Growth Factor-beta Research Articles

Expression of platelet-derived growth factor alpha and beta genes PDGFRA and PDGFRB associated with biochemical recurrence of prostate cancer after radical prostatectomy

We performed genome-wide transcriptome meta-analysis of prostate cancer samples after radical prostatectomy of patients without lymph node metastasis. Significant associations were determined between expression of platelet-derived growth factor alpha and beta genes (PDGFRA and PDGFRB) and probability and time of onset of biochemical recurrence.

Phenotype of regenerative epithelium in idiopathic interstitial pneumonias.

The epithelial alteration in interstitial pneumonias is one of the repair processes at the sites of disease activity. Regenerative epithelial cells may participate in remodeling of the lung. To determine the phenotype of regenerative epithelial cells in usual interstitial pneumonia (UIP) and nonspecific interstitial pneumonia (NSIP), the expression of Clara cell 10KD protein (CC10), cytokeratin (CK) 14 and 17, surfactant apoprotein (SP)-A, KL-6/MUC1, transforming growth factor (TGF) beta2 were examined in 25 patients with UIP, 9 patients with NSIP and normal lung tissues from 10 patients with lung cancer. In honeycomb lesions of UIP, non-ciliated columnar cells mainly expressed CC10, cuboidal cells expressed CC10, CK17, CK14 and SP-A in descending order. Fibroblastic foci are covered by CK17, CK14, CC10, and a few SP-A positive flattened or cuboidal cells. Regenerative epithelium in NSIP mainly comprised cuboidal cells expressing SP-A, CC10 and CK17. KL-6 was more remarkably expressed in cuboidal and non-ciliated columnar cells both in UIP and NSIP. Expression of TGFbeta2 was observed in cuboidal and flattened epithelium. In severe fibrotic areas, CC10 expressing cells were more prominent, while SP-A positive cells were more prominent in less fibrotic areas. Regenerative epithelial cells in remodeling area in UIP may be derived from bronchiolar basal cells and Clara cells, while most of those in NSIP may be derived from type II pneumocytes. The different origin of regenerative epithelium may reflect the severity and extent of the injury and the degree of consequent fibrosis in UIP and NSIP.

Discovery of a Small-Molecule BMP Sensitizer for Human Embryonic Stem Cell Differentiation.

Sorely missing from the "toolkit" for directed differentiation of stem/progenitor cells are agonists of the BMP-signaling pathway. Using a high-throughput chemical screen, we discovered that PD407824, a checkpoint kinase 1 (CHK1) inhibitor, increases the sensitivity of cells to sub-threshold amounts of BMP4. We show utility of the compound in the directed differentiation of human embryonic stem cells toward mesoderm or cytotrophoblast stem cells. Blocking CHK1 activity using pharmacological compounds or CHK1 knockout using single guide RNA (sgRNA) confirmed that CHK1 inhibition increases the sensitivity to BMP4 treatment. Additional mechanistic studies indicate that CHK1 inhibition depletes p21 levels, thereby activating CDK8/9, which then phosphorylates the SMAD2/3 linker region, leading to decreased levels of SMAD2/3 protein and enhanced levels of nuclear SMAD1. This study provides insight into mechanisms controlling the BMP/transforming growth factor beta (TGF-β) signaling pathways and a useful pharmacological reagent for directed differentiation of stem cells.

A randomized controlled experimental study of the efficacy of platelet-rich plasma and hyaluronic acid for the prevention of adhesion formation in a rat uterine horn model.

