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Little K.M.,La Jolla Institute for Allergy and Immunology | Little K.M.,University of Virginia | Smalley D.M.,Maine Institute for Human Genetics and Health | Ley K.,La Jolla Institute for Allergy and Immunology
Seminars in Thrombosis and Hemostasis | Year: 2010

All cell types shed ectosomes and exosomes, collectively known as microparticles (MP; 0.1 to 1.5 m in diameter), when activated or stressed; normal human plasma contains ∼2 g MP protein/mL. The cellular composition of plasma MP is altered in many diseases, including acute coronary syndrome, diabetes mellitus, sepsis, and sickle cell disease. We measured the plasma MP protein composition of 42 patients (median age 69.5 years, most with cardiovascular disease) by label-free liquid chromatography coupled to tandem mass spectrometry. Among 458 proteins detected with high confidence (identified by at least two unique peptides with SEQUEST XCor (Thermo Electron Corp., San Jose, CA) 2.0, 2.2, and 3.3 for charge states +1, +2, and +3, respectively), 130 were present in most patients, representing a core set of plasma MP proteins. This core is enriched in cytoskeletal, integrin complex, and hemostasis proteins, and spectral counts of several proteins correlate with patient age and gender. We conclude that the MP proteome may be a useful and reliable source of biologically relevant disease biomarkers. Copyright © 2010 by Thieme Medical Publishers, Inc.


Perry J.J.P.,University of California at Riverside | Perry J.J.P.,Amrita University | Ballard G.D.,Maine Institute for Human Genetics and Health | Albert A.E.,Maine Institute for Human Genetics and Health | And 6 more authors.
Cell Reports | Year: 2015

Recent evidence supports the presence of an L-glutamylmethyltransferase(s) in eukaryotic cells, but this enzyme class has been defined only in certainprokaryotic species. Here, we characterize the human C6orf211 gene product as "acidic residue methyltransferase-1" (Armt1), an enzyme that specifically targets proliferating cell nuclear antigen (PCNA) in breast cancer cells, predominately methylating glutamate side chains. Armt1 homologs share structural similarities with the SAM-dependent methyltransferases, and negative regulation of activity by automethylation indicates a means for cellular control. Notably, shRNA-based knockdown of Armt1 expression in two breast cancer cell lines altered survival in response to genotoxic stress. Increased sensitivity to UV, adriamycin, and MMS was observed in SK-Br-3 cells, while in contrast, increased resistance to these agents was observed in MCF7 cells. Together, these results lay the foundation for defining the mechanism by which this post-translational modification operates in the DNA damage response (DDR). © 2015 The Authors.


Chen Y.,University of Massachusetts Medical School | Sullivan C.,Maine Institute for Human Genetics and Health | Peng C.,University of Massachusetts Medical School | Shan Y.,University of Massachusetts Medical School | And 3 more authors.
Blood | Year: 2011

We have shown that Alox5 is a critical regulator of leukemia stem cells (LSCs) in a BCR-ABL-induced chronic myeloid leukemia (CML) mouse model, and we hypothesize that the Alox5 pathway represents a major molecular network that regulates LSC function. Therefore, we sought to dissect this pathway by comparing the gene expression profiles of wild type and Alox5-/- LSCs. DNA microarray analysis revealed a small group of candidate genes that exhibited changes in the levels of transcription in the absence of Alox5 expression. In particular, we noted that the expression of the Msr1 gene was upregulated in Alox5-/- LSCs, suggesting that Msr1 suppresses the proliferation of LSCs. Using CML mouse model, we show that Msr1 is downregulated by BCR-ABL and this down-regulation is partially restored by Alox5 deletion, and that Msr1 deletion causes acceleration of CML development. Moreover, Msr1 deletion markedly increases LSC function through its effects on cell cycle progression and apoptosis. We also show that Msr1 affects CML development by regulating the PI3K-AKT pathway and β-Catenin. Together, these results demonstrate that Msr1 suppresses LSCs and CML development. The enhancement of the tumor suppressor function of Msr1 may be of significance in the development of novel therapeutic strategies for CML. © 2011 by The American Society of Hematology.


