Potential therapeutic effect of SO2 on fibrosis.

Fibrosis is a pathological feature of most chronic diseases and leads to the dysfunction of various organs. However, there is currently no effective method for treating fibrosis. In recent years, a small gas, sulfur dioxide (SO2), which can be generated endogenously in mammals, has been found to have vasorelaxation activity, improve cardiac function and decrease myocardial injury. Endogenous SO2 also mediates the process of fibrosis. Inhibition of endogenous SO2 can aggravate small pulmonary artery remodeling and abnormal collagen accumulation. SO2 treatment significantly improves pulmonary fibrosis and pulmonary arterial remodeling. Overexpression of the key enzymes associated with endogenous SO2 generation, aspartate aminotransferase (AAT) 1 and AAT2, mimics the effect of SO2 on the down-regulation of collagen synthesis, while AAT1 or AAT2 knockdown aggravates abnormal collagen accumulation in vascular smooth muscle cells (VSMCs). SO2 also improves myocardial fibrosis induced by myocardial infarction or diabetes in rats, and inhibits myocardial fibroblast proliferation and migration by the extracellular signal-regulated protein kinase pathway. The mechanisms underlying the inhibition of fibrosis by SO2 are related to its antioxidant effect, anti-inflammation effect, improvement in cardiac function, and cell proliferation inhibition. Therefore, SO2 has a potential therapeutic effect on fibrosis.

The effects of microRNA-1224-5p on hepatocellular carcinoma tumor endothelial cells.

AIM: The aim of this study was to investigate the effect of microRNA-1224-5p (miR-1224-5p) on tumor endothelial cells (TECs) of human hepatocellular carcinoma (HCC). SUBJECTS AND METHODS: Oligonucleotides were chemically synthesized and transfected into TECs using Lipofectamine 2000. TECs were divided into three groups, namely a control (CON) group without transfection, a negative control (NC) group transfected with negative control oligonucleotides and green fluorescent protein (GFP), and a micro-up (MU) group transfected with miR-1224-5p mimic and GFP. The expression of miR-1224-5p was quantified via quantitative reverse-transcription polymerase chain reaction (qRT-PCR). The proliferation of TECs was detected using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay, and the optical density value at 490 nm was measured after every 24 h. Apoptosis was detected via flow cytometry using a 7-aminoactinomycin/APC Annexin V kit. The migration and invasion of TECs were detected using transwell assay. The tube formation ability was evaluated using the tube formation assay. RESULTS: Oligonucleotides were successfully transduced into TECs, and the expression of miR-1224-5p was specifically upregulated. The results of qRT-PCR analysis showed that the expression of miR-1224-5p was significantly upregulated in the MU group (2-ΔΔCt = 3.27 ± 0.15) than in the CON group (2-ΔΔCt = 1) and NC group (2-ΔΔCt = 1.08 ± 0.11) (P < 0.01). The results of MTT assay showed that the cell proliferation was significantly inhibited in the MU group at four time points than in the CON and NC groups (P < 0.01). Flow cytometry analysis revealed the significant increase in apoptosis of cells from the MU group (19.29% ± 0.95%) than those from the CON (8.73% ± 0.64%) and NC (9.51% ± 0.56%) (P < 0.01) groups. The migration ability was significantly inhibited in MU group (51.0 ± 3.6) as compared with CON (77.7 ± 2.5) and NC (79.2 ± 3.5) groups (P < 0.01). The invasion ability of TECs was significantly inhibited in MU group (9.8 ± 1.3) than in CON (15.8 ± 0.8) and NC (15.4 ± 0.9) groups (P < 0.01). The ability of tube formation of TECs was completely inhibited in MU group but remained unaffected in CON and NC groups. CONCLUSIONS: miR-1224-5p may serve as a potential tumor suppressor in HCC. Upregulation in miR-1224-5p expression may decrease proliferation, induce apoptosis, inhibit migration and invasion, and suppress tube formation in TECs of human HCC.

Effects of hepatic blood inflow on liver ultrastructure and regeneration after extensive liver resection in rats with cirrhosis.

