Invasion Of SGC-7901 Cells Research Articles

The mediating role of AKT/ERK/JNK signaling on the malignant phenotype of microcystin-LR in gastric adenocarcinoma cells

Microcystin-leucine arginine (MC-LR), a widely distributed and highly toxic environmental pollutant, plays crucial roles in cancer malignancy by activating characteristically toxic signaling pathways. Traditional animal-based toxicity evaluation methods have proven insufficient for identifying the specific role of these signaling pathways. Therefore, this study aimed to uncover the regulatory relationship between the toxic pathways and the progression of gastric cancer (GC). The findings provide novel avenues for conducting in vitro toxicity tests based on the investigated pathways. We found that MC-LR promoted the migration and invasion of SGC-7901 cells while simultaneously inhibiting their apoptosis in a dose-dependent manner. This observed cytotoxicity was primarily mediated through the AKT, JNK, and ERK signaling pathways. By using a mediation analysis model, we determined that AKT and ERK exhibited competitive effects in MC-LR-treated GC malignancy, while AKT and JNK acted independently from one another. This study establishes an in vitro toxicity test model of MC-LR based on toxicity-related pathways and underscores the pivotal roles of AKT, ERK, and JNK signaling in MC-LR toxicity. The findings offer a novel, fundamental framework for conducting chemical toxicity risk assessment.

Functional Study of SAMD9L in Familial Gastric Cancer.

Familial aggregation occurs in approximately 10% of cases of gastric cancer. The genetic predisposition or cause of the disease in only about 40% of hereditary gastric cancer cases is known, while the genetic factors of the remaining cases remain to be studied. Samples were collected from a family with gastric cancer, including 3 gastric cancer and 17 healthy samples. Whole-exome sequencing was performed on samples from 3 patients with gastric cancer and 1 sample from healthy peripheral blood. SAMD9L was knocked down using small interfering RNAs and short hairpin RNA. The expression of SAMD9L was detected by quantitative real-time polymerase chain reaction and Western blot in SGC-7901 cells. CCK-8 assay was used to detect the proliferation of gastric cancer cells. The migration and invasion of gastric cancer cells were detected by Transwell assay and scratch assay. The cell apoptosis was detected by flow cytometry. Twelve single-nucleotide variants and 9 insertions/deletions mutation sites were identified as candidate genes. Among them, SAMD9L regulates cell proliferation as a tumor suppressor gene. The experiments of knocking down SAMD9L in SGC-7901 cells revealed that reduced expression of SAMD9L significantly enhanced the proliferation, migration, and invasion of SGC-7901 cells. These results suggest that SAMD9L inhibits the proliferation of gastric cancer cells, thereby increasing the risk of gastric cancer in people with SAMD9L downregulation. Therefore, SAMD9L may represent a susceptibility gene of this gastric cancer family.

Interleukin-8 Regulates the Autophagy and Apoptosis in Gastric Cancer Cells via Regulating PI3K/Akt Signaling Pathway.

Objective To explore the role and mechanism of interleukin-8-mediated autophagy regulation of gastric cancer (GC) cells in GC. Methods After cell culture, the SGC7901 cell line was separated into the control group and IL-8 (20 ng/mL) group, IL-8 (40 ng/mL) group, and IL-8 (60 ng/mL) group, to verify the effects of the PI3K/Akt signal path on the modulation of autophagy in GC cells. Western blot detected autophagy markers, ATG12-ATG5 complexes, autophagy-associated pathways, and apoptosis-associated factors in GC cells. Transwell was utilized to identify invasion capability. Results Compared with the control group, the expression of LC3II, Atg5, ATG7, Beclin1, Bax, C-cas3, C-cas9, P-PI3K, P-Akt, and ATG12-ATG5 was remarkably elevated in the IL-8 (60 ng/mL) group, IL-8 (20 ng/mL) group, and the IL-8 (40 ng/mL) group. The expression of P62 and Bcl-2 in the IL-8 (60 ng/mL) group was also lower than that of the IL-8 (20 ng/mL) group and IL-8 (40 ng/mL) group, in contrast to the controls. The invasive quantity of GC SGC7901 cells in the IL-8 (60 ng/mL) group was also remarkably higher in contrast to the IL-8 (20 ng/mL) and IL-8 (40 ng/mL) groups. The relative expressions of LC3II, Atg5, ATG7, Beclin1, Bax, C-cas3, C-cas9, P-PI3K, P-Akt, and ATG12-ATG5 complex proteins in LY294002 group were considerably elevated. LC3II, Atg5, ATG7, Beclin1, Bax, C-cas3, C-cas9, P-PI3K, P-Akt, and ATG12-ATG5 were decreased in the IL-8 + LY294002 group. The relative expressions of P62 and Bcl-2 proteins in the IL-8 + LY294002 group were remarkably elevated, and the invasion of SGC7901 cells in the IL-8 group was elevated. In contrast to the IL-8 group, the invasion quantity of gastric cancer SGC7901 cells in the IL-8 + LY294002 group was considerably decreased. Conclusion IL-8 promotes autophagy and aggression and suppresses apoptosis of GC SGC7901 cells by regulating PI3K/AKT pathway phosphorylation.

