Animal Model Of Gastric Cancer Research Articles

Naringenin-Loaded Bovine Serum Albumin Nanoparticles Inhibit Reactive Oxygen Species (ROS) to Prevent Ulcer and Gastric Cancer

Gastric cancer is a malignance of digestive system and effective treatment measures are key to treatment of gastric cancer. In this experiment, we assessed the effect of bovine serum albumin nanoparticle (BASNP)-coated naringenin (NGN) on reactive oxygen species (ROS) in gastric cancer. After preparation of NGN-BASNP and animal model of gastric cancer, rats were administered with NGN-BASNP, ROS agonists and ROS inhibitors, when the model group was set. After one week of intervention, gastric ulcers in rats were measured and Hematoxylin-eosin (HE) staining was performed. Transwell chamber was used to detect cell invasion ability, while 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) was detected proliferation ability of gastric cancer cells. Real Time Quantitative Polymerase Chain Reaction (RT-qPCR) and Western blot determined TNF-α mRNA expression and ROS. With about 100 nm diameter of NGN-BASNP nanoparticles, the nanoparticles presented in good shape. Compared with lesions in the model group, NGN-BASNP treatment greatly improved the condition, relieving the ulcer and decreasing the ulcer area (P < 0.05). After adding ROS agonist, inhibitory effect of NGN-BASNP intervention was amplified (P < 0.01) when the ROS level in the NGN-BASNP+ROS agonist group was decreased and TNF-α expression decreased. Moreover, NGN-BASNP effectively suppressed gastric cancer cell proliferation and migration but induced apoptosis. NGN-BASNP inhibited the expression of TNF-α mRNA and ROS level in gastric cancer cells, thereby alleviating gastric ulcer and delaying gastric cancer cell growth.

The ketogenic diet could improve the efficacy of curcumin and Oldenlandia diffusa extract in the treatment of gastric cancer by increasing miR340 expression and apoptosis mediated by autophagy, oxidative stress, and angiogenesis.

The pathogenesis of gastric cancer is a multistage process that involves glucose metabolism, inflammation, oxidative damage, angiogenesis, autophagy, and apoptosis. Moreover, microRNA-340 (miR340) also plays a vital role in tumorigenesis and the biology of gastric cancer as an epigenetic factor. It seems that the use of ketogenic diets (KDs) and plant extracts that have antitumor, anti-inflammatory, and antioxidant properties can be good treatment options to cure gastric cancer. The aim of this study was to investigate the role of miR-340 on pathways involved in the pathogenesis of gastric cancer and the improving effects of the KD, Oldenlandia diffusa extract (ODE), and curcumin in the animal model of gastric cancer. One hundred and ten male Wistar rats were divided into control and treatment groups. The expression of miR-340 along with genes involved in inflammation, oxidative damage, angiogenesis, and apoptosis were assessed. The results showed that the KD and different doses of curcumin and ODE in a dose-dependent behavior could induce apoptosis and the expression of the Akt/mTORC1 pathway and inhibit inflammation, oxidative damage, and angiogenesis in the gastric tissue of rats with cancer. In addition, there was no significant difference between cancer groups receiving ODE and curcumin. These results also showed that consumption of KD could significantly increase the efficacy of ODE and curcumin which may be due to increasing miR-340 expression. The results of this study suggested well that the KD along with conventional therapies in traditional medicine can be a useful solution for the prevention and treatment of gastric cancer. PRACTICAL APPLICATIONS: Gastric cancer is the third leading cause of cancer death, and genetic and epigenetic factors, including miR-340, are involved in its pathogenesis. However, the use of ketogenic diets (KDs) and plant products such as curcumin and Oldenlandia diffusa extract (ODE) can play an effective role in inhibiting tumorigenesis in some cancers. Our results showed that the KD and different doses of curcumin and ODE could induce apoptosis and the expression of the Akt/mTORC1 pathway and inhibit inflammation, oxidative damage, and angiogenesis in the gastric tissue. Moreover, the KD could significantly increase the efficacy of ODE and curcumin which may be due to an increase in miR-340 expression. These findings provide novel perceptions about the mechanisms of the KD, curcumin, and ODE to cure gastric cancer. It suggested that the KD as adjunctive therapy along with conventional therapies in traditional medicine could be considered a useful solution to prevent and treat gastric cancer.

