Identification of cell type-specific correlations between ERK activity and cell viability upon treatment with ERK1/2...

Area of Science:

• Oncology
• Molecular Biology
• Pharmacology

Background:

• Mitogen-activated protein kinase (MAPK) signaling is crucial for cancer cell survival.
• Directly inhibiting extracellular signal-regulated kinases 1 and 2 (ERK1/2) is a potential cancer treatment strategy.
• The dynamics and selectivity of ERK1/2 inhibitors are less understood than those of BRAF or MEK inhibitors.

Purpose of the Study:

• To investigate the relationship between ERK inhibition and drug-induced toxicity across various cancer cell lines.
• To evaluate the dynamics of ERK1/2 reactivation and drug resistance.
• To identify selective and effective ERK1/2 inhibitors for cancer therapy.

Main Methods:

• Utilized reporter cell lines for ERK1/2 and downstream kinase ELK1 in lung cancer, colon cancer, neuroblastoma, and leukemia.
• Examined five ERK inhibitors (SCH772984, ravoxertinib, LY3214996, ulixertinib, VX-11e) and one MEK inhibitor (PD0325901).
• Assessed cell viability, ERK inhibition, and drug-induced toxicity.

Main Results:

• Different cancer cell lines exhibited varying dependencies on ERK signaling.
• SCH772984 and VX-11e showed excessive toxicity unrelated to ERK1/2 inhibition in certain cell lines.
• PD0325901, LY3214996, and ulixertinib demonstrated propensity for ERK1/2 reactivation over time, with two distinct reactivation patterns observed.
• Cancer cells resistant to MEK1/2 inhibitor PD0325901 due to ERK1/2 reactivation remained sensitive to ERK1/2 inhibitor ulixertinib.

Conclusions:

• Correlating ERK inhibition with drug-induced toxicity in diverse cell lines aids in identifying more selective and effective ERK1/2 inhibitors.
• Understanding ERK reactivation mechanisms is vital for overcoming drug resistance in cancer treatment.
• ERK inhibitors may offer therapeutic advantages over MEK inhibitors in specific resistant contexts.