Proliferation Of SGC-7901 Cells Research Articles

Synthesis and antitumor activity of novel 6,7,8-trimethoxy N-aryl-substituted-4-aminoquinazoline derivatives

A series of 6,7,8-trimethoxy N-aryl-substituted-4-aminoquinazoline derivatives were synthesized as epidermal growth factor receptor (EGFR) inhibitors, and their antitumor activities were assessed in the gastric cancer cell line SGC7901 using MTT assay. All compounds of Tg1–14 were found to inhibit SGC7901 cell proliferation, and compound Tg11 (IC50 = 0.434 μM) was found to be slightly more effective against SGC7901 cells than epirubicin (IC50 = 5.16 μM). This suggests that compound Tg11 can be used as a new substitution structure to develop more efficacious antitumor agents. Western blot analysis showed that treatment with Tg11 (40 μM for 30 min) resulted in near complete inhibition of EGF-induced ERK1/2 phosphorylation, indicating that its anti-proliferative effect is largely associated with inhibition of ERK1/2 activation. These data imply that Tg11 is a potential anticancer agent capable of inhibiting cell proliferation.

MicroRNA-107 inhibits gastric cancer cell proliferation and metastasis by targeting PI3K/AKT pathway

The present study was aimed to investigate the effect of miR-107 transfection on gastric cancer cell growth. Results from qRT-PCR revealed that level of miR-107 in SGC-7901 and MKN1 cell lines was down-regulated in comparison to the normal cells, GES-1. CCK-8 assay revealed a significant reduction in the proliferation of SGC-7901 cells on transfection with miR-107. The tumor growth was very slow in the mice implanted with SGC-7901/miR-107 compared to those bearing SGC-7901/miR-NC. In SGC-7901 cells metastasis potential after miR-107 transfection was examined using wound-healing and Transwell invasion assays. The migration as well as invasion potential of SGC-7901 cells was significantly lower on transfection with miR-107. The activity of luciferase was reduced markedly in SGC-7901 cells co-transfected with miR-107 mimic compared to miR-NC. However, miR-107 mimic co-transfection did not affect the luciferase activity in SGC-7901 cells bearing mutant-type BDNF 3′UTR. Western blot assay showed that miR-107 overexpression causes inhibition of BDNF mRNA and protein expression in SGC-7901 cells. The CCK8 assay showed that pBDNF transfection prevented miR-107 mediated inhibition of SGC-7901 cell proliferation. miR-107 mimic transfection inhibited expression of BDNF and activation of PI3K (p-PI3K) and AKT (p-AKT) in SGC-7901 cells. In order to confirm whether activation of PI3K and AKT by miR-107 mimic involves inhibition of BDNF, the cells were co-transfected with si-BDNF. The results revealed that si-BDNF transfection led to inhibition of BDNF expression and PI3K and AKT activation in SGC-7901 cells. In summary, the present study demonstrates that miR-107 expression inhibits proliferation and metastasis in gastric cancer cells. Therefore, miR-107 acts as tumor inhibitor for gastric cancer through targeting BDNF expression. Thus miR-107 can be used for treatment of gastric cancer.

Anti-proliferative effect of Shenqi Fuzheng injection on gastric cancer cell line SGC7901 via STAT3 pathway

Objective To study the effect of Shenqi Fuzheng injection on proliferation of gastric cancer cell line SGC7901, and to explore its mechanism associated with the STAT3 pathway. Methods The human gastric cancer cell line SGC7901 was used as the research object, the effects of different concentrations of Shenqi Fuzheng injection on the activity of SGC7901 cells were observed by MTT method, the levels of interleukin (IL)-6, IL-8 and IL-11 were detected by enzyme-linked immunosorbent assay (ELISA), and the expressions of Janus kinase 2 (JAK2), STAT3 and phosphorylated-STAT3 (p-STAT3) were detected by Western blot. Results Compared with the control group, the activity of SGC7901 cells in the treatment group decreased significantly, and the concentration of Shenqi Fuzheng injection reached 0.1 mg/ml, the inhibitory rate of SGC7901 cells reached (10.8±0.7)%, and the difference was statistically significant (P < 0.01). With the increase of Shenqi Fuzheng injection concentration, the inhibition rate of SGC7901 cells increased gradually (F = 12.319, P = 0.000). Compared with the control group, with the increase of Shenqi Fuzheng injection concentration, IL-6, IL-8 and IL-11 contents were decreased in SGC7901 cells, the differences were statistically significant (IL-6: F = 31.256, P = 0.000; IL-8: F = 16.857, P = 0.000; IL-11: F = 21.319, P = 0.000); JAK2 and p-STAT3 protein levels were significantly reduced (JAK2: F = 12.315, P = 0.000; p-STAT3: F = 16.728, P = 0.000) in the treatment groups. Conclusion Shenqi Fuzheng injection can inhibit the proliferation of SGC7901 cells, and the mechanism may be related to the inhibition of STAT3 pathway. Key words: Stomach neoplasms; STAT3 transcription factor; Signal transduction; Shenqi Fuzheng injection

