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

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.

Impact of Alternative Splicing Variants on Liver Cancer Biology

Simple Summary

Among the top ten deadly solid tumors are the two most frequent liver cancers, hepatocellular carcinoma, and intrahepatic cholangiocarcinoma, whose development and malignancy are favored by multifactorial conditions, which include aberrant maturation of pre-mRNA due to abnormalities in either the machinery involved in the splicing, i.e., the spliceosome and associated factors, or the nucleotide sequences of essential sites for the exon recognition process. As a consequence of cancer-associated aberrant splicing in hepatocytes- and cholangiocytes-derived cancer cells, abnormal proteins are synthesized. They contribute to the dysregulated proliferation and eventually transformation of these cells to phenotypes with enhanced invasiveness, migration, and multidrug resistance, which contributes to the poor prognosis that characterizes these liver cancers.

Abstract

The two most frequent primary cancers affecting the liver, whose incidence is growing worldwide, are hepatocellular carcinoma (HCC) and intrahepatic cholangiocarcinoma (iCCA), which are among the five most lethal solid tumors with meager 5-year survival rates. The common difficulty in most cases to reach an early diagnosis, the aggressive invasiveness of both tumors, and the lack of favorable response to pharmacotherapy, either classical chemotherapy or modern targeted therapy, account for the poor outcome of these patients. Alternative splicing (AS) during pre-mRNA maturation results in changes that might affect proteins involved in different aspects of cancer biology, such as cell cycle dysregulation, cytoskeleton disorganization, migration, and adhesion, which favors carcinogenesis, tumor promotion, and progression, allowing cancer cells to escape from pharmacological treatments. Reasons accounting for cancer-associated aberrant splicing include mutations that create or disrupt splicing sites or splicing enhancers or silencers, abnormal expression of splicing factors, and impaired signaling pathways affecting the activity of the splicing machinery. Here we have reviewed the available information regarding the impact of AS on liver carcinogenesis and the development of malignant characteristics of HCC and iCCA, whose understanding is required to develop novel therapeutical approaches aimed at manipulating the phenotype of cancer cells.

Tandem mass tag-based proteomics for studying the effects of a biotechnologically produced oyster mushroom against hepatic steatosis in obese Zucker rats

Hepatic steatosis is a very common response to liver injury and often attributed to metabolic disorders. Prior studies have demonstrated the efficacy of a biotechnologically produced oyster mushroom (Pleurotus sajor-caju, PSC) in alleviating hepatic steatosis in obese Zucker rats. This study aims to elucidate molecular events underlying the anti-steatotic effects of PSC. Tandem mass tag (TMT) peptide labeling coupled with LC-MS/MS/MS was used to quantify and compare proteins in the livers of lean Zucker rats fed a control diet (LC), obese Zucker rats fed the same control diet (OC) and obese Zucker rats fed the control diet supplemented with 5% PSC (OPSC) for 4 weeks. Using this technique 3128 proteins could be quantified, out of which 108 were differentially abundant between the OPSC and OC group. Functional enrichment analysis of the up-regulated proteins showed that these proteins were mainly involved in metabolic processes, while the down-regulated proteins were involved in inflammatory processes. Results from proteomic analysis were successfully validated for two up-regulated (carbonic anhydrase 3, regucalcin) and two down-regulated (cadherin-17, ceruloplasmin) proteins by means of immunoblotting. SIGNIFICANCE: Valorization of low-grade agricultural waste by edible fungi, such as the mushroom Pleurotus sajor-caju (PSC), represents a promising strategy for the production of protein rich biomass since they boast of a unique enzyme system that has the ability to recover nutrients and energy from biodegradable waste. Herein, we describe the metabolic effects of PSC feeding using a combined quantitative proteomics and bioinformatics approach. In total, 108 proteins were identified to be regulated by PSC feeding in the liver of the obese rats. Complementary usage of a bioinformatics approach allowed us to decipher the mechanisms underlying the recently observed lipid-lowering and anti-inflammatory activity of PSC feeding in obese Zucker rats, namely a reduction of fatty acid synthesis, an improvement of hepatoprotective mechanisms and an enhancement of anti-inflammatory effects.