Betulinic acid targets drug-resistant human gastric cancer cells by inducing autophagic cell death, suppresses cell migration and invasion, and modulates the ERK/MEK signaling pathway.

The main purpose of this study was to examine the anticancer effects of betulinic acid - a plant triterpene, against gastric cancer, along with demonstrating its underlying mechanism. The MTT assay and clonogenic assays were executed to assess cellular viability in control and betulinic acid treated cells. Transmission electron microscopy and western blotting were implemented to study autophagy stimulation by betulinic acid. The ERK/MEK signaling pathway was monitored by western blotting. Migration and invasion of SGC-7901 cells was investigated via transwell chamber assay. Results of this investigation indicated that betulinic acid induced remarkable cytotoxicity against gastric cancer SGC-7901 cells, in contrast to normal gastric GES-1 cells. The cytotoxicity of betulinic acid was observed due to its autophagy stimulation tendency in target cells. Autophagic cell death was supported by the data attained from western blotting showing enhanced LC3-II, and lowered LC3-I and p62 expressions. Moreover, betulinic acid was observed to block the ERK/MEK signaling pathway in SGC-7901 cells, which was associated with declined levels of expressions of the phosphorylated ERK and MEK proteins. Finally, the transwell chamber assay revealed a potential lowering of migration and invasion by betulinic acid in the SGC-7901 cells. In conclusion, these results demonstrated that betulinic acid exhibited significant anti-gastric cancer effects mediated via autophagy induction, blocking of ERK/MEK signaling and suppression of migration and invasion. Therefore, betulinic acid may prove as a lead molecule in gastric cancer management and research.

IGHG1 induces EMT in gastric cancer cells by regulating TGF-β/SMAD3 signaling pathway.

Objective: Gastric cancer is one of the most common malignant tumors in the world. IGHG1 is a differentially expressed protein screened out in gastric cancer in the early stage of the subject group. This topic explores the expression of IGHG1 in gastric cancer and the effect of IGHG1 on the proliferation, migration, invasion and EMT of gastric cancer SGC7901 cells and its mechanism of action.Methods: Twenty cases of gastric cancer were purified by laser Capture Microdissection. The isotopic tags for relative and absolute quantification was used to label the proteins, and then analyzed and identified them by quantitative proteomics. Immunohistochemical staining method was used to detect the expression of IGHG1 protein in gastric cancer tissues. Western blot was used to detect the expression of IGHG1 in gastric cancer cells. The MTT and Petri dish clone formation experiment analyzed the effect of low expression of IGHG1 on the proliferation of SGC7901 cells. Scratch test and Transwell migration and invasion test to observe the effect of low expression of IGHG1 on the migration and invasion of SGC7901 cells. Western blot was used to detect the effect of low expression of IGHG1 on the expression of EMT-related proteins.Results: 243 proteins related to gastric mucosal lesions were preliminarily identified. We found that IGHG1 is highly expressed in gastric cancer tissues compared with normal control tissues. IGHG1 promotes the proliferation, migration and invasion of gastric cancer cells. Compared with the control group, the expression of EMT-related proteins Vimentin, N-cadherin, TGF-β, P-SMAD3 was decreased and the expression of E-cadherin was increased after IGHG1 low expression.Conclusions: IGHG1 induces EMT in SGC7901 cells by regulating the TGF-β/SMAD3 signaling pathway.