Role of anti-interferon-induced protein with tetratricopeptide repeats 2 in gastric cancer cell lines

Objective To investigate the role of anti-interferon-induced protein with tetratricopeptide repeats 2 (IFIT2) in human gastric cancer. Methods IFIT2 was down-regulated by RNA interference (RNAi) method, and the role of IFIT2 in regulation of biological behaviors in human gastric cancer cell lines SGC-7901 and AGS was investigated. Polymerase chain reaction (PCR) and Western blotting were used to examine the mRNA and protein level of IFIT2 expression in the LV-IFIT2-short hairpin RNA (shRNA) and LV-NC groups in both SGC-7901 and AGS cells. Results The Real-time PCR results showed that the mRNA expression level of IFIT2 in SGC-7901 as well as AGS cell lines in LV-IFIT2-shRNA group was significantly lower than that in LV-NC group (SGC-7901: 0.426±0.140 vs. 1.000±0.157, P=0.004; AGS: 0.232±0.090 vs. 1.000±0.194, P=0.003). Western blotting results indicated that the IFIT2 expression at the protein level was significantly decreased in the LV-IFIT2-shRNA group compared with the LV-NC group in both SGC-7901 and AGS cells (SGC-7901: 0.344±0.041 vs. 1.000±0.062, P=0.002; AGS: 0.091±0.001 vs. 1.000±0.106, P=0.000). We performed cell counting kit-8 (CCK-8) assay, wound healing assay, transwell assay and cell cycle assay to examine the role of IFIT2 in cell viability, migration and cell cycle, respectively in human gastric cancer cell lines SGC-7901 and AGS. After 48 and 72 hours of cell culture, the absorbance valueof LV-IFIT2-shRNA group was significantly higher than LV-NC group (SGC-7901: 48 h: 0.348±0.031 vs. 0.276±0.026, P=0.013; 72 h: 0.523±0.042 vs. 0.411±0.027, P=0.004; AGS: 48 h: 0.454±0.034 vs. 0.362±0.038, P=0.011; 72 h: 0.696±0.053 vs. 0.553±0.030, P=0.003), which indicated decreased IFIT2 could markedly inhibit SGC-7901 and AGS cell proliferation. Wound healingassay showed decreased IFIT2 expression in human gastric cancer cell lines SGC-7901 and AGS significantly increasedcell migration (SGC-7901: 0.640±0.029 vs. 0.447±0.056, P=0.006; AGS: 0.444±0.036 vs. 0.166±0.034, P=0.001). The transwellassay also showed decreased IFIT2 expression in human gastric cancer cell lines SGC-7901 and AGS significantly increasedcell invasion, and the number of migrating cells stained by crystal violetof LV-IFIT2-shRNA group was significantly higher than LV-NC group (SGC-7901: 299.3±45.6 vs. 162.3±25.9, P=0.011; AGS: 404.0±44.5 vs. 235.0±30.0, P=0.003). According to the cell cycle analyzed by flow cytometry, the ratios of cell in S phase in LV-IFIT2-shRNA group increased compared to the LV-NC group, which indicated down-regulated IFIT2 in gastric cell lines also had an impact on cell cycle. Conclusion Our present study demonstrated that the decreased IFIT2 expression was involved in the promotion of gastric cancer progression. Key words: Anti-interferon-induced protein with tetratricopeptide repeats 2; Gastric cancer; RNA interference

Fisetin inhibits the proliferation of gastric cancer cells and induces apoptosis through suppression of ERK 1/2 activation.

