Characteristics of early gastric tumors with different differentiation and predictors of long-term outcomes after endoscopic submucosal dissection.

BACKGROUND: Gastric cancer is a common malignant tumor of the digestive tract, and endoscopic submucosal dissection (ESD) is the preferred treatment for early-stage gastric cancer. The analysis of the epidemiological characteristics of gastric mucosal tumors with different differentiation degrees and the influencing factors of long-term ESD efficacy may have certain significance for revealing the development of gastric cancer and ESD. AIM: To analyze the features of gastric mucosal tumors at different differentiation levels, and to explore the prognostic factors of ESD. METHODS: We retrospectively studied 301 lesions in 285 patients at The Second Affiliated Hospital of Xi'an Jiaotong University from 2014 to 2021, according to the latest Japanese guidelines (sixth edition), and divided them into low-grade intraepithelial neoplasia (LGIN), high-grade intraepithelial neoplasia (HGIN), and differentiated and undifferentiated early carcinoma. They are followed up by endoscopy, chest and abdominal computed tomography at 3, 6 and 12 months after ESD. We compared clinicopathologic characteristics, ESD efficacy, and complications with different degrees of differentiation, and analyzed the related factors associated with ESD. RESULTS: HGIN and differentiated carcinoma patients were significantly older compared with LGIN patients (P < 0.001) and accounted for more 0-IIc (P < 0.001), atrophic gastritis was common (P < 0.001), and irregular microvascular patterns (IMVPs) and demarcation lines (DLs) were more obvious (P < 0.001). There was more infiltration in the undifferentiated carcinoma tissue (P < 0.001), more abnormal folds and poorer mucosal peristalsis (P < 0.001), and more obvious IMVPs, irregular microsurface patterns and DLs (P < 0.05) than in the LGIN and HGIN tissues. The disease-free survival rates at 2, 5, and 8 years after ESD were 95.0%, 90.1%, and 86.9%, respectively. Undifferentiated lesions (HR 5.066), white moss (HR 7.187), incomplete resection (HR 3.658), and multiple primary cancers (HR 2.462) were significantly associated with poor prognosis. CONCLUSION: Differentiations of gastric mucosal tumors have different epidemiological and endoscopic characteristics, which are closely related to the safety and efficacy of ESD.

The lncRNA lnc-TSI antagonizes sorafenib resistance in hepatocellular carcinoma via downregulating miR-4726-5p expression and upregulating KCNMA1 expression.

Acquired drug resistance is a main reason for limiting the application of sorafenib in HCC treatment. This study aimed to explore the role and mechanisms of a novel long non-coding RNA (lncRNA), lnc-TSI, in sorafenib resistance of HCC. The interaction between lnc-TSI and miR-4726-5p, and miR-4726-5p and KCNMA1 were predicted using bioinformatic tools. Expression of the molecules in the lnc-TSI/miR-4726-5p/KCNMA1 axis in clinical samples and cell lines, as well as the sorafenib resistant HCC cell lines, was determined using qRT-PCR or western blotting. Expressions of lnc-TSI, miR-4726-5p, and KCNMA1 were manipulated in HepG2 and Huh7 cells through plasmid transfection or lentivirus infection. The CCK-8, flow cytometry, and Tunel assays were employed to determine the role of this axis on sorafenib resistance of HCC. A xenograft model was established using sorafenib-resistant HepG2 and Huh7 cells followed by in vivo sorafenib treatments to confirm the in vitro findings. Lnc-TSI and KCNMA1 expressions were significantly downregulated in HCC clinical samples and cell lines, especially in sorafenib resistance ones, while mi-4726-5p presented a reversed expression pattern. Lnc-TSI interacted with miR-4726-5p, and Lnc-TSI acts as a ceRNA via sponging miR-4726-5p in HCC cells. Overexpression of lnc-TSI and KCNMA1 promoted apoptosis and decreased cell viability of sorafenib-treated HCC cells, thus alleviated sorafenib resistance. miR-4726-5p mimic reversed the KCNMA1-mediated sorafenib sensitivity-promoting effect, while additional overexpression of lnc-TSI reversed the effect of miR-4726-5p. In vivo analysis also showed that overexpression of ln-TSI diminished sorafenib resistance in mice inoculated with sorafenib-resistant HCC cells via increasing KCNMA1 expression and decreasing miR-4726-5p expression. The lnc-TSI/miR-4726-5p/KCNMA1 axis plays a critical role in regulating the resistance of HCC to sorafenib, and might serve as a therapeutic target to manage sorafenib resistance of HCC in clinic.

