Gupta Suresh, Pal Rahul, Schmidt Eric J, Krishnamoorthy Murali, Leporati Anita, Kumar Anand T N, Bogdanov Alexei
Department of Radiology, UMASS Chan Medical School, Worcester, MA, USA.
Mike Toth Head and Neck Cancer Research Center, Massachusetts Eye and Ear, Boston, MA, USA.
iScience. 2024 May 24;27(8):110102. doi: 10.1016/j.isci.2024.110102. eCollection 2024 Aug 16.
Clinical imaging-assisted oncosurgical navigation requires cancer-specific miniaturized optical imaging probes. We report a near-infrared (NIR) Fab'-based epidermal growth factor receptor (EGFR)-specific probe carrying 3 NIR fluorophores (Fab'-800CW), which retained high-affinity binding to EGFR ectodomain (equilibrium K = 1 nM). Fab'-800CW showed a robust 4-times gain of fluorescence intensity (FI) and a 20% lifetime (FLT) increase under the conditions mimicking intracellular degradation. The probe was tested by using triple-negative breast cancer (TNBC) cell lines obtained by applying CRISPR interference (CRISPRi) effect of -targeting sgRNA and dCas9-KRAB chimera coexpression in MDA-MB-231 cells (WT cells). FI imaging in cell culture proved a 50% EGFR expression attenuation by CRISPRi. FI imaging in animals harboring attenuated or WT TNBC tumors with corroboration identified differences between WT and CRISPRi tumors FI at 30 min post injection. Our results suggest the feasibility of EGFR expression imaging using a Fab'-based probe relevant for imaging-guided cancer surgery.
临床成像辅助肿瘤手术导航需要癌症特异性的小型化光学成像探针。我们报告了一种基于近红外（NIR）Fab'的表皮生长因子受体（EGFR）特异性探针，其携带3种近红外荧光团（Fab'-800CW），该探针与EGFR胞外域保持高亲和力结合（平衡解离常数K = 1 nM）。在模拟细胞内降解的条件下，Fab'-800CW的荧光强度（FI）增强了4倍，荧光寿命（FLT）增加了20%。通过在MDA-MB-231细胞（野生型细胞）中应用靶向sgRNA和dCas9-KRAB嵌合体共表达的CRISPR干扰（CRISPRi）效应获得的三阴性乳腺癌（TNBC）细胞系对该探针进行了测试。细胞培养中的FI成像证明CRISPRi使EGFR表达衰减了50%。在携带衰减型或野生型TNBC肿瘤的动物中进行的FI成像，并通过相关验证确定了注射后30分钟时野生型和CRISPRi肿瘤之间的FI差异。我们的结果表明，使用基于Fab'的探针进行EGFR表达成像对于成像引导的癌症手术具有可行性。
