysis of Fas, FasL, FAP-1, and bcl-2

The immunostaining with each antibody was judged to be antibody specific by several criteria, including absence of consistent immunostaining of any cells with normal rabbit or goat or mouse serum at the same dilution; reduction of signal intensity as the dilution of the antibodies was increased; and abrogation of the positive immunostaining by preincubation of Fas, FasL, or FAP-1 antibody with blocking peptide (Fig 1A).

. Detection of Fas, FasL, FAP-1, and bcl-2 expression by immunohistochemistry

Discussion

Recent studies show that many tumor cells express both Fas, a death receptor, and FasL, a death factor, on their surfaces.39, 40 Thus, it has remained a mystery why such cells do not spontaneously become apoptotic. Moreover, it is generally believed that to escape a cytotoxic attack by FasL-bearing T cells, the tumor cells must achieve resistance to FasL-induced killing. In this study, we have examined the possible inhibitory alterations of Fas pathway molecules in tissue sections of HCC. In

References (50)

  • QR Huang et al.

    Identification and characterization of polymorphisms in the promoter region of the human Apo-1/Fas (CD95) gene

    Mol Immunol

    (1997)
  • JC Reed

    Double identity for proteins of Bcl-2 family

    Nature

    (1997)
  • BC Trauth et al.

    Monoclonal antibody-mediated tumor regression by induction of apoptosis

    Science

    (1989)
  • S Yonehara et al.

    A cell-killing monoclonal antibody (anti-Fas) to a cell surface antigen co-downregulated with the receptor of tumor necrosis factor

    J Exp Med

    (1989)
  • F Leithäser et al.

    Constitutive and induced expression of APO-1, a new member of the new grow factor/tumor necrosis receptor superfamily, in normal and neoplastic cells

    Lab Invest

    (1993)
  • LB Owen-Schaub et al.

    Anti-Fas on nonhematopoietic tumors: levels of Fas/APO-1 and bcl-2 are not predictive of biological responses

    Cancer Res

    (1994)
  • J Cheng et al.

    Protection from Fas-mediated apoptosis by a soluble form of the Fas molecule

    Science

    (1994)
  • RM Pitti et al.

    Genomic amplification of a decoy receptor for Fas ligand in lung and colon cancer

    Nature

    (1998)
  • Y Nambu et al.

    Lack of cell surface Fas/APO-1 expression in pulmonary adenocarcinomas

    J Clin Invest

    (1998)
  • T Sato et al.

    FAP-1: a protein tyrosine phosphatase that associates with Fas

    Science

    (1995)
  • A Kawahara et al.

    Inhibition of Fas-induced apoptosis by Bcl-2

    Oncogene

    (1998)
  • M Irmler et al.

    Inhibition of death receptor signals by cellular FLIP

    Nature

    (1997)
  • DA Martin et al.

    Defective CD95/APO-1/Fas signal complex formation in the human autoimmune lymphoproliferative syndrome, type Ia

    Proc Natl Acad Sci USA

    (1999)
  • J Drappa et al.

    Fas gene mutations in the Canale-Smith syndrome, an inherited lymphoproliferative disorder associated with autoimmunity

    N Engl J Med

    (1996)
  • TH Landowsky et al.

    Mutations in the Fas antigen in patients with multiple myeloma

    Blood

    (1997)

    • Cited by (0)

    *

    Supported by funding from the Korea Research Foundation in the program year of 1998 (F-05).

    **

    Address correspondence and reprint requests to Nam Jin Yoo, MD, Department of Pathology, College of Medicine, The Catholic University of Korea, 505 Banpo-dong, Socho-gu, Seoul 137-701, Korea.

    View full text
    Copyright © 2001 W.B. Saunders Company. Published by Elsevier Inc. All rights reserved.