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Introduction: Trastuzumab is commonly used to treat human epidermal growth factor receptor-2-positive (HER2+) breast cancer, but its efficacy is often limited by chemotherapy resistance. Recent studies have indicated that long non-coding RNAs (lncRNAs) play important roles in tumor progression and response to therapy. However, the regulatory mechanisms associating lncRNAs and trastuzumab resistance remain unknown. Methods: Quantitative polymerase chain reaction was performed to detect the expression of related genes. Western blot and immunofluorescence assays were used to evaluate protein expression levels. A series of gain- or loss-of-function assays confirmed the function of AGAP2-AS1 in trastuzumab resistance, both in vitro and in vivo. RNA immunoprecipitation and pull-down analyses were conducted to verify the interaction between METTL3/YTHDF2 and lncRNA AGAP2-AS1. Results: AGAP2-AS1 was upregulated in trastuzumab-resistant cells and SKBR-3R-generated xenografts in nude mice. Silencing AGAP2-AS1 significantly decreased trastuzumab-induced cytotoxicity both in vitro and in vivo. Furthermore, m6A methylation of AGAP2-AS1 was reduced in trastuzumab-resistant cells compared to that in parental cells. In addition, METTL3 increased m6A methylation of AGAP2-AS1, which finally induced the suppressed AGAP2-AS1 expression. Moreover, YTHDF2 was essential for METTL3-mediated m6A methylation of AGAP2-AS1. Functionally, AGAP2-AS1 regulated trastuzumab resistance by inducing autophagy and increasing ATG5 expression. Conclusion: we demonstrated that METTL3/YTHDF2-mediated m6A methylation increased the expression of AGAP2-AS1, which could promote trastuzumab resistance in breast cancer. AGAP2-AS1 regulates trastuzumab resistance by inducing autophagy. Therefore, AGAP2-AS1 may be a promising predictive biomarker and therapeutic target in patients with breast cancer. [ABSTRACT FROM AUTHOR]

Long non-coding RNAs (lncRNAs) are well known for their oncogenic or anti-oncogenic roles in cancer development. AGAP2-AS1, a new lncRNA, has been extensively demonstrated as an oncogenic lncRNA in various cancers. Abundant experimental results have proved the aberrantly high level of AGAP2-AS1 in a great number of malignancies, such as glioma, colorectal, lung, ovarian, prostate, breast, cholangiocarcinoma, bladder, colon and pancreatic cancers. Importantly, the biological functions of AGAP2-AS1 have been extensively demonstrated. It could promote the proliferation, migration and invasion of cancer cells. Simultaneously, the clinical significances of AGAP2-AS1 were also illustrated. AGAP2-AS1 was exceptionally overexpressed in various cancer tissues. Clinical studies disclosed that the abnormal overexpression of AGAP2-AS1 was tightly connected with overall survival (OS), lymph nodes metastasis (LNM), clinical stage, tumor infiltration, high histological grade (HG), serous subtype and PFI times. However, to date, the biological actions and clinical significances of AGAP2-AS1 have not been systematically reviewed in human cancers. In the present review, the authors overviewed the biological actions, potential mechanisms and clinical features of AGAP2-AS1 according to the previous studies. In summary, AGAP2-AS1, as a vital oncogenic gene, is a promising biomarker and potential target for carcinoma prognosis and therapy. [ABSTRACT FROM AUTHOR]