The aim of the present study was to investigate the effects of hepatic blood inflow on liver function, liver ultrastructure and the regeneration of future liver remnant (FLR) following major hepatectomy in rats with liver cirrhosis. A rat model of cirrhosis was established through intraperitoneal injection of carbon tetrachloride for 8 consecutive weeks. Extensive liver resection and different blood inflow models by portal vein (PV) and/or hepatic artery (HA) stenosis were conducted on the cirrhosis rats. Animal models were constructed as follows: Control (group A), low-flow PV + high-flow HA (group B), low-flow PV + low-flow HA (group C), high-flow PV + high-flow HA (group D) and high-flow PV + low-flow HA (group E). Hepatic blood inflow was detected by laser speckle contrast analysis, liver function and pathological changes were analyzed, Masson staining was used to identify the fibrosis of the liver and Periodic acid-Schiff staining was used to identify glycogen synthesis and hepatocyte function. The liver cell ultrastructure was evaluated by transmission electron microscopy, and the expression of Ki-67 in hepatocytes and the weight of the FLR were recorded to determine the regeneration of the FLR. Five days after major hepatectomy and liver blood inflow modulation, pathological examination of the livers from groups B and C revealed less congestion and less extensive hepatocellular injury. The serum alanine aminotransferase level of group B at 1, 3 and 5 days after hepatectomy and blood inflow modulation was 460.9±31.7, 331.0±22.0 and 285.6±15.8 U/l, respectively (control group: 676.9±41.7, 574.9±28.0 and 436.1±32.7 U/l, respectively; P<0.05); the total bilirubin of group B at 1, 3 and 5 days was 20.4±1.5, 16.1±1.0 and 13.5±0.6 µmol/l, respectively (control group: 30.3±1.4, 26.5±0.8 and 22.1±1.2 µmol/l, respectively; P<0.05). The size of the endoplasmic reticulum in the low-flow PV groups increased significantly and the mitochondrial swelling was alleviated. The positive rate of Ki-67 in the hepatocytes of groups B, C and D was 23.9±3.6, 15.7±2.3 and 12.9±2.4%, respectively (control group: 10.1±2.1%, P<0.05), and the positive rate of Ki-67 in group E was 6.1±1.4% (compared with that of the control group, P<0.05). The remnant liver weight of group B was 15.4±1.0 g (compared with that of the control group, P<0.05). Therefore, decreased portal blood flow combined with increased hepatic arterial blood flow alleviated the congestion in the liver following major hepatectomy in cirrhotic rats, improved the pathological status and liver function, increased the expression of Ki-67 and promoted liver regeneration.

Sulfur dioxide ameliorates rat myocardial fibrosis by inhibiting endoplasmic reticulum stress.

Myocardial remodeling occurs after myocardial infarction (MI), the leading cause of mortality worldwide. Although myocardial fibrosis plays an important role in the process of myocardial remodeling, there is not yet an effective method of reducing it. The aim of the present study was to determine the effects of sulfur dioxide (SO2) on myocardial fibrosis and the possible mechanisms of these effects. SO2 treatment reduced the extent of myocardial fibrosis and post-MI levels of collagens I and III in the left-ventricular myocardium. SO2 also improved MI-induced thinning of the left ventricular wall while enlarging the left ventricular internal diameter. SO2 was able to reduce matrix metalloproteinase (MMP)-9 activity and increase tissue matrix metalloproteinase inhibitor (TIMP)-1 content in myocardium after MI. However, the mechanism underlying these effects of SO2 on myocardial fibrosis are unknown. Western blot analysis of endoplasmic reticulum (ER) stress-related proteins showed that glucose-regulated protein 78, C/EBP homologous protein, caspase-12, and phosphorylated eukaryotic initiation factor 2α expression levels were significantly increased in MI rats and decreased by SO2 treatment. The ER stress promoter dithiothreitol reversed these effects of SO2. In conclusion, SO2 alleviated myocardial fibrosis in MI rats through a mechanism related to inhibition of excessive ER stress.

Sulfur dioxide: foe or friend for life?

