Platelet-derived Growth Factor Alpha Research Articles

Human Wharton's Jelly Mesenchymal Stromal Cell-Derived Small Extracellular Vesicles Drive Oligodendroglial Maturation by Restraining MAPK/ERK and Notch Signaling Pathways.

Peripartum cerebral hypoxia and ischemia, and intrauterine infection and inflammation, are detrimental for the precursor cells of the myelin-forming oligodendrocytes in the prematurely newborn, potentially leading to white matter injury (WMI) with long-term neurodevelopmental sequelae. Previous data show that hypomyelination observed in WMI is caused by arrested oligodendroglial maturation rather than oligodendrocyte-specific cell death. In a rat model of premature WMI, we have recently shown that small extracellular vesicles (sEV) derived from Wharton’s jelly mesenchymal stromal cells (WJ-MSC) protect from myelination deficits. Thus, we hypothesized that sEV derived from WJ-MSC directly promote oligodendroglial maturation in oligodendrocyte precursor cells. To test this assumption, sEV were isolated from culture supernatants of human WJ-MSC by ultracentrifugation and co-cultured with the human immortalized oligodendrocyte precursor cell line MO3.13. As many regulatory functions in WMI have been ascribed to microRNA (miR) and as sEV are carriers of functional miR which can be delivered to target cells, we characterized and quantified the miR content of WJ-MSC-derived sEV by next-generation sequencing. We found that WJ-MSC-derived sEV co-localized with MO3.13 cells within 4 h. After 5 days of co-culture, the expression of myelin basic protein (MBP), a marker for mature oligodendrocytes, was significantly increased, while the oligodendrocyte precursor marker platelet-derived growth factor alpha (PDGFRα) was decreased. Notch and MAPK/ERK pathways known to inhibit oligodendrocyte maturation and differentiation were significantly reduced. The pathway enrichment analysis showed that the miR present in WJ-MSC-derived sEV target genes having key roles in the MAPK pathway. Our data strongly suggest that sEV from WJ-MSC directly drive the maturation of oligodendrocyte precursor cells by repressing Notch and MAPK/ERK signaling.

Mdm2 and Egfr Expression and Prognosis in 16 Pulmonary Artery Sarcomas

There are few studies investigating the biomarker signatures and their relations with prognosis of pulmonary artery sarcoma patients. In the present study, we performed a cohort study on 16 cases of pulmonary artery sarcoma in an attempt to identify the potential diagnostic markers and molecular therapeutic targets of that vascular sarcoma. Patients who had undergone pulmonary artery sarcoma tumorectomy over 7 ½ years in our hospital were enrolled in this retrospective study. The resected tumors were analyzed by histopathology, the expression and mutation of Murine Double Minute 2 (MDM2), Epidermal Growth Factor Receptor (EGFR), and Platelet-Derived Growth Factor Alpha (PDGFRA) by immunohistochemistry (IHC) and fluorescence in situ hybridization (FISH). The correlations between patients’ outcomes and tumor histological, IHC and FISH features were statistically analyzed. MDM2 immunostaining was seen mainly in intimal sarcoma. At univariate analysis, MDM2 expression had a positive correlation with shorter progression free survival (PFS). MDM2 and EGFR co-expression also had a positive correlation with shorter PFS and tumor metastasis. This study investigated MDM2, EGFR, and PDGFRA as potential biomarkers for diagnosis of pulmonary artery sarcoma and therapeutic targets.

Expression of PDGF-A, PDGFRA, integrin subunit alpha V and selectin E is increased in canine cutaneous fibrosarcomas

ABSTRACT We investigated the expression of platelet derived growth factor alpha (PDGFA); its receptor, PDGFRA; integrin subunit alpha V; and selectin E in cutaneous fibrosarcomas in dogs. Ten cases of canine fibrosarcomas were obtained from the archive of the Department of Pathology, Ondokuz Mayis University, Samsun. Tissue sections were cut and stained with hematoxylin and eosin, Alcian blue-periodic acid Schiff, Masson’s trichrome, and also immunostained. Eight tumors classified as spontaneous fibrosarcomas exhibited interwoven bundles of spindle shaped cells with oval to plump nuclei and scant cytoplasm, while two tumors exhibited features of injection site fibrosarcoma with peripheral infiltration of mononuclear cells and intratumor necrosis. We found that neoplastic cells from all cases exhibited cytoplasmic expression of PDGFA, and cytoplasmic and nuclear staining for PDGFRA. Integrin subunit alpha V immunostaining was observed in all cases, while selectin E expression was observed in vascular endothelial cells and neoplastic cells. A significant positive correlation was found between the expression of PDGFA and integrin subunit alpha V. Our findings indicate that PDGFA, PDGFRA, integrin subunit alpha V and selectin E are expressed strongly in canine cutaneous fibrosarcomas and may contribute to tumor progression.

