scholarly journals Polyunsaturated Fatty Acids ω-3 and ω-6 Regulate the Proliferation Invasion and Angiogenesis of Human Gastric Cancer Through COX/PGE Signaling Pathway

Author(s):  
JIachi Ma ◽  
Chensong Zhang ◽  
Wanqing Liang ◽  
Lei Li ◽  
Jun Du ◽  
...  

Abstract Background: To investigate the effect of polyunsaturated fatty acids ω-3 and ω-6 and their metabolites prostaglandin PGE2 and PGE3 on the proliferation, invasion and neovascularization of gastric cancer.Methods: RT-PCR and ELISA were used to detect the gene and protein expression of COX-1 and COX-2 in gastric cancer cell lines, respectively. The effects of ω-3, ω-6, PFG2 and PEG3 on the proliferation, invasion and neovascularization of gastric cancer cells were detected by cell proliferation, invasion and neovascularization assay in vitro. COX-2 siRNA was synthesized by short gene interfering RNA (siRNA) technique and transfected into gastric cancer cells, and the expression of COX-2 protein in gastric cancer cell lines was detected again by Western blot. The effects of COX-2 gene silencing on proliferation, invasion and neovascularization of gastric cancer cells were detected by WST-1 assay, transwell chamber assay and gastric cancer neovascularization assay, respectively.Results: COX-2 was only expressed in MKN74 and MKN45 cell lines, while COX-1 was expressed in four gastric cancer cell lines. In gastric cancer cell lines with positive COX-2 expression, ω-6 and PEG2 could significantly enhance the proliferation, invasion and neovascularization of gastric cancer cells, and after transfection with COX-2 siRNA, the effects of ω-6 and PEG2 on enhancing the proliferation, invasion and neovascularization of gastric cancer cells were significantly attenuated; ω-3 and PEG3 could inhibit the proliferation, invasion and neovascularization of gastric cancer cells. In gastric cancer cell lines with negative COX-2 expression, ω-6 and PEG2 had no significant effect on the proliferation, invasion and neovascularization of gastric cancer; ω-3 and PEG3 could significantly inhibit the proliferation, invasion and neovascularization of gastric cancer.Conclusion: ω-6 PUFAs reinforce the metastatic potential energy of gastric cancer cells via COX-2/PGE2; ω-3 PUFAs inhibit the metastatic potential energy of gastric cancer via COX-1/PGE3.

2019 ◽  
Vol 37 (15_suppl) ◽  
pp. e15571-e15571
Author(s):  
Zhi-Qiang Ling

e15571 Background: Therapies targeted to the immune checkpoint mediated by PD-1 and PD-L1 show antitumor activity in some solid tumors. We have now examined PD-L1 expression and its regulation in gastric cancer with p-PAQR3Thr32 protein. Methods: The expression of PD-L1 at the protein and mRNA levels in gastric cancer cell lines was examined by flow cytometry, real-time RT-PCR and western blot analysis, respectively. The expression of PD-L1 and p-PAQR3Thr32 protein in 319 surgically resected gastric cancer specimens was evaluated by immunohistochemical analysis. Results: The PD-L1 expression level was higher in gastric cancer cell lines positive for p-PAQR3Thr32 protein induced by glucose starvation than in those negative for the p-PAQR3Thr32 protein. Forced expression of p-PAQR3Thr32 protein in gastric cancer cells markedly increased PD-L1 expression, whereas endogenous PD-L1 expression in p-PAQR3Thr32 protein positive gastric cancer cells was attenuated by treatment with PAQR3 siRNAs. Furthermore, expression of PD-L1 was downregulated by inhibitors of the IRF1 and STAT1 in IFNs-PDL1 signaling pathway in gastric cancer cells positive for p-PAQR3Thr32 protein. At clinical tissue level, the expression level of PD-L1 was positively associated with the presence of p-PAQR3Thr32 protein in gastric cancer specimens. Moreover, the expression level of p-PAQR3Thr32 protein was negatively correlated with CD3, CD8, GZMA (CD8 T cell secretory factor) and positively correlated with CD68 (macrophage marker). Conclusions: Our findings that p-PAQR3Thr32 protein induced by glucose deficiency upregulate PD-L1 by activating IFNs-PDL1 signaling pathway in gastric cancer reveal a direct link between p-PAQR3Thr32 protein and PD-L1 expression. It is suggested that p-PAQR3Thr32 protein may be involved in tumor immunosuppression by inhibiting the proliferation and activity of CD8 T cells in gastric cancer tissues.


