Cadherin-17 Expression Research Articles

Expression profiles of cadherin 17 and claudin 18.2 in comparison with peptide hormonal expression in pancreatic neuroendocrine tumours: Implications for targeted immunotherapy

Cadherin 17 (CDH17) and claudin 18.2 (CLDN18.2) are highly selective markers of intestinal and gastric lineages and are expressed in adenocarcinomas of various organs. They have also been identified as potential targets for immunotherapy. Expression of CDH17 and CLDN18.2 has been observed in a subset of pancreatic neuroendocrine tumours (PanNETs). This study investigates the immunohistochemical expression of CDH17 and CLDN18 in PanNETs in comparison with hormonal expression profiles to provide baseline data for determining candidate indications for targeted therapy with CDH17 and CLDN18.2 in PanNETs, including insulinomas (n = 22), glucagonomas (n = 13), gastrinomas (n = 3), serotoninomas (n = 2) and PanNETs not otherwise specified (NOS) (n = 17). In the normal pancreas, CDH17 was expressed in the lateral membrane of ducts and some islet cells, whereas CLDN18 was occasionally expressed in the intercalated ducts and centroacinar cells. In PanNETs, CDH17 and CLDN18 was detected by membranous staining. CDH17 expression was observed in 10 of 17 (58.8 %) PanNETs NOS, 3 of 13 (23.1 %) glucagonomas, 1 of 3 (33.3 %,) gastrinomas, 1 of 2 (50 %) serotoninomas, and none of the insulinomas. According to predefined criteria, 7 of 17 (41.2 %) PanNETs NOS, 1 of 3 (33.3 %) gastrinomas, and 1 of 2 (50 %) serotoninomas were classified as CDH17-positive. There were no significant differences in clinicopathological features between CDH17-positive and CDH17-negative PanNETs, except for a higher tumour grade in the former (p<0.05). For CLDN18, expression was noted in 2 out of 3 (66.7 %) gastrinomas, one with focal staining and the other with diffuse staining. One of three (33.3 %) gastrinomas was classified as CLDN18-positive using predefined criteria. These findings suggest that a particular subset of PanNETs, including PanNET NOS, gastrinoma, and serotoninoma, may be potential candidates for CDH17-targeted immunotherapy. Additionally, gastrinoma may be a potential candidate for immunotherapy targeting CLDN18.2.

Abstract 1900: TORL-3-600, a novel antibody drug conjugate directed against cadherin 17 (CDH17), has preclinical efficacy in colorectal, gastric, and pancreatic cancer

Abstract Cadherin 17 (CDH17) is a cell-to-cell adhesion protein that is a member of the cadherin superfamily. In normal tissues, expression of this single pass transmembrane protein is restricted to the lateral surfaces of intestinal and pancreatic ductal epithelial cells. However, in cancer, CDH17 is frequently overexpressed in tumors of the colon, stomach, and pancreas. The selective expression of this cell surface protein in these hard-to-treat cancer makes it an attractive target for the development of antibody-based therapeutics. Here, we describe the preclinical development of TORL-3-600, a novel CDH17-targeting antibody drug conjugate (ADC). CDH17 specific monoclonal antibodies were generated using traditional hybridoma technology and splenocytes isolated from mice immunized with cocktails of NIH3T3 cells overexpressing full length hCHD17 plus purified mammalian expressed hCDH17 extracellular domain protein (aa 23-787). Selective mAb binding was confirmed by flow cytometry and mAb internalization rate was assessed by immunofluorescence (IF). TORL-3-600 was generated from a fully humanized CDH17 mAb by MMAE conjugation with a cleavable linker. Cell membrane staining of CDH17 in patient tumor microarrays (TMAs), cell line (CDX) and patient derived xenografts (PDX) was evaluated by IHC assay. Selective binding of the TORL-3-600 to CDH17 was confirmed in human cancer cell lines and cells engineered to overexpress CDH17. Binding of TORL-3-600 to cell surface CDH17 induced Internalization and translocation to the lysosome of the protein-ADC complex for release of the MMAE payload. Treatment with TORL-3-600 induced significant regressions and tumor growth inhibition (TGI) in four CDH17-positive (CDH17+) human colorectal cancer (CRC) CDXs (103.6 - 140.4% TGI) and three CDH17+ CRC PDXs (63.3 - 102.2% TGI). Responses in these models were sustained for up to nine-weeks following cessation of treatment. Sustained inhibition of xenograft tumor progression was also observed in a cell line model of CDH17+ pancreatic cancer (85.8% TGI). In contrast, greatly reduced responses (37.3 - 58.2% TGI) to TORL-3-600 were observed in the CDH17- human colon cancer CDX and PDX models. Each of the doses tested in this study were well tolerated in mice with no dose-limiting toxicities observed. Analyses of large human patient TMAs by CDH17 IHC assay demonstrated detectable expression of CDH17 in 90.1% (173/193) of CRC, 51.8% (86/166) of gastric and 20.4% (69/331) of pancreatic cancers. These numbers suggest that an ADC directed against CDH17 could provide benefit to a significant number of patients diagnosed with these cancers. These data support the clinical development of TORL-3-600 for the treatment of CDH17+ cancers. TORL-3-600 has completed IND enabling toxicity studies with acceptable PK and toxicity profiles and is now in phase 1 clinical testing (NCT05948826). Citation Format: Neil A. O'Brien, Martina SJ McDermott, Jun Zhang, Ming Lu, Ke Wei Gong, Benjamin Hoffstrom, Wei Ping Jia, Tong Luo, Athena M. Madrid, Min Liang, John A. Glaspy, Dennis J. Slamon. TORL-3-600, a novel antibody drug conjugate directed against cadherin 17 (CDH17), has preclinical efficacy in colorectal, gastric, and pancreatic cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 1900.

