Inactivation of NF1 Promotes Resistance to EGFR Inhibition in KRAS/NRAS/BRAFV600 -Wild-Type Colorectal Cancer.

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ICR Authors

Authors

Georgiou, A
Stewart, A
Cunningham, D
Banerji, U
Whittaker, SR

Document Type

Journal Article

Date

2020-06-01

Date Accepted

2020-02-20

Abstract

Through the use of an unbiased, genome-scale CRISPR modifier screen, we identified NF1 suppression as a mechanism of resistance to EGFR inhibition in NRAS/KRAS/BRAFV600 -wild-type colorectal cancer cells. Reduced NF1 expression permitted sustained signaling through the MAPK pathway to promote cell proliferation in the presence of EGFR inhibition. Targeting of MEK in combination with EGFR inhibition leads to synergistic antiproliferative activity. Human KRAS/NRAS/BRAFV600 -wild-type colorectal cancer cell lines with NF1 mutations displayed reduced NF1 mRNA or protein expression and were resistant to EGFR blockade by gefitinib or cetuximab. Cooccurring loss-of-function mutations in PTEN were associated with resistance to dual EGFR/MEK inhibition but cotreatment with a PI3K inhibitor further suppressed proliferation. Loss of NF1 may be a useful biomarker to identify patients that are less likely to benefit from single-agent anti-EGFR therapy in colorectal cancer and may direct potential combination strategies. IMPLICATIONS: This study suggests that further clinical validation of NF1 status as predictor of response to anti-EGFR targeting antibodies in patients with colorectal cancer with KRAS/NRAS/BRAFV600 -wild-type tumors is warranted.

Citation

Molecular cancer research : MCR, 2020, 18 (6), pp. 835 - 846

Source Title

Publisher

AMER ASSOC CANCER RESEARCH

ISSN

1541-7786

eISSN

1557-3125

Collections

Research Team

Clinical Pharmacology – Adaptive Therapy
Medicine (RMH Smith Cunningham)

Notes