HGC-27 Cells Research Articles

MiR-193a Directly Targets PSEN1 and Inhibits Gastric Cancer Cell Growth, the Activation of PI3K/Akt Signaling Pathway, and the Epithelial-to-Mesenchymal Transition.

Background Gastric cancer, a kind of gastrointestinal malignancy, is the second type of leading death cancer. miR-193a is a key tumor suppressor in several diseases. PSEN1 is mainly related to Alzheimer's disease and may be involved in the cleavage of the Notch receptor. Material and Methods. RT-PCR and western blot were applied to evaluate miR-193a and the expression level of PSEN1. Luciferase reporter assay was applied to verify whether PSEN1 was a target of miR-193a. The Kaplan–Meier method was employed to calculate the 5-year overall survival of gastric cancer patients. Results miR-193a was downregulated in gastric cancer tissues and cell lines, and downregulation of miR-193a predicted poor 5-year overall survival of gastric cancer. miR-193a inhibited the proliferation and the activation of the PI3K/AKT signaling pathway in gastric cancer cells. miR-193a inhibited gastric cancer tumor growth in vivo. miR-193a impaired cell invasion and epithelial-to-mesenchymal transition (EMT) in HGC-27 cells. In addition, PSEN1 was a direct target of miR-193a and PSEN1 reversed partial functions of miR-193a in cell proliferation and invasion. Conclusion miR-193a prominently decreased the proliferation, invasion, and activation of the PI3K/Akt signaling pathway and the abilities of epithelial-to-mesenchymal transition in gastric cancer cells. The newly identified miR-193a/PSEN1 axis provides novel insight into the pathogenesis of gastric cancer.

LncRNA DLEU2 promotes gastric cancer progression through ETS2 via targeting miR-30a-5p

BackgroundGastric cancer (GC) remains an important cancer worldwide. Further understanding of the molecular mechanisms of gastric carcinogenesis will enhance the diagnosis and treatment of GC.MethodsThe expression of DLEU2 and ETS2 was analyzed in several GC cell lines using GEPIA online analyze, qRT-PCR and immunohistochemistry. The biological behavior of GC cells was detected by CCK8, clone formation, transwell, wound healing, western blot, and flow cytometry assay. More in-depth mechanisms were studied.ResultsDLEU2 was significantly up-regulated in GC tissues and cell lines. The expression of DLEU2 was significantly associated with pathological grading and TNM stage of GC patients. Furthermore, knockdown of DLEU2 inhibited the proliferation, migration, and invasion of AGS and MKN-45 cells, while overexpression of DLEU2 promoted the proliferation, migration, and invasion of HGC-27 cells. MiR-30a-5p could directly bind to the 3’ UTR region of ETS2. Moreover, DLEU2 bound to miR-30a-5p through the same binding site, which facilitated the expression of ETS2. Knockdown of DLEU2 reduced the protein level of intracellular ETS2 and inhibited AKT phosphorylation, while overexpression of DLEU2 induced the expression of ETS2 and the phosphorylation of AKT. ETS2 was highly expressed in GC tissues. The expression of ETS2 was significantly associated with age, pathological grading, and TNM stage. ETS2 overexpression promoted cell proliferation and migration of AGS and MKN-45 cells. Furthermore, ETS2 overexpression rescued cell proliferation and migration inhibition induced by DLEU2 down-regulation and miR-30a-5p up-regulation in AGS and MKN-45 cells.ConclusionsDLEU2 is a potential molecular target for GC treatment.

CPEB1 enhances erastin-induced ferroptosis in gastric cancer cells by suppressing twist1 expression.

