No abstract

The ruthenium complex sodium trans-[tetrachloridobis(1H-indazole)ruthenate(III)] (KP1339/IT-139) showed preclinical activity in a variety of in vivo tumor models including a highly predictive colon cancer model. The compound has entered clinical trials, where patients experienced disease stabilization accompanied by mild side effects.KP1339, a GRP78 inhibitor, disrupts endoplasmic reticulum (ER) homeostasis leading to cell death. The PERK/eIF2a-branch of the ER plays an essential role in the cascade of events triggering immunogenic cell death (ICD). ICD makes dying cancer cells 'visible' to the immune system, initiating a prolonged immune response against the tumor. As some metal-based chemotherapeutics such as oxaliplatin are able to induce ICD, we investigate whether KP1339 could also trigger induction of the ICD signature. For this, we employ a three-dimensional colon cancer spheroid model and show for the first time that the treatment with KP1339, a ruthenium-based complex, triggers an ICD signature hallmarked by phosphorylation of PERK and eIF2a, exposure of calreticulin on the cell membrane, release of high mobility group box 1 and secretion of ATP. Significance to metallomicsThe impact of metal-based compounds on the immunological aspects of cancer is now emerging as a critical component of their therapeutic potential. It has been demonstrated based on preclinical and clinical data, that the immunomodulatory effects of platinum complexes provide a promising platform for their combination with immunotherapies. However, further studies are necessary to elucidate the complex interaction between cancer and the immune system and the role of metal-based drugs in modulating their intricate interplay. Our work highlights the importance of studying the immunological aspects of metal-based compounds, and emphasizes the potential of rutheniumderived complexes in this emerging field. Metallomics COMMUNICATION

No abstract

Atomic force microscopy (AFM) cell loading/unloading curves were used to provide comprehensive insights into biomechanical behavior of cardiomyocytes carrying the lamin A/C (LMNA) D192G mutation known to cause defective nuclear wall, myopathy and severe cardiomyopathy. Our results suggested that the LMNA D192G mutation increased maximum nuclear deformation load, nuclear stiffness and fragility as compared to controls. Furthermore, there seems to be a connection between this lamin nuclear mutation and cell adhesion behavior since LMNA D192G cardiomyocytes displayed loss of AFM probe-to-cell membrane adhesion. We believe that this loss of adhesion involves the cytoskeletal architecture since our microscopic analyses highlighted that mutant LMNA may also lead to a morphological alteration in the cytoskeleton. Furthermore, chemical disruption of the actin cytoskeleton by cytochalasin D in control cardiomyocytes mirrored the alterations in the mechanical properties seen in mutant cells, suggesting a defect in the connection between the nucleoskeleton, cytoskeleton and cell adhesion molecules in cells expressing the mutant protein. These data add to our understanding of potential mechanisms responsible for this fatal cardiomyopathy, and show that the biomechanical effects of mutant lamin extend beyond nuclear mechanics to include interference of whole-cell biomechanical properties.

The mycotoxin deoxynivalenol (DON) is an abundant contaminant of cereal based food and a severe issue for global food safety. We report the discovery of DON-3-sulfate as a novel human metabolite and potential new biomarker of DON exposure. The conjugate was detectable in 70% of urine samples obtained from pregnant women in Croatia. For the measurement of urinary metabolites, a highly sensitive and selective LC-MS/MS method was developed and validated. The method was also used to investigate samples from a duplicate diet survey for studying the toxicokinetics of DON-3-sulfate. To get a preliminary insight into the biological relevance of the newly discovered DON-sulfates, in vitroexperiments were performed. In contrast to DON, sulfate conjugates lacked potency to suppress protein translation. However, surprisingly we found that DON-sulfates enhanced proliferation of human HT-29 colon carcinoma cells, primary human colon epithelial cells (HCEC-1CT) and, to some extent, also T24 bladder cancer cells. A proliferative stimulus, especially in tumorigenic cells raises concern on the potential impact of DON-sulfates on consumer health. Thus, a further characterization of their toxicological relevance should be of high priority.