[Corrigendum] Downregulation of heparanase by RNA interference inhibits invasion and tumorigenesis of hepatocellular cancer cells in vitro and in vivo.

Following the publication of this article, an interested reader drew to the authors' attention that two images in Fig. 1B (the a and d panels) appeared to represent the same clone, albeit with different intensities and the panels were cropped differently. The authors were able to confirm that Figs. 1B(a) and B(d) were inadvertently selected from the same set of images but with different exposure times: Owing to an error in data handling, a wrong image was chosen during the grouping the figures. The corrected version of Fig. 1 is shown on the next page, featuring the correct image for Fig. 1B(d). The authors regret that this error was not picked up upon before the paper was sent to press, although the error did not affect the major conclusions reported in the paper. The authors thank the Editor of International Journal of Oncology for allowing them the opportunity to publish a Corrigendum. and regret any inconvenience caused to the readership. [the origional article was published on International Journal of Oncology 40: 1601­1609, 2012; DOI: 10.3892/ijo.2012.1338].

Role of Kruppel-Like Factor 5 in Deoxycholic Acid-Mediated Intestinal Transdifferentiation of Esophageal Squamous Epithelium.

Barrett's esophagus (BE) is an acquired condition in which normal squamous epithelium is replaced with metaplastic columnar epithelium as a consequence of gastroesophageal reflux disease. BE is known as a precursor of esophageal adenocarcinoma. Currently, the molecular mechanism underlying epithelial metaplasia in BE patients remains unknown. Therefore, we investigated the role of Krüppel-like factor 5 (KLF5) signaling in the initiation of BE-associated metaplasia. Sprague-Dawley (SD) rats were used to create a surgical model of bile reflux injury. Immunohistochemistry was performed to analyze human and mouse esophageal specimens. Human esophageal squamous epithelial (HET-1A) cells were treated with bile acid and used in transfection experiments. Quantitative real-time PCR and western blot analysis were performed to detect the expression of KLF5, CDX2, MUC2 and villin. Epithelial tissue from both the rat BE model and human BE patients strongly expressed KLF5, CDX2, MUC2, and villin. Bile acid treatment also increased the expression of KLF5, CDX2, MUC2 and villin in esophageal epithelial cells in a time-dependent manner. Moreover, siRNA-mediated knockdown of KLF5 blocked the expression of CDX2, MUC2 and villin, but transfection of a KLF5 expression vector into esophageal epithelial cells promoted their transdifferentiation into columnar-like cells, as demonstrated by increased expression of the intestinal markers CDX2, MUC2 and villin. Thus, in addition to its function as a transcription factor, KLF5 may be linked to an increased risk of BE development.

A population-based study on prevalence and risk factors of gastroesophageal reflux disease in the Tibet Autonomous Region, China.

OBJECTIVE: To investigate the prevalence and risk factors of gastroesophageal reflux disease (GERD) in the Tibet Autonomous Region, China. METHODS: In this cross-sectional study, a stratified random sampling method was used for collecting samples in the Tibet Autonomous Region. A total of 10,000 individuals were selected from October 2016 to June 2017. A previously-published, validated questionnaire including six items related to the symptoms of GERD was used for evaluating GERD. In addition, basic demographic data, lifestyle, dietary habits, medical history and family history of GERD were investigated to identify risk factors of GERD. RESULTS: A total of 5,680 completed questionnaires were collected and analyzed. The prevalence of GERD in this area was 10.8%. Age (30-40 years vs. under 18 years, odds ratio (OR): 3.025; 40-50 years vs. under 18 years, OR: 4.484), education level (high school vs. primary, OR: 0.698; university vs. primary, OR: 2.804), ethnic group (Han vs. Tibetan, OR: 0.230; others vs. Tibetan, OR: 0.304), altitude of residence (4.0-4.5 km vs. 2.5-3.0 km, OR: 2.469), length of residence (<5 years vs. ≥5 years, OR: 2.218), Tibetan sweet tea (yes vs. no, OR: 2.158), Tibetan barley wine (yes vs. no, OR: 1.271), Tibetan dried meat (yes vs. no, OR: 1.278) and staying up late (yes vs. no, OR: 1.223) were significantly (all P < 0.05) and independently associated with GERD. CONCLUSIONS: The prevalence of GERD is high in the Tibet Autonomous Region, China. Geographic conditions, ethnic group and lifestyle are risk factors for GERD.

