BGC-823 Cells Research Articles

Silencing Stat3 inhibits viability and induces apoptosis in BGC-823 human gastric cancer cell line

ABSTRACT Gastric cancer (GC) is characterized by infrequent early diagnosis, poor prognosis and high mortality. Signal transducer and activator of transcription 3 (Stat3) and signal transducer and activator of transcription 5b (Stat5b) play multiple roles in the development and progression of many human cancers. We investigated the effects of silencing Stat3 and Stat5b on the viability and apoptosis of the human gastric cancer cell line, BGC-823. We found that Stat3 and Stat5b were expressed in both the nucleus and cytoplasm of BGC-823 cells. Silencing of Stat3 caused significantly decreased viability and increased apoptosis, as well as attenuated B-cell lymphoma-2 (Bcl-2) expression in BGC-823 cells. Silencing of Stat5b, however, had no significant effect on these events. Stat3, but not Stat5b, plays an important role in the viability and apoptosis of human gastric cancer cell line, BGC-823, which suggests that Stat3 is a potential target for gastric cancer therapy.

Resistance to FGFR1-targeted therapy leads to autophagy via TAK1/AMPK activation in gastric cancer.

Fibroblast growth factor receptor 1 (FGFR1) is frequently dysregulated in various tumors. FGFR inhibitors have shown promising therapeutic value in several preclinical models. However, tumors resistant to FGFR inhibitors have emerged, compromising therapeutic outcomes by demonstrating markedly aggressive metastatic progression; however, the underlying signaling mechanism of resistance remains unknown. We established FGFR inhibitor-resistant cell models using two gastric cancer (GC) cell lines, MGC-803 and BGC-823. RNA-seq was performed to determine the continuous cellular transcriptome changes between parental and resistant cells. We explored the mechanism of resistance to FGFR inhibitor, using a subcutaneous tumor model and GC patient-derived tumor organotypic culture. We observed that FGFR1 was highly expressed in GC and FGFR1 inhibitor-resistant cell lines, demonstrating elevated levels of autophagic activity. These resistant cells were characterized by epithelial-mesenchymal transition (EMT) required to facilitate metastatic outgrowth. In drug-resistant cells, the FGFR1 inhibitor regulated GC cell autophagy via AMPK/mTOR signal activation, which could be blocked using either pharmacological inhibitors or essential gene knockdown. Furthermore, TGF-β-activated kinase 1 (TAK1) amplification and metabolic restrictions led to AMPK pathway activation and autophagy. In vitro and in vivo results demonstrated that the FGFR inhibitor AZD4547 and TAK1 inhibitor NG25 synergistically inhibited proliferation and autophagy in AZD4547-resistant cell lines and patient-derived GC organotypic cultures. We elucidated the molecular mechanisms underlying primary resistance to FGFR1 inhibitors in GC, and revealed that the inhibition of FGFR1 and TAK1 signaling could present a potential novel therapeutic strategy for FGFR1 inhibitor-resistant GC patients.

Oridonin Suppresses Human Gastric Cancer Growth in Vitro and in Vivo via Inhibition of VEGF, Integrin β3, and PCNA.

The diterpenoid oridonin is an extract from the herb Rabdosia rubescens, commonly used in Traditional Chinese medicine. Oridonin has putative inhibitory activity in many human cancers. This study continued investigations into the therapeutic potential of oridonin against gastric carcinoma, and the underlying mechanism. An in vitro 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay with BGC823 cells was used to examine the cytotoxicity and apoptosis associated with oridonin treatment. RT-PCR and immunocytochemistry results showed evaluated levels of vascular endothelial growth factor (VEGF), cluster of differentiation 31 (CD31), integrin β3, and proliferating cell nuclear antigen (PCNA) in BGC823 cells, or BGC823 xenografts nude mice. The inhibitory effect of oridonin was determined in vivo using the xenograft model, comparing tumor weight and volume, and calculating the tumor inhibition rate. The oridonin treatment and control groups were compared for associations between microvessel density and tumor inhibition rate, VEGF mRNA, integrin β3 mRNA, and PCNA protein. The IC50s of oridonin at 12 and 72 h were 17.08 ± 2.38 and 8.76 ± 0.90 µg/mL, respectively. VEGF protein levels dramatically decreased in a time- and dose-dependent manner with oridonin treatment. BGC823 xenograft growth was notably less in the oridonin treatment groups, responding in a dose-dependent manner. After 14 d of treatment, VEGF, integrin β3, and PCNA levels were dramatically lower, and positively correlated with CD31 levels. Oridonin was associated with inhibition of BGC823 cell growth and tumor angiogenesis, in vitro and in vivo, in a dose-and-time dependent manner with lower levels of VEGF, integrin β3, and PCNA. Oridonin is a potential candidate agent for chemotherapy of gastric carcinoma.

