Delicaflavone induces autophagic cell death in lung cancer via Akt/mTOR/p70S6K signaling pathway

J Mol Med (Berl). 2017 Mar;95(3):311-322. doi: 10.1007/s00109-016-1487-z. Epub 2016 Nov 12.

Abstract

Searching for potential anticancer agents from natural sources is an effective strategy for developing novel chemotherapeutic agents. In this study, data supporting the in vitro and in vivo anticancer effects of delicaflavone, a rarely occurring biflavonoid from Selaginella doederleinii, were reported. Delicaflavone exhibited favorable anticancer properties, as shown by the MTT assay and xenograft model of human non-small cell lung cancer in male BALB/c nude mice without observable adverse effect. By transmission electron microscopy with acridine orange and Cyto-ID®Autophagy detection dyes, Western blot analysis, and RT-PCR assay, we confirmed that delicaflavone induces autophagic cell death by increasing the ratio of LC3-II to LC3-I, which are autophagy-related proteins, and promoting the generation of acidic vesicular organelles and autolysosomes in the cytoplasm of human lung cancer A549 and PC-9 cells in a time- and dose-dependent manner. Delicaflavone downregulated the expression of phospho-Akt, phospho-mTOR, and phospho-p70S6K in a time- and dose-dependent manner, suggesting that it induced autophagy by inhibiting the Akt/mTOR/p70S6K pathway in A549 and PC-9 cells. Delicaflavone is a potential anticancer agent that can induce autophagic cell death in human non-small cell lung cancer via the Akt/mTOR/p70S6K signaling pathway. Delicaflavone showed anti-lung cancer effects in vitro and in vivo. Delicaflavone induced autophagic cell death via Akt/mTOR/p70S6K signaling pathway. Delicaflavone did not show observable side effects in a xenograft mouse model. Delicaflavone may represent a potential therapeutic agent for lung cancer.

Key messages: Delicaflavone showed anti-lung cancer effects in vitro and in vivo. Delicaflavone induced autophagic cell death via Akt/mTOR/p70S6K signaling pathway. Delicaflavone did not show observable side effects in a xenograft mouse model. Delicaflavone may represent a potential therapeutic agent for lung cancer.

Keywords: Akt/mTOR/p70S6K signaling pathway; Autophagy; Delicaflavone; Human lung cancer A549 cell; PC-9 cell.

MeSH terms

  • Animals
  • Antineoplastic Agents, Phytogenic / chemistry
  • Antineoplastic Agents, Phytogenic / therapeutic use*
  • Autophagy / drug effects*
  • Cell Line, Tumor
  • Flavones / chemistry
  • Flavones / therapeutic use*
  • Humans
  • Lung / drug effects*
  • Lung / metabolism
  • Lung / pathology
  • Lung Neoplasms / drug therapy*
  • Lung Neoplasms / metabolism
  • Lung Neoplasms / pathology
  • Male
  • Mice
  • Mice, Inbred BALB C
  • Mice, Nude
  • Proto-Oncogene Proteins c-akt / metabolism
  • Ribosomal Protein S6 Kinases, 70-kDa / metabolism
  • Selaginellaceae / chemistry
  • Signal Transduction / drug effects*
  • TOR Serine-Threonine Kinases / metabolism

Substances

  • Antineoplastic Agents, Phytogenic
  • Flavones
  • Proto-Oncogene Proteins c-akt
  • Ribosomal Protein S6 Kinases, 70-kDa
  • TOR Serine-Threonine Kinases