半胱氨酸组织蛋白酶B(CTS-B)是一种重要的酶,在许多恶性肿瘤中过度表达,并有助于癌症的侵袭和转移。因此,本研究旨在开发和评估一种针对CTS-B的基于活动的多模态治疗诊断药物,用于癌症成像和治疗.基于CTS-B活动的探测器,BMX2被合成并用68Ga和90Y有效标记以产生用于多模态成像的68Ga-BMX2和用于放射治疗的90Y-BMX2。使用重组的活性人CTS-B酶(rh-CTS-B)和包括HeLa在内的四种癌细胞系,通过荧光蛋白质印迹确定BMX2与CTS-B酶结合的亲和力和特异性,HepG2、MCF7和U87MG,以CA074作为CTS-B抑制剂进行对照。还进行了共聚焦激光扫描显微镜成像和细胞摄取测量。然后,在HeLa异种移植物上获得体内PET成像和荧光成像。最后,测试了90Y-BMX2的治疗效果.BMX2可以被rh-CTS-B特异性激活并与酶稳定结合。BMX2与CTS-B的结合是时间依赖性和酶浓度依赖性的。虽然CTS-B表达在细胞系之间不同,均显示BMX2和68Ga-BMX2的显著摄取。体内光学和PET成像显示肿瘤对BMX2和68Ga-BMX2的高摄取和积累超过24h。90Y-BMX2可以显着抑制HeLa肿瘤的生长。放射性和荧光双模态治疗剂68Ga/90Y-BMX2的研制,证明了一种有效的PET诊断成像治疗方法,荧光成像,和癌症的放射性核素治疗,这可能有潜在的临床翻译癌症疗法在未来。
Cysteine cathepsin B (CTS-B) is a crucial enzyme that is overexpressed in numerous malignancies and contributes to the invasion and metastasis of cancer. Therefore, this study sets out to develop and evaluate an activity-based multimodality theranostic agent targeting CTS-B for cancer imaging and therapy. A CTS-B activity-based probe, BMX2, was synthesized and labeled efficiently with 68Ga and 90Y to produce 68Ga-BMX2 for multimodality imaging and 90Y-BMX2 for radiation therapy. The affinity and specificity of BMX2 binding with the CTS-B enzyme were determined by fluorescent western blots using recombined active human CTS-B enzyme (rh-CTS-B) and four cancer cell lines including HeLa, HepG2, MCF7, and U87MG, with CA074 as the CTS-B inhibitor for control. Confocal laser scanning microscope imaging and cell uptake measurement were also performed. Then, in vivo PET imaging and fluorescence imaging were acquired on HeLa xenografts. Finally, the therapeutic effect of 90Y-BMX2 was tested. BMX2 could be specifically activated by rh-CTS-B and stably bound to the enzyme. The binding of BMX2 with CTS-B is time-dependent and enzyme concentration-dependent. Although CTS-B expression varied between cell lines, all showed significant uptake of BMX2 and 68Ga-BMX2. In vivo optical and PET imaging showed a high tumor uptake of BMX2 and 68Ga-BMX2 and accumulation for more than 24 h. 90Y-BMX2 could significantly inhibit HeLa tumor growth. The development of 68Ga/90Y-BMX2, a radioactive and fluorescent dual modality theranostic agent, demonstrated an effective theranostic approach for PET diagnostic imaging, fluorescence imaging, and radionuclide therapy of cancers, which may have a potential for clinical translation for cancer theranostics in the future.