Long noncoding RNA CDKN2B‐AS1 silencing protects against esophageal cancer cell invasion and migration by inactivating the TFAP2A/FSCN1 axis

Abstract

Abstract Esophageal cancer (EC) is the most aggressive malignancy in the gastrointestinal tract. Long noncoding RNA cyclin‐dependent kinase inhibitor 2 B antisense RNA 1 (CDKN2B‐AS1) is implicated in EC development. However, the specific mechanisms involved remain poorly defined. Therefore, this research aimed to explore the mechanism of action of CDKN2B‐AS1 in EC. Quantitative real‐time polymerase chain reaction was conducted to measure CDKN2B‐AS1 expression in EC cells and western blotting was utilized to evaluate transcription factor AP‐2 alpha (TFAP2A) and fascin actin‐bundling protein 1 (FSCN1) expression. After gain‐of‐function and loss‐of‐function assays, cell proliferation, migration, invasion, apoptosis, and apoptosis‐related protein expression were assessed using cell counting kit‐8, scratch tests, Transwell assays, flow cytometry, and western blotting, respectively. The binding relationship between CDKN2B‐AS1 and TFAP2A was assessed by RNA immunoprecipitation and RNA pull‐down assays. The binding relationship between TFAP2A and FSCN1 was evaluated using dual‐luciferase reporter and chromatin immunoprecipitation assays. Tumor xenografts from nude mice were used for in vivo verification. CDKN2B‐AS1, TFAP2A, and FSCN1 were upregulated in EC cells. Mechanistically, CDKN2B‐AS1 transcriptionally activated FSCN1 by recruiting TFAP2A to the FSCN1 promoter. Silencing CDKN2B‐AS1 or TFAP2A suppressed EC cell proliferative, migrating, and invasive properties and augmented apoptosis. TFAP2A was bound to CDKN2B‐AS1 and the FSCN1 promoter. Overexpression of TFAP2A or FSCN1 abolished the effects of CDKN2B‐AS1‐silencing on EC cell function. CDKN2B‐AS1 silencing curtailed tumorigenesis in nude mice, which was nullified by the upregulation of TFAP2A or FSCN1. Our findings demonstrated the antioncogenic effects of silencing CDKN2B‐AS1 in EC through inactivation of the TFAP2A/FSCN1 axis.

Keywords

• esophageal cancer
• fascin actin‐bundling protein 1
• long noncoding RNA CDKN2B‐AS1
• malignant behaviors
• transcription factor AP‐2 alpha