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The hallmark of mechanosensory hair cells is the stereocilia, where mechanical stimuli are converted into electrical signals. These delicate stereocilia are susceptible to acoustic trauma and ototoxic drugs. While hair cells in lower vertebrates and the mammalian vestibular system can spontaneously regenerate lost stereocilia, mammalian cochlear hair cells no longer retain this capability. We explored the possibility of regenerating stereocilia in the noise-deafened guinea pig cochlea by cochlear inoculation of a viral vector carrying Atoh1, a gene critical for hair cell differentiation. Exposure to simulated gunfire resulted in a 60-70 dB hearing loss and extensive damage and loss of stereocilia bundles of both inner and outer hair cells along the entire cochlear length. However, most injured hair cells remained in the organ of Corti for up to 10 days after the trauma. A viral vector carrying an EGFP-labeled Atoh1 gene was inoculated into the cochlea through the round window on the seventh day after noise exposure. Auditory brainstem response measured one month after inoculation showed that hearing thresholds were substantially improved. Scanning electron microscopy revealed that the damaged/lost stereocilia bundles were repaired or regenerated after Atoh1 treatment, suggesting that Atoh1 was able to induce repair/regeneration of the damaged or lost stereocilia. Therefore, our studies revealed a new role of Atoh1 as a gene critical for promoting repair/ regeneration of stereocilia and maintaining injured hair cells in the adult mammal cochlea. Atoh1-based gene therapy, therefore, has the potential to treat noise-induced hearing loss if the treatment is carried out before hair cells die. [ABSTRACT FROM AUTHOR]

Aim: The study was designed to explore the effects of antisense human telomerase RNA (ahTR) on the malignant phenotype of gastric carcinoma cell line SGC-7901, and its potential role in gene therapy for tumors. Methods: An ahTR eukaryotic expression vector, including the sequence of template region of telomere repeats, was constructed by recombinant technology of molecules and then transfected into gastric carcinoma cell line SGC-7901 by liposome DOTAP. Subsequently, the expression of hTR RNA and ahTR RNA by reverse transcription-polymerase chain reaction, telomerase activity by telomeric repeat amplification protocol-ELISA (TRAP-ELISA), telomere length by Southern blotting, cell morphology under light microscope, cellular proliferation capacity by 3-(4,5-dimethyl-2 thiazoyl)-2,5-diphenyl-2H-tetrazolium bromide assay, cell-cycle distribution by flow cytometry, efficiency of clone formation in soft agar, and tumorigenecity in nude mice were examined and evaluated in ahTR-transfected cells, control plasmid pCI-neo transfected cells and their parental cells. Results: An ahTR eukaryotic expression vector was constructed and successfully transfected into SGC7901 cells. The telomerase activity in ahTR-transfected SGC-7901 cells decreased from 100% to approximately 25%, and telomere length in the cells shortened to 3.35 from 4.08 Kb at 60 population doublings. Compared with the parental cells and pCI-neo transfected cells, ahTR-transfected cells displayed some morphological changes, such as decreased atypia, and recovery of contact inhibition and density inhibition under light microscope. Furthermore, ahTR-transfected cells displayed decreased invasive capacity in Borden's chamber invasive model, increased G[sub 0]/G[sub 1] phase rate and apoptotic rate. Surprisingly, ahTR-transfected SGC-7901 cells lost their capacity for clone formation in soft agar and tumorigencity in nude mice. Conclusion: Antisense-hTR transfection can inhibit the growth of SGC-7901 cells and... [ABSTRACT FROM AUTHOR]

