Doxorubicin inhibits osteosarcoma progression by regulating circ_0000006/miR-646/ BDNF axis

Osteosarcoma in a ceRNET perspective

Osteosarcoma (OS) is the most prevalent and fatal type of bone tumor. It is characterized by great heterogeneity of genomic aberrations, mutated genes, and cell types contribution, making therapy and patients management particularly challenging. A unifying picture of molecular mechanisms underlying the disease could help to transform those challenges into opportunities.This review deeply explores the occurrence in OS of large-scale RNA regulatory networks, denominated "competing endogenous RNA network" (ceRNET), wherein different RNA biotypes, such as long non-coding RNAs, circular RNAs and mRNAs can functionally interact each other by competitively binding to shared microRNAs. Here, we discuss how the unbalancing of any network component can derail the entire circuit, driving OS onset and progression by impacting on cell proliferation, migration, invasion, tumor growth and metastasis, and even chemotherapeutic resistance, as distilled from many studies. Intriguingly, the aberrant expression of the networks components in OS cells can be triggered also by the surroundings, through cytokines and vesicles, with their bioactive cargo of proteins and non-coding RNAs, highlighting the relevance of tumor microenvironment. A comprehensive picture of RNA regulatory networks underlying OS could pave the way for the development of innovative RNA-targeted and RNA-based therapies and new diagnostic tools, also in the perspective of precision oncology.

Alteration in the Expression of Circular Rnas and its association with the Development and Progression of Osteosarcoma, an Integrative Review with High Sensitivity Research

BACKGROUND

Osteosarcoma is the most common primary malignant bone tumor, mainly affecting children, young adults, and the elderly. It is an aggressive cancer with a poor prognosis, exhibiting low survival rates even with standard treatment. Recently, circular RNA molecules capable of influencing gene expression through various functions, with their main role being acting as microRNA sponges and reducing their intracellular expression, have been identified. Recent studies have linked circular RNAs to osteosarcoma development and progression. Therefore, the present study aimed to investigate the alteration in circular RNA expression during osteosarcoma development and progression.

METHODS

An integrative literature review was conducted from September 10th to November 12th, 2021, using the following databases: PubMed/MEDLINE, SCOPUS, Web of Science, OVID, and EMBASE. 129 full articles were included in the review. The obtained data were organized using a standardized data collection instrument, which included the following information: altered expression profile of circular RNAs, associated cancer hallmarks, clinical-pathological relationships of circular RNAs, and perspectives on the studied circular RNAs.

RESULTS

A total of 94 distinct circular RNAs were identified, predominantly showing an increased expression pattern. Approximately 91% of the studies that aimed to identify the mechanisms of action of circular RNAs highlighted the function of circular RNAs as microRNA sponges. The most associated cancer hallmarks with the identified circular RNAs were proliferative signaling induction, invasion and metastasis, and resistance to cell death. The altered expression of these circular RNAs generally correlated with a worse prognosis for patients, as evidenced by clinical features such as shorter survival, advanced Enneking and/or TNM stage, higher incidence of metastasis, larger tumor size, and increased chemoresistance.

CONSLUSION

These findings indicate the significance of circular RNA molecules in osteosarcoma carcinogenesis, suggesting their potential as new prognostic and/or diagnostic biomarkers, as well as alternative therapeutic targets in the fight against osteosarcoma.

Bone-Targeted Exosomes: Strategies and Applications

As the global population ages, bone-related diseases have increasingly become a major social problem threatening human health. Exosomes, as natural cell products, have been used to treat bone-related diseases due to their superior biocompatibility, biological barrier penetration, and therapeutic effects. Moreover, the modified exosomes exhibit strong bone-targeting capabilities that may improve efficacy and avoid systemic side effects, demonstrating promising translational potential. However, a review of bone-targeted exosomes is still lacking. Thus, the recently developed exosomes for bone-targeting applications in this review are focused. The biogenesis and bone-targeting regulatory functions of exosomes, the constructive strategies of modified exosomes to improve bone-targeting, and their therapeutic effects for bone-related diseases are introduced. By summarizing developments and challenges in bone-targeted exosomes, It is striven to shed light on the selection of exosome constructive strategies for different bone diseases and highlight their translational potential for future clinical orthopedics.

Anti-Invasive and Anti-Migratory Effects of Ononin on Human Osteosarcoma Cells by Limiting the MMP2/9 and EGFR-Erk1/2 Pathway

Osteosarcoma is a common malignancy of the bone. Due to its high metastatic properties, osteosarcoma becomes the leading cause of cancer death worldwide. Ononin is an isoflavone glycoside known to have various pharmacological properties, including antioxidant and anti-inflammatory activities. In the present study, we aimed to investigate the efficacy of ononin on osteosarcoma cell migration, invasion, and the underlying mechanisms. The in vitro anti-tumorigenic and anti-migratory properties of ononin were determined by MTT, colony formation, invasion, and migration in MG-63 and U2OS osteosarcoma cell lines. The results were compared with the standard chemotherapeutic drug, doxorubicin (DOX), as a positive control. The dose-dependent manners of ononin treatment increased the expression of apoptosis and inhibition of cell proliferation through the EGFR-Erk1/2 signaling pathways. Additionally, ononin significantly inhibited the invasion and migration of human osteosarcoma cells. For consistency, we used the MG-63-xenograft mice model to confirm the in vivo anti-tumorigenic and anti-migratory efficacy of ononin by inhibiting the protein expressions of EGFR-Erk1/2 and MMP2/9. According to the histological study, ononin had no adverse effect on the liver and kidney. Overall, our findings suggested that ononin could be a potentially effective agent against the development and metastasis of osteosarcoma.

Analysis of the Efficacy of Multidrug Combination Chemotherapy Regimens for Osteosarcoma and the Management of Chemotherapeutic Reactions

Purpose

To analyse the efficacy of high-dose methotrexate + adriamycin + cisplatin (HD-MTX + ADR + PDD, MAP) regimens applied to osteosarcoma and the pretreatment and resolution of chemotherapeutic reactions.

Methods

The clinical data of 21 patients with osteosarcoma in our hospital from January 2015 to January 2018 were retrospectively analysed. All patients were treated with the MAP protocol, 21 days for 1 cycle, and treated with artificial joint replacement or amputation after 3∼4 cycles of treatment. The tumour tissue necrosis rate, limb preservation success rate after treatment, and chemotherapy response during chemotherapy were counted and analysed for all patients. A local recurrence rate, a distant metastasis rate, and an overall survival rate were recorded during the 3-year follow-up period.

Results

After treatment, the percentage of tumour tissue necrosis ≥90% was 85.71% (18/21) and the percentage of successful limb preservation was 57.14% (12/21) in 21 patients with osteosarcoma. During chemotherapy, all 21 patients with osteosarcoma experienced various degrees of chemotherapy reactions, mainly bone marrow suppression of 100% (21/21), gastrointestinal reactions of 100% (21/21), liver function impairment of 66.67% (14/21), and cardiotoxicity of 52.38% (11/21), all of which improved and completed treatment after treatment. During the 3-year follow-up period, the 21 patients with osteosarcoma had a local recurrence rate of 9.52% (2/21), a distant metastasis rate of 28.57% (6/21), and an overall survival rate of 80.95% (17/21).

Conclusion

With stringent protection and relief measures, patients with osteosarcoma treated with the MAP regimen have promising near-term outcomes, with high survival rates over 3 years and tolerable chemotherapy responses. The clinical trial is registered under L2015093.