Resveratrol Counteracts Hypoxia-Induced Gastric Cancer Invasion and EMT through Hedgehog Pathway Suppression.

Gastric Cancer (GC) is one of the most malignant and lethal tumors worldwide. The hypoxic microenvironment is correlated with GC cell invasion, metastasis and Epithelial-Mesenchymal Transition (EMT). Resveratrol is a compound extracted from various plants, including grapes, berries, and some traditional Chinese medicines. Recently, the anticancer properties of resveratrol against many cancers have been reported in a range of studies. However, the exact mechanism through which resveratrol prevents GC invasion and metastasis under hypoxic conditions remains unclear. The objective of this study is to show to what extent resveratrol could inhibit the hypoxia-induced malignant biological behavior of GC. SGC-7901 cells were cultured in a consistent 3% O2 hypoxic condition or 21% O2 normal condition for 48 hours to establish an in vitro hypoxia model. Western blot and qRT-PCR were used to detect EMT markers of SGC- 7901 cells, including E-cadherin, HIF-1a, Vimentin, etc. Transwell Matrigel Invasion Assays were used to test the invasive ability of SGC-7901 cells. The siRNA targeting Gli-1 showed its role in hypoxia-induced EMT and invasion of SGC-7901 cells. Resveratrol was found to significantly decrease HIF-1α protein levels induced by hypoxia in SGC-7901 cells. HIF-1α accumulation was found to promote cell proliferation, migration, and invasive capacities in addition to EMT changes through the activation of the Hedgehog pathway. These effects were found to be reversed by resveratrol. Therefore, these data indicate that resveratrol may serve as a potential anticancer agent for the treatment of GC, even in a hypoxic tumor microenvironment.

Curcumin Promoted miR-34a Expression and Suppressed Proliferation of Gastric Cancer Cells.

Background: To investigate the effects of curcumin on miR-34a and proliferation of gastric cancer cells. Materials and Methods: Human gastric cancer cell line SGC-7901 was divided into control, curcumin, miR-34a agomir (miR-34a), miR-34a agomir negative control, and curcumin combined miR-34a antagomir (combine) groups. 3-(4, 5-dimethylthiazolyl-2)-2, 5-diphenyltetrazolium bromide assay, scratch damage test, and transwell assay were used to detect cell proliferation, migration, and invasion. The cell apoptosis and cell cycle were detected by flow cytometry. Western blot was used to detect the expression of B-cell lymphoma-2 (Bcl-2), cyclin-dependent kinase 4 (CDK4), and cyclin D1. Terminal deoxynucleotidyl transferase-mediated dUTP nick-end labeling was used to detect apoptosis of tumors and Western blot was used to detect the expression of Bcl-2, CDK4, and cyclin D1 in tumors. Results: The results showed that curcumin markedly increased the content of miR-34a microRNA (mRNA) in SGC-7901 cells, inhibited proliferation, migration, and invasion of SGC-7901 cells, when compared to control group (p < 0.05). Compared with control group, curcumin significantly inhibited cell cycle progression in G0/G1-S phase, increased the cell number of G0/G1 phase, and downregulated the Bcl-2, CDK4, and cyclin D1 protein expression in cells and tissues (p < 0.05). After transfection of miR-34a agomir or antagomir into cells it was found that miR-34a agomir and curcumin had similar effects on resisting malignant biological behavior. Curcumin combined with miR-34a antagomir could weaken or reverse the above results. Conclusions: Curcumin could inhibit the proliferation and induce apoptosis of SGC-7901 cells. Its mechanism might be related to the miR-34a expression in cells, thus affecting the expression of Bcl-2, CDK4, and cyclin D1.