Background: Barrett's esophagus (BE), a squamous-to-columnar metaplasia, may originate from growth-promoting mutations in metaplastic stem cells. Nucleostemin is a protein highly expressed in undifferentiated embryonic stem cells. The objectives of this study were to explore the potential role of nucleostemin in the pathogenesis of BE METHODS: The expression profiles of 30,968 genes were compared between BE and normal esophageal tissues (n = 6 in each group) by using oligo microarray. Three siRNA plasmid expression vectors against nucleostemin, pRNAi-1, pRNAi-2, and pRNAi-3, were constructed and transfected into HT29 cells. In addition, HT29 cells were exposed to 100-1,000 microM chenodeoxycholic acid (CDC), a bile acid, for 2, 12, and 24 h, and then messenger RNA and protein expressions of nucleostemin and CDX2 were determined by reverse-transcriptase polymerase chain reaction and Western blotting.Results: Four hundred and twenty-six differentially expressed genes were detected in BE; 142 were upregulated and 284 downregulated. Nucleostemin was downregulated while CDX2 was upregulated. In vitro, all the recombinant plasmids inhibited the nucleostemin expression in transfected HT29 cells, with pRNAi-1 being the most effective. CDX2 expression was significantly increased in pRNAi-1-transfected HT29 cells, compared with that in the empty plasmid (pRNAT-U6.1/Neo) transfected or untransfected HT29 cells. In addition, CDX2 expression was increased whereas nucleostemin expression was decreased in a dose- and time-dependent manner in HT29 cells treated with CDC.Conclusion: These findings suggest that the inhibition of nucleostemin expression in "esophageal stem cells" in response to bile acid exposure may be involved in the pathogenesis of BE through upregulating CDX2 expression. [ABSTRACT FROM AUTHOR]

Cathepsin C (CtsC) functions as a central coordinator for activation of many serine proteases in immune cells. However, CtsC expression in gastric epithelial cells and its role in Helicobacter pylori infection remain unclear. Real-time PCR, Western blot, and immunohistochemistry analyses identified that CtsC was decreased in gastric mucosa of H. pylori-infected patients and mice. Isolated gastric epithelial cells and cell lines were stimulated with H. pylori and/or TGF-ß1 showed that down-regulation of CtsC in gastric epithelial cells largely depended on H. pylori cagAvia Src/ERK and Janus kinase (JAK)/signal transducer and activator of transcription 3 (STAT3) pathways, and the effect could be synergistically augmented by TGF-ß1 in an autocrine manner. In human gastric mucosa, CtsC expression was negatively correlated with bacteria colonization; accordingly, provision of exogenous active CtsC overwhelmed H. pylori persistence in gastric mucosa of mice. In the presence of active CtsC, isolated human neutrophils activated via NF-κB pathway with augmented bactericidal capacity in vitro. We also found that neutrophils activated and cleared bacteria in active CtsC-injected mice and that there was no bactericidal capacity in mice that were simultaneously neutrophil-depleted by Ly6G antibody. Our findings identified a mechanism that H. pylori abrogate CtsC to impair neutrophil activation and to ensure persistence in gastric mucosa. Efforts to enable and boost this neutrophil activation pathway by active CtsC may therefore become valuable strategies in treating H. pylori infection. [ABSTRACT FROM AUTHOR]

The article looks at a study which demonstrate procolonization and proinflammation role of matrix metallopeptidase-10 (MMP-10) in Helicobacter pylori–induced gastric bacterial colonization and gastritis. It mentions MMP-10 is elevated in gastric mucosa and is produced by gastric epithelial cells synergistically induced by Helicobacter pylori and Interleukin-22 (IL-22) via the ERK pathway. It also mentions influence of MMP-10 decrease Reg3a, epithelial cadherin, and zonula occludens–1 proteins.