Effectiveness of Water-Assisted Colonoscopy without Sedation in Patients with Ulcerative Colitis.

BACKGROUND: Studies have found that water-assisted colonoscopy (WAC) including water immersion colonoscopy (WIC) and water exchange colonoscopy (WEC) is superior to air insufflation colonoscopy (AIC) in terms of the cecal intubation rate. However, the application of WAC in ulcerative colitis (UC) has rarely been reported. This study aimed to explore the effectiveness of WAC without sedation in patients with UC. METHODS: One hundred and seventy-two UC patients were randomly divided into the AIC group (n = 56), WIC group (n = 58), and WEC group (n = 58). The cecal intubation rate, abdominal pain score, operator difficulty, bowel cleanliness, insertion, and total time were compared. RESULTS: The cecal intubation rate was higher in the WIC (91.4% vs. 75.0%; mean difference = 16.4%; 95% CI: 3.0-29.8%) and WEC (93.1% vs. 75.0%; mean difference = 18.1%; 95% CI: 5.0-31.2%) compared to the AIC group, while there was no difference between the WIC and WEC groups. The abdominal pain score and operator difficulty were lower in the WIC and WEC groups than in the AIC group, while there was no difference between the WIC and WEC groups. The bowel cleanliness during withdrawal was higher in the WIC and WEC groups than in the AIC group, while the WEC was superior to WIC. Compared with the AIC and WIC groups, the insertion time and total time were longer in the WEC group, and there was no difference in the AIC group and WIC group. CONCLUSION: In comparison with AIC, WAC can increase the cecal intubation rate, reduce abdominal pain scores and improve bowel cleanliness in patients with UC.

4D dual-mode staring hyperspectral-depth imager for simultaneous spectral sensing and surface shape measurement.

A 4D dual-mode staring hyperspectral-depth imager (DSHI), which acquire reflectance spectra, fluorescence spectra, and 3D structural information by combining a staring hyperspectral scanner and a binocular line laser stereo vision system, is introduced. A 405 nm laser line generated by a focal laser line generation module is used for both fluorescence excitation and binocular stereo matching of the irradiated line region. Under the configuration, the two kinds of hyperspectral data collected by the hyperspectral scanner can be merged into the corresponding points in the 3D model, forming a dual-mode 4D model. The DSHI shows excellent performance with spectral resolution of 3 nm, depth accuracy of 26.2 µm. Sample experiments on a fluorescent figurine, real and plastic sunflowers and a clam are presented to demonstrate system's with potential within a broad range of applications such as, e.g., digital documentation, plant phenotyping, and biological analysis.

Transmembrane Protein 100 Inhibits the Progression of Colorectal Cancer by Promoting the Ubiquitin/Proteasome Degradation of HIF-1α.

Transmembrane protein 100 (TMEM100) is involved in embryonic cardiovascular system development. However, the biological role of TMEM100 in human cancers, particularly colorectal cancer (CRC), is unclear. In this study, tissue microarrays were stained using immunohistochemistry methods to evaluate the association between TMEM100 levels and clinic-pathological features for CRC. Kaplan-Meier and log-rank tests revealed that decreased levels of TMEM100 correlated with shorter overall survival. Cox regression revealed that reduced levels of TMEM100 was an independent prognostic factor for detrimental survival in CRC. A lentiviral vector was used to overexpress TMEM100 in HCT116 cells, and small interfering RNA was used to knockdown TMEM100 in SW480 cells. The CCK-8 assay, colony formation analysis, cell cycle analysis, cell migration assay, mouse xenograft model and mouse lung metastasis model showed that TMEM100 suppressed CRC cell proliferation and migration in vitro and in vivo. IHC scores of TMEM100 and HIF-1α were significantly negatively correlated. A half-time determination analysis in which cells were treated with cycloheximide revealed that TMEM100 shortened the HIF-1α half-life. Further immunoprecipitation experimental results showed that TMEM100 promoted the ubiquitination of HIF-1α, which caused HIF-1α degradation via the 26S proteasome pathway. Angiogenesis assay and migration assay results revealed that TMEM100 suppressed the migration and angiogenesis induction capacities of HCT116 cells, but this inhibitory effect was abolished when HIF-1α degradation was blocked by MG132 treatment. These results indicated that TMEM100 inhibited the migration and the angiogenesis induction capacities of CRC cells by enhancing HIF-1α degradation via ubiquitination/proteasome pathway.