The induction of ferroptosis is considered a new strategy for cancer treatment. Cytoplasmic polyadenylation element binding protein 1 (CPEB1) is a post-transcriptional regulatory factor, whose low expression has been reported to link to the enhanced metastasis and angiogenesis of gastric cancer (GC). In this study, to explore the role of CPEB1 in ferroptosis, GC cells with overexpressed or silenced CPEB1 expression were treated with erastin, a classic ferroptosis inducer. The results showed that erastin dose-dependently decreased the viability of four GC cell lines (AGS, SNU-1, Hs-746 T, and HGC-27), suggesting that ferroptosis could be triggered in these GC cells. Interestingly, HGC-27 cells overexpressing CPEB1 were more sensitive to erastin, generated more lipid reactive oxygen species (ROS) and malondialdehyde (MDA), and their glutathione peroxidase 4 (Gpx4) expression and GSH content were reduced. Contrarily, CPEB1-silenced AGS cells were more resistant to erastin. Mechanically, we demonstrated that CPEB1 overexpression reduced the expression of twist1, an inhibitor of activating transcription factor 4 (ATF4), thereby activating the ATF4/ChaC Glutathione Specific Gamma-Glutamylcyclotransferase 1 (CHAC1) pathway (CHAC1, a molecule known to induce GSH degradation). Furthermore, re-expression of twist1 in GC cells impaired the effects of CPEB1 overexpression in presence of erastin. Additionally, similar to the in vitro results, the growth-inhibiting effects of erastin on GC xenografted tumors were also augmented by CPEB1 overexpression in vivo. Collectively, we demonstrate that CPEB1 facilitates erastin-induced ferroptosis by inhibiting twist1.

CircRNA_100290 promotes GC cell proliferation and invasion via the miR-29b-3p/ITGA11 axis and is regulated by EIF4A3

BackgroundCircular RNAs (circRNAs) have been reported to be important regulators of the development and progression of various carcinomas. However, the role of circRNA_100290 in gastric cancer (GC) is still unclear. This study aimed to investigate the role of circRNA_100290 in GC invasion and metastasis and the possible underlying mechanism.MethodsThe expression of circRNA_100290 in GC cells and tissues was examined using quantitative real-time polymerase chain reaction (qRT-PCR). The role of circRNA_100290 in cell proliferation, migration, and invasion was evaluated in the AGS and HGC-27 cell lines in vitro. Bioinformatics tools, dual-luciferase reporter assays, Western blot assays and qRT-PCR were used to explore the pathways downstream of circRNA_100290. The mechanism underlying the regulation of circRNA_100290 expression was explored using RNA immunoprecipitation, qRT-PCR, and Western blot assays.ResultsThe expression of circRNA_100290 was significantly upregulated in GC cells and 102 GC tissues, and high circRNA_100290 expression in GC was closely related to Borrmann’s type, lymph node metastasis and tumour-node-metastasis stage. In vitro, knockdown of circRNA_100290 in AGS and HGC-27 cells significantly inhibited cell proliferation, migration, and invasion. Mechanistically, a dual-luciferase reporter assay confirmed the direct interaction between circRNA_100290 and miR-29b-3p, which targets ITGA11, an oncogene that is closely related to epithelial–mesenchymal transition (EMT). In addition, EIF4A3, an RNA-binding protein (RBP), could inhibit the formation of circRNA_100290 by binding to the flanking sites of circRNA_100290. Low EIF4A3 expression in GC was related to a poor prognosis.ConclusionsElevated circRNA_100290 expression in GC promotes cell proliferation, invasion and EMT via the miR-29b-3p/ITGA11 axis and might be regulated by EIF4A3. CircRNA_100290 might be a promising biomarker and target for GC therapy.Graphical abstract

Physalin B inhibits cell proliferation and induces apoptosis in undifferentiated human gastric cancer HGC-27 cells.

Physalin B (PB) from Physalis angulata L. (Solanaceae) is a naturally occurring secosteroid with multiple biological activities, including anti-inflammatory and anticancer activity. However, PB's effects and mechanisms in human gastric cancer (GC) cells are not well characterized. The undifferentiated GC cell line HGC-27 and semi-differentiated GC cell line SGC-7901 were treated with PB. Cell counting kit-8 (CCK-8) and colony formation assays were performed to evaluate cell viability. Apoptosis and the cell cycle were assessed by Annexin V/PI and PI/RNase DNA staining assays, respectively, and Western blotting was used to evaluate the expression of a protein. PB significantly inhibited the proliferation of HGC-27 cells in a dose- and time-dependent manner. Moreover, PB induced G0/G1 cycle arrest and caspase-dependent apoptosis of HGC-27 cells. Cleaved caspases 8, 3, and 7, poly(ADP)-ribose polymerase (PARP), and the cyclin-dependent kinase (CDK) inhibitor p-Chk2 was induced by PB in HGC-27 cells, while the cell cycle-related proteins cyclin D1, cyclin D3, CDK4, CDK6, cyclin E, and phosphorylated retinoblastoma tumor suppressor protein (p-Rb) were downregulated in a dose-dependent manner. PB inhibits proliferation via cyclin-dependent kinase and induces caspase-dependent apoptosis in HGC-27 cells, suggesting that PB might be a novel and effective agent for undifferentiated GC therapy.