2016 ◽  
Vol 39 (2) ◽  
pp. 453-466 ◽  
Author(s):  
Qi Zhou ◽  
Xiao Zheng ◽  
Lujun Chen ◽  
Bin Xu ◽  
Xin Yang ◽  
...  

Background/Aims: Transforming growth factor beta (TGF-β) plays a major role in tumorigenesis. MicroRNA-181b (miRNA-181b) is a multifaceted miRNA that has been implicated in many cellular processes such as cell fate determination and cellular invasion. This study aimed to confirm the relationship of miRNA-181b and the TGF-β-Smad2/3/4 pathway with the induction of the epithelial-to-mesenchymal transition (EMT) in gastric cancer. Methods: This study investigated the ability of TGF-β to induce migration by wound healing and transwell invasion assays in human gastric cancer cell lines. miRNA expression was altered using miRNA-181b mimic and inhibitor in the same system. Expression of miRNA-181b, the hypothetical target gene Timp3 and EMT-related markers were analyzed by real-time real-time quantitative RT-PCR. Immunoblotting was used to investigate the levels of phospho-Smad2 and Smad4. Dual-luciferase reporter assays were performed to confirm the direct binding of miRNA-181b to Timp3. Results: miRNA-181b was significantly upregulated in response to TGF-β treatment in gastric cancer cell lines. Overexpression of miR-181b mimic induced an in vitro EMT-like change to a phenotype similar to that following TGF-β treatment alone and was reversed by miRNA-181b inhibitor. Inhibition of TGF-β−Smad2/3 signaling with SD-208 significantly attenuated the upregulation of miRNA-181b. Knockdown of Smad4 in gastric cancer cells strongly attenuated the upregulation of miRNA-181b. Moreover, miR-181b was found to directly target the 3′ untranslated region (3′UTR) of Timp3 mRNA affecting TGF-β-induced EMT. Conclusions: Our results elucidate a novel mechanism through which the TGF-β pathway regulates the EMT of gastric cancer cells by increasing the levels of miRNA-181b to target Timp3 via the Smad2/3/4-dependent pathway. These findings provide insights into the cellular and environmental factors regulating EMT, which may guide future studies on therapeutic strategies targeting these cells.


2020 ◽  
Author(s):  
Ru Chen ◽  
Kenji Masuo ◽  
Akitada Yogo ◽  
Shoko Yokoyama ◽  
Aiko Sugiyama ◽  
...  

Abstract Among cancer cells, there are specific cell populations of whose activities are comparable to those of stem cells in normal tissues, and for whom the levels of cell dedifferentiation are reported to correlate with poor prognosis. Information concerning the mechanisms that modulate the stemness like traits of cancer cells is limited. Therefore, we examined five gastric cancer cell lines and isolated gastric oncospheres from three gastric cancer cell lines. The gastric cancer cells that expanded in the spheres expressed relatively elevated proportion of CD44, which is a marker of gastric cancer stem cells, and displayed many properties of cancer stem cells, for example: chemoresistance, tumorigenecity and epithelial-mesenchymal transition (EMT) acquisition. SNAIL, which is a key factor in EMT, was highly expressed in the gastric spheres. Microarray analysis in gastric cancer cell line HGC27 showed that CCN3 and NEFL displayed the greatest differential expression by knocking down of SNAIL; the former was up-regulated and the latter down-regulated, respectively. Down-regulation of CCN3 and up-regulation of NEFL gene expression impaired the SNAIL-dependent EMT activity: high tumorigenicity, and chemoresistance in gastric cancer cells. Thus, approach that disrupts SNAIL/CCN3/NEFL axis may be credible in inhibiting gastric cancer development.


