ABSTRACT
BACKGROUND: Although Dickkopf-1 (DKK1) is known to be a negative regulator of the Wnt/ß-catenin pathway, it has been recently found to be upregulated in cancers. AIMS: We investigated the clinical and prognostic significance of both serum and transcript DKK1 and its functional roles in human hepatocellular carcinoma (HCC). METHODS: We evaluated the expression level of DKK1 in both tissue and serum samples from patients with HCC using GeneChip microarray and real-time-quantitative PCR and sandwich ELISA system respectively. The clinicopathological and prognostic significance of serum and tissue DKK1 levels was examined. Functional characterization of DKK1 with regard to cell migration, invasion and tumour growth was performed. RESULTS: Both DKK1 transcript and serum protein were upregulated in a stepwise manner in human HCCs. Its transcript levels were associated with more aggressive tumour behaviour, in terms of venous invasion (P = 0.003), advanced tumour stage (P = 0.003). DKK1 transcript correlated with shorter overall (P = 0.006) and disease-free survival (P = 0.012), and higher serum DKK1 levels correlated with shorter disease-free survival (P = 0.046). Knockdown of DKK1 significantly reduced both migratory and invasive abilities of HCC cells, whereas overexpression of DKK1 enhanced the tumour formation efficiency and tumour growth in vivo. CONCLUSIONS: Serum and tissue DKK1 levels increased in a stepwise manner in multistep hepatocarcinogenesis and had prognostic significance. DKK1 plays a functional role in cell migration, invasion and tumour growth.
Subject(s)
Biomarkers, Tumor/metabolism , Carcinoma, Hepatocellular/blood , Carcinoma, Hepatocellular/metabolism , Intercellular Signaling Peptides and Proteins/metabolism , Liver Neoplasms/blood , Liver Neoplasms/metabolism , Adult , Aged , Biomarkers, Tumor/blood , Cell Line, Tumor , Cell Movement/genetics , Cell Movement/physiology , Enzyme-Linked Immunosorbent Assay , Female , Gene Knockdown Techniques , Hong Kong , Humans , Immunohistochemistry , Intercellular Signaling Peptides and Proteins/blood , Male , Middle Aged , Neoplasm Invasiveness/physiopathology , Oligonucleotide Array Sequence Analysis , Real-Time Polymerase Chain Reaction , Statistics, NonparametricABSTRACT
This study was undertaken to determine AM expression in carbon tetrachloride (CCl4)-induced liver cirrhosis developed with peritoneal ascites. Sprague-Dawley rats received subcutaneous injections of CCl4 twice weekly in olive oil (1:1, 0.3 ml per kg body weight) for 6 or 12 weeks until ascites developed, or saline in olive oil as control. At 6 weeks, fibrosis developed and at 12 weeks cirrhosis developed with ascites formation. At both 6 and 12 weeks, increases in plasma renin and AM were evident, as was the gene expression of AM. At 12 weeks after CCl4 injection, the gene expression of calcitonin-like-receptor (CRLR) and receptor activity modifying proteins (RAMP1, RAMP2 and RAMP3) were all elevated when compared to the control. The results suggest that liver cirrhosis increases mRNA expressions of AM, CRLR and RAMP1, RAMP2 and RAMP3 and that the increase in AM gene expression precedes the development of cirrhosis. The increase in AM synthesis as reflected by an increase in AM gene expression, together with a lack of increase in AM peptide at both 6 and 12 weeks may suggest an elevation of AM release. Given the potent vasodilatory action of AM, the increase in the synthesis and release of AM in the cirrhotic liver may also contribute to peripheral vasodilatation in liver cirrhosis.
Subject(s)
Adrenomedullin/metabolism , Carbon Tetrachloride/toxicity , Intracellular Signaling Peptides and Proteins/metabolism , Liver Cirrhosis, Experimental/chemically induced , Membrane Proteins/metabolism , Receptors, Calcitonin/metabolism , Adrenomedullin/genetics , Animals , Calcitonin Receptor-Like Protein , Gene Expression Regulation , Intracellular Signaling Peptides and Proteins/genetics , Liver/cytology , Liver/metabolism , Liver/pathology , Male , Membrane Proteins/genetics , Nitrates/metabolism , Nitrites/metabolism , Protein Isoforms/metabolism , Rats , Rats, Sprague-Dawley , Receptor Activity-Modifying Protein 1 , Receptor Activity-Modifying Protein 2 , Receptor Activity-Modifying Protein 3 , Receptor Activity-Modifying Proteins , Receptors, Calcitonin/genetics , Renin/bloodABSTRACT
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.
Subject(s)
Adenocarcinoma/metabolism , Biomarkers, Tumor/metabolism , Cadherins/metabolism , Homeodomain Proteins/metabolism , Stomach Neoplasms/metabolism , Adenocarcinoma/pathology , Adult , Aged , Aged, 80 and over , Biomarkers, Tumor/genetics , CDX2 Transcription Factor , Cadherins/genetics , Disease Progression , Female , Homeodomain Proteins/genetics , Humans , Immunoenzyme Techniques , Lymphatic Metastasis , Male , Metaplasia/metabolism , Middle Aged , Neoplasm Proteins/genetics , Neoplasm Proteins/metabolism , Neoplasm Staging , Precancerous Conditions/metabolism , RNA, Messenger/genetics , Reverse Transcriptase Polymerase Chain Reaction/methods , Stomach/pathology , Stomach Neoplasms/pathology , Up-RegulationABSTRACT
BACKGROUND AND AIM: Decrease in expression of the E-cadherin-catenin complex is an important element in gastric carcinogenesis. However, the expression of the complex in gastric precancerous lesions has not been well studied. The present study aimed to examine the serial change in expression of E-cadherin-catenin complex in the precancerous lesions of gastric cancer patients. METHODS: Gastrectomy specimens of 40 patients with gastric cancer were retrieved. Areas with chronic gastritis, atrophic gastritis, intestinal metaplasia and adenocarcinoma were identified and immunostained for alpha-catenin, beta-catenin and E-cadherin. The results were scored semiquantitatively by two independent pathologists using a validated scoring system. RESULTS: A significant decrease in score was observed in 5% (1/22) of alpha-catenin, 0% (0/22) of beta-catenin and 9% (2/22) of E-cadherin in chronic atrophic gastritis patients, and in 28% (5/18) of alpha-catenin, 67% (10/15) of beta-catenin and 57% (8/14) of E-cadherin in intestinal metaplasia patients. The scoring of alpha-catenin, beta-catenin and E-cadherin correlated with each other. Forty-three percent of patients had concordant changes of scores along the gastritis-adenocarcinoma sequence. There was no association between Helicobacter pylori status and E-cadherin-catenin complex expression. CONCLUSION: Deregulation of the E-cadherin-catenin complex was observed in the majority of precancerous lesions in patients with gastric adenocarcinoma, which has potential diagnostic and therapeutic implications.