Patient-Derived Xenograft: A More Standard "Avatar" Model in Preclinical Studies of Gastric Cancer.

Despite advances in diagnosis and treatment, gastric cancer remains the third most common cause of cancer-related death in humans. The establishment of relevant animal models of gastric cancer is critical for further research. Due to the complexity of the tumor microenvironment and the genetic heterogeneity of gastric cancer, the commonly used preclinical animal models fail to adequately represent clinically relevant models of gastric cancer. However, patient-derived models are able to replicate as much of the original inter-tumoral and intra-tumoral heterogeneity of gastric cancer as possible, reflecting the cellular interactions of the tumor microenvironment. In addition to implanting patient tissues or primary cells into immunodeficient mouse hosts for culture, the advent of alternative hosts such as humanized mouse hosts, zebrafish hosts, and in vitro culture modalities has also facilitated the advancement of gastric cancer research. This review highlights the current status, characteristics, interfering factors, and applications of patient-derived models that have emerged as more valuable preclinical tools for studying the progression and metastasis of gastric cancer.

Chemopreventive Effects of Dietary Isothiocyanates in Animal Models of Gastric Cancer and Synergistic Anticancer Effects With Cisplatin in Human Gastric Cancer Cells.

Naturally occurring isothiocyanates (ITCs) from edible vegetables have shown potential as chemopreventive agents against several types of cancer. The aims of the present study were to study the potential of ITCs in chemoprevention and in potentiating the efficacy of cytotoxic drugs in gastric cancer treatment. The chemoprevention was studied in chemically induced mouse model of gastric cancer, namely N-methyl-N-nitrosourea (MNU) in drinking water, and in a genetically engineered mouse model of gastric cancer (the so-called INS-GAS mice). The pharmacological effects of ITCs with or without cisplatin were studied in human gastric cell lines MKN45, AGS, MKN74 and KATO-III, which were derived from either intestinal or diffused types of gastric carcinoma. The results showed that dietary phenethyl isothiocyanate (PEITC) reduced the tumor size when PEITC was given simultaneously with MNU, but neither when administrated after MNU nor in INS-GAS mice. Treatments of gastric cancer cells with ITCs resulted in a time- and concentration-dependent inhibition on cell proliferation. Pretreatment of gastric cancer cells with ITCs enhanced the inhibitory effects of cisplatin (but not 5-fluorouracil) in time- and concentration-dependent manners. Treatments of gastric cancer cells with PEITC plus cisplatin simultaneously at different concentrations of either PEITC or cisplatin exhibited neither additive nor synergetic inhibitory effect. Furthermore, PEITC depleted glutathione and induced G2/M cell cycle arrest in gastric cancer cells. In conclusion, the results of the present study showed that PEITC displayed anti-cancer effects, particularly when given before the tumor initiation, suggesting a chemopreventive effect in gastric cancer, and that pretreatment of PEITC potentiated the anti-cancer effects of cisplatin, possibly by reducing the intracellular pool of glutathione, suggesting a possible combination strategy of chemotherapy with pretreatment with PEITC.

Circular RNA circAFF2 accelerates gastric cancer development by activating miR-6894-5p and regulating ANTXR 1 expression

BackgroundCircular RNAs (circRNAs) contain a new class of non-coding RNAs that play an important role in adjusting biological function and gene expression. But the function of circRNAs in gastric cancer remains unclear. In the present research, we explored the functions of circular RNA AFF2(circAFF2, hsa_circ_0001947) in gastric cancer cells and an animal model of gastric cancer. MethodsThe expression of circAFF2, microRNA-6894-5p (miR-6894-5p), and Anthrax toxin receptor 1 (ANTXR 1) were determined by quantitative reverse transcription polymerase chain reaction (qRT-PCR). Cell counting kit 8 (CCK-8) and transwell assays were used to analyze the knockdown effects of circAFF2, miR-6894-5p, and overexpression of ANTXR 1 on cell proliferation, migration, and invasion abilities. Binding interactions between, circAFF2 and miR-6894-5p and between, miR-6894-5p and ANTXR 1 were detected by Dual-luciferase reporter assays. Levels of protein expression were analyzed by Western blotting. Tumor models were established by subcutaneous injection of tumor cells in nude mice. ResultThe result showed that circAFF2 expression was significantly increased in gastric cancer cell lines and tissues. The knockdown of circAFF2 dramatically suppressed the cell migration, invasion and proliferation of gastric cancer cells. In vivo studies showed that knockdown of circAFF2 delayed tumor growth. Furthermore, we revealed that circAFF2 functioned as a sponge to absorb miR-6984-5p and elevated the expression of ANTXR 1. ConclusionCircAFF2 acts as an oncogene in gastric cancer and exerts its effects via miR-6894-5p/ANTXR 1 signaling.

