20.500.12556/DiRROS-29262 Thymidine kinase as a biomarker of chemoresistance in epithelial ovarian cancer using the KELIM model Background: Ovarian cancer (OC) remains the most lethal gynecological malignancy, with platinum sensitivity being a key determinant of treatment outcomes. The KELIM model, derived from CA-125 kinetics, is a promising biomarker for predicting chemosensitivity. Thymidine kinase 1 (TK1), a proliferation marker, has shown relevance in various cancers but its role in chemotherapy response for OC is unclear.Methods: In this retrospective study, we assessed the association between TK1 protein (TK1p) and enzymatic activity (TK1a) and chemosensitivity (KELIM), platinum-free interval (PFI), and chemotherapy response score (CRS) in 28 patients with epithelial OC treated with platinum-based chemotherapy. Biomarker dynamics were measured at multiple timepoints. KELIM was calculated using CA-125 kinetics; relationships with CRS and PFI were evaluated.Results: KELIM demonstrated robust predictive performance (correlating with favorable CRS [rho = 0.731, p = 0.011] and longer PFI [rho = 0.437, p = 0.007]). TK1p and TK1a showed no significant correlations with KELIM, PFI, or CRS. ROC analysis for preoperative TK1p yielded an AUC of 0.6941, indicating moderate discriminative potential. TK1a increased postoperatively but lacked predictive value for chemoresistance.Conclusion: Our findings reinforce the value of KELIM as a reliable predictor of platinum sensitivity in OC. TK1 dynamics reflect tumor proliferation but did not significantly predict chemotherapy response. Larger cohorts and further research are required to explore whether TK1 can complement established biomarkers. biomarker CA-125 chemoresistance epithelial ovarian cancer KELIM ovarian cancer thymidine kinase biomarkerji CA-125 kemorezistentnost epitelijski rak jajčnikov KELIM rak jajčnikov timidin kinaza true false true Angleški jezik Slovenski jezik Neznano 2026-05-05 10:42:12 2026-05-05 10:42:12 2026-05-06 03:51:47 0000-00-00 00:00:00 2026 0 0 Nasl. z nasl. zaslona; Opis vira z dne 4. 5. 2026; 11 str. [article no.] ǂ1617484 Vol. 17 2026 0000-00-00 Zaloznikova Objavljeno NiDoloceno 0000-00-00 0000-00-00 0000-00-00 616-006:618.11 1663-9812 10.3389/fphar.2026.1617484 276854531 RAZ_Lukanovic_David_2026.pdf RAZ_Lukanovic_David_2026.pdf 1 354821780B8AECCBCB4EA984CDFB1CFF 2eeefc18c11ad6b1f37bd19869e8b252f9c5755a50551ec333bf44b4b5b31e3d 76830969-485e-11f1-969d-001a4af901a5 https://dirros.openscience.si/Dokument.php?lang=slv&id=43787 https://www.frontiersin.org/journals/pharmacology/articles/10.3389/fphar.2026.1617484/full 1 51101b84-485e-11f1-969d-001a4af901a5 https://dirros.openscience.si/Dokument.php?lang=slv&id=43786 Univerzitetni klinični center Ljubljana 0 0 0