Oleanolic acid inhibits colon cancer cell stemness and reverses chemoresistance by suppressing JAK2/STAT3 signaling pathway

Background:Oleanolic acid(OA),a pentacyclic triterpenoid exhibiting specific anti-cancer properties and highly effective antioxidant activity,was isolated from traditional Chinese medicinal herbs.Conversely,the OA that impacts colon cancer(CC)cells and its underlying mechanisms remain poorly understood.Methods:The cytotoxic effect of OA alone or OA-5-Fluorouracil(5-FU)combination on normal and CC cells was analyzed by methyl thiazolyl diphenyl-tetrazolium bromide(MTT).Then,the impact of OA on CC cell lines(LoVo and HT-29)proliferation and stemness were measured using colon formation and tumorsphere formation assays.Octamer-binding transcription factor 4(Oct4),Prominin-1(CD133),Nanog,and transcription factor SOX-2(SOX2)are cell stemness-related indicators whose expression was assessed usingfluorescence qPCR assay,Western blotting,and immunohistochemistry.The effect of OA on the proliferative potency of CC cells was evaluated using an in vivo model.Results:The stem-like characteristics and clone production of colon cancer cells were markedly reduced by OA alone or in combination with OA-5-FU.Moreover,OA increases the susceptibility of CC cells to 5-FU by blocking the cell stemness-related markers(CD133,Nanog,SOX2,and Oct4)expression levels both in vitro and in vivo,as well as by inactivating the activator of transcription 3(STAT3 signaling)and Janus kinase 2/signal transducer(JAK2).Conclusion:Thesefindings imply that oleanolic acid,both in vitro and in vivo,suppresses the JAK2/STAT3 pathway,which in turn reverses chemoresistance and decreases colon cancer cell stemness.Therefore,by reducing the recommended amount of 5-FU,this strategy may improve chemotherapeutic effectiveness and minimize undesired side effects.

Down-regulation of mi R-30a-3p/5p promotes esophageal squamous cell carcinoma cell proliferation by activating the Wnt signaling pathway

AIM To investigate the potential role of micro RNA-30 a(mi R-30 a) in esophageal squamous cell carcinoma(ESCC).METHODS Expression of mi R-30 a-3 p/5 p was analyzed using microarray data and fresh ESCC tissue samples. Both in vitro and in vivo assays were used to investigate the effects of mi R-30 a-3 p/5 p on ESCC cell proliferation. Furthermore,Kyoto Encyclopedia of Genes and Genomes analysis was performed to explore underlying mechanisms involved in ESCC,and then,assays were carried out to verify the potential molecular mechanism of mi R-30 a in ESCC.RESULTS Low expression of mi R-30 a-3 p/5 p was closely associated with advanced ESCC progression and poor prognosis of patients with ESCC. Knock-down of mi R-30 a-3 p/5 p promoted ESCC cell proliferation. Increased mi R-30 a-3 p/5 p expression inhibited the Wnt signaling pathway by targeting Wnt2 and Fzd2.CONCLUSION Down-regulation of mi R-30 a-3 p/5 p promotes ESCC cell proliferation by activating the Wnt signaling pathway through inhibition of Wnt2 and Fzd2.

MiR-19a-3p regulates the Forkhead box F2-mediated Wnt/β-catenin signaling pathway and affects the biological functions of colorectal cancer cells

