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1.
China Journal of Chinese Materia Medica ; (24): 3199-3206, 2023.
Article in Chinese | WPRIM | ID: wpr-981456

ABSTRACT

Based on the Janus kinase 2/signal transducer and activator of transcription 3(JAK2/STAT3) signaling pathway, this study investigated the effect of medicated serum of Sparganii Rhizoma(SR) and Curcumae Rhizoma(CR) on the proliferation, apoptosis, migration, and secretion of inflammatory factors of ectopic endometrial stromal cells(ESCs). Specifically, human ESCs were primary-cultured. The effect of different concentration(5%, 10%, 20%) of SR-, CR-, and SR-CR combination-medicated serum, and AG490 solution(50 μmol·L~(-1)) on the proliferation of ESCs was detected by methyl thiazolyl tetrazolium(MTT) assay, and the optimal dose was selected accordingly for further experiment. The cells were classified into normal serum(NS) group, SR group(10%), CR group(10%), combination(CM) group(10%), and AG490 group. The apoptosis level of ESCs was detected by flow cytometry, and the migration ability was examined by wound healing assay. The secretion of interleukin(IL)-1β, IL-6, and tumor necrosis factor(TNF)-α was determined by enzyme-linked immunosorbent assay(ELISA). The protein levels of cysteinyl aspartate specific protei-nase-3(caspase-3), B-cell lymphoma(Bcl-2), and Bcl-2-associated X protein(Bax) and the levels of phosphorylated(p)-JAK2 and p-STAT3 were detected by Western blot. The results showed that the viability of ESCs cells was lowered in the administration groups compared with the blank serum group(P<0.01), especially the 10% drug-medicated serum, which was selected for further experiment. The 10% SR-medicated serum, 10% CR-medicated serum, and 10% CM-medicated serum could increase the apoptosis rate(P<0.01), up-regulate the protein expression of caspase-3 and Bax in cells(P<0.05 or P<0.01), down-regulate the expression of Bcl-2(P<0.01), decrease the cell migration rate(P<0.05 or P<0.01), and reduce the secretion levels of IL-1β, IL-6, and TNF-α(P<0.05 or P<0.01), and levels of p-JAK2 and p-STAT3(P<0.05 or P<0.01). Compared with the SR and CR groups, CM group showed low cell viability(P<0.01), high protein expression of caspase-3 and Bax(P<0.05 or P<0.01), and low protein expression of Bcl-2 and p-JAK2(P<0.05). After incubation with CM, the apoptosis rate was higher(P<0.05) and the migration rate was lower(P<0.01) than that of the CR group. The p-STAT3 protein level of CM group was lower than that of the RS group(P<0.05). The mechanism of SR, CR, and the combination underlying the improvement of endometriosis may be that they blocked JAK2/STAT3 signaling pathway, inhibited ESC proliferation, promoted apoptosis, weakened cell migration, and reduced the secretion of inflammatory factors. The effect of the combination was better than that of RS alone and CR alone.


Subject(s)
Female , Humans , Janus Kinase 2 , Caspase 3 , bcl-2-Associated X Protein , Interleukin-6/genetics , Apoptosis , Signal Transduction , Cell Proliferation , STAT3 Transcription Factor/genetics
2.
Chinese Journal of Preventive Medicine ; (12): 185-191, 2022.
Article in Chinese | WPRIM | ID: wpr-935268

