MiR-92a Inhibits the Progress of Osteosarcoma Cells and Increases the Cisplatin Sensitivity by Targeting Notch1

MicroRNA-92a-3p Enhances Cisplatin Resistance by Regulating Krüppel-Like Factor 4-Mediated Cell Apoptosis and Epithelial-to-Mesenchymal Transition in Cervical Cancer

Recent studies have confirmed the existence and key roles of microRNA (miRNAs) in cancer drug resistance, including cervical cancer (CC). The present study aims to establish a novel role for miR-92a-3p and its associated gene networks in cisplatin (DDP) resistance of CC. First, the disparities in miRNA expression between CC tissues and adjacent normal tissues were screened based on GSE19611 microarray data that retrieved from Gene Expression Omnibus (GEO), and we identified several miRs that were significantly downregulated or upregulated in CC tissues including miR-92a-3p. Moreover, miR-92a-3p was significantly up-regulated in DDP-resistant cells and was the most differently expressed miRNA. Functionally, knockdown of miR-92a-3p increased the sensitivity of DDP-resistant cells to DDP via inhibiting cell proliferation, migration and invasion, and promoting apoptosis. Conversely, overexpression of miR-92a-3p significantly induced DDP resistance in CC parental cells including HeLa and SiHa cells. Moreover, Krüppel-like factor 4 (KLF4) was identified as a direct target of miR-92a-3p, and an obvious inverse correlation was observed between the expression of miR-92a-3p and KLF4 in 40 pairs of cancer tissues. Furthermore, KLF4 knockdown reversed the promoting effect of miR-92a-3p inhibition on DDP sensitivity in DDP-resistant CC cells. Besides, high expression of miR-92a-3p was associated with DDP resistance, as well as a short overall survival in clinic. Taken together, these findings provide important evidence that miR-92a-3p targets KLF4 and is significant in DDP resistance in CC, indicating that miR-92a-3p may be an attractive target to increase DDP sensitivity in clinical CC treatment.

Hsa-miR-557 Inhibits Osteosarcoma Growth Through Targeting KRAS

Objective: Osteosarcoma is the most common malignancy in the skeletal system; studies showed an important role of miRNAs in tumorigenesis, indicating miRNAs as possible therapeutic molecules. This study found abnormal hsa-miR-557 expression levels in osteosarcoma and tried to explore the potential function and the mechanism.

Methods: Differential expression genes of osteosarcoma were analyzed using GSE28423 from the GEO database. Survival analysis of miRNAs was conducted with data obtained from the TARGET-OS database. STRING and miRDIP were used to predict target genes of hsa-miR-557; KRAS was then verified using dual-luciferase reporter assay. Expression of genes was detected by qPCR, and levels of proteins were detected by Western blot. The proliferation ability of cells was detected by CCK-8 and cell cycle analysis. Tumor formation assay in nude mice was used to detect the influence of osteosarcoma by hsa-miR-557 in vivo.

Results: Analysis from the GEO and TARGET databases found 12 miRNAs that are significantly related to the osteosarcoma prognosis, 7 downregulated (hsa-miR-140-3p, hsa-miR-564, hsa-miR-765, hsa-miR-1224-5p, hsa-miR-95, hsa-miR-940, and hsa-miR-557) and 5 upregulated (hsa-miR-362-3p, hsa-miR-149, hsa-miR-96, hsa-miR-744, and hsa-miR-769-5p). CCK-8 analysis and cell cycle analysis found that hsa-miR-557 could significantly inhibit the proliferation of osteosarcoma cells. The tumor formation assay in nude mice showed that tumor sizes and weights were inhibited by hsa-miR-557 transfection. Further studies also proved that hsa-miR-557 could target the 3′UTR of KRAS and modulate phosphorylation of downstream proteins.

Conclusion: This study showed that hsa-miR-557 could inhibit osteosarcoma growth both in vivo and in vitro, by modulating KRAS expression.

Osteosarcoma and Metastasis

Osteosarcoma is the most common primary bone malignancy in adolescents. Its high propensity to metastasize is the leading cause for treatment failure and poor prognosis. Although the research of osteosarcoma has greatly expanded in the past decades, the knowledge and new therapy strategies targeting metastatic progression remain sparse. The prognosis of patients with metastasis is still unsatisfactory. There is resonating urgency for a thorough and deeper understanding of molecular mechanisms underlying osteosarcoma to develop innovative therapies targeting metastasis. Toward the goal of elaborating the characteristics and biological behavior of metastatic osteosarcoma, it is essential to combine the diverse investigations that are performed at molecular, cellular, and animal levels from basic research to clinical translation spanning chemical, physical sciences, and biology. This review focuses on the metastatic process, regulatory networks involving key molecules and signaling pathways, the role of microenvironment, osteoclast, angiogenesis, metabolism, immunity, and noncoding RNAs in osteosarcoma metastasis. The aim of this review is to provide an overview of current research advances, with the hope to discovery druggable targets and promising therapy strategies for osteosarcoma metastasis and thus to overcome this clinical impasse.