Genomic Study of Chinese Quadruple-negative GISTs Using Next-generation Sequencing Technology.

Approximately 10% of gastrointestinal stromal tumors (GISTs) are devoid of KIT, PDGFRA (platelet-derived growth factor-alpha), BRAF, and SDH alterations. The aim of this study was to characterize molecular drivers in Chinese patients with quadruple-negative GISTs. In 1022 Chinese patients with GIST, mutations of KIT and PDGFRA were analyzed by direct sequencing. Of these mutations, 142 KIT/PDGFRA wild-type (WT) GISTs were detected, and succinate dehydrogenase (SDH) deficiency was determined using immunohistochemistry analysis of succinate dehydrogenase B. In 78 KIT/PDGFRA/SDH cases, we performed targeted 425 cancer-related gene analysis using next-generation sequencing. The correlation between molecular findings and clinicopathologic features was also analyzed. We defined 72 quadruple-negative GISTs from enrollments. They featured nongastric localization with histologic characteristics of spindle cells and male predilection. An overall 27.78% (20/72) of quadruple-negative tumors carried TP53, and 25.00% (18/72) carried RB1 mutations, which were frequently associated with high mitotic index and large size. TP53 analyses demonstrated coexistence with mutational activation of other oncogenes in 12 of 20 cases. A total of 18 RB1-mutated cases were independent of TP53. Further, no tumors carried NF1 and BRAF mutations. We report the genomic analysis of Chinese quadruple-negative patients. These databases may help advance our understanding of quadruple-negative GISTs' progression. Next-generation sequencing from GISTs is feasible to provide relevant data for guiding individualized therapy.

Clinicopathological features and prognosis of gastrointestinal stromal tumor with PDGFRA-D842V mutation

Objective: Platelet-derived growth factor alpha (PDGFRA) mutations are respectively rare in gastrointestinal stromal tumors (GIST). Most GIST with PDGFRA exon 18 mutations including D842V mutation are highly resistant to imatinib. The treatment of GIST harboring PDGFRA primary drug-resistant mutation is a major challenge. This article aims to investigate clinicopathologic features of GIST with PDGFRA-D842V mutation and the efficacy of comprehensive treatment, providing a reference for clinical practice. Methods: A retrospective cohort study was conducted to collect the clinicopathological and follow-up data of patients with GIST harboring PDGFRA mutation who were diagnosed and treated in the GIST Clinic of Renji Hospital from January 2005 to May 2020. According to the mutation site, the enrolled patients were divided into D842V mutation group and non-D842V mutation group. The differences of clinicopathologic characteristics between the two groups were compared. Furthermore, overall survival and prognostic factors were analyzed. Results: A total of 71 patients with PDGFRA-mutant GIST were included in this study, including 47 cases of D842V mutation (66.2%) and 24 cases of non-D842V mutation (33.8%). There were 28 male patients and 19 female patients in D842V mutation group, with a median age of 60 (36-82) years. There were 16 male patients and 8 female patients in non-D842V mutation group, with a median age of 62 (30-81) years. There were no significant differences in age, gender, primary location, surgical procedure, tumor size, mitotic count, expression of CD117 and DOG1, Ki-67 proliferation index and modified NIH grade between the two groups (all P>0.05). The positive rate of CD34 was 89.4% (42/47) and 62.5% (15/24) in the D842V mutation group and the non-D842V mutation group, respectively, with a statistically significant difference (χ(2)=5.644, P=0.018). Among all the cases, 66 cases underwent R0 resection without preoperative treatment; two cases underwent emergency operation with R1 resection because of tumor rupture; 2 cases were not operated after the pathological and mutation types were confirmed by biopsy (one case received avapritinib treatment and obtain partial remission). One case was diagnosed as wild-type GIST per needle biopsy in another institute, and underwent R0 resection after preoperative imatinib treatment for 6 months. After surgery, 5 high-risk GIST patients with D842V mutation and 5 high-risk GIST patients with non-D842V mutation were treated with imatinib for more than one year. The median follow-up time was 37 (1-153) months. As of the last follow-up among the patients who received R0 resection, 4 patients with D842V mutation had relapse, of whom 1 was in the period of imatinib administration, and the 3-year relapse-free survival rate was 94.2%; none of the patients with non-D842V mutation had relapse. There was no statistically significant difference in relapse-free surivval between two groups (P=0.233). Univariate analysis revealed that mitotic count (P=0.002), Ki-67 proliferation index (P<0.001) and modified NIH grade (P=0.025) were the factors associated with relapse-free survival of patients with D842V mutation after R0 resection (all P<0.05). However, the above factros were not testified as independant prognostic facors in multivariate Cox analysis (all P<0.05). Conclusion: Clinicopathologic features and the efficacy of radical resection in patients with PDGFRA-D842V mutation are similar to those in patients with non-D842V mutation.

