The Role of HER2 in Self-Renewal, Invasion, and Tumorigenicity of Gastric Cancer Stem Cells.

BACKGROUND: Deregulation of HER2 expression could affect the biological characteristics of gastric cancer cells and treatment option for gastric cancer patients. This research aims to investigate the impact of HER2 on biological characteristics of gastric cancer stem cells (GCSCs) and prognosis of gastric cancer patients. METHODS: HER2 knockdown in GCSCs were constructed by lentivirus transfection. Alterations of proliferation, self-renewal, invasion, migration, colony formation, and tumorigenicity of GCSCs were examined. The changes of gene expressions after HER2 interference in GCSCs were detected by gene microarray. The impact of concentration of serum HER2 and expression of HER2 in tumor tissues on survival of 213 gastric cancer patients was also analyzed. RESULTS: Down-regulation of HER2 decreased the self-renewal, colony formation, migration, invasion, proliferation, and chemotherapy resistance of GCSCs. However, the tumorigenicity of GCSCs in vivo was increased after down-regulation of HER2. The results of gene microarray showed that HER2 gene might regulate the signal transduction of mTOR, Jak-STAT, and other signal pathways and affect the biological characteristics of GCSCs. Furthermore, survival analyses indicated that patients with high concentration of HER2 in serum had a favorable overall survival. However, there was no significant correlation between expression of HER2 in tumor tissue and overall survival. CONCLUSION: Interference of HER2 in GCSCs decreased the capacity of self-renewal, proliferation, colony formation, chemotherapy resistance, invasion, and migration but might increase the tumorigenicity in vivo. Patients with high concentration of HER2 in serum seemed to have a favorable prognosis.

Burkholderia pseudomallei was Identified in a Melioidosis Aneurysm using Polymerase Chain Reaction Targeting 23S rRNA.

Melioidosis abdominal aortic aneurysm and splenic abscesses lead to poor prognosis and high mortality rate as high as 50% due to delayed/missed diagnosis. We describe an attempt to identify Burkholderia pseudomallei immediately, which was confirmed by polymerase chain reaction (PCR) and gene sequence analysis of 23S rRNA gene. PCR is not only an unambiguous identification of B. pseudomallei but also a rapid detection because B. pseudomallei may not be readily isolated. For patients of melioidosis abdominal aortic aneurysm with spleen abscess, prolonged antibiotic therapy, splenectomy and artificial vessel replacement provided an excellent result in our study. The progression, roentgenographic findings and histopathology character of melioidosis are similar to those of tuberculosis disease. PCR is useful to differentiate B. pseudomallei from Mycobacterium tuberculosis.

Sodium tanshinone IIA sulfonate protects against acute exacerbation of cigarette smoke-induced chronic obstructive pulmonary disease in mice.

Exacerbation of chronic obstructive pulmonary disease (COPD) is characterized by acute airway inflammation and mucus hypersecretion, which is by far the most costly aspect of its management. Thus, it is essential to develop therapeutics with low side effects for CODP exacerbation. Sodium tanshinone IIA sulfonate (STS) is a water-soluble derivative of tanshinone IIA isolated as the major active component of Chinese herbal medicine Danshen. Although it possesses anti-inflammatory, anti-oxidative and anti-apoptotic properties, it remains unknown whether STS protects against COPD exacerbation. In this study, we challenged cigarette smoke (CS)-exposed mice with lipopolysaccharide (LPS), and then treated these mice with STS. We found that STS significantly ameliorated pulmonary inflammatory responses, mucus hypersecretion and lung function decline in CS-exposed mice challenged with LPS. STS treatment also significantly attenuated increased IL-6 and IL-8 releases from cigarette smoke extract (CSE)-treated human bronchial epithelial cells (16HBE) challenged with LPS. Mechanistically, STS reduced activation of ERK1/2 and NF-κB in lungs of CS-exposed mice and CSE-treated 16HBE cells challenged with LPS. Taken together, STS protects against acute exacerbation of CS-induced lung injury, which provides a promising and potential therapeutic avenue to halt acute exacerbation of COPD.