ABSTRACT

To investigate the associations between gene polymorphisms of signal transducer and activator of transcription 3 (STAT3) and liver cirrhosis (LC) after hepatitis B virus (HBV) infection. A case-control study was conducted in 243 patients with hepatitis B cirrhosis (HBV-LC, case group) and 486 HBV-infected subjects without LC (non-LC, control group) collected from January 2018 to September 2020 at the Changsha Central Hospital Affiliated to Nanhua University. Three single nucleotide polymorphisms (SNPs) of STAT3 gene, including rs4796793C>G, rs2293152C>G, and rs1053004T>C were selected through literature and biological information database, and the genotypes were detected by real-time fluorescent quantitative PCR (RFQ-PCR). The distribution differences of STAT3 SNPs genotypes between the two groups were compared using Chi-square test and haplotype analysis was conducted by Shesis online. The proportion of HBV C genotype in HBV-LC patients was significantly higher than that in the control group (80.91% vs. 70.79%, χ2=7.109, P=0.008), while the logarithm of ALT was significantly lower than that of the control group (1.78±0.43 vs. 1.95±0.54, t=3.801, P=0.000). The genotypes distributions of rs4796793, rs2293152, and rs1053004 were not significantly different between HBV-LC and non-LC in overall analysis and stratified analysis by gender (χ²=2.610, 1.505, 0.586, 2.653, 2.685, 1.583, 0.351, 5.388, 0.339, respectively, P>0.05 for each). Among the subjects infected with HBV genotype C, rs1053004 CC (vs. TT) significantly increased the risk of HBV-LC [odds ratio (OR) = 1.40, 95% confidence interval (CI): 1.03-1.91]. Among the HBV-infected subjects with HBeAg negative, rs4796793 GG genotype (vs. CC) and G allele (vs. C) significantly increased the risks of HBV-LC (OR = 2.17, 95%CI: 1.11-4.23; OR = 1.45, 95%CI: 1.06-1.97, respectively). Haplotypes analysis showed that the frequency of haplotype C-G-T composed of rs4796793, rs2293152, and rs1053004 was significantly lower in HBV-LC than that in the control group (non-LC) (27.3% vs. 35.6%, χ²=9.949, P = 0.001). The correlation between STAT3 and HBV-LC is different in HBV-infected subjects with different infection status. The HBV-infected subjects carrying haplotype rs4796793C-rs2293152G-rs1053004T of STAT3 gene have significantly decreased risk of LC.


Subject(s)
Humans , Carcinoma, Hepatocellular/genetics , Case-Control Studies , Genetic Predisposition to Disease , Genotype , Hepatitis B virus/genetics , Hepatitis B, Chronic/genetics , Liver Cirrhosis/genetics , Liver Neoplasms/genetics , Polymorphism, Single Nucleotide , STAT3 Transcription Factor/genetics
3.
Chinese Journal of Natural Medicines (English Ed.) ; (6): 815-824, 2021.
Article in English | WPRIM | ID: wpr-922764

ABSTRACT

Cervical cancer (CC) is recognized as the most common neoplasm in the female reproductive system worldwide. The lack of chemotherapeutic agents with outstanding effectiveness and safety severely compromises the anti-cipated prognosis of patients. Aloperine (ALO) is a natural quinolizidine alkaloid with marked anti-cancer effects on multiple malignancies as well as favorable activity in relieving inflammation, allergies and infection. However, its therapeutic efficacy and underlying mechanism in CC are still unclear. In the current study, MTT assay was employed to evaluate the viability of HeLa cells exposed to ALO to preliminarily estimate the effectiveness of ALO in CC. Then, the effects of ALO on the proliferation and apoptosis of HeLa cells were further investigated by plate colony formation and flow cytometry, respectively, while the migration and invasion of ALO-treated HeLa cells were evaluated using Transwell assay. Moreover, nude mice were subcutaneously inoculated with HeLa cells to demonstrate the anti-CC properties of ALO in vivo. The molecular mechanisms underlying these effects of ALO were evaluated by Western blot and immunohistochemical analysis. This study experimentally demonstrated that ALO inhibited the proliferation of HeLa cells via G2 phase cell cycle arrest. Simultaneously, ALO promoted an increase in the percentage of apoptotic HeLa cells by increasing the Bax/Bcl-2 ratio. Additionally, the migration and invasion of HeLa cells were attenuated by ALO treatment, which was considered to result from inhibition of epithelial-to-mesenchymal transition. For molecular mechanisms, the expression and activation of the IL-6-JAK1-STAT3 feedback loop were markedly suppressed by ALO treatment. This study indicated that ALO markedly suppresses the proliferation, migration and invasion and enhances the apoptosis of HeLa cells. In addition, these prominent anti-CC properties of ALO are associated with repression of the IL-6-JAK1-STAT3 feedback loop.


