Tumor- and metastasis-promoting roles of miR-488 inhibition via HULC enhancement and EZH2-mediated p53 repression in gastric cancer.

Dysregulation of microRNAs (miRNAs or miRs) is implicated in the development of gastric cancer (GC), which is possibly related to their roles in targeting tumor-suppressive or tumor-promoting genes. Herein, the current study was intended to ascertain the function of miR-488 and its modulatory mechanism in GC. Initially, human GC cells were assayed for their in vitro malignancy after miRNA gain- or loss-of-function and RNA interference or overexpression. Also, tumorigenesis and liver metastasis were evaluated in nude mouse models. Results demonstrated that miR-488 elevation suppressed GC (MKN-45 and OCUM-1) cell proliferation, migration, and invasiveness in vitro and reduced their tumorigenesis and liver metastasis in vivo. The luciferase assay identified that miR-488 bound to HULC and inhibited its expression. Furthermore, HULC could enhance EZH2-H3K27me3 enrichment at the p53 promoter region and epigenetically repress the p53 expression based on the data from RIP- and ChIP-qPCR assay. Additionally, HULC was validated to enhance GC growth and metastasis in vitro and in vivo. Overall, HULC re-expression elicited by miR-488 inhibition can enhance EZH2-H3K27me3 enrichment in the p53 promoter and repress the p53 expression, thus promoting the growth and metastasis of GC.

AMPK activation suppresses mTOR/S6K1 phosphorylation and induces leucine resistance in rats with sepsis.

Although it has been known that protein synthesis is suppressed in sepsis, which cannot be corrected by leucine supplement (also known as leucine resistance), the molecular signaling mechanism remains unclear. This study aimed to investigate the AMP-activated protein kinase/mammalian target of rapamycin (AMPK/mTOR) pathway in sepsis-induced leucine resistance and its upstream signals, and to seek a way to correct leucine resistance in sepsis. Sepsis was produced by cecal ligation and puncture (CLP) model in rat. Both septic rats and sham operation rat received total parenteral nutrition (TPN) with or without leucine for 24 h, and then protein synthesis and AMPK/mTOR and protein kinase B (PKB) were tested. In vitro C2C12 cells were treated with or without leucine, and we tested the AMPK/mTOR pathway and protein synthesis. We blocked AMPK by compound C and stimulated it by 5-aminoimidazole-4-carboxamide ribonucleoside (AICAR) individually. The results showed that AMPK was highly phosphorylated and suppressed mTOR/S6K1 activation in CLP rats. In vitro when AMPK was activated by AICAR, protein synthesis was suppressed and leucine resistance was observed. High phosphorylation of AMPK was accompanied by PKB inactivation in CLP rats. When PKB was blocked, both AMPK activation and leucine resistance were observed. In CLP rats, nutrition support with intensive insulin therapy reversed leucine resistance by activating PKB and suppressing AMPK phosphorylation. These findings suggest that high phosphorylation of AMPK induced by PKB inactivation in sepsis suppresses mTOR, S6K1 phosphorylation, and protein synthesis and leads to leucine resistance. Intensive insulin treatment can reverse leucine resistance by suppressing AMPK activation through activation of PKB.

Preoperative Oral Carbohydrate Reduces Postoperative Insulin Resistance by Activating AMP-Activated Protein Kinase after Colorectal Surgery.

BACKGROUND: Postoperative insulin resistance (PIR) is a common response after colorectal surgery and an independent risk factor for recovery. Preoperative oral carbohydrate (POC) has been known to reduce PIR. Herein, we investigated whether its mechanism of action involves AMP-activated protein kinase (AMPK) and mTOR/S6K1/insulin receptor substrate-1 (IRS-1) pathways. METHODS: Patients undergoing colorectal cancer resection were randomly assigned to a POC, fasting, or placebo group. The exclusion criteria were association with diseases or intake of medication affecting insulin sensitivity. Pre- and postoperative insulin resistance, and protein phosphorylation of AMPK, mTOR, and IRS-1 in the rectus abdominis muscle were evaluated. RESULTS: From January 2017 to December 2017, 70 patients were randomized and 63 were evaluated. No difference was found in the clinical and operative characteristics among the 3 groups. In the POC group, the levels of blood glucose, blood insulin, and homeostasis model assessment of insulin resistance were significantly lower in the POC group than the fasting and placebo groups, and the insulin sensitivity index was significantly higher. The phosphorylation of AMPK in the POC group was significantly higher than that in the other 2 groups, whereas the phosphorylation of mTOR and IRS-1 was significantly lower. CONCLUSION: PIR involves AMPK and mTOR/S6K1/IRS-1 pathways. POC reduces PIR by the stimulation of AMPK, which suppresses the phosphorylation of mTOR/IRS-1 and attenuates PIR after colorectal resection.