BACKGROUND Colorectal cancer(CRC)is one of the most common malignancies worldwide.AIM To explore the expression of microRNA miR-19a-3p and Forkhead box F2(FOXF2)in patients with CRC and the relevant mechanisms.METHODS Sixty-two CRC patients admitted to the hospital were enrolled into the study group,and sixty healthy people from the same period were assigned to the control group.Elbow venous blood was sampled from the patients and healthy individuals,and blood serum was saved for later analysis.MiR-19a-3p mimics,miR-19a-3p inhibitor,miR-negative control,small interfering-FOXF2,and short hairpin-FOXF2 were transfected into HT29 and HCT116 cells.Then quantitative polymerase chain reaction was performed to quantify the expression of miR-19a-3p and FOXF2 in HT29 and HCT116 cells,and western blot(WB)analysis was conducted to evaluate the levels of FOXF2,glycogen synthase kinase 3 beta(GSK-3β),phosphorylated GSK-3β(p-GSK-3β),β-catenin,p-β-catenin,α-catenin,Ncadherin,E-cadherin,and vimentin.The MTT,Transwell,and wound healing assays were applied to analyze cell proliferation,invasion,and migration,respectively,and the dual luciferase reporter assay was used to determine the correlation of miR-19a-3p with FOXF2.RESULTS The patients showed high serum levels of miR-19a-3p and low levels of FOXF2,and the area under the curves of miR-19a-3p and FOXF2 were larger than 0.8.MiR-19a-3p and FOXF2 were related to sex,tumor size,age,tumor-nodemetastasis staging,lymph node metastasis,and differentiation of CRC patients.Silencing of miR-19a-3p and overexpression of FOXF2 suppressed the epithelialmesenchymal transition,invasion,migration,and proliferation of cells.WB analysis revealed that silencing of miR-19a-3p and FOXF2 overexpression significantly suppressed the expression of p-GSK-3β,β-catenin,N-cadherin,and vimentin;and increased the levels of GSK-3β,p-β-catenin,α-catenin,and Ecadherin.The dual luciferase reporter assay confirmed that there was a targeted correlation of miR-19a-3p with FOXF2.In addition,a rescue experiment revealed that there were no differences in cell proliferation,invasion,and migration in HT29 and HCT116 cells co-transfected with miR-19a-3p-mimics+sh-FOXF2 and miR-19a-3p-inhibitor+si-FOXF2 compared to the miR-negative control group.CONCLUSION Inhibiting miR-19a-3p expression can upregulate the FOXF2-mediated Wnt/β-catenin signaling pathway,thereby affecting the epithelial-mesenchymal transition,proliferation,invasion,and migration of cells.Thus,miR-19a-3p is likely to be a therapeutic target in CRC.

Diabetes and inflammatory diseases:An overview from the perspective of Ca^(2+)/3'-5'-cyclic adenosine monophosphate signaling

A large amount of evidence has supported a clinical link between diabetes and inflammatory diseases,e.g.,cancer,dementia,and hypertension.In addition,it is also suggested that dysregulations related to Ca^(2+)signaling could link these diseases,in addition to 3'-5'-cyclic adenosine monophosphate(cAMP)signaling pathways.Thus,revealing this interplay between diabetes and inflammatory diseases may provide novel insights into the pathogenesis of these diseases.Publications involving signaling pathways related to Ca^(2+)and cAMP,inflammation,diabetes,dementia,cancer,and hypertension(alone or combined)were collected by searching PubMed and EMBASE.Both signaling pathways,Ca^(2+)and cAMP signaling,control the release of neurotransmitters and hormones,in addition to neurodegeneration,and tumor growth.Furthermore,there is a clear relationship between Ca^(2+)signaling,e.g.,increased Ca^(2+)signals,and inflammatory responses.cAMP also regulates pro-and anti-inflammatory responses.Due to the experience of our group in this field,this article discusses the role of Ca^(2+)and cAMP signaling in the correlation between diabetes and inflammatory diseases,including its pharmacological implications.As a novelty,this article also includes:(1)A timeline of the major events in Ca^(2+)/cAMP signaling;and(2)As coronavirus disease 2019(COVID-19)is an emerging and rapidly evolving situation,this article also discusses recent reports on the role of Ca^(2+)channel blockers for preventing Ca^(2+)signaling disruption due to COVID-19,including the correlation between COVID-19 and diabetes.

外源性Wnt5a激活K562细胞非经典Wnt5a／Ca^2＋信号途径研究

目的观察外源性Wat5a对K562细胞非经典Wnt5a/Ca2+途径的影响,进一步研究外源性Wnt5a诱导K562细胞的分化机制。方法激光共聚焦显微镜观察Ca2+内流的变化,以RT-PCR及免疫组化检测β-catenin的表达变化,以Western blot检测cyclinD1的表达变化。结果外源性Wnt5a能明显促进K562细胞Ca2+内流,显著下调cyclinD1表达,且能下调K562细胞β-catenin表达,但β-catenin表达下调无统计学意义。结论外源性Wnt5a能激活K562细胞非经典Wnt5a/Ca2+途径,外源性Wnt5a诱导K562细胞分化机制可能与此相关。

