A Novel Epigenetic Strategy to Concurrently Block Immune Checkpoints PD-1/PD-L1 and CD155/TIGIT in Hepatocellular Carcinoma

Reem A Assal; Noha M Elemam; Radwa Y Mekky; Abdelrahman A Attia; Aya Hesham Soliman; Asmaa Ibrahim Gomaa; Eleni K Efthimiadou; Maria Braoudaki; Sherif Ashraf Fahmy; Rana A Youness

doi:10.1016/j.tranon.2024.101961

A Novel Epigenetic Strategy to Concurrently Block Immune Checkpoints PD-1/PD-L1 and CD155/TIGIT in Hepatocellular Carcinoma

Transl Oncol. 2024 Apr 16:45:101961. doi: 10.1016/j.tranon.2024.101961. Online ahead of print.

Authors

Affiliations

¹ Department of Pharmacology and Toxicology, Heliopolis University for Sustainable Development, Cairo-Ismailia Desert Road, 11785, Cairo, Egypt.
² Clinical Sciences Department, College of Medicine, University of Sharjah, 27272, Sharjah, United Arab Emirates; Research Institute for Medical and Health Sciences, University of Sharjah, 27272, Sharjah, United Arab Emirates.
³ Department of Pharmacology and Toxicology, Faculty of Pharmacy, October University for Modern Sciences and Arts (MSA University), Cairo, Egypt.
⁴ General Surgery Department, Ain Shams University, Demerdash Hospital, Cairo, Egypt.
⁵ Pharmaceutical Biology Department, Faculty of Pharmacy and Biotechnology, German University in Cairo, 11835, Cairo, Egypt.
⁶ Department of Hepatology, National Liver Institute, Menoufiya University, Shebin El-Kom, Egypt.
⁷ Inorganic Chemistry Laboratory, Chemistry Department, National and Kapodistrian University of Athens, Athens, Greece.
⁸ Department of Clinical, Pharmaceutical, and Biological Science, School of Life and Medical Sciences, University of Hertfordshire, Hatfield AL10 9AB, UK.
⁹ Chemistry Department, School of Life and Medical Sciences, University of Hertfordshire Hosted by Global Academic Foundation, New Administrative Capital, 11835, Cairo, Egypt.
¹⁰ Pharmaceutical Biology Department, Faculty of Pharmacy and Biotechnology, German University in Cairo, 11835, Cairo, Egypt; Molecular Biology and Biochemistry Department, Molecular Genetics Research Team (MGRT), Faculty of Biotechnology, German International University (GIU), New Administrative Capital, 11835, Cairo, Egypt. Electronic address: rana.youness21@gmail.com.

Abstract

Tumor microenvironment is an intricate web of stromal and immune cells creating an immune suppressive cordon around the tumor. In hepatocellular carcinoma (HCC), Tumor microenvironment is a formidable barrier towards novel immune therapeutic approaches recently evading the oncology field. In this study, the main aim was to identify the intricate immune evasion tactics mediated by HCC cells and to study the epigenetic modulation of the immune checkpoints; Programmed death-1 (PD-1)/ Programmed death-Ligand 1 (PD-L1) and T cell immunoreceptor with Ig and ITIM domains (TIGIT)/Cluster of Differentiation 155 (CD155) at the tumor-immune synapse. Thus, liver tissues, PBMCs and sera were collected from Hepatitis C Virus (HCV), HCC as well as healthy individuals. Screening was performed to PD-L1/PD-1 and CD155/TIGIT axes in HCC patients. PDL1, CD155, PD-1 and TIGIT were found to be significantly upregulated in liver tissues and peripheral blood mononuclear cells (PBMCs) of HCC patients. An array of long non-coding RNAs (lncRNAs) and microRNAs validated to regulate such immune checkpoints were screened. The lncRNAs; CCAT-1, H19, and MALAT-1 were all significantly upregulated in the sera, PBMCs, and tissues of HCC patients as compared to HCV patients and healthy controls. However, miR-944-5p, miR-105-5p, miR-486-5p, miR-506-5p, and miR-30a-5p were downregulated in the sera and liver tissues of HCC patients. On the tumor cell side, knocking down of lncRNAs-CCAT-1, MALAT-1, or H19-markedly repressed the co-expression of PD-L1 and CD155 and accordingly induced the cytotoxicity of co-cultured primary immune cells. On the immune side, ectopic expression of the under-expressed microRNAs; miR-486-5p, miR-506-5p, and miR-30a-5p significantly decreased the transcript levels of PD-1 in PBMCs with no effect on TIGIT. On the other hand, ectopic expression of miR-944-5p and miR-105-5p in PBMCs dramatically reduced the co-expression of PD-1 and TIGIT. Finally, all studied miRNAs enhanced the cytotoxic effects of PBMCs against Huh7 cells. However, miR-105-5p showed the highest augmentation for PBMCs cytotoxicity against HCC cells. In conclusion, this study highlights a novel co-targeting strategy using miR-105-5p mimics, MALAT-1, CCAT-1 and H19 siRNAs to efficiently hampers the immune checkpoints; PD-L1/PD-1 and CD155/TIGIT immune evasion properties in HCC.

Keywords: CCAT-1; H19; HCC; Immune checkpoint inhibitors (ICI); MALAT-1; Programmed death-ligand 1 (PD-L1); T cell immunoreceptor with Ig and ITIM domains (TIGIT).