Optimized high-dose amoxicillin-proton-pump inhibitor dual therapies fail to achieve high cure rates in China.

Background\Aim: Quadruple daily administration of proton-pump inhibitor (PPI) therapy achieves potent acid inhibition, and combined with amoxicillin, with its pharmacodynamic and pharmacokinetic characteristics, may be efficient for Helicobacter pylori eradication. We compared the efficacy of two optimized high-dose dual therapies with a bismuth-containing quadruple regimen for treating H. pylori infection. Rabeprazole dosages for H. pylori eradication were also evaluated. PATIENTS AND METHODS: Treatment-naive and H. pylori-positive subjects were recruited and randomly apportioned to three treatment groups: Group A (n = 87), rabeprazole 10 mg plus amoxicillin 750 mg (4 times/day for 14 days); Group B (n = 87), rabeprazole 20 mg plus amoxicillin 750 mg (4 times/day for 14 days); and Group C (n = 89), bismuth-containing quadruple regimen consisting of rabeprazole 20 mg, bismuth 220 mg, amoxicillin 1000 mg, and clarithromycin 500 mg (2 times/day for 14 days). Four weeks after treatment discontinuation, patients were examined for H. pylori infection by 13C-urea breath test. The rates of adverse effects, compliance, and eradication were evaluated. RESULTS: Eradication rates in groups A, B, and C were 78.1, 81.6, and 84.3%, respectively, based on intention-to-treat analysis, or 79.1, 83.5, and 86.2%, according to per-protocol analysis. Rates of adverse events and compliance of the three groups were similar. CONCLUSION: For treating H. pylori infection, optimized high-dose amoxicillin-PPI dual therapies failed to achieve high cure rates in China and held no advantage over a bismuth-containing quadruple regimen.

Low expression of occludin: a predictor of poor prognosis in esophageal squamous cell carcinoma.

Occludin is transmembrane protein and a key constituent of tight junction, and might participate in barrier function and fence function of epithelia and endothelia. It has been shown to be aberrantly expressed in malignant tumors and plays a role in carcinogenesis and tumor progression. The prognostic significance of Occludin expression has been implicated in various human cancers. However, the prognostic significance of Occludin expression in esophageal squamous cell carcinoma (ESCC) has not been established. In this study, we screened the tight junction genes aberrantly expressed based on two published gene microarray datasets (GSE20347 and GSE23400), and examined 95 esophageal cancer cases to assess immunohistochemical expression patterns of Occludin based on tissue array. Down-regulation of Occludin expression was shown in ESCC as compared with adjacent non-neoplastic specimens (P = 0.003). Decreased expression of Occludin was correlated with high histological grade (P = 0.017). Decreased expression of Occludin was also correlated with short overall survival (P = 0.014). The results indicated Loss of Occludin expression was associated with poor prognosis in ESCC, and Occludin expression was potentially a good predictor of prognosis in ESCC.

BMP4 promotes a phenotype change of an esophageal squamous epithelium via up-regulation of KLF4.

