{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,10,22]],"date-time":"2026-10-22T15:41:30Z","timestamp":1792683690101,"version":"4.5.0"},"reference-count":0,"publisher":"The Scientific and Technological Research Council of Turkey (TUBITAK-ULAKBIM) - DIGITAL COMMONS JOURNALS","issue":"6","content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Turkish Journal of Medical Sciences"],"abstract":"<jats:p>Background\/aim: Intravesical BCG treatment fails inexplicably in 30%-45% of patients for high-grade nonmuscle-invasive bladder cancer (NMIBC). We aimed to investigate the role of PD-1\/PD-L1 interaction on BCG failure of high-grade NMIBC and to identify biomarkers for predicting BCG responsive cases. Materials and methods: Thirty BCG responsive and 29 nonresponsive NMIBCs were included in the study. Expressions of PDL1(SP-263), MSH2, MSH6, PMS2, and MLH1 were evaluated on pre- and post-BCG transurethral resection (TUR-B) specimens by immunohistochemistry. PD-L1(SP-263) expression was categorised as negative\/low, high. DNA mismatch repair protein (MMR) expressions were classified as 'reduced' if \u226430% of nuclei stained, 'preserved' if &gt;30% of nuclei stained. Microsatellite instability (MSI) testing was performed by PCR using five mononucleotide markers. Results: Reduced DNA MMR protein expression was found to be significantly higher in the pretreatment biopsies of BCG-responsive group than the BCG nonresponsive tumour group (p = 0.022). PD-L1 expression did not show any significant difference between the pre- and posttreatment TUR-B specimens of the BCG nonresponsive tumour group or between the pretreatment TUR-B specimens of BCG nonresponsive and the BCG responsive groups (p = 0.508, p = 0.708, respectively). Conclusion: Immune escape of tumour cells by PD-1\/PD-L1 interaction does not seem to have any role in BCG failure of NMIBCs. Reduced MMR expression may help to determine cases that will respond well to BCG therapy. A better antitumour activity of BCG in NMIBCs with reduced MMR expression may be related to the ongoing accumulation of cancer neoantigens in correlation with increased tumour mutation load as a result of DNA repair defects.<\/jats:p>","DOI":"10.55730\/1300-0144.5526","type":"journal-article","created":{"date-parts":[[2022,12,23]],"date-time":"2022-12-23T07:37:00Z","timestamp":1671781020000},"page":"1802-1813","source":"Crossref","is-referenced-by-count":0,"title":["Role of PD-1\/PD-L1-mediated tumour immune escape mechanism and microsatellite instability in the BCG failure of high-grade urothelial carcinomas"],"prefix":"10.55730","volume":"52","author":[{"given":"FAD\u0130ME G\u00dcL","family":"SALMAN","sequence":"first","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"DUYGU","family":"KANKAYA","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"H\u0130LAL","family":"\u00d6ZAKINCI","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"YASEM\u0130N","family":"\u015eAH\u0130N","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"ERALP","family":"KUB\u0130LAY","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"EVREN","family":"S\u00dcER","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"SERHAT","family":"HAYME","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"S\u00dcMER","family":"BALTACI","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"34691","published-online":{"date-parts":[[2022,1,1]]},"container-title":["Turkish Journal of Medical Sciences"],"original-title":[],"language":"en","deposited":{"date-parts":[[2026,10,22]],"date-time":"2026-10-22T14:57:31Z","timestamp":1792681051000},"score":1,"resource":{"primary":{"URL":"https:\/\/journals.tubitak.gov.tr\/medical\/vol52\/iss6\/9"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2022,1,1]]},"references-count":0,"journal-issue":{"issue":"6","published-online":{"date-parts":[[2022,1,1]]}},"URL":"https:\/\/doi.org\/10.55730\/1300-0144.5526","relation":{},"ISSN":["1300-0144"],"issn-type":[{"value":"1300-0144","type":"electronic"}],"subject":[],"published":{"date-parts":[[2022,1,1]]}}}