Sulfur dioxide (SO2) is a toxic gas and air pollutant. The toxic effects of SO2 have been extensively studied. Oxidative damage due to SO2 can occur in multiple organs. Inhaled SO2 can also cause chromosomal aberrations, DNA damage and gene mutations in mammals. However, SO2 can also be generated from the sulfur-containing amino acid, L-cysteine. Recent studies have shown that SO2 has a vasorelaxant effect, and ameliorates pulmonary hypertension and vascular remodeling. SO2 can also reduce lung injury and myocardial injury in rats. In addition, SO2 reduces myocardial ischemia-reperfusion injury and atherosclerotic lesions. Therefore, SO2 exerts both detrimental and protective effects in mammals. Is SO2 a foe or friend for life?.

Sulfur dioxide: a physiologic endothelium-derived relaxing factor.

The gasotransmitter nitric oxide was classified as the first endothelium-derived relaxant factor, and opened a new era in cardiovascular research. Another small gas, sulfur dioxide (SO2), can also be generated endogenously in mammals. Recent studies have shown that SO2 may play important roles in the cardiovascular system. At low concentrations, the vasodilatory effect of SO2 is endothelium-dependent. The vasodilation induced by an endothelium-derived relaxant factor is achieved by the opening of potassium channels, and hyperpolarization of the membranes of vascular smooth muscle cells. This feature is in accordance with that of SO2. The vasodilatory effect of SO2 is related to the opening of adenosine triphosphate-sensitive potassium channels and high-conductance calcium-activated potassium channels. The 3'-5'-cyclic guanosine monophosphate pathway and activation of nitric oxide synthase are also involved in the endothelium-derived relaxant factor effect of SO2. The vasodilatory effect of gaseous SO2 is much stronger than that of its derivatives (bisulfite and sulfite). It is suggested that SO2 may be a candidate endothelium-derived relaxant factor, which could lead to a new era of research into cardiovascular disease in mammals.

Interaction of Heat Shock Protein Cpn10 with the Cyclin E/Cdk2 Substrate Nuclear Protein Ataxia-Telangiectasia (NPAT) Is Involved in Regulating Histone Transcription.

Precise modulation of histone gene transcription is critical for cell cycle progression. As a direct substrate of Cyclin E/CDK2, nuclear protein ataxia-telangiectasia (NPAT) is a crucial factor in regulating histone transcription and cell cycle progression. Here we identified that Cpn10/HSPE, a 10-kDa heat shock protein, is a novel interacting partner of NPAT. A pool of Cpn10 is colocalized with NPAT foci during G1 and S phases in nuclei. Gain- and loss-of-function experiments unraveled an essential role of Cpn10 in histone transcription. A conserved DLFD motif within Cpn10 was critical for targeting NPAT and modulating histone transcription. More importantly, knockdown of Cpn10 disrupted the focus formation of both NPAT and FADD-like interleukin-1ß-converting enzyme-associated huge protein without affecting Coilin-positive Cajal bodies. Finally, Cpn10 is important for S phase progression and cell proliferation. Taken together, our finding revealed a novel role of Cpn10 in the spatial regulation of NPAT signaling and disclosed a previously unappreciated link between the heat shock protein and histone transcription regulation.

Signal pathways involved in the biological effects of sulfur dioxide.

Gasotransmitters, such as nitric oxide, carbon monoxide and hydrogen sulfide, play important roles in life and have attracted great interest in scientists. In recent years, sulfur dioxide (SO2) has also been found to play important roles in mammals. The redox pathway is involved in the biological effects of SO2, such as the protective effect on myocardial ischemia reperfusion, myocardial injury, pulmonary hypertension and atherosclerosis. Ion channels, such as L-type calcium and adenosine triphosphate-sensitive potassium channels, as well as 3'-5'-cyclic guanosine monophosphate and 3'-5'-cyclic adenosine monophosphate pathways are also involved in the vasorelaxant effect of SO2. The mitogen-activated protein kinase pathway plays roles in vascular remodeling during pulmonary hypertension and vascular smooth muscle cell proliferation. Understanding these signaling mechanisms would help to clarify the pathophysiological effect and therapeutic potential of SO2.

Surgical treatment of huge hepatocarcinoma with invasion or severe adhesion of diaphragm using the technique of orthotopic liver resection.