INTRODUCTION: Barrett's esophagus is a metaplastic lesion. However, the cellular and molecular mechanisms involved are poorly understood. The aim of this study was to investigate the roles of KLF4 and BMP4 in the pathogenesis of Barrett's epithelium. MATERIALS AND METHODS: Immunohistochemistry was used to analyse the expression of KLF4, BMP4, CDX2, MUC2 and MUC5AC in human esophageal specimens. Human esophageal squamous epithelial cells were subjected to bile acid treatment and used in transfection experiments. Quantitative real-time PCR and Western blot analysis were used to detect the expression of KLF4, BMP4, CDX2, MUC2 and MUC5ac. RESULTS: In human tissues, Barrett's epithelium strongly expressed BMP4, p-Smad1/5/8 and KLF4. Furthermore, bile acids increased the expression of BMP4, KLF4, p-Smad1/5/8, CDX2, MUC2 and MUC5ac in esophageal epithelial cells in a time-dependent manner. Moreover, we found that BMP4 up-regulated the expression of KLF4, CDX2, MUC2 and MUC5ac, but Noggin, a specific BMP4 antagonist, can block the expression of KLF4, CDX2, MUC2 and MUC5ac induced by BMP4. However, BMP4 cannot induce the expression of CDX2, MUC2 and MUC5ac in cells with KLF4 siRNA, and Noggin cannot block the expression of KLF4, CDX2, MUC2 and MUC5ac in cells transfected with the KLF4 expression vector. CONCLUSION: Our results demonstrate that BMP4 promotes a phenotype change of an esophageal squamous epithelium via up-regulation of KLF4.

H. pylori infection is related to mitochondrial microsatellite instability in gastric carcinogenesis.

BACHGROUND: To assess the correlation of H. pylori infection with mitochondrial microsatellite instability (mtMSI) and IL-8 in gastric carcinogenesis. METHODS: H. pylori infection was evaluated through histology and a urease breath test; mtMSI was measured using PCR-single strand conformation polymorphism (PCR-SSCP); IL-8 was analyzed with ELISA methods. RESULTS: The detection rate of mtMSI was significantly higher in specimens with H. pylori infection than in those without H. pylori infection (P < 0.05). The levels of IL-8 were significantly higher in specimens with mtMSI than in those without mtMSI (P < 0.01).An association of mtMSI with the intestinal histological type was found (P < 0.05). Increased IL-8 levels induced by H. pylori were related to the invasion, lymphnode spreading and clinical stage of gastric cancer (P < 0.05). CONCLUSIONS: H. pylori infection is related to mitochondrial microsatellite instability in the early steps of gastric cancer development. IL-8 may play a role in the development of mtMSI induced by H. pylori. Our results support a role for mtMSI in different mechanisms of gastric carcinogenesis.

Multicenter Study of Antibiotic Resistance Profile of H. pylori and Distribution of CYP2C19 Gene Polymorphism in Rural Population of Chongqing, China.

This study was to investigate the antibiotic resistance profile of H. pylori and the distribution of CYP2C19 gene polymorphism in rural population of Chongqing, China. 214 and 111 strains of H. pylori were isolated from rural and urban patients, respectively. 99.53%, 20.09%, and 23.36% of the isolates in rural patients were found to be resistant to metronidazole, clarithromycin, and levofloxacin, while the resistant rate in urban patients was 82.88%, 19.82%, and 24.32%. The multiple antibiotic resistance percentage significantly increased from 28.26% (below 45 years) to 41.80% (above 45 years) in rural patients. Up to 44.39%, 45.79%, and 9.81% of rural patients from whom H. pylori was isolated were found to be extensive metabolizers, intermediate metabolizers, and poor metabolizers. No correlation was observed between antibiotic resistance profile of H. pylori and genetic polymorphism of CYP2C19 among rural population. There was a high prevalence of H. pylori strains resistant to metronidazole, clarithromycin, and levofloxacin in rural patients in Chongqing, China. The choice of therapy in this area should be based on local susceptibility patterns. Amoxicillin, gentamicin, and furazolidone are recommended as the first-line empiric regimen.

Deoxycholic acid (DCA) confers an intestinal phenotype on esophageal squamous epithelium via induction of the stemness-associated reprogramming factors OCT4 and SOX2.