Subject(s)
Animals , Female , Humans , Mice , Apoptosis , Cell Line, Tumor , Cell Movement , Cell Proliferation , Feedback , HeLa Cells , Interleukin-6/genetics , Janus Kinase 1 , Mice, Nude , Quinolizidines , STAT3 Transcription Factor/genetics , Signal Transduction , Uterine Cervical Neoplasms/drug therapy
4.
Chinese Journal of Contemporary Pediatrics ; (12): 397-401, 2021.
Article in Chinese | WPRIM | ID: wpr-879866

ABSTRACT

A boy, aged 4 years and 6 months, had disease onset of fever, cough, pale complexion, and weakness, with hepatosplenomegaly, lymphadenectasis, and pancytopenia. He had been having repeated respiratory and digestive tract infections. Gene detection showed a pathogenic heterozygous mutation, c.C2147 > T(p.T716M), in the


Subject(s)
Child, Preschool , Humans , Male , Fever , Heterozygote , Immune System Diseases/genetics , Mutation , STAT3 Transcription Factor/genetics , Syndrome
5.
Rev. chil. endocrinol. diabetes ; 14(4): 159-165, 2021. tab, ilus
Article in Spanish | LILACS | ID: biblio-1344801

ABSTRACT

La diabetes Tipo 1 (DT1) es una compleja enfermedad autoinmune con una etiología aún desconocida. La vitamina D ha sido ampliamente estudiada debido a su potencial terapéutico en los potenciales nuevos casos de DT1. Por otra parte, los microARNs (miRs) han sido propuestos como posibles biomarcadores en diversos procesos biológicos como en la apoptosis e inflamación. El objetivo de este estudio fue evaluar el efecto de la suplementación con vitamina D sobre el perfil de expresión del miR-21 y marcadores de apoptosis tales como: BCL2, STAT3, TIPE2 y DAXX, en células mononucleares periféricas provenientes de pacientes con DT1 y sujetos controles. RESULTADOS: El perfil de expresión de miR-21 se encontró disminuido en los pacientes con DT1 en comparación con los controles. La expresión relativa de BCL2 se encontró aumentada en controles al comparar con pacientes DT1 en todas las condiciones experimentales. La expresión relativa de DAXX mostró un perfil de expresión diferencial al comparar pacientes con DT1 versus controles (p=0.006). CONCLUSIÓN: El estímulo con vitamina D parece tener un posible efecto regulador sobre los genes BCL2 y DAXX.


Type 1 diabetes (T1D) is a complex chronic autoimmune disease. Vitamin D has been one of the most studied therapeutic potential outbreaks related to T1D. Specific miRNAs have been proposed as potential biomarkers in several biological processes as apoptosis and inflammation. The aim of this study was to evaluate the effect of vitamin D on the expression profiles of miR-21 and apoptotic markers BCL2, STAT3, TIPE2 and DAXX, in PBMCs from T1D patients and control subjects. RESULTS: miR-21 expression was increased in controls regarding T1D patients. BCL2 was increased in controls compared to T1D patients in all experimental conditions. DAXX showed different expression patterns between T1D patients and controls (p=0.006). CONCLUSION: Vitamin D showed a possible regulation effect on apoptosis markers mainly through the regulation of BCL2 and DAXX


Subject(s)
Humans , Child , Adolescent , Vitamin D/administration & dosage , Apoptosis , Diabetes Mellitus, Type 1/metabolism , Vitamin D/metabolism , Biomarkers , Molecular Chaperones/drug effects , Molecular Chaperones/genetics , Molecular Chaperones/metabolism , Proto-Oncogene Proteins c-bcl-2/drug effects , Proto-Oncogene Proteins c-bcl-2/genetics , Proto-Oncogene Proteins c-bcl-2/metabolism , MicroRNAs/drug effects , MicroRNAs/genetics , MicroRNAs/metabolism , STAT3 Transcription Factor/drug effects , STAT3 Transcription Factor/genetics , STAT3 Transcription Factor/metabolism , Co-Repressor Proteins/drug effects , Co-Repressor Proteins/genetics , Co-Repressor Proteins/metabolism , Glucose/administration & dosage
6.
Journal of Zhejiang University. Science. B ; (12): 327-340, 2020.
Article in English | WPRIM | ID: wpr-1010538

