Human Gastric Cancer SGC-7901 Research Articles

Activation of hypermethylated P2RY1 mitigates gastric cancer by promoting apoptosis and inhibiting proliferation.

The P2RY1 receptor is known to cause cancer by activating the ERK signal pathway, and its DNA methylation status and corresponding regulatory mechanism remain unknown. This study used the DNA methylation chip to profile the genome-wide DNA methylation level in gastric cancer tissues. The proliferation and apoptosis of the SGC7901 gastric cancer cell line were determined after treatment with a selective P2RY1 receptor agonist, MRS2365. The promoter region of P2RY1 was found to be highly methylated with four hypermethylated sites (|Δβ value| > 0.2) in diffuse gastric cancer and was validated by bioinformatics analysis in the TCGA database. Also, immunohistochemical staining data obtained from the HPA database demonstrated the downregulated expression of proteins encoded by P2RY1 in stomach cancer tissue. The analysis of MRS2365-treated cells by annexin V/propidium iodide staining and caspase-3 activity assays indicated the induction of apoptosis in SGC7901 cells. The P2RY1 receptor activation in human SGC7901 gastric cancer cells via the MRS2365 agonist induced apoptosis and reduced cell growth. High DNA methylation in the promoter region of P2RY1 might have contributed to the reduced expression of P2RY1's mRNA, which was likely responsible for the "aggressive" nature of the diffuse gastric cancer.

Licoflavone A Suppresses Gastric Cancer Growth and Metastasis by Blocking the VEGFR-2 Signaling Pathway.

Objectives Licoflavone A (LA) is a natural flavonoid compound derived from the root of Glycyrrhiza. This study investigated the antitumor effect and underlying molecular mechanisms of LA against gastric cancer (GC) in vitro and in vivo. Materials and Methods A CCK8 assay was used to measure the antiproliferative activity of LA in human GC SGC-7901, MKN-45, MGC-803 cells, and human GES-1 cells. Target prediction and protein-protein interaction (PPI) analysis were used to identify the potential molecular targets of LA. The binding pattern of LA to VEGFR-2 was analyzed by molecular docking and molecular dynamic (MD). The affinity of LA for VEGFR-2 was determined by microscale thermophoresis (MST). The protein tyrosine kinase activity of VEGFR-2 in the presence of LA was determined by an enzyme activity test. The effect of LA on the proliferation of VEGF-stimulated MKN-45 cells was measured with CCK8 assays, clone formation assays, and 3D microsphere models. Hoechst 33342 staining, FCM, MMP, and WB assays were used to investigate the ability of LA to block cell cycle and promote apoptosis of VEGF-stimulated MKN-45 cells. Transwell matrix assays were used to measure migration and invasion, and WB assays were used to measure EMT. Results LA inhibited the proliferation of SGC-7901, MKN-45, and MGC-803 cells and VEGF-stimulated MKN-45 cells. VEGFR-2 was identified as the target of LA. LA could also block cell cycle, induce apoptosis, and inhibit migration, invasion, and EMT of VEGF-stimulated MKN-45 cells. Functional analyses further revealed that the cytotoxic effect of LA on VEGF-stimulated MKN-45 cells potentially involved the PI3K/AKT and MEK/ERK signaling pathways. Conclusions This study demonstrates that LA has anti-GC potency in vitro and in vivo. LA affects the proliferation, cycle, apoptosis, migration, invasion, and EMT by targeting VEGFR-2 and blocks the PI3K/AKT and MEK/ERK signaling pathways in VEGF-stimulated MKN-45 cells.

