A specific expression profile of LC3B and p62 is associated with nonresponse to neoadjuvant chemotherapy in esophageal adenocarcinomas

PLoS One. 2018 Jun 13;13(6):e0197610. doi: 10.1371/journal.pone.0197610. eCollection 2018.

Abstract

Paclitaxel is a powerful chemotherapeutic drug, used for the treatment of many cancer types, including esophageal adenocarcinomas (EAC). Autophagy is a lysosome-dependent degradation process maintaining cellular homeostasis. Defective autophagy has been implicated in cancer biology and therapy resistance. We aimed to assess the impact of autophagy on chemotherapy response in EAC, with a special focus on paclitaxel. Responsiveness of EAC cell lines, OE19, FLO-1, OE33 and SK-GT-4, to paclitaxel was assessed using Alamar Blue assays. Autophagic flux upon paclitaxel treatment in vitro was assessed by immunoblotting of LC3B-II and quantitative assessment of WIP1 mRNA. Immunohistochemistry for the autophagy markers LC3B and p62 was applied on tumor tissue from 149 EAC patients treated with neoadjuvant chemotherapy, including pre- and post-therapeutic samples (62 matched pairs). Tumor response was assessed by histology. For comparison, previously published data on 114 primary resected EAC cases were used. EAC cell lines displayed differing responsiveness to paclitaxel treatment; however this was not associated with differential autophagy regulation. High p62 cytoplasmic expression on its own (p ≤ 0.001), or in combination with low LC3B (p = 0.034), was associated with nonresponse to chemotherapy, regardless of whether or not the regiments contained paclitaxel, but there was no independent prognostic value of LC3B or p62 expression patterns for EAC after neoadjuvant treatment. p62 and related pathways, most likely other than autophagy, play a role in chemotherapeutic response in EAC in a clinical setting. Therefore p62 could be a novel therapeutic target to overcome chemoresistance in EAC.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adenocarcinoma / drug therapy*
  • Adenocarcinoma / genetics
  • Adenocarcinoma / pathology
  • Adult
  • Aged
  • Autophagy / genetics
  • Biopsy
  • Disease-Free Survival
  • Esophageal Neoplasms / drug therapy*
  • Esophageal Neoplasms / genetics
  • Esophageal Neoplasms / pathology
  • Female
  • Gene Expression Regulation, Neoplastic
  • Humans
  • Kaplan-Meier Estimate
  • Male
  • Microtubule-Associated Proteins / genetics*
  • Middle Aged
  • Neoadjuvant Therapy / adverse effects
  • Paclitaxel / administration & dosage
  • Paclitaxel / adverse effects
  • RNA-Binding Proteins / genetics*
  • Transcription Factors

Substances

  • MAP1LC3B protein, human
  • Microtubule-Associated Proteins
  • P62 protein, human
  • RNA-Binding Proteins
  • Transcription Factors
  • Paclitaxel

Supplementary concepts

  • Adenocarcinoma Of Esophagus

Grants and funding

This study was supported by a grant from the Swiss Cancer League (KFS-3083-02-2013) awarded to RL.