The present study aimed to investigate the effect of fisetin on proliferation and apoptosis of gastric cancer cells, as well as the underlying mechanism. Proliferation in SGC7901 cancer and GES-1 normal cells was analyzed using a CCK-8 assay. Apoptosis was analyzed using an Annexin V/Propidium Iodide apoptosis kit and phosphorylation of extracellular signal-regulated kinase (ERK) 1/2 was analyzed by western blot assay. Treatment of SGC7901 cells with various concentrations (1, 5, 10, 15 and 20 µM) of fisetin for 48 h resulted in a concentration dependent reduction in proliferation. Flow cytometry revealed a marked increase in apoptosis from 5 µM concentration of fisetin after 48 h. The percentage of apoptotic cells increased to 87% following treatment with 15 µM fisetin for 48 h, compared with 2% in control. Treatment of SGC7901 cells with fisetin for 48 h resulted in a reduction in the activation of ERK 1/2 in a concentration-dependent manner. The reduction in activation of ERK 1/2 was significant following treatment with 15 µM fisetin for 48 h. The inhibitory effect of fisetin on activation of ERK 1/2 was further demonstrated using the ERK 1/2 inhibitor, PD98059. The results indicated a significant reduction in the proliferation of SGC7901 cells following treatment with PD98059 (P<0.002). The reduction by PD98059 administration was comparable to that observed following fisetin treatment for 48 h. In conclusion, the current study demonstrates that fisetin inhibits the proliferation of gastric cancer cells and induces apoptosis through suppression of ERK 1/2 activation. Thus, fisetin may have therapeutic applications in the treatment of gastric cancer.

IGF-1-induced MMP-11 expression promotes the proliferation and invasion of gastric cancer cells through the JAK1/STAT3 signaling pathway.

The present study aimed to investigate the association between insulin-like growth factor-1 (IGF-1) and matrix metalloproteinase-11 (MMP-11) expression in gastric cancer (GC) and the underlying mechanisms in SGC-7901 cells. Reverse transcription-quantitative polymerase chain reaction analysis revealed that the expression of IGF-1 and MMP-11 was significantly upregulated in GC tissues compared with normal gastric tissue. Furthermore, IGF-1 significantly and dose-dependently promoted MMP-11. Western blotting revealed that the addition of IGF-1 to SGC-7901 cells led to an evident enhancement in signal transducer and activator of transcription 3 (STAT3), IGF-1R and Janus kinase 1 (JAK1) phosphorylation at 20 and 40 min. A decrease in the extent of the elevated expression of MMP-11 and the enhanced phosphorylation of STAT3, JAK1 and IGF-1 receptor (IGF-1R) induced by IGF-1 in SGC-7901 cells were observed following treatment with NT157 (an IGF-1R inhibitor). Furthermore, piceatannol (a JAK1 inhibitor) or small interfering RNA against STAT3 reduced the extent of the increased expression of MMP-11 induced by IGF-1 in SGC-7901 cells. Piceatannol treatment induced the dose-dependent decline in the enhancement of STAT3 phosphorylation induced by IGF-1, indicating that the JAK1/STAT3 pathway may be implicated in the elevated expression of MMP-11 induced by IGF-1 in SGC-7901 cells. Finally, IGF-1 treatment significantly promoted the proliferation and invasion of SGC-7901 cells, which was inhibited following NT157, piceatannol or si-STAT3 treatment. The present study therefore demonstrated that IGF-1-induced MMP-11 may have facilitated the proliferation and invasion of SGC-7901 cells via the JAK1/STAT3 pathway.

Application values of miR-194 and miR-29 in the diagnosis and prognosis of gastric cancer.

