Actin Filament-associated Protein 1 Antisense RNA 1 Research Articles

Knockdown of Long Non-Coding RNA AFAP1-AS1 Promoted Viability and Suppressed Death of Cardiomyocytes in Response to I/R In Vitro and In Vivo.

Long non-coding RNA (lncRNA) plays a pivotal role in the development of myocardial infarction (MI). The aim of this study was to investigate the effects of lncRNA actin filament-associated protein 1 antisense RNA 1 (AFAP1-AS1) on cell cycle, proliferation, and apoptosis. RT-qPCR was used to detect the expression levels of AFAP1-AS1, miR-512-3p, and reticulon 3 (RTN3) in rat model of I/R. The simulated MI environment was constructed. MTT assay and flow cytometry were used to detect changes in cardiomyocyte viability and cell cycle/apoptosis after MI by AFAP1-AS1 silencing or RTN3 silencing. The targeting relationship of miR-512-3p and AFAP1-AS1 and RTN3 in cardiomyocytes was verified by dual luciferase reporter assay. The expression levels of AFAP1-AS1 and RTN3 were significantly upregulated in a rat model of LAD ligation (or MI) ligation, while the expression level of miR-512-3p was significantly reduced. Overexpressed AFAP1-AS1 and RTN3 promoted cardiomyocyte apoptosis and inhibited cardiomyocyte proliferation. MiR-512-3p was a direct target of AFAP1-AS1, and RTN3 was a direct target of miR-512-3p. AFAP1-AS1 promoted the progression of MI by targeting miR-512-3p. AFAP1-AS1 promoted the progression of MI by modulating the miR-512-3p/RTN3 axis. AFAP1-AS1 may be a potential therapy target for MI. Graphical Abstract The role of AFAP1-AS1 in regulating MI injury in vivo. (A) Effect of AFAP1-AS1 in MI injury in vivo. (B) The mRNA level of RTN3 in MI injury in vivo. (C) The protein level of RTN3 in MI injury in vivo. (D) Effect of miR-512-3p in MI model group. (E) TUNEL assay. *P < 0.05, **P < 0.01 vs the sham group; #P< 0.05, ##P < 0.01 vs the MI group.

Bidirectional interaction of lncRNA AFAP1-AS1 and CRKL accelerates the proliferative and metastatic abilities of hepatocarcinoma cells

Actin filament-associated protein 1 antisense RNA 1 (AFAP1-AS1), a long non-coding RNA transcribed from the antisense strand of protein coding gene AFAP1, has attracted attention in cancer research. Despite, its biological function and regulatory mechanism in hepatocellular carcinoma still unknown. The present study revealed AFAP1-AS1 mediated hepatocarcinoma progression through targeting CRKL. The bidirectional interaction of AFAP1-AS1 and oncogenic protein CRKL, and the deregulation of AFAP1-AS1 effects on Ras, MEK and c-Jun activities were investigated in depth. AFAP1-AS1 was upregulated in surgical tumorous tissues from hepatocarcinoma patients compared with the paired paracancerous non-tumor liver tissues, and in hepatocarcinoma Huh7, HCCLM3 and HepG2 cell lines compared with LO2, a normal liver cell line. AFAP1-AS1 knockdown noticeably suppressed the proliferative, migratory and invasive properties, and the epithelial-mesenchymal transition (EMT) process of HepG2 and HCCLM3 through upregulating E-cadherin and downregulating N-cadherin and vimentin. CRKL knockdown reduced AFAP1-AS1 expression levels in HepG2 and HCCLM3 cells. AFAP1-AS1 suppression impaired CRKL expression in HepG2 and HCCLM3. AFAP1-AS1 level change was positively correlated with the expression level changes of Ras, MEK and c-Jun in mediating the invasiveness of hepatocarcinoma cells. Current work demonstrated AFAP1-AS1 to be an applicable progression indicator of hepatocarcinoma. AFAP1-AS1 probably promotes the proliferation, EMT progression and metastasis of hepatocarcinoma cells via CRKL mediated Ras/MEK/c-Jun and cadherin/vimentin signaling pathways. AFAP1-AS1-CRKL bidirectional feedback signaling is worthy of further study on the monitoring, diagnosis and treatment of cancers.

