HLA-G在肿瘤组织中表达情况研究进展

The Research Progress of HLA-G Expression on Tumor Tissues

人类白细胞抗原G(human leukocyte antigen,HLA-G)属于非经典HLA-I类分子,在多种肿瘤细胞上均有表达。从结构上可以将HLA-G分为7种亚型:膜结合型HLA-G1-HLA-G4和可溶型HLA-G5-HLA-G7。研究表明,HLA-G1和HLA-G5具有明确的生物学活性也是研究较为深入的两种亚型,他们可以与T淋巴细胞、B淋巴细胞和NK细胞表面的ILT2/CD85j/LILRB1,ILT4/CD85d/LILRB2,KIR2DL4/CD158d受体结合而发挥免疫抑制功能。目前,HLA-G分子可以在肝癌、肾癌、肺癌、胃癌、食道癌、鼻咽癌、卵巢癌、乳腺癌、宫颈癌、直肠癌和血液肿瘤中表达。本文从HLA-G分子的结构和功能出发,综述了HLA-G分子在上述肿瘤中表达的情况,旨在分析HLA-G在各种肿瘤组织中表达的特点以及临床意义,为临床早期诊断和治疗肿瘤提供参考。

Human leukocyte antigen G （HLA-G）, a nonclassical HLA class I molecule, is selectively expressed in many cancer cells. HLA-G encoding gene has limited polymorphisms. Structurally, there are seven isoforms that can be translated from HLA-G primary transcripts： HLA-G1 to HLA-G4 as membrane-bound proteins and HLA-G5 to HLA-G7 as soluble molecules. HLA-G1 and HLA-G5 molecules were the ones to be heavily involved in various physiological situations and, of course, mostly studied. They can bind ILT2/CD85j/LILRB1, ILT4/CD85d/LILRB2, and KIR2DLA/CD158d receptors located in the surface of T lymphocytes, B lymphocytes and NK cells, and perform immunosuppressive functions. To date, HLA-G can express on liver cancer, renal cancer, lung cancer, gastric cancer, esophagus cancer, nasopharynx cancer, ovarian cancer, breast cancer, cervical cancer, rectal cancer and leukemia. This article analyzed molecular structure and function of HLA-G, and reviewed expression of HLA-G on tumor cells. From analysis of characteristics of HLA G molecule expressed on some kinds of tumor tissue and its clinical significance, some reference for clinical early diagnosis and treatment of tumor was conducted.