Long non-coding RNA LUCAT1 promotes proliferation and invasion in gastric cancer by regulating miR-134-5p/YWHAZ axis

PurposeThe aim of this study was to research the function of lncRNA LUCAT1 in gastric cancer. MethodsHuman gastric cancer tissues and paracancer tissues were obtained from 98 patients undergoing surgical resection in our hospital. The human gastric cancer cell lines (HGC27, BGC823, MGC803, SGC7901 and AGS), and normal gastric mucosal cell line GSE1 were used to research the role of lncRNA LUCAT1. ShRNAs specifically targeting lncRNA LUCAT1, miR-134-5p mimic, miR-134-5p inhibitor and their related controls were transfected into cells. Quantitative real-time PCR was used to detect the expression of lncRNA LUCAT1, miR-134-5p and YWHAZ. The cell proliferation of SGC7901 cells was determined by CCK8 kit. Colony formation assay was undertaken. Cell apoptosis assay was processed using the Annexin V-FITC / propidium iodide (annxinV/PI) apoptosis detection kit. Migration and invasion were detected by transwell assay. Tumor xenograft model was conducted to calculate the size and weight of the tumors. Luciferase reporter assay was used to confirm the interactions among lncRNA LUCAT1, miR-134-5p and YWHAZ. ResultsLncRNA LUCAT1 was confirmed to be highly expressed in gastric cancer. Patients with high LUCAT1 level displayed short overall survival and disease-free survival periods. LUCAT1 knockdown or miR-134-5p overexpression decreased the proliferation, colony formation, migration and invasion of SGC7901 cells. ConclusionsLncRNA LUCAT1 could promote proliferation and invasion of gastric cancer by regulating miR-134-5p/YWHAZ axis.

Strategy and validation of a structure-based method for the discovery of selective inhibitors of PAK isoforms and the evaluation of their anti-cancer activity

p21 activated kinase 4 (PAK4), which belongs to the serine/threonine (Ser/Thr) protein kinase family, is a representative member of the PAK family and plays a significant role in multiple processes associated with cancer development. In this study, structure-based virtual screening was performed to discover novel and selective small molecule scaffolds, and a 6-hydroxy-2-mercapto-3-phenylpyrimidin-4(3H)-one-based compound (SPU-106, 14#) was identified as an effective PAK4 inhibitor. By combining both a molecular docking study and molecular dynamics (MD) simulation strategies, the binding mode was determined in the PAK4 site. The SPU-106 compound could efficiently and selectively bind to the PAK4 kinase domain at an IC50 of 21.36 μM according to the kinase analysis. The designed molecular probe demonstrated that SPU-106 binds to the kinase domain in the C-terminus of PAK4. Further investigation revealed that the SPU-106 had a strong inhibitory effect on the invasion of SGC7901 cells but without any cytotoxicity. The western blot analysis indicated that the compound potently inhibited the PAK4/LIMK1/cofilin and PAK4/SCG10 signaling pathways. Thus, our work shows the successful application of computational strategies for the discovery of selective hits, and SPU-106 may be an effective PAK4 inhibitor for further development as an antitumor agent.

Expression of pleomorphic adenoma gene like-2 in gastric carcinoma and its possible mechanism on invasion and epithelial-mesenchymal transition of gastric carcinoma

