J Cancer 2019; 10(5):1154-1161. doi:10.7150/jca.29052 This issue

Research Paper

PD-L1 expression patterns in tumour cells and their association with CD8+ tumour infiltrating lymphocytes in clear cell renal cell carcinoma

Qian Zhu1,2, Mu-Yan Cai1,3, De-Sheng Weng1,2, Jing-Jing Zhao1,2, Qiu-Zhong Pan1,2, Qi-Jing Wang1,2, Yan Tang1,2, Jia He1,2, Min Li1,3, Jian-Chuan Xia1,2✉

1. Collaborative Innovation Center for Cancer Medicine, State Key Laboratory of Oncology in South China, Sun Yat-Sen University Cancer Center, Guangzhou, P. R. China
2. Department of Biotherapy, Sun Yat-Sen University Cancer Center, Guangzhou 510060, People's Republic of China
3. Department of Pathology, Sun Yat-Sen University Cancer Center, Guangzhou 510060, People's Republic of China

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Citation:
Zhu Q, Cai MY, Weng DS, Zhao JJ, Pan QZ, Wang QJ, Tang Y, He J, Li M, Xia JC. PD-L1 expression patterns in tumour cells and their association with CD8+ tumour infiltrating lymphocytes in clear cell renal cell carcinoma. J Cancer 2019; 10(5):1154-1161. doi:10.7150/jca.29052. Available from https://www.jcancer.org/v10p1154.htm

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Abstract

Purpose: To evaluate the tumour cell PD-L1 (TC-PD-L1) expression patterns in the local microenvironment of clear cell renal cell carcinoma (ccRCC).

Materials and Methods: 30 fresh primary ccRCC tissues were used to detect the association between TC-PD-L1 and CD8+TILs at mRNA level. The in vitro incubation experiment was used to confirm the association between extrinsic TC-PD-L1 expression and IFNγ. A cohort of 135 ccRCC patients treated between January 2009 and August 2013 was included for survival analysis.

Results: Our results confirmed that ccRCC cell lines were capable of expressing PD-L1. The incubation experiment in vitro demonstrated the positive correlation of TC-PD-L1 expression with interferon-gamma (IFNγ). Additionally, survival analysis was investigated in 135 ccRCC patients and found no independent correlation of TC-PD-L1 expression in multivariate analysis, whereas more distinct prognostic differences were detected when TC-PD-L1-positive ccRCC were sub-classified as with or without CD8+ T cell infiltration.

Conclusion: The intrinsic and extrinsic expression patterns are both detected in ccRCC. High positive rate of TC-PD-L1 correlated closely to the strong infiltration of CD8+ TILs. TC-PD-L1-positive ccRCC patients with abundant CD8+ TILs infiltration confer the high risk of death and disease relapse.

Keywords: PD-L1, local microenvironment, intrinsic expression, extrinsic expression, clear cell renal cell carcinoma