Type 1 diabetes is characterized by the destruction of pancreatic β cells, and generating new insulin-producing cells from other cell types is a major aim of regenerative medicine. One promising approach is transdifferentiation of developmentally related pancreatic cell types, including glucagon-producing α cells. In a genetic model, loss of the master regulatory transcription factor Arx is sufficient to induce the conversion of α cells to functional β-like cells.
View Article and Find Full Text PDFThe clinical development of anticancer metallodrugs is often hindered by the elusive nature of their molecular targets. To identify the molecular targets of an antimetastatic ruthenium organometallic complex based on 1,3,5-triaza-7-phosphaadamantane (RAPTA), we employed a chemical proteomic approach. The approach combines the design of an affinity probe featuring the pharmacophore with mass-spectrometry-based analysis of interacting proteins found in cancer cell lysates.
View Article and Find Full Text PDFA growing number of gene mutations, which are recognized as cancer drivers, can be successfully targeted with drugs. The redundant and dynamic nature of oncogenic signaling networks and complex interactions between cancer cells and the microenvironment, however, can cause drug resistance. While these challenges can be addressed by developing drug combinations or polypharmacology drugs, this benefits greatly from a detailed understanding of the proteome-wide target profiles.
View Article and Find Full Text PDFGenotoxic chemotherapy is the most common cancer treatment strategy. However, its untargeted generic DNA-damaging nature and associated systemic cytotoxicity greatly limit its therapeutic applications. Here, we used a haploid genetic screen in human cells to discover an absolute dependency of the clinically evaluated anticancer compound YM155 on solute carrier family member 35 F2 (SLC35F2), an uncharacterized member of the solute carrier protein family that is highly expressed in a variety of human cancers.
View Article and Find Full Text PDFDeregulation of protein tyrosine kinase signaling has been linked to many diseases, most notably cancer. As a consequence, small molecule inhibitors of protein tyrosine kinases may provide powerful strategies for treatment. Following the successful introduction of imatinib in the treatment of chronic myelogenous leukemia, such drugs are also now evaluated for other types of cancer.
View Article and Find Full Text PDFActivated RAS GTPase signalling is a critical driver of oncogenic transformation and malignant disease. Cellular models of RAS-dependent cancers have been used to identify experimental small molecules, such as SCH51344, but their molecular mechanism of action remains generally unknown. Here, using a chemical proteomic approach, we identify the target of SCH51344 as the human mutT homologue MTH1 (also known as NUDT1), a nucleotide pool sanitizing enzyme.
View Article and Find Full Text PDFPhiladelphia chromosome-positive acute lymphoblastic leukemia (Ph+ ALL) is in part driven by the tyrosine kinase bcr-abl, but imatinib does not produce long-term remission. Therefore, second-generation ABL inhibitors are currently in clinical investigation. Considering different target specificities and the pronounced genetic heterogeneity of Ph+ ALL, which contributes to the aggressiveness of the disease, drug candidates should be evaluated with regard to their effects on the entire Ph+ ALL-specific signaling network.
View Article and Find Full Text PDFWhile targeted therapy based on the idea of attenuating the activity of a preselected, therapeutically relevant protein has become one of the major trends in modern cancer therapy, no truly specific targeted drug has been developed and most clinical agents have displayed a degree of polypharmacology. Therefore, the specificity of anticancer therapeutics has emerged as a highly important but severely underestimated issue. Chemical proteomics is a powerful technique combining postgenomic drug-affinity chromatography with high-end mass spectrometry analysis and bioinformatic data processing to assemble a target profile of a desired therapeutic molecule.
View Article and Find Full Text PDFOccurrence of the BCR-ABL(T315I) gatekeeper mutation is among the most pressing challenges in the therapy of chronic myeloid leukemia (CML). Several BCR-ABL inhibitors have multiple targets and pleiotropic effects that could be exploited for their synergistic potential. Testing combinations of such kinase inhibitors identified a strong synergy between danusertib and bosutinib that exclusively affected CML cells harboring BCR-ABL(T315I).
View Article and Find Full Text PDFBioactive small molecules act through modulating a yet unpredictable number of targets. It is therefore of critical importance to define the cellular target proteins of a compound as an entry point to understanding its mechanism of action. Often, this can be achieved in a direct fashion by chemical proteomics.
View Article and Find Full Text PDFThe water extract of the lettuce Lactuca sativa, but not the ethyl acetate extract, inhibited the growth of HL-60 leukaemia cells and MCF-7 breast cancer cells. This correlated with the activation of checkpoint kinase 2 (Chk2), the induction of the tumour suppressor p21, and the severe downregulation of the proto-oncogene cyclin D1. The ethyl acetate extract, but not the water extract, induced HL-60 cell death, which correlated with the acetylation of alpha-tubulin.
View Article and Find Full Text PDFThe Aracea Anthurium schlechtendalii and Syngonium podophyllum are traditional remedies for the treatment of severe and chronic inflammatory conditions. We cross-examined these plants regarding their anti-neoplastic properties, because several anti-inflammatory molecular targets are common for both pathologic conditions due to similar signalling pathways. Two malignant cell lines, HL-60 and MCF-7, were treated with increasing concentrations of plant extracts of increasing polarity.
View Article and Find Full Text PDFHypericum perforatum (St. John's wort) is well-established for its antidepressant activity throughout the world and also various other species within this genus are used in different folk medicines. Hyperforin of St.
View Article and Find Full Text PDFEstrogenic procarcinogenic effects of piceatannol (PIC) contrast reports about anticarcinogenic activities of PIC. To explain this contradiction, we investigated PIC in estrogen-dependent MCF-7 breast cancer cells and elucidated those cellular mechanisms that correlated with the observed cell effects induced by PIC. Low PIC concentrations (50 nM) induced c-Myc that depended on progesterone receptor (PR) and estrogen receptor (ER).
View Article and Find Full Text PDFAim Of This Study: Within the genus Scutellaria various species are used in different folk medicines throughout Asia. Traditional Chinese Medicine (TCM) uses S. baicalensis (Labiatae) to treat various inflammatory conditions.
View Article and Find Full Text PDFThe effects of heat shock (HS; 42 degrees C) on the cell cycle and underlying molecular mechanisms are astonishingly unexplored. Here, we show that HS caused rapid Cdc25A degradation and a reduction of cell cycle progression. Cdc25A degradation depended on Ser75-Cdc25A phosphorylation caused by p38MAPK and Chk2, which phosphorylated Ser177-Cdc25A that is specific for 14.
View Article and Find Full Text PDFMany traditional healing plants successfully passed several hundred years of empirical testing against specific diseases and thereby demonstrating that they are well tolerated in humans. Although quite a few ethno-pharmacological plants are applied against a variety of conditions there are still numerous plants that have not been cross-tested in diseases apart from the traditional applications. Herein we demonstrate the anti-neoplastic potential of two healing plants used by the Maya of the Guatemala/Belize area against severe inflammatory conditions such as neuritis, rheumatism, arthritis, coughs, bruises and tumours.
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