A ranking-based meta-analysis reveals let-7 family as a meta-signature for grade classification in breast cancer

Breast cancer is one of the most important causes of cancer-related deaths worldwide in women. In addition to gene expression studies, the progressing work in the miRNA area including miRNA microarray studies, brings new aspects to the research on the cancer development and progression. Microarray technology has been widely used to find new biomarkers in research and many transcriptomic microarray studies are available in public databases. In this study, the breast cancer miRNA and mRNA microarray studies were collected according to the availability of their data and clinical information, and combined by a newly developed ranking-based meta-analysis approach to find out candidate miRNA biomarkers (meta-miRNAs) that classify breast cancers according to their grades and explain the relation between miRNAs and mRNAs. This approach provided meta-miRNAs specific to breast cancer grades, pointing out let-7 family members as grade classifiers. The qRTPCR studies performed with independent breast tumors confirmed the potential biomarker role of let-7 family members (meta-miRNAs). The concordance between the meta-mRNAs and miRNA target genes specific to tumor grade (common genes) supported the idea of mRNAs as miRNA targets. The pathway analysis results showed that most of the let-7 family miRNA targets, and also common genes, were significantly taking part in cancer-related pathways. The qRT-PCR studies, together with bioinformatic analyses, confirmed the results of meta-analysis approach, which is dynamic and allows combining datasets from different platforms. © 2015 Oztemur et al

Determination of effective miRNAs in wound healing in an experimental Rat Model

The larvae of Lucilia sericata have been used for centuries as medicinal maggots in the healing of wounds. The present study aimed to screen potential microRNAs related to ES-induced wound healing in rat skin wounds and to investigate the potential mechanisms contributing to accelerated wound healing. Healthy, male, 12 weeks old Wistar albino rats weighing 250-300 g were supplied by the Animal Experimental Center. All animal studies were performed in accordance with the NIH Guide for the Care and Use of Laboratory Animals. Wistar albino rats were treated by ES after post wounding and the differentially expressed miRNAs in wound biopsies were screened by microarray analysis at the end of treatments for 4,7 and 10 days. In addition, bioinformatics approaches were used to identify the potential target genes of differentially expressed miRNAs and the functions of their target genes. We found a significant up-regulation of rno-miR-99a* and rno-mir-877 in response to ES treatment. Further investigation of rno-miR-99a* and rno-mir-877 and their target genes (TGFa, TNF, TAGLN, MAPK1, MMP-9) implicated in present study could provide new insight for an understanding lead to the development of new treatment strategies. The identified miRNAs can be new biomarkers for ES-induced wound healing