The effects of hypoxia on mitochondrial function and metabolism in gastric cancer cells.

BackgroundA number of studies have found that metabolic disorders are the characteristic manifestations of tumor cells. However, the effects of hypoxic environment on mitochondrial function and glucose metabolism of tumor cells were still unclear. The study wanted to explore the regulatory mechanism of hypoxic environment on mitochondrial function and metabolism in gastric cancer cells.MethodsThe animal model of gastric cancer and MKN45 were treated in a hypoxic environment. Mitochondrial membrane potential and reactive oxygen species (ROS) levels were analyzed by flow cytometry, qPCR was used to detect the expression levels of glycose metabolism key enzymes, damage repair genes and mitochondrial DNA (mtDNA) copy numbers in gastric cancer.ResultsCompared with 2,000 m normal gastric cancer tissue, the decreased of mitochondrial membrane potential and the production of ROS reduced, the expressions of glucose metabolism genes [the M1 isoform of Hexokinase (HK1), pyruvate kinase (PKM), Succinate dehydrogenase (SDHA), Glucose-6-phosphate dehydrogenase (G6PD)], homologous recombination repair gene (RAD51) and repair DNA double-stranded broken gene (ASTCT2) increased, and aerobic respiration reduced in gastric cancer cells. In the hypoxic environment, the decreased of mitochondrial membrane potential reduced, the production of ROS and mtDNA copies increased, HK1 expression increased, the expressions of SDHA, G6PD, RAD51 and ASCT-2 decreased, and the aerobic respiration decreased.ConclusionsHypoxia plays an important role in maintaining mitochondrial functions in gastric cancer cells by promoting glycolysis and inhibiting mitochondrial aerobic respiration capacity.

Inhibitory effect of endostar combined with radiotherapy on gastric cancer animal models

BackgroundInhibitory effect of endostar combined with radiotherapy on gastric cancer (GC) animal models and its effect on transforming growth factor-β1 (TGF-β1) and inter-leukin-10 (IL-10) were evaluated.MethodsForty mice of GC model xenograft tumors were prepared and randomly divided into blank control group, endostar group, radiotherapy group, and endostar combined with radiotherapy group (combination group). From the 14th day, a vernier caliper was used for measuring the long and short diameters of the xenograft tumors. The formula V = ab2/2 was used for calculating the tumor volume and to obtain its average value. Tumor growth curves were plotted to calculate the tumor inhibition rate. The growth of xenograft tumors and the behavioral changes of mice were observed. Enzyme-linked immunosorbent assay (ELISA) was used for detecting the expression levels of IL-10 and TGF-β1.ResultsThe tumor growth in the combination group was significantly inhibited, and the tumor volume was the smallest compared with the other groups (p < 0.05). Compared to the blank control group, the tumor inhibition rate was 11.8% in endostar group, 33.0% in radiotherapy group, and 52.1% in combination group (p < 0.01). Endostar combined with radiotherapy had an interaction in decreasing the expression levels of TGF-β1 and IL-10 (F = 4.35 and 5.12, p < 0.05). Leucocyte count was significantly higher in control and combination groups than that in endostar and radiotherapy groups. The body weight of mice in endostar and radiotherapy groups decreased after treatment (p < 0.05). The body weight of mice after treatment in control and combination groups increased, with a statistically significant difference compared to that before treatment (p < 0.05). There was a statistically significant difference among all groups after treatment (F = 198.1, p < 0.01).ConclusionsEndostar combined with radiotherapy can inhibit tumor growth and downregulate the expression levels of TGF-β1 and IL-10 through synergistic action.