Significant change of cytochrome P450s activities in patients with hepatocellular carcinoma

The lack of information concerning individual variation in drug-metabolizing enzymes is one of the most important obstacles for designing personalized medicine approaches for hepatocellular carcinoma (HCC) patients. To assess cytochrome P450 (CYP) in the metabolism of endogenous and exogenous molecules in an HCC setting, the activity changes of 10 major CYPs in microsomes from 105 normal and 102 HCC liver tissue samples were investigated. We found that CYP activity values expressed as intrinsic clearance (CL_int) differed between HCC patients and control subjects. HCC patient samples showed increased CL_int for CYP2C9, CYP2D6, and CYP2E1 compared to controls. Meanwhile, CYP1A2, CYP2C8, and CYP2C19 CL_int values decreased and CYP2A6, CYP2B6, and CYP3A4/5 activity was unchanged relative to controls. For patients with HCC accompanied by fibrosis or cirrhosis, the same activity changes were seen for the CYP isoforms, except for CYP2D6 which had higher values in HCC patients with cirrhosis. Moreover, CYP2D6*10 (100C>T), CYP2C9*3 (42614 A>C), and CYP3A5*3 (6986A>G) polymorphisms had definite effects on enzyme activities. In the HCC group, the CL_int of CYP2D6*10 mutant homozygote was decreased by 95% compared to wild-type samples, and the frequency of this homozygote was 2.8-fold lower than the controls.

In conclusion, the activities of CYP isoforms were differentially affected in HCC patients. Genetic polymorphisms of some CYP enzymes, especially CYP2D6*10, could affect enzyme activity. CYP2D6*10 allelic frequency was significantly different between HCC patients and control subjects. These findings may be useful for personalizing the clinical treatment of HCC patients as well as predicting the risk of hepatocarcinogenesis.

Changes in cytochrome P450s-mediated drug clearance in patients with hepatocellular carcinoma in vitro and in vivo: a bottom-up approach

Hepatocellular carcinoma (HCC) accompanied by severe liver dysfunction is a serious disease, which results in altered hepatic clearance. Generally, maintenance doses depend upon drug clearance, so individual dosage regimens should be customized for HCC patients based on the condition of patients. Based on clearance of CYP isoform-specific substrates at the microsomal level (CL_M), microsomal protein per gram of liver (MPPGL), liver weight, hepatic blood flow, hepatic clearance values (CL_H) for 10 CYPs in HCC patients (n=102) were extrapolated using a predictive bottom-up pharmacokinetic model. Compared with controls, the CL_M values for CYP2C9, 2D6, 2E1 were significantly increased in HCC patients. Additionally, CYP1A2, 2C8, 2C19 CL_M values decreased while the values for CYP2A6, 2B6, 3A4/5 were unchanged. The MPPGL values in HCC tissues were significantly reduced. CL_H values of HCC patients for CYP1A2, 2A6, 2B6, 2C8, 2C19, and 3A4/5 were significantly reduced, while this for CYP2E1 were markedly increased and those for CYP2C9 and 2D6 did not change. Moreover, disease (fibrosis and cirrhosis) and polymorphisms of the CYP genes have influenced the CL_H for some CYPs. Prediction of the effects of HCC on drug clearance may be helpful for the design of clinical studies and the clinical management of drugs in HCC patients.

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.

Anti-cadherin-17 antibody modulates beta-catenin signaling and tumorigenicity of hepatocellular carcinoma

Cadherin-17 (CDH17) is an oncofetal molecule associated with poor prognostic outcomes of hepatocellular carcinoma (HCC), for which the treatment options are very limited. The present study investigates the therapeutic potential of a monoclonal antibody (Lic5) that targets the CDH17 antigen in HCC. In vitro experiments showed Lic5 could markedly reduce CDH17 expression in a dose-dependent manner, suppress β-catenin signaling, and induce cleavages of apoptotic enzymes caspase-8 and -9 in HCC cells. Treatment of animals in subcutaneous HCC xenograft model similarly demonstrated significant tumor growth inhibition (TGI) using Lic5 antibody alone (5 mg/kg, i.p., t.i.w.; ca.60–65% TGI vs. vehicle at day 28), or in combination with conventional chemotherapy regimen (cisplatin 1 mg/kg; ca. 85–90% TGI). Strikingly, lung metastasis was markedly suppressed by Lic5 treatments. Immunohistochemical and western blot analyses of xenograft explants revealed inactivation of the Wnt pathway and suppression of Wnt signaling components in HCC tissues. Collectively, anti-CDH17 antibody promises as an effective biologic agent for treating malignant HCC.