Mutations in components of the Wnt signaling pathway in gastric cancer

AIM: To explore the contribution of AXIN1, AXIN2 and beta-catenin, components of Wnt signaling pathway, to the carcinogenesis of gastric cancer (GC), we examined AXIN1, AXIN2 exon7 and CTNNB1 (encoding beta- catenin) exon3 mutations in 70 GCs. METHODS: The presence of mutations was identified by polymerase chain reaction (PCR)-based denaturing high-performance liquid chromatography and direct DNA sequencing. Beta-catenin expression was detected by immunohistochemical analysis. RESULTS: Among the 70 GCs, 5 (7.1%) had mutations in one or two of these three components. A frameshift mutation (1 bp deletion) in exon7 of AXIN2 was found in one case. Four cases, including the case with a mutation in AXIN2, had frameshift mutations and missense mutations in AXIN1. Five single nucleotide polymorphisms (SNPs), 334 C>T, 874 C>T, 1396 G>A, 1690 C>T and 1942 T>G, were identified in AXIN1. A frameshift mutation (27 bp deletion) spanning exon3 of CTNNB1 was observed in one case. All four cases with mutations in AXIN1 and AXIN2 showed nuclear beta- catenin expression. CONCLUSION: These data indicate that the mutationsin AXIN1 and AXIN2 may contribute to gastric carcino- genesis.

Neuroprotection mediated by the Wnt/Frizzled signaling pathway in early brain injury induced by subarachnoid hemorrhage

The Wnt/Frizzled signaling pathway participates in many inflammation-linked diseases. However, the inflammatory response mediated by the Wnt/Frizzled signaling pathway in experimental subarachnoid hemorrhage has not been thoroughly investigated. Consequently, in this study, we examined the potential role of the Wnt/Frizzled signaling pathway in early brain injury in rat models of subarachnoid hemorrhage.Simultaneously, possible neuroprotective mechanisms were also investigated. Experimental subarachnoid hemorrhage rat models were induced by injecting autologous blood into the prechiasmatic cistern. Experiment 1 was designed to examine expression of the Wnt/Frizzled signaling pathway in early brain injury induced by subarachnoid hemorrhage. In total, 42 adult rats were divided into sham(injection of equivalent volume of saline), 6-, 12-, 24-, 48-, 72-hour, and 1-week subarachnoid hemorrhage groups. Experiment 2 was designed to examine neuroprotective mechanisms of the Wnt/Frizzled signaling pathway in early brain injury induced by subarachnoid hemorrhage. Rats were treated with recombinant human Wnt1(rhwnt1), small interfering Wnt1(siwnt1) RNA, and monoclonal antibody of Frizzled1(anti-Frizzled1) at 48 hours after subarachnoid hemorrhage. Expression levels of Wnt1, Frizzled1, β-catenin, peroxisome proliferator-activated receptor-γ, CD36, and active nuclear factor-κB were examined by western blot assay and immunofluorescence staining. Microglia type conversion and inflammatory cytokine levels in brain tissue were examined by immunofluorescence staining and enzyme-linked immunosorbent assay. Our results show that compared with the sham group, expression levels of Wnt1, Frizzled1, and β-catenin were low and reduced to a minimum at 48 hours, gradually returning to baseline at 1 week after subarachnoid hemorrhage. rhwnt1 treatment markedly increased Wnt1 expression and alleviated subarachnoid hemorrhage-induced early brain injury(within 72 hours), including cortical cell apoptosis, brain edema, and neurobehavioral deficits, accompanied by increasing protein levels of β-catenin, CD36, and peroxisome proliferator-activated receptor-γ and decreasing protein levels of nuclear factor-κB. Of note, rhwnt1 promoted M2-type microglia conversion and inhibited release of inflammatory cytokines(interleukin-1β, interleukin-6, and tumor necrosis factor-α). In contrast, siwnt1 RNA and anti-Frizzled1 treatment both resulted in an opposite effect. In conclusion, the Wnt/Frizzled1 signaling pathway may participate in subarachnoid hemorrhage-induced early brain injury via inhibiting the inflammatory response, including regulating microglia type conversion and decreasing inflammatory cytokine release. The study was approved by the Animal Ethics Committee of Anhui Medical University and First Affiliated Hospital of USTC,Division of Life Sciences and Medicine, University of Science and Technology of China(approval No. LLSC-20180202) in May 2017.

