lectroacupuncture stimulation at CV4 sites prevents breast cancer-induced osteoporosis by activating the Wnt/β-catenin signaling pathway

Abstract

Osteoporosis is a common condition among breast cancer patients, characterized by decreased bone density due to chemotherapy and hormone therapy. However, the application of electroacupuncture (EA) stimulation at Guanyuan (CV4) sites has been found to be beneficial in enhancing bone mineral density. In this study, we aimed to investigate the efficacy of EA stimulation at CV4 sites in breast cancer-induced osteoporosis and elucidate the potential underlying mechanisms. A breast cancer model in mice was established, EA stimulation at CV4 sites was performed, and hematoxylin-eosin (HE) stain was conducted to assess the bone mineral density and trabecular bone volume of femur tissues. Additionally, Tartrate-resistant acid phosphatase (TRAP) staining was performed to identify and visualize osteoclasts. Furthermore, Western blots were used to evaluate the expression levels of various proteins, including c-src, Cathepsin K (CtSK), matrix metalloproteinase 9 (MMP9), Collagen 1A1 (COL1A1), Osteopontin (OPN), Runt-related transcription factor 2 (RUNX2), Wnt3a and β-catenin, and Enzyme Linked Immunosorbent Assay (ELISA) to measure the concentration of Alkaline phosphatase (ALP), NO synthase 2 (NOS2), glutathione reductase (GSR), superoxide dismutase (SOD), reactive oxygen species (ROS) and lactate dehydrogenase (LDH) in the serum. The results revealed that EA stimulation in the breast cancer model resulted in higher bone mineral density and trabecular bone volume, along with a reduction in the number of osteoclasts. EA stimulation at CV4 site significantly decreased the protein levels of c-src, CtSK and MMP9, while also reducing ROS and LDH production. Conversely, it promoted the expression of COL1A1, OPN, RUNX2, Wnt3a and β-catenin. Additionally, it elevated the concentration of ALP, NOS2, GSR and SOD in the serum. Overall, EA stimulation at the CV4 site may inhibit bone loss and promote bone differentiation by activating the Wnt/β-catenin pathway, indicating its potential use for breast cancer-induced osteoporosis treatment.