Underwater endoscopic mucosal resection for rectal neuroendocrine tumors (with videos): a single center retrospective study.

BACKGROUND: Underwater endoscopic mucosal resection (UMER) is a new method of endoscopic resection to completely remove the lesion without submucosal injection. But few attempts have been carried out for rectal neuroendocrine tumors (rectal NETs). METHODS: We retrospectively investigated data on the tumor characteristics and outcomes of patients with ≤ 10 mm rectal NETs who underwent UEMR or endoscopic submucosal dissection (ESD) from January 2019 to June 2021 in our institute. RESULTS: The endoscopic resection rate was 100% in both UEMR and ESD groups. The histological complete resection rate of the UEMR group (95.5%) was lower than that of the ESD group (96.4%) with no significant difference. The average operation time, hospitalization time and operation cost of UEMR group were less than those of ESD group (P < 0.05). The incidence of postoperative abdominal pain and abdominal distention in the UEMR group was lower than that in the ESD group (P < 0.05). There was no significant difference in the incidence of delayed bleeding and perforation between the two groups. There was no local recurrence or distant metastasis in the two groups during the follow-up period. CONCLUSIONS: Both the UEMR and ESD can effectively treat ≤ 10 mm rectal NETs with invasion depth confined to the mucosa and submucosa. UEMR is superior to ESD in operation time, hospitalization time, operation cost, postoperative abdominal pain and abdominal distention.

Suppression of rhomboid domain-containing 1 produces anticancer effects in pancreatic adenocarcinoma through affection of the AKT/GSK-3ß/ß-catenin pathway.

The protumor role of rhomboid domain-containing 1 (RHBDD1) has been observed in multiple cancers. However, the relationship between RHBDD1 and pancreatic adenocarcinoma has not been addressed. This project focused on the potential relevance of RHBDD1 in pancreatic adenocarcinoma. Bioinformatic analysis by publicly available data revealed that RHBDD1 was abundantly expressed in pancreatic adenocarcinoma. We further verified that RHBDD1 was expressed highly in clinical specimens of pancreatic adenocarcinoma. The Kaplan-Meier curve demonstrated that high-RHBDD1 expression was associated with poor prognosis in pancreatic adenocarcinoma patients. The functional studies revealed that depletion of RHBDD1 produced in vitro anticancer effects in pancreatic adenocarcinoma cells, including retardation of proliferation, reduction of metastatic potential, and induction of cell-cycle arrest at the G0/G1 phase and apoptosis. Mechanistic studies indicated that loss of RHBDD1 affected the activation of ß-catenin via regulation of AKT. Forced expression of ß-catenin reversed the RHBDD1-loss-induced anticancer effects in pancreatic adenocarcinoma cells. Crucially, depletion of RHBDD1 retarded the growth of pancreatic adenocarcinoma xenografts in vivo, a phenomenon associated with the AKT/ß-catenin pathway. Collectively, these findings delineated that restraint of RHBDD1 displayed remarkable anticancer effects in pancreatic adenocarcinoma by affecting the AKT/ß-catenin pathway. Our work unveils a pivotal role of RHBDD1 in pancreatic adenocarcinoma and proposes it as a novel candidate target for anticancer therapy of pancreatic adenocarcinoma.

Activation of YAP1 by STK25 contributes to the progression of hepatocellular carcinoma.