Predominant differentiation of rat fetal neural stem cells into functional oligodendrocytes in vitro

Oligodendrocytes form myelin in the CNS. A fast method to produce large quantity of oligodendrocytes that have the capacity of myelinating CNS neurons would be very useful for treating CNS injuries or demyelinating diseases, or for research purposes. We developed a simple standard protocol for predominant differentiation of rat fetal neural stem cells (NSCs) into oligodendrocytes. We adopted a new method to purify the oligodendrocytes and co-cultured the newly differentiated oligodendrocytes with hippocampal neurons to confirm their myelination capability. NSCs from embryonic day 14 (E14) were propagated at the presence of basic fibroblast growth factor and platelet derived growth factor alpha, and then differentiated in the medium containing triiodothyronine. Four extracellular matrix (ECM), poly-d-lysine (PDL), PDL-laminin, fibronectin, and matrigel, were examined for NSC differentiation. About 90 % of NSCs differentiated into oligodendrocytes on matrigel compared to 32 % on PDL or PDL-laminin, and 26 % on fibronectin after 3 weeks of differentiation, demonstrating the significant influence of ECM. Further, newly differentiated oligodendrocytes were co-cultured with hippocampal neurons from E18 rat embryos resulting in robust myelination of neurites at three weeks. In summary, we present a simplified and efficient method to predominantly generate oligodendrocytes from NSCs that is potentially very useful for CNS demyelination diseases.

The Emerging Role of the FGF/FGFR Pathway in Gastrointestinal Stromal Tumor.

Gastrointestinal stromal tumors (GIST) are rare neoplasms of mesenchymal origin arising in the gastrointestinal tract. The vast majority are characterized by mutually exclusive activating mutations in KIT or Platelet-derived growth factor alpha (PDGFRA) receptors, or less frequently by succinate dehydrogenase complex (SDH) or NF1 inactivation, with very rare cases harboring mutant BRAF or RAS alleles. Approximately 5% of GISTs lack any of such mutations and are called quadruple wild-type (WT) GISTs. Recently, deregulated Fibroblast Growth Factor (FGF)/FGF-receptor (FGFR) signaling emerged as a relevant pathway driving oncogenic activity in different molecular subgroups of GISTs. This review summarizes all the current evidences supporting the key role of the FGF/FGFR pathway activation in GISTs, whereby either activating mutations, oncogenic gene fusions, or autocrine/paracrine signaling have been detected in quadruple WT, SDH-deficient, or KIT-mutant GISTs.

Astaxanthin Reduces Demyelination and Oligodendrocytes Death in A Rat Model of Multiple Sclerosis.

Objective Astaxanthin (AST) is a carotenoid with anti-oxidative, anti-inflammatory, and anti-apoptotic properties. It has also been reported that AST exerts protective effects against neurodegenerative diseases and reduces oxidative stress-induced the central nervous system (CNS) injury. In this study, we aimed to evaluate the protective potential of AST in inhibiting demyelination and oligodendrocyte death in a rat model of multiple sclerosis (MS). Materials and Methods In this experimental study, forty Wistar rats were randomly assigned to four experimental groups: control group (with normal feeding), cuprizone (CPZ group) that daily received 0.6% CPZ for 4 weeks, sham group that daily received 0.6% CPZ plus dimethyl sulfoxid (DMSO) for 4 weeks, and AST group that daily received 0.6% CPZ and after 12 hours were treated with AST (3 mg/kg), for 4 weeks. Muscle strength was evaluated by the behavioral basket test at the end of every week for 4 weeks. Luxol Fast Blue (LFB) staining was utilized for the identification of myelination and demyelination. Myelin density was evaluated by the ImageJ software. The expression of A2B5 (oligodendrocyte precursor protein) and myelin oligodendrocyte protein (MOG) were assessed by immunohistochemistry (IHC) and the expression of myelin basic protein (MBP), MOG, and platelet-derived growth factor-alpha (PDGFR-α) genes was examined by the real-time polymerase chain reaction (RT-PCR) technique. Results The administration of AST reduced the oligodendrocyte damage and myelin sheath disruption in a rat model of MS. The basket behavioral test showed the improvement of muscle strength in the AST group compared with CPZ and sham groups. Besides, the results of real-time PCR and IHC indicated the beneficial effects of AST in declining demyelination and oligodendrocyte death in a rat model of MS. ConclusionAST reduces damages to the myelin sheath and oligodendrocyte death in a rat model of MS.

MiR-181a/b-5p regulates human umbilical vein endothelial cell angiogenesis by targeting PDGFRA.

