Copyright ©The Author(s) 2021. Published by Baishideng Publishing Group Inc. All rights reserved.
World J Clin Cases. Dec 6, 2021; 9(34): 10438-10450
Published online Dec 6, 2021. doi: 10.12998/wjcc.v9.i34.10438
Role of immune escape in different digestive tumours
Xin-Zhu Du, Bin Wen, Lin Liu, Ying-Ting Wei, Kui Zhao
Xin-Zhu Du, Bin Wen, Lin Liu, Ying-Ting Wei, Kui Zhao, Department of Gastroenterology, The Affiliated Hospital of Zunyi Medical University, Zunyi 563000, Guizhou Province, China
Author contributions: Du XZ performed the literature search and wrote the manuscript; Wen B categorized the information; Liu L proofread the manuscript; Wei YT checked the information; and Zhao K revised the manuscript.
Conflict-of-interest statement: The authors have no conflicts of interest to disclose.
Open-Access: This article is an open-access article that was selected by an in-house editor and fully peer-reviewed by external reviewers. It is distributed in accordance with the Creative Commons Attribution NonCommercial (CC BY-NC 4.0) license, which permits others to distribute, remix, adapt, build upon this work non-commercially, and license their derivative works on different terms, provided the original work is properly cited and the use is non-commercial. See:
Corresponding author: Kui Zhao, MD, Doctor, Department of Gastroenterology, The Affiliated Hospital of Zunyi Medical University, No. 201 Dalian Road, Zunyi 563000, Guizhou Province, China.
Received: July 25, 2021
Peer-review started: July 25, 2021
First decision: August 8, 2021
Revised: August 15, 2021
Accepted: October 18, 2021
Article in press: October 18, 2021
Published online: December 6, 2021

A counterbalance between immune cells and tumour cells is key to fighting tumours, and immune escape is an important mechanism for the survival of tumour cells in the body. Tumor cells and their cytokines impair the activity of T cells, NK cells, macrophages and other immune cells through various ways, and change the expression of their own surface antigens so as to avoid the clearance of the immune system. Changes in major histocompatibility complex molecules, high expression of programmed death-ligand 1, and the presence of immunosuppressive cells in the tumor microenvironment (TME) are main means by which tumors impair the function of immune cells. During the development of tumours of the digestive system, different mechanisms acting on tumour cells, the TME, and immune cells lead to immune escape and promote tumour progression. In this paper, the mechanisms of immune escape in tumour cells of the digestive system are reviewed to provide a theoretical basis for the immunotherapy of gastrointestinal tumours.

Keywords: Gastrointestinal tumors, Immune escape, Immune cells, Tumor microenvironment, Molecular, Mechanism

Core Tip: To summarize and analyze the mechanisms of immune escape of tumor cells in the digestive system and provide help for immunotherapy. In this paper, the mechanisms can be analyzed from many aspects, including not only tumor cells themselves, but also immune cells and some other external factors. Through the summary of these mechanisms, we find some deficiencies in the research in this area, which may provide some ideas for the follow-up research.