RETRACTED ARTICLE: Synthesis, Crystal Structure, and Anti-Gastric Cancer Activity of a Heterometallic Coordination Polymer Based on Flexible 6,6-Dithiodinicotinic Acid

A new bimetallic coordination polymer [In2Na(H2O)2(ddca)3](NO3)·4H2O (1, H2ddca = 6,6′-dithiodinicotinic acid) is produced via a hydrothermal reaction of In(NO3)3, H2ddca with NaOH as the pH modulator. Various characterization methods, such as thermogravimetric analysis (TGA), elemental analysis (EA), single crystal and powder X-ray diffraction measurements, are used. Furthermore, a process of sonochemistry with oleic acid at 453 K is used to produce nanoparticles of 1 (nano-1). In terms of the biological function of the synthesized complex, the real-time reverse transcription-polymerase chain reaction is carried out to explore the relative mRNA expression of miR-181 in MGC-803, BGC-823, and SGC-7901 gastric cancer cell lines, and the western blot is used to explore the protein expression of apoptotic protein Bcl-2.

PRKAA1 Promotes Proliferation and Inhibits Apoptosis of Gastric Cancer Cells Through Activating JNK1 and Akt Pathways.

PRKAA1 (protein kinase AMP-activated catalytic subunit α 1) is a catalytic subunit of AMP-activated protein kinase (AMPK), which plays a key role in regulating cellular energy metabolism through phosphorylation, and genetic variations in the PRKAA1 have been found to be associated with gastric cancer risk. However, the effect and underlying molecular mechanism of PRKAA1 on gastric cancer tumorigenesis, especially the proliferation and apoptosis, are not fully understood. Our data showed that PRKAA1 is highly expressed in BGC-823 and MKN45 cells and is expressed low in SGC-7901 and MGC-803 cells in comparison with the other gastric cancer cells. PRKAA1 downregulation by shRNA or treatment of AMPK inhibitor compound C significantly inhibited proliferation as well as promoted cell cycle arrest and apoptosis of BGC-823 and MKN45 cells. Moreover, the expression of PCNA and Bcl-2 and the activity of JNK1 and Akt signaling were also reduced in BGC-823 and MKN45 cells after PRKAA1 downregulation. In vivo experiments demonstrated that tumor growth in nude mice was significantly inhibited after PRKAA1 silencing. Importantly, inactivation of JNK1 or Akt signaling pathway significantly inhibited PRKAA1 overexpression-induced increased cell proliferation and decreased cell apoptosis in MGC-803 cells. In conclusion, our findings suggest that PRKAA1 increases proliferation and restrains apoptosis of gastric cancer cells through activating JNK1 and Akt pathways.

