GC-C Agonists: Specific Probes for the Detection of Colorectal Tumors

GC-C 激动剂：用于检测结直肠肿瘤的特异性探针

• 批准号: 8228577
• 负责人: MARGIE L. CLAPPER
• 金额: $ 17.66万
• 依托单位: BARUCH S. BLUMBERG INSTITUTE
• 依托单位国家: 美国
• 财政年份: 2012
• 资助国家: 美国
• 起止时间: 2012-03-01 至 2014-02-28
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8228577
• 关键词: Address; Adenocarcinoma; Affinity; Agonist; Amino Acids; Animals; Applications Grants; Area; Binding; Biological Markers; Biomedical Research; Cell Line; Clinical; Clinical Trials; Colitis; Collaborations; Colon; Colon Adenocarcinoma; Colon Carcinoma; Colonic Neoplasms; Colonic Polyps; Colorectal; Colorectal Adenoma; Colorectal Cancer; Colorectal Neoplasms; Colorectal Polyp; Cyclic GMP; Data; Detection; Development; Digestion; Dose; Early Diagnosis; Ectopic Expression; Ensure; Epithelial Cells; Evaluation; Fluorescent Probes; Fluorochrome; Future; Gastrointestinal tract structure; Glycoproteins; Goals; Growth; Guanylate Cyclase; Histologic; Homeostasis; Human; Image; In Vitro; Incubated; Inflammation; Intestinal Neoplasms; Intestines; Ions; Large Intestine Carcinoma; Lead; Lesion; Ligands; Liquid substance; Malignant Epithelial Cell; Malignant Neoplasms; Measurable; Methods; Microscopic; Morbidity - disease rate; Morphology; Mouse Strains; Mucous Membrane; Mus; NIH Program Announcements; Natriuretic Factors; Neoplasm Metastasis; Neoplastic Processes; Normal tissue morphology; Oral Administration; Pathology; Peptide Hydrolases; Peptides; Pharmacodynamics; Physiological; Polyps; Production; Proteolysis; Public Health; Reporting; Research; Research Project Grants; Resistance; Schedule; Sensitivity and Specificity; Signal Transduction; Simulate; Specificity; Stomach; Testing; Tissues; Translations; Traveler' s diarrhea; Tumor Tissue; United States National Institutes of Health; Upper digestive tract structure; Validation; Water; analog; base; brush border membrane; cancer type; design; disulfide bond; enterotoxin ST; gastrointestinal; guanylin; imaging modality; imaging probe; in vivo; innovation; mRNA Expression; mortality; mouse model; neoplastic cell; novel strategies; overexpression; peptide hormone; phase 1 study; pre-clinical; preclinical study; programs; receptor; response; selective expression; time interval; tumor; uroguanylin

DESCRIPTION (provided by applicant): Uroguanylin (UG) and guanylin (GN) are endogenous agonists of the guanylate cyclase C (GC-C) receptor that were discovered as natriuretic hormones based on their structural similarity to bacterial enterotoxin (ST), the secreted peptide that is responsible for traveler's diarrhea. Binding of these peptide hormones to the GC-C receptor stimulates intracellular production of cyclic guanosine monophosphate (cGMP), which in turn regulates ion and water homeostasis within the gastrointestinal mucosa. This group was the first to report that the expression of mRNAs encoding UG and GN are markedly reduced in cultured human colon carcinoma cells as well as human colon polyps and adenocarcinomas. In contrast, GC-C is overexpressed in human colon polyps and tumor tissues, perhaps to compensate for the reduced supply of UG and GN. The hypothesis of the proposed study is that near-infrared (NIR) fluorochrome-tagged SP-333, a stable analog of UG, can be used as a noninvasive probe for the reliable detection of spontaneous colorectal polyps in multiple intestinal neoplasia mice, in particular lesions that lack an elevated growth component. Preliminary data indicate that SP-333, a proteolytically resistant analog of UG, 1) possesses a high binding affinity for GC-C receptors; 2) is stable in simulated human gastric and intestinal fluids at 37oC; 3) can be tagged with an NIR fluorochrome; and 4) localizes preferentially to colorectal polyps, as compared to adjacent normal colonic mucosa, when incubated with mouse tissue ex vivo. These data support the further characterization and validation of NIR fluorochrome-tagged SP-333 as a specific probe for the detection of colorectal tumors in Dr. Clapper's strain of mice (Apc?FCCC) that uniquely develops multiple colorectal polyps. Specific Aim 1 will focus on determining the stability of NIR fluorochrome-tagged SP-333 in simulated intestinal and gastric fluids as well as the specificity of its binding to human carcinoma cells in vitro and excised colon tissue (normal and tumor). Once the optimal dose and schedule for probe administration have been established, its sensitivity and specificity to detect spontaneous colorectal polyps following oral administration to mice will be determined (Specific Aim 2). The proposed research will be accomplished jointly in collaboration with Dr. Clapper's group, who has recently established several imaging modalities for the detection of colorectal polyps in Apc?FCCC mice. Successful completion of the proposed research will have demonstrated the proof-of-concept that the GC-C agonist SP-333 can be used as a probe to reliably detect primary colon tumors, thus supporting its further development for translation to a clinical setting. Future evaluation of the utility of the probe to detect colorectal metastases may also be warranted. PUBLIC HEALTH RELEVANCE: Relevance to Public Health Use of SP-333 as a fluorescent probe to detect colon tumor cells could lead to early diagnosis of colon polyps and tumors, potentially resulting reduced morbidity and mortality associated with colon cancer.