Analysis of Peganum harmala, Melia azedarach and Morus alba extracts against six lethal human cancer cells and oxidative stress along with chemical characterization through advance Fourier Transform and Nuclear Magnetic Resonance spectroscopic methods towards green chemotherapeutic agents

Traditional medicines implicate consumption of plant crude extracts, which may consist of extensive phytochemical diversity. Overall, the most biologically active extract of Peganum harmala (seeds) exhibited significant cytotoxic activity on Artemia salina with LC50 value of 61.547 µg/mL, while P. harmala (roots) [LC50 = 124.229 µg/mL] and M. azedarach (fruits) [LC50 = 147.813 µg/mL] showed moderate cytotoxic potential. P. harmala (seeds) extract also showed the maximum antitumor potential with 52.278 µg/mL LC50. Branches of P. harmala and Morus alba were not active in both bioassays. These outcomes were further reinforced by the levels of phenolics and flavonoids checked against gallic acid and quercetin equivalents, respectively, by standard curves. Current study aims to isolate, structurally characterize and analyze the bioactive compound from plant extracts by using chromatographic and spectrophotometric techniques. Bioactivity guided isolation of extracts led to the isolation of PH-HM-16 from ethyl acetate fraction P. harmala seeds. Chemical structure of PH-HM-16 was elucidated by ESI-MS, 1H NMR, 13C NMR, HSQC and IR spectrum. The results demonstrated significant positive anticancer activities against six human cancer cell lines assessed through MTT cancer cell growth inhibition assay. PH-HM-16 was most effective against prostate cancer cell lines [IC50 = 17.63 µg/mL] followed by breast cancer cell line MCF7 [IC50 value of 41.81 µg/mL]. IC50 value of PH-HM-16 against human myeloid leukemia cell line HL-60 and human colorectal tumor cells HCT-116 was observed as 68.77 µg/mL and 71.54 µg/mL respectively. The IC 50 value of PH-HM-16 compound was not significant against human gastric cancer SGC-7901 (111.89 µg/mL) and human lung adenocarcinoma epithelial cell line A549 (176.04 µg/mL). Isolated bioactive metabolite PH-HM-16 possesses significant antitumor potential so this could be the first step to develop an effective anticancer agent. Hence, this compound represents a promising potential to be chemically standardized or developed into pharmaceuticals for the chemoprevention and/or the treatment of certain types of cancer, especially as adjuvant phytotherapeutics in conventional chemotherapy.

Phosphatidylethanolamine binding protein 1 enhances sensitivity of gastric cancer cell to 5-fluorouracil via inhibition of cell proliferation, migration and invasion

Purpose: To determine the association between phosphatidylethanolamine binding protein 1, which is an Raf kinase inhibitor protein (RKIP), and 5-fluorouracil (5-FU) via analysis of the association between RKIP and clinical responses in individuals treated using fluorouracil-based chemotherapy.Methods: Human gastric cancer cell lines MGC-803 and SGC-7901 were used in this study. Cell viability was measured using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. Apoptosis and migration were determined with flow cytometry and Transwell chamber assays, respectively. The mRNA and protein expressions of apoptosis-related factors were assayed using realtime polymerase chain reaction (RT-PCR) and Western blotting, respectively, while the expression of RKIP was determined by immunohistochemical staining.Results: Chemotherapeutic drug (5-FU) treatment induced low RKIP expression levels in tumorigenic GC cells, thereby sensitizing the cells to apoptosis (8.57 vs 1.25 %, p < 0.01). The highest RKIP level correlated well with initiation of apoptosis (4.20 vs 1.25 %, p < 0.01). Following in vitro downregulation of RKIP, there was increase in the viability and proliferation of RKIP-inhibited cells over time, and these changes were linked to alterations in cell cycle phases and increased optical density in MTT proliferation assay (1.55 vs 1.18, p < 0.01). In vitro Transwell assay measurement revealed an association between RKIP downregulation and enhancement of cell migration potential (652 vs 436, p < 0.01). Ectopic RKIP expression restored the apoptotic sensitivity of resistant cells (14.30 vs 1.36 %, p <0.01). This sensitization was annulled by upregulation of survival routes. Reduction of RKIP by expression of antisense and siRNA conferred resistance on cancer cells sensitive to 5-FU-mediated apoptosis (6.88 vs 2.13 %, p < 0.01).Conclusion: Thus, RKIP is a promising therapeutic strategy for improving the efficacy of clinically relevant chemotherapeutic drugs for GC.
 Keywords: Gastric cancer, Raf kinase inhibitor protein, Cell proliferation, Invasion, Apoptosis, Chemotherapy, Phosphatidylethanolamine binding protein 1