RETRACTED ARTICLE: Exosome-mediated lncRNA AFAP1-AS1 promotes trastuzumab resistance through binding with AUF1 and activating ERBB2 translation

BackgroundAlthough trastuzumab provides significant clinical benefit for HER2-positive breast cancers, responses are limited by the emergence of resistance. Recent evidence suggests that long noncoding RNAs (lncRNAs) play important roles in tumorigenesis and chemoresistance. However, the regulatory mechanism of lncRNAs in trastuzumab resistance is not well established to date. In this research, we identified the differentially expressed lncRNA and investigated its regulatory role in trastuzumab resistance of breast cancer.MethodsLncRNA microarray and qRT-PCR were performed to identify the dysregulated lncRNAs. Transmission electron microscopy, differential ultracentrifugation and qRT-PCR were used to verify the existence of exosomal AFAP1-AS1 (actin filament associated protein 1 antisense RNA 1). Bioinformatics prediction, RNA fluorescence in situ hybridization (RNA-FISH) and immunoprecipitation assays were performed to identify the direct interactions between AFAP1-AS1 and other associated targets, such as AU-binding factor 1 (AUF1) and ERBB2. Finally, a series gain- or loss-functional assays were done to prove the precise role of AFAP1-AS1 in trastuzumab resistance.ResultsAFAP1-AS1 was screened out due to its higher expression in trastuzumab-resistant cells compared to sensitive cells. Increased expression of AFAP1-AS1was associate with poorer response and shorter survival time of breast cancer patients. AFAP1-AS1 was upregulated by H3K27ac modification at promoter region, and knockdown of AFAP1-AS1 reversed trastuzumab resistance. Moreover, extracellular AFAP1-AS1 secreted from trastuzumab resistant cells was packaged into exosomes and then disseminated trastuzumab resistance of receipt cells. Mechanically, AFAP1-AS1 was associated with AUF1 protein, which further promoted the translation of ERBB2 without influencing the mRNA level.ConclusionExosomal AFAP1-AS1 could induce trastuzumab resistance through associating with AUF1 and promoting ERBB2 translation. Therefore, AFAP1-AS1 level may be useful for prediction of trastuzumab resistance and breast cancer treatment.

Long Noncoding RNA AFAP1-AS1 Promotes Cell Proliferation and Metastasis via the miR-155-5p/FGF7 Axis and Predicts Poor Prognosis in Gastric Cancer.

Background Actin filament-associated protein 1-antisense RNA 1 (AFAP1-AS1) plays an important role in the development and progression of several human cancers. However, its biological function in gastric cancer (GC) progression is still unknown. Methods We used qRT-PCR to detect the relative expression of AFAP1-AS1 in GC tissues and cell lines. The loss-of-function assays were conducted to detect the effect of AFAP1-AS1 on GC development. Bioinformatics analysis, luciferase reporter gene analysis, and RIP analysis were used to identify and validate target genes of AFAP1-AS1. Finally, rescue tests were performed to confirm the influence of the AFAP1-AS1-miR-155-5p-FGF7 axis on GC development. Results AFAP1-AS1 was upregulated in GC tissues and cell lines and was closely correlated with poor prognosis of GC patients. AFAP1-AS1 knockdown inhibited proliferation, migration, and invasion of GC cells, indicating that AFAP1-AS1 acts as an oncogene in GC. Bioinformatics analysis, dual-luciferase reporter gene detection, and RIP assays validated that AFAP1-AS1 directly interacts to miR-155-5p and could positively affect cell proliferation, migration, and invasion by regulation of the expression of miR-155-5p and FGF7. Further rescue assays revealed that AFAP1-AS1 promotes cell proliferation and metastasis through the miR-155-5p/FGF7 axis in GC. Conclusions AFAP1-AS1 might be an oncogenic lncRNA that promoted GC progression by acting as a competing endogenous RNA (ceRNA) that regulates the expression of FGF7 through sponging miR-155-5p, suggesting that AFAP1-AS1 may be a novel potential therapeutic target for GC.