Wnt5a/Frizzled-2/Ca^(2+)和Wnt3a/Frizzled通路的生理及病理学研究进展

Wnt信号通路是一种古老且高度保守的信号通路,由Wnt配体蛋白、Wnt受体及其相关附件组成。Wnt通路可分为依赖β-连环蛋白(β-catenin)的经典信号通路和非依赖β-catenin的非经典信号通路两大类。Wnt3a和Wnt5a可分别激活经典的Wnt/β-catenin通路和非经典的Wnt/Ca^(2+)信号通路。2种通路在神经和心血管等各系统中广泛分布,参与调控胚胎发育、细胞增殖分化和癌症等重要生理和病理过程。Wnt5a/Frizzled-2/Ca^(2+)通路刺激成骨细胞和肺上皮细胞生成,维持成熟海马的突触可塑性和结构并营养神经元,加剧损伤后神经细胞和心肌细胞中的钙超载,维持心脏发育,在癌症的发生发展过程中起促进或抑制的双重作用。Wnt3a/Frizzled通路参与炎症反应并起抗炎作用,减少阿尔茨海默病等疾病中的神经元凋亡,与Frizzled-1或Frizzled-2结合可分别促进或抑制心脏成纤维细胞分化,促进肿瘤增殖、迁移和侵袭。现综述Wnt5a/Frizzled-2/Ca^(2+)和Wnt3a/Frizzled信号通路在胚胎发育、炎症、神经系统、心血管系统和癌症发生过程中的异常激活和抑制引起的生理及病理变化以及对疾病的发生发展及修复的影响,为Wnt信号通路在多系统生理及病理状态下作为研究和治疗靶点提供思路。

Ubiquitin-like modifier activating enzyme 2 promotes cell migration and invasion through Wnt/β-catenin signaling in gastric cancer

AIM To investigate the function and mechanism of ubiquitinlike modifier activating enzyme 2(Uba2) in progression of gastric cancer(GC) cells.METHODS Uba2 level in patients with GC was analyzed by Western blotting and immunohistochemistry. MTT and colony formation assays were performed to examine cell proliferation.Flow cytometry was used for cell cycle analysis.Wound healing and Transwell assays were conducted to examine the effects of Uba2 on migration and invasion.Expression levels of cell cycle-related proteins, epithelial-mesenchymal transition(EMT) biomarkers, and involvement of the Wnt/β-catenin pathway was assessed by Western blotting. Activation of the Wnt/β-catenin pathway was confirmed by luciferase assay.RESULTS Uba2 expression was higher in GC than in normal tissues.Increased Uba2 expression was correlated with tissue differentiation, Lauren's classification, vascular invasion,and TNM stage, as determined by the analysis of 100 GC cases(P < 0.05). Knock-down of Uba2 inhibited GC cell proliferation, induced cell cycle arrest, and altered expression of cyclin D1, P21, P27, and Bcl-2, while upregulation of Uba2 showed the opposite effects. The wound healing and Transwell assays showed that Uba2 promoted GC cell migration and invasion. Western blotting revealed alterations in EMT biomarkers, suggesting the role of Uba2 in EMT. Furthermore, the luciferase reporter assay indicated the involvement of the Wnt/β-catenin signaling pathway as a possible modulator of Uba2 oncogenic functions.CONCLUSION Uba2 plays a vital role in GC cell migration and invasion,possibly by regulating the Wnt/β-catenin signaling pathway and EMT.

Angelica sinensis polysaccharides ameliorate 5-flourouracil-induced bone marrow stromal cell proliferation inhibition via regulating Wnt/β-catenin signaling

Chemotherapy may cause cellular oxidative stress to bone marrow.Oxidative damage of bone marrow hematopoietic microenvironment is closely related to chronic myelosuppression after chemotherapeutic treatment.Angelica sinensis polysaccharides(ASP)are major effective ingredients of traditional Chinese medicine Angelica with multi-target anti-oxidative stress features.In the current study,we investigated the protective roles and mechanisms of ASP on chemotherapy-induced bone marrow stromal cell(BMSC)damage.The human bone marrow stromal cell line HS-5 cells were divided into control group,5-FU group,5-FU+ASP group,and 5-FU+LiCl group to investigate the mechanism of ASP to alleviate 5-FU-induced BMSC proliferation inhibition.The results showed that 5-FU inhibits the growth of HS-5 cells in a time and dose-dependent manner;however,ASP partially counteracted the 5-FU-induced decrease in cell viability,whereas Wnt signaling inhibitor Dkk1 antagonized the effect of ASP on HS-5 cells.ASP reversed the decrease in total cytoplasmicβ-catenin,p-GSK-3β,and CyclinD1 following 5-FU treatment and modulated nuclear expression ofβ-catenin,Lef-1,and C-myc proteins.Furthermore,ASP also enhanced the antioxidant capacity of cells and reduced 5-FU-induced oxidative stress,attenuated FoxO1 expression,thus weakened its downstream apoptosis-related proteins and G0/G1 checkpoint-associated p27^(Kip1) expression to alleviate 5-FU-induced apoptosis and to promote cell cycle progression.All the results above suggest that the protective role of ASP in 5-FU-treated BMSCs proliferation for the chemotherapy may be related to its activating Wnt/β-catenin signaling and keeping homeostasis betweenβ-catenin and FoxO1 under oxidative stress.The study provides a potential therapeutic strategy for alleviating chemotherapeutic damage on BMSCs.