Objective To detect the expression of pleomorphic adenoma gene like-2 (PLAGL2) in human gastric cancer and cell lines, and its role in cell invasion and epithelial-mesenchymal transition (EMT) and the molecular mechanism involved. Methods Fifteen cases of pathologically confirmed gastric cancer tissues and their adjacent normal tissues were collected during operation in our hospital from Jan. 10, 2016 to Mar. 20, 2018. Gastric cancer cell lines MKN-28, BGC-823, NCI-N87 and SGC-7901 were cultured. The expression levels of PLAGL2 in gastric cancer tissue samples and MKN-28, BGC-823, NCI-N87 and SGC-7901 cells were determined by real-time quantitative polymerase chain reaction (Real-time PCR) and Western blotting. After successful transfection with PLAGL2-small interfering RNA (siRNA) in SGC-7901 cells, the expression levels of PLAGL2 mRNA and protein were detected by Real-time PCR and Western blotting respectively. Cell invasion was detected by Transwell assay. The expression levels of N-cadherin, Vimentin and E-cadherin, which were EMT related markers, and Wnt/β-catenin related proteins were detected by Western blotting. After PLAGL2-siRNA SGC-7901 cells were treated with Wnt pathway agonist SKL2001 and inhibitor XAV939, the changes of cell invasion ability were retested by Transwell assay. Results The expression levels of PLAGL2 mRNA (1.11±0.27) and protein (0.98±0.26) in gastric cancer tissues were significantly higher than those in the adjacent tissues (mRNA: 0.37±0.10; protein: 0.28±0.11; t=-20.941, P<0.01; t=-20.186, P<0.01). The expression levels of PLAGL2 mRNA and protein in MKN-28, BGC-823, NCI-N87 and SGC-7901 were significantly higher than GES-1 cells (mRNA: t=-12.327, P<0.01; t=-19.812, P<0.01; t=-13.080, P<0.01; t=-15.218, P<0.01; protein: t=-11.816, P<0.01; t=-21.162, P<0.01; t=-14.517, P<0.01; t=-15.899, P<0.01). The expression levels of PLAGL2 mRNA and protein in SGC-7901 cells were significantly decreased after PLAGL2-siRNA transfection (mRNA: 2.10±0.29; protein: 1.96±0.27) as compared with control siRNA group (mRNA: 6.61±0.73; protein: 6.46±0.71; t=-1.000, P<0.01; t=-1.000, P<0.01). The number of invasive cells at 24, 48, 72 hin PLAGL2-siRNA transfection group [(30.75±5.74), (48.75±6.90) and (64.50±4.80) cells] was significantly less than in control siRNA group [(51.00±4.97), ( 75.75±4.92) and (132.50±5.57) cells; t=-1.000, P<0.05; t=-1.000, P<0.01; t=-1.000, P<0.01]. The expression of N-cadherin, Vimentin, β-catenin, matrix metalloproteinase (MMP)-7 and c-Myc proteins was significantly down-regulated, and that of E-cadherin protein was significantly up-regulated (t=-1.000, P<0.01; t=-1.000, P<0.01; t=-1.000, P<0.01; t=-1.000, P<0.01; t=-1.000, P<0.01; t=-8.205, P<0.01). SKL2001 could reverse the inhibitory effect on EMT and invasion of SGC-7901 cells after PLAGL2-siRNA transfection, while XAV939 enhanced the above effects of PLAGL2-siRNA. Conclusion PLAGL2 is highly-expressed in gastric cancer. Inhibition of PLAGL2 gene by siRNA can inhibit the invasion of gastric cancer cells probably by down-regulating the Wnt/β-catenin signaling pathway. Key words: Gastric cancer; Invasion; Pleomorphic adenoma gene like-2; Epithelial-mesenchymal transition; Wnt/β-cateninn signaling pathway

Mechanism of β-carboline alkaloids inhibiting migration and invasion of SGC-7901 cells

To explore the mechanism of β-carboline alkaloids inhibiting the migration and invasion of SGC-7901 cells and its correlation with FAK gene expression,CCK-8 method was used to determine the inhibitory rate of β-carboline alkaloids on the proliferation of gastric cancer SGC-7901 cells under different concentrations.The effect of β-carboline alkaloids on the migration and invasion of SGC-7901 cells was used by Transwell compartment.Detection of mRNA and protein expression of FAK genes were used by qRT-PCR and Western blot.Then si-FAK-1051 recombinant plasmid was transfected into SGC-7901 cells.FAK gene silencing effect was identified by qRT-PCR and Western blot technique again.Finally,the effects of FAK gene silencing on proliferation and migration of gastric cancer SGC-7901 cells were detected by CCK-8 kit and Transwell chamber assay respectively.With the increase of the concentration ofβ-carboline alkaloids,the inhibitory rate of SGC-7901 cells in human gastric cancer cells increased gradually,with IC5013.364 mg·L-1.The number of SGC-7901 cells of Transwell compartment in the positive experimental group(5-FU,5 mg·L-1) and the β-carboline alkaloids group decreased significantly(P<0.01) and the number of SGC-7901 cells in the β-carboline alkaloids group was significantly lower than that in the positive experimental group(P<0.01).Compared with the blank control group,the mRNA and protein expression level of FAK genes in the positive experimental group was significantly lower than that in the experimental group of β-carboline alkaloids(P<0.05).After transfection of si-FAK-1051 into gastric cancer SGC-7901 cells,the expression of mRNA and protein of FAK gene was significantly down regulated(P<0.05).SGC-7901 cell proliferation and cell migration ability also decreased significantly(P<0.05).β-carboline alkaloids are more effective than 5-FU in inhibiting migration and invasion of gastric cancer SGC-7901 cells,and the mechanism may be related to the inhibition of mRNA and protein expression of FAK gene by β-carboline alkaloids.