[Development of Portable Bowel Sound Monitor].

This paper designs and implements a low power portable bowel sound monitor, which adopts bone conduction transducer to collect bowel sound continuously for long time and transmit to phone by Bluetooth. Then the phone application can record, play and analyse the bowel sound digital data in real time. This paper also designs an experiment to collect bowel sound from healthy people and patients with intestinal obstruction. It is verified by clinicians that this monitor can accurately record and preserve the bowel sound of the detected people, and is not disturbed by the external environment.

TRIM32 promotes cell proliferation and invasion by activating ß-catenin signalling in gastric cancer.

The tripartite motif (TRIM) family comprises more than 70 members involved in the regulation of many cellular pathways. TRIM32 acts as an E3 ubiquitin ligase and has been reported to participate in many human cancers. Here, we aimed to investigate the role of TRIM32 in gastric cancer (GC) and the clinical implications. High expression of TRIM32 was observed in GC tissues and cell lines, and was significantly associated with poor prognosis. Knockdown TRIM32 expression remarkably suppressed the proliferation, migration, and invasion of GC cells in vitro and tumour growth in vivo, whereas overexpression of TRIM32 yielded the opposite results. Western blotting and quantitative reverse-transcription PCR (qRT-PCR) analyses revealed that up-regulation of TRIM32 significantly enhanced expression of ß-catenin protein and of its downstream targets TCF1, cyclin D1, Axin2 and MMP7 mRNAs. Moreover, we found that the mechanism behind the TRIM32-promoted GC progression was related to the ß-catenin signalling pathway. Collectively, these data suggest that TRIM32 promotes GC cell proliferation, migration, and invasion by activating the ß-catenin signalling pathway.

Curcumin regulates proliferation, autophagy, and apoptosis in gastric cancer cells by affecting PI3K and P53 signaling.

In this study, we aimed to investigate the effects of curcumin on cell activities of gastric cancer (GC), and the connection between curcumin and P53, as well as, PI3K signaling. This study was conducted with two cell lines SGC-7901 and BGC-823, both were exposed to curcumin at the concentrations of 0, 10, 20, and 40 µm. MTT assay, flow cytometry (FCM) assay, transmission electron microscopy (TEM) were used to study the underlying mechanisms of curcumin in respective of proliferation, apoptosis, and autophagy. Western blot assay was also employed to detect impacts of curcumin on tophosphatidylinositol-3 kinase (PI3K) and P53 signaling pathways-related proteins. MTT assay displayed that curcumin inhibited GC cell proliferation. FCM results indicated that curcumin induced the apoptosis of GC cells. TEM revealed that curcumin induced autophagy in GC cells. Western blot results showed that curcumin activated P53 signaling pathway and inhibited PI3K signaling pathway. Curcumin may inhibit proliferation and induce the autophagy and apoptosis in GC cells. Additionally, curcumin activated the P53 signaling pathway by up-regulating P53 and P21, which also inhibited PI3K pathway through down-regulating PI3K, p-Akt, and p-mTOR.

Integrin ß1 promotes gemcitabine resistance in pancreatic cancer through Cdc42 activation of PI3K p110ß signaling.