Nitrogen-doped fluorescent carbon dots used for the imaging and tracing of different cancer cells.

Here, we report the synthesis of nitrogen-doped fluorescent carbon (C) dots using a one-pot hydrothermal method. Transmission electron microscopy results reveal that the particle size of the nitrogen-doped C-dots is very small, with an average diameter of 4.6 nm. After being kept in water for 10 days, the nitrogen-doped C-dots can still dissolve well in the water, showing good stability and compatibility in aqueous solution. The fluorescence spectra show that the nitrogen-doped C-dots exhibit emission-tunable color from blue to green upon excitation from 230 to 520 nm. Cell tests show that the C-dots are low in cytotoxicity and can be used for imaging, detecting and tracing between hepatoma and HeLa cells, because hepatoma and HeLa cells show different sensitivity to different fluorescent colors pumped at different excitation wavelengths.

Identification of surrogate prognostic biomarkers for allergic asthma in nasal epithelial brushing samples by WGCNA.

BACKGROUND: Allergic asthma is a lower respiratory tract disease of Th2 inflammation with multiple molecular mechanisms. The upper and lower airways can be unified by the concept of a united airway and, as such, gene expression studies of upper epithelial cells may provide effective surrogate biomarkers for the prognostic study of allergic asthma. OBJECTIVE: To identify surrogate biomarkers in upper airway epithelial cells for the prognostic study of allergic asthma. METHODS: Nasal epithelial cell gene expression in 40 asthmatic and 17 healthy control subjects were analyzed by weighted gene coexpression network analysis (WGCNA) to identify gene network modules and profiles in allergic asthma. Functional enrichment analysis was performed on the coexpression genes in certain highlighted modules. RESULTS: A total of 13 coexpression modules were constructed by WGCNA from 2804 genes in nasal epithelial brushing samples of the 40 asthmatic and 17 healthy subjects. The number of genes in these modules ranged from 1086 (Turquoise module) to 45 (Salmon). Eight coexpression modules were found to be significantly correlated (P < 0.05) with two clinic traits, namely disease status, and severity. Four modules were positively correlated ( P < 0.05) with the traits and these, therefore, contained genes that are mostly overexpressed in asthma. Contrastingly, the four other modules were found to be negatively correlated with the clinic traits. Functional enrichment analysis of the positively correlated modules showed that one (Magenta) was mainly enriched in mast cell activation and degranulation; another (Pink) was largely involved in immune cell response; the third (Yellow) was predominantly enriched in transmembrane signal pathways; and the last (Blue) was mainly enriched in substructure components of the cells. The hub genes in the modules were KIT, KITLG, GATA2, CD44, PTPRC, and CFTR, and these were confirmed as having significantly higher expression in the nasal epithelial cells. Combining the six hub genes enabled a relatively high capacity for discrimination between asthmatics and healthy subjects with an area under the receiver operating characteristic (ROC) curve of 0.924. CONCLUSIONS: Our findings provide a framework of coexpression gene modules from nasal epithelial brushing samples that could be used for the prognostic study of allergic asthma.

A large lung gene expression study identifying IL1B as a novel player in airway inflammation in COPD airway epithelial cells.

