Pan-ERBB Inhibitors Synergize With KRAS Inhibitors in Rectal Cancer

Area of Science:

• Oncology
• Molecular Biology
• Cancer Therapeutics

Background:

• KRAS mutations are implicated in various cancers, with emerging inhibitors showing promise but facing resistance.
• Rectal cancer (RC) patients with KRAS mutations exhibit reduced response to neoadjuvant therapy.
• Understanding KRAS mutation impact and resistance mechanisms is crucial for optimizing rectal cancer treatment.

Purpose of the Study:

• To investigate the association of KRAS mutations with disease-free survival and treatment response in rectal cancer.
• To evaluate the efficacy of KRAS inhibitors in preclinical rectal cancer models.
• To explore adaptive resistance mechanisms and identify effective combination strategies.

Main Methods:

• Retrospective analysis of 390 rectal cancer patients.
• In vitro and in vivo assessment of KRAS inhibitors in cell lines, organoids, and patient-derived models.
• Transcriptomic profiling and drug screening to identify resistance pathways and combinatorial therapies.

Main Results:

• KRAS mutations, particularly G12C and G12V, correlated with reduced disease-free survival and poorer response to neoadjuvant therapy in rectal cancer.
• KRAS-mutated cells developed adaptive resistance to KRAS inhibitors via MYC, E2F, and ERBB2/3 pathway reactivation.
• Combination therapy with EGFR inhibitors demonstrated synergistic anti-tumor effects and overcame resistance in patient-derived models.

Conclusions:

• KRAS mutations significantly worsen rectal cancer treatment outcomes.
• Upregulation of ERBB genes drives adaptive resistance to KRAS inhibitors.
• Combination of KRAS inhibitors with pan-ERBB inhibitors shows therapeutic potential for KRAS-mutated rectal cancer.