A multi-omics approach to understanding the tumour microenvironment in non-muscle invasive bladder cancer and its response to BCG immunotherapy
Creators: name: Wooldridge, Tyler Floyd
Publisher: name: University of Surrey
Year: 2023

description: Bladder cancer (BC) is the 10th most common cancer world-wide with an estimated 570,000+ people
description: being diagnosed in 2020. BC can be broadly subdivided into non-muscle invasive (NMI) and muscle
description: invasive (MI) BC, with further subdivisions of low-grade and high-grade disease. A common
description: immunotherapeutic treatment for HG NMIBC is intravesical Bacillus Calmette-Guerin (BCG) vaccine,
description: following tumour resection. Although this post-surgical instillation regime has shown to dramatically
description: reduce the likelihood of disease recurrence, some 30-40% of patients fail to clinically respond to BCG
description: therapy. Additionally, the exact immunotherapeutic mechanism and factors affecting efficacy are yet
description: to be fully elucidated. From this, we postulate that gaining a deeper understanding of the tumour
description: microenvironment, via a holistic multi-omics approach, will provide valuable insight into these factors.<br>
description: <br>
description: Bacterial signatures within patient catheterised urine (n=67) and FFPE tissues (n=72), (matching
description: patients n=44), were determined using 16s rRNA sequencing, processed through QIIME2 and clustered
description: into Operational Taxonomic Units (OTUs). Alpha (Shannon and observed) and Beta (Bray-Curtis)
description: diversity analysis was performed. RNA extracted from FFPE BC tissues (n=106) generated gene
description: expression data using the Nanostring IO360 panel (770 gene CodeSet). 9-colour multiplex
description: immunohistochemistry (mIHC) using PhenoimagerHT (Akoya Biosciences) was performed to
description: investigate and spatially define immune cell types within the TME (n=75). Urine specimens (n=69)
description: underwent investigation of 23 cytokines using the IsoSpark proteomics systems (IsoPlexis). Patient
description: FFPE tissues and urines were derived from Royal Surrey County Hospital, Guildford, UK, with medical
description: histories, questionnaires, and NHS histopathologist assistances for sample validation.<br>
description: <br>
description: Results revealed via using mIHC, that BCG non-responders may have an innate immunosuppressive
description: TME (increased PD-L1+, higher Tregs counts, closer proximities of Treg:CD8+ and Treg:NK cells) at
description: baseline before BCG immunotherapy compared to BCG responders. Gene expression data suggests
description: that genes involved in mast cell activation (SPP1 and C5AR1) may have a role in BCG response, with
description: differential gene expression of samples positive for LPS (bacterial marker) showing an upregulation in
description: mast cells count. Bacterial analysis showed a decrease in bacterial diversity with increasing disease
description: progression, alongside an increased population of anaerobic taxa. Urine specimens was shown to be
description: an unreliable proxy for the bacteria composition in matched FFPE tissues. Linear discrimination
description: analysis showed an increase in Pseudomonas, Vibrio and Kocuria, amongst others in the treatment
description: naïve known BCG responder cohort. Cytokine analysis suggests BCG responders have elevated levels
description: of various pro-inflammatory cytokines at baseline compared to BCG non-responders.<br>
description: <br>
description: Ultimately, these findings will aid in our understanding of the BC TME and possibly lead to better
description: patient treatment stratification, novel therapeutic targets, and improved therapeutic outputs.<br>