Search results for "Sms"
showing 10 items of 10610 documents
Measuring spectrally-resolved information transfer.
2020
Information transfer, measured by transfer entropy, is a key component of distributed computation. It is therefore important to understand the pattern of information transfer in order to unravel the distributed computational algorithms of a system. Since in many natural systems distributed computation is thought to rely on rhythmic processes a frequency resolved measure of information transfer is highly desirable. Here, we present a novel algorithm, and its efficient implementation, to identify separately frequencies sending and receiving information in a network. Our approach relies on the invertible maximum overlap discrete wavelet transform (MODWT) for the creation of surrogate data in t…
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 (…
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…
Customised in vitro model to detect human metabolism-dependent idiosyncratic drug-induced liver injury
2017
Drug-induced liver injury (DILI) has a considerable impact on human health and is a major challenge in drug safety assessments. DILI is a frequent cause of liver injury and a leading reason for post-approval drug regulatory actions. Considerable variations in the expression levels of both cytochrome P450 (CYP) and conjugating enzymes have been described in humans, which could be responsible for increased susceptibility to DILI in some individuals. We herein explored the feasibility of the combined use of HepG2 cells co-transduced with multiple adenoviruses that encode drug-metabolising enzymes, and a high-content screening assay to evaluate metabolism-dependent drug toxicity and to identify…
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…
Shikonin derivatives for cancer prevention and therapy.
2019
Abstract Phytochemicals gained considerable interest during the past years as source to develop new treatment options for chemoprevention and cancer therapy. Motivated by the fact that a majority of established anticancer drugs are derived in one way or another from natural resources, we focused on shikonin, a naphthoquinone with high potentials to be further developed as preventive or therapeutic drug to fight cancer. Shikonin is the major chemical component of Lithospermum erythrorhizon (Purple Cromwell) roots. Traditionally, the root extract has been applied to cure dermatitis, burns, and wounds. Over the past three decades, the anti-inflammatory and anticancer effects of root extracts, …
Kinase Inhibitors in Multitargeted Cancer Therapy
2017
The old-fashioned anticancer approaches, aiming in arresting cancer cell proliferation interfering with non-specific targets (e.g. DNA), have been replaced, in the last decades, by more specific target oriented ones. Nonetheless, single-target approaches have not always led to optimal outcomes because, for its complexity, cancer needs to be tackled at various levels by modulation of several targets. Although at present, combinations of individual single-target drugs represent the most clinically practiced therapeutic approaches, the modulation of multiple proteins by a single drug, in accordance with the polypharmacological strategy, has become more and more appealing. In the perspective of…
Treg cells as potential cellular targets for functionalized nanoparticles in cancer therapy.
2016
Treg cell-mediated immune suppression appears to represent a significant barrier to effective anticancer immune responses and their inactivation or removal is viewed as a potential therapeutic approach. Although suitable tools for selective Treg cell manipulation in man are missing, their number and function can be altered by a number of drugs and biologicals and by reprogramming tumor-infiltrating antigen presenting cells. Nanoparticles offer exceptional new options in drug and gene delivery by prolonging the circulation time of their cargo, protecting it from degradation and promoting its local accumulation in cells and tissues. In tumor therapy, the use of nanoparticles is expected to o…