Overexpression of LI-cadherin in gastric cancer is associated with lymph node metastasis

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

BACKGROUND

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).

METHODS

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.

RESULTS

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.

CONCLUSIONS

The preclinical data open further venues for the clinical use of CDH17 CAR-T cells as an immunotherapeutic strategy for SCLC treatment.

Proteomic profiling and network biology of colorectal cancer liver metastasis

INTRODUCTION

Tissue-based proteomic studies of colorectal cancer (CRC) metastasis have delivered fragmented results, with very few therapeutic targets and prognostic biomarkers moving beyond the discovery phase. This situation is likely due to the difficulties in obtaining and analyzing large numbers of patient-derived metastatic samples, the own heterogeneity of CRC, and technical limitations in proteomics discovery. As an alternative, metastatic CRC cell lines provide a flexible framework to investigate the underlying mechanisms and network biology of metastasis for target discovery.

AREAS COVERED

In this perspective, we comment on different in-depth proteomic studies of metastatic versus non-metastatic CRC cell lines. Identified metastasis-related proteins are introduced and discussed according to the spatial location in different cellular fractions, with special emphasis on membrane/adhesion proteins, secreted proteins, and nuclear factors, including miRNAs associated with liver metastasis. Moreover, we analyze the biological significance and potential therapeutic applications of the identified liver metastasis-related proteins.

EXPERT OPINION

The combination of protein discovery and functional analysis is the only way to accelerate the progress to clinical translation of the proteomic-derived findings in a relatively fast pace. Patient-derived organoids represent a promising alternative to patient tissues and cell lines, but further optimizations are still required for achieving solid and reproducible results.

Mechanism of dimerization and structural features of human LI-cadherin

Liver intestine (LI)-cadherin is a member of the cadherin superfamily, which encompasses a group of Ca2+-dependent cell-adhesion proteins. The expression of LI-cadherin is observed on various types of cells in the human body, such as normal small intestine and colon cells, and gastric cancer cells. Because its expression is not observed on normal gastric cells, LI-cadherin is a promising target for gastric cancer imaging. However, because the cell adhesion mechanism of LI-cadherin has remained unknown, rational design of therapeutic molecules targeting this cadherin has been hampered. Here, we have studied the homodimerization mechanism of LI-cadherin. We report the crystal structure of the LI-cadherin homodimer containing its first four extracellular cadherin repeats (EC1-4). The EC1-4 homodimer exhibited a unique architecture different from that of other cadherins reported so far, driven by the interactions between EC2 of one protein chain and EC4 of the second protein chain. The crystal structure also revealed that LI-cadherin possesses a noncanonical calcium ion-free linker between the EC2 and EC3 domains. Various biochemical techniques and molecular dynamics simulations were employed to elucidate the mechanism of homodimerization. We also showed that the formation of the homodimer observed in the crystal structure is necessary for LI-cadherin-dependent cell adhesion by performing cell aggregation assays. Taken together, our data provide structural insights necessary to advance the use of LI-cadherin as a target for imaging gastric cancer.

Inhibition of CDH17 gene expression via RNA interference reduces proliferation and apoptosis of human MKN28 gastric cancer cells

Gastric cancer is the fourth most common type of cancer and the second cause of cancer-related mortalities worldwide despite the use of multimodal therapy. Cadherins are transmembrane glycoproteins that are involved in tumorigenesis. CDH17 has been found to be over-expressed in gastric cancer and its overexpression was associated with lymph node metastasis and tumor-node-metastasis stage of the patients, yet the exact role and molecular mechanism of CDH17 in gastric cancer have not been determined. Using a lentiviral system as a delivery mediator of RNA interference, we found that inhibition of CDH17 can lead to reduce proliferation and increase apoptosis of gastric cancer cell line MKN28 in vitro and significantly diminish their tumorigenicity in vivo. Our results of the present study suggest that CDH17 may be a promising candidate for the therapeutic targeting of gastric cancer.

Knockdown of LI-cadherin alters expression of matrix metalloproteinase-2 and -9 and galectin-3

Liver-intestine cadherin (LI-cadherin), a novel member of the cadherin family, has been associated with the ability of a tumor to acquire an aggressive phenotype in several types of cancer. However, the exact function of LI-cadherin in the process of tumor invasion and metastasis remains predominantly unknown. To explore the effect of LI-cadherin on the regulation of matrix metalloproteinase-2 (MMP-2), MMP-9 and galectin-3 in LoVo human colorectal cancer cells, a RNA interference technique was applied to suppress the expression of LI‑cadherin. Subsequently, the mRNA levels and activities of MMP-2 and -9 were analyzed by semi-quantitative reverse transcription-polymerase chain reaction and gelatin zymography, respectively. Additionally, the protein expression level of galectin-3 was determined by western blot analysis. The results of the present study demonstrated that short hairpin RNA (shRNA)-silencing of LI-cadherin significantly increased the mRNA levels and activities of MMP‑2 and ‑9, and significantly reduced the protein levels of galectin‑3 in LoVo cells compared with control shRNA (P<0.05). These data indicate that knockdown of LI‑cadherin facilitates the invasion of cancer cells by degrading extracellular matrix components via activation of MMP‑2 and ‑9, and increases cancer cell adhesion and migration via altered expression of galectin‑3. This suggests that LI‑cadherin serves an important role in the invasion and metastasis of colorectal cancer, and may be used as a potential therapeutic target.

