PD37-11 TROPOMYOSIN ISOFORM SWITCHING IN UROTHELIAL BLADDER CANCER AS A DIAGNOSTIC BIOMARKER

Abstract

You have accessJournal of UrologyBladder Cancer: Basic Research & Pathophysiology I (PD37)1 Sep 2021PD37-11 TROPOMYOSIN ISOFORM SWITCHING IN UROTHELIAL BLADDER CANCER AS A DIAGNOSTIC BIOMARKER Nada Humayun-Zakaria, Douglas Ward, Ben Abbotts, Maurice Zeegers, KK Cheng, Nick James, Richard Bryan, and Roland Arnold Nada Humayun-ZakariaNada Humayun-Zakaria More articles by this author , Douglas WardDouglas Ward More articles by this author , Ben AbbottsBen Abbotts More articles by this author , Maurice ZeegersMaurice Zeegers More articles by this author , KK ChengKK Cheng More articles by this author , Nick JamesNick James More articles by this author , Richard BryanRichard Bryan More articles by this author , and Roland ArnoldRoland Arnold More articles by this author View All Author Informationhttps://doi.org/10.1097/JU.0000000000002047.11AboutPDF ToolsAdd to favoritesDownload CitationsTrack CitationsPermissionsReprints ShareFacebookLinked InTwitterEmail Abstract INTRODUCTION AND OBJECTIVE: The urgent unmet need for biomarker discovery for the early detection and surveillance of bladder cancer in parallel with advancements in high throughput sequencing has fuelled understanding of molecular biology and pathology, paving the way for ‘precision medicine’. Transcriptomic analyses of Tropomyosin (TPM) have revealed differential expression of isoforms with ‘isoform switching’ in the presence of urothelial bladder cancer (UBC) making them promising candidates as diagnostic biomarkers. METHODS: RNA-sequence quantification was performed on 3 cancer datasets (Cancer Cell Line Encyclopaedia (CCLE), The Cancer Genome Atlas (TCGA) and West Midland’s Bladder Cancer Prognosis Program (BCPP)) and one non-cancer dataset (GEO Accession number GSE133624) using a bespoke bioinformatics pipeline – ‘IsoTPM’. Wilcoxon rank sum determined p-values for pairwise-comparison of isoform expression in cancer vs non-cancer. Subsequent qPCR analysis with isoform-specific primers was performed on in-house CCLE cell lines followed by Sanger sequencing. Evaluation of TPM isoform expression at protein level was achieved using mass spectrometry (MS) on CCLE and BCPP samples to delineate peptides of interest. RESULTS: The differential expression (DE) of two TPM1 isoforms, TPM1-201 and TPM1-206, appeared as dominant transcripts in non-cancer and cancer datasets, respectively. TPM4 analyses revealed high abundance of TPM4-218 in cancer datasets in comparison to TPM4-221 found exclusively in non-cancer. Additionally, TPM4-205 was expressed in non-muscle-invasive tumours (BCPP). qPCR analysis showed the relative expressions of TPM1-206 and TPM4-218 in a range of cell lines. MS revealed ∼20 peptides, including splice-junction exons from TPM4-218 and TPM1-206, from both cancer datasets (BCPP and CCLE). CONCLUSIONS: Comparative analysis of non-cancer and cancer datasets demonstrates that TPM1-201 isoform switching to TPM1-206 accompanies early bladder tumorigenesis and/or epithelial-mesenchymal-transition (EMT). TPM4-218 is upregulated in all cancer datasets accompanied by downregulation of TPM4-221 also suggesting an association with bladder tumorigenesis. Source of Funding: QEHB charities funded NH-Z's research © 2021 by American Urological Association Education and Research, Inc.FiguresReferencesRelatedDetails Volume 206Issue Supplement 3September 2021Page: e659-e660 Advertisement Copyright & Permissions© 2021 by American Urological Association Education and Research, Inc.MetricsAuthor Information Nada Humayun-Zakaria More articles by this author Douglas Ward More articles by this author Ben Abbotts More articles by this author Maurice Zeegers More articles by this author KK Cheng More articles by this author Nick James More articles by this author Richard Bryan More articles by this author Roland Arnold More articles by this author Expand All Advertisement Loading ...