Forkhead box Q1 (FoxQ1) is a master regulator of tumor metastasis. However, the molecular mechanism of FoxQ1 in regulating hepatocellular carcinoma (HCC) metastasis remains unknown. Here we report a novel function for FoxQ1 in modifying the tumor microenvironment to promote HCC metastasis. FoxQ1 expression was an independent and significant risk factor for the recurrence and survival in two independent cohorts totaling 1,002 HCC patients. FoxQ1 induced epithelial-mesenchymal transition (EMT) through the transactivation of ZEB2 expression by directly binding to the ZEB2 promoter. Knockdown of ZEB2 decreased FoxQ1-enhanced HCC metastasis, whereas up-regulation of ZEB2 rescued the decreased metastasis induced by FoxQ1 knocking down. Additionally, serial deletion, site-directed mutagenesis, and a chromatin immunoprecipitation assays showed that VersicanV1, which promoted HCC metastasis and macrophage attraction, was a direct transcriptional target of FoxQ1. FoxQ1-induced VersicanV1 expression promoted the secretion of chemokine (C-C motif ) ligand 2 (CCL2) from HCC cells. Chemotaxis assay showed that the culture media from FoxQ1-overexpressing HCC cells increased the migratory activity of the macrophages. Inhibition of VersicanV1 and CCL2 expression significantly inhibited FoxQ1-mediated macrophage migration. In animal studies, the up-regulation of FoxQ1 in HCC cells promoted HCC metastasis and intratumoral tumor associated macrophage (TAM) infiltration, whereas knockdown of VersicanV1 reduced FoxQ1-mediated HCC metastasis and intratumoral TAM infiltration. Depletion of macrophages using clodronate liposomes dramatically decreased FoxQ1-enhanced HCC metastasis. In human HCC tissues, FoxQ1 expression was positively correlated with ZEB2 and VersicanV1 expression and intratumoral TAM infiltration. Patients with positive coexpression of FoxQ1 and ZEB2, FoxQ1, and VersicanV1, or FoxQ1 and intratumoral TAMs were associated with poorer prognosis. Conclusion: FoxQ1 promotes HCC metastasis by transactivating ZEB2 and VersicanV1 expression, resulting in the induction of EMT and the recruitment of macrophage infiltration. (HEPATOLOGY 2014;59:958-973) H epatocellular carcinoma (HCC) is the fifth most common malignancy worldwide and the second leading cause of cancer death in Asia.1 Although the survival of patients with HCC has improved due to advances in surgical techniques, longterm survival after surgical resection remains low. Metastasis is the major reason for the high mortality of HCC patients after surgical resection. 2 Nonetheless,

Metastasis is the main reason for high recurrence and poor survival of hepatocellular carcinoma (HCC) after curative resection. However, the molecular mechanism underlying HCC metastasis remains unclear. Here, we report on a novel function of SRY (sex determining region Y)-box 12 (Sox12), a member of the SYR-related high mobility group box family proteins, in promoting HCC metastasis. Overexpression of Sox12 was significantly correlated with loss of tumor encapsulation, microvascular invasion, and a higher tumor-nodulemetastasis (TNM) stage and indicated poor prognosis in human HCC patients. Sox12 expression was an independent and significant risk factor for recurrence and reduced survival after curative resection. Overexpression of Sox12 induced epithelial-mesenchymal transition by transactivating Twist1 expression. Down-regulation of Twist1 decreased Sox12-enhanced HCC migration, invasion, and metastasis, whereas up-regulation of Twist1 rescued the decreased migration, invasion, and metastasis induced by Sox12 knockdown. Additionally, serial deletion, site-directed mutagenesis, and chromatin immunoprecipitation assays showed that fibroblast growth factor binding protein 1 (FGFBP1) was a direct transcriptional target of Sox12. Knockdown of FGFBP1 decreased Sox12-mediated HCC invasion and metastasis, whereas overexpression of FGFBP1 rescued the decreased invasion and metastasis induced by Sox12 knockdown. Furthermore, forkhead box Q1 (FoxQ1) directly bound to the Sox12 promoter and transactivated its expression, which contributed to Sox12 overexpression in human HCC. Knockdown of Sox12 dramatically decreased FoxQ1-mediated HCC metastasis. In two independent cohorts of human HCC tissues, Sox12 expression was positively correlated with Twist1, FGFBP1, and FoxQ1 expression, and patients with positive coexpression of Sox12/Twist1, Sox12/FGFBP1, or FoxQ1/Sox12 were associated with poorer prognosis. Conclusion: Up-regulated Sox12 induced by FoxQ1 promotes HCC invasion and metastasis by transactivating Twist1 and FGFBP1 expression. Thus, our study implicates Sox12 as a potential prognostic biomarker and a novel therapeutic target for HCC. (HEPATOLOGY 2015;61:1920-1933 H epatocellular carcinoma (HCC) is the thirdleading cause of cancer-related death worldwide. Liver resection is still the best therapeutic strategy to treat HCC, with a 5-year survival rate in approximately 30%.1 Metastasis is the main risk for the long-term survival of HCC patients after liver resection

No abstract