Mutated RAS and constitutively activated Akt delineate distinct oncogenic pathways, which independently contribute to...

Area of Science:

• Oncology
• Molecular Biology
• Cancer Signaling

Background:

• Constitutive Akt activity is observed in approximately 50% of multiple myeloma (MM) samples.
• The Akt pathway is a key signaling conduit for oncogenic RAS.
• Activating mutations in K-RAS and N-RAS are frequent in MM.

Purpose of the Study:

• To investigate the relationship between RAS mutation status and Akt dependency in MM.
• To elucidate the role of oncogenic RAS in MM cell survival.
• To evaluate combined therapeutic targeting of RAS and Akt pathways in MM.

Main Methods:

• Analysis of RAS mutation and Akt dependency in 65 MM patient biopsies and CD138-purified cells.
• Assessment of MM cell line viability with differing RAS mutation status.
• Gene knockdown experiments targeting K-RAS and N-RAS isoforms.
• Evaluation of combined RAS and Akt inhibition on MM cell death.

Main Results:

• RAS mutations did not predict Akt dependency in MM.
• Oncogenic RAS plays a critical role in MM cell survival, with isoform-specific knockdown reducing viability.
• Silencing oncogenic RAS did not impact the Akt pathway, suggesting independent signaling.
• Combined inhibition of RAS and Akt significantly enhanced MM cell death.

Conclusions:

• Oncogenic RAS and Akt signaling independently contribute to MM cell survival.
• Targeting both oncogenic RAS and dysregulated Akt pathways presents a potential therapeutic strategy for MM.
• This dual-targeting approach may benefit MM patients with both oncogenic RAS mutations and aberrant Akt signaling.