Effects of neddylation modification inhibitor MLN4924 on proliferation and migration of human gastric cancer cells

Objective To explore the effects of NEDD8 activating enzyme (NAE) inhibitor MLN4924 on gastric cancer cell proliferation and migration. Methods Human gastric cancer cell lines NCI-N87 and SGC-7901 were treated with different concentrations of MLN4924, and the inhibitory concentrations were detected by cell counting kit-8 (CCK-8) method. 20% maximal inhibitory concentration (IC20) was used to treat gastric cancer cells. The cell proliferation was measured by CCK-8 and clone formation assay, and cell migration was determined by cell scratch test. Results When human gastric cancer cell lines NCI-N87 and SGC-7901 were treated with 0.528 and 0.375 μmol/L respectively, the inhibitory rate reached to 20%. CCK-8 method showed that MLN4924 inhibited the proliferation of human gastric cells in a dose- and time-dependent manner. In the clone formation assay, the clone number of NCI-N87 cells was 71.00±10.19 in MLN4924 treated group and 215.33±9.56 in the control group. The clone number of SGC-7901 cells was 23.66±18.66 in MLN4924-treated group, and 32.33±34.12 in the control group.In vitro wound scratch assay revealed that the healing rate of MLN4924-treated NCI-N87 cells was (5.30±0.78)%, and (51.05±6.35)% in the control group, and that of MLN4924-treated SGC-7901 cells was (3.12±0.52)%, and (23.05±2.01)% in the control group. Conclusion Neddylation modification inhibitor MLN4924 suppresses the growth and migration of gastric cancer cells. Key words: Gastric cancer; Neddylation modification inhibitor; Proliferation; Migration

Effects of microRNA-155 on biological functions of gastric cancer cells and possible mechanism

Objective To discuss the deregulation expression level of microRNA (miRNA, miR)-155 in gastric cancer tissue, and its effect on the gastric cancer cell proliferation and cell biology functions such as proliferation and adhesion. Methods We performed a real-time reverse transcriptase-polymerase chain reaction in 42 cases of gastric cancer and the corresponding cancer adjacent tissues, and quantitatively determined the expression level of the miR-155. At the same time, a variety of experimental methods were used to determine whether the abnormal expression of miR-155 could inhibit or promote the viability, proliferation and invasion of the SGC-7901 cells in gastric cancer. Results As compared with normal tissues and cells, the expression of miR-155 in human gastric cancer tissues and SGC-7901 cells was decreased. The proliferation of miR-155 mimics (29.912±1.786) was significantly lower than that of the control group (34.962±1.413), and the differences were statistically significant. The cell viability test revealed that cells in the 50 nmol/L mimics transfection group (91.34±1.33) and the 100 nmol/L transfection group (84.59±1.63) showed significantly lower survival rate than normal gastric cancer cells (94.39±1.07) (P<0.05). Cell adhesion test showed that the absorbance of miR-155 mimics in each experimental group was 0.861±0.051 (30 nmol/L), 0.738±0.055 (50 nmol/L), 0.665±0.042 (80 nmol/L), 0.531±0.032 (100 nmol/L), significantly lower than that in the control group (1.098±0.054) (P<0.01). Conclusion The abnormal low expression of miR-155 may participate in the development process of gastric cancer, and enhance the vitality of gastric cancer cell proliferation and other biological characteristics to achieve the function as a recessive cancer gene. Key words: Gastric cancer; MicroRNA; MicroRNA-155; Proliferation

Hint1 expression inhibits proliferation and promotes radiosensitivity of human SGC7901 gastric cancer cells.