BACKGROUND: Chronic obstructive pulmonary disease (COPD) is a chronic and progressive lung disease characterized by a mixture of small airway disease and lung tissue parenchymal destruction. Abnormal inflammatory responses to cigarette smoking and other noxious particles are generally thought to be responsible for causing of COPD. Since airway inflammation is a key factor in COPD progress, it is crucial to unravel its underlying molecular mechanisms. Unbiased analysis of genome-wide gene expression profiles in lung small airway epithelial cells provides a powerful tool to investigate this. METHODS: Gene expression data of GSE611906, GSE20257, GSE8545 were downloaded from GEO database. All 288 lung small airway samples in these cohorts, including donors with (n = 61) and without (n = 227) COPD, were chosen for differential gene expression analysis. The gene ontology (GO) function, Kyoto Encyclopedia of Genes and Genomes pathway (KEGG) enrichment analyses, gene co-expression network analysis (WGCNA) and protein-protein interaction (PPI) network analysis were performed. Subsequently, the analyses of IL1B expression level, the Pearson correlation between IL1B and several COPD biomarkers were performed using other cohorts to validate our main findings. RESULTS: With a change ≥ twofold and P value < 0.05 cutoff, we found 38 genes were up-regulated and 114 genes were down-regulated in patients with COPD compared with health controls, while using cutoff fold change 1.5 and P value < 0.05, there were 318 genes up-regulated and 333 genes down-regulated. Among the most up-regulated genes were IL1B, CCL2, CCL23, and CXCL14, all implicated in inflammation triggering. GO, KEGG and WGCNA analysis all disclosed IL1B was highly correlated to COPD disease trait. The expression profile of IL1B was further validated using independent cohorts from COPD airway epithelium, lung tissue, sputum, and blood. We demonstrated higher IL1B gene expression in COPD small airway epithelial cells, but not in COPD lung tissue, sputum, and blood. Strong co-expression of IL1B with COPD biomarkers, such as DUOX2, MMP12, CCL2, and CXCL14, were validated in silico analysis. Finally, PPI network analysis using enriched data showed IL1B, CCL2, CCL7 and BMP7 were in the same hub node with high degrees. CONCLUSIONS: We identified IL1B was significantly up-regulated in COPD small airway epithelial cells and propose IL1B as a novel player in airway inflammation in COPD.

Reconstruction of Tragus and External Auditory Meatus using Remnant Auricle during Microtia Reconstruction.

This article investigates an effective method with which to reconstruct the tragus and external auditory meatus for microtia reconstruction. The external ear was reconstructed using a delayed postauricular skin flap in patients with congenital microtia. After the first stage of delaying the postauricular skin flap and the second stage of otoplasty with ear framework fabricated from autogenous rib cartilage draping with the delayed skin flap, the third stage involved tragus and external auditory meatus canaloplasty. After designing the remnant auricle flap, the lower part was trimmed and the tragus was reconstructed. The upper part was trimmed into a thin skin flap, which was rotated and used to cover the hollowed wound posterosuperior to the tragus so as to mimic the external auditory meatus. If remnant wounds were present, skin grafting was conducted. In total, 121 patients with congenital microtia were treated from March 2010 to March 2016. The reconstructed tragus and external auditory meatus were well formed, and all wounds healed well. No severe complications such as flap necrosis occurred. Six months postoperatively, the morphology of the reconstructed tragus and external auditory meatus was good. Overall, the patients and their families were satisfied. The use of remnant auricle to reconstruct the tragus and external auditory meatus is an effective auricular reconstruction technique.

Negative regulation of Sirtuin 1 by AMP-activated protein kinase promotes metformin-induced senescence in hepatocellular carcinoma xenografts.

Increasing evidence suggests that therapy-induced senescence (TIS), a novel therapeutic approach in which low doses of therapeutic drugs or radiation are used to induce senescence, suppresses tumor development. Our previous in vitro studies have demonstrated that a low dose of metformin promoted hepatoma cell senescence instead of apoptosis via activation of AMP-activated protein kinase (AMPK) and inactivation of Sirtuin 1 (SIRT1) deacetylase activity. However, the intricate relationship between AMPK and SIRT1, and how they cooperate to induce senescence remains elusive. We showed here that persistent exposure to a low concentration of metformin led to AMPK activation in a mouse xenograft model of human hepatocellular carcinoma (HCC), resulting in senescence. Intriguingly, AMPK counter-regulated SIRT1 via direct phosphorylation in metformin-mediated senescence in hepatoma cells. Taken together, these findings suggest that a low dose of metformin could potentially be used as a TIS-inducing therapeutic drug for HCC, and that this occurs by inducing senescence of HCC cells via the AMPK-SIRT1 pathway.

