Gastric Cancer Cell Line HGC-27 Research Articles

Dual PI3K/mTOR inhibitor PF-04979064 regulates tumor growth in gastric cancer and enhances drug sensitivity of gastric cancer cells to 5-FU

Gastric cancer (GC) is characterized by high tumor heterogeneity, increased surgical difficulty, and limited chemotherapy efficacy, and it is associated with a poor prognosis. The abnormal proliferation of cells involves abnormal activation of the PI3K/AKT/mTOR signaling pathway. Inhibition of this signaling pathway can inhibit tumor cell proliferation and induce cell apoptosis. This study evaluated the effect of PF-04979064, a dual inhibitor of PI3K and mTOR, on human GC cells. PF-04979064 significantly inhibited the proliferation of human gastric adenocarcinoma AGS cells and the undifferentiated GC cell line HGC-27, promoting cell apoptosis. Combination treatment with PF-04979064 and the GC first-line clinical drug 5-FU showed synergistic effects, and PF-04979064 markedly increased the sensitivity of GC cells to chemotherapy drugs. Western blot results showed that PF-04979064 significantly inhibited the PI3K/AKT/mTOR signaling pathway in GC cells, whereas RNA seq results demonstrated substantial alterations in gene expression profiles upon treatment with PF-04979064. This study provides insight into the effects of PF-04979064, thereby establishing a solid foundation for its potential clinical application in the treatment of GC.

Forkhead Box M1 Regulates the Proliferation,Invasion,and Drug Resistance of Gastric Cancer Cells via circ_NOTCH1

Objective To investigate the impacts of forkhead box M1(FOXM1)on the proliferation,invasion,and drug resistance of gastric cancer cells by regulating the circular RNA circ_NOTCH1.Methods Western blotting and real-time quantitative PCR were performed to determine the expression of FOXM1 protein and circ_NOTCH1,respectively,in the gastric cancer tissue,para-carcinoma tissue,human normal gastric mucosa epithelial cell line GES-1 and gastric cancer cell lines MGC-803,HGC-27,and BGC-823.BGC-823 cells were classified into the following groups:control,short hairpin RNA FOXM1(sh-FOXM1)and negative control(sh-NC),small interfering RNA circ_NOTCH1(si-circ_NOTCH1)and negative control(si-NC),and sh-FOXM1+circ_NOTCH1 overexpression plasmid(sh-FOXM1+pcDNA-circ_NOTCH1)and sh-FOXM1+negative control(sh-FOXM1+pcDNA).CCK-8 assay and clone formation assay were employed to measure the cell proliferation,and Transwell assay to measure cell invasion.After treatment with 1.0 mg/L adriamycin for 48 h,the cell resistance in each group was analyzed.Western blotting was employed to determine the expression levels of FOXM1,proliferating cell nuclear antigen(PCNA),Bax,multi-drug resistance-associated protein 1(MRP1),and multi-drug resistance gene 1(MDR1).RNA pull-down and RNA immunoprecipitation were employed to examine the binding of circ_NOTCH1 to FOXM1 protein.Results Compared with those in the para-carcinoma tissue,the expression levels of FOXM1 protein and circ_NOTCH1 in the gastric cancer tissue were up-regulated(all P<0.001).Compared with GES-1 cells,MGC-803,HGC-27,and BGC-823 cells showed up-regulated expression levels of FOXM1 protein and circ_NOTCH1(all P<0.001).Compared with the control group and sh-NC group,the sh-FOXM1 group with down-regulated expression of FOXM1 protein and circ_NOTCH1 showed decreased optical density value,clone formation rate,cell invasion number,and cell viability,down-regulated expression of PCNA,MRP1,and MDR1,and up-regulated expression of Bax protein in BGC-823 cells(all P<0.001).Compared with the control group and the si-NC group,the si-circ_NOTCH1 group with down-regulated expression of circ_NOTCH1 showed decreased optical density value,clone formation rate,cell invasion number,and cell viability,down-regulated expression of PCNA,MRP1,and MDR1,and up-regulated expression of Bax protein in BGC-823 cells(all P<0.001).Compared with sh-FOXM1 group and sh-FOXM1+pcDNA group,the sh-FOXM1+pcDNA-circ_NOTCH1 group with up-regulated expression of circ_NOTCH1 showed increased optical density value,clone formation rate,cell invasion number,and cell viability,up-regulated expression of PCNA,MRP1,and MDR1,and down-regulated expression of Bax protein(all P<0.001).FOXM1 protein was able to interact with circ_NOTCH1.Conclusion Interference with FOXM1 may inhibit the proliferation,invasion,and drug resistance of gastric cancer cells by silencing circ_NOTCH1 expression.