The object of this study was to analyze the expression of miR-194 and miR-29 in gastric cancer and their roles in the regulation of malignant phenotype of gastric cancer cells, and to explore the application value of miR-194 and miR-29 in diagnosis and prognosis of gastric cancer. Tumor tissue and adjacent healthy tissue of 165 gastric cancer patients diagnosed by pathologic examinations were collected. Expression of miR-194 and miR-29 in the tissues was detected by RT-PCR. The relationship between miR-194 and miR-29 expression and clinical data was analyzed. SGC7901 cells were treated with miR-194 and miR-29 mimics, respectively. Effects of miR-194 and miR-29 on proliferation and invasion of SGC7901 cells were investigated. Expression levels of miR-194 and miR-29 in tumor tissue were lower than those in adjacent tissues (P<0.001). There was no significant difference in expression level of miR-194 and miR-29 in cancer tissues derived from gastric cancer patients in different age and gender groups (P>0.05). Expression of miR-194 and miR-29 in tumor tissue was closely related to TNM stage, differentiation degree of cancer cells and lymph node metastasis (P<0.05). Proliferation and migration of SGC7901 cells were significantly inhibited by miR-194 mimic and miR-29 mimic transfection (P<0.05). miR-194 and miR-29 are downregulated in gastric cancer, and the expression levels of miR-194 and miR-29 were closely related to tumor differentiation and metastasis. Overexpression of miR-194 and miR-29 significantly inhibited the proliferation and migration of gastric cancer. The detection of the expression of miR-194 and miR-29 can provide basis for the diagnosis and prognosis of gastric cancer.

Integration of microRNA-mRNA profiles and pathway analysis of plant isoquinoline alkaloid berberine in SGC-7901 gastric cancers cells.

PurposeBerberine (BBR) is a traditional Chinese medicine normally used for gastroenteritis, and recent research found that it could fight against tumors. In this study, we focused on integrating miRNA sequencing and RNA sequencing of SGC-7901 gastric cancer cells treated by BBR to elucidate their underlying mechanisms.Materials and methodsWST-1 assay and flow cytometry were used to check the effects of BBR on SGC-7901. miRNA sequencing and RNA sequencing were used to establish the miRNA and mRNA profiles of BBR-treated SGC-7901.ResultsThe results showed that BBR could inhibit the proliferation of SGC-7901 cells and induce G1 arrest in cell cycle phase and apoptosis. A total of 1,960 upregulated genes and 4,837 downregulated genes were identified in the RNA sequencing and 347 upregulated and 93 downregulated miRNAs in the miRNA sequencing. A total of 78 novel miRNAs were also found. Gene Ontology and Kyoto Encyclopedia of Genes and Genomes analysis showed that the genes were related to pathways in cancer and metabolism. We also analyzed the miRNA–mRNA network of genes grouped into cell cycle, apoptosis, inflammation, metabolism, cell junction, acetylization process, TGF-β pathway, and Wnt signaling pathway.ConclusionBBR could inhibit the proliferation of SGC-7901 cells and induce apoptosis. Integrated analysis of microRNA–mRNA profiles is a promising approach to validate gene expression patterns associated with malignant phenotype and study the mechanisms of anticancer.

Potential mechanism of specific small interfering RNA against ubiquitin-specific protease 22 gene on proliferation of human gastric carcinoma cells

Objective To explore the effects of ubiquitin-specific protease 22 (USP22) on the proliferation of human gastric carcinoma cells and the potential mechanism. Methods The specific small interfering RNA (siRNA) fragments of USP22 were designed, and the highest efficient siRNA was selected by real-time quantitative reverse transcriptase-polymerase chain reaction (RT-qPCR) and Western blotting. The proliferation of SGC-7901 cells was tested using methyl thiazol tetrazolium (MTT) assay after USP22 silencing, and the cell cycle and apoptosis were tested by flow cytometry. The altered expression of cell cycle and apoptosis related proteins was detected by Western blotting. Results The efficiency of USP22 siRNA was more than 80%. The proliferation of SGC-7901 cells was significantly suppressed after USP22 silencing, and the cell cycle was arrested in G0/G1 phase [(52.87±1.41)% vs. (73.73±1.78)%, t=15.491, P=0.000]. Meanwhile, the apoptosis rate was significantly increased by USP22 silencing [(19.63±0.82)% vs. (4.54±0.46)%, t=58.051, P=0.000]. The results of Western blotting revealed that the expression of B cell lymphoma/leukemia-2 associated X protein (bax) was significantly increased (t=10.630, P=0.000), whereas that of B-cell lymphoma/leukemia-2 (bcl-2) and pro-cysteinyl aspartate-specific protease (Caspase)-3 was significantly reduced (t=6.674, 7.269; P=0.000). Furthermore, the phosphorylation of protein kinase B (Akt) and glycogen synthase kinase 3β (GSK3β) was significantly reduced (t=13.512, 6.846; P=0.003). Conclusion Cell growth of SGC-7901 cells was inhibited by USP22 silencing via reducing the activity of Akt. Key words: Ubiquitin-specific protease 22; Gastric carcinoma; Proliferation; Apoptosis; Protein kinase B

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.

