Huan Tong

Recurrent Variceal Bleeding and Shunt Patency: Prospective Randomized Controlled Trial of Transjugular Intrahepatic Portosystemic Shunt Alone or Combined with Coronary Vein Embolization

PURPOSE To prospectively evaluate the efficacy of a transjugular intrahepatic portosystemic shunt (TIPS) alone and TIPS in association with embolotherapy (TIPS+E) in the variceal coronary vein to prevent recurrent variceal bleeding and stent dysfunction after TIPS creation. MATERIALS AND METHODS Institutional review board approval was obtained; all participants provided informed consent. A total of 106 patients (66 men, 40 women; age range, 18-70 years) with recurrent variceal bleeding due to hepatic cirrhosis were assigned randomly to the TIPS+E (n = 54) or TIPS (n = 52) group from May 2007 to July 2011. The TIPS was created by using covered stents. Patients in the TIPS+E group underwent embolotherapy via the jugular vein before TIPS implantation. Rates of recurrent variceal bleeding, stent patency, and survival were evaluated. Scores for liver function and life quality were calculated. RESULTS TIPS placement was successful in all patients. Recurrent variceal bleeding ranked second among causes of death after TIPS placement. Although the 3-year cumulative rates of shunt patency, recurrent variceal bleeding, and survival in the two groups were not significantly different (P > .05), the 6-month overall rate of shunt patency in the TIPS+E group was significantly higher than that in the TIPS group (96.2% vs 82.0%, P = .019), and the 6-month overall rate of recurrent variceal bleeding was also significantly lower than that in the TIPS group (5.7% vs 20.0%, P = .029). CONCLUSION The TIPS+E regimen may reduce the risk of recurrent variceal bleeding during the first 6 months after the TIPS procedure by preventing shunt dysfunction, which may improve liver function and quality of life.

Celecoxib Ameliorates Portal Hypertension of the Cirrhotic Rats through the Dual Inhibitory Effects on the Intrahepatic Fibrosis and Angiogenesis

Background Increased intra-hepatic resistance to portal blood flow is the primary factor leading to portal hypertension in cirrhosis. Up-regulated expression of cyclooxygenase-2 (COX-2) in the cirrhotic liver might be a potential target to ameliorate portal hypertension. Objective To verify the effect of celecoxib, a selective inhibitor of COX-2, on portal hypertension and the mechanisms behind it. Methods Cirrhotic liver model of rat was established by peritoneal injection of thiacetamide (TAA). 36 rats were randomly assigned to control, TAA and TAA+celecoxib groups. Portal pressures were measured by introduction of catheters into portal vein. Hepatic fibrosis was assessed by the visible hepatic fibrotic areas and mRNAs for collagen III and α-SMA. The neovasculature was determined by hepatic vascular areas, vascular casts and CD31 expression. Expressions of COX-2, vascular endothelial growth factor (VEGF), VEGF receptor-2 (VEGFR-2) and related signal molecules were quantitated. Results Compared with TAA group, the portal pressure in TAA+celecoxib group was significantly decreased by 17.8%, p<0.01. Celecoxib treatment greatly reduced the tortuous hepatic portal venules. The data of fibrotic areas, CD31expression, mRNA levels of α-SMA and collagen III in TAA+celecoxib group were much lower than those in TAA group, p<0.01. Furthermore, the up-regulation of hepatic mRNA and protein levels of VEGF, VEGFR-2 and COX-2 induced by TAA was significantly inhibited after celecoxib treatment. The expressions of prostaglandin E2 (PGE2), phosphorylated extracellular signal-regulated kinase (p-ERK), hypoxia-inducible factor-1α (HIF-1α), and c-fos were also down-regulated after celecoxib treatment. Conclusions Long term administration of celecoxib can efficiently ameliorate portal hypertension in TAA rat model by its dual inhibitory effects on the intrahepatic fibrosis and angiogenesis. The anti-angiogenesis effect afforded by celecoxib may attribute to its modulation on VEGF/VEGFR-2 through the down-regulation of integrated signal pathways involving PGE2- HIF-1α- VEGF and p-ERK- c-fos- VEGFR-2.

Celecoxib attenuates hepatic cirrhosis through inhibition of epithelial-to-mesenchymal transition of hepatocytes

The epithelial–mesenchymal transition (EMT) of hepatocytes is a key step for hepatic fibrosis and cirrhosis. Long‐term administration of celecoxib, a selective cyclooxygenase‐2 (COX‐2) inhibitor, can ameliorate hepatic fibrosis. This research aimed to examine the effect of celecoxib on the EMT of hepatocytes during the development of liver cirrhosis.

Targeting inhibition of extracellular signal-regulated kinase kinase pathway with AZD6244 (ARRY-142886) suppresses growth and angiogenesis of gastric cancer.

