Proliferation Of BGC-823 Cells Research Articles

Evodiamine Inhibits the Proliferation of BGC-823 and SGC-7901 Cells by Inducing Cell Cycle Arrest and Apoptosis in Gastric Cancer

Gastric cancer represents a major cause of cancer-related death worldwide. Although various tactics and anti-tumor drugs have been used to improve curative effects, five-year survival rate of lung cancer patients remains poor. Evodiamine, a sophora alkaloid, has been demonstrated to exert antitumor effects on many types of cancer. However, the molecular mechanism of evodiamine against gastric cancer has not been clearly elucidated. In this study, we investigated the anti-tumor activity and the underlying mechanisms of EVO on gastric cancer cells, and found that it significantly inhibited the proliferation of BGC-823 and SGC-7901 cells by inducing cell cycle arrest at G2/M phase and cell apoptosis in a dose- and time-dependent manner. Its molecular mechanism may be that it reduces the expression of cell cycle- promoting protein Cdc25C and promotes the expression of cell cycle inhibitor p53, as well as prompts the activity of caspases pathways, such as the expression level of cleaved caspase-3 and cleaved caspase-8; cleaved caspase-9 and cleaved PARP-1 are up-regulated, treated with EVO (10 μM) at different points in time (0, 3, 6, 9, 12, 24 h). Collectively, our data demonstrated that EVO was a potential anti-tumor agent against gastric cancer.

Anti-Tumor Effect and Mechanism of Parthenolide in Gastric Cancer Cellline BGC-823

Objective: To study the anti-tumor effect and mechanism of parthenolide in gastric cancer cell BGC-823. Methods: The cck8 assay was used to detect the changes of BGC-823 cells viability after treatment with different con-centrations of parthenolide at different time points. The proliferation ability of BGC-823 cells was detected by clone formation assay. And the cell cycle and apoptosis were measured by flow cytometry. Meanwhile, to detect the different in intracellular ROS production levels, the fluorescence assay was used. And with the help of western blotting, cell cycle- and apoptosis-related protein expression can be detected. Results: Parthenolide could inhibit the viability of BGC-823 cells in a dose- and time-dependent manner (P < 0.01). In BGC-823 cells exposed to parthenolide, the apoptosis rate was found significantly increased (P < 0.01), and the protein expression of cleaved-caspase3, cleaved-caspase8, and cleaved-caspase9 significantly increased (P < 0.01); the cell cycle was arrested at G1phase (P < 0.01); the protein levels of CyclinD1 and CyclinE1 decreased (P < 0.01), and the expression of P53 and P21 protein increased (P < 0.01); massive intracellular ROS generation was found (P < 0.01). Furthermore, the nuclear protein levels of c-Myc, E2F1, and NF-κB and the protein level of phosphorylated STAT3 decreased in BGC-823 cells exposed to parthenolide (P < 0.01). Conclusion: Parthenolide may inhibit the proliferation of BGC-823 cells and induce G1-phase cell cycle arrest and apoptosis via inhibiting STAT3-c-Myc-E2F1 axis.

Profiling and targeting of cellular mitochondrial bioenergetics: inhibition of human gastric cancer cell growth by carnosine.

L-Carnosine (β-alanyl-L-histidine) is a naturally occurring dipeptide distributed in various organs of mammalians. We previously showed that carnosine inhibited proliferation of human gastric cancer cells through targeting both mitochondrial bioenergetics and glycolysis pathway. But the mechanism underlying carnosine action on mitochondrial bioenergetics of tumor cells remains unclear. In the current study we investigated the effect of carnosine on the growth of human gastric cancer SGC-7901 cells in vitro and in vivo. We firstly showed that hydrolysis of carnosine was not a prerequisite for its anti-gastric cancer effect. Treatment of SGC-7901 cells with carnosine (20 mmol/L) significantly decreased the activities of mitochondrial respiratory chain complexes I-IV and mitochondrial ATP production, and downregulated 13 proteins involved in mitochondrial bioenergetics. Furthermore, carnosine treatment significantly suppressed the phosphorylation of Akt, while inhibition of Akt activation with GSK690693 significantly reduced the localization of prohibitin-1 (PHB-1) in the mitochondria of SGC-7901 and BGC-823 cells. In addition, we showed that silencing of PHB-1 gene with shRNA markedly reduced the mitochondrial PHB-1 in SGC-7901 cells, and significantly decreased the colony formation capacity and growth rate of the cells. In SGC-7901 cell xenograft nude mice, administration of carnosine (250 mg kg/d, ip, for 3 weeks) significantly inhibited the tumor growth and decreased the expression of mitochondrial PHB-1 in tumor tissue. Taken together, these results suggest that carnosine may act on multiple mitochondrial proteins to down-regulate mitochondrial bioenergetics and then to inhibit the growth and proliferation of SGC-7901 and BGC-823 cells.