Abstract 1061: Diagnostic application of a novel blood CDH17 immunoassay in the detection of colorectal adenoma

Abstract Background: Colorectal cancer (CRC) is the most prevalent gastrointestinal (GI) cancer and contribute significantly to global cancer deaths. The mechanism of CRC development is a complex multistage process from hyperplastic lesions to the formation of adenomas, followed by the progression into malignancy. Hence, early detection during hyperplastic and adenomatous stages warrants new screening tests for effective interception of malignancy progression. Cadherin-17 (CDH17) is a biomarker characterized by its overexpression in several GI cancers, but restricted expression in intestinal mucosal epithelium of normal tissues. We have developed a blood immunoassay using a panel of RUO grade antibodies that unveiled CDH17 as a potential marker with high detection sensitivity and specificity for detecting adenomas. Our immunoassay is useful in identifying high-risk individuals with adenomas that may develop into CRC, which can significantly improve the diagnostic efficiency of colonoscopy that is currently lacking. Methods: The study recruited 66 patients (54 adenoma and 12 hyperplasia) and 39 normal samples (no abnormality by colonoscopy). CDH17 level in plasma samples were measured using the CDH17 immunoassay. Results: The novel CDH17 diagnostic assay showed an operating dynamic range from 90ng to 123pg. We observed a progressive and significant increase in the circulating CDH17 level from normal samples to the hyperplasia group, followed by the adenoma group (mean: 1.66ng/mL, 3.20ng/mL, 4.93ng/mL, respectively P&amp;lt;0.0001). The assay performance by ROC curve demonstrated an AUC of &amp;gt;0.9, with a sensitivity of 85% and specificity of 86%. NPV and PPV were 84% and 87%, respectively. The assay outperforms two market available FIT-DNA tests at predicting adenomas (Table. 1). Conclusion: The novel CDH17 immunoassay is potentially a powerful tool for the detection of aberrant plasma CDH17 expression, improving the surveillance and the detection of high-risk individuals for CRC. CDH17 immunoassay outperforms market availalble FIT-DNA tests at detecting hyperplasia and adenoma FIT-DNA test 1 FIT-DNA test 2 CDH17 blood immunoassay Age 40-74 Age 50-84 Age 45-93 Sensitivity (%) Advanced adenoma 63.5 42.4 85.0 Non-advanced adenoma (i.e Hyperplasia) Unavailable 17.2 58.3 Specificity (%) Normal control (no abnormality by colonoscopy) 87.1 89.8 86.1 NPV (%) Advanced adenoma Unavailable Unavailable 83.8 Non-advanced adenoma (i.e Hyperplasia) Unavailable Unavailable 86.1 PPV (%) Advanced adenoma Unavailable Unavailable 87.2 Non-advanced adenoma (i.e Hyperplasia) Unavailable Unavailable 58.3 Citation Format: Ng Lui, Felix Hon, Stella Sun, Pauline Leung, David Ho, John Moon Luk, Dominic Chi-Chung Foo. Diagnostic application of a novel blood CDH17 immunoassay in the detection of colorectal adenoma [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 1061.

Targeting CDH17 with Chimeric Antigen Receptor-Redirected T Cells in Small Cell Lung Cancer.

Chimeric antigen receptor T cell (CAR-T) therapy stands as a precise and targeted approach in the treatment of malignancies. In this study, we investigated the feasibility of targeting Cadherin 17 (CDH17) with CDH17 CAR-T cells as a therapeutic modality for small cell lung cancer (SCLC). CDH17 expression levels were assessed in human SCLC tumor tissues and cell lines using qPCR and Western blot. Subsequently, we established CDH17 CAR-T cells and assessed their cytotoxicity by co-culturing them with various SCLC cell lines at different effector-to-target (E:T) ratios, complemented by ELISA assays. To ascertain the specificity of CDH17 CAR-T cells, we conducted experiments on SCLC cells with and without CDH17 expression (shRNAs). Furthermore, we employed an SCLC xenograft model to evaluate the in vivo efficacy of CDH17 CAR-T cells. Our results revealed a significant upregulation of CDH17 in both SCLC tissues and cell lines. CDH17 CAR-T cells exhibited robust cytotoxic activity against SCLC cells in vitro, while demonstrating no cytotoxicity towards CDH17-deficient SCLC cells and HEK293 cells that lack CDH17 expression. Importantly, the production of IFN-γ and TNF-α by CDH17 CAR-T cells correlated with their cytotoxic potency. Additionally, treatment with CDH17 CAR-T cells significantly decelerated the growth rate of SCLC-derived xenograft tumors in vivo. Remarkably, no significant difference in body weight was observed between the control group and the group treated with CDH17 CAR-T cells. The preclinical data open further venues for the clinical use of CDH17 CAR-T cells as an immunotherapeutic strategy for SCLC treatment.