LncRNA AFAP1-AS1 promotes osteoblast differentiation of human aortic valve interstitial cells through regulating miR-155/SMAD5 axis

AimDegenerative calcific aortic valve disease (DCAVD) is a common valve disease characterized by massive calcium deposits in the aortic valve. Osteoblast differentiation of valve interstitial cells (VICs) is responsible for the formation of calcific nodules. This study aims to explore the function and underlying mechanism of long non-coding RNA (lncRNA) AFAP1-AS1 (actin filament-associated protein 1 antisense RNA 1) in the pathogenesis of DCAVD. MethodsAFAP1-AS1, miR-155 and mRNA levels were detected by qRT-PCR. Protein levels were measured by Western blot. Calcification deposition was examined by Alizarin Red staining. The interaction between AFAP1-AS1 and miR-155, as well as miR-155 and SMAD5 was evaluated using luciferase reporter assay. ResultsAFAP1-AS1 expression was increased both in calcified aortic valves from DCAVD patients and after osteogenic induction in human VICs. Furthermore, AFAP1-AS1 overexpression promoted osteogenic differentiation of VICs, whereas AFAP1-AS1 knockdown inhibited osteogenic differentiation. Mechanistically, AFAP1-AS1 acted as a sponge for miR-155 to elevate SMAD5 expression. Further functional assays revealed that miR-155 mimic and SMAD5 silencing effectively reversed AFAP1-AS1-promoted osteogenic differentiation of VICs. ConclusionCollectively, AFAP1-AS1 promotes osteogenic differentiation of VICs, at least in part, by sponging miR-155 to upregulate SMAD5. This study sheds new light on lncRNA-directed therapeutics in DCAVD.

Long non-coding RNA AFAP1-AS1 promotes proliferation and migration of gastric cancer by downregulating KLF2.

To clarify the function of actin filament associated protein 1-antisense RNA1 (AFAP1-AS1) to promote the proliferation and migration of gastric cancer (GC) cells by downregulating Krüppel-like factor 2 (KLF2). Expression level of AFAP1-AS1 in GC tissues and matched paracancerous tissues was determined by quantitative real-time polymerase chain reaction (qRT-PCR). Besides, its level in GC either with lymphatic metastasis or not, and those in different tumor stages were determined as well. Regulatory roles of AFAP1-AS1 in cellular behaviors of GC cells were evaluated by functional experiments. The ability of AFAP1-AS1 to recruit EZH2 was evaluated through chromatin immunoprecipitation (ChIP) assay. The expression level of KLF2 in GC cells influenced by AFAP1-AS1 and EZH2 was detected by Western blot. Finally, a series of rescue experiments were conducted to clarify the role of AFAP-AS1/KLF2 in GC cell performances. AFAP1-AS1 was upregulated in GC tissues, and its expression in lymph node metastasis and progressive gastric cancer tissues were much higher. Knockdown of AFAP1-AS1 reduced the viability, proliferative and migratory abilities, but induced apoptosis of GC cells. AFAP1-AS1 was verified to bind to EZH2. After knockdown of AFAP1-AS1, the ability of AFAP1-AS1 to recruit EZH2 was remarkably attenuated. Knockdown of AFAP1-AS1 or EZH2 upregulated KLF2 expression in GC cells. Notably, knockdown of KLF2 partially reversed the effect of AFAP1-AS1 on GC cell performances. LncRNA AFAP1-AS1 accelerates the proliferative and migratory abilities of GC cells by downregulating the expression of KLF2, thus promoting the progression of GC.

Expression and functions of long non-coding RNA actin filament-associated protein 1-antisense RNA1 in oral squamous cell carcinoma

To analyze the expression and clinical significance of long non-coding RNA (lncRNA) actin filament-associated protein 1-antisense RNA1 (AFAP1-AS1) in oral squamous cell carcinoma (OSCC) and its effect on the biobehavior of OSCC cells. Quantitative real-time polymerase chain reaction (qRT-PCR) was used to detect the expression of lncRNA AFAP1-AS1 in the tumor tissue and matching adjacent normal tissue of OSCC patients (n=55), SCC25 cells, and normal oral keratinocyte lines (NOK) cells. The correlation between AFAP1-AS1 expression and the clinicopathological characteristics of OSCC patients was analyzed. The relationship between AFAP1-AS1 and prognosis was also studied with the Kaplan-Meier method. AFAP1-AS1 siRNA was transfected into the SCC25 cells. Cell counting kit-8 (CCK-8) and Trans-well were used to detect cell proliferation, invasion, and migration. The expression of the invasion-associated protein, AFAP1, and Rho GTPase family members, was detected by Western blot. In addition, the immunofluorescence of the cytoskeletal actin filament was observed. The expression of AFAP1-AS1 was higher in the OSCC tissues than in the NOK cells, and the relative expression of AFAP1-AS1 was higher in the SCC25 cells than in the NOK cells (P<0.001). AFAP1-AS1 expression was associated with the degree of diffe-rentiation, TNM stage, lymphatic metastasis, and poor prognosis of OSCC (P<0.05). Patients with a high expression of AFAP1-AS1 had lower survival rates than those with a low expression of AFAP1-AS1 (P<0.05). After transfected by AFAP1-AS1 siRNA, the expression of AFAP1-AS1 was downregulated. The inhibition of AFAP1-AS1 expression consequently suppressed the proliferation, invasion, and migration of SCC25. Moreover, AFAP1-AS1 siRNA upregulated the expression levels of AFAP1, RhoA, Rac2, Rab10, RhoGDI, and Pfn1 but downregulated the expression of RhoC. Immunofluorescence showed that AFAP1-AS1 also reduced the formation of stress filaments in the cytoskeleton and affected the integrity of the actin fila-ment. The expression of AFAP1-AS1 was high in the OSCC tissues and SCC25 cells and is associated with the development and prognosis of OSCC. The knockdown of AFAP1-AS1 might inhibit the proliferation and invasion of OSCC cells by regulating the integrity of the actin filament.

