Expression and functional characterization of platelet-derived growth factor receptor-like gene

AIM:To investigate the role of platelet-derived growth factor receptor-like gene(PDGFRL)in the anti-cancer therapy for colorectal cancers(CRC).METHODS:PDGFRL mRNA and protein levels were measured by reverse transcription-polymerase chain reaction(RT-PCR)and immunohistochemistry in CRC and colorectal normal tissues.PDGFRL prokaryotic expression vector was carried out in Escherichia coli(E.coli),and purified by immobilized metal affinity chromatography.The effect of PDGFRL protein on CRC HCT-116 cells was detected by 3-(4,5-dimethylthiazolyl-2)-2,5-diphenyltetrazolium bromide(MTT),clone counting,cell cycle,and wound healing assay.RESULTS:Both RT-PCR and immunohistochemistry showed that the expression of PDGFRL in colorectal normal tissues was higher than in cancer tissues.Recombinant pET22b-PDGFRL prokaryotic expression vector was successfully expressed in E.coli,and the target protein was expressed in the form of inclusion bodies.After purification and refolding,recombinant human PDGFRL(rhPDGFRL)could efficiently inhibit the proliferation and invasion of CRC HCT-116 cells detected by MTT,clone counting and wound healing assay.Moreover,rhPDGFRL arrested HCT-116 cell cycling at the G0/G1 phase.CONCLUSION:PDGFRL is a potential gene for application in the anti-cancer therapy for CRC.

Enhanced expression of epidermal growth factor receptor gene in gastric mucosal cells by the serum derived from rats treated with electroacupuncture at stomach meridian acupoints

AIM: To investigate the effect of serum derived from rats treated with electroacupuncture at stomach meridian acupoints on the expression of epidermal growth factor receptor (EGFR) gene in gastric mucosal cells. METHODS: The stress-induced gastric mucosal injury in rat model was established by water-immersion and restrained stress methods. 52 rats were randomly divided into: normal group (n = 8), model group (n = 8), model serum group (n = 12), stomach serum group (n = 12), and gallbladder serum group (n = 12). The gastric mucosal cells were separated by pronase-EDTA digestion method and incubated with serum. The EGFR gene expression in gastric mucosal cells was detected by reverse transcription-polymerase chain reaction (RT-PCR) method. RESULTS: Compared with normal group (0.6860 ± 0.0594), the serum derived from rats of the stomach group (1.2272 ± 0.0813, P = 0.00 < 0.01) and gallbladder group (0.9640 ± 0.0387, P = 0.00 < 0.01) had a tendency to enhance the EGFR gene expression in gastric mucosal cells. Such tendency existed in the model group (0.7104 ± 0.0457) but with no signifi cant difference (P = 0.495 > 0.05) and in model serum group (0.8516 ± 0.0409) with an extremely obvious difference (P = 0.001 < 0.01). Furthermore, the EGFR gene expression in stomach serum group was significantly higher than that in gallbladder serum group (P = 0.00 < 0.01). CONCLUSION: The present study shows that serumderived from rats treated with electroacupuncture at stomach meridian acupoints can distinctly increase the EGFR gene expression of gastric mucosal cells. Therefore, there is certain meridian specificity in the serum, which could provide a proof for the TCM theory “particular relation between meridian and internal organ”.

Implication of platelet-derived growth factor receptor alpha in prostate cancer skeletal metastasis

Metastasis represents by far the most feared complication of prostate carcinoma and is the main cause of death for patients.The skeleton is frequently targeted by disseminated cancer cells and represents the sole site of spread in more than 80% of prostate cancer cases.Compatibility between select malignant phenotypes and the microenvironment of colonized tissues is broadly recognized as the culprit for the organ-tropism of cancer cells.Here,we review our recent studies showing that the expression of platelet-derived growth factor receptor alpha(PDGFR a) supports the survival and growth of prostate cancer cells in the skeleton and that the soluble fraction of bone marrow activates PDGFR a in a ligand-independent fashion.Finally,we offer pre-clinical evidence that this receptor is a viable target for therapy.