Gastric cancer is a prevalent, malignant tumor that frequently escapes treatment. Histidine triad nucleotide-binding protein 1 (Hint1) is a haploinsufficient tumor suppressor gene which contributes to intercellular communication, helps to regulate cell proliferation and survival, and is frequently underexpressed in gastric cancer. To examine the involvement of Hint1 in gastric cancer, small interfering RNA was used to knock down Hint1 expression in the human gastric cancer cell line SGC-7901. The data revealed that Hint1 inhibited cell proliferation, reduced radiation-induced DNA damage repair and caused G1 phase arrest, which increased the radiosensitivity of gastric cancer cells. Further mechanistic studies revealed a novel function of Hint1, whereby it acted as a negative regulator of extracellular signal-regulated kinase. These results demonstrated the critical function of Hint1 in the biology of human gastric cancer. Acting as a tumor growth suppressor and a radiosensitive agent, this protein is a potential biomarker and may be an attractive target for specific therapeutic interventions against gastric cancer.

Combined 18F-FDGPET/CT imaging and a gastric orthotopic xenograft model in nude mice are used to evaluate the efficacy of glycolysis-targeted therapy.

As discovered by Warburg 80years ago most malignant cells rely more on glycolysis than normal cells. The high rate of glycolysis provides faster ATP production and greater lactic acid for tumor proliferation and invasion, thus indicating a potential target in anticancer therapy. Our previous studies demonstrated that 3-bromopyruvate (3-BrPA) and sodium citrate (SCT) inhibited tumor cell proliferation invitro. However, the underlying mechanisms still warrant further investigation. In the present study, we employed the human SGC-7901 gastric cancer cell line, built an orthotopic xenograft model in nude mice, examined the treatment response by 18F-FDGPET/CT and investigated the mechanisms of 3-BrPA and SCT invivo. Our results demonstrated that glycolysis and tumor growth were inhibited by intraperitoneal injection of 3-BrPA and SCT, which were imaged using an 18F-FDGPET/CT scanner. In addition, apoptosis induced by 3-BrPA and SCT was initiated by the upregulation of Bax and downregulation of Bcl-2, which promote cytochromec release and subsequently activate caspase-9 and-3, and ultimately execute mitochondria-mediated apoptosis. Furthermore, apoptosis was also modulated by the generation of ROS and inhibition of survivin. Accordingly, 3-BrPA and SCT can inhibit glycolysis and induce gastric cancer apoptosis through the mitochondrial caspase-dependent pathway.

Dihydrotanshinone induces apoptosis of SGC7901 and MGC803 cells via activation of JNK and p38 signalling pathways

Context: Dihydrotanshinone (DHT), a natural compound from Salvia miltiorrhiza Bunge (Lamiaceae), showed higher cytotoxic potential compared with other tanshinones. Its effect and mechanism on gastric cancer have not been investigated.Objective: This study evaluates the effects of DHT on cell proliferation and apoptosis on gastric cancer cells, and elucidates its molecular mechanisms.Materials and methods: Human gastric cancer MGC803 and SGC7901 cells were treated with various concentrations of DHT (0–15 μM) for 24 and 48 h, and cell growth was measured by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide assay. Cell apoptosis was analysed by flow cytometry and DAPI staining. Western blots were performed to investigate changes in the level of apoptosis related genes in gastric cancer cell.Results: DHT exhibited obvious inhibition of the survival of gastric cancer cells. The IC50 values in SGC7901 and MGC803 cells were 9.14 and 5.39 μM for 24 h, respectively. Cells treated with 6 μM DHT resulted in 41.3% and 35.4% apoptotic cell fractions in SGC7901 and MGC803 cells, respectively, significantly higher than that of the control. Hallmarks of apoptosis were observed in gastric cancer cells after DHT exposure. DHT enhanced the expression levels of cleaved caspase-3, caspase-9 and poly-ADP-ribose polymerases. Furthermore, DHT increased the phosphorylation of JNK and p38 in SGC7901 and MGC803 cells.Conclusion: DHT induced growth inhibition and apoptosis of gastric cancer cells, involving activation of caspase proteins and the JNK/p38 signaling pathway. The results indicated that DHT has a promising chemotherapeutic potential for human gastric cancer.

Ginsenoside-Rh2 Inhibits Proliferation and Induces Apoptosis of Human Gastric Cancer SGC-7901 Side Population Cells.

