Strand Joanna, Sjöström Kjell, Lamminmaki Urpo J, Vilhelmsson Timmermand Oskar, Strand Sven-Erik, Tran Thuy A
Department of Oncology, Department of Clinical Sciences, Lund University, 22243 Lund, Sweden.
Innovagen AB, 22362 Lund, Sweden.
Pharmaceuticals (Basel). 2021 Dec 1;14(12):1251. doi: 10.3390/ph14121251.
Metastatic castration-resistant prostate cancer is today incurable. Conventional imaging methods have limited detection, affecting their ability to give an accurate outcome prognosis, and current therapies for metastatic prostate cancer are insufficient. This inevitably leads to patients relapsing with castration-resistant prostate cancer. Targeting prostate-specific antigens whose expression is closely linked to the activity in the androgen receptor pathway, and thus the pathogenesis of prostate cancer, is a possible way to increase specificity and reduce off-target effects. We have humanized and evaluated radioimmunoconjugates of a previously murine antibody, m5A10, targeting PSA intended for theranostics of hormone-refractory prostate cancer. The humanized antibody h5A10 was expressed in mammalian HEK293 cells transfected with the nucleotide sequences for the heavy and light chains of the antibody. Cell culture medium was filtered and purified by Protein G chromatography, and the buffer was changed to PBS pH 7.4 by dialysis. Murine and humanized 5A10 were conjugated with p-SCN-Bn-CHX-A"-DTPA. Surface plasmon resonance was used to characterize the binding to PSA of the immunoconjugates. Immunoconjugates were labeled with either indium-111 or lutetium-177. Biodistribution studies of murine and humanized 5A10 were performed in mice with LNCaP xenografts. 5A10 was successfully humanized, and in vivo targeting showed specific binding in xenografts. The results thus give an excellent platform for further theranostic development of humanized 5A10 for clinical applications.
转移性去势抵抗性前列腺癌目前无法治愈。传统成像方法的检测能力有限，影响了其给出准确预后结果的能力，并且目前用于转移性前列腺癌的治疗方法并不充分。这不可避免地导致患者复发去势抵抗性前列腺癌。靶向前列腺特异性抗原，其表达与雄激素受体途径的活性密切相关，进而与前列腺癌的发病机制相关，是提高特异性并减少脱靶效应的一种可能方法。我们已经对一种先前的鼠源抗体m5A10进行了人源化并评估了其放射性免疫缀合物，该抗体靶向用于激素难治性前列腺癌诊疗的前列腺特异性抗原（PSA）。人源化抗体h5A10在转染了该抗体重链和轻链核苷酸序列的哺乳动物HEK293细胞中表达。细胞培养基经过过滤并用蛋白G色谱法纯化，然后通过透析将缓冲液换成pH 7.4的磷酸盐缓冲液（PBS）。将鼠源和人源化的5A10与p-SCN-Bn-CHX-A”-DTPA缀合。使用表面等离子体共振来表征免疫缀合物与PSA的结合。免疫缀合物用铟-111或镥-177进行标记。在具有LNCaP异种移植瘤的小鼠中进行了鼠源和人源化5A10的生物分布研究。5A10成功实现了人源化，并且体内靶向显示在异种移植瘤中有特异性结合。因此，这些结果为进一步将人源化5A10用于临床应用的诊疗开发提供了一个出色的平台。
