Smith Jill P, Shivapurkar Narayan, Chen Wenqiang, Chekuri Godhanjali, Dabney Amani, Holmes Kyle, Cao Hong, Kularatne Ruvanthi N, Stern Stephan T
Department of Medicine, Georgetown University, Washington, District of Columbia.
The Nanotechnology Characterization Laboratory, Cancer Research Technology Program, Frederick National Laboratory for Cancer Research Sponsored by the National Cancer Institute, Frederick, Maryland.
Mol Cancer Ther. 2025 Aug 1;24(8):1277-1288. doi: 10.1158/1535-7163.MCT-24-1059.
Precision medicine and genomic profiling with target-specific therapy directed to cancer cell receptors have improved the outcome of many recalcitrant cancers. Strategies to deliver gene therapy to downregulate cancer driver genes have been challenging in vivo. Pancreatic cancer has the poorest survival of all solid tumors due to the lack of target-specific therapies and its characteristic tumor microenvironment with dense fibrosis and abundant immunosuppressive M2-polarized macrophages. In this study, we designed a panel of locked nucleic acid gapmer antisense oligonucleotides directed to human gastrin mRNA. We tested their efficacy by downregulation of mRNA and growth inhibition in vitro. The most effective gapmer, gapmer-90, was modified for in vivo therapeutics by thiol-maleimide click chemistry to render it target-specific to the cholecystokinin-B receptor. This G-protein-coupled receptor is overexpressed in pancreatic cancers. Mice bearing orthotopic human pancreatic tumors were treated with PBS (control), an untargeted gapmer, or receptor-targeted gapmers at low (60 nmol/L) and high (120 nmol/L) concentrations. Uptake of the gapmer was measured in tissues using a complementary probe. We found that the receptor-targeted gapmer significantly enhanced uptake in vivo and decreased growth and metastases of human pancreatic tumors in a dose-related fashion without off-target toxicity. The target-specific gapmer also altered the tumor microenvironment by decreasing fibrosis and reducing M2-polarized macrophages. Collectively, our results provide evidence that locked nucleic acid gapmers are a unique tool to deliver antisense oligonucleotides for therapy to recalcitrant cancers. Rendering the gapmers target-specific allows for selective uptake by receptor internalization, improving efficacy and decreasing off-target toxicity.
精准医学以及针对癌细胞受体的靶向特异性治疗的基因组分析改善了许多难治性癌症的治疗结果。在体内，将基因疗法用于下调癌症驱动基因的策略一直具有挑战性。由于缺乏靶向特异性疗法以及其具有致密纤维化和丰富免疫抑制性M2极化巨噬细胞的特征性肿瘤微环境，胰腺癌在所有实体瘤中生存率最低。在本研究中，我们设计了一组针对人胃泌素mRNA的锁核酸缺口mer反义寡核苷酸。我们通过在体外下调mRNA和抑制生长来测试它们的功效。最有效的缺口mer，即缺口mer-90，通过硫醇-马来酰亚胺点击化学进行修饰以用于体内治疗，使其对胆囊收缩素B受体具有靶向特异性。这种G蛋白偶联受体在胰腺癌中过表达。将携带原位人胰腺肿瘤的小鼠用PBS（对照）、非靶向缺口mer或低浓度（60 nmol/L）和高浓度（120 nmol/L）的受体靶向缺口mer进行治疗。使用互补探针在组织中测量缺口mer的摄取。我们发现受体靶向缺口mer显著增强了体内摄取，并以剂量相关方式降低了人胰腺肿瘤的生长和转移，且无脱靶毒性。靶向特异性缺口mer还通过减少纤维化和降低M2极化巨噬细胞改变了肿瘤微环境。总体而言,我们的结果提供了证据，表明锁核酸缺口mer是一种独特的工具，可用于将反义寡核苷酸递送至难治性癌症进行治疗。使缺口mer具有靶向特异性可通过受体内化实现选择性摄取，提高疗效并降低脱靶毒性。