To observed the effects of ginsenoside -Rh2 (GS-Rh2) on proliferation and apoptosis of side population (SP) human gastric cancer SGC-7901 cells. SGC-7901 SP and Non-SP cells were sorted by flow cytometry and assessed using the cck-8 method. Expression of apoptosis-related proteins Bax and Bcl-2 of SP before and after the intervention was determined by Western-blotting. It was found that the proliferation of SP was significantly faster than that of NSP (<0.05). In addition, GS-Rh2 inhibited proliferation of gastric cancer SP cells, induced cell cycle arrest and cell apoptosis, and changed the expression of BAX/Bcl-2 proteins in a time-dependent and concentration-dependent manner (<0.05). With increase of GS-Rh2 dose, GS-Rh2 gradually inhibit the proliferation of SGC-7901 SP cells, which have high proliferation rate, through G1/G0 phase arrest, followed by apoptosis which involves the up-regulation of Bax and the down-regulation of Bcl-2.

MicroRNA-524-5p suppresses the growth and invasive abilities of gastric cancer cells.

Previous studies have demonstrated that microRNAs (miRNAs) are associated with tumor development and progression. miRNA-524-5p (miR-524-5p) has been reported to be involved in the development and progression of several types of cancer, but its role in gastric cancer has not been fully elucidated to date. Therefore, the aim of the present study was to investigate the expression levels and function of miR-524-5p in human gastric cancer. The expression levels of miR-524-5p were assessed in gastric cancer specimens and cell lines, including MKN-45, SGC-7901 and MGC-803 cell lines and gastric epithelial mucosa GES-1 cells, using reverse transcription-quantitative polymerase chain reaction (RT-qPCR). Cell proliferation and cell apoptosis assays and invasion analysis in gastric cancer cell lines were performed to evaluate the effects of miR-524-5p on gastric cancer cells in vitro. The expression levels of matrix metallopeptidase (MMP)-2 and MMP-9 were determined by RT-qPCR and western blot analysis. The expression of miR-524-5p was significantly decreased in gastric cancer tissues and cell lines. Additionally, the results of the in vitro experiments demonstrated that overexpression of miR-524-5p inhibited cell proliferation and invasion, and promoted cell apoptosis in gastric cancer cells. Human gastric cancer SGC-7901 and MGC-803 cell lines transfected with miR-524-5p exhibited reduced expression levels of MMP-2 and MMP-9. Taken together, the results of the present study indicated that miR-524-5p may function as a novel tumor suppressor gene in gastric cancer, and may serve as a biomarker and therapeutic target for the treatment of gastric cancer.

Upregulation of microRNA-31 targeting integrin α5 suppresses tumor cell invasion and metastasis by indirectly regulating PI3K/AKT pathway in human gastric cancer SGC7901 cells.

To verify the hypothesis that upregulation of microRNA-31 (miR-31) targeting integrin α5 (ITGA5) suppresses tumor cell invasion and metastasis by indirectly regulating phosphoinositide 3-kinase (PI3K)/protein kinase B (AKT) signaling pathway in human SGC7901 gastric cancer (GC) cells. The miRTarBase was used to predict whether ITGA5 is the target gene of miR-31, which was further confirmed by luciferase reporter gene assay. The SGC7901 GC cells were divided into five groups including the blank, miR-31 mimic, miR-31 mimic control, miR-31 inhibitor, and miR-31 inhibitor control groups. Reverse transcriptase-polymerase chain reaction (RT-PCR), western blotting, cell scratch test, and transwell assays were respectively performed in our study. TGA5 was found as the target gene of miR-31. The RT-PCR detection revealed that, compared with the blank group, ITGA5 messenger RNA (mRNA) expression decreased in the miR-31 mimic group, but increased in the miR-31 inhibitor group. The western blotting examination suggested that the expressions of ITGA5, PI3K, and AKT proteins reduced in the miR-31 mimic group, but enhanced in the miR-31 inhibitor group when compared to the blank group, respectively. The cell scratch and transwell assays indicated that the miR-31 expressions were negatively associated with GC cell migration and invasion. Besides, RT-PCR combined with western blotting demonstrated that the miR-31 expressions were higher in the normal tissues than those in the GC tissues, while the ITGA5 mRNA and protein showed lower expression in the normal tissues than they did in the GC tissues. Our study concluded that upregulation of miR-31 targeting ITGA5 may suppress tumor cell invasion and metastasis by indirectly regulating PI3K/AKT signaling pathway in human SGC7901 GC cells.

