Microgravity induces autophagy via mitochondrial dysfunction in human Hodgkin's lymphoma cells

Sci Rep. 2018 Oct 2;8(1):14646. doi: 10.1038/s41598-018-32965-3.

Abstract

Gravitational forces can impose physical stresses on the human body as it functions to maintain homeostasis. It has been reported that astronauts exposed to microgravity experience altered biological functions and many subsequent studies on the effects of microgravity have therefore been conducted. However, the anticancer mechanisms of simulated microgravity remain unclear. We previously showed that the proliferation of human Hodgkin's lymphoma (HL) cells was inhibited when these cells were cultured in time-averaged simulated microgravity (taSMG). In the present study, we investigated whether taSMG produced an anticancer effect. Exposure of human HL cells to taSMG for 2 days increased their reactive oxygen species (ROS) production and NADPH oxidase family gene expression, while mitochondrial mass, ATPase, ATP synthase, and intracellular ATP levels were decreased. Furthermore, human HL cells exposed to taSMG underwent autophagy via AMPK/Akt/mTOR and MAPK pathway modulation; such autophagy was inhibited by the ROS scavenger N-acetylcysteine (NAC). These results suggest an innovative therapeutic approach to HL that is markedly different from conventional chemotherapy and radiotherapy.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Acetylcysteine / pharmacology
  • Autophagy / drug effects
  • Autophagy / physiology*
  • Cell Line, Tumor
  • Cell Proliferation / drug effects
  • Cell Proliferation / physiology
  • Gene Expression Regulation, Neoplastic
  • Hodgkin Disease / pathology
  • Hodgkin Disease / therapy*
  • Humans
  • Mitochondria / drug effects
  • Mitochondria / metabolism*
  • Oxidative Stress / drug effects
  • Oxidative Stress / physiology*
  • Reactive Oxygen Species / metabolism
  • Stress, Physiological / drug effects
  • Weightlessness Simulation*

Substances

  • Reactive Oxygen Species
  • Acetylcysteine