Cancer Letters

Cancer Letters

Volume 314, Issue 1, 1 January 2012, Pages 73-81
Cancer Letters

Elevated fibroblast growth factor-inducible 14 expression promotes gastric cancer growth via nuclear factor-κB and is associated with poor patient outcome

https://doi.org/10.1016/j.canlet.2011.09.016Get rights and content

Abstract

The fibroblast growth factor-inducible 14 (Fn14) gene encodes a type I transmembrane protein that belongs to the tumor necrosis factor receptor superfamily and regulates multiple cellular processes in diverse physiological and pathological conditions, including cancer. Here, we describe an important role for Fn14 in regulating the growth of gastric cancer cells. Previous gene expression data analysis demonstrated that Fn14 was up-regulated in various tumor tissues, including gastric cancer. Using qRT-PCR, we showed that Fn14 was overexpressed in gastric tumor tissues compared to normal tissues. Furthermore, Fn14 expression levels were inversely correlated with gastric cancer patient survival. Using ectopic overexpression and shRNA-mediated knockdown of Fn14, we demonstrated that the expression level of Fn14 affected cell growth in gastric cancer. The effect of Fn14 on cell growth was mediated by the NF-κB activity and eventually by the transcriptional regulation of the anti-apoptotic Bcl-2 family gene (Bcl-xL). These results suggest that Fn14 may play an important role in gastric tumor growth by regulating NF-κB-mediated anti-apoptosis and that Fn14 may be a useful prognostic marker for gastric cancer.

Introduction

Gastric cancer is the second most common cause of cancer death in the world, and its incidence rate is particularly high in East Asia, Eastern Europe, and parts of Latin America [1]. Knowledge of gastric cancer has steadily increased. However, the precise mechanisms that promote gastric cancer growth are not fully understood.

Cancer develops when cells in a particular part of the body begin to grow out of control and continue to grow and divide without dying. The transcription factor nuclear factor-κB (NF-κB) regulates the expression of various genes that are involved in immunity, inflammation, cell survival, or oncogenesis [2], [3], [4]. NF-κB stimulates cell-cycle progression through the transcriptional activation of cell-cycle genes, especially cyclin D1 [5]. NF-κB also activates the transcription of anti-apoptotic members of the Bcl-2 family (Bcl-2, Bcl-xL and BFL1), which inhibit pro-apoptotic proteins [6], [7]. Overexpression of these members is associated with the inhibition of apoptosis and the resistance to anti-cancer drugs, resulting in poor prognosis and shortened survival [8], [9]. Inhibition of NF-κB increases the number of apoptotic hepatocytes and reduces tumor multiplicity [10], which suggests that NF-κB/Bcl-2-related proteins are involved in a pathway that is important for cancer cell survival.

Fibroblast growth factor inducible-14 (Fn14) was first identified as one of the growth factor-inducible genes in murine fibroblasts [11]. Fn14 is the smallest member of the tumor necrosis factor (TNF) superfamily of receptors lacking the cytoplasmic death domain [11], [12], [13]. The Fn14 gene, which is located on human chromosome 6, is expressed in various tissues including heart, placenta, kidney, lungs, and pancreas [12]. In tumor tissues, Fn14 expression is elevated in hepatocellular [12], glioblastoma multiforme [14], and pancreatic cancer [15]. Activation of Fn14 by the addition of TNF-like weak inducer of apoptosis (TWEAK), which is an exclusive ligand for Fn14, enhances glioma cell survival [16] and promotes the growth of human hepatocellular carcinoma cells [17]. The binding of TWEAK to the Fn14 also stimulates human glioma cell migration [14]. The TWEAK/FN14 pathway activates the nuclear factor (NF)-κB signaling pathway and stimulates the expression of various NF-κB-regulated pro-inflammatory molecules [18].

Using a database to mine gene expression data, we identified Fn14 as an overexpressed gene in gastric cancer patients. Here, we explored the effects of Fn14 overexpression in gastric cancer and demonstrated that the expression level of Fn14 affected the growth of gastric cancer cells. Our results show that Fn14-induced NF-κB activation underlies the molecular basis for survival in gastric cancer cells, in part, by up-regulating the expression of the anti-apoptotic gene, Bcl-xL. In addition, we found that high Fn14 expression was associated with poor prognosis in gastric cancer patients.

Section snippets

Cell lines and tissue samples

Gastric cancer cell lines were cultured in complete RPMI 1640 medium. 293T and GP-293 packaging cell lines were maintained in complete DMEM media. All cell lines were obtained from the Korean Cell Line Bank (http://cellbank.snu.ac.kr/index.htm), and all complete media contained 10% fetal bovine serum (Hyclone), 100 U/ml of penicillin/streptomycin (Invitrogen, Carlsbad, CA), 2 mM L-glutamine, and 0.5 mM HEPES. A total of 191 frozen tumors were collected from Chungnam National University Hospital.

Increased expression of Fn14 in many cancers, including gastric cancer

We investigated the expression levels of Fn14 in various cancers using the GENT database (available at http://medical-genome.kribb.re.kr/GENT/) [20]. Fn14 was overexpressed in many cancer types, including cancers of the bladder, brain, cervix, colon, esophagus, liver, lung, ovary, pancreas, skin, stomach, thyroid, vagina, and vulva (Fig. 1). However, in some tissues, the expression profile of Fn14 was similar compared to the expression profile of Fn14 in the matched normal tissues (Fig. 1).