BACKGROUND/AIMS: To explore the clinical application and significance of the technique of orthotopic liver resection. METHODOLOGY: From January 2004 to December 2011, five patients with huge hepatocellular carcinoma with invasion or severe adhesion of diaphragm were undergone right semi-liver resection using the technique of orthotopic liver resection. The right hemi-liver was isolated from the first liver portal, second liver portal and third liver portal, then isolated from the normal liver, finally the tumor and the invaded diaphragm were resected or removed from the severe adhesion. The approach to hepatic resection involved routine use of Peng's multifunctional operative dissector, selective control of in and out-flow of liver, control of inferior vena cava (IVC) and liver hanging maneuver, anterior approach, etc. RESULTS: The operations were successfully performed in 5 patients. Operative time was 120, 180, 150, 150 and 160 min, respectively. The amount of blood loss were 350, 350, 400, 450, 600 ml, respectively. Postoperative complications were pleural effusion in 3 cases, and other 2 cases recovered without complications. CONCLUSIONS: Although the technique of orthotopic liver resection has a high technical requirement for surgeons, it provides a surgical method and operative opportunity for the patients whose tumor has invaded diaphragm or has been severe adhesion with diaphragm and conventional liver resection cannot be performed.

Methylated TIMP-3 DNA in body fluids is an independent prognostic factor for gastric cancer.

CONTEXT: Fluid methylated DNA may be a suitable biomarker for cancer patients. OBJECTIVE: To investigate whether circulating methylated tissue inhibitor of metalloproteinase 3 (TIMP-3) DNA in body fluids is a useful prognostic biomarker in gastric cancer (GC). DESIGN: TIMP-3 methylation was detected by real-time methylation-specific polymerase chain reaction in tumor tissues, paired preoperative peritoneal washes (PPWs), and paired serum samples from 92 GC patients. RESULTS: The frequency of TIMP-3 methylation was significantly elevated in GC tissues (63.04%; 58 of 92) compared with that in paired adjacent normal tissue (4.3%; 4 of 92) (P < .001). TIMP-3 methylation correlated closely with peritoneal metastasis and TNM stage (all P < .001). The frequency of TIMP-3 methylation in preoperative peritoneal washes and serum samples was 53.3% (49 of 92) and 58.7% (54 of 92), respectively. The Aζ values of the receiver operator characteristic curve for methylated TIMP-3 were 0.966 and 0.922 for serum and preoperative peritoneal washes, respectively, compared with those in GC tissues. The patients with elevated methylated TIMP-3 levels in body fluids had poorer disease-free survival rates than those without (all P < .001). Cox regression analysis showed that detection of methylated TIMP-3 DNA in body fluids was an independent risk factor for GC patients, with a remarkable decrease in disease-free survival 30 months after surgical resection of the gastric tumor. CONCLUSION: Presence of methylated TIMP-3 DNA in body fluids is a useful biomarker for predicting the progression and prognosis of GC patients.

Enhanced serum methylated p16 DNAs is associated with the progression of gastric cancer.

OBJECTIVE: The present study is to evaluate the effect of methylated p16 on the progression in patients with gastric cancer (GC), and develop a useful biomarker for predicting patient's prognosis. DESIGN AND METHODS: Methylation status of p16 in GC, their corresponding para-cancerous histological normal tissues (PCHNTs), preoperative peritoneal washes (PPWs) and serum were assessed using real-time methylation specific-PCR (MSP). RESULTS: The frequency of p16 methylation was significantly higher in GC tissues (85.9%; 79/92) than that in paired PCHNTs (12.0%; 11/92) (P<0.0001). p16 methylation correlated closely with lymph node metastasis, peritoneal metastasis, TNM stage, et al (all P<0.05). Both frequency of p16 methylation in PPWs and serum were 79.7% (63/92). The Aζ value of the receiver-operator characteristic curve for methylated p16 was 0.899 for serum and PPWs, compared to that in GC tissues. The patients with elevated methylated p16 levels in tumor tissues had poorer disease-free survival (DFS) rates than those without (P=0.042). There is a narrow significant difference in median survival time of more than 30 months between patients with and without preoperatively detectable methylated p16 in serum (P=0.057). Methylated p16 in PPWs revealed no significant association with survival (P=0.129). Cox regression analysis showed that serum methylated p16 DNAs was an independent risk factor for GC patients, with a remarkable decrease in DFS 30 months after surgical resection of the gastric tumor. CONCLUSIONS: Serum methylated p16 DNAs might serve as a potential biomarker for the progression and a prognostic factor in gastric cancer patients.