Palbociclib induces cell senescence and apoptosis of gastric cancer cells by inhibiting the Notch pathway.

Palbociclib (PD0332991), a selective cyclin-dependent kinase 4/6 (CDK4/6) inhibitor, has been reported to exert anticancer activity in some cancers, including gastric cancer (GC). However, the role of palbociclib in GC remains largely unknown. The present study aimed to investigate the effects of palbociclib on the progression of GC and the potential mechanisms underlying its effects. The colony formation, proliferation, senescence, as well as apoptosis and cell cycle progression of AGS and HGC-27 cells following treatment with palbociclib were analyzed using colony formation assays, MTT assays, senescence-associated β-galactosidase (SA-β-gal) staining and flow cytometry, respectively. The protein expression levels of Bax, Caspase-3, Bcl-2, p16, p21, p53, Notch1, Notch2 and hairy and enhancer of split 1 (Hes1) were measured in AGS and HGC-27 cells using western blotting. Moreover, the mRNA expression levels of Notch1, Notch2 and Hes1 in AGS and HGC-27 cells were determined by reverse transcription-quantitative PCR. In the present study, palbociclib significantly inhibited cell proliferation and induced cell senescence, cell cycle arrest and apoptosis in both cell lines in a dose-dependent manner. Additionally, palbociclib significantly increased the expression levels of Bax, Caspase-3, p16, p21 and p53, whilst decreasing the expression of Bcl-2, Notch1, Notch2 and Hes1 in AGS and HGC-27 cells. Furthermore, the Notch pathway activator Jagged-1/FC reversed the effects of palbociclib on cell proliferation, apoptosis, senescence and cell cycle progression. These findings demonstrated that palbociclib could inhibit proliferation and induce senescence, cell cycle arrest and apoptosis in GC cells by inhibiting the Notch pathway.

Trifunctional Graphene Quantum Dot@LDH Integrated Nanoprobes for Visualization Therapy of Gastric Cancer.

Visualization technology has become a trend in tumor therapy in recent years. The superior optical properties of graphene quantum dots (GQDs) make them suitable candidates for tumor diagnosis, but their tumor targeting and drug-carrying capacities are still not ideal for treatment. Sulfur-doped graphene quantum dots (SGQDs) with stable fluorescence are prepared in a previous study. A reliable strategy by associating layered double hydroxides (LDHs) and etoposide (VP16) is designed for precise visualization therapy. Trifunctional LDH@SGQD-VP16 integrated nanoprobes can simultaneously achieve targeted aggregation, fluorescence visualization, and chemotherapy. LDH@SGQD-VP16 can accumulate in the tumor microenvironment, owing to pH-sensitive properties and long-term photostability in vivo, which can provide a basis for cancer targeting, real-time imaging, and effect tracking. The enhanced therapeutic and attenuated side effects of VP16 are demonstrated, and the apoptosis caused by LDH@SGQD-VP16 is ≈2.7 times higher than that of VP16 alone, in HGC-27 cells. This work provides a theoretical and experimental basis for LDH@SGQD-VP16 as a potential multifunctional agent for visualization therapy of gastric cancer.

