Metalloporphyrins inactivate caspase-3 and -8

Activation of caspases represents one of the earliest biochemical indicators for apoptotic cell death. Therefore, measurement of caspase activity is a widely used and generally accepted method to determine apoptosis in a wide range of in vivo and in vitro settings. Numerous publications characterize the role of the heme-catabolizing enzyme heme oxygenase-1 (HO-1) in regulating apoptotic processes. Different metalloporphyrins representing inducers and inhibitors of this enzyme are often used, followed by assessment of apoptotic cell death. In the present work, we found that caspase-3-like activity, as well as activity of caspase-8 measured in either Fas (CD95) ligand-treated Jurkat T-lymphocytes or by the use of recombinant caspase-3 or -8, was inhibited by different metalloporphyrins (cobalt(III) protoporphyrin IX, tin and zinc II) protoporphyrin-IX). Moreover, employing the mouse model of Fas-induced liver apoptosis these properties of porphyrins could also be demonstrated in vivo. The metalloporphyrins were shown to inhibit caspase-3-mediated PARP cleavage. Molecular modeling studies demonstrated that porphyrins can occupy the active site of caspase-3 in an energetically favorable manner and in a binding mode similar to that of known inhibitors. The data shown here introduce metalloporphyrins as direct inhibitors of caspase activity. This finding points to the need for careful employment of metalloporphyrins as modulators of HO-1

Metabolic implication of tigecycline as an efficacious second-line treatment for sorafenib-resistant hepatocellular carcinoma

Sorafenib represents the current standard of care for patients with advanced-stage hepatocellular carcinoma (HCC). However, acquired drug resistance occurs frequently during therapy and is accompanied by rapid tumor regrowth after sorafenib therapy termination. To identify the mechanism of this therapy-limiting growth resumption, we established robust sorafenib resistance HCC cell models that exhibited mitochondrial dysfunction and chemotherapeutic crossresistance. We found a rapid relapse of tumor cell proliferation after sorafenib withdrawal, which was caused by renewal of mitochondrial structures alongside a metabolic switch toward high electron transport system (ETS) activity. The translation-inhibiting antibiotic tigecycline impaired the biogenesis of mitochondrial DNA-encoded ETS subunits and limited the electron acceptor turnover required for glutamine oxidation. Thereby, tigecycline prevented the tumor relapse in vitro and in murine xenografts in vivo. These results offer a promising second-line therapeutic approach for advanced-stage HCC patients with progressive disease undergoing sorafenib therapy or treatment interruption due to severe adverse events

A combined computational and functional approach identifies IGF2BP2 as a driver of chemoresistance in a wide array of pre-clinical models of colorectal cancer

Aim Chemoresistance is a major cause of treatment failure in colorectal cancer (CRC) therapy. In this study, the impact of the IGF2BP family of RNA-binding proteins on CRC chemoresistance was investigated using in silico, in vitro, and in vivo approaches. Methods Gene expression data from a well-characterized cohort and publicly available cross-linking immunoprecipi‑ tation sequencing (CLIP-Seq) data were collected. Resistance to chemotherapeutics was assessed in patient-derived xenografts (PDXs) and patient-derived organoids (PDOs). Functional studies were performed in 2D and 3D cell culture models, including proliferation, spheroid growth, and mitochondrial respiration analyses. Results We identifed IGF2BP2 as the most abundant IGF2BP in primary and metastastatic CRC, correlating with tumor stage in patient samples and tumor growth in PDXs. IGF2BP2 expression in primary tumor tissue was signif‑ cantly associated with resistance to selumetinib, geftinib, and regorafenib in PDOs and to 5-fuorouracil and oxalipl‑ atin in PDX in vivo. IGF2BP2 knockout (KO) HCT116 cells were more susceptible to regorafenib in 2D and to oxaliplatin, selumitinib, and nintedanib in 3D cell culture. Further, a bioinformatic analysis using CLIP data suggested stabiliza‑ tion of target transcripts in primary and metastatic tumors. Measurement of oxygen consumption rate (OCR) and extracellular acidifcation rate (ECAR) revealed a decreased basal OCR and an increase in glycolytic ATP production rate in IGF2BP2 KO. In addition, real-time reverse transcriptase polymerase chain reaction (qPCR) analysis confrmed decreased expression of genes of the respiratory chain complex I, complex IV, and the outer mitochondrial membrane in IGF2BP2 KO cells. Conclusions IGF2BP2 correlates with CRC tumor growth in vivo and promotes chemoresistance by altering mito‑ chondrial respiratory chain metabolism. As a druggable target, IGF2BP2 could be used in future CRC therapy to overcome CRC chemoresistance

Diterpenoid Alkaloids of Aconitum vulparia Rchb.

From the roots of Aconitum vulparia Rchb., collected in Prum (Germany), a new norditerpenoid alkaloid, named alexhumboldtine, has been isolated along with the known norditerpenoid alkaloids lappaconitine, anthranoyllycoctonine, lycoctonine, puberaconitine, ajacine, and septentriodine. The structure of alexhumboldtine was established on the basis of H-1, C-13, DEPT, homonuclear H-1 COSY, NOESY, HSQC, and HMBC NMR studies. From the aerial parts of the plant another norditerpenoid alkaloid, aconorine, has been isolated

Festival de primavera 1985

Orquestra Simfònica del Gran Teatre del Liceu, dirigida per Heinz FrickePrograma de mà de l'òpera La Valquíria, de Richard Wagner, la qual va ser representada els dies 28 i 31 de maig i 2 de juny del 1985. Els cantants van ser Siegfried Jerusalem (Siegmund) ; Hans Tschammer, Kurt Rydl i Aage Haugland (Hunding) ; Hans Kiemer (Wotan) ; Sabine Haas i Carmen Reppel (Sieglinde) ; Lia Frey-Rabine (Brünnhilde) ; Nadine Denize (Fricka) ; Linda plech (Gerhilde) ; Helga Thieme (Ortlinde) ; Mariana Cioromila (Waltraute) ; Anna Gonda (Schwertleite) ; Nancy Johnson (Helmwige) ; Heide Rabal (Segrune) ; Karen Johnson (Grimgerde) ; Brigitta Wutscher (Rossweisse). L'orquestra estava dirigida per Heinz Frick

The International Human Epigenome Consortium: A Blueprint for Scientific Collaboration and Discovery.

The International Human Epigenome Consortium (IHEC) coordinates the generation of a catalog of high-resolution reference epigenomes of major primary human cell types. The studies now presented (see the Cell Press IHEC web portal at http://www.cell.com/consortium/IHEC) highlight the coordinated achievements of IHEC teams to gather and interpret comprehensive epigenomic datasets to gain insights in the epigenetic control of cell states relevant for human health and disease. PAPERCLIP