Berberine represses human gastric cancer cell growth in vitro and in vivo by inducing cytostatic autophagy via inhibition of MAPK/mTOR/p70S6K and Akt signaling pathways

Berberine, an isoquinoline alkaloid from Coptidis Rhizoma, has been characterized as a potential anticancer drug due to its good anti-tumor effects. However, the molecular mechanisms involved in anti-gastric cancer remain poorly understood. Herein, the role of berberine in gastric cancer suppression by inducing cytostatic autophagy in vitro and in vivo was first investigated. Results showed that berberine induced an obvious growth inhibitory effect on gastric cancer BGC-823 cells without toxicity to human peripheral blood mononuclear cells. Treatment with berberine triggered cell autophagy, as demonstrated by the punctuate distribution of monodansylcadaverine staining and GFP-LC3, as well as the LC3-II, Beclin-1 and p-ULK1 promotion, and p62 degradation. Inhibition of autophagy by 3-MA, CQ, Baf-A1 and BECN1 siRNA obviously increased cell viability of berberine-exposed gastric cancer cells, which confirmed the anti-cancer role of autophagy induced by berberine. Mechanistic studies showed that berberine inhibited mTOR, Akt and MAPK (ERK, JNK and p38) pathways thereby inducing autophagy. Inhibition of above pathways increases berberine induced autophagy and cytotoxicity. Interestingly, mTOR/p70S6K was inhibited by the MAPK but not Akt. Furthermore, inhibition of autophagy reversed berberine down-regulated mTOR, Akt and MAPK. In xenografts, the berberine induced autophagy leads to suppression of tumor proliferation with no side-effect, and western blotting displayed an apparent attenuation of p-mTOR, p-p70S6K, p-Akt, p-ERK, p-JNK and p-p38 in tumors from berberine treated mice. Briefly, these results indicated that berberine repressed human gastric cancer cell growth in vitro and in vivo by inducing cytostatic autophagy via inhibition of MAPK/mTOR/p70S6K and Akt, and provided a molecular basis for the treatment of gastric cancer.

Evaluation of 111In-DOTA-F56 peptide targeting VEGFR1 for potential non-invasive gastric cancer xenografted tumor mice Micro-SPECT imaging

Non-invasive imaging of vascular endothelial growth factor receptor 1 (VEGFR1) remains a great challenge in the early diagnosis of tumors, especially in gastric cancer. Here, we designed and evaluated a novel 111In-DOTA-F56 peptide as a radioactive analogue of F56 (peptide WHSDMEWWYLLG) to bind VEGFR1. It was obtained by radiolabeling DOTA-F56 with 111InCl3 with 98% radiochemical purity and 1.4 ± 0.4 GBq/µmol specific activity. 111In-DOTA-F56 was obtained by the reaction of DOTA-F56 (10 µg) with 111InCl3 in pH 4.0 sodium acetate buffer at 85 °C for 20 min. 111In-DOTA-F56 shows good stability in 0.01 M Phosphate Buffered Saline (PBS) and 5% Human Serum Albumin (HSA). 111In-DOTA-F56 has a high binding affinity for human gastric cancer BGC-823 cells. Bio-distribution studies of 111In-DOTA-F56 were performed in nude mice xenografted with human gastric cancer BGC-823 cells and the results revealed tumor uptake accumulation. A blocking dose of DOTA-F56 significantly reduced the tumor uptake of 111In-DOTA-F56. Tumors were observed with Micro-SPECT images, and the uptake in the tumor increased with time from 4 h to 24 h. The MIP of the Micro-SPECT also showed that the excess DOTA-F56 can specifically block 111In-DOTA-F56 in a mouse tumor model. We successfully synthesized the 111In-DOTA-F56 VEGFR1-targeted peptide as a non-invasive molecule with fine radiochemical properties. Micro-SPECT indicates tumor uptake, which can be further blocked by excess of the F56 peptide, indicating that 111In-DOTA-F56 peptide has potential for early detection of VEGFR1 positive gastric cancer and is worthy of further clinical investigations.