Down-regulation of XIAP enhances the radiosensitivity of esophageal cancer cells in vivo and in vitro.

The study investigated the effects of X-chromosome-linked inhibitor of apoptosis (XIAP) gene silencing on the radiosensitivity of esophageal cancer (EC) cells. Western blotting was used to select EC cell lines with XIAP overexpression. Selected EC9706 and KYSE30 cell lines were both divided into four groups: the blank control group, the negative control (NC) group (transfected with pBSHH1), the siRNA-enhanced group (transfected with pBSHH1-XIAP1-siRNA), and the siRNA-decreased group (transfected with pBSHH1-XIAP2-siRNA). Expressions of XIAP were measured by reverse-transcription quantitative PCR (RT-qPCR) and Western blotting, cell survival and viability by MTT assay and colony formation assay, and cell apoptosis by flow cytometry, respectively. Caspase-3 and caspase-9 activity were detected using caspase-3 and caspase-9 activity detection kits. A nude mice model of EC9706 cell line was established to measure tumorigenesis ability. Compared with the NC group, XIAP mRNA and protein expressions were decreased, caspase-3 and caspase-9 activity and apoptosis were up-regulated, and cell survival rate and colony-forming efficiency were lower in the siRNA-enhanced and siRNA-decreased groups in both the cell lines; while the opposite trends were found in the siRNA-decreased group compared with the siRNA-enhanced group. Tumor weight and volume of nude mice were decreased in the siRNA-enhanced and siRNA-decreased groups than those in the NC group, and were elevated in the siRNA-decreased group compared with the siRNA-enhanced group. These results indicate that XIAP gene silencing would strengthen the radiosensitivity of EC9706 cells, which provides a novel target for the treatment of EC.

Heat stress induces intestinal injury through lysosome- and mitochondria-dependent pathway in vivo and in vitro.

Damage to the small intestine secondary to heat stroke is a major factor in heat stroke-related morbidity and mortality. However, the underlying mechanisms by which heat stroke causes small intestinal lesions and dysfunction remain unclear. To explore the pathogenesis of small intestinal tissue and epithelial cell injury, the SW480 cell heat stress model and the mice heat stroke model were established to mimic heat stroke. Morphologic changes in intestinal tissue and increased TUNEL-positive index were induced by heat stress in vivo. Heat stress activated the lysosomal-mitochondrial apoptotic pathway in SW480 cells, increasing intracellular reactive oxygen species and causing lysosomal membrane permeabilization with subsequent release of cathepsin B to the cytosol, mitochondrial depolarization, and cytochrome C release to cytosol. An increase in the Bax/Bcl2 ratio, caspase-9 and caspase-3 were observed. N-Acetyl-L-Cysteine was shown to inhibit ROS generation, suppress permeabilization of lysosomal membranes, decrease levels of cathepsin B and cytochrome C in the cytosol, and inhibit Bax/Bcl2 ratio, caspase-9 and caspase-3 activity both in vitro and in vivo. Mitochondrial damage was alleviated when the models were pre-treated with CA-074 Me both in vitro and in vivo, decreasing cathepsin B and cytochrome C levels in the cytosol, Bax/Bcl2 ratio, caspase-9 and caspase-3 activity. In our models, heat stress-induced apoptosis of small intestinal tissue and epithelial cells through accumulation of ROS and activation of the lysosomal-mitochondrial apoptotic pathway involved the release of cathepsin B. These findings may offer potentially pharmaceutical targets and strategies to repair intestinal injury caused by heat stroke.

Learning curve for gastric cancer patients with laparoscopy-assisted distal gastrectomy: 6-year experience from a single institution in western China.