F-box protein 11 promotes the growth and metastasis of gastric cancer via PI3K/AKT pathway-mediated EMT

F-box protein 11 (FBXO11) has both the E3 ubiquitin ligase activity and the methyltrasferase activity, and regulates metastasis, apoptosis and chemosensitivity in human cancer. However, the clinical significance and biological function of FBXO11 in gastric cancer (GC) are rarely known. Here, we demonstrated up-regulated expression of FBXO11 in GC tissues in comparison with that in tumor-adjacent tissues. Clinical analysis based on our specimens and the TCGA database revealed that FBXO11 overexpression was associated with large tumor size, lymph node metastasis and advanced TNM stage. Notably, GC patients with high FBXO11 expression showed a significant shorter overall survival. Cell proliferation and mobility were measured by CCK-8 and Transwell assays. FBXO11 silencing by transfection with two specific shRNAs attenuated proliferation, migration and invasion of MGC-803 cells. In accordance, FBXO11 overexpression promoted these cellular processes in SGC-7901 cells. Mechanistically, FBXO11 obviously facilitated epithelial-mesenchymal transition (EMT) process as suggested by immunoblotting and immunofluorescence data. Moreover, we found that FBXO11 promoted the activation of AKT pathway with increased phosphorylated AKT level in SGC-7901 cells. LY294002 and Wortmannin, phosphotidylinsitol-3-kinase (PI3K) inhibitors, blocked FBXO11 induced EMT, proliferation, migration and invasion of SGC-7901 cells. Phosphatase and tensin homolog (PTEN), which played a crucial role in regulating PI3K/AKT pathway, was negatively modulated by FBXO11 in GC cells. Taken together, our findings contribute to current understanding of the functions of FBXO11 and suggest a mechanism by which FBXO11 plays an oncogenic role in the development of GC possibly by inhibiting PTEN and subsequently promoting PI3K/AKT pathway activation.

Mangiferin prevents the growth of gastric carcinoma by blocking the PI3K-Akt signalling pathway.

The aim of the present study was to investigate the effects of mangiferin on gastric carcinoma cells and to determine the possible mechanisms underlying such effects. The MTT assay was performed to evaluate the antiproliferative effect of mangiferin. Following treatment, apoptosis rates of SGC-7901 were established by flow cytometry and laser confocal microscopy, and western blot analysis was used to detect the expression of apoptosis-related proteins. The MTT assay showed that mangiferin inhibited the proliferation of SGC-7901 and BCG-823 cells in a dose-dependent and time-dependent manner. After SGC-7901 cells were exposed to mangiferin for 24, 48 and 72 h, the half-maximal inhibitory concentration values were 16.00, 8.63 and 4.79 µmol/l, respectively. SGC-7901 cell apoptosis induced by mangiferin was observed by Annexin V/PI doubling staining and terminal deoxynucleotidyl transferase dUTP nick end labeling-positive staining. We found a significant decrease in Bcl-2, Bcl-xL and Mcl-1 expression and a significant increase in Bax, Bad and cleaved caspase-3 and caspase-9 expression in SGC-7901 cells by mangiferin treatment. Moreover, mangiferin significantly decreased the levels of p-PI3K, p-Akt and p-mTOR, but had no effects on those of PI3K, Akt and mTOR in epidermal growth factor-treated SGC-7901 cells. Interestingly, the proapoptotic effect of mangiferin on SGC-7901 cells was partially blocked by the Akt activator SC79, whereas LY294002 significantly increased mangiferin-induced apoptosis and growth inhibition. Taken together, our findings indicate that mangiferin effectively inhibits cell growth and induces apoptosis of gastric cancer cells through inhibiting the PI3K/Akt pathways with relative safety, and may be used as a novel chemotherapeutic agent against gastric cancer.

