Upregulation of autophagy-related gene-5 (ATG-5) is associated with chemoresistance in human gastric cancer

PLoS One. 2014 Oct 17;9(10):e110293. doi: 10.1371/journal.pone.0110293. eCollection 2014.

Abstract

Autophagy-related gene-5 (ATG-5) is one of the key regulators of autophagic cell death. It has been widely regarded as a protective molecular mechanism for tumor cells during the course of chemotherapy. In the present study, we investigated the expression pattern of ATG-5 and multidrug resistance-associated protein-1 (MRP-1) in 135 gastric cancers (GC) patients who were treated with epirubicin, cisplatin and 5-FU adjuvant chemotherapy (ECF) following surgical resection and explored their potential clinical significance. We found that both ATG-5 (77.78%) and MRP-1 (79.26%) were highly expressed in GC patients. ATG-5 expression was significantly associated with depth of wall invasion, TNM stages and distant metastasis of GC (P<0.05), whereas MRP-1 expression was significantly linked with tumor size, depth of wall invasion, lymph node metastasis, TNM stages and differentiation status (P<0.05). ATG-5 expression was positively correlated with MRP-1 (rp = 0.616, P<0.01). Increased expression of ATG-5 and MPR-1 was significantly correlated with poor overall survival (OS; P<0.01) and disease free survival (DFS; P<0.01) of our GC cohort. Furthermore, we demonstrated that ATG-5 was involved in drug resistant of GC cells, which was mainly through regulating autophagy. Our data suggest that upregulated expression of ATG-5, an important molecular feature of protective autophagy, is associated with chemoresistance in GC. Expression of ATG-5 and MRP-1 may be independent prognostic markers for GC treatment.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Aged
  • Autophagy-Related Protein 5
  • Disease-Free Survival
  • Drug Resistance, Neoplasm / genetics*
  • Female
  • Humans
  • Male
  • Microtubule-Associated Proteins / genetics
  • Microtubule-Associated Proteins / metabolism*
  • Middle Aged
  • Multidrug Resistance-Associated Proteins / genetics
  • Multidrug Resistance-Associated Proteins / metabolism
  • Stomach Neoplasms / diagnosis
  • Stomach Neoplasms / drug therapy
  • Stomach Neoplasms / genetics*
  • Up-Regulation*

Substances

  • ATG5 protein, human
  • Autophagy-Related Protein 5
  • Microtubule-Associated Proteins
  • Multidrug Resistance-Associated Proteins
  • multidrug resistance-associated protein 1

Grants and funding

This work was supported by National Natural Science Foundation of Hunan Province, China (No. 2012FJ6088). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.