38 research outputs found

    Erythropoietins (Epostim®) during chemoradiotherapy for malignancies in anemic patients

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    Anemia in female patients with solid neoplasms is corrected to normalize hemoglobin levels, to increase quality of life, and to improve antitumor therapy tolerance. The clinical application of recombinant human erythropoietin preparations has become an important treat- ment step that permits multiple hemotransfusions to be avoided. Epostim is effective and safe in increasing hemoglobin and packed cell volume and in overcoming the additive toxicity of chemo- and radiotherapy

    A novel HSP90 inhibitor-drug conjugate to SN38 is highly effective in small cell lung cancer

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    ©2016 AACR.Purpose: Small cell lung cancer (SCLC) is a highly aggressive disease representing 12% to 13% of total lung cancers, with median survival of <2 years. No targeted therapies have proven effective in SCLC. Although most patients respond initially to cytotoxic chemotherapies, resistance rapidly emerges, response to second-line agents is limited, and dose-limiting toxicities (DLT) are a major issue. This study performs preclinical evaluation of a new compound, STA-8666, in SCLC. Experimental Design: To avoid DLT for useful cytotoxic agents, the recently developed drug STA-8666 combines a chemical moiety targeting active HSP90 (concentrated in tumors) fused via cleavable linker to SN38, the active metabolite of irinotecan. We compare potency and mechanism of action of STA-8666 and irinotecan in vitro and in vivo. Results: In two SCLC xenograft and patient-derived xenograft models, STA-8666 was tolerated without side effects up to 150 mg/kg. At this dose, STA-8666 controlled or eliminated established tumors whether used in a first-line setting or in tumors that had progressed following treatment on standard first- and second-line agents for SCLC. At 50 mg/kg, STA-8666 strongly enhanced the action of carboplatin. Pharmacokinetic profiling confirmed durable STA-8666 exposure in tumors compared with irinotecan. STA-8666 induced a more rapid, robust, and stable induction of cell-cycle arrest, expression of signaling proteins associated with DNA damage and cell-cycle checkpoints, and apoptosis in vitro and in vivo, in comparison with irinotecan. Conclusions: Together, these results strongly support clinical development of STA-8666 for use in the first- or second-line setting for SCLC

    Screening of conditionally reprogrammed patient-derived carcinoma cells identifies ERCC3-MYC interactions as a target in pancreatic cancer

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    ©2016 AACR.Purpose: Even when diagnosed prior to metastasis, pancreatic ductal adenocarcinoma (PDAC) is a devastating malignancy with almost 90% lethality, emphasizing the need for new therapies optimally targeting the tumors of individual patients. Experimental Design: We first developed a panel of new physiologic models for study of PDAC, expanding surgical PDAC tumor samples in culture using short-term culture and conditional reprogramming with the Rho kinase inhibitor Y-27632, and creating matched patient-derived xenografts (PDX). These were evaluated for sensitivity to a large panel of clinical agents, and promising leads further evaluated mechanistically. Results: Only a small minority of tested agents was cytotoxic in minimally passaged PDAC cultures in vitro. Drugs interfering with protein turnover and transcription were among most cytotoxic. Among transcriptional repressors, triptolide, a covalent inhibitor of ERCC3, was most consistently effective in vitro and in vivo causing prolonged complete regression in multiple PDX models resistant to standard PDAC therapies. Importantly, triptolide showed superior activity in MYC-amplified PDX models and elicited rapid and profound depletion of the oncoprotein MYC, a transcriptional regulator. Expression of ERCC3 and MYC was interdependent in PDACs, and acquired resistance to triptolide depended on elevated ERCC3 and MYC expression. The Cancer Genome Atlas analysis indicates ERCC3 expression predicts poor prognosis, particularly in CDKN2A-null, highly proliferative tumors. Conclusions: This provides initial preclinical evidence for an essential role of MYC-ERCC3 interactions in PDAC, and suggests a new mechanistic approach for disruption of critical survival signaling in MYC-dependent cancers

    Synergy between inhibitors of androgen receptor and MEK has therapeutic implications in estrogen receptor-negative breast cancer

