Development of the First Small-Molecule Inhibitor Targeting Oncostatin M for Treatment of Breast Cancer

Area of Science:

• Biochemistry
• Oncology
• Pharmacology

Background:

• Oncostatin M (OSM) is a proinflammatory cytokine linked to inflammatory diseases and cancers, particularly breast cancer.
• Currently, no federally approved therapeutics specifically target OSM.
• There is a critical need for novel anti-OSM agents to combat breast cancer progression.

Purpose of the Study:

• To computationally screen for and identify small-molecule inhibitors (SMIs) of Oncostatin M (OSM).
• To validate identified SMIs in human breast cancer models and assess their therapeutic potential.
• To develop the first-in-class anti-OSM therapeutic for breast cancer treatment.

Main Methods:

• Computational screening of approximately 1.65 million compounds to identify OSM inhibitors.
• In vitro validation using breast cancer cell lines (T47D, MCF-7) to assess inhibition of OSM signaling (STAT3 phosphorylation).
• Biophysical characterization of SMI/OSM interactions using fluorescence quenching, NMR, and surface plasmon resonance (SPR).
• In vivo efficacy studies in a human breast cancer mouse model.

Main Results:

• A tetrasubstituted furan derivative, SMI-10, was identified and optimized into SMI-10B and SMI-10B13 with low micromolar affinity for OSM.
• SMI-10B13 potently inhibited OSM-mediated STAT3 phosphorylation in breast cancer cells (IC50 = 136-164 nM).
• In vivo, SMI-10B13 significantly reduced tumor growth (p < 0.001) and improved survival (p = 0.04) in a breast cancer mouse model.

Conclusions:

• SMI-10B13 represents a promising first-in-class small-molecule inhibitor of Oncostatin M.
• This novel therapeutic candidate demonstrates efficacy in reducing breast cancer progression and extending survival in preclinical studies.
• Further development of SMI-10B13 holds significant potential for a new therapeutic strategy against breast cancer.