Tumor Suppressor WWOX inhibits osteosarcoma metastasis by modulating RUNX2 function

Area of Science:

• Oncology
• Molecular Biology
• Cancer Research

Background:

• Osteosarcoma (OS) is a primary bone cancer common in adolescents and young adults, known for its high metastatic potential, particularly to the lungs.
• WW domain-containing oxidoreductase (WWOX) is frequently inactivated in OS, and its reduced levels correlate with increased aggressiveness and metastasis.
• The precise role of WWOX in OS metastasis remains largely unexplored.

Purpose of the Study:

• To investigate the function of the tumor suppressor WWOX in inhibiting pulmonary osteosarcoma metastasis.
• To elucidate the molecular mechanisms by which WWOX influences OS cell invasion, migration, and metastatic colonization.

Main Methods:

• Ectopic expression of WWOX in WWOX-negative OS cell lines (HOS, LM-7) for in vitro and in vivo studies.
• Assessment of OS cell invasion and migration using in vitro assays.
• Evaluation of tumor burden, metastatic seeding, and colonization in vivo models.
• Analysis of WWOX's impact on the expression of RUNX2 metastatic target genes.

Main Results:

• Ectopic WWOX expression significantly inhibited OS cell invasion and migration in vitro.
• In vivo, WWOX expression led to reduced tumor burden and suppressed metastatic colonization in the lungs.
• WWOX's suppressive effect on metastasis was linked to decreased levels of RUNX2 target genes involved in cell adhesion and motility.

Conclusions:

• WWOX acts as a crucial tumor suppressor in osteosarcoma, specifically by inhibiting pulmonary metastasis.
• WWOX influences OS aggressiveness by modulating RUNX2-mediated pathways regulating adhesion and motility.
• WWOX represents a promising therapeutic target for combating metastatic osteosarcoma in adolescents.