Abstract
In this study, we investigated the role of the spindle checkpoint protein SPC24 in osteosarcoma progression. SPC24 knockdown in 143B and U2OS osteosarcoma cells decreased cell growth, survival and invasiveness. The SPC24 knockdown cells also exhibited low EGFR, Ras and phospho-ERK levels and high E-cadherin levels, suggesting inhibition of EGFR/Ras/ERK signaling and epithelial-to-mesenchymal transitioning. Xenografted SPC24 knockdown osteosarcoma cells showed reduced tumor growth in nude mice with decreased EGFR and phospho-ERK levels and increased E-cadherin levels. By contrast, human osteosarcoma tissue samples showed high SPC24 and phospho-ERK levels and low E-cadherin levels. These results suggest SPC24 promotes osteosarcoma progression by increasing EGFR/Ras/ERK signaling.