Identification of RAS-mitogen-activated protein kinase signaling pathway modulators in an ERF1 redistribution screen

Area of Science:

• Oncology
• Molecular Biology
• Drug Discovery

Background:

• The RAS-mitogen-activated protein kinase (MAPK) signaling pathway is crucial for cell growth and survival, making it a key target for anticancer drug development.
• Existing therapeutic strategies often focus on kinase inhibitors, with several compounds currently in clinical trials.
• Identifying novel compounds with different mechanisms of action is essential for expanding cancer treatment options.

Purpose of the Study:

• To identify novel compounds that modulate the RAS-MAPK signaling pathway using a cell-based, high-throughput screen.
• To evaluate the efficacy of identified compounds in inhibiting the proliferation of MAPK pathway-dependent cancer cells.
• To characterize the mechanism of action and drug-like properties of the identified compounds.

Main Methods:

• A novel ERF1 Redistribution assay was employed for high-throughput screening of compounds.
• Hit compounds were validated using a functional cell proliferation assay specific for MAPK pathway-dependent cancer cells.
• In vitro kinase assays were performed to assess the inhibitory activity against RAF, MEK, and ERK kinases.

Main Results:

• Two cell membrane-permeable compounds were identified that modulate the RAS-MAPK pathway via the ERF1 Redistribution assay.
• These compounds selectively inhibited the proliferation of MAPK pathway-dependent malignant melanoma cells with high potency (IC50=< 5 microM).
• The identified compounds possess drug-like structures and did not inhibit RAF, MEK, or ERK kinases in vitro, suggesting a non-canonical mechanism.

Conclusions:

• Novel compounds targeting the RAS-MAPK pathway have been discovered using a cell-based Redistribution assay.
• These compounds demonstrate selective anti-proliferative activity against MAPK-dependent cancer cells and possess favorable drug-like properties.
• The findings highlight the utility of high-content Redistribution screens for identifying compounds with diverse mechanisms and novel therapeutic targets in cancer treatment.