A pathogenic role of serine/threonine protein kinase 25 (STK25) has been observed in several chronic liver diseases. However, whether STK25 participates in hepatocellular carcinoma (HCC) remains unexplored. The current work aimed to explore the role and mechanism of STK25 in HCC. A high STK25 level was found in HCC tissue, which was associated with reduced overall survival. HCC cells with STK25 silencing displayed a marked decrease in proliferative and invasive ability, but were highly sensitive to apoptosis induced by the chemotherapy drug sorafenib. Reciprocally, HCC cells with forced expression of STK25 displayed the opposite effects. Further data unveiled that STK25 silencing restrained the activation of Yes-associated protein 1 (YAP1) associated with regulation of mammalian STE20-like protein kinase 1/2 (MST1/2). Forced expression of constitutively active YAP1 abolished STK25 silencing-induced antitumor effects, while repression of YAP1 reversed STK25 upregulation-induced protumor effects. Additionally, HCC cells with STK25 silencing exhibited reduced tumorigenic potential in vivo. Collectively, the results show that STK25 exerts a protumor function in HCC by enhancing YAP1 activation via regulation of MST1/2. These findings propose STK25 as a viable target for the development of anti-HCC therapy.

Spindle and kinetochore-associated protein 2 facilitates the proliferation and invasion of hepatocellular carcinoma via the regulation of Wnt/ß-catenin signaling.

Recent studies have shown that spindle and kinetochore-associated protein 2 (SKA2) is dysregulated in multiple tumors and acts as a key regulator of tumor progression. However, whether SKA2 plays a role in hepatocellular carcinoma (HCC) has not been fully elucidated. The purpose of this study was to explore the expression, function and underlying molecular mechanism of SKA2 in HCC. We found that SKA2 was highly expressed in HCC tissues and cell lines. Knockdown of SKA2 caused marked reductions in the proliferative, colony-forming and invasive capacities of HCC cells, while SKA2 overexpression had opposite effects. Further experiments revealed that overexpression of SKA2 enhanced expression levels of phosphorylated glycogen synthase kinase-3ß (GSK-3ß) and active ß-catenin in HCC cells. Moreover, SKA3 overexpression enhanced transcriptional activity mediated by Wnt/ß-catenin signaling. Knockdown of SKA3 downregulated the activation of Wnt/ß-catenin signaling, and the effect was significantly reversed by the inhibition of GSK-3ß. Notably, inhibition of Wnt/ß-catenin signaling markedly abrogated SKA2-mediated promotion effect on HCC proliferation and invasion. In addition, knockdown of SKA2 impeded tumor formation and growth in HCC cells in a nude mouse in vivo model. Overall, these findings indicate that SKA2 accelerates the progression of HCC through the upregulation of Wnt/ß-catenin signaling. Our study highlights a potential role of SKA2 in HCC progression and suggests it as a possible target for HCC treatment.

MicroRNA-383 inhibits proliferation, migration, and invasion in hepatocellular carcinoma cells by targeting PHF8.

BACKGROUND: To study the effect of microRNA-383 (miR-383) on cell proliferation, migration, and invasion of hepatocellular carcinoma (HCC) cells, and explore its mechanism. METHODS: The expressions of miR-383 and plant homology domain that refers to protein 8 (PHF8) were detected in tissues and cells by quantitative real-time polymerase chain reaction (qRT-PCR) or western blot respectively. The miR-383 group (transfected miR-383 mimics), miR-con group (transfected miR-con), si-con group (transfected si-con), si-PHF8 group (transfected si-PHF8), miR-383 + ctrl group (cotransfected miR-383 mimics and pcDNA-3.1), miR-383 + PHF8 group (cotransfected miR-383 mimics and pcDNA-3.1-PHF8) were transfected into HepG2 cells by liposome method. Cell proliferation, migration and invasion were measured by 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2-H-tetrazolium bromide (MTT) or trans-well assays respectively. The luciferase activity of each group was detected by dual luciferase reporter gene assay. RESULTS: Compared with normal adjacent tissues, the expression of miR-383 was significantly down-regulated and the expression of PHF8 was significantly up-regulated (p < .05). Compared with normal hepatocellular cell LO2, the expression of miR-383 was significantly reduced (p < .05) in HCC cells. Moreover, overexpression of miR-383 or silencing of PHF8 significantly inhibited the proliferation, migration, and invasion of HCC cells. In addition, PHF8 was targeted by miR-383 and its restoration rescued the inhibitory effect of miR-383 on cell proliferation, migration, and invasion of HCC cells. CONCLUSION: miR-383 could inhibit the proliferation, migration, and invasion of HCC cells by targeting PHF8, which will provide a basis for miR-383 targeted therapy for HCC.

