Hsa_circ_0008259 modulates miR-21-5p and PDCD4 expression to restrain osteosarcoma progression

Area of Science:

• Oncology
• Molecular Biology
• Genetics

Background:

• Osteosarcoma (OS) is a common pediatric bone cancer with poorly understood molecular mechanisms.
• Circular RNAs (circRNAs) are increasingly recognized for their roles in cancer progression.
• This study investigates the role of circ_0008259 in OS tumorigenesis.

Purpose of the Study:

• To identify and characterize the function of circ_0008259 in osteosarcoma.
• To elucidate the molecular mechanism by which circ_0008259 influences OS progression.
• To explore the regulatory relationship between circ_0008259, miR-21-5p, and PDCD4 in OS.

Main Methods:

• Differential expression analysis of circRNAs in OS tissues to identify circ_0008259.
• Quantitative real-time PCR (qRT-PCR) to measure expression levels of circ_0008259, miR-21-5p, and PDCD4 mRNA.
• In vitro assays including cell counting kit-8, Transwell, and flow cytometry to assess cell viability, metastasis, and apoptosis.
• Bioinformatics analysis, dual-luciferase reporter assays, RNA-binding protein immunoprecipitation, and RNA-pull down assays to determine molecular interactions.
• Western blot to detect protein expression levels.

Main Results:

• Circ_0008259 and PDCD4 expression were downregulated, while miR-21-5p was upregulated in OS tissues and cells.
• Overexpression of circ_0008259 significantly suppressed OS cell proliferation and metastasis while promoting apoptosis.
• PDCD4 was confirmed as a target of miR-21-5p, and circ_0008259 competitively bound to miR-21-5p, thereby increasing PDCD4 expression in OS cells.

Conclusions:

• Circ_0008259 functions as a tumor suppressor in osteosarcoma.
• The circ_0008259/miR-21-5p/PDCD4 axis plays a critical role in regulating OS progression.
• Targeting the circ_0008259/miR-21-5p/PDCD4 pathway may offer a novel therapeutic strategy for osteosarcoma.