437 research outputs found

    Obinutuzumab, a potent anti-B-cell agent, for rituximab-unresponsive IgM anti-MAG neuropathy.

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    Anti-MAG demyelinating neuropathy is difficult to treat. All immunotherapies have failed except for rituximab, a chimeric B-cell–depleting monoclonal antibody against CD20, that helps up to 40% of patients based on 2 controlled and several uncontrolled series.1,–,3 Because the majority of these patients are left disabled, stronger anti–B-cell agents might be promising. We describe clinical response and autoantibody changes after treatment with obinutuzumab (Gazyva), a new generation of humanized anti-CD20 monoclonal antibodies, in 2 patients with anti-MAG neuropathy who continued to worsen despite multiple courses of rituximab. Obinutuzumab, approved for chronic lymphocytic leukemia (CLL), exerts greater peripheral and lymphoid B-cell depletion4 and might be more effective in rituximab-refractory patients. © Rakocevic et al

    Metformin as a Therapeutic Target in Endometrial Cancers.

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    Endometrial cancer is the most common gynecologic malignancy in developed countries. Its increasing incidence is thought to be related in part to the rise of metabolic syndrome, which has been shown to be a risk factor for the development of hyperestrogenic and hyperinsulinemic states. This has consequently lead to an increase in other hormone-responsive cancers as well e.g., breast and ovarian cancer. The correlation between obesity, hyperglycemia, and endometrial cancer has highlighted the important role of metabolism in cancer establishment and persistence. Tumor-mediated reprogramming of the microenvironment and macroenvironment can range from induction of cytokines and growth factors to stimulation of surrounding stromal cells to produce energy-rich catabolites, fueling the growth, and survival of cancer cells. Such mechanisms raise the prospect of the metabolic microenvironment itself as a viable target for treatment of malignancies. Metformin is a biguanide drug that is a first-line treatment for type 2 diabetes that has beneficial effects on various markers of the metabolic syndrome. Many studies suggest that metformin shows potential as an adjuvant treatment for uterine and other cancers. Here, we review the evidence for metformin as a treatment for cancers of the endometrium. We discuss the available clinical data and the molecular mechanisms by which it may exert its effects, with a focus on how it may alter the tumor microenvironment. The pleiotropic effects of metformin on cellular energy production and usage as well as intercellular and hormone-based interactions make it a promising candidate for reprogramming of the cancer ecosystem. This, along with other treatments aimed at targeting tumor metabolic pathways, may lead to novel treatment strategies for endometrial cancer

    Editorial: cancer ecosystems

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    Oncology research pioneers such as Stephen Paget focused on how cancer cells favor particular environments and Judah Folkman on how nutrients are provided to these harsh environments. The tumors consist of a heterogeneous population of cancer cells and a stroma with different cell types that define a specific microenvironment and form a tumoral ecosystem. The evolution of the tumors depends on the interactions of the cancer cells with their tumor microenvironment (TME), determining the progression, eradication, or tumor metastasis. A coral ecosystem is similar to tumors in that it is highly complex and energetically productive. A tropical reef-building coral holobiont is composed of the coral metazoan host (the polyp), its endosymbiotic photosynthetic dinoflagellates (Symbiodiniaceae) and other microorganisms, including protozoans, fungi, bacteria, and archaea. Despite their complexity and very high productivity, corals commonly thrive in nutrient-poor environments, which are similar to what is observed in tumors. The contradiction of high coral productivity and limited nutrient availability has been named as the 'Darwin Paradox,' in reference to its first discoverer. This paradox can be explained by the high uptake and efficient recycling of nutrients by coral reef organisms. A similar paradox has been observed in tumors since it is unclear how this complex ecosystem thrives in such nutrient deprived conditions

    Primary stroke in a woman with sickle cell anemia responsive to hydroxyurea therapy.

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    The most common cause of stroke in children with sickle cell anemia is infarction due to ischemia. In adults, however, stroke is most commonly hemorrhagic in nature. Other causes of stroke in patients with sickle cell disease are very rare. In this short communication, we describe a woman with sickle cell anemia responsive to hydroxyurea (HU) therapy who had primary stroke due to paradoxical embolization caused by a large atrial septal defect. Successful management of the stroke included surgical closure of the defect with trans-esophageal echocardiographic guidance. To the best of our knowledge, this is the first patient with sickle cell anemia and stroke due to congenital heart disease who did not require open heart surgery for successful management

    Mutation signature analysis identifies increased mutation caused by tobacco smoke associated DNA adducts in larynx squamous cell carcinoma compared with oral cavity and oropharynx.