Correlations between the serum bilirubin level and ulcerative colitis: a case-control study.

OBJECTIVE: To analyze whether the bilirubin level is a protective factor in ulcerative colitis (UC) and the predictive value of the bilirubin level. PATIENTS AND METHODS: We compared the bilirubin levels of 100 UC patients and 140 healthy controls as well as those of the subgroups of patients with different UC severities and then analyzed the correlation between the bilirubin level and UC and the correlations among the erythrocyte sedimentation rate (ESR), high sensitivity C-reactive protein (hs-CRP) level, UC severity, and bilirubin level. The predictive value of the bilirubin level for UC was determined by constructing a receiver operating characteristic (ROC) curve. RESULTS: The mean levels of the total bilirubin (TBIL) and indirect bilirubin (IBIL) in the UC were lower in comparison with the mean TBIL and IBIL levels in the control group, and the TBIL and IBIL levels were significantly higher in the mild activity subgroup than in the moderate and severe activity subgroups (P<0.05). TBIL (P<0.001, 95% confidence interval: 0.794-0.918) and especially IBIL (P<0.001, 95% confidence interval: 0.646-0.809) were independent protective factors for UC. There were also significant differences in the serum ESR and hs-CRP levels between the patients with different UC severities (ESR=χ: 23.975; hs-CRP=χ: 26.626, P<0.001), and there was a positive correlation between these two parameters (ESR=r: 0.472; hs-CRP=r: 0.495, P<0.001). However, the TBIL and IBIL levels were correlated negatively with the ESR (rtotal=-0.429, rindirect=-0.461, P<0.001) and hs-CRP (rtotal=-0.289, rindirect=-0.25, P<0.05) levels. The ROC curve showed that the threshold values of TBIL and IBIL were 8.87 and 6.735 µmol/l, the areas under the maximum ROC curve were 0.664 and 0.716, the sensitivities were 0.450 and 0.61, and the specificities were 0.800 and 0.786, respectively. CONCLUSION: TBIL and especially IBIL may be independent protective factors for UC because of their antioxidant and anti-inflammatory effects. A low level of IBIL has a moderate predictive value for UC, and an IBIL level less than 6.735 µmol/l can be used as a defining index for predicting UC.

p62 functions as an oncogene in colorectal cancer through inhibiting apoptosis and promoting cell proliferation by interacting with the vitamin D receptor.

OBJECTIVES: The role of p62 in cancer is controversial. Evidence has shown that p62 is upregulated in different cancers and promotes tumour growth, such as in liver cancer and lung cancer. However, a recent study showed that the downregulation of p62 in hepatic stellate cells (HSCs) promotes hepatocellular carcinoma (HCC) development. How p62 is regulated in colorectal cancer (CRC) remains largely unknown. In this study, we aimed to investigate the roles and molecular mechanisms of p62 in CRC. MATERIALS AND METHODS: The expression levels of p62 in CRC tissues and adjacent non-tumour tissues were determined by immunohistochemistry (IHC). Stable p62-overexpression HCT116 cells and p62-knockdown SW480 cells were established with lentiviral vectors. The role of p62 in CRC was investigated in in vitro and in vivo functional studies. The relationship between p62 and the vitamin D receptor (VDR) was investigated by coimmunoprecipitation (Co-IP) assays. RESULTS: p62 was significantly upregulated in CRC, and a high p62 level was an independent risk factor for a poor prognosis in CRC patients. p62 promoted CRC migration and invasion by inhibiting apoptosis and promoting cell proliferation in vitro, and p62 aggravated tumour growth and metastasis in vivo. Co-IP assays indicated that p62 interacts with the VDR and may target the NRF2-NQO1 axis. CONCLUSIONS: Our study suggested that p62 functions as an oncogene in CRC through inhibiting apoptosis and promoting cell proliferation by interacting with the VDR.