The purpose of this study was to examine the morphological and functional development of the lateral wall of the scala media of the cochlea in miniature pigs; light and transmission electron microscopy and electrophysiology were used for this purpose. We showed that the lateral wall of the scala media of the cochlea appears at embryonic Day 21 (E21) when the cochlear duct begins to form. From E28 to E49, the lateral wall can be distinguished according to its position along the cochlea. At E56, cells in the lateral wall begin to differentiate into three different types. At E70, three cell types, marginal, intermediate and basal, can be clearly distinguished. At E91, the stria vascularis is adult-like and the organ of Corti is also morphologically mature. The average endocochlear potential measured from the second turn of the cochlea (atE98, postnatalDay 1 (P1), P13 and P30)was 71.4±2.5 (n=7), 78.8±1.5 (n=10), 77.3±2.3 (n=10) and 78.0±2.1mV (n=10), respectively. Our results suggest that in miniature pigs the stria vascularis develops during the embryonic period, concurrent with maturation of the organ of Corti. The magnitude of the endocochlear potential reached its mature level when the stria vascularis was morphologically adult-like at E98. These findings provide a morphological and functional basis for future animal studies using the miniature pig model concerning the pathogenesis of various inner-ear diseases. [ABSTRACT FROM AUTHOR]

Objective Helper T (Th) cell responses are critical for the pathogenesis of Helicobacter pylori-induced gastritis. Th22 cells represent a newly discovered Th cell subset, but their relevance to H. pylori-induced gastritis is unknown. Design Flow cytometry, real-time PCR and ELISA analyses were performed to examine cell, protein and transcript levels in gastric samples from patients and mice infected with H. pylori. Gastric tissues from interleukin (IL)-22-deficient and wild-type (control) mice were also examined. Tissue inflammation was determined for pro-inflammatory cell infiltration and proinflammatory protein production. Gastric epithelial cells and myeloid-derived suppressor cells (MDSC) were isolated, stimulated and/or cultured for Th22 cell function assays. Results Th22 cells accumulated in gastric mucosa of both patients and mice infected with H. pylori. Th22 cell polarisation was promoted via the production of IL-23 by dendritic cells (DC) during H. pylori infection, and resulted in increased inflammation within the gastric mucosa. This inflammation was characterised by the CXCR2-dependent influx of MDSCs, whose migration was induced via the IL-22-dependent production of CXCL2 by gastric epithelial cells. Under the influence of IL-22, MDSCs, in turn, produced pro-inflammatory proteins, such as S100A8 and S100A9, and suppressed Th1 cell responses, thereby contributing to the development of H. pylori-associated gastritis. Conclusions This study, therefore, identifies a novel regulatory network involving H. pylori, DCs, Th22 cells, gastric epithelial cells and MDSCs, which collectively exert a pro-inflammatory effect within the gastric microenvironment. Efforts to inhibit this Th22-dependent pathway may therefore prove a valuable strategy in the therapy of H. pylori-associated gastritis. [ABSTRACT FROM AUTHOR]

Helicobacter pylori (H. pylori) infection is strongly associated with the development of gastric diseases but also with several extragastric diseases. The clinical outcomes caused by H. pylori infection are considered to be associated with a complex combination of host susceptibility, environmental factors and bacterial isolates. Infections involving H. pylori strains that possess the virulence factor CagA have a worse clinical outcome than those involving CagA-negative strains. It is remarkable that CagA-positive H. pylori increase the risk for gastric cancer over the risk associated with H. pylori infection alone. CagA behaves as a bacterial oncoprotein playing a key role in H. pylori-induced gastric cancer. Activation of oncogenic signaling pathways and inactivation of tumor suppressor pathways are two crucial events in the development of gastric cancer. CagA shows the ability to affect the expression or function of vital protein in oncogenic or tumor suppressor signaling pathways via several molecular mechanisms, such as direct binding or interaction, phosphorylation of vital signaling proteins and methylation of tumor suppressor genes. As a result, CagA continuously dysregulates of these signaling pathways and promotes tumorigenesis. Recent research has enriched our understanding of how CagA effects on these signaling pathways. This review summarizes the results of the most relevant studies, discusses the complex molecular mechanism involved and attempts to delineate the entire signaling pathway. [ABSTRACT FROM AUTHOR]