ABSTRACT

Combined radiation-wound injury (CRWI) is characterized by blood vessel damage and pro-inflammatory cytokine deficiency. Studies have identified that the direct application of leptin plays a significant role in angiogenesis and inflammation. We established a sustained and stable leptin expression system to study the mechanism. A lentivirus method was employed to explore the angiogenic potential and peripheral inflammation of irradiated human umbilical vein endothelial cells (HUVECs). Leptin was transfected into human placenta-derived mesenchymal stem cells (HPMSCs) with lentiviral vectors. HUVECs were irradiated by X-ray at a single dose of 20 Gy. Transwell migration assay was performed to assess the migration of irradiated HUVECs. Based on the Transwell systems, co-culture systems of HPMSCs and irradiated HUVECs were established. Cell proliferation was measured by cell counting kit-8 (CCK-8) assay. The secretion of pro-inflammatory cytokines (human granulocyte macrophage-colony stimulating factor (GM-CSF), interleukin (IL)-1α, IL-6, and IL-8) was detected by enzyme-linked immunosorbent assay (ELISA). The expression of pro-angiogenic factors (vascular endothelial growth factor (VEGF) and basic fibroblast growth factor (bFGF)) mRNA was detected by real-time quantitative polymerase chain reaction (RT-qPCR) assay. Relevant molecules of the nuclear factor-κB (NF-κB) and Janus kinase (JAK)/signal transducer and activator of transcription (STAT) signaling pathways were detected by western blot assay. Results showed that leptin-modified HPMSCs (HPMSCs/ leptin) exhibited better cell proliferation, migration, and angiogenic potential (expressed more VEGF and bFGF). In both the single HPMSCs/leptin and the co-culture systems of HPMSCs/leptin and irradiated HUVECs, the increased secretion of pro-inflammatory cytokines (human GM-CSF, IL-1α, and IL-6) was associated with the interaction of the NF-κB and JAK/STAT signaling pathways. We conclude that HPMSCs/leptin could promote angiogenic potential and peripheral inflammation of HUVECs after X-ray radiation.


Subject(s)
Female , Humans , Pregnancy , Cell Proliferation , Cells, Cultured , Cytokines/biosynthesis , Human Umbilical Vein Endothelial Cells/radiation effects , Inflammation/etiology , Leptin/pharmacology , Mesenchymal Stem Cells/physiology , Neovascularization, Physiologic/physiology , Placenta/cytology , STAT3 Transcription Factor/genetics , Transcription Factor RelA/genetics , X-Rays
7.
Journal of Experimental Hematology ; (6): 1853-1858, 2020.
Article in Chinese | WPRIM | ID: wpr-879983

ABSTRACT

OBJECTIVE@#To investigate the effect of miR-29b-3p on apoptosis and proliferation of acute myeloid leukemia (AML) cells by targeting signal transducer and activator of transcription 3 (STAT3).@*METHODS@#TargetScan and miRanda online databases were used to predict the binding sites of miR-29b-3p and STAT3 3'UTR. The targeting relationship between them was estimated by Dual-Luciferase reporter assay experiment. After miR-29b-3p over-expression, qPCR and Western blot were used to detect the expression of STAT3 mRNA and proteins, flow cytometry to determine the apoptosis of AML cells, and MTS to detect the changes of cell proliferation in each group.@*RESULTS@#Dual-Luciferase reporter assay confirmed that STAT3 was the target gene of miR-29b-3p. After miR-29b-3p overexpression, the expression of STAT3 mRNA and protein decreased. Compared with the control groups, the proliferation of AML cells in the overexpression group decreased and the apoptosis increased (P<0.05).@*CONCLUSION@#MiR-29b-3p can inhibit the proliferation and induce apoptosis of AML cells by down-regulating STAT3.


Subject(s)
Humans , Apoptosis , Cell Proliferation , Leukemia, Myeloid, Acute/genetics , MicroRNAs/genetics , STAT3 Transcription Factor/genetics
8.
Ann. hepatol ; 16(1): 77-85, Jan.-Feb. 2017. graf
Article in English | LILACS | ID: biblio-838089