Circulatinglong non-coding RNA FEZF1-AS1 and AFAP1-AS1 serve as potential diagnostic biomarkers for gastric cancer

BackgroundGrowing evidence indicates that two long non-coding RNAs (lncRNAs), FEZ family zinc finger 1 antisense RNA 1 (FEZF1-AS1) and Actin filament associated protein 1 antisenseRNA1 (AFAP1-AS1), are highly expressed in different cancers, including gastric cancer (GC). However, the expression pattern and clinical utility of these two lncRNAs are still unknown. MethodsSerum expression levels of FEZF1-AS1 andAFAP1-AS1 were measured by quantitative real-time polymerase chain reaction (qRT-PCR). CEA and CA19-9 were detected by ARCHITET I2000 SR. Analyses were all performed using SPSS software version 20.0 (SPSS Inc., Chicago, USA). P < 0.05 was considered statistically significant. ResultsDetection of serum FEZF1-AS1 and AFAP1-AS1 showed both of them were up-regulated in GC patients compared with the normal controls (p < 0.0001), and high serum expression levels were correlated with tumor size, tumor-node-metastasis (TNM) stage and lymph node metastasis. Besides, the area under the ROC curve (AUC) demonstrated the two lncRNAs had higher diagnostic utility than CEA and CA19-9. Furthermore, when combined the two lncRNAs as a model, it yielded an AUC of 0.866, and the combination of the model, CEA and CA19-9 could observably improve diagnostic sensitivity to 95.5 %. What’s more, circulating FEZF1-AS1 and AFAP1-AS1 were significantly decreased after the GC patients underwent the operation (both p < 0.001). ConclusionOur study indicated that serum FEZF1-AS1 and AFAP1-AS1 had better sensitivity and efficiency for the diagnosis of GC and the combination of the two lncRNAs might be used as a potential prognostic indicator in GC.

LncRNA AFAP1-AS1 Supresses miR-139-5p and Promotes Cell Proliferation and Chemotherapy Resistance of Non-small Cell Lung Cancer by Competitively Upregulating RRM2.

Non-small cell lung cancer (NSCLC) is the leading cause of cancer-related death worldwide. This study aims to understand the underlying mechanism of lncRNA, actin filament-associated protein 1 antisense RNA 1(AFAP1-AS1) in mediating chemotherapeutic resistance in NSCLC. The levels of AFAP1-AS1 in NSCLC tissues and cells were determined using RT-PCR. The protein levels of RRM2, EGFR, and p-AKT were analyzed using Western blotting. Binding between AFAP1-AS1 and miR-139-5p was confirmed using dual luciferase reporter and RNA immunoprecipitation (RIP) assays, and binding between miR-139-5p and RRM2 was confirmed by a dual luciferase reporter assay. NSCLC cell proliferation, apoptosis, and colony formation were examined using MTT, flow cytometry, and colony formation assays, respectively. It was found that AFAP1-AS1 expression was upregulated in NSCLC tissues and cells. In addition, AFAP1-AS1 bound to and downregulated the expression of miR-139-5p, which was reduced in NSCLC tissues. Knockdown of AFAP1-AS1 and overexpression of miR-139-5p inhibited NSCLC cell proliferation, colony formation and chemotherapy resistance and increased cell apoptosis. Additionally, AFAP1-AS1 upregulates RRM2 expression via sponging miR-139-5p. Furthermore, AFAP1-AS1 enhanced NSCLC cell proliferation and chemotherapy resistance through upregulation of RRM2 by inhibiting miR-139-5p expression. Moreover, RRM2 promoted cellular chemotherapy resistance by activating EGFR/AKT. Finally, knockdown of AFAP1-AS1 significantly suppressed tumor growth and chemoresistance in nude mice. In conclusion, AFAP1-AS1 promoted chemotherapy resistance by supressing miR-139-5p expression and promoting RRM2/EGFR/AKT signaling pathway in NSCLC cells.