Many new therapies are currently being used to treat cancer. Among these new methods, chemotherapy based on peptides has been of great interest due to the unique advantages of peptides, such as a low molecular weight, the ability to specifically target tumor cells, and low toxicity in normal tissues. In treating cancer, peptide-based chemotherapy can be mainly divided into three types, peptide-alone therapy, peptide vaccines, and peptide-conjugated nanomaterials. Peptide-alone therapy may specifically enhance the immune system's response to kill tumor cells. Peptide-based vaccines have been used in advanced cancers to improve patients' overall survival. Additionally, the combination of peptides with nanomaterials expands the therapeutic ability of peptides to treat cancer by enhancing drug delivery and sensitivity. In this review, we mainly focus on the new advances in the application of peptides in treating cancer in recent years, including diagnosis, treatment, and prognosis. [ABSTRACT FROM AUTHOR]

Background/Aims: Upregulated CD64 expression on neutrophils is the most useful marker for acute bacterial infections and systemic inflammation. However, it is unknown whether CD64 is involved in the pathogenesis of acute pancreatitis (AP). This study was designed to determine whether CD64 is implicated in severe acute pancreatitis (SAP), and thus, is a suitable marker for SAP. Methods: SAP was induced in rats with an intraperitoneal injection of L-arginine. CD64 expression in the rat pancreas was determined by quantitative real-time polymerase chain reaction (qRT-PCR) and immunohistochemistry. Additionally, the CD64 mRNA expression in peripheral blood leukocytes from 21 patients with mild acute pancreatitis (MAP) and 10 patients with SAP was investigated at the time of admission and during remission by qRT-PCR. Results: CD64 mRNA and protein expression in the pancreas was significantly higher in rats with SAP, compared to the controls. The CD64 expression was higher in the patients with SAP than in the patients with MAP. During remission, CD64 mRNA decreased in both the MAP and SAP patients. The area under the curve of CD64 expression for the detection of SAP was superior to both the Ranson and the Acute Physiology and Chronic Health Evaluation II scores. Conclusions: The CD64 level was significantly increased in correlation with the disease severity in SAP and may act as a useful marker for predicting the development of SAP. [ABSTRACT FROM AUTHOR]

Background and study aims: Delayed perforation is a rare complication of therapeutic colonoscopy, and it is severe and sometimes lethal. This paper reports on a new minimally invasive method for the treatment of delayed colonic perforation. Patients and methods: Three patients with delayed colonic perforation underwent the therapy, which involved three steps: (1) closure with endoclips and loop, (2) overtube placement, and (3) antibiotic wash through a nasobiliary tube. Results: The procedure was successful in all three patients and no recurrence was observed during 5-41 months of follow-up. Conclusions: Although this study involved only a small number of patients and no control arm, the method involving an overtube appears to be a feasible and effective endoscopic treatment for delayed colonic perforation. [ABSTRACT FROM AUTHOR]

Aim. To investigate the diagnostic yield and etiologies of patients with obscure gastrointestinal bleeding (OGIB) using capsule endoscopy (CE) or double-balloon enteroscopy (DBE). Method. We studied the data of 532 consecutive patients with OGIB that were referred to Xinqiao Hospital in Chongqing from December 2005 to January 2012. A lesion that was believed to be the source of the bleeding (ulceration, mass lesion, vascular lesion, visible blood, inflammation, or others) was considered to be a positive finding. We analyzed the diagnostic yield of CE and SBE and the etiologies of OGIB. Result. CE and SBE have similar diagnostic yields, at 71.9% (196/231) and 71.8% (251/304), respectively. The most common etiology was erosions/ulceration (27.1%) followed by mass lesion (19.4%) and angiodysplastic/vascular lesions (13.9%). By stratified analysis, we found that erosions/ulceration (27.1%) was the most common etiology for the 21-40-year age group. Mass lesion was the most common etiology in the 41-60-year age group. However, in the > 60 years age group, angiodysplastic/vascular lesions were significantly increased compared with the other groups, even though erosions/ulceration was most common. Conclusion. In this study, we found that CE and SBE have similar diagnostic yields and erosions/ulceration was the most common reason for OGIB, followed by mass lesion and angiodysplasias. [ABSTRACT FROM AUTHOR]