Highly expressed lncRNA FAL1 promotes the progression of gastric cancer by inhibiting PTEN.

The aim of this study was to investigate the function of FAL1 in gastric cancer (GC) development and to examine its underlying mechanism. Our study might provide a theoretical basis for developing novel diagnostic markers for GC. FAL1 expression in GC tissues and adjacent tissues was detected by quantitative Real Time-Polymerase Chain Reaction (qRT-PCR). The serum level of FAL1 in GC patients with different pathological grades was further detected. The effects of FAL1 on cell proliferation and cell cycle were detected by cell counting kit-8 (CCK-8) assay and flow cytometry, respectively. Meanwhile, Western blot was used to detect the protein expression of PTEN after FAL1 overexpression or knockdown in GC cells. In addition, rescue experiments were conducted to verify the regulatory effect of FAL1 on PTEN. QRT-PCR results showed that the expression of FAL1 in GC tissues was remarkably higher than that of adjacent tissues. FAL1 expression was correlated with pathological grades of GC patients. Meanwhile, FAL1 overexpression promoted the proliferation and cell cycle of BGC-823 and MGC-803 cells. Western blot analysis demonstrated that FAL1 could inhibit the protein expression of PTEN in GC cells. In addition, rescue experiments indicated that the overexpression of PTEN could partially reverse the effect of FAL1 on the proliferation and cell cycle of BGC-823 and MGC-803 cells. The overexpression of FAL1 can promote cell proliferation and cell cycle of GC via inhibiting PTEN.

Circ_0009910 regulates growth and metastasis and is associated with poor prognosis in gastric cancer.

Circular RNAs (circRNAs) have recently shown capabilities as gene regulators in mammals. In this study, we aimed to evaluate the effects and mechanism of circ_0009910 in gastric cancer (GC). Circ_0009910 expression was quantified by Real-time PCR in human GC cell lines and tissues. Association between circ_0009910 levels and clinicopathological factors and patient's prognosis was analyzed. The roles of circ_0009910 in regulating GC cell proliferation, colony formation, migration, and invasion were evaluated in vitro. Western blot analysis was conducted to detect the expressions of molecular markers of epithelial-mesenchymal transition (EMT). Circ_0009910 expression level was elevated in GC tissues and cell lines and associated with clinical stage (p = 0.032), distant metastasis (p = 0.028) and differentiation (p = 0.007). Kaplan-Meier survival analysis indicated that circ_0009910 expression in positive group has a worse overall survival compared to the negative group (p = 0.0013). Multivariate analysis showed that circ_0009910 was an independent risk factor for GC (HR = 2.346, 95% CI: 1.673-3.775, p = 0.006). Knockdown of circ_0009910 expression can suppress BGC823 and AGS cells proliferation, migration and invasion in vitro experiments. The results of Western blot indicated that knockdown of circ_0009910 increased expression of E-cadherin and decreased expression of the mesenchymal markers, snail and N-cadherin. Altogether, we demonstrate that circ_0009910 acts as a prognostic biomarker and promote cell proliferation, migration, invasion and EMT in GC, indicating that circ_0009910 may be a novel potential biomarker and therapeutic target of GC.