AZD6244 (ARRY-142886), a highly selective MAPK-ERK kinase inhibitor, has shown excellent clinical efficacy in many tumors. However, the anti-tumor and anti-angiogenesis efficacy of AZD6244 on gastric cancer has not been well characterized. In this study, high p-ERK expression was associated with advanced TNM stage, increased lymphovascular invasion and poor survival. For absence of NRAS, KRAS and BRAF mutation, SGC7901 and BGC823 gastric cancer cells were relative resistance to AZD6244 in vitro. And such resistance was not attributed to the insufficient inhibition of ERK phosphorylation. However, tumor growth was significantly suppressed in SGC7901 xenografts by blockage of angiogenesis. This result was further supported by suppression of tube formation and migration in HUVEC cells after treatment with AZD6244. Moreover, the anti-angiogenesis effect of AZD6244 may predominantly attribute to its modulation on VEGF through p-ERK − c-Fos − HIF-1α integrated signal pathways. In conclusions, High p-ERK expression was associated with advanced TNM stage, increased lymphovascular invasion and poor survival. Targeting inhibition of p-ERK by AZD6244 suppress gastric cancer xenografts by blockage of angiogenesis without systemic toxicity. The anti-angiogenesis effect afford by AZD6244 may attribute to its modulation on p-ERK − c-Fos − HIF-1α − VEGF integrated signal pathways.

Transcatheter arterial embolization followed by octreotide and celecoxib synergistically prolongs survival of rabbits with hepatic VX2 allografts

To validate the efficacy of an innovative multimodality therapy with transcatheter arterial embolization (TAE) plus octreotide and celecoxib in reducing neoangiogenesis and prolonging the survival of rabbits with hepatocellular carcinoma.

Celecoxib and octreotide synergistically ameliorate portal hypertension via inhibition of angiogenesis in cirrhotic rats

Abnormal angiogenesis is critical for portal hypertension in cirrhosis. Except for etiological treatment, no efficient medication or regime has been explored to treat the early stage of cirrhosis when angiogenesis is initiated or overwhelming. In this study, we explored an anti-angiogenesis effort through non-cytotoxic drugs octreotide and celecoxib to treat early stage of cirrhotic portal hypertension in an animal model. Peritoneal injection of thioacetamide (TAA) was employed to induce liver cirrhosis in rats. A combination treatment of celecoxib and octreotide was found to relieve liver fibrosis, portal venous pressure, micro-hepatic arterioportal fistulas, intrahepatic and splanchnic angiogenesis. Celecoxib and octreotide exerted their anti-angiogenesis effect via an axis of cyclooxygenase-2/prostaglandin E2/EP-2/somatostatin receptor-2, which consequently down-regulated phosphorylation of extracellular signal-regulated kinase (p-ERK)–hypoxia-inducible factor-1α (HIF-1α)–vascular endothelial growth factor (VEGF) integrated signaling pathways. In conclusions, combination of celecoxib and octreotide synergistically ameliorated liver fibrosis and portal hypertension of the cirrhotic rats induced by TAA via the inhibition of intrahepatic and extrahepatic angiogenesis. The potential mechanisms behind the regimen may due to the inactivation of p-ERK–HIF-1α–VEGF signaling pathway.

Expression of cyclooxygenase-2 is correlated with lncRNA-COX-2 in cirrhotic mice induced by carbon tetrachloride

Multiple long non-coding RNAs (lncRNAs) have been demonstrated to be involved in liver disease. Increased cyclooxygenase-2 (COX-2) levels have also been reported to be involved in the progression of liver cirrhosis. In the present study, the correlations between lncRNA-COX-2 RNA expression levels, COX-2 mRNA expression levels and liver fibrosis were examined. Liver fibrosis was induced by intraperitoneal injection of carbon tetrachloride (CCl4) in mice for 2 months (CCl4-2M) or 3 months (CCl4-3M). Liver histopathological evaluation was conducted using hematoxylin and eosin and Masson trichrome staining. Hepatic expression of COX-2 and lncRNA-COX-2 was evaluated by reverse transcription-quantitative polymerase chain reaction and immunohistochemical staining. Compared with the control group, fibrotic areas were increased four and nine times in the CCl4-2M group and the CCl4-3M group, respectively. LncRNA-COX-2 and COX-2 upregulation were observed in the cirrhotic liver. COX-2 mRNA expression levels and lncRNA-COX-2 RNA expression levels were significantly positively correlated with the fibrotic area. In addition, COX-2 mRNA expression was significantly positively correlated with lncRNA-COX-2 expression. These results suggest that expression of COX-2 and lncRNA-COX-2 increased with the progression of liver fibrosis. LncRNA-COX-2 may potentially be considered as a novel therapeutic target for liver fibrosis.