Author(s):  
Ting Kang ◽  
Maolin Ge ◽  
Ruiheng Wang ◽  
Zhen Tan ◽  
Xiuli Zhang ◽  
...  

Abstract Background Arsenic sulfide was found to have potential anti-cancer activities, especially in gastric cancer. However, the underlying mechanism need to be further explored. This study was aimed to investigate the mechanism of arsenic compounds on gastric cancer. Methods Gastric cancer cell lines were infected with lentiviral vector carrying shNFATc3 and/or treated with arsenic sulfide. MTT assay were performed to assess cell growth. Flow cytometer assays were used to detect cell cycle and reactive oxygen species (ROS) level of gastric cancer cells. Western blot was carried out to detect nuclear factor of activated T-cells, cytoplasmic 3 (NFATc3), cell cycle markers, DNA damage pathway protein expression as well as other protein expression in gastric cancer cell lines. The expression of recombination activating gene 1 (RAG1) in gastric cancer cell lines was determined by RNA-sequencing analyses and Real-Time qPCR. The effect of NFATc3 on RAG1 were determined by CHIP-qPCR assay. The effect of arsenic sulfide on AGS cells was evaluated in vivo. Results We show that arsenic sulfide as well as knockdown of NFATc3 resulted in increased double-strand DNA damage in gastric cancer cells by increasing the expression of RAG1, an endonuclease essential for immunoglobulin V(D) J recombination. Overexpression of NFATc3 blocked the expression of RAG1 expression and DNA damage induced by arsenic sulfide. Arsenic sulfide induced cellular oxidative stress to redistribute NFATc3, thereby inhibiting its transcriptional function, which can be reversed by N-acetyl-L-cysteine (NAC). We show that NFATc3 targets the promoter of RAG1 for transcriptional inhibition. We further showed that NFATc3 upregulation and RAG1 downregulation significantly associated with poor prognosis in patients with gastric cancer. Our in vivo experiments further confirmed that arsenic sulfide exerted cytotoxic activity against gastric cancer cells through inhibiting NFATc3 to activate RAG1 pathway. Conclusion These results demonstrate that arsenic sulfide targets NFATc3 to induce double strand DNA break (DSB) for cell killing through activating RAG1 expression. Our results link arsenic compound to the regulation of DNA damage control and RAG1 expression as a mechanism for its cytotoxic effect.


2018 ◽  
Vol 6 (10) ◽  
pp. 2704-2713 ◽  
Author(s):  
Minjeong Jang ◽  
Ilkyoo Koh ◽  
Jae Eun Lee ◽  
Ju Yeon Lim ◽  
Jae-Ho Cheong ◽  
...  

We studied the effect of ECM density on both intercellular- and ECM-interactions according to alterations of ECM-mediated signaling in gastric cancer cell lines.


2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Nihal Karakaş ◽  
Mehmet Evren Okur ◽  
Nurşah Öztunç ◽  
Derya Çiçek Polat ◽  
Ayşe Esra Karadağ

AbstractObjectivesLaurocerasusofficinalis Roem. fruits are traditionally used for several health problems. Although there are some studies about its antiproliferative effects on different cancer cells, no study was reported about its potential therapeutic efficacy against gastric cancers which is the most malignant disease in the digestive system with high morbidity and mortality.MethodsThis study was aimed to evaluate L. officinalis fruit extract phytochemical contents as well as to compare anticancer effects on gastric cancer cells. The antioxidant activities were determined by ABTS and DPPH assays. Anticancer effects were measured by cell viability assays, then apoptotic proteins were analyzed by western blotting and flow cytometry.ResultsLaurocerasus officinalis fruit methanol extract showed moderate antioxidant activity by ABTS• and DPPH• assays. Significant cytotoxic activities and caspase mediated apoptosis were detected in the extract treated MKN-45 and AGS gastric cancer cells respectively while sparing healthy cells.ConclusionOur results showed that the L. officinalis Roem. extract has significant anticancer efficacy on gastric cancer cell lines; therefore, it can be further studied to determine its potential therapeutic components.


