YKL-40/CHI3L1 facilitates migration and invasion in HER2 overexpressing breast epithelial progenitor cells and generates a niche for capillary-like network formation

Publisher's version (útgefin grein).Epithelial to mesenchymal transition (EMT) is a developmental event that is hijacked in some diseases such as fibrosis and cancer. In cancer, EMT has been linked to increased invasion and metastasis and is generally associated with a poor prognosis. In this study, we have compared phenotypic and functional differences between two isogenic cell lines with an EMT profile: D492M and D492HER2 that are both derived from D492, a breast epithelial cell line with stem cell properties. D492M is non-tumorigenic while D492HER2 is tumorigenic. Thus, the aim of this study was to analyze the expression profile of these cell lines, identify potential oncogenes, and evaluate their effects on cellular phenotype. We performed transcriptome and secretome analyses of D492M and D492HER2 and verified expression of selected genes at the RNA and protein level. One candidate, YKL-40 (also known as CHI3L1), was selected for further studies due to its differential expression between D492M and D492HER2, being considerably higher in D492HER2. YKL-40 has been linked to chronic inflammation diseases and cancer, yet its function is not fully understood. Knock-down experiments of YKL-40 in D492HER2 resulted in reduced migration and invasion as well as reduced ability to induce angiogenesis in an in vitro assay, plus changes in the EMT-phenotype. In summary, our data suggest that YKL-40 may provide D492HER2 with increased aggressiveness, supporting cancer progression and facilitating angiogenesis.This work was supported by Grants from Landspitali University Hospital Science Fund, University of Iceland Research Fund, and Icelandic Science and Technology Policy—Grant of Excellence: 152144051. ‘Göngum saman,’ a supporting group for breast cancer research in Iceland ( www.gongumsaman.is ). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.Peer Reviewe

YKL-40/CHI3L1 facilitates migration and invasion in HER2 overexpressing breast epithelial progenitor cells and generates a niche for capillary-like network formation

Publisher's version (útgefin grein).Epithelial to mesenchymal transition (EMT) is a developmental event that is hijacked in some diseases such as fibrosis and cancer. In cancer, EMT has been linked to increased invasion and metastasis and is generally associated with a poor prognosis. In this study, we have compared phenotypic and functional differences between two isogenic cell lines with an EMT profile: D492M and D492HER2 that are both derived from D492, a breast epithelial cell line with stem cell properties. D492M is non-tumorigenic while D492HER2 is tumorigenic. Thus, the aim of this study was to analyze the expression profile of these cell lines, identify potential oncogenes, and evaluate their effects on cellular phenotype. We performed transcriptome and secretome analyses of D492M and D492HER2 and verified expression of selected genes at the RNA and protein level. One candidate, YKL-40 (also known as CHI3L1), was selected for further studies due to its differential expression between D492M and D492HER2, being considerably higher in D492HER2. YKL-40 has been linked to chronic inflammation diseases and cancer, yet its function is not fully understood. Knock-down experiments of YKL-40 in D492HER2 resulted in reduced migration and invasion as well as reduced ability to induce angiogenesis in an in vitro assay, plus changes in the EMT-phenotype. In summary, our data suggest that YKL-40 may provide D492HER2 with increased aggressiveness, supporting cancer progression and facilitating angiogenesis.This work was supported by Grants from Landspitali University Hospital Science Fund, University of Iceland Research Fund, and Icelandic Science and Technology Policy—Grant of Excellence: 152144051. ‘Göngum saman,’ a supporting group for breast cancer research in Iceland ( www.gongumsaman.is ). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.Peer Reviewe

Characterization of natterin-like genes in Arctic charr (Salvelinus alpinus)

Natterins are a recently discovered gene family from the venom gland of Thalassophryne nattereri. Natterin proteins contain a lectin-like domain and a pore-forming toxin-like domain and can cause edema and pain due to their kiniogenase activity. Several natterin-like genes have been found in non-toxic fish species and this indicates other functions of natterin in fish than toxicity. Recently, natterin was found in Arctic charr during a transcriptome study on the different morphs from Lake Thingvallavatn (South Iceland). This species is highly polymorphic and in Lake Thingvallavatn four phenotypic morphs have evolved (small benthic (SB), large benthic (LB), Murta (limnetic, M) and piscivorous limnetic (PI) morph). The transcriptome data revealed that natterin is differentially expressed between the different charr morphs and this lead us to investigate its role in charr in more detail. Charr was found to have at least three natterin paralogues and primers binding the conserved region (general natterin) as well as the different paralogues were designed to examine natterin expressions using quantitative real-time PCR(qPCR). We found that natterin (both general and paralogues) was expressed during embryonic development and the expression was significantly different between morphs (highest in SB) and timepoints (highest in early stages). While general natterin was highest expressed in SB at the early timepoints, the expression of paralogues 1 and 3 was constitutive and the expression of paralogue 2 increased in the later stages in SB. In adult fish tissues the expression of general natterin was highest in the gills whereas natterin paralogue 1 was highest expressed in the kidney and paralogues 2 & 3 in the skin. Natterin paralogue 2 showed the highest expression level during development and in adult fish compared to the other paralogues. However, the observed expression differences of general natterin could not be explained by the differentially expressed paralogues, suggesting the presence of other natterin paralogues or genes in Arctic charr. These results indicate a role of natterin both during Arctic charr embryonic development and in adult fish.RANNÍS and University of Iceland Research Fun

Fungal and cyanobacterial gene expression in a lichen symbiosis: Acclimatization and adaptation to temperature and habitat

How do organisms react to a warming environment? How do such environmental changes affect species interactions? These are key questions in times of global warming. One strategy of coping with environmental changes is acclimatization. Therefore, species evolved complex molecular stress-response mechanisms including heat-shock systems (protein repair) and DNA repair pathways. Here, we analyzed candidate gene expression in the lichen fungus Peltigera membranacea and its cyanobacterial Nostoc symbiont, a key player in carbon and nitrogen cycling in terrestrial ecosystems at northern latitudes. Do increasing temperatures cause a stress response reflected in expression levels of selected stress-response genes and do stress response patterns differ between coastal and inland habitats? As mutualistic symbioses, lichens offer the possibility of analyzing molecular stress responses in a particularly tight interspecific relationship. Using real-time PCR quantification of 38 transcripts, differential expression was demonstrated for nine cyanobacterial and nine fungal stress response genes (plus the fungal symbiosis related lec2 gene) at 15°C and 25°C vs. 5°C indicating temperature stress for both symbionts. Principle component analysis (PCA) revealed two gene groups differing in temperature response patterns. Whereas a set of cyanobacterial DNA repair genes and the fungal lec2 (PC1 group) showed a strongly correlated expression drop at 15°C vs. 5°C, most fungal candidates (PC2 group) showed increased expression at 25°C vs. 5°C. Furthermore, PC1 genes differed more strongly in temperature response along an elevation gradient than between habitat categories. The correlated downregulation of lec2 and cyanobacterial DNA repair genes suggests a possible interplay between the symbionts warranting further studies.Icelandic Research Fund (RANNÍS