LincRNA-P21 knockdown facilitates esophageal squamous cell carcinoma cell progression by upregulating cadherin 5 via YTH domain containing 1.

LincRNA-P21 is a tumor suppressor in esophageal squamous cell carcinoma (ESCC). Cell adhesion modules play vital roles in cell-cell and cell-extracellular matrix (ECM) interactions and malignant cancer progression. In this study, we investigate whether lincRNA-P21 exerts its functions by regulating the cell adhesion molecule cadherin 5 (CDH5) in ESCC. Moreover, the RNA binding protein (RBP) mediators of lincRNA-P21 and CDH5 are further examined. Cell viability, growth and migratory ability are assessed by calcein-AM/PI double staining, CCK-8, EdU, Transwell, and wound healing assays. The expression of collagen I and fibronectin is examined by immunofluorescence (IF). LincRNA-P21 and CDH5 are quantified by RT-qPCR and western blot analysis. Potential lincRNA-P21 targets are identified by RNA sequencing. RBPs that can interact with lincRNA-P21 and CDH5 are identified by RNA immunoprecipitation (RIP) assay. LincRNA-P21 knockdown increases cell viability, growth, cell migration, and collagen I and fibronectin expression in ESCC cells. LincRNA-P21 depletion induces the dysregulation of 316 genes, including CDH5, in TE-1 cells. CDH5 is identified as a downstream molecule of lincRNA-P21 given its close correlation with cell adhesion, ECM reconstruction, and cancer progression. LincRNA-P21 exerts its functions by negatively regulating CDH5 expression. YTH domain containing 1 (YTHDC1) mediates the regulatory effect of lincRNA-P21 on CDH5. LincRNA-P21 knockdown elevates cell viability and growth, promotes cell migration, and induces ECM reorganization by upregulating CDH5 via RBP YTHDC1 in ESCC.

Phase 1A, first-in-human study of ARB202, bispecific antibody to CDH17 and CD3, in advanced gastrointestinal malignancies expressing CDH17.

25 Background: Cadherin-17 (CDH17) is a highly specific therapeutic cancer target, of which aberrant expression has been reported in 50-95% in GI tumor samples (including stomach, pancreas, liver/bile duct, rectum, and colon). Normal CDH17 expression is primarily in the water-tight junction between mucosal epithelial cells which is potentially “masked” from the immune system (Feng, Z., et al., Nat Cancer, 2022). A bispecific T-cell engager ARB202 using CD3 to aid the formation of an immunological synapse CDH17 tumor cells and T-cells is being studied. Methods: In an ongoing dose-escalation phase IA part of a continuous study, patients with advanced CD17+ solid tumors are being given up to 3 doses of ARB202 bispecific. In part 1, 28 pts can be treated at dose levels from 0.0003 mg/kg to 10 mg/kg; Based on clinical response intra-dosing of tolerated (higher) doses can occur in for the 2nd and 3rd doses. Second and 3 doses are planned at the 4th cohort starting at a dose of 0.010 mg/kg when tissue levels are likely physiologically active. Minimum anticipated biological effect level (MABEL) dosing which is based on the most sensitive in vitro assay is being used to set the initial 3 doses to ensure safety of any T-cell engagement at low levels in circulation. Data cutoff 10.04.23. Results: Colorectal, gastric, pancreatic and cholangiocarcinoma patients have screened positive for CDH17 by semi-automated tissue immunostaining. Seven patients have completed dosing in the first 3 cohorts and have shown tolerability to 0.0003 to 0.003 mg/kg single IV doses. The Cmax measured within 1 hour of dosing has confirmed the circulating PK range of 10-20 ng/ml for the 2nd cohort and 40-50 ng/ml in the 3rd cohort consistent with the expected PK of antibody-like volume of distribution. The safety review committee has approved the dose escalation to proceed to the 4th cohort Identifier: NCT05411133. Conclusions: ARB202 a bispecific T-cell engager has shown tolerability up to 40ng/ml Cmax in circulation suggesting no clinically significant CD3 only binding cell activation at these levels. These data allow for higher dosing to achieve tissue ARB202 concentrations where anti-CDH17/CD3 aided synapse formation between tissue tumor cells and T-cells can lead to clinical evidence of bispecific target engagement and their expected effects. Clinical trial information: NCT05411133 .