All-trans retinoic acid inhibits the proliferation of SGC7901 cells by regulating caveolin-1 localization via the ERK/MAPK signaling pathway.

Caveolin-1 is a scaffold protein of caveolae in the mucosa of the gastrointestinal tract and acts as a tumor modulator by interacting with cell adhesion molecules and signaling receptors. Caveolin-1 stabilizes cell-cell and cell-matrix contacts and is a hallmark of a number of different types of human cancer, including gastric cancer. All-trans retinoic acid (ATRA), a derivative of vitamin A, has been demonstrated to exhibit tumor inhibitory effects in acute leukemia and certain types of solid tumor. In the present study, treatment with ATRA was demonstrated to inhibit the proliferation of gastric cancer cell line SGC7901, in a time- and dose-dependent manner. The markedly increased membrane localization of caveolin-1 was observed in the cells that were treated with 10 µmol/l ATRA for > 48 h. In addition, it was observed that treatment with ATRA was able to regulate the level of phosphorylation of extracellular signal-regulated kinase (ERK). Therefore, the SGC7901 cells were treated with a specific agonist of ERK/mitogen-activated protein kinase (MAPK) investigate whether ATRA mediated its effects via the ERK/MAPK signaling pathway. The results of the present study demonstrated that ATRA-induced increase in membrane localization of caveolin-1 was reversed by treatment with a specific agonist of ERK/MAPK. Together, these results suggest that ATRA exhibits anti-gastric cancer effects. ATRA may regulate the membrane localization of caveolin-1 in order to inhibit the proliferation of SGC7901 cells. These effects of ATRA may be mediated by inhibiting the activation of ERK/MAPK signaling pathway. These results contribute to the current knowledge on the potential use of ATRA as therapy for solid tumors and provide further insight into the potential molecular mechanisms of ATRA action.

MiR-613 inhibits gastric cancer progression through repressing brain derived neurotrophic factor.

MicroRNA (miR)-613 has been reported to function as a tumor suppressor in several types of cancer. However, the biological function and underlying mechanism in gastric cancer (GC) has remained elusive. Therefore, the aim of the present study was to assess the expression and biological role of miR-613 in GC tissues and cell lines. miR-613 expression was found to be downregulated in 38 GC tissue samples compared to that in their adjacent non-cancerous tissues, and low expression of miR-613 was associated with lymph node metastasis and advanced tumor-nodes-metastasis stage. A gain-of-function assay demonstrated that miR-613 overexpression reduced tumor cell proliferation, migration and invasion of SGC-7901 cells, as determined by MTT and Transwell assays. Furthermore, brain-derived neutrophic factor (BDNF) was identified as a direct target of miR-613 in GC cells by a luciferase reporter assay. BDNF expression was upregulated and inversely correlated with miR-613 levels in GC tissues. In addition, knockdown of BDNF expression mimicked the tumor suppressive effect of miR-613 in GC cells. In conclusion, these findings demonstrated that miR-613 functions as a tumor suppressor in GC by targeting BDNF. Thus, miR-613 is a potential therapeutic target for GC.

Downregulation of Inhibition of Apoptosis-Stimulating Protein of p53 (iASPP) Suppresses Cisplatin-Resistant Gastric Carcinoma In Vitro.

BackgroundGastric cancer (GC) with cisplatin resistance is one of the leading causes of limitations to therapy. Inhibition of apoptosis-stimulating protein of p53 (iASPP) plays a key role in GC. However, the role of iASPP in GC with cisplatin resistance remains unclear. The aim of this study was to investigate iASPP expression in GC, and the functions of iASPP in cisplatin-resistant cell lines.Material/MethodsIn this study, the expression of iASPP was investigated in normal GC patients and patients with cisplatin resistance, along with GC cell lines and cell lines with cisplatin resistance. Furthermore, knockdown of iASPP was conducted in cell lines; and cell proliferation, apoptosis rate, cell cycle distribution, and cell migration and invasion were determined through CCK8, flow cytometry, Scratch test and Transwell assay, respectively.ResultsThe expression of iASPP in GC patients with cisplatin resistance was significant higher than in the health control group. Higher expression of iASPP was detected in cisplatin-resistant cancer cell lines. Cell proliferation of SGC-7901 and MGC-803 was inhibited by transfection with siRNA, along with evaluated apoptosis rate and G1 phase retardant. Furthermore, cells viability, including migration and invasion, was suppressed post-transfection with siRNA.ConclusionsiASPP induced cisplatin resistance in GC patients. Thus, knockdown of iASPP might be a novel therapeutic strategy for the treatment of GC cisplatin-resistant patients.