Effects of MTA1 on biological behaviors of gastric cancer cells

Objective: To study the effects of metastasis associated 1 (MTA1) on biological characteristics such as migration, invasion and proliferation of gastric cancer (GC) cells. Methods: pSilencer3.1-MTA1-siRNA vector was used to establish human gastric cancer BGC-823 cell lines with constitutive MTA1-knockdown. Boyden, wound healing, clony forming assay and 3-(4, 5-dimethyl-2-thiazolyl)-2, 5-diphenyl-2H tetrazolium bromide (MTT) assay were performed to identify the effects of MTA1-deficiency on the biological behaviors of BGC-823 cells in vitro. Simultaneously, MTA1 overexpressed BGC-823 cell line was established by pcDNA3-MTA1 plasmid transfection for reverse verification. In addition, the role of MTA1 in the tumorigenicity of gastric cancer BGC823 cells in vivo was examined by subcutaneous injection of BGC-823 cells expressing different MTA1 levels into nude mice. Reverse transcription-polymerase chain reaction (RT-PCR) and western blot were used to detect the expression levels of integrin β1, cyclin D1 and uPAR in pSilencer3.1-MTA1-siRNA, pcDNA3-MTA1 transfected cells and control cells. Results: MTA1 knocked down or upregulated BGC-823 cell lines were successfully generated by transfecting pSilencer3.1-MTA1-siRNA or pcDNA3-MTA1 vector with lipofectamine 2000, respectively. The Boyden and wound healing experiments showed metastasis and invasion ability in MTA1 knocked down cells (25±2, 12±1) were significantly decreased when compared with those of control (78±2, 50±2) and MTA1-overexpressed groups (218±2, 269±3; P<0.05). The results of MTT assay and colony forming assay were significantly decreased when compared with those of showed that MTA1 overexpressed cells grew more rapidly and formed more colonies in vitro and induced worse malignant tumors in vivo, while MTA1 knocked down cells presented the reversed phenotype[control group (1 482.41±511.90) mm(3,) (1.39±0.29)g; MTA1 overexpressed group [(3 158.73±1 823.22) mm(3,) (2.23±0.51)g; MTA1-downregulated group (711.32±284.30)mm(3,) (0.87±0.21) g ; P<0.05)]. In addition, RT-PCR result showed that the expression level of MTA1 was positively correlated with the known metastasis-related genes (integrinβ1, cyclinD1, uPAR). Conclusions: MTA1 promotes the invasion, migration and proliferation of human gastric cancer BGC-823 cells. On the contrary, down-regulation of MTA1 significantly inhibits tumorigenicity of BGC-823 cells and induces favorable phenotypes. MTA1 may promote the malignant phenotype of BGC-23 cells via regulating the expressions of integrinβ1, cyclinD1 and uPAR.

Dextran sulfate inhibition on human gastric cancer cells invasion, migration and epithelial-mesenchymal transformation.

The objective of the present study was to observe the influence of dextran sulfate (DS) on the proliferation, invasion and migration of AGS, BGC-23, GES-1, MGC-803 and SGC-7901 cells. Additionally, the possible inhibition mechanism of DS on BGC-823 cells epithelial-mesenchymal transition (EMT) was explored. The cells in the control and experimental group were treated with PBS and DS respectively. The effect of DS on the invasion and migration of these five types of cells were investigated using Transwell invasion and migration assays. Immunocytochemistry, western blotting and reverse transcription-polymerase chain reaction (RT-PCR) assays were used to measure gene and protein expression of hypoxia-inducible factor 1α (HIF1-a) and EMT associated factors [Twist, E-cadherin, N-cadherin and β-catenin] of BGC-823 cells. According to the results of CCK-8, DS significantly decreased the proliferation of AGS, SGC-7901 and BGC-823 cells to different extents, but there were no notable differences for MGC-803 cells. Transwell migration and invasion results demonstrated that, compared with the control group, DS reduced the migration and invasion of every types of cells to different extents, and the inhibition to BGC-823 cells invasion is the most notably. Immunofluorescence, RT-PCR and western blot analysis results indicated that HIF-1α, Twist and N-cad expressions levels had different degrees of reduction in the experimental group following DS treatment; however, the expression level of E-cad had increased. In conclusion, DS inhibited the proliferation of AGS, BGC-823, SGC-7901 and GES-1 cells, the inhibition degree may be associated with the differentiation degree of every cancer cell, the higher the differentiation degree, the stronger the inhibition. DS inhibited migration and invasion of the five types of gastric cancer cells in different degree. DS may inhibit EMT of BGC-823 by inhibiting Wnt signaling.

Hydroxysafflor-Yellow A Induces Human Gastric Carcinoma BGC-823 Cell Apoptosis by Activating Peroxisome Proliferator-Activated Receptor Gamma (PPARγ).

