Hematopoietic lineage cell-specific
protein 1 (HS1), which is the hematopoietic homolog of
cortactin, is an
actin-binding protein and Lyn substrate. It is upregulated in several
cancers and its expression level is associated with increased cell migration,
metastasis, and poor prognosis. Here we investigated the expression and roles of HS1 in ovarian
carcinoma cells. We analyzed the expression of HS1 in 171
ovarian cancer specimens and determined the association between HS1 expression and clinicopathological characteristics, including patient outcomes. In patients with stage II-IV disease, positive HS1 expression was associated with significantly worse overall survival than negative expression (P < 0.05). HS1 was localized in invadopodia in some
ovarian cancer cells and was required for invadopodia formation. Migration and invasion of
ovarian cancer cells were suppressed by down-regulation of HS1, but increased in cells that over-expressed exogenous HS1. Furthermore,
ovarian cancer cells that expressed HS1
shRNA exhibited reduced
tumor formation in a mouse xenograft model. Finally, we found that
tyrosine phosphorylation of HS1 was essential for cell migration and invasion. These findings show that HS1 is a useful
biomarker for the prognosis of patients with ovarian
carcinoma and is a critical regulator of cytoskeleton remodeling involved in cell migration and invasion.