Kaichun Wu

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)

Recurrence and metastasis remain the most common causes of lethal outcomes in hepatocellular carcinoma (HCC) after curative resection. Thus, it is critical to discover the mechanisms underlying HCC metastasis. Forkhead box C1 (FoxC1), a member of the Fox family of transcription factors, induces epithelial-mesenchymal transition (EMT) and promotes epithelial cell migration. However, the role of FoxC1 in the progression of HCC remains unknown. Here, we report that FoxC1 plays a critical role in HCC metastasis. FoxC1 expression was markedly higher in HCC tissues than in adjacent noncancerous tissues. HCC patients with positive FoxC1 expression had shorter overall survival times and higher recurrence rates than those with negative FoxC1 expression. FoxC1 expression was an independent, significant risk factor for recurrence and survival after curative resection. FoxC1 overexpression induced changes characteristic of EMT and an increase in HCC cell invasion and lung metastasis. However, FoxC1 knockdown inhibited these processes. FoxC1 transactivated Snai1 expression by directly binding to the Snai1 promoter, thereby leading to the inhibition of E-cadherin transcription. Knockdown of Snai1 expression significantly attenuated FoxC1-enhanced invasion and lung metastasis. FoxC1 expression was positively correlated with Snai1 expression, but inversely correlated with E-cadherin expression in human HCC tissues. Additionally, a complementary DNA microarray, serial deletion, site-directed mutagenesis, and a chromatin immunoprecipitation assay confirmed that neural precursor cell expressed, developmentally down-regulated 9 (NEDD9), which promotes the metastasis of HCC cells, is a direct transcriptional target of FoxC1 and is involved in FoxC1-mediated HCC invasion and metastasis. Conclusions: FoxC1 may promote HCC metastasis through the induction of EMT and the up-regulation of NEDD9 expression. Thus, FoxC1 may be a candidate prognostic biomarker and a target for new therapies.