Targeting cadherin-17 inactivates Ras/Raf/MEK/ERK signaling and inhibits cell proliferation in gastric cancer

Cadherin-17 (CDH17), one member of 7D-cadherin superfamily, was overexpressed in gastric cancer (GC) and was associated with poor survival, tumor recurrence, metastasis, and advanced tumor stage. So far the cellular function and signaling mechanism of CDH17 in GC remains unclear. In this study, we showed that over 66% of GC cell lines (20/30) were CDH17 positive. Tissue microarray (TMA) assay showed that 73.6% Chinese GC tissues (159/216) were CDH17 positive, while 37% respective adjacent normal tissues were CDH17 positive. Knockdown of CDH17 inhibited cell proliferation, migration, adhesion and colony formation, and also induced a cell cycle arrest and apoptosis in AGS human GC cells. On the other side, overexpression of CDH17 facilitated MGC-803 GC tumor growth in nude mice. Antibody array and Western blotting assay demonstrated that knockdown of CDH17 in AGS cells down-regulated integrin β series proteins, further inactivated the Ras/Raf/MEK/ERK pathway and led to p53 and p21 accumulation, which resulted in proliferation inhibition, cell-cycle arrest and apoptosis induction. Collectively, our data firstly demonstrate the capacity of CDH17 to regulate the activity of Ras/Raf/MEK/ERK pathway for cell proliferation in GC, and suggest that CDH17 can serve as an attractive therapeutic target for future research.

Significance of preoperative tissue levels of vascular-endothelial cadherin, liver-intestine cadherin and vascular endothelial growth factor in gastric cancer

BACKGROUND/AIMS

The aims of this study were to examine the expressions of endothelium specific VE-cadherin, intestine specific LI-cadherin, and vascular endothelial growth factor (VEGF), and to determine their relationships with the clinicopathological parameters of gastric cancer.

METHODS

A total 47 patients with gastric cancer who underwent surgery were enrolled. Endoscopic biopsies were obtained from the cancer and normal mucosa, respectively. Using semiquantitative RT-PCR, the mRNA expression levels of VE-cadherin, LI-cadherin and VEGF were measured by tumor/normal (T/N) ratios. The protein expressions of VE-cadherin, LI-cadherin and VEGF were examined by Western blot and immunohistochemical stain in surgically resected tissues. The clinicopathological variables were reviewed and analyzed, retrospectively.

RESULTS

Twenty two cases (46.8%) of VE-cadherin, 25 cases (53.2%) of LI-cadherin and 27 cases (51.1%) of VEGF mRNA expressions were overexpressed in gastric cancer compared to normal tissue. There was a tendency for T/N ratio of VE-cadherin mRNA to correlate with the lymphatic invasion (p=0.07) and the lymph node metastasis (p=0.099) in advanced gastric cancer. The T/N ratio of LI-cadherin mRNA showed significant association with distant metastasis (p=0.031) and lymphatic invasion especially in advanced gastric cancer (p=0.023). There was a tendency for the T/N ratio of VEGF mRNA to correlate with the distant metastasis (p=0.073) in advanced gastric cancer.

CONCLUSIONS

As increased mRNA expression of LI-cadherin was associated with distant metastasis and lymphatic invasion especially in the biopsy specimen of advanced gastric cancer before surgery, it may provide useful preoperative information on tumor aggressiveness.

Cadherin-17 induces tumorigenesis and lymphatic metastasis in gastric cancer through activation of NFκB signaling pathway

Cadherin-17 (CDH17), as a structurally unique member of the cadherin superfamily, has been identified to predict a poor prognosis for gastric cancer (GC). Our previous study demonstrated the positive correlation between CDH17 and lymph node micrometastasis in GC. We sought to further identify the role of CDH17 in the tumorigenesis and lymphatic metastasis of GC. Hence, we inhibited the CDH17 expression in MKN-45 gastric cancer cells by using RNA interference. Consequently, the malignant potency of cancer cells was evaluated, and the change in NFκB signaling pathway was also probed. Tumor growth and lymphatic metastasis model were conducted in nude mice to confirm the hypothesis. Downregulation of CDH17 not only suppressed the proliferation, adherence and invasion potency of MKN-45 cells, but also induced cell cycle arrest. Meanwhile, the NFκB signaling pathway was inactivated as well, with the reductions of downstream proteins including VEGF-C and MMP-9. Moreover, silencing CDH17 inhibited tumor growth in vivo significantly, and there was no lymph node metastasis detected in the mice without CDH17 expression, as opposed to the positive nodes found in controls. CDH17 is a novel oncogene in gastric cancer cells, which is associated with lymphatic metastasis and proliferation strongly. The inactivation of NFκB signaling pathway might be involved in targeting CDH17 in GC. On the whole, CDH17 is proposed to serve as a biomarker and attractive therapeutic target in GC.

Single nucleotide polymorphisms in the CDH17 gene of colorectal carcinoma

AIM: To investigate the relationship between c.343A>G and c.2216A>C polymorphism sites in the CDH17 gene and colorectal carcinoma.

METHODS: Ninety-three non-consanguineous colorectal carcinoma patients admitted to the Department of Oncology at the First Affiliated Hospital of Zhengzhou University were included in this study. Ninety-three peripheral venous blood samples, of approximately one milliliter from each patient, were collected between December 2009 and August 2010. The genomic DNA of these peripheral venous blood samples were extracted and purified using a Fermentas Genomic DNA Purification Kit (Fermentas, CA) according to the manufacturer’s protocol. The single nucleotide polymorphisms (SNPs) of the liver-intestine cadherin (CDH17) gene c.343A>G and c.2216A>C were determined by the polymerase chain reaction-single strand conformation polymorphism method (PCR-SSCP) in 93 peripheral venous blood samples from patients suffering with colorectal carcinoma. Typical samples that showed different migration bands in SSCP were confirmed by sequencing. Directed DNA sequencing was used to check the correctness of the genotype results from the PCR-SSCP method.

