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Recent studies have demonstrated that lncRNAs play an important role in cancers, particularly osteosarcoma. ZFAS1 is a newly identified and characterized lncRNA linked to a variety of cancers. The role of ZFAS1 in osteosarcoma is mainly unknown. This study discovered that ZFAS1 was upregulated in osteosarcoma patient tissues, which correlates with elevated SRSF3 protein levels. Higher levels of ZFAS1 or SRSF3 were linked to a poor prognosis of osteosarcoma. ZFAS1 knockdown decreased SRSF3 protein levels but had a negligible effect on SRSF3 mRNA expression. Further research indicated that ZFAS1 could bind to the SRSF3 protein directly and prevent degrading. Functional studies revealed that ZFAS1 knockdown inhibited osteosarcoma cell proliferation as measured by the CCK-8 assay, colony formation assay, and Ki-67 immunofluorescence staining. Furthermore, ZFAS1 knockdown reduced the expression of PCNA, CDK1, CDK4, and CDK6, increasing p53 and p16. IT has also been observed that ZFAS1 knockdown inhibited osteosarcoma cell migration and invasion as measured by the wound healing assay and the trans-well assay with or without Matrigel.Furthermore, exogenous SRSF3 expression in ZFAS1-depleted osteosarcoma cells restored SRSF3 expression while simultaneously inhibiting cell proliferation and metastasis. Our findings show that ZFAS1 plays an essential role in osteosarcoma progression by stabilizing the SRSF3 protein. Our study provides novel insight into the role of ZFAS1 in osteosarcoma. ZFAS1 has the potential to be used as a prognostic biomarker as well as a therapeutic target in the treatment of osteosarcoma.

Osteosarcoma is a primary malignant bone tumor, which affects children, adolescents, and young adults commonly. MicroRNAs (miRNAs) have been proved to be dysregulated in different cancers, including osteosarcoma. Although miR-320a has been implicated in many types of malignancies, little is known about the role of miR-320a in osteosarcoma. In this study, we show that the overexpression of miR-320a or knockdown of cytoplasmic polyadenylation element-binding protein 1 (CPEB1) inhibited osteosarcoma cell migration and invasion. miR-320a downregulates CPEB1 expression by directly targeting the CPEB1 3'-UTR. Furthermore, CPEB1 reintroduction reversed the antiproliferation, antimigration, and antiinvasion roles of miR-320a, indicating that miR-320a might function as a tumor suppressor in osteosarcoma through CPEB1. In conclusion, our study demonstrates that miR-320a plays a critical role in osteosarcoma progression and may provide a potential therapeutic target for osteosarcoma., (© 2020 The Authors. Cancer Medicine published by John Wiley & Sons Ltd.)

Long noncoding RNA focally amplified lncRNA on chromosome 1 (FAL1) plays an important role in the development of several human malignancy entities. However, the expression and function of FAL1 in the carcinogenesis and development of osteosarcoma remain unknown. In this study, we detected the FAL1 levels in human osteosarcoma tissues and cell lines by quantitative real-time polymerase chain reaction and investigated its role in osteosarcoma using in vitro assays. Our results showed that FAL1 expression was significantly upregulated in human osteosarcoma tissues and cell lines compared with their normal controls. FAL1 expression level was positively correlated with the distance metastasis (P = .008) and tumor stage ( P = .013). Higher expression of FAL1 conferred a significantly poorer survival, as determined by the Kaplan-Meier method with the log-rank test. Multivariate Cox proportional hazards analysis revealed that FAL1 was probably an independent risk of overall survival. Additionally, the serum FAL1 expression level was associated with osteosarcoma status in patients. Receiver operating characteristic curve analysis demonstrated that FAL1 expression was different between patients with osteosarcoma and healthy cohorts (area under the curve, 0.839; P < .001). Furthermore, knockdown of FAL1 by small interfering RNA significantly inhibited cell proliferation via inducing G2/M arrest in osteosarcoma cells. Depletion of FAL1 also suppressed osteosarcoma cell migration and invasion, which might be mediated by inhibiting the epithelial-mesenchymal transition (EMT) program. Taken together, our study showed that lncRNA FAL1 exhibits an important pro-oncogenic effect on osteosarcoma progression by targeting EMT, which may serve as a potential therapeutic target for osteosarcoma., (© 2018 Wiley Periodicals, Inc.)

Osteosarcoma is the most common primary bone malignancy; however, the molecular mechanisms of development are not well understood. Progestin and AdipoQ receptors (PAQR3), a protein specifically localized in the Golgi apparatus, was recently characterized as a new tumor suppressor. Little is known about the expression and function of PAQR3 in osteosarcoma. Here, we showed that PAQR3 was downregulated in osteosarcoma tissues compared with the adjacent normal regions in 80 paired samples. Moreover, lower levels of PAQR3 were associated with metastasis in clinical osteosarcoma patients. In addition, overexpression of PAQR3 in the osteosarcoma cell line MG-63 inhibited cell proliferation, migration, and invasion by promoting ERK phosphorylation. Taken together, our results indicated that PAQR3 might act as a tumor suppressor in osteosarcoma, providing a novel diagnostic and therapeutic option for human osteosarcoma in the future.

Osteosarcoma is among the commonly observed malignancies worldwide. High-mobility group box 1 protein (HMGB1) is a highly conserved protein and is involved in the progression of various types of human cancer. The aim of the present study was to explore whether the level of HMGB1 was involved in the necrosis of osteosarcoma cells. Doxorubicin (DXR), as an inducer of necrosis, was administered to human osteosarcoma cell lines (MG63, Saos-2 and U2OS), and the results indicated that 0.5 µg/ml DXR significantly induced the necrosis of MG63 cells (P<0.01), while 0.5 and 1.0 µg/ml DXR suppressed the viability of MG63 and U2OS cells (P<0.05), relative to untreated controls. Additionally, treatment with DXR was observed by western blot analysis to markedly increase the expression levels of HMGB1 in MG63 cells, and to significantly increase the levels of secreted HMGB1 in the supernatants of MG63 and U2OS cells (P<0.01). In conclusion, cell necrosis increased the level of HMGB1 in osteosarcoma cells, as well as the level of secreted HMGB1 in cell supernatants. Therefore, HMGB1 may be a potential target in molecular therapy for patients with osteosarcoma. [ABSTRACT FROM AUTHOR]

Osteosarcoma is the most common primary bone malignancy; however, the molecular mechanisms of development are not well understood. Progestin and AdipoQ receptors (PAQR3), a protein specifically localized in the Golgi apparatus, was recently characterized as a new tumor suppressor. Little is known about the expression and function of PAQR3 in osteosarcoma. Here, we showed that PAQR3 was downregulated in osteosarcoma tissues compared with the adjacent normal regions in 80 paired samples. Moreover, lower levels of PAQR3 were associated with metastasis in clinical osteosarcoma patients. In addition, overexpression of PAQR3 in the osteosarcoma cell line MG-63 inhibited cell proliferation, migration, and invasion by promoting ERK phosphorylation. Taken together, our results indicated that PAQR3 might act as a tumor suppressor in osteosarcoma, providing a novel diagnostic and therapeutic option for human osteosarcoma in the future. [ABSTRACT FROM AUTHOR]