2021 ◽  
Vol 11 ◽  
Author(s):  
Kuo-Liang Wei ◽  
Jian-Liang Chou ◽  
Yin-Chen Chen ◽  
Jie-Ting Low ◽  
Guan-Ling Lin ◽  
...  

PurposeThe purpose of this study was to identify genes that were epigenetically silenced by STAT3 in gastric cancer.MethodsMBDcap-Seq and expression microarray were performed to identify genes that were epigenetically silenced in AGS gastric cancer cell lines depleted of STAT3. Cell lines and animal experiments were performed to investigate proliferation and metastasis of miR-193a and YWHAZ in gastric cancer cell lines. Bisulfite pyrosequencing and tissue microarray were performed to investigate the promoter methylation of miR-193a and expression of STAT3, YWHAZ in patients with gastritis (n = 8) and gastric cancer (n = 71). Quantitative methylation-specific PCR was performed to examine miR-193a promoter methylation in cell-free DNA of serum samples in gastric cancer patients (n = 19).ResultsAs compared with parental cells, depletion of STAT3 resulted in demethylation of a putative STAT3 target, miR-193a, in AGS gastric cancer cells. Although bisulfite pyrosequencing and epigenetic treatment confirmed that miR-193a was epigenetically silenced in gastric cancer cell lines, ChIP-PCR found that it may be indirectly affected by STAT3. Ectopic expression of miR-193a in AGS cells inhibited proliferation and migration of gastric cancer cells. Further expression microarray and bioinformatics analysis identified YWHAZ as one of the target of miR-193a in AGS gastric cancer cells, such that depletion of YWHAZ reduced migration in AGS cells, while its overexpression increased invasion in MKN45 cells in vitro and in vivo. Clinically, bisulfite pyrosequencing revealed that promoter methylation of miR-193a was significantly higher in human gastric cancer tissues (n = 11) as compared to gastritis (n = 8, p < 0.05). Patients infected with H. pylori showed a significantly higher miR-193a methylation than those without H. pylori infection (p < 0.05). Tissue microarray also showed a positive trend between STAT3 and YWHAZ expression in gastric cancer patients (n = 60). Patients with serum miR-193a methylation was associated with shorter overall survival than those without methylation (p < 0.05).ConclusionsConstitutive activation of JAK/STAT signaling may confer epigenetic silencing of the STAT3 indirect target and tumor suppressor microRNA, miR-193a in gastric cancer. Transcriptional suppression of miR-193a may led to overexpression of YWHAZ resulting in tumor progression. Targeted inhibition of STAT3 may be a novel therapeutic strategy against gastric cancer.


2018 ◽  
Vol 19 (11) ◽  
pp. 3616 ◽  
Author(s):  
Rui Wang ◽  
Xiaoyan Deng ◽  
Chengfu Yuan ◽  
Hongmei Xin ◽  
Geli Liu ◽  
...  