Effects of long intergenic non-coding RNA FEZF1-AS1 on proliferation and invasion of gastric cancer cells SGC-7901

Objective To investigate the effects of long intergenic non-coding RNA (Linc) FEZF1-AS1 on proliferation and invasion of SGC-7901 cells. Methods The SGC-7901 cells were classified into two groups: FEZF1-AS1 small interfering RNA (si-FEZF1-AS1) and the negative control siRNA (si-NC). Linc FEZF1-AS1 was knocked down in si-FEZF1-AS1 group by small interfering RNA (siRNA). The proliferative activity of SGC-7901 cells was determined by colony formation assay and cell counting kit-8 (CCK-8) assay, and the invasion ability was studied by wound healing assay and Transwell assay. The expression levels of epithelial-mesenchymal transition (EMT)-related molecules was detected by RT-PCR and Western blotting. Results The results of colony formation assay showed that the colony-forming capacity was impaired in si-FEZF1-AS1 group compared to the si-NC group [(26.78±3.34)% vs. (43.22±4.35)%, t=5.194, P=0.007]; CCK-8 results revealed that the proliferation of SGC-7901 cells was dramatically inhibited in si-FEZF1-AS1 group after 3 days [(31.32±4.48)% vs. (13.86±0.64)%, t=11.590, P=0.000]; Scratch tests showed that, 48 h after scratches in SGC-7901 cells, the space between scratches was significantly increased as compared with that in si-NC group [(598.67±18.81) vs. (428.32±13.90) μm, t=12.620, P=0.000]; The results of Transwell assay also indicated that the number of metastatic cells in the si-FEZF1-AS1 group was significantly decreased compared to the si-NC group [(60.50±5.13) vs. (103.50±9.54), t=7.942, P=0.001]; The results of RT-PCR showed that the relative mRNA expression levels of E-cadherin were increased in si-FEZF1-AS1 group [(2.01±0.36), t=5.435, P=0.002], and those of Vimentin and β-catenin were decreased [(0.54±0.05), t=9.734, P=0.000; (0.50±0.10), t=8.019, P=0.000]. The results of Western blotting revealed that the expression levels of E-cadherin in si-FEZF1-AS1 group were significantly increased as compared with the si-NC group [(86 304±447) vs. (35 623±227), t=175.100, P=0.000], and those of Vimentin and β-catenin in the si-FEZF1-AS1 group were significantly decreased as compared with the si-NC group [(29 135±89) vs. (82 253±353), t=252.800, P=0.000; (15 283±147) vs. (42 506±245), t=165.200, P=0.000]. Conclusion Dysregulation of Linc FEZF1-AS1 can suppress proliferation and invasion of SGC-7901 cells, which may be related to the Wnt/β-catenin signaling pathway. Key words: Gastric cancer; Long intergenic non-coding RNA; Proliferation; Invasion

Retracted: Suppression of BMX‐ARHGAP fusion gene inhibits epithelial‐mesenchymal transition in gastric cancer cells via RhoA‐mediated blockade of JAK/STAT axis