RESULTS: There was a significant association between the c.2216 A>C SNPs of the CDH17 gene and the tumor-node-metastasis (TNM) grade, as well as with lymph node status, in 93 peripheral venous blood samples from colorectal carcinoma patients. The genotype frequencies of A/C, A/A, and C/C were 12.90%, 33.33% and 53.76%, respectively. There was a significant correlation between lymph node metastasis, TNM grade, and the genotype distribution (P < 0.05). The C/C genotype raised the risk of lymph node metastasis and the TNM grade. There was a significant difference in the TNM grade and lymph node metastasis between the A/A and C/C genotypes (P = 0.003 and P = 0.013, respectively). Patients with colorectal carcinoma carrying the C allele tended to have a higher risk of lymph node metastasis and have a higher TNM grade. The difference between the TNM grades, as well as the lymph node metastasis of the two alleles, was statistically significant (P < 0.01).

CONCLUSION: The SNPs of the CDH17 gene c.2216 A>C might be clinically important in the prognosis of colorectal carcinoma.

Tissue-specific cadherin CDH17 is a useful marker of gastrointestinal adenocarcinomas with higher sensitivity than CDX2

Cadherin 17 (CDH17) is a cell adhesion molecule expressed in intestinal epithelium and transcriptionally regulated by CDX2. We compared the usefulness of CDH17 as an immunohistochemical intestinal marker to that of CDX2 in gastrointestinal and extragastrointestinal carcinomas and nonneoplastic tissues. Nonneoplastic intestinal and pancreatic duct epithelia were CDH17-positive. Most esophageal (79%), gastric (86%), and colonic (99%) adenocarcinomas were CDH17-positive/CDX2-positive, whereas 1% of colonic, 18% of esophageal, and 10% of gastric adenocarcinomas were CDH17-negative/CDX2-negative. Rare colonic, esophageal, and gastric adenocarcinomas were CDH17-positive/CDX2-negative (1%, 3%, and 4%, respectively), and none were CDH17-negative/CDX2-positive. Diffuse CDH17 was also observed in all metastatic colon carcinomas, 20% of which were only focally CDX2-positive. Of intestinal low-grade neuroendocrine tumors, 74% coexpressed CDX2 and CDH17. CDH17 was also positive in 12% of pancreatic and 24% of bronchial neuroendocrine tumors, all of which were CDX2-negative. Pancreatic adenocarcinomas and cholangiocarcinomas were more frequently CDH17-positive than CDX2-positive (50% vs 27%, 53% vs 27%). One (2%) hepatocellular carcinoma was CDH17-positive/CDX2-negative. Nine percent of non-small cell lung cancers and 7% of endometrial carcinomas were CDH17-positive, whereas 3% of lung, 5% of endometrial, 3% of ovarian, and 2% of breast carcinomas were CDX2-positive. Thus, CDH17 is slightly more sensitive than CDX2 when detecting gastrointestinal adenocarcinomas.

The predictive effect of cadherin-17 on lymph node micrometastasis in pN0 gastric cancer

BACKGROUND

Previous studies identified cadherin-17 (CDH17) as one of the most upregulated genes in node-positive gastric cancer. However, the prognostic significance of CDH17 in pN0 gastric cancer and its association with lymph node micrometastasis (LNMM) have not been investigated.

METHODS

Clinicopathologic features of 191 patients with node-negative gastric cancer were studied retrospectively. All dissected lymph nodes were immunostained by cytokeratin to detect micrometastasis. CDH17 and lymphatic invasion (LVI) in primary carcinoma were evaluated by immunostaining of monoclonal CDH17 and D2-40 antibody. Correlation of CDH17 with clinicopathologic characteristics was subsequently assessed. Risk factors of LNMM were analyzed by univariate and multivariate logistic regression. Cox's proportional hazard model was applied to investigate independent prognostic factors of pN0 gastric cancer. Overall survival rates of patients with positive and negative CDH17 were compared, stratifying by pT stage, Lauren grade, and LNMM status.

RESULTS

CDH17 was observed in 126 patients (66.0%). Positive expression of CDH17 was significantly associated with the age, tumor size, pT, Lauren grade, LVI, and LNMM, and identified as one of the independent risk factors of LNMM. Negative predictors of pN0 gastric cancer included pT, Lauren grade, LNMM, and CDH17. Furthermore, in tumors of pT2-3, intestinal histotype, and negative-LNMM, the survival rate of patients with CDH17 was significantly lower than that of patients without CDH17.

CONCLUSIONS

CDH17 was positively associated with larger tumor size, deeper invasion, diffuse/mixed histotype, LVI, and LNMM, predicting a poor prognosis in pN0 gastric cancer. Additionally, CDH17 may also serve as a potential indicator of LNMM.