Expression profile and co-expression analysis of ADH1A in human solid tumors.

e13533 Background: The human alcohol dehydrogenase (ADH) gene family is associated with various solid cancers. It seems that the ADH1 gene cluster plays an important role in various solid tumors, so it aroused our interest in studying these genes to find out their functions and biological process within different solid tumors. Methods: Paired tumor and normal tissues gathered from 38 tumor patients, and 5 male BALB/c mice tissues were collected and Immunohistochemistry (IHC) assay was performed. The expression of ADH1A at RNA level in normal tissues and pan-solid tumors and the main functions of ADH1A in different solid tumors were analyzed by Bioinformatics mining. Results: At the RNA level, ADH1A was highly expressed in normal hepatocytes and was expressed lower in the tumor tissues than in the adjacent normal tissues or the corresponding normal tissues, suggesting the At the protein level, ADH1A was expressed to varying degrees in human alveoli, kidney, stomach, colon, and rectum. We predicted three major conserved functions of ADH1A, including angiogenesis, cell adhesion, and leukocyte migration function which might influence the prognosis of the immunotherapy and the immune response, and constructed an upstream regulation network of ADH1A and a downstream protein network. Besides, we also explored the functional differences of ADH1A in lung adenocarcinoma and lung squamous cell carcinoma and its effect on overall survival. And for investigating ADH1A, the BALB/c mice might be an option to consider in constructing an animal model of gastric cancer (GC), esophageal carcinoma (ESCA), liver hepatocellular carcinoma (LIHC), and pancreatic adenocarcinoma (PAAD). Conclusions: ADH1A has potential diagnostic and prognostic value in various solid tumors. Our findings highlight new avenues for further investigation of ADH1A biology process and provide a novel potential prognostic biomarker of immunotherapy.

Knockdown of serine/threonine-protein kinase 24 promotes tumorigenesis and myeloid-derived suppressor cell expansion in an orthotopic immunocompetent gastric cancer animal model.

A higher incidence of gastric cancer has been found in East Asia compared to the incidence in other regions. Gastric cancer patients have a poor prognosis due to distant metastasis and advanced cancer stages. Tumor escape pathways include the expansion of the immunosuppressive myeloid-derived suppressor cells (MDSCs) in the tumor microenvironment. We have successfully established an orthotopic immunocompetent gastric cancer model in C57BL/6 mice. The cell line is named M12 and was deposited at the Bioresource Collection and Research Center of Taiwan on Sep. 13, 2016 (Patent No. I604054). The orthotopic animal model of gastric cancer has similar biological characteristics as human gastric cancer. Serine/threonine-protein kinase 24 (STK24) is a member of the germinal center kinase (GCK)-III family. GCKs participate in cancer and immunological disorders. The effects of STK24 in gastric cancer are less well understood. CRISPR (clustered regularly interspaced short palindromic repeats)/Cas9 technology was used to induce a STK24 genetic knockout at the genomic DNA level in tumor cells. The knockdown of the STK24 gene increased the tumor growth in an orthotopic model of gastric cancer. The STK24 gene silencing in tumors induced the expansion of CD11b+Ly6C+ cells and F4/80+ macrophages in vivo. To our knowledge, we have developed the first orthotopic transplantable model of gastric cancer in syngeneic inbred mice. Our results further indicate that STK24 is important for immune regulation during the tumorigenesis of gastric cancer.

Diagnosis: gastric intestinal metaplasia - what to do next?

One of the most vexing problems for gastroenterologists is what actions to take after receiving a histological diagnosis of gastric intestinal metaplasia. We approach the problem by starting with suggesting a biopsy protocol that ensures obtaining the biopsies required for diagnosis, assessing the status of the gastric mucosa, and effective communication with the pathologist and patient. The rediscovery and integration of the long history of gastric damage and repair resulting in pseudopyloric metaplasia (called SPEM) into the thinking of investigators working with animal models of gastric cancer has resulted in improved ability to separate changes associated with benign repair from those associated with inflammation-associated gastric carcinogenesis. Gastric intestinal metaplasia is a potential reversible product of injury and repair and not directly connected with carcinogenesis. Intestinal metaplasia is a biomarker for prior gastric injury and repair. The risk of gastric cancer is best assessed in relation to the severity, extent, and, most importantly, the cause of the atrophic changes.

