BACKGROUND The mechanisms of paraneoplastic thrombocytosis in ovarian cancer and the role that platelets play in abetting cancer growth are unclear. METHODS We analyzed clinical data on 619 patients with epithelial ovarian cancer to test associations between platelet counts and disease outcome. Human samples and mouse models of epithelial ovarian cancer were used to explore the underlying mechanisms of paraneoplastic thrombocytosis. The effects of platelets on tumor growth and angiogenesis were ascertained. RESULTS Thrombocytosis was significantly associated with advanced disease and shortened survival. Plasma levels of thrombopoietin and interleukin-6 were significantly elevated in patients who had thrombocytosis as compared with those who did not. In mouse models, increased hepatic thrombopoietin synthesis in response to tumor-derived interleukin-6 was an underlying mechanism of paraneoplastic thrombocytosis. Tumor-derived interleukin-6 and hepatic thrombopoietin were also linked to thrombocytosis in patients. Silencing thrombopoietin and interleukin-6 abrogated thrombocytosis in tumor-bearing mice. Anti–interleukin-6 antibody treatment significantly reduced platelet counts in tumor-bearing mice and in patients with epithelial ovarian cancer. In addition, neutralizing interleukin-6 significantly enhanced the therapeutic efficacy of paclitaxel in mouse models of epithelial ovarian cancer. The use of an antiplatelet antibody to halve platelet counts in tumor-bearing mice significantly reduced tumor growth and angiogenesis. CONCLUSIONS These findings support the existence of a paracrine circuit wherein increased production of thrombopoietic cytokines in tumor and host tissue leads to paraneoplastic thrombocytosis, which fuels tumor growth. We speculate that countering paraneoplastic thrombocytosis either directly or indirectly by targeting these cytokines may have therapeutic potential. (Funded by the National Cancer Institute and others.)

Background: Ascending thoracic aortic aneurysm (ATAA) is caused by the progressive weakening and dilatation of the aortic wall and can lead to aortic dissection, rupture, and other life-threatening complications. To improve our understanding of ATAA pathogenesis, we aimed to comprehensively characterize the cellular composition of the ascending aortic wall and to identify molecular alterations in each cell population of human ATAA tissues. Methods: We performed single-cell RNA sequencing analysis of ascending aortic tissues from 11 study participants, including 8 patients with ATAA (4 women and 4 men) and 3 control subjects (2 women and 1 man). Cells extracted from aortic tissue were analyzed and categorized with single-cell RNA sequencing data to perform cluster identification. ATAA-related changes were then examined by comparing the proportions of each cell type and the gene expression profiles between ATAA and control tissues. We also examined which genes may be critical for ATAA by performing the integrative analysis of our single-cell RNA sequencing data with publicly available data from genome-wide association studies. Results: We identified 11 major cell types in human ascending aortic tissue; the high-resolution reclustering of these cells further divided them into 40 subtypes. Multiple subtypes were observed for smooth muscle cells, macrophages, and T lymphocytes, suggesting that these cells have multiple functional populations in the aortic wall. In general, ATAA tissues had fewer nonimmune cells and more immune cells, especially T lymphocytes, than control tissues did. Differential gene expression data suggested the presence of extensive mitochondrial dysfunction in ATAA tissues. In addition, integrative analysis of our single-cell RNA sequencing data with public genome-wide association study data and promoter capture Hi-C data suggested that the erythroblast transformation-specific related gene( ERG ) exerts an important role in maintaining normal aortic wall function. Conclusions: Our study provides a comprehensive evaluation of the cellular composition of the ascending aortic wall and reveals how the gene expression landscape is altered in human ATAA tissue. The information from this study makes important contributions to our understanding of ATAA formation and progression.

