Hoskin, Peter J
West, Catharine M L
Illidge, Timothy M
AffiliationDivision of Cancer Sciences, University of Manchester, M20 4BX, Manchester, UK
MetadataShow full item record
AbstractIntroduction: Recent data has demonstrated that hypoxia drives an immunosuppressive tumour microenvironment (TME) via various mechanisms including hypoxia inducible factor (HIF)-dependent upregulation of programmed death ligand 1 (PD-L1). Both hypoxia and an immunosuppressive TME are targetable independent negative prognostic factors for bladder cancer. Therefore we sought to investigate whether hypoxia is associated with upregulation of PD-L1 in the disease. Materials and methods: Three human muscle-invasive bladder cancer cell lines (T24, J82, UMUC3) were cultured in normoxia (20% oxygen) or hypoxia (1 and 0.1% oxygen) for 24 h. Differences in PD-L1 expression were measured using Western blotting, quantitative polymerase chain reaction (qPCR) and flow cytometry (≥3 independent experiments). Statistical tests performed were unpaired t tests and ANOVA. For in silico work an hypoxia signature was used to apply hypoxia scores to muscle-invasive bladder cancers from a clinical trial (BCON; n = 142) and TCGA (n = 404). Analyses were carried out using R and RStudio and statistical tests performed were linear models and one-way ANOVA. Results: When T24 cells were seeded at < 70% confluence, there was decreased PD-L1 protein (p = 0.009) and mRNA (p < 0.001) expression after culture in 0.1% oxygen. PD-L1 protein expression decreased in both 0.1% oxygen and 1% oxygen in a panel of muscle-invasive bladder cancer cells: T24 (p = 0.009 and 0.001), J82 (p = 0.008 and 0.013) and UMUC3 (p = 0.003 and 0.289). Increasing seeding density decreased PD-L1 protein (p < 0.001) and mRNA (p = 0.001) expression in T24 cells grown in both 20 and 1% oxygen. Only when cells were 100% confluent, were PD-L1 protein and mRNA levels higher in 1% versus 20% oxygen (p = 0.056 and p = 0.037). In silico analyses showed a positive correlation between hypoxia signature scores and PD-L1 expression in both BCON (p = 0.003) and TCGA (p < 0.001) cohorts, and between hypoxia and IFNγ signature scores (p < 0.001 for both). Conclusion: Tumour hypoxia correlates with increased PD-L1 expression in patient derived bladder cancer tumours. In vitro PD-L1 expression was affected by cell density and decreased PD-L1 expression was observed after culture in hypoxia in muscle-invasive bladder cancer cell lines. As cell density has such an important effect on PD-L1 expression, it should be considered when investigating PD-L1 expression in vitro.
CitationSmith V, Mukherjee D, Lunj S, Choudhury A, Hoskin P, West C, et al. The effect of hypoxia on PD-L1 expression in bladder cancer Vol. 21, BMC Cancer. Springer Science and Business Media LLC; 2021.
- Effects of programmed death-ligand 1 expression on OK-432 immunotherapy following transurethral resection in non-muscle invasive bladder cancer.
- Authors: Liu ZH, Zheng FF, Mao YL, Ye LF, Bian J, Lai DH, Ye YL, Dai YP
- Issue date: 2017 Jun
- Shuyu pills inhibit immune escape and enhance chemosensitization in hepatocellular carcinoma.
- Authors: Deng Z, Teng YJ, Zhou Q, Ouyang ZG, Hu YX, Long HP, Hu MJ, Mei S, Lin FX, Dai XJ, Zhang BY, Feng T, Tian XF
- Issue date: 2021 Nov 15
- Expression of programmed death-ligand 1 and hypoxia-inducible factor-1α proteins in endometrial carcinoma.
- Authors: Tawadros AIF, Khalafalla MMM
- Issue date: 2018 Dec
- Prognostic significance of the programmed death ligand 1 expression in clear cell renal cell carcinoma and correlation with the tumor microenvironment and hypoxia-inducible factor expression.
- Authors: Tatli Dogan H, Kiran M, Bilgin B, Kiliçarslan A, Sendur MAN, Yalçin B, Ardiçoglu A, Atmaca AF, Gumuskaya B
- Issue date: 2018 Aug 25
- Correlation between messenger RNA expression and protein expression of immune checkpoint-associated molecules in bladder urothelial carcinoma: A retrospective study.
- Authors: Le Goux C, Damotte D, Vacher S, Sibony M, Delongchamps NB, Schnitzler A, Terris B, Zerbib M, Bieche I, Pignot G
- Issue date: 2017 May