Laparoscopy-assisted distal gastrectomy (LADG) is widely used for gastric cancer (GC) patients nowadays. This study aimed to investigate the time trend of outcomes so as to describe the learning curve for GC patients with LADG at a single medical institution in western China over a 6-year period.A total of 246 consecutive GC patients with LADG were divided into 5 groups (group A: 46 patients from 2006 to 2007; group B: 47 patients in 2008; group C: 49 patients in 2009; group D: 73 patients in 2010; and group E: 31 patients in 2011). All surgeries were conducted by the same surgeon. Comparative analyses were successively performed by Mann-Whitney U test or Student t test among the 5 different groups for the clinical data, including clinicopathologic characteristics, surgical parameters, postoperative course, and survival outcomes, through which the learning curve was described.There were no differences in the baseline information among the 5 groups (P > 0.05), and the proportion of advanced GC patients with LADG slightly increased from 58.7% to 77.4% during the 6 years. Besides, the proportion of D2/D2+ lymphadenectomy and the number of retrieved lymph nodes gradually grew from 60.9% to 80.6% and from 20.0 to 28.8, respectively. In addition, the operation time decreased from 299.2 to 267.8 minutes, while the estimated blood loss dropped from 175.2 to 146.8 mL. Furthermore, some surgical parameters (surgical duration and blood loss) and postoperative course (such as postoperative complications, the time to ambulation, to first flatus, and to first liquid intake as well as the length of hospital stay) were all observed to be significantly different between group A and other groups (P < 0.05), illustrating a similar downward trend and remaining stable to form a plateau after 46 cases in group A. However, no difference on overall survival was found among these 5 groups, and multivariate analysis indicated that factors, such as age, tumor differentiation, tumor size, and T stage as well as N stage, were independent prognostic factors for patients with LADG.Improvement on surgical parameters and postoperative course can be seen over the past years, and the cutoff value of the learning curve of LADG for surgeons with rich experience in open operation might be 46 cases.

Clinical significance of putative markers of cancer stem cells in gastric cancer: A retrospective cohort study.

Cancer stem cells (CSCs) are thought as the source of tumor maintaining and many CSCs markers have been identified. Regarding the heterogeneity in gastric cancer (GC), TNM stage is not enough to accurately predict the prognosis. The aim of this study was to investigate the clinical significance of CSCs markers (Lgr5, Oct4, CD133, EpCAM, CD54 and Sox2) and establish a new model based on these markers to accurately predict prognosis of GC. We retrospectively enrolled 377 GC tissues from January 2006 to October 2012 to perform immunohistochemistry (IHC), and 93 pairs of GC tissues and corresponding adjacent normal gastric tissues to perform quantitative PCR (qPCR) from December 2011 to October 2012. The clinicopathological and follow-up characteristics were collected. In IHC, Oct4, CD133 and EpCAM were independently related to tumor progression, while Sox2 were associated with well or moderate differentiation (all p<0.05). Cox regression showed that Oct4-EpCAM was an independently prognostic factor, indicating that double low expression of Oct4-EpCAM group had significantly better prognosis than control group (p=0.035). Regarding qPCR, CD133 was an independent prognostic factor, showing that the prognosis of patients with CD133 high expression was significantly worse than that of patients with CD133 low expression (p<0.001). The prognostic prediction accuracy of nomogram based on Oct4-EpCAM expression in IHC was significantly better than TNM stage alone (p=0.003). Low expressions of Oct4-EpCAM in IHC and CD133 in qPCR were favorable prognostic factors in GC. The nomogram based on Oct4-EpCAM was valuable in prognostic prediction of GC patients.

Clinical characteristics and prognostic factors of primary gastric lymphoma: A retrospective study with 165 cases.

