TLR4 predicts patient prognosis and immunotherapy efficacy in clear cell renal cell carcinoma

Zhentao Zhang; Shuo Wang; Ye Lu; Demeng Xia; Ying Liu

doi:10.7150/jca.84502

TLR4 predicts patient prognosis and immunotherapy efficacy in clear cell renal cell carcinoma

J Cancer. 2023 Jul 16;14(12):2181-2197. doi: 10.7150/jca.84502. eCollection 2023.

Authors

Zhentao Zhang¹, Shuo Wang², Ye Lu³, Demeng Xia⁴, Ying Liu⁵

Affiliations

¹ College of Basic Medicine, Naval Medical University, Shanghai 200433, China.
² Naval Hospital of Eastern Theater of PLA, Zhoushan, Zhejiang 316000, China.
³ Department of Anesthesiology, Second Affiliated Hospital of Naval Medical University, Shanghai 200433, China.
⁴ Department of Pharmacy, Seventh People's Hospital of Shanghai University of Traditional Chinese Medicine, Shanghai 200433, China.
⁵ Institute of Translational Medicine, Shanghai University, Shanghai, 201900, China.

Abstract

Background: Clear cell renal cell carcinoma (ccRCC) constitutes the commonest kidney malignancy. Immunogenic cell death (ICD) is a type of regulated cell death (RCD), which sufficiently activates adaptive immunity. However, ICD's involvement in cancer development is unclear, as well as the associations of ICD effectors with ccRCC prognosis. Methods: RNA-sequencing expression profiles of ccRCC in The Cancer Genome Atlas (TCGA) and normal samples in Gene Expression Omnibus (GEO) were comprehensively investigated. Consensus clustering analysis was employed to determine subgroup members linked to ICD-related genes. Functional enrichment analysis was utilized for the examination of TLR4's biological role, and in vitro cellular assays were utilized for further confirmation. We also used Kaplan-Meier (KM) and Cox regression analyses to assess TLR4's prognostic value. Finally, "CIBERSORT" was employed for immune score evaluation. Results: The associations of ICD effectors with ccRCC prognosis were examined based on TCGA, and 12 genes showed upregulation in ccRCC tissue specimens. Meanwhile, ccRCC cases with upregulated ICD-related genes had increased overall survival. Among these ICD-related genes, TLR4 was selected for subsequent analysis. TLR4 was upregulated in ccRCC samples and independently predicted ccRCC. TLR4 also enhanced the proliferative, migratory and invasive abilities in cultured ccRCC cells. Moreover, TLR4 had close relationships with immune checkpoints and infiltrated immune cells. ccRCC cases with elevated TLR4 expression had prolonged overall survival, suggesting a prognostic value for TLR4. Finally, a pan-cancer analysis demonstrated TLR4 had differential expression in various malignancies in comparison with normal tissue samples. Conclusions: This study revealed prognostic values for ICD-associated genes, particularly TLR4, and experimentally validated the inducing effects of TLR4 on ccRCC progression in vitro. We also demonstrated the associations of TLR4 with immune cell infiltration, providing a novel strategy for prognostic evaluation and a novel therapeutic target in ccRCC.

Keywords: Clear cell Renal cell carcinoma; Immune cell infiltration; Immunogenic cell death; TLR4.