Hamideh Monfared; Yavar Jahangard; Maryam Nikkhah; Seyed Javad Mirnajafi-Zade; Seyed Javad Mowla
Abstract
There are different subtypes of brain tumors, classified according to the origin of the abnormally proliferated glial cells. Glioblastoma multiforma (GBM) is the grade 4 of brain tumors, gliomas, with the least life expectancy. microRNAs (miRNAs) are small, single stranded, non-coding ...
Read More
There are different subtypes of brain tumors, classified according to the origin of the abnormally proliferated glial cells. Glioblastoma multiforma (GBM) is the grade 4 of brain tumors, gliomas, with the least life expectancy. microRNAs (miRNAs) are small, single stranded, non-coding RNAs with 20-25 nt length with post-transcriptional gene regulatory activities. An altered expression of miRNAs is linked to developmental disorders and some diseases, most importantly cancers. miR-21 is a well-known microRNA, overexpressed in almost all cancer types, including brain tumors. It targets several genes with vital roles in cellular pathways involve in proliferation, invasion and metastatic behaviors. Exosomes are 30-100 nm extracellular vesicles which are packed with various molecules, including miRNAs. Here, we suppressed miR-21 expression level in HEK-293T cells by transfecting them with the miRZip-21 vector. However, when U87-MG cells were cultured in the presence of exosomes isolated from conditioned medium of engineered HEK-293T cells derived exosomes, we did not observe any suppressing effect on host cells’ miR-21 expression level. Moreover, by analyzing the effects of miRZip-21-enriched cell’s conditioned media on three other brain cell lines including 1321N1, A-172 and DAOY, cell type-specific effects of exocrine miRZip-21 were revealed. These data suggested that cell lines from different brain tumor subtypes could exert different responses to microRNA-based therapies, based on their cellular origin and clinical behaviors.
Nazila Nouraee; Mohammad Vasei; Shahriar Semnani; Seyed Javad Mowla
Abstract
MicroRNAs (miRNAs) are a group of short non-coding RNAs implicated in numerous fundamental cellular
processes, and their disregulations have been linked to several pathologic conditions, mainly cancers.
Determining tissue distribution of miRNAs is a prerequisite for understanding their exact functions ...
Read More
MicroRNAs (miRNAs) are a group of short non-coding RNAs implicated in numerous fundamental cellular
processes, and their disregulations have been linked to several pathologic conditions, mainly cancers.
Determining tissue distribution of miRNAs is a prerequisite for understanding their exact functions during
development, tissue homeostasis and abnormality. In situ hybridization is a powerful technique to delineate the
sub-cellular localization and tissue distribution patterns of mRNAs as well as miRNAs. Due to the important
role of miRNAs in tumorigenesis, we optimized an ISH technique for detection of two well-known miRNAs
(miR-302 and miR-21) in formalin-fixed paraffin-embedded (FFPE) tumor samples along with a pluripotent
embryonal carcinoma cell line, NTERA-2 (NT2). After fixation of cells on slides/sectioning of FFPE blocks,
proteinase K digestion, probe concentration, antibody development and light sensitive color reaction were
optimized for both the FFPE samples and cell line. Signals for U6 snRNA, as an internal control, were detected
in the nuclei of the cells. MiR-21 and miR-302 expression was detected in the cytoplasm of FFPE samples of
seminoma carcinoma and in NT2 cell line, respectively. In this study, we optimized ISH for miRNA detection
in FFPE samples and NT2 cell line.
