PO.TB04.05 · 肿瘤生物学
ADC 旁观者杀伤效应的体外和体内评估
In vitro and in vivo evaluation of the bystander-killing effect of ADCs
作者与单位 Authors & Affiliations
摘要 Abstract
中文摘要
抗体药物偶联物（ADC）代表了一类颇具前景的疗法，由于其高效且特异性的药物递送，具有比传统化疗药物更宽的治疗窗口。此外，某些 ADC 通过可溶性毒性介质、缝隙连接细胞间通讯、免疫介导的杀伤或 Fc 介导的效应功能等机制产生旁观者杀伤效应。这种效应不仅有益于表达抗原的肿瘤细胞，也作用于邻近的抗原阴性细胞。滋养层细胞表面抗原 2（Trop-2）是一种在许多上皮性癌症中高表达的跨膜糖蛋白，是 ADC 开发的一个有吸引力的靶点。在本研究中，我们评估了两种靶向 Trop-2 的 ADC——sacituzumab govitecan（SG）和 datopotamab deruxtecan（Dato-DXd）的旁观者杀伤效应。为评估该效应，我们采用了体外共培养实验和体内混合细胞异种移植肿瘤模型。根据 Trop-2 表达情况，选择了三对细胞系（BxPC-3/UM-UC-3、HCC1806/UM-UC-3、NCI-N87/UM-UC-3）用于体外实验。与仅表现出极少载荷释放的单独 UM-UC-3 相比，Dato-DXd 在 BxPC-3 组和 BxPC-3/UM-UC-3 共培养组中均表现出更高的载荷释放。相比之下，SG 在所有组中表现出相似的载荷释放。细胞增殖实验显示，Dato-DXd 对 Trop-2 阳性细胞（BxPC-3、HCC1806、NCI-N87）具有强效细胞毒性，但对 UM-UC-3 细胞无效。相反，SG 在全部四种细胞系中表现出相当的细胞毒性。值得注意的是，Dato-DXd 在所有共培养组中都降低了 UM-UC-3 细胞的活力，其中 BxPC-3/UM-UC-3 组显示出最强的旁观者效应（对 UM-UC-3 细胞的抑制率达 80%）。与 Dato-DXd 不同，SG 在共培养组和 UM-UC-3 组中均表现出强烈的细胞毒性。在使用 BxPC-3 与 UM-UC-3-Luc 混合的细胞系来源异种移植模型的体内实验中也观察到了类似结果，肿瘤体积通过成像监测。这些结果表明，共培养系统和体内成像是 ADC 药物发现的宝贵工具。体外和体内实验对于理解旁观者杀伤机制和预测临床成功均至关重要。
查看英文原文 English abstract
Antibody-drug conjugates (ADCs) represent a promising class of therapeutics with a broader therapeutic window than conventional chemotherapeutic agents, owing to their efficient and specific drug delivery. In addition, some ADCs produce a bystander-killing effect through mechanisms such as soluble toxic mediators, gap junction intercellular communication, immune-mediated killing, or Fc-mediated effector functions. This effect benefits not only antigen-expressing tumor cells, but also adjacent antigen-negative cells. Trophoblast cell-surface antigen 2 (Trop-2) is a transmembrane glycoprotein highly expressed in many epithelial cancers and serves as an attractive target for ADC development. In this study, we assessed the bystander-killing effect of two Trop-2-targeted ADCs-sacituzumab govitecan (SG) and datopotamab deruxtecan (Dato-DXd). To evaluate this effect, we used both in vitro co-culture assays and in vivo mixed-cell xenograft tumor models. Three cell line pairs (BxPC-3/UM-UC-3, HCC1806/UM-UC-3, NCI-N87/UM-UC-3) were selected for the in vitro assay based on Trop-2 expression. Dato-DXd exhibited higher payload release in both the BxPC-3 group and the BxPC-3/UM-UC-3 co-culture group compared to UM-UC-3 alone, which showed minimal payload release. In contrast, SG demonstrated similar payload release across all groups. Cell proliferation assays revealed that Dato-DXd had potent cytotoxicity against Trop-2-positive cells (BxPC-3, HCC1806, NCI-N87) but was ineffective in UM-UC-3 cells. Conversely, SG exhibited comparable cytotoxicity across all four cell lines. Notably, Dato-DXd reduced the viability of UM-UC-3 cells in all co-culture groups, with the BxPC-3/UM-UC-3 group showing the strongest bystander effect (80% inhibition of UM-UC-3 cells). Unlike Dato-DXd, SG exhibited strong cytotoxicity in both co-culture and UM-UC-3 groups. A similar observation was made in vivo using a mixture of BxPC-3 and UM-UC-3-Luc cell line-derived xenograft model, with tumor volume monitored via imaging. These results demonstrate that co-culture systems and in vivo imaging are valuable tools for ADC drug discovery. Both in vitro and in vivo assays are essential for understanding bystander-killing mechanisms and predicting clinical success.
利益披露 Disclosure
C. Wang, None..
M. Tong, None..
T. Pang, None..
J. Huang, None.