Related Experiment Video
Updated: Jun 13, 2026
Genome-wide RNAi Screening to Identify Host Factors That Modulate Oncolytic Virus Therapy
Published on: April 3, 2018
Genome-wide siRNA screen for modulators of cell death induced by proteasome inhibitor bortezomib
Siquan Chen1, Jonathan L Blank, Theodore Peters
1Discovery Technologies, Discovery Oncology Biology, and Medical Biostatistics, Millennium Pharmaceuticals, Inc., Cambridge, MA 02139, USA.
Abstract:
Multiple pathways have been proposed to explain how proteasome inhibition induces cell death, but mechanisms remain unclear. To approach this issue, we performed a genome-wide siRNA screen to evaluate the genetic determinants that confer sensitivity to bortezomib (Velcade (R); PS-341). This screen identified 100 genes whose knockdown affected lethality to bortezomib and to a structurally diverse set of other proteasome inhibitors. A comparison of three cell lines revealed that 39 of 100 genes were commonly linked to cell death. We causally linked bortezomib-induced cell death to the accumulation of ASF1B, Myc, ODC1, Noxa, BNIP3, Gadd45alpha, p-SMC1A, SREBF1, and p53. Our results suggest that proteasome inhibition promotes cell death primarily by dysregulating Myc and polyamines, interfering with protein translation, and disrupting essential DNA damage repair pathways, leading to programmed cell death.
Insights
Proteasome inhibitors like bortezomib induce cell death through complex mechanisms. This study identified key genes involved, revealing links to Myc dysregulation, protein translation interference, and DNA repair pathway disruption.
Area of Science:
- Molecular Biology
- Genetics
- Cell Biology
Background:
- Proteasome inhibition is a therapeutic strategy, but its precise mechanisms of inducing cell death remain incompletely understood.
- Identifying genetic factors influencing sensitivity to proteasome inhibitors is crucial for understanding drug action and resistance.
Purpose of the Study:
- To identify genetic determinants of cell death induced by proteasome inhibitors, specifically bortezomib.
- To elucidate the molecular pathways through which proteasome inhibition leads to programmed cell death.
Main Methods:
- A genome-wide siRNA screen was employed to assess gene knockdown effects on cell lethality in response to bortezomib.
- Comparative analysis across three cell lines was performed to identify commonly associated genes.
- Causal links between specific gene accumulations and bortezomib-induced cell death were established.
Main Results:
- The screen identified 100 genes affecting sensitivity to bortezomib and other proteasome inhibitors.
- 39 genes were commonly linked to cell death across three different cell lines.
- Bortezomib-induced cell death was causally linked to the accumulation of specific proteins including Myc, ASF1B, and p53.
Conclusions:
- Proteasome inhibition triggers cell death via dysregulation of Myc and polyamine metabolism.
- Interference with protein translation and disruption of DNA damage repair pathways are critical mechanisms.
- These disruptions collectively lead to programmed cell death, highlighting novel therapeutic targets.
