Xu Caiyun, Zhang Hong
Department of Nuclear Medicine, The Second Affiliated Hospital of Zhejiang University School of Medicine, Hangzhou, Zhejiang 310009, China ; Zhejiang University Medical PET Center, Zhejiang University, Hangzhou, Zhejiang 310009, China ; Institute of Nuclear Medicine and Molecular Imaging, Zhejiang University, Hangzhou, Zhejiang 310009, China ; Key Laboratory of Medical Molecular Imaging of Zhejiang Province, Hangzhou, Zhejiang 310009, China.
Biomed Res Int. 2015;2015:917968. doi: 10.1155/2015/917968. Epub 2015 Mar 24.
Somatostatin (SST) receptors (SSTRs) belong to the typical 7-transmembrane domain family of G-protein-coupled receptors. Five distinct subtypes (termed SSTR1-5) have been identified, with SSTR2 showing the highest affinity for natural SST and synthetic SST analogs. Most neuroendocrine tumors (NETs) have high expression levels of SSTRs, which opens the possibility for tumor imaging and therapy with radiolabeled SST analogs. A number of tracers have been developed for the diagnosis, staging, and treatment of NETs with impressive results, which facilitates the applications of human SSTR subtype 2 (hSSTr2) reporter gene based imaging and therapy in SSTR negative or weakly positive tumors to provide a novel approach for the management of tumors. The hSSTr2 gene can act as not only a reporter gene for in vivo imaging, but also a therapeutic gene for local radionuclide therapy. Even a second therapeutic gene can be transfected into the same tumor cells together with hSSTr2 reporter gene to obtain a synergistic therapeutic effect. However, additional preclinical and especially translational and clinical researches are needed to confirm the value of hSSTr2 reporter gene based imaging and therapy in tumors.
生长抑素（SST）受体（SSTRs）属于典型的G蛋白偶联受体7跨膜结构域家族。已鉴定出五种不同的亚型（称为SSTR1 - 5），其中SSTR2对天然SST和合成SST类似物表现出最高亲和力。大多数神经内分泌肿瘤（NETs）具有高水平的SSTRs表达，这为用放射性标记的SST类似物进行肿瘤成像和治疗提供了可能性。已经开发了许多用于NETs诊断、分期和治疗的示踪剂，取得了令人瞩目的结果，这促进了基于人SSTR亚型2（hSSTr2）报告基因的成像和治疗在SSTR阴性或弱阳性肿瘤中的应用，为肿瘤管理提供了一种新方法。hSSTr2基因不仅可以作为体内成像的报告基因，还可以作为局部放射性核素治疗的治疗基因。甚至可以将第二个治疗基因与hSSTr2报告基因一起转染到同一肿瘤细胞中以获得协同治疗效果。然而，需要额外的临床前研究，特别是转化研究和临床研究来证实基于hSSTr2报告基因的成像和治疗在肿瘤中的价值。
