Inhibition and Mechanism of Imatinib on A549 Xenograft Tumor in Nude Mice via PDGF/PDGFR Pathway / 肿瘤防治研究

Objective To investigate the effect of imatinib on the growth of A549 non-small cell lung cancer transplanted tumors and the expression of PDGFB and PDGFRβ proteins in tumor tissues and stroma in nude mice and to explore the underlying tumor suppression mechanism. Methods A transplantation tumor model of A549 non-small cell lung cancer was established in nude mice. The mice were then randomly divided into four groups: control group (0.9%NaCl), low-dose imatinib group (50 mg/(kg·d)), medium-dose imatinib group (100 mg/(kg·d)), and high-dose imatinib group (200 mg/(kg·d)). The effect of different concentrations of imatinib administered by continuous gavage on tumor growth was observed for 28 days. HE staining was performed to observe the pathological changes of tumor tissues. The expression of PDGF/PDGFR pathway-related proteins and the phosphorylation levels of AKT and ERK1/2 proteins in tumor tissues were detected by Western blot analysis. Double immunofluorescence staining was used to detect the expression of PDGFB and PDGFRβ proteins in the tumor stroma. Results Imatinib inhibited the growth of A549 non-small cell lung cancer cells in nude mice, suppressed the expression of PDGFB in tumor tissues, and decreased the phosphorylation levels of PDGFRβ, AKT, and ERK1/2. The expression of PDGFB and PDGFRβ in tumor stromal fibroblasts of the administered group was significantly lower than that of the control group. Conclusion Imatinib exhibits a pronounced inhibitory effect on A549 xenografts of nude mice with non-small cell lung cancer, and its antitumor mechanism may involve the downregulation of PDGFB and PDGFRβ expression in tumor stromal fibroblasts.

Correlation between cerebrospinal fluid soluble platelet-derived growth factor receptor β and cognitive damage and cerebrospinal fluid core biological markers in Alzheimer′s disease / 中华神经科杂志

Objective:To investigate the relationship between the concentration of soluble platelet-derived growth factor receptor β (sPDGFRβ) in the cerebrospinal fluid (CSF) of patients with Alzheimer′s disease (AD) and the degree of cognitive impairment and cerebrospinal fluid biomarkers.Methods:A total of 50 patients with AD in the Department of Neurology of Provincial Hospital Affiliated to Anhui Medical University from September 2018 to August 2020 were selected as AD group, and 33 patients with normal cognition who had no significant difference in age and gender in the same period served as control group. The neuropsychological evaluation was conducted. According to the Clinical Dementia Rating scale scores, the AD patients were divided into mild AD group and moderate to severe AD group.The clinical data and cognitive function of the three groups were compared. And the level of CSF sPDGFRβ, CSF amyloid-β (Aβ) 1-40, CSF Aβ 1-42, CSF total tau protein (T-tau), CSF phosphorylated tau protein (P-tau) were measured by enzyme linked immunosorbent assay in each group. According to whether apolipoprotein E4 (ApoE4) gene was carried, the patients with AD were divided into ApoE4 + group and ApoE4 - group. Differences among the three groups were compared and the correlation analysis was carried out. Results:The levels of sPDGFRβ in the CSF of the mild AD group [(219.301±69.711) pg/ml] and the moderate to severe AD group [(235.358±86.187) pg/ml] were significantly higher than that of the control group [(184.878±52.944) pg/ml, F=3.90, P=0.024], while there was no significant difference in the level of CSF sPDGFRβ between the ApoE4 + group [(219.493±76.745) pg/ml] and the ApoE4 - group [(222.802±81.665) pg/ml, t=-0.13, P=0.900]. And the level of sPDGFRβ in the CSF in the mild AD group was positively correlated with the level of CSF P-tau ( r=0.43, P=0.019), but not correlated with Aβ 1-42, T-tau, Mini-Mental State Examination scores or Montreal Cognitive Assessment scores, whereas no significant correlation was found in the control group and the moderate to severe AD group. Conclusions:Expression of sPDGFRβ in CSF of AD patients is increased, and may relate to P-tau. Pericyte injury may be involved in the phosphorylation of tau protein in the brain of AD patients.