Targeting CDH17 suppresses tumor progression in gastric cancer by downregulating Wnt/β-catenin signaling

PURPOSE

Gastric cancer remains one of the leading causes of cancer death worldwide. Patients usually present late with local invasion or metastasis, for which there are no effective therapies available. Following previous studies that identified the adhesion molecule Cadherin-17(CDH17) as a potential marker for gastric carcinoma, we performed proof-of-principle studies to develop rational therapeutic approaches targeting CDH17 for treating this disease.

METHODS

Immunohistochemistry was used to study the expression of CDH17 in 156 gastric carcinomas, and the relationship between survival and CDH17 expression was studied by multivariate analyses. The effect of RNA interference-mediated knockdown of CDH17 on proliferation of gastric carcinoma cell lines was examined in vitro and in vivo, as well as the effects on downstream signaling by immunoblotting.

RESULTS

CDH17 was consistently up-regulated in human gastric cancers, and overall survival in patients with CDH17 upregulation was poorer than in those without expression of this gene (5 yrs overall survival rate 29.0% vs. 45.0%, P<0.01). Functional assays demonstrated that CDH17 knockdown inhibited cell proliferation, adhesion, migration, invasion, clonogenicity and induce G0/G1 arrest. In mice, shRNA-mediated CDH17 knockdown markedly inhibits tumor growth; intratumoral injection of CDH17 shRNAs results in significant antitumor effects on transplanted tumor models. The antitumor mechanisms underlying CDH17 inhibition involve inactivation of Wnt/β-catenin signaling.

CONCLUSION

Our results identify CDH17 as a biomarker of gastric carcinoma and attractive therapeutic target for this aggressive malignancy.

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.

A new method for post Genome-Wide Association Study (GWAS) analysis of colorectal cancer in Taiwan

Recently, single nucleotide polymorphisms (SNPs) located in specific loci or genes have been identified associated with susceptibility to colorectal cancer (CRC) in Genome-Wide Association Studies (GWAS). However, in different ethnicities and regions, the genetic variations and the environmental factors can widely vary. Therefore, here we propose a post-GWAS analysis method to investigate the CRC susceptibility SNPs in Taiwan by conducting a replication analysis and bioinformatics analysis. One hundred and forty-four significant SNPs from published GWAS results were collected by a literature survey, and two hundred and eighteen CRC samples and 385 normal samples were collected for post-GWAS analysis. Finally, twenty-six significant SNPs were identified and reported as associated with susceptibility to colorectal cancer, other cancers, obesity, and celiac disease in a previous GWAS study. Functional analysis results of 26 SNPs indicate that most biological processes identified are involved in regulating immune responses and apoptosis. In addition, an efficient prediction model was constructed by applying Jackknife feature selection and ANOVA testing. As compared to another risk prediction model of CRC for European Caucasians population, which performs 0.616 of AUC by using 54 SNPs, the proposed model shows good performance in predicting CRC risk within the Taiwanese population, i.e., 0.724 AUC by using 16 SNPs. We believe that the proposed risk prediction model is highly promising for predicting CRC risk within the Taiwanese population. In addition, the functional analysis results could be helpful to explore the potential associated regulatory mechanisms that may be involved in CRC development.

Genomic and metabolic responses to methionine-restricted and methionine-restricted, cysteine-supplemented diets in Fischer 344 rat inguinal adipose tissue, liver and quadriceps muscle

BACKGROUND/AIMS

Methionine restriction (MR) is a dietary intervention that increases lifespan, reduces adiposity and improves insulin sensitivity. These effects are reversed by supplementation of the MR diet with cysteine (MRC). Genomic and metabolomic studies were conducted to identify potential mechanisms by which MR induces favorable metabolic effects, and that are reversed by cysteine supplementation.

METHODS

Gene expression was examined by microarray analysis and TaqMan quantitative PCR. Levels of selected proteins were measured by Western blot and metabolic intermediates were analyzed by mass spectrometry.