Bufalin targeting BFAR inhibits the occurrence and metastasis of gastric cancer through PI3K/AKT/mTOR signal pathway.

Gastric cancer (GC) is the most common malignant tumor of digestive system. Bufalin extracted from Venenum Bufonis is one of the most effective anticancer monomers, which has been proved to play anticancer roles in a variety of cancers such as ovarian cancer, prostate cancer and neuroblastoma. However, there are few studies on bufalin in GC, and lack of clear targets. The effect of bufalin on the proliferation and migration of GC cells was detected by CCK-8, scratch wound healing assay, transwell assay and Western blotting. The potential direct interaction proteins of bufalin were screened by human proteome microarray containing 21,838 human proteins. The target protein was determined by bioinformatics, and the binding sites were predicted by molecular docking technique. Biological experiments in vitro and in vivo were conducted to verify the effect of bufalin directly interaction protein and the mechanism of bufalin targeting the protein to inhibit the development of GC. The results showed that bufalin inhibited the proliferation and migration of MKN-45 and HGC-27 GC cell lines in vitro. BFAR, a direct interaction protein of bufalin has several potential binding sites to bufalin. BFAR is highly expressed in GC and promotes the occurrence and metastasis of GC by activating PI3K/AKT/mTOR signal pathway in vitro and in vivo. Bufalin reversed the promoting effect of BFAR on the carcinogenesis and metastasis of GC by down-regulating the expression of BFAR. Our results show that bufalin targeting BFAR inhibits the occurrence and metastasis of GC through PI3K/AKT/mTOR signal pathway. These results provide a new basis for bufalin as a promising drug for the treatment of GC.

Effect of COP1 in Promoting the Tumorigenesis of Gastric Cancer by Down-Regulation of CDH18 via PI3K/AKT Signal Pathway.

In recent years, the involvement of E3 ubiquitin ligase constitutive photomorphogenesis 1 (COP1) in the tumorigenesis of gastric cancer (GC) has been elucidated. However, the exact underlying mechanism remains to be clarified. In the present study, the expression profiles of COP1 in GC were derived from the Gene Expression Omnibus (GEO) and the Cancer Genome Atlas (TCGA) databases, followed by verification via immunohistochemical staining (IHC), Western blotting (WB), and quantitative real-time polymerase chain reaction (qRT-PCR) reaction assays on clinical samples. In vitro, the gain- and loss-of-function experiments of COP1 protein were conducted to explore its role in GC cell lines HGC-27 and SGC-7901. Furthermore, we screened the interaction protein of COP1 by yeast two-hybrid experiment and verified their combination by co-immunoprecipitation (co-IP). We preliminary explored the possible underlying mechanisms of COP1 protein in GC cell lines via WB. COP1 was upregulated in GC tissues compared with the corresponding non-carcinoma tissues. In vitro, the upregulation of COP1 protein promoted the proliferation and migration of GC cells. The yeast two-hybrid experiment and co-IP indicated that Cadherin 18 (CDH18) could constitute a complex with COP1. Moreover, cells with COP1 over-expression showed low levels of CDH18 expression, with the intracellular PI3K/AKT pathway activated and the malignancy of GC cell lines enhanced. Our findings demonstrated that COP1 promoted the GC tumorigenesis by downregulated CDH18 with the involvement of PI3K/AKT signaling pathway in cell lines, suggesting the potential of COP1 as a prognostic biomarker and therapeutic target for GC.

ALCAM, Activated Leukocyte Cell Adhesion Molecule, in Clinical Gastric Cancer and Patient's Response to Chemotherapies.