Pancreatic ductal adenocarcinoma (PDAC) is one of the most common malignancies with very poor prognosis due to its broad resistance to chemotherapy. Our previous study showed that integrin ß1 expression is upregulated in PDAC and confers gemcitabine resistance in PDAC cells via the signaling pathway including Cdc42 and AKT activation. But the accurate signal transductions are not clear. Here, we aimed to illuminate the signal transductions of integrin ß1 in the acquisition of gemcitabine resistance in PDAC. Drug-resistance (DR) cells from AsPC-1 parent cell line (PCL) were selected. Integrin ß1 expression was determined using western blot assay. Changes in drug response and the activity of phosphatidylinositol 3-kinase (PI3K) signaling after knockdown of integrin ß1, Cdc42 or p110ß were evaluated using MTT, cleaved caspase-3 immunofluorescence and western blot assay. Western blot assays also detected the variations in Cdc42 activity and p110ß expression after integrin ß1 knockdown. The interaction between Cdc42 and p110ß was determined by Glutathione S-transferase (GST) pull-down assay. The results showed that integrin ß1 expression was upregulated in DR-AsPC-1 cells, and integrin ß1 knockdown significantly decreased the activity of Cdc42, a target molecule of integrin ß1, and p110ß expression. Knockdown of anyone of integrin ß1, Cdc42 and p110ß inhibited the activity of PI3K signaling, and sensitized DR-AsPC-1 cells to gemcitabine. GST pull-down assay showed that GTP-Cdc42 interacted with p110ß. Collectively, these data indicated that integrin ß1 promoted gemcitabine resistance in PDAC through Cdc42 activation of PI3K p110ß signaling. In vivo experiments also confirmed this conclusion. These findings contribute to a better understanding the molecular mechanism of chemoresistance and facilitate the development of more targeted and effective treatment strategy for PDAC.

[Development of Abdominal Vacuum Extractor Characterized by Portability and Constant Negative Pressure Which Applying to Battlefield].

There are some problems such as difficulty of pressure control, inconvenience of use and carry, congested easily and dredged hardly in clinical application of vacuum extractor in common use. For solving the above problems, researchers have designed a new portable and pressure stabilized abdominal drainage system which was composed of integral double spherical aspirator and separated double cannula. The new apparatus has achieved good effects in drainage which is suitable for not only rescuing of abdominal trauma and war wound, but also abdominal surgery that manifested as sucking safe and effective, using easily and convenient, that was verified by testing.

Integrinß1 modulates tumour resistance to gemcitabine and serves as an independent prognostic factor in pancreatic adenocarcinomas.

Pancreatic ductal adenocarcinoma (PDAC) is one of the most lethal malignancies because of its broad resistance to chemotherapy. Numerous evidence indicates that integrinß1 is upregulated in some human cancers, and it is correlated with resistance to various therapies. However, the role of integrinß1 in chemotherapy is not clear in pancreatic cancer. The present study evaluates the potential of integrinß1 to predict chemoresistance and prognosis in patients and to modulate resistance to gemcitabine in PDAC cells. Primary drug-resistance (DR) cancer cells were isolated, and DR cells from MiaPaCa-2 and AsPC-1 parent cell lines (PCL) were selected. Integrinß1 expression was determined using immunohistochemistry (IHC), quantitative real-time PCR (qRT-PCR) and Western blotting. Changes in drug response after knockdown of integrinß1 via RNA interference (RNAi) were evaluated using the viability of cancer cells as colon formation, proliferation using Western blot of Ki-67 and apoptosis using cleaved caspase-3 immunofluorescence. qRT-PCR and Western blot also detected variations in the activities of cdc42 and AKT after integrinß1 suppression. Patient survival and relative factors were assessed using Kaplan-Meier and Cox regression analyses. Integrinß1 expression was upregulated in PDAC, which was significantly associated with intrinsic and acquired gemcitabine resistance and worse outcomes. The downregulation of integrinß1 attenuated PDAC chemoresistance, and this attenuation partially correlated with reduced Cdc42 and AKT activity, which are target molecules of integrinß1 in some human cancers. These findings identified integrinß1 as a special marker of drug resistance and a serious prognosis, and they furthermore support the use of integrinß1 as a novel potential therapeutic target to overcome chemotherapy resistance. The results also suggest a possible drug-resistant signalling pathway of integrinß1 in PDAC.

The MSHA strain of Pseudomonas aeruginosa (PA-MSHA) inhibits gastric carcinoma progression by inducing M1 macrophage polarization.

Macrophages play crucial roles in promoting tumor development and progression. In the present study, we found that the mannose-sensitive hemagglutination pilus strain of Pseudomonas aeruginosa (PA-MSHA) was efficient in inducing M1 macrophage polarization. PA-MSHA treatment increases expression of M1-related cytokines and promotes activation of murine peritoneal macrophages (MPM). Interestingly, PA-MSHA inhibits cell proliferation and migration and induces the apoptosis of gastric carcinoma cells. These effects of PA-MSHA on M1 polarization were associated with activation of NF-κB expression. Thus, inducing polarization of M1 by PA-MSHA may be one potential strategy for inhibiting gastric carcinoma progression in mice.

