MYC drives platinum resistant SCLC that is overcome by the dual PI3K-HDAC inhibitor fimepinostat

Jasmine Chen, Aleks C. Guanizo, W. Samantha N. Jakasekara, Chaitanya Inampudi, Quinton Luong, Daniel J. Garama, Muhammad Alamgeer, Nishant Thakur, Michael DeVeer, Vinod Ganju, D. Neil Watkins, Jason E. Cain, Daniel J. Gough

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10 Citations (Scopus)

Abstract

Background: Small cell lung cancer (SCLC) is an aggressive neuroendocrine cancer with an appalling overall survival of less than 5% (Zimmerman et al. J Thor Oncol 14:768-83, 2019). Patients typically respond to front line platinum-based doublet chemotherapy, but almost universally relapse with drug resistant disease. Elevated MYC expression is common in SCLC and has been associated with platinum resistance. This study evaluates the capacity of MYC to drive platinum resistance and through screening identifies a drug capable of reducing MYC expression and overcoming resistance. Methods: Elevated MYC expression following the acquisition of platinum resistance in vitro and in vivo was assessed. Moreover, the capacity of enforced MYC expression to drive platinum resistance was defined in SCLC cell lines and in a genetically engineered mouse model that expresses MYC specifically in lung tumors. High throughput drug screening was used to identify drugs able to kill MYC-expressing, platinum resistant cell lines. The capacity of this drug to treat SCLC was defined in vivo in both transplant models using cell lines and patient derived xenografts and in combination with platinum and etoposide chemotherapy in an autochthonous mouse model of platinum resistant SCLC. Results: MYC expression is elevated following the acquisition of platinum resistance and constitutively high MYC expression drives platinum resistance in vitro and in vivo. We show that fimepinostat decreases MYC expression and that it is an effective single agent treatment for SCLC in vitro and in vivo. Indeed, fimepinostat is as effective as platinum-etoposide treatment in vivo. Importantly, when combined with platinum and etoposide, fimepinostat achieves a significant increase in survival. Conclusions: MYC is a potent driver of platinum resistance in SCLC that is effectively treated with fimepinostat.

Original languageEnglish
Article number100
Number of pages14
JournalJournal of Experimental and Clinical Cancer Research
Volume42
Issue number1
DOIs
Publication statusPublished - Dec 2023

Keywords

  • Fimepinostat
  • Mouse models
  • MYC
  • Platinum resistance
  • Small cell lung cancer

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