Overexpression of lncRNA AFAP1-AS1 promotes cell proliferation and invasion in gastric cancer.

Long non-coding RNA (lncRNA) actin filament-associated protein 1 antisense RNA 1 (AFAP1-AS1) has been revealed to be associated with certain types of cancer. However, whether the lncRNA AFAP1-AS1 is involved in the development and progression of gastric cancer (GC) remains unknown. The present study investigated the clinical significance and biological functions of AFAP1-AS1 in GC. The expression levels of lncRNA AFAP1-AS1 in 52 patients with GC, and in 1 normal gastric mucosal cell line and 3 GC cell lines, were evaluated by reverse transcription quantitative polymerase chain reaction analysis. Small interfering RNAs were used to suppress AFAP1-AS1 expression in GC cell lines. The results indicated that AFAP1-AS1 expression levels were significantly increased in GC tissues and cell lines compared with the corresponding noncancerous tissues and normal gastric cells. In addition, the patients with GC with increased AFAP1-AS1 expression exhibited an advanced clinical stage and an association with the occurrence of lymph node metastasis compared with those with decreased AFAP1-AS1 expression. In vitro assays demonstrated that knockdown of AFAP1-AS1 decreased levels of cell proliferation and migration. In addition, the results of flow cytometry demonstrated that knockdown of AFAP1-AS1 caused cell cycle arrest. In conclusion, AFAP1-AS1 is a novel molecule involved in GC progression, which may be a potential prognostic biomarker and target for therapeutic intervention.

Long noncoding RNA actin filament-associated protein 1 antisense RNA 1 promotes malignant phenotype through binding with lysine-specific demethylase 1 and repressing HMG box-containing protein 1 in non-small-cell lung cancer.

The number of documented long noncoding RNAs (lncRNAs) has dramatically increased, and their biological functions and underlying mechanisms in pathological processes, especially cancer, remain to be elucidated. Actin filament‐associated protein 1 antisense RNA 1 (AFAP1‐AS1) is a 6810‐nt lncRNA located on chromosome 4p16.1 that was first reported to be upregulated in esophageal adenocarcinoma tissues and cell lines. Here we reported that AFAP1‐AS1, recruiting and binding to lysine‐specific demethylase 1 (LSD1), was generally overexpressed in human non‐small‐cell lung cancer (NSCLC) tissues using quantitative real‐time PCR. Higher AFAP1‐AS1 expression was significantly correlated with larger tumor size (P = .008), lymph node metastasis (P = .025), higher TNM stage (P = .024), and worse overall survival in NSCLC patients. In vitro experiments revealed that AFAP1‐AS1 downregulation inhibited cell migration and induced apoptosis; AFAP1‐AS1 knockdown also hindered tumorigenesis in vivo. Moreover, mechanistic investigations including RNA immunoprecipitation and ChIP assays validated that AFAP1‐AS1 repressed HMG box‐containing protein 1 (HBP1) expression by recruiting LSD1 to the HBP1 promoter regions in PC‐9 and H1975 cells. Furthermore, HBP1 functions as a tumor suppressor, and its ectopic expression hindered cell proliferation. Rescue assays determined that the oncogenic effect of AFAP1‐AS1 is partially dependent on the epigenetic silencing of HBP1. In conclusion, our results indicate that AFAP1‐AS1 is carcinogenic and that the AFAP1‐AS1/LSD1/HBP1 axis could constitute a new therapeutic direction for NSCLC.