Alderfer M.A.,Children's Hospital of Philadelphia | Long K.A.,University of Pittsburgh | Lown E.A.,San Francisco State University | Marsland A.L.,University of Pittsburgh | And 3 more authors.
Psycho-Oncology | Year: 2010

Objectives: To promote a broader understanding of the psychosocial impact of childhood cancer on siblings, a systematic review was undertaken. Directions for future research are proposed and clinical strategies are suggested for addressing the needs of these children. Methods: Searches of Medline, PsycINFO and CINAHL revealed 65 relevant qualitative, quantitative, or mixed methods' papers published between 1997 and 2008. These papers were rated for scientific merit and findings were extracted for summary. Results: Siblings of children with cancer do not experience elevated mean rates of psychiatric disorders, but a significant subset experiences post-traumatic stress symptoms, negative emotional reactions (e.g. shock, fear, worry, sadness, helplessness, anger, and guilt), and poor quality of life in emotional, family, and social domains. In general, distress is greater closer to time of diagnosis. School difficulties are also evident within 2 years of diagnosis. Qualitative studies reveal family-level themes such as loss of attention and status as well as positive outcomes including increased sibling maturity and empathy. Conclusions: Research regarding siblings of children with cancer continues to be methodologically limited. The conclusions of qualitative and quantitative studies differ considerably. We propose a research agenda to propel this field forward including greater attention to alterations in normative development (as opposed to psychiatric conditions), development of more appropriate quantitative measures, examination of potential moderators of adaptation, and use of prospective longitudinal designs. Siblings of children with cancer are a psychosocially at-risk group and should be provided with appropriate supportive services. Copyright © 2009 John Wiley & Sons, Ltd.


Ma J.,University of Sichuan | Li M.,University of Sichuan | Hock J.,Maine Institute for Human Genetics and Health | Yu X.,University of Sichuan
Journal of Orthopaedic Research | Year: 2012

Individuals with nerofibromatosis Type 1 (NF1) frequently suffer a spectrum of bone pathologies, such as abnormal skeletal development (scoliosis, congenital bowing, and congenital pseudoarthroses, etc), lower bone mineral density with increased fracture risk. These skeletal problems may result, in part, from abnormal osteoclastogenesis. Enhanced RAS/PI3K activity has been reported to contribute to abnormal osteoclastogenesis in Nf1 heterozygous (Nf1+/-) mice. However, the specific downstream pathways linked to NF1 abnormal osteoclastogenesis have not been defined. Our aim was to determine whether mammalian target of rapamycin (mTOR) was a key effector responsible for abnormal osteoclastogenesis in NF1. Primary osteoclast-like cells (OCLs) were cultured from Nf1 wild-type (Nf1+/+) and Nf1+/- mice. Compared to Nf1+/+ controls, there were 20% more OCLs induced from Nf1+/- mice. Nf1+/- OCLs were larger and contained more nuclei. Hyperactive mTOR signaling was detected in Nf1+/- OCLs. Inhibition of mTOR signaling by rapamycin in Nf1+/- OCLs abrogated abnormalities in cellular size and number. Moreover, we found that hyperactive mTOR signaling induced abnormal osteoclastogenesis major through hyper-proliferation. Our research suggests that neurofibromin directly regulates osteoclastogenesis through mTOR signaling pathway. Inhibiting mTOR may represent a viable strategy to treat NF1 bone diseases. © 2011 Orthopaedic Research Society Published by Wiley Periodicals, Inc. J Orthop Res 30:144-152, 2012 Copyright © 2011 Orthopaedic Research Society.


Sullivan C.,Maine Institute for Human Genetics and Health | Peng C.,University of Massachusetts Medical School | Chen Y.,University of Massachusetts Medical School | Li D.,Edith Cowan University | Li S.,University of Massachusetts Medical School
Biochemical Pharmacology | Year: 2010

Inhibition of BCR-ABL with kinase inhibitors has become a well-accepted strategy for targeted therapy of Philadelphia-positive (Ph+) chronic myeloid leukemia (CML) and has been shown to be highly effective in controlling the disease. However, BCR-ABL kinase inhibitors do not efficiently kill leukemic stem cells (LSCs), indicating that this therapeutic strategy does not lead to a cure of CML. Development of curative therapies of CML require the identification of genes/pathways that play critical roles in survival and self-renewal of LSCs. Targeting of these key BCR-ABL downstream genes provides an opportunity to eradicate LSCs, as shown in our work that identifies the Alox5 gene as a key regulator of the function of CML LSCs. Immediate clinical trials are necessary to test the effectiveness of targeting a key BCR-ABL downstream gene in eradicating LSCs in CML patients. In this review, we will discuss current targeted therapies of CML using BCR-ABL kinase inhibitors, with a focus on the importance of developing a targeted therapy of CML through identification of target genes in CML LSCs. © 2010 Elsevier Inc.