ABSTRACT

Abstract: Nonalcoholic fatty liver disease (NAFLD) is the most common cause of chronic liver disease worldwide. We have previously shown that hepatic reticuloendothelial system (RES) iron deposition is associated with an advanced degree of nonalcoholic steatohepatitis (NASH) in humans. In this study, we aimed to determine differentially expressed genes related to iron overload, inflammation and oxidative stress pathways, with the goal of identifying factors associated with NASH progression. Seventy five patients with NAFLD were evaluated for their biochemical parameters and their liver tissue analyzed for NASH histological characteristics. Gene expression analysis of pathways related to iron homeostasis, inflammation and oxidative stress was performed using real-time PCR. Gene expression was compared between subjects based on disease status and presence of hepatic iron staining. We observed increased gene expression of hepcidin (HAMP) (2.3 fold, p = 0.027), transmembrane serine proteinase 6 (TMPRSS6) (8.4 fold, p = 0.003), signal transducer and activator of transcription 3 (STAT3) (5.5 fold, p = 0.004), proinflammatory cytokines; IL-1β (2.7 fold, p = 0.046) and TNF-α (3.8 fold, p = 0.001) in patients with NASH. TMPRSS6, a negative regulator of HAMP, is overexpressed in patients with NASH and HIF1α (hypoxia inducible factor-1) is downregulated. NAFLD patients with hepatic iron deposition exhibited higher hepcidin expression (3.1 fold, p = 0.04) but lower expression of cytokines. In conclusion, we observed elevated hepatic HAMP expression in patients with NASH and in NAFLD patients who had hepatic iron deposition, while proinflammatory cytokines displayed elevated expression only in patients with NASH, suggesting a regulatory role for hepcidin in NAFL to NASH transition and in mitigating inflammatory responses.


Subject(s)
Humans , Male , Female , Middle Aged , Oxidative Stress/genetics , Iron Overload/genetics , Non-alcoholic Fatty Liver Disease/genetics , Inflammation/genetics , Iron/analysis , Liver/chemistry , Serine Endopeptidases/genetics , Gene Expression Regulation , Tumor Necrosis Factor-alpha/genetics , Tumor Necrosis Factor-alpha/blood , Inflammation Mediators/blood , Iron Overload/diagnosis , Iron Overload/blood , STAT3 Transcription Factor/genetics , Interleukin-1beta/genetics , Interleukin-1beta/blood , Real-Time Polymerase Chain Reaction , Hepcidins/genetics , Non-alcoholic Fatty Liver Disease/diagnosis , Non-alcoholic Fatty Liver Disease/blood , Inflammation/diagnosis , Inflammation/blood , Liver/pathology , Membrane Proteins/genetics
10.
Experimental & Molecular Medicine ; : e145-2015.
Article in English | WPRIM | ID: wpr-57306

ABSTRACT

Scoparone, which is a major constituent of Artemisia capillaries, has been identified as an anticoagulant, hypolipidemic, vasorelaxant, anti-oxidant and anti-inflammatory drug, and it is used for the traditional treatment of neonatal jaundice. Therefore, we hypothesized that scoparone could suppress the proliferation of VSMCs by interfering with STAT3 signaling. We found that the proliferation of these cells was significantly attenuated by scoparone in a dose-dependent manner. Scoparone markedly reduced the serum-stimulated accumulation of cells in the S phase and concomitantly increased the proportion of cells in the G0/G1 phase, which was consistent with the reduced expression of cyclin D1, phosphorylated Rb and survivin in the VSMCs. Cell adhesion markers, such as MCP-1 and ICAM-1, were significantly reduced by scoparone. Interestingly, this compound attenuated the increase in cyclin D promoter activity by inhibiting the activities of both the WT and active forms of STAT3. Similarly, the expression of a cell proliferation marker induced by PDGF was decreased by scoparone with no change in the phosphorylation of JAK2 or Src. On the basis of the immunofluorescence staining results, STAT3 proteins phosphorylated by PDGF were predominantly localized to the nucleus and were markedly reduced in the scoparone-treated cells. In summary, scoparone blocks the accumulation of STAT3 transported from the cytosol to the nucleus, leading to the suppression of VSMC proliferation through G1 phase arrest and the inhibition of Rb phosphorylation. This activity occurs independent of the form of STAT3 and upstream of kinases, such as Jak and Src, which are correlated with abnormal vascular remodeling due to the presence of an excess of growth factors following vascular injury. These data provide convincing evidence that scoparone may be a new preventative agent for the treatment of cardiovascular diseases.