Circular RNA circHECTD1 prevents Diosbulbin-B-sensitivity via miR-137/PBX3 axis in gastric cancer

BackgroundsGastric cancer (GC) is general disease in human digestive system with malignancy. Emerging findings indicated that hsa_circ_0031452 (circHECTD1) was strictly associated with carcinogenesis. Nevertheless, the role of circHECTD1 in drug-resistance still needed to be explained.MethodsQuantitative real-time polymerase chain reaction (qRT-PCR) was employed to examine the expression profiles of circHECTD1, microRNA (miR)-137, and pre-leukemia transcription factor 3 (PBX3). The function of circHECTD1 in tumorigenesis was evaluated via xenograft tumor model. The IC50 of Diosbulbin-B (DB) was detected using Cell Counting Kit-8 (CCK8). Cell-cycle and apoptosis were reckoned by flow cytometry. Besides, western blot was administrated to reckon the levels of PBX3 and cell apoptotic indicators. Moreover, the interrelation between miR-137 and circHECTD1 or PBX3 was expounded by dual-luciferase reporter, RNA immunoprecipitation (RIP) and RNA pull down assays.ResultsWe uncovered that circHECTD1 was ectopically up-regulated in GC tissues and cells. CircHECTD1 deficiency sensitized DB-treatment in DB-evoked AGS and HGC-27 cells. In vivo assay, circHECTD1 silencing led to the tumor reduction. Also, circHECTD1 served as miR-137 sponge in a sequence-complementary manner. Furthermore, transfection of miR-137 inhibitor markedly eliminated circHECTD1 absence-mediated promotion of DB-sensitivity in GC cells. Moreover, PBX3, a target of miR-137, play a DB-resistant role in GC cells. Fascinatingly, the deletion of PBX3 reversed the impact of miR-137 repression and circHECTD1 knockdown on DB-sensitivity in vitro.ConclusionsCircHECTD1 served as an oncogene by a novel miR-137/PBX3 axis, which might supply an underlying biomarker for the diagnosis and prognosis of GC management.

Expression and mechanism of exosome-mediated A FOXM1 related long noncoding RNA in gastric cancer

BackgroundForkhead box protein M1 (FOXM1) is an oncogene regulating tumor growth and metastasis. Exosome was suggested to mediate cell communication by delivering active molecules in cancers. However, the existence of FOXM1 in circulating exosomes and the role of exosome FOXM1 in gastric cancer (GC) were not clear. This study aims to investigate the potential role of FOXM1 related long noncoding RNA (FRLnc1) in exosomes in GC.ResultsThe prepared CD63 immunomagnetic beads (CD63-IMB) had the characteristics of good dispersity and high magnetic response. The isolated exosomes were presented with elliptical membranous particles under a transmission electron microscope (TEM), with the particle size of 89.78 ± 4.8 nm. Western blot (WB) results showed that the exosomes were rich in CD9 and CD81. The Dil-labeled exosomes were distributed around cytoplasm and nucleus of cells by imaging flow cytometry (IFC) analysis. The results of quantitative real-time PCR (qRT-PCR) revealed that the FRLnc1 expressions were up-regulated in GC cells, tumor tissues, and serum of GC patients. An obviously up-regulated FRLnc1 expression was found in serum exosomes of GC patients. Up-regulation of FRLnc1 expression was closely correlated to lymph node metastasis (LNM) and TNM stage with the combination of relevant clinicopathological parameter analysis. The in vitro functional analyses demonstrated that FRLnc1 knockdown by RNA interference suppressed cell proliferation and migration in HGC-27 cells, whereas FRLnc1 overexpression promoted cell proliferation and migration in MKN45 cells. After exosome treatment, the FRLnc1 expression was significantly increased in MKN45 cells, and the MKN45 cells showed increased ability of proliferation and migration.ConclusionGC cells-derived exosomes played roles in promoting the growth and metastasis of GC by transporting FRLnc1, suggesting that FRLnc1 in the exosomes may be a potential biomarker for the diagnosis and treatment of GC. The delivery of FRLnc1 by the exosomes may provide a new way for the treatment of GC.Trial registration 2020-KYSB-094. Registered 23 March 2020—Retrospectively registeredGraphic abstract

Identification of active components of Dendrobium inhibit growth of gastric cancer cells based on component-activity relationship