Gastric cancer (GC) is one of the main causes of cancer-related mortality worldwide. Epithelial-mesenchymal transition (EMT) is an important biological process involving the process by which malignant tumor cells obtain the ability of migration, invasion, resistance of apoptosis, and degradation in the extracellular matrix. The current study aimed at investigating whether bone marrow X kinase Rho GTPase activating protein 12 (BMX-ARHGAP) fusion gene affects GC. First, short hairpin RNA (shRNA) against BMX-ARHGAP or BMX-ARHGAP were introduced to treat SGC-7901 cells with the highest BMX-ARHGAP among the five GC cell lines (SGC-7901, MKN-45, NCI-N87, SNU-5, and AGS). Next, cell vitality, drug resistance, migration, and invasion of SGC-7901 cells, activities of Rho and JAK/STAT axis, as well as EMT and lymph node metastasis (LNM) were evaluated. The survival rate of the mice was then determined through the transfection of the specific pathogen-free NOD-SCID mice with treated SGC-7901 cells. The results showed that BMX-ARHGAP expression was associated with the infiltration degree of GC tumor and poor prognosis for patients with GC. BMX-ARHGAP silencing was found to play an inhibitory role in the Rho and JAK/STAT axis to reduce cell vitality, drug resistance, migration and invasion, reverse EMT process, as well as inhibit LNM. BMX-ARHGAP overexpression was observed to have induced effects on GC cells as opposed to those inhibited by BMX-ARHGAP silencing. The survival rate of mice was increased after transfection with silenced BMX-ARHGAP. These findings provided evidence that the suppression of BMX-ARHGAP resulted in the inhibition of RhoA to restraint the development of GC cells by blocking the JAK/STAT axis.

TMEM119 promotes gastric cancer cell migration and invasion through STAT3 signaling pathway.

ObjectiveTMEM119 is a member of transmembrane proteins family, which is abnormally expressed in human cancers and associated with tumorigenesis. In this study, we focused on the expression of TMEM119 and its role in cell invasion and migration in gastric cancer.MethodsReal-time polymerase chain reaction, Western blotting, and immunohistochemistry were performed to examine the expression of TMEM119 in gastric cancer tissues and cell lines. After transfection with TMEM119 siRNA or recombined TMEM119-expressing vector, the invasion and migration ability of MKN45 and SGC-7901 cells was measured by transwell assay. The expression of TMEM119, p-STAT3, STAT3, VEGF, MMP2, and MMP9 proteins in SGC-7901 and MKN45 cells treated with TMEM119 siRNA, TMEM119-expressing vector, or AG490 was measured by Western blotting.ResultsWe found that higher TMEM119 expression was found in gastric cancer tissues and cell lines and was associated with lower survival rate. TMEM119 knockdown inhibited SGC-7901 cell invasion and migration, along with the expression of p-STAT3, VEGF, MMP2, and MMP9. TMEM119 overexpression promoted MKN45 cell invasion and migration, along with the expression of p-STAT3, VEGF, MMP2, and MMP9. Additionally, AG490 treatment significantly corrected TMEM119-induced MKN45 cell migration and invasion and expression of p-STAT3, VEGF, MMP9, and MMP2 proteins.ConclusionThe results indicated that TMEM119 promotes gastric cancer cell migration and invasion through activation of STAT3 signaling pathway, and TMEM119 may therefore act as a novel therapeutic target for gastric cancer.

MiR-449c inhibits migration and invasion of gastric cancer cells by targeting PFKFB3.

microRNAs (miRNAs) are important regulators in the development and progression of human gastric cancer (GC). However, the expression and biological function of miR-449c in GC remains unknown. In the present study, miR-449c was demonstrated to be downregulated in GC tissues and cell lines compared with normal. Decreased miR-449c levels were associated with poor prognosis in GC patients. Overexpression of miR-449c inhibited migration and invasion in SGC-7901 cells, while inhibition of miR-449c enhanced migration and invasion in MGC-803 cells. Furthermore, 6-phosphofructo-2-kinase (PFKFB3) was identified to be a downstream target of miR-449c in GC cells. miR-449c directly regulated the expression of PFKFB3 in GC cells. Overexpression of PFKFB3 abrogated the inhibitory effect of miR-449c on the migration and invasion of GC cells. In conclusion, the present study suggests that miR-449c may be a novel biomarker and potential therapeutic target in GC.