Subject(s)
Animals , Humans , Rats , Active Transport, Cell Nucleus , Biomarkers , Cell Cycle Proteins/genetics , Cell Movement/drug effects , Cell Proliferation/drug effects , Cells, Cultured , Coumarins/pharmacology , Gene Expression Regulation/drug effects , Hep G2 Cells , Muscle, Smooth, Vascular/cytology , Myocytes, Smooth Muscle/metabolism , Proto-Oncogene Proteins c-sis/metabolism , STAT3 Transcription Factor/genetics , Signal Transduction/drug effects , Transcription, Genetic
11.
The Korean Journal of Parasitology ; : 459-469, 2014.
Article in English | WPRIM | ID: wpr-7401

ABSTRACT

Entamoeba histolytica is a tissue-invasive protozoan parasite causing dysentery in humans. During infection of colonic tissues, amoebic trophozoites are able to kill host cells via apoptosis or necrosis, both of which trigger IL-8-mediated acute inflammatory responses. However, the signaling pathways involved in host cell death induced by E. histolytica have not yet been fully defined. In this study, we examined whether calpain plays a role in the cleavage of pro-survival transcription factors during cell death of colonic epithelial cells, induced by live E. histolytica trophozoites. Incubation with amoebic trophozoites induced activation of m-calpain in a time- and dose-dependent manner. Moreover, incubation with amoebae resulted in marked degradation of STAT proteins (STAT3 and STAT5) and NF-kappaB (p65) in Caco-2 cells. However, IkappaB, an inhibitor of NF-kappaB, was not cleaved in Caco-2 cells following adherence of E. histolytica. Entamoeba-induced cleavage of STAT proteins and NF-kappaB was partially inhibited by pretreatment of cells with a cell-permeable calpain inhibitor, calpeptin. In contrast, E. histolytica did not induce cleavage of caspase-3 in Caco-2 cells. Furthermore, pretreatment of Caco-2 cells with a calpain inhibitor, calpeptin (but not the pan-caspase inhibitor, z-VAD-fmk) or m-calpain siRNA partially reduced Entamoeba-induced DNA fragmentation in Caco-2 cells. These results suggest that calpain plays an important role in E. histolytica-induced degradation of NF-kappaB and STATs in colonic epithelial cells, which ultimately accelerates cell death.


Subject(s)
Humans , Caco-2 Cells , Calcium-Binding Proteins , Calpain/genetics , Caspase 3/genetics , Caspases , Cell Death , Colon/cytology , Entamoeba histolytica/physiology , Epithelial Cells/cytology , I-kappa B Proteins/metabolism , Intestinal Mucosa/cytology , NF-kappa B/genetics , RNA Interference , RNA, Small Interfering , STAT3 Transcription Factor/genetics , STAT5 Transcription Factor/genetics , Signal Transduction
12.
Journal of Veterinary Science ; : 257-262, 2013.
Article in English | WPRIM | ID: wpr-92906

ABSTRACT

Vitamin D3 up-regulated protein 1 (VDUP1) is a potent growth suppressor that inhibits tumor cell proliferation and cell cycle progression when overexpressed. In a previous study, we showed that VDUP1 knockout (KO) mice exhibited accelerated liver regeneration because such animals could effectively control the expression of cell cycle regulators that drive the G1-to-S phase progression. In the present study, we further investigated the role played by VDUP1 in initial priming of liver regeneration. To accomplish this, VDUP1 KO and wild-type (WT) mice were subjected to 70% partial hepatectomy (PH) and sacrificed at different times after surgery. The hepatic levels of TNF-alpha and IL-6 increased after PH, but there were no significant differences between VDUP1 KO and WT mice. Nuclear factor-kappaB (NF-kappaB), c-Jun-N-terminal kinase (JNK), and signal transducer and activator of transcription 3 (STAT-3) were activated much earlier and to a greater extent in VDUP1 KO mice after PH. A single injection of TNF-alpha or IL-6 caused rapid activation of JNK and STAT-3 expression in both mice, but the responses were stronger and more sustained in VDUP1 KO mice. In conclusion, our findings provide evidence that VDUP1 plays a role in initiation of liver regeneration.