Type 2 diabetes mellitus (T2DM) is a growing burden in low-and middle-income countries. Changing lifestyles and lack of physical activity are some of the reasons contributing to this epidemic increase. Co-morbidities associated with T2DM are largely due to the complications which arise as a consequence of endothelial dysfunction. Platelet derived growth factor-alpha (PDGFRA) is a protein responsible for cell proliferation, angiogenesis, migration and invasion. Increased levels of PDGFRA have been reported in T2DM. This study assessed the epigenetic regulation of PDGFRA through microRNAs (miR-181a/b-5p).Using a bioinformatics-based approach, we assessed the binding of miR-181a/b-5p to PDGFRA. Experimentally, this binding was confirmed using a dual luciferase reporter assay. Further, we overexpressed miR-181a/b-5p in Human umbilical vein endothelial cells (HUVECs) and the influence of over-expression on cell proliferation, migration and angiogenesis was assessed using in-vitro approaches. The influence of miR-181a/b-5p over expression on cellular apoptosis was ascertained using a TUNEL assay with concomitant changes being observed in the levels of Bcl-2 and cleaved Caspase-3.In HUVECs, PDGFRA is a direct target for miR-181a/b-5p. Over expression of miR-181a/b-5p decreased cellular proliferation, migration, invasion, and tube formation-a surrogate marker for angiogenesis. miR-181a/b-5p may be used as a therapeutic intervention to restrict uncontrolled levels of PDGFRA and thereby rescue the phenotypes of increased cell proliferation, migration, invasion and tube formation. miR-181a/b negatively regulates PDGFRA levels. Significance of the study: T2DM and its associated complications emerge from endothelial dysfunction. The associated phenotypes are regulated by a number of proteins, one such member being, PDGFRA. PDGFRA is in turn regulated by miR-181a/b-5p. Complementation with miR-181a/b-5p resulted in reversion of phenotypes. Thus, miR-181a/b-5p-mediated suppression of PDGFRA may be used as a therapeutic intervention in the management of type 2 diabetes.

Bone marrow-derived neural crest precursors improve nerve defect repair partially through secreted trophic factors

BackgroundEmerging evidence suggests that neural crest-derived cells (NCCs) present important functions in peripheral nerve regeneration to correct the insufficiency of autogenous Schwann cells. Postmigratory NCCs have been successfully isolated from adult rat bone marrow in our previous work. In this study, we aim to provide neural crest-derived Schwann cell precursors (SCPs) for repair of nerve defects in adult rats, and partially reveal the mechanisms involved in neuroregeneration of cell therapy.MethodsA clonal cell line of neural crest precursors of rat bone marrow origin (rBM-NCPs) with SCP identity was expanded in adherent monolayer culture to ensure the stable cell viability of NCPs and potentiate the repair of nerve defects after rBM-NCPs implantation based on tissue engineering nerve grafts (TENG). Here the behavioral, morphological, and electrophysiological detection was performed to evaluate the therapy efficacy. We further investigated the treatment with NCP-conditioned medium (NCP-CM) to sensory neurons after exposure to oxygen-glucose-deprivation (OGD) and partially compared the expression of trophic factor genes in rBM-NCPs with that in mesenchymal stem cells of bone marrow origin (rBM-MSCs).ResultsIt was showed that the constructed TENG with rBM-NCPs loaded into silk fibroin fiber scaffolds/chitosan conduits repaired 10-mm long sciatic nerve defects more efficiently than conduits alone. The axonal regrowth, remyelination promoted the reinnervation of the denervated hind limb muscle and skin and thereby alleviated muscle atrophy and facilitated the rehabilitation of motor and sensory function. Moreover, it was demonstrated that treatment with NCP-CM could restore the cultured primary sensory neurons after OGD through trophic factors including epidermal growth factor (EGF), platelet-derived growth factor alpha (PDGFα), ciliary neurotrophic factor (CNTF), and vascular endothelial growth factor alpha (VEGFα).ConclusionsIn summary, our findings indicated that monolayer-cultured rBM-NCPs cell-based therapy might effectively repair peripheral nerve defects partially through secreted trophic factors, which represented the secretome of rBM-NCPs differing from that of rBM-MSCs.

Increased protease activated receptors in the colon of patients with Hirschsprung's disease

PurposeThe pathophysiology of Hirschsprung's associated enterocolitis (HAEC) is not understood. Abnormal intestinal motility and altered intestinal epithelial barrier function have been suggested to play a key role in the causation of HAEC. Protease-activated receptors (PARs) 1 and 2, have been implicated in inflammatory reactions, intestinal permeability and modulation of motility in the gut. MethodsWe investigated PAR-1 and PAR-2 protein expression in aganglionic and ganglionic regions of patients with Hirschsprung's Disease (HSCR) (n = 10) versus normal control colon (n = 10). Protein distribution was assessed by using immunofluorescence and confocal microscopy. Gene and protein expression were quantified using quantitative real-time polymerase chain reaction (qPCR), western blot analysis, and densitometry. ResultsqPCR and Western blot analysis revealed that PAR-1 and PAR-2 expression was significantly increased in ganglionic and aganglionic bowel in HSCR compared to controls (p < 0.003). Confocal microscopy revealed strong PAR-1 and PAR-2 expression in smooth muscles, interstitial cells of Cajal (ICCs), platelet-derived growth factor-alpha receptor-positive (PDGFRα+) cells, enteric neurons and epithelium in the ganglionic and aganglionic bowel compared to controls. ConclusionIncreased PAR-1 and PAR-2 expression in the colon of patients with HSCR suggests that excessive local release of PAR activating proteases may trigger inflammatory responses leading to HAEC.

