No abstract

Magnetic iron oxide nanoparticles are a well‐explored class of nanomaterials known for their high magnetization and biocompatibility. They have been used in various biomedical applications such as drug delivery, biosensors, hyperthermia, and magnetic resonance imaging (MRI) contrast agent. It is necessary to surface modify the nanoparticles with a biocompatible moiety to prevent their agglomeration and enable them to target to the defined area. Dendrimers have attracted considerable attention due to their small size, monodispersed, well‐defined globular shape, and a relative ease incorporation of targeting ligands. In this study, superparamagnetic iron oxide nanoparticles were synthesized via a coprecipitation method. The magnetic nanoparticles (MNPs) had been modified with (3‐aminopropyl) triethoxysilane, and then polyamidoamine functionalized MNPs had been synthesized cycling. Various characterization techniques had been used to reveal the morphology, size, and structure of the nanoparticles such as scanning electron microscopy, transmission electron microscope, X‐ray diffraction analysis, and vibrating sample magnetometer, Fourier‐transform infrared spectroscopy and zeta potential measurements. In addition, the cytotoxicity property of G3–dendrimer functionalized MNPs were evaluated using 3‐[4,5‐dimethylthiazol‐2‐yl]‐2, 5‐diphenyl tetrazolium bromide assay which confirmed the biocompatibility of the nanocomposites. Dendrimer functionalized MNPs are able to act as contrast agents for MRI and magnetic fluid hyperthermia mediators. A superior heat generation was achieved for the given concentration according to the hyperthermia results. MRI results show that the synthesized nanocomposites are a favorable option for MRI contrast agent. We believe that these dendrimer functionalized MNPs have the potential of integrating therapeutic and diagnostic functions in a single carrier.

Background Anaplastic thyroid carcinoma (ATC) is the most lethal malignancy in thyroid carcinomas. Long non-coding RNAs (lncRNAs) are a member of non-coding RNAs, regulating the expression of gene. Metastasis-associated lung adenocarcinoma transcript 1 (MALAT1) is an onco-lncRNA that is overexpressed in several carcinomas including ATC. Evidence showed that MALAT1 has a crucial function in apoptosis, and cell cycle progression. Objectives In order to take advantage of 3D cell culture system in cancer investigation, we have used a 3D in vitro ATC model to determine the effect of dual MEK/Aurora kinase inhibitor BI-847325 anticancer drug on the fundamental molecular mechanisms of MALAT1-mediated gene regulation in ATC. Methods In this study, ATC cell lines (C643 and SW1736) were grown in alginate scaffold. Encapsulated cells were treated by BI-847325. Changes in expression of MALAT1, Mcl1, miR-363-3p, and cyclinD1 were measured by qRT-PCR. Results and conclusion MALAT1 gene expression following BI-847325 treatment was significantly downregulated in C643 and SW1736 cell lines. Reversely, miR-363-3p expression was significantly upregulated by BI-847325 in both ATC cell lines. Mcl1 expression was significantly downregulated after treatment in C643 cell lines. Moreover, the expression of this gene was not significantly reduced following BI-847325 treatment in SW1736 cell line. Additionally, cyclin D1 expression was significantly downregulated after treatment in both ATC cell lines. Altogether, the result of this study was the first report of MALAT1's molecular function in ATC and suggested that BI-847325 which inhibits both MEK and Aurora kinase family could be effective against ATC by regulating the genes involved in cell cycle and apoptosis including MALAT1and its downstream genes.

Patients with poor prognosis in thyroid cancers resistant to currently available therapeutic modalities are often in search of a new treatment. The epidermal growth factor receptor (EGFR) vIII, a ligand-independent, constitutively active, mutated form of EGFR has been shown to play a role in the pathogenesis of some cancers. Consequently, the immunohistochemical detection of EGFRvIII with novel camel antibodies, which are valuable for their ability to interact with less antigenic epitopes in contrast to the conventional antibodies, might be worthy in diagnostic techniques of thyroid neoplasms. EGFRvIII was evaluated on paraffin-embedded tissue specimens of 40 samples of follicular carcinomas, papillary carcinomas, medullary carcinomas, follicular adenomas, and goiter of the thyroid gland by immunohistochemistry. Positive immunostaining of neoplastic tissues with camel and rabbit polyclonal, as a control, were 81.3% and 39.1%, respectively. No goiter tissue was stained with either antibody preparation. Also, the results showed that the sensitivity of camel heavy chain antibodies (65%) is higher in contrast to conventional rabbit under the same conditions (39.1%). Considering the results of this study, exploiting the smaller heavy chain antibodies of camels against EGFRvIII seems promising in the diagnosis procedures of thyroid neoplasms.

Background New insights on cellular and molecular aspects of both oligodendrocyte (OL) differentiation and myelin synthesis pathways are potential avenues for developing a cell-based therapy for demyelinating disorders comprising multiple sclerosis. MicroRNAs (miRNA) have broad implications in all aspects of cell biology including OL differentiation. MiR-184 has been identified as one of the most highly enriched miRNAs in oligodendrocyte progenitor cells (OPCs). However, the exact molecular mechanism of miR-184 in OL differentiation is yet to be elucidated. Methods and results Based on immunochemistry assays, qRT-PCR, and western blotting findings, we hypothesized that overexpression of miR-184 in either neural progenitor cells (NPCs) or embryonic mouse cortex stimulated the differentiation of OL lineage efficiently through regulating crucial developmental genes. Luciferase assays demonstrated that miR-184 directly represses positive regulators of neural and astrocyte differentiation, i.e., SOX1 and BCL2L1, respectively, including the negative regulator of myelination, LINGO1. Moreover, blocking the function of miR-184 reduced the number of committed cells to an OL lineage. Conclusions Our data highlighted that miR-184 could promote OL differentiation even in the absence of exogenous growth factors and propose a novel strategy to improve the efficacy of OL differentiation, with potential applications in cell therapy for neurodegenerative diseases. Electronic supplementary material The online version of this article (10.1186/s13287-019-1208-y) contains supplementary material, which is available to authorized users.