Subject(s)
Animals , Male , Blotting, Western , Carrier Proteins/genetics , Cell Proliferation , Gene Expression Regulation , Hepatectomy , Hepatocytes/cytology , JNK Mitogen-Activated Protein Kinases/genetics , Liver/physiology , Mice, Knockout , NF-kappa B/genetics , Polymerase Chain Reaction , Regeneration , STAT3 Transcription Factor/genetics , Thioredoxins/genetics
13.
Experimental & Molecular Medicine ; : 94-101, 2009.
Article in English | WPRIM | ID: wpr-103079

ABSTRACT

Phosphatidic acid (PA), the product of a PLD-mediated reaction, is a lipid second messenger that participates in various intracellular signaling events and is known to regulate a growing list of signaling proteins. We found that Bcl-2 was upregulated by PA treatment in HeLa cells. However, how PA upregulates Bcl-2 expression has not yet been studied. In this study, we tried to discover the mechanisms of Bcl-2 up-regulation by PA treatment in HeLa cells. Treatment with PA resulted in significantly increased expression of Bcl-2 in HeLa cells. Moreover, PA-induced Bcl-2 expression was blocked by mepacrine, an inhibitor of PLA2, but not by propranolol, an inhibitor of PA phospholyhydrolase (PAP). Treatment of 1,2-dipalmitoryl-sn-glycero-3-phosphate (DPPA) also increased Bcl-2 expression. These results indicate that Bcl-2 expression is mediated by lysophosphatidic acid (LPA), not by arachidonic acid (AA). Thereafter, we used MEK1/2 inhibitor, PD98059 to investigate the relationship between ERK1/2 MAPK and PA-induced Bcl-2 expression. PA-induced Bcl-2 expression was decreased when ERK1/2 was inhibited by PD98059. The transcription factor such as STAT3 which is controlled by ERK1/2 MAPK was increased along with Bcl-2 expression when the cells were treated with PA. Furthermore, STAT3 siRNA treatments inhibited PA-induced Bcl-2 expression, suggesting that STAT3 (Ser727) is involved in PA-induced Bcl-2 expression. Taken together, these findings indicate that PA acts as an important mediator for increasing Bcl-2 expression through STAT3 (Ser727) activation via the ERK1/2 MAPK pathway.


Subject(s)
Humans , Enzyme Inhibitors/pharmacology , Gene Expression Regulation, Neoplastic , HeLa Cells , Mitogen-Activated Protein Kinase Kinases/genetics , Phosphatidic Acids/genetics , Propranolol/pharmacology , Proto-Oncogene Proteins c-bcl-2/genetics , Quinacrine/pharmacology , RNA, Small Interfering/genetics , STAT3 Transcription Factor/genetics
14.
The Korean Journal of Laboratory Medicine ; : 230-238, 2008.
Article in English | WPRIM | ID: wpr-206226

ABSTRACT

BACKGROUND: Mac-2 binding protein (Mac-2BP) is a secreted glycoprotein from the culture fluid of several human cancer cells, especially breast, lung, and gastric cells. Mac-2BP plays a role in immune response and cell adhesion activity in patients with various cancer and infectious diseases. In this study, we attempted to identify the regulators of Mac-2BP expression at the transcriptional level. METHODS: To determine the effect of epidermal growth factor (EGF) to Mac-2BP expression in gastric cancers, we constructed the different lengths of Mac-2BP promoter plasmids and measured the promoter activity and Mac-2BP expression. In addition to investigating the role of signal transducer and activator of transcription3 (STAT3) or human telomerase reverse transcriptase (hTERT) as a regulator of Mac-2BP, we transfected the small interfering RNA (siRNA) specific for STAT3 or hTERT, and Mac-2BP level was observed by a quantitative ELISA. RESULTS: EGF treatment could suppress the Mac-2BP transcription in HEK293 or gastric cancer cell lines (SNU-638 or AGS). In 5'-deleted promoter experiment, pGL3-Mac Pro-2377 transfected cells showed a decreased luciferase activity compared to pGL3-Mac Pro-2277. We also identified that (-2,366/-2,356) on Mac-2BP promoter is a putative STAT3 binding site and suppression of STAT3 with STAT3 specific siRNA increased the Mac-2BP level, suggesting the role of STAT3 as a negative regulator, in contrast to hTERT, which is known as a positive regulator. CONCLUSIONS: EGF signal is critical for the Mac-2BP expression, and more importantly, STAT3 could work as a negative regulator, while hTERT as a positive regulator in Mac-2BP transcription.