Three cancer cell lines including gastric cancer SGC-7901, HGC-27, and MGC-803 cells were employed to evaluate the bioactivity of seven Dendrobium species. Simultaneously, these Dendrobium species were assessed with UPLC-Q-TOF-MS, and 504 common peaks were found. Based on the hypothesis that biological effects varied with differences in components, multivariate relevance analysis for chemical component-activity relationship of Dendrobium, including grey relation(GRA) and partial least squares(PLS) analysis were performed to evaluate the contribution of each identified component. The target peaks were identified by standards toge-ther with databases of Dendrobium, Nature Chemistry, MassBank, etc. Finally, four active components, including 3,5,9-trihydroxy-23-methylergosta-7,22-dien-6-one, diacylglycerol(14∶1/22∶6/0∶0), pipercitine, and 22-tricosenoic acid, might have negative effect on the growth of gastric cancer cells.

Expression pattern of histone lysine-specific demethylase 6B in gastric cancer.

Over the last few decades, predictive markers for the prognosis of gastric cancer have not been extensively investigated. The present study aimed to evaluate the expression profile of histone demethylase lysine (K)-specific demethylase 6B (KDM6B) in gastric cancer and healthy control tissues, as well as its value in prognosis prediction as a clinical marker. Within the framework of these criteria, the diagnostic role of KMD6B for gastric cancer was investigated, which may provide insights into novel treatment targets. Immunohistochemistry was applied to detect KMD6B expression in 100 gastric cancer tissues and matching para-cancerous tissues to analyze the association between KMD6B expression and clinicopathological features. Based on the follow-up data, the value of KMD6B in prognosis assessment was further explored. The role of KMD6B in gastric cancer cell proliferation, cell cycle distribution and the expression of cell cycle-associated proteins was investigated by inhibiting KMD6B activity using the specific inhibitor GSK J4. KMD6B was mostly distributed in cytoplasm and nucleus in gastric cancer tissue. The expression level was significantly higher in cancer tissues compared with that in the corresponding non-cancerous tissues. The expression of KMD6B was significantly associated with sex, lymph node and distant metastasis status and clinical stage (P<0.05). Cell proliferation was significantly decreased with the inhibition of KMD6B activity, and the cell cycle in HGC27 cells was arrested in the G2/M phase after being treated with GSK J4 for 24 h. The expression of cyclin B and Cdc2 were significantly decreased, while p21 was upregulated. It was concluded that the dysregulated expression of KMD6B is associated with the malignant progression of gastric cancer and could be a potential marker for prognosis. Blocking the demethylase activity of KMD6B induced G2/M arrest and inhibited the proliferation of gastric cancer cells, suggesting that KMD6B is a potential novel therapeutic target for gastric cancer.

LINC00514 promotes gastric cancer cell growth and EMT progression via miR-204-3p/KRAS.

Long noncoding RNAs (LncRNAs) participate in tumor development and tumorigenesis. However, the mechanism, function and expression of LINC00514 in GC remain unknown. We showed that LINC00514 was upregulated in GC specimens compared with nontumor specimens. Overexpression of LINC00514 induced cell growth and EMT progression in GC cells. By using bioinformatics prediction, we found that miR-204-3p contained binding sequences for LINC00514. Luciferase reporter analysis noted that miR-204-3p overexpression decreased the luciferase expression under LINC00514-wild-type and KRAS-wild-type reporters but not that under mutant reporter. Ectopic LINC00514 expression decreased miR-204-3p expression. miR-204-3p expression was decreased in GC specimens compared with nontumor specimens and that LINC00514 was negatively correlated with miR-204-3p in GC specimens. Furthermore, KRAS was identified as a target gene for miR-204-3p according to TargetScan. Elevated miR-204-3p expression inhibited KRAS expression in HGC-27 cells, and ectopic expression of LINC00514 enhanced KRAS expression. Elevated LINC00514 expression enhanced cell growth and EMT progression by sponging KRAS. Our data indicated that LINC00514 may act as an oncogene and therapeutic target for GC.

Apatinib inhibits gastric carcinoma development by regulating the expression levels of IL-17 via the Bax/Bcl-2 signaling pathway.