Long noncoding RNAs (lncRNAs) are RNA molecules of 200 nucleotides or more in length that are not translated into proteins. Their expression is tissue-specific, with the vast majority involved in the regulation of cellular processes and functions. Many human diseases, including cancer, have been shown to be associated with deregulated lncRNAs, rendering them potential therapeutic targets and biomarkers for differential diagnosis. The expression of lncRNAs in the nervous system varies in different cell types, implicated in mechanisms of neurons and glia, with effects on the development and functioning of the brain. Reports have also shown a link between changes in lncRNA molecules and the etiopathogenesis of brain neoplasia, including glioblastoma multiforme (GBM). GBM is an aggressive variant of brain cancer with an unfavourable prognosis and a median survival of 14–16 months. It is considered a brain-specific disease with the highly invasive malignant cells spreading throughout the neural tissue, impeding the complete resection, and leading to post-surgery recurrences, which are the prime cause of mortality. The early diagnosis of GBM could improve the treatment and extend survival, with the lncRNA profiling of biological fluids promising the detection of neoplastic changes at their initial stages and more effective therapeutic interventions. This review presents a systematic overview of GBM-associated deregulation of lncRNAs with a focus on lncRNA fingerprints in patients' blood. [ABSTRACT FROM AUTHOR]

Background: Glioma (GBM) is the most prevalent malignancy worldwide with high morbidity and mortality. Exosome-mediated transfer of long noncoding RNA (lncRNA) has been reported to be associated with human cancers, containing GBM. Meanwhile, myeloid-derived suppressor cells (MDSCs) play a vital role in mediating the immunosuppressive environments in GBM. Objectives: This study is designed to explore the role and mechanism of exosomal (Exo) lncRNA AGAP2-AS1 on the MDSC pathway in GBM. Methods: AGAP2-AS1, microRNA-486-3p (miR-486-3p), and Transforming growth factor beta-1 (TGF-β1) levels were detected by real-time quantitative polymerase chain reaction (RT-qPCR). Cell proliferation, apoptosis, migration, and invasion were detected by 5-ethynyl-2′-deoxyuridine (EdU), flow cytometry, and Transwell assays. E-cadherin, Vimentin, CD9, CD81, and TGF-β1 protein levels were examined using Western blot. Exosomes were detected by a transmission electron microscope (TEM). Binding between miR-486-3p and AGAP2-AS1 or TGF-β1 was predicted by LncBase or TargetScan and then verified using a dual-luciferase reporter assay. Results: AGAP2-AS1 was highly expressed in GBM tissues and cells. Functionally, AGAP2-AS1 absence or TGF-β1 knockdown repressed tumor cell growth and metastasis. Furthermore, Exo-AGAP2-AS1 from GBM cells regulated TGF-β1 expression via sponging miR-486-3p in MDSCs. Exo-AGAP2-AS1 upregulation facilitated GBM cell growth and metastasis via the MDSC pathway. Conclusion: Exo-AGAP2-AS1 boosted GBM cell development partly by regulating the MDSC pathway, hinting at a promising therapeutic target for GBM treatment.

Abstract Background Increasing evidence highlights the potential role of long non-coding RNAs (lncRNAs) in the biological behaviors of renal cell carcinoma (RCC). Here, we explored the mechanism of AGAP2-AS1 in the occurrence and development of clear cell RCC (ccRCC) involving IGF2BP3/miR-9-5p/THBS2. Methods The expressions of AGAP2-AS1, IGF2BP3, miR-9-5p, and THBS2 and their relationship were analyzed by bioinformatics. The targeting relationship between AGAP2-AS1 and miR-9-5p and between miR-9-5p and THBS2 was evaluated with their effect on cell biological behaviors and macrophage polarization assayed. Finally, we tested the effect of AGAP2-AS1 on ccRCC tumor formation in xenograft tumors. Results IGF2BP3 could stabilize AGAP2-AS1 through m6A modification. AGAP2-AS1 was highly expressed in ccRCC tissues and cells. The lentivirus-mediated intervention of AGAP2-AS1 induced malignant behaviors of ccRCC cells and led to M2 polarization of macrophages. In addition, THBS2 promoted M2 polarization of macrophages by activating the PI3K/AKT signaling pathway. AGAP2-AS1 could directly bind with miR-9-5p and promote the expression of THBS2 downstream of miR-9-5p. These results were further verified by in vivo experiments. Conclusion AGAP2-AS1 stabilized by IGF2BP3 competitively binds to miR-9-5p to up-regulate THBS2, activating the PI3K/AKT signaling pathway and inducing macrophage M2 polarization, thus facilitating the development of RCC.