Cross-talk among AFAP1-AS1, ACVR1 and microRNA-384 regulates the stemness of pancreatic cancer cells and tumorigenicity in nude mice

BackgroundPancreatic cancer (PC) represents one of the most aggressive forms of cancer. The role of long non-coding RNAs (lncRNAs) has been highlighted in various malignancies including PC. The aim of the present study was to investigate the effects associated with actin filament-associated protein 1 antisense RNA 1 (AFAP1-AS1) on the progression of PC and the underlying mechanism.MethodsMicroarray-based gene expression profiling of PC was performed to identify PC-related lncRNAs, after which the expression of AFAP1-AS1 and cancer stem cell (CSC) markers in PC tissues and cells were determined accordingly. The potential microRNA-384 (miR-384) capable of binding to AFAP1-AS1, in addition to its ability to regulate activin receptor A type I (ACVR1) were analyzed. In order to investigate the effect of the AFAP1-AS1/miR-384/ACVR1 axis on self-renewal ability, tumorigenicity, invasion, migration and stemness of PC cells, shRNA-AFAP1-AS1, miR-384 mimic and inhibitor were cloned into cells.ResultsHigh expression of AFAP1-AS1 and ACVR1 with low expression of miR-384 were detected in PC tissues. ACVR1 was determined to be down-regulated when miR-384 was overexpressed, while the inhibition of AFAP1-AS1 decreased its ability to binding competitively to miR-384, resulting in the down-regulation of ACVR1 and enhancing miR-384 expression, ultimately inhibiting the progression of PC. The knockdown of AFAP1-AS1 or overexpression of miR-384 was confirmed to impair PC cell self-renewal ability, tumorigenicity, invasion, migration and stemness.ConclusionsTaken together, AFAP1-AS1 functions as an endogenous RNA by competitively binding to miR-384 to regulate ACVR1, thus conferring inhibitory effects on PC cell stemness and tumorigenicity.

Cloning and characterization of the putative AFAP1-AS1 promoter region.

Actin filament-associated protein 1-antisense RNA1 (AFAP1-AS1), a cancer-related long non-coding RNA, has been found to be upregulated in multiple types of cancers. AFAP1-AS1 is important for the initiation, progression and poor prognosis of many cancers, including nasopharyngeal carcinoma (NPC). However, the mechanism underlying the regulation of AFAP1-AS1 expression is not well-understood. In our study, the potential promoter region of AFAP1-AS1 was predicted by comprehensive bioinformatics analysis. Moreover, promoter deletion analysis identified the sequence between positions -359 and -28 bp as the minimal promoter region of AFAP1-AS1. The ChIP assay results indicate that the AFAP1-AS1 promoter is responsive to the transcription factor c-Myc, which can promote high AFAP1-AS1 expression. This study is the first to clone and characterize the AFAP1-AS1 promoter region. Our findings will help to better understand the underlying mechanism of high AFAP1-AS1 expression in tumorigenesis and to develop new strategies for therapeutic high expression of AFAP1-AS1 in NPC.

Long non-coding RNA AFAP1-AS1 promoting epithelial-mesenchymal transition of endometriosis is correlated with transcription factor ZEB1.

The role of the long non-coding RNA (lncRNA) actin filament associated protein 1 antisense RNA1 (AFAP1-AS1) in the etiology of endometriosis is unknown. Expression of epithelial-mesenchymal transition (EMT) markers was quantified using qRT-PCR, immunohistochemistry, and Western blotting. The proliferation, migration, and invasion of ectopic endometrial epithelial cells and Ishikawa cells were evaluated by MTT, EdU, wound healing, and transwell assays. Inflammatory cytokine levels were detected by ELISA. Luciferase assays were used to measure activity of the ZEB1 promoter site pGL3-P886. AFAP1-AS1 levels were much higher in ectopic endometrial tissues than that in eutopic tissues. Expression of ZEB1, E-cadherin, and keratin was obviously higher in eutopic tissues than those in ectopic tissues. In contrast, expression of vimentin and N-cadherin was significantly lower in eutopic tissue than those in ectopic tissues. After knockdown of AFAP1-AS1, the morphology of endometrial epithelial cells varied from spindle fiber shaped to polygon epithelioid and proliferation, migration, and invasion were each inhibited. The knockdown of AFAP1-AS1 significantly inhibited expression from promoter site pGL3-P886 of the EMT-related transcription factor ZEB1. The size of subcutaneous tumours in nude mice was significantly reduced after down-regulation of AFAP1-AS1 expression. Higher expression of AFAP1-AS1 positively correlated with greater EMT in ectopic endometrium of patients with endometriosis. Knockdown of AFAP1-AS1 inhibited E2-induced activity of promoter site pGL3-P886 of transcription factor ZTB1, suggesting that AFAP1-AS1 knockdown inhibited growth of endometrial epithelial cells and that pathogenesis may be correlated with EMT.

