Human Gastric Carcinoma Cell Line Research Articles

Engineering MnO2 Nanomulberries for Enhancing PTT/PDT Synergistic Cancer Therapy

AbstractConsidering the great catalyzation ability to degrade H2O2 into O2, MnO2 nanoparticles are utilized as nanocarriers in phototherapies for anticancer treatments to overcome the hypoxia tumor microenvironment (TME). However, the confliction of size requirement between promoting tumor delivery and cellular uptake and catalyzing H2O2 degradation limits the functions of MnO2 nanoparticles. Herein, this work presents strategy to cross‐link small‐sized MnO2 nanoparticles, during which the indocyanine green (ICG) is loaded, thus obtaining large‐sized MnO2 nanomulberries (MnINCs) for overcoming the size requirement confliction. The MnINCs present great performances in both photothermal therapy (PTT) and photodynamic therapy (PDT) effects. This work tests the therapeutic efficacy of MnINCs in various human cancer cell lines including human cervical cancer cell line (HeLa), human breast cancer cell line (MCF‐7), human hepatoma cell line (HepG‐2), human gastric carcinoma cell line (MGC803), and a Hela cell‐derived xenograft model. The satisfying growth inhibition effects are observed in all these cell lines and the tumor model. The demonstrations for using MnINCs to overcome the size requirement confliction between promoting tumor delivery and cellular uptake and catalyzing H2O2 degradation highlight the promising application potentials of the clustering strategy for developing innovative treatments in cancer therapy.

M6A methylation of FKFB3 reduced pyroptosis of gastric cancer by NLRP3.

Gastric cancer is a kind of malignant tumor that seriously endangers human life and health. Its incidence rate and mortality rate are among the highest in the global malignant tumors. Therefore, this study explored the role of 6-phosphofructo-2-kinase/fructose-2,6-bisphosphatase 3 (PFKFB3) in the progression of gastric cancer and its underlying mechanism. Patients with gastric cancer were collected, and human GC cell lines (stomach gastric carcinoma 7901, stomach gastric carcinoma 823 , human gastric carcinoma cell line 803 and adenocarcinoma gastric stomach) were used in this study. We utilized glucose consumption, cell migration, and ELISA assay kits to investigate the function of GC. To understand its mechanism, we employed quantitative PCR (qPCR), western blot, and m6A methylated RNA immunoprecipitation assay. FKFB3 protein expression levels in patients with gastric cancer were increased. The induction of PFKFB3 mRNA expression levels in patients with gastric cancer or gastric cancer cell lines. Gastric cancer patients with high PFKFB3 expression had a lower survival rate. PFKFB3 high expression possessed the probability of pathological stage, lymph node metastasis or distant metastasis in patients with gastric cancer. PFKFB3 upregulation promoted cancer progression and Warburg effect progression of gastric cancer. PFKFB3 upregulation reduced pyroptosis and suppressed nucleotidebinding domain, leucinerich repeat containing protein 3-induced pyroptosis of gastric cancer. M6A-forming enzyme methyltransferase-like 3 increased PFKFB3 stability. Taken together, the M6A-forming enzyme methyltransferase-like 3 increased PFKFB3 stability and reduced pyroptosis in the model of gastric cancer through the Warburg effect. The PFKFB3 gene represents a potential therapeutic strategy for the treatment of gastric cancer.

Aporphine and amide alkaloids from Illigera parviflora

Three undescribed alkaloids (+)-9-hydroxy-N-acetylnordicentrine (1), illigeparvinine (2), and deca-(2E,4Z)-2,4-dienoic acid 4-hydroxy-2-phenethyl amide (3), along with 19 known analogues (4–22), were isolated from the ethnic medicinal plant Illigera parviflora. Their structures were established using NMR, MS, and other spectroscopic analyses as well as X-ray diffraction. Moderate inhibition of human gastric carcinoma (MGC-803) and breast adenocarcinoma (T-47D) cell lines proliferation was observed for actinodaphnine (4) with IC50 values of 28.74 and 11.65 μM, respectively. These findings contribute new anticancer potential compounds and expand the chemical diversity known from the valuable traditional medicinal plant I. parviflora.

