Objective

This study was conducted to dissect the role and potential mechanism of microRNA (miR)-455-3p on osteosarcoma (OS) development.

Methods

miR-455-3p and HSF1 expression in OS tissues were detected by RT-qPCR and western blot. Later, gain- and loss-of-function assays were implemented in OS cells U–2OS and MNNG. The expression of apoptosis-related genes was measured by RT-qPCR and western blot. MTT, Transwell, scratch test, and flow cytometry were utilized to test OS cell viability, invasion, migration, and apoptosis. The targeting relationship between miR-455-3p and HSF1 was assessed with a dual-luciferase reporter gene assay. The transplantation tumor experiment in nude mice was utilized for in vivo confirmation.

Results

Downregulated miR-455-3p and upregulated HSF1 were displayed in OS tissues and cells. Mechanistically, miR-455-3p negatively targeted HSF1. MiR-455-3p inhibition or HSF1 overexpression increased MNNG and U–2OS cell proliferative, invasive, and migrating capabilities, while diminishing U–2OS cell apoptosis. Moreover, HSF1 overexpression negated the impacts of miR-455-3p upregulation on OS cell proliferative, invasive, migrating, and apoptotic abilities. Likewise, overexpressing miR-455-3p curtailed the growth of transplanted OS tumors through HSF1 repression.

Conclusion

MiR-455-3p inhibits the development of OS cells by downregulating HSF1, highlighting the possibility of miR-455-3p as an innovative indicator of prognosis and a therapeutic target for OS.

中文翻译：

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MicroRNA-455-3p 通过 HSF1 下调抑制骨肉瘤进展

客观的

本研究旨在剖析 microRNA (miR)-455-3p 在骨肉瘤 (OS) 发展中的作用和潜在机制。

方法

通过RT-qPCR和蛋白质印迹检测OS组织中miR-455-3p和HSF1的表达。后来，在OS 细胞U-2OS 和 MNNG中进行了功能获得和丧失的检测。通过RT-qPCR和western blot检测凋亡相关基因的表达。采用MTT、Transwell、划痕试验和流式细胞仪检测OS细胞活力、侵袭、迁移和凋亡。通过双荧光素酶报告基因测定评估 miR-455-3p 和 HSF1 之间的靶向关系。采用裸鼠移植瘤实验进行体内验证。

结果

OS 组织和细胞中显示下调的 miR-455-3p 和上调的 HSF1。从机制上讲，miR-455-3p 负向靶向 HSF1。MiR-455-3p 抑制或 HSF1 过表达可增加 MNNG 和 U-2OS 细胞的增殖、侵袭和迁移能力，同时减少 U-2OS 细胞凋亡。此外，HSF1过表达抵消了miR-455-3p上调对OS细胞增殖、侵袭、迁移和凋亡能力的影响。同样，过表达 miR-455-3p 通过抑制 HSF1 抑制了移植 OS 肿瘤的生长。

结论

miR-455-3p 通过下调 HSF1 抑制 OS 细胞的发育，凸显了 miR-455-3p 作为 OS 预后创新指标和治疗靶点的可能性。