Preparation and application of a PDGFRβ-targeted near-infrared fluorescent probe for molecular optical imaging of lung cancer / 中国胸心血管外科临床杂志

@#Objective    To prepare platelet-derived growth factor receptor β (PDGFRβ)-targeted near-infrared molecular probe and evaluate its potential in optical molecular imaging of lung cancer. Methods    PDGFRβ-specific affibody Z-tri was recombinantly expressed in Escherichia coli (E. coli) and purified using affinity chromatography. In vitro cell-binding of Z-tri was analyzed by flow cytometry. Cellular distribution of Z-tri in tumor grafts was determined by protein-tracing. The molecular probe CF750-Z-tri was prepared by conjugating near-infrared fluorescent dye CF750 to Z-tri. The optical images of xenografts of lung cancer were obtained by using CF750-Z-tri combined with optical imaging system. Results    PDGFRβ-specific affibody Z-tri was highly expressed in E. coli and purified to homogeneity. Z-tri could bind PDGFRβ-positive cells but not PDGFRβ-negative cells cultured in vitro. In the tumor xenografts of human lung cancer, intravenously injected Z-tri was predominantly distributed on cells overexpressing PDGFRβ. The near infrared fluorescent dye CF750 was efficiently conjugated to Z-tri. Optical images with high contrast of lung cancer xenografts were produced by using the near-infrared fluorescent probe CF750-Z-tri combined with optical imaging system. Conclusion    The near-infrared fluorescent probe CF750-Z-tri can be used for optical imaging of human lung cancer, which takes great potential in optical imaging-guided surgery of lung cancer.

Changes of pdgfr-β+ microvascular wall cells in blood-brain barrier permeability of SD rats after status epilepticus / 国际儿科学杂志

Objective To investigate the blood-brain barrier permeability of platelet-derived growth factor receptor-β + (pdgfi-β +) vascular wall cells at 2h,24h,3 d,7 d,14 d and 21 d after lithium-pilocarpine-inducedstatus epilepticus.Methods One hundred and thirty-five clean male Sprague-Dawley rats were randomly divided into control group (n =15) and model group (n =120).The model group was divided into 2h,24h,3d,7d,14d and21d after SE.We evaluated the permeability of blood-brain barrier in hippocampus of rats in each group after status epilepticus by Evans blue method and wet and dry weight method.We observed the ultrastructural changes of pericytes and blood-brain barriers at different stages after onset by electron microscopy.We used Western Blot to detect the expression of pericyte marker pdgfr-β and α-SMA in hippocampus at different stages after onset.Results (1) The blood-brain barrier permeability increased after epileptic seizures (P ＜ 0.05),and the permeability was the highest at 24h after onset (P ＜ 0.01),and gradually returned to normal after 3d and later.(2) Transmission electron microscopy showed that the ultrastructure of cerebral microvascular pericytes and their basement membranes were degenerated after SE.(3) Western blot showed that the expression level of pdgfr-β and α-SMA at 24 h after SE was significantly higher than that of the control group (P ＜0.05),and gradually became stable after 3d and later.Conclusion Pdgfr-β + microvascular wall cells in brain microvessels may be involved in the opening of blood-brain barrier after status epilepticus,and may be dedicated to the conversion of disease into refractory epilepsy.

Mechanism of CCT2, a new downstream substrate of PDGFRα, on proliferation of tumor cells / 上海交通大学学报（医学版）

Objective: To study the molecular mechanism of chaperonin containing TCP1 subunit 2(CCT2), a new downstream substrate of platelet derived growth factor receptor α(PDGFRα), in tumorigenesis. Methods: Non-small cell lung cancer cell line H1703 was used. Western blotting was used to measure the phosphorylation of CCT2 upon PDGFRα inhibitor Gleevec treatment and PDGF stimulation. H1703 cells were divided into siCon group, siPDGFRα group and siCCT2 group; 48 h later, cell number counting was used to test the effect of CCT2 on cell growth after siRNA transfection. H1703 cells were divided into siCon group, siPDGFRα group, siAKT group and siCCT2 group; Western blotting was used to measure the protein level of PDGFRα and PARP. Cell fractionation was used to detect the cellular localization of CCT2 and co-immunoprecipitation was used to test the interaction between CCT2 and PDGFRα. Results: CCT2 phosphorylation was inhibited by Gleevec and induced by PDGF. Compared to the control group, the number of cells transfected by siCCT2 reduced by 30% (P=0.006). The protein level of PDGFRα was also decreased in siCCT2 transfected cells, whereas the cleavage of PARP was increased. CCT2 was localized in both cytoplasmic and membrane fractions and interacted with PDGFRα directly. Conclusion: CCT2 is a new downstream substrate of PDGFRα. CCT2 can promote tumor cells growth by interacting and stabilizing PDGFRα.