Platelet-rich plasma (PRP) has been known to possess an efficacy in tissue regeneration. The aim of this study was to determine the role of PRP on post-operative adhesion formation in an experimental rat study. Thirty Sprague-Dawley rats were randomly divided into control, hyaluronic acid, and PRP treatment groups and operated on for uterine horn adhesion modeling. Blood was collected to produce a PRP with platelet counts of 688×10(3)/μL, and 1ml of either hyaluronic acid gel or PRP was administered over the standard lesions, while the control group received no medication. The evaluation of post-operative adhesions was done on the 30th post-operative day. The location, extent, type, and tenacity of adhesions as well as total adhesion scores, tissue inflammation, fibrosis and transforming growth factor-1beta (TGF-1β) expressions were evaluated. The total adhesion score was significantly lower in the PRP group (3.2±1.5) compared with the hyaluronic acid (5.0±1.3) and control (8.1±1.7) groups. The extent of the adhesions was significantly lower in the PRP group. There was no significant difference in the type and tenacity of adhesions between the hyaluronic acid and the PRP group. The level of inflammation was significantly higher in the control group than the others, while there was no difference between the PRP and hyaluronic acid groups. TGF-1β expression was significantly lesser in the PRP group than the control and hyaluronic acid groups. PRP is more effective than hyaluronic acid treatment in preventing post-operative adhesion formation in an experimental rat uterine horn adhesion model.

Abstract C199: PI3K/AKT/mTOR inhibitors enhance the anti-tumor activity of the FGFR, VEGFR and PDGFR inhibitor lucitanib in FGF-dependent breast cancer models

Abstract Lucitanib (S 80881, E-3810, CO-3810) is a potent inhibitor of the fibroblast growth factor receptors 1-3 (FGFR1-3), vascular endothelial growth factor receptors 1-3 (VEGFR1-3) and platelet-derived growth factor receptors alpha and beta (PDGFRα/β). A Phase 1/2 clinical study (Soria et al., 2014) of lucitanib showed a RECIST response rate of 50% in breast cancer patients with FGF-aberrant (FGFR1 and/or FGF3/4/19 gene amplified) tumors. Here we explored potential drug partners that can be used in combination with lucitanib to increase cell cytotoxicity. Five FGF-dependent breast carcinoma cell lines were evaluated - MFM-223 (human TNBC, FGFR1 / FGFR2 amplified, PIK3CA H1047R); HCC38 (human TNBC, FGFR1 high expression, PIK3CA W386L); CAL-120 (human TNBC, FGFR1 / FRS2 amplified, PIK3CA wild-type); EFM-19 (human ER+ BC, FGFR2 K659E, PIK3CA H1047L); and 4T1 (mouse TNBC, FGFR2 high expression, PIK3CA wild-type). Single agent and lucitanib drug-drug combinations were evaluated in 2D monolayer and/or 3D spheroid culture using a broad (MFM-223; n = 350 compounds) or a more focused compound library (cell lines CAL-120, EFM-19 and MFM-223; n = 70 compounds approved or in clinical trials). Drug combinations were evaluated at a concentration range of 0.06-5000 nM and co-cultured with 0.2 μM lucitanib in a 72-hour cell viability assay. Combination efficacy was determined by comparing cell viability with and without lucitanib either by direct comparison of raw RLU or by fold change in calculated GI50. Several compounds were identified that enhanced cell killing when combined with lucitanib, including HDAC inhibitors (vorinostat, entinostat and belinostat), PI3K/Akt/mTOR pathway inhibitors (GDC-0941, GDC-0980 and BLY719), EGFR/HER2 inhibitors (afatinib and lapatinib), and CDK inhibitors (AT7519 and flavopiridol). These combinations were examined for efficacy across all five cell lines, and combination indexes (CI) were calculated to determine synergy. The PI3K/Akt/mTOR and lucitanib combination demonstrated consistent synergy across all cell lines independent of PIK3CA mutation status. For example, the PI3K inhibitor GDC-0941 showed a CI range of 0.04-0.58 at the GI50 (CI < 1 synergistic). Greater cell killing by combined PI3K/AKT and FGFR inhibition was also shown to correlate with increased inhibition of p-AKT by immunoblotting. In conclusion, the activity of lucitanib in FGFR-driven breast carcinoma cells is augmented by the addition of PI3K/AKT/mTOR inhibitors, and dual targeting of AKT and FGFR signaling may enhance the clinical activity of these agents. Citation Format: Minh Nguyen, Liliane Robillard, Andrew D. Simmons, Henry J. Haringsma, Thomas C. Harding. PI3K/AKT/mTOR inhibitors enhance the anti-tumor activity of the FGFR, VEGFR and PDGFR inhibitor lucitanib in FGF-dependent breast cancer models. [abstract]. In: Proceedings of the AACR-NCI-EORTC International Conference: Molecular Targets and Cancer Therapeutics; 2015 Nov 5-9; Boston, MA. Philadelphia (PA): AACR; Mol Cancer Ther 2015;14(12 Suppl 2):Abstract nr C199.

