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Previous studies reported on the broad-spectrum antiviral function of heparin. Here we investigated the antiviral function of magnesium-modified heparin and found that modified heparin displayed a significantly enhanced antiviral function against human adenovirus (HAdV) in immortalized and primary cells. Nuclear magnetic resonance analyses revealed a conformational change of heparin when complexed with magnesium. To broadly explore this discovery, we tested the antiviral function of modified heparin against herpes simplex virus type 1 (HSV-1) and found that the replication of HSV-1 was even further decreased compared to aciclovir. Moreover, we investigated the antiviral effect against the new severe acute respiratory syndrome coronavirus type 2 (SARS-CoV-2) and measured a 55-fold decreased viral load in the supernatant of infected cells associated with a 38-fold decrease in virus growth. The advantage of our modified heparin is an increased antiviral effect compared to regular heparin.

Background: Several physiological (fertilization, placentation, wound healing) and pathophysiological processes (infection with enveloped viruses, cancer) depend on cell fusion. In cancer it was postulated that the fusion of cancer cells with normal cells such as macrophages or stem cells may not only give rise to hybrid cells exhibiting novel properties, such as an increased metastatic capacity and drug resistance, but possibly also cancer stem/ initiating cell properties. Hence, hybrid clone cells (M13HS, M13MDA435 and M13MDA231) that were derived from spontaneous fusion events of human M13SV1-EGFP-Neo breast epithelial cells and HS578T-Hyg, MDA-MB-435-Hyg and MDA-MB-231-Hyg cancer cells were investigated regarding potential in vitro cancer stem/ initiating cell properties., Methods: CD44/CD24 expression pattern and ALDH1 activity of parental cells and hybrid clones was determined by flow cytometry. A colony formation and mammosphere formation assay was applied to determine the cells' capability to form colonies and mammospheres. Sox9, Slug and Snail expression levels were determined by Western blot analysis., Results: Flow cytometry revealed that all hybrid clone cells were CD44 + /CD24 -/low , but differed markedly among each other regarding ALDH1 activity. Likewise, each hybrid clone possessed a unique colony formation and mammosphere capacity as well as unique Snail, Slug and Sox9 expression patterns. Nonetheless, comparison of hybrid clones revealed that M13HS hybrids exhibited more in vitro cancer stem/ initiating cell properties than M13MDA231 and M13MDA435 hybrids, such as more ALDH1 positive cells or an increased capacity to form colonies and mammospheres., Conclusion: The fate whether cancer stem/ initiating cells may originate from cell fusion events likely depends on the specific characteristics of the parental cells.

The interplay of ErbB receptor homo- and heterodimers plays a crucial role in the pathology of breast cancer since activated signal transduction cascades coordinate proliferation, survival and migration of cells. EGF and β-Heregulin are well characterised ligands known to induce ErbB homo- and heterodimerisation, which have been associated with disease progression. In the present study, we investigated the impact of both factors on the migration of MDA-NEO and MDA-HER2 human breast cancer cells. MDA-NEO cells are positive for EGFR and HER3, while MDA-HER2 cells express EGFR, HER2 and HER3. Cell migration analysis revealed that β-Heregulin potently impaired EGF induced migration in both cell lines. Western blot studies showed that both ErbB receptor and PLC-γ1 tyrosine phosphorylation levels were diminished in EGF and β-Heregulin co-treated MDA-NEO and MDA-HER2 cells, which was further correlated to a significantly impaired calcium influx. Our data indicate that EGF and HRG may interfere with each other for receptor binding and dimerisation, which ultimately has an impact on signalling outcome., (Copyright © 2018 Elsevier Inc. All rights reserved.)

Background: In addition to physiological events such as fertilisation, placentation, osteoclastogenesis, or tissue regeneration/wound healing, cell fusion is involved in pathophysiological conditions such as cancer. Cell fusion, which applies to both the proteins and conditions that induce the merging of two or more cells, is not a fully understood process. Inflammation/pro-inflammatory cytokines might be a positive trigger for cell fusion. Using a Cre-LoxP-based cell fusion assay we demonstrated that the fusion between human M13SV1-Cre breast epithelial cells and human MDA-MB-435-pFDR1 cancer cells was induced by the pro-inflammatory cytokine tumour necrosis factor-α (TNF-α)., Methods: The gene expression profile of the cells in the presence of TNF-α and under normoxic and hypoxic conditions was analysed by cDNA microarray analysis. cDNA microarray data were verified by qPCR, PCR, Western blot and zymography. Quantification of cell fusion events was determined by flow cytometry. Proteins of interest were either blocked or knocked-down using a specific inhibitor, siRNA or a blocking antibody., Results: The data showed an up-regulation of various genes, including claudin-1 (CLDN1), ICAM1, CCL2 and MMP9 in M13SV1-Cre and/or MDA-MB-435-pFDR1 cells. Inhibition of these proteins using a blocking ICAM1 antibody, CLDN1 siRNA or an MMP9 inhibitor showed that only the blockage of MMP9 was correlated with a decreased fusion rate of the cells. Likewise, the tetracycline-based antibiotic minocycline, which exhibits anti-inflammatory properties, was also effective in both inhibiting the TNF-α-induced MMP9 expression in M13SV1-Cre cells and blocking the TNF-α-induced fusion frequency of human M13SV1-Cre breast epithelial cells and human MDA-MB-435-pFDR1 cancer cells., Conclusions: The matrix metalloproteinase-9 (MMP9) is most likely involved in the TNF-α-mediated fusion of human M13SV1-Cre breast epithelial cells and human MDA-MB-435-pFDR1 cancer cells. Likewise, our data indicate that the tetracycline-based antibiotic minocycline might exhibit anti-fusogenic properties because it inhibits a cell fusion-related mechanism.