Quantitative Evaluation and Selection of Reference Genes for Quantitative RT-PCR in Mouse Acute Pancreatitis

The analysis of differences in gene expression is dependent on normalization using reference genes. However, the expression of many of these reference genes, as evaluated by quantitative RT-PCR, is upregulated in acute pancreatitis, so they cannot be used as the standard for gene expression in this condition. For this reason, we sought to identify a stable reference gene, or a suitable combination, for expression analysis in acute pancreatitis. The expression stability of 10 reference genes (ACTB, GAPDH, 18sRNA, TUBB, B2M, HPRT1, UBC, YWHAZ, EF-1α, and RPL-13A) was analyzed using geNorm, NormFinder, and BestKeeper software and evaluated according to variations in the raw Ct values. These reference genes were evaluated using a comprehensive method, which ranked the expression stability of these genes as follows (from most stable to least stable): RPL-13A, YWHAZ > HPRT1 > GAPDH > UBC > EF-1α > 18sRNA > B2M > TUBB > ACTB. RPL-13A was the most suitable reference gene, and the combination of RPL-13A and YWHAZ was the most stable group of reference genes in our experiments. The expression levels of ACTB, TUBB, and B2M were found to be significantly upregulated during acute pancreatitis, whereas the expression level of 18sRNA was downregulated. Thus, we recommend the use of RPL-13A or a combination of RPL-13A and YWHAZ for normalization in qRT-PCR analyses of gene expression in mouse models of acute pancreatitis.

Inhibition of cyclooxygenase-2 alleviates liver cirrhosis via improvement of the dysfunctional gut-liver axis in rats

Inflammatory transport through the gut-liver axis may facilitate liver cirrhosis. Cyclooxygenase-2 (COX-2) has been considered as one of the important molecules that regulates intestinal epithelial barrier function. This study was aimed to test the hypothesis that inhibition of COX-2 by celecoxib might alleviate liver cirrhosis via reduction of intestinal inflammatory transport in thiacetamide (TAA) rat model. COX-2/prostaglandin E2 (PGE2)/EP-2/p-ERK integrated signal pathways regulated the expressions of intestinal zonula occludens-1 (ZO-1) and E-cadherin, which maintain the function of intestinal epithelial barrier. Celecoxib not only decreased the intestinal permeability to a 4-kDa FITC-dextran but also significantly increased expressions of ZO-1 and E-cadherin. When celecoxib greatly decreased intestinal levels of LPS, TNF-α, and IL-6, it significantly enhanced T cell subsets reduced by TAA. As a result, liver fibrosis induced by TAA was significantly alleviated in the celecoxib group. These data indicated that celecoxib improved the integrity of intestinal epithelial barrier, blocked inflammatory transport through the dysfunctional gut-liver axis, and ameliorated the progress of liver cirrhosis.

Methylation of mitochondrial DNA displacement loop region regulates mitochondrial copy number in colorectal cancer

It is not established whether de-methylation of the displacement loop (D-loop) region if mitochondrial DNA (mtDNA) directly influences mtDNA copy number and further alters the cell cycle, apoptosis and cell proliferation in colorectal cancer. The current study employed cell viability assays, cell cycle analysis, and mtDNA methylation analysis using 5 colorectal cancer cell lines. The present results demonstrated that 5-aza-2′-deoxycytidine (5-AZA), a DNA hypomethylating agent, significantly increased proliferation of Lovo and Colo-205 colorectal cancer cell lines. In Colo-205 cells, the proportion of G0/G1 phase cells was increased following 5-AZA treatment. Additionally, the apoptosis rate in Colo-205 cells was decreased by 5-AZA treatment. Compared with their controls, a significantly higher mtDNA copy number was observed in Colo-205 and Lovo cells following 5-AZA treatment. Notably, the Colo-205 and Lovo cells had relatively higher methylation levels at the 4 and 6th/7th CpG sites of D-loop region, respectively, compared with the levels at the corresponding sites following 5-AZA treatment. However, in HCT116, SW480, LS-174T, and HT-29 cells, 5-AZA treatment did not induce a significant change in proliferation, cell cycle, apoptosis and mtDNA copy number. Demethylation at the 4 and 6th/7th CpG sites of the D-loop region of HCT116, SW480, LS-174T and HT-29 cells was not observed following 5-AZA treatment. In conclusion, de-methylation of specific sites on CpG islands of D-loop promoter may lead to the elevation of mtDNA copy number in colorectal cancer, triggering alterations in biological behaviors, including increased cell proliferation, reduced apoptosis and a relative cell cycle arrest in G0/G1 phase.