Effect of montelukast sodium on TGF- 1 level of peripheral blood mononuclear cells from children with mild persistent asthma

Objective To explore the effect and mechanism of montelukast sodium on transforming growth factorβ1 (TGF-β1) expression in children with asthma. Methods 80 children with asthma were divided into 2 groups.The control group was treated with common medicine, and the observation group was treated with montelukast sodium.The clinical effect of two groups was evaluated.The peripheral eosinophile granulocyte(EOS) count of children was measured before and after treatment.Double antibody sandwich enzyme-linked immunosorbent assay (DAS-ELISA) was used to detect the serum levels of TGF-β1 and leukotriene E4 (LTE4) before and after treatment. Results The total effective rate of montelukast sodium group was 95.0%, remarkable effect in 28 cases, 10 cases were effective, and 2 cases failed.The total effective rate of the control group was 82.5%, 23 cases had remarkable effect, effective in 10 cases, ineffective in 7 cases.The effective rate of the montelukast sodium group was statistically higher than the control group(χ2=4.200, P 0.05). After treatment, the levels of serum TGF- 1, LTE4 of the observation group decreased more remarkably when compared with the control group (TGF-β1: t=2.06, P<0.05; LTE4: t=2.14, P<0.05). Conclusion Montelukast sodium has good clinical effect on childhood asthma.It can inhibit the expression of TGF- 1 in childhood asthma, and its mechanism may be related to eosinophils and the level of LTE4. Key words: Asthma; Growth factor beta 1; Montelukast sodium; Child

Abstract 784: Nonclinical activity of the FGFR, VEGFR and PDGFR inhibitor lucitanib in FGFR3 translocated tumor models

Abstract Lucitanib (S 80881, E-3810, CO-3810) is an oral, potent inhibitor of the tyrosine kinase activity of fibroblast growth factor receptors 1 through 3 (FGFR1-3), vascular endothelial growth factor receptors 1 through 3 (VEGFR1-3) and platelet-derived growth factor receptors alpha and beta (PDGFRα-ß). A Phase 1/2 clinical study (Soria et al., 2014, Ann. Oncol. 25(11):2244-51) showed compelling activity of lucitanib in solid tumors and, in particular, a 50% (6 of 12 patients) RECIST partial response rate in breast cancer patients with FGF-aberrant (FGFR1 and/or FGF3/4/19 gene amplified) tumors. On-going clinical studies are further defining the activity of lucitanib in breast (NCT02053636; NCT02202746) and lung cancer (NCT02109016). FGFR gene translocations (fusions; e.g. FGFR3-TACC3) resulting in constitutively active FGFR signaling and tumor proliferation are observed in a wide variety of cancers (Stransky et al., 2014; Nat. Comm. (5):5006), and inhibition of FGFR signaling in FGFR translocated tumors with lucitanib may be a potential new therapeutic strategy. We evaluated the nonclinical activity of lucitanib in FGFR3 translocated models with the hypothesis that the combined blockade of FGFR and VEGFR signaling would be more effective than targeting each receptor tyrosine kinase independently. The in vitro activity of lucitanib was first evaluated in a panel of bladder carcinoma cell lines (n = 8) with and without FGFR3 translocation. Lucitanib preferentially inhibited the growth of cell lines with FGFR3 translocations in 2D and 3D cell culture, with GI50 values of 80-120 nM in a 72-hour cell viability assay, coincident with a reduction in phosphorylated FGFR3 with an IC50 of ∼60 nM. Minimal activity was observed in five wild-type FGFR3 cell lines (GI50 &amp;gt; 5 μM) with the exception of the JMSU1 bladder cell line that is reported to be dependent on FGFR1 signaling for proliferation (Tomlinson et al., 2009, Cancer Res. 69(11):4613-20). The anti-tumor activity of lucitanib dosed orally at 20 mg/kg/day was evaluated in three bladder carcinoma cell-line derived xenografts with FGFR3 translocation (RT112/84, RT4 and SW780) and a patient-derived xenograft (PDX) model of glioblastoma (BN2289; Crown Bioscience) harboring a FGFR3-TACC3 fusion. Administration of lucitanib resulted in significant (p&amp;lt;0.0001) tumor growth inhibition and, in some cases, tumor regression. The anti-tumor activity of lucitanib in these xenograft models was greater than that observed with either sunitinib (VEGFR/PDGFR inhibitor; 40 mg/kg/day) or BGJ398 (FGFR1-4 inhibitor; 20 mg/kg/day). Together, these results provide a strong nonclinical rationale for further exploration of lucitanib in tumors with FGFR translocations in clinical studies. Citation Format: Minh Nguyen, Kevin K. Lin, Mike F. Burbridge, Andrew D. Simmons, Thomas C. Harding. Nonclinical activity of the FGFR, VEGFR and PDGFR inhibitor lucitanib in FGFR3 translocated tumor models. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 784. doi:10.1158/1538-7445.AM2015-784