Annona cherimola Seed Extracts Trigger an Early Apoptosis Response and Selective Anticlonogenic Activity against the Human Gastric Carcinoma Cell Line SNU-1.

The aim of this study was to evaluate, for the first time, the antiproliferative, apoptotic and diminishing effects of the anchored growth-independent capacity of an ethanol macerate extract from the Annona cherimola seed (EMCHS) in the human gastric cancer cell line SNU-1. The cells treated with EMCHS (20 μg/mL) significantly reduced the capacity to form clones of the tumor cell. Moreover, 50 μg/mL of EMCHS extract induced apoptosis, as was shown by the Annexin-V assay. UHPLC-MS/MS analysis detected two acetogenins (Annonacinone and Annonacin) in the EMCHS, which could be largely responsible for its selective antiproliferative effect. The identification of fatty acids by GC-FID showed the presence of eight fatty acids, among which was, oleic acid, which has recognized activity as an adjuvant in antitumor treatments. Taken together, our results indicate that the EMCHS seems promising for use as a natural therapy against gastric cancer disease.

Synthesis of S-2-phenylchromane Derivatives and Evaluation of the Antiproliferative Properties as Apoptosis Inducers in Cancer Cell Lines.

Cancer remains one of the major health issues globally, where chemotherapy forms the main treatment mode for different types of cancers. Due to cancer cell ability to develop resistance, decreased clinical effectiveness of anticancer drugs can occur. Therefore, the need to synthesize novel antitumor drugs remains important. The aim of our work consisted of synthesizing S-2-phenylchromane derivatives containing the tertiary amide or 1,2,3-triazole fragments with promising anticancer activity. A series of S-2-phenylchromane derivatives were synthesized and evaluated for cytotoxic activity against three selected cancer cell lines (HGC-27 human gastric carcinoma cell line, Huh-7 epithelial-like tumorigenic cells, and A549 adenocarcinomic human alveolar basal epithelial cells) using the 3-(4,5-dimethylthiazol-2-yl)-2,5- diphenyltetrazolium bromide (MTT) assay. Hoechst staining was used to detect the effects of S-2-phenylchromane derivatives on apoptosis. The apoptosis percentages were detected by annexin V-fluoresceine isothiocyanate/propidium iodide (Annexin V-FITC/PI) double staining assay with flow cytometry. Expression levels of apoptosis-related proteins were detected by western blot. Cell line A549, consisting of adenocarcinomic human alveolar basal epithelial cells, displayed the highest sensitivity to the S-2-phenylchromane derivatives. Among these compounds, E2 showed the most potent antiproliferative activity against A549 cells with an IC50 value of 5.60 μM. Hoechst staining and flow cytometry analysis revealed apoptosis in A549 cells by compound E2. In addition, activation of the expression levels of caspase-3, caspase-7, and their substrate poly (ADP-ribose) polymerase (PARP) by E2 was detected by western blot. In summary, results point towards compound E2, an S-2-phenylchromane derivative, as a potential lead molecule in anticancer agents for human adenocarcinomic alveolar basal cells based on the induction of apoptosis.

In-vitro anticancer and antibacterial activities and comparative of eco-friendly synthesized silver nanoparticles using hull of Pistacia vera and rhizome of Sambucus ebulus extracts