Primary gastric lymphoma (PGL) is the most common extranodal non-Hodgkin lymphoma. This retrospective study aimed to analyze the clinical characteristics, prognostic factors, and roles of different treatment modalities in patients with PGL.From January 2003 to November 2014, 165 patients who were diagnosed with PGL at West China Hospital were enrolled in this study. The clinical features, treatment, and follow-up information were analyzed.In this study, diffuse large B-cell lymphoma (DLBCL) (108, 65.5%) and mucosa-associated lymphoid tissue (MALT) lymphoma (52, 31.5%) were two predominant histological subtypes. One-year and 5-year overall survival (OS) rates of all patients were 95.2% and 79.5%, respectively; in whom 110 (66.7%) underwent surgery, 110 (66.7%) received chemotherapy, 12 (7.3%) received radiotherapy, and 10 (6.1%) received Helicobacter pylori eradication. And 75 patients (45.5%) were treated with at least 2 different types of therapies. Elevated lactic dehydrogenase (LDH) levels, poor performance status (PS), advanced stage, International Prognostic Index (IPI) score ≥3, conservative treatment, and high-grade histological subtype were associated with worse prognosis in univariate analysis. Cox regression analysis showed that LDH levels, PS, staging, and histological subtype were independent predictors of survival outcomes. In the DLBCL type, 5-year OS was significantly better in the surgically treated group (80.1%) than that of patients conservatively treated (49.8%) (P = 0.001). Surgical treatment had almost no impact on OS in the MALT type than conservative treatment (P = 0.597). The proportion of patients received conservative treatment increased from 4.5% in period 1 to 51.7% in period 4.High LDH levels, poor PS, advanced staging, and malignant pathological type at diagnosis are significantly associated with poor OS. Our data suggest that surgery is superior in prognosis over conservative treatment in the DLBCL type, but not in the MALT type. Recently, conservative treatment is becoming more preferred approach in patients with PGL.

A new predictive model combined of tumor size, lymph nodes count and lymphovascular invasion for survival prognosis in patients with lymph node-negative gastric cancer.

BACKGROUND: Various factors may affect the clinical prognosis of lymph node-negative gastric cancer (GC) patients. This study aimed to provide evaluable prognostic information of combination of tumor size (Ts), lymph nodes count (LNs) and lymphovascular invasion (LVI) in lymph node-negative GC patients. METHODS: A total of 1,019 node-negative GC patients were enrolled in this retrospective study from 2000 to 2010. The cutoff points of Ts and LNs were determined using X-tile and patients were randomly categorized into training and validation sets by the sample size ratio 1:1. The clinicopathologic characteristics were analyzed and survival prognostic factors were identified, whereas the survival prediction accuracy was also compared by C-index during the different independent prognostic factors. RESULTS: The cutoff points for Ts were 3cm and 5cm, while 14 was the cutoff point for LNs. Age, T stage, Ts, LNs and LVI were identified as independent prognostic factors in node-negative GC patients, and a new prognostic predictive model, TsNL staging system which was composed of Ts, LNs and LVI, was proposed in this study. Compared with T staging system, significant improvement of predictive accuracy for TsNL system was found. Furthermore, nomogram based on TsNL was more accurate in prognostic prediction than that based on Ts, LNs and LVI, separately. CONCLUSIONS: Age, T stage, Ts, LNs and LVI were independent prognostic factors in lymph node-negative GC patients. The TsNL staging system, composed of Ts, LNs and LVI, which was closely associated with clinicopathologic features, may improve the prognostic prediction accuracy in node-negative GC patients.

A nomogram composed of clinicopathologic features and preoperative serum tumor markers to predict lymph node metastasis in early gastric cancer patients.

Predicting lymph node metastasis (LNM) accurately is of great importance to formulate optimal treatment strategies preoperatively for patients with early gastric cancer (EGC). This study aimed to explore risk factors that predict the presence of LNM in EGC. A total of 697 patients underwent gastrectomy enrolled in this study, were divided into training and validation set, and the relationship between LNM and other clinicopathologic features, preoperative serum combined tumor markers (CEA, CA19-9, CA125) were evaluated. Risk factors for LNM were identified using logistic regression analysis, and a nomogram was created by R program to predict the possibility of LNM in training set, while receiver operating characteristic (ROC) analysis was applied to assess the predictive value of the nomogram model in validation set. Consequently, LNM was significantly associated with tumor size, macroscopic type, differentiation type, ulcerative findings, lymphovascular invasion, depth of invasion and combined tumor marker. In multivariate logistic regression analysis, factors including of tumor size, differentiation type, ulcerative findings, lymphovascular invasion, depth of invasion and combined tumor marker were demonstrated to be independent risk factors for LNM. Moreover, a predictive nomogram with these independent factors for LNM in EGC patients was constructed, and ROC curve demonstrated a good discrimination ability with the AUC of 0.847 (95% CI: 0.789-0.923), which was significantly larger than those produced in previous studies. Therefore, including of these tumor markers which could be convenient and feasible to obtain from the serum preoperatively, the nomogram could effectively predict the incidence of LNM for EGC patients.

