Zhao J, Lu B, Xu H et al.
Second Military Medical University, Shanghai, People’s Republic of China.
Hepatology 2008;48:265–75.
Editor’s note: Osteopontin is an extracellular matrix protein that is secreted by many cancers. It binds to receptors that then propagate intracellular signals, which enable tumor progression (
Trends Cell Biol 2006;16:79–87). High concentrations of osteopontin also correlate with increased tumor invasion and metastases. Several transcription factors are responsible for the over-expression of osteopontin in certain types of cancer. The 30-kilodalton Tat-interacting protein (TIP30) is a probable tumor suppressor, with studies showing a high incidence of hepatocellular carcinoma (HCC) in TIP30-deficient mice (
Cancer Res 2003;63:8763–7). TIP30 is frequently down-regulated in many cancers.