Involvement of autophagy in antitumor activity of folate-appended methyl-β-cyclodextrin

Sci Rep. 2014 Mar 20:4:4417. doi: 10.1038/srep04417.

Abstract

Autophagy, the major lysosomal pathway for recycling intracellular components including organelles, is emerging as a key process regulating tumorigenesis and cancer therapy. Most recently, we newly synthesized folate-appended methyl-β-cyclodextrin (FA-M-β-CyD), and demonstrated the potential of FA-M-β-CyD as a new antitumor drug. In this study, we investigated whether anticancer activity of FA-M-β-CyD in folate receptor-α (FR-α)-positive tumor cells is involved in autophagy. In contrast to methyl-β-cyclodextrin (M-β-CyD), FA-M-β-CyD entered KB cells (FR-α (+)) through CLIC/GEEC endocytosis. No significant depression in the DNA content was observed in KB cells after treatment with FA-M-β-CyD. Additionally, the transmembrane potential of mitochondria after treatment with FA-M-β-CyD was drastically elevated. Meanwhile, FA-M-β-CyD induced the formation of autophagic vacuoles, which were partially colocalized with mitochondria, in KB cells. Taken together, these results suggest that FR-α-expressing cell-selective cytotoxic activity of FA-M-β-CyD could be mediated by the regulation of autophagy, rather than the induction of apoptosis.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Antineoplastic Agents / chemical synthesis
  • Antineoplastic Agents / pharmacology*
  • Autophagy / drug effects*
  • Folate Receptor 1 / genetics*
  • Folate Receptor 1 / metabolism
  • Folic Acid / chemistry*
  • Gene Expression
  • Humans
  • KB Cells
  • Ligands
  • Protein Binding
  • beta-Cyclodextrins / chemical synthesis
  • beta-Cyclodextrins / pharmacology*

Substances

  • Antineoplastic Agents
  • Folate Receptor 1
  • Ligands
  • beta-Cyclodextrins
  • methyl-beta-cyclodextrin
  • Folic Acid