Long noncoding RNA AFAP1-AS1 promotes tumor progression and invasion by regulating the miR-2110/Sp1 axis in triple-negative breast cancer

Abstract

Long noncoding ribonucleic acids (LncRNAs) have been found to be involved in the proliferation, apoptosis, invasion, migration, and other pathological processes of triple-negative breast cancer (TNBC). Expression of the lncRNA actin filament-associated protein 1 antisense RNA1 (AFAP1-AS1) has been found to be significantly higher in TNBC than in other subtypes or in normal tissue samples, but the specific mechanism by which AFAP1-AS1 affects the occurrence and development of TNBC is yet to be revealed. In this study, we used Cell Counting Kit-8 (CCK-8), colony formation, wound healing migration, Transwell invasion, and nude mouse xenograft assays to confirm the role of AFAP1-AS1 in the proliferation, migration of TNBC cells in vitro and in vivo. In addition, we performed bioinformatics analyses, reverse transcriptase quantitative polymerase chain reaction (RT-qPCR), western blot (WB), and dual-luciferase reporter assays (dual-LRA) to confirm interaction among AFAP1-AS1, micro-RNA 2110 (miR-2110), and Sp1 transcription factor (Sp1). We found that silencing AFAP1-AS1 and Sp1 or upregulating miR-2110 suppressed the proliferation, migration, and invasion of MDA–MB-231 and MDA–MB-468 cells in vitro as well as tumor growth in vivo. Mechanistically, the dual-LRA highlighted that miR-2110 was an inhibitory target of AFAP1-AS1, and that AFAP1-AS1 functioned as a miR-2110 sponge to increase Sp1 expression. AFAP1-AS1 silencing led to a reduction in Sp1 mRNA and protein levels, which could be reversed by joint transfection with miR-2110 inhibitor. Our findings demonstrated that AFAP1-AS1 could modulate the progression of breast cancer cells and affect tumorigenesis in mice by acting as a miR-2110 sponge, resulting in regulation of Sp1 expression. Therefore, AFAP1-AS1 could play a pivotal role in the treatment of TNBC.

lncRNA ACTA2-AS1 inhibits malignant phenotypes of gastric cancer cells

“…The assay was performed to determine the migratory capacity of GC cells according to the study [ 38 ]. SGC7901 and AGS cells were seeded into 6-well plates (3 × 10 5 cells/well) until 90% confluence.…”

A Review on the Role of AFAP1-AS1 in the Pathoetiology of Cancer

“…Thus, the effects of AFAP1-AS1 in enhancement of proliferation and invasiveness of TNBC are exerted through miR-145/MTH1 axis ( 18 ). Moreover, in this type of cancer, AFAP1-AS1 can sequester miR-2110 to enhance expression of Sp1 ( 19 ). AFAP1-AS1 has also been shown to enhance EMT of TNBC cells via influencing Wnt/β-catenin signaling ( 20 ).…”

GH and IGF System: The Regulatory Role of miRNAs and lncRNAs in Cancer

“…In the same year, Fei et al showed that lncRNA AFAP-AS1 was upregulated in osteosarcoma both in tissues and cell lines (85). Functional evaluation highlighted that AFAP-AS1 knockdown significantly inhibited proliferation, colony formation, suppressed migration and invasion and increased apoptosis in vitro.…”

“…IGF1R was a predicted target of miR-497, and the authors showed that IGF1R negatively correlated with miR-497 and correlated positively with AFAP-AS1 expression in osteosarcoma tissues. Therefore, AFAP-AS1 exerted tumor-promoting actions regulating IGF1R expression by sponging miR-497 (85). The possible role of AFAP-AS1 as a proto-oncogene could represent a promising therapeutic target for osteosarcoma.…”