HNF1α and CDX2 transcriptional factors bind to cadherin-17 (CDH17) gene promoter and modulate its expression in hepatocellular carcinoma

Cadherin-17 (CDH17) belongs to the cell adhesion cadherin family with a prominent role in tumorigenesis. It is highly expressed in human hepatocellular carcinoma (HCC) and is proposed to be a biomarker and therapeutic molecule for liver malignancy. The present study aims to identify the transcription factors which interact and regulate CDH17 promoter activity that might contribute to the up-regulation of CDH17 gene in human HCC. A 1-kb upstream sequence of CDH17 gene was cloned and the promoter activity was studied by luciferase reporter assay. By bioinformatics analysis, deletion and mutation assays, and chromatin immunoprecipitation studies, we identified hepatic nuclear factor 1α (HNF1α) and caudal-related homeobox 2 (CDX2) binding sites at the proximal promoter region which modulate the CDH17 promoter activities in two HCC cell lines (Hep3B and MHCC97L). A consistent down-regulation of CDH17 and the two transcriptional activators (HNF1α and CDX2) expression was found in the liver of mouse during development, as well as in human liver cancer cells with less metastatic potential. Suppression of HNF1α and CDX2 expression by small interfering RNA (siRNA) significantly down-regulated expressions of CDH17 and its downstream target cyclin D1 and the viability of HCC cells in vitro. In summary, we identified the minimal promoter region of CDH17 that is regulated by HNF1α and CDX2 transcriptional factors. The present findings enhance our understanding on the regulatory mechanisms of CDH17 oncogene in HCC, and may shed new insights into targeting CDH17 expression as potential therapeutic intervention for cancer treatment.

Knockdown of Li-cadherin increases metastatic behaviors of LoVo cells

PURPOSE

The aim of this study was to investigate the role of Li-cadherin in invasion and metastasis in LoVo cells.

METHODS

We applied RNA interference mediated downregulation of Li-cadherin expression in LoVo cells. Li-cadherin expression in LoVo cells was examined by semiquantitative polymerase chain reaction, immunofluorescence, western blot, and immunoprecipitation, respectively. Effect of suppression of Li-cadherin expression on cell migration, invasion, and adhesion was detected by wound healing assay, migration assay, invasion assay, and adhesion assay. Expression and activity of MMP-2 and MMP-9 were analyzed by gelatin zymography.

RESULTS

Cell migration, invasion, and adhesion were increased concomitantly with the reduction in Li-cadherin protein expression. Furthermore, downregulation of Li-cadherin expression induced secretion of proMMP-9, active MMP-9 and active MMP-2.

CONCLUSIONS

This study suggests that silencing Li-cadherin has positive actions in the processes of LoVo cells invasion and metastasis, and the interactions among MMP-2, MMP-9, and Li-cadherin participate in the multiple steps of invasion and metastasis in LoVo colorectal cancer cells.

Comparison of six immunohistochemical markers for the histologic diagnosis of neoplasia in Barrett's esophagus

In esophageal neoplasms, the histopathologic differentiation between Barrett's esophagus with or without intraepithelial neoplasia and adenocarcinoma is often challenging. Immunohistochemistry might help to differentiate between these lesions. The expression of CDX2, LI-cadherin, mucin 2 (MUC2), blood group 8 (BG8, Lewis(y)), claudin-2, and villin was investigated in normal gastroesophageal (n = 23) and in Barrett's (n = 17) mucosa, in low-grade (n = 12) and high-grade (n = 9) intraepithelial neoplasia (IEN) as well as in esophageal adenocarcinoma (n = 16), using immunohistochemistry. For CDX2 and LI-cadherin, the immunoreactivity score was highest in IEN while for MUC2, BG8, and villin, it dropped gradually from Barrett's via IEN to adenocarcinoma, and expression of Claudin-2 was only weak and focal in all lesions. The expression of MUC2 and LI-cadherin differed significantly between all examined lesions except between low-grade and high-grade IEN. MUC2 and LI-cadherin are useful immunohistochemical markers for the differentiation between normal glandular mucosa, Barrett's mucosa, IEN, and invasive carcinoma of the esophagus; however, none of the examined markers was helpful for the differentiation between low-grade and high-grade IEN.

Role of cadherin-17 in oncogenesis and potential therapeutic implications in hepatocellular carcinoma

Cadherin is an important cell adhesion molecule that plays paramount roles in organ development and the maintenance of tissue integrity. Dysregulation of cadherin expression is often associated with disease pathology including tissue dysplasia, tumor formation, and metastasis. Cadherin-17 (CDH17), belonging to a subclass of 7D-cadherin superfamily, is present in fetal liver and gastrointestinal tract during embryogenesis, but the gene becomes silenced in healthy adult liver and stomach tissues. It functions as a peptide transporter and a cell adhesion molecule to maintain tissue integrity in epithelia. However, recent findings from our group and others have reported aberrant expression of CDH17 in major gastrointestinal malignancies including hepatocellular carcinoma (HCC), stomach and colorectal cancers, and its clinical association with tumor metastasis and advanced tumor stages. Furthermore, alternative splice isoforms and genetic polymorphisms of CDH17 gene have been identified in HCC and linked to an increased risk of HCC. CDH17 is an attractive target for HCC therapy. Targeting CDH17 in HCC can inhibit tumor growth and inactivate Wnt signaling pathway in concomitance with activation of tumor suppressor genes. Further investigation on CDH17-mediated oncogenic signaling and cognate molecular mechanisms would shed light on new targeting therapy on HCC and potentially other gastrointestinal malignancies.

CDX2 and LI-cadherin expression in esophageal mucosa: use of both markers can facilitate the histologic diagnosis of Barrett's esophagus and carcinoma

BACKGROUND

Barrett's mucosa is a risk factor for esophageal adenocarcinoma and should be detected at an early stage. CDX2 and liver-intestine (LI)-cadherin are intestine-specific markers. Aberrant CDX2 expression has been demonstrated in Barrett's metaplasia, esophagitis, and intestinal metaplasia of the stomach.