IntroductionThe association between malignant tumors and elevated platelet counts raises the possibility of a pathophysiologic interaction between platelets and cancer cells. Cancer cells activate and aggregate platelets. 1-3 Conversely, platelets promote metastasis by protecting cancer cells against natural killer (NK) cells in the blood, 4 by enhancing attachment of cancer cells to the blood vessel wall, 5 by disrupting endothelial junctions, 6 and by promoting angiogenesis through selective sequestering, transporting, and releasing of several growth factors. [7][8][9][10][11] In murine models of metastasis, a deficiency in platelet adhesion molecules, such as P-selectin, glycoprotein Ib␣ (GPIb␣), or GPIIIa, reduces the number of metastatic lesions. [12][13][14][15] Recently, Labelle et al showed that TGF-␤1 secreted from platelets enhances an epithelial to mesenchymal transition in cancer cells promoting metastasis via activation of TGF-␤/Smad and NF-B pathways. 16 We have recently shown that reducing platelet counts decreased the size and number of tumor nodules in a murine model of orthotopic ovarian cancer. 17 In the same study, we detected extravasation of platelets from tumor vasculatures and direct contact between platelets and cancer cells. In the current study, we investigated whether platelets directly affect tumor growth. Methods Coincubation of platelets with ovarian cancer cellsGel-filtered murine or human platelets were isolated from whole blood. 17 Twenty million resting or lysed platelets (prepared by 3 cycles of freeze-and-thaw) were incubated with cancer cells. In some experiments, platelets were isolated from C57BL/6 mice with syngeneic tumors induced 3-4 weeks after intraperitoneal injection of 1 ϫ 10 6 ID8 murine ovarian cancer cells. 17 A total of 50 000 murine ID8 or 2C6 and human SKOV3 or OVCA5 ovarian cancer cells were incubated with serum-free media overnight. In some experiments, cancer cells were transfected with TGF-␤R1 siRNA using 2 g siRNA and 3 L of lipofectamine reagent (Invitrogen). Approximately 20 ϫ 10 6 platelets were added to each well and incubated for 24 hours at 37°C. Murine cancer cells were incubated with murine platelets and human cancer cells with human platelets. In some experiments, different concentrations of blocking antibodies to GPIb␣ (Xia-B2, Emfret Analytics), P-selectin (RB40.34, BD Biosciences), TGF-␤1 (N1C2, Gene Tex Inc); or eptifibatide (0.5M, Merck); or aspirin (15 g/mL, SigmaAldrich) were added to platelets before incubation with cancer cells. In control samples, appropriate buffer was added to the cells instead of platelets. To differentiate between the effect of direct contact between platelets and cells from an indirect paracrine effect, we seeded platelets either on cancer cells or on porous membranes (0.4 m, PET membrane, BD Biosciences) separated from cells in a coculture system. To determine cell proliferation, we measured incorporation of fluorescence-conjugated EdU (5-ethynil-2Ј-deoxyuridine) to newly synthesized DNA according to the manufact...

SUMMARY We describe a role for the complement system in enhancing cancer growth. Cancer cells secrete complement proteins that stimulate tumor growth upon activation. Complement promotes tumor growth via a direct autocrine effect that is partially independent of tumor-infiltrating cytotoxic T cells. Activated C5aR and C3aR signal through the PI3K/AKT pathway in cancer cells, and silencing the PI3K or AKT gene in cancer cells eliminates the progrowth effects of C5aR and C3aR stimulation. In patients with ovarian or lung cancer, higher tumoral C3 or C5aR mRNA levels were associated with decreased overall survival. These data identify a role for tumor-derived complement proteins in promoting tumor growth, and they therefore have substantial clinical and therapeutic implications.

Hematologic malignancies are frequently associated with cardiac pathologies. Mutations of isocitrate dehydrogenase 1 and 2 (IDH1/2) occur in a subset of acute myeloid leukemia patients, causing metabolic and epigenetic derangements. We have now discovered that altered metabolism in leukemic cells has a profound effect on cardiac metabolism. Combining mathematical modeling and in vivo as well as ex vivo studies, we found that increased amounts of the oncometabolite D-2-hydroxyglutarate (D2-HG), produced by IDH2 mutant leukemic cells, cause contractile dysfunction in the heart. This contractile dysfunction is associated with impaired oxidative decarboxylation of α-ketoglutarate, a redirection of Krebs cycle intermediates, and increased ATP citrate lyase (ACL) activity. Increased availability of D2-HG also leads to altered histone methylation and acetylation in the heart. We propose that D2-HG promotes cardiac dysfunction by impairing α-ketoglutarate dehydrogenase and induces histone modifications in an ACL-dependent manner. Collectively, our results highlight the impact of cancer cell metabolism on function and metabolism of the heart. D-2-hydroxyglutarate | IDH2 | metabolism | cardiomyopathy | flux rate analysis M etabolic dysregulation in cancer cells changes the way nutrients are consumed and macromolecules are produced to meet the increased demands for cell growth. Somatic mutations in isocitrate dehydrogenase 1 and 2 (IDH1/2) are common and are described in several cancer types (i.e., gliomas and acute myeloid leukemia). IDH mutations lead to increased production and accumulation of the oncometabolite D-2-hydroxyglutarate (D2-HG) through a neomorphic enzymatic function (1). WT IDH1/2 catalyzes the oxidative decarboxylation of isocitrate to α-ketoglutarate (α-KG), while reducing NADP + to NADPH either in the cytosol and peroxisome (IDH1), or in mitochondria (IDH2). In this reaction, D2-HG is produced in small amounts but converted back to its structural homolog α-KG by D2-HG dehydrogenase. Common features of tumors with IDH1/2 mutations are abnormal histone and DNA methylation, connecting metabolic changes with epigenetic control of gene expression (2). In hematologic malignancies, IDH1/2 are often co-mutated with epigenetic regulatory genes encoding enzymes that are important in DNA hydroxymethylation (i.e., tet methylcytosine dioxygenase 2, TET2) and methylation (i.e., DNA methyltransferase 3 A, DNMT3A) (3). Accumulation of D2-HG contributes to leukemogenesis, likely due to inhibition of α-KG-dependent dioxygenases, including histone lysine demethylases (KDMs) and TET2 (4). This hypothesis has been supported by recent reports linking the hypermethylation phenotype in cancer cells to IDH, fumarate hydratase, and succinate dehydrogenase mutations (5, 6).The starting point for the present work were reports that myeloid malignancies are associated with cardiac pathologies, which are commonly considered a side effect of chemotherapy (7). Other recent reports suggest that systemically produced D2-HG by neomorphic ...