Changes and meaning of Serum IL-4, IL-10, IFN-gamma, TGF-beta 1 level in patients with delayed encepha-lopathy after carbon monoxide poisoning

Objective To study changes and meaning of serum IL-4,IL-10,IFN-gamma, TGF-beta 1 level in patients with delayed encephalopathy after carbon monoxide poisoning. Methods From January 2011 and June 2014 in our hospital,40 cases of DEACMP patients were selected as group A; the 40 patients with DEACMP was divided into 12 cases of mild cognitive dysfunction, mild cognitive dysfunction in 20 cases,8 cases of severe cognitive dysfunction.40 cases with acute carbon monoxide poisoning(ACMP)patients were selected as group B;40 cases of healthy subjects were selected as healthy controls. Serum interleukin 4 and interleukin 10(IL-4)(IL-10), interferon gamma(IFN-gamma), conversion, growth factor beta 1(TGF-beta 1)content were tested. Results In Group A and group B serum IL-4 levels were lower than that of healthy controls(P<0.01), and serum levels of IL-10 in group B were higher than that in group A and healthy controls(P<0.01), serum level of IFN-gamma in group A and group B was higher than the healthy controls(P<0.01), and in group A IFN-gamma levels were higher than group B(P<0.01), while in group A serum TGF-beta 1 level was lower than B group and the control group(P< 0.01), and in group B TGF-beta 1 level was higher than the control group(P<0.01);With cognitive impairment aggravating of DEACMP patients, IL-4,IL-10,TGF-beta 1 levels were on the decline, and IFN-gamma level was increasing(P<0.01). Conclusion DEACMP patients serum and cerebrospinal fluid of IL-4,IL-10, IFN-gamma, TGF-beta measures such as abnormal expression, showed that the onset of DEACMP may be related to neural immune injury. Serum IL-4,IL-10,IFN-gamma and TGF-beta of DEACMP patients exists abnormal expression Serum IL-4,IL-10,IFN-gamma and TGF-beta levels are also related to the degree of cognitive impairment of DEACMP patients. The onset and progress of DEACMP may be associated with neural immune injury. Key words: Carbon monoxide poisoning; Delayed encephalopathy after.Immune function damage; Mechanism