Gastric carcinoma is a common type of gastrointestinal tumor with high morbidity and mortality rates. IL-17 is a newly discovered cytokine that has been reported to serve an important role in the development of gastric carcinoma. The potential effect of apatinib on IL-17 expression levels in the development of gastric carcinoma has been rarely reported. The present study aimed to investigate the potential mechanism of IL-17 and apatinib in the development of gastric carcinoma. A total of 30 tumor and para-carcinoma tissues were collected from 30 patients with gastric carcinoma between January 2019 and December 2019 and the expression levels of IL-17 in the tissues were analyzed by reverse transcription-quantitative PCR and western blotting. An in vitro model of gastric carcinoma was also established using the HGC-27 cell line, in which the cells were divided into control, IL-17, IL-17-apatinib and apatinib groups. The expression levels of IL-17, Bax, Bcl-2 and caspase-3 were analyzed using reverse transcription-quantitative PCR and western blotting. An MTT assay and flow cytometry were used to analyze the proliferation and apoptosis of HGC-27 cells, respectively, and a Transwell assay was used to analyze the invasive ability of HGC-27 cells. The results revealed that the expression levels of IL-17 were significantly upregulated in the gastric carcinoma tissues compared with the para-carcinoma tissues. In vitro, IL-17 treatment promoted the proliferation and invasive ability of HGC-27 cells, but inhibited the apoptosis with the significantly downregulated expression levels of Bax and caspase-3 and the upregulated expression levels of Bcl-2 than control group. Conversely, apatinib treatment significantly inhibited the proliferative and invasive abilities of HGC-27 cells, but promoted cell apoptosis in the IL-17 and IL-17-apatinib groups.. Collectively, the present results suggested that the upregulation of IL-17 may be associated with the occurrence and development of gastric carcinoma. The findings indicated that apatinib may inhibit gastric carcinoma development by regulating IL-17 expression via the Bax/Bcl-2 signaling pathway. Therefore, the present findings may enhance the current knowledge of the effect of apatinib on gastric carcinoma cells.

Evaluation of the efficacy and safety of a new formulation-lipid emulsion-based PTX injection: Pharmacokinetics, tissue distributions and anticancer effect on human gastric cancer cells in vitro.

Paclitaxel (PTX) is one of the most widely used chemotherapeutic agents. The commercial PTX formulation was based on Cremophor EL and ethanol owing to its poor aqueous solubility. However, Cremophor EL has been shown to cause toxic effects such as life-threatening anaphylaxis. In our study, we diluted PTX in a commercially available 20% (w/v) lipid emulsion (Lip-PTX) in order to avoid Cremophor EL. The purpose of this study was to evaluate the pharmacokinetics and tissue distributions between Lip-PTX and PTX injection. We also investigated the effects of Lip-PTX and PTX injection on human gastric cancer cells HGC-27 by MTT assay. The apoptosis was detected by flow cytometry with Annexin V/propidium iodide (PI) double staining. Furthermore, the safety such as acute toxicity was also assessed. The results showed that PTX in Sprague-Dawley rats administered Lip-PTX exhibited extended half-life, increased clearance (P < 0.05) and smaller area under the concentration-time curve compared with PTX injection and there was little significant difference in the distribution of PTX in Sprague-Dawley rats or tumor-bearing mice between Lip-PTX and PTX injection. The cells treated with Lip-PTX had a higher percentage of apoptosis and a higher G2 /M phase ratio, which indicated that the anticancer effect of Lip-PTX was significantly better than that of PTX injection. Moreover, our study highlighted the safety of Lip-PTX. This study demonstrated the feasibility and potential advantages of Lip-PTX for clinical therapy.

MSC-AS1 induced cell growth and inflammatory mediators secretion through sponging miR-142-5p/DDX5 in gastric carcinoma.