Sulfur dioxide, a double-faced molecule in mammals.

Sulfur dioxide (SO2) is a common air pollutant and is detrimental to many organs. Its toxic effects including oxidative damage, deoxyribonucleic acid (DNA) damage and inflammation have been extensively studied. However, recent studies showed that SO2 can be generated endogenously in mammals. In contrast to the toxic effects of SO2, protective effects have also been found in mammals. Endogenous SO2 has antioxidant, anti-inflammatory, anti-hypertension, and anti-atherogenic effects and regulates vascular tone and cardiac function in mammals. SO2 may have a dual role in regulating physiological and pathophysiological effects in mammals. The biological effects of SO2 in mammals are reviewed in this study.

Circulating methylated MINT2 promoter DNA is a potential poor prognostic factor in gastric cancer.

BACKGROUND AND AIM: Aberrant DNA methylation has been shown to be associated with the growth, development, metastasis, and prognosis of tumors. Methylated DNAs may be suitable biomarkers for cancer patients. Here, we investigated whether circulating methylated MINT2 DNAs represent a potential poor prognostic factor in gastric cancer (GC). METHODS: MINT2 methylation was detected by real-time methylation-specific PCR in tumor tissues, pairing preoperative peritoneal lavage fluid (PPLF) and blood from 92 GC patients. The theory meaning and clinical practicality value of MINT2 methylation in different specimens were analyzed. RESULTS: The methylation status of the MINT2 gene was found to be significantly higher in tumor tissues (44.6%, 41/92) than in adjacent normal tissues (3.3%, 3/92). No MINT2 methylation was found in healthy controls, and partial MINT2 methylation was observed in three (6.25%, 3/48) patients with chronic atrophic gastritis. The frequency of MINT2 methylation in pairing PPLF and blood samples from 92 GC patients was 40.2% (37/92) and 39.1% (36/92), respectively. Methylated MINT2 in tumor tissues, pairing PPLF, and blood samples were very approximate. Aberrant MINT2 methylation in tumor tissues and pairing PPLF or blood samples were closely related to peritoneal dissemination, tumor progression, and poor prognosis (all P < 0.0001). CONCLUSIONS: Aberrant MINT2 methylation in PPLF/blood may predict peritoneal micrometastasis for GC patients, which is a potential poor prognostic factor in GC.

Belinostat-induced apoptosis and growth inhibition in pancreatic cancer cells involve activation of TAK1-AMPK signaling axis.

Pancreatic cancer accounts for more than 250,000 deaths worldwide each year. Recent studies have shown that belinostat, a novel pan histone deacetylases inhibitor (HDACi) induces apoptosis and growth inhibition in pancreatic cancer cells. However, the underlying mechanisms are not fully understood. In the current study, we found that AMP-activated protein kinase (AMPK) activation was required for belinostat-induced apoptosis and anti-proliferation in PANC-1 pancreatic cancer cells. A significant AMPK activation was induced by belinostat in PANC-1 cells. Inhibition of AMPK by RNAi knockdown or dominant negative (DN) mutation significantly inhibited belinostat-induced apoptosis in PANC-1 cells. Reversely, AMPK activator AICAR and A-769662 exerted strong cytotoxicity in PANC-1 cells. Belinostat promoted reactive oxygen species (ROS) production in PANC-1 cells, increased ROS induced transforming growth factor-ß-activating kinase 1 (TAK1)/AMPK association to activate AMPK. Meanwhile, anti-oxidants N-Acetyl-Cysteine (NAC) and MnTBAP as well as TAK1 shRNA knockdown suppressed belinostat-induced AMPK activation and PANC-1 cell apoptosis. In conclusion, we propose that belinostat-induced apoptosis and growth inhibition require the activation of ROS-TAK1-AMPK signaling axis in cultured pancreatic cancer cells.