TGF-β1-induced regulatory T cells

Besides central tolerance peripheral tolerance is an important mechanism to avoid development of autoimmunity. Naturally occurring thymic-derived regulatory T cells (nTreg) mediate peripheral tolerance by suppressing autoreactive T cells clones having escaped thymic deletional control. This implies that nTreg have therapeutic potential to dampen autoimmune disease. However, one of the main challenges for the therapeutic application of nTreg still remains the scarce amount of nTreg available.Transforming growth factor beta (TGF-β1) plays a critical role in the generation and immunosuppressive function of nTreg thereby contributing to immune homeostasis. TGF-β1 is thought to be essential for the generation and function of nTreg and regulatory T cells with suppressive properties can be induced in vitro by TGF-β1. These so-called TGF-β1-induced regulatory T cells (iTreg) can be induced in vitro from conventional CD4+ T cells by addition of TGF-β1 and this discovery has added new options to use regulatory T cells therapeutically.Here we discuss the generation and in vitro and in vivo functions of murine and human TGF-β1-induced regulatory T cells in light of potential application as treatment for autoimmune diseases including current problems and drawbacks in their therapeutic use.

P0427 : Platelet-derived growth factor-D intensifies fibrogenesis through upregulation of TIMP-1 and signaling via both platelet-derived growth factor receptor type alpha and beta

P0427 : Platelet-derived growth factor-D intensifies fibrogenesis through upregulation of TIMP-1 and signaling via both platelet-derived growth factor receptor type alpha and beta

Oxidative stress and cell damage in a model of precancerous lesions and advanced hepatocellular carcinoma in rats

Hepatocellular carcinoma (HCC) is the third most frequent cause of cancer deaths throughout the world. This study was aimed to analyze oxidative stress and cell damage in a multistage model of liver carcinogenesis induced by diethylnitrosamine (DEN) in rats. Male Wistar rats weighing 145–150g were divided into three groups: control, precancerous lesions (PL) (which received 100mg DEN once a week every 6 weeks up to 28 weeks), and advanced HCC (50mg DEN once/twice per week up to 19 weeks). Lipid peroxidation (TBARS), superoxide dismutase (SOD) activity, and expression of transforming growth factor-1 beta (TGF)-1β, endothelial and inducible nitric oxide syntahese (eNOS, iNOS), NADPH quinone oxireductase (NQO)-1, nuclear factor erythroid 2-related factor (NrF)2, kelch-like ECH-associated protein (Keap)1 and heat shock protein (HSP)70 were measured. TBARS concentration was augmented in the PL and advanced HCC groups. SOD activity, TGF-1β and Nrf2 expression were higher in animals with precancerous lesions. In advanced HCC, expression of NQO1 and iNOS increased while there was a decrease in HPS70 expression. Data obtained provide evidence for the differential activation of proteins involved in oxidative stress and cell damage during progression of carcinogenesis in an animal model of HCC.

Role of bradykinin and endothelin-converting enzyme-1 in pulmonary hypertension

By histological analysis, pulmonary vascular remodeling induced by MCT was also inhibited (vessel wall thickness: MCT 0.44 vs. M/A 0.31, p b 0.001). MCT treatment increased mRNA levels of endothelin (ET) receptor-A, ET receptor-B, ET-1 and transforming growth factor (TGF)beta in the lung. ADRCs therapy suppressed these increased mRNA (p b 0.05). Conclusion ADRC therapy inhibited the development of PAH by reversing the changes in ET expression and inflammatory cytokines. These findings suggest that ADRC therapy may open a novel strategy to treat PAH.

AB0056 The abnormality and clinical significance of T helper 9 cells in patients with rheumatoid arthritis

BackgroundTo investgate the expression of Th9 in the peripheral blood and the level of IL-9 in serm of rheumatoid arthritis (RA)Objectivesanalysis the relationship between this cells and disease activity, bone...