Owing to the lack of biomarkers for early diagnosis, gastric cancer (GC) is often associated with a poor prognosis. Thus, there is an urgent need to identify early molecular targets in GC. Dysregulated long noncoding RNAs (lncRNAs) have been evaluated by integrated bioinformatics analysis; and we investigate their specific role and potential mechanism via N6‐methyladenosine (m6A) methylation modification in the carcinogenesis and progression of GC. In this study, we report upregulation of lncRNA AGAP2‐AS1, activated by a gain of H3K4Me3, in GC tissues and cells. AGAP2‐AS1 was linked to adverse prognosis in patients with GC. Functionally, AGAP2‐AS1 knockdown inhibited cell proliferation and migration of GC cells. Mechanistically, AGAP2‐AS1 bound WT1‐associated protein (WTAP) to promote the formation of the WTAP/methyltransferase‐like 3 (METTL3)/METTL14 m6A methyltransferase complex. AGAP2‐AS1 stabilized signal transducer and activator of transcription 3 (STAT3) mRNA in an m6A‐dependent manner and, thus, activated the interleukin 6 (IL6)/STAT3 pathway. Importantly, activation of the AGAP2‐AS1/WTAP/STAT3 pathways promoted cell proliferation and migration in GC. Collectively, the present findings revealed a novel regulatory relationship between lncRNA and m6A modification. Furthermore, targeting the AGAP2‐AS1/WTAP/STAT3 axis may be a promising strategy for the inhibition of inflammation‐mediated carcinogenesis and progression in GC.LncRNA AGAP2‐AS1 was activated by a gain of H3K4Me3 in gastric cancer tissues and cells. Mechanistically, AGAP2‐AS1 bound WT1‐associated protein (WTAP) to promote the formation of the WTAP/methyltransferase‐like 3 (METTL3)/METTL14 m6A methyltransferase complex. AGAP2‐AS1 stabilized signal transducer and activator of transcription 3 (STAT3) mRNA in an m6A‐dependent manner and, thus, activated the interleukin 6 (IL6)/STAT3 pathway. [ABSTRACT FROM AUTHOR]

Long non-coding RNAs (lncRNAs) are well known for their oncogenic or anti-oncogenic roles in cancer development. AGAP2-AS1, a new lncRNA, has been extensively demonstrated as an oncogenic lncRNA in various cancers. Abundant experimental results have proved the aberrantly high level of AGAP2-AS1 in a great number of malignancies, such as glioma, colorectal, lung, ovarian, prostate, breast, cholangiocarcinoma, bladder, colon and pancreatic cancers. Importantly, the biological functions of AGAP2-AS1 have been extensively demonstrated. It could promote the proliferation, migration and invasion of cancer cells. Simultaneously, the clinical significances of AGAP2-AS1 were also illustrated. AGAP2-AS1 was exceptionally overexpressed in various cancer tissues. Clinical studies disclosed that the abnormal overexpression of AGAP2-AS1 was tightly connected with overall survival (OS), lymph nodes metastasis (LNM), clinical stage, tumor infiltration, high histological grade (HG), serous subtype and PFI times. However, to date, the biological actions and clinical significances of AGAP2-AS1 have not been systematically reviewed in human cancers. In the present review, the authors overviewed the biological actions, potential mechanisms and clinical features of AGAP2-AS1 according to the previous studies. In summary, AGAP2-AS1, as a vital oncogenic gene, is a promising biomarker and potential target for carcinoma prognosis and therapy.