Tissue cadherin 17 (CDH17): A favorable prognostic determinant of colorectal cancer using digital image analysis.

e14651 Background: Colorectal cancer (CRC) is the third most diagnosed malignancy and the second leading cause of cancer-death globally. The identification of robust prognostic markers for risk stratification of CRC would facilitate the accurate selection of high-risk patients for adjuvant therapies, hence improving patients’ survival and quality of living. Cadherin 17 (CDH17) is a validated biomarker for CRC characterized by its overexpression in tumor tissues (Zheng et al., 2021). CDH17 expression in tissue samples can be reliably detected by immunohistochemistry (IHC), which could potentially provide useful information for malignancy monitoring and prognosis. Nevertheless, the implementation of IHC in clinical settings is hindered by the lack of standardized guidelines. In this regard, the present study employed a standardized automated IHC platform and a digitalized sample scoring system to investigate CDH17 tissue expression and examine its clinical prognostic value in CRC. Methods: IHC was performed to assess CDH17 expression on paired tumor and adjacent non-tumor tissues from a cohort of 198 retrospective CRC cases, using the Lic3 antibody and an automated IHC system integrated with AI-digital imaging analysis. The M-score was generated for CDH17 membrane staining according to the formula (1 × % of weakly stained cells + 2 × % moderately stained cells + 3 × % of strongly stained cells)/6. Clinical correlation analysis with TNM, differentiation, and metastasis was determined. The prognostic value of tissue CDH17 was evaluated by Kaplan-Meier curves and Cox regression analyses on patients’ OS and RFS. Comparison of M-score and pathologist visual scoring was made to assess the validity of software-derived IHC scoring. Results: A significantly higher tissue CDH17 level was observed in CRC patients with advanced tumour staging (Early vs. Late stage, p = 0.0493; Mann-Whitney U test) and distant metastasis (p = 0.0188; Mann-Whitney U test). CRC patients with high M-score (M-ScoreHigh; cut-off = 30) were associated with poorer OS and shorter RFS (OS, p = 0.015; RFS, p = 0.018; Log-rank test). Subgroup analysis revealed that M-ScoreHigh in early-stage CRC predicts patients’ disease recurrence of less than 2 years after curative surgery (p = 0.025; Log rank test). Multivariate cox regression analysis showed that CDH17 was an independent prognostic factor for OS (HR = 1.918, 95% CI = 1.001-3.676, p = 0.05). A comparison of software-derived CDH17 M-score with pathologist scoring demonstrated good correlation of 0.7257 (p &lt; 0.0001, n = 36; Pearson correlation). Conclusions: The present study suggests that CDH17 is a potential biomarker of poor prognosis for CRC. Quantification of tissue CDH17 level using a standardized automated IHC platform and digital image analysis could aid in patient stratification which allows efficient treatment strategies for better survival outcomes.

Diagnostic application of circulating CDH17 biomarker for screening GI malignancies.

3058 Background: Colorectal cancer (CRC) is the most common and treatable gastrointestinal (GI) cancer, yet it remains the second leading cause of cancer associated deaths globally. Cadherin-17 (CDH17) is a biomarker for GI cancers characterized by its overexpression in stomach, liver, and colorectal cancers but controlled expression in normal tissues from healthy adults. Although an improvement in the detection strategy of CDH17 is essential to apply it for large scale CRC screening. We have developed a novel diagnostic immunoassay using a panel of highly specific antibodies (PCT/US2019/032752) that unveiled CDH17 as a potential diagnostic maker with high detection sensitivity and specificity in CRC. Methods: The study recruited 150 patients (Retrospective specimens - 50 colorectal adenomas and 100 colorectal cancer) and 50 asymptomatic 18-80 years old blood donors (prospective specimens). CDH17 expression levels were measured within the individual blood-plasma samples using an enzyme-linked immunoassay. Results: The novel CDH17 diagnostic assay showed a wide operating dynamic range extending from 90ng to a lower limit of detection at 123pg. Using the assay, we observed a progressive and a significant increase in the plasma CDH17 concentration from the asymptomatic individuals to the colorectal adenoma group, while the CRC patients showed the highest expression of the circulating protein (median: 2.5ng/mL vs 4.5ng/mL vs 8.0ng/mL, P&lt;0.0001). Within the CRC group, a higher CDH17 expression was associated with advanced tumor invasion, occurrence of nodal or distant metastases, as well as a clinical presentation of an advanced stage disease. The diagnostic power of the assay in terms of ROC AUC values was higher than 0.9 with an overall sensitivity of 82% that extended to 100% for metastatic CRC, while the specificity was at 94% for all stages combined (P&lt;0.0001). Plasma CDH17 outperformed the clinically applied CEA and CA19-9 markers in differentiating the CRC patients from the asymptomatic population. Conclusions: The CDH17 immunoassay is potentially a diagnostics tool aid for the detection of CDH17 within blood samples prompting the early diagnosis of CRC. [Table: see text]

Integrated transcriptomics and proteomics data analysis identifies CDH17 as a key cell surface target in colorectal cancer