Activated leukocyte cell adhesion molecule (ALCAM/CD166), a member of the immunoglobulin superfamily, has been shown to regulate cell adhesion through both homotypic and heterotypic interactions. In cancer, it might be involved in disease progression and chemotherapy drug resistance. The present study explored the clinical and prognostic significance of ALCAM in gastric cancer and its impact on patient's responses to neoadjuvant chemotherapies and cancer cells' response to chemodrugs in vitro. Two independent cohorts were included to evaluate the link between ALCAM and the clinical outcomes and pathological factors of the patients. The gastric cancer cell lines HGC27 and AGS were used to generate ALCAM knockdown cell models. The cytotoxicity of chemotherapy drugs was examined using ALCAM knockdown cell models. Patients with gastric cancer who had high levels of ALCAM transcripts showed a significantly shorter overall survival in both cohorts (p=0.043 and 0.006, respectively). Patients who resisted to neoadjuvant chemotherapy had marginally higher levels of ALCAM than those responded (p=0.056). Patients with low levels of ALCAM expression and resisted to neoadjuvant chemotherapy had the worst clinical outcome with a significantly shorter overall survival (p=0.004) and disease-free survival (p=0.006), whereas such results did not appear in high ALCAM expression patients. ALCAM knockdown cells were more sensitive to Cisplatin, Oxaliplatin and 5-Fluorouracil compared with their respective control cells. ALCAM acts as a negative prognostic indicator in patients with gastric cancer and high levels of ALCAM expression result in increased chemotherapy drug resistance.

Effects of Astragalin on apoptosis of undifferentiated gastric cancer cells

To investigate the effects and related molecular mechanisms of Astragalin on undifferentiated gastric cancer cell HGC-27. Astragalin was used to treat HGC-27 cells, the cell proliferation activity was detected by CCK-8 method, the cell morphology was observed under inverted microscope, hoechst 33342 and JC-1 staining were used to observe the changes of nucleus formation and mitochondrial membrane potential, the cell cycle and apoptosis rate were detected by flow cytometry, the reverse transcription level of the gene was analyzed by the second-generation sequencer. Astragalin inhibited the proliferation of HGC-27 significantly (P＜0.01), down-regulated mitochondrial membrane potential, induced cell apoptosis, blocked the cell cycle in G1 prophase. At the same time, Astragalin up-regulated the transcription levels of genes bax and bad, down-regulated the transcription levels of genes egf, egfr, pik3cb, pdk1, akt3 and bcl-2. Western blot analysis also showed that the expressions of PI3K and Akt protein were decreased, and the proportion of Bax and BCL-2 protein was increased significantly (P＜0.01). The apoptosis of undifferentiated gastric cancer cell line HGC-27 can be induced by Astragalin through inhibition of EGFR/PDK/Akt signaling pathway, and the cell cycle can be blocked in G1 phase, which has a certain therapeutic effect on undifferentiated gastric cancer.

Effects of rhein on gastric cancer cells HGC-27 apoptosis and its mechanisms

To investigate the effects of rhein on proliferation and apoptosis of gastric cancer cell line HGC-27 and its related mechanisms. Human gastric cancer cells HGC-27 were treated with 0, 5, 10 or 20 mg/L rhein respectively for 24, 48 and 72 h in vitro, three duplicate wells were set in each group. The proliferation activity of HGC-27 cells was detected with CCK-8 method, the growth status of HGC-27 cells was observed by small high-content microscope, hoechst staining was used to analyze the karyotype of HGC-27 cells. Mitochondrial membrane potential was detected by JC-1 staining and flow cytometry, cell cycle was analyzed with flow cytometry, the levels of mRNA transcribing of bcl-2, bax, caspase-3, jak1, jak2, stat3 and notch genes were investigated with RT-qPCR method. Protein expressions were determined by Western blot. Compared with HGC-27 cells treated with 0 mg/L rhein, HGC-27 cells treated with 5, 10 and 20 mg/L rhein for 24 h showed decreased mitochondrial membrane potential ( P＜0.01), the cell proliferation activity was inhibited and apoptosis was induced. The effects were enhanced with the increase of rhein concentration and the extension of treatment time, but the cell cycle did not change significantly, and the expressions of bcl-2, jak1, jak2, stat3 and notch genes were down-regulated. The expression levels of bax and caspase-3 genes were increased significantly ( P＜0.01). Rhein can induce apoptosis of HGC-27 cells by influencing NOTCH/JAK/STAT signaling pathway, and has anti-gastric cancer effect.