BackgroundAnti-tumor properties of hydroxysafflor-yellow A (HSYA) have been recently revealed, as a series of apoptotic factors were confirmed to be regulated by HSYA and associated with peroxisome proliferator-activated receptor Gamma (PPARγ). In this study, we investigated the cell apoptosis mechanism of HSYA via activated PPARγ signal in human gastric carcinoma cells.Material/MethodsBGC-823 cells were cultured and divided into 5 independent groups: Tumor, HSYA, HSYA+PPARγ inhibitor (GW9662), and PPARγ agonist (RGZ), RGZ+GW9662. Cell proliferative activity was measured by MTT. Apoptosis and cell cycle were detected by flow cytometry. The nuclear translocation of PPARγ was detected by immunofluorescence staining chemistry, and mRNA levels of PPARγ and caspase-3 were measured by real-time qPCR.ResultsCompared to the RGZ group, the HSYA group (100 μM) showed a similar inhibitory effect on the proliferation process of BGC-823 cells, inducing their apoptosis. As a result, the transition of BGC-823 cells from G0/G1 phase to S phase was blocked. HSYA was also found to promote the nuclear translocation of PPARγ, leading to increased expression of PPARγ and caspase-3. The regulatory effect of HSYA on BGC-823 cells could be further inhibited by PPARγ inhibitor in group GW9662.ConclusionsWe report the inhibitory effect of HSYA on the proliferation of BGC-823 cells, which results in activating PPARγ-dependent cell cycle blocking and cell apoptosis, suggesting that PPARγ is a specific type of HSYA that can induce apoptosis of BGC-823 cells.

Effect of lncRNA BNC2-AS1 on the Proliferation, Migration and Invasion of Gastric Cancer Cells.

Background: Gastric cancer is one of the most common cancers and is the second leading cause of cancer mortality worldwide. The present study aimed to investigate the potential biological effect of long non-coding RNA (lncRNA) BNC2-AS1 on the proliferation, migration, and invasion of cervical cancer cells. Methods: BNC2-AS1 small interfering RNA (siRNA) was transfected into SGC7901 and BGC823 gastric cancer cell lines, with negative siRNA serving as a control. A reverse transcription-quantitative polymerase chain reaction assay was performed to confirm the knockdown of BNC2-AS1. Cell Counting Kit (CCK)-8 and colony-forming unit (CFU) assays were performed to evaluate the effect of BNC2-AS1-knockdown on SGC7901 and BGC823 cell proliferation. A wound healing assay was performed to evaluate the effect of BNC2-AS1-knockdown on SGC7901 and BGC823 cell proliferation and migration. A tumor invasion assay was used to evaluate the effect of BNC2-AS1-knockdown on SGC7901 and BGC823 cell invasion. The expression level of BNC2-AS1 was efficiently knocked down by siRNA 48 hours post-transfection. Results: The results of CCK8 and CFU assays showed that BNC2-AS1-knockdown significantly decreased gastric cancer cell proliferation. Wound healing assay results indicated that BNC2-AS1-knockdown markedly suppressed gastric cancer cell proliferation and migration. Tumor invasion assay results demonstrated that BNC2-AS1-knockdown significantly suppressed gastric cancer cell invasion. Conclusions: BNC2-AS1 levels in gastric cancer SGC7901 and BGC823 cell lines can be efficiently knocked down using the siRNA strategy, and the BNC2-AS1 knockdown can significantly suppress the tumor characteristics of gastric cancer cells, including the ability of proliferation, migration, and invasion.

RPS15a Silencing Suppresses Cell Proliferation and Migration of Gastric Cancer.

PurposeInformation on the possible role of the ribosomal protein S15a (RPS15a) in gastric cancer is scarce. The aim of this study was to evaluate the impact of RPS15a gene expression on the growth and cell cycle of gastric cancer cells in vitro and in vivo.Materials and MethodsRPS15a mRNA expression was examined in cancer tissues and their corresponding adjacent normal tissues of 40 gastric adenocarcinoma patients. Next, RPS15a was knocked down using a lentivirus-mediated RNA interference (short hairpin RNA) system in the gastric cancer cell line BGC823. The effect of RPS15a knockdown was examined using CCK-8 assay, cell scratch test, colony formation assay, and flow cytometry. Finally, in nude mice, a tumorigenicity test was performed, and the tumor volume and weight were measured.ResultsRPS15a expression in tumor tissue was significantly greater than that in the adjacent normal tissue of gastric cancer patients. After RPS15a silencing, the BGC823 cell proliferation rate decreased significantly; most cells were arrested in the G0/G1 phase, cell growth was inhibited, and the migration rate was decreased. Colony formation assay showed that the number and size of clones in the RPS15a-silenced cells were fewer and smaller, compared to control cells. The nude mouse tumorigenicity test showed that RPS15a silencing had an inhibitory effect on tumor volume and mice weight.ConclusionThe present study found RPS15a expression to be higher in gastric tumors and its silencing in gastric cancer cells to inhibit the proliferation, growth, and migration thereof. Accordingly, RPS15a may be considered as a potential therapeutic target in gastric cancer.