Predictors of iatrogenic splenic injury in radical gastrectomy for gastric cancer.

Background: Iatrogenic splenic injury (ISI) is a recognized complication in radical gastrectomy that may result in incidental splenectomy (IS). However, the predictors of such events remain largely unknown. Methods: Medical records of the patients who underwent radical gastrectomy at our institution between January 2015 and December 2022 were retrospectively reviewed. Potential predictors of ISI and IS were collected and analyzed by multivariate logistic regression. Results were reported as an odds ratio (OR) with 95% confidence intervals (CI). Results: A total of 2916 patients were included, of whom 211 patients (7.2%) suffered from ISI and 75 patients (2.6%) underwent IS. Multivariate analysis demonstrated that BMI≥25 (OR: 3.198 (2.356-4.326), p<0.001), total gastrectomy (OR: 2.201 (1.601-3.025), p<0.001), and the existence of "criminal fold" (OR: 13.899 (2.824-251.597), p=0.011) were independent predictive risk factors for ISI; whereas laparoscopic surgical approach (OR: 0.048 (0.007-0.172), p<0.001) was a protective factor for ISI. Moreover, the existence of "criminal fold" (OR: 15.745 (3.106-288.470), p=0.008) and BMI≥25 (OR: 2.498 (1.002-6.046), p=0.044) were identified as independent risk factors of ISI under laparoscopic gastrectomy. There was no association between sex, age, previous abdominal surgery, neoadjuvant therapy, outlet obstruction, tumor stage, nodal stage, and total lymph node retrieved and ISI. Conclusions: BMI≥25 and total gastrectomy can predict high risk of ISI during radical gastrectomy. Laparoscopic surgery is superior to open gastrectomy in lowing the risk of ISI.

One-pot assay using a target-driven split aptamer recognition and assembly strategy for convenient and rapid detection of gliotoxin.

An aptamer targeting gliotoxin (GTX) was optimized to increase the binding affinity by approximately 20 times and achieve higher structural stability and targeting specificity. Molecular dynamics simulations were used to explore the molecular mechanism and key action sites underlying the recognition of GTX by the optimized aptamer. Subsequently, the optimized aptamer was split into two fragments and a convenient and rapid one-pot assay for GTX detection was successfully established using a target-driven split aptamer recognition and assembly strategy. The method exhibited a good linear range of 0.128 nM to 2 µM, a low detection limit of 0.07 nM, and excellent selectivity for GTX. Furthermore, the method had good accuracy and stability in real sample analysis. Therefore, the developed one-pot method provides a reliable, convenient, and cost-effective approach for the widespread application of GTX detection.

The Antitumor Effect of TPD52L2 Silencing on Oxaliplatin-Resistant Gastric Carcinoma Is Related to Endoplasmic Reticulum Stress In Vitro.

Tumor protein D52-like 2 or simply TPD52L2 belongs to the TPD52 family which has been implicated in a variety of human carcinomas. However, the TPD52L2 function in the gastric carcinoma oxaliplatin (OXA) resistance remains elusive. The main objective of this study is to evaluate the TPD52L2 effect in OXA-resistant gastric carcinoma cells in vitro. Oxaliplatin-resistant gastric carcinoma cells were generated in MGC-803 and SGC-7901 cells. siRNA-mediated knockdown of TPD52L2 was investigated in OXA-resistant MGC-803-OXA and SGC-7901-OXA cells. qRT-PCR was performed to assess the expression level of TPD52L2 mRNA. TPD52L2 protein expression level, apoptosis, and endoplasmic reticulum (ER) stress-associated proteins were identified via immunoblotting analysis. MTT assay was conducted for the evaluation of cell viability, while colony-forming activity was carried out via crystal violet staining. SGC-7901-OXA and MGC-803-OXA cells were found to be more resistant to OXA, as compared to the parental cell lines. The expression of TPD52L2 was found to be upregulated in OXA-resistant cells. Knockdown of TPD52L2 suppressed cell colony-forming potency, cell growth, and development in OXA-resistant cells. TPD52L2 knockdown also enhanced the PARP and caspase-3 cleavage. ER-associated proteins such as PERK, GRP78, CHOP, and IRE1α were found to be elevated in TPD52L2 knockdown cells. ER stress might be involved in TPD52L2 knockdown-induced apoptosis in OXA-resistant gastric carcinoma cells.

