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Objective: To investigate the effects of miR-27a on Proliferation, invasion and migration of cutaneous squamous cell carcinoma (CSCC) cells and its targeting relationship with forkhead box G1 (FOXG1). Methods: 30 cases CSCC tissues and 30 cases normal skin tissues were collected. A431 cells were cultured. miR-NC, miR-27a mimics, si-NC, si-miR-27a, Scramble, si-FOXG1, Vector, and OE-FOXG1 plasmids were transfected into the cells and defined as miR-NC group, miR-27a group, si-NC group, si-miR-27a group, Scramble group, si-FOXG1 group, Vector group and FOXG1 group. The si-FOXG1 and Scramble plasmids were transfected into the cells of miR-27a group and recorded as miR-27a+Scramble group and miR-27a+si-FOXG1 group. The cell Proliferation ability was detected by tetramethylazole blue (MTT). The cell invasion and migration ability were detected by Transwell assays. FOXG1 gene mRNA and miR-27a level were detected by fluorescence quantitative polymerase chain reaction (RT-PCR). FOXG1 protein level were detected by Western blot. TargetScan online website was used to predict the binding site of miR-27a and FOXG1. Dual luciferase reporter gene assay was used to verify the targeting relationship between miR-27a and FOXG1. Results: The levels of FOXG1 gene mRNA and miR-27a in CSCC tissues were higher than normal skin tissues (P<0.05), and the levels of FOXG1 gene mRNA in CSCC tissues were positively correlated with and miR-27a level (r=0.801, P=0.000). Up-regulation of miR-27a and FOXG1 promoted cell proliferation, invasion and migration, and silencing of miR-27a and FOXG1 inhibited cell proliferation, invasion, migration and EMT. Down-regulation of miR-27a reversed the the promotive effect of cell Proliferation, invasion and migration by overexpression of FOXG1. miR-27a positively regulated FOXG1 expression. Conclusion: miR-27a and FOXG1 are highly expressed in CSCC tissues. miR-27a positively regulates FOXG1 to promote proliferation, invasion, and migration of CSCC cells. [ABSTRACT FROM AUTHOR]

This study was aimed to investigate the effect of Forkhead Box G1 (FOXG1) on the epithelial-mesenchymal transition (EMT) of colorectal cancer (CRC) cells and the underlying mechanism. For this purpose, FOXG1 lentiviral interference (shRNA) plasmid and expression plasmid were constructed. Western blotting was used to analyze the expression of FOXG1 protein in five CRC cells, namely RKO, SW480, SW620, LoVo and DLD-1. The shRNA fragment of FOXG1 (shFOXG1) was designed and synthesized. Recombinant plasmids were obtained with the aid of DNA recombination technique. Double digestion and sequencing were used to identify the recombinant plasmids, and then lentivirus packaging, purification and stable transfection were carried out. Additionally, stable CRC cell lines were screened out. The changes of FOXG1 knockdown and overexpression efficiency, E-cadherin, Vimentin, Fibronectin, Snail, Twist mRNA and protein were investigated respectively by Western blotting and qRT-PCR analysis. Furthermore, the changes of cell morphology after knockdown and cell migration ability were evaluated respectively with optical microscopy, scratch test and Transwell assay. FOXG1 had the highest protein expression in RKO and the lowest in DLD-1 among the five CRC cells. Compared with those of the control group, the cell morphology in FOXG1 knockdown RKO group was changed from spindle into round or polygonal shape, cell polarization was enhanced and tight junction assembly was acclerated while cell migration distance was noticeably decreased. Moreover, the number of cells invaded and migrated through chambers was significantly reduced. Among these key factors of EMT, the expression of E-cadherin was increased while the expressions of Vimentin, Fibronectin, Snail and Twist were decreased. The opposite was the case in the overexpressed FOXG1 group. The overexpression of FOXG1 in CRC promoted the invasion and metastasis of CRC cells and played a crucial role in regulating the EMT. Thus, FOXG1 might be a novel therapeutic target in CRC treatment.