Division of Otolaryngology, Head and Neck Surgery, University of California, San Diego, La Jolla, CA, USA.
Department of Microbiology and Immunology, Albert Einstein College of Medicine, New York, NY, USA.
Oral Oncol. 2017 Aug;71:156-162. doi: 10.1016/j.oraloncology.2017.06.009. Epub 2017 Jun 27.
Ratiometric cell-penetrating-peptides (RACPP) are hairpin-shaped molecules that undergo cleavage by tumor-associated proteases resulting in measurable Cy5:Cy7 fluorescence ratiometric change to label cancer in vivo. We evaluated an MMP cleavable RACPP for use in the early detection of malignant lesions in a carcinogen-induced rodent tumor model.
Wild-type immune-competent mice were given 4-nitroquinoline-oxide (4NQO) for 16weeks. Oral cavities from live mice that had been intravenously administered MMP cleavable PLGC(Me)AG-RACPP were serially imaged from week 11 through week 21 using white-light reflectance and Cy5:Cy7 ratiometric fluorescence.
In an initial study we found that at week 21 nearly all mice (13/14) had oral cavity lesions, of which 90% were high-grade dysplasia or invasive carcinoma. These high-grade lesions were identifiable with white light reflectance and RACPP Cy5:Cy7 ratiometric fluorescence with similar detectability, Area Under Curve (AUC) for RACPP detection was 0.97 (95% Confidence interval (CI)=0.92-1.02, p<0.001), sensitivity=89%, specificity=100%. In a follow up study, oral cavity lesions generated by 4NQO were imaged and histologically analyzed at weeks 16, 18 and 21. In this study we showed that RACPP-fluorescence detection positively identified 15 squamous cell carcinomas (in 6 separate mice) that were poorly visible or undetectable by white light reflectance.
RACPP ratiometric fluorescence can be used to accurately detect carcinogen-induced carcinoma in immunocompetent mice that are poorly visible or undetectable by white light reflectance.
比率型细胞穿透肽（RACPP）是一种发夹状分子，可被肿瘤相关蛋白酶切割，导致可测量的 Cy5：Cy7 荧光比率变化，从而在体内标记癌症。我们评估了一种 MMP 可切割的 RACPP，用于在致癌物诱导的啮齿动物肿瘤模型中早期检测恶性病变。
给予野生型免疫功能正常的小鼠 4-硝基喹啉-1-氧化物（4NQO）16 周。从第 11 周到第 21 周，通过静脉注射 MMP 可切割的 PLGC（Me）AG-RACPP 后，对活体小鼠的口腔进行连续白光反射和 Cy5：Cy7 比率荧光成像。
在一项初步研究中，我们发现第 21 周时，几乎所有小鼠（13/14）的口腔均有病变，其中 90%为高级别发育不良或浸润性癌。这些高级别病变可通过白光反射和 RACPP Cy5：Cy7 比率荧光检测到，检测的曲线下面积（AUC）为 0.97（95%置信区间（CI）=0.92-1.02，p<0.001），敏感性为 89%，特异性为 100%。在后续研究中，对 4NQO 诱导的口腔病变在第 16、18 和 21 周进行成像和组织学分析。在这项研究中，我们表明 RACPP 荧光检测可准确识别 15 个鳞状细胞癌（在 6 只单独的小鼠中），这些癌在白光反射下难以看到或无法检测到。
RACPP 比率荧光可用于准确检测免疫功能正常的小鼠中致癌物诱导的癌，这些癌在白光反射下难以看到或无法检测到。
