抑制CD47表达对肿瘤放射治疗增敏和辐射保护作用的研究进展

Progress on blocking CD47 expression for tumor sensitization and normal tissue protection in radiotherapy

放射治疗在恶性肿瘤的治疗中具有重要作用,然而肿瘤细胞对放射治疗的抵抗性和放射治疗的不良反应一直是亟待解决的问题。如何增强放射治疗的增敏性和辐射防护是目前放射治疗面临的难题及研究热点。近年来研究发现,CD47作为细胞表面跨膜Ig超家族的成员,是信号调节蛋白α(signal-regulatory proteinα,SIRPα)的细胞外配体,具有调节肿瘤发生和调节正常组织放射性损伤后的修复功能。阻断CD47表达可增强对正常组织的辐射保护作用,同时增强肿瘤对放射的敏感性。因此,本文首次提出了以CD47作为肿瘤放射治疗增敏的靶点,在提高正常组织对放射性损伤耐受度的同时,可以增强肿瘤组织对放射治疗的敏感性,从而综合提高肿瘤放射治疗的效果。

Radiation therapy plays an important role in the treatment of carcinoma. Though radiation can kill tumor cells, the radioresistance of tumor cells and the side effects of radiotherapy are still problems to be solved urgently in the treatment of clinical tumors. How to enhance radiosensitivity and radioprotection is a research hotspot and difficult problem for radiologists. In recent years, it has been found that CD47, as a member of the transmembrane Ig superfamily on the cell surface and an extracellular ligand of signal-regulatory protein α （SIRPα）, regulates tumorigenesis and repair function of normal tissues after radiation injury. Blocking the expression of CD47 has been found to confer radioprotection of normal tissues while enhancing tumor radiosensitivity. This paper puts forward that CD47 can be regarded as a target of radiosensitization for improving the tolerance of normal tissues to radiotherapy while enhancing the radiosensitivity of tumor tissues, so as to improve the curative effect of tumor radiotherapy.