Exosome miR-3184-5p inhibits gastric cancer growth by targeting XBP1 to regulate the AKT, STAT3, and IRE1 signalling pathways.

MicroRNAs can regulate the transcription of protein-coding genes associated with the development and progression of cancer. In this study, we explored the potential diagnostic function of exosome miR-3184-5p in gastric cancer. This exosome was isolated from the blood samples of 150 patients with gastric cancer and 60 healthy participants. The mean particle size and concentration of serum exosome in the patients with gastric cancer were 104.6 nm (93.97-115.84) and 6.21e+009 particles/ml (5.15e+009-7.12e+009), respectively. miR-3184-5p expression was substantially downregulated in the patients with gastric cancer compared with that in the healthy participants. The gastric cancer cell line HGC-27 was cultured and transfected with the mimic and an inhibitor to overexpress and inhibit miR-3184-5p expression. miR-3184-5p strongly suppressed cell proliferation, migration, and invasion but induced cell apoptosis. Luciferase reporter assay revealed that XBP1 was the target of miR-3184-5p. miR-3184-5p substantially downregulated the expression of CD44, cyclin D1, MMP2, p65, p-AKT, and p-STAT3 but upregulated that of GRP78, IRE1, p-JNK, and CHOP. Moreover, miR-3184-5p cleaved caspase-12 and inhibited BCL-2 expression. These results suggested that the downregulation of miR-3184-5p in patients with gastric cancer might regulate the AKT, STAT3, and IRE1 pathways to promote the vitality of gastric cancer cells.

Inhibition of Musashi-1 enhances chemotherapeutic sensitivity in gastric cancer patient-derived xenografts.

Musashi-1 (MSI1), a neural RNA-binding protein, is considered a gastric and intestinal stem cell marker. Although the function of MSI1 in gastric cancer has attracted increasing interest, it is not known whether MSI1 can be used as a biomarker to monitor gastric cancer development and response to treatment. Here, the role of MSI1 in the chemotherapeutic sensitivity of gastric cancer was investigated. Patients with high MSI1 levels had poor outcomes, implicating the gene in the development and progression of the disease. We overexpressed and silenced MSI1 in the human gastric cancer cell lines MKN45 and HGC27, finding that knockdown reduced proliferation, invasion, and migration, while promoting apoptosis. A patient-derived xenograft gastric cancer model was constructed in which mice received chemical drugs, si-MSI1, or a drug-si-MSI1 combination. It was found that blocking MSI1 expression reduced gastric cancer drug tolerance. The combination treatment with si-MSI1 was superior to 5F-dUMP and cisplatin, either separately or in combination, indicating that including si-MSI1 was better than drug therapy alone. Transcriptome sequencing analysis showed that MSI1 altered cell cycle regulation and growth signal transduction, including that of blood vessel epicardial substance (BVES). These results suggest that MSI1 reduces the tolerance of gastric cancer to chemical drugs through modulation of MSI1/BVES signaling.

Distinctive Prognostic Value and Cellular Functions of Osteopontin Splice Variants in Human Gastric Cancer.

