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Genome-wide RNAi Screening to Identify Host Factors That Modulate Oncolytic Virus Therapy
08:51

Genome-wide RNAi Screening to Identify Host Factors That Modulate Oncolytic Virus Therapy

Published on: April 3, 2018

Virus-tumor interactome screen reveals ER stress response can reprogram resistant cancers for oncolytic

Douglas J Mahoney1, Charles Lefebvre, Kristina Allan

  • 1Children's Hospital of Eastern Ontario Research Institute, Ottawa, Ontario K1H 8L1, Canada.

Cancer Cell
|October 22, 2011
PubMed

Insights

Researchers identified endoplasmic reticulum (ER) stress response pathways as key targets to enhance oncolytic viral therapy. Inhibiting ER stress sensitizes cancer cells to viral infection, significantly boosting therapeutic potency.

Area of Science:

  • Oncology
  • Virology
  • Molecular Biology

Background:

  • Oncolytic viral therapy utilizes viruses to selectively infect and kill cancer cells.
  • Identifying host factors that modulate viral oncolysis is crucial for improving therapeutic efficacy.
  • Endoplasmic reticulum (ER) stress response pathways are implicated in cellular responses to various stimuli, including viral infection.

Purpose of the Study:

  • To discover host factors that enhance rhabdovirus-mediated oncolysis using genome-wide RNAi screens.
  • To elucidate the mechanism by which ER stress response pathways modulate oncolytic viral therapy.
  • To evaluate the therapeutic potential of targeting ER stress for improving oncolytic virus efficacy in cancer.

Main Methods:

  • Genome-wide RNA interference (RNAi) screens were employed to identify host factors modulating rhabdoviral oncolysis.
  • Investigated the role of endoplasmic reticulum (ER) stress response pathways in rhabdovirus-induced cytotoxicity.
  • Utilized small molecule inhibitors targeting IRE1α in in vivo tumor models.

Main Results:

  • Genome-wide screens identified ER stress response pathways as critical modulators of rhabdovirus oncolysis.
  • Inhibition of ER stress response preconditioned cancer cells, sensitizing them to rhabdovirus infection via caspase-2-dependent apoptosis.
  • This mechanism demonstrated tumor cell specificity, increasing oncolytic virus potency by up to 10,000-fold.
  • In vivo studies confirmed enhanced oncolytic efficacy in resistant tumor models using an IRE1α inhibitor.

Conclusions:

  • Functional genomics screens can identify novel strategies to enhance oncolytic viral therapy.
  • Targeting ER stress response pathways represents a promising approach to improve the efficacy of oncolytic viruses.
  • This study provides proof of concept for developing improved biotherapeutic agents for cancer treatment.

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