METHODS

The relationship between CDX2 and LI-cadherin expression was investigated in normal gastroesophageal (n = 24) and in Barrett's (n = 20) mucosa, in low-grade (n = 15) and high-grade (n = 13) intraepithelial neoplasia (IEN) as well as in esophageal adenocarcinoma (n = 16), using immunohistochemistry.

RESULTS

Nuclear positivity for CDX2 coupled with membranous expression of LI-cadherin was observed in about 70% of the epithelial cells of Barrett's mucosa. The intensity of staining and the percentage of positive cells increased within the sequential steps of low-grade to high-grade IEN, whereas the normal cylindric epithelium lacked the expression of both. In adenocarcinoma, the expression of LI-cadherin and CDX2 was significantly weaker or absent.

CONCLUSIONS

CDX2 and LI-cadherin are sensitive markers of intestinal metaplasia with or without dysplasia in the upper gastrointestinal tract. Both can be helpful for the early histologic diagnosis of Barrett's esophagus and its subsequent lesions; however, they do not significantly discern between different grades of dysplasia.

Targeting cadherin-17 inactivates Wnt signaling and inhibits tumor growth in liver carcinoma

Hepatocellular carcinoma (HCC) is a lethal malignancy for which there are no effective therapies. To develop rational therapeutic approaches for treating this disease, we are performing proof-of-principle studies targeting molecules crucial for the development of HCC. Here, we show that cadherin-17 (CDH17) adhesion molecule is up-regulated in human liver cancers and can transform premalignant liver progenitor cells to produce liver carcinomas in mice. RNA interference-mediated knockdown of CDH17 inhibited proliferation of both primary and highly metastatic HCC cell lines in vitro and in vivo. The antitumor mechanisms underlying CDH17 inhibition involve inactivation of Wnt signaling, because growth inhibition and cell death were accompanied by relocalization of beta-catenin to the cytoplasm and a concomitant reduction in cyclin D1 and an increase in retinoblastoma.

CONCLUSION

Our results identify CDH17 as a novel oncogene in HCC and suggest that CDH17 is a biomarker and attractive therapeutic target for this aggressive malignancy.

Liver-intestine cadherin predicts microvascular invasion and poor prognosis of hepatitis B virus-positive hepatocellular carcinoma

BACKGROUND

Liver-intestine cadherin (LI-cadherin; CDH-17) is a new member of the cadherin superfamily with distinct structural and functional features. The study was designed to investigate the role of LI-cadherin in tumor invasion and prognosis of human hepatitis B virus (HBV)-positive hepatocellular carcinoma (HCC).

METHODS

LI-cadherin expression in HBV-positive hepatocellular carcinoma cell lines with low- and high-invasive potentials was evaluated by Western-blot, immunofluorescence, and real-time polymerase chain reaction (PCR) analyses. The role of LI-cadherin in tumor invasion was also evaluated in vitro by a small-interfering ribonucleic acid (siRNA)-mediated approach. The prognostic significance of LI-cadherin was validated in a cohort of HBV-positive HCC patients by immunohistochemistry and Western-blot.

RESULTS

Significant high levels of LI-cadherin mRNA and protein were found in the high-invasive HCCLM3 as compared with those in low-invasive PLC/PRF/5 and Hep3B cell line. Cell migration, adhesion to extracellular matrix, and matrigel invasion were significantly reduced after LI-cadherin knockdown in HCCLM3 cells. Immunohistochemical analysis of 255 HBV-positive HCC cases showed that overexpression of LI-cadherin was well correlated with microvascular invasion, which was confirmed by Western-blot in 32 tumor tissues, and its overexpression was strongly associated with shorter overall survival as well as higher incidence of tumor recurrence.

CONCLUSIONS

LI-cadherin is predictive of microvascular invasion and poor prognosis of HBV-positive HCC, and would be a potential useful intervention target for HCC.

Transcriptome dissection of gastric cancer: identification of novel diagnostic and therapeutic targets from pathology specimens

Gastric cancer is the fourth most common malignancy in the world, and mortality due to gastric cancer is second only to that from lung cancer. 'Transcriptome dissection' is a detailed analysis of the entire expressed transcripts from a cancer, for the purpose of understanding the precise molecular mechanism of pathogenesis. Serial analysis of gene expression (SAGE) is a suitable technique for performing transcriptome dissection. Gastric cancers of different stages and histology were analyzed on SAGE, and one of the largest gastric cancer SAGE libraries in the world was created (GEO accession number GSE 545). Through SAGE, many candidate genes have been identified as potential diagnostic and therapeutic targets for the treatment of gastric cancer. Regenerating islet-derived family, member 4 (Reg IV) participated in 5-fluorouracil (5-FU) resistance and peritoneal metastasis, and its expression was associated with an intestinal phenotype of gastric cancer and with endocrine differentiation. GW112 expression correlated with advanced tumor stage. Measurement of Reg IV and GW112 levels in sera indicated a sensitivity of 57% for detection of cancer. SPC18 participated in tumor growth and invasion through transforming tumor growth factor-alpha upregulation. Palate, lung, and nasal epithelium carcinoma-associated protein (PLUNC) was a useful marker for gastric hepatoid adenocarcinoma. Expression of SOX9, HOXA10, CDH17, and loss of claudin-18 expression were associated with an intestinal phenotype of gastric cancer. Information obtained from transcriptome dissection greatly contributes to diagnosis and treatment of gastric cancer.