Soil nutrients and density and biomass of annual plants underneath and outside the canopy of Porlieria chilensis shrubs were measured at the end of the growing season in a protected arid coastal site in Chile. Levels of soil nitrogen, phosphorus and organic matter were significantly higher underneath than outside the canopies of shrubs. Almost 4 times as many plants occurred outside than underneath shrubs, but no significant differences in total aboveground biomass were found. Several species had higher densities and/or biomass outside rather than underneath shrubs, whereas others showed the oppsite trend. Species richness was lower underneath P. chilensis canopy. The spatial microdistribution of ephemeral species may be explained by differential water and nutrient requirements. Comparison of the patterns observed in our protected site versus surrounding unprotected areas supports the generalization that man, by removing shrubs and trees, has changed a previous heterogeneous spatial distribution of nutrients to a more homogenous one.

Cardiac dysfunction in patients with liver cirrhosis is strongly associated with increased serum bile acid concentrations. Here we show that excess bile acids decrease fatty acid oxidation in cardiomyocytes and can cause heart dysfunction, a cardiac syndrome that we term Cholecardia. Fxr; Shp double knockout (DKO) mice, a model for bile acid overload, display cardiac hypertrophy, bradycardia, and exercise intolerance. In addition, DKO mice exhibit an impaired cardiac response to catecholamine challenge. Consistent with this decreased cardiac function, we show that elevated serum bile acids reduce cardiac fatty acid oxidation both in vivo and ex vivo. We find that increased bile acid levels suppress expression of Pgc1α, a key regulator of fatty acid metabolism, and that Pgc1α overexpression in cardiac cells was able to rescue the bile acid-mediated reduction in fatty acid oxidation genes. Importantly, intestinal bile acid sequestration with cholestyramine was sufficient to reverse the observed heart dysfunction in the DKO mice. Conclusions Overall, we propose that decreased Pgc1α expression contributes to the metabolic dysfunction in Cholecardia, and that reducing serum bile acid concentrations will be beneficial against metabolic and pathological changes in the heart.

Mitochondrial dysfunction and metabolic remodeling are pivotal in the development of cardiomyopathy. Here, we show that myocardial COUP-TFII overexpression causes heart failure in mice, suggesting a causal effect of elevated COUP-TFII levels on development of dilated cardiomyopathy. COUP-TFII represses genes critical for mitochondrial electron transport chain enzyme activity, oxidative stress detoxification and mitochondrial dynamics, resulting in increased levels of reactive oxygen and lower rates of oxygen consumption in mitochondria. COUP-TFII also suppresses the metabolic regulator PGC-1 network and decreases expression of key glucose and lipid utilization genes, leading to a reduction in both glucose and oleate oxidation in hearts. These data suggest that COUP-TFII affects mitochondrial function, impairs metabolic remodeling and plays a key role in dilated cardiomyopathy. Lastly, COUP-TFII haploinsufficiency attenuates the progression of cardiac dilation and improves survival in a calcineurin transgenic mouse model, indicating that COUP-TFII may serve as a therapeutic target for treatment of dilated cardiomyopathy.