Effect of protease activated receptor 2 on colonic motility in diabetes mice / 上海交通大学学报（医学版）

Objective • To observe the effect of protease activated receptor 2 (PAR2) on the colonic motility in diabetic mice and investigate the mechanism. Methods • The mouse model of type 1 diabetes mellitus was established by intraperitoneal injection of streptozotocin. The smooth muscle strips and segments of colons were isolated. The effects of PAR2 agonist on colonic motility were observed by muscle strip tension contraction and colonic migrating motor complex experiments. The effect of small conductance calcium-activated potassium channel (SK3 channel) antagonist on it was also observed. Results • PAR2 agonist inhibited colonic motility and colonic smooth muscle was more sensitive to PAR2 agonist in diabetic mice. PAR2 agonist-induced inhibition was inhibited by SK3 channel antagonist. Conclusion • PAR2 activity in diabetic mice colons is significantly enhanced, which may inhibit colonic motility through SK3 channel.

The role of PDGF-D/PDGFR-β signaling in myocardial fibroplasia in rats resuscitated from cardiac arrest / 中华急诊医学杂志

Objective To investigate the effects of PDGF-D/PDGFR-β signaling on interstitial collagen hyperplasia and fibroplasia of myocardium following cardiopulmonary resuscitation (CPR)in rats.Methods A total of 90 male Sprague-Dawley (SD) rats were randomly (random number) assigned into 5 groups:sham,control,Imatinib,Ad-GFP and Ad-PDGFR groups.Each group was further subdivided into post-resuscitation (PR) 4 h and PR 72 h groups.The ventricular fibrillation cardiopulmonary resuscitation (CPR) model was used.Cardiac collagen volume fraction (CVF) was measured with Sirius red staining.Platelet derived growth factor D (PDGF-D) was detected by enzyme-linked immunosorbent assay (ELISA).Collagen Ⅰ,α smooth muscle actin (α-SMA),vimentin and PDGF receptor β (PDGFRβ) were detected by Western blot.The data were analyzed by a two-way ANOVA and Bonferroni test.P ＜0.05 was considered statistically significant.Results (1) At PR 72 h,the CVF value in the control group was significantly higher than that in the sham group [(11.24 ± 0.31) vs (1.65 ± 0.19),t =10.81,P ＜0.05] and in the Ad-PDGFR group significantly higher than that in Ad-GFP group [(25.60 ±4.09) vs (10.73 ± 2.42),t =16.77,P ＜0.05],respectively.Compared to the control group,the level of CVF in the Imatinib group significantly decreased [(5.11 ± 0.29)vs (11.24 ± 0.31),t =3.892,P ＜0.05].(2) At PR 4 h,compared with the sham group,the expression of serum PDGF-D was greatly increased in the control,Imatinib,Ad-GFP and Ad-PDGFR groups (all P＜0.05).At PR 72 h,serum PDGF-D was continuously significantly higher in the Ad-PDGFR group when compared with the sham group [(296.46± 30.82) pg/mL vs (93.74 ± 5.43) pg/mL,t =7.755,P ＜0.05].(3) At PR 72 h,the expression of Collagen I,α-SMA,Vimentin and PDGFR-β in the control and Ad-PDGFR groups were significantly increased than those in the sham and Ad-GFP groups,respectively (all P＜0.05).However,compared with the control group,Imatinib significantly decreased the expressions of the above proteins (all P＜0.05).Conclusions The interstitial collagen hyperplasia and fibroplasia of myocardium at 72 h following CPR in rats might be related to the increased levels of PDGF-D in serum and PDGFR-β in myocardium.

Pathomechanisms of pericyte-myofibroblast transition in kidney and interventional effects of Chinese herbal medicine / 中国中药杂志

In the kidney, pericyte is the major source of myofibroblast (MyoF) in renal interstitium. It is reported that pericyte-myofibroblast transition（PMT）is one of the important pathomechanisms of renal interstitial fibrosis（RIF）. Among them, the main reasons for promoting RIF formation include pericyte recruitment, activation and isolation, as well as the lack of pericyte-derived erythropoietin. During the PMT startup process, pericyte activation and its separation from microvessels are controlled by multiple signal transduction pathways, such as transforming growth factor-β（TGF-β）pathway, vascular endothelial growth factor receptor (VEGFR) pathway and platelet derived growth factor receptor (PDGFR) pathway;Blocking of these signaling pathways can not only inhibit PMT, but also suppress renal capillaries reduction and further alleviate RIF. In clinic, many traditional Chinese medicine compound prescriptions, single traditional Chinese herbal medicine (CHM) and their extracts have the clear effects in alleviating RIF, and some of their intervention actions may be related to pericyte and its PMT. Therefore, the studies on PMT and its drug intervention will become the main development direction in the research field of anti-organ fibrosis by CHM.