The biogenic method of synthesizing nanoparticles offers an effective alternative to traditional chemical synthesis systems. Additionally, the rapid development of eco-friendly techniques for producing metallic nanoparticles is driven by their extensive applications in various scientific fields. The present study investigated the production of silver nanoparticles (AgNPs) using hull of Pistacia vera (PV-AgNPs) and rhizomes of Sambucus ebulus (SE-AgNPs) extracts. The eco-friendly synthesis of Ag nanoparticles was carried out by optimizing three physicochemical parameters, including silver salt concentration, temperature, and pH. Biogenic silver nanoparticles were characterized using several analytical techniques, including FESEM, EDS, XRD, TEM and UV-Vis. The average sizes of PV-AgNPs and SE-AgNPs were determined to be 19.32 nm and 15.63 nm, respectively, using X-ray diffraction patterns. These findings were consistent with the results obtained from scanning electron microscopy. The antibacterial efficacy of AgNPs was evaluated against both Gram-negative and Gram-positive pathogens. AgNPs exhibited the highest antibacterial activity against S. aureus and E. faecalis, with a minimum inhibitory concentration (MIC) value of 12.5 µg/ml for PV-AgNPs. Additionally, for SE-AgNPs, the MIC value against S. aureus was found to be 2 µg/ml, indicating a potent antibacterial effect. Moreover, the anticancer potential of AgNPs was assessed using the MTT assay on MCF-7 (breast cancer) and AGS (human gastric carcinoma) cell lines as representative cancer cell models. The IC50 value of SE-AgNPs on MCF-7 and AGS was found to be 24.3 and 32.5 μg/ml, respectively. Hence, the present study indicates that biologically synthesized AgNPs have significant potential for exploitation in various biological applications.

Controlled synthesis of zinc oxide nanoparticles through flame spray pyrolysis and evaluation of their anticancer effects against gastric cancer cell

Although zinc oxide nanoparticles (ZnO NPs) have demonstrated promising anticancer activity, their therapeutic performances are frequently influenced by the synthesis routes and associated distinct physicochemical characteristics. Herein, ZnO NPs were synthesized through a cost-effective flame spray pyrolysis-assisted approach and their selective anticancer effects and underlying intrinsic apoptosis signaling pathway in human gastric carcinoma cell line (AGS) were examined. Transmission electron microscopy (TEM), Fourier-transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD), and dynamic light scattering (DLS) investigations were used to characterize the synthesized ZnO NPs. Afterwards, AGS and normal fibroblast cells (L-929) were treated with various concentrations of ZnO NPs, and cell proliferation was examined by the MTT assay to determine the IC50 concentration of NPs. Furthermore, the quantification of ROS and apoptosis was done by fluorometer and flow cytometry assays. Additionally, superoxide dismutase (SOD) and catalase (CAT) activity assays were performed to evaluate the oxidative stress-induced cytotoxicity mediated by ZnO NPs against AGS cells. Moreover, caspase-3/-8/-9 activity and mitochondrial membrane potential (MMP) assays were done. Finally, the expression levels of p53, Bax, Bcl-2, caspase-9/-8/-3, and cytochrome c were assessed by quantitative real time PCR and western blot analyses to explore the probable mitochondrial apoptosis signaling pathway induced by ZnO NPs in AGS cells. The results showed that ZnO NPs with an absorption maximum at 350 nm, an average size of 70 nm, a hydrodynamic radius of 92.89 nm, and a zeta potential of −43.13 mV potentially and selectively inhibited the proliferation of AGS cells in comparison with L-929 cells through a remarkable increase in the production of ROS, induction of apoptosis, reduction of SOD and CAT activity, activation of caspase-9/-3, and MMP disruption. Moreover, ZnO NPs triggered up-regulation of p53, Bax, caspase-9/-3, cytochrome c and down-regulation of Bcl-2 at mRNA and protein levels. This study suggests that synthesized ZnO NPs through flame spray pyrolysis can induce selective anticancer effects against gastric cancer cells via intrinsic apoptosis signaling pathway.

A Comparative Analysis between the Phenolic Content, Key Enzyme Inhibitory Potential, and Cytotoxic Activity of Arum italicum Miller in Two Different Organs

The present study assessed two different plant parts (leaves and tubers) of Arum italicum species growing in Northeast Algeria for their phytochemical composition and pharmacological effects. The phytochemical content was determined using ultra-high-performance liquid chromatography coupled with a diode array detector and an electrospray mass spectrometer (UHPLC-DAD-ESI/MS). The results revealed that the tuber extract was rich in lignans with a fraxiresinol glycoside as the major compound. In contrast, the leaf extract was rich in flavonoid glycosides, described for the first time in the aerial part of this species. The extract’s inhibitory activity against key enzymes was linked to hyperglycemia, α-glucosidase, and α-amylase, and their ability to inhibit the growth of human gastric carcinoma (AGS) and lung carcinoma (A549) cancer cell lines was also assessed. A cell line morphology study was also conducted with the most effective extract. The chromatin status of the cells was evaluated using DAPI, while the cytoplasmic morphology was evaluated using phalloidin. The tuber extract generally inhibited α-glucosidase and α-amylase enzymes more efficiently than the leaf extract. Its inhibition effect against the α-glucosidase was significantly higher when compared to the standard acarbose. The tuber extract also caused more viability loss of AGS and A549 cancer cells than the leaf extract in the cytotoxicity assay. In conclusion, our findings show that, compared to the leaf extract, the tuber extract exhibited more pronounced biological effects. The strong inhibitory potential of the tuber extract against the α-glucosidase enzyme should also be highlighted, which suggests it is a good candidate for discovering new antidiabetic agents.