Sulfur dioxide preconditioning increases antioxidative capacity in rat with myocardial ischemia reperfusion (I/R) injury.

BACKGROUND: The study was designed to explore if sulfur dioxide (SO2) preconditioning increased antioxidative capacity in rat with myocardial ischemia reperfusion (I/R) injury. METHODS: The myocardial I/R model was made by left coronary artery ligation for 30min and reperfusion for 120min in rats. Myocardial infarct size and plasma lactate dehydrogenase (LDH) and creatine kinase (CK) activities, plasma superoxide dismutase (SOD), malondialdehyde (MDA), glutathione peroxidase (GSH-Px) and glutathione (GSH) changes were detected for the rats. The contents of myocardial hydrogen sulfide (H2S) and nitric oxide (NO) were measured. Myocardial protein expressions of SOD1, SOD2, cystathionine γ-lyase (CSE) and iNOS were tested using Western blot. RESULTS: Myocardial infarction developed and plasma CK and LDH activities were significantly increased in I/R group compared with those in control group, but SO2 preconditioning significantly reduced myocardial infarct size, and plasma CK and LDH activities. SO2 preconditioning successfully increased plasma SOD, GSH and GSH-Px levels and myocardial SOD1 protein expression, but decreased MDA level in rats of I/R group. Compared with controls, the myocardial H2S level and CSE expression were decreased after I/R, but myocardial NO level and iNOS expression were increased. With the treatment of SO2, myocardial H2S level and CSE expression were increased, but myocardial NO level and iNOS expression were decreased compared with those in I/R group. CONCLUSIONS: SO2 preconditioning could significantly reduce I/R-induced myocardial injury in vivo in association with increased myocardial antioxidative capacity, upregulated myocardial H2S/CSE pathway but downregulated NO/iNOS pathway.

The PI3K/Akt pathway mediates the protection of SO(2) preconditioning against myocardial ischemia/reperfusion injury in rats.

AIM: To explore the mechanisms underlying the protection by SO2 preconditioning against rat myocardial ischemia/reperfusion (I/R) injury. METHODS: Male Wistar rats underwent 30-min left coronary artery ligation followed by 120-min reperfusion. An SO2 donor (1 µmol/kg) was intravenously injected 10 min before the ischemia, while LY294002 (0.3 mg/kg) was intravenously injected 30 min before the ischemia. Plasma activities of LDH and CK were measured with an automatic enzyme analyzer. Myocardial infarct size was detected using Evans-TTC method. The activities of caspase-3 and -9 in myocardium were assayed using a commercial kit, and the levels of p-Akt, Akt, PI3K and p-PI3K were examined with Western blotting. RESULTS: Pretreatment with SO2 significantly reduced the myocardial infarct size and plasma LDH and CK activities, as well as myocardial caspase-3 and -9 activities in the rats. Furthermore, the pretreatment significantly increased the expression levels of myocardial p-Akt and p-PI3K p85. Administration of the PI3K inhibitor LY294002 blocked all the effects induced by SO2 pretreatment. CONCLUSION: The results suggest that the PI3K/Akt pathway mediates the protective effects of SO2 preconditioning against myocardial I/R injury in rats.

[Methylation status of CDH1 gene in preoperative abdominal lavage of patients with gastric cancer and its clinical significance].

OBJECTIVE: To explore the association between the progression of gastric cancer and the aberrant methylation of CDH1 gene in preoperative abdominal lavage fluid. METHODS: Real-time methylation-specific polymerase chain reaction(qMSP) was used to investigate the methylation status of the CDH1 gene promoter 5'-CpG islands from preoperative abdominal lavage fluid in 92 patients with gastric cancer. The associations between methylation of CDH1 genes and clinicopathologic features and prognosis were investigated. RESULTS: Among the 92 patients with gastric cancer, aberrant methylation of CDH1 gene was detected in 45(48.9%) patients, including total aberrant methylation in 12(13.0%) cases and partly aberrant methylation in 33(35.9%) cases. Significant associations were found between CDH1 methylation status and tumor size, growth pattern, differentiation, lymphovascular invasion, infiltration depth, lymph node metastasis, distant metastasis, and clinical staging(all P<0.05). However, there were no significant associations between CDH1 methylation status with gender, age, tumor location, or Helicobacter pylori infection(all P>0.05). The median progression-free survival was 20 months for CDH1 methylation group and 38 months for non-methylated group, and the difference was statistically significant(P<0.01). Cox model analysis revealed that CDH1 methylation status in preoperative peritoneal lavage fluid was an independent factor associated with postoperative survival in patients with gastric cancer(P=0.000, RR=332.88, 95%CI:21.71-5105.07). CONCLUSIONS: The aberrant methylation of 5'-CpG of CDH1 gene promoter is common in gastric cancer. The examination of CDH1 methylation status of abdominal lavage should be considered in the progression of gastric cancer.