RESULTS

MR increased lipid metabolism in inguinal adipose tissue and quadriceps muscle while it decreased lipid synthesis in liver. In inguinal adipose tissue, MR not only caused the transcriptional upregulation of genes associated with fatty acid synthesis but also of Lpin1, Pc, Pck1 and Pdk1, genes that are associated with glyceroneogenesis. MR also upregulated lipolysis-associated genes in inguinal fat and led to increased oxidation in this tissue, as suggested by higher levels of methionine sulfoxide and 13-HODE + 9-HODE compared to control-fed (CF) rats. Moreover, MR caused a trend toward the downregulation of inflammation-associated genes in inguinal adipose tissue. MRC reversed most gene and metabolite changes induced by MR in inguinal adipose tissue, but drove the expression of Elovl6, Lpin1, Pc, and Pdk1 below CF levels. In liver, MR decreased levels of a number of long-chain fatty acids, glycerol and glycerol-3-phosphate corresponding with the gene expression data. Although MR increased the expression of genes associated with carbohydrate metabolism, levels of glycolytic intermediates were below CF levels. MR, however, stimulated gluconeogenesis and ketogenesis in liver tissue. As previously reported, sulfur amino acids derived from methionine were decreased in liver by MR, but homocysteine levels were elevated. Increased liver homocysteine levels by MR were associated with decreased cystathionine β-synthase (CBS) protein levels and lowered vitamin B6 and 5-methyltetrahydrofolate (5MeTHF) content. Finally, MR upregulated fibroblast growth factor 21 (FGF21) gene and protein levels in both liver and adipose tissues. MRC reversed some of MR's effects in liver and upregulated the transcription of genes associated with inflammation and carcinogenesis such as Cxcl16, Cdh17, Mmp12, Mybl1, and Cav1 among others. In quadriceps muscle, MR upregulated lipid metabolism-associated genes and increased 3-hydroxybutyrate levels suggesting increased fatty acid oxidation as well as stimulation of gluconeogenesis and glycogenolysis in this tissue.

CONCLUSION

Increased lipid metabolism in inguinal adipose tissue and quadriceps muscle, decreased triglyceride synthesis in liver and the downregulation of inflammation-associated genes are among the factors that could favor the lean phenotype and increased insulin sensitivity observed in MR rats.

Up-regulation of cadherin 17 and down-regulation of homeodomain protein CDX2 correlate with tumor progression and unfavorable prognosis in epithelial ovarian cancer

OBJECTIVE

Cadherin 17 (CDH17), belonging to the 7D-cadherin superfamily, represents a novel oncogene, which is involved in tumor invasion and metastasis. Its expression has been demonstrated to be regulated by caudal-related homeobox transcription factor CDX2. The roles of 2 biomarkers have been conflictingly explained. Therefore, the aims of this study were to investigate the expression patterns of CDH17 and CDX2 in human epithelial ovarian cancer (EOC) and to evaluate the clinical significance of these 2 markers in the progression and prognosis of EOC.

METHODS

CDH17 and CDX2 expressions in 182 paraffin-embedded EOC specimens were detected by immunohistochemical staining. Associations of their expression with clinical pathological factors and overall survival were statistically evaluated.

RESULTS

Compared with normal surface ovarian epithelium tissues, CDH17 expression was upregulated and CDX2 expression was downregulated in EOC tissues. There was a negative correlation between CDH17 and CDX2 expression in EOC tissues (r = -0.76, P = 0.001). Tumors with high CDH17 expression were more likely to have advanced stage (P = 0.01) and higher grade (P = 0.03). Patients with low CDX2 expression were more frequently to be at the advanced stage of disease (P = 0.01). In addition, univariate analysis indicated that the patients with high CDH17 expression correlated with poor prognosis in patients with EOC (P = 0.001), as opposed to CDX2 (P = 0.003). Especially, the survival rate of patients with EOC with CDH17-high/CDX2-low expression was the lowest (P < 0.001). Multivariate statistical analysis showed that the conjoined expression of CDH17/CDX2 was an independent prognostic indicator of EOC (P = 0.01).