Synthesis, structures, antiproliferative activity of a series of ruthenium(II) arene derivatives of thiosemicarbazones ligands

A series of [(p-cymene)Ru(TSC)Cl]Cl compounds ([1]Cl, [2]Cl and [3]Cl) and their corresponding [(p-cymene)Ru(TSC)Cl][(p-cymene)RuCl3] derivatives ([1][(p-cymene)RuCl3], [2][(p-cymene)RuCl3] and [3][(p-cymene)RuCl3]) have been synthesized and characterized by H1 NMR, elemental analysis and HR-ESI-mass spectrometry. The molecular structures of [2]Cl, [3]Cl, [1][(p-cymene)RuCl3], [2][(p-cymene)RuCl3] and [3][(p-cymene)RuCl3] have been characterized by single-crystal X-ray diffraction analysis. The complexes have been further evaluated for their in vitro antiproliferative activities against the SGC-7901 human gastric cancer, BEL-7404 human liver cancer and HEK-293T noncancerous cell lines. Furthermore, the interactions of the complexes [1]Cl and [1][(p-cymene)RuCl3] with HSA have been followed by fluorescence spectrometry studies.

CXC chemokine receptor 5 expression in gastric cancer and its clinical significance

Objective To investigate the expression of CXC chemokine receptor 5(CXCR5)in human gastric cancer cell lines and gastric carcinoma tissues and its clinical significance. Methods Flow cytometry was performed to analyze the CXCR5 expression in human gastric cancer cell lines, BGC-823, SGC-7901 and HGC-27.Immunohistochemistry and tissue-microarray were used to detect the CXCR5 expression in human gastric cancer tissues and adjacent normal tissues from 90 patients. Results The flow cytometry revealed that the CXCR5 expression was detectable in BGC-823, SGC-7901 and HGC-27 cells.The results of tissue microarray and immunohistochemistry showed that the ratio of higher CXCR5 expression in gastric cancer tissues was 52. 87%.The CXCR5 expression level in patients with tumor size≤2. 8 cm group was significantly lower than that in patients with tumor size> 2. 8 cm(χ2= 3. 995,P 0. 05).Survival analysis showed that the overall survival rate of the patients with high CXCR5 expression was lower than that of the patients with low CXCR5 expression[hazard ratio(HR)= 1. 810,95% confidence interval(CI):0. 980 3-3. 341 0,P> 0. 05]. Conclusion CXCR5 is involved in the oncogenesis and progression of human gastric cancer. Key words: Gastric cancer; CXC chemokine receptor 5

Synergistic Effect of Zuo Jin Wan on DDP-Induced Apoptosis in Human Gastric Cancer SGC-7901/DDP Cells.

A traditional Chinese medicine (TCM) formula, Zuo Jin Wan (ZJW), has been found as an anticancer drug in human cancer. In this study, we investigated the synergistic effect of ZJW extracts on DDP-induced apoptosis in human gastric cancer SGC-7901/DDP cells. Our results demonstrated that ZJW extracts could increase the sensitivity of SGC-7901/DDP cells to DDP by increasing the concentration of DDP in cytoplasm and enhance the proapoptosis of DDP by upregulating the JNK and Bax expression, downregulating the Bcl-2 expression, increasing the accumulation of Cytochrome C in cytoplasm, and promoting the activities of caspase-3 and caspase-9. In vivo, ZJW extracts enhanced the inhibiting effect of DDP on tumor growth in SGC-7901/DDP xenograft model and upregulated the expression of p-JNK and Bax but downregulated the Bcl-2 expression in xenograft tumors. In conclusion, in vitro and in vivo, ZJW extracts could enhance the proapoptotic effect of DDP by promoting the activation of JNK and the expression of Bcl-2, inhibiting the Bax expression, followed by increasing the release of Cytochrome C from mitochondria to cytoplasm, and finally activating the caspase cade reaction. Our results implied that ZJW might serve as a synergistic drug with chemotherapeutic drugs DDP in the treatment of gastric cancer.