Stepwise cumulation of RUNX3 methylation mediated by Helicobacter pylori infection contributes to gastric carcinoma progression.

BACKGROUND: Helicobacter pylori has been recognized as a definite carcinogen for gastric cancer (GC); however, the pathogenesis of H. pylori infection remains unclear. Runt-related transcription factor 3 (RUNX3) is a candidate tumor suppressor gene whose deficiency is causally related to GC. However, in H. pylori infection-associated GC, the role of RUNX3 has not been studied. METHODS: The authors used real-time methylation-specific polymerase chain reaction analysis to determine methylation status of the RUNX3 promoter in a spectrum of gastric lesions, including 220 samples of chronic atrophic gastritis, 196 samples of intestinal metaplasia, 134 samples of gastric adenoma, 102 samples of dysplasia, and 202 samples of GC with paired noncancerous mucosa tissues and corresponding blood specimens. The association of abnormal methylation with precancerous gastric lesions was evaluated along with the association between RUNX3 methylation and H. pylori infection, and the concordance of methylation levels was investigated between serum and tissues. RESULTS: The results indicated that increasing RUNX3 promoter methylation was correlated with distinct stages of GC progression. GC tissues had the highest methylation proportion (75.2%) compared with precancerous gastric lesions, including chronic atrophic gastritis (15.9%), intestinal metaplasia (36.7%), gastric adenoma (41.8%), and dysplasia (54.9%). H. pylori infection, a major risk factor for GC, contributed to the inactivation of RUNX3 in gastric epithelial cells through promoter hypermethylation. The levels of RUNX3 methylation in serum were in significant concordance with the methylation levels observed in GC tissues (P = .887). CONCLUSIONS: The current findings supported RUNX3 methylation as a risk factors for the carcinogenesis of chronic atrophic gastritis with H. pylori infection and indicated that circulating RUNX3 methylation is a valuable biomarker for the detection of early GC.

CDH1 methylation in preoperative peritoneal washes is an independent prognostic factor for gastric cancer.

BACKGROUND AND OBJECTIVES: To investigate the clinical value of CDH1 methylation in preoperative peritoneal washes (PPW) from gastric cancer patients. METHODS: CDH1 methylation was detected by real-time methylation specific-PCR in tumor tissues and corresponding PPW from 92 gastric cancer patients, gastric mucosa from 40 chronic gastritis patients and 48 normal persons. RESULTS: CDH1 methylation was found in 75 of 92 (81.5%) gastric cancer tissues, which significantly correlated with size, growth pattern, differentiation, lymphatic invasion, venous invasion, invasion depth, lymph node metastasis, distant metastasis, and TNM stage of tumor (all P < 0.05), but its relationship to age, gender, tumor site, and H. pylori infection was not found (all P > 0.05). The percentage of CDH1 methylation in PPW was 48.9%, of which the Aζ value of ROC curve was 0.8 compared to that in gastric cancer tissues. Kaplan-Meier analysis showed that there was a significant difference in disease-free survival (DFS) between the patients with or without methylated CDH1 in their PPW (χ(2) = 109.64, P < 0.000). Cox regression analysis revealed CDH1 methylation in PPW was an independent risk factor for gastric cancer patients, with a remarkable decrease in DFS after postoperative 30 months. CONCLUSIONS: Methylated CDH1 in PPW predicts poor prognosis for gastric cancer patients.