Endoscopic ultrasonography for preoperative staging of esophageal carcinoma.

OBJECTIVE: To evaluate the diagnostic value of endoscopic ultrasonography (EUS) in preoperative staging of esophageal carcinoma (EC). MATERIAL AND METHODS: A total of 86 surgical patients with EC who were confirmed by endoscopy and biopsy underwent preoperative TN staging with EUS examination. The EUS findings were compared with surgical pathologic results. RESULTS: The accuracy of EUS in T and N staging of EC was 82.6% and 84.9%, respectively. While determining whether EC invades the muscularis propria or outer membrane, EUS had the favorable sensitivity, specificity, positive predictive value and negative predictive value. The short-axis diameter of lymph nodes of 5mm had high sensitivity and negative predictive value to determine malignance with low specificity and positive predictive value. The short-axis diameter of 10mm presented the satisfactory sensitivity, specificity, positive predictive value and negative predictive value. CONCLUSION: EUS can accurately determine the TN staging of EC and provide a reliable basis for the treatment of EC.

Loss of miR-638 promotes invasion and epithelial-mesenchymal transition by targeting SOX2 in hepatocellular carcinoma.

Aberrant expression of microRNAs has been identified as regulators of biological processes of hepatocellular carcinoma (HCC) by negatively regulating protein-coding mRNAs. Several studies have demonstrated that miR-638 expression was dysregulated in various human cancers. However, the clinical significance and underlying mechanisms of miR-638 involved in HCC remain to be elucidated. Herein, we confirmed that a reduced miR-638 expression was present in HCC tissues and cell lines. Our clinical analysis revealed that the downregulated miR-638 expression was significantly correlated with poor prognostic features including high Edmondson-Steiner grade, venous infiltration and advanced tumor-node-metastasis (TNM) stage. Moreover, we demonstrated that miR-638 was a novel independent prognostic marker for predicting 5-year survival of HCC patients. Functionally, overexpressed miR-638 expression inhibited cell migration and invasion, while downregulated miR-638 reversed the effect. In addition, miR-638 could regulate SOX2 by directly binding to its 3'-UTR. Alternation of SOX2 expression at least partially abolished the migration and invasion effects of miR-638 on HCC cells. Aberrant miR-638 expression could regulate the expression level of epithelial-to-mesenchymal transition markers in vitro and in vivo by modulating SOX2 expression. In conclusion, our data indicated that miR-638 functioned as a tumor suppressor gene and play a critical role in the development of HCC.

Decreased expression of TLR7 in gastric cancer tissues and the effects of TLR7 activation on gastric cancer cells.

The present study aimed to determine the expression of Toll-like receptor 7 (TLR7) in gastric cancer tissues and investigate the effects of its activation on gastric cancer cells. Patients with gastric cancer (n=30) and patients without gastric cancer (control; n=14) who underwent gastroscopy were enrolled in the study. Gastric cancer and cancer-adjacent tissues were obtained from the patients with gastric cancer, and normal gastric epithelial tissues were obtained from the control patients. The TLR7 mRNA and protein expressions in different tissues were investigated by reverse transcription-quantitative polymerase chain reaction, western blotting and immunohistochemistry. The present study also determined the effects of TLR7 activation by the agonist imiquimod on TLR7 protein expression, proinflammatory cytokine secretion and viability in SGC-7901 gastric cancer cells. The mRNA and protein expression levels of TLR7 were significantly downregulated in gastric cancer tissues compared with cancer-adjacent and normal gastric epithelial tissues (P<0.01). Imiquimod significantly increased TLR7 protein expression levels, and promoted the secretion of proinflammatory cytokines tumor necrosis factor-α and interleukin-6 in SGC-7901 cells. Furthermore, imiquimod inhibited the proliferation of SGC-7901 cells in a dose- and time-dependent manner. Thus, the present study identified that the expression of TLR7 was decreased in gastric cancer tissues, and TLR7 activation enhanced TLR7 expression, promoted the production of proinflammatory cytokines and inhibited the growth of gastric cancer cells.

