Concanavalin-A-induced autophagy biomarkers requires membrane type-1 matrix metalloproteinase intracellular signaling in glioblastoma cells

Glycobiology. 2012 Sep;22(9):1245-55. doi: 10.1093/glycob/cws093. Epub 2012 Jun 12.

Abstract

Pre-clinical trials for cancer therapeutics support the anti-neoplastic properties of the lectin from Canavalia ensiformis (Concanavalin-A, ConA) in targeting apoptosis and autophagy in a variety of cancer cells. Given that membrane type-1 matrix metalloproteinase (MT1-MMP), a plasma membrane-anchored matrix metalloproteinase, is a glycoprotein strongly expressed in radioresistant and chemoresistant glioblastoma that mediates pro-apoptotic signalling in brain cancer cells, we investigated whether MT1-MMP could also signal autophagy. Among the four lectins tested, we found that the mannopyranoside/glucopyranoside-binding ConA, which is also well documented to trigger MT1-MMP expression, increases autophagic acidic vacuoles formation as demonstrated by Acridine Orange cell staining. Although siRNA-mediated MT1-MMP gene silencing effectively reversed ConA-induced autophagy, inhibition of the MT1-MMP extracellular catalytic function with Actinonin or Ilomastat did not. Conversely, direct overexpression of the recombinant Wt-MT1-MMP protein triggered proMMP-2 activation and green fluorescent protein-microtubule-associated protein light chain 3 puncta indicative of autophagosomes formation, while deletion of MT1-MMP's cytoplasmic domain disabled such autophagy induction. ConA-treated U87 cells also showed an upregulation of BNIP3 and of autophagy-related gene members autophagy-related protein 3, autophagy-related protein 12 and autophagy-related protein 16-like 1, where respective inductions were reversed when MT1-MMP gene expression was silenced. Altogether, we provide molecular evidence supporting the pro-autophagic mechanism of action of ConA in glioblastoma cells. We also highlight new signal transduction functions of MT1-MMP within apoptotic and autophagic pathways that often characterize cancer cell responses to chemotherapeutic drugs.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Acridine Orange
  • Autophagy / drug effects*
  • Autophagy / genetics
  • Brain Neoplasms / drug therapy
  • Brain Neoplasms / pathology*
  • Cell Line, Tumor
  • Concanavalin A / pharmacology*
  • Fluorescent Dyes
  • Gene Expression Regulation, Neoplastic / drug effects
  • Gene Silencing
  • Glioblastoma / drug therapy
  • Glioblastoma / pathology*
  • Humans
  • Hydroxamic Acids / pharmacology
  • Indoles / pharmacology
  • Mannose / chemistry
  • Mannose / metabolism
  • Matrix Metalloproteinase 14 / genetics
  • Matrix Metalloproteinase 14 / metabolism*
  • Neoplasm Proteins / genetics
  • Neoplasm Proteins / metabolism*
  • Protein Structure, Tertiary
  • RNA, Small Interfering / genetics
  • Signal Transduction / drug effects*
  • Signal Transduction / genetics
  • Vacuoles / genetics
  • Vacuoles / metabolism

Substances

  • Fluorescent Dyes
  • Hydroxamic Acids
  • Indoles
  • Neoplasm Proteins
  • RNA, Small Interfering
  • Concanavalin A
  • MMP14 protein, human
  • Matrix Metalloproteinase 14
  • Acridine Orange
  • ilomastat
  • actinonin
  • Mannose