Macrophages are widely distributed innate immune cells that play indispensable roles in the innate and adaptive immune response to pathogens and in-tissue homeostasis.Macrophages can be activated by a variety of stimuli and polarized to functionally different phenotypes. Two distinct subsets of macrophages have been proposed, including classically activated (M1) and alternatively activated (M2)macrophages.M1macrophages express a series of proinflammatory cytokines, chemokines, and effectormolecules, such as IL-12, IL-23, TNF-α, iNOS and MHCI/II. In contrast, M2 macrophages express a wide array of anti-inflammatory molecules, such as IL-10, TGF-β, and arginase1. In most tumors, the infiltrated macrophages are considered to be of the M2 phenotype, which provides an immunosuppressive microenvironment for tumor growth. Furthermore, tumor-associated macrophages secrete many cytokines, chemokines, and proteases, which promote tumor angiogenesis, growth, metastasis, and immunosuppression. Recently, it was also found that tumor-associated macrophages interact with cancer stem cells. This interaction leads to tumorigenesis, metastasis, and drug resistance. So mediating macrophage to resist tumors is considered to be potential therapy. [ABSTRACT FROM AUTHOR]

Vaccine-induced cytotoxic T lymphocytes (CTLs) play a critical role in adaptive immunity against cancers. An important goal of current vaccine research is to induce durable and long-lasting functional CTLs that can mediate cytotoxic effects on tumor cells. To attain this goal, there are four distinct steps that must be achieved. To initiate a vaccine-induced CTL antitumor immune response, dendritic cells (DCs) must capture antigens derived from exogenous tumor vaccines in vivo or autologous DCs directly loaded in vitro with tumor antigens must be injected. Next, tumor-antigen-loaded DCs must activate CTLs in lymphoid organs. Subsequently, activated CTLs must enter the tumor microenvironment to perform their functions, at which point a variety of negative regulatory signals suppress the immune response. Finally, CTL-mediated cytotoxic effects must overcome the tolerance induced by tumor cells. Each step is a complex process that may be impeded in many ways. However, if these steps happen under appropriate regulation, the vaccine-induced CTL antitumor immune response will be more successful. For this reason, we should gain a better understanding of the basic mechanisms that govern the immune response. This paper, based on the steps necessary to induce an immune response, discusses current strategies for enhancing vaccine-induced CTL antitumor immune responses. [ABSTRACT FROM AUTHOR]

Vaccine-induced cytotoxic T lymphocytes (CTLs) play a critical role in adaptive immunity against cancers. An important goal of current vaccine research is to induce durable and long-lasting functional CTLs that can mediate cytotoxic effects on tumor cells. To attain this goal, there are four distinct steps that must be achieved. To initiate a vaccine-induced CTL antitumor immune response, dendritic cells (DCs) must capture antigens derived from exogenous tumor vaccines in vivo or autologous DCs directly loaded in vitro with tumor antigens must be injected. Next, tumor-antigen-loaded DCs must activate CTLs in lymphoid organs. Subsequently, activated CTLs must enter the tumor microenvironment to perform their functions, at which point a variety of negative regulatory signals suppress the immune response. Finally, CTL-mediated cytotoxic effects must overcome the tolerance induced by tumor cells. Each step is a complex process that may be impeded in many ways. However, if these steps happen under appropriate regulation, the vaccine-induced CTL antitumor immune response will be more successful. For this reason, we should gain a better understanding of the basic mechanisms that govern the immune response. This paper, based on the steps necessary to induce an immune response, discusses current strategies for enhancing vaccine-induced CTL antitumor immune responses. [ABSTRACT FROM AUTHOR]