Astragaloside IV inhibits pathological functions of gastric cancer-associated fibroblasts.

AIMTo investigate the inhibitory effect of astragaloside IV on the pathological functions of cancer-associated fibroblasts, and to explore the underlying mechanism.METHODSPaired gastric normal fibroblast (GNF) and gastric cancer-associated fibroblast (GCAF) cultures were established from resected tissues. GCAFs were treated with vehicle control or different concentrations of astragaloside IV. Conditioned media were prepared from GNFs, GCAFs, control-treated GCAFs, and astragaloside IV-treated GCAFs, and used to culture BGC-823 human gastric cancer cells. Proliferation, migration and invasion capacities of BGC-823 cells were determined by MTT, wound healing, and Transwell invasion assays, respectively. The action mechanism of astragaloside IV was investigated by detecting the expression of microRNAs and the expression and secretion of the oncogenic factor, macrophage colony-stimulating factor (M-CSF), and the tumor suppressive factor, tissue inhibitor of metalloproteinase 2 (TIMP2), in different groups of GCAFs. The expression of the oncogenic pluripotency factors SOX2 and NANOG in BGC-823 cells cultured with different conditioned media was also examined.RESULTSGCAFs displayed higher capacities to induce BGC-823 cell proliferation, migration, and invasion than GNFs (P < 0.01). Astragaloside IV treatment strongly inhibited the proliferation-, migration- and invasion-promoting capacities of GCAFs (P < 0.05 for 10 μmol/L, P < 0.01 for 20 μmol/L and 40 μmol/L). Compared with GNFs, GCAFs expressed a lower level of microRNA-214 (P < 0.01) and a higher level of microRNA-301a (P < 0.01). Astragaloside IV treatment significantly up-regulated microRNA-214 expression (P < 0.01) and down-regulated microRNA-301a expression (P < 0.01) in GCAFs. Reestablishing the microRNA expression balance subsequently suppressed M-CSF production (P < 0.01) and secretion (P < 0.05), and elevated TIMP2 production (P < 0.01) and secretion (P < 0.05). Consequently, the ability of GCAFs to increase SOX2 and NANOG expression in BGC-823 cells was abolished by astragaloside IV.CONCLUSIONAstragaloside IV can inhibit the pathological functions of GCAFs by correcting their dysregulation of microRNA expression, and it is promisingly a potent therapeutic agent regulating tumor microenvironment.

Effect of silencing colon cancer-associated transcript 2 on the proliferation, apoptosis and autophagy of gastric cancer BGC-823 cells.

The role of long non-coding RNAs (lncRNAs) in the carcinogenesis and progression of tumors has been receiving increasing attention. Colon cancer-associated transcript 2 (CCAT2), a type of oncogenic lncRNA, is regarded as a novel biomarker of poor prognosis and metastasis in various types of cancer. However, the molecular contributions of CCAT2 to gastric cancer (GC) progression remain largely unclear. The aim of the present study was to demonstrate the effect of silencing CCAT2 on the biological behavior of GC BGC-823 cells and illustrate the potential underlying molecular mechanisms. A short hairpin RNA interference plasmid pRNAT-U6.1-CCAT2 targeting CCAT2 was successfully constructed. At 48 h after transfection with the interference plasmid, the survival rate of BGC-823 cells was significantly decreased, as determined by the MTT assay. In addition, RT-qPCR results revealed that CCAT2 gene expression was effectively suppressed by the transfection, while POU domain class 5 transcription factor 1B (POU5F1B) gene expression was significantly decreased. Terminal deoxynucleotidyl transferase dUTP nick end labeling assay further revealed that the apoptotic index was significantly higher in the interference group. Western blot analysis also demonstrated that the expression of beclin-1 protein was significantly increased, whereas the expression levels of phosphoinositide 3-kinase (PI3K) and mammalian target of rapamycin (mTOR) proteins were downregulated in the interference group. In conclusion, CCAT2 was able to positively regulate the expression of POU5F1B gene. Furthermore, silencing of CCAT2 gene inhibited the proliferation of BGC-823 cells, as well as induced apoptosis and autophagy in BGC-823 cells, by suppression of the PI3K/mTOR signaling pathways.

