Gastric Cancer Cell Lines MKN74 Research Articles

RhoA G17E/Vav1 Signaling Induces Cancer Invasion via Matrix Metalloproteinase-9 in Gastric Cancer.

RAS homolog family member A (RhoA), a member of the Rho family of small GTPases, and Vav1, a guanine nucleotide exchange factor for Rho family GTPases, have been reported to activate pathways related to the actin cytoskeleton and regulation of cell shape, attachment, and motility. The interaction between these molecules in lymphoma is involved in malignant signaling, but its function in epithelial malignancy is unknown. Here, we investigated the malignant signal of mutant RhoA in gastric cancer and demonstrated the potential of RhoA G17E/Vav1 as a therapeutic target for diffuse gastric cancer. The RhoA mutants R5W, G17E, and Y42C were retrovirally transduced into the gastric cancer cell line MKN74. The stably transduced cells were used for morphology, proliferation, and migration/invasion assays in vitro. MKN74 cells stably transduced with ectopic wild-type RhoA and mutant RhoA (G17E) were used in a peritoneal xenograft assay. The RhoA mutations G17E and Y42C induced morphological changes in MKN74. G17E induced Vav1 expression at the mRNA and protein levels and promoted the migration and invasion of MKN74. An RNA interference assay of Vav1 revealed that RhoA G17E enhanced cancer cell invasion via Vav1. Furthermore, immunoprecipitation revealed that Vav1 and RhoA G17E specifically bind and function together through matrix metalloproteinase -9. In a peritoneal xenograft model of nude mice, RhoA G17E promoted peritoneal dissemination, whereas Vav1 knockdown suppressed it. Overall, our findings indicate that RhoA G17E is associated with Vav1 and promoted cancer invasion via matrix metalloproteinase -9 in gastric cancer cells. Thus, RhoA G17E/Vav1 signaling in diffuse gastric cancer may be a useful therapeutic target.

Antihypertensive drug telmisartan suppresses the proliferation of gastric cancer cells invitro and invivo.

Gastric cancer is one of the most common malignancies diagnosed worldwide. Telmisartan, an angiotensin receptor blocker (ARB), suppresses the proliferation of cancer cells and the growth of tumors through an unknown mechanism. To identify the mechanism, the present study was designed to evaluate the effects of telmisartan on gastric cancer cell lines and tumors invitro and invivo and the associated signaling molecules were identified. It was shown here that telmisartan suppressed the proliferation of the cultured human gastric cancer cell lines MKN74, MKN1 and MKN45 as detected in the CCK‑8 assay. In a mouse xenograft model of gastric cancer, telmisartan suppressed tumor growth by arresting the cell cycle at the G0/G1phase through inhibition of the expression of cyclinD1, the catalytic subunit of cyclin dependent kinase4 (CDK4), as well as the phosphorylation of the tumor suppressor retinoblastoma (pRb) protein as detected by western blotting. Notably, telmisartan did not induce apoptosis, as indicated by consistent levels of caspase‑cleaved keratin18 in MKN74cells. Furthermore, telmisartan inhibited the phosphorylation of epidermal growth factor receptor (EGFR) and increased the levels of the angiogenesis‑related protein tissue inhibitor of metalloproteinase‑1 (TIMP‑1). Analyses of microarrays revealed that telmisartan altered the expression of miRNAs in MKN74cells. In conclusion, telmisartan suppressed the proliferation of human gastric cancer cells by inducing cell cycle arrest.

Cytotoxic Effect of Geranylphenol Derivatives in the Human Breast Cancer Cell Line MDA-MB-231 and Gastric Cancer Cell Line MKN74

Background: Previous studies have demonstrated that geranyl metabolites, found mainly in marine organisms, exhibit interesting antimicrobial and antifungal activities. In addition, linear geranyl derivatives have been synthesized as drugs and reported cytotoxic and anticancer activities.
 Aims: Considering the biological testing and the structural features of these compounds, we evaluated seven linear geranylphenol derivatives on the human breast cancer cell line MDA-MB-231, and the human gastric cancer cell line MKN74.
 Results: We found that compounds 2, 5 and 7 were cytotoxic for both cancer cell lines. From them, the most potent was compound 2, with an IC50=7.5 μM for MKN74 cells, and compound 7, with an IC50=14.73 μM for MDA-MB-231 cells. By nuclear staining and inmunocytochemistry, we detected that the three compounds induced cell death, and by Western blot analysis, we observed a remarkable decrease in the expression of cyclin D1 and the retinoblastoma protein, key regulators of the cell cycle.
 Conclusion: Considering that compounds 2 and 7 were the most potent compounds inducing cell death, and were able to decrease the expression of retinoblastoma protein and cyclin D1, proteins usually altered in different types of cancers, they appear as promising therapeutic agents against cancer.
 Bangladesh Journal of Medical Science Vol.19(3) 2020 p.486-500

Invivo effects of mutant RHOA on tumor formation in an orthotopic inoculation model.

