Citations

AbstractObjectivesApproximately 15% of patients with multiple myeloma (MM) exhibit a t(4;14) translocation, which often results in constitutive activation of the receptor tyrosine kinase (RTK) fibroblast growth factor receptor 3 (FGFR3). This study evaluated the efficacy and safety of dovitinib, an RTK inhibitor with in vitro inhibitory activity against FGFR, in patients with relapsed or refractory MM with or without t(4;14) translocation.MethodsAdult patients with relapsed or refractory MM who had received ≥2 prior regimens were enrolled in this multicenter, 2‐stage, phase 2 trial. Patients were grouped based on their t(4;14) status. Dovitinib (500 mg/day orally) was administered on a 5‐days‐on/2‐days‐off schedule. The primary endpoint was overall response rate by local investigator review (per International Myeloma Working Group criteria). In non‐responding patients, treatment could continue with the addition of low‐dose dexamethasone.ResultsIn total, 43 patients (median age, 63 years) were enrolled (13 t(4;14) positive, 26 t(4;14) negative, and 4 t(4;14) status non‐interpretable). Patients had received a median of 5 prior regimens. Median duration of treatment was 8.7 weeks in the t(4;14)‐positive group and 3.7 weeks in the t(4;14)‐negative group. None of the patients on dovitinib had objective responses. The stable disease rate was 61.5% in the t(4;14)‐positive group and 34.6% in the t(4;14)‐negative group. Overall, 39 patients (90.7%) had adverse events suspected to be related to study drug, most commonly diarrhea (60.5%), nausea (58.1%), vomiting (46.5%), and fatigue (32.6%).ConclusionDovitinib showed no single‐agent activity in relapsed or refractory MM but may stabilize disease in some t(4;14)‐positive patients.

Approximately, twenty years ago, the Rare Cancer Network (RCN) was formed in Lausanne, Switzerland, to support the study of rare malignancies. The RCN has grown over the years and now includes 130 investigators from twenty-four nations on six continents. The network held its first international symposium in Nice, France, on March 21-22, 2014. The proceedings of that meeting are presented in two companion papers. This manuscript reviews the history of the growth of the RCN and contains the abstracts of fourteen oral presentations made at the meeting of prior RCN studies. From 1993 to 2014, 74 RCN studies have been initiated, of which 54 were completed, 10 are in progress or under analysis, and 9 were stopped due to poor accrual. Forty-four peer reviewed publications have been written on behalf of the RCN.

Abstract There is a significant unmet medical need to develop more effective treatments for cancers of the central and peripheral nervous systems. Glioblastoma multiforme (GBM) is the most common form of brain cancer, and successful long-term treatment has not been realized. Neuroblastomas (NB) arise in the sympathetic nervous system and are the most common extracranial solid tumor of childhood. Survival of children with disseminated, high-risk NB tumors is less than 50%, even with intensive multimodal treatment. To improve treatment outcome, inhibition of murine double minute 2 (MDM2) function in the context of front-line therapy is being explored. MDM2 is a multi-functional protein that plays a critical role in controlling cell growth and migration. MDM2 is a negative regulator of p53 and p73 and, under low stress conditions, sequesters them in the cytoplasm. However, inhibition of MDM2 interactions with p53 and p73 by the MDM2 antagonist nutlin3a can lead to activation of p53/p73-mediated cell-death in tumor cells. The objective of the present study was to evaluate the extent to which blockade of MDM2-p53/p73 interactions by nutlin3a, alone or in combination with front-line therapies, could augment cell death in GBM and NB cells with a variety of molecular profiles. Using the median effect model, we found that temozolomide (TMZ) and nutlin3a were synergistic in increasing cell death in wtp53 U87 and U373 but were predominantly additive in mtp53 U118 cells. Primary patient GBM cells were typically resistant to TMZ relative to established cell lines. However, resistance to TMZ was decreased in the presence of nutlin3a. Further, TMZ and nutlin3a were synergistic in primary GBM10 and GBM43 but not in recurrent primary IU-GBM16, IU-GBM23, IU-GBM27, and IU-GBM32 cells. Moreover, in NB cells with wtp53, nutlin3a and cisplatin were synergistic in MYCN nonamplified SK-N-SH and additive in MYCN amplified IMR5. In mtp53 NB cells, nutlin3a and cisplatin were synergistic in MYCN nonamplified SK-N-FI as well as in MYCN amplified SK-N-DZ. Nutlin3a alone produced dose-related increases in cell death of all GBM and NB cell lines irrespective of p53 status, suggesting that p53-independent mechanisms play a role in inhibition of cell growth produced by blockade of MDM2-mediated signaling. Consistent with this hypothesis, nutlin3a increased p73 protein levels in mtp53 GBM43 cells that were exposed to TMZ. Inhibition of MDM2 function also inhibited repair of TMZ-mediated DNA damage in GBM. In comet assays, nutlin3a+TMZ decreased DNA repair relative to TMZ alone in wtp53 U87 and GBM10 and in mtp53 GBM43 cells. The present results demonstrate that MDM2 is a valid therapeutic target in GBM and NB cells with varying genetic profiles. In conclusion, inhibition of MDM2 signaling by nutlin3a is generally synergistic to additive in combination with front-line chemotherapeutics used to treat cancers of the central and peripheral nervous systems. Citation Format: Harlan E. Shannon, Haiyan Wang, Shanbao Cai, Wei Michael Liu, Lawrence M. Gelbert, Aaron A. Cohen-Gadol, Jann N. Sarkaria, Lindsey D. Mayo, Karen E. Pollok. MDM2 as a therapeutic target: improving upon front-line chemotherapy for nervous system tumors. [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 3435. doi:10.1158/1538-7445.AM2013-3435