Cyclooxygenase-2 mediated synergistic effect of ursolic acid in combination with paclitaxel against human gastric carcinoma.

Ursolic acid (UA) induces apoptosis in gastric cancer cells by inhibiting cyclooxygenase-2 (COX-2). Paclitaxel (PTX) is an important chemotherapy agent used to treat solid tumors. We evaluated the in vitro antitumor activity of UA in combination with PTX against gastric cancer cells and investigated the mechanisms underlying the combined effects. A cytotoxicity test and flow cytometry were utilized to study the effects of UA and PTX on proliferation and apoptosis, respectively. To further elucidate the mechanism, Western blot analysis was used to assess changes in the expression of a series of related proteins, including COX-2, proliferating cell nuclear antigen (PCNA), Bcl-2, and Bax. UA and PTX dose- and time-dependently inhibited BGC-823 and SGC-7901 gastric cancer cell proliferation. Combined delivery of UA and PTX synergistically reduced cell proliferation and induced apoptosis in these cells by lowering COX-2, PCNA, and Bcl-2 expression and by increasing Bax expression. These results indicate that the synergistic inhibition of proliferation and induction of apoptosis by UA and PTX may be induced by reducing COX-2 expression in gastric cancer cells.

Long noncoding RNA SNHG20 promotes gastric cancer progression by inhibiting p21 expression and regulating the GSK-3β/ β-catenin signaling pathway.

Recent studies have indicated that long non-coding RNAs (lncRNAs) play important regulatory roles in tumor development and progression. However, the contribution of small nucleolar RNA host gene 20 (SNHG20) to gastric cancer development remains largely unknown. The aim of the study is to investigate the functional significance of SNHG20 involved in gastric cancer (GC) progression. In the study, our results demonstrated that the expression levels of SNHG20 were remarkably up-regulated in GC cells. Functionally, SNHG20 promoted the GC MKN45 and BGC-823 cells proliferation and invasion. Furthermore, knockdown of SNHG20 significantly inhibited the epithelial-mesenchymal transition (EMT) in MKN45 and BGC-823 cells, whereas, the overexpression of SNHG20 had the promoting effects. Moreover, we found that overexpression of SNHG20 in MKN45 and BGC-823 cells significantly inhibited the expression of E-cadherin and p21 via binding to EZH2 and regulated the GSK-3β/β-catenin signaling pathway. Thus, the results showed that SNHG20 acted as an oncogene in GC and targeting SNHG20 may serve as a therapeutic target for GC.

Retraction Note: Astragalus saponins affect proliferation, invasion and apoptosis of gastric cancer BGC-823 cells

Astragalus memebranaceus is a traditional Chinese herbal medicine used in treatment of common cold, diarrhea, fatigue, anorexia and cardiac diseases. Recently, there are growing evidences that Astragalus extract may be a potential anti-tumorigenic agent. Some research showed that the total saponins obtained from Astragalus membranaceus possess significant antitumorigenic activity. Gastric cancer is one of the most frequent cancers in the world, almost two-thirds of gastric cancer cases and deaths occur in less developed regions. But the effect of Astragalus membranaceus on proliferation, invasion and apoptosis of gastric cancer BGC-823 cells remains unclear. Astragalus saponins were extracted. Cells proliferation was determined by CCK-8 assay. Cell cycle and apoptosis were detected by the flow cytometry. Boyden chamber was used to evaluate the invasion and metastasis capabilities of BGC-823 cells. Tumor growth was assessed by subcutaneous inoculation of cells into BALB/c nude mice. The results demonstrated that total Astragalus saponins could inhibit human gastric cancer cell growth both in vitro and in vivo, in additional, Astragalus saponins deceased the invasion ability and induced the apoptosis of gastric cancer BGC-823 cells. Total Astragalus saponins inhibited human gastric cancer cell growth, decreased the invasion ability and induced the apoptosis. This suggested the possibility of further developing Astragalus as an alternative treatment option, or perhaps using it as adjuvant chemotherapeutic agent in gastric cancer therapy.

