Splicing factor proline- and glutamine-rich (SFPQ) protein regulates platinum response in ovarian cancer-modulating SRSF2 activity

Oncogene. 2020 May;39(22):4390-4403. doi: 10.1038/s41388-020-1292-6. Epub 2020 Apr 24.

Abstract

In epithelial ovarian cancer (EOC), response to platinum (PT)-based chemotherapy dictates subsequent treatments and predicts patients' prognosis. Alternative splicing is often deregulated in human cancers and can be altered by chemotherapy. Whether and how changes in alternative splicing regulation could impact on the response of EOC to PT-based chemotherapy is still not clarified. We identified the splicing factor proline and glutamine rich (SFPQ) as a critical mediator of response to PT in an unbiased functional genomic screening in EOC cells and, using a large cohort of primary and recurrent EOC samples, we observed that it is frequently overexpressed in recurrent PT-treated samples and that its overexpression correlates with PT resistance. At mechanistic level, we show that, under PT treatment, SFPQ, in complex with p54nrb, binds and regulates the activity of the splicing factor SRSF2. SFPQ/p54nrb complex decreases SRSF2 binding to caspase-9 RNA, favoring the expression of its alternative spliced antiapoptotic form. As a consequence, SFPQ/p54nrb protects cells from PT-induced death, eventually contributing to chemoresistance. Overall, our work unveils a previously unreported SFPQ/p54nrb/SRSF2 pathway that in EOC cells plays a central role in regulating alternative splicing and PT-induced apoptosis and that could result in the design of new possible ways of intervention to overcome PT resistance.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Antineoplastic Agents, Alkylating / pharmacology*
  • Antineoplastic Agents, Alkylating / therapeutic use
  • Apoptosis
  • Caspase 8 / metabolism
  • Caspase 9 / genetics
  • Caspase 9 / metabolism
  • Caspase Inhibitors / pharmacology
  • Cell Line, Tumor
  • Cisplatin / pharmacology*
  • Cisplatin / therapeutic use
  • DNA-Binding Proteins / antagonists & inhibitors
  • DNA-Binding Proteins / genetics
  • DNA-Binding Proteins / physiology*
  • Drug Resistance, Neoplasm / drug effects
  • Female
  • Gene Knockdown Techniques
  • Humans
  • Mice
  • Neoplasm Proteins / physiology*
  • Ovarian Neoplasms / drug therapy*
  • Ovarian Neoplasms / metabolism
  • PTB-Associated Splicing Factor / physiology*
  • RNA Splicing
  • RNA, Messenger / metabolism
  • RNA, Neoplasm / metabolism
  • RNA-Binding Proteins / antagonists & inhibitors
  • RNA-Binding Proteins / genetics
  • RNA-Binding Proteins / physiology*
  • Recurrence
  • Serine-Arginine Splicing Factors / physiology*
  • Spliceosomes / metabolism

Substances

  • Antineoplastic Agents, Alkylating
  • Caspase Inhibitors
  • DNA-Binding Proteins
  • NONO protein, human
  • Neoplasm Proteins
  • PTB-Associated Splicing Factor
  • RNA, Messenger
  • RNA, Neoplasm
  • RNA-Binding Proteins
  • SRSF2 protein, human
  • Serine-Arginine Splicing Factors
  • CASP8 protein, human
  • Caspase 8
  • Caspase 9
  • Cisplatin