MiR-203a suppresses cell proliferation by targeting E2F transcription factor 3 in human gastric cancer.

MicroRNAs (miRs) are a class of short non-coding RNAs that serve an essential role in the tumorigenesis of gastric cancer (GC). MiR-203a has been reported as a tumor repressor in various types of human cancer. In the present study, the function of miR-203a on the proliferation of GC cells was investigated. Bioinformatics analyses revealed that miR-203a targets the 3'-untranslated region of E2F transcription factor 3 (E2F3) messenger RNA. A luciferase reporter assay and western blot analysis were performed to confirm whether E2F3 was a target of miR-203a. The relative luciferase activity was decreased when overexpressing miR-203a with E2F3-wild type pmirGLO-3'-untranslated region vector, compared with the control group in HEK293 cells. Overexpression of miR-203a suppressed cell proliferation and colony formation of SGC-7901 and AGS GC cells. Inhibition of miR-203a promoted the proliferation of GC cells. Collectively, the results indicated that miR-203a may function as a tumor suppressor in GC by targeting E2F3.

MiR-93-5p promotes gastric cancer-cell progression via inactivation of the Hippo signaling pathway

MiR-93-5p has been previously found to be associated with gastric cancer (GC) tumorigenesis; however, the current understanding of its function in this context remains largely incomplete. In the present study, we showed that miR-93-5p was upregulated in GC tissues. We also demonstrated that miR-93-5p overexpression promoted the proliferation, migration, invasion, and chemoresistance of SGC-7901 cells in vitro, and conversely, that endogenously silencing miR-93-5p expression induced the opposite effects in HGC-27 cells. Overexpression of miR-93-5p was found to inactivate the Hippo pathway, and furthermore, miR-93-5p knockdown activated Hippo signaling. MiR-93-5p upregulation was also shown to inhibit the expression of two well-characterized Hippo pathway regulators, protocadherin Fat 4 (FAT4), and large tumor suppressors 2 (LATS2), at both the mRNA and protein level. Additionally, the results of bioinformatics analyses and luciferase reporter assays indicated that miR-93-5p directly targets the 3′-UTR of FAT4 and LATS2. Taken together, these results demonstrate that miR-93-5p promotes GC-cell progression via the inactivation of the Hippo signaling pathway, and thus, represents a potential therapeutic target for the treatment of GC.

Inhibitory effect of the low-toxic exogenous aryl hydrocarbon receptor modulator 3'3-diindolylmethane on gastric cancer in mice.

3'3-Diindolylmethane (DIM) has been proved to exhibit anticancer properties in many solid tumors. In our previous study, we demonstrated that DIM inhibited SGC7901 cell proliferation by inducing apoptosis and delaying cell cycle progression. Herein, we further explored the anti-tumor effect of DIM on SGC-7901 tumor bearing mice. Tumors were excised, weighed, and tested by western blot and TdT-UTP nick-end labeling (TUNEL) assay. Blood samples were collected for biochemical analysis. The expression levels of AhR and cytochrome P450, family 1, subfamily A, polypeptide 1 (CYP1A1) protein were evaluated by western-blot assay. Our data show that with the increase of DIM dose (0, 5, 10, 20 mg/kg/day), AhR protein gradually decreased as CYP1A1 protein increased. The weight of the tumors found in the treated animals was significantly lower than that of the control group (0.845±0.096 vs. 1.275±0.236 g, 0.768±0.161 vs. 1.275±0.236 g, 0.607±0.106 vs. 1.275±0.236 g, P<0.05). TUNEL test showed that DIM induced increased apoptosis in the treatment groups in a dose-dependent manner. Blood tests also indicated that DIM showed no toxic effect on animal weight or liver and kidney function. These results indicated that DIM agent could be a safe and potent drug in therapy of gastric cancer.