Superiority of lymph node ratio-based staging system for prognostic prediction in 2575 patients with gastric cancer: validation analysis in a large single center.

This study aimed to evaluate the prognostic significance of node ratio (Nr), the ratio of metastatic to retrieved lymph nodes, and to investigate whether a modified staging system based on Nr can improve prognostic ability for gastric cancer patients following gastrectomy. A total of 2572 patients were randomly divided into training set and validation set, and the cutoff points for Nr were produced using X-tile. The relationships between Nr and other clinicopathologic factors were analyzed, while survival prognostic discriminatory ability and accuracy were compared among different staging systems by AIC and C-index in R program. Patients were categorized into four groups as follows: Nr0, Nr1: 0.00-0.15, Nr2: 0.15-0.40 and Nr3: > 0.40. Nr was significantly associated with clinicopathologic factors including macroscopic type, tumor differentiation, lymphovascular invasion, perineural invasion, tumor size, T stage, N stage and TNM stage. Besides, for all patients, Nr and TNrM staging system showed a smaller AIC and a larger C-index than that of N and TNM staging system, respectively. Moreover, in subgroup analysis for patients with retrieved lymph nodes < 15, Nr was demonstrated to have a smaller AIC and a larger C-index than N staging system. Furthermore, in validation analysis, Nr, categorized by our cutoff points, showed a larger C-index and a smaller AIC value than those produced in previous studies. Nr could be considered as a reliable prognostic factor, even in patients with insufficient (< 15) retrieved lymph nodes, and TNrM staging system may improve the prognostic discriminatory ability and accuracy for gastric cancer patients undergoing radical gastrectomy.

Metformin suppresses hypoxia-induced stabilization of HIF-1α through reprogramming of oxygen metabolism in hepatocellular carcinoma.

Overexpression of hypoxia-induced factor 1α (HIF-1α) has been shown to be involved in the development and progression of hepatocellular carcinoma (HCC). HIF-1α should therefore be a promising molecular target for the development of anti-HCC agents. Metformin, an established antidiabetic drug, has proved to also be effective in treating cancer although the precise underlying mechanisms of this activity are not fully elucidated. The aim of this study was to investigate the effects of metformin on the expression of HIF-1α and oxygen metabolism in HCC. The results showed that metformin inhibited hypoxia-induced HIF-1α accumulation and activation independent of AMP-activated protein kinase (AMPK). Moreover, this decrease in HIF-1α accumulation was accompanied by promotion of HIF-1α protein degradation. In addition, metformin significantly decreased oxygen consumption, ultimately leading to increased intracellular oxygen tension and decreased staining with the hypoxia marker pimonidazole. In vivo studies demonstrated that metformin delayed tumor growth and attenuated the expression of HIF-1α in HCC tumor xenografts. Together, these findings suggest that metformin decreases hypoxia-induced HIF-1α accumulation by actively suppressing mitochondrial oxygen consumption and enhancing cellular oxygenation ability, providing a fundamental mechanism of metformin activity against HCC.

[Inlaid labial versus bladder mucosal graft repair for complex urethral skin fistula].