Genetic association between corneal curvature-related genes and high myopia in Chinese Han population / 中华实验眼科杂志

Background High myopia is one of the primary factors of visual impairment,and its prevention and management are researching hot topics.Corneal curvature (CC) measures the steepness of the cornea which is an important parameter leading to myopia.Genome-wide association study (GWAS) showed that several genes are associated with CC in Asian populations.However,the association of corneal curvature-related genes with high myopia is unclear up to now.Objective This study was to investigate the association between single nucleotide polymorphism (SNP) in the rs74225573 (mechanistic target of rapamycin [MTOR]),rs60078183 (cytidine/uridine monophosphate kinase 1 [CMPK1]),rs1800813 (platelet derived growth factor receptor alpha [PDGFRA]),rs11204213 (retinol binding protein 3 [RBP3]) and high myopia in Chinese Han population.Methods A prospective cohort study was performed.Four hundreds and eighty-three patients with high myopia were collected in Sichuan Provincial People's Hospital from February 2012 to August 2013,with the diopter (-10.84±4.69)D in the right eyes and (-10.35±4.67)D in the left eyes or ocular axial length of (28.15±2.27)mm in the right eyes and (27.72±2.51)mm in the left eyes.Five hundreds and nineteen normal volunteers matched in age and gender were included in the same period as controls,and all the subjects were Chinese Han people without genetic relationship.The periphery blood of 4 ml was obtained for the DNA extraction from each subject under the written informed consent.The primers of rs74225573,rs60078183,rs1800813 and rs1 1204213 were designed based on the information of NCBI website.The four SNPs were amplified by real-time PCR and genotyped by SNaPshot method.Results All the genotype frequencies of these four SNPs were in Hardy-Weinberg equilibrium (HWE).There are no significant differences in minor allele frequency (MAF) distribution of rs74225573,rs60078183 and rs11204213 between high myopia group and normal control group (rs74225573:Pag-corrected =0.935,OR =0.98;rs60078183:Page-currected =0.782,OR =1.04;rs11204213:Page-currected =0.058,OR =1.66),and the M AF of rs1800813 was significantly higher in the high myopia group than that in the normal control group (Page-currected =0.001,OR =0.64).The genotype frequency of rs74225573,rs60078183 and rs11204213 was not evidently different in additive model 1 (AB vs.BB),additive model 2 (AA vs.BB),dominant model (AA+AB vs.BB) and recessive model (AA vs.AB+BB) (all at P＞0.05),while significant differences were found in genotype frequency of rs1800813 both in additive model 1 and dominant model (additive model 1:P=0.002,OR=0.59;dominant model:P=0.001,OR=0.58).Conclusions The SNP of rs1800813 in the PDGFRA gene is associated with the pathogenesis of high myopia in the Chinese Han population,but the SNPs of rs74225573 (MTOR gene),rs60078183 (CMPK1 gene) and rs11204213 (RBP3 gene) appear to be not associated with high myopia.

Effects of PDGFRα on melanocyte apoptosis induced by hydrogen perox-ide / 中国病理生理杂志

