Dickkopf-1 is regulated by the mevalonate pathway in breast cancer

Area of Science:

• Oncology
• Molecular Biology
• Pharmacology

Background:

• Amino-bisphosphonates and statins target the mevalonate pathway, potentially offering anti-tumor effects.
• Dickkopf-1 (DKK-1), a Wnt inhibitor, promotes osteolytic bone lesions and is an adverse marker in various cancers.
• This study investigates the impact of mevalonate pathway inhibition on DKK-1 expression in osteotropic breast cancer.

Purpose of the Study:

• To assess the effects of mevalonate pathway inhibition on DKK-1 expression in breast cancer.
• To analyze the role of the mevalonate pathway and its downstream targets in DKK-1 regulation.
• To evaluate the potential of breast cancer cells to influence osteoblastogenesis via DKK-1.

Main Methods:

• Assessed DKK-1 regulation by bisphosphonates and statins in human breast cancer cell lines.
• Analyzed the mevalonate pathway and downstream targets.
• Studied breast cancer cell modulation of osteoblastogenesis in mC2C12 cells.
• Validated clinical relevance by examining DKK-1 in tissues and serum of breast cancer patients treated with bisphosphonates.

Main Results:

• DKK-1 was highly expressed in receptor-negative breast cancer cell lines and elevated in patients with these tumors.
• Zoledronic acid and atorvastatin significantly suppressed DKK-1 in vitro by inhibiting geranylgeranylation of CDC42 and Rho.
• DKK-1 suppression reduced breast cancer cells' ability to inhibit osteoblast differentiation.
• Treatment with zoledronic acid decreased DKK-1 levels by 60% in breast cancer patients after 12 months.

Conclusions:

• Dickkopf-1 (DKK-1) is identified as a novel target within the mevalonate pathway.
• Zoledronic acid and atorvastatin effectively suppress DKK-1 in breast cancer.
• Targeting DKK-1 represents a potential therapeutic strategy for breast cancer, particularly in bone metastasis.