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Article: p85β alters response to EGFR inhibitor in ovarian cancer through p38 MAPK-mediated regulation of DNA repair

Titlep85β alters response to EGFR inhibitor in ovarian cancer through p38 MAPK-mediated regulation of DNA repair
Authors
KeywordsEpidermal growth factor receptor
Erlotinib
PI3K
p85 regulatory subunit
DNA repair
p38 MAPK
Issue Date2021
PublisherElsevier Inc. The Journal's web site is located at http://www.neoplasia.org
Citation
Neoplasia, 2021, v. 23 n. 7, p. 718-730 How to Cite?
AbstractEGFR signaling promotes ovarian cancer tumorigenesis, and high EGFR expression correlates with poor prognosis. However, EGFR inhibitors alone have demonstrated limited clinical benefit for ovarian cancer patients, owing partly to tumor resistance and the lack of predictive biomarkers. Cotargeting EGFR and the PI3K pathway has been previously shown to yield synergistic antitumor effects in ovarian cancer. Therefore, we reasoned that PI3K may affect cellular response to EGFR inhibition. In this study, we revealed PI3K isoform-specific effects on the sensitivity of ovarian cancer cells to the EGFR inhibitor erlotinib. Gene silencing of PIK3CA (p110α) and PIK3CB (p110β) rendered cells more susceptible to erlotinib. In contrast, low expression of PIK3R2 (p85β) was associated with erlotinib resistance. Depletion of PIK3R2, but not PIK3CA or PIK3CB, led to increased DNA damage and reduced level of the nonhomologous end joining DNA repair protein BRD4. Intriguingly, these defects in DNA repair were reversed upon erlotinib treatment, which caused activation and nuclear import of p38 MAPK to promote DNA repair with increased protein levels of 53BP1 and BRD4 and foci formation of 53BP1. Remarkably, inhibition of p38 MAPK or BRD4 re-sensitized PIK3R2-depleted cells to erlotinib. Collectively, these data suggest that p38 MAPK activation and the subsequent DNA repair serve as a resistance mechanism to EGFR inhibitor. Combined inhibition of EGFR and p38 MAPK or DNA repair may maximize the therapeutic potential of EGFR inhibitor in ovarian cancer.
Persistent Identifierhttp://hdl.handle.net/10722/308452
ISSN
2023 Impact Factor: 6.3
2023 SCImago Journal Rankings: 1.887
PubMed Central ID
ISI Accession Number ID

 

DC FieldValueLanguage
dc.contributor.authorMak, VCY-
dc.contributor.authorLi, X-
dc.contributor.authorRao, L-
dc.contributor.authorZhou, Y-
dc.contributor.authorTsao, SW-
dc.contributor.authorCheung, LWT-
dc.date.accessioned2021-12-01T07:53:32Z-
dc.date.available2021-12-01T07:53:32Z-
dc.date.issued2021-
dc.identifier.citationNeoplasia, 2021, v. 23 n. 7, p. 718-730-
dc.identifier.issn1476-5586-
dc.identifier.urihttp://hdl.handle.net/10722/308452-
dc.description.abstractEGFR signaling promotes ovarian cancer tumorigenesis, and high EGFR expression correlates with poor prognosis. However, EGFR inhibitors alone have demonstrated limited clinical benefit for ovarian cancer patients, owing partly to tumor resistance and the lack of predictive biomarkers. Cotargeting EGFR and the PI3K pathway has been previously shown to yield synergistic antitumor effects in ovarian cancer. Therefore, we reasoned that PI3K may affect cellular response to EGFR inhibition. In this study, we revealed PI3K isoform-specific effects on the sensitivity of ovarian cancer cells to the EGFR inhibitor erlotinib. Gene silencing of PIK3CA (p110α) and PIK3CB (p110β) rendered cells more susceptible to erlotinib. In contrast, low expression of PIK3R2 (p85β) was associated with erlotinib resistance. Depletion of PIK3R2, but not PIK3CA or PIK3CB, led to increased DNA damage and reduced level of the nonhomologous end joining DNA repair protein BRD4. Intriguingly, these defects in DNA repair were reversed upon erlotinib treatment, which caused activation and nuclear import of p38 MAPK to promote DNA repair with increased protein levels of 53BP1 and BRD4 and foci formation of 53BP1. Remarkably, inhibition of p38 MAPK or BRD4 re-sensitized PIK3R2-depleted cells to erlotinib. Collectively, these data suggest that p38 MAPK activation and the subsequent DNA repair serve as a resistance mechanism to EGFR inhibitor. Combined inhibition of EGFR and p38 MAPK or DNA repair may maximize the therapeutic potential of EGFR inhibitor in ovarian cancer.-
dc.languageeng-
dc.publisherElsevier Inc. The Journal's web site is located at http://www.neoplasia.org-
dc.relation.ispartofNeoplasia-
dc.rightsThis work is licensed under a Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International License.-
dc.subjectEpidermal growth factor receptor-
dc.subjectErlotinib-
dc.subjectPI3K-
dc.subjectp85 regulatory subunit-
dc.subjectDNA repair-
dc.subjectp38 MAPK-
dc.titlep85β alters response to EGFR inhibitor in ovarian cancer through p38 MAPK-mediated regulation of DNA repair-
dc.typeArticle-
dc.identifier.emailMak, VCY: vicmak8@hku.hk-
dc.identifier.emailZhou, Y: yzhou@hku.hk-
dc.identifier.emailTsao, SW: gswtsao@hku.hk-
dc.identifier.emailCheung, LWT: lydiacwt@hku.hk-
dc.identifier.authorityTsao, SW=rp00399-
dc.identifier.authorityCheung, LWT=rp02137-
dc.description.naturepublished_or_final_version-
dc.identifier.doi10.1016/j.neo.2021.05.009-
dc.identifier.pmid34144267-
dc.identifier.pmcidPMC8220107-
dc.identifier.scopuseid_2-s2.0-85108014415-
dc.identifier.hkuros330468-
dc.identifier.volume23-
dc.identifier.issue7-
dc.identifier.spage718-
dc.identifier.epage730-
dc.identifier.isiWOS:000668101100007-
dc.publisher.placeUnited States-

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