Identifying Secondary Mutations in Chinese Patients with Imatinib-Resistant Gastrointestinal Stromal Tumors (GISTs) by Next Generation Sequencing (NGS).

The aim of this study was to characterize secondary kinase mutations in Chinese patients with imatinib-resistant gastrointestinal stromal tumors (GISTs). Mutations in receptor tyrosine kinase (KIT; exons 9, 11, 13, 14, 17, and 18) and platelet-derived growth factor-alpha (PDGFRA; exons 12, 14, and 18) were analyzed by direct sequencing. After imatinib treatment, 425 cancer-related target genes were analyzed by next generation sequencing (NGS) in imatinib-resistant patients. Correlation of sequencing results with clinicopathologic features were analyzed. We identified 320 patients with secondary acquired resistance. We determined that 65.63% (210/320) of resistant patients had secondary KIT mutations in exon 13 (n = 134), exon 14 (n = 10), or exon 17 (n = 66), and 4.38% (14/320) had additional PDGFRA mutations in exon 14 (n = 3) or exon 18 (n = 11). All secondary KIT mutations were missense mutations and were mostly located in kinase domains. Ninety-six imatinib-resistant GIST patients did not have secondary KIT or PDGFRA mutations. Common independent mutation events were found in retinoblastoma protein 1 (RB1) (18/96 cases), SWI/SNF-related matrix associated actin-dependent regulator of chromatin subfamily B member 1 (SMARCB1) (16/96 cases), and myc-associated factor X (MAX) (10/96 cases). RB1 or SMARCB1 mutations coexisted with activation of other oncogenes in 6 or 15 cases, respectively. Multiple mutations were also seen in cases with MAX mutations. These mutations are frequently associated with clinicopathological factors. Secondary mutations of KIT/PDGFRA were the most important contributors in GISTs developing resistance to imatinib treatment. Additional genetic events including RB1, SMARCB1, and MAX except secondary KIT/PDGFRA mutations are the most common for GISTs to evolve into resistant disease. Clinical assessment of the effect of these mutations may benefit existing risk assessment models and selection of adjuvant therapies in GIST patients.

PDGFRα marks distinct perivascular populations with different osteogenic potential within adipose tissue.

The perivascular niche within adipose tissue is known to house multipotent cells, including osteoblast precursors. However, the identity of perivascular subpopulations that may mineralize or ossify most readily is not known. Here, we utilize inducible PDGFRα (platelet-derived growth factor alpha) reporter animals to identify subpopulations of perivascular progenitor cells. Results showed that PDGFRα-expressing cells are present in four histologic niches within inguinal fat, including two perivascular locations. PDGFRα+ cells are most frequent within the tunica adventitia of arteries and veins, where PDGFRα+ cells populate the inner aspects of the adventitial layer. Although both PDGFRα+ and PDGFRα- fractions are multipotent progenitor cells, adipose tissue-derived PDGFRα+ stromal cells proliferate faster and mineralize to a greater degree than their PDGFRα- counterparts. Likewise, PDGFRα+ ectopic implants reconstitute the perivascular niche and ossify to a greater degree than PDGFRα- cell fractions. Adventicytes can be further grouped into three distinct groups based on expression of PDGFRα and/or CD34. When further partitioned, adventicytes co-expressing PDGFRα and CD34 represented a cell fraction with the highest mineralization potential. Long-term tracing studies showed that PDGFRα-expressing adventicytes give rise to adipocytes, but not to other cells within the vessel wall under homeostatic conditions. However, upon bone morphogenetic protein 2 (BMP2)-induced ossicle formation, descendants of PDGFRα+ cells gave rise to osteoblasts, adipocytes, and "pericyte-like" cells within the ossicle. In sum, PDGFRα marks distinct perivascular osteoprogenitor cell subpopulations within adipose tissue. The identification of perivascular osteoprogenitors may contribute to our improved understanding of pathologic mineralization/ossification.

