The P2RX7B splice variant modulates osteosarcoma cell behaviour and metastatic properties.

Area of Science:

• Oncology
• Molecular Biology
• Pharmacology

Background:

• Osteosarcoma (OS) is a prevalent bone cancer in children and adolescents with poor survival rates.
• Existing treatments lack efficacy, necessitating novel therapeutic approaches.
• Purinergic signaling, particularly the P2RX7 receptor B isoform (P2RX7B), is implicated in OS progression.

Purpose of the Study:

• To investigate the role of P2RX7B in osteosarcoma (OS) progression and metastasis.
• To evaluate P2RX7B as a potential therapeutic target for OS.

Main Methods:

• Osteosarcoma cell lines (TE85, MNNG-HOS) were transfected with P2RX7B.
• In vitro assays assessed proliferation, adhesion, migration, and invasion.
• In vivo xenograft mouse models were used to analyze primary tumor growth, bone metastasis, and lung metastasis.
• RNA sequencing (RNA-seq) identified P2RX7B-responsive pathways.

Main Results:

• P2RX7B expression enhanced OS cell survival in vitro, an effect reversed by P2RX7 antagonist A740003.
• P2RX7B reduced cell adhesion and promoted invasion and migration in vitro.
• In vivo, P2RX7B expression led to increased tumor growth and lung metastasis, with ectopic bone formation observed.
• A740003 treatment abrogated these effects and identified a novel gene axis (FN1/LOX/PDGFB/IGFBP3/BMP4).

Conclusions:

• P2RX7B plays a significant role in osteosarcoma tumor growth, progression, and metastasis.
• P2RX7B represents a promising therapeutic target for human osteosarcoma.