Folate Decorated Multifunctional Biodegradable Nanoparticles for Gastric Carcinoma Active Targeting Theranostics.

Introduction: Gastric cancer remains a major clinical issue and little progress has been made in the treatment of gastric cancer patients during recent decades. Nanoparticles provide a versatile platform for the diagnosis and treatment of gastric cancer. Methods: We prepared 7-ethyl-10-hydroxycamptothecin (SN-38) 125I-radiolabelled biodegradable nanoparticles with folate surface modification (125I-SN-38-FA-NPs) as a novel nanoplatform for targeted gastric carcinoma theranostics. We characterized this system in terms of particle size, morphology, radiostability, and release properties and examined the in vitro cytotoxicity and cellular uptake properties of 125I-SN-38-FA-NPs in MNK 7 and NCI-N7 cells. The pharmacokinetics and biodistribution of 125I-SN-38-FA-NPs were imaged by single photon emission computer tomography (SPECT). An MNK7 tumor-bearing model were established and the in vivo antitumor activity of 125I-SN-38-FA-NPs was evaluated. Results: SN-38 was readily radiolabeled with 125I and exhibited high radiostability. Poly-lactic-co-glycolic acid (PLGA) nanoparticles (NPs) were formed by solvent exchange, and displayed spherical morphology of 100 nm in diameter as characterized by dynamic light scattering (DLS) and transmission electron microscopy (TEM). A 2.5-fold greater uptake of 125I-radiolabelled SN-38-loaded folate-decorated PLGA nanoparticles (125I-SN-38-FA-NPs) than 125I-radiolabelled SN-38-loaded PLGA nanoparticles (125I-SN-38-NPs) were record in MKN7 tumor cells. NPs and folate-decorated PLGA nanoparticles (FA-NPs) also had good biocompatibility in methyl thiazolyl tetrazolium (MTT) assays. Pharmacokinetic, biodistribution and SPECT imaging studies showed that 125I-SN-38-FA-NPs had prolonged circulation, were distributed in the reticuloendothelial system, and had high uptake in tumors with a higher tumor accumulation of 125I-SN-38-FA-NPs than 125I-SN-38-NPs recorded at 24 h postinjection. In vivo SN-38-FA-NPs significantly inhibited tumor growth without causing obvious side effects. Conclusion: Folate receptor alpha (FOLR1) targeted drug-loaded nanoparticles enable SPECT imaging and chemotherapy, and provide a novel nanoplatform for gastric carcinoma active targeting theranostics.

Comparative Study of Pyloromyotomy and H-M Pyloroplasty in Proximal Gastrectomy for Adenocarcinoma of Esophageal-Gastric Junction.

INTRODUCTION: The incidence of adenocarcinoma of esophageal-gastric junction (AEJ) has been increasing in recent years. Esophagogastrostomy after proximal gastrectomy (PG-EG) is the most commonly used surgical method for this disease which causes a constant spasm of the pyloric sphincter by cutting the vagus nerve around the esophagus, so H-M pyloroplasty (Heineke-Mikulicz pyloroplasty) is often operated after PG-EG to prevent delayed gastric emptying. However, H-M pyloroplasty destroys anti-reflux structure of pylorus and leads to serious bile reflux. The present study was designed to compare pyloromyotomy and H-M pyloroplasty in proximal subtotal gastrectomy through clinical studies and animal experiments. METHODS: We retrospectively evaluated the outcomes of 73 AEJ patients (39 underwent PG-EG with an H-M pyloroplasty and 34 underwent PG-EG with a pyloromyotomy) between January 2016 and August 2020, and perioperative variables were compared. In the animal experiment, 48 rats were randomly divided into four groups (n = 12): vagotomy group (V group), H-M pyloroplasty group (HM group), pyloromyotomy group (PM group), and control group (O group). Gastric emptying and bile reflux were evaluated in each group. RESULTS: In the retrospective clinic study, pyloromyotomy and H-M pyloroplasty could all prevent delayed gastric emptying effectively, and the incidence of bile reflux found by electronic gastroscopy in the PM group was significantly lower than that in the HM group (HM, 14/39; PM, 4/34; P = 0.028). In the animal experiment, there was no significant between-group difference of gastric emptying rate (%) in the HM group and PM group (HM, 70.6 ± 16; PM, 72.3 ± 12; P = 0.68) while the gastric emptying rate (%) was significantly lower in the V group than in the HM, PM, and control group (P values were 0.037, 0.021, and 0.001 respectively). The gastric mucosa bile acid concentration was significantly higher in the HM group than other group (P values were all less than 0.001). CONCLUSIONS: The pyloromyotomy could prevent delayed gastric emptying effectively after PG-EG for types II and III AEJ and reduce bile reflux compared to Heineke-Mikulicz pyloroplasty.

