Overexpressed Claudin-1 Can Be Visualized Endoscopically in Colonic Adenomas In Vivo.
Overexpressed Claudin-1 Can Be Visualized Endoscopically in Colonic Adenomas In Vivo.
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DOI：
10.1016/j.jcmgh.2015.12.001
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发表时间：
2016-03
影响因子：
7.2
通讯作者：
Wang TD
中科院分区：
文献类型：
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作者：
Rabinsky EF;Joshi BP;Pant A;Zhou J;Duan X;Smith A;Kuick R;Fan S;Nusrat A;Owens SR;Appelman HD;Wang TD
传统的白光结肠镜检查旨在降低结直肠癌（CRC）的发病率和死亡率。结直肠癌是由息肉样和扁平癌前病变引起的。我们的目的是建立概念验证的实时内镜成像的结肠腺瘤使用近红外肽是特异性的claudin-1。我们利用基因表达谱鉴定了claudin-1作为CRC早期靶点，并对claudin-1的细胞外环（氨基酸53-80）进行噬菌体展示，鉴定了肽RTSPSSR。通过Cy5.5标签，我们表征了结合参数，并显示了与人类CRC细胞的特异性结合。我们在CPC内窥镜下收集了体内近红外荧光图像；Apc小鼠，自发发生结肠腺瘤。通过免疫荧光，我们验证了特异性肽与近端人类结肠腺瘤的结合。我们发现人类结肠腺瘤中claudin-1的基因表达比正常人增加2.5倍。我们在敲低和竞争研究中发现了RTSPSSR与claudin-1的特异性结合，并测量了其对SW620细胞的亲和力为42 nmol/L，时间常数为1.2分钟。在小鼠体内，我们发现与正常小鼠相比，息肉样腺瘤和扁平腺瘤的靶背景比明显更高。在免疫荧光上，我们发现人类腺瘤（平均±SD， 25.5±14.0）比正常（平均±SD， 9.1±6.0）和增生性息肉（平均±SD， 3.1±3.7；P分别= 10-5和8 × 10-12）和无根锯齿状腺瘤（平均±SD， 20.1±13.3）比正常和增生性息肉（P分别= 0.02和3 × 10-7）明显更高。Claudin-1在结肠癌前病变中过表达，可以通过近红外标记肽在体内内镜下检测到。
Conventional white-light colonoscopy aims to reduce the incidence and mortality of colorectal cancer (CRC). CRC has been found to arise from missed polypoid and flat precancerous lesions. We aimed to establish proof-of-concept for real-time endoscopic imaging of colonic adenomas using a near-infrared peptide that is specific for claudin-1. We used gene expression profiles to identify claudin-1 as a promising early CRC target, and performed phage display against the extracellular loop of claudin-1 (amino acids 53–80) to identify the peptide RTSPSSR. With a Cy5.5 label, we characterized binding parameters and showed specific binding to human CRC cells. We collected in vivo near-infrared fluorescence images endoscopically in the CPC;Apc mouse, which develops colonic adenomas spontaneously. With immunofluorescence, we validated specific peptide binding to adenomas from the proximal human colon. We found a 2.5-fold increase in gene expression for claudin-1 in human colonic adenomas compared with normal. We showed specific binding of RTSPSSR to claudin-1 in knockdown and competition studies, and measured an affinity of 42 nmol/L and a time constant of 1.2 minutes to SW620 cells. In the mouse, we found a significantly higher target-to-background ratio for both polypoid and flat adenomas compared with normal by in vivo images. On immunofluorescence, we found significantly greater intensity for human adenomas (mean ± SD, 25.5 ± 14.0) vs normal (mean ± SD, 9.1 ± 6.0) and hyperplastic polyps (mean ± SD, 3.1 ± 3.7; P = 10-5 and 8 × 10-12, respectively), and for sessile serrated adenomas (mean ± SD, 20.1 ± 13.3) vs normal and hyperplastic polyps (P = .02 and 3 × 10-7, respectively). Claudin-1 is overexpressed in premalignant colonic lesions, and can be detected endoscopically in vivo with a near-infrared, labeled peptide.