Abstract Background Clear cell renal cell carcinoma (ccRCC) is the most common subtype of renal cancer and one of the most common cancers. While survival for localized ccRCC is good, the survival of metastatic disease is not, and thirty percent of patients with ccRCC develop metastases during follow-up. Although current scoring methods accurately identify patients at low progression risk, a small subgroup of those patients still experience metastasis. We therefore aimed to identify ccRCC progression biomarkers in “low-risk” patients who were potentially eligible for adjuvant treatments or more intensive follow-up. Methods We assembled a cohort of ccRCC patients (n = 443) and identified all “low-risk” patients who later developed progressing tumors (n = 8). Subsequently, we performed genome-wide expression profiling from formalin-fixed samples obtained at initial surgery from these “low-risk” patients and 16 matched patients not progressing to recurrence with metastasis. The patients were matched for Leibovich sore, creatinine, age, sex, tumor size and tumor stage. Key results were confirmed with qPCR and external data from The Cancer Genome Atlas. Results Principal component analysis indicated that systematic transcriptomic differences were already detectable at the time of initial surgery. One thousand one hundred sixty-seven genes, mainly associated with cancer and immune-related pathways, were differentially expressed between progressors and nonprogressors. A search for a classifier revealed that overexpression of AGAP2-AS1, an antisense long noncoding RNA, correctly classified 23 of 24 samples, years (4.5 years average) in advance of the discovery of metastasis and without requiring larger gene panels. Subsequently, we confirmed AGAP2-AS1 gene overexpression by qPCR in the same samples (p

Objective: To investigate serum Lipocalin-2, osteoblast specific factor 2 (periodin) and long-chain noncoding RNA NR_ Correlation between the expression of 027032 (agap2-as1) and the clinical features and prognosis of patients with non-small cell lung cancer (NSCLC). Methods: 84 patients with NSCLC diagnosed in our hospital from december2015 to December 2017 were selected as the study group, and healthy people who underwent physical examination in our hospital at the same time were selected as the healthy control group. The levels of serum Lipocalin-2 and periodin were detected by ELISA, and the expression levels of serum exosomes agap2-as1 were detected by fluorescent quantitative PCR, and their expression differences were analyzed; To analyze the correlation between the levels of serum Lipocalin-2, periodin and agap2-as1 and the clinicopathological features and prognosis of NSCLC patients. Results: The expression levels of serum Lipocalin-2, periodin and agap2-as1 in patients with NSCLC were significantly higher than those in healthy controls(P<0.05), and were correlated with lymph node metastasis, TNM stage and differentiation (P<0.05). Serum Lipocalin-2 was positively correlated with periodin and agap2-as1 in NSCLC blood (P<0.01 or <0.05). The median OS in patients with NSCLC with high expression of serum Lipocalin-2, periodin and agap2-as1 were significantly lower than those with low expression (P<0.05). Conclusion: The expression of serum Lipocalin-2, periodin and agap2-as1 is increased in NSCLC patients. The expression levels of serum Lipocalin-2, periodin and agap2-as1 in NSCLC patients are correlated with the degree of differentiation, TNM stage, lymph node metastasis and prognosis; It is expected to be a biomarker to evaluate the prognosis of NSCLC patients. [ABSTRACT FROM AUTHOR]

Long non-coding RNAs (lncRNAs) are closely associated with the pathogenesis of numerous diseases including cancers. LncRNA AGAP2 Antisense RNA 1 (AGAP2-AS1) has been found to participate in the tumorigenesis of several kinds of human cancers. Nonetheless, its potential function in colorectal cancer (CRC) was still poorly investigated. The expression level of RNAs or proteins was assessed by RT-qPCR or western blot analysis. Functional experiments were performed to analyze the role of AGAP2-AS1 in CRC in vitro and in vivo. Mechanism investigations were fulfilled to determine the potential mechanism of the molecules. AGAP2-AS1 expression was significantly elevated in CRC cells and could be transcriptionally activated by E2F Transcription Factor 4 (E2F4). Down-regulated AGAP2-AS1 could weaken CRC cell growth, migration, invasion, and epithelial-mesenchymal transition (EMT). MicroRNA-182-5p (miR-182-5p) was the target downstream molecule of AGAP2-AS1. Furthermore, Cofilin 1 (CFL1) was proved as the target of miR-182-5p. Mechanically, AGAP2-AS1 could boost the CFL1 expression via competitively binding to miR-182-5p in CRC. Importantly, CFL1 restoration could counteract the in vitro and in vivo suppression of depleted AGAP2-AS1 on CRC progression. E2F4-stimulated AGAP2-AS1 aggravated CRC development through regulating miR-182-5p/CFL1 axis, implying that AGAP2-AS1 might become a potent new target for future therapies for CRC. [ABSTRACT FROM AUTHOR]

