Oncogenic PI3Kα variants reveal graded conformational spectrum with mutation-specific cryptic pockets

Area of Science:

• Oncology
• Molecular Biology
• Biophysics

Background:

• Cancer development necessitates at least two mutations.
• Cancer-prone alleles frequently harbor hotspot mutations.
• PI3Kα variants can present with oncogenic, benign tumor, or neurodevelopmental disorder-associated mutations.

Purpose of the Study:

• To investigate the impact of combined mutations on PI3Kα variant behavior.
• To explore the hypothesis of "one-two punch" cancer emergence.
• To identify potential drug targets and therapeutic strategies for PI3Kα variants.

Main Methods:

• Statistical analysis of same-allele double mutations in PI3Kα.
• Atomistic molecular dynamics (MD) simulations of PI3Kα variants.
• Identification of mutation-specific cryptic pockets.

Main Results:

• Combined hotspot and weak/moderate mutations create a graded clinical phenotypic spectrum.
• Double mutations shift PI3Kα conformational ensembles towards the active form more than single mutations.
• Mutation-specific cryptic pockets were identified, offering potential drug-targeting sites.

Conclusions:

• The "one-two punch" hypothesis is supported by PI3Kα mutation data.
• A conformational selection strategy combined with allosteric drugs may effectively treat PI3Kα variants.
• Allosteric potential co-existing pockets were identified in double mutants, guiding future drug development.