Synthesis, Characterization, and Anticancer Activity of a Series of Ketone-N4-Substituted Thiosemicarbazones and Their Ruthenium(II) Arene Complexes

A series of ketone-N(4)-substituted thiosemicarbazone (TSC) compounds (L1-L9) and their corresponding [(η(6)-p-cymene)Ru(II)(TSC)Cl](+/0) complexes (1-9) were synthesized and characterized by NMR, IR, elemental analysis, and HR-ESI-mass spectrometry. The molecular structures of L4, L9, 1-6, and 9 were determined by single-crystal X-ray diffraction analysis. The compounds were further evaluated for their in vitro antiproliferative activities against the SGC-7901 human gastric cancer, BEL-7404 human liver cancer, and HEK-293T noncancerous cell lines. Furthermore, the interactions of the compounds with DNA were followed by electrophoretic mobility spectrometry studies.

Biological role of β-arrestin1 in human gastric cancer BGC-823 cells

Objective To investigate the effects of β-arrestinl on proliferation, migration, invasion and apoptosis of human gastric cancer BGC-823 cell line. Methods The expression of β- arrestinl in human gastric epithelial cell line GES, human gastric cancer cell line BGC-823, MKN-28 and SGC-7901 was detected by realtime-polymerase chain reaction （PCR） and Western blot. The stable β-arrestinl and negative control interfered BGC-823 cell line were established by RNA interference technology. The cell proliferation, migration, invasion and cell apoptosis of β-arrestinl stable interfered BGC-823 cell line was examined by cell counting, scratch test, Transwell chamber test and flow cytometry assays. The data were analyzed by t test. Results The expression of β- arrestinl in cell line GES, MKN-28, SGC-7901 and BGC-823 was 0. 001 ± 0. 001, 0. 002±0. 000, 0. 003± 0. 002 and 0. 005 ± 0. 000 respectively. The inhibition ratio of proliferation in β-arrestinl interfered BGC-823 cells and negative control cells were -30.2% and 100.0%. The invasion ability was also inhibited, the number of migratory cells was 126. 25±3.24 and 213. 50±6.27 （t=0. 000, P〈0.01）, and the apoptosis rate was （41. 350±1. 053）% and （11. 497±0. 589）% （t=0. 015, P〈0.05）. Conclusions β-arrestinl is highly expressed in gastric carcinoma, and the expression increased along with the malignancy degree. The cell proliferation, migration and invasion is inhibited by interference of β-arrestinl in BGC-823 cells, while the cell apoptosis is promoted. Key words: β-arrestinl; Stomach neoplasms; RNA interference; Tumor cells, cultured

Synthesis and in vitro Antitumor Activity of 6-Chloro-4-piperazinquinazolinethiosemicarbazone Derivatives

Three new quinazoline derivatives 5a~5c bearing piperazine have been designed and synthesized by four-step reactions of cyclization,chlorination,substitution and condensation using 2-amino-5-chlorobenzoic acid and formamide as starting materials.Their structures were confirmed by 1H NMR,13C NMR,ESI-MS and IR.The in vitro cytotoxicities against SGC-7901(human gastric cancer),KB(human oral epidermoid cancer) and HT-1080(human fibrosarcoma) cell lines of compounds 5a~5c were tested with colorimetric MTT assay.The results indicated that compounds 5a~5c had poor anticancer activities against SGC-7901 and HT-1080 cell lines,while had no notable inhibitory activity against KB cell lines.