Efficacy of Yisui granule(益髓颗粒)on myelodysplastic syndromes in SKM-1 mouse xenograft model through suppressing Wnt/β-catenin signaling pathway

OBJECTIVE:To unmask the underlying mechanisms of Yisui granule(益髓颗粒,YSG)for the treatment of Myelodysplastic syndromes(MDS).METHODS:Our study used an SKM-1 mouse xenograft model of MDS to explore the anti-tumor potential of YSG and its safety,assess its effect on overall survival(OS),and evaluate whether its mechanism is associated with the demethylation of the secreted frizzled related protein 5(s FRP5)gene and suppressing Wnt/β-catenin pathway.Bisulfite amplicon sequencing was applied to detect the level of methylation of the s FRP5 gene;western blotting,immunofluorescence staining,and real-time Polymerase Chain Reaction were performed to detect DNA methyltransferase 1(DNMT1),s FRP5,and other Wnt/β-catenin pathway-related m RNA and protein expression.RESULTS:The results showed that high-dosage YSG exerted an anti-tumor effect similar to that of decitabine,improved OS,and reduced long-term adverse effects in the long term.Mechanically,YSG reduced the expression of DNMT1 methyltransferase,decreased the methylation,and increased the expression of the Wnt/β-catenin pathway antagonist-s FRP5.Furthermore,components of the Wnt/β-catenin pathway,including Wnt3a,β-catenin,c-Myc,and cyclin D1,were down-regulated in response to YSG,suggesting that YSG could treat MDS by demethylating the s FRP5 gene and suppressing the Wnt/β-catenin pathway.CONCLUSIONS:Our findings demonstrated that YSG could be used alone or in combination with decitabine to improve outcomes in the MDS animal model,providing an alternative solution for treating MDS.

NETO2 promotes melanoma progression via activation of the Ca^(2+)/CaMKⅡ signaling pathway

Melanoma is the most aggressive cutaneous tumor.Neuropilin and tolloid-like 2(NETO2)is closely related to tumorigenesis.However,the functional significance of NETO2 in melanoma progression remains unclear.Herein,we found that NETO2 expression was augmented in melanoma clinical tissues and associated with poor prognosis in melanoma patients.Disrupting NETO2 expression markedly inhibited melanoma proliferation,malignant growth,migration,and invasion by downregulating the levels of calcium ions(Ca^(2+))and the expression of key genes involved in the calcium signaling pathway.By contrast,NETO2 overexpression had the opposite effects.Importantly,pharmacological inhibition of CaMKII/CREB activity with the CaMKII inhibitor KN93 suppressed NETO2-induced proliferation and melanoma metastasis.Overall,this study uncovered the crucial role of NETO2-mediated regulation in melanoma progression,indicating that targeting NETO2 may effectively improve melanoma treatment.

Expression of hepatic Wnt5a and its clinicopathological features in patients with hepatocellular carcinoma

Backgroud： Wingless-type MMTV integration site family member 5a （Wnt5a） is involved in carcinogenesis.However, little data are available in Wnt5a signaling with hepatocellular carcinoma （HCC）. In thepresent study, we investigated the expression of hepatic Wnt5a in HCC and the role of Wnt5a in HCCprogression and outcome.

Hypoglycemic effect and the mechanism of action of a polysaccharide from sweet corncob in a high-fat diet and streptozotocin-induced diabetic mice

Type 2 diabetes mellitus(T2DM)is a metabolic disease caused by a glycolipid metabolism disorder and isletβ-cell dysfunction.SCP-80-I is a biologically active water-soluble polysaccharide isolated from sweet corncob,an agricultural byproduct.The hypoglycemic effects of SCP-80-I on T2DM mice and its mechanisms were investigated in this study.SCP-80-I was found to significantly reduce blood glucose and lipid deposition levels in T2DM mice,as well as decrease serum leptin and increase adiponectin secretion.Interestingly,real time-polymerase chain reaction(RT-PCR)and Western blotting results revealed that SCP-80-I could regulate the expression of several glycolipid metabolisms and insulin secretion genes and proteins,including 5'-AMP-activated protein kinase(AMPK),carnitine palmitoyltransferase I(CPTI),and acetyl coenzyme A carboxylase(ACC)in the liver and AMPK,sirtuin1(Sirtl),peroxisome proliferator-activated receptorycoactivator-1(PGC-1α),and uncoupling protein 2(UCP2)in the pancreas.To have a hypoglycemic effect,SCP-80-1 regulated glycolipid metabolism and islet cell function in the liver by regulating the AMPK/AC C/CPT1 signaling pathway and the AMPK/Sirt1/PGC-1αand AMPK/Sirtl/UCP2 signaling pathways.These findings improve our understanding of polysaccharides derived from sweet corncob and the use of SCP-80-I in the production of hypoglycemic foods.

