Royal College of Surgeons in Ireland
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Markers of MEK inhibitor resistance in low-grade serous ovarian cancer: EGFR is a potential therapeutic target.

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posted on 2022-03-23, 11:51 authored by Marta L. Fernandez, Amy Dawson, Joshua Hoenisch, Hannah Kim, Sylvia Bamford, Clara Salamanca, Gabriel DiMattia, Trevor Shepherd, Mattia Cremona, Bryan HennessyBryan Hennessy, Shawn Anderson, Stanislav Volik, Colin C. Collins, David G. Huntsman, Mark S. Carey

Background: Although low-grade serous ovarian cancer (LGSC) is rare, case-fatality rates are high as most patients present with advanced disease and current cytotoxic therapies are not overly effective. Recognizing that these cancers may be driven by MAPK pathway activation, MEK inhibitors (MEKi) are being tested in clinical trials. LGSC respond to MEKi only in a subgroup of patients, so predictive biomarkers and better therapies will be needed.

Methods: We evaluated a number of patient-derived LGSC cell lines, previously classified according to their MEKi sensitivity. Two cell lines were genomically compared against their matching tumors samples. MEKi-sensitive and MEKi-resistant lines were compared using whole exome sequencing and reverse phase protein array. Two treatment combinations targeting MEKi resistance markers were also evaluated using cell proliferation, cell viability, cell signaling, and drug synergism assays.

Results: Low-grade serous ovarian cancer cell lines recapitulated the genomic aberrations from their matching tumor samples. We identified three potential predictive biomarkers that distinguish MEKi sensitive and resistant lines:

Conclusions: KRAS mutations and the protein expression of EGFR and PKC-alpha should be evaluated as predictive biomarkers in patients with LGSC treated with MEKi. Combination therapy using a MEKi with EGFR inhibition may represent a promising new therapy for patients with MEKi-resistant LGSC.


British Columbia Cancer Foundation (BCCF),Vancouver General Hospital Foundation. Cancer Research Society. Canadian Institute of Health Research Grant #136836. BCCF, University of British Columbia (UBC) Hospital Foundation. Canadian Institute of Health Research (CIHR), Canada Research Society.



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Published Citation

Fernandez ML, Dawson A, Hoenisch J, Kim H, Bamford S, Salamanca C, DiMattia G, Shepherd T, Cremona M, Hennessy B, Anderson S, Volik S, Collins CC, Huntsman DG, Carey MS. Markers of MEK inhibitor resistance in low-grade serous ovarian cancer: EGFR is a potential therapeutic target. Cancer Cell International. 2019;19:10.

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  • Beaumont Hospital
  • Medicine
  • Molecular Medicine