Targeting SLC1a5-mediated glutamine dependence in non-small cell lung cancer

Int J Cancer. 2015 Oct 1;137(7):1587-97. doi: 10.1002/ijc.29535. Epub 2015 May 6.

Abstract

We previously elucidated the pleotropic role of solute carrier family A1 member 5 (SLC1A5) as the primary transporter of glutamine (Gln), a modulator of cell growth and oxidative stress in non-small cell lung cancer (NSCLC). The aim of our study was to evaluate SLC1A5 as a potential new therapeutic target and candidate biomarker predictive of survival and response to therapy. SLC1A5 targeting was examined in a panel of NSCLC and human bronchial cell lines by RNA interference and by a small molecular inhibitor, gamma-l-glutamyl-p-nitroanilide (GPNA). The effects of targeting SLC1A5 on cell growth, Gln uptake, ATP level, autophagy and cell death were examined. Inactivation of SLC1A5 genetically or pharmacologically decreased Gln consumption, inhibited cell growth, induced autophagy and apoptosis in a subgroup of NSCLC cell lines that overexpress SLC1A5. Targeting SLC1A5 function decreased tumor growth in NSCLC xenografts. A multivariate Cox proportional hazards analysis indicates that patients with increased SLC1A5 mRNA expression have significantly shorter overall survival (p = 0.01, HR = 1.24, 95% CI: 1.05-1.46), adjusted for age, gender, smoking history and disease stage. In an immunohistochemistry study on 207 NSCLC patients, SLC1A5 protein expression remained highly significant prognostic value in both univariate (p < 0.0001, HR = 1.45, 95% CI: 1.15-1.50) and multivariate analyses (p = 0.04, HR = 1.22, 95% CI: 1.01-1.31). These results position SLC1A5 as a new candidate prognostic biomarker for selective targeting of Gln-dependent NSCLC.

Keywords: biomarker; glutamine transporters; lung cancer.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Amino Acid Transport System ASC / antagonists & inhibitors*
  • Amino Acid Transport System ASC / biosynthesis
  • Amino Acid Transport System ASC / genetics
  • Amino Acid Transport System ASC / metabolism*
  • Animals
  • Carcinoma, Non-Small-Cell Lung / metabolism*
  • Carcinoma, Non-Small-Cell Lung / pathology
  • Carcinoma, Non-Small-Cell Lung / therapy*
  • Cell Line, Tumor
  • Gene Knockdown Techniques
  • Glutamine / metabolism*
  • Humans
  • Lung Neoplasms / metabolism*
  • Lung Neoplasms / pathology
  • Lung Neoplasms / therapy*
  • Mice
  • Minor Histocompatibility Antigens
  • Molecular Targeted Therapy
  • Prognosis
  • RNA, Small Interfering / administration & dosage
  • RNA, Small Interfering / genetics
  • Xenograft Model Antitumor Assays

Substances

  • Amino Acid Transport System ASC
  • Minor Histocompatibility Antigens
  • RNA, Small Interfering
  • SLC1A5 protein, human
  • Glutamine