Li-cadherin is inversely correlated with galectin-3 expression in gastric cancer

The aims of this study were to examine the expressions of Li-cadherin and Galectin-3 in gastric cancer, and the correlation between Li-cadherin and Galectin-3 in gastric cancer was also analyzed. The present study investigated the expression level of Li-cadherin and Galectin-3 by immunohistochemistry and semiquantitative polymerase chain reaction (PCR), and correlated this with clinicopathologic parameters in 91 cases of gastric cancer. The correlation between expression levels of Li-cadherin and Galectin-3 was analyzed by Spearman correlation analysis. The expression level of Li-cadherin mRNA was correlated to differentiation and lymph node metastasis, and the expression level of Galectin-3 was related to TNM staging, differentiation and lymph node metastasis. On Spearman correlation analysis, a definitive negative correlation was found between the expression levels of Li-cadherin and Galectin-3 in gastric cancerous tissues. We postulate that interaction between Li-cadherin and Galectin-3 may play an important role in the development of gastric cancer.

High DcR3 expression predicts stage pN2-3 in gastric cancer

BACKGROUND

A soluble decoy receptor 3 (DcR3), also known as TR6 or M68, is a member of the TNF receptor family. It has been reported that high DcR3 expression occurs in many tumors.

METHODS

This prospective study evaluated the DcR3 tissue status by RT-PCR and its correlation with the lymph node (N) stages in 62 primary gastric cancers.

RESULTS

DcR3 expression levels in patients with pN2-3 disease were much higher than those in patients with pN0-1 disease (median values 1.31 vs. 0, P < 0.01). Using ROC analysis, a cutoff level of DcR3 expression at 1.20 was found to be associated with optimal sensitivity and specificity of 62.5% (15 of 24) and 92.1% (35 of 38) respectively, in the prediction of stage pN2-3. According to the cutoff value, patients were divided into 2 groups with relatively high and low levels of DcR3 expression. Among the 18 patients with high DcR3 expression, 83.3% (15 of 18) were staged as pN2-3. In the other 44 patients with low DcR3 expression, only 20.5% (9 of 44) were identified as pN2-3. Logistic regression analysis for stage pN2-3 revealed that high DcR3 expression was an independent risk factor.

CONCLUSION

Gastric cancer patients with high DcR3 expression presented more advanced pN2-3 disease than those with low DcR3 expression. Preoperative checking DcR3 expression might be an additional approach to imaging modalities for evaluating N stages in gastric cancer to guide the operative procedures.

Liver intestine-cadherin (CDH17) haplotype is associated with increased risk of hepatocellular carcinoma

PURPOSE

Hepatocellular carcinoma (HCC), the most common form of liver cancer, is a leading cause of cancer death worldwide. We previously showed that aberrant mRNA splicing of the liver intestine-cadherin gene CDH17 in liver tissues was triggered by the specific constellation of two CDH17 single nucleotide polymorphisms (651T and IVS6+35G). CDH17 aberrant splicing was highly associated with tumor dissemination and shorter survival of HCC patients. Consequently, it is highly relevant to assess whether the presence of these single nucleotide polymorphisms in the general population represents a risk to the development of HCC.

EXPERIMENTAL DESIGN

We conducted a case-control study including 164 HCC and 99 cirrhosis patients and 293 healthy controls. Genotyping was done by PCR and direct sequencing. Odds ratio (OR) and chi2 analysis were used to analyze genotypes and haplotypes.

RESULTS

Genotypes 651TT [OR, 2.62; 95% confidence interval (95% CI), 1.34-5.03] and IVS6+35 GG (OR, 1.95; 95% CI, 1.04-3.62) were highly associated with HCC disease. The 651T (C>T) and IVS6+35G (A>G) alleles were also overrepresented in HCC patients and, in particular, the T-G haplotype was the most prevalent in HCC patients when compared with healthy controls (OR, 1.57; 95% CI, 1.167-2.109; P=0.004), which was in agreement with the aberrant splicing observed in tumor tissues. There was no significant difference in genotype and allele frequencies between cirrhosis patients and controls.

CONCLUSION

The functional T-G haplotype of CDH17 (651 C>T and IVS6+35A>G) is a genetic susceptibility factor for the development of HCC in a Chinese population.

The prognostic significance of E-cadherin and liver intestine-cadherin expression in colorectal cancer

PURPOSE

The significance of liver intestine-cadherin as a potential marker has been growing in the field of oncology, because of its unique features compared with classic cadherins. We investigated the coexpression patterns of E-cadherin and liver intestine-cadherin in colorectal cancer, and determined whether differences in expression patterns were associated with clinicopathologic parameters and also which relationship between these two adhesion molecules existed in colorectal cancer.

METHODS

Expression pattern of E-cadherin and liver intestine-cadherin was investigated immunohistochemically in 207 colorectal cancers along with clinicopathologic parameters.

RESULTS

Reduced expression of liver intestine-cadherin was detected in 51 percent (n = 105) of tumors. Such expression was found to be associated with tumoral dedifferentiation (P = 0.015) and in a multivariate analysis was associated with a significant worse overall survival after adjustment for tumor stage, differentiation, and E-cadherin status (hazard ratio, 1.951; 95 percent confidence interval, 1.06-3.592; P = 0.032). Fifteen percent (n = 32) of tumors showed reduced expression of E-cadherin and had relationship with tumoral dedifferentiation (P < 0.001), lymph node metastasis (P = 0.004), and advanced stage (P = 0.029). Reduced expression of E-cadherin was associated with short overall survival (P = 0.028); however, in a multivariate analysis, it was not statistically significant.