Abstract Background LncRNA can regulate gene at various levels such as apparent genetics, alternative splicing, and regulation of mRNA degradation. However, the molecular mechanism of LncRNA in cholangiocarcinoma is still unclear. This deserves further exploration. Methods We investigated the expression of AGAP2-AS1 in 32 CCA tissues and two CCA cell lines. We found a LncRNA AGAP2-AS1 which induced by SP1 has not been reported in CCA, and Knockdown and overexpression were used to investigate the biological role of AGAP2-AS1 in vitro. CHIP and RIP were performed to verify the putative targets of AGAP2-AS1. Results AGAP2-AS1 was significantly upregulated in CCA tumor tissues. SP1 induced AGAP2-AS1 plays an important role in tumorigenesis. AGAP2-AS1 knockdown significantly inhibited proliferation and caused apoptosis in CCA cells. In addition, we demonstrated that AGAP2-AS1 promotes the proliferation of CCA. Conclusions We conclude that the long non-coding RNA AGAP2-AS1 plays a role in promoting the proliferation of cholangiocarcinoma.

• AGAP2-AS1 levels in psoriatic skin were higher than those in healthy controls. • AGAP2-AS1 expression was increased via an m6A-YTHDF2-dependent manner. • AGAP2-AS1 promotes keratinocyte proliferation through miR-424–5p/AKT3 axis. Psoriasis is a chronic, complicated, and recurrent inflammatory skin disease. However, the precise molecular mechanisms remain largely elusive and the present treatment is unsatisfactory. This study aimed to unravel the functions of long noncoding RNA (lncRNA) AGAP2-AS1 and its biological mechanism in psoriasis pathogenesis, hinting for the new therapeutic targets in psoriasis. The expression of AGAP2-AS1 in the skin tissue of psoriasis patients and healthy controls were detected by qRT-PCR and RNAscope®. Cell Counting Kit‑8 (CCK8) and clone formation assays were utilized to assess proliferation. Methylated RNA immunoprecipitation (MeRIP) was performed to detect the N6-methyladenosine (m6A) modification. RNA immunoprecipitation (RIP) was used to detect the interaction of AGAP2-AS1 with YTH domain family 2(YTHDF2). The relationships among AGAP2-AS1, miR-424–5p and AKT3 were examined by dual-luciferase reporter assay and RIP assay. We found that AGAP2-AS1 level was upregulated in the skin tissue of psoriasis patients than that of healthy controls and AGAP2-AS1 could promote proliferation and inhibit apoptosis of keratinocytes. Methyltransferase like 3(METTL3)-mediated m6A modification suppressed the expression of AGAP2-AS1 via YTHDF2-dependent AGAP2-AS1 stability. Thus, downregulation of METTL3 resulted in the upregulation of AGAP2-AS1 in psoriasis. AGAP2-AS1 functioned as a competitive endogenous RNA by sponging miR-424–5p to upregulate AKT3, activate AKT/mTOR pathway, as well as promote cell proliferation in keratinocytes. AGAP2-AS1 is upregulated in the skin tissue of psoriasis patients and m6A methylation was involved in its upregulation. AGAP2-AS1 promotes keratinocyte proliferation through miR-424–5p/AKT/mTOR axis and may be a promising target for psoriasis therapy. [ABSTRACT FROM AUTHOR]

Background: Clear cell renal cell carcinoma (ccRCC) is the most common subtype of renal cancer and one of the most common cancers. While survival for localized ccRCC is good, the survival of metastatic disease is not, and thirty percent of patients with ccRCC develop metastases during follow-up. Although current scoring methods accurately identify patients at low progression risk, a small subgroup of those patients still experience metastasis. We therefore aimed to identify ccRCC progression biomