In vitro and in vivo assessment of biocompatibility of AZ31 alloy as biliary stents: a preclinical approach.

INTRODUCTION: Biomaterial technology due to its lack of or minimal side effects in tissues has great potential. Traditionally biomaterials used were cobalt-chromium, stainless steel and nitinol alloys. Biomaterials such as magnesium (Mg) and zinc (Zn) have good biocompatibility and consequently can be a potential material for medical implants. To date, the effects of AZ31 alloy stent on cell apoptosis are still unclear. The current investigation was designed to determine the effect of AZ31 alloy stent on necrosis and apoptosis of common bile duct (CBD) epithelial cells. MATERIAL AND METHODS: We experimented with application of different concentrations of AZ31 alloy stent to primary mouse extrahepatic bile epithelial cells (MEBECs) and estimated the effect on apoptosis and necrotic cells. Apoptosis and pro-apoptosis expression were estimated through real-time PCR. For in vivo protocol, we used rabbits, implanted the AZ31 bile stent, and estimated its effect on the CBD. AZ31 (40%) concentration showed an effect on the apoptotic and necrotic cells. RESULTS: Real-time PCR revealed that AZ31 (40%) concentration increased the apoptotic genes such as NF-κB, caspase-3, Bax and Bax/Bcl-2 ratio as compared to the control group. In the in vivo experiment, AZ31 alloy stents were implanted into the CBD and showed an effect on the alteration the hematological, hepatic and non-hepatic parameters. CONCLUSIONS: To conclude, it can be stated that AZ31 induces apoptosis via alteration in genes including nuclear factor kappa-B (NF-κB), caspase-3, Bax and Bax/Bcl-2 ratio and improved the hematological, hepatic and non-hepatic parameters.

LOXL2 upregulates hypoxia­inducible factor­1α signaling through Snail­FBP1 axis in hepatocellular carcinoma cells.

Lysyl oxidase­like 2 (LOXL2), a member of the lysyl oxidase gene family, is involved in the progression of hepatocellular carcinoma progression and metastasis. Increased expression of LOXL2 has been identified in several types of cancer, including hepatocellular carcinoma. Recently, LOXL2 has been reported to promote epithelial­mesenchymal transition by reducing E­cadherin expression via the upregulation of Snail expression. The present study provided evidence demonstrating that LOXL2 inhibited the expression of fructose­1, 6­biphosphatase (FBP1) and enhanced the glycolysis of Huh7 and Hep3B hepatocellular carcinoma cell lines in a Snail­dependent manner. Overexpression of the point­mutated form of LOXL2 [LOXL2(Y689F)], which lacks enzymatic activity, does not affect the expression of Snail1 or FBP1. Notably, targeting extracellular LOXL2 of Huh7 cells with a therapeutic antibody was unable to abolish its regulation on the expression of Snail and FBP1. Knockdown of LOXL2 also interrupted the angiogenesis of Huh7 and Hep3B cells, and this effect could be rescued by the overexpression of Snail. Furthermore, upregulation of hypoxia­inducible factor 1α (HIF­1α) and vascular endothelial growth factor (VEGF) expression was observed in Huh7 and Hep3B cells expressing wild­type LOXL2. Notably, the selective LOXL2 inhibitor LOXL2­IN­1 could upregulate the expression of FBP1 and inhibit the expression of Snail, HIF­1α and VEGF in HCC cells, but not in FBP1­knockdown cells. The results of the present study indicated that the intracellular activity of LOXL2 upregulated HIF­1α/VEGF signaling pathways via the Snail­FBP1 axis, and this phenomenon could be inhibited by LOXL2 inhibition. Collectively, these findings further support that LOXL2 exhibits an important role in the progression of hepatocellular carcinoma and implicates LOXL2 as a potential therapeutic agent for the treatment of this disease.

MTP18 overexpression contributes to tumor growth and metastasis and associates with poor survival in hepatocellular carcinoma.

BACKGROUND: Human MTP18 (mitochondrial protein 18 kDa) is a novel nuclear-encoded mitochondrial membrane protein that is involved in controlling mitochondrial fission. Our bioinformatic analysis of TCGA data revealed an aberrant overexpression of MTP18 in hepatocellular carcinoma (HCC). We analyzed its biological effects and prognostic significance in this malignancy. METHODS: MTP18 expression was evaluated by qRT-PCR and western blot analysis in 20 paired tumor and peritumor tissues. Clinical impact of MTP18 overexpression was assessed in 156 patients with HCC. The effects of MTP18 knockdown or overexpression on cell growth and metastasis were determined by cell proliferation, colony formation, cell cycle, apoptosis, migration, and invasion assays. Furthermore, the underlying molecular mechanisms by which MTP18 overexpression promoted HCC cell growth and metastasis were explored. RESULTS: MTP18 was commonly overexpressed in HCC tissues mainly due to the downregulation of miR-125b, which significantly contributed to poor prognosis of HCC patients. Functional experiments revealed that MTP18 promoted both the growth and metastasis of HCC cells by inducing the progression of cell cycle, epithelial to mesenchymal transition (EMT) and production of MMP-9, and suppressing cell apoptosis. Mechanistically, increased mitochondrial fission and subsequent ROS production was found to be involved in the promotion of growth and metastasis by MTP18 in HCC cells. CONCLUSIONS: MTP18 plays a pivotal oncogenic role in hepatocellular carcinogenesis; its overexpression may serve as a novel prognostic factor and a therapeutic target in HCC.

Knockdown of TRIM31 suppresses proliferation and invasion of gallbladder cancer cells by down-regulating MMP2/9 through the PI3K/Akt signaling pathway.

Tripartite motif (TRIM) 31, a member of the TRIM protein family, contributes to a wide range of biological processes and its altered expression exerts a non-negligible effect on multiple pathological conditions such as immunological disorders and retroviral protective activity. Recently, increasing evidence has demonstrated an important role of TRIM31 in the development of various cancers. However, the role of TRIM31 in gallbladder cancer (GBC) remains unclear. In this study, we showed that TRIM31 was elevated in GBC tissues and cell lines and associated with the clinicopathological features of GBC patients. Down-regulation of TRIM31 suppressed GBC cell proliferation, migration and invasion in vitro as well as inhibited tumor growth and metastasis in vivo. In addition, knockdown of TRIM31 reduced the expression of MMP2, MMP9 and p-Akt. Taken together, these findings indicated that knockdown of TRIM31 suppressed proliferation and invasion of GBC cells and was associated with PI3K/Akt signaling inactivation. Thus, TRIM31 may be a potential therapeutic target for the treatment of GBC.

Heparanase expression in blood is sensitive to monitor response to anticancer treatment in pancreatic cancer, a pilot study.

BACKGROUND: /Objectives: High heparanase level was shown in maliganant tumor; however, whether or not heparanase may serve as a sensitive marker to monitor response to anticancer treatment is still unknown. METHODS: In the pilot study, heparanase mRNA expression in peripheral blood mononuclear cell fraction (PBMC) and activity in plasma and urine were detected by quantitative real time RT-PCR and heparan-degrading enzyme assay in 31 pancreatic cancer patients. RESULTS: Heparanase mRNA and activity in samples from cancer patients were significantly higher than that in healthy donors. Both heparanase mRNA and activity in plasma and urine decreased significantly in 17 patients who underwent R0 resection, but increased remarkably in 6 patients when recurrence or metastasis occurred (P < 0.05). However, those who underwent R1 or R2 resection in 6 patients kept stable. For 8 patients who received chemotherapy, heparanase mRNA and activity in plasma and urine decreased in each of the samples (P < 0.05). Patients with high heparanase mRNA (≥a cutoff value of 1.84) in PBMC and activity in plasma (≥1.30U/ml) were associated with a poor postoperative survival (P = 0.02 and P = 0.04). CONCLUSIONS: Heparanase mRNA in PBMC and activity in plasma are closely correlated with therapeutic responsiveness and survival time, indicating that heparanase level in blood might be a sensitive but non-specific marker to monitor patients' response to anticancer treatment and to predict survival.

Remote ischemic conditioning protects against acetaminophen-induced acute liver injury in mice.

AIM: Acetaminophen (APAP) overdose is a major cause of drug-induced acute liver failure. Studies have shown that remote ischemic pre- and post-conditioning (R-IPC and R-IPOST) can protect the liver against ischemia-reperfusion (I/R) and lipopolysaccharide-induced injuries. The aim of this study was to investigate the effect of R-IPC and R-IPOST on APAP-induced hepatotoxicity in mice. METHODS: Mice were randomized (n = 6 per group) to seven major groups: (i) normal control; (ii) sham operated; (iii) APAP; (iv) R-IPC + APAP; (v) R-IPC + APAP + zinc protoporphyrin (ZnPP); (vi) R-IPOST + APAP; and (vii) R-IPOST + APAP + ZnPP. Sixteen hours after APAP treatment, mouse liver and serum were collected to determine the severity of liver injury. RESULTS: The results showed that R-IPC and R-IPOST significantly decreased APAP-induced serum levels of alanine aminotransferase, aspartate aminotransferase, tumor necrosis factor-α, interleukin-6, and hepatic malondialdehyde, as well as nitrotyrosine formation. Both R-IPC and R-IPOST could improve the hepatic superoxide dismutase, glutathione, and glutathione peroxidase activities and depress the expressions of pro-inflammatory associated proteins, such as inducible nitric oxide synthetase and nuclear factor-κB. They could also increase heme oxygenase-1 expression; however, ZnPP could counteract this protective effect. CONCLUSION: Remote ischemic conditioning has significant therapeutic potential in APAP-induced hepatotoxicity by inhibiting oxidative stress and inflammation and promoting heme oxygenase-1 expression.