MiRNA-339-5p suppresses the malignant development of gastric cancer via targeting ALKBH1

ObjectiveTo uncover the role of microRNA-339-5p (miRNA-339-5p) in the development of gastric cancer (GC) and its possible molecular mechanism. MethodsDifferential expressions of miRNA-339-5p in GC and adjacent normal tissues were detected. The relationship between miRNA-339-5p level and clinical features in GC patients was analyzed. Proliferative and migratory changes in BGC-823 and SGC-7901 cells overexpressing miRNA-339-5p were examined. Finally, luciferase assay and rescue experiments were conducted to explore the regulatory mechanism of miRNA-339-5p in its downstream gene ALKBH1, and their interaction in the development of GC. ResultsMiRNA-339-5p was downregulated in GC tissues. Lowly expressed miRNA-339-5p was unfavorable to prognosis in GC because of high rates of lymphatic metastasis and distant metastasis. Overexpression of miRNA-339-5p markedly reduced proliferative and migratory abilities in GC cells. ALKBH1 was identified to be the downstream gene of miRNA-339-5p. In GC tissues, ALKBH1 was upregulated and negatively correlated to miRNA-339-5p level. Overexpression of ALKBH1 was able to reverse the inhibitory effects of overexpressed miRNA-339-5p on proliferative and migratory abilities in GC. ConclusionsLowly expressed miRNA-339-5p is closely related to metastasis and poor prognosis in GC patients. MiRNA-339-5p suppresses the malignant development of GC by negatively regulating ALKBH1.

RETRACTED: In Vitro Antitumor Activities of Biologically Active Extracts and Isolated Phytochemicals From Rabdosia latifolia C. Y. Wu Et H. W. Li in Addenda

To investigate the antitumor activities, as well as phytochemical constituents of Rabdosia latifolia C. Y. Wu et H. W. Li in Addenda ( R. latifolia) extracts, the light petroleum, dichloromethane, ethyl acetate, n-butanol, and water extracts from R. latifolia were determined by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assays on MCF-7, HepG2, A549, Hela, and BGC-823 cells. We further examined cell cycle and apoptosis of the biologically active extracts on MCF-7 cells. The constituents of the biologically active extracts were determined using ultra-performance liquid chromatography/quadrupole time-of-flight mass spectrometry (UPLC-Triple-TOF/MS) and gas chromatography–mass spectrometric (GC–MS) analysis. MTT assays showed that the dichloromethane extract had an inhibitory effect on MCF-7 and BGC-823 cells and that at 50 µg/mL showed 9.9% ± 1.7% inhibition of MCF-7 cells and 81.7% ± 9.5% of BGC-823 cells, respectively. The data for cell cycle analysis clearly showed a significant block in the S-phase. The dichloromethane extract induced apoptosis of MCF-7 cells, and the cell apoptosis rate showed time and concentration effects. UPLC- Triple-TOF/MS analysis revealed the presence of 16 structurally characterized compounds in the dichloromethane extract, all of which were identified for the first time in this species. Ent-kauranoids, such as henryin (9) and its analogs, were the predominant compounds. Subsequently, GC–MS analysis showed the presence of 20 volatile compounds, including γ-sitostenone, β-amyrone, γ-tocopherol, and dotriacontane. Based on the results of this study and previous literature reports, it is concluded that the ent-kauranoids, such as henryin, were the predominant components of R. latifolia with antitumor activity.

The Synergistic Antitumor Activity of Chidamide in Combination with Bortezomib on Gastric Cancer.

PurposeThe aim of this study was to investigate the antitumor effect of chidamide in combination with bortezomib on gastric cancer cell lines.Materials and MethodsFirst, the sensitivity and IC50 values of chidamide and bortezomib in several gastric cancer cell lines (MGC-803, BGC-823, SGC-7901, and MKN45) were measured using the CCK-8 assay. Then, the relatively insensitive gastric cancer cell lines (MGC-803 and BGC-823) were treated with low concentrations of chidamide alone, bortezomib alone, or chidamide and bortezomib combination to detect the effects on cell proliferation, apoptosis, migration, and invasion. Finally, the inhibitory effect of the combined chidamide and bortezomib treatment on MGC-803 cells was verified in vivo through tumor formation experiments in nude mice.ResultsCompared with low-dose chidamide or bortezomib alone, the low-dose drug combination significantly inhibited the proliferation, migration, and invasion of MGC-803 and BGC-823 cells and induced apoptosis of the cells. The effects of the low-dose chidamide and bortezomib combination reduced the growth on gastric cancer in vivo were investigated by using a subcutaneous tumor mouse model.ConclusionOur results suggest that the combination of chidamide and bortezomib can significantly reduce the proliferation, invasion, and migration of MGC-803 and BGC-823 cells, providing a framework for the clinical evaluation of combined therapies for gastric cancers.