Background The human protection of telomeres 1 (hPOT1) protein, a single-strand telomeric DNA binding protein, plays an important role in telomere protection and telomere length regulation. However, its effect on invasion of gastric cancer remains unclear. Aims To explore the role of hPOT1 in the proliferation and invasion of gastric cancer cells. Methods The gastric expression of hPOT1 was examined in normal gastric mucosa (n=25), intestinal metaplasia (n=20), gastric dysplasia (n=20) and gastric cancer (n=150) by immunohistochemistry. The mean optical density (MOD) of the immunostaining was determined by semi-quantitative image analysis. The role of hPOT1 in the cell proliferation, apoptosis and invasion of gastric cancer 7901 cells was determined by means of the RNA interference (RNAi) of hPOT1 mRNA. The effects of hPOT1 RNAi on the expression of hPinX1 and hTERT were detected with western blotting. Results The hPOT1 MOD was progressively increased from the normal mucosa to intestinal metaplasia, dysplasia, and gastric cancer. An increased hPOT1 expression significantly correlated with tumour serosal invasion, node metastasis and advanced stage. Transfection of hPOT1 siRNA into SGC-7901 cells led to a decrease in cell proliferation, colony formation and invasion, and also an increase of apoptosis. An upregulation of hPinX1 and down-regulation of hTERT were found in gastric cancer cells with hPOT1 siRNA. Conclusions Increased hPOT1 expression is associated with an advanced tumour stage. hPOT1 RNAi inhibits proliferation and invasion, and induces apoptosis of gastric cancer cells. The effects of hPOT1 RNAi seem to be functionally linked to up-regulation of PinX1 and down-regulation of hTERT. INSET: Take-home messages. [ABSTRACT FROM AUTHOR]

Background: In mammals, hair cells do not undergo spontaneous regeneration when they are damaged and result in permanent hearing loss. Previous studies in cultured Organ of Corti dissected from neonatal animals have shown that both DAPT (r-secretase inhibitor in the Notch signal pathway) treatment and Atoh1 overexpression can induce supernumerary hair cells. The effects of simultaneous DAPT treatment and Atoh1 over expression in the cells of cultured Organ of Corti from neonatal rats are still obscure. Principal Findings: In this study, we set out to investigate the interaction of DAPT treatment and Atoh1 overexpression as well as culture time and the location of basilar fragment isolated form neonatal rat inner ear. Our results showed that DAPT treatment induced more hair cells in the apical turn, while Atoh1 overexpression induced more extra hair cells in the middle turn of the cultured Organ of Corti. When used together, their effects are additive but not synergistic. In addition, the induction of supernumerary hair cells by both DAPT and Atoh1 overexpression is dependent on the treatment time and the location of the cochlear tissue. Moreover, DAPT treatment causes dramatic changes in the orientation of the stereociliary bundles of hair cells, whereas Atoh1 overexpression didn't induce drastic change of the polarity of stereociliary bundles. Conclusions/Significance: Taken together, these results suggest that DAPT treatment are much more potent in inducing supernumerary hair cells than Atoh1 overexpression and that the new hair cells mainly come from the trans-differentiation of supporting cells around hair cells. The orientation change of stereociliary bundle of hair cells may be attributed to the insertion of the newly formed hair cells. The immature hair bundles on the newly formed hair cells may also contribute to the overall chaos of the stereociliary bundle of the sensory epithelia. [ABSTRACT FROM AUTHOR]

Introduction: The aim of this study was to investigate the role of Mad1/c-Myc in telomerase regulation in gastric cancer cells in order to gain insight into telomerase activity and to evaluate PinX1 as a putative inhibitor of gastric cancer.Methods: PinX1 and PinX1siRNA eukaryotic expression vectors were constructed by recombinant technology and transfected into gastric carcinoma cells using Lipofectamine 2000. Telomerase activity was measured by the telomeric repeat amplification protocol. Apoptosis of gastric cancer cells was analyzed by flow cytometry and transmission electron microscopy. Reverse transcription-polymerase chain reaction and Western blotting were used to assess the expression levels of PinX1 and Mad1/c-Myc.Results: We found that PinX1-negative gastric cancer cells showed significantly higher telomerase activity than did the PinX1-postive cells. PinX1-transfection reduced telomerase activity in PinX1-negative gastric cancer cells and exhibited an upregulation of Mad1 and downregulation of c-Myc expression. Pinx1 RNAi treatment led to downregulation of Mad1 and upregulation of c-Myc.Conclusion: Suppression of telomerase activity mediated by PinX1 is involved in the Mad1/c-Myc pathway. [ABSTRACT FROM AUTHOR]