Two new isoquinoline alkaloids from Hypecoum leptocarpum Hook. f. et Thoms

Two new isoquinoline alkaloids, hypecocarpinine (1) and leptocaramine (2) along with five known ones including leptopidine (3), corydamine (4), protopine (5), dihydroprotopine (6) and oxohydrastinine (7), were isolated from Hypecoum leptocarpum Hook. f. et Thoms. Structures of the compounds were elucidated using spectroscopic methods, including UV, IR, HR-ESI-MS, 1 D and 2 D NMR. The cytotoxic activities of these compounds were evaluated using MTT assay. The results showed that compounds 2, 4, and 7 have moderate cytotoxicity against human lung cancer (A549) and human gastric carcinoma (MGC-803) cell lines.

Systematic molecular analysis of the human secretome and membrane proteome in gastrointestinal adenocarcinomas.

The human secretome and membrane proteome are a large source of cancer biomarkers. Membrane‐bound and secreted proteins are promising targets for many clinically approved drugs, including for the treatment of tumours. Here, we report a deep systematic analysis of 957 adenocarcinomas of the oesophagus, stomach, colon and rectum to examine the cancer‐associated human secretome and membrane proteome of gastrointestinal tract adenocarcinomas (GIACs). Transcriptomic data from these GIACs were applied to an innovative majority decision‐based algorithm. We quantified significantly expressed protein‐coding genes. Interestingly, we found a consistent pattern in a small group of genes found to be overexpressed in GIACs, which were associated with a cytokine–cytokine interaction pathway (CCRI) in all four cancer subtypes. These CCRI associated genes, which spanned both one secretory and one membrane isoform were further analysed, revealing a putative biomarker, interleukin‐1 receptor accessory protein (IL1RAP), which indicated a poor overall survival, a positive correlation with cancer stemness and a negative correlation with several kinds of T cells. These results were further validated in vitro through the knockdown of IL1RAP in two human gastric carcinoma cell lines, which resulted in a reduced indication of cellular proliferation, migration and markers of invasiveness. Following IL1RAP silencing, RNA seq results showed a consistent pattern of inhibition related to CCRI, proliferation pathways and low infiltration of regulatory T cells (Tregs) and CD8 naive cells. The significance of the human secretome and membrane proteome is elucidated by these findings, which indicate IL1RAP as a potential candidate biomarker for cytokine‐mediated cancer immunotherapy in gastric carcinoma.

Inhibition of Membrane-Associated Catalase, Extracellular ROS/RNS Signaling and Aquaporin/H2O2-Mediated Intracellular Glutathione Depletion Cooperate during Apoptosis Induction in the Human Gastric Carcinoma Cell Line MKN-45.

