A retrospective clinico-pathological study was performed on 208 consecutively recruited patients (94 males, 114 females, median age 67 years) with idiopathic (primary) osteo-/ myelofibrosis (IMF). According to bone marrow histology (cellularity) as well as extent (semiquantitative grading) and quality (reticulin/collagen) of myelofibrosis, stages of the disease process were determined. At closure of this study (observation time 65 months) 133 patients were dead and 75 alive and median survival was 56 months. The wide spectrum of clinical signs and symptoms and laboratory data on admission was reflected by a corresponding variety of histological features. Significant differences of hematological values could be calculated between patients with or without early reticulin fibrosis (fiber scores 0 and 1) and advanced fibro-osteosclerotic stages (fiber scores 2 and 3). Evolution of disease features was elicited by longitudinal follow-up studies and sequential bone marrow biopsies. Morphometric assessment of fiber density in patients without preceding chemotherapy revealed an unpredictable and varying progression of myelofibrosis associated with alterations of certain laboratory parameters (hemoglobin level, spleensize, thrombocytosis). Differentiation from essential (primary) thrombocythemia (ET) was required in 25 patients who fulfilled the postulated diagnostic criteria. In fact, this group was consistent with hypercellular, early stages of IMF without relevant reticulin fibrosis and an excessively raised platelet count (> or = 1000 x 10(9)/1). Discrimination was only feasible by regarding histology carefully, particularly abnormalities of megakaryopoiesis and follow-up data. Parameters of predictive value indicating a significant loss in life expectancy in comparison with a sex- and age-adjusted normal population included: age (> or = 60 years), hemoglobin levels (< or = 10 g/dl), thrombocyte count (< or = 600 x 10(9)/1) and the presence of myeloblasts and promyelocytes. Statistical analysis disclosed that in the so-called early stages of IMF without relevant myelofibrosis, findings indicative for extramedullary hemopoiesis or generalization of the disease process exerted an unfavourable influence on survival.

Antibody-drug conjugates (ADC) are emerging as powerful treatment strategies with outstanding targetspecificity and high therapeutic activity in patients with cancer. Brentuximab vedotin represents a first-in-class ADC directed against CD30 þ malignancies. We hypothesized that its sustained clinical responses could be related to the stimulation of an anticancer immune response. In this study, we demonstrate that the dolastatin family of microtubule inhibitors, from which the cytotoxic component of brentuximab vedotin is derived, comprises potent inducers of phenotypic and functional dendritic cell (DC) maturation. In addition to the direct cytotoxic effect on tumor cells, dolastatins efficiently promoted antigen uptake and migration of tumor-resident DCs to the tumordraining lymph nodes. Exposure of murine and human DCs to dolastatins significantly increased their capacity to prime T cells. Underlining the requirement of an intact host immune system for the full therapeutic benefit of dolastatins, the antitumor effect was far less pronounced in immunocompromised mice. We observed substantial therapeutic synergies when combining dolastatins with tumor antigen-specific vaccination or blockade of the PD-1-PD-L1 and CTLA-4 coinhibitory pathways. Ultimately, treatment with ADCs using dolastatins induces DC homing and activates cellular antitumor immune responses in patients. Our data reveal a novel mechanism of action for dolastatins and provide a strong rationale for clinical treatment regimens combining dolastatin-based therapies, such as brentuximab vedotin, with immune-based therapies. Cancer Immunol Res; 2(8); 741-55. Ó2014 AACR.

Integrated analysis of genomes, transcriptomes, proteomes and drug responses of cancer cell lines (CCLs) is an emerging approach to uncover molecular mechanisms of drug action. We extend this paradigm to measuring proteome activity landscapes by acquiring and integrating quantitative data for 10,000 proteins and 55,000 phosphorylation sites (p-sites) from 125 CCLs. These data are used to contextualize proteins and p-sites and predict drug sensitivity. For example, we find that Progesterone Receptor (PGR) phosphorylation is associated with sensitivity to drugs modulating estrogen signaling such as Raloxifene. We also demonstrate that Adenylate kinase isoenzyme 1 (AK1) inactivates antimetabolites like Cytarabine. Consequently, high AK1 levels correlate with poor survival of Cytarabine-treated acute myeloid leukemia patients, qualifying AK1 as a patient stratification marker and possibly as a drug target. We provide an interactive web application termed ATLANTiC ( http://atlantic.proteomics.wzw.tum.de ), which enables the community to explore the thousands of novel functional associations generated by this work.

IntroductionChronic lymphocytic leukemia (CLL) is a clonal B-cell disorder that is not curable by conventional chemoimmunotherapies. The leukemic transformation may be initiated by specific genomic alterations (eg, del13q) that may cause the deletion of specific micro-RNA genes (eg, miR15 and miR16) and increase the resistance of B cells toward apoptosis. 1,2 Survival of CLL cells depends on a permissive microenvironment composed of cellular components, such as macrophages, T cells, or stromal follicular dendritic cells. [3][4][5] This microenvironment provides various chemokines and angiogenic factors, which interact with leukemic cells via appropriate surface receptors and adhesion molecules. 2,5 Macrophage migration inhibitory factor (MIF) is a proinflammatory and immunoregulatory cytokine that seems to be involved in the pathogenesis of various malignant diseases. 6-9 MIF was identified as a product of T cells 10 but also other cells of the immune system (B cells, monocytes/macrophages). 11 Later, MIF was found to be an almost ubiquitous mediator secreted by a wide variety of cells in the mammalian organism, such as endothelial cells, epithelial cells, or fibroblasts. 12 Macrophages are considered to be a prime source for MIF, as they are able to secrete large amounts of MIF in response to various stimuli. 13 MIF binds to the surface receptors CD74 and CXCR2/CXCR4, thereby stimulating signaling pathways, such as MAPK, NF-B, and AKT. [14][15][16] In B cells, activation of the surface receptor complex CD74/CD44 by MIF induces the proteolytic release of the intracellular domain of CD74, which in turn initiates a signaling cascade composing Syk, AKT, and NF-B; this leads to the production of IL-8 and to an increased resistance to apoptosis via the up-regulation of BCL-2. 17,18 Thus, the MIF-MIF receptor system may be seen as a part of the B-cell costimulatory signals that are required for full B-cell activation and maturation. MIF-deficient mice do not show developmental abnormalities and appear to have normal numbers of B cells. 6 However, they exhibit a number of immune dysfunctions when challenged by antigens or infectious agents. [19][20][21][22] Even more importantly, MIF seems to be required for bone marrow-derived dendritic cells to maintain mature B cells in the bone marrow compartment. 23 Submitted May 22, 2012; accepted October 14, 2012. Prepublished online as Blood First Edition paper, November 1, 2012; DOI 10.1182/blood-2012-05-431452.The online version of this article contains a data supplement.The publication costs of this article were defrayed in part by page charge payment. Therefore, and solely to indicate this fact, this article is hereby marked ''advertisement'' in accordance with 18 USC section 1734. MIF is overexpressed in a variety of malignancies compared with the respective primary tissues (eg, prostate, 24 colon, 25 melanoma, 26 glioblastoma, 27 breast cancer 28,29 ). This overexpression might be caused by the tumor-activated HSP90 chaperone complex that protects MIF from degradation, a...

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