P11.54 Identification of PDGFRA and MYC(N) as somatic driver genes in Glioblastoma

Abstract BACKGROUND Somatic oncogene amplification happens frequently in glioblastoma (GBM). The second most frequently amplified gene encoding receptor tyrosine kinases in GBMs is platelet derived growth factor alpha (PDGFRA) (15%). In contrast, MYC and MYCN amplification occurs in 1.6% and 2.9%, respectively. Our goal was to characterize the role of PDGFRɑ and Myc in GBM. MATERIAL AND METHODS Neurosphere cultures were implanted in cohorts of 10–15 nude mice. 5 PDX lines, presenting median survival of 29–59 days were classified as short survivors, and 5 lines with median survival between 104–134 days classified as long survivors. Total RNA was extracted from PDX terminal tumors (3 biological replicates) and sequenced in a paired-end read format. Mouse reads were filtered out using Xenome. MYC and PDGFRA expression patterns were analyzed in tissue microarrays representing duplicated samples from 40 glioma neurosphere-derived PDX lines by IHC (1 anaplastic oligodendroglioma, 8 recurrent GBM with 2 newly diagnosed/recurrent pairs). Normalized staining intensity (MI) and area (A) were quantified using Fiji/ImageJ. RESULTS PDGFRA, MYC, MYCN gene amplifications were represented in a molecularly diverse panel of GBM patient-derived cancer stem-like cells (CSC) and orthotopic mouse xenografts (PDX). Transforming to a normal distribution (log10), 4/13 of cell lines had a PDGFRA mRNA expression (RPKM) higher than 1.5. Similarly, one PDX line had a staining index of greater than 10, 11 (27.5%) had an index between 5–10. The range of intra-tumoral variance, represented by standard deviation, was 0.09–24.25 highlighting the heterogeneity of PDGFRɑ expression. PDGFRɑ phosphorylation (Y754) did not differ between 8 cell lines cultured in NMGF, but deviated in alternate medias without growth factors, supplemented with FBS. In comparison, MYC(N) mRNA expression is only elevated in the context of a known amplification. Furthermore, a a MYC activity signature consisting of 18 target genes was only evident in the 5 amplified CSC lines. Taking advantage of genomic heterogeneity, we have isolated subclones lacking PDGFRA amplification from a PDGFRA amplified GBM CSC. The absence of PDGFRA amplification reduced the self-renewal potential to 37% of the PDGFRA amplified cell population (p=0.001) in clone 1 and 57% in clone 2 (p=0.013). Pertaining to determinants of in vivo survival, MYC was altered in 80% of short survivors (2/5 MYC, 2/5 MYCN amplification) and in 0% of long survivors. Myc signature was highly correlated with in vivo survival (Pearsons’ corr. = -0.77) and MYC gene expression was correlated with in vivo TMZ resistance (corr. = 0.7). CONCLUSION These results suggest that PDGFRɑ expression and activity can occur in the absence of gene amplification, while Myc activity is dependent on gene amplification. Both oncogenes drive oncogenic pathways that should be explored as therapeutic targets.

Acrylamide-induced adverse cerebellar changes in rats: possible oligodendrogenic effect of omega 3 and green tea

Humans are widely exposed to acrylamide (ACR) and its neurotoxicity is a significant public health issue attracting wide attention. The aim of the study was to investigate ACR-induced adverse cerebellar changes in rats and study the possible oligodendrogenic effect of omega 3 and green tea. Twenty-four adult albino rats weighing 150-200 g were randomly divided into four equal groups (6 rats each): control group (Group I), the rats that received ACR 45 mg/kg/day (Group II), the rats that received ACR concomitant with omega 3 at a dosage of 200 mg/kg/day (Group III), the rats that received ACR concomitant with green tea dissolved in drinking water at a dosage of 5 g/L (Group IV). The rats were euthanized after 8 weeks of the experiment. Malondialdehyde (MDA) and glutathione (GSH) were measured in cerebellar homogenates. Sections of 5 μm thickness from specimens from the cerebellum were stained with haematoxylin and eosin, silver stain and immunohistochemical stains: platelet-derived growth factor alpha (PDGFα; for oligodendrocytes), glial fibrillary acidic protein (GFAP; for astrocytes) and BCL2 (antiapoptotic). Omega 3 and green tea had improved MDA and GSH as compared to the ACR group. Histologically, the ACR group showed variable degrees of cellular degeneration. Omega 3 had induced oligodendrogenesis in Group III. The optical density of silver stain was significantly (p < 0.05) increased in Groups III and IV as compared to the ACR group. Area per cent of positive PDGFα was significantly increased in the ACR + omega 3 group as compared to the ACR group. Area per cent of positive GFAP was significantly decreased in Groups III and IV as compared to the ACR group. Area per cent of positive BCL2 was significantly increased in the omega 3-trated group as compared to the ACR group. Concomitant administration of omega 3 or green tea with ACR might mitigate the adverse cerebellar changes caused by ACR thanks to an oligodendrogenic effect of omega 3.