The human gastric carcinoma cell line MKN-45 is a prototype of bona fide tumor cells, as it is protected from the NADPH oxidase-1 (NOX-1)-driven HOCl- and nitric oxide (NO)/peroxynitrite apoptosis-inducing signaling pathways by a membrane-associated catalase. The use of inhibitors/scavengers shows that inhibition of membrane-associated catalase is sufficient for the activation of NO/peroxynitrite or HOCl signaling. However, this signaling is not sufficient for apoptosis induction, as intracellular glutathione peroxidase/glutathione counteracts these signaling effects. Therefore, intrusion of extracellular tumor cell-derived H2O2 through aquaporins is required for the full apoptosis-inducing effect of extracellular reactive oxygen/nitrogen species. This secondary step in apoptosis induction can be prevented by inhibition of aquaporins, inhibition of NOX1 and decomposition of H2O2. Pretreatment with inhibitors of glutathione synthase or the cysteine-glutamine antiporter (xC transporter) abrogate the requirement for aquaporin/H2O2-mediated glutathione depletion, thus demonstrating that intracellular glutathione is the target of intruding H2O2. These data allow definition of mechanistic interactions between ROS/RNS signaling after inhibition of membrane-associated catalase, the sensitizing effects of aquaporins/H2O2 and the counteraction of the xC transporter/glutathione synthase system. Knowledge of these mechanistic interactions is required for the understanding of selective apoptosis induction in tumor cells through reestablishment of apoptosis-inducing ROS/RNS signaling.

A feasible strategy of fabricating hybrid drugs encapsulated polymeric nanoparticles for the treatment of gastric cancer therapy

Chemotherapy of hybrid-drugs has become one of the widely used therapies for the prevention of cancers with promising clinical results. This study aimed to create compostable polymeric nanoparticles (PPNPs) for the codelivery of capsaicin (CAPS) and biotin (BT) and to examine the anticancer activity of the drug delivery mechanism (CAPS/BT@PPNPs) against in vitro and in vivo gastric cancer cells. Because of the insufficiency of double antitumor drugs BT and CAPS compressed in polymer-based bio-degradable nanoparticles, the encapsulation of BT and CAPS antitumor drugs co-loaded with polyethylene glycol and polylactidecoglycolide nanoparticles (PPNPs) is effective. Transmission electron microscopy (TEM) was utilized to investigate the structure of BT@PPNPs, CAPS@PPNPs, and BT/CAPS@PPNPs, as well as their shape and size. Human gastric carcinoma cell lines, such as SGC-791 and NCI-N87, were also induced to apoptosis in vitro by BT/CAPS@PPNPs. Morphologies and cell death were observed using bio-chemical staining methods, AO/EB (acridine orange/ethidium bromide) and Hoechst. Flow cytometry in dual staining was also used to confirm the mechanistic investigations of apoptosis. Overall, this dual drug delivery strategy suggests that BT/CAPS@PPNPs could be used as a new method to increase the efficacy of gastric therapeutics.

Helicobacter pylori promotes gastric cancer progression by upregulating semaphorin 5A expression via ERK/MMP9 signaling

Helicobacter pylori (H. pylori) infection is the strongest risk factor for the occurrence and development of gastric carcinoma. However, the molecular mechanism underlying H. pylori-induced pathogenesis has not yet been fully characterized. Here, we explored whether H. pylori upregulates semaphorin 5A to promote gastric cancer progression via the extracellular regulated protein kinases/matrix metalloproteinase (ERK/MMP9) signaling pathway. In this study, H. pylori upregulated semaphorin 5A expression in vitro and in vivo. Using the human gastric carcinoma cell lines SGC7901, SGC7901-siScrambled, and SGC7901-siSema 5A, our studies showed that H. pylori increased the proliferation, growth, migration, and invasiveness of gastric cancer cells via its effects on semaphorin 5A and that H. pylori increased the expression of MMP9 in gastric cancer cells via the semaphorin 5A-mediated ERK signaling pathway. Further analysis revealed that the ERK inhibitor PD98059 and MMP9 antibody (Ab) attenuated H. pylori-induced gastric cancer cell invasion and metastasis in vitro through a semaphorin 5A-dependent mechanism. In conclusion, H. pylori could promote gastric cancer progression in a semaphorin 5A-dependent manner via the ERK/MMP9 signaling pathway. Semaphorin 5A and its related signaling molecules potentially represent latent targets for H. pylori-related gastric cancer therapy.

Gold Nanoparticles Prepared with Phyllanthus emblica Fruit Extract and Bifidobacterium animalis subsp. lactis Can Induce Apoptosis via Mitochondrial Impairment with Inhibition of Autophagy in the Human Gastric Carcinoma Cell Line AGS.

