Variants in the 14q32 miRNA cluster are associated with osteosarcoma risk in the Spanish population

Signatures of genetic variation in human microRNAs point to processes of positive selection and population-specific disease risks

The occurrence of natural variation in human microRNAs has been the focus of numerous studies during the last 20 years. Most of them have been focused on the role of specific mutations in disease, while a minor proportion seek to analyse microRNA diversity in the genomes of human populations. We analyse the latest human microRNA annotations in the light of the most updated catalogue of genetic variation provided by the 1000 Genomes Project. By means of the in silico analysis of microRNA genetic variation we show that the level of evolutionary constraint of these sequences is governed by the interplay of different factors, like their evolutionary age or genomic location. The role of mutations in the shaping of microRNA-driven regulatory interactions is emphasized with the acknowledgement that, while the whole microRNA sequence is highly conserved, the seed region shows a pattern of higher genetic diversity that appears to be caused by the dramatic frequency shifts of a fraction of human microRNAs. We highlight the participation of these microRNAs in population-specific processes by identifying that not only the seed, but also the loop, are particularly differentiated regions among human populations. The quantitative computational comparison of signatures of population differentiation showed that candidate microRNAs with the largest differences are enriched in variants implicated in gene expression levels (eQTLs), selective sweeps and pathological processes. We explore the implication of these evolutionary-driven microRNAs and their SNPs in human diseases, such as different types of cancer, and discuss their role in population-specific disease risk.

MicroRNAs signatures, bioinformatics analysis of miRNAs, miRNA mimics and antagonists, and miRNA therapeutics in osteosarcoma

MicroRNAs (miRNAs) involved in key signaling pathways and aggressive phenotypes of osteosarcoma (OS) was discussed, including PI3K/AKT/MTOR, MTOR AND RAF-1 signaling, tumor suppressor P53- linked miRNAs, NOTCH- related miRNAs, miRNA -15/16 cluster, apoptosis related miRNAs, invasion-metastasis-related miRNAs, and 14Q32-associated miRNAs cluster. Herrin, we discussed insights into the targeted therapies including miRNAs (i.e., tumor-suppressive miRNAs and oncomiRNAs). Using bioinformatics tools, the interaction network of all OS-associated miRNAs and their targets was also depicted.

miR-328-3p mediates the anti-tumor effect in osteosarcoma via directly targeting MMP-16

Background

Increasing reports demonstrated that dysregulated expression of microRNAs (miRNAs) leads to the progression of various tumors. Previous studies revealed that miR-328-3p exhibited dysregulated expression in various types of tumors. However, its function and underlying mechanism in osteosarcoma (OS) are still unexplored.

Methods

The expression of miR-328-3p in the tissues and OS cell lines was detected by qRT-PCR analysis. The effects of miR-328-3p in the proliferation were analyzed by MTT assay. The proliferation and apoptosis of OS cells were examined by colony formation assay and TUNEL staining respectively. The migration and tumor formation ability of OS cells were measured by wound healing assay and xenograft in vivo mice assay. Furthermore, the regulatory roles of miR-328-3p/MMP16 were determined by western blot and luciferase reporter assay.

Results

The expression of miR-328-3p was significantly decreased in OS tissues and cell lines. Furthermore, overexpression of miR-328-3p inhibited the cell proliferation and migration, but promoted the apoptosis of OS cells in vitro. Moreover, the analysis in vivo showed that miR-328-3p effectively suppressed the formation of tumors. According to the results of western blot analysis and luciferase reporter assay, we identified matrix metalloproteinase-16 (MMP-16) acted as a direct target of miR-328-3p. Moreover, the expression level of MMP-16, which participates in the occurrence and development of many cancers, was negatively correlated with the miR-328-3p expression in OS cells.

Conclusion

miR-328-3p inhibited the proliferation, migration but accelerated the apoptosis of OS by directly inhibiting MMP-16. And miR-328-3p/MMP-16 axis may be one of the mechanisms of OS development and a novel potential method for the treatment of OS in clinic.

Dissecting the functional role of microRNA 21 in osteosarcoma

Osteosarcoma (OS) is considered to be a malignant bone tumour that mainly affects the long bones, but it is also involved in other bones of the body. Currently, surgery and chemotherapy have achieved some response to patients with OS, but they are not increasing the survival rate as well as treatment options. Researchers made lot of drug options for OS, but yet, no treatment is existing in sight for the disease and needs a new insight into the molecular and signaling pathways for the disease. Now, it is necessary to develop a novel and alternative strategy for the prognosis, diagnosis and treatment options for OS. MicroRNAs (miRNAs) are a small non-coding RNA, and their size ranges from 18 to 22 nt in length. In the nucleus, miRNAs originate and transcribe into primary transcripts and later cleaved to produce stem loop-structured precursor nucleotides. microRNA 21 (miR-21) is considered to be a trivial marker for many diseases and has been upregulated in many cancers. Moreover, it plays a main role in proliferation, migration, invasion and apoptosis. miR-21 and its associated pathways are very important and play a critical role in the pathogenesis of OS and are considered to be a biomarker and a therapeutic target for OS. To our knowledge, there is no paper that demonstrates the responsibility and the role of miR-21 in OS and the number of studies related to miR-21 in OS is spare. Therefore, the main aim of this paper is to give an outline of the recent clinical investigation and importance of miR-21 in OS. It has been suggested that the up- and downregulation of miRNAs plays a crucial role in the pathogenesis and progression of OS. Normally, miR-21 was found to be upregulated in OS; however, we summarize the clinical relevance and the recent research findings associated with miR-21 in OS.