CONCLUSIONS

Reduced expression of liver intestine-cadherin had a significant correlation with tumoral dedifferentiation and short overall survival in this series. In addition, early and frequent loss of liver intestine-cadherin expression might be a more sensitive indicator than E-cadherin to predict more aggressive tumoral behavior.

Phenotypic classification of gastric signet ring cell carcinoma and its relationship with clinicopathologic parameters and prognosis

AIM: To distinguish subtypes of gastric signet ring cell (SRC) carcinoma by investigating the expression of gastric and intestinal phenotypic markers, and to study the significance of phenotypic classification in predicting tumor progression and outcome.

METHODS: Immunohistochemistry was performed in 66 cases of SRC carcinoma with MUC2, VILLIN, CDX2, Li-cadherin antibodies as intestinal phenotype markers and MUC5AC, HGM, MUC6 antibodies as gastric phenotype markers, and the relationship was analyzed between the phenotypic expression pattern and clinicopathologic parameters, as well as the 3-year survival rate.

RESULTS: Expression of intestinal phenotypic markers was positively associated with tumor size, wall invasion, vascular invasion, lymph node metastasis and tumor-node-metastasis (TNM) stage. Cases expressing one or more intestinal markers had a significant lower survival rate than cases expressing none of the intestinal markers.

CONCLUSION: The SRC carcinomas expressing intestinal phenotype markers exhibited a high pro-liferative potential, bad biological behaviors and poor prognosis. Examination of phenotype expression may be useful in distinguishing histological type and in predicting the prognosis of gastric SRC carcinoma.

MUC4 Mucin Potentiates Pancreatic Tumor Cell Proliferation, Survival, and Invasive Properties and Interferes with Its Interaction to Extracellular Matrix Proteins

MUC4, a transmembrane mucin, is aberrantly expressed in pancreatic adenocarcinomas while remaining undetectable in the normal pancreas. Recent studies have shown that the expression of MUC4 is associated with the progression of pancreatic cancer and is inversely correlated with the prognosis of pancreatic cancer patients. In the present study, we have examined the phenotypic and molecular consequences of MUC4 silencing with an aim of establishing the mechanistic basis for its observed role in the pathogenesis of pancreatic cancer. The silencing of MUC4 expression was achieved by stable expression of a MUC4-specific short hairpin RNA in CD18/HPAF, a highly metastatic pancreatic adenocarcinoma cell line. A significant decrease in MUC4 expression was detected in MUC4-knockdown (CD18/HPAF-siMUC4) cells compared with the parental and scrambled short interfering RNA-transfected (CD18/HPAF-Scr) control cells by immunoblot analysis and immunofluorescence confocal microscopy. Consistent with our previous observation, inhibition of MUC4 expression restrained the pancreatic tumor cell growth and metastasis as shown in an orthotopic mouse model. Our in vitro studies revealed that MUC4-associated increase in tumor cell growth resulted from both the enhanced proliferation and reduced cell death. Furthermore, MUC4 expression was also associated with significantly increased invasiveness (P < or = 0.05) and changes in actin organization. The presence of MUC4 on the cell surface was shown to interfere with the tumor cell-extracellular matrix interactions, in part, by inhibiting the integrin-mediated cell adhesion. An altered expression of growth- and metastasis-associated genes (LI-cadherin, CEACAM6, RAC1, AnnexinA1, thrombomodulin, epiregulin, S100A4, TP53, TP53BP, caspase-2, caspase-3, caspase-7, plakoglobin, and neuregulin-2) was also observed as a consequence of the silencing of MUC4. In conclusion, our study provides experimental evidence that supports the functional significance of MUC4 in pancreatic cancer progression and indicates a novel role for MUC4 in cancer cell signaling.

Altered expression of a Li-cadherin in gastric cancer and intestinal metaplasia

The aims of this study were to examine Li-cadherin expression in 74 gastric carcinoma tissues, 10 cases with normal gastric tissues, and 21 cases with intestinal metaplasia and to investigate the role of Li-cadherin in cell differentiation, cancer invasion, and metastasis. Expression of Li-cadherin was analyzed by immunohistochemistry and semiquantitative polymerase chain reaction and correlated with clinicopathological parameters. Immunohistochemistry showed that Li-cadherin was mainly present on the cell membrane and there was no staining for liver-intestine cadherin in normal tissues. The reduction of Li-cadherin mRNA expression was inversely correlated with the grade of differentiation (P < 0.05). Significant differences in the expression of liver-intestine cadherin were found in lymphatic metastasis of the tumors (P < 0.05), but the expression of liver-intestine cadherin was not associated with gender (P=0.748), serosal invasion (P=0.136), TNM stage (P=0.172), Helicobacter pylori infection (P=0.572), liver metastasis (P=0.374), or peritoneal metastasis (P=0.621). Multivariate analysis revealed that the expression of Li-cadherin is an important predictor of lymph node metastasis. We conclude that there is a significant correlation between Li-cadherin expression and the differentiation of gastric carcinoma, and Li-cadherin can be a good marker to detect gastric cancer at early stages. Increased Li-cadherin expression may contribute to gastric cancer invasion to lymph nodes.