Xiamenmycin Attenuates Hypertrophic Scars by Suppressing Local Inflammation and the Effects of Mechanical Stress

Hypertrophic scarring is a common disease affecting millions of people around the world, but there are currently no satisfactory drugs to treat the disease. Exaggerated inflammation and mechanical stress have been shown to be two main mechanisms of excessive fibrotic diseases. Here we found that a benzopyran natural product, xiamenmycin, could significantly attenuate hypertrophic scar formation in a mechanical stretch-induced mouse model. The compound suppressed local inflammation by reducing CD4+ lymphocyte and monocyte/macrophage retention in fibrotic foci and blocked fibroblast adhesion with monocytes. Both in vivo and in vitro studies found that the compound inhibited the mechanical stress-induced profibrotic effects by suppressing proliferation, activation, fibroblast contraction, and inactivating FAK, p38, and Rho guanosine triphosphatase signaling. Taken together, the compound could simultaneously suppress both the inflammatory and mechanical stress responses, which are the two pivotal pathological processes in hypertrophic scar formation, thus suggesting that xiamenmycin can serve as a potential agent for treating hypertrophic scar formation and other excessive fibrotic diseases.

Chronic treatment with the glucocorticoid receptor antagonist RU486 inhibits diabetes-induced enhancement of experimental periodontitis

Chronic hypothalamic-pituitary-adrenal (HPA) axis hyperactivity and excessive glucocorticoid hormone release have been associated with diabetes, altered immune responses and increased susceptibility to periodontitis. In the present study we tested the impact of streptozotocin (STZ)-induced diabetes on ligature-induced periodontitis and the effect of subsequent treatment with the glucocorticoid receptor (GR) antagonist, RU486. A single dose of STZ [45mg/kg, intraperitoneally (i.p.)] or vehicle was given 10d before induction of ligature-induced periodontitis and implantation subcutaneously of a drug pellet containing the GR antagonist, RU486, or a placebo pellet. Periodontitis was assessed when the ligatures had been in place for 21d. Two hours before decapitation all rats received gram-negative bacterial lipopolysaccharide (LPS) (150μg/kg, i.p.) to induce a robust immune and stress response. Compared with control rats, STZ-treated rats developed significantly more periodontal bone loss, and RU486 treatment of STZ -treated rats significantly inhibited this effect. STZ-treated rats also showed significantly higher levels of the HPA axis-derived hormone, corticosterone, as well as of the proinflammatory cytokine, tumor necrosis factor-alpha (TNF-α), but lower levels of the anti-inflammatory cytokines interleukin-10 (IL-10) and transforming growth factor-1beta (TGF-1β) after LPS stimulation. GR blockade had no statistically significant effects on these measurements in diabetic rats, but tended to enhance the levels of TNF-α and TGF-1β, and reduce the levels of IL-10 and blood glucose. In diabetic subjects, excessive GR activation as a result of chronic high levels of glucocorticoid hormones may alter immune-system responses in a manner that may increase the susceptibility to periodontitis.

Abstract LB-244: MiR-34a/c-dependent PDGFR-α/β reduction inhibits tumorigenesis and sensitizes TRAIL-induced apoptosis in lung cancer.

Abstract Lung cancer is the most common cause of cancer death worldwide. Despite years of research, the prognosis for patients with lung cancer remains dismal. The most frequent type, non-small cell lung cancer (NSCLC) (85%), shows an overall five year survival of 15%. Isoforms of platelet-derived growth factor receptor (PDGFR) and its ligand, PDGF, constitute a family of receptors and ligands involved in proliferative and prosurvival signaling within cells. MicroRNAs (miRNAs), a class of ~ 22 nt endogenous RNAs, are important regulators of gene expression and have been implicated in the regulation of critical processes that are deregulated in cancer cells, as proliferation differentiation and apoptosis. Alterations in miRNA expression in cancer have been documented in numerous studies and suggest that miRNAs critically contribute to the cancer cell phenotype. In mammalians, the miR-34 family comprises three processed miRNAs that are encoded by two different genes: miR-34a is encoded by its own transcript, whereas miR-34b and miR-34c share a common primary transcript. In this study we found that miR-34a/c and not miR-34b, suppress the metastatic capacity of NSCLC by targeting platelet-derived growth factor receptor alpha and beta (PDGFR-α and PDGFR-β). We also observed an inverse relation between PDGFR-α/β mRNAs and miR-34a/c expression in lung tumor compared to normal lung samples. Finally, miR34-a/c-dependent PDGFR-α/β suppression or knocking-down of PDGFR-α/β by siRNAs sensitized NSCLC cells to TNF-related apoptosis inducing ligand (TRAIL)-induced apoptosis. Taken together our findings could be helpful for future anti-tumor therapy of lung cancer. Citation Format: Young-Jun Jeon, Gerard J. Nuovo, Justin Midddleton, Pooja Joshi, Natalya Nazaryan, Gianpiero Di Leva, Giulia Romano, Melissa Crawford, Patrick Nana-Sinkam, Michela Garofalo, Carlo M. Croce. MiR-34a/c-dependent PDGFR-α/β reduction inhibits tumorigenesis and sensitizes TRAIL-induced apoptosis in lung cancer. [abstract]. In: Proceedings of the 104th Annual Meeting of the American Association for Cancer Research; 2013 Apr 6-10; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2013;73(8 Suppl):Abstract nr LB-244. doi:10.1158/1538-7445.AM2013-LB-244