Imiquimod inhibits the growth of SGC­7901 cells in vitro through induction of autophagy and apoptosis.

Imiquimod, the most prominent Toll­like receptor 7 agonist, has direct anti­tumor activity and can induce autophagy and apoptosis in various types of human cancer. The aim of the present study was to examine the anti­tumor effects of imiquimod and their underlying mechanisms in SGC­7901 cells. Imiquimod exerted an inhibitory effect on cell proliferation in a dose­ and time­dependent manner as indicated by an MTT assay. Imiquimod induced autophagy as well as apoptosis, while simultaneous treatment with 3­methyladenine (3-MA), an autophagy inhibitor, decreased the toxicity of imiquimod. Furthermore, blocking of autophagy by 3­MA exerted an inhibitory effect on imiquimod-induced apoptosis, which indicated that autophagy can function as a mechanism which, upon activation, directly leads to apoptosis and cell death of SGC­7901 cells. The results of the present study suggested that imiquimod has potent direct activity against gastric cancer cells by inducing autophagy and apoptosis.

Extrinsic ghrelin in the paraventricular nucleus increases small intestinal motility in rats by activating central growth hormone secretagogue and enteric cholinergic receptors.

BACKGROUND/OBJECTIVES: Ghrelin is a brain-gut peptide that regulates gastrointestinal (GI) motility. We hypothesized that the excitatory effect of ghrelin on the paraventricular nucleus (PVN) increases GI motility by activating the central growth hormone secretagogue receptor (GHSR) and central neuropeptide Y (NPY) signaling pathways, leading to increased enteric cholinergic activity. METHODS: Thirty-six male Sprague Dawley rats were maintained on duodenal catheterization and PVN cannulation. Small intestinal transit (SIT) was observed and rats were divided as follows: experimental animals received ghrelin injections in the PVN (0.03, 0.08, or 0.24 nM); 1 nM GHSR antagonist D-Lys3-GHRP6 alone; 1nM D-Lys3-GHRP6 before ghrelin injection in the PVN, respectively. Electrophysiologic parameters of the interdigestive myoelectric complex (IMC) were examined by administration of 0.24 nM ghrelin in the PVN after small intestinal electrode implantation and PVN cannulation. GI cholinergic pathway activation was analyzed after intravenous atropine administration. The involvement of central NPY signaling was evaluated by injecting an anti-NPY immunoglobulin (IgG) in the PVN. Neuronal expression of c-Fos in the brain and GI tract was examined using immunohistochemistry. RESULTS: Injection of ghrelin in the PVN dose-dependently accelerated SIT, and this excitatory effect was competitively inhibited by a GHSR antagonist. The excitatory effect of ghrelin on IMC activity was diminished by GHSR antagonism and NPY neutralization, as well as by blockade of peripheral muscarinic acetylcholine receptors. Extrinsic ghrelin significantly upregulated c-Fos expression in the PVN and other central nuclei, as well as in the enteric nervous plexuses of the stomach, duodenum, and proximal colon. The ghrelin-induced upregulation of central and enteric c-Fos expression was also dependent on central GHSR activation. CONCLUSIONS: Ghrelin positively regulates GI motility by exciting both central and enteric neurons, including those of the PVN, by activating GHSR and NPY pathways, and peripheral muscarinic acetylcholine receptors.

[Expression of chemokine receptor CXCR7 in gastric cancer tissues and cell lines].

OBJECTIVE: To investigate the expression status of CXCR7 in gastric cancer tissues and cell lines. METHODS: The expression status of CXCR7 was detected in 35 primary gastric cancer tissues and matched adjacent tissues by immunohistochemistry and RT-PCR. The correlation of CXCR7 expression with the clinicopathological parameters and risk factors of gastric cancer was analyzed. The expression of CXCR7 in gastric cell lines (HGC-27, MGC-803, BGC-823, SGC-7901 and MKN-28) was also detected by immunofluorescence assay. RESULTS: The expression of CXCR7 was significantly higher in gastric cancer tissues than in adjacent tissues (P<0.01). CXCR7 expression was not correlated with age, gender, smoking history, Helicobacter pylori infection, tumor location or the pathological type, but showed a higher expression level in patients with a alcohol-drinking history than in those without (P<0.05). CXCR7 was expressed with variable intensities in the 5 gastric cancer cell lines without correlation with the degrees of cell differentiation; its expression was the highest in SGC-7901 cells, a moderately differentiated human gastric adenocarcinoma cell line. CONCLUSIONS: CXCR7 is highly expressed in gastric cancer tissues with variable intensities in 5 gastric cancer cell lines, suggesting its important role in gastric cancer progression.