(1) Background: Nanotechnology is being widely applied for anticancer strategies with few side effects. Nanoparticles (NPs) prepared from natural extracts are promising candidates for cancer treatment because of their unique physicochemical characteristics. This study aimed to prepare gold nanoparticles (AuNPs) from Phyllanthus emblica fruit extract (PEFE) using Bifidobacterium animalis subsp. lactis (B. lactis) and to evaluate their anticancer activity against the human gastric adenocarcinoma cell-line (AGS). (2) Methods: The safety of microbial biosynthesis AuNPs (PEFE-AuNPs) was assessed by evaluating the cytotoxicity. The anticancer activity of PEFE-AuNPs was investigated in AGS cells in terms of apoptosis and autophagy. (3) Results: PEFE-AuNPs exhibited significant cytotoxicity against AGS cells but not against normal cells. The apoptosis induced by PEFE-AuNPs in AGS cells was associated with PTEN-induced kinase 1 (PINK1)-Parkin mediated reduction of mitochondrial membrane potential and activation of intracellular signaling apoptosis pathways. The anticancer activity of PEFE-AuNPs was associated with induction of apoptosis through inhibition of autophagy, downregulation of LC3-II/LC3-I and Beclin-1 expression, and upregulation of p62 expression in AGS cells. (4) Conclusions: This study is the first to demonstrate the anticancer activity of PEFE-AuNPs against AGS cells. Our results provide a good starting point for the development of new anticancer products based on gold nanoparticles of P. emblica fruit extract.

Membrane Filtration-Assisted Enzymatic Hydrolysis Affects the Biological Activity of Potato Juice.

The results of recently published studies indicate that potato juice is characterized by interesting biological activity that can be particularly useful in the case of gastrointestinal symptoms. Moreover, the studies also described the high nutritional value of its proteins. This article is a report on the impact of the enzymatic hydrolysis of proteins combined with membrane filtration. The obtained potato juice protein hydrolysate (PJPH) and its concentrate (cPJPH) were characterized in terms of their nutritional value and biological activity. The amino acid profile and scoring, the content of mineral compounds, and the antioxidant and in vitro cytotoxic activity were assessed. The study proved that the antioxidant activity of PJPH is higher than that of fresh potato juice, and the cytotoxicity against human gastric carcinoma cell line (Hs 746T), human colon cancer cell line (Caco-2), human colorectal adenocarcinoma cell line (HT-29), and human normal colon mucosa cell line (CCD 841 CoN) showed biological activity specifically targeted against cancer cells. Therefore, it can be concluded that the membrane filtration-assisted enzymatic hydrolysis of potato juice proteins may increase their biological activity and allow for potato juice to be used in the production of medicinal preparations.

Pyruvate Kinase M2 Knockdown Suppresses Migration, Invasion, and Epithelial-Mesenchymal Transition of Gastric Carcinoma via Hypoxia-Inducible Factor Alpha/B-Cell Lymphoma 6 Pathway.

Gastric carcinoma is a common malignant cancer. Pyruvate kinase M2 (PKM2) is highly expressed in cancers, including gastric carcinoma. However, its function and molecular mechanism in gastric carcinoma remains unclear. Here, we aimed to explore the function and the underlying mechanism of PKM2 on malignant phenotypes in gastric carcinoma. In this study, the mRNA levels and protein levels of PKM2 in gastric carcinoma cell lines and normal gastric mucosa epithelial cell lines were detected using quantitative real-time PCR and western blot, respectively. PKM2 was downregulated by siRNA transfection. HIF-1α or BCL-6 was upregulated by corresponding overexpression plasmid. Cell viability was detected using CCK-8 assay. Cell invasion and migration were determined using transwell assay. Higher expression of PKM2 was observed in human gastric carcinoma cell lines MKN-45 and SGC-7901 than in the normal gastric mucosa epithelial cell line GES-1. PKM2 knockdown suppressed cancer cell invasion and migration and inhibited the epithelial-mesenchymal transition (EMT) phenotype by inhibiting E-cadherin and promoting vimentin and N-cadherin expression. Also, we observed that PKM2 knockdown suppressed the hypoxia-inducible factor alpha (HIF-1α) and B-cell lymphoma 6 (BCL-6) signaling pathway. HIF-1α overexpression reversed the function of PKM2 silencing on cell invasion, migration, EMT, and BCL-6 expression. BCL-6 overexpression also reversed the function of PKM2 silencing on cell invasion, migration, and EMT but did not affect HIF-1α expression. Taken together, data from our study suggest that PKM2 knockdown impeded cell migration, invasion, and EMT of gastric carcinoma cells via the HIF-1α/BCL-6 pathway.