描述（由申请人提供）：尿鸟苷素 (UG) 和鸟苷素 (GN) 是鸟苷酸环化酶 C (GC-C) 受体的内源性激动剂，由于其与细菌肠毒素 (ST) 的结构相似性而被发现为利尿钠激素，而细菌肠毒素 (ST) 是导致旅行者腹泻的分泌肽。这些肽激素与 GC-C 受体的结合刺激细胞内产生环磷酸鸟苷 (cGMP)，从而调节胃肠粘膜内的离子和水稳态。该小组首次报道了在培养的人结肠癌细胞以及人结肠息肉和腺癌中编码UG和GN的mRNA表达显着降低。相比之下，GC-C 在人类结肠息肉和肿瘤组织中过度表达，这可能是为了补偿 UG 和 GN 供应的减少。该研究的假设是，近红外（NIR）荧光染料标记的 SP-333（UG 的稳定类似物）可用作非侵入性探针，用于可靠检测多发性肠道肿瘤小鼠中的自发性结直肠息肉，特别是缺乏升高的生长成分的病变。初步数据表明，SP-333是UG的一种蛋白水解抗性类似物，1)对GC-C受体具有高结合亲和力； 2）在37℃模拟人体胃液和肠液中稳定； 3) 可以用近红外荧光染料标记； 4) 当与小鼠组织离体培养时，与邻近的正常结肠粘膜相比，优先定位于结直肠息肉。这些数据支持进一步表征和验证近红外荧光染料标记的 SP-333 作为一种特异性探针，用于检测 Dr. Clapper 小鼠品系 (Apc?FCCC) 中的结直肠肿瘤，该小鼠品系独特地产生多发性结直肠息肉。具体目标 1 将重点确定 NIR 荧光染料标记的 SP-333 在模拟肠液和胃液中的稳定性，以及其与体外人类癌细胞和切除的结肠组织（正常和肿瘤）结合的特异性。一旦确定了探针给药的最佳剂量和时间表，将确定其在小鼠口服给药后检测自发性结直肠息肉的敏感性和特异性（具体目标 2）。拟议的研究将与 Clapper 博士的团队合作共同完成，Clapper 博士的团队最近建立了几种用于检测 Apc?FCCC 小鼠结直肠息肉的成像模式。拟议研究的成功完成将证明 GC-C 激动剂 SP-333 可用作可靠检测原发性结肠肿瘤的探针，从而支持其进一步开发并转化为临床环境。未来对探针检测结直肠转移的效用进行评估也可能是有必要的。 公共卫生相关性：与公共卫生的相关性 使用 SP-333 作为荧光探针来检测结肠肿瘤细胞可以实现结肠息肉和肿瘤的早期诊断，从而可能降低与结肠癌相关的发病率和死亡率。