Ras homolog family member A (RHOA) mutations are driver genes in diffuse-type gastric cancers (DGCs), and we previously revealed that RHOA mutations contribute to cancer cell survival and cell migration through their dominant negative effect on Rho-associated kinase (ROCK) signaling in vitro. However, how RHOA mutations contribute to DGC development in vivo is poorly understood. In the present study, the contribution of RHOA mutations to tumor morphology was investigated using an orthotopic xenograft model using the gastric cancer cell line MKN74, in which wild-type (WT) or mutated (Y42C and Y42S) RHOA had been introduced. When we conducted RNA sequencing to distinguish between the genes expressed in human tumor tissues from those in mouse stroma, the expression profiles of the tumors were clearly divided into a Y42C/Y42S group and a mock/WT group. Through gene set enrichment analysis, it was revealed that inflammation- and hypoxia-related pathways were enriched in the mock/WT tumors; however, cell metabolism- and cell cycle-related pathways such as Myc, E2F, oxidative phosphorylation and G2M checkpoint were enriched in the Y42C/Y42S tumors. In addition, the gene set related to ROCK signaling inhibition was enriched in the RHOA-mutated group, which indicated that a series of events are related to ROCK inhibition induced by RHOA mutations. Histopathological analysis revealed that small tumor nests were more frequent in RHOA mutants than in the mock or WT group. In addition, increased blood vessel formation and infiltration of macrophages within the tumor mass were observed in the RHOA mutants. Furthermore, unlike mock/WT, the RHOA-mutated tumor cells had little antitumor host reaction in the invasive front, which is similar to the pattern of mucosal invasion in clinical RHOA-mutated DGC. These transcriptome and pathological analyses revealed that mutated RHOA functionally contributes to the acquisition of DGC features, which will accelerate our understanding of the contribution of RHOA mutations in DGC biology and the development of further therapeutic strategies.

Enrichment and purification process of astragalosides and their anti-human gastric cancer MKN-74 cell proliferation effect.

Radix astragali mainly contains saponins, polysaccharides, flavonoids, amino acids and other chemical constituents of which total astragalosides have immunomodulatory, anti-viral, hepatoprotective, and gastric mucosa protective effects. To investigate the process conditions for extraction, purification and enrichment of total astragalosides by macroporous adsorption resin, and to study the inhibitory effect of total astragalosides on growth of human gastric cancer cell line MKN-74. UV spectrophotometry was applied to determine the adsorption and desorption capacity of macroporous adsorption resin on total astragaloside content, MTT assay was used to determine the inhibition of MKN-74 cell growth by total astragalosides. The dynamic adsorption performance of DA201 adsorption resin was examined, and the dynamic adsorption curve of total astragalosides on DA201 resin column was plotted. Meanwhile, eluent and elution flow rate were investigated, the results showed that the choice of eluent of 80% ethanol, and a flow rate of 5 BV/h could maximize the yield of total astragalosides. MTT assay found that astragalosides could relatively pronouncedly inhibit the proliferation of MKN-74 cells, and the inhibitory effect was enhanced with the increase of astragaloside dose and the extension of processing time, which showed a dose-and time-dependence. DA201 resin can effectively enrich total astragalosides, total astragalosides have an inhibitory effect on growth of MKN-74 cells.

Prognostic significance of mortalin expresion in gastric adenocarcinoma with wild-type p53.

e14662 Background: Mortalin is a heat non-inducible member of the heat shock protein 70 family that is expressed in various stress responses such as glucose deprivation, low-dose ionizing radiation, and caloric restriction. Mortalin and p53 form a complex in the cytoplasm or in the centrosome, which compromises the p53 activity, and thus prevents apoptosis under stress conditions. Methods: This study included 182 unselected Japanese patients with primary gastric cancer. The expression of mortalin and aberrant p53 was investigated by immunohistochemical staining. In addition, the human fibroblast cell line MRC-5 and the gastric cancer cell line MKN-74, which has a mutation in the TP53 gene, were grown under normal or hypoxic conditions, and changes in localization of mortalin and p53 were examined. Results: Mortalin-positive and aberrant-p53-positive samples were found in 75.2% and 62.6% of cases, respectively. The Mortalin and aberrant p53 expression was associated with tumor invasion and lymph node and l...

Molecular cloning and characterization of LZIC, a novel gene encoding ICAT homologous protein with leucine zipper domain.

ICAT inhibits the interaction between beta-catenin and TCF transcription factors. As ICAT might be a tumor suppressor gene with the potential to negatively regulate the WNT - beta-catenin - TCF signaling pathway, ICAT related gene in the human genome draft sequence was searched for. Here, the LZIC gene, a novel gene encoding a 190-amino-acid polypeptide with leucine zipper domain and ICAT homologous domain, was cloned and characterized. Amino-acid identity between LZIC and ICAT in the ICAT homologous domain was 38%. The LZIC gene, consisting of at least 8 exons, was located in the human chromosome 1p36.32-pter region. The major 5.2-kb LZIC mRNA and minor 2.1-, 1.6-, and 1.0-kb LZIC mRNAs were expressed almost ubiquitously in normal human tissues. LZIC was expressed in all cancer cell lines examined in this study, and was significantly up-regulated in a gastric cancer cell line MKN74 and 5 cases of primary gastric cancer. As LZIC contains ICAT homologous domain, LZIC might inhibit the interaction between beta-catenin and TCF transcription factors, just like ICAT, and, up-regulation of LZIC in gastric cancer might be due to a negative feed-back mechanism to inhibit the WNT - beta-catenin - TCF signaling pathway.