Ursolic Acid Protects Against Proliferation and Inflammatory Response in LPS-Treated Gastric Tumour Model and Cells by Inhibiting NLRP3 Inflammasome Activation.

BackgroundInflammation is considered as one of the hallmarks of cancer development and progression. Ursolic acid (UA) showed strong effects as an anti-inflammatory and antioxidant. However, the anti-cancer effects of ursolic acid require further study.MethodsThis study aimed to investigate the role of ursolic acid in a lipopolysaccharide (LPS)-treated gastric tumour mouse model and in a human gastric carcinoma cell line (BGC-823 cells). This study also aimed to confirm whether ursolic acid can protect against proliferation and the inflammatory response induced by LPS, by inhibiting the activation of the NLRP3 inflammasome via the NF-κB pathway.ResultsThe present study demonstrated that ursolic acid significantly attenuated LPS-treated proliferation in a gastric tumour mouse model and the human gastric carcinoma BGC-823 cell line, reduced the expression of the NLRP3 inflammasome and suppressed the release of pro-inflammatory cytokines. In addition, ursolic acid inhibited the LPS-induced activation of NF-κB. Furthermore, the NF-κB pathway regulated the activation of the NLRP3 inflammasome.ConclusionIn conclusion, these results demonstrated that ursolic acid could suppress proliferation and the inflammatory response in an LPS-induced mouse gastric tumour model and human BGC-823 cells by inhibiting the activation of the NLRP3 inflammasome via the NF-κB pathway. This indicates that ursolic acid can be a potential therapeutic agent for the treatment of gastric cancer.

Niclosamide exerts anti-tumor activity through generation of reactive oxygen species and by suppression of Wnt/ β-catenin signaling axis in HGC-27, MKN-74 human gastric cancer cells

Introduction Gastric carcinoma (GC) remains a therapeutic challenge despite having many potent drugs to treat. Various studies emphasized the role of dysregulated Wnt/β-catenin pathway in cancer. In the present study, we examined the anti-cancer effect of Niclosamide and its effect on the dysregulated β-catenin pathway in human gastric carcinoma cell lines. Methods Cytotoxicity of compound to gastric cancer cell line was assessed by MTT cell viability assay, cell cycle analysis, and apoptosis assay was done using standard kits of Muse™ Cell Analyser. Reactive oxygen species (ROS) generation and mitochondrial membrane potential were analyzed by 2′,7′-Dichlorodihydrofluorescein diacetate (DCFDA) and tetraethylbenzimidazolylcarbocyanine iodide (JC-1) staining respectively. Protein expression studies were carried out by standard western blotting protocols. Results Niclosamide treatment resulted in a dose-dependent inhibition of viability of the gastric carcinoma cell-lines induced cell cycle arrest in the G0/G1 phase and strongly induced apoptosis in a concentration-dependent manner by downregulating Cyclin-D1 and CDK4 levels, critical proteins required for G1-S phase progression. DCFDA and JC-1 staining results indicated that Niclosamide enhanced intracellular ROS generation and disrupted mitochondrial membrane potential. Furthermore, niclosamide treatment decreased the expression of NF-KB, Bcl-2 and increased the expression of Bax protein. Niclosamide treatment significantly decreased the β-catenin mediated transcriptional activity and down-regulated β-catenin levels and its downstream proteins cyclinD1, CDK-4, and c-myc expression and also impeded Akt phosphorylation, a common internode in the Wnt and Akt/mTOR signaling in HGC-27 cells. Conclusion This study demonstrated that Niclosamide might become a promising therapeutic agent for the management of gastric cancer and further warrants its clinical trials in gastric cancer patients.