A four-lncRNA signature for predicting prognosis of recurrence patients with gastric cancer.

PURPOSE: This study aimed to develop a multi-long noncoding RNA (lncRNA) signature for the prediction of gastric cancer (GC) based on differential gene expression between recurrence and nonrecurrence patients. METHODS: By repurposing microarray expression profiles of RNAs from The Cancer Genome Atlas (TCGA), we performed differential expression analysis between recurrence and nonrecurrence patients. A prognostic risk prediction model was constructed based on data from TCGA database, and its reliability was validated using data from Gene Expression Omnibus database. Furthermore, the lncRNA-associated competing endogenous RNA (ceRNA) network was constructed, namely, DIANA-LncBasev2 and starBase database. RESULTS: We identified 363 differentially expressed RNAs (317 mRNAs, 18 lncRNAs, and 28 microRNAs [miRNAs]). Principal component analysis showed that the seven-feature lncRNAs screened by support vector machine-recursive feature elimination algorithm was more informative for predicting recurrence of GC in comparison with the eight-feature lncRNAs screened by random forest-out-of-bag algorithm. Four of the seven-feature lncRNAs including LINC00843, SNHG3, C21orf62-AS1, and MIR99AHG were chosen to develop a four-lncRNA risk score model. This risk score model was able to distinguish patients with high and low risk of recurrence, and was tested in two independent validation sets. The ceRNA network of this four-lncRNA signature included 10 miRNAs and 178 mRNAs. The mRNAs significantly related to the Wnt-signaling pathway and relevant biological processes. CONCLUSION: A useful four-lncRNA signature recurrence was established to distinguish GC patients with high and low risk of recurrence. Regulating the relevant miRNAs and Wnt pathway might partly affect GC metastasisby.

Neoadjuvant Intraperitoneal and Systemic Chemotherapy Versus Neoadjuvant Systemic Chemotherapy With Docetaxel, Oxaliplatin, and S-1 for Gastric Cancer With Peritoneal Metastasis: A Propensity Score Matched Analysis.

BACKGROUND: The optimal treatment for gastric cancer with peritoneal metastasis (GCPM) remains debatable. This study aimed to compare the efficacy and safety of neoadjuvant intraperitoneal and systemic chemotherapy (NIPS) versus neoadjuvant systemic chemotherapy (NSC) for GCPM. METHODS: Patients of GCPM received neoadjuvant chemotherapy with docetaxel, oxaliplatin and S-1 between January 2011 and June 2019 were retrospectively evaluated. Propensity score matched (PSM) analysis was carried out to reduce the selection bias. Multivariate Cox regression model was applied to screen the prognostic factors. RESULTS: After PSM processing, 71 patients in each group were matched among the 186 GCPM patients included. NIPS yielded a better ascites and cytology response to chemotherapy, higher conversion resection rate and R0 resection rate than NSC. The overall survival (OS) rate in NIPS group was better than that in NSC group. Multivariate analysis revealed that the P stage, ascites response, conversion surgery rate and R0 resection rate were independent prognostic factors. Subgroup analysis indicated that NIPS showed a survival benefit over NSC only in patients with cT3-4a, P1-2, whose cytology turned negative, and who received conversion surgery; while not in patients with cT4b, P0 or P3, whose cytology did not turn negative, or who did not receive conversion surgery. CONCLUSIONS: NIPS is a safe and feasible treatment for GCPM, which showed more benefit than NSC.

CircHIPK3 Promotes the Tumorigenesis and Development of Gastric Cancer Through miR-637/AKT1 Pathway.