Abstract Glioblastoma (GBM) is the most common and malignant form of primary brain tumor. Average survival rate of GBM is 12-15 months from diagnosis. Due to its highly invasive nature, current treatment options have not been able to improve the survival rate in past 20 years. In order to discover GBM therapeutic targets, omics technologies have been widely used in order to identify potential biomarkers. Identification of cancer biomarkers for diagnosis and prognosis continues to evolve as clinical specimen pipelines and technologies are optimized. This research study focused on investigating proteins, metabolites and lipids biomarkers and patterns of human GBM xenografts employing mass spectrometry. Human tumor cell lines GBM 10 and GBM 43 were injected in the right cerebral hemisphere and flank sites in NOD/SCID mice (n = 10 mice per group). After harvesting brain and flank tumors and control brain from mouse models, protein, metabolites, and lipids of tumor samples were collected through one simple extraction procedure, which may solve sample preparation difficulties in omics studies, developed by Dr. Jiri Adamec. These samples were analyzed by reverse phase high performance liquid chromatography - Fourier transform ion cyclotron resonance mass spectrometry (LC-FTMS). FTMS analyzers have the highest resolving power of all MS instruments, which is ideal for complex mixtures such as GBM tissue. Spectra obtained from the FTMS analysis were analyzed using Student t-tests to detect significant differences in tissue profiles at a level of p = 0.05. Compounds below this threshold were identified through a database using the m/z ratio. Lipidomic analysis indicated the possible up and down-regulation of several lipids classes in GBM tissue connected to metabolic pathways, tumor proliferation and immunodepression, such as glycerophospholipids, both up- and down-regulated (e.g. PC38:4 or PG 35:2, respectively), and down-regulated glycosphingolipids (Galβ1-3GlcNAcβ1-3Galβ1-4Glc-Cer, Galβ1-4GlcNAcβ1-3Galβ1-4Glc-Cer), and triglycerides (TG 55:9, 53:4,52:8). We expect that integrated studies of proteomics, metabolomics, and lipidomics increase the confidence of identification of potential biomarkers. Accompanying these studies is a collaborative effort to improve the effectiveness and efficiency of computational pipelines that are imperative to the analytics, visualization, identification, and interpretation of the omics data. Only by carefully integrating the computational pipelines can we successfully perform the types of integrative studies needed to advance the identification of cancer biomarkers for diagnosis and prognosis, and our integrative studies serve as a case study for our pipeline advancement efforts. Citation Information: Mol Cancer Ther 2013;12(11 Suppl):B37. Citation Format: Soo Jung Ha, Gordon Showalter, Jenna Rickus, Shanbao Cai, Haiyan Wang, Wei Michael Liu, Jann N. Sarkaria, John Springer, Jiri Adamec, Karen E. Pollok, Kari L. Clase. Proteomic and metabolomic analyses of glioblastoma using mass spectrometry. [abstract]. In: Proceedings of the AACR-NCI-EORTC International Conference: Molecular Targets and Cancer Therapeutics; 2013 Oct 19-23; Boston, MA. Philadelphia (PA): AACR; Mol Cancer Ther 2013;12(11 Suppl):Abstract nr B37.

