Osteopontin is a promoter for hepatocellular carcinoma metastasis: a summary of 10 years of studies.

In this review, we summarize the novel findings from our series of studies on the leading metastasis-related gene, osteopontin (OPN). In our previous gene expression profiling study, OPN was identified as one of the leading genes associated with the metastasis of hepatocellular carcinoma (HCC). We focused on OPN to evaluate its prognostic values and important roles in HCC metastasis. A retrospective study of large cohorts of HCC patients demonstrated that plasma OPN level was one of the leading independent prognostic factors for HCC patients, even in the early stage of HCC, and could serve as a surrogate serologic biomarker for monitoring the treatment response and tumor recurrence after HCC resection. Using both in vitro and in vivo investigations, we found that OPN has an important role in metastasis and tumor growth of HCC and is an attractive potential therapeutic target for combating HCC metastasis. We also found that OPN⁺ HCC cells have much more amplifications at chromosomal regions, and promoter polymorphisms are important in the regulation of OPN expression and tumor growth and lung metastasis of HCC.