AIM:To investigate the effects of platelet-derived growth factor receptor α(PDGFRα) on melano-cyte apoptosis induced by hydrogen peroxide(H2O2). METHODS:Melanocyte PIGI was used as the research object. Af-ter exposed to H2O2at different concentrations,the cell viability was detected by MTT assay. The PIGI cells were transfec-ted with empty vector pCMV6 or PDGFRα over-expression vector pCMV6-PDGFRα. The transfection efficiency was deter-mined by RT-qPCR and Western blot. The effect of H2O2on the viability of the PIGI cells after over-expression of PDGFRα was measured by MTT assay. The cell apoptosis was analyzed by flow cytometry. The protein levels of p38, p-p38 and cleaved caspase-3 in the cells were detected by Western blot. DCDHF-DA was used to estemate the generation of reactive oxygen species (ROS) in the cells. RESULTS:The viability of PIGI cells decreased after exposed to H2O2(P<0.05), and the half maximal inhibitory concentration of H2O2was 0.7 mmol/L. Transfection with PDGFRα over-expression vector successfully induced high expression of PDGFRα at mRNA and protein levels in the PIGI cells,and increased the viability of the cells with H2O2treatment(P<0.05). Over-expression of PDGFRα decreased the apoptotic rate of PIGI cells trea-ted with H2O2(P<0.05),and the level of ROS in the cells(P<0.05). The protein levels of cleaved caspase-3 and p-p38 were also decreased (P <0.05). CONCLUSION:PDGFRα inhibits the apoptosis of melanocytes induced by H2O2,partially reverses the growth inhibition of melanocytes by H2O2,and decreases the ROS level. The mechanism may be related to regulating the protein levels of p-p38 and cleaved caspase-3 in the cells.

Efficacy of Imatinib in Patients with Platelet-Derived Growth Factor Receptor Alpha-Mutated Gastrointestinal Stromal Tumors / Journal of the Korean Cancer Association, 대한암학회지

PURPOSE: The incidence of gastrointestinal stromal tumors (GISTs) harboring platelet-derived growth factor receptor alpha (PDGFRA) mutations is low, therefore further investigation of the efficacy of imatinib in this subgroup was needed. MATERIALS AND METHODS: Patients with PDGFRA-mutant GISTs who received imatinib as primary therapy for advanced disease between January 2000 and June 2012 were identified from the GIST registry of Asan Medical Center, Seoul, Korea. RESULTS: KIT and PDGFRA genotyping in 823 patients identified 18 patients (2%) with PDGFRA mutations who were treated with first-line imatinib. Exon 18 D842V substitution, non-D842V exon 18 mutations, and exon 12 mutations were detected in nine (50%), four (22%), and five (28%) patients, respectively. Objective response rate differed significantly between patients with the D842V mutation and those with non-D842V mutations (0% [0/5] vs. 71% [5/7], p=0.03). In all patients, median progression-free survival (PFS) and overall survival (OS) was 24.8 months (95% confidence interval [CI], 0.0 to 57.2) and 51.2 months (95% CI, 37.1 to 65.3), respectively. Significantly, poorer PFS was observed for patients with D842V-mutant GISTs than those with non-D842V PDGFRA-mutant GISTs: median 3.8 months (95% CI, 1.4 to 6.3) versus 29.5 months (95% CI, 18.3 to 40.7) (p < 0.001). Patients with the D842V mutation had poorer OS than those with non-D842V PDGFRA mutations: median 25.2 months (95% CI, 12.7 to 37.8) versus 59.8 months (95% CI, 43.0 to 76.5) (p=0.02). CONCLUSION: Imatinib is active against non-D842V PDGFRA-mutant GISTs, whereas GISTs harboring the D842V mutation are primarily resistant to imatinib.

Role of PDGFR-βsignal pathway in morphine tolerance / 医学研究生学报

Objective Beta platelet-derived growth factor receptor ( PDGFR-β)-mediated signaling plays a key role in mor-phine tolerance , but its molecular mechanisms are not yet completely understood .The present study aims to investigate whether the ex-tracellular signal-regulated kinase ( ERK) and cyclic AMP response element binding protein ( REB) signaling pathways are involved in the development of PDGFR-βactivation-induced morphine tolerance in rats . Methods Thirty-six adult male SD rats were randomly divided into six groups of equal number:normal saline (20μL), morphine (15μg), morphine +imatinib (morphine 15μg +ima-tinib 10μg), morphine +PDGF-BB (morphine 15μg +PDGF-BB 10 ng), imatinib (10μg), and PDGF-BB (10 ng), all treated intrathecally at 20μL once daily for 7 consecutive days .Paw withdrawal latency ( PWL ) was measured 1 d before and 30 min after medication at 1, 3, 5, and 7 days, respectively, followed by calculation of the maximal possible effect of analgesia (MPE).On the 8th day, PWL was again obtained from all the rats at 30 min after intrathecal injection of morphine (15μg).Then, all the animals were sacrificed and the L4-5 segment of the spinal cord was isolated for determination of the expressions of ERK , phosphorylated ERK ( p-ERK) , CREB, and phosphorylated CREB ( p-CREB) by Western blot. Results At 5 and 7 days after medication, MPE was significant decreased in the morphine group ([52.90 ±8.20] and [15.12 ±3.80] %) and the morphine +PDGF-BB group ([43.51 ±5.42] and [14.81 ±3.60] %) as compared with (100.00 ± 0.00) %in both groups at 1 day (P<0.05), but had no significant changes in the morphine +imatinib group at 1, 3, 5, and 7 days.After intrathecal injection of morphine on the 8th day, MPE was (16.22 ±2.51) %in the morphine group, (15.22 ±3.50) %in the morphine +PDGF-BB group, and (35.21 ±4.51) %in the PDGF-BB group, all remarkably lower than (100.00 ±0.00) %in the control group (P<0.05).There were no significant differences in the expression levels of ERK and CREB among the six groups.The expressions of spinal p-ERK and p-CREB were markedly increased in the morphine , morphine +PDGF-BB, and PDGF-BB groups as compared with the control group (P<0.05), but significantly decreased in the morphine +imatinib group in compari-son with the morphine group, (P<0.05). Conclusion The PDGFR-βsignaling pathway plays an important role in the develop-ment of tolerance to morphine-induced analgesia and its underlying mechanisms may be associated with the activation of the ERK and CREB pathways .