Subject(s)
Humans , Antigens, Neoplasm/genetics , Cell Line , Cell Line, Tumor , Down-Regulation , Epidermal Growth Factor/metabolism , Membrane Glycoproteins/genetics , RNA, Small Interfering , STAT3 Transcription Factor/genetics , Telomerase/metabolism , Transfection
15.
Experimental & Molecular Medicine ; : 479-485, 2008.
Article in English | WPRIM | ID: wpr-84655

ABSTRACT

Hypoxia-inducible factor 1alpha (HIF-1alpha) is rapidly degraded by the ubiquitin-proteasome pathway under normoxic conditions. Ubiquitination of HIF-1alpha is mediated by interaction with von Hippel-Lindau tumor suppressor protein (pVHL). In our previous report, we found that hypoxia-induced active signal transducer and activator of transcription3 (STAT3) accelerated the accumulation of HIF-1alpha protein and prolonged its half-life in solid tumor cells. However, its specific mechanisms are not fully understood. Thus, we examined the role of STAT3 in the mechanism of pVHL-mediated HIF-1alpha stability. We found that STAT3 interacts with C-terminal domain of HIF-1alpha and stabilizes HIF-1alpha by inhibition of pVHL binding to HIF-1alpha. The binding between HIF-1alpha and pVHL, negative regulator of HIF-1alpha stability, was interfered dose-dependently by overexpressed constitutive active STAT3. Moreover, we found that the enhanced HIF-1alpha protein levels by active STAT3 are due to decrease of poly-ubiquitination of HIF-1alpha protein via inhibition of interaction between pVHL and HIF-1alpha. Taken together, our results suggest that STAT3 decreases the pVHL-mediated ubiquitination of HIF-1alpha through competition with pVHL for binding to HIF-1alpha, and then stabilizes HIF-1alpha protein levels.


Subject(s)
Animals , Humans , COS Cells , Cell Line, Tumor , Chlorocebus aethiops , Hypoxia-Inducible Factor 1, alpha Subunit/genetics , Immunoblotting , Immunoprecipitation , Protein Binding , STAT3 Transcription Factor/genetics , Signal Transduction/genetics , Transfection , Ubiquitination , Von Hippel-Lindau Tumor Suppressor Protein/genetics
16.
Experimental & Molecular Medicine ; : 514-522, 2008.
Article in English | WPRIM | ID: wpr-84651

ABSTRACT

Tumor migration/invasion is the main cause of tumor progression and STAT3 is needed to enhance tumor migration/invasion by up-regulating MMP-9. Thus, agents that inhibit STAT3 activation may be used as an anticancer drug. We present herein that 6-methyl-2-propylimino-6, 7-dihydro-5H-benzo [1, 3]-oxathiol- 4-one (LYR71) , a derivative of trimeric resveratrol, has an anticancer activity through inhibition of STAT3 activation. We found that LYR71 suppressed STAT3 activation and inhibited the expression and activity of MMP-9 in RANTES-stimulated breast cancer cells. In addition, LYR71 reduced RANTES-induced MMP-9 transcripts by blocking STAT3 recruitment, dissociating p300 and deacetylating histone H3 and H4 on the MMP-9 promoter. Furthermore, LYR71 inhibited tumor migration/invasion in RANTES-treated breast cancer cells and consequently blocked tumor progression in tumor-bearing mice. Taken together, the results of this study suggest that LYR71 can be therapeutically useful due to the inhibition effect of STAT3-mediated MMP-9 expression in breast cancer cells.


Subject(s)
Animals , Female , Humans , Mice , Antineoplastic Agents/chemistry , Bridged Bicyclo Compounds, Heterocyclic/chemistry , Blotting, Western , Breast Neoplasms/genetics , Cell Line, Tumor , Cell Movement/drug effects , Cell Survival/drug effects , Chromatin Immunoprecipitation , Gene Expression/drug effects , Imines/chemistry , Immunohistochemistry , Mammary Neoplasms, Experimental/pathology , Matrix Metalloproteinase 9/genetics , Mice, Inbred BALB C , Mice, Nude , Molecular Structure , Phosphorylation/drug effects , Reverse Transcriptase Polymerase Chain Reaction , STAT3 Transcription Factor/genetics , Stilbenes/chemistry , Xenograft Model Antitumor Assays/methods
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