CONCLUSIONS

Our data suggest that both the up-regulation of CDH17 and the down-regulation of CDX2 may be associated with the advanced stage of EOC. A conjoined detection of CDH17/CDX2 expression may be associated with unfavorable prognosis in patients with this disease.

Genetic risk of hepatocellular carcinoma in patients with hepatitis C virus: a case control study

BACKGROUND AND AIM

Chronic hepatitis C virus (HCV) infection is a well known risk factor for hepatocellular carcinoma (HCC). The aim of this study is to elucidate the genetic risk of development and recurrence of HCC in patients with HCV.

METHODS

A total of 468 patients with HCV, including 265 with HCC were enrolled. We genotyped 88 single nucleotide polymorphisms (SNPs) in 81 genes expected to influence hepatocarcinogenesis using the iPLEX assay. Risk of HCC was clarified by stratifying patients into risk groups based on the multiplied odds ratio (MOR) for SNPs associated with HCC, and the cumulative effects on the development and recurrence of HCC were analyzed.

RESULTS

Six SNPs associated with risk of HCC were identified (OR range: 0.29-1.76). These included novel SNPs for hepatocarcinogenesis with HCV CCND2 rs1049606, RAD23B rs1805329, CEP164 rs573455, and GRP78rs430397 in addition to the known SNPs MDM2 rs2279744 and ALDH2 rs671. MOR analysis revealed that the highest risk group exerted about a 19-fold higher relative OR compared with the lowest risk group (P = 1.08 × 10(-5)). Predicted 10-year HCC risk ranged from 1.7% to 96% depending on the risk group and the extent of fibrosis. Recurrence-free survival of radiofrequency ablation-treated HCC in the high risk group (n = 53) was lower than that of low risk group (n = 58, P = 0.038).

CONCLUSION

Single nucleotide polymorphisms of CCND2, RAD23B, GRP78, CEP164, MDM2, and ALDH2 genes were significantly associated with development and recurrence of HCC in Japanese patients with HCV.

Blockade of proliferation and migration of gastric cancer via targeting CDH17 with an artificial microRNA

Liver-intestine cadherin (CDH17) is a novel member of the cadherin superfamily implicated in gastric cancer progression. To determine the role of CDH17 in the process of gastric cancer invasive growth, in the present study, RNA interference mediated by recombinant lentivirus vectors expressing artificial CDH17 miRNA was applied to induce a long-lasting down-regulation of CDH17 gene expression in BGC823 cells. The expression levels of CDH17, tumor cell motility, migration potential, and pro-liferation were measured by flow cytometry, real-time RT-PCR, Western blot analysis, immunofluorescence staining, wound healing assay, and MTT assay, respectively. Results show that four recombinant plasmid expression vectors encoding pre-miRNA against CDH17, pcDNA-CDH17-miR-SR1, -SR2, -SR3, and -SR4 were constructed correctly and down-regulated the CDH17 mRNA levels by 5.5, 57, 91, and 98%, respectively, in BGC823 cells which had an overexpression of CDH17. We packaged the recombinant lentiviral vector for CDH17 RNA interference with pcDNA-CDH17-miR-SR4 which had the highest interfering efficiency and succeeded in construction of the stable transfectants. Of note, more than 90% knockdown of CDH17 expression in BGC823 cells was obtained by miRNA technique. The CDH17-miRNA-transfected cells showed significant decrease in cell proliferation, cell motility, and migration in comparison with the control cells. Thus, we proposed that CDH17 may be an oncogene up-regulating invasive features of gastric cancer cells and could be a hopeful target for the control of gastric cancer progression.

Dickkopfs and Wnt/β-catenin signalling in liver cancer

Liver cancer is the fifth and seventh most common cause of cancer in men and women, respectively. Wnt/β-catenin signalling has emerged as a critical player in both the development of normal liver as well as an oncogenic driver in hepatocellular carcinoma (HCC). Based on the current understanding, this article summarizes the possible mechanisms for the aberrant activation of this pathway with specific focus on HCC. Furthermore, we will discuss the role of dickkopfs (DKKs) in regulating Wnt/β-catenin signalling, which is poorly understood and understudied. DKKs are a family of secreted proteins that comprise at least four members, namely DKK1-DKK4, which act as inhibitors of Wnt/β-catenin signalling. Nevertheless, not all members antagonize Wnt/β-catenin signalling. Their functional significance in hepatocarcinogenesis remains to be further characterized for which these studies should provide new insights into the regulatory role of DKKs in Wnt/β-catenin signalling in hepatic carcinogenesis. Because of the important oncogenic roles, there are an increasing number of therapeutic molecules targeting β-catenin and the Wnt/β-catenin pathway for potential therapy of HCC.