Peptide tyrosine-tyrosine combined with its receptors exhibits an anti-cancer potential in pancreatic cancer MiaPaCa-2 cell.

BACKGROUND: Pancreatic cancer is a common malignant tumor of the digestive system. It is the fourth major cause of tumor-related death and its morbidity is increasing, and hence it is imperative to develop effective forms of therapy for pancreatic cancer. Peptide tyrosine-tyrosine (PYY) is an important gastrointestinal peptide hormone. According to previous literatures, PYY has been shown to inhibit tumor proliferation in cellular and animal models, but there has been limited research on the detailed mechanism of PYY in pancreatic cancer. This study was to observe the effects of PYY on pancreatic cancer cell and investigate the possible mechanism. METHODS: The expression of Y1, Y2, and Y5 receptors on pancreatic cancer cell lines were detected by reverse transcription quantitative polymerase chain reaction (RT-qPCR). The cytotoxicity of PYY toward the MiaPaCa-2 cell was evaluated by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay; the cell morphology and structure changes were observed under inverted microscope and transmission electron microscope respectively. Apoptosis and cell cycle were evaluated by flow cytometry. The activity of caspase-3 was determined by activity assay kits and Western blotting. The expression of survivin, vascular endothelial growth factor (VEGF), and cyclooxygenase-2 (COX-2) were determined by RT-qPCR and Western blotting. RESULTS: Expression of Y2 receptor is the most abundant PYY receptor on pancreatic cancer cell. PYY inhibited MiaPaCa-2 cell proliferation, blocked it in G0/G1 phase, increased the proportion of apoptosis cells and caspase-3 activity, and reduced the expression of survivin, VEGF, and COX-2. CONCLUSIONS: PYY weakened the ability of the pancreatic MiaPaCa-2 cell viability through cell cycle blocking and apoptosis inducing. The inhibition effect of PYY may be mediated by the Y2 receptor. The increased caspase-3 activity and reduced expression of survivin, VEGF, and COX-2 may serve as a novel mechanism in PYY inhibition effect on MiaPaCa-2 cell.

Decreased expression of gastrokine 1 in gastric mucosa of gastric cancer patients.

AIM: To investigate the expression of gastrokine 1 (GKN1) in normal gastric mucosa, precancerous lesions and gastric cancer tissues, and to analyse its correlations with tumour site and pathological pattern. METHODS: Thirty gastric cancer patients (12 cases of diffuse type and 18 cases of intestinal type), 13 atrophic gastritis patients and 15 healthy volunteers with almost normal gastric mucosa (superficial gastritis) were enrolled in this study. Helicobacter pylori (H. pylori) infection was examined in all subjects. All gastric mucosa biopsy specimens were obtained. Cancer-adjacent specimens were taken from corresponding gastric cancer patients. Immunohistochemistry and real-time PCR were performed to determine the expressions of the GKN1 protein and mRNA, respectively. RESULTS: H. pylori infection had no significant association with age, gender, tumour site or pathological pattern in all subjects. Compared with the superficial gastritis and atrophic gastritis groups, the expression of GKN1 protein (P = 0.011) and mRNA (P < 0.001) in gastric cancer was significantly decreased. The GKN1 mRNA level in diffuse type gastric cancer was significantly lower than in intestinal type gastric cancer (0.296 ± 0.076 vs 0.525 ± 0.164, P < 0.001). CONCLUSION: Compared with almost normal gastric mucosa, GKN1 expression in the gastric mucosa of gastric cancer patients is decreased; this is associated with progression and prognosis of gastric cancer.