Immunotherapy development against colorectal cancer (CRC) is hindered by the lack of cell surface target highly expressed in cancer cells but with restricted presence in normal tissues to minimize off-tumor toxicities. In this in silico analysis, a longlist of genes (n = 13,488) expressed in CRCs according to the Human Protein Atlas (HPA) database were evaluated to shortlist for potential surface targets based on the following prerequisites: (i) Absent from the brain and lung tissues to minimize the likelihood of neurologic and pulmonary toxicities; (ii) Restricted expression profile in other normal human tissues; (iii) Genes that potentially encode cell surface proteins and; (iv) At least moderately expressed in CRC cases. Fifteen potential targets were shortlisted and subsequently ranked according to the combination of their transcript and protein expression levels in CRCs derived from multiple datasets (i.e. DepMap, TCGA, CPTAC-2, and HPA CRCs). The top-ranked target with the highest and homogenous expression in CRCs was cadherin 17 (CDH17). Downstream analysis of CRC transcriptomics and proteomics datasets showed that CDH17 was significantly correlated with carcinoembryonic antigen expression. Moreover, CDH17 expression was significantly lower in CRC cases with high microsatellite instability, as well as negatively associated with immune response gene sets and the expression of MHC class I and II molecules. CDH17 represents an optimal target for therapeutic development against CRCs, and this study provides a novel framework to identify key cell surface targets for therapeutic development against other malignancies.

CDH17+/CDX2+ Can be Helpful in Providing Support for Small Intestinal Origin Versus Pancreatic or Biliary Origin.

Because of the distinct and complex anatomy of the ampullary region, the exact origin of the periampullary tumors was often difficult to ascertain. In this study, we evaluated 78 patient samples, including 26 small intestinal adenocarcinomas, 35 pancreatic ductal adenocarcinomas, and 17 cholangiocarcinomas by immunohistochemical detection of cadherin-17 (CDH17), CDX2, CK20, and CK19 protein expression. The result showed that CDH17 and CDX2 expression was higher in small intestinal adenocarcinoma (73.1% and 65.4%) than in pancreatic (14.3% and 2.9%) and bile duct (41.2% and 23.5%) cancers, respectively. CK20 expression was low in 78 tumor tissues, but relatively high in small intestinal adenocarcinoma (42.3%). CK19 showed a strong positive expression in all 78 adenocarcinoma tissues. The CDH17-high/CDX2-high pattern was predominantly expressed in small intestinal cancer tissues (75%), whereas the CDH17-low/CDX2-low pattern was observed in pancreatic cancers (63.8%) and bile duct cancers (20.9%). The study concluded that CDH17-high/CDX2-high adenocarcinomas more likely originated from small intestine versus pancreas or bile duct, whereas CDH17-low/CDX2-low ones are more likely of pancreatic origin. The combined use of CDH17 and CDX2 could be helpful in providing support for the histologic origin of periampullary adenocarcinoma.

Clinical correlation of cadherin-17 (CA17 aka CDH17) marker with advanced tumor stages and poor prognosis of cholangiocarcinoma in a retrospective cohort of 180 patients.

344 Background: Aberrant expression of cadherin-17 (CA17, aka CDH17) cancer marker is often observed in major gastrointestinal (GI) cancers. In this retrospective study, we examined the CA17 tissue expression and analyzed its clinical significance in cholangiocarcinoma (CCA). Methods: A total of 180 patients with detailed demographic and clinical data were enrolled in this study and randomly divided into a training cohort (N = 120) and a validation cohort (N = 60). Biopsy samples (tumor and adjacent normal tissue) collected for tissue microarray were examined by immunohistochemistry using a mouse anti-CA17 monoclonal antibody (Clone 7C5). Image pro plus was applied to score the staining intensity and expression level of CA17 marker. Kaplan-Meier analysis, Cox's proportional hazards regression, and nomogram were applied to evaluate the prognostic significance of CA17. Results: CA17 cancer biomarker over-expression was significantly observed in CCA compared to their non-tumor counterparts (P &lt; 0.001), and positively correlated with aggressive tumor phenotypes, like larger tumor size (P = 0.004), lymph node metastasis (P &lt; 0.001), and advanced TNM stage (P &lt; 0.001). Meanwhile, patients with high expression of CA17 correlated with worse postoperative overall survival (OS)(P = 0.002) and recurrence-free survival (P = 0.03). Besides, multivariate analysis identified that CA17 expression was an independent prognostic factor for cholangiocarcinoma patients (Training cohort: HR:1.716, 95% CI:1.116-2.638; P = 0.014; Validation cohort: HR: 1.811, 95%CI:1.028-3.892; P = 0.035), which indicated that the CA17 is much more efficient than serum CA19-9 (Training cohort: HR: 1.000, 95%CI: 1.000-1.001; P = 0.006; Validation cohort: HR: 1.000,95%CI:1.000-1.001; P = 0.013) in predicting the OS of CCA patients. Notably, the nomogram integrating CA17 expression had a better prognostic performance as compared with current TNM staging systems. Conclusions: CA17 cancer biomarker was aberrantly expressed in CCA tumor tissues, and its high expression level positively correlated with aggressive tumor phenotypes. Furthermore, CA17 was an independent adverse prognostic factor for CCA patients’ survival, which may serve as a potential drug target for CCA patients.

Clinical utility of CDH17 biomarker in tumor tissues and liquid biopsies for detection and prognostic staging of colorectal cancer (CRC).