Serum Response Factor Is Essential for Prenatal Gastrointestinal Smooth Muscle Development and Maintenance of Differentiated Phenotype

BACKGROUND/AIMS: Smooth muscle cells (SMCs) characteristically express serum response factor (SRF), which regulates their development. The role of SRF in SMC plasticity in the pathophysiological conditions of gastrointestinal (GI) tract is less characterized. METHODS: We generated SMC-specific Srf knockout mice and characterized the prenatally lethal phenotype using ultrasound biomicroscopy and histological analysis. We used small bowel partial obstruction surgeries and primary cell culture using cell-specific enhanced green fluorescent protein (EGFP) mouse lines to study phenotypic and molecular changes of SMCs by immunofluorescence, Western blotting, and quantitative polymerase chain reaction. Finally we examined SRF change in human rectal prolapse tissue by immunofluorescence. RESULTS: Congenital SMC-specific Srf knockout mice died before birth and displayed severe GI and cardiac defects. Partial obstruction resulted in an overall increase in SRF protein expression. However, individual SMCs appeared to gradually lose SRF in the hypertrophic muscle. Cells expressing low levels of SRF also expressed low levels of platelet-derived growth factor receptor alpha (PDGFRalphalow) and Ki67. SMCs grown in culture recaptured the phenotypic switch from differentiated SMCs to proliferative PDGFRalphalow cells. The immediate and dramatic reduction of Srf and Myh11 mRNA expression confirmed the phenotypic change. Human rectal prolapse tissue also demonstrated significant loss of SRF expression. CONCLUSIONS: SRF expression in SMCs is essential for prenatal development of the GI tract and heart. Following partial obstruction, SMCs down-regulate SRF to transition into proliferative PDGFRalphalow cells that may represent a phenotype responsible for their plasticity. These findings demonstrate that SRF also plays a critical role in the remodeling process following GI injury.

5,8-Dimethoxy-2-Nonylamino-Naphthalene-1,4-Dione Inhibits Vascular Smooth Muscle Cell Proliferation by Blocking Autophosphorylation of PDGF-Receptor beta

As the abnormal proliferation of vascular smooth muscle cells (VSMCs) plays a critical role in the development of atherosclerosis and vascular restenosis, a candidate drug with antiproliferative properties is needed. We investigated the antiproliferative action and underlying mechanism of a newly synthesized naphthoquinone derivative, 5,8-dimethoxy-2-nonylamino-naphthalene-1,4-dione (2-nonylamino-DMNQ), using VSMCs treated with platelet-derived growth factor (PDGF). 2-Nonylamino-DMNQ inhibited proliferation and cell number of VSMCs induced by PDGF, but not epidermal growth factor (EGF), in a concentration-dependent manner without any cytotoxicity. This derivative suppressed PDGF-induced [3H]-thymidine incorporation, cell cycle progression from G0/G1 to S phase, and the phosphorylation of phosphor-retinoblastoma protein (pRb) as well as the expression of cyclin E/D, cyclin-dependent kinase (CDK) 2/4, and proliferating cell nuclear antigen (PCNA). Importantly, 2-nonylamino-DMNQ inhibited the phosphorylation of PDGF receptorbeta(PDGF-Rbeta) enhanced by PDGF at Tyr579, Tyr716, Tyr751, and Tyr1021 residues. Subsequently, 2-nonylamino-DMNQ inhibited PDGF-induced phosphorylation of STAT3, ERK1/2, Akt, and PLCgamma1. Therefore, our results indicate that 2-nonylamino-DMNQ inhibits PDGF-induced VSMC proliferation by blocking PDGF-Rbeta autophosphorylation, and subsequently PDGF-Rbeta-mediated downstream signaling pathways.