Increased invasiveness of MUC1 and cDNA-transfected human gastric cancer MKN74 cells.

MUC1 mucin is an anti-adhesion molecule expressed in a wide variety of tumors. To examine whether MUC1 mucin is involved in tumor invasion, we have prepared MUC1 transfectants using the human gastric cancer cell line MKN74 and performed an in vivo tumor assay by transplanting these into nude mice. Tumor weight at 71 days after s.c. injection of transfectants was measured, showing that the in vivo growth of MUC1 transfectants was increased compared to that of mock transfectants. Furthermore, MUC1-transfectant tumors invaded into the muscle layer, whereas mock-transfectant tumors did not. In vitro invasion, adhesion to extracellular matrix components and phagokinetic track motility were then evaluated to analyze the mechanisms for the in vivo invasiveness of the transfectants. MUC1 transfectants exhibited an increased in vitro invasiveness, decreased binding to laminin, fibronectin, type I collogen and type IV collagen and increased motility. These effects of MUC1 mucin over-expression in MKN74 cells were abolished by the treatment of transfectants with an inhibitor of O-glycan biosynthesis, benzyl-alpha-GalNAc. Our data suggest that MUC1 mucin could be related to the increased invasive ability of MKN74 cells, whereas O-glycan might play an essential role.

A novel tumor-associated, developmentally regulated glycolipid antigen defined by monoclonal antibody ACFH-18.

A mouse IgM monoclonal antibody, ACFH-18, was established after immunization of mice with the human gastric cancer cell line MKN74. The antibody reacts strongly with gastrointestinal carcinoma and showed a clear dependence on the degree of differentiation of gastric cancer cells. The antibody defines a series of glycolipid species with extremely slow TLC mobility present in both acidic and neutral glycolipid fractions of the extract from gastrointestinal adenocarcinoma and the original MKN74 cells. Isolation and structural study of the active glycolipids present in the acidic and neutral fractions and comparison of the antibody reactivity with glycolipids having related structures revealed a novel specificity. The minimum requirement for the maximal reactivity of ACFH-18 was identified as VII3Fuc-nLc10 (Structure A below and Fig. 8 in text). Since the antibody did not react with III3Fuc-nLc6 (Structure B below), which shares the same terminal sequence as VII3Fuc-nLc10, and since it cross-reacted with VII3Fuc-nLc8 (Z1 glycolipid) and VII3Fuc,V3-Fuc,III3Fuc-nLc8 (Z3 glycolipid), antibody ACFH-18 is capable of recognizing a fucosyl residue plus an internal repeating N-acetyllactosamine proximal to ceramide, as indicated by lines in Fig. 8 (Structures A, B, and E-G). (Formula: see text).

The monoclonal antibody directed to difucosylated type 2 chain (Fuc alpha 1 leads to 2Gal beta 1 leads to 4[Fuc alpha 1 leads to 3]GlcNAc; Y Determinant).

One of the monoclonal (AH-6) antibodies prepared by hybridoma technique against human gastric cancer cell line MKN74 was found to react with a series of glycolipids having the Y determinant (Fuc alpha 1 leads to 2Gal beta 1 leads to 4[Fuc alpha 1 leads to 3]GlcNAc). The structure of one such glycolipid isolated from human colonic cancer and from dog intestine was identified as lactodifucohexaosyl-ceramide (Fuc alpha 1 leads to 2Gal beta 1 leads to 4[Fuc alpha 1 leads to 3]GlcNAc beta 1 leads to 3Gal beta 1 leads to 4Glc beta 1 leads to 1-ceramide; IV3,III3Fuc2nLc4Cer). The hapten glycolipid did not react with monoclonal antibodies directed to Lea, Leb, and X-hapten structures, and the AH-6 antibody did not react with the X-hapten ceramide pentasaccharide (Gal beta 1 leads to 4[Fuc alpha 1 leads to 3]GlcNAc beta 1 leads to 3Gal beta 1 leads to 4Glc beta 1 leads to 1-ceramide), H1 glycolipid (Fuc alpha 1 leads to 2Gal beta 1 leads to 4GlcNAc beta 1 leads to 3Gal beta 1 leads to 4Glc beta 1 leads to 1-ceramide), nor with glycolipids having the Leb (Fuc alpha 1 leads to 2Gal beta 1 leads to 3[Fuc alpha 1 leads 4]GlcNAc beta 1 leads to R) determinant. The antibody reacted with blood group O erythrocytes, but not with A erythrocytes. Immunostaining of thin layer chromatography with the monoclonal antibody AH-6 indicated that a series of glycolipids with the Y determinant is present in tumors and in O erythrocytes.