53 Background: Cancer surveillance using blood-based biomarker tests allows for early cancer detection and more effective prompt treatment. Immunohistochemical staining of tumor-specific antigens can also provide valuable prognostic information and contribute to the design of treatment strategy. Our early studies and work from other investigators have identified cadherin-17 (CDH17) as a promising biomarker in both tumor tissues and liquid biopsies. CDH17 overexpression in cancer tissue was found predictive of poor prognosis in patients with gastric cancer, hepatocellular carcinoma and ovarian cancer. Plasma CDH17 was elevated in patients with gastric cancer when compared to healthy subjects. However, despite the diagnostic and prognostic value of CDH17, robust and accurate assays for CDH17 detection in liquid and tumor biopsies have yet to be developed. Methods: In order to establish CDH17 immunoassays, we have first generated a proprietary library of more than 300 antibodies against CDH17, and from this library, isolated a panel of monoclonal antibodies (mAbs) exhibiting specific and high-affinity binding to the different extracellular domains of CDH17. Results: The immunohistochemical staining of CRC tissues with one of our mAbs revealed a stepwise increase in CDH17 with the progression of cancer from early to late CRC. A sandwich-ELISA was also developed to show significantly elevated plasma CDH17 in patients with CRC when compared to healthy individuals. Like CDH17 expression in CRC tissues, plasma CDH17 also showed a gradual increase with progression to more advanced stages of CRC. The newly developed ELISA also demonstrated that the number of CDH17-containing exosomes was significantly higher in blood isolated from patients with CRC. Notably, our mAbs could also enumerate CDH17-positive circulating tumor cells (CTCs), of which the level was associated with tumor stage. Conclusions: All these findings clearly indicate the clinical utility of CDH17 in tumor tissues and liquid biopsies for detection and prognostic staging of CRC. Further validation of our proprietary CDH17 immunoassays are being conducted in multiple independent CRC cohorts.

Pharmacologic studies of CDH17/CD3 bispecific antibodies to treat colorectal and pancreatic cancers.

116 Background: Immunotherapy has emerged as a new hope for cancer patients who do not respond to conventional therapies. In addition to the widely investigated immune checkpoint inhibitors such as PD-L1 antibody, bispecific T cell redirecting antibodies have also drawn much attention from pharmaceutical companies. The popularity of bispecific T cell engager has been increasing since the US FDA’s accelerated approval of blinatumomab for treatment of haematological malignancies. The clinical efficacy of such engagers in solid tumors have however remained to be demonstrated. Cadherin-17 (CDH17) is a promising immunotherapeutic target for gastrointestinal (GI) cancers. It is a highly tumor-specific antigen with restricted expression limited to the tight junction of intestine that is normally inaccessible to biologics. CDH17 overexpression correlates with tumor burden and poor prognosis. Methods: Fully humanized CDH17/CD3 bispecific antibodies were generated. T cell-mediated cytotoxicity was tested in vitro and in vivo. Safety was addressed in cynomolgus monkeys with intestinal CDH17 level equivalent to that of human. Results: One lead antibody, ARB202 exhibited high-affinity binding to CDH17 and CD3. In the presence of CDH17-positive pancreatic cancer cells, ARB202 stimulated in vitro IL-2 release in CD3/CD28-expanded PBMC. In the absence of tumor cells ARB202 stimulated cytokine production in PBMCs required over 600-fold greater concentrations. ARB202 specifically directed in vitro T cell killing of GI cancer cells expressing CDH17, but not of cells lacking CDH17 expression. In mouse xenograft models reconstituted with human immune cells, ARB202 demonstrated significant tumor growth inhibition with concomitant IL-2 response. No dose-dependent toxicities on cynomolgus monkeys were observed over a 3-log dose range. ARB202 displayed favourable in vivo pharmacokinetic profiles in mice and monkeys. ARB202 is a stable bispecific antibody retaining functional activity after incubation for a month at 37°C at pH6.0. Conclusions: ARB202 is a promising candidate for clinical trials. A proprietary cell line is generated for the pilot manufacturing of ARB202 for IND enabling studies.

Silencing of cadherin-17 enhances apoptosis and inhibits autophagy in colorectal cancer cells.

Cadherin-17 (CDH17), a structurally unique member of the non-classical cadherin family, is associated with poor survival, cell proliferation, and metastasis in colorectal cancer. However, the role of CDH17 in the apoptosis and autophagy of colorectal cancer cells remains unclear. Here, we aimed to investigate the effect of CDH17 knockdown on autophagy and apoptosis in colorectal cancer cells. We inhibited CDH17 expression in KM12SM and KM12C colorectal cancer cells by RNA interference and found that silencing of CDH17 significantly inhibited cell viability and increased apoptosis in KM12SM and KM12C cells. In addition, silencing of CDH17 significantly increased the expression of cleaved caspase-3 and Bax and decreased the expression of Bcl-2. Concurrently, silencing of CDH17 significantly inhibited the conversion of LC3-I to LC3-II and decreased the formation of LC3+ autophagic vacuoles and the accumulation of acidic vesicular organelles, indicating that autophagy was significantly inhibited in KM12SM and KM12C cells. Additionally, treatment with the autophagy-specific activator rapamycin attenuated apoptosis in CDH17-knockdown cells and as indicated by decreased caspase-3 activity, decreased expression of cleaved caspase-3 and Bax, and increased expression of Bcl-2. In conclusion, CDH17 silencing induced apoptosis and inhibited autophagy in KM12SM and KM12C cells, and this autophagy protected the cells from apoptotic cell death.