Background: The biological phenomenon of cell fusion has been associated with cancer progression since it was determined that normal cell × tumor cell fusion-derived hybrid cells could exhibit novel properties, such as enhanced metastatogenic capacity or increased drug resistance, and even as a mechanism that could give rise to cancer stem/initiating cells (CS/ICs). CS/ICs have been proposed as cancer cells that exhibit stem cell properties, including the ability to (re)initiate tumor growth., Methods: Five M13HS hybrid clone cells, which originated from spontaneous cell fusion events between M13SV1-EGFP-Neo human breast epithelial cells and HS578T-Hyg human breast cancer cells, and their parental cells were analyzed for expression of stemness and EMT-related marker proteins by Western blot analysis and confocal laser scanning microscopy. The frequency of ALDH1-positive cells was determined by flow cytometry using AldeRed fluorescent dye. Concurrently, the cells' colony forming capabilities as well as the cells' abilities to form mammospheres were investigated. The migratory activity of the cells was analyzed using a 3D collagen matrix migration assay., Results: M13HS hybrid clone cells co-expressed SOX9, SLUG, CK8 and CK14, which were differently expressed in parental cells. A variation in the ALDH1-positive putative stem cell population was observed among the five hybrids ranging from 1.44% (M13HS-7) to 13.68% (M13HS-2). In comparison to the parental cells, all five hybrid clone cells possessed increased but also unique colony formation and mammosphere formation capabilities. M13HS-4 hybrid clone cells exhibited the highest colony formation capacity and second highest mammosphere formation capacity of all hybrids, whereby the mean diameter of the mammospheres was comparable to the parental cells. In contrast, the largest mammospheres originated from the M13HS-2 hybrid clone cells, whereas these cells' mammosphere formation capacity was comparable to the parental breast cancer cells. All M13HS hybrid clones exhibited a mesenchymal phenotype and, with the exception of one hybrid clone, responded to EGF with an increased migratory activity., Conclusion: Fusion of human breast epithelial cells and human breast cancer cells can give rise to hybrid clone cells that possess certain CS/IC properties, suggesting that cell fusion might be a mechanism underlying how tumor cells exhibiting a CS/IC phenotype could originate.

At the annual prestigious International Symposium of the Fritz-Bender Foundation, Munich, 18-20 May, 2016, researchers, clinicians, and students discussed the state of the art and future perspectives of genomic medicine in cancer. Genomic medicine (also known as precision medicine/oncology) should help clinicians to provide a more precise diagnosis and therapy in oncology for individual patients. The meeting focused on next-generation sequencing methods, analytical computational analysis of big data, and data mining on the way to translational and evidence-based medicine. The meeting covered the social and ethical impact of genomic medicine as well as news and views on antibody targeting of intracellular proteins, on the architecture of intracellular proteins and their impact on carcinogenesis, and on the adaptation of tumor therapy in due consideration of tumor evolution. Subheadings like "Genetic Profiling of Patients and Risk Prediction," "Molecular Profiling of Tumors and Metastases," "Tumor-Host Microenvironment Interaction and Metabolism," and "Targeted Therapy" were subsumed under the main heading of "Personalized Cancer Care.", (Copyright © 2016 by S. Karger AG, Basel.)

TLRs are important receptors of cells of the innate immune system since they recognize various structurally conserved molecular patterns of different pathogens as well as endogenous ligands. In cancer, the role of TLRs is still controversial due to findings that both regression and progression of tumors could depend on TLR signaling. In the present study, M13SV1-EGFP-Neo human breast epithelial cells, MDA-MB-435-Hyg human breast cancer cells and two hybrids M13MDA435-1 and -3 were investigated for TLR4 and TLR9 expression and signaling. RT-PCR data revealed that LPS and CpG-ODN induced the expression of pro-inflammatory cytokines, like IFN-β, TNF-α, IL-1β and IL-6 in hybrid cells, but not parental cells. Interestingly, validation of RT-PCR data by Western blot showed detectable protein levels solely after LPS stimulation, suggesting that regulatory mechanisms are also controlled by TLR signaling. Analysis of pAKT and pERK1/2 levels upon LPS and CpG-ODN stimulation revealed a differential phosphorylation pattern in all cells. Finally, the migratory behavior of the cells was investigated showing that both LPS and CpG-ODN potently blocked the locomotory activity of the hybrid cells in a dose-dependent manner. In summary, hybrid cells exhibit differential TLR4 and TLR9 signaling.