Molecular characteristics of differentiated-type gastric carcinoma with distinct mucin phenotype: LI-cadherin is associated with intestinal phenotype

Gastric carcinomas (GC) are classified into four phenotypes on the basis of the mucin expression profile: G type (gastric or foveolar phenotype), I type (intestinal phenotype), GI type (intestinal and gastric mixed phenotype) and N type (neither gastric nor intestinal phenotype). Immunohistochemistry was used to examine the expression of epidermal growth factor receptor (EGFR), E-cadherin, liver-intestine (LI)-cadherin, CD44v9 and p53 and correlation of these molecules with mucin phenotype and tumor stage was evaluated. Overexpression of EGFR and LI-cadherin, reduced expression of E-cadherin and abnormal expression of p53 were observed more frequently in advanced GC than in early GC. Among I-type GC, overexpression of EGFR and reduced expression of E-cadherin were observed more frequently in advanced tumors than in early tumors. Among G-type GC, reduced expression of E-cadherin was significantly associated with advanced tumors. With respect to the relationship between mucin phenotype and expression of cancer-related molecules, overexpression of LI-cadherin was observed more frequently in I-type (12/25, 48.0%) than in G-type (1/14, 7.1%) GC. I-type GC tended to express LI-cadherin more frequently than GI-type GC. These results provide insights into the molecular characteristics of the distinct mucin phenotype of differentiated-type GC and suggest that LI-cadherin may contribute to the biological behavior of I-type GC.

Clinicopathological significant and prognostic influence of cadherin-17 expression in gastric cancer

Cadherin-17 (CDH17), also called liver-intestine cadherin, is a structurally unique member of the cadherin superfamily. Our serial analysis of gene expression demonstrated that CDH17 was one of the most up-regulated genes in advanced gastric carcinomas. CDH17 expression is known to be regulated by Cdx2. In the present study, we examined the expression of CDH17 in primary gastric carcinoma tissues by immunohistochemistry, and analyzed the correlation of CDH17 expression with clinicopathological characteristics and patients prognosis. CDH17 expression was detected in 63/94 (67%) of gastric adenocarcinomas in addition to intestinal metaplasia. The expression of CDH17 tended to be associated with intestinal type carcinoma, and carcinomas with CDH17 expression was significantly more frequent in advanced stage cases (80%) than in early stage (53%). The prognosis of patients with positive CDH17 expression was significantly poorer than that of the negative cases (P=0.0314). However, multivariate analysis revealed that CDH17 was not an independent prognostic factor. Six of seven cases that showed positive expression of Cdx2 simultaneously expressed CDH17 protein. These results suggested that the expression of CDH17 was characteristic of the advanced gastric carcinoma that is associated with poor prognosis.

CDX2 co-localizes with liver-intestine cadherin in intestinal metaplasia and adenocarcinoma of the stomach

CDX2 and liver-intestine (LI)-cadherin are intestine-specific markers and both are physiologically expressed in the small intestine and colon. Recent studies have demonstrated that CDX2 regulates LI-cadherin gene (CDH17) expression in colorectal cancer. The present study investigated the relationship of CDX2 and LI-cadherin expression in gastric cancer. One hundred and nine pairs of tumour and non-cancerous gastric mucosa were collected from gastrectomy specimens. Protein expression levels of CDX2 and LI-cadherin were determined by immunohistochemical staining. Semi-quantitative RT-PCR showed that the mRNAs of both CDX2 and CDH17 were highly expressed in tumour compared with non-cancerous mucosa. Overexpression of CDX2 was significantly associated with CDH17 in gastric adenocarcinoma. Furthermore, the expression of CDX2 and LI-cadherin proteins was strongly coupled in intestinal metaplasia. In conclusion, overexpression of CDH17 is significantly associated with CDX2.

Alternative mRNA Splicing of Liver Intestine-Cadherin in Hepatocellular Carcinoma

Purpose: To identify alternative splicing of the liver intestine-cadherin (LI-cadherin) gene in hepatocellular carcinoma (HCC) and correlate its aberrant expression with clinical outcomes.

Experimental Design: Reverse transcription-PCR (RT-PCR) and quantitative real-time RT-PCR were used to examine alternative mRNA splicing and mRNA level of LI-cadherin in 50 paired tumor-peritumor tissues of 50 HCC and 8 normal liver specimens. The minigene exon-trapping strategy was employed to investigate the splicing mechanism introduced by nucleotide polymorphisms. Association of LI-cadherin splicing with tumor venous infiltration, first-year tumor recurrence, and overall survival after partial hepatectomy were determined.

Results: Alternative mRNA splicing of LI-cadherin was identified in half of the HCC specimens. Sequencing analysis indicated the loss of exon 7 in the spliced LI-cadherin gene. LI-cadherin mRNA was up-regulated from 2.58-fold to 800-fold in over 80% of HCC samples when compared with normal liver by quantitative PCR. Furthermore, nucleotide polymorphisms were identified in putative branch point at IVS6 + 35 (intron 6) as well as in coding sequence 651 (exon 6) in HCC tissues, which may affect alternative mRNA splicing. Clinically, those patients who harbored the alternative splicing of LI-cadherin were strongly associated with shorter overall survival time (P &lt; 0.01) as well as higher incidences of tumor recurrences and venous infiltration (both P &lt; 0.05) after hepatectomy.

Conclusions: Over-expression of LI-cadherin was frequently detected in liver cancer patients. Aberrant alternative splicing of LI-cadherin was detected in 50% of HCC specimens and its clinical significance hinted at early tumor recurrence and poor overall survival of HCC patients.