Effect of 15-PGDH on the Proliferation and Migration of Human Gastric Cancer Cells

Objective: To investigate the effect of stable transfection with NAD+-linked 15-hydroxyprostaglandin dehydrogenase (15-PGDH) on the growth, proliferation and migration of gastric cancer cells. Methods: The levels of 15-PGDH in four kinds of gastric cancer cells with different differentiation rates were compared by RT-PCR measurements, and the poorly differentiated gastric cancer cells SGC7901 were chose to perform follow-up experiments. SGC7901 cells were transfected with recombinant plasmid pcDNA3/15-PGDH and empty plasmid pcDNA3 as a control by using lipofectamine 2000. Cells with steady expression capability were sorted out by G418. RT-PCR and Western blot were used to confirm the transfection and expression of 15-PGDH in SGC7901 cells. MTT, cell scratch assay, soft-agar colony formation assays were used to determine the proliferation, migration and cell clone formation activities of SGC7901 with stable transfection of 15-PGDH. Flow cytometry assay was used to examine the effect of 15-PGDH on cell cycle and apoptosis. RT-PCR was used to analyze the levels of cell cycle-related genes (p53, p21 and p16) and apoptosis-related genes (Survivin, BCL-2 and Caspase3). Results: Both recombinant plasmid pcDNA3/15-PGDH and empty vector plasmid pcDNA3 were successfully transfected into human gastric cancer SGC7901 cell line. Proliferation, migration and cell clone formation capabilities of pcDNA3/15-PGDH groups were significantly inhibited compared with other two control groups (P<0.05). Flow cytometry results demonstrated an increased fraction of sub-G1 phase and the increase of apoptotic cells for pcDNA3/15-PGDH groups compared with other two control groups (P<0.05). The levels of p16, p21 and p53 mRNA for pcDNA3/15-PGDH groups were higher than those in other two control groups (p<0.05). pcDNA3/15-PGDH groups exhibited a higher level of caspase3 mRNA but lower levels of survivin and BCL-2 mRNA in SGC7901 cells compared with other two control groups (P< 0.05). Conclusion: The gene transfection of 15-PGDH has negative effects on the growth, proliferation and migration of gastric cancer SGC7901 cells by inducing apoptosis and cell cycle arrest.

Effect of FABP5 gene silencing on the proliferation, apoptosis and invasion of human gastric SGC-7901 cancer cells.

The aim of the present study was to examine the effect of fatty acid binding protein-5 (FABP-5) gene on the proliferation, apoptosis and invasion of human gastric cancer SGC-7901 cells. The viability, apoptosis and cell invasion of SGC-7901 cells before and after FABP5 knockdown were taken as the study objects, design and synthesis of siRNA interference sequence were conducted according to FABP-5 mRNA coding sequences, and SGC-7901 cells were transiently transfected. The human gastric cancer SGC-7901 cells were divided into three groups: FABP-5 siRNA group, negative control group and blank control group. FABP-5 gene mRNA and protein expression levels were detected by RT-PCR and western blot analysis. The CCK-8 assay was used to detect in vitro cell proliferation, flow cytometry (FCM) was used to detect changes in cell cycle and apoptosis in each group, TUNEL staining was used to detect apoptosis in each group, and the cell invasion chamber assay was used to detect cell invasiveness in each group. Each test was repeated three times. The results of the RT-PCR and western blot analysis showed that, expression of FABP-5 mRNA and protein in the FABP-5 siRNA group was significantly decreased compared with the negative and blank control groups. The cell growth rate in the FABP-5 siRNA group was significantly retarded, cell cycle was arrested in G0/G1 phase, the number of cells in S phase was reduced, and compared with the negative and blank control groups, the apoptotic rate in the FABP-5 siRNA group was significantly increased (P<0.01), while proliferation and invasiveness were significantly decreased (P<0.05). In conclusion, specific FABP-5 gene silencing may reduce the invasiveness of gastric cancer cells, inhibit cell proliferation, and arrest cell cycle in G0/G1 phase, resulting in a significant increase in apoptosis.