A genome-wide RNAi screen identifies multiple synthetic lethal interactions with the Ras oncogene

Area of Science:

• Oncology
• Molecular Biology
• Genetics

Background:

• Oncogenic mutations in the small GTPase Ras are common in many cancers.
• Understanding the specific vulnerabilities of Ras-mutant cancers is crucial for developing targeted therapies.

Purpose of the Study:

• To identify synthetic lethal interactions with the KRAS oncogene using a genome-wide RNAi screen.
• To uncover potential therapeutic targets for Ras-mutant cancers.

Main Methods:

• Genome-wide RNA interference (RNAi) screen to identify genes synthetically lethal with KRAS.
• Functional analysis of identified genes, focusing on mitotic functions.
• Gene expression analysis to correlate pathway activity with patient survival.

Main Results:

• A diverse set of proteins, enriched for mitotic functions, were identified whose depletion selectively impaired Ras-mutant cell viability.
• A specific pathway involving PLK1, the anaphase-promoting complex/cyclosome, and the proteasome was identified.
• Inhibition of this pathway led to prometaphase accumulation and death in Ras-mutant cells.
• Reduced expression of genes in this pathway correlated with improved survival in patients with Ras-mutant tumors.

Conclusions:

• Ras plays an underappreciated role in mitotic progression.
• Targeting the identified pathway offers a pharmacologically tractable strategy for treating Ras-mutant cancers.