Leveraging RAS-mSIN1 interaction to selectively inhibit mTORC2 employing competitive RAS binding peptide:...

Area of Science:

• Oncology
• Molecular Biology
• Drug Discovery

Background:

• The mechanistic target of rapamycin complex 2 (mTORC2) plays a critical role in cancer progression and metastasis.
• Selective inhibition of mTORC2, without affecting mTORC1, is a significant unmet need in cancer therapy.

Purpose of the Study:

• To develop a strategy for selective mTORC2 inhibition by targeting the RAS-mSIN1 interaction.
• To investigate the efficacy of a novel peptide, S-016-1034, derived from the RAS-Binding-Domain of mSIN1.

Main Methods:

• Development of an 11-mer peptide (S-016-1034) targeting the RAS-Binding-Domain of mSIN1.
• Cell-free Biolayer-Interferometry (BLI) to confirm peptide-Ras binding.
• Confocal microscopy and flow cytometry to assess cell-membrane penetration.
• Cell-based assays (immunoprecipitation, in-situ proximity-ligation) to evaluate Ras-mSin1 interaction disruption.
• Transcriptomics, cell-based assays, and in vivo models (C. elegans, 4T1/Balb/c mice) to confirm mTORC2 specificity.

Main Results:

• The peptide S-016-1034 demonstrated direct binding to Ras.
• The peptide successfully penetrated cell membranes via a non-endosomal route.
• S-016-1034 selectively inhibited mTORC2 over mTORC1 by disrupting the Ras-mSin1 interaction.
• Specificity of mTORC2 inhibition was confirmed across various models, including breast cancer mouse models.

Conclusions:

• The Ras-binding peptide S-016-1034 selectively inhibits mTORC2.
• Further optimization of this peptide may lead to promising therapeutic strategies for halting cancer cell invasion and metastasis.