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    Squamous cell carcinomas of the head and neck (HNSCC) arise from mucosal keratinocytes of the upper aero-digestive tract. Despite a common cell of origin and similar driver-gene mutations which divert cell fate from differentiation to proliferation, HNSCC are considered a heterogeneous group of tumors categorized by site of origin within the aero-digestive mucosa, and the presence or absence of HPV infection. Tobacco use is a major driver of carcinogenesis in HNSCC and is a poor prognosticator that has previously been associated with poor immune cell infiltration and higher mutation numbers. Here, we study patterns of mutations in HNSCC that are derived from the specific nucleotide changes and their surrounding nucleotide context (also known as mutation signatures). We identify that mutations linked to DNA adducts associated with tobacco smoke exposure are predominantly found in the larynx. Presence of this class of mutation, termed COSMIC signature 4, is responsible for the increased burden of mutation in this anatomical sub-site. In addition, we show that another mutation pattern, COSMIC signature 5, is positively associated with age in HNSCC from non-smokers and that larynx SCC from non-smokers have a greater number of signature 5 mutations compared with other HNSCC sub-sites. Immunohistochemistry demonstrates a significantly lower Ki-67 proliferation index in size matched larynx SCC compared with oral cavity SCC and oropharynx SCC. Collectively, these observations support a model where larynx SCC are characterized by slower growth and increased susceptibility to mutations from tobacco carcinogen DNA adducts

    MCT1 in Invasive Ductal Carcinoma: Monocarboxylate Metabolism and Aggressive Breast Cancer.

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    Introduction: Monocarboxylate transporter 1 (MCT1) is an importer of monocarboxylates such as lactate and pyruvate and a marker of mitochondrial metabolism. MCT1 is highly expressed in a subgroup of cancer cells to allow for catabolite uptake from the tumor microenvironment to support mitochondrial metabolism. We studied the protein expression of MCT1 in a broad group of breast invasive ductal carcinoma specimens to determine its association with breast cancer subtypes and outcomes. Methods: MCT1 expression was evaluated by immunohistochemistry on tissue micro-arrays (TMA) obtained through our tumor bank. Two hundred and fifty-seven cases were analyzed: 180 cases were estrogen receptor and/or progesterone receptor positive (ER+ and/or PR+), 62 cases were human epidermal growth factor receptor 2 positive (HER2+), and 56 cases were triple negative breast cancers (TNBC). MCT1 expression was quantified by digital pathology with Aperio software. The intensity of the staining was measured on a continuous scale (0-black to 255-bright white) using a co-localization algorithm. Statistical analysis was performed using a linear mixed model. Results: High MCT1 expression was more commonly found in TNBC compared to ER+ and/or PR+ and compared to HER-2+ (p \u3c 0.001). Tumors with an in-situ component were less likely to stain strongly for MCT1 (p \u3c 0.05). High nuclear grade was associated with higher MCT1 staining (p \u3c 0.01). Higher T stage tumors were noted to have a higher expression of MCT1 (p \u3c 0.05). High MCT1 staining in cancer cells was associated with shorter progression free survival, increased risk of recurrence, and larger size independent of TNBC status (p \u3c 0.05). Conclusion: MCT1 expression, which is a marker of high catabolite uptake and mitochondrial metabolism, is associated with recurrence in breast invasive ductal carcinoma. MCT1 expression as quantified with digital image analysis may be useful as a prognostic biomarker and to design clinical trials using MCT1 inhibitors

    TP53-inducible Glycolysis and Apoptosis Regulator (TIGAR) Metabolically Reprograms Carcinoma and Stromal Cells in Breast Cancer.