Elevated levels of hsa_circ_006100 in gastric cancer promote cell growth and metastasis via miR-195/GPRC5A signalling.

ObjectivesCircular RNAs (circRNAs) are non‐coding RNAs, some of which are thought to be involved in gastric cancer development. Here, we examined the functions of circRNA hsa_circ_006100 in gastric cancer cells and an animal model of gastric cancer.Materials and MethodsThe expression of hsa_circ_006100, miR‐195 and various functional genes was determined by quantitative RT‐PCR. Cell viability, clone formation, apoptosis and cell migration/invasion abilities were analysed by the CCK‐8 assay, crystal violet staining, Hoechst staining and Transwell assay, respectively. A tumour model was established by subcutaneously injecting tumour cells into nude mice. Levels of protein expression were analysed by Western blotting and immunohistochemistry.ResultsA bioinformatics analysis showed that miR‐195 was negatively co‐expressed with hsa_circ_006100. Patients with a high hsa_circ_006100 level or low miR‐195 level had tumours with a high TNM stage, poor cellular differentiation and lymph node metastasis. miR‐195 was targeted and inhibited by hsa_circ_006100. Overexpression of hsa_circ_006100 enhanced cellular viability and proliferation, while miR‐195 suppressed hsa_circ_006100‐enhanced cell growth and induced apoptosis in MGC‐803 and AGS cells. Forced hsa_circ_006100 expression promoted the migration and invasion of MGC‐803 and AGS cells, while those activities were inhibited by miR‐195. Mechanistically, GPRC5A was predicted as a target of miR‐195 and was upregulated in gastric cancer. A miR‐195 inhibitor restored cell viability, proliferation, migration and invasion, and repressed apoptosis via GPRC5A. In vivo studies showed that knockdown of hsa_circ_006100 delayed tumour growth, reduced PCNA expression and upregulated miR‐195 and BCL‐2 expression which was restored by miR‐195 inhibition due to GPRC5A/EGFR signalling, and changed the EMT phenotype in vivo.ConclusionsHsa_circ_006100 functions as an oncogene in gastric cancer and exerts its effects via miR‐195/GPRC5A signalling.

Tu1156 – Evaluation of Serum Tff3 Levels in Gastric Cancerpatients Long After Gastrectomy and the Origin of High Serum Tff3 in Gastric Cancer Animal Models

Tu1156 – Evaluation of Serum Tff3 Levels in Gastric Cancerpatients Long After Gastrectomy and the Origin of High Serum Tff3 in Gastric Cancer Animal Models

Impact factors that modulate gastric cancer risk in Helicobacter pylori-infected rodent models.

Gastric cancer causes a large social and economic burden to humans. Helicobacter pylori (Hpylori) infection is a major risk factor for distal gastric cancer. Detailed elucidation of Hpylori pathogenesis is significant for the prevention and treatment of gastric cancer. Animal models of Hpylori-induced gastric cancer have provided an invaluable resource to help elucidate the mechanisms of Hpylori-induced carcinogenesis as well as the interaction between host and the bacterium. Rodent models are commonly used to study Hpylori infection because Hpylori-induced pathological processes in the stomachs of rodents are similar to those in the stomachs of humans. The risk of gastric cancer in Hpylori-infected animal models is greatly dependent on host factors, bacterial determinants, environmental factors, and microbiota. However, the related mechanisms and the effects of the interactions among these impact factors on gastric carcinogenesis remain unclear. In this review, we summarize the impact factors mediating gastric cancer risk when establishing Hpylori-infected animal models. Clarifying these factors and their potential interactions will provide insights to construct animal models of gastric cancer and investigate the in-depth mechanisms of Hpylori pathogenesis, which might contribute to the management of Hpylori-associated gastric diseases.