Adding a "Notch" to Cardiovascular Disease Therapeutics: A MicroRNA-Based Approach

Dysregulation of the Notch pathway is implicated in the pathophysiology of cardiovascular diseases (CVDs), but, as of today, therapies based on the re-establishing the physiological levels of Notch in the heart and vessels are not available. A possible reason is the context-dependent role of Notch in the cardiovascular system, which would require a finely tuned, cell-specific approach. MicroRNAs (miRNAs) are short functional endogenous, non-coding RNA sequences able to regulate gene expression at post-transcriptional levels influencing most, if not all, biological processes. Dysregulation of miRNAs expression is implicated in the molecular mechanisms underlying many CVDs. Notch is regulated and regulates a large number of miRNAs expressed in the cardiovascular system and, thus, targeting these miRNAs could represent an avenue to be explored to target Notch for CVDs. In this Review, we provide an overview of both established and potential, based on evidence in other pathologies, crosstalks between miRNAs and Notch in cellular processes underlying atherosclerosis, myocardial ischemia, heart failure, calcification of aortic valve, and arrhythmias. We also discuss the potential advantages, as well as the challenges, of using miRNAs for a Notch-based approach for the diagnosis and treatment of the most common CVDs.

Recent Developments in Nanomedicine for Pediatric Cancer

Cancer is the second biggest cause of death in children in the US. With the development of chemotherapy, there has been a substantial increase in the overall survival rate in the last 30 years. However, the overall mortality rate in children with cancer remains 25%, and many survivors experience a decline in overall quality of life and long-term adverse effects caused by treatments. Although cancer cells share common characteristics, pediatric cancers are different from adult cancers in their prevalence, mutation load, and drug response. Therefore, there is an urgent unmet need to develop therapeutic approaches specifically designed for children with cancer. Nanotechnology can potentially overcome the deficiencies of conventional methods of administering chemotherapy and ultimately improve clinical outcomes. The nanoparticle-based drug delivery systems can decrease the toxicity of therapy, provide a sustained or controlled drug release, improve the pharmacokinetic properties of loading contents, and achieve a targeted drug delivery with achievable modifications. Furthermore, therapeutic approaches based on combining nanoformulated drugs with novel immunotherapeutic agents are emerging. In this review, we discussed the recently developed nanotechnology-based strategies for treating blood and solid pediatric cancers.

Circulating microRNA-92a-3p in colorectal cancer: a review

Recent studies have found that microRNAs (miRNAs) are present in body fluids, including blood, cerebrospinal fluid, tears, saliva, breast milk, and urine in a stable form, and are called circulating miRNAs. Although their biological roles remain to be determined, circulating miRNAs are considered as mediators of intercellular communication like hormones and cytokines. Because circulating miRNAs can be collected in a non-invasive manner called as "liquid biopsy", they have also been studied as potential biomarkers for early detection, evaluation of therapeutic effects, and prediction of prognosis in various diseases, including cancers. In this review, we focus on the studies on circulating microRNA-92a-3p (miR-92a-3p) in colorectal cancer (CRC), considering their existence form, isolation methods, potential as biomarkers, and roles in CRC development and progression.

Notch-1 promotes the malignant progression of osteosarcoma through the activation of cell division cycle 20

The molecular mechanism of osteosarcoma (OS) pathogenesis is poorly understood. The Notch signaling pathway has been shown to be critically involved in tumorigenesis, including OS. Therefore, we explored the molecular mechanism by which the Notch-1 signaling pathway is involved in OS progression. Several approaches were carried out to determine the biological function of Notch-1 in OS cells. The MTT results revealed that Notch-1 overexpression increased the viability of OS cells, whereas Notch-1 downregulation reduced cell viability. Consistently, modulation of Notch-1 regulated apoptosis and the migratory and invasive abilities of OS cells. Mechanistic studies showed that Notch-1 overexpression augmented cell division cycle 20 (Cdc20) expression in OS cells. Moreover, overexpression of Cdc20 alleviated the inhibitory effects of Notch-1 downregulation on the viability, migration and invasion of OS cells. Our study offers a promising OS treatment strategy by inhibiting Notch-1.

Role of microRNA-92a in metastasis of osteosarcoma cells in vivo and in vitro by inhibiting expression of TCF21 with the transmission of bone marrow derived mesenchymal stem cells

Background

This study aims to investigate the role of microRNA-92a (miR-92a) in metastasis of osteosarcoma (OS) cells in vivo and in vitro by regulatingTCF21 with the transmission of bone marrow derived mesenchymal stem cells (BMSCs).

Methods

BMSCs were isolated, purified and cultured from healthy adult bone marrow tissues. The successfully identified BMSCs were co-cultured with OS cells, and the effects of BMSCs on the growth metastasis of OS cells in vitro and in vivo were determined. qRT-PCR and western blot analysis was used to detect the expression of miR-92a and TCF21 in OS cells and OS cells co-cultured with BMSCs. Proliferation, invasion and migration of OS cells transfected with miR-92a mimics and miR-92a inhibitors was determined, and the tumorigenesis and metastasis of OS cells in nude mice were observed. Expression of miR-92a and TCF21 mRNA in tissue specimens as well as the relationship between the expression of miR-92a and the clinicopathological features of OS was analyzed.

Results

BMSCs promoted proliferation, invasion and migration of OS cells in vitro together with promoted the growth and metastasis of OS cells in vivo. Besides, high expression of miR-92a was found in OS cells co-cultured with BMSCs. Meanwhile, overexpression of miR-92a promoted proliferation, invasion and migration of OS cells in vitro as well as promoted growth and metastasis of OS cells in vivo. The expression of miR-92a increased significantly, and the expression of TCF21 mRNA and protein decreased significantly in OS tissues. Expression of miR-92a was related to Ennecking staging and distant metastasis in OS patients.

Conclusion

Collectively, this study demonstrates that the expression of miR-92a is high in OS and BMSCs transfers miR-92a to inhibit TCF21 and promotes growth and metastasis of OS in vitro and in vivo.