1. Assessing expression patterns of PTGR1, a potential biomarker for acylfulven sensitivity in urothelial carcinoma.
- Author
-
Stormoen DR, Lehn S, Mouw KW, Szallasi Z, Melchior LC, Dohn LH, Börcsok J, Rossing M, Toft BG, and Pappot H
- Subjects
- Humans, Male, Female, Aged, Middle Aged, Prognosis, Cell Line, Tumor, Urinary Bladder Neoplasms genetics, Urinary Bladder Neoplasms pathology, Urinary Bladder Neoplasms metabolism, Urinary Bladder Neoplasms mortality, Retrospective Studies, Aged, 80 and over, Gene Expression Regulation, Neoplastic, Carcinoma, Transitional Cell genetics, Carcinoma, Transitional Cell metabolism, Carcinoma, Transitional Cell pathology, Carcinoma, Transitional Cell mortality, Immunohistochemistry methods, Mutation, Biomarkers, Tumor metabolism, Biomarkers, Tumor genetics
- Abstract
Background: Metastatic urothelial carcinoma (mUC) has a poor prognosis, despite recent therapeutic advancements. Prostaglandin Reductase 1 (PTGR1) is essential for activating acylfulvens, a promising class of drugs for treating a subset of urothelial carcinoma (UC) patients. The efficacy of acylfulvens depends on PTGR1 activity and defects in the nucleotide excision repair (NER) pathway, notably ERCC2 mutations present in 10-15% of bladder tumors. This study identifies patients eligible to be included in acylfulven clinical trials based on the presence of PTGR-1 by immunohistochemistry (IHC) staining, RNA expression level and mutations in the NER pathway. Additionally, it evaluates PTGR-1 expression as a prognostic biomarker., Methods: Three PTGR-1 antibodies were tested in a kidney cancer cell line A498 and in tissues with known PTGR1 expression (liver, tonsils, pancreas, small intestine, etc.). Patients with untreated mUC receiving 1st line platinum from Dec. 2019 to Dec. 2021 in the Capital Region, Denmark, were included retrospectively. FFPE tumor samples were collected, and tissue microarrays (TMAs) were constructed. TMAs were stained with the best-performing PTGR1 antibody, RNA expression was analyzed using Nanostring nCounter PanCancer panel and gene mutations were assessed using a targeted genomic panel (TSO-500). Kaplan-Meier and multivariate Cox regression assessed overall survival and covariate impacts., Results: The AB181131 PTGR1 antibody was the most reliable in validation tissues. Tumors from 71 mUC patients were used to construct the TMA, and 40% of tumors scored positive for PTGR1 by IHC staining. A normalized PTGR1 RNA cutoff at 2,550 normalized counts achieved an AUC of 0.9, defining 35 samples as positive with a sensitivity of 96% and specificity of 85% in relation to IHC-positivity. Differential expression showed a significant upregulation of PTGR1 RNA in PTGR1 IHC-positive cases. NER-deficiency and PTGR1 positivity (mutations in ERCC1, ERCC2, ERCC3, ERCC4) was seen in 9 patients (13%). Median overall survival was 16 months in the cohort. Overall survival (OS) analysis indicates that overexpression of PTGR1 RNA was associated with a reduced median OS (12 months vs. 25 months, p = 0.039, log-rank)., Conclusion: PTGR1 IHC staining pattern using the Abcam AB181131 antibody is highly correlated with PTGR1 RNA expression. 13% in our cohort were identified as NER deficient and PTGR1 positive. Lower levels of PTGR1 indicates better outcome in this cohort., Competing Interests: Declarations Competing interests The authors declare no competing interests. Conflict of interest D.R.S. received educational and research funding from Pfizer and Merck Serono and served on advisory boards for Merck Sharp and Dome (MSD), Bristol Meyers Squibb (BMS), and Johnson and Johnson, unrelated to this study. S.L. No COI to report. B.G.T. Speaker fee from BMS unrelated to this study. L.H.D: No COI to report. L.C.M.: No COI to report. Z.S: Research funding from Lantern Pharma Inc; M.R: received personal fees from AstraZeneca and MSD and served on advisory board of MSD outside the submitted work.; H.P: Research funding from Pfizer and Merck unrelated to this study. K.W.M: Advisory/consulting work for EMD Serono, Pfizer, UroGen, and Riva Therapeutics; has received research support from Pfizer and Novo Ventures; has equity in Riva Therapeutics; has received writing/editor fees from UpToDate; has received speaking fees from OncLive; and is a co-inventor listed on an institutional patent application for analysis of mutational signatures of DNA repair deficiency., (© 2024. The Author(s).)
- Published
- 2024
- Full Text
- View/download PDF