Inhibition of Serine Metabolism Promotes Resistance to Cisplatin in Gastric Cancer.

BackgroundSerine provides important precursors of protein, lipid, and nucleotide synthesis needed for tumor cell growth. Phosphoglycerate dehydrogenase (PHGDH), a key rate-limiting enzyme in the serine de novo synthesis pathway, is highly expressed in many tumor types (including gastric cancer) and negatively correlated with overall survival. Cisplatin is a chemotherapeutic drug commonly used in the treatment of gastric cancer. In this study, we mainly investigated the relationship between serine metabolism and resistance to cisplatin in gastric cancer cells, as well as the regulatory mechanism involved in this process.Materials and MethodsWe determined the effect of different concentrations of serine or a PHGDH inhibitor combined with cisplatin or oxaliplatin on the viability and apoptosis of SGC7901, BGC823, and MGC803 cells via the Cell Counting Kit-8 and Hoechst 33258 staining, respectively. Western blotting was utilized to detect the relative protein expression. Furthermore, we investigated DNA damage through the micrococcal nuclease sensitivity assay detected using agarose gels.ResultsWe found that reduced concentrations of serine or inhibition of PHGDH hindered the toxicity and pro-apoptotic effects of cisplatin on gastric cancer cells. Moreover, the addition of serine could reverse the sensitivity of gastric cancer cells to cisplatin. Moreover, we found that DNA damage was reduced by treatment with PHGDH inhibitor NCT-503 or CBR-5884. Inhibition of serine metabolism induced a decrease in H3K4 tri-methylation, which was reversed by JIB-04 (inhibitor of H3K4 demethylase). The tolerance of gastric cancer cells to cisplatin was relieved by JIB-04. Through micrococcal nuclease experiments, we further found that inhibiting the activity of PHGDH strengthened chromatin tightness.ConclusionInhibition of serine metabolism reduced H3K4 tri-methylation and increased the density of chromatin, which leads to decreased toxicity and pro-apoptotic effect of platinum chemotherapeutic drugs on gastric cancer cells.

Role of Long Non-Coding RNA Zinc Finger E-Box Binding Homeobox 1 Antisense 1 in Regulating the microRNAs-200b/Wnt1 Axis Effects on Proliferation, Invasion, and Apoptosis of Gastric Carcinoma Cells

ZEB1-AS1 is an Long non-coding RNA (lncRNA) that is abnormally expressed in various tumor types and affects tumor etiology and progression. ZEB1-AS1 can affect the malignant progression of gastric cancer through the miRNA-200b/Wnt1 axis. However, its effect on proliferation, invasion, and apoptosis of gastric cancer is unclear. Using BGC-803 cells, we studied the effects of lncRNA ZEB1-AS1 and miRNA-200b on the proliferation, invasion, and apoptosis of gastric cancer. Using qRT-PCR, we found that the expression of ZEB1-AS1 was significantly increased and the expression of miRNA-200b was significantly decreased in BGC-803 cells. By CCK-8, Transwell, and flow cytometry assays, we also found that down-regulation of ZEB1-AS1 and upregulation of miRNA-200b inhibited the proliferation and invasion of BGC-803 cells and promoted apoptosis. Furthermore, upregulation of ZEB1-AS1 and miRNA-200b reversed these effects. LncRNA ZEB1-AS1 inhibits the proliferation and invasion of gastric cancer cells and induces apoptosis by regulating the miRNA-200b/Wnt1 molecular axis.

HPLC-DAD-Guided Isolation of Diversified Chaetoglobosins from the Coral-Associated Fungus Chaetomium globosum C2F17.