加味小陷胸汤水提物通过Wnt5a/Ca^(2+)/NFAT信号通路抑制TGF-β1介导的人胃癌MGC-803细胞上皮-间质转化及侵袭迁移

目的:观察加味小陷胸汤水提物对转化生长因子-β1(transforming growth factor-β1,TGF-β1)介导的人胃癌MGC-803细胞上皮-间质转化(epithelial-mesenchymal transformation,EMT)及侵袭迁移能力的影响,探讨其调控Wnt5a/Ca^(2+)/活化T细胞核因子(nuclear factor of activated T-cells,NFAT)信号通路抑制MGC-803细胞EMT和侵袭转移的作用机制。方法:用TGF-β1(10μg·L^(-1))诱导人胃癌MGC-803细胞EMT及侵袭转移模型,分别采用Transwell小室实验、划痕愈合实验、蛋白免疫印迹和免疫荧光法检测细胞侵袭迁移能力,EMT标志蛋白表达和Wnt5a/Ca^(2+)/NFAT信号通路关键蛋白表达以及细胞内Ca^(2+)浓度。结果:TGF-β1能够显著增强MGC-803细胞侵袭迁移能力(P<0.01),下调上皮细胞黏附分子(E-cadherin)水平(P<0.01),上调间质细胞标志蛋白(N-cadherin),转录因子(Snail)和细胞骨架蛋白(Vimentin)表达(P<0.01),并诱导细胞Wnt5a,钙调神经磷酸酶(calcineurin,CaN),活化T细胞核因子1(nuclear factor of activated T-cells1,NFAT1)总蛋白,磷酸化蛋白p-NFAT1和NFAT1核蛋白表达上调及Ca^(2+)胞内蓄积(P<0.01);而加味小陷胸汤(10,20,40 mg·L^(-1))均可明显抑制这一现象,且40 mg·L^(-1)效果最佳(P<0.05,P<0.01);Wnt5a/Ca^(2+)/NFAT信号通路特异性抑制剂(R)-(+)-Bay-K-8644与加味小陷胸汤40 mg·L^(-1)均可明显抑制MGC-803细胞经TGF-β1介导后的侵袭迁移,上调E-cadherin水平,下调N-cadherin,Snail,Vimentin,Wnt5a,CaN,NFAT1蛋白表达及减少Ca^(2+)在胞内蓄积(P<0.05,P<0.01),且(R)-(+)-Bay-K-8644协同加味小陷胸汤40 mg·L^(-1)抑制作用效果更强(P<0.05,P<0.01)。结论:以上结果提示加味小陷胸汤能通过Wnt5a/Ca^(2+)/NFAT信号通路抑制TGF-β1介导的EMT,进而降低MGC-803细胞侵袭迁移能力。

