Hsa_circ_0064636 regulates voltage dependent anion channel 1/ubiquitination factor E4A through miR­326/miR­503­5 in osteosarcoma.

Circular RNAs (circRNAs) are a subclass of non-coding RNAs that are important for the regulation of gene expression in eukaryotic organisms. CircRNAs exert various regulatory roles in cancer progression. However, the role of hsa_circ_0064636 in osteosarcoma (OS) remains poorly understood. In the present study, the expression of hsa_circ_0064636 in OS cell lines was measured by reverse transcription-quantitative PCR (RT-qPCR). Differentially expressed mRNAs and microRNAs (miRNA or miRs) were screened using mRNA(GSE16088) and miRNA(GSE65071) expression datasets for OS. miRNAs that can potentially interact with hsa_circ_0064636 were predicted using RNAhybrid, TargetScan and miRanda. Subsequently, RNAhybrid, TargetScan, miRanda, miRWalk, miRMap and miRNAMap were used for target gene prediction based on the overlapping miRNAs to construct a circ/miRNA/mRNA interaction network. Target genes were subjected to survival analysis using PROGgeneV2, resulting in a circRNA/miRNA/mRNA interaction sub-network with prognostic significance. miRNA and circRNA in the subnetwork may also have survival significance, but relevant data are lacking and needs to be further proved. RT-qPCR demonstrated that hsa_circ_0064636 expression was significantly increased in OS cell lines. miR-326 and miR-503-5p were identified to be target miRNAs of hsa_circ_0064636. Among the target genes obtained from the miR-326 and miR-503-5p screens, ubiquitination factor E4A (UBE4A) and voltage dependent anion channel 1 (VDAC1) were respectively identified to significantly affect prognosis; only miR-326 targets UBE4A and only miR-503 targets VDAC1. To conclude, these aforementioned findings suggest that hsa_circ_0064636 may be involved in the development of OS by sponging miR-503-5p and miR-326to inhibit their effects, thereby regulating the expression of VDAC1 and UBE4A.

Investigation of cellular communication and signaling pathways in tumor microenvironment for high TP53-expressing osteosarcoma cells through single-cell RNA sequencing.

Osteosarcoma (OS) stands as the most prevalent primary bone cancer in children and adolescents, and its limited treatment options often result in unsatisfactory outcomes, particularly for metastatic cases. The tumor microenvironment (TME) has been recognized as a crucial determinant in OS progression. However, the intercellular dynamics between high TP53-expressing OS cells and neighboring cell types within the TME are yet to be thoroughly understood. In our study, we harnessed the single-cell RNA sequencing (scRNA-seq) technology in combination with the computational tool-Cellchat, aiming to elucidate the intercellular communication networks present within OS. Through meticulous quantitative inference and subsequent analysis of these networks, we succeeded in identifying significant signaling pathways connecting high TP53-expressing OS cells with proximate cell types, namely Macrophages, Monocytes, Endothelial Cells, and PVLs. This research brings forth a nuanced understanding of the intricate patterns and coordination involved in the TME's intercellular communication signals. These findings not only provide profound insights into the molecular mechanisms underpinning OS but also indicate potential therapeutic targets that could revolutionize treatment strategies.

Hsa_circ_0007031 promotes the proliferation and migration of osteosarcoma cells by sponging miR-196a-5p to regulate the HOXB6.

Circular RNAs (circRNAs), a subclass of noncoding RNAs, have been demonstrated to play an essential role in osteosarcoma (OS) development. However, there is still a significant gap in investigating its biological functions and underlying molecular mechanisms, and novel targets of circRNAs have yet to be fully explored. Herein, we found that hsa_circ_0007031 is noticeably raised in OS clinical tissues and cell lines. Hsa_circ_0007031 accelerates OS cell proliferation and migration in vitro and tumor growth and metastasis in vivo and is strongly linked with the stemness of cancer stem cells in OS. Mechanistically, hsa_circ_0007031 shares miRNA response elements with Homeobox B6 (HOXB6), which is identified as a novel pro-tumorigenic gene of OS. Hsa_circ_0007031 competitively binds to miR-196a-5p to prevent miR-196a-5p from lowering the level of HOXB6, which modulates chemokines of cytokine-cytokine receptor interaction signaling pathway and finally promotes OS malignant behavior. In summary, our data unveiled that hsa_circ_0007031/miR-196a-5p/HOXB6 axis-mediated cytokine-cytokine receptor interaction facilitates the progression of OS and maintains the properties of tumor stem cells, which could be a promising therapeutic target for OS.

Identification of Candidate MicroRNA-mRNA Subnetwork for Predicting the Osteosarcoma Progression by Bioinformatics Analysis.

Osteosarcoma (OS) is the pretty common primary cancer of the bone among the malignancies in adolescents. A single molecular component or a limited number of molecules is insufficient as a predictive biomarker of OS progression. Hence, it is necessary to find novel network biomarkers to improve the prediction and therapeutic effect for OS. Here, we identified 230 DE-miRNAs and 821 DE-mRNAs through two miRNA expression-profiling datasets and three mRNA expression-profiling datasets. We found that hsa-miR-494 is closely linked with the survival of OS patients. In addition, we analyzed GO and KEGG enrichment for targets of hsa-miR-494-5p and hsa-miR-494-3p through R programming. And five mRNAs were predicted as common targets of hsa-miR-494-5p and hsa-miR-494-3p. We further revealed that upregulated TRPS1 was strongly correlated with poor outcomes in OS patients through the survival analysis based on the TARGET database. The qRT-PCR study verified that the expression of hsa-miR-494-5p and hsa-miR-494-3p was declined considerably, while TRPS1 was notably raised in OS cells when compared to the osteoblasts. Thus, we generated a new regulatory subnetwork of key miRNAs and target mRNAs using Cytoscape software. These results indicate that the novel miRNA-mRNA subnetwork composed of hsa-miR-494-5p, hsa-miR-494-3p, and TRPS1 might be a characteristic molecule for assessing the prognostic value of OS patients.