Cytochalasans have continuously aroused considerable attention among the chemistry and pharmacology communities due to their structural complexities and pharmacological significances. Sixteen structurally diverse chaetoglobosins, 10-(indol-3-yl)-[13]cytochalasans, including a new one, 6-O-methyl-chaetoglobosin Q (1), were isolated from the coral-associated fungus Chaetomium globosum C2F17. Their structures were accomplished by extensive spectroscopic analysis combined with single-crystal X-ray crystallography and ECD calculations. Meanwhile, the structures and absolute configurations of the previously reported compounds 6, 12, and 13 were confirmed by single-crystal X-ray analysis for the first time. Chaetoglobosins E (6) and Fex (11) showed significant cytotoxicity against a panel of cancer cell lines, K562, A549, Huh7, H1975, MCF-7, U937, BGC823, HL60, Hela, and MOLT-4, with the IC50 values ranging from 1.4 μM to 9.2 μM.

MUC1 is associated with TFF2 methylation in gastric cancer

BackgroundEmerging evidence has shown that MUC1 and TFF2 play crucial roles in the H. pylori-infected pathogenesis of gastric cancer (GC). A recent study revealed that H. pylori infection induced obviously increased Tff2 methylation levels in Muc1−/− mice compared with controls. However, little is known of the molecular mechanism on MUC1 regulating the expression of TFF2.MethodsWe conducted a correlation analysis of MUC1 and TFF2 in public databases and our adjacent GC tissues. Besides, MUC1 overexpression vector or small interfering RNA (siRNA) was transfected into GC cells to assess the change in TFF2 expression. Furthermore, the methylation status of TFF2 was measured by bisulfite sequencing PCR (BSP).ResultsThe expression of MUC1 was significantly lower in non-cardia and cardia tumor tissues than that in normal tissues. Downregulation of TFF2 expression was also observed in GC tissues. In addition, we found that MUC1 expression was positively associated with TFF2 expression in GC tissues, especially among GC patients with H. pylori infection. Overexpression of MUC1 in BGC-823 and SGC-7901 cell lines substantially increased the TFF2 expression, whereas knockdown of MUC1 reverted this effect. Moreover, MUC1 was negatively related to the methylation of TFF2 in the co-expression analysis. The results of BSP experiments showed that compared with negative vector group, the methylation level of TFF2 was decreased in GC cells transfected with MUC1 overexpression vector. Additionally, survival analysis indicated that GC patients with lower level of MUC1 or TFF2 had a worse outcome.ConclusionOur results indicated that MUC1 was associated with the methylation of TFF2, which may have implications for TFF2 expression in GC. These findings warrant further research toward the underlying mechanism of MUC1 influenced the TFF2 methylation.

BGC823 Cell Line with the Stable Expression of iRFP720 Retains Its Primary Properties with Promising Fluorescence Imaging Ability.

Reliable animal models are required for understanding the molecular events of gastric tumor growth and metastasis. Tracing techniques based on iRFP720 may optimize the noninvasive monitoring of tumors in vivo. The present study established a human gastric adenocarcinoma cell line BGC823-iRFP720-GFP (abbreviated as BGC823-iRFP) that stably expressed iRFP720 and green fluorescent protein (GFP) by piggyBac transposon system. The monoclonal cell line BGC823-iRFP was isolated under puromycin selection. The cell morphology and proliferation ability of BGC823-iRFP cells in vitro were similar to that of the BGC823 cells. The iRFP720 and GFP expressions were confirmed by laser confocal microscopy and Cytation™ 5. Hematoxylin and eosin staining, immunohistochemical analysis, and animal experiments also revealed that BGC823-iRFP exhibited no significant changes in morphology, growth kinetics, and tumorigenicity in vivo. IVIS Lumina III imaging indicated that the iRFP720 signals of the BGC823-iRFP cells could be used to evaluate the antitumor efficacy of oncolytic viruses and chemotherapy drugs. Therefore, the BGC823-iRFP cells would be a useful tool for gastric cancer research and antitumor drug evaluation.

MTH1 Inhibitor TH287 Suppresses Gastric Cancer Development Through the Regulation of PI3K/AKT Signaling.