AbstractObjectivesWith clinical use of high‐sensitivity troponin I (hsTnI), more frequent troponin elevations will occur. However, the burden and implications of these elevations are not well understood. The authors quantified the prevalence of elevated hsTnI in patients presenting with possible acute coronary syndrome (ACS) who do not have elevated troponin with a current generation assay (cardiac troponin I [cTnI]) and determined the association of these newly detected elevations with a composite of all‐cause mortality and subsequent cardiac hospitalization.MethodsThis was a prospective observational study of 808 subjects evaluated for possible ACS and followed for up to 1 year. Troponin values were measured with hsTnI (Abbott Laboratories) and cTnI (Abbott and Beckman Coulter). Cardiac hospitalization was defined as hospitalization for ACS, revascularization, acute heart failure (AHF), or tachy/brady arrhythmia that occurred after the index emergency department (ED) visit or hospital discharge.ResultsForty subjects (5%) were diagnosed with ACS (26 myocardial infarction and 14 unstable angina). On the initial sample, the prevalence of elevated hsTnI among subjects with nonelevated cTnI was 9.2% using a gender‐neutral cutoff (95% confidence interval [CI] = 7.1% to 11.4%) and 11.1% using a gender‐specific cutoff (95% CI = 8.8% to 13.4%). Adjudicated diagnoses for subjects whose initial samples had elevated hsTnI but nonelevated cTnI (gender‐neutral cutoff) were as follows: three (4.6%) ACS, 15 (23.1%) AHF, three (4.6%) volume overload etiology unclear/noncardiac, three (4.6%) cardiac (non‐ACS), and 41 (63.1%) other. Of the 65 patients whose initial samples had hsTnI but nonelevated cTnI, eight developed cTnI elevation on subsequent serial sampling. After traditional cardiovascular risk factors and renal function were adjusted for, subjects with elevated initial hsTnI but nonelevated cTnI (initial and serial sampling) had a higher risk of all‐cause mortality and subsequent cardiac hospitalization than subjects with both nonelevated hsTnI and nonelevated cTnI (hazard ratio [HR] = 1.91, 95% CI = 1.14 to 3.19).ConclusionsOn the initial sample, 9% to 11% of subjects without cTnI elevation had hsTnI elevation. Although the majority of the patients with these newly detected hsTnI elevations did not have ACS, they had a higher risk for all‐cause mortality and subsequent cardiac hospitalization.

Summary The transcription factor forkhead box N4 (Foxn4) is a key regulator in a variety of biological processes during development. In particular, Foxn4 plays an essential role in the genesis of horizontal and amacrine neurons from neural progenitors in the vertebrate retina. Although the functions of Foxn4 have been well established, the transcriptional regulation of Foxn4 expression during progenitor cell differentiation remains unclear. Here, we report that an evolutionarily conserved 129 bp noncoding DNA fragment (Foxn4CR4.2 or CR4.2), located ∼26 kb upstream of Foxn4 transcription start site, functions as a cis-element for Foxn4 regulation. CR4.2 directs gene expression in Foxn4-positive cells, primarily in progenitors, differentiating horizontal and amacrine cells. We further determined that the gene regulatory activity of CR4.2 is modulated by Meis1 binding motif, which is bound and activated by Meis1 transcription factor. Deletion of the Meis1 binding motif or knockdown of Meis1 expression abolishes the gene regulatory activity of CR4.2. In addition, knockdown of Meis1 expression diminishes the endogenous Foxn4 expression and affects cell lineage development. Together, we demonstrate that CR4.2 and its interacting Meis1 transcription factor play important roles in regulating Foxn4 expression during early retinogenesis. These findings provide new insights into molecular mechanisms that govern gene regulation in retinal progenitors and specific cell lineage development.

Abstract Altered B cell function is important in the pathogenesis of rheumatoid arthritis (RA). In this report, we show that patients with active RA have an increased frequency of CD32B low/neg cells in the CD27+IgD− memory B cell subset and that these changes are associated with phenotypic and functional B cell activation. Studies using PBMCs from healthy donors revealed that downregulation of CD32B on B cells is mediated by CD40–CD40L interactions and is potentiated by IL-4 and inhibited by both IL-10 and IL-21. These findings appear physiologically relevant because CD4 T cell expression of CD40L correlated with the frequency of CD32B low/neg cells in the CD27+IgD− memory B subset in patients with RA. Our data support a model in which high levels of CD40L, present on circulating T cells in patients with RA, causes B cell activation and CD32B downregulation, resulting in secondary protection of memory B cells from CD32B-mediated cell death.

Bone marrow‐derived macrophages (BMMs) treated with granulocyte‐macrophage colony‐stimulating factor (GM‐CSF) or macrophage colony‐stimulating factor (M‐CSF), differentiate into GM‐CSF‐induced mouse bone marrow‐derived macrophages (GM‐BMMs) or M‐CSF‐induced mouse bone marrow‐derived macrophages (M‐BMMs), which have an M1 or M2 profile, respectively. GM‐BMMs produce large amounts of proinflammatory cytokines and mediate resistance to pathogens, whereas M‐BMMs produce antiinflammatory cytokines that contribute to tissue repair and remodeling. M‐BMMs stimulated with lipopolysaccharide (LPS) are in an antiinflammatory state, with an IL‐12lowIL‐10high phenotype. However, the regulation of this process remains unclear. Klf10 belongs to the family of Krüppel‐like transcription factors and was initially described as a TGF‐β inducible early gene 1. IL‐12p40 is upregulated in LPS‐stimulated M‐BMMs from Klf10‐deficient mice, but downregulated during Klf10 overexpression. Klf11, another member of the Krüppel‐like factor family, can also repress the production of IL‐12p40. Furthermore, Klf10 binds to the CACCC element of the IL‐12p40 promoter and inhibits its transcription. We have therefore identified Klf10 as a transcription factor that regulates the expression of IL‐12p40 in M‐BMMs.