The relationship between Fn14 mRNA expression and prognosis

To

Discussion

The TNFR superfamily receptors activate signaling cascades to regulate cell proliferation or apoptosis [23]. Fn14 is a member of the TNF superfamily of receptors thought to be involved in cell growth, adhesion and migration [13]. Roles of TWEAK/Fn14 in tumorigenesis have been well studied in a few cancer types, however their role in gastric cancer is not well known. In the current study, we described a role for Fn14 in promoting gastric cancer cell growth through the transcriptional regulation

Acknowledgements

This work was supported by Grants from the National R & D Program for Cancer Control, the Ministry for Health and Welfare, the Republic of Korea (1020360), the KRIBB-Pfizer Collaboration Research Program (IGE1641012), and the KRIBB Research Initiative Grant.

References (38)

  • S. Han et al.

    TNF-related weak inducer of apoptosis receptor a TNF receptor superfamily member, activates NF-kappa B through TNF receptor-associated factors

    Biochem. Biophys. Res. Commun.

    (2003)
  • C.A. Smith et al.

    The TNF receptor superfamily of cellular and viral proteins: activation costimulation, and death

    Cell

    (1994)
  • J.A. Winkles et al.

    TWEAK and Fn14: new molecular targets for cancer therapy?

    Cancer Lett.

    (2006)
  • R.O. Escarcega et al.

    The transcription factor nuclear factor-kappa B and cancer

    Clin. Oncol.

    (2007)
  • T. Saitoh et al.

    TWEAK induces NF-kappaB2 p100 processing and long lasting NF-kappaB activation

    J. Biol. Chem.

    (2003)
  • L. Oliver et al.

    Influence of bcl-2-related proteins on matrix metalloproteinase expression in a rat glioma cell line

    Biochem. Biophys. Res. Commun.

    (2000)
  • D.M. Parkin et al.

    Estimates of the worldwide incidence of 25 major cancers in 1990

    Int. J. Cancer

    (1999)
  • N. Silverman et al.

    NF-kappaB signaling pathways in mammalian and insect innate immunity

    Genes Dev.

    (2001)
  • M. Karin et al.

    NF-kappaB at the crossroads of life and death

    Nat. Immunol.

    (2002)
  • Cited by (33)

    • Regulation of fibroblast growth factor-inducible 14 (Fn14) expression levels via ligand-independent lysosomal degradation

      2014, Journal of Biological Chemistry
      Citation Excerpt :

      The TWEAK receptor Fn14 is expressed at low levels in most normal tissue but is rapidly up-regulated during tissue injury and inflammation. Given that the expression of Fn14 is also elevated in a variety of chronic inflammatory conditions (12–15) and in numerous invasive cancers (16–18), we wanted to better understand the post-translational regulation of Fn14. Through this work, we have identified a previously unrecognized aspect of Fn14 regulation.

    • Pyruvate kinase M2 affects liver cancer cell behavior through up-regulation of HIF-1α and Bcl-xL in culture

      2015, Biomedicine and Pharmacotherapy
      Citation Excerpt :

      NF-κB p65 binding to the Bcl-xL promoter up-regulates Bcl-xL gene expression, and protects cells from radiation-induced apoptosis [43]. Kwon et al. demonstrated that one of the reasons why PKM2 expression is associated with poor prognosis may be PKM2-mediated regulation of Bcl-xL expression [16]. Furthermore, PKM2-mediated stabilization of p65 may be one of the important mechanisms in regulating the expression of Bcl-xL gene at the transcriptional level in gastric cancer cells.

    • TWEAK/Fn14 axis: The current paradigm of tissue injury-inducible function in the midst of complexities

      2014, Seminars in Immunology
      Citation Excerpt :

      TWEAK is also present in tumor specimens, some apparently produced by tumor cells themselves, with sTWEAK detected in the conditioned media of some tumor cell lines [45] and some likely produced by leukocytes in the tumor microenvironment, and mTWEAK reported on hepatocellular carcinomas [46]. Notably, a significant correlation between increased Fn14 expression and higher tumor grade or poor prognosis has been documented in glioma, neuroblastoma, renal cell carcinoma, breast, esophageal, and gastric cancers [25,27,47–50], implying that the TWEAK/Fn14 pathway is protumorigenic in many tumor types. Alternatively, it is formally possible that some tumors express sufficiently high levels of Fn14 such that protumoral signaling occurs independent of ligand (Section 2.2).

    • Genetics/Genomics/Proteomics of Gastric Adenocarcinoma

      2013, Gastroenterology Clinics of North America
      Citation Excerpt :

      Additionally, protein chip array and surface-enhanced laser desorption/ionization time-of-flight mass spectrometry (SELDI-TOF-MS) analyses have demonstrated upregulation of pepsinogen C and pepsin A, as well as downregulation of alpha-defensins in patients with GC.131 Fibroblast growth factor–inducible factor 14 (Fn14), a type 1 transmembrane protein that belongs to the tumor necrosis factor (TNF) superfamily that functions through the NF-kB pathway, was found to be overexpressed in GC compared with normal tissue.132 Moreover Fn14 expression levels were inversely correlated with patient survival in 87 patients with late-stage GC.

    View all citing articles on Scopus
    1

    Contributed equally.

    View full text