Ligand exchange triggered controlled-release targeted drug delivery system based on core–shell superparamagnetic mesoporous microspheres capped with nanoparticles

We report a new controlled-release targeted drug delivery system based on core–shell structured silica mesoporous microspheres capped with superparamagnetic iron oxide nanoparticles. A ligand exchange strategy was developed to release guest molecules loaded in the mesopores. The system possesses a stimuli-responsive release property for the entrapped guest molecules, which is important for the delivery of toxic anticancer drugs in chemotherapy. A variety of stimulating agents, such as EDTA and sodium citrate, have been used to release the entrapped guest molecules, relying on the new ligand exchange triggered release mechanism. The release rate of guest molecules can be controlled by using different trigger-agents. The drug delivery system possesses high saturation magnetization (∼58 emu g−1) and superparamagnetic character, and thus can be easily enriched by a permanent magnet and re-dispersed in PBS solutions, which greatly facilitates its manipulation in practical applications. Cytotoxicity analyses of the drug delivery system based on human gastric cancer SGC-7901 and rat pheochromocytoma PC12 cells show low cytotoxicity and good biocompatibility. The uptake properties of the system by SGC-7901 and human cervical carcinoma HeLa cells demonstrate their great potential for applications in drug delivery. Furthermore, in vitro experiments show that cancer cells can be effectively killed by anticancer drug (paclitaxel) released from the system, further indicating the promise of the controlled-release drug delivery system in cancer treatment.

C-Jun N-terminal kinase is required for thermotherapy-induced apoptosis in human gastric cancer cells

To investigate the role of c-Jun N-terminal kinase (JNK) in thermotherapy-induced apoptosis in human gastric cancer SGC-7901 cells. Human gastric cancer SGC-7901 cells were cultured in vitro. Following thermotherapy at 43°C for 0, 0.5, 1, 2 or 3 h, the cells were cultured for a further 24 h with or without the JNK specific inhibitor, SP600125 for 2 h. Apoptosis was evaluated by immunohistochemistry [terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL)] and flow cytometry (Annexin vs propidium iodide). Cell proliferation was determined by 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide. The production of p-JNK, Bcl-2, Bax and caspase-3 proteins was evaluated by Western blotting. The expression of JNK at mRNA level was determined by reverse transcription polymerase chain reaction. The proliferation of gastric carcinoma SGC-7901 cells was significantly inhibited following thermotherapy, and was 32.7%, 30.6%, 43.8% and 52.9% at 0.5, 1, 2 and 3 h post-thermotherapy, respectively. Flow cytometry analysis revealed an increased population of SGC-790l cells in G0/G1 phase, but a reduced population in S phase following thermotherapy for 1 or 2 h, compared to untreated cells (P < 0.05). The increased number of SGC-790l cells in G0/G1 phase was consistent with induced apoptosis (flow cytometry) following thermotherapy for 0.5, 1, 2 or 3 h, compared to the untreated group (46.5% ± 0.23%, 39.9% ± 0.53%, 56.6% ± 0.35% and 50.4% ± 0.29% vs 7.3% ± 0.10%, P < 0.01), respectively. This was supported by the TUNEL assay (48.2% ± 0.4%, 40.1% ± 0.2%, 61.2% ± 0.29% and 52.0% ± 0.42% vs 12.2% ± 0.22%, P < 0.01) respectively. More importantly, the expression of p-JNK protein and JNK mRNA levels were significantly higher at 0.5 h than at 0 h post-treatment (P < 0.01), and peaked at 2 h. A similar pattern was detected for Bax and caspase-3 proteins. Bcl-2 increased at 0.5 h, peaked at 1 h, and then decreased. Furthermore, the JNK specific inhibitor, SP600125, suppressed p-JNK, Bax and caspase-3 at the protein level in SGC790l cells following thermotherapy, compared to mock-inhibitor treatment, which was in line with the decreased rate of apoptosis. The expression of Bcl-2 was consistent with thermotherapy alone. Thermotherapy induced apoptosis in gastric cancer cells by promoting p-JNK at the mRNA and protein levels, and up-regulated the expression of Bax and caspase-3 proteins. Bcl-2 may play a protective role during thermotherapy. Activation of JNK via the Bax-caspase-3 pathway may be important in thermotherapy-induced apoptosis in gastric cancer cells.