基于Wnt5a/Ca^(2+)/NFAT信号通路研究小陷胸汤调控Ca^(2+)载量抑制MGC-803细胞侵袭迁移和上皮间质转化作用

目的探讨小陷胸汤对转化生长因子-β_(1)(TGF-β_(1))诱导胃癌MGC-803细胞侵袭转移及上皮间质转化的影响,并探讨其可能的机制。方法通过CB-DOCK在线平台(http://clab.labshare.cn/cb-dock/)预测小陷胸汤与活化T细胞核转录因子(NFAT)分子对接。使用质量浓度为10μg·L^(-1)的TGF-β_(1)建立人胃癌MGC-803细胞侵袭转移模型,将MGC-803细胞分为空白组、模型组、小陷胸汤组(0.1、0.2、0.4 g·L^(-1)),为进一步探讨Wnt5a/Ca^(2+)/NFAT信号通路在小陷胸汤抑制胃癌中的关键参与作用,将Wnt5a过表达质粒转染MGC-803细胞,分为空白质粒组、Wnt5a-OE组、空白质粒+小陷胸汤(0.4 g·L^(-1))组和Wnt5a-OE+小陷胸汤(0.4 g·L^(-1))组。分别使用细胞增殖与活性检测(CCK-8)法、Transwell小室实验、划痕愈合实验、蛋白免疫印迹法(Western blot)、免疫荧光法检测MGC-803细胞活力、侵袭能力、迁移能力、E-钙黏蛋白(E-cadherin)、N-钙黏蛋白(N-cadherin)、波形蛋白(Vimentin)、锌指蛋白(Snail)、Wnt5a/Ca^(2+)/NFAT信号通路关键蛋白Wnt5a、钙调神经磷酸酶(CaN)、NFAT1、磷酸化(p)-NFAT1和NFAT1核蛋白表达以及细胞Ca^(2+)浓度变化。结果分子对接提示小陷胸汤作用于Wnt5a/Ca^(2+)/NFAT信号通路。与模型组比较,小陷胸汤(0.1、0.2、0.4 g·L^(-1))能明显促进MGC-803细胞活力的丧失,可通过基质凝胶侵入Transwell下室抑制细胞,并以剂量依赖性的方式减缓细胞划痕愈合,并促进E-cadherin的表达,抑制N-cadherin、Vimentin和Snail的表达(P<0.05,P<0.01)。进一步实验表明,与模型组比较,小陷胸汤可以抑制Wnt5a、CaN、NFAT1和p-NFAT1的表达,降低NFAT1核表达和NFAT1介导的转录活性,从而降低细胞Ca^(2+)浓度,且可逆转Wnt5a的作用(P<0.05,P<0.01)。结论小陷胸汤可通过Wnt5a/Ca^(2+)/NFAT通路减弱人胃癌MGC-803细胞的侵袭转移和上皮间质转化(EMT),从而减弱TGF-β_(1)诱导的促瘤作用。这提示小陷胸汤可能通过调节胃癌的侵袭、转移和EMT来预防和治疗胃癌。

靶向抑制frizzled-2对脑损伤后wnt5a/Ca^(2+)介导的神经细胞钙超载的抑制性研究（英文）

目的探讨Wnt5a/Frizzled-2信号在创伤性颅脑损伤(TBI)后神经细胞钙超载过程中的作用。方法体内实验:成年Sprague-Dawley大鼠(96只),随机分为正常组A(32只),单纯损伤组B(32只)和RNAi抑制组C(32只)。B组和C组Fenny式法制作中型颅脑损伤模型。其中C组模型建立前48 h采用立体定向海马区注射RNAi以抑制Frizzled-2的表达。伤后24 h处死大鼠,取伤侧海马组织,用western blotting方法检测其中Frizzled-2和Wnt5a含量,用免疫荧光染色和激光共聚焦显微镜检测其中钙离子浓度。单因素方差分析比较各组间的差别。结果 A组大鼠海马组织细胞中稳定表达着Wnt5a/Frizzled-2信号。TBI后,与A组相比,B组海马组织中的Wnt5a和Frizzled-2的表达分别升高了2倍和5倍(P<0.01),海马细胞中钙离子的含量显著增高(P<0.01)。与B组相比,随着Frizzled-2的抑制,C组海马细胞中的Wnt5a和Frizzled-2的表达分别降低1倍、3.5倍(P<0.01),同时细胞中的钙离子含量显著降低1.5倍,接近A组(P<0.01)。结论在生理和病理条件下,Wnt5a/Frizzled-2信号在调节神经细胞中的钙离子浓度变化中起到重要的作用,同时我们的研究提示该信号的相关重要组成因子Wnt5a,Fzd2和P-CamKII以及针对Frizzled-2设计的特异性RNAi可以作为日后TBI研究和治疗的相关靶点。

Calycosin-7-O-β-D-glucopyranoside stimulates osteoblast differentiation through regulating the BMP/WNT signaling pathways

The iso fl avone calycosin-7-O-β-D-glucopyranoside(CG) is a principal constituent of Astragalus membranaceus(AR) and has been reported to inhibit osteoclast development in vitro and bone loss in vivo. The aim of this study was to investigate the osteogenic effects of CG and its underlying mechanism in ST2 cells. The results show that exposure of cells to CG in osteogenic differentiation medium increases ALP activity, osteocalcin(Ocal) m RNA expression and the osteoblastic mineralization process. Mechanistically, CG treatment increased the expression of bone morphogenetic protein 2(BMP-2), p-Smad 1/5/8, β-catenin and Runx2, all of which are regulators of the BMP- or wingless-type MMTV integration site family(WNT)/β-catenin-signaling pathways. Moreover, the osteogenic effects of CG were inhibited by Noggin and DKK-1 which are classical inhibitors of the BMP and WNT/β-catenin-signaling pathways, respectively. Taken together, the results indicate that CG promotes the osteoblastic differentiation of ST2 cells through regulating the BMP/WNT signaling pathways. On this basis, CG may be a useful lead compound for improving the treatment of bone-decreasing diseases and enhancing bone regeneration.