AFAP1-AS1 Promotes Epithelial-Mesenchymal Transition and Tumorigenesis Through Wnt/β-Catenin Signaling Pathway in Triple-Negative Breast Cancer.

Long non-coding RNA (LncRNA) actin filament-associated protein1-antisense RNA 1 (AFAP1-AS1) is overexpressed in various types of cancers and plays an important role in tumor progression and prognosis. This study investigates the role of AFAP1-AS1 in tumor progression in triple-negative breast cancer (TNBC). We found that AFAP1-AS1 was overexpressed in TNBC tissues and cells. Overexpression of LncRNA AFAP1-AS1 was associated with poor prognosis in TNBC patients. Moreover, we demonstrated that upregulation of AFAP1-AS1 promoted cell proliferation and invasion, and inhibited cell apoptosis in vitro, while overexpression of AFAP1-AS1 promoted tumor growth in vivo. Our results also revealed that upregulation of AFAP1-AS1 activated Wnt/β-catenin pathway to promote tumorigenesis and cell invasion by increasing the expression of C-myc and epithelial-mesenchymal transition-related molecules in TNBC. Collectively, AFAP1-AS1 can be an independent prognostic marker and an effective therapeutic target of triple- negative breast cancer.

Long non-coding RNA AFAP1-AS1 plays an oncogenic role in promoting cell migration in non-small cell lung cancer.

Long non-coding RNA (lncRNA) plays an important role in tumor progression and metastasis. Emerging evidence indicates that lncRNA actin filament-associated protein 1-antisense RNA 1 (AFAP1-AS1) is dysregulated in certain tumors. However, the function of AFAP1-AS1 in non-small cell lung cancer (NSCLC) remains elusive. In this study, we conducted global lncRNA profiling and identified that AFAP1-AS1 is significantly upregulated in NSCLC, suggesting that AFAP1-AS1 may be important for lung cancer development. For the first time, the transcription initiation and termination sites of AFAP1-AS1 were identified by rapid amplification of cDNA ends technology, and the sequencing data indicated that AFAP1-AS1 in lung cancer cells is a novel transcript variant. Through gain- and loss-of-function studies, AFAP1-AS1 was demonstrated to promote cell migration and invasion. Mechanistically, AFAP1-AS1 functions through positively regulating the expression of AFAP1 protein. On the other hand, the expression of lncRNA AFAP1-AS1 negatively correlates with CpG methylation status of its gene promoter, identified in both lung cancer cells and patient tissues, and treatment with DNA methyltransferase inhibitor decitabine significantly activates AFAP1-AS1 expression, strongly supporting that AFAP1-AS1 expression is tightly regulated by DNA methylation. Taken together, this study demonstrates that AFAP1-AS1 acts as an oncogene in NSCLC to promote cell migration partly by upregulating AFAP1 expression, while its own expression is controlled by DNA methylation, and highlights its diagnostic and therapeutic values for NSCLC patients.

Cucurbitacin B suppresses proliferation of pancreatic cancer cells by ceRNA: Effect of miR-146b-5p and lncRNA-AFAP1-AS1.

Cucurbitacin B (CuB) is a natural tetracyclic triterpene product that displays antitumor activity against a wide variety of cancers. In this study, we explored the antipancreatic cancer activity of CuB via the inhibition of expression of the cancer-related long noncoding RNA, actin filament-associated protein 1-antisense RNA 1 (AFAP1-AS1). CuB arrested pancreatic cancer (PC) cells in the G2/M cell cycle phase by suppressingthe expression of AFAP1-AS1. Insights into the mechanisms of competing endogenous RNAs (ceRNAs) gained from bioinformatics analysis and luciferase activity assays showed that the epidermal growth factor receptor (EGFR) and AFAP1-AS1 directly compete for miR-146b-5p binding. CuB-induced high miR-146b-5p expression and inhibited the expression of AFAP1-AS1. In summary, reducing the expression of endogenous AFAP1-AS1 effectively increased the available concentration of miR-146b-5p in PC, whereas miR-146b-5p overexpression prevented the expression of endogenous AFAP1-AS1. In particular, we hypothesized that AFAP1-AS1 might act as a ceRNA, effectively becoming a sponge for miR-146b-5p, thereby activating the expression of the EGFR. Thus, CuB suppresses the proliferation, in vitro and in vivo, ofPC cells through the ceRNA effect of AFAP1-AS1 on miR-146b-5p.

