Search results for "Resistance"
showing 10 items of 3641 documents
Identification of novel drug resistance mechanisms by genomic and transcriptomic profiling of glioblastoma cells with mutation-activated EGFR.
2021
Abstract Aims Epidermal growth factor receptor (EGFR) is not only involved in carcinogenesis, but also in chemoresistance. We characterized U87.MGΔEGFR glioblastoma cells with constitutively active EGFR due to deletion at the ligand binding domain in terms of gene expression profiling and chromosomal aberrations. Wild-type U87.MG cells served as control. Materials and methods RNA sequencing and network analyses (Ingenuity Pathway Analysis) were performed to identify novel drug resistance mechanisms related to expression of mutation activated EGFR. Chromosomal aberrations were characterized by multicolor fluorescence in situ hybridization (mFISH) and array comparative genomic hybridization (…
Oridonin Targets Multiple Drug-Resistant Tumor Cells as Determined by in Silico and in Vitro Analyses
2018
Drug resistance is one of the main reasons of chemotherapy failure. Therefore, overcoming drug resistance is an invaluable approach to identify novel anticancer drugs that have the potential to bypass or overcome resistance to established drugs and to substantially increase life span of cancer patients for effective chemotherapy. Oridonin is a cytotoxic diterpenoid isolated from Rabdosia rubescens with in vivo anticancer activity. In the present study, we evaluated the cytotoxicity of oridonin toward a panel of drug-resistant cancer cells overexpressing ABCB1, ABCG2, or ΔEGFR or with a knockout deletion of TP53. Interestingly, oridonin revealed lower degree of resistance than the control dr…
Reversal of multidrug resistance by Marsdenia tenacissima and its main active ingredients polyoxypregnanes.
2016
Abstract Ethnopharmacological relevance Multidrug resistance (MDR) of cancer is often associated with the overexpression of ATP-binding cassette (ABC) transporters, such as P-glycoprotein (P-gp), multidrug resistance-associated protein-1 (MRP-1) and breast cancer resistance protein (BCRP or ABCG2), in cancer cells, which facilitates the active efflux of a wide variety of chemotherapeutic drugs out of the cells. Marsdenia tenacissima is a traditional Chinese medicinal herb that has long been clinically used for treatment of cancers, particularly in combinational use with anticancer drugs. Polyoxypregnanes (POPs) are identified as main constituents of this herb, and three of them have been re…
The emergence of drug resistance to targeted cancer therapies: Clinical evidence.
2019
For many decades classical anti-tumor therapies included chemotherapy, radiation and surgery; however, in the last two decades, following the identification of the genomic drivers and main hallmarks of cancer, the introduction of therapies that target specific tumor-promoting oncogenic or non-oncogenic pathways, has revolutionized cancer therapeutics. Despite the significant progress in cancer therapy, clinical oncologists are often facing the primary impediment of anticancer drug resistance, as many cancer patients display either intrinsic chemoresistance from the very beginning of the therapy or after initial responses and upon repeated drug treatment cycles, acquired drug resistance deve…
Cancer combination therapies with artemisinin-type drugs
2017
Artemisia annua L. is a Chinese medicinal plant, which is used throughout Asia and Africa as tea or press juice to treat malaria. The bioactivity of its chemical constituent, artemisinin is, however, much broader. We and others found that artemisinin and its derivatives also exert profound activity against tumor cells in vitro and in vivo. Should artemisinin-type drugs be applied routinely in clinical oncology in the future, then it should probably be as part of combination therapy regimens rather than as monotherapy. In the present review, I give a comprehensive overview on synergistic and additive effects of artemisinin-type drugs in combination with different types of cytotoxic agents an…
Functional characterization of circulating tumor cells (CTCs) from metastatic ER+/HER2− breast cancer reveals dependence on HER2 and FOXM1 for endocr…
2021
Simple Summary Acquired endocrine resistance and late recurrence in patients with ER+/HER2− breast cancer are complex and not fully understood. Here, we evaluated mechanisms of acquired resistance in circulating tumor cells (CTCs) from an ER+/HER2− breast cancer patient who initially responded but later progressed under endocrine treatment. We found a switch from ERα-dependent to HER2-dependent and ERα-independent expression of FOXM1, which may enable disseminated ER+/HER2− cells to re-initiate tumor cell growth and metastasis formation in the presence of endocrine treatment. We found that NFkB signaling sustains HER2 and FOXM1 expression in CTCs in the presence of ERα inhibitors suggesting…
Partial resistance to homologous challenge infections of the digenean Echinostoma caproni in ICR mice
2015
AbstractIn the present paper, we analyse the effect of a primary infection of ICR mice with Echinostoma caproni (Trematoda: Echinostomatidae) on the generation of resistance against homologous challenge infections. In ICR mice, E. caproni induces chronic infections concomitantly with strong responses characterized by the development of T-helper 1 (Th1)-type local immune responses with elevated levels of local interferon-gamma (IFN-γ) and inflammatory and antibody responses. Here, the effect of the response generated against a primary infection with E. caproni in the generation of resistance against subsequent homologous infections was analysed. For this purpose, ICR mice were challenged wit…
Long-range vortex transfer in superconducting nanowires
2019
Under high-enough values of perpendicularly-applied magnetic feld and current, a type-II superconductor presents a fnite resistance caused by the vortex motion driven by the Lorentz force. To recover the dissipation-free conduction state, strategies for minimizing vortex motion have been intensely studied in the last decades. However, the non-local vortex motion, arising in areas depleted of current, has been scarcely investigated despite its potential application for logic devices. Here, we propose a route to transfer vortices carried by non-local motion through long distances (up to 10 micrometers) in 50nm-wide superconducting WC nanowires grown by Ga+ Focused Ion Beam Induced Deposition.…
The emergence of loss of efficacy during antidepressant drug treatment for major depressive disorder: An integrative review of evidence, mechanisms, …
2018
The re-emergence (i.e. ‘breakthrough’) of depressive symptoms despite maintenance treatment of depression with antidepressant drugs is a complex clinical phenomenon referred to as tolerance. Herein we critically appraise evidence from both pre-clinical and clinical studies, focusing on putative mechanisms as well as clinical correlates and implications of the emergence tolerance during antidepressant treatment for major depressive disorder (MDD). It is firstly unclear to what extent this phenotype reflects a pharmacological effect of an antidepressant, is driven by non-adherence, is a marker of latent bipolarity or another comorbidity, a marker of neuroprogression of the underlying disorder…
Drying parameters greatly affect the destruction of Cronobacter sakazakii and Salmonella Typhimurium in standard buffer and milk
2017
International audience; Salmonella Typhimurium and Cronobacter sakazakii are two foodborne pathogens involved in neonatal infections from milk powder and infant formula. Their ability to survive in low-moisture food and during processing from the decontamination to the dried state is a major issue in food protection. In this work, we studied the effects of the drying process on Salmonella Typhimurium and Cronobacter sakazakii, with the aim of identifying the drying parameters that could promote greater inactivation of these two foodborne pathogens. These two bacteria were dried under different atmospheric relative humidities in milk and phosphate-buffered saline, and the delays in growth re…