Background: Osteopontin (OPN) splice variants are identified as predictors of tumour progression and therapeutic resistance in certain types of solid tumours. However, their roles in gastric cancer (GC) remain poorly characterized. The current study sought to assess the prognostic value of the three OPN splice variants (namely OPN-a, OPN-b, and OPN-c) in gastric cancer and their potential functions within gastric cancer cells. Methods: RNA extraction and reverse transcription were performed using our clinical cohort of gastric carcinomas and matched normal tissues (n = 324 matched pairs). Transcript levels were determined using real-time quantitative PCR. Three OPN splice variants overexpressed cell lines were created from the gastric cancer cell line HGC-27. Subsequently, biological functions, including cell growth, adhesion, migration, and invasion, were studied. The potential effects of OPN isoforms on cisplatin and 5-Fu were evaluated by detecting cellular reactive oxygen species (ROS) levels in the HGC-27-derived cell lines. Results: Compared with normal tissues, the expression levels of three splice variants were all elevated in gastric cancer tissues in an order of OPN-a > OPN-b > OPN-c. The OPN-a level significantly increased with increasing TNM staging and worse clinical outcome. There appeared to be a downregulation for OPN-c in increasing lymph node status (p < 0.05), increasing TNM staging, and poor differentiation. High levels of OPN-a and OPN-b were correlated with short overall survival and disease-free survival of gastric cancer patients. However, the low expression of OPN-c was significantly associated with a poor prognosis. Functional analyses further showed that ectopic expression of OPN-c suppressed in vitro proliferation, adhesiveness, migration, and invasion properties of HGC-27 cells, while the opposite role was seen for OPN-a. Cellular ROS detection indicated that OPN-a and OPN-c significantly promoted ROS production after treatment with 5-Fu comparing to OPN-vector, while only OPN-a markedly induced ROS production after treatment with cisplatin. Conclusion: Our results suggest that OPN splice variants have distinguished potential to predict the prognosis of gastric cancer. Three OPN variants exert distinctive functions in gastric cancer cells. Focusing on specific OPN isoforms could be a novel direction for developing diagnostic and therapeutic approaches in gastric cancer.

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.

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.

SNAIL regulates gastric carcinogenesis through CCN3 and NEFL.

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 (CSCs), and displayed many properties of CSCs, for example: chemoresistance, tumorigenicity 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 upregulated and the latter downregulated, respectively. Downregulation of CCN3 and upregulation 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.

Regulation of miR-596 on the Apoptosis of Gastric Cancer Cells through Its Targeting Inhibition of BCL-2

Background: We aimed to investigate the relationship between miR-596, BCL-2, and apoptosis of gastric cancer cells, and to explore the mechanism of miR-596 in gastric cancer. Besides, this study aimed to find the target of miR-596 and explore the mechanism of action of miR-596 in gastric cancer. Methods: Eighteen samples of gastric cancer tissues and 18 samples of corresponding tumor-adjacent tissues were collected from 18 gastric cancer patients (aged from 40 to 55 yr) admitted to Zhuji People's Hospital, Zhuji, China from March 2017 to May 2018. The expression levels of miR-596 and BCL-2 were detected to verify the regulation of miR-596 on the apoptosis and proliferation of gastric cancer cell lines MKN-45 and HGC-27 and its effect on BCL-2 expression. Results: The expression level of miR-596 was notably lower in gastric cancer tissues than in adjacent tissues, and BCL-2 level was notably higher in gastric cancer tissues than in adjacent tissues. After the up-regulation of miR-596 expression, the proliferation of MKN-45 and HGC-27 cells was significantly decreased, the level of apoptosis was significantly increased (P&lt;0.05), and the expression of BCL-2 was decreased. The dual-luciferase report showed that miR-596 had a targeting inhibition of BCL-2. Gastric cancer cells with up-regulated miR596 and BCL-2 had significantly higher proliferation and lower apoptosis than cells with up-regulated miR-596. Conclusions: miR-596 can inhibit the proliferation of gastric cancer cells and promote the apoptosis through its targeting inhibition of BCL-2 expression.

Downregulation of TRIM27 suppresses gastric cancer cell proliferation via inhibition of the Hippo-BIRC5 pathway