Quercetin exerts synergetic anti-cancer activity with 10-hydroxy camptothecin

Quercetin (Qu) is known as a dietary antioxidant with numerous bioactivities, but its function in anti-cancer has not been fully investigated. Here, we show that Qu at low doses (≤10μM) significantly enhances the inhibition of 10-hydroxy camptothecin (HCPT) on the proliferation of MCF7, BGC823 and HepG2 cells. A plasmid DNA relaxation assay indicates that the inhibition of HCPT on the catalytic activity of topoisomerase I (Topo I) is increased by Qu at 10μM. Compared to the treatment by Qu or HCPT alone, phosphorylation at Ser139 of γH2A.X in MCF7 cells starts to increase significantly (P<0.05) at 6h when treated by the combination of 10μM Qu and 0.62μM HCPT. Moreover, the combinational group successively arrests MCF7 cells at G1, S and G2/M phases from 12h to 48h via up-regulation of p21 and induces apoptosis at 24h by triggering intrinsic cell death pathways. In addition, the inhibition effects of the combinational group on the proliferation of MCF7 cells are eliminated by pretreatment with 100μM Z-VAD-FMK (a caspase inhibitor). Finally, by using nude mice xenografting assay of MCF7 cells, we demonstrate that tumor inhibition rates of combinational group are significantly higher than single-drug group. In summary, the synergic anti-cancer mechanism of Qu and HCPT in MCF7 cells is through the combined inhibitory effects of Qu and HCPT on Topo I, which synergistically induce cell cycle arrest and apoptosis by triggering DNA damage.

Dysregulated lncRNA-UCA1 contributes to the progression of gastric cancer through regulation of the PI3K-Akt-mTOR signaling pathway.

The long non-coding RNA (lncRNA) urothelial carcinoma-associated 1 (UCA1) has been recently shown to be dysregulated during disease occurrence and to play an important role in the progression of several cancers. However, the biological role and potential regulation mechanism of UCA1 in the carcinogenesis of gastric cancer remain unclear. In the present study, we found that UCA1 was aberrantly upregulated in gastric cancer tissues and gastric cancer cell lines, and was associated with TNM stage and metastasis. UCA1 silencing significantly inhibited gastric cancer BGC-823 cell proliferation and increased its apoptosis. We also found that UCA1 played an important role in the migration and invasion of gastric cancer cells in vitro and in vivo. The molecular mechanism of UCA1 suggested that UCA1 regulates the PI3K-Akt-mTOR signaling proteins and their downstream mediators, to alter gastric cancer progression in vitro and in vivo. Collectively, the results showed a pivotal role of UCA1 in the tumorigenesis of gastric cancer. In addition, the study characterized a novel lncRNA-mRNA regulatory network, which may lead to a better understanding of the pathogenesis of gastric cancer and assist in lncRNA-directed diagnosis and therapy for this malignancy.

Induction of apoptotic DNA fragmentation mediated by mitochondrial pathway with caspase-3-dependent BID cleavage in human gastric cancer cells by a new nitroxyl spin-labeled derivative of podophyllotoxin

Purpose4-[4′′-(2′′, 2′′, 6′′, 6′′-tetramethyl-l′′-piperidinyloxy) amino]–4′-demethyl-epipodophyllotoxin (GP7) is a new semi-synthesized nitroxyl spin-labeled derivative of podophyllotoxin with anti-leukemic and anti-osteosarcoma effects. The purpose of the present study is to investigate the anti-gastric cancer (GC) effects of GP7 and the possible involvement of caspase pathway in GP7-induced apoptotic DNA fragmentation in human GC cells. Materials and methodsEffects of GP7 on the proliferation of human GC cell lines MKN28, AGS, BGC-823 and HGC-27 in different degrees of differentiation and normal human gastric epithelial cell line GES-1 were studied by MTT assay and compared with the effects of etoposide. Effects of GP7 on cell viability and heat shock protein 90 expression of BGC-823 and HGC-27 cells were analyzed by trypan blue exclusion test and western blotting, respectively. Effects of GP7 on apoptotic DNA fragmentation and caspase pathway of BGC-823 and HGC-27 cells were detected by agarose gel electrophoresis, colorimetric assay and western blotting. Caspase-3 inhibitor was used to manipulate the activity of caspase-3. ResultsGP7 inhibited concentration- and time-dependently the proliferation of human GC cells, and the inhibitory effect of GP7 on the proliferation of BGC-823 or HGC-27 cells was 1.15- or 1.21-fold higher than that of etoposide. GP7 downregulated heat shock protein 90, improved the anti-GC effects of adriamycin, cisplatin, 5-fluorouracil and their combinations, induced apoptotic DNA fragmentation, activations of caspase-9 and -3 but not -8, cytochrome-c release and BID cleavage in BGC-823 and HGC-27 cells. Caspase-3 inhibitor abrogated GP7-induced BID cleavage, decreased cytochrome-c release, caspase-9 and -3 activities and apoptotic DNA fragmentation but increased cell viability in BGC-823 and HGC-27 cells. ConclusionOur findings indicate that GP7 is a promising anti-GC derivative of podophyllotoxin, and GP7-induced apoptosis in human GC cells may be mediated by mitochondrial pathway with caspase-3-dependent BID cleavage.