Barrett's esophagus (BE) is essentially a metaplasia in which the normal stratified squamous epithelium is replaced by columnar epithelium. This study focuses on the involvement of OCT4 and SOX2, 2 key cell-reprogramming factors, in the deoxycholic acid (DCA)-induced expression of the intestinal hallmarks Cdx2 and MUC2 using both in vivo and in vitro models. Up-regulated expression of OCT4 and down-regulated expression of SOX2 were observed in BE compared with normal esophagus and esophagitis. Consistent with the data in vivo, DCA induced time-dependent expression of OCT4 at both the mRNA and protein levels and decreased nuclear expression of SOX2 in Het-1A cells. Down-regulation of OCT4 expression by siRNA abrogated DCA-induced expression of Cdx2 and MUC2, whereas siRNA against SOX2 significantly upregulated the expression of both Cdx2 and MUC2. Our data indicate that both OCT4 and SOX2 play important roles in the development of BE triggered by bile acid reflux.

Demethylation of the hTERT promoter in normal human gastric mucosal epithelial cells following N-methyl-N'-nitro-N-nitrosoguanidine exposure.

N-methyl-N'-nitro-N-nitrosoguanidine (MNNG) is an alkylating agent that can induce gastric carcinoma. As a well-known human carcinogen, MNNG has been universally recognized as a methylating agent and is believed to act through methylation mechanism. In the present study, the epigenetic status of the human telomerase reverse transcriptase (hTERT) promoter was investigated in MNNG-treated normal human gastric mucosal epithelial cells. After 4 h exposure to MNNG at different concentrations, 6.8 and 68 µM, bisulfite sequencing polymerase chain reaction showed that five methylated cytosines outside the CpG dinucleotides in the 290-bp fragment from the hTERT promoter were demethylated and all the methylated cytosines in CpG dinucleotides remained intact. Furthermore, the epigenetic status of the target region following MNNG exposure was extremely similar to those of the BGC-823, SGC-7901 and MKN-28 lines; the three cell lines from human gastric adenocarcinoma. The result indicates that MNNG-induced demethylation in cytosines outside the CpG dinucleotides may be an early molecular lesion with the potential for impacting malignant transformation and a possible underlying carcinogenic mechanism of MNNG. Thus, it may provide another insight into the mechanisms of MNNG carcinogenesis.

Bio-functionalized dense-silica nanoparticles for MR/NIRF imaging of CD146 in gastric cancer.

PURPOSE: Nano dense-silica (dSiO2) has many advantages such as adjustable core-shell structure, multiple drug delivery, and controllable release behavior. Improving the gastric tumor-specific targeting efficiency based on the development of various strategies is crucial for anti-cancer drug delivery systems. METHODS: Superparamagnetic iron oxide nanoparticles (SPION) were coated with dSiO2 as core-shell nanoparticles, and labeled with near infra-red fluorescence (NIRF) dye 800ZW (excitation wavelength: 778 nm/emission wavelength: 806 nm) and anti-CD146 monoclonal antibody YY146 for magnetic resonance (MR)/NIRF imaging study in xenograft gastric cancer model. The morphology and the size of pre- and postlabeling SPION@dSiO2 core-shell nanoparticles were characterized using transmission electron microscopy. Iron content in SPION@dSiO2 nanoparticles was measured by inductively coupled plasma optical emission spectrometry. Fluorescence microscopy and fluorescence-activated cell sorter studies were carried out to confirm the binding specificity of YY146 and 800ZW-SPION@dSiO2-YY146 on MKN45 cells. In vivo and in vitro NIRF imaging, control (nanoparticles only) and blocking studies, and histology were executed on MKN45 tumor-bearing nude mice to estimate the affinity of 800ZW-SPION@dSiO2-YY146 to target tumor CD146. RESULTS: 800ZW-SPION@dSiO2-YY146 nanoparticles were uniformly spherical in shape and dispersed evenly in a cell culture medium. The diameter of the nanoparticle was 20-30 nm with 15 nm SPION core and ~10 nm SiO2 shell, and the final concentration was 1.7 nmol/mL. Transverse relaxivity of SPION@dSiO2 dispersed in water was measured to be 110.57 mM(-1)·s(-1). Fluorescence activated cell sorter analysis of the nanoparticles in MKN45 cells showed 14-fold binding of 800ZW-SPION@dSiO2-YY146 more than the control group 800ZW-SPION@dSiO2. Series of NIRF imaging post intravenous injection of 800ZW-SPION@dSiO2-YY146 demonstrated that the MKN45 xenograft tumor model could be clearly identified as early as a time point of 30 minutes postinjection. Quantitative analysis revealed that the tumor uptake peaked at 24 hours postinjection. CONCLUSION: This is the first successful study of functional nanoparticles for MR/NIRF imaging of cell surface glycoprotein CD146 in gastric cancer model. Our results suggest that 800ZW-SPION@dSiO2-YY146 nanoparticles will be applicable in tumor for image-guided therapy/surgery.