Influence of PDZK1 on the initiation and development of gastric cancer via PDGFR-β pathway / 国际外科学杂志

As the second cause of cancer relative deaths,gastric cancer's different biological characteristics lead to obviously different treatment results and prognosis.The mechanism to determine the initiation,lead to obviously different development and the biological characreristics of gastric cancer is doctors' interest.Recently,platelet-de-rived growth factor receptor-β (PDGFR-β) become one of hot research fields,its excessive activation and abnormal expression can induce tumor angiogenesis,and promote tumor growth,and can also degrade extracellular matrix,reduce the number of cell adhesion molecular.Through these,PDGFR-β was directly or indirectly involved in tumor invasion and metastasis.PDZK1 can bind with PDGFR-β specifically and futher affect the downstream of PDGFR-β signaling pathway (Ras-MAPK signaling pathway,the PI3K-Akt signaling pathway,PLC signaling pathway),and then affect cell proliferation,differentiation and migration.

Isosorbide mononitrate upregulates platelet-derived growth factor receptor β and promotes angiogenesis in zebrafish / 第二军医大学学报

Objective To investigate the pro-angiogenesis mechanism of isosorbide mononitrate by observeing its effect on the angiogenesis in Tg(flk1:EGFP) transgenic zebrafish. Methods The embryos incubated with isosorbide mononitrate (100, 300, 500, and 1 000 μg/ml) were taken as the experiment groups, and the embryos exposed to 0. 5% DMSO were identified as the controls. The embryos were treated one hour before the postfertilization stage, and the status and length of the newly- formed blood vesseis were observed under fluorescence microscope 24-26 h after treatments. The total RNAs were extracted from zebrafish embryos at 0, 6, 12, and 24 h after treatment; real-time quantitative RT-PCR was performed to examine the ievel of Platelet-derived growth factor receptor β(PDGFRβ). Resutts Isosorbide mononitrate greatly promoted the growth of the intersegmental vessels in zebrafish (P<0. 01). It also dose-dependently promoted the growth of vascular at concentrations 100, 300, and 500 μg/ml. The expression levels of PDGFRβ gene were increased in the experiment groups compared with DMSO group, with significant difference found at 12 h and 24 h after treatment (P<0. 05, P<0. 01). Conclusion Our data suggest that isosorbide mononitrate can up-regulate PDGFRf expression and promote angiogenesis in zebrafish.

Mutation-Free Expression of c-Kit and PDGFRA in Phyllodes Tumors of the Breast / 한국유방암학회지

PURPOSE: Phyllodes tumors (PTs) of the breast have been classified as benign, borderline, or malignant based on their histopathologic features. However, predicting clinical behavior based on these features has proven to be difficult given that local recurrence occurs in both benign and malignant PTs. Recurrence has been shown to mirror the histologic pattern of the primary tumor or to show dedifferentiation. The aim of this study was to assess the value of the histopathologic parameters, expression or mutation of c-Kit and platelet derived growth factor receptor alpha (PDGFRA) in predicting tumor recurrence. METHODS: Representative areas from 39 benign, 16 borderline, and 12 malignant PTs were selected for construction of tissue microarrays. Immunohistochemical analyses for p53, Ki-67, c-Kit, and PDGFRA were performed and SSCP-PCR analysis was carried out to identify mutations in exons 9, 11, 13, and 17 of the c-Kit gene and exons 12 and 18 of the PDGFRA gene. Clinicopathologic features, including tumor recurrence and margin status, were also evaluated. RESULTS: Of the 67 PTs, 11 cases (16.4%) recurred from 3 to 92 months following initial diagnosis (4 benign, 2 borderline, and 5 malignant). One benign PT case recurred as a borderline tumor and two borderline PT cases recurred as malignancies. Three patients died of malignant PT. No mutations of the c-Kit or PDGFRA genes were found and there was no statistically significant association of either p53 or p16 immunostaining with recurrent disease (p>0.05). However, histologic grade (p=0.033), margin status (p<0.001), Ki-67 (p=0.012), c-Kit (p=0.002), and PDGFRA (p=0.007) stromal immunopositivity were significantly correlated with recurrence. CONCLUSION: Even though positive or close margins were significantly associated with tumor recurrence, stromal c-Kit, PDGFRA positivity, and the Ki-67 index were useful for predicting recurrent PTs. Despite this, no c-Kit or PDGFRA mutations were found.