CDH17 alters MMP-2 expression via canonical NF-κB signalling in human gastric cancer

Gastric cancer (GC), one of the most common cancers of the digestive system, results in high morbidity and mortality, but the molecular mechanisms underlying GC remain largely unknown. Cadherin-17 (CDH17) is a nonclassical member of the cadherin (CDH) superfamily of calcium-dependent proteins. Despite recent advances in the understanding of CDH17 biology, the mechanism of CDH17 in GC proliferation, migration, and invasion has not been extensively studied. In the present study, we observed that CDH17 expression was increased in GC tissues compared with para-carcinoma tissues and was correlated with lymph node metastasis and the AJCC stage. Additionally, a significant correlation was found between CDH17 protein expression and the number of blood and lymph vessels in GC tissues. Furthermore, in vitro suppression of CDH17 expression using short-interfering RNA (siRNA) decreased AGS cell proliferation, migration and invasion. Conversely, overexpression of CDH17 through plasmid transfection enhanced the malignant activity of AGS cells. Moreover, CDH17 increased the matrix metallopeptidase 2 (MMP-2) levels via the canonical nuclear factor-kappaB (NF-κB) pathway. Our findings offer new insights into the mechanism of the CDH17/NF-κB/MMP-2 axis, and the associated signalling pathways might represent novel targets for the treatment of GC.

Inhibition of hsa-miR-6086 protects human umbilical vein endothelial cells against TNFα-induced proliferation inhibition and apoptosis via CDH5

MiRNAs are considered as a novel class of biomarkers or treatment targets for cardiovascular diseases. Hsa-miR-6086, a novel mi-RNA, was reported to be downregulated during the differentiation of human embryonic stem cells into endothelial cells (ECs). Interestingly, CDH5 (cadherin 5), encoding a classical cadherin of the cadherin superfamily, is a cellular marker of ECs and has been reported to be a target of hsa-miR-6086. However, the role of hsa-miR-6086 in ECs is virtually unknown. Herein, we report that hsa-miR-6086 was markedly induced by TNFα stimulation in human umbilical vein endothelial cells (HUVECs), whereas CDH5 expression was greatly reduced. Importantly, TNFα-induced suppression of CDH5 expression was largely prevented by inhibiting hsa-miR-6086, and hsa-miR-6086 mimic greatly decrease CDH5 expression in HUVECs, suggesting that the induction of hsa-miR-6086 is responsible for CDH5 downregulation by TNFα. In addition, restoration of CDH5 expression level by either inhibiting hsa-miR-6086 or exogenously expressing CDH5 cDNA that is not affected by hsa-miR-6086 protected HUVECs against TNFα-induced apoptosis and cell growth inhibition. Taken together, our study reveals that hsa-miR-6086 is induced by TNFα and mediates TNFα-induced HUVEC growth inhibition through downregulating CDH5 expression. Hence, hsa-miR-6086 might be a new target for treating TNFα-induced endothelial dysfunction.

Cadherin 5 Is a Significant Risk Factor for Hematogenous Recurrence and a Prognostic Factor in Locally Advanced Gastric Cancer.

Cadherin 5 (CDH5) is important for adhesion in epithelial cells, and expressed in tumor cells in several malignancies. In the present study, we evaluated the clinical significance of CDH5 protein expression in locally advanced gastric cancer. Tumor tissues obtained from 113 patients with advanced gastric adenocarcinoma who underwent gastrectomy were analyzed. High CDH5 expression was significantly associated with recurrence (p=0.017), especially hematological recurrence (p=0.022). High CDH5 expression was a significant risk factor for hematogenous recurrence on multivariate analysis (odds ratio[OR]=3.9, confidential interval [CI] 1.0-15, p=0.043). Patients with high CDH5 expression had a significantly shorter progression-free interval (RFI, p=0.010) than patients with low CDH5 expression. High CDH5 expression was an independent prognostic factor on multivariate analysis of RFI (hazard ratio[HR]=2.2, 95% CI 1.1-4.3, p=0.021). CDH5 may play a key role in hematogenous recurrence of advanced gastric cancer and may be a viable treatment target.

Cadherin 17 is related to recurrence and poor prognosis of cytokeratin 19-positive hepatocellular carcinoma.