Long noncoding RNA AFAP1-AS1 is upregulated in NSCLC and associated with lymph node metastasis and poor prognosis.

Long noncoding RNA (lncRNA) has been indicated to have an important role in various types of malignant tumors; however, only a small number of lncRNAs have been entirely elucidated. In the present study, a novel lncRNA, actin filament associated protein 1 antisense RNA 1 (AFAP1-AS1), was investigated, which is highly expressed in non-small cell lung cancer (NSCLC). Reverse transcription-quantitative polymerase chain reaction and in situ hybridization were performed to detect AFAP1-AS1 expression in frozen tissues and tissue microarrays, respectively. The results revealed that the expression level of AFAP1-AS1 was significantly increased in tumor tissues, compared with the paired non-cancerous tissues. It was also determined that the AFAP1-AS1 expression level was higher in patients with lymph node metastasis than those without lymph node metastasis (P=0.014). Kaplan-Meier analysis was conducted to evaluate the overall survival of patients with NSCLC and different expression levels of AFAP1-AS1, and the results indicated that patients with high AFAP1-AS1 expression had a reduced survival time, compared with those with low AFAP1-AS1 expression (P=0.011). Cox regression analysis was also performed to analyze the prognostic value of lncRNA AFAP1-AS1. The obtained data demonstrated that lncRNA AFAP1-AS1 was an unfavorable prognostic biomarker for NSCLC (HR: 3.12, 95% CI (1.05–9.25), P=0.040). In conclusion, it was demonstrated that lncRNA AFAP1-AS1 is overexpressed in NSCLC and an unfavorable biomarker for patients with NSCLC.

LncRNA AFAP1-AS1 is a prognostic biomarker and serves as oncogenic role in retinoblastoma.

The actin filament-associated protein 1 antisense RNA 1 (AFAP1-AS1) has been found to serve as an oncogenic long noncoding RNA (lncRNA) in most types of human cancer. The role of AFAP1-AS1 in retinoblastoma remains unknown. The purpose of the present study is to explore the clinical significance and biological function of AFAP1-AS1 in retinoblastoma. Levels of AFAP1-AS1 expression were measured in retinoblastoma tissues and cell lines. Loss-of-function study was performed to observe the effects of AFAP1-AS1 on retinoblastoma cell proliferation, cell cycle, migration, and invasion. In our results, AFAP1-AS1 expression was elevated in retinoblastoma tissues and cell lines, and associated with tumor size, choroidal invasion, and optic nerve invasion. Moreover, high expression of AFAP1-AS1 was an independent unfavorable prognostic factor in retinoblastoma patients. The experiment in vitro suggested down-regulation of AFAP1-AS1 inhibited retinoblastoma cell proliferation, migration and invasion, and blocked cell cycle. In conclusion, AFAP1-AS1 functions as an oncogenic lncRNA in retinoblastoma.

Expression analysis of AFAP1-AS1 and AFAP1 in breast cancer.

Long non-coding RNAs (lncRNA) constitute a significant percentage of RNAs with no translation to proteins. Their participation in fundamental aspects of cell physiology as well as their dysregulation in a number of pathologic conditions such as cancer have been documented. Among lncRNAs is actin filament associated protein 1 antisense RNA1 (AFAP1-AS1) whose elevated expression levels have been demonstrated in different cancers. In the in the present study we evaluated expression levels of AFAP1-AS1 and its antisense protein coding gene AFAP1 in breast cancer samples compare with adjacent non-cancerous tissues (ANCTs) as well as breast cancer cell lines with special focus on the assessment of the association between their transcript levels and patients' clinicopathological data. AFAP1-AS1 has shown significant up-regulation in both MDA-MB-231 and MCF-7 compared with control sample. AFAP1-AS1 has been shown to be expressed in all of tumor tissues but 76% (39 out of 51) ANCTs. AFAP1 expression was not significantly different between tumor samples and ANCTs. AFAP1-AS1 has been demonstrated to be significantly up-regulated in tumor tissues compared with ANCTs (fold change = 4.65, P= 0.028). No significant correlation has been detected between the levels of these two transcripts in tumor tissues (R=2 0.081) or ANCTs (R=2 0.115). No significant associations have been found between expression levels of these genes and patients' characteristics. However, both genes were significantly down-regulated in Ki-67 negative tumor samples. The observed up-regulation of AFAP1-AS1 in tumor samples compared with ANCTs implies its involvement in breast cancer pathogenesis and potentiates it as a biomarker or therapeutic target.