Prolonged propagation of rat neural stem cells relies on inhibiting autocrine/paracrine bone morphogenetic protein and platelet derived growth factor signals

Continuous expansion of rat neural stem cell lines has not been achieved due to proliferation arrest and spontaneous differentiation in vitro. In the current study, neural precursor cells derived from the subventricular zone of adult rats spontaneously underwent astroglial and oligodendroglial differentiation after limited propagation. This differentiation was largely induced by autocrine or paracrine bone morphogenetic protein and platelet derived growth factor signals. The results showed that, by inhibiting bone morphogenetic protein and platelet derived growth factor signals, adult rat neural precursor cells could be extensively cultured in vitro as tripotent stem cell lines. In addition to adult rat neural stem cells, we found that bone morphogenetic protein antagonists can promote the proliferation of human neural stem cells. Therefore, the present findings illustrated the role of autocrine or paracrine bone morphogenetic protein and platelet derived growth factor signaling in determining neural stem cell self-renewal and differentiation. By antagonizing both signals, the long-term propagation of rat neural stem cell lines can be achieved.

Deficiency of platelet-derived growth factor receptor-α-positive cells in Hirschsprung's disease colon

AIM: To investigate whether the expression of platelet-derived growth factor receptor-α-positive (PDGFRα+)-cells is altered in Hirschsprung’s disease (HD).METHODS: HD tissue specimens (n = 10) were collected at the time of pull-through surgery, while colonic control samples were obtained at the time of colostomy closure in patients with imperforate anus (n = 10). Immunolabelling of PDGFRα+-cells was visualized using confocal microscopy to assess the distribution of these cells, while Western blot analysis was undertaken to quantify PDGFRα protein expression.RESULTS: Confocal microscopy revealed PDGFRα+-cells within the mucosa, myenteric plexus and smooth muscle in normal controls, with a marked reduction in PDGFRα+-cells in the HD specimens. Western blotting revealed high levels of PDGFRα protein expression in normal controls, while there was a striking decrease in PDGFRα protein expression in the HD colon.CONCLUSION: These findings suggest that the altered distribution of PDGFRα+-cells in both the aganglionic and ganglionic HD bowel may contribute to the motility dysfunction in HD.

Vascular endothelial growth factor/platelet-derived growth factor receptor pathway is involved in bone marrow mesenchymal stem cell differentiation and directional migration toward gliomas

BACKGROUND： Vascular endothelial growth factor （VEGF） induces bone marrow-derived mesenchymal stem cell （BMSC） differentiation into vascular endothelial-like cells and promotes BMSC migration toward gliomas. However, the molecular mechanisms by which VEGF induces BMSC differentiation and migration remain poorly understood. OBJECTIVE; To investigate the role of platelet-derived growth factor （PDGF） receptor （PDGFR） in BMSC differentiation and migration induced by VEGE DESIGN, TIME AND SETTING： A parallel, controlled, in vitro experiment was performed at the Molecular Neurobiology ＆ Neural Regeneration and Repairing Laboratory, Anhui Provincial Hospital of Anhui Medical University, China from June 2008 to March 2009. MATERIALS： U87 glioma cells were purchased from Shanghai Institutes for Biological Sciences; mouse anti-human PDGFR and VEGF receptor （VEGFR） monoclonal antibodies were purchased from Peprotech, USA. METHODS： Isolated BMSCs were precultured with neutralizing antibody for VEGFR-1, VEGFR-2, PDGFR-α, and PDGFR-β to block biological activity of related receptors, followed by induced differentiation with 50μg/L VEGF. BMSCs induced with 50μg/L VEGF alone served as the VEGF-induced group. The control group remained untreated. MAIN OUTCOME MEASURES： Cell surface markers were identified by flow cytometry; BMSC surface cytokine receptor expression was detected by reverse transcription-polymerase chain reaction; the Transwell model was used to observe cell migration. RESULTS： After blocking the PDGFR, VEGF did not induce BMSC cell surface marker CD-31 or von Willebrand factor （vWF） expression. However, inhibition with VEGF receptor blocking agents, VEGF induced BMSCs to express CD-31 and vWE Following inhibition of the PDGFR, the number of cells migrating through the polycarbonate membrane Transwell chamber was decreased, as well as the number of BMSCs migrating to glioma cells. However, through the use of VEGF receptor blocking agents, the number of migrating cells remained unchanged. VEGF preculture increased the number of BMSCs migrating to gliomas. CONCLUSION： VEGF interacts with PDGFRs on the BMSC surface to attract BMSC directional migration and induce BMSC differentiation. The VEGF/PDGFR pathway participates in BMSC directional migration to glioma. VEGF pretreatment increased efficiency of BMSC migration to glioma.

