Forkhead box protein k1 recruits TET1 to act as a tumor suppressor and is associated with MRI detection.

Abstract

Today, more and more evidence suggests that Foxk proteins (Foxk1 and Foxk2) work as transcriptional repressors in different kinds of cancer, but whether Foxk1 has a role in mediating tumorigenesis in breast cancer, the evidence is rare. MCF-7 cells transfected with shFoxk1 displayed a mesenchymal morphology and reduced the expression of E-cadherin, and increased the expression of N-cadherin. Transwell invasion assay and living imaging assay show that the overexpression of Foxk1 could inhibit metastasis in vitro and in vivo. Ribonucleic acid sequencing revealed that the knockdown of Foxk1 resulted in the up-regulation of different oncogenes, which was implicated in metastasis and tumor angiopoiesis. Quantitative chromatin immunoprecipitation, chromatin immunoprecipitation and Luciferase reporter assays suggested that Foxk1 could bind to the promoter of epithelial-mesenchymal transition inducer Twist and vascular endothelial growth factor, VEGF. Mass Spectrometry, co-immunoprecipitation assays and glutathione-S-transferase pull-down assay detected that Foxk1 was physically associated with Ten-eleven translocation 1, TET1, in vivo and in vitro. We reported that the mean expression level of Foxk1 in breast cancer was significantly lower than the adjacent noncarcinoma tissue. The higher Foxk1 expression was associated with better prognosis. Endothelial tube formation assays indicated that Foxk1 might regulate breast cancer angiogenesis through transcriptional repression of vascular endothelial growth factor. Furthermore, in vivo magnetic resonance imaging revealed the overexpression of Foxk1 could enhance the detection of the tumors. Further, a strong negative correlation was observed between Foxk1 and Twsit or between Foxk1 and vascular endothelial growth factor, and the higher Foxk1 expression is correlated with better over all survivals and better relapse-free survivals. Together, our data indicated the function of Foxk1 as a tumor suppressor in facilitating angiogenesis and metastasis in breast cancer.