PTEN/AKT/mTOR signaling mediates anticancer effects of epigallocatechin‑3‑gallate in ovarian cancer

Oncol Rep. 2020 Jun;43(6):1885-1896. doi: 10.3892/or.2020.7571. Epub 2020 Mar 31.

Abstract

Epigallocatechin‑3‑gallate (EGCG), a polyphenol present in green tea, exhibits anticancer effects in various types of cancer. A number of studies have focused on the effects of EGCG on lung cancer, but not ovarian cancer. Previous reports have implicated that EGCG suppressed ovarian cancer cell proliferation and induced apoptosis, but its potential anticancer mechanisms and signaling pathways remain unclear. Thus, it is necessary to determine the anti‑ovarian cancer effects of EGCG and explore the underlying mechanisms. In the present study, EGCG exerted stronger proliferation inhibition on SKOV3 cells compared with A549 cells and induced apoptosis in SKOV3 cells, as well as upregulated PTEN expression and downregulated the expression of phosphoinositide‑dependent kinase‑1 (PDK1), phosphor (p)‑AKT and p‑mTOR. These effects were reversed by the PTEN inhibitor VO‑Ohpic trihydrate. The results of the mouse xenograft experiment demonstrated that 50 mg/kg EGCG exhibited increased tumor growth inhibition compared with 5 mg/kg paclitaxel. In addition, PTEN expression was upregulated, whereas the expression levels of PDK1, p‑AKT and p‑mTOR were downregulated in the EGCG treatment group compared with those in untreated mice in vivo. In conclusion, the results of the present study provided a new underlying mechanism of the effect of EGCG on ovarian cancer and may lead to the development of EGCG as a candidate drug for ovarian cancer therapy.

Keywords: epigallocatechin-3-gallate; ovarian cancer; proliferation; apoptosis; VO-Ohpic trihydrate.

MeSH terms

  • A549 Cells
  • Animals
  • Antineoplastic Agents, Phytogenic / administration & dosage*
  • Antineoplastic Agents, Phytogenic / pharmacology
  • Catechin / administration & dosage
  • Catechin / analogs & derivatives*
  • Catechin / pharmacology
  • Cell Line, Tumor
  • Cell Proliferation / drug effects
  • Cell Survival / drug effects
  • Female
  • Gene Expression Regulation, Neoplastic / drug effects
  • Humans
  • Mice
  • Ovarian Neoplasms / drug therapy*
  • Ovarian Neoplasms / metabolism
  • PTEN Phosphohydrolase / metabolism
  • Proto-Oncogene Proteins c-akt / metabolism
  • Signal Transduction / drug effects*
  • TOR Serine-Threonine Kinases / metabolism
  • Xenograft Model Antitumor Assays

Substances

  • Antineoplastic Agents, Phytogenic
  • Catechin
  • epigallocatechin gallate
  • MTOR protein, human
  • Proto-Oncogene Proteins c-akt
  • TOR Serine-Threonine Kinases
  • PTEN Phosphohydrolase
  • PTEN protein, human