A previous study demonstrated that cytokeratin 19 (CK19) expression in hepatocellular carcinoma (HCC) is an indicator of HCC invasiveness, including lymph node metastasis (LNM), tumor infiltration/non-encapsulation and poor prognosis. The exact mechanism by which CK19 expression results in poor prognosis remains unclear. Through the use of an Affymetrix U133A oligonucleotide microarray [20 patients with hepatitis B virus (HBV)-HCC], it was demonstrated that cadherin 17 (CDH17) significantly correlated with CK19 expression (R2, 0.867; P<0.001) in HBV-HCC. Immunohistochemical analysis (114 patients with HBV-HCC) also demonstrated a significant correlation between CK19 and CDH17 expressions in primary tumor tissue (R2, 0.414; P<0.001). In addition, CK19 and CDH17 expressions levels revealed a significant association with LNM (P<0.001). Cox regression multivariate analysis demonstrated that indocyanine green retention at 15 min >10% and CDH17 expression were independent prognostic factors for disease free survival (P=0.010 and 0.002, respectively). In vitro studies showed that epidermal growth factor can induce the expression of both CK19 and CDH17, and CDH17 in turn can enhance the expression of CK19 in HCC. In summary, this study demonstrated that the early recurrence and poor prognosis of CK19(+) HCC may be due to the expression of CDH17, a gene known to be associated with vascular invasion, tumor metastasis, and advanced tumor stage of HCC. Thus, novel therapeutics by targeting CDH17 may be beneficial for CK19(+) HCC.

Plasma expression of the intestinal metaplasia markers CDH17 and TFF3 in patients with gastric cancer.

Few reliable blood markers are available for detecting gastric cancer, mainly owing to the heterogeneity of the cancer. To establish gastric cancer diagnostic markers, we evaluated the levels of plasma cadherin 17 (CDH17) and trefoil factor 3 (TFF3), which are secretory proteins and known markers for intestinal metaplasia (IM), in patients with gastric cancer. The protein expression level was analyzed in blood plasma samples from 111 gastric cancer patients and 44 healthy individuals, using a sandwich ELISA kit, followed by statistical analyses. Overall, the plasma levels of CDH17 and TFF3 were not significantly different between groups (p= 0.160 and p= 0.113, respectively). However, CDH17 expression was significantly elevated in patients with stage II and III gastric cancers compared to that in healthy controls (p= 0.023 and p= 0.037, respectively). In contrast, TFF3 levels were significantly elevated in patients with stage I (p= 0.001) and T1 gastric cancer (p= 0.013). The sensitivity and specificity of CDH17 were 66.7 and 61.4%, respectively (cutoff point: 0.189 ng/mL); for TFF3, these values were 62.2 and 56.8%, respectively (cutoff point: 5.215 ng/mL). These findings indicate that secretory protein markers for metaplastic lineages can be used as blood markers for gastric cancer.

Abstract 3089: Combining MEK and HDAC inhibitors as a therapeutic strategy to promote differentiation of colorectal cancer

Abstract The five-year survival rate for patients with metastatic colorectal cancer is less than 15%, necessitating an urgent need to develop novel therapeutic strategies for this disease. Loss of differentiation is associated with worse overall survival in colorectal cancer, suggesting that strategies to re-induce differentiation may provide clinical benefit. Differentiation therapy is effective in the treatment of acute promyelocytic leukemia but whether this approach can be efficacious in treating colorectal cancer is unknown. Inhibitors of the MAPK signaling pathway including the MEK inhibitor Trametinib can induce markers of differentiation in colorectal cancer cells. Trametinib also induces expression of Cdx-2, a known driver of colonic cell differentiation. Similarly, histone deacetylase inhibitors (HDACi) induce markers of differentiation in multiple tumor cell lines, including colon cancer cells. The aim of this study was to assess the potential therapeutic benefit of combining MEK (Trametinib) and HDAC (Panobinostat) inhibitors to further promote differentiation in colorectal cancer cells, and to elucidate the mechanistic basis for this effect. Combination treatment of HT29 and T84 cells with Trametinib and Panobinostat significantly enhanced mRNA and protein expression of the differentiation markers Cadherin 17 (CDH17) and Keratin 20 (KRT20), compared to either agent alone. Trametinib also induced expression of Cdx-2, an effect that was enhanced upon combination treatment with Panobinostat. Notably, Cdx-2 knockdown attenuated CDH17 and KRT20 induction by the combination, establishing a direct role for Cdx-2 in differentiation induction by the Trametinib/Panobinostat combination. Concomitant with inducing differentiation, the drug combination also invoked more apoptosis than either agent alone. To validate these findings in vivo, HT29 cells grown as xenografts were treated with Trametinib and Panobinostat alone and in combination. Mice treated with the combination had significantly smaller tumours than mice treated with vehicle or either agent alone. Consistent with the in vitro findings, immunostaining of the tumour xenografts demonstrated a strong increase in CDH17, KRT20 and Cdx2 expression upon treatment with the drug combination. Collectively, this study highlights a drug combination strategy to re-induce differentiation for the treatment of colorectal cancers. Citation Format: Laura J. Jenkins, Ian Y. Luk, Janson W. Tse, Jennifer Mooi, Amardeep S. Dhillon, John M. Mariadason. Combining MEK and HDAC inhibitors as a therapeutic strategy to promote differentiation of colorectal cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 3089. doi:10.1158/1538-7445.AM2017-3089