Involvement of microRNAs-MMPs-E-cadherin in the migration and invasion of gastric cancer cells infected with Helicobacter pylori

It has been found that Helicobacter pylori （H. pylori）is not only the main cause of gastric cancer, but also closely related to its metastasis. E-cadherin cleavage induced by matrix metalloproteinases (MMPs) plays an important role in the tumor metastasis. In the present study, we investigated the role of microRNAs-MMPs-E-cadherin in migration and invasion of gastric cancer cells treated with H. pylori. The results showed that H. pylori induced migration and invasion of SGC-7901 cells with a down-regulation of E-cadherin expression, which were abolished by MMPs knock down, E-cadherin overexpression, mimics of miR128 and miR148a. MiR128/miR148a inhibitors restored MMP-3/MMP-7 expression, down-regulated E-cadherin level, and accelerated cellular migration and invasion. This study suggests that H. pylori induces migration and invasion of gastric cancer cells through reduction of E-cadherin function by activation of MMP-3, − 7. The present results also suggest that the activated MMPs/E-cadherin pathway is related with down-regulation of miR128/miR148a in the human gastric cancer cells infected with H. pylori.

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.

Resveratrol inhibits Interleukin-6 induced invasion of human gastric cancer cells

Previous studies show that migration and invasion are the primary causes of death in patients with gastric carcinoma. Increasing evidences have been shown Interleukin-6 could stimulate cancer cells invasion and be associated with cancer development. However, its role in gastric cancer has never been investigated. As an anticancer drug isolated from Chinese medicine, resveratrol was reported to inhibit cancer cells growth and induce apoptosis, but its roles in gastric cancer have not been well understood. In this study, we found that Interleukin-6 was upregulated in blood of gastric cancer patients by enzyme-linked immunosorbent assay. In gastric cancer cell line model, we found that non-cytotoxic concentration of resveratrol inhibited the Interleukin-6 induced SGC7901 cell invasion and matrix metalloproteinases activation. Our studies showed that IL-6 induced SGC7901 cell invasion depends on the Raf/MAPK pathway activation, resveratrol could inhibit this pathway activation. We further showed that resveratrol inhibits the IL-6 induced metastasis by vein injection of luciferase-labeled cancer cells. In conclusion, these results indicate that Interleukin-6 promotes tumor growth and metastasis in gastric cancer, resveratrol has the potential to prevent the Interleukin-6 induced gastric cancer metastasis by blocking the Raf/MAPK signaling activation.

Promotion of Sema4D expression by tumor-associated macrophages: Significance in gastric carcinoma.

AIMTo study the role of semaphorin 4D (Sema4D) expression promoted by tumor-associated macrophages (TAMs) in gastric carcinoma cells and its clinical significance in the invasion and metastasis of gastric carcinoma.METHODSCD68 and Sema4D expression was analyzed in gastric carcinoma and adjacent normal tissues from 290 patients using the immunohistochemical streptavidin-peroxidase method, and their relationships with clinicopathological features were evaluated. Human M2 macrophages were induced in vitro and co-cultured in non-contact with gastric carcinoma SGC-7901 cells. Changes in the secretory Sema4D level in the SGC-7901 cell supernatant were measured using an enzyme-linked immunosorbent assay. The effects of TAMs on SGC-7901 cell invasion and migration were assessed with invasion and migration assays, respectively.RESULTSCD68 and Sema4D protein expression was significantly higher in gastric carcinoma tissues than in adjacent normal tissues (71.7% vs 33.8% and 74.5% vs 42.8%, respectively; P < 0.01). CD68 and Sema4D protein expression was significantly associated with histological differentiation, TNM stage, and lymph node metastasis (P < 0.05), and their expression levels were positively correlated with one another (r = 0.467, P < 0.01). In the in vitro experiment, secretory Sema4D protein expression was significantly increased in the supernatant of SGC-7901 cells co-cultured with TAMs compared with the blank control (1224.13 ± 29.43 vs 637.15 ± 33.84, P < 0.01). Cell invasion and metastasis were enhanced in the Transwell invasion and migration assays (P < 0.01).CONCLUSIONTAMs promote the invasion and metastasis of gastric carcinoma cells possibly through upregulated secretory Sema4D protein expression. Combined detection of TAM markers, CD68 and Sema4D, in gastric carcinoma tissue shows potential to predict the trend of gastric carcinoma progression.