Divergent effects of TGF-β inhibition in bone metastases in breast and lung cancer

Background: The objective of this study lies in the determination of the validity of transforming growth factor β (TGF-β) as a therapeutic target in models of metastasis deriving from different histological types of lung cancer. Material and methods: 4-week-old immunodeficient mice inoculated with lung and breast cancer lines were treated with cytokine inhibitor peptide, control peptide or placebo. Weekly bioluminescence and microradiographic measurements were taken to determine the effects of the treatment on tumor burden and metastatic lesions in the long bones. Results: Treatment with the specific peptide against TGF-β has a protector effect in the bone of animals inoculated with the breast cancer lines, unlike what happens in the control peptide and placebo groups. However, the anti-TGF-β treatment lacks the significant therapeutic effects on the bone metastases which develop in lung cancer bearing animals. Conclusions: The role of TGF-β as a potential therapeutic target in bone metastasis is highly dependent on the histopathological type and subtype of tumor.