Epigenetic inactivation of secreted frizzled-related protein 2 in esophageal squamous cell carcinoma

AIM： To investigate the expression and methylation status of the secreted frizzled-related protein 2 （SFRP2） in esophageal squamous cell carcinoma （ESCC） and ex- plore its role in ESCC carcinogenesis.METHODS： Seven ESCC cell lines （KYSE 30, KYSE150, KYSE410, KYSE510, EC109, EC9706 and TE-1） and one immortalized human esophageal epithelial cell line （Het- 1A）, 20 ESCC tissue samples and 20 paired adjacent non-tumor esophageal epithelial tissues were analyzed in this study. Reverse-transcription polymerase chain reaction （RT-PCR） was employed to investigate the expression of SFRP2 in cell lines, primary ESCC tumor tissue, and paired adjacent normal tissue. Methylation status was evaluated by methylation-specific PCR and bisulfite sequencing. The correlation between expres- sion and promoter methylation of the SFRP2 gene was confirmed with treatment of 5-aza-2＇-deoxycytidine. To assess the potential role of SFRP2 in ESCC, we es-tablished stable SFRP2-transfected cells and examined them with regard to cell proliferation, colony formation, apoptosis and cell cycle in vivo and in vitro.RESULTS： SFRP2 mRNA was expressed in the im- mortalized normal esophageal epithelial cell line but not in seven ESCC cell lines. By methylation-specific PCR, complete methylation was detected in three cell lines with silenced SFRP2 expression, and extensive methylation was observed in the other four ESCC cell lines. 5-aza-2＇-deoxycytidine could restore the expres- sion of SFRP2 mRNA in the three ESCC cell lines lack- ing SFRP2 expression. SFRP2 mRNA expression was obviously lower in primary ESCC tissue than in adjacent normal tissue （0.939 ± 0.398 vs 1.51 ± 0.399, P 〈 0.01）. SFRP2 methylation was higher in tumor tissue than in paired normal tissue （95% vs 65%, P 〈 0.05）. The DNA methylation status of the SFRP2 correlated inversely with the SFRP2 expression. To assess the potential role of SFRP2 in ESCC, we established stable SFRP2 transfectants and control counterparts by in- troducing pcDNA3.1/v5 hisA -SFRP2 or pcDNA3.1/v5 hisA -empty vector into KYSE30 cells lacking SFRP2 expression. After transfection, the forced-expression of SFRP2 was confirmed by the RT-PCR. In comparison with the control groups, stably-expressed SFRP2 in KYSE 30 cells significantly reduced colony formation in vitro （47.17% 4± 15.61% vs 17% ：1： 3.6%, P = 0.031） and tumor growth in nude mice （917.86：1：249.35 mm3 vs 337.23 ± 124.43 mm3, P 〈 0.05）. Using flow cytom- etry analysis, we found a significantly higher number of early apoptotic cells in SFRP2-transfected cells than in the control cells （P = 0.025）. The mean cell number in the S and G2-M phases of the cell cycle was also significantly lower in SFRP2-transfected KYSE30 cells compared with mock transfected counterparts. CONCLUSION： Silencing of SFRP2 expression through promoter hypermethylation may be a factor in ESCC carcinogenesis through loss of its tumor-suppressive activity.

Kremen2生物学功能研究进展

Kremen2 (kringle-containing transmembrane protein 2)是经典Wnt 信号通路中的重要调控因子。起初Kremen2 蛋白仅被认为是Wnt 信号通路的抑制因子,但后期研究发现Kremen2 蛋白在某些特定的生物环境中却发挥促进Wnt 信号通路活化的作用。在对Wnt 信号通路的调控过程中,Kremen2 蛋白需要与多种蛋白质调控因子相互作用,以参与胚胎发育、骨形成、肿瘤发生等多种生理病理过程。通过对Kremen2 相关研究文献的整理,本文综述了Kremen2 蛋白的发现与分子结构,以及其主要的相互作用因子和蛋白质功能,并提出了相关研究展望。