Exploring the role of dosing procedure and chemical properties in in vitro assays using a fish gill cell line

Author(s):  
Kristin Schirmer ◽  
Katrin Tanneberger ◽  
Nynke I. Kramer ◽  
Frans J.M. Busser ◽  
Joop L.M. Hermens ◽  
...  
2014 ◽  
Vol 9 (1) ◽  
pp. 54-63 ◽  
Author(s):  
Yang Yue ◽  
Renata Behra ◽  
Laura Sigg ◽  
Paloma Fernández Freire ◽  
Smitha Pillai ◽  
...  

2020 ◽  
Author(s):  
Tulin Okbinoglu ◽  
Pierre Kennepohl

Molecules containing sulfur-nitrogen bonds, like sulfonamides, have long been of interest due to their many uses and chemical properties. Understanding the factors that cause sulfonamide reactivity is important, yet their continues to be controversy regarding the relevance of S-N π bonding in describing these species. In this paper, we use sulfur K-edge x-ray absorption spectroscopy (XAS) in conjunction with density functional theory (DFT) to explore the role of S<sub>3p</sub> contributions to π-bonding in sulfonamides, sulfinamides and sulfenamides. We explore the nature of electron distribution of the sulfur atom and its nearest neighbors and extend the scope to explore the effects on rotational barriers along the sulfur-nitrogen axis. The experimental XAS data together with TD-DFT calculations confirm that sulfonamides, and the other sulfinated amides in this series, have essentially no S-N π bonding involving S<sub>3p</sub> contributions and that electron repulsion and is the dominant force that affect rotational barriers.


2021 ◽  
Vol 22 (3) ◽  
pp. 1163
Author(s):  
Gaia Palmini ◽  
Cecilia Romagnoli ◽  
Simone Donati ◽  
Roberto Zonefrati ◽  
Gianna Galli ◽  
...  

Telangiectatic osteosarcoma (TOS) is an aggressive variant of osteosarcoma (OS) with distinctive radiographic, gross, microscopic features, and prognostic implications. Despite several studies on OS, we are still far from understanding the molecular mechanisms of TOS. In recent years, many studies have demonstrated not only that microRNAs (miRNAs) are involved in OS tumorigenesis, development, and metastasis, but also that the presence in high-grade types of OS of cancer stem cells (CSCs) plays an important role in tumor progression. Despite these findings, nothing has been described previously about the expression of miRNAs and the presence of CSCs in human TOS. Therefore, we have isolated/characterized a putative CSC cell line from human TOS (TOS-CSCs) and evaluated the expression levels of several miRNAs in TOS-CSCs using real-time quantitative assays. We show, for the first time, the existence of CSCs in human TOS, highlighting the in vitro establishment of this unique stabilized cell line and an identification of a preliminary expression of the miRNA profile, characteristic of TOS-CSCs. These findings represent an important step in the study of the biology of one of the most aggressive variants of OS and the role of miRNAs in TOS-CSC behavior.


Cancers ◽  
2021 ◽  
Vol 13 (12) ◽  
pp. 3055
Author(s):  
Elisabetta Stanzani ◽  
Leire Pedrosa ◽  
Guillaume Bourmeau ◽  
Oceane Anezo ◽  
Aleix Noguera-Castells ◽  
...  

Therapeutic resistance after multimodal therapy is the most relevant cause of glioblastoma (GBM) recurrence. Extensive cellular heterogeneity, mainly driven by the presence of GBM stem-like cells (GSCs), strongly correlates with patients’ prognosis and limited response to therapies. Defining the mechanisms that drive stemness and control responsiveness to therapy in a GSC-specific manner is therefore essential. Here we investigated the role of integrin a6 (ITGA6) in controlling stemness and resistance to radiotherapy in proneural and mesenchymal GSCs subtypes. Using cell sorting, gene silencing, RNA-Seq, and in vitro assays, we verified that ITGA6 expression seems crucial for proliferation and stemness of proneural GSCs, while it appears not to be relevant in mesenchymal GSCs under basal conditions. However, when challenged with a fractionated protocol of radiation therapy, comparable to that used in the clinical setting, mesenchymal GSCs were dependent on integrin a6 for survival. Specifically, GSCs with reduced levels of ITGA6 displayed a clear reduction of DNA damage response and perturbation of cell cycle pathways. These data indicate that ITGA6 inhibition is able to overcome the radioresistance of mesenchymal GSCs, while it reduces proliferation and stemness in proneural GSCs. Therefore, integrin a6 controls crucial characteristics across GBM subtypes in GBM heterogeneous biology and thus may represent a promising target to improve patient outcomes.