Inhibitory effects of human epidermal growth factor receptor-2-single-chain antibody on human epidermal growth factor receptor-2 positive tumors

Objective To study the inhibitory effect of single-chain antibody (scFv) against human epidermal growth factor receptor-2 (Her-2) on tumor cell T6-17 proliferation. To investigate the potential of Her-2-scFv protein targeted therapy of Her-2 positive tumors. Methods In our study, Her-2-scFv gene fragment was amplified from plasmid pUC57-Her-2-scFv by polymerase chain reaction (PCR). Then Her-2-scFv gene fragment was cloned into the prokaryotic expression vector pET28a though double enzyme, and get the recombinant plasmid pET28a-Her-2-scFv. Plasmid pET28a-Her-2-scFv was transformed into Rosetta of E. coli. Her-2-scFv protein successful expression was detected by Western blotting. Her-2 positive tumor cell T6-17 proliferation inhibition were tested by methyl thiazol tetrazolium (MTT) assay. The tumor volume was measured by animal model of gastric cancer in vivo test. Results Her-2-scFv gene fragments were received by PCR successfully. Location of Her-2-scFv gene and its sequence in recombinant plasmid pET28a-Her-2-scFv is in a right direction by gene sequencing. MTT assay showed that the growth inhibition ratio of Her-2-positive tumor cell T6-17 in Her-2-scFv group was 33.52%, trastuzumab treatment group was 34.79%, with no statistic significance between them (P=0.429). Compared with the negative control group (PBS group), the differences were statistically significant (P=0.000). In vivo experiments: The inhibiting tumor rates of 100 ng/kg group, 250 ng/kg group, 500 ng/kg group were 33.7%, 27.2%, 63.3%, separately. Compared with the control group, the difference were statistically significant (P=0.027, 0.035, 0.000). In Hessaitin group, the inhibition rate was 70.2%, compared with 500 ng/kg group, there was no statistically significant difference (P=0.643). Conclusion Her-2-scFv protein can inhibit the proliferation of T6-17 positive tumor cells in vitro and in vivo. Key words: Human epidermal growth factor receptor-2; Single-chain antibody; Tumor cell T6-17

Abstract B14: Discoidin domain receptor 1 activity drives an aggressive phenotype in gastric adenocarcinoma

Abstract Purpose: Stromal content in gastric cancer patients inversely correlates with outcome. However, underlying molecular mechanisms for these clinical observations have not been determined. Here, we investigated the contribution of the collagen receptor, discoidin domain receptor-1 (DDR1), in the aggressive phenotype of gastric cancer induced by tumor stroma. Experimental Design: We conducted immunohistochemical analyses with a tissue microarray of 217 gastric cancer specimens. We examined the effect of collagen-induced activation of DDR1 on cell signaling, tumorigenesis and cell migration in gastric cancer, and evaluated the effects of DDR1 inhibition in organotypic culture and xenograft animal models of gastric cancer. Results: High DDR1 expression in gastric cancer tissue significantly correlated with poor prognosis. Gastric cancer patients were classified into two groups based on the stromal collagen and the expression of DDR1 was significantly associated with cancer invasion and lymph node metastasis in the collagen-positive group. Decreased expression of E-cadherin was associated with cancer progression in the collagen and DDR1 positive groups. We also demonstrated that collagen activated DDR1 and increased clonogenicity and cell migration. Importantly, we demonstrated that a DDR1 inhibitor, 7rh benzamide, reduced the invasiveness of gastric cancer in organotypic culture system and suppressed tumor growth in gastric cancer xenografts. Conclusions: Taken together, these findings suggest that collagen enhances the aggressive phenotype of gastric cancer through the DDR1 signaling pathway and that inhibition of DDR1 is an attractive candidate for the therapy of aggressive gastric cancer. Citation Format: Hoon Hur, In-hye Ham, Da Keun Lee, Hye-Jin Jin, Aguilera Kristina Y., Hae Jeong Oh, Sang-Uk Han, Ji-Eun Kwon, Young Bae Kim, Ke Ding, Rolf Brekken. Discoidin domain receptor 1 activity drives an aggressive phenotype in gastric adenocarcinoma. [abstract]. In: Proceedings of the AACR Special Conference: Function of Tumor Microenvironment in Cancer Progression; 2016 Jan 7–10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2016;76(15 Suppl):Abstract nr B14.