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    Introduction: Estrogen receptor-negative (ER-) breast cancer is a heterogeneous disease with limited therapeutic options. The molecular apocrine subtype constitutes 50% of ER-tumors and is characterized by overexpression of steroid response genes including androgen receptor (AR). We have recently identified a positive feedback loop between the AR and extracellular signal-regulated kinase (ERK) signaling pathways in the molecular apocrine subtype. In this feedback loop, AR regulates ERK phosphorylation through the mediation of ErbB2 and, in turn, ERK-CREB1 signaling regulates the transcription of AR in molecular apocrine cells. In this study, we investigated the therapeutic implications of the AR-ERK feedback loop in molecular apocrine breast cancer.Methods: We examined a synergy between the AR inhibitor flutamide and the MEK inhibitor CI-1040 in the molecular apocrine cell lines MDA-MB-453, HCC-1954 and HCC-202 using MTT cell viability and annexin V apoptosis assays. Synergy was measured using the combination index (CI) method. Furthermore, we examined in vivo synergy between flutamide and the MEK inhibitor PD0325901 in a xenograft model of the molecular apocrine subtype. The effects of in vivo therapies on tumor growth, cell proliferation and angiogenesis were assessed.Results: We demonstrate synergistic CI values for combination therapy with flutamide and CI-1040 across three molecular apocrine cell lines at four dose combinations using both cell viability and apoptosis assays. Furthermore, we show in vivo that combination therapy with flutamide and MEK inhibitor PD0325901 has a significantly higher therapeutic efficacy in reducing tumor growth, cellular proliferation and angiogenesis than monotherapy with these agents. Moreover, our data suggested that flutamide and CI-1040 have synergy in trastuzumab resistance models of the molecular apocrine subtype. Notably, the therapeutic effect of combination therapy in trastuzumab-resistant cells was associated with the abrogation of an increased level of ERK phosphorylation that was developed in the process of trastuzumab resistance.Conclusions: In this study, we demonstrate in vitro and in vivo synergies between AR and MEK inhibitors in molecular apocrine breast cancer. Furthermore, we show that combination therapy with these inhibitors can overcome trastuzumab resistance in molecular apocrine cells. Therefore, a combination therapy strategy with AR and MEK inhibitors may provide an attractive therapeutic option for the ER-/AR+ subtype of breast cancer

    Planowanie obciążeń stacji transfromatorowych przy rozbudowie miejskich systemów elektroenergetycznych

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    In work the system approach to formation of the urban power supply system is given. The hierarchical structure of the construction, voltage levels and load densities is considered. The mathematical and geometrical modeling of service areas for transformer substations of diff erent voltage is fulfi lled. Determination of perspective loads of transformer substations is given. The method of graphic placement of transformer substations in the city territory for new substations at existing structure of networks is off ered. The calculation program Microsoft EXCEL and the graphic program AutoCad are used for realization of method. The method allows fi nding a rational decision for the development of urban power supply system on the beginning design stages in conditions of the information uncertaintyW artykule zaprezentowano systemowe podejście do tworzenia miejskiego systemu elektroenergetycznego. Uwzględniono hierarchiczną strukturę budowy poziomów napięcia i gęstości obciążenia. Wykonano matematyczne i geometryczne modelowanie obszarów obsługi dla stacji transformatorowych różnych napięć. Podano sposób planowania obciążeń stacji transformatorowych. Zaproponowano metodę graficznego rozmieszczenia stacji transformatorowych na terenie miasta dla nowych stacji w obecnej strukturze sieci. Przy zastosowaniu tej metody wykorzystuje się arkusz kalkulacyjny Microsoft Excel oraz program graficzny AutoCAD. Metoda ta umożliwia racjonalne podejmowanie decyzji co do rozbudowy miejskiego systemu elektroenergetycznego na początkowych etapach projektowania w warunkach, gdy nie dysponuje się pełną informacją

    Role of palmitate-induced sphingoid base-1-phosphate biosynthesis in INS-1 &#946;-cell survival

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    Sphingoid base-1-phosphates represent a very low portion of the sphingolipid pool but are potent bioactive lipids in mammals. This study was undertaken to determine whether these lipids are produced in palmitate-treated pancreatic \u3b2 cells and what role they play in palmitate-induced \u3b2 cell apoptosis. Our lipidomic analysis revealed that palmitate at low and high glucose supplementation increased (dihydro)sphingosine-1-phosphate levels in INS-1 \u3b2 cells. This increase was associated with an increase in sphingosine kinase 1 (SphK1) mRNA and protein levels. Over-expression of SphK1 in INS-1 cells potentiated palmitate-induced accumulation of dihydrosphingosine-1- phosphate. N,N-dimethyl-sphingosine, a potent inhibitor of SphK, potentiated \u3b2-cell apoptosis induced by palmitate whereas over-expression of SphK1 significantly reduced apoptosis induced by palmitate with high glucose. Endoplasmic reticulum (ER)-targeted SphK1 also partially inhibited apoptosis induced by palmitate. Inhibition of INS-1 apoptosis by over-expressed SphK1 was independent of sphingosine-1-phosphate receptors but was associated with a decreased formation of pro-apoptotic ceramides induced by gluco-lipotoxicity. Moreover, over-expression of SphK1 counteracted the defect in the ER-to-Golgi transport of proteins that contribute to the ceramide-dependent ER stress observed during gluco-lipotoxicity. In conclusion, our results suggest that activation of palmitate-induced SphK1-mediated sphingoid base-1-phosphate formation in the ER of \u3b2 cells plays a protective role against palmitate-induced ceramide-dependent apoptotic \u3b2 cell death
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