Heparanase is expressed in almost all advanced tumors, and therefore it may serve as a potential target for tumor therapy. Our previous study has shown that heparanase can serve as a potential universal tumor-associated antigen (TAA) for the immunotherapy of advanced tumors. Further study demonstrated that the HLA-A*0201-restricted Cytotoxic T lymphocytes (CTL) epitopes Hpa525 (PAFSYSFFV), Hpa277 (KMLKSFLKA) and Hpa405 (WLSLLFKKL) from human heparanase could induce a potent anti-tumor immune response in vitro. The present study was designed to investigate whether the above peptides could induce immune responses in mice. Our results demonstrated that the effectors from heparanase peptide-immunized mice could effectively lyse various tumor cells that were heparanase positive and HLA-A*0201 matched. We also found that these peptide-specific CTLs did not lyse autologous lymphocytes that had low heparanase activity. Further study revealed that Hpa525, Hpa277, and Hpa405 peptides increased the frequency of IFN-γ-producing T cells as compared to a negative peptide. These results suggest that Hpa525, Hpa277, and Hpa405 peptides are novel HLA-A*0201-restricted CTL epitopes capable of inducing heparanase-specific CTLs in mice. Because heparanase is expressed in most advanced malignant tumors, Hpa525, Hpa277, and Hpa405 peptide-based vaccines may be useful for the immunotherapy of patients with advanced tumors. [ABSTRACT FROM AUTHOR]

Objective: Tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) is thought to be a promising anti-neoplastic agent because of its ability to selectively induce apoptosis in cancer cells. However, some cancer cells are resistant to TRAIL. The mechanisms underlying this resistance are unclear. The aim of this study was to explore the role of programmed cell death 4 (PDCD4) in regulating TRAIL sensitivity in gastric cancer cells. Methods: PDCD4 complementary DNA and PDCD4-specific short-hairpin RNA (shRNA) fragments were transfected into TRAIL-sensitive and -resistant gastric cancer cells. Expression of PDCD4 and Akt was detected via western blot. Cell survival and apoptosis were measured using 3-(4,5-dimethylthiazolyl)-2,5-diphenyltetrazolium bromide (MTT) and flow cytometry (FCM) assays. Results: We found that upregulation of PDCD4 enhanced TRAIL sensitivity in gastric cancer cells. Downregulation of PDCD4 decreased TRAIL sensitivity. Inhibition of Akt by the phosphoinositide 3-kinase (PI3K) inhibitor LY294002 induced PDCD4 activity and enhanced TRAIL sensitivity in TRAIL-resistant gastric cancer cells. Conclusion: We demonstrated that PDCD4 regulates TRAIL sensitivity in gastric cancer cells by inhibiting the PI3K/Akt signaling pathway [ABSTRACT FROM AUTHOR]