Prevalence, histologic and clinical characteristics of heterotopic gastric mucosa in Chinese patients.

AIM: To determine the prevalence, demographic, clinical and histopathologic features of heterotopic gastric mucosa (HGM) in Chinese patients. METHODS: Patients referred to three endoscopy units were enrolled in this study. The macroscopic characteristics of HGM were documented. Biopsies were obtained and observed using hematoxylin and eosin staining. Helicobacter pylori colonization was examined by Whartin-Starry staining. RESULTS: HGM was observed in 420 Chinese patients, yielding a prevalence of 0.4%. The majority of patients had a single patch (300/420; 71.4%), while the remainder had two (84/420; 20%) or multiple patches (36/420; 8.6%). The size of the patches and the distance from the patch to the frontal incisor teeth varied significantly. The large majority of HGM patches were flat (393/420; 93.6%), whereas the remaining patches were slightly elevated. The primary histological characteristic was fundic-type (216/420; 51.4%) within the HGM patch, and antral- (43/420; 10.2%) and transitional-type (65/420; 15.5%) mucosa were also observed. The prevalence of intestinal metaplasia was 3.1% (13/420) and the prevalence of dysplasia was 1.4% (6/420), indicating the necessity for endoscopic follow-up in patients with HGM. Esophageal and extraesophageal complaints were also observed in patients with HGM. Dysphagia and epigastric discomfort (odds ratios: 6.836 and 115.826, respectively; Ps < 0.05) were independent risk factors for HGM. CONCLUSION: Clinical complaints should be considered to improve the detection rate of HMG. The prevalence of intestinal metaplasia and dysplasia also indicates a need for endoscopic follow-up.

Efficacy and safety of esomeprazole with flupentixol/melitracen in treating gastroesophageal reflux disease patients with emotional disorders.

BACKGROUND AND AIM: This study was designed to demonstrate the safety and efficacy of esomeprazole combined with flupentixol/melitracen for the treatment of gastroesophageal reflux disease (GERD) patients with emotional disorders. METHODS Two hundred eighty-nine GERD patients with emotional disorders were divided randomly into two groups: group 1 received esomeprazole only (monotherapy) and group 2 received esomeprazole and flupentixol/melitracen (combination therapy). The patients' GERD questionnaire (GerdQ) and hospital anxiety and depression (HAD) scores were obtained before and after treatment. Changes in the scores, rates of symptom remission, and adverse effects were compared between the two groups. RESULTS: After 2 weeks of treatment, the average decrease in GerdQ score in the combination group (4.04 ± 2.34) was significantly greater than that in the monotherapy group (3.34 ± 2.74; P < 0.05). Significant differences between the two groups were also found for changes in HAD anxiety scores (5.45 ± 2.41 vs 3.34 ± 2.43, P < 0.05), depression scores (5.47 ± 2.47 vs 3.00 ± 3.28, P < 0.05), and anxiety-depression scores (5.20 ± 2.71 vs 3.60 ± 2.56, P < 0.05). The remission of symptoms (eructation, abdominal pain, anorexia, and other accompanying symptoms) in the combination group was significantly better than that in the monotherapy group, and no significant difference in the incidence of adverse events was observed between the two groups. CONCLUSIONS: The combination therapy has better efficacy than the monotherapy in improving the symptoms of gastroesophageal reflux in patients with emotional disorders. In addition, this combination treatment is safe, with a low incidence of adverse events.