The biological phenomenon of cell fusion in a cancer context is still a matter of controversial debates. Even though a plethora of in vitro and in vivo data have been published in the past decades the ultimate proof that tumor hybrid cells could originate in (human) cancers and could contribute to the progression of the disease is still missing, suggesting that the cell fusion hypothesis is rather fiction than fact. However, is the lack of this ultimate proof a valid argument against this hypothesis, particularly if one has to consider that appropriate markers do not (yet) exist, thus making it virtually impossible to identify a human tumor cell clearly as a tumor hybrid cell. In the present review, we will summarize the evidence supporting the cell fusion in cancer concept. Moreover, we will refine the cell fusion hypothesis by providing evidence that cell fusion is a potent inducer of aneuploidy, genomic instability and, most likely, even chromothripsis, suggesting that cell fusion, like mutations and aneuploidy, might be an inducer of a mutator phenotype. Finally, we will show that "accidental" tissue repair processes during cancer therapy could lead to the origin of therapy resistant cancer hybrid stem cells.

There is a growing list of data indicating that cancer (stem) cells could functionally adapt foreign tissue features, such as endothelial-like cells or neuroendocrine cells, express lineage markers or could differentiate into various lineages in response to appropriate differentiation criteria. The finding that cancer (stem) cells may possess some kind of differentiation capacity poses the question whether this might be an inherent or acquired property. Cancer stem cells share stem cell characteristics and may thus possess an inherent differentiation capacity enabling the cells to respond to various differentiation stimuli. Considering the plasticity of cancer (stem) cells, even non-tumorigenic (and putatively non-differentiable) tumor cells could give rise to tumorigenic tumor stem cells, exhibiting stem cell characteristics including an inherent differentiation capacity. On the contrary, cancer (stem) cells may have acquired differentiation capacity as a consequence of a previous cell fusion event with cell types exhibiting differentiation potential and being fusogenic, such as macrophages or stem cells. Of pivotal interest in a tumor context are macrophages, which chiefly foster the chronically inflamed tumor microenvironment. Because chronically inflamed tissue is a well-known trigger for cell fusion and both macrophages and stem cells are highly fusogenic we conclude that cell fusion events between these cell types and cancer (stem) cells should frequently occur, thereby giving rise to hybrid cells exhibiting not only novel properties, like an enhanced metastatogenic phenotype, but also parental characteristics, such as differentiation capacity. Conceivably, the combination of both properties might be advantageous for metastasizing cancer (stem) cells to adapt better and faster to a foreign organ tissue environment., (Copyright © 2015 Elsevier Ltd. All rights reserved.)

Background: Tumor cell migration is a prerequisite for metastasis formation. The role of the actin-modulating protein, gelsolin, in metastasis is controversial, as previous studies have reported associations with both worse and better prognosis., Materials and Methods: We analysed the association of gelsolin mRNA levels with metastasis-free survival in three cohorts (n=766) of patients with node-negative breast cancer. To determine its effect on migration, gelsolin expression was down-regulated as well as overexpressed in breast cancer cell lines., Results: Higher gelsolin expression correlated with lower tumor stage and grade, and slower cell proliferation, and was associated with longer metastasis-free survival (hazard ratio (HR)=0.60, p<0.001) in patients with estrogen receptor-positive (ER(+)) erb-b2 receptor tyrosine kinase 2-negative (HER2(-)) tumors. Conversely, the opposite association was observed in those with ER(-)HER(-) tumors (HR=1.95, p=0.014). Down-regulation of gelsolin using siRNA in MCF-7 and MDA-MB-468 cells increased cell migration, whereas overexpression had the opposite effect., Conclusion: High gelsolin levels are associated with better prognosis in ER(+)HER2(-) breast cancer and a reduction in tumor cell migration., (Copyright© 2015 International Institute of Anticancer Research (Dr. John G. Delinassios), All rights reserved.)

The biological phenomenon of cell fusion plays an important role in several physiological processes, like fertilization, placentation, or wound healing/tissue regeneration, as well as pathophysiological processes, such as cancer. Despite this fact, considerably less is still known about the factors and conditions that will induce the merging of two plasma membranes. Inflammation and proliferation has been suggested as a positive trigger for cell fusion, but it remains unclear, which of the factor(s) of the inflamed microenvironment are being involved. To clarify this we developed a reliable assay to quantify the in vitro fusion frequency of cells using a fluorescence double reporter vector (pFDR) containing a LoxP-flanked HcRed/DsRed expression cassette followed by an EGFP expression cassette. Because cell fusion has been implicated in cancer progression four human breast cancer cell lines were stably transfected with a pFDR vector and were co-cultured with the stably Cre-expressing human breast epithelial cell line. Cell fusion is associated with a Cre-mediated recombination resulting in induction of EGFP expression in hybrid cells, which can be quantified by flow cytometry. By testing a panel of different cytokines, chemokines, growth factors and other compounds, including exosomes, under normoxic and hypoxic conditions our data indicate that the proinflammatory cytokine TNF-α together with hypoxia is a strong inducer of cell fusion in human MDA-MB-435 and MDA-MB-231 breast cancer cells.