In vitro research of proliferative inhibition of human gastric cancer cell BGC-823 by magnesium cantharidate and the underlying mechanism

Objective To evaluate the inhibitory effects of magnesium cantharidate on human gastric cancer cell BGC-823 lines in vitro and the relative mechanisms. Methods Twenty-four h after adding 0.52, 1.04, 2.08, 4.17, and 8.34 μmol/L magnesium cantharidate, cell counting kit-8 (CCK-8) assay was used to observe the proliferation of BGC-823 cells; morphological changes of apoptosis were observed using the light microscope and trans mission electron microscope; propidiumiodide (PI) single staining was used to detect the changes of cell cycle, and apoptotic cell percentage was detected by flow cytometry; The expression levels of cyclin-dependent kinase 1 (CDK1) and cyclin B1 proteins were tested by Western blotting. Results Magnesium cantharidate had obviously an inhibitory effect on BGC-823 cells in a dose-dependent manner (P=0.000). The inhibitory concentration (IC50) of magnesium cantharidate was 4.868 μmol/L. 24 h after treatment with 4.868 μmol/L magnesium cantharidate, BGC-823 cells represented nuclear abnormity, cleavage and fragmentation, and endoplasmic reticulum and mitochondria swelling. Affter treatment with 4.868 μmol/L magnesium cantharidate for 24 h, the apoptosis rate of BGC-823 cells increased (P=0.010) and the cells were significantly blocked in G2/M phase (P=0.009). 24 h after treatment with 2.434, 4.868, 7.302 μmol/L magnesium cantharidate, the expression of CDK1 and Cyclin B1 decreased significantly in BGC-823 cells (P=0.000). Conclusion Magnesium cantharidate can inhibit the proliferation of BGC-823 cells, and significantly block the cells in G2/M phase. Key words: Cantharidin magnesium; Gastric cancer; Inhibitory concentration; Cell cycle; Cyclin

Blocking autophagy enhances the pro-apoptotic effect of bufalin on human gastric cancer cells through endoplasmic reticulum stress.

ABSTRACTBufalin has been used to treat cancer for several years. However, the molecular mechanisms for its anti-tumor function are not fully understood. This work aimed to investigate the effect of bufalin on the proliferation and apoptosis of human gastric cancer (HGC) cells and the roles of endoplasmic reticulum (ER) stress and autophagy in bufalin-induced apoptosis. HGC cell lines, SGC7901 and BGC823, were treated with different concentrations of bufalin or 80 nmol/l bufalin for 1, 2, 3 and 4 days. Cell counting kit-8 (CCK-8) assay and direct cell counting method were used to detect proliferation. Cell cycle arrest and apoptosis was detected using flow cytometry. Protein levels of caspase-3, -8, Bax/Bcl-2, Beclin-1, LC3, inositol-requiring enzyme 1 (IRE1) and C/EBP homologous protein (CHOP) were determined using western blotting. Autophagy was blocked using 3-methyladenine (3MA) or Atg5 siRNA to evaluate the effect of autophagy on bufalin-induced apoptosis. The IRE1 and CHOP were knocked down using specific siRNA to determine the pathway involved in bufalin-induced autophagy. It was found that bufalin significantly suppressed proliferation of SGC7901 and BGC823 cells and induced apoptosis in a time- and dose-dependent manner. The mechanism responsible for bufalin-induced apoptosis was the formation of ER stress via the IRE1-JNK pathway. Moreover, autophagy was activated during ER stress, and blocking autophagy significantly exacerbated bufalin-induced apoptosis.