C-met inhibition blocks bone metastasis development induced by renal cancer stem cells

Area of Science:

• Oncology
• Bone Metastasis Research
• Cancer Stem Cell Biology

Background:

• Cancer stem cells (CSCs) drive bone metastasis in renal tumors.
• Overexpression of the HGF receptor c-MET in renal CSCs suggests c-MET as a therapeutic target.
• Understanding c-MET's role in bone metastasis is crucial for developing effective treatments.

Purpose of the Study:

• To investigate the role of the c-MET pathway in renal cancer bone metastasis.
• To evaluate the efficacy of a c-MET inhibitor (JNJ-38877605) in preventing bone metastasis.
• To explore the clinical relevance of c-MET and related factors in human bone metastases.

Main Methods:

• Isolation of renal CD105+/CD24- CSCs expressing c-MET.
• In vivo studies using NOD/SCID mice with human bone implants treated with JNJ-38877605.
• Analysis of osteoclast and osteoblast activity, bone turnover markers, and serum levels of osteotropic factors (IL-11, CCL20).
• Immunohistochemical analysis of c-MET expression in human renal cancer bone metastases and serum CCL20 levels in patients.

Main Results:

• JNJ-38877605 significantly inhibited bone metastasis formation in mice.
• The c-MET inhibitor reduced osteoclast activation and stimulated osteoblast activity, decreasing bone turnover.
• Reduced levels of IL-11 and CCL20 were observed in treated mice.
• Increased c-MET expression was detected in human bone metastatic lesions, and elevated serum CCL20 correlated with bone metastasis.

Conclusions:

• The c-MET pathway is critical in the pathogenesis of bone metastases initiated by renal cancer stem cells.
• Targeting c-MET with JNJ-38877605 effectively inhibits bone metastasis by modulating bone remodeling.
• These findings support the clinical relevance of c-MET as a therapeutic target for renal cancer bone metastasis in both preclinical models and human patients.