Although tripartite motif containing 27 (TRIM27) protein has been implicated in the progression of many cancer types, its role in gastric cancer (GC) remains poorly understood. Given that TRIM27 may be associated with the baculoviral inhibitor of apoptosis repeat containing 5 (BIRC5) gene, which is downstream of the Hippo pathway, we clarified their relationship in GC progression. In vitro cultures of 7 GC cell lines, 92 GC patient tumor samples and 46 normal clinical samples were used to examine the influence of changes in TRIM27 expression, which was assessed by quantitative PCR, immunohistochemistry, western blot analysis, and cell viability assays. We found that TRIM27 overexpression was correlated with tumor size, depth of invasion, and poor GC prognosis, while TRIM27 small interfering RNA knockdown inhibited cell proliferation and colony formation, induced apoptosis, and increased sensitivity towards 5-fluorouracil treatment in MGC-803 and HGC-27 GC cell lines. Notably, TRIM27 downregulation resulted in BIRC5 suppression via large tumor suppressor kinase 2 (LATS2) upregulation and subsequent Yes-associated protein 1 (YAP1) inhibition in MGC-803 and HGC-27 GC cell lines. In conclusion, our findings revealed the positive correlation between TRIM27 and GC progression through mediation of the Hippo-BIRC5 axis in GC.

Aspeterreurone A, a Cytotoxic Dihydrobenzofuran-Phenyl Acrylate Hybrid from the Deep-Sea-Derived Fungus Aspergillus terreus CC-S06-18.

A new dihydrobenzofuran-phenyl acrylate hybrid, aspeterreurone A (1), was obtained from the culture of the deep-sea-derived fungus Aspergillus terreus CC-S06-18. The relative configuration of 1 was elucidated by HSQMBC NMR, calculated NMR chemical shifts coupled with a statistical procedure (DP4+), and the absolute configuration was established by ECD calculations. 1 exhibited cytotoxicities against the gastric cancer cell lines HGC27, MGC803, BGC823, and AGS, with minimal effects on normal gastric epithelial cell line GES-1. Further studies showed that 1 inhibited cell cycle progression and induced apoptosis of gastric cancer MGC803 cells in a concentration-dependent manner. Western blot analysis indicated that 1 inhibited the phosphorylation of STAT3, which might contribute to its cytotoxic activity.

Effect of epiberberine from Coptis chinensis Franch on inhibition of tumor growth in MKN-45 xenograft mice

Gastric cancer is one of the major malignancies worldwide. Epiberberine (EPI) is a major alkaloid from Coptis chinensis Franch and the antitumor property of EPI remains poorly understood. The inhibition on gastric cancer cells was observed by MTT assays and colony formation experiments. The apoptosis, cell cycle, and reactive oxygen species (ROS) and mitochondrial membrane potential (ΔΨm) in gastric cancer cells were analyzed by Flow cytometry. The anti-tumor effect of EPI was evaluated with the MKN-45-beraring nude mice, and the potential mechanisms were explored by RNA-seq, qPCR, siRNA silencing and western blotting. EPI inhibited the proliferation of human gastric cancer cell lines MKN-45 (harboring wild-type p53) and HGC-27 (harboring mutant p53) in a dose dependent manner. EPI induced the apoptosis and cell cycle arrest in these two cell lines, of which MKN-45 cells are more sensitive to EPI than HGC-27 cells. Further experiments indicated that EPI induced the accumulation of ROS and decreased of ΔΨm in MKN-45 cells. The significant differentially expressed genes obtained by RNA-seq were distinctly enriched in the p53 signaling pathway. The apoptosis induced by EPI in MKN-45 cells would be effectively inhibited with the treatment of p53 siRNA and p53 inhibitor PFT-α. Western blotting demonstrated that EPI diminished the expression of Bcl-2 and XIAP, and increased those of p53, Bax, p21, p27, Cytochrome C and Cleaved-caspase 3. Animal experiments confirmed that EPI significantly alleviated tumor growth in MKN-45 xenograft mice via p53/Bax pathway. These data indicated that EPI could be a novel anti-tumor candidate against MKN-45-related gastric cancer via targeting p53-dependent mitochondria-associated pathway.