Gong M.,University of Sichuan | Gong M.,Maine Institute for Human Genetics and Health | Ma J.,University of Sichuan | Ma J.,Maine Institute for Human Genetics and Health | And 6 more authors.
Molecular Cancer Research | Year: 2014

Small cell lung cancer (SCLC) is a rapidly progressing, incurable cancer that frequently spreads to bone. New insights are needed to identify therapeutic targets to prevent or retard SCLC metastatic progression. Human SCLC SBC-5 cells in mouse xenograft models home to skeletal and nonskeletal sites, whereas human SCLC SBC-3 cells only pervade nonskeletal sites. Because microRNAs (miRNA) often act as tumor regulators, we investigated their role in preclinical models of SCLC. miRNA expression profiling revealed selective and reduced expression of miRNA (miR)-335 and miR-29a in SBC-5 cells, compared with SBC-3 cells. In SBC-5 cells, miR-335 expression correlated with bone osteolytic lesions, whereas miR-29a expression did not. Overexpression of miR-335 in SBC-5 cells significantly reduced cell migration, invasion, proliferation, colony formation, and osteoclast induction in vitro. Importantly, in miR-335 overexpressing SBC-5 cell xenografts (n = 10), there were minimal osteolytic lesions in the majority of mice and none in three mice. Expression of RANK ligand (RANKL) and insulin-like growth factor-I receptor (IGF-IR), key mediators of bone metastases, were elevated in SBC-5 as compared with SBC-3 cells. Mechanistically, overexpression of miR-335 in SBC-5 cells reduced RANKL and IGF-IR expression. In conclusion, loss of miR-335 promoted SCLC metastatic skeletal lesions via deregulation of IGF-IR and RANKL pathways and was associated with metastatic osteolytic skeletal lesions. © 2013 AACR.


Chen Y.,University of Massachusetts Medical School | Peng C.,University of Massachusetts Medical School | Sullivan C.,Maine Institute for Human Genetics and Health | Li D.,Edith Cowan University | Li S.,University of Massachusetts Medical School
Leukemia | Year: 2010

Inhibition of BCR-ABL with kinase inhibitors in the treatment of Philadelphia-positive (Ph+) chronic myeloid leukemia (CML) is highly effective in controlling but not curing the disease. This is largely due to the inability of these kinase inhibitors to kill leukemia stem cells (LSCs) responsible for disease relapse. This stem cell resistance is not associated with the BCR-ABL kinase domain mutations resistant to kinase inhibitors. Development of curative therapies for CML requires the identification of crucial molecular pathways responsible for the survival and self-renewal of LSCs. In this review, we will discuss our current understanding of these crucial molecular pathways in LSCs and the available therapeutic strategies for targeting these stem cells in CML. © 2010 Macmillan Publishers Limited All rights reserved.


Gong M.,University of Sichuan | Gong M.,Maine Institute for Human Genetics and Health | Ma J.,University of Sichuan | Li M.,University of Sichuan | And 4 more authors.
Neuro-Oncology | Year: 2012

Malignant peripheral nerve sheath tumors (MPNSTs) are highly aggressive soft tissue sarcomas accounting for 310 of all soft tissue sarcomas. Neurofibromatosis type 1 (NF1) is the most important known risk factor. MPNSTs are often diagnosed at an advanced stage when distant metastases have developed. Although surgical resection remains the main treatment for MPNSTs, complete surgical resection is rarely possible. The prognosis for patients with MPNSTs is poor. There is an urgent need for improved therapies. To this end, we investigated whether microRNA (miR), specifically miR-204, might be implicated in MPNSTs because it is located at a cancer-associated genomic region exhibiting high frequency of loss of heterozygosity in tumors. We show that miR-204 expression is downregulated in NF1 and non-NF1 MPNST tumor tissues and in tumor cell lines. Restoring miR-204 expression in MPNST cell lines STS26T (non-NF1), ST88-14 (NF1), and T265p21 (NF1) significantly reduces cellular proliferation, migration, and invasion in vitro. Restoring miR-204 expression in STS26T decreases tumor growth and malignant progression in vivo. We also report that miR-204 inhibits Ras signaling and expression of high mobility group gene A2. These findings support the hypothesis that miR-204 plays critical roles in MPNST development and tumor progression. miR-204 may represent a novel biomarker for diagnosis and a candidate target with which to develop effective therapies for MPNSTs. © The Author(s) 2012.


Patent
Maine Institute For Human Genetics And Health | Date: 2012-02-28

The invention relates to the treatment of cancer using DNA damaging agents. The invention provides methods for treating a mammal with cancer, the method comprising inhibiting in the mammal acidic residue methyltransferase (Arm1) in combination with administering to the mammal a DNA damaging agent. The invention further provides pharmaceutical formulations comprising an inhibitor of acidic residue methyltransferase (Arm1) and a DNA damaging agent.

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