ABSTRACT
MiR-302-367 is a cluster of polycistronic microRNAs that are exclusively expressed in embryonic stem [ES] cells. The miR-302-367 promoter is functional during embryonic development but is turned off in later stages. Motivated by the cancer stem cell hypothesis, we explored the potential expression of miR-302 in brain tumor cell lines. In the present experimental study, we have tried to expand our knowledge on the expression pattern and functionality of miR302 cluster by quantifying its expression in a series of glioma [A-172, 1321N1, U87MG] and medulloblastoma [DAOY] cell lines. To further assess the functionality of miR-302 in these cell lines, we cloned its promoter core region upstream of the enhanced green fluorescent protein [EGFP] or luciferase encoding genes. Our data demonstrated a very low expression of miR-302 in glioma cell lines, compared with that of embryonal carcinoma cell line NT2 being used as a positive control. The expression of miR-302 promoter-EGFP construct in the aforementioned cell lines demonstrated GFP expression in a rare subpopulation of the cells. Serum deprivation led to the generation of tumorospheres, enrichment of miR-302 positive cells and upregulation of a number of pluripotency genes. Taken together, our data suggest that miR-302 could potentially be used as a novel putative cancer stem cell marker to identify and target cancer stem cells within tumor tissues
Subject(s)
Humans , Glioma , Serum , Cell Line , MedulloblastomaABSTRACT
The current methods for bladder cancer diagnosis suffer from low sensitivity and specificity. Therefore, finding a novel tumor markers with high specificity and sensitivity is of great interest. MicroRNAs [miRNA, miR] are small endogenously-produced, non-coding RNAs with an important role in regulating gene expression. Recent studies show that miRNAs expression profiles represent significant tumor-specific changes that are unique for most cancers. The aim of this study was to optimize miRNA containing total RNA extraction from urine and use it as a reliable and repeatable technique for miRNA detection in urine of patients with bladder cancer. Total RNA was extracted from the urine of patients with bladder cancer and normal individuals using RNX and Trizol solutions with and without modifications of original protocols. Real-time quantitative RT-PCR was then used to detect miRNAs with a potential link to bladder tumorigenesis. RNX and the modified Trizol are practical methods for RNA extraction from urine samples. The mir-21 amplification of the extracted RNAs using modified Trizol method was more efficient than that of RNX method. It is noteworthy that, the levels of miRNAs expression were much higher in the frozen urines compared to the fresh ones. We have succeeded to set-up a protocol to easily amplify miRNAs in urine samples. Based on the data, microRNAs seem to be good biomarkers for early detection and screening of bladder cancer
ABSTRACT
Clinical application of embryonic stem[ES] cells faces difficulties regarding tissue rejection as well as ethical limitations. One solution for these issues is to reprogram somatic cells by the injection of their nucleus into an enucleated oocyte or zygote. However, technical complications and ethical considerations have impeded the therapeutic implications of this technology. An approach which is most recently developed is in vitro induction of reprogramming in adult cells. This was first achieved by using four transcription factors, including Oct4, Sox2, c-Myc and Klf4. Subsequently, many ongoing efforts were performed for enhancing this method, also for making it compatible with clinical applications. However, there is still a long road ahead. In this paper we review strategies to reprogram somatic cells to embryonic state and discuss about the recent strategy and the relevant developments