Association of hepatocyte-derived growth factor receptor/caudal type homeobox 2 co-expression with mucosal regeneration in active ulcerative colitis

AIM:To characterize the regeneration-associated stem cell-related phenotype of hepatocyte-derived growth factor receptor(HGFR)-expressing cells in active ulcerative colitis(UC).METHODS:On the whole 38 peripheral blood samples and 38 colonic biopsy samples from 18 patients with histologically proven active UC and 20 healthy control subjects were collected.After preparing tissue microarrays and blood smears HGFR,caudal type homeobox 2(CDX2),prominin-1(CD133) and Musashi-1conventional and double fluorescent immunolabelings were performed.Immunostained samples were digitalized using high-resolution Mirax Desk instrument,and analyzed with the Mirax TMA Module software.For semiquantitative counting of immunopositive lamina propria(LP) cells 5 fields of view were counted at magnification x 200 in each sample core,then mean ± SD were determined.In case of peripheral blood smears,30 fields of view with 100 μm diameter were evaluated in every sample and the number of immunopositive cells(mean ± SD) was determined.Using 337 nm UVA Laser MicroDissection system at least 5000 subepithelial cells from the lamina propria were collected.Gene expression analysis of HGFR,CDX2,CD133,leucine-rich repeat-containing G-protein coupled receptor 5(Lgr5),Musashi-1 and cytokeratin20(CK20) were performed in both laser-microdisscted samples and blood samples by using real time reverse transcription polymerase chain reaction(RT-PCR).RESULTS:By performing conventional and double fluorescent immunolabelings confirmed by RT-PCR,higher number of HGFR(blood:6.7 ± 1.22 vs 38.5 ±3.18;LP:2.25 ± 0.85 vs 9.22 ± 0.65;P < 0.05),CDX2(blood:0 vs 0.94 ± 0.64;LP:0.75 ± 0.55 vs 2.11± 0.75;P < 0.05),CD133(blood:1.1 ± 0.72 vs 8.3± 1.08;LP:11.1 ± 0.85 vs 26.28 ± 1.71;P < 0.05)and Musashi-1(blood and LP:0 vs scattered) positive cells were detected in blood and lamina propria of UC samples as compared to controls.HGFR/CDX2(blood:0 vs 1± 0.59;LP:0.8 ± 0.69 vs 2.06 ± 0.72,P < 0.05)and Musashi-1/CDX2(blood and LP:0 vs scattered) coexpressions were found in blood and lamina propria of UC samples.HGFR/CD133 and CD133/CDX2 coexpressions appeared only in UC lamina propria samples.CDX2,Lgr5 and Musashi-1 expressions in UC blood samples were not accompanied by CK20 mRNA expression.CONCLUSION:In active UC,a portion of circulating HGFR-expressing cells are committed to the epithelial lineage,and may participate in mucosal regeneration by undergoing mesenchymal-to-epithelial transition.