Telomerase and hTERT: can they serve as markers for gastric cancer diagnosis?

AIM: To investigate telomerase activity and human telomerase reverse transcriptase (hTERT) expression in normal human gastric mucosal epithelial cells (nhGMECs) and fibroblasts (nhGMFs). METHODS: nhGMECs and nhGMFs were isolated and cultured from specimens obtained during routine surgery for bleeding peptic ulcer. Telomerase activity in nhGMFs, nhGMECs, and the tumor cell lines BGC-823, SGC-7901 and MKN-28 cells was analyzed using the telomeric repeat amplification protocol assay. hTERT protein was determined in nhGMECs, nhGMFs, BGC-823, SGC-7901 and MKN-28 cells by indirect immunofluorescence. RESULTS: A similar level of telomerase activity was observed in nhGMECs, nhGMFs and BGC-823, SGC-7901, MKN-28 cell lines. Positive hTERT immunostaining was detected in nhGMECs, nhGMFs, BGC-823, SGC-7901 and MKN-28 cell lines. CONCLUSION: The use of telomerase or hTERT as diagnostic markers for gastric cancer may require further studies.

E2F1 acts as a negative feedback regulator of c-Myc­induced hTERT transcription during tumorigenesis.

Since induction of hTERT expression and subsequent telomerase activation play a critical role in the multistep process of tumorigenesis, a better understanding of hTERT regulation may provide not only a rationale for the molecular basis of cancer progression but also a path to the development of cancer prevention. The c-Myc oncoprotein can function effectively in activating the transcriptional expression of hTERT through E-box elements on its promoter. E2F transcription factor 1 (E2F1) was found to be a repressor of hTERT transcription by directly binding to its promoter, thereby inhibiting hTERT protein expression. For the extensively crosstalk between c-Myc and E2F1 signals, which is now known to be vital to cell fate, we speculated that E2F1 may play a negative regulatory role in c-Myc-induced hTERT transcription. In the present study, we chose to use human embryonic fibroblast cells as an experimental model system, and present evidence that the E2F1 transcription factor constitutes a negative regulatory system to limit c-Myc transcriptional activation of hTERT in normal cells. Furthermore, we demonstrated that upregulation of the miR-17-92 cluster (miR-20a/miR-17-5p) is involved in the regulation of E2F1-mediated negative feedback of the c-Myc/hTERT pathway. Our results not only reveal novel insights into how normal cells control the transmission of c-Myc-mediated oncogenic signals, but also further establish E2F1 as an important molecular target for cancer therapy.

Consensus on the Prevention, Screening, Early Diagnosis and Treatment of Colorectal Tumors in China: Chinese Society of Gastroenterology, October 14-15, 2011, Shanghai, China.