Lentiviral-mediated miRNA against liver-intestine cadherin suppresses tumor growth and invasiveness of human gastric cancer

Liver-intestine cadherin (CDH17) represents a novel type of cadherin within the cadherin superfamily, and is distinguished from other cadherins by its distinct structural and functional features. Our previous studies had identified that increased CDH17 was significantly associated with tumor differentiation and lymph node metastasis in gastric cancer. In this study, we tested the hypothesis that CDH17 was associated with proliferation and invasiveness in gastric cancer using recombinant lentivirus-mediated miRNA targeting to CDH17 both in vitro and in vivo. We also detected the activity of matrix metalloproteinase (MMP)-2 and MMP-9 with gelatin zymography to explore the mechanisms underlying the inhibition of the CDH17 gene. Our results showed that a well-differentiated gastric cancer cell line had higher CDH17 expression. Down-regulation of CDH17 inhibited proliferation, adherence, and invasion of the poorly differentiated BGC823 gastric cancer cells in vitro, and induced cell cycle arrest. The activities of MMP-2 and MMP-9 were lower in the CDH17-miRNA-transfected cells compared to the control cells. Using an in vivo tumor growth assay, we confirmed that CDH17 silencing could obviously slow the growth of gastric cancer derived from BGC823 cells. Taken together, we have demonstrated that CDH17 maybe a positive regulator for proliferative, adhesive, and invasive behaviors of gastric cancer.

Impairment of pre-mRNA splicing in liver disease: Mechanisms and consequences

Pre-mRNA splicing is an essential step in the process of gene expression in eukaryotes and consists of the removal of introns and the linking of exons to generate mature mRNAs. This is a highly regulated mechanism that allows the alternative usage of exons, the retention of intronic sequences and the generation of exonic sequences of variable length. Most human genes undergo splicing events, and disruptions of this process have been associated with a variety of diseases, including cancer. Hepatocellular carcinoma (HCC) is a molecularly heterogeneous type of tumor that usually develops in a cirrhotic liver. Alterations in pre-mRNA splicing of some genes have been observed in liver cancer, and although still scarce, the available data suggest that splicing defects may have a role in hepatocarcinogenesis. Here we briefly review the general mechanisms that regulate pre-mRNA splicing, and discuss some examples that illustrate how this process is impaired in liver tumorigenesis, and may contribute to HCC development. We believe that a more thorough examination of pre-mRNA splicing is still needed to accurately draw the molecular portrait of liver cancer. This will surely contribute to a better understanding of the disease and to the development of new effective therapies.

Genomic and proteomic biomarkers for diagnosis and prognosis of hepatocellular carcinoma

Hepatocellular carcinoma is one of the most deadly liver malignancies found worldwide, with hepatitis virus infection being the prominent risk factor for this lesion. Patients with hepatocellular carcinoma are usually first diagnosed when in the advanced stage; thus, long-term clinical outcomes are poor and patients have limited treatment options. Currently, surveillance of hepatocellular carcinoma relies upon serological testing of alpha-fetoprotein levels and hepatic ultrasonography, which have low sensitivity and specificity, and are sometimes operator-dependent, respectively. Therefore, discovery of new biomarkers for early and accurate detection of hepatocellular carcinoma would be of great clinical value. Genomic and proteomic approaches are two major laboratory platforms for the identification of candidate hepatocellular carcinoma biomarkers based on profiling and validating with tumor and nontumor clinical samples. Frequently, these diagnostic markers have been found in association with genetic aberrations, protein-level alterations, post-translational modifications and immune functions. With the discovery of these biomarkers, earlier detection of hepatocellular carcinoma in high-risk subjects (e.g., cirrhosis and hepatitis carriers) becomes possible, which will enable clinicians to offer patients better clinical management and more effective treatment modalities.

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.

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.