2004 ◽  
Vol 49 (3) ◽  
pp. 165-172 ◽  
Author(s):  
M. Yazgan ◽  
A. Tanik

The study covers the investigation of pesticides in terms of consumption, toxicological classification and various intrinsic physical and chemical properties like DT50, KOC, GUS, solubility that describe the important mechanisms prevailing in soil, namely persistence and mobility. These mechanisms help to estimate the transportation pathways of pesticides on soil till they reach the receiving water after being applied on land. Classification is done in three groups, those likely to appear in surface flow, those that appear in groundwater and those that present transient conditions. Such an approach that also takes into account toxicological levels and annual consumption values of pesticides will act as a tool to prepare the priority list of pesticides that need special care during their transportation. The fate of pesticides is a difficult task to solve, however, such a methodology, puts forth a rough estimate on their behavior in spite of uncertainties in many of the parameters describing mechanisms like persistence and mobility. The agricultural areas of two watersheds of Istanbul are selected as target areas to describe the approach, which is also checked with another approach estimating pesticide pollution potential that considers various other properties of pesticides. Almost similar findings are depicted with 85% proximity. The methodology presented in the paper illustrates and emphasizes the significant role of pesticide properties in determining their fate in soil after being applied.


Nanomaterials ◽  
2018 ◽  
Vol 9 (1) ◽  
pp. 9 ◽  
Author(s):  
Artiom Skripka ◽  
Dominyka Dapkute ◽  
Jurga Valanciunaite ◽  
Vitalijus Karabanovas ◽  
Ricardas Rotomskis

Nanomaterials have permeated various fields of scientific research, including that of biomedicine, as alternatives for disease diagnosis and therapy. Among different structures, quantum dots (QDs) have distinctive physico-chemical properties sought after in cancer research and eradication. Within the context of cancer therapy, QDs serve the role of transporters and energy donors to photodynamic therapy (PDT) drugs, extending the applicability and efficiency of classic PDT. In contrast to conventional PDT agents, QDs’ surface can be designed to promote cellular targeting and internalization, while their spectral properties enable better light harvesting and deep-tissue use. Here, we investigate the possibility of complex formation between different amphiphilic coating bearing QDs and photosensitizer chlorin e6 (Ce6). We show that complex formation dynamics are dependent on the type of coating—phospholipids or amphiphilic polymers—as well as on the surface charge of QDs. Förster’s resonant energy transfer occurred in every complex studied, confirming the possibility of indirect Ce6 excitation. Nonetheless, in vitro PDT activity was restricted only to negative charge bearing QD-Ce6 complexes, correlating with better accumulation in cancer cells. Overall, these findings help to better design such and similar complexes, as gained insights can be straightforwardly translated to other types of nanostructures—expanding the palette of possible therapeutic agents for cancer therapy.


2017 ◽  
Vol 32 (4) ◽  
pp. 403-408 ◽  
Author(s):  
Hongfen Liu ◽  
Qiang Zhen ◽  
Yakun Fan

Background Recent studies have shown that long noncoding RNA (IncRNA) gastric carcinoma highly expressed transcript 1 (GHET1) was involved in the progression of tumors. However, the role of GHET1 in esophageal squamous cell carcinoma (ESCC) remains unclear. Methods The expression of IncRNA GHET1 was examined in 55 paired ESCC tissues and adjacent nontumor tissues. Molecular and cellular techniques were used to explore the role of GHET1 on ESCC cells. Results Our data showed that GHET1 expression was significantly increased in ESCC tissues and cell lines. High GHET1 expression in ESCC tissues was significantly associated with poor differentiation, advanced tumor nodes metastasis stage, and lymph node metastasis. GHET1 showed high sensitivity and specificity for diagnosing ESCC. Our data from in vitro assays showed that GHET1 inhibition suppressed ESCC cells proliferation, migration, and invasion, and induced cells apoptosis. Furthermore, western blot showed that GHET1 inhibition significantly decreased the expression of vimentin and N-cadherin while it increased the expression of E-cadherin. Conclusions Our study indicates that GHET1 acts as an oncogene in ESCC and may represent a novel therapeutic target for the treatment of ESCC patients.


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