Gene mutation and prognosis of extragastrointestinal stromal tumor / 中华普通外科杂志

Objective To evaluate prognostic significance of c-kit and PDGFR-α gene mutation in extragastrointestinal stromal tumors(EGIST). Methods Paraffin embedded tissue specimens from 23 EGISTs were tested for CD117,CD34 and Ki-67 expression by immunohistochemical method.EGIST cases were also tested for the presence of c-kit exons 9,11,13,17 mutations and PDGFR-α exons 12,18 mutations.Kaplan-meier survival rate was used to evaluate the prognostic factors. Results Of 23 cases of EGIST,23(100%)were positive for CD117,17(74%)were positive for CD34.For Ki-67 labeling index(Ki-67 LI):30%were＜1%,44%were between 1%-5%,26%were＞5%.C-kit mutations were detected in 44% of EGIST patients and all were of exon 11 mutations.PDGFR-α mutations were found in 13%of all the 23 cases and all were of exon 18 mutations(The commonest type of mutation D842V).Survival analysis indicated that mitotic count and Ki-67 index were significant predictors for survival.Conclusion The pattern of c-kit and PDGFR-α mutation in EGIST was essentially similar to that in GIST.But the mutation frequency of PDGFR-α was slightly higher in EGIST than in GIST.EGIST could be a special subtype of GIST.The results of this study also show combination of mitotic counts and Ki-67 labeling index may be useful for predicting the prognosis of EGIST.

Effect of Ligustrazine on Expression of Platelet-Derived Growth Factor-? Receptor and Extracellular Signal Regulated Kinase in Neonatal Rat Cardiac Myocytes in Vitro Induced by Angiotensin Ⅱ / 实用儿科临床杂志

Objective To investigate the effect of ligustrazine on the expression of platelet-derived growth factor-?(PDGF-?) receptor and extracellular signal regulated kinase(ERK1/2) induced by angiotensin Ⅱ(AngⅡ) in cardiac myocytes,and explore the mechanism of therapeutic.Methods Cultured cardiac myocytes of neonatal rats were treated with 10-7 mol/L AngⅡ as Ang Ⅱ group,10-7 mol/L AngⅡ plus 10 mg/L ligustrazine as ligustrazine group,the normally cultured neonatal rat cardiac myocytes as control group.Protein synthesis was measured by -leucine incorporation,and the expression of PDGF-? receptor and ERK1/2 was detected by Western blot.SPSS 11.0 software was used to analyze the data.Results There were significant differences among 3 groups(F=20.71 P

Inhibitory effect of ethanol extract from Java Brucea Fruit on cell migration mediated by platelet-derived growth factor receptor ? / 吉林大学学报(医学版)

Objective To study the effects of ethanol extract from Java Brucea Fruit on platelet-derived growth factor receptor ?(PDGFR?) mediated cell migration and to obtain the valuable messages on the characteristics of its active ingredient.Methods PAE cells was transfected with the vector expressing human PDGFR? with Transfectom 2000;After screening by G418 resisitance,RT-PCR was used to monitor the expression of PDGFR? in the cells;Wound healing of the cells was used to examine the lowest consistency of PDGFBB and inhibitory effect of ethanol extract of Java Brucea Fruit on cell migration after restoring 24 h.Results Human PDGFR? was stably expressed in PAE cells transfected with the expressing vector.The lowest consistency of exogenous PDGFBB which promoted PDGFR? mediated cell migration was 10 ?g?L-1.70% ethanol extract of Java Brucea Fruit which strongly inhibited PDGFR? mediated cell migration was dose-dependent(P10 ?g?L-1) mainly caused the death of the cell.Conclusion Ethanol extract of Java Brucea Fruit has a strongly inhibitory effect on the PDGFR? mediated cell migration which could play a major role in its effects against metastasis of malignant tumor,the active ingredients of it could be more dissolvable in the 70% ethanol.