OBJECTIVE: To compare the effect of inlaid labial mucosal graft repair (LMGR) with that of bladder mucosal graft repair (BMGR) in the treatment of complex urethral skin fistula after hypospadias repair. METHODS: This study included 55 cases of complex urethral skin fistula following hypospadias repair. We randomly assigned them to receive inlaid LMGR (n=36) or BMGR (n=19). After surgery, we compared the incidence of complications and recurrence rate of urinary fistula between the two groups of patients. RESULTS: The success rates of operation were 91.7% and 84.2% in the LMGR and BMGR groups, respectively, and the penile appearance was desirable in both groups. Postoperative complications included 2 cases of urinary fistula and 1 case of urethral stricture in each group. There were no statistically significant differences between the two groups in the success rate of operation (P>0.05) or the incidence rate of postoperative complications (P>0.05). CONCLUSIONS: Both inlaid LMGR and BMGR yield satisfactory results in the treatment of complex urethral skin fistula. However, LMGR involves less injury in mucosa collection and is easier to perform and therefore deserves more clinical attention.

Downregulation of miR203 induces overexpression of PIK3CA and predicts poor prognosis of gastric cancer patients.

BACKGROUND: Despite advances in clinical therapies and technologies, the prognosis for patients with gastric cancer is still poor. The aim of this study is to investigate new predictive markers for prognosis of gastric cancer. METHODS: In this study, we evaluated the expression pattern of PIK3CA in 107 gastric cancer specimens and their adjacent nontumorous tissues. PIK3CA siRNA was synthesized and transfected into gastric cancer cell lines. Colony formation and MTT assays were employed to analyze the cell proliferation. PIK3CA expression was examined by using immunohistochemical analysis and Western blot assay. Transwell invasion assay was used to detect the invasion capability of the cells. Luciferase activity was examined by using 3'-untranslated region luciferase reporter assays. RESULTS: We observed that PIK3CA was significantly upregulated in gastric cancer tissues. High expression level of PIK3CA was detectable in 48 (44.86%) of the gastric cancer specimens, and correlated with poor prognosis. In addition, our study indicated that miR203 inhibits cell proliferation and invasion via directly targeting and suppressing the PIK3CA expression. MiR203 expression is downregulated in gastric cancer tissues. Moreover, low expression level of miR203 predicted poor prognosis of gastric patients and induced overexpression of PIK3CA. Our further study also reported that overexpression of miR203 inhibited phosphorylation of AKT, while cotransfection of PIK3CA reversed the effect of miR203. CONCLUSION: Our study suggested a miR203-PIK3CA-AKT signaling pathway in gastric cancer cells. This signaling pathway might play an important role in gastric cancer genesis and development.

Low concentration of metformin induces a p53-dependent senescence in hepatoma cells via activation of the AMPK pathway.

The induction of senescence for cancer treatment has provoked considerable interest recently. Metformin, a first-line drug for diabetes mellitus type 2, appears to be associated with a lower risk and improved outcomes in hepatocellular carcinoma (HCC). The mechanism involved in function of metformin in HCC is poorly understood. We show that low doses of metformin induced hepatoma cell senescence characterized by accumulation of senescence-associated ß-galactosidase activity (SA-ß-gal) and the senescence marker Dec1, whereas the higher doses initiated apoptotic cell death. Metformin-induced senescence was accompanied by enhanced phosphorylation levels of AMP-activated protein kinase (AMPK) and its downstream target acetyl-CoA carboxylase (ACC). The expression of acetylated p53 at Lys382 (Ac-p53) and p21 was also increased, while phosphorylation of p53 at Ser15 (p-p53), p53, p16 and pRB was rarely altered after metformin treatment. Moreover, inhibition of AMPK decreased p-AMPK, p-ACC, Ac-p53 and p21 expression, diminished SA-ß-gal staining and restored hepatoma cell proliferation. In addition, p53 siRNA transfection attenuated metformin-induced SA-ß-gal staining. Intriguingly, co-expression of SIRT1 and p53 dramatically reduced the levels of Ac-p53, however, low doses of metformin treatment partially reversed the effect of SIRT1 on p53 acetylation and elevated SA-ß-gal activity. These observations indicate that activation of the AMPK pathway promotes senescence in hepatoma cells exposed to low concentrations of metformin in a p53-dependent manner. Further, low doses of metformin may have the potential to be used as an adjuvant to HCC therapy.