Parameritannin A-2 from Urceola huaitingii enhances doxorubicin-induced mitochondria-dependent apoptosis by inhibiting the PI3K/Akt, ERK1/2 and p38 pathways in gastric cancer cells

Parameritannin A-2 (PA-2) is a natural product extracted from the stems of the plant Urceola huaitingii. Our previous studies have shown that PA-2 exhibits significant synergistic anticancer effects with doxorubicin (DOX) in HGC27 gastric cancer cell lines. Here we report that our isobolographic analysis confirms the synergistic cytotoxic effects of PA-2 and DOX in HGC27 cells. Flow cytometry and immunoblotting indicate that PA-2 enhances DOX-mediated apoptosis. Importantly, PA-2 enhances the intracellular accumulation of DOX in HGC27 cells. The combination of DOX and PA-2 remarkably increases the release of cytochrome C and the activation of caspase-3 and caspase-9, compared with DOX treatment alone. Moreover, PA-2 attenuates the DOX-induced activation of Akt, ERK1/2 and p38 signaling pathways, providing a molecular mechanism for the synergistic effects of DOX and PA-2 in the induction of apoptosis. In conclusion, our studies demonstrate that PA-2 and DOX synergistically induce mitochondria-dependent apoptosis as PA-2 inhibits the PI3K/Akt, ERK1/2 and p38 pathways in HGC27 cells. These findings suggest that the combination treatment with PA-2 and DOX may represent a potent therapy for gastric cancer.

MiR-181d inhibits cell proliferation and metastasis through PI3K/AKT pathway in gastric cancer.

Gastric cancer is the second highest mortality tumor and the fourth most common cancer worldwide that has high aggressiveness. MicroRNA-181d (miR-181d) has been established to be a tumor suppressor, by suppressing cell proliferation, cell cycle, and promoting apoptosis in several cancers. The purpose of this study is to explore the great roles of miR-181d in gastric cancer. The Real Time-quantitative Polymerase Chain Reaction (RT-qPCR) and Western blot were applied to calculate the mRNA and protein levels of miR-181d and genes. MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide) and transwell assays were utilized to measure the proliferative and invasive abilities. The Kaplan-Meier method was conducted to calculate the overall survival of gastric cancer patients. MiR-181d was detected to be downregulated in gastric cancer tissues and cell lines compared to the peritumoral normal tissues and normal cell line. Downregulation of miR-181d predicted poor prognosis of gastric cancer patients. Cylindromatosis gene (CYLD) was overexpressed in gastric cancer tissues, which was confirmed to be a target gene of miR-181d in gastric cancer cell line HGC-27. Moreover, miR-181d inhibited the proliferation through CYLD/phosphatidylinositol 3-kinase (PI3K)/protein kinase B (AKT) pathway and inhibited the invasion-mediated epithelial-mesenchymal transition (EMT) in HGC-27 cells. In addition, overexpression of miR-181d suppressed tumor growth and xenograft tumorigenesis of HGC-27 cells in vivo. MiR-181d functioned as a tumor suppressor by inhibiting the proliferation via PI3K/AKT pathway in vitro and in vivo and inhibiting invasion-mediated epithelial-mesenchymal transition (EMT) by targeting CYLD in gastric cancer. The newly identified miR-181d/CYLD axis provides novel insight into the pathogenesis of gastric cancer.

Oncogenic role of long non-coding RNA SNHG12 in gastric cancer cells by targeting miR-16.

The long non-coding RNA small nucleolar RNA host gene 12 (SNHG12) has recently been reported to have an oncogenic role in gastric cancer (GC), but the molecular mechanisms remain largely elusive. In the present study, it was observed that SNHG12 was significantly upregulated in GC tissues and cell lines. High expression of SNHG12 was associated with GC progression and poor prognosis of patients. Knockdown of SNHG12 markedly inhibited the proliferation and migration of the BGC823 and HGC27 GC cell lines. MicroRNA (miR)-16 was identified as a target of SNHG12, and its expression was negatively regulated by SNHG12 in BGC823 and HGC27 cells. In addition, the expression of miR-16 was significantly decreased in GC tissues and cell lines, and inversely associated with the expression of SNHG12 in GC tissues. Furthermore, knockdown of miR-16 impaired the inhibitory effects on GC cell proliferation and migration induced by downregulation of SNHG12. In conclusion, the present study demonstrates that inhibition of SNHG12 suppresses GC cell proliferation and migration by modulation of miR-16 expression, and thus suggests that the SNHG12/miR-16 interaction may be used as a promising target for GC treatment.