Background: Cancer cells evade oxidative stress through the MutT homologue-1 (MTH1), a member of the Nudix family. MTH1 maintains genome integrity and the viability of tumor cells. A new class of MTH1 inhibitors have attracted interest as anticancer agents, but their mechanisms of action remain poorly characterized. In this study, the authors evaluated the anticancer effects of the MTH1 inhibitor TH287 on gastric cancer (GCa) cells. Materials and Methods: BGC-823 and SGC-7901 cells were treated with TH287 and CCK-8, and colony-forming assays were performed. Cell migration was assessed through Transwell and scratch assays. Apoptotic status was measured via flow cytometry and 5,5',6,6'-tetrachloro-1,1',3,3'-tetraethylbenzimidazolyl-carbocyanine iodide (JC-1) staining. Cell cycle status was assessed by propidium iodide (PI) staining. The expression of PI3K/AKT signaling-related proteins was verified by western blotting. Results: TH287 inhibited cell viability, reduced cell proliferation, inhibited apoptosis, induced G2/M arrest, and suppressed cell migration. A loss of mitochondrial membrane potential and reduced Bcl-2/Bax expression were also observed in TH287-treated cells. These effects were mediated through the inhibition of pro-oncogenic PI3K/AKT signaling. Conclusions: These findings indicate that the MTH1 inhibitor TH287 mediates an array of anticancer effects in GCa cells through its effects on mitochondrial function and PI3K/AKT signaling. Collectively, these data highlight the promise of TH287 as a novel therapeutic option for GCa cells.

Novel unsymmetrical silicon(IV) phthalocyanines as highly potent anticancer photosensitizers. Synthesis, characterization, and in vitro photodynamic activities

A series of novel unsymmetrical silicon (IV) phthalocyanines (SiPcs) di-substituted axially with tyramine and different oligomeric ethylene glycol moieties have been synthesized by alkoxy exchange reactions, and their singlet oxygen quantum yields (ΦΔ) and in vitro photodynamic activities have also been evaluated. The unsymmetrical SiPcs 2–5 show slightly higher photosensitizing efficiency (ΦΔ = 0.08–0.12) than the corresponding symmetrical SiPc 1 (ΦΔ = 0.05), but are less efficient compared to the symmetrical SiPc 6 (ΦΔ = 0.33). All the compounds exhibit high photocytotoxicities against BGC-823 cancer cells with IC50 values ranging from 3 nM to 20 nM. Particularly for the unsymmetrical SiPc 5, the IC50 value toward BGC-823 cells is significantly lower than its corresponding symmetrical SiPcs 1 and 6, which could be attributed to its higher cellular uptake. In addition, SiPc 5 can essentially bind to mitochondria and induces cell death of BGC-823 cells mainly through apoptosis. So SiPc 5 is a highly promising photosensitizer for photodynamic therapy.

Evaluation of Pan-SSTRs Targeted Radioligand [64Cu]NOTA-PA1 Using Micro-PET Imaging in Xenografted Mice

64Cu-labeled new pan-somatostatin receptors (pan-SSTRs) probe PA1 was synthesized, characterized, and evaluated by in vitro and in vivo experiments. [64Cu]NOTA-PA1 was obtained with high specific activity, high radiochemical purity, and good stability. Cell uptake of [64Cu]NOTA-PA1 was higher than that of [64Cu]DOTA-TATE in MCF-7, A549, BGC823, and HT-29 cell lines. [64Cu]NOTA-PA1 showed high binding affinity for SSTRs expressed in A549 cells. The in vivo biodistribution and micropositron emission tomography (micro-PET) imaging studies of [64Cu]NOTA-PA1 revealed good detection ability in MCF-7 and A549 xenografted nude mice. The radiosynthesis, quality control, and preliminary biological evaluation of [64Cu]NOTA-PA1 have broaden the application of radiolabeled octreotide for SSTRs imaging, which could act as a potential multisubtypes targeted radiotracer for imaging SSTRs-positive tumors.