Recurrent CEP85L–PDGFRB fusion in patient with t(5;6) and imatinib-responsive myeloproliferative neoplasm with eosinophilia

Fusion genes involving the catalytic domain of tyrosine kinases (TKs) play an important role in the pathogenesis of hematological malignancies and solid tumors. In BCR–ABL1-negative myeloproliferative neoplasms (MPNs) several different tyrosine kinase fusion events have been described, most commonly involving the genes encoding the platelet-derived growth factor receptor alpha (PDGFRA) or beta (PDGFRB). Since the introduction of small molecule kinase inhibitors, TK fusions have emerged as prime therapeutic targets. Here, we report a recurrent CEP85L–PDGFRB fusion in a patient with eosinophilia and an MPN. The fusion was confirmed by specific amplification of the genomic breakpoints and reverse transcription polymerase chain reaction (PCR). The patient was treated with imatinib and achieved hematologic and cytogenetic remission. Minimal residual disease screening over 3 years with nested PCR failed to detect CEP85L–PDGFRB mRNA or genomic DNA, confirming a long-term molecular remission on imatinib.

Translating an Understanding of the Pathogenesis of Hepatic Fibrosis to Novel Therapies

The response to injury is one of wound healing and fibrogenesis, which ultimately leads to fibrosis. The fibrogenic response to injury is a generalized one across virtually all organ systems. In the liver, the injury response, typically occurring over a prolonged period of time, leads to cirrhosis (although it should be pointed out that not all patients with liver injury develop cirrhosis). The fact that many different diseases result in cirrhosis suggests a common pathogenesis. The study of hepatic fibrogenesis over the past 2 decades has been remarkably active, leading to a considerable understanding of this process. It clearly has been shown that the hepatic stellate cell is a central component in the fibrogenic process. It also has been recognized that other effector cells are important in the fibrogenic process, including resident fibroblasts, bone marrow-derived cells, fibrocytes, and even perhaps cells derived from epithelial cells (ie, through epithelial to mesenchymal transition). A key aspect of the biology of fibrogenesis is that the fibrogenic process is dynamic; thus, even advanced fibrosis (or cirrhosis) is reversible. Together, an understanding of the cellular basis for liver fibrogenesis, along with multiple aspects of the basic pathogenesis of fibrosis, have highlighted many exciting potential therapeutic opportunities. Thus, although the most effective antifibrotic therapy is simply treatment of the underlying disease, in situations in which this is not possible, specific antifibrotic therapy is likely not only to become feasible, but will soon become a reality. This review highlights the mechanisms underlying fibrogenesis that may be translated into future antifibrotic therapies and to review the current state of clinical development.