The assembly and maintenance of cilia depend on intraflagellar transport (IFT) proteins, which play an important role in development and homeostasis. IFT80 is a newly defined IFT protein and partial mutation of IFT80 in humans causes diseases such as Jeune asphyxiating thoracic dystrophy (JATD) and short rib polydactyly (SRP) type III, both characterized by abnormal skeletal development. However, the role and mechanism of IFT80 in the invasion of gastric cancer is unknown. We established SGC-7901 and MKN-45 gastric cancer cell lines that stably overexpressed IFT80, as verified by quantitative reverse transcription-PCR, Western blot, and immunofluorescence. Matrix metalloproteinase-9 (MMP9) plays an important role in tumor invasion, and its expression was assessed by quantitative reverse transcription-PCR, Western blotting, and immunofluorescence. The invasion ability of IFT80 on SGC-7901 and MKN-45 cells was examined by the Matrigel invasion assay. The relationship between p75NGFR, and the p75NGFR antagonists, PD90780 and IFT80, were detected by quantitative reverse transcription-PCR and Western blotting. We first detected an IFT80 expression pattern, and found that IFT80 was highly expressed in gastric cancer clinical samples. Overexpression of IFT80 in the gastric cancer cell lines, SGC-7901 and MKN-45, led to lengthening cilia. Additionally, overexpression of IFT80 significantly improved proliferation and invasion, but inhibited apoptosis, in gastric cancer cells. We further found that overexpression of IFT80 increased p75NGFR and MMP9 mRNA and protein expression. Treatment with the p75NGFR antagonist PD90780 inhibited the increased invasion ability resulting from overexpression of IFT80 in SGC-7901 and MKN-45 gastric cancer cells. Thus, these results suggest that IFT80 plays an important role in invasion of gastric cancer through regulating the ift80/p75NGFR/MMP9 signal pathways.


2015 ◽  
Vol 11 (1) ◽  
pp. 63
Author(s):  
Shang-Jin Peng ◽  
Jue-Wei Chen

<p class="Abstract">The present study investigates the effect of rubriflordilactone A on the viability and its underlying mechanism in gastric cancer cell lines (SNU-1 and SNU-5) and normal gastric epithelial cell line (GES‑1). Incubation of the gastric cancer and non cancer cell lines in acidic media led to reduction in the viability of the non cancer cells without any effect on cancer cells. Apoptosis in SNU-1 and SNU-5 cells was induced on exposure to rubriflordilactone A after 48 hours compared to the control cells (p&lt;0.01). The percentage of apoptosis in SNU-1 and SNU-5 cells on exposure to rubriflordilactone A was 79.3 ± 4.7 and 74.0 ± 5.1, respectively after 48 hours. Exposure of SNU-1 and SNU-5 cancer cell lines to rubriflordilactone A at a concentration of 10 μM in media with acidic pH decreased phosphorylation of ERK ½. The similar reduction was caused by ERK 1/2 phosphorylation inhibition, PD98059. Thus rubriflordilactone A reduces viability of gastric cancer cell lines by inducing apoptosis through the reduction of ERK 1/2 phosphorylation.</p><p> </p>


2009 ◽  
Vol 31 (6) ◽  
pp. 475-485
Author(s):  
R. Sitarz ◽  
R. J. Leguit ◽  
W. W. J. de Leng ◽  
F. H. M. Morsink ◽  
W. P. Polkowski ◽  
...  

Background: COX-2 and E-cadherin, involved in invasion and metastasis, are molecules critical for gastric carcinogenesis. A relationship between them is documented in non-small cell lung and prostate cancer. We present novel evidence of a relationship between COX-2 and E-cadherin expression in gastric cancer.Methods: Using qPCR and Western blots analysis on celecoxib and PGE2 treated and untreated gastric cancer cell lines derived from tumours of the intestinal type (MKN45, MKN28, AGS3, MKN7) and immunohistochemistry of 178 gastric cancers on tissue microarrays (TMA), we examined the COX-2/E-cadherin relationship.Results: Down-regulation of COX-2 by celecoxib led to up-regulation of E-cadherin mRNA and protein levels in conventional gastric cancer cell lines, whereas expression was down regulated in the early-onset gastric cancer (EOGC) cell line. Immunohistochemistry on TMAs of 178 gastric cancers showed no correlation between COX-2 and E-cadherin expression in the conventional or early gastric cancer groups.Conclusions: The results suggest that COX-2 has an impact on transcriptional regulation of E-cadherin in gastric cancer and our findings further highlight the intriguing nature of EOGCs which appear to have a molecular phenotype distinct from conventional gastric cancer. In addition, our findings also suggest that reduction of COX-2 using nonsteroidal anti-inflammatory drugs in gastric cancer chemoprevention may only be relevant for older patients.


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