Emerging studies have noted that dysregulated lncRNAs are implicated in cancer progression and tumorigenesis. We first showed that MSC-AS1 was overexpressed in gastric cancer (GC) cells (HGC-27, MKN-45, SGC-7901 and MGC-803 cells) compared with GES cells. We observed that MSC-AS1 was upregulated in GC specimens compared with paired normal specimens. MSC-AS1 increased cell growth and cycle progression. Moreover, the overexpression of MSC-AS1 enhanced the secretion of the inflammatory mediators IL-1β, IL-6 and TNF-α. We found that the overexpression of MSC-AS1 inhibited the expression of miR-142-5p in HGC-27 cells. We noted that DDK5 was a target gene of miR-142-5p. The overexpression of miR-142-5p suppressed the luciferase activity of wild-type DDX5, but the luciferase activity of the mutant DDX5 was not changed. We showed that miR-142-5p was downregulated in GC specimens compared with paired normal specimens. MSC-AS1 expression was inversely correlated with miR-142-5p expression in GC specimens. MSC-AS1 induced cell growth, cell cycle progression and inflammatory mediator secretion by modulating DDX5. These results showed that MSC-AS1 functions as a key oncogene in the development of GC.

LINC00152 mediates CD8+ T-cell infiltration in gastric cancer through binding to EZH2 and regulating the CXCL9, 10/CXCR3 axis.

This study aimed to annotate the role of long intergenic non-coding RNA 152 (LINC00152) in CD8+ T cells mediated immune responses in gastric cancer (GC) and the underlying mechanism. LINC00152 expression levels were detected through RT-PCR. For tumor engraftment, HGC-27 cells that received LINC00152 shRNA, LINC00152 overexpression vectors, enhancer of zeste homolog 2 (EZH2) shRNA or combination transfection were injected into mice. Chromatin immunoprecipitation (ChIP) assay was used to explore the interaction between LINC00152, Cys-X-cys ligand 9 (CXCL9) and Cys-X-cys ligand 10 (CXCL10). Flow cytometry was adopted to measure the CD8+ T-cell infiltration in tumor issue. In this study, we found increased LINC00152 expression levels are positively associated with the poor prognosis of GC patients and negatively associated with the CD8 levels. ChIP assay verified that LINC00152 recruits EZH2 to the promoters of CXCL9 and CXCL10, thus the silencing of LINC00152 promoted the production of CXCL9 and CXCL10. Knockdown of LINC00152 suppressed tumor cells growth in vivo and in vitro, increased tumor-infiltrating CD8+ T cells numbers and promoted the expression of CXCL9, CXCL10 and C-X-C Motif Chemokine Receptor 3 (CXCR3) in xenograft tumors. While CD8+ T cell depletion reversed the tumor suppression effect of LINC00152 silence. Besides, the silencing of EZH2 partly inhibited the promotion effect LINC00152 on tumor growth. Our study indicated that LINC00152 inhibition suppressed the tumor progress may through promoting CD8+ T-cell infiltration.

Primary cilia regulate gastric cancer-induced bone loss via cilia/Wnt/β-catenin signaling pathway.

Cancer-associated bone disease is a frequent occurrence in cancer patients and is associated with pain, bone fragility, loss, and fractures. However, whether primary or non-bone metastatic gastric cancer induces bone loss remains unclear. Here, we collected clinical evidence of bone loss by analyzing serum and X-rays of 25 non-bone metastatic gastric cancer patients. In addition, C57BL mice were injected with the human gastric cancer cell line HGC27 and its effect on bone mass was analyzed by Micro-CT, immunoblotting, and immunohistochemistry. Furthermore, the degree of the proliferation and osteogenic differentiation of mesenchymal stem cells (MSCs) co-cultured with HGC-27 or SGC-7901 cells was analyzed by colony-formation assay, alizarin red staining, immunofluorescence, qPCR, immunoblotting, and alkaline phosphatase activity assay. These indicated that gastric cancer could damage bone tissue before the occurrence of bone metastases. We also found that cilia formation of MSCs was increased in the presence of HGC27 cells, which was associated with abnormal activation of the Wnt/β-catenin pathway. Expression of DKK1 inhibited the Wnt/β-catenin signaling pathway and partially rescued osteogenic differentiation of MSCs. In summary, our results suggest that gastric cancer cells might cause bone damage prior to the occurrence of bone metastasis via cilia-dependent activation of the Wnt/β-catenin signaling pathway.

Self-Monitoring and Self-Delivery of Self-Assembled Fluorescent Nanoparticles in Cancer Therapy.