BACKGROUND: Colorectal cancer (CRC) is steadily increasing in China. Colorectal adenoma (CRA) is the most important precancerous disease of CRC. Screening for colorectal tumors can aid early diagnosis. Advances in endoscopic mucosal resection and endoscopic submucosal dissection can aid the early treatment of colorectal tumors. Furthermore, because of high risk of recurrence after removal of adenomas under endoscopy, factors contributing to recurrence, the follow-up mode and the interval established, and the feasibility of application and the time of various chemical preventions should be concerned. However, a relevant consensus on the screening, early diagnosis and treatment, and prevention of colorectal tumors in China is lacking. SUMMARY: The consensus recommendations include epidemiology, pathology, screening, early diagnosis, endoscopic treatment, monitoring and follow-up, and chemoprevention of colorectal tumors in China. KEY MESSAGE: This is the first consensus on the prevention, screening, early diagnosis and treatment of CRA and CRC in China based on evidence in the literature and on local data. PRACTICAL IMPLICATIONS: Through reviewing the literature, regional data and passing the consensus by an anonymous vote, gastroenterology experts from all over China launch the consensus recommendations in Shanghai. The incidence and mortality of CRC in China has increased, and the incidence or detection rate of CRA has increased rapidly. Screening for colorectal tumors should be performed at age 50-74 years. Preliminary screening should be undertaken to find persons at high risk, followed by colonoscopy. A screening cycle of 3 years is recommended for persistent interventions. Opportunistic screening is a mode suitable for the current healthcare system and national situation. Colonoscopy combined with pathological examination is the standard method for the diagnosis of colorectal tumors. CRA removal under endoscopy can prevent CRC to some extent, but CRA has an obvious recurrence trend. The follow-up interval after the removal or surgery of colorectal tumors should be different with lesions. Primary prevention of CRA includes improved diet with more fiber, supplements containing calcium and vitamin D, supplements containing folic acid for those with low hemoglobin levels, and cessation of tobacco smoking. Non-steroidal anti-inflammatory drugs and selective cyclooxygenase-2 inhibitors have been recognized to prevent recurrence after adenoma removal.

Knockdown of nucleostemin can inhibit the proliferation of esophageal carcinoma cells in vitro through upregulating p21.

BACKGROUND/AIMS: Esophageal squamous cell carcinoma is a common digestive tract cancer with poor prognosis. Nucleostemin is a nucleolar protein expressed in stem and cancer cells, involved in the regulation of cell proliferation. p21 plays an important role in negative regulation of the cell-cycle. We investigated the role of nucleostemin through regulating p21 expression in the occurrence and progression of human esophageal carcinoma. METHODOLOGY: The expression of nucleostemin and p21 protein and of nucleostemin was knocked-down by means of RNA interference (RNAi) in Eca109 cells. Then, mRNA and protein expressions of nucleostemin and p21 were determined by reverse transcriptase polymerase chain reaction and Western blotting, respectively. In addition, the effect of nucleostemin RNAi on cell proliferation and cell cycle distribution of Eca109 cells were observed. RESULTS: Nucleostemin was high expressed, but p21 was low expressed in esophageal carcinoma tissues while increased level of nucleostemin protein was associated with reduced p21. inhibition of nucleostemin resulted in an increased expression of p21 and inhibition of cell proliferation, cause G1/G0 phase cells increased and S-phase cells reduced greatly in Eca109 cells. CONCLUSION: Silence of nucleostemin inhibit cell proliferation through up-regulating p21 expression and nucleostemin may be involved in the pathogenesis of esophageal squamous cell carcinoma.

In vitro and ex vivo evaluation of a multi-epitope heparinase vaccine for various malignancies.

Previous studies have indicated that heparanase (Hpa) might represent a candidate universal tumor-associated antigen. However, vaccine therapy targeting only one cytotoxic T lymphocyte (CTL) epitope is suboptimal in preventing cancer. In the present study, we designed heparanase multi-epitope vaccines to increase the immune response to standard single heparanase epitopes. The results showed that multi-epitope vaccines Hpa525 + 277 + 405 + 16 and Hpa8 + 310 + 315 + 363 induced higher Hpa-specific lysis of various cancer cells from different tissues in a HLA-A2-restricted and heparanase-specific manner compared with the single epitope vaccines Hpa525, Hpa277, Hpa405, Hpa16, Hpa8, Hpa310, Hpa315 and Hpa363, both in vitro and ex vivo. Heparanase multi-epitope vaccines not only induced the heparanase-specific CTL to lyse tumor cells but also increased CTL secretion of interferon-γ. However, these heparanase-specific CTL did not lyse heparanase-expressing autologous lymphocytes and dendritic cells, which confirms the safety of these multi-epitope vaccines. Therefore, the present study provides theoretical evidence for the use of heparanase multi-epitope vaccines for clinical application.