Preventive Effects of Oral Tolerance on Allergic Inflammation and Airway Remodeling in a Murine Model

Oral tolerance (OT) is considered as a preventive and therapeutic strategy for treating asthma and allergic rhinitis (AR). We investigated the preventive effects of OT on allergic inflammation and remodeling in the upper and lower airways in a mouse model of allergy. BALB/c mice were divided into four groups: control, allergy, low-dose OT, and high-dose OT. To induce OT, mice were fed ovalbumin (OVA) before sensitization with OVA/Al(OH)(3) at a dose of 1 mg for 6 days in low-dose OT group and a single dose of 25 mg in high-dose OT group. After sensitization followed by OVA challenge, nasal symptoms, interleukin (IL)-13, interferon (IFN)-gamma, IL-10, and transforming growth factor (TGF) beta-1 levels in nasal lavage (NAL) and bronchoalveolar lavage (BAL) fluids were measured, and OVA-specific IgE, IgG1, and IgG2a levels were measured in the serum. The airway hyperresponsiveness (AHR) was measured by enhanced pause. The goblet cell hyperplasia and the thickness of lamina propria were observed in the upper and lower airways. In the allergy group, the allergic behavior scores, AHR, and OVA-specific IgE, IgG1, and IgG2a levels; inflammatory cells; IFN-gamma levels; and IL-13 levels in NAL/BAL fluids were elevated compared with the control group, low-dose OT group, and high-dose OT group. The allergy group had higher levels of IL-10 and TGF-beta-1 in BAL fluids when compared with the other groups. The goblet cell hyperplasia and the thickness of the lamina propria were attenuated in both OT groups compared with the allergy group. OT may effectively prevent AHR, allergic inflammation, and airway remodeling in the upper and lower airways.

Abstract 3683: Crenolanib, a novel Type I, mutant-specific inhibitor of Class III receptor tyrosine kinases, preferentially binds to phosphorylated kinases

Abstract Introduction: Crenolanib (CP-868,596) is a benzimidazole tyrosine kinase inhibitor (TKI), known to potently inhibit the platelet derived growth factor receptors (PDGFR) alpha and beta, and the Fms-like tyrosine kinase 3 (FLT3). Crenolanib has been evaluated as a single agent (Lewis N, et al, J Clin Oncol 2009), and in combination with docetaxel ± axitinib (Michael M, et al, Br J Cancer 2010), and was found to be well tolerated, with transient elevation of liver enzymes at higher doses. We describe here the characterization of crenolanib as a unique chemotype, mutant-specific Type I TKI. Methods: The relative affinities of tyrosine kinase inhibitors for phosphorylated and non-phosphorylated ABL1 have been previously used to accurately distinguish type I from type II inhibitors (Wodicka LM, et al, Chem Biol 2010). The effect of ABL1 A-loop phosphorylation on crenolanib affinity was investigated in a competition binding assay (Karaman MW, et al, Nat Biotech 2008). The binding constants (Kds) of crenolanib for FLT3 (wild-type and five mutant isoforms) were also determined using the KINOMEscan KdELECT Assay (DiscoveRx, San Diego, CA), and compared with the Kds of 442 TKIs reported (Davis MI, et al, Nat Biotech 2011). The Kds of crenolanib for PDGFRα, PDGFRα, and c-KIT (wild-type and two mutant isoforms) are being determined. Results: The Kd of crenolanib for phosphorylated ABL1 and ABL(T315I) were 7- and 15-fold lower than the Kds for non-phosphorylated ABL1 and ABL(T315I) respectively. Based on this higher affinity for p-ABL1 relative to np-ABL1, crenolanib appears to be a Type I inhibitor. Furthermore, crenolanib has a 10-fold affinity shift between the non-autoinhibited and autoinhibited states of FLT3, which is in the range of affinity shifts reported for other Type I TKIs, in contrast to the 100- to 1000-fold affinity shift reported for Type II TKIs. Crenolanib also has the highest affinity for three constitutively activate isoforms of FLT3 (FLT3-ITD, FLT3-D835Y, FLT3-D835V) compared to 442 kinases reported (Davis MI, et al, Nat Biotech 2011). Crenolanib is a next-generation, mutant-specific TKI, currently in Phase II development in adult and pediatric gliomas, and in PDGFRAD842V-mutant GIST. The unique and specific kinase inhibition profile is hypothesized to translate to greater therapeutic effect, accompanied by fewer adverse events in the clinic. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 3683. doi:1538-7445.AM2012-3683