3-bromopyruvate and sodium citrate target glycolysis, suppress survivin, and induce mitochondrial-mediated apoptosis in gastric cancer cells and inhibit gastric orthotopic transplantation tumor growth.

Glycolysis is the primary method utilized by cancer cells to produce the energy (adenosine triphosphate, ATP) required for cell proliferation. Therefore, inhibition of glycolysis may inhibit tumor growth. We previously found that both 3-bromopyruvate (3-BrPA) and sodium citrate (SCT) can inhibit glycolysis in vitro; however, the underlying inhibitory mechanisms remain unclear. In the present study, we used a human gastric cancer cell line (SGC-7901) and an orthotopic transplantation tumor model in nude mice to explore the specific mechanisms of 3-BrPA and SCT. We found that both 3-BrPA and SCT effectively suppressed cancer cell proliferation, arrested the cell cycle, induced apoptosis, and decreased the production of lactate and ATP. 3-BrPA significantly reduced the glycolytic enzyme hexokinase activity, while SCT selectively inhibited phosphofructokinase-1 activity. Furthermore, 3-BrPA and SCT upregulated the expression of pro-apoptotic proteins (Bax, cytochrome c, and cleaved caspase-3) and downregulated the expression of anti-apoptotic proteins (Bcl-2 and survivin). Finally, our animal model of gastric cancer indicated that intraperitoneal injection of 3-BrPA and SCT suppressed orthotopic transplantation tumor growth and induced tumor apoptosis. Taken together, these results suggest that 3-BrPA and SCT selectively suppress glycolytic enzymes, decrease ATP production, induce mitochondrial-mediated apoptosis, downregulate survivin, and inhibit tumor growth. Moreover, an intraperitoneal injection is an effective form of administration of 3-BrPA and SCT.

Effect of BRMS1 expression on proliferation, migration and adhesion of mouse forestomach carcinoma.

To discuss the effect of BRMS1 on the proliferation, migration and adhesion of mouse forestomach carcinoma. The constructed pCMV-myc-BRMS1 recombinant plasmid and blank plasmid were transfected into mouse forestomach carcinoma. MTT method was employed to measure the activity of gastric cancer cell; the scratch assay and Transwell assay to measure the migration and invasion of gastric cancer cell; the adhesion assay to measure the adhesion of gastric cancer cell; while the Western blot assay to measure the expression of The NF-κB signal pathway, downstream matrix metalloproteinase (MMP)-2, MMP-9 and osteopontin and E-cadherin in the gastric cancer cell. Besides, the transplanted animal model of gastric cancer in mice was constructed to measure the size of tumor xenograft. Results of MTT assay showed that, compared with the empty vector control group, the activity of gastric cancer cell was not affected in the BRMS1 transfection group. The improved expression of BRMS1 could inhibit the adhesion, migration and invasion of gastric cancer cell (P<0.01). Besides, compared with the empty vector control group, the phosphorylation of NF-κB p65 and IκBα was reduced in the BRMS1 transfection group, with the decreased expression of MMP-2, MMP-9 and osteopontin and the increased expression of E-cadherin (P<0.01). Results of animal experiment also showed that the expression of BRMS1 did not affect the transplanted tumor. The expression of BRMS1 can significantly inhibit the adhesion, migration, invasion and metastasis of mouse forestomach carcinoma gastric cancer cell, which is related to The NF-κB signal pathway.

3-Bromopyruvate inhibits human gastric cancer tumor growth in nude mice via the inhibition of glycolysis.

Tumor cells primarily depend upon glycolysis in order to gain energy. Therefore, the inhibition of glycolysis may inhibit tumor growth. Our previous study demonstrated that 3-bromopyruvate (3-BrPA) inhibited gastric cancer cell proliferation in vitro. However, the ability of 3-BrPA to suppress tumor growth in vivo, and its underlying mechanism, have yet to be elucidated. The aim of the present study was to investigate the inhibitory effect of 3-BrPA in an animal model of gastric cancer. It was identified that 3-BrPA exhibited strong inhibitory effects upon xenograft tumor growth in nude mice. In addition, the antitumor function of 3-BrPA exhibited a dose-effect association, which was similar to that of the chemotherapeutic agent, 5-fluorouracil. Furthermore, 3-BrPA exhibited low toxicity in the blood, liver and kidneys of the nude mice. The present study hypothesized that the inhibitory effect of 3-BrPA is achieved through the inhibition of hexokinase activity, which leads to the downregulation of B-cell lymphoma 2 (Bcl-2) expression, the upregulation of Bcl-2-associated X protein expression and the subsequent activation of caspase-3. These data suggest that 3-BrPA may be a novel therapy for the treatment of gastric cancer.

