The Current Understanding of MicroRNA's Therapeutic, Diagnostic, and Prognostic Role in Chordomas: A Review of the Literature

Potential molecular mechanism in self-renewal is associated with miRNA dysregulation in sacral chordoma - A next-generation RNA sequencing study

Background

Chordoma, the most frequent malignant primary spinal neoplasm, characterized by a high rate of recurrence, is an orphan disease where the clarification of the molecular oncogenesis would be crucial to developing new, effective therapies. Dysregulated expression of non-coding RNAs, especially microRNAs (miRNA) has a significant role in cancer development.

Methods

Next-generation RNA sequencing (NGS) was used for the combinatorial analysis of mRNA-miRNA gene expression profiles in sacral chordoma and nucleus pulposus samples. Advanced bioinformatics workflow was applied to the data to predict miRNA-mRNA regulatory networks with altered activity in chordoma.

Results

A large set of significantly dysregulated miRNAs in chordoma and their differentially expressed target genes have been identified. Several molecular pathways related to tumorigenesis and the modulation of the immune system are predicted to be dysregulated due to aberrant miRNA expression in chordoma. We identified a gene set including key regulators of the Hippo pathway, which is targeted by differently expressed miRNAs, and validated their altered expression by RT-qPCR. These newly identified miRNA/RNA interactions are predicted to have a role in the self-renewal process of chordoma stem cells, which might sustain the high rate of recurrence for this tumor.

Conclusions

Our results can significantly contribute to the designation of possible targets for the development of anti-chordoma therapies.

Recurrent Metastatic Chordoma to the Liver: A Case Report and Review of the Literature

Chordoma is a rare malignant neoplasm derived from notochordal tissue that primarily affects the axial skeleton. Almost 40% of patients have non-cranial chordoma metastases. The most common metastatic sites are the lungs, bones, lymph nodes, and subcutaneous tissue. We present a 52-year female with a history of sacral chordoma presenting with abdominal fullness, early satiety, and a palpable abdominal mass. Abdominal magnetic resonance imaging (MRI) revealed an isolated, highly vascularized, and multilobed liver mass in the left lateral segment. The mass was surgically removed using a clean surgical margin. A histological examination and immunohistochemical staining were consistent with a metastatic chordoma. Two years later, follow-up imaging studies showed a 6.5 × 4.0 × 2.0 cm right liver lesion with multiple lungs, chest wall, pleural, and diaphragmatic lesions. Microscopic- and immunohistochemical staining revealed a recurrent metastatic chordoma. Herein, we present a unique case of metastatic recurrent chordoma in the liver with the involvement of other sites. To the best of our knowledge, no other case of recurrent liver metastasis has been reported.

mmu-miR-145a-5p Accelerates Diabetic Wound Healing by Promoting Macrophage Polarization Toward the M2 Phenotype

Diabetic wounds are recalcitrant to healing. One of the important characteristics of diabetic trauma is impaired macrophage polarization with an excessive inflammatory response. Many studies have described the important regulatory roles of microRNAs (miRNAs) in macrophage differentiation and polarization. However, the differentially expressed miRNAs involved in wound healing and their effects on diabetic wounds remain to be further explored. In this study, we first identified differentially expressed miRNAs in the inflammation, tissue formation and reconstruction phases in wound healing using Illumina sequencing and RT-qPCR techniques. Thereafter, the expression of musculus (mmu)-miR-145a-5p (“miR-145a-5p” for short) in excisional wounds of diabetic mice was identified. Finally, expression of miR-145a-5p was measured to determine its effects on macrophage polarization in murine RAW 264.7 macrophage cells and wound healing in diabetic mice. We identified differentially expressed miRNAs at different stages of wound healing, ten of which were further confirmed by RT-qPCR. Expression of miR-145a-5p in diabetic wounds was downregulated during the tissue formation stage. Furthermore, we observed that miR-145a-5p blocked M1 macrophage polarization while promoting M2 phenotype activation in vitro. Administration of miR-145a-5p mimics during initiation of the repair phase significantly accelerated wound healing in db/db diabetic mice. In conclusion, our findings suggest that rectifying macrophage function using miR-145a-5p overexpression accelerates diabetic chronic wound healing.

An Antisense Oligonucleotide Drug Targeting miR-21 Induces H1650 Apoptosis and Caspase Activation

Non-small cell lung cancer is the most common malignant tumor in the world. Currently, chemotherapy is still the major method for non-small cell lung cancer treatment, but the problem of cancer drug resistance still exists, so we designed 5 different phosphorothioate oligonucleotides to silence key genes in tumor cell development, which could help avoid inducing cancer cell drug resistance. MicroRNAs have been shown to play a crucial role in the pathogenesis and progression of many malignancies, such as breast, colon, lung, and pancreatic cancer. According to the data from the Gene Expression Omnibus database, miR-21 has been reported to be one of the top 20 differentially expressed microRNAs screened using the Morpheus online tool, and miR-21 has been revealed to regulate a series of biological behaviors in cancer cells, including cell proliferation, migration, invasion, metastasis, and apoptosis. In recent years, gene therapy has emerged as a new therapeutic strategy for cancer treatment. Antisense oligonucleotides have recently been suggested as a novel approach for targeting microRNAs by antisense-based gene silencing. Five phosphorothioate oligonucleotides were designed, synthesized, and screened for anticancer activity. Reverse transcription-polymerase chain reaction was used to detect the relative expression of miR21. Among these 5 sequences, only phosphorothioate oligonucleotide 4 inhibited the proliferation of H1650 cells, and this effect was due to the induction of cancer cell apoptosis by activating the caspase-8 apoptotic pathway. In conclusion, this research confirmed the anticancer activity of phosphorothioate oligonucleotide 4 and revealed the underlying mechanism, which has the potential to be a novel anticancer strategy.

MiR-19-3p Induces Tumor Cell Apoptosis via Targeting FAS in Rectal Cancer Cells

MicroRNAs are reported as a vital important factor in cancer cell initiation and progression processes. MicroRNA-19-3p has drawn the attention of many researchers in recent years because of its wide expression and its key role in serious kinds of tumor cells. However, the detailed mechanism of microRNA-19a-3p in these tumors is still poorly understood. So, in the present study, we aimed to explore the biological function and potential molecular mechanism of microRNA-19a-3p in different cancer cells. We first detect the relative level of miR-19a-3p in cancer cell lines and tumor tissues compared to normal cells and tissues. Results indicated the messenger RNA expression of microRNA-19a-3p existing in an aberrant low level in cancer cells and tissues. The overexpression of microRNA-19a-3p significantly reduced the cell proliferation, migration, and invasion ability in HCT116 cells. In addition to this, increased microRNA-19a-3p could induce cell apoptosis via promoting reactive oxygen species (ROS) accumulation, whereas inhibition of microRNA-19a-3p exhibited an opposite effect. Moreover, we predicated the target genes and the binding sites of microRNA-19a-3p and confirmed FAS as the targeting of microRNA-19a-3p through luciferase activity assay. Taken together, these results indicated that microRNA-19a-3p overexpression inhibited HCT116 cell proliferation, migration and invasion, induced cell apoptosis, and ROS accumulation via FAS targeting effect. It was conceivable that microRNA-19a-3p might serve as a potential molecular target for breast and liver cancer treatment.