The Snf1-Related Kinase, Hunk, Is Essential for Mammary Tumor Metastasis

We previously identified a novel SNF1/AMPK-related protein kinase, Hunk, from a mammary tumor arising in an MMTV-neu transgenic mouse. The function of this kinase is unknown. Using targeted deletion in mice, we now demonstrate that Hunk is required for the metastasis of c-myc-induced mammary tumors, but is dispensable for normal development. Reconstitution experiments revealed that Hunk is sufficient to restore the metastatic potential of Hunk-deficient tumor cells, as well as defects in migration and invasion, and does so in a manner that requires its kinase activity. Consistent with a role for Hunk in the progression of human cancers, the human homologue of Hunk is overexpressed in aggressive subsets of carcinomas of the ovary, colon, and breast. In addition, a murine gene expression signature that distinguishes Hunk-wild type from Hunk-deficient mammary tumors predicts clinical outcome in women with breast cancer. Together, these findings establish a role for Hunk in metastasis and an in vivo function for this kinase.

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Wertheim GB, Yang TW, Pan TC, Ramne A, Liu Z, Gardner HP, Dugan KD, Kristel P, Kreike B, van de Vijver MJ, Cardiff RD, Reynolds C, Chodosh LA