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    A subgroup of breast cancers has several metabolic compartments. The mechanisms by which metabolic compartmentalization develop in tumors are poorly characterized. TP53 inducible glycolysis and apoptosis regulator (TIGAR) is a bisphosphatase that reduces glycolysis and is highly expressed in carcinoma cells in the majority of human breast cancers. Hence we set out to determine the effects of TIGAR expression on breast carcinoma and fibroblast glycolytic phenotype and tumor growth. The overexpression of this bisphosphatase in carcinoma cells induces expression of enzymes and transporters involved in the catabolism of lactate and glutamine. Carcinoma cells overexpressing TIGAR have higher oxygen consumption rates and ATP levels when exposed to glutamine, lactate, or the combination of glutamine and lactate. Coculture of TIGAR overexpressing carcinoma cells and fibroblasts compared with control cocultures induce more pronounced glycolytic differences between carcinoma and fibroblast cells. Carcinoma cells overexpressing TIGAR have reduced glucose uptake and lactate production. Conversely, fibroblasts in coculture with TIGAR overexpressing carcinoma cells induce HIF (hypoxia-inducible factor) activation with increased glucose uptake, increased 6-phosphofructo-2-kinase/fructose-2,6-bisphosphatase-3 (PFKFB3), and lactate dehydrogenase-A expression. We also studied the effect of this enzyme on tumor growth. TIGAR overexpression in carcinoma cells increases tumor growth in vivo with increased proliferation rates. However, a catalytically inactive variant of TIGAR did not induce tumor growth. Therefore, TIGAR expression in breast carcinoma cells promotes metabolic compartmentalization and tumor growth with a mitochondrial metabolic phenotype with lactate and glutamine catabolism. Targeting TIGAR warrants consideration as a potential therapy for breast cancer

    Faint solar analogs: at the limit of no reddening

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    The flux distribution of solar analogs is required for calculating the spectral albedo of Solar System bodies such as asteroids and trans-Neptunian objects. Ideally a solar analog should be comparably faint as the target of interest, but only few analogs fainter than V = 9 were identified so far. Only atmospheric parameters equal to solar guarantee a flux distribution equal to solar as well, while only photometric colors equal to solar do not. Reddening is also a factor to consider when selecting faint analog candidates. We implement the methodology for identifying faint analogs at the limit of precision allowed by current spectroscopic surveys. We quantify the precision attainable for the atmospheric parameters effective temperature (TeffT_{eff}), metallicity ([Fe/H]), surface gravity (log gg) when derived from moderate low resolution (R=8000) spectra with S/N ∼100\sim 100. We calibrated TeffT_{eff} and [Fe/H] as functions of equivalent widths of spectral indices by means of the PCA regression. We derive log gg, mass, radius, and age from the atmospheric parameters, Gaia parallaxes and evolutionary tracks. We obtained TeffT_{eff}/[Fe/H]/log gg with precision of 97 K/0.06 dex/0.05 dex. We identify five solar analogs with V∼10.5V\sim10.5 (located at ∼135\sim135 pc): HIP 991, HIP 5811, HIP 69477, HIP 55619 and HIP 61835. Other six stars have TeffT_{eff} close to solar but slightly lower [Fe/H]. Our analogs show no evidence of reddening but for four stars, which present E(B−V)≥0.06E(B-V) \geq 0.06 mag, translating to at least a 200 K decrease in photometric TeffT_{eff}.Comment: Paper accepted. Fundamental parameters of the solar analogs are in Table

    Transient transfection of porcine granulosa cells after 3D culture in barium alginate capsules

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    Three-dimensional culture systems in barium alginate capsules can be employed to maintain primary granulosa cells in an undifferentiated state for almost 6 days. This is due to a self-organization of cells in a pseudofollicular structure. The transfection of primary granulosa cells is a necessary condition when employing these culture systems for several purposes, for example as an in vitro toxicity test or the development of oocytes or zygotes. In this work, the feasibility of two transient transfection techniques (liposome-mediated and electroporation) was assessed in primary porcine granulosa cells after a 6-day culture in an artificial extracellular matrix (barium alginate membrane). Human recombinant green fluorescent protein was chosen as a molecular readout, and protein expression was assessed after 48 hours from transfection. Liposome-mediated transfection gave low transfection levels, with increasing yields from 2 to 12 microgDNA/ml of medium; the maximum percentage (85.7%) was reached at 12 microgDNA/ml of medium. Electroporation-mediated transfection yields were higher: the best results (81.7% of transfected cells) were achieved with two 50V pulses and 12 microg/ml DNA. The application of a single or double pulse (50V) at 4 mgDNA/ml gave negligible results. These results indicate that primary granulosa cell cultured in barium alginate capsules can be transfected by electroporation with high transfection yields
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