Peptide vaccination for cancer immunotherapy requires identification of peptide epitopes derived from antigenic proteins associated with tumors. Heparanase (Hpa) is broadly expressed in various advanced tumors and seems to be an attractive new tumor-associated antigen. The present study was designed to predict and identify HLA-A2-restricted cytotoxic T lymphocyte (CTL) epitopes in the protein of human Hpa. For this purpose, HLA-A2-restricted CTL epitopes were identified using the following four-step procedure: 1) a computer-based epitope prediction from the amino acid sequence of human Hpa, 2) a peptide-binding assay to determine the affinity of the predicted protein with the HLA-A2 molecule, 3) stimulation of the primary T-cell response against the predicted peptides in vitro, and 4) testing of the induced CTLs toward different kinds of carcinoma cells expressing Hpa antigens and/or HLA-A2. The results demonstrated that, of the tested peptides, effectors induced by peptides of human Hpa containing residues 525-533 (PAFSYSFFV, Hpa525), 277-285 (KMLKSFLKA, Hpa277), and 405-413 (WLSLLFKKL, Hpa405) could effectively lyse various tumor cell lines that were Hpa-positive and HLA-A2-matched. We also found that these peptide-specific CTLs could not lyse autologous lymphocytes with low Hpa activity. Further study revealed that Hpa525, Hpa277, and Hpa405 peptides increased the frequency of IFN-γ-producing T cells compared to a negative peptide. Our results suggest that Hpa525, Hpa277, and Hpa405 peptides are new HLA-A2-restricted CTL epitopes capable of inducing Hpa-specific CTLs in vitro. Because Hpa is expressed in most advanced malignant tumors, Hpa525, Hpa277, and Hpa405 peptide-based vaccines may be useful for the immunotherapy for patients with advanced tumors. [ABSTRACT FROM AUTHOR]

To investigate the effects of surface gastric pacing on gastric myoelectrical activity and plasma motilin concentration in a canine model of gastric motility disorders. Ten healthy mongrel dogs were divided into two groups: an experimental group of six dogs and control group of four dogs. The model of gastric motility disorders was established in the experimental group with truncal vagotomy combined with injection of glucagon. Gastric serosal myoelectrical activity was recorded with a four-channel computer analysis device. Plasma motilin concentration was measured with a radioimmunoassay (RIA) kit. Surface gastric pacing at 1.1–1.2-fold the intrinsic slow-wave frequency superimposed with a series of high frequency pulses (10–30 Hz) was performed for 45 min daily for 1 month in the conscious dogs. The basic electrical rhythm (BER) amplitude (2.32 ± 0.35 mV) and propagation velocity (4.06 ± 0.40 cm/s) of the dogs with bilateral truncal vagotomy in the fed state decreased more significantly than those of the controls (4.25 ± 0.12 mV, 6.92 ± 0.24 cm/s) ( P < 0.03). After long-term surface gastric pacing, the BER amplitude (3.97 ± 0.19 mV) and propagation velocity (5.57 ± 0.48 cm/s) was increased significantly compared with before pacing ( P < 0.05). Postprandial gastric dysrhythmias were provoked by large doses of glucagon; the percentage of regular slow waves of the dogs with vagotomy was markedly reduced from 67.4 ± 6.2% at baseline to 10.0 ± 6.7% ( P < 0.001), and that of the control was also decreased from 87.1 ± 6.9% to 35.0 ± 11.0% ( P < 0.01), but the entrainment of gastric slow waves was 100% by means of gastric pacing at optimal parameters. There was a significant increase in the plasma concentration of motilin at the phase III of the interdigestive myoelectrical complex (IMC III) in the dogs with bilateral truncal vagotomy (baseline vs vagotomy, 184.29 ± 9.81 pg/mL vs 242.09 ± 17.22 pg/mL; P < 0.01). However, the plasma motilin concentration (212.55 ± 11.20 pg/mL; P < 0.02) was decreased significantly after long-term gastric pacing. Before gastric pacing, the plasma motilin concentration showed an equally negative correlation with the BER amplitude, and propagation velocity in the dogs with vagotomy in the fed state ( r = −0.473, r = −0.807, P < 0.04), but after long-term gastric pacing, the plasma motilin concentration showed an equally positive correlation with the BER amplitude and propagation velocity ( r = 0.523, r = 0.896, P < 0.02). Surface gastric pacing with optimal pacing parameters is able to entrain completely propagated slow waves, improve the parameters of gastric myoelectrical activity and normalize gastric dysrhythmias induced by a pharmacological agent. Surface gastric pacing might be useful in the treatment of gastric dysrhythmia. The gastric myoelectrical activity correlated well with the plasma motilin concentration before and after pacing, which suggests that motilin could modulate the effect of gastric pacing through alteration of the gastric myoelectrical parameters. [ABSTRACT FROM AUTHOR]