Synergistic effects of tanshinone IIA and andrographolide on the apoptosis of cancer cells via crosstalk between p53 and reactive oxygen species pathways.

Tanshinone IIA (Tan IIA) and andrographolide (Andro) are natural compounds that are reported to exhibit anticancer activities against various types of cancers. The aim of this study is to evaluate the synergistic anticancer effects of the combination of Tan IIA and Andro, and to investigate the mechanisms of pharmacological effect and their potential applications as an anticancer therapy in clinics. The anticancer effects of the combination of Tan IIA and Andro on MCF7, SMMC7721, and BGC823 cells were explored. The apoptosis of the cancer cells was determined by MTT and AV-PI dual stain assays. The intracellular GSH level was measured by DTNB assay, and the intracellular levels of reactive oxygen species (ROS) were examined by flow cytometry. The expression of the proteins in the apoptosis pathway was determined by immunobloting. The combination of Tan IIA and Andro exhibited significant synergistic anticancer effects against cancer cells, especially at low concentrations. Andro reacted with the thiol group of intracellular GSH, thus disrupting the GSH redox cycle and eventually increasing the level of intracellular ROS. Tan IIA triggered p53 responses and apoptosis by binding to the DNA of cancer cells. The crosstalk between ROS and p53 exhibited a synergistic effect on the apoptosis of cancer cells. The combination of Tan IIA and Andro showed significant synergistic effects on cancer cell apoptosis by promoting crosstalk between ROS and p53, providing a novel and effective combination that has the potential to be applied in clinical anticancer therapy.

Exosomal transfer of miR-15b-3p enhances tumorigenesis and malignant transformation through the DYNLT1/Caspase-3/Caspase-9 signaling pathway in gastric cancer

BackgroundExosomes are essential for tumor growth, metastasis, and are used as novel signaling molecules in targeted therapies. Therefore, exosomal miRNAs can be used in new diagnostic and therapeutic approaches due to their involvement in the development of cancers. However, the detailed biological function, potential molecular mechanism and clinical application of exo-miR-15b-3p in gastric cancer (GC) remains unclear.MethodsmiR-15b-3p mRNA levels in tissues, serum, cells and exosomes were analyzed using qRT-PCR assays. qRT-PCR, immunohistochemical and western blotting analyses were utilized for the determination of DYNLT1 expression. The interrelationship connecting miR-15b-3p with DYNLT1 was verified using Dual-luciferase report, western blotting and qRT-PCR assays. Fluorescent PKH-26 or GFP-Lv-CD63 labeled exosomes, as well as Cy3-miR-15b-3p, were utilized to determine the efficacy of the transfer of exo-miR-15b-3p between BGC-823 and recipient cells. Several in vitro assays and xenograft tumor models were conducted to determine exo-miR-15b-3p impact on GC progression.ResultsThis is the first study to confirm high miR-15b-3p expression in GC cell lines, tissues and serum. Exosomes obtained from 108 GC patient serum samples and GC cell-conditioned medium were found to show upregulation of exo-miR-15b-3p, with the area under the ROC curve (AUC) being 0.820 [0.763–0.876], which is superior to the AUC of tissues and serum miR-15b-3p (0.674 [0.600–0.748] and 0.642 [0.499–0.786], respectively). In addition, high exo-miR-15b-3p expression in serum was found to accurately predict worse overall survival. SGC-7901 and GES-1 cells are capable of internalizing BGC-823 cell-derived exosomes, allowing the transfer of miR-15b-3p. Migration, invasion, proliferation and inhibition of apoptosis in vitro and in vivo were enhanced by exo-miR-15b-3p, by restraining DYNLT1, Cleaved Caspase-9 and Caspase-3 expression.ConclusionsThis study identified a previously unknown regulatory pathway, exo-miR-15b-3p/DYNLT1/Caspase-3/Caspase-9, which promotes GC development and GES-1 cell malignant transformation. Therefore, serum exo-miR-15b-3p may be a potential GC diagnosis and prognosis biomarker, which can be used in precise targeted GC therapy.