Research models that replicate the diverse genetic and molecular landscape of breast cancer are critical for developing the next generation therapeutic entities that can target specific cancer subtypes. Patient-derived tumorgrafts, generated by transplanting primary human tumor samples into immune-compromised mice, are a valuable method to model the clinical diversity of breast cancer in mice, and are a potential resource in personalized medicine. Primary tumorgrafts also enable in vivo testing of therapeutics and make possible the use of patient cancer tissue for in vitro screens. Described in this unit are a variety of protocols including tissue collection, biospecimen tracking, tissue processing, transplantation, and 3-dimensional culturing of xenografted tissue, that enable use of bona fide uncultured human tissue in designing and validating cancer therapies.

Gene expression profiling of early eosinophil development shows increased transcript levels of proinflammatory cytokines, chemokines, transcription factors, and a novel gene, EGO (eosinophil granule ontogeny). EGO is nested within an intron of the inositol triphosphate receptor type 1 (ITPR1) gene and is conserved at the nucleotide level; however, the largest open reading frame (ORF) is 86 amino acids. Sucrose density gradients show that EGO is not associated with ribosomes and therefore is a noncoding RNA (ncRNA). EGO transcript levels rapidly increase following interleukin-5 (IL-5) stimulation of CD34 ؉ hematopoietic progenitors. EGO RNA also is highly expressed in human bone marrow and in mature eosinophils. RNA silencing of EGO results in decreased major basic protein (MBP ) and eosinophil derived neurotoxin (EDN ) mRNA expression in developing IntroductionEosinophils are tissue-dwelling hematopoietic cells that likely play a role in parasitic immunity and allergic disease, such as asthma. 1 Activated eosinophils secrete toxic basic proteins such as major basic protein (MBP) and are postulated to cause bronchial hyperreactivity, damage of the bronchial mucosa, and remodeling of the airways. 1 Mice lacking eosinophils fail to show hallmarks of asthma such as airway hyperresponsiveness, tissue remodeling, and mucous metaplasia. 2,3 A more complete understanding of eosinophil development could lead to drugs targeting eosinophil progenitors prior to migration to the asthmatic lung.Eosinophils develop in the bone marrow from hematopoietic stem cells and migrate mainly to the gut or to sites of inflammation. Eosinophils, neutrophils, and monocytes have a common progenitor in the myeloid pathway of development. The combinatorial interactions of several transcription factors, including GATA-1, PU.1, and the CCAAT enhancer binding proteins, c/EBP␣ and ⑀, are important to eosinophil development. [4][5][6][7] High levels of PU.1 specify myeloid differentiation by antagonizing GATA-1 in the earliest stages of stem cell commitment. 8 In particular, a highaffinity GATA-1 binding site within the GATA-1 promoter appears to be critical for eosinophil development; deletion of this binding site in mice specifically abolishes the entire eosinophil lineage. 9 During later stages of eosinophil development, an intermediate level of GATA-1 in synergy with PU.1 directs the formation of the eosinophil lineage by activating dual binding sites in the MBP promoter. [10][11][12] GATA-1 also activates the eotaxin receptor CC chemokine receptor-3 (CCR3) promoter and the interleukin-5 (IL-5) receptor ␣ (IL-5R␣) gene. 13 The CCAAT enhancer binding protein, c/EBP␣, is important in early myeloid development, whereas c/EBP⑀ plays a later role. 14 Mouse knockouts of c/EBP⑀ affect both neutrophil and eosinophil development at the myelocyte to metamyelocyte stage. 14 Other genes involved in eosinophil development include the helix-loop-helix transcription factors, Id 1 and 2, and FOG (friend of GATA). FOG inhibits eosinophil development by intera...

Background-Mepolizumab, a monoclonal anti-interleukin-5 (IL-5) antibody, is an effective corticosteroid-sparing agent for patients with F/P-negative hypereosinophilic syndrome. Lymphocytic variant hypereosinophilic syndrome (L-HES) is characterized by marked overproduction of IL-5 by dysregulated T-cells.

Serum EDN levels were significantly higher in subjects with EE than in controls, and the results suggest a possible role, after additional future studies, for serum EDN in establishing EE diagnosis, assessing response to therapy, and/or monitoring for relapse or quiescence.