Effect of healthy tissue ablation surrounding VX2 rabbit liver tumors by high-intensity focused ultrasound combined with an ultrasound contrast agent.

OBJECTIVES: The purpose of this study was to determine the minimum amount of healthy peripheral tissue that should be ablated when treating VX2 liver tumors with high-intensity focused ultrasound combined with an ultrasound contrast agent. METHODS: Fifty-one rabbits with hepatic tumors were established and randomly divided into the following groups: group A, which only had their tumors ablated; group B, which had their tumors and 2 mm of healthy adjacent tissue ablated; and group C, which had their tumors and 4 mm of healthy adjacent tissue ablated. The pathologic characteristics of the target tissue, serum alanine aminotransferase (ALT) level, presence of intrahepatic and distant metastases, and survival time between different groups were compared after high-intensity focused ultrasound treatment. RESULTS: After ablation, coagulative necrosis was observed in all targeted tissue. The serum ALT level in group C was the highest and the level in group A was the lowest on the third and fifth days after ablation (P < .05), respectively. Fourteen days later, the serum ALT level in groups B and C decreased to normal, whereas the level in group A was abnormal and significantly higher (P < .05). Compared with group A, the prevalence of metastases in groups B and C was significantly lower (P < .05), and the survival time was significantly longer (P < .05); there appeared to be no statistically significant difference between groups B and C (P > .05). CONCLUSIONS: Ablation of a tumor along with 2 mm of healthy surrounding tissue is a more effective strategy for treating hepatic cancer with high-intensity focused ultrasound coupled with an ultrasound contrast agent.

Effects of modified splenocaval shunt plus devascularization on esophagogastric variceal bleeding: a comparative study of this treatment and devascularization only in cirrhotic portal hypertension.

BACKGROUND: Pericardial devascularization (PCDV) and portosystemic shunt were reported to have favorable results for the management of portal hypertension in cirrhotic patients in China and the West, respectively. This study was undertaken to investigate the effects of a modified proximal splenocaval shunt plus PCDV on variceal bleeding in patients with portal hypertension. METHODS: From January 1997 to December 2007, 168 patients with portal hypertension of cirrhotic origin received an operation for gastroesophageal variceal bleeding. Of these, 90 patients received a splenocaval shunt plus a PCDV procedure (Combined Group) and the other 78 patients received a PCDV procedure only (PCDV Group). The procedure-related morbidity and mortality, rebleeding, encephalopathy, and survival rates were analyzed. RESULTS: Postoperative mortality was 3.3% in the combined group and 5.1% in the PCDV group (P > 0.05). Overall morbidity was 13.3% in the combined group and 15.4% in the PCDV group (P > 0.05). The rate for rebleeding, including variceal bleeding and gastropathy, was 5.1% in the combined group, which was significantly lower than that in the PCDV group, at 16.7% (P < 0.05). The incidence of encephalopathy was 6.63% in the combined group and 6.67% in the PCDV group (P > 0.05). The 1-, 3-, 5- and 10-year survival rates were 97.4, 91.7, 80.0, and 60.0% in the combined group and 96.7, 83.3, 73.3, and 53.3% in the PCDV group (P > 0.05). CONCLUSIONS: The modified splenocaval shunt plus PCDV is a safe and effective procedure for the long-term control of variceal bleeding; the procedure may not only maintain the portal flow to the liver, but may also protect the liver function in cirrhotic patients. The better clinical outcome means that the procedure may be one of the best choices for treating portal hypertension of cirrhotic origin.

Hypoxia activates heparanase expression in an NF-kappaB dependent manner.

Hypoxia was shown to increase tumor cell invasion into the extracellular matrix in vitro. This result suggests that heparanase (Hpa), one of the key enzymes involved in tumor invasion and metastasis, may be regulated by hypoxia. RT-PCR, Western blot and Matrigel invasive assays were used to study the regulation of Hpa under hypoxia in human pancreatic MIA PaCa-2 cancer cells. Compared with those in normoxia (20% O2), Hpa mRNA, protein and enzymatic activity levels, were up-regulated by a reduction in the oxygen level (1% O2). Invasion by tumor cells into the extracellular matrix was found to be significantly enhanced. A reduction in Hpa protein levels was observed when nuclear factor kappaB (NF-kappaB) activation was blocked by pyrrolidine dithiocarbamate. The levels of Hpa were also reduced when Hpa was inhibited by an Hpa-specific antisense oligonucleotide. The MMP-9 mRNA, protein and gelatinase B activity levels in supernatants decreased significantly when Hpa was inhibited. We conclude that up-regulation of Hpa by hypoxia is NF-kappaB-dependent in MIA PaCa-2 cells and inhibition of Hpa reduces MMP-9 activity. This reduction in MMP-9 activity may be an important mechanism in tumor metastasis.