Circular RNA is a kind of RNA with a covalently closed loop, which has a complex ability to modulate genes in the process of tumorigenesis and metastasis. Nevertheless, how circular RNA functions in gastric cancer (GC) remains unclear. The effect of circHIPK3 in vitro was studied here. Quantitative real-time PCR (qRT-PCR) was employed to found that circHIPK3 markedly increased in GC tissues and cell lines. And low expression of circHIPK3 suppressed the GC cells growing and metabolizing. Then the bioinformatics tool predicted the downstream target of circHIPK3, and it was proved by the dual-luciferase report experiment. According to the results of bioinformatics analysis and experimental data, it was clarified that circHIPK3 acted as a sponge of miR-637, releasing its direct target AKT1. The dual-luciferase assay revealed that mir-637 could bind circHIPK3 and AKT1. qRT-PCR data indicated that overexpression circHIPK3 led to the low level of miR-637 and overexpressed miR-637 would reduce AKT1 level. Finally, we demonstrated that the low expression of miR-637 or overexpression of AKT1 could attenuate the anti-proliferative effects of si-circHIPK3. These results suggest that the circHIPK3/miR-637/AKT1 regulatory pathway may be associated with the oncogene and growth of gastric cancer. In short, a new circular RNA circHIPK3 and its function are identified, and the regulatory pathway of circHIPK3/miR-637/AKT1 in the tumorigenesis and development of gastric cancer is discovered.

Phloretin flavonoid exhibits selective antiproliferative activity in doxorubicin-resistant gastric cancer cells by inducing autophagy, inhibiting cell migration and invasion, cell cycle arrest and targeting ERK1/2 MAP pathway.

PURPOSE: Studies have shown that Phloretin exerts anticancer effects on several types of cancer cells. Nonetheless, the anticancer effects of Phloretin have not been fully explored against the human gastric cancer cells. Therefore, this study was undertaken to evaluate the anticancer effects of Phloretin against the human gastric cancer cells. METHODS: Cell proliferation was evaluated by WST-1 assay while cell cycle analysis was carried out by flow cytometry. The effects on cell migration and invasion were evaluated by wound healing assay and transwell assays, respectively. Electron microscopy and western blot methods were used to study effects on autophagy and ERK1/2/MAPK signalling pathway. RESULTS: The results showed that Phloretin inhibited the proliferation rate of the human SNU-1 gastric cancer cells and showed an IC50 of 18 µM. However, Phloretin showed very high IC50 (80 µM) against the normal GES-1 normal gastric cells. Electron microscopy showed that Phloretin triggered autophagy in the SNU-1 gastric cancer cells which was accompanied by enhancement in the expression of LC3B II and Beclin 1. Cell cycle analysis showed that Phloretin caused accumulation of the SNU-1 cells in the G0/G1 phase of the cell cycle triggering G0/G1 cell cycle arrest. The G0/G1 arrest of SNU-1 cells was also associated with depletion of cyclin D1 and D2 expression. Wound healing and transwell assays showed that Phloretin suppressed the migration of the SNU-1 gastric cancer cells, suggestive of the anti-metastatic potential of this molecule. Finally, this molecule also blocked the ERK1/2/MAPK signalling pathway in SNU-1 cells in a concentration-dependent manner. CONCLUSIONS: Phloretin may prove beneficial as a promising drug candidate for gastric cancer treatment provided further studies are carried out on it, especially toxicological studies.

miR-519 inhibits epithelial-mesenchymal transition and biologic behavior of gastric cancer cells by down-regulating FOXQ1.

In recent years, a number of studies have shown that forkhead box Q1 (FOXQ1) plays an important role in the process of epithelial-mesenchymal transition (EMT) of tumors. The aim of this study is to investigate the biologic functions of FOXQ1 and miR-519 in gastric cancer. It was found that FOXQ1 was highly expressed in gastric cancer cells and tumor tissues, and promoted proliferation, migration, invasion, and EMT of gastric cancer cells. miR-519 was weakly expressed in both gastric cancer tissues and gastric cancer cells, up-regulation of miR-519 inhibited the biologic behavior of gastric cancer cells, while down-regulation of miR-519 showed the opposite results. Additionally, miR-519 directly targeted FOXQ1 and inhibited FOXQ1 mRNA and protein expression. Overexpression of FOXQ1 in gastric cancer cells reversed the inhibitory effect of miR-519 on cellular biologic behavior. The results of the present study suggest that the abnormal expression of miR-519 and FOXQ1 may be closely related to gastric cancer development, and miR-519 may play an important role in suppressing tumor related genes in gastric cancer by targeting and regulating FOXQ1.