Interim analysis of a real-world precision medicine platform for molecular profiling of metastatic or advanced cancers: MONDTI

BackgroundHigh-throughput genomic profiling of tumour specimens facilitates the identification of individual actionable mutations which could be used for individualised targeted therapy. This approach is becoming increasingly more common in the clinic; however, the interpretation of results from molecular profiling tests and efficient guiding of molecular therapies to patients with advanced cancer offer a significant challenge to the oncology community.Experimental designMONDTI is a precision medicine platform for molecular characterisation of metastatic solid tumours to identify actionable genomic alterations. From 2013 to 2016, comprehensive molecular profiles derived from real-time biopsy specimens and archived tumour tissue samples of 295 patients were performed. Results and treatment suggestions were discussed within multidisciplinary tumour board meetings.ResultsThe mutational profile was obtained from 293 (99%) patients and a complete immunohistochemical (IHC) and cytogenetic profile was obtained in 181 (61%) and 188 (64%) patients. The most frequent cancer types were colorectal cancer (12%), non-Hodgkin’s lymphomas (9.8%) and head and neck cancers (7.8%). The most commonly detected mutations were TP53 (39%), KRAS (19%) and PIK3CA (9.5%), whereas ≥1 mutation were identified in 217 (74%) samples. Regarding the results for IHC testing, samples were positive for phospho-mammalian target of rapamycin (phospho-mTOR) (71%), epidermal growth factor receptor (EGFR) (68%), mesenchymal epithelial transition (MET) (56%) and/or platelet-derived growth factor alpha (PDGFRα)-expression (48%). Of the 288 tumour samples with one or more genetic alteration detected, 160 (55.6%) targeted therapy recommendations through 67 multidisciplinary tumour board meetings were made; in 69 (24%) cases, an individual treatment concept was initiated.ConclusionsThe results reveal that the open concept for all solid tumours characterised for molecular profile and immunotherapy could not only match individualised treatment concepts at a high rate but also underscores the challenges encountered when offering molecularly matched therapies to a patient population with an advanced stage cancer.

The effects of a combination of ion channel inhibitors on pathology in a model of demyelinating disease

BackgroundMultiple sclerosis (MS) has been shown to feature oxidative damage, which can be modelled using the cuprizone model of demyelinating disease. Oxidative damage can occur as a result of excessive influx of calcium ions (Ca2+) and oligodendroglia are particularly vulnerable. However, the effects of limiting excess Ca2+ influx on oxidative damage, oligodendroglia and myelin structure are unknown. ObjectiveThis study investigated the effects of limiting excess Ca2+ flux on oxidative damage and associated changes in oligodendroglial densities and Node of Ranvier structure in the cuprizone model. MethodsThe effects of three weeks of cuprizone administration and of treatment with a combination of three ion channel inhibitors (Lomerizine, Brilliant Blue G (BBG) and YM872), were semi-quantified immunohistochemically. Outcomes assessed were protein nitration (3-nitrotyrosine (3NT)) oxidative damage to DNA (8-hydroxy deoxyguanosine (8OHDG)), advanced glycation end-products (carboxymethyl lysine (CML)), immunoreactivity of microglia (Iba1) and astrocytes (glial acidic fibrillary protein (GFAP)), densities of oligodendrocyte precursor cells (OPCs) (platelet derived growth factor alpha receptor (PDGFαR) with olig2) and oligodendrocytes (olig2 and CC1), and structural elements of the Node of Ranvier (contactin associated protein (Caspr)). ResultsThe administration of cuprizone resulted in increased protein nitration, DNA damage, and astrocyte and microglial immunoreactivity, a decrease in the density of oligodendrocytes and OPCs, together with altered structure of the Node of Ranvier and reduced myelin basic protein immunoreactivity. Treatment with the ion channel inhibitor combination significantly lowered protein nitration, increased the density of OPCs and reduced the number of atypical Node of Ranvier complexes; other outcomes were unaffected. ConclusionOur findings suggest that excess Ca2+ influx contributes to protein nitration, and associated changes to OPC densities and Node of Ranvier structure in demyelinating disease.

Microscopy-Based Automated Live Cell Screening for Small Molecules That Affect Ciliation.

