G15, a GPR30 antagonist, induces apoptosis and autophagy in human oral squamous carcinoma cells

Chem Biol Interact. 2013 Nov 25;206(2):375-84. doi: 10.1016/j.cbi.2013.10.014. Epub 2013 Oct 23.

Abstract

As GPR30 has been implicated in mediating cancer cell proliferation, this study aimed to examine the antitumor effect of the GPR30 antagonist G15 in human oral squamous cell carcinoma (OSCC). G15 induced dose-dependent cytotoxicity, apoptosis and G2/M cell cycle arrest in a panel of OSCC cells. The results showed that G15 could inhibit the growth of the oral cancer cells with IC50 value 11.2 μM for SCC4, 15.6 μM for SCC9, and 7.8 μM for HSC-3, respectively. Flow cytometric analysis and Comet assay indicated that G15 suppressed the viability of SCC4 and HSC-3 cells by inducing apoptosis and G2/M arrest. In addition, G15 down regulated the expression of Akt, cell cycle-related proteins, and mitogen-activated protein kinases, but increased the levels of LC3B-II and the accumulation of autophagosomes. Inhibition of autophagy by chloroquine does not affect the G15-induced apoptosis in SCC4 cells. Mechanistic evidence indicated that the antiproliferative effect was mediated through the downregulation of cdc2, cdc25c and NF-κB expression. Taken together, our findings suggest the potential of G15 in treating OSCC.

Keywords: Apoptosis; Autophagy; G15; GPR30; Oral cancer.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Apoptosis / drug effects*
  • Autophagy / drug effects*
  • Benzodioxoles / chemical synthesis
  • Benzodioxoles / chemistry
  • Benzodioxoles / toxicity*
  • Carcinoma, Squamous Cell / metabolism
  • Carcinoma, Squamous Cell / pathology
  • Caspases / metabolism
  • Cell Line, Tumor
  • Chloroquine / chemistry
  • Chloroquine / pharmacology
  • G2 Phase Cell Cycle Checkpoints / drug effects
  • Humans
  • M Phase Cell Cycle Checkpoints / drug effects
  • Microtubule-Associated Proteins / metabolism
  • Mouth Neoplasms / metabolism
  • Mouth Neoplasms / pathology
  • NF-kappa B / metabolism
  • Phosphorylation / drug effects
  • Proto-Oncogene Proteins c-akt / metabolism
  • Quinolines / chemical synthesis
  • Quinolines / chemistry
  • Quinolines / toxicity*
  • Receptors, Estrogen / antagonists & inhibitors*
  • Receptors, Estrogen / metabolism
  • Receptors, G-Protein-Coupled / antagonists & inhibitors*
  • Receptors, G-Protein-Coupled / metabolism
  • Signal Transduction / drug effects

Substances

  • 4-(6-bromo-1,3-benzodioxol-5-yl)-3a,4,5,9b-3H-cyclopenta(c)quinoline
  • Benzodioxoles
  • GPER1 protein, human
  • MAP1LC3B protein, human
  • Microtubule-Associated Proteins
  • NF-kappa B
  • Quinolines
  • Receptors, Estrogen
  • Receptors, G-Protein-Coupled
  • Chloroquine
  • Proto-Oncogene Proteins c-akt
  • Caspases