Establishment of Mongolian gerbil model of gastric cancer induced by Helicobacter pylori infection and its proteomics analysis

To establish an animal model of gastric cancer by long-term infection of Helicobacter pylori (H.pylori) and to elucidate the pathogenesis by proteomics analysis. Fifty male Mongolian gerbils (4-5 week-old and weighted 60-100 g) were infected with H.pylori and the gastric tissues were obtained after the infection at 3, 6, 12 and 24 months. Histological changes were evaluated by H-E staining of the gastric tissue sections. Detection of H.pylori was performed by in-vitro culture of fresh gastric tissue samples, PCR amplification of H.pylori 16s rRNA and localization by silver staining. In addition, proteins extracted from gastric tissue samples were subjected to two-dimensional electrophoresis (2-DE) at various infection time points. Protein spots with increased quantity over the course of H.pylori infection were selected and analyzed by LC-MS/MS. Finally, differentially expressed proteins between human gastric cancer tissue samples and lymph nodes were analyzed by real-time RT-PCR. Colonization of H.pylori was observed in gastric tissue of gerbils as early as 3 months after H.pylori infection, and persisted till 24 months. Pathological examination of infected animals showed various histological changes including acute gastritis, atrophic gastritis, intestinal metaplasia and gastric carcinoma. Seventy-eight differentially expressed proteins were identified by proteomics analysis, among which 36 proteins were up-regulated and 42 were down-regulated. Analyzed by LC-MS/MS, ten proteins were identified, including lactate dehydrogenase, ATP synthase, fatty acid-binding protein, COX5B, peroxiredoxin-4, peroxide reductase, transgelin, succinyl-CoA ligase, keratin and protein disulfide-isomerase A2, among which transgelin, ATP synthase and lactate dehydrogenase were highly expressed in human gastric carcinoma and lymph nodes. H.pylori infection induces the expression of transgelin, ATP synthase and lactate dehydrogenase, implying possible roles in the pathogenesis of gastric diseases including cancer.

Effect of brachytherapy on NF-κB and VEGF in gastric carcinoma xenografts.

Iodine-125 (125I) seed irradiation can be used as an important supplementary treatment for unresectable advanced gastric cancer. However, the radiobiological mechanism underlying brachytherapy remains unclear. Therefore, we investigated the influence of continuous and low-energy 125I irradiation on the cell cycle distribution, apoptosis, expression of NF-κB and VEGF and tumor growth in a human gastric cancer xenograft model. To create an animal model of gastric cancer, SGC-7901 cells were surgically implanted into mice. The 60 mice bearing SGC-7901 gastric cancer xenografts were randomly separated into 2 groups. Sham seeds (0 mCi) were implanted into the control group (n=30); 125I seeds (0.6 mCi) were implanted into the treatment group (n=30). At 28 days after irradiation, apoptosis was detected by flow cytometry. fluorescence micrograph detected intense VEGF and NF-κB immunofluorescence in the tumor samples, and changes in NF-κB and VEGF mRNA and protein expression were assessed by real-time PCR and western blot analysis, respectively. The tumor volume and weight were measured 0-28 days after 125I seed implantation. 125I seed irradiation induced significant apoptosis and G2/M phase arrest. Reduction in the intensities of VEGF and NF-κB immunofluorescence in tumor vessels was observed after treatment. NF-κB and VEGF mRNA and protein expression levels were substantially lower in the implantation treatment group than in the control group. Consequently, 125I seed implantation inhibited cancer growth and reduced cancer volume. The present study revealed that 125I seed irradiation significantly induced apoptosis and cell cycle arrest in the human gastric cancer xenografts. 125I-induced changes in NF-κB and VEGF expression are suggested as potential mechanisms underlying effective brachytherapy.