The primary monocilium, or cilium, is a single antenna-like organelle that protrudes from the surface of most mammalian cell types, and serves as a signaling hub. Mutations of cilia-associated genes result in severe genetic disorders termed ciliopathies. Among these, the most common is autosomal dominant polycystic kidney disease (ADPKD); less common genetic diseases include Bardet–Biedl syndrome, Joubert syndrome, nephronophthisis, and others. Important signaling cascades with receptor systems localized exclusively or in part at cilia include Sonic Hedgehog (SHH), platelet derived growth factor alpha (PDGFRα), WNTs, polycystins, and others. Changes in ciliation during development or in pathological conditions such as cancer impacts signaling by these proteins. Notably, ciliation status of cells is coupled closely to the cell cycle, with cilia protruding in quiescent (G0) or early G1 cells, declining in S/G2, and absent in M phase, and has been proposed to contribute to cell cycle regulation. Because of this complex biology, the elaborate machinery regulating ciliary assembly and disassembly receives input from many cellular proteins relevant to cell cycle control, development, and oncogenic transformation, making study of genetic factors and drugs influencing ciliation of high interest. One of the most effective tools to investigate the dynamics of the cilia under different conditions is the imaging of live cells. However, developing assays to observe the primary cilium in real time can be challenging, and requires a consideration of multiple details related to the cilia biology. With the dual goals of identifying small molecules that may have beneficial activity through action on human diseases, and of identifying ciliary activities of existing agents that are in common use or development, we here describe creation and evaluation of three autofluorescent cell lines derived from the immortalized retinal pigmented epithelium parental cell line hTERT-RPE1. These cell lines stably express the ciliary-targeted fluorescent proteins L13-Arl13bGFP, pEGFP-mSmo, and tdTomato-MCHR1-N-10. We then describe methods for use of these cell lines in high throughput screening of libraries of small molecule compounds to identify positive and negative regulators of ciliary disassembly.

Evaluation of the role of platelet derived growth factor in papillary thyroid carcinoma by targeted ultrasound contrast agent

Objective To explore the role of targeted ultrasound contrast agent in the evaluation of angiogenesis in papillary thyroid carcinoma (PTC) in nude mice by constructing platelet derived growth factor receptor α (PDGFRα)-targeted ultrasound contrast agents, and to explore the effect of platelet derived growth factor (PDGF) on angiogenesis in PTC. Methods PDGFRα-targeted ultrasound contrast agents were constructed through biotin-avidin linkage, and blank micro-bubbles were served as control group. After the siRNA-PDGF BCPAP cell line was established, well prepared BCPAP cells or siRNA-PDGF-BCPAP cells were injected subcutaneously into the back of male BABL/C nude mice. The growth of the tumors was observed closely. All tumors of the normal group and the siRNA-PDGF group were examined by PDGFRα-targeted ultrasound contrast agents or blank micro-bubbles, and the dynamic images were analyzed quantitatively by QontraXt software.All mice were sacrificed after ultrasonography. Microvessels density (MVD) in the tumors was counted by CD31 staining and the expressions of vascular endothelial growth factor(VEGF) and PDGF were detected by Western Blot. Results PTCs in nude mice were enhanced well by PDGFRα-targeted ultrasound contrast agent or blank micro-bubbles. The peak of tumors in siRNA-PDGF group was significantly lower than that in the normal group [(43.085±13.244)% vs (57.428±10.952)%, P=0.004]; MVD of the siRNA-PDGF group was significantly less than that of the normal group [(23.200±6.017)strips/view vs (35.000±8.456)strips/view, P=0.012]. The protein expression of PDGF and VEGF in siRNA-PDGF group were significantly lower than those in the normal group, respectively (0.142±0.058 vs 0.269±0.102, P=0.002; 0.096±0.036 vs 0.158±0.072, P=0.016). Conclusions PDGF plays an important role in angiogenesis of PTC, it maybe a new ultrasound molecular imaging method for monitoring tumor angiogenesis. Key words: Ultrasonography; Thyroid neoplasms; Receptor, platelet derived growth factor alpha; Contrast media, Target; Angiogenesis

PDGFRA mRNA overexpression is associated with regional metastasis and reduced survival in oral squamous cell carcinoma

Platelet-derived growth factor alpha (PDGFRA) is a gene encoding tyrosine kinase receptor and both EGFR and PDGFRA activate tyrosine kinases. The implication of PGFRA in many cancers and its prognostic significance irrespective to EGFR status in spinal chordoma, gliomas, and uterine cancers have shown a need for its investigation in oral squamous cell carcinoma (OSCC). We investigated the prognostic value of PDGFRA mRNA expression in OSCC. The study was conducted in the department of oral maxillofacial surgery-head and neck oncology, at a tertiary hospital. The data on PDGFRA mRNA expression and immunohistochemical staining status in primary OSCC patients treated for curative surgery from 2010 to 2012 were analyzed. Univariate and multivariate analyses were performed with other cofactors for survival. A total of 114 consecutive patients with primary OSCC who received treatment were studied. Thirty-one patients died of the disease. Strong PDGFRA immunohistochemical staining and high expression of PDGFRA mRNA were associated with positive pN status (P<.001), disease-free survival (P<.001), and overall survival (P<.001) in multivariate cox regression when all other factors such as pN status and histological grading were analyzed. Kaplan-Meier analysis revealed that the 2-year survival and 3-year survival of patients with PDGFRA mRNA low expression were 96.83%. However, 2-year survival for PDGFRA mRNA high expression level was 59.64%, which decreased to 45.57% by 3-years. PDGFRA overexpression in oral SCC, in respect to strong PDGFRA immunohistochemical staining and high PDGFRA mRNA expression, was positively associated with regional metastasis and reduced patient survival.