Abstract B73: Development of anti-human CLDN18.2 monoclonal antibody as cancer therapeutics

Abstract Claudin-18 (CLDN18) is a member of a large family of four-span transmembrane proteins, claudins. These proteins are the essential components of the mammalian tight junctions (TJs) in the epithelial cells. Claudin-18 has two splice variants, 18.1 and 18.2. While CLDN18.1 is specifically expressed in the lung tissue, CLDN18.2 expression in normal tissue is more restricted and is only detected in small patches of stomach mucosal. CLDN18.2 expression is elevated in many types of epithelial cancers including stomach, esophagus, pancreatic and ovarian cancers. The expression of CLDN18.2 is not only detected in primary tumors, but also in the metastatic sites. Therefore, CLDN18.2 is an ideal target for monoclonal antibody-based cancer therapies. Anti-CLDN18.2 monoclonal antibody claudiximab (IMAB362) demonstrated promising results in the phase II clinic trial for gastric cancer. CLDN18.2 specific antibodies are difficult to generate due to its high homology to CLDN18.1. There are only 7-8 amino acid differences between these two splice variants in the first extracellular loop. Using a combination of DNA, protein, and transfected cells as immunogens, coupled with high-throughput FACS-based hybridoma screening approach, we have generated a panel of mouse monoclonal antibodies that are highly specific for CLDN 18.2. These antibodies had high affinities for CLDN18.2 while they did not bind to CLDN18.1. The lead antibodies had similar or better binding affinity for CLDN18.2, compared to the IMAB362. The anti-CLDN18.2 antibodies bound to human gastric carcinoma cell line KATO III. Our IHC data showed that the antibody specifically bound to gastric and pancreatic cancer tissues. In addition, we demonstrated that anti-CLDN18.2 antibodies induced receptor internalization in CHO cell line expressing CLDN18.2. The humanized anti-CLDN18.2 antibodies have been generated and showed similar binding specificity as the mouse antibodies. Lead anti-CLDN18.2 antibodies have been selected for CMC optimization and preclinical studies for further development as cancer therapeutics. Citation Format: Haishan Lin, Richard Zhang. Development of anti-human CLDN18.2 monoclonal antibody as cancer therapeutics [abstract]. In: Proceedings of the AACR Special Conference on Tumor Immunology and Immunotherapy; 2018 Nov 27-30; Miami Beach, FL. Philadelphia (PA): AACR; Cancer Immunol Res 2020;8(4 Suppl):Abstract nr B73.

Circular RNA hsa-circ-0007766 modulates the progression of Gastric Carcinoma via miR-1233-3p/GDF15 axis.

Circular RNAs (circRNAs), a new kind of non-coding RNAs, have gradually been proved to be critical regulators of gene expression; however, the underlying mechanisms still need to be elaborated. In the present study, we investigated the role of hsa-circ-0007766 in gastric carcinoma (GC). Quantitative real-time PCR was applied to detect the differential expression levels of circRNA, miRNAs, and mRNAs in human tissues and specific cell lines. GC cell lines were transiently transfected with siRNA. Then the proliferation, migration, and invasion assays were performed to evaluate the effect of hsa-circ-0007766 in GC cell lines. Fluorescence in situ hybridization, RNA pulldown assay was used to confirm the location of hsa-circ-0007766 and its relationship with miR-1233-3p. Luciferase reporter assay was then conducted to verify the interaction between miR-1233-3p and GDF15. Interestingly, we found that hsa-circ-0007766 was highly expressed in human GC tissues and GC cell lines. Knock-down of hsa-circ-0007766 inhibited cell proliferation, migration, invasion, and down-regulated the expression of GDF15. Moreover, hsa-circ-0007766 was identified as a sponge of miR-1233-3p, which could target gene GDF15 to regulate the progression of GC. Finally, hsa-circ-0007766 was evaluated to be a valuable diagnostic marker with a sensitivity of 53.33% and specificity of 83.33% by ROC analysis. This study unveils a mechanism by which hsa-circ-0007766 regulates GDF15 via hsa-circ-0007766/miR-1233-3p/GDF15 axis, which may provide new insight for GC therapeutic strategies.