Co-transduction of ribosomal protein L23 enhances the therapeutic efficacy of adenoviral-mediated p53 gene transfer in human gastric cancer.

Induction of murine double minute 2 (MDM2) expression is thought to be a determinant of resistance to p53 gene therapy for cancer. Previous studies have revealed that ribosomal protein L23 (RPL23) inhibits MDM2-mediated p53 degradation through direct binding to MDM2. In addition, ectopically expressed RPL23 was reported to interact with MDM2 in both the nucleus and cytoplasm, by which RPL23 indirectly inhibited MDM2-p53 binding. Based on the known molecular properties of the RPL23 protein, it was speculated that co-transduction of RPL23 may protect wild­type p53 protein from MDM2-mediated inactivation and, thus, improve the effect of delivering therapeutic exogenous p53. To test this hypothesis, we constructed a bicistronic adenoviral vector expressing both the RPL23 and p53 genes (Ad-RPL23/p53) and compared its tumor-suppressor activity in human gastric cancer with that of a single gene vector for p53 (Ad-p53). In the in vivo and in vitro experiments, we observed that treatment with Ad-RPL23/p53 resulted in a stronger antitumor response compared to that obtained using Ad-p53. Moreover, the antitumor response of the bicistronic adenovirus was obtained not only in MGC803 cells (endogenous mutant p53) but also in MKN45 cells (endogenous wild­type p53) which were initially resistant to p53 gene transfer, indicating that co-transduction of RPL23 also expanded the utility of p53 gene therapy. Furthermore, in an orthotopic nude mouse model of human gastric cancer, we found that the survival benefit was greater after Ad-RPL23/p53 treatment than after Ad-p53. Taken together, the data presented here demonstrate that co-transduction of RPL23 enhances the therapeutic efficacy of adenoviral-mediated p53 gene transfer in models of human gastric cancer and support the use of this strategy for cancer treatment.

Sodium nitroprusside (SNP) sensitizes human gastric cancer cells to TRAIL-induced apoptosis.

AIM: To investigate the effects of the nitrous oxide (NO)-donor sodium nitroprusside (SNP) on tumor necrosis factor-related apoptosis-inducing ligand (TRAIL)-mediated apoptosis in human gastric cancer cells. METHODS: The MTT assay and flow cytometry were used to detect cellular proliferation and markers of apoptosis, respectively. Expression levels of caspases-8, and 9 were determined by Western blot. Changes in Nitric Oxide Synthase (NOS) activity, NO production, and caspase activation were also evaluated. RESULTS: We found that TRAIL induced apoptosis and cell cycle arrest in human gastric cancer cell lines, and that this effect was mediated by NO production, and activation of both the extrinsic and intrinsic signaling pathways of apoptosis. In addition, we found that the NO-donor SNP sensitizes gastric cancer cells to TRAIL-mediated apoptosis. Treatment of cells with both TRAIL and SNP resulted in increased activation of caspase-8 and caspase-9 and NO release. Inhibition of caspase-8 blocked cell TRAIL-induced apoptosis, while a selective caspase-9 inhibitor was unable to prevent apoptosis induced by either TRAIL or TRAIL plus SNP. Inhibition of NOS could block the activation of caspase-9, but had no obvious effect on cell apoptosis. CONCLUSIONS: SNP-sensitized gastric cancer cells to TRAIL-induced cytotoxicity by stimulating the release of NO, in turn facilitating the mitochondria-mediated signal transduction pathway. The engagement of the mitochondria signaling pathways along with the TRAIL death receptor signaling pathway synergistically increase levels of apoptosis in these cells.