PurposeDue to the shortcomings of nanocarriers, the development of carrier-free nanodelivery systems has attracted more and more attention in cancer treatment. However, there are few studies on carrier-free nanosystems that can simultaneously achieve monitoring functions. Here a multifunctional carrier-free nanosystem loaded with curcumin and irinotecan hydrochloride was established for the treatment and monitoring of gastric cancer.MethodsIn this study, an irinotecan hydrochloride-curcumin nanosystem in the early stage (the system is named SICN) was prepared. Based on the fluorescence of curcumin, flow cytometry, laser confocal microscopy, and zebrafish fluorescence imaging were used to study the monitoring function of SICN in vivo and in vitro. In addition, HGC-27 human gastric cancer cells were used to study SICN cytotoxicity.ResultsFlow cytometry and zebrafish fluorescence imaging monitoring results showed that the uptake of SICN was significantly higher than free curcumin, and the excretion rate was lower. SICN had higher accumulation and retention in cells and zebrafish. Laser confocal microscopy monitoring results showed that SICN was internalized into HGC-27 cells through multiple pathways, including macropinocytosis, caveolin, and clathrin-mediated and clathrin -independent endocytosis, and distributed intracellularly throughout the whole cytoplasm, including lysosomes and Golgi apparatus. In vitro cell experiments showed that SICN nanoparticles were more toxic than single components, and HGC-27 cells had more absorption and higher toxicity to nanoparticles under slightly acidic conditions.ConclusionSICN is a promising carrier-free nanoparticle, and the combination of two single-component therapies can exert a synergistic antitumor effect. When exposed to a tumor acidic environment, SICN showed stronger cytotoxicity due to charge conversion. More importantly, the nanoparticles’ self-monitoring function has been developed, opening up new ideas for combined tumor therapy.

STAM2 knockdown inhibits proliferation, migration, and invasion by affecting the JAK2/STAT3 signaling pathway in gastric cancer.

Signal transducing adaptor molecule 2 (STAM2) is a phosphotyrosine protein, which regulates receptor signaling and trafficking of mammalian cells. However, its role in gastric cancer (GC) remains undiscovered. In this study, we aimed to investigate the functions of STAM2 in GC. The mRNA and protein expression levels of STAM2 were measured by quantitative real-time PCR, western blot analysis, and immunohistochemistry. STAM2 was stably silenced in AGS and HGC-27 cells using small interfering RNA. The function of STAM2 in GC cells was further investigated by CCK-8 assay, EdU incorporation assay, flow cytometry, and scratch wound healing and Boyden chamber assays. Additionally, we conducted biological pathway enrichment analysis and rescue assays to explore the effects of STAM2 on JAK/STAT signaling pathway. Our results showed that STAM2 is remarkably highly expressed in GC tissues and cells, and overexpressed STAM2 is correlated with tumor size, advanced tumor node metastasis stage, and poor prognosis. In addition, STAM2 knockdown could significantly inhibit proliferation, block cell cycle, and restrain migration and invasion capabilities of GC cells. Mechanistically, we found that STAM2 knockdown effectively decreased the expressions of MMP2 and MMP9 and the phosphorylation levels of JAK2 and STAT3. Taken together, this study revealed that STAM2 knockdown could suppress malignant process by targeting the JAK2/STAT3 signaling pathway in GC.

Design, synthesis, and biological evaluation of 3',4',5'-trimethoxy evodiamine derivatives as potential antitumor agents.

A series of compounds bearing 3',4',5'-trimethoxy module into the core structure of evodiamine were designed and synthesized. The synthesized compounds were screened in vitro for their antitumor potential. MTT results showed that compounds 14a-14c and 14i-14j had significant effects, with compound 14h being the most prominent, with an IC50 value of 3.3 ± 1.5μM, which was lower than evodiamine and 5-Fu. Subsequent experiments further confirmed that compound 14h could inhibit cell proliferation and migration, and induce G2/M phase arrest to inhibit the proliferation of HGC-27 cells, which is consistent with the results of the cytotoxicity experiment. Besides, 14h could inhibit microtubule assembly and might kill tumor cells by inhibiting VEGF and glycolysis. All experimental results indicate that compound 14h might be a potential drug candidate for the treatment of gastric cancer and was worthy of further study.