KIT and platelet-derived growth factor receptor α wild-type gastrointestinal stromal tumor associated with neurofibromatosis type 1: Two case reports

BACKGROUND Gastrointestinal stromal tumors(GISTs) associated with neurofibromatosis are uncommon compared to their gastrointestinal counterparts. Patients with neurofibromatosis type 1(NF-1) have an increased risk of developing gastrointestinal tumors, including rare types such as GIST.CASE SUMMARY A 60-year-old male Chinese patient was diagnosed with NF-1 10 years ago and presented with upper abdominal discomfort and black stools. Endoscopic ultrasonography and an enhanced abdominal computed tomography scan revealed a mass located 4 cm from the muscular layer of the descending duodenum. A 59-year-old Chinese woman who was diagnosed with NF-1 25 years ago presented with sudden unconsciousness and black stools. Multiple masses in the duodenum were noted by echogastroscopy and an enhanced abdominal computed tomography scan. Both patients presented with cutaneous neurofibromas. The histologic examination of tumors from both patients revealed spindle cells and low mitotic activity. Immunohistochemically, the tumor cells showed strong positivity for KIT(CD117), DOG-1, CD34, and Dehydrogenase Complex Subunit B, and negativity for SMA, desmin, S-100, and β-catenin. None of the six tumors from two patients had KIT exon 9, 11, 13, or 17 or platelet-derived growth factor receptor α exon 12 or 18 mutation, which is a typical finding for sporadic GISTs. None of the six tumors from the two patients had a BRAFV600 E mutation. The patients were alive and well during the follow-up period(range:0.6-5 yr).CONCLUSION There have been only a few previous reports of GISTs associated with NF-1.Although GISTs associated with NF-1 have morphologic and immunohistochemical similarities with GISTs, the pathogenesis, incidence,genetic background, and prognosis are not completely known. A medical history of NF-1 in a patient who has gastrointestinal bleeding or anemia and an intraabdominal mass with nonspecific computed tomography features may help in diagnosing GIST by virtue of the well-known association of these two entities.Molecular genetic studies of cases indicated that GISTs in NF-1 patients have a different pathogenesis than sporadic GISTs.

Distribution of platelet-derived growth factor-alpha receptor expressing oligodendrocyte precursor cells in the adult rat brain

BACKGROUND： Studies have demonstrated that NG2-positive glial cells in the adult rats are predominantly located in the gray and white matter of the cerebral cortex and hippocampus. Platelet-derived growth factor-a receptor （PDGF-αR） cells are a subset of oligodendrocytes, which are not as mature as NG2-positive cells. Distribution and migration of PDGF-αR-positive cells in the rat brain remain poorly understood. OBJECTIVE： Using immunohistochemical methods, the distribution of oligodendrocyte precursor cells （PDGF-αR-positive） was analyzed in the adult rat brain. DESIGN, TIME AND SETTING： Immunohistochemical study was performed at the Department of Histology and Embryology of the Third Military Medical University from September 2007 to September 2008. MATERIALS： Rabbit anti-PDGF-αR polyclonal antibody was purchased from Santa Cruz Biotechnology, USA. Streptomycin-avidin-biotin complex immunohistochemistry kit was purchased from Zhongshan Goldenbridge Biotechnology, China. METHODS： Whole brains from 5 healthy, adult, Wistar rats were collected for immunohistochemistry, and the mean value of PDGF-αR-expressing cells was quantified. The absolute values were translated to ranked data of high, moderate, and low grades （high grade： 10 positive cells; moderate grade： 5-9 cells; low grade： 〈 5 cells in a 400 × visual field）. Based on the number of cell processes and branches, as well as the number of PDGF-αR-positive cells, in different regions, the cells were classified into three categories, i.e., type Ⅰ-Ⅲ. From type I to type Ill, the number of processes gradually increased. MAIN OUTCOME MEARSURES： The number and distribution of PDGF-αR-positive cells in different brain regions of adult rats. RESULTS： PDGF-αR-positive cells were located in the forebrain and midbrain, but not in the cerebellum or brainstem. In the olfactory bulb and hippocampus, a total of 60% PDGF-αR-positive cells were type Ⅰ and these cells were not mature as others. In the cerebral cortex, olfactory system, hippocampus, and optic chiasma, where neuronal bodies aggregated, approximately 40% of the PDGF-αR-positive cells were type Ⅱ, with few type Ⅲ cells. In the white matter, corpus callosum, basal nucleus, and thalamus, PDGF-αR-positive cell density was moderate. In the olfactory bulb and hippocampus, PDGF-αR-positive cell density was high. PDGF-αR-positive cells were not observed in the cerebellum or brainstem CONCLUSION： PDGF-αR-positive cells were aggregated in the olfactory bulb and hippocampus in the adult, rat brain, but few cells were detected in the cerebellum and brainstem.

Expression of NG2 and platelet-derived growth factor receptor alpha in the developing neonatal rat brain

Platelet-derived growth factor receptor alpha （PDGFRct） is a marker of oligodendrocyte precursor cells in the central nervous system. NG2 is also considered a marker of oligodendrocyte precursor cells. However, whether there are differences in the distribution and morphol- ogy of oligodendrocyte precursor cells labeled by NG2 or PDGFRa in the developing neonatal rat brain remains unclear. In this study, by immunohistochemical staining, NG2 positive （NG2＋） cells were ubiquitous in the molecular layer, external pyramidal layer, internal pyramidal layer, and polymorphic layer of the cerebral cortex, and corpus callosum, external capsule, piriform cortex, and medial septal nucleus. NG2~ cells were stellate or fusiform in shape with long processes that were progressively decreased and shortened over the course of brain development. The distribution and morphology of PDGFRct positive （PDGFRa＋） cells were coincident with NG2＋ cells. The co- localization of NG2 and PDGFRu in the cell bodies and processes of some cells was confirmed by double immunofluorescence labeling. Moreover, cells double-labeled for NG2 and PDGFRa were predominantly in the early postnatal stage of development. The numbers of NG2＋/PDGFRa＋ cells and PDGFRa＋ cells decreased, but the number of NG2＋ cells increased from postnatal days 3 to 14 in the developing brain. In addition, amoeboid microglial cells of the corpus callosum, newborn brain macrophages in the normal developing brain, did not express NG2 or PDGFRu, but NG2 expression was detected in amoeboid microglia after hypoxia. The present results suggest that NG2 and PDGFRct are specific markers of oligodendrocyte precursor cells at different stages during early development. Additionally, the NG2 protein is involved in inflammatory and pathological processes of amoeboid microglial cells.

Up and Down Expression of Androgen Receptor, Estrogen Receptor beta and Platelet Derived Growth Factor beta by Testosterone in Aortic Vascular Smooth Muscle Tissues

Objectives To investigate the effects of testosterone enanthate (TE) on serum lip- ids and lipoproteins metabolism and the expression of androgen receptor (AR) , estrogen receptor beta ( ER - β) and platelet derived growth factor beta ( PDGFR - β) in aortic vascular smooth muscle tissues (VSMTs). Methods Forty aged male rats were ran- domly divided into 4 groups, group A (placebo group) , group B (2. 5 mg/kg intramuscular injection of TE once a week ) , group C (5.0 mg/kg intramuscular injection of TE once a week ) , group D ( 10. 0 mg/kg intramus- cular injection of TE once a week). All animals were fed freely during 16 - week treatment periods. The ex- pression of AR ,ER - βand PDGFR - β were studied by Western bolt. Results Average serum LDL - C was lower in group D than that in group A ( p < 0. 01 ). Compared with the other groups, average serum TC was also lower in group D (p <0. 05). AR expression in aortic vascular smooth muscle tissues could be regulated by TE: 99.50 ±21.74, 125.38 ±28.68 and 101.98 ± 15.42 for TE concentrations at 2.5 mg/kg, 5.0 mg/kg and 10.0 mg/kg, respectively , the expression of ER - β could be regulated by TE: 92. 34 ± 18. 68, 47. 72 ± 18.12, 82.13 ±23.50, and the expression of PDGFR - β could be regulated as well by TE: 219.70 ±45. 59, 50.16 ±9. 72, 125.36 ±15. 74(Data for AR ,ER-β and PDGFR - β protein band intensity were expressed with x ± s, with control group taken as 100 ).Conclusions This study indicates that androgens have significant effects on serum lipids and lipoprotein metabolism. Testosterone enanthate at 5. 0 mg/kg can stimulate the expression of AR, but inhibite the expres- sion of PDGFR. Testosterone enanthate at the concen- trations of 5. 0 mg/kg and 10. 0 mg/kg can inhibite the expression of ER - β.

Gene expression of hepatocyte growth factor and its receptor in HCC and nontumorous liver tissues

AIM To study the changes of gene expression of hepatocyte growth factor (HGF) and hepatocyte growth factor receptor (HGFr) in hepatocellular carcinoma (HCC) tissue and nontumorous liver tissue and the relationship between these changes and the biological behavior of the tumor.METHODS Gene expression of HGF and HGFr in 26 cases of HCC tissue and their adjacent nontumorous liver tissues was determined with digoxigenin-labeled DNA probes.RESULTS Positive expression of HGF in HCC tissue was similar to that in the adjacent nontumorous liver tissue, but positive rate of HGF expression was lower than HGFr gene expression. However, HGFr expression was higher in the metastatic cases than in those without metastasis. It was found that HGFr was overexpressed in HCC tissue as well as in the adjacent nontumorous liver tissue.CONCLUSION There seems to be a close relationship between overexpression of HGFr gene and tumor metastasis, and the HGF and HGFr system plays an important role in regulating tumor growth and metastasis.

Decreased serum platelet derived growth factor BB levels in acute and increased in chronic pancreatitis

AIM: To examine circulating growth factor concentrations in patients with acute pancreatitis (AP) and chronic pancreatitis (CP), and walled-off pancreatic necrosis (WOPN).

Association of vascular endothelial growth factor-634G/C and receptor for advanced glycation end products G82S gene polymorphisms with diabetic retinopathy

AIMTo investigate the association of receptor for advanced glycation end products (RAGE) G82S and vascular endothelial growth factor (VEGF) -634 G/C gene polymorphisms with diabetic retinopathy (DR).METHODSOur cross-sectional study included 61 diabetic patients, 12 of them had proliferative diabetic retinopathy (PDR), 15 had non proliferative diabetic retinopathy (NPDR), 34 had no diabetic retinopathy (NDR) and 61 healthy controls. Participants were tested for RAGE G82S and VEGF -634 G/C polymorphisms by polymerase chain reaction-restriction fragment length polymorphism.RESULTSWe found a significant association between VEGF -634 G/C polymorphism and PDR as PDR patients had increased incidence of VEGF -634 CC genotype compared to NDR patients [odds ratio for CC vs (GC+GG)=6.5, 95% CI=1.5-27.8, P=0.021]. Also VEGF -634 CC genotype and C allele were significantly higher in the PDR than in NPDR patients, which is a novel finding in our study (P=0.024, 0.009 respectively). The mean triglycerides level was significantly higher in diabetic patients with CC genotype (P=0.01) as compared to patients with other genotypes. All cases and control subjects were of the same heterozygous RAGE 82G/S genotype.CONCLUSIONPatients carrying VEGF -634 C polymorphism have a higher risk of PDR development, so VEGF -634 G/C polymorphism could be used as a predictive marker for PDR in diabetic patients. We could not find a significant association between RAGE G82S polymorphism and DR.

Associations Between Epidermal Growth Factor Receptor Gene Mutation and Serum Tumor Markers in Advanced Lung Adenocarcinomas: A Retrospective Study

Objective To investigate the associations between epidermal growth factor receptor （EGFR） gene mutations and serum tumor markers in advanced lung adenocarcinomas. Methods We investigated the association between EGFR gene mutations and clinical features, including serum tumor marker levels, in 97 advanced lung adenocarcinomas patients who did not undergo the treatment of EGlaR tyrosine kinase inhibitors. EGFR gene mutation was detected by real-time PCR at exons 18, 19, 20, and 21. Serum tumor marker concentrations were analyzed by chemiluminescence assay kit at the same time. Results EGFR gene mutations were detected in 42 （43%） advanced lung adenocarcinoma patients. Gender （P=0.003）, smoking status （P=0.001）, and abnormal serum status of carcinoembryonic antigen （CEA, P=0.028） were significantly associated with EGFR gene mutation incidence. Multivariate analysis showed the abnormal CEA level in serum was independently associated with the incidence of EGFR gene mutation （P=0.046） with an odds ratio of 2.613 （95% Ch 1.018-6.710）. However, receiver operating characteristic （ROC） curve analysis revealed CEA was not an ideal predictive marker for EGFR gene mutation status in advanced lung adenocarcinoma （the area under the ROC curve was 0.608, P=0.069）. Conclusions EGFR gene mutation status is significantly associated with serum CEA status in advanced lung adenocarcinmoas. However, serum CEA is not an ideal predictor for EGFR mutation.

Pirfenidone suppresses the abnormal activation of human Müller cells after platelet-derived growth factor-BB stimulation

AIM: To determine the effect of pirfenidone on the activated human Müller cells by platelet-derived growth factor-BB(PDGF-BB). METHODS: The primary human Müller cells were separated from retinal tissues and established the pathogenic model by stimulated with PDGF-BB. The Müller cells behaviour of normal group and the model group was measured by MTT assay, Trypan blue assay, cell migration assay, and collagen contraction assay. The expression of transforming growth factor(TGF)-β1,-β2, and pigment epithelium-derived factor(PEDF) was estimated with realtime polymerase chain reaction(PCR), Western blot and immunofluorescence analyses. RESULTS: A pathogenic/proliferative model of Müller cells was established by stimulating normal cultured Müller cells with 10 ng/mL PDGF-BB for 48 h. After treated with 0.2 and 0.3 mg/mL pirfenidone, the proliferation, migration and collagen contraction was statistically significantly depressed in the model group compared with the normal groups. The expression levels of TGF-β1 and TGF-β2 were significantly down-regulated, while the PEDF expression was significantly up-regulated after treated with 0.2 and 0.3 mg/mL pirfenidone in the model group. CONCLUSION: Pirfenidone effectively suppress the proliferation, migration and collagen contraction of the human Müller cells stimulated with PDGF-BB through down-regulation of TGF-β1/TGF-β2 and up-regulation of PEDF.

SIMULTANEOUS OVER-EXPRESSION OF INSULIN-LIKE GROWTH FACTOR- Ⅱ (IGF- Ⅱ ) AND IGF- Ⅱ RECEPTOR(IGF- Ⅱ R) GENES IN HUMAN PRIMARY CANCER-IMPLICATION OF AUTOCRINE AND PARACRINE MECHANISM IN AUTONOMOUS GROWTH OF HEPATIC CANCER

This is first report about the simultaneous over-expression of both Insulin-like growth factor (IGF- I ) and its receptor (IGF- I R) at mRNA level in human primary hepatic Cancer (PHC). In 10 PHC samples from China, IGF-I and IGF- I R were both over-expressed, whereas only a background signal was detected in normal liver. In 5 pairs of PHC and its non- tumorous adjacent liver tissues from South Africa, IGF- I and IGF- I R were also over-expressed in PHC. mRNA expression of IGF- I in all 5 cases and IGF- I R in 4 of 5 cases were higher in cancer than non- tumorous adjacent liver tissues. These results strongly implicate that an autocrine and/ or paracrine mechanism might be Involved in formation and progression of PHC.

Relationship between epidermal growth factor receptor gene mutation and copy number in Chinese patients with non-small cell lung cancer

Epidermal growth factor receptor(EGFR) gene mutation and copy number are useful predictive markers that guide the selection of non-small cell lung cancer(NSCLC) patients for EGFR-targeting therapy.This study aimed to investigate the correlation between EGFR gene mutation and copy number and clinicopathologic characteristics of Chinese patients with NSCLC.NSCLC specimens collected from 205 patients between November 2009 and January 2011 were selected to detect EGFR gene mutations with real-time polymerase chain reaction(RT-PCR) and to detect EGFR gene copy number with fluorescence in situ hybridization(FISH).EGFR mutations primarily occurred in females,non-smokers,and patients with adenocarinomas(all P < 0.001).Tissues from 128(62%) patients were FISH-positive for EGFR,including 37(18%) with gene amplification and 91(44%) with high polysomy.EGFR gene mutation was correlated with FISH-positive status(R = 0.340,P < 0.001).Multivariate analysis showed that not smoking(OR = 5.910,95% CI = 2.363-14.779,P < 0.001) and having adenocarcinoma(OR = 0.122,95% CI = 0.026-0.581,P = 0.008) were favorable factors for EGFR gene mutation.These results show a high frequency of EGFR FISH positivity in NSCLC tissues from Chinese patients and a significant relevance between EGFR gene mutations and FISH-positive status.Among the FISH-positive samples,EGFR gene mutation occurred more frequently in samples with gene amplification compared to those with high polysomy,suggesting that EGFR mutation and gene amplification should be used as clinical decision parameters to predict response to EGFR-targeting therapy.

Effect of recombinant human platelet-derived growth factor B on cat corneal endothelial cell viability mediated by adeno-associated virus

AIM: To transduce recombinant human platelet-derived growth factor B (PDGF-B) gene adeno-associated virus(AAV) to in vitro cultured cat corneal endothelial cell (CEC) and observe the effect of the expressed PDGF-BB protein on the viability of cat CEC. METHODS: Cat cornea endothelium was torn under microscope and rapidly cultivated in DMEM to form single layer CEC and the passage 2 endothelial cells were used in this study. The recombinant human PDGF-B gene AAV was constructed and transduced into cat CEC directly. Three groups were as following: blank control group, AAV control group and recombinant AAV group. At 24 hours, 48 hours, and 5 days after transduction, total RNA was extracted from the CEC by Trizol and the expression of PDGF-B gene was detected by fluorescence quantitative polymerase chain reaction. Viability of the transduced CEC was detected at 48 hours after transduction by MTT assay. Cell morphology was observed under inverted phase contrast microscope. RESULTS: With the torn endothelium culture technique, we rapidly got single layer cat CEC. At 24 hours, 48 hours and 5 days after transduction, fluorescence quantitative polymerase chain reaction showed there was no significant difference of the expressed PDGF-B gene mRNA between blank control group and AAV control group (P>0.05). In contrast, there were significant differences between two control groups and recombinant AAV group (P<0.05). MTT assay showed that in recombinant AAV group, the expressed PDGF-BB protein could promote the viability of cat CEC. Morphology observation showed at 48 hours after transduction, cells in CEC-AAV-PDGF-B group proliferated into bigger scales in regular triangle to hexagon shape with distinct boundary, while the number of cells was significantly less in the two control groups. CONCLUSION: The recombinant AAV-PDGF-B expresses biological active PDGF-BB protein in cat CEC, which promotes the viability and proliferation of cells.

Platelet-derived growth factor signaling in human malignancies

Platelet-derived growth factors (PDGFs) and their receptors were identified and purified decades ago. PDGFs are important during normal development and in human cancers. In particular, autocrine PDGF signaling has been implicated in various types of malignancies such as gliomas and leukemia. In contrast, paracrine signaling was found in cancers that originate from epithelial cells, where it may be involved in stromal cell recruitment, metastasis, and epithelial-mesenchymal transition. This editorial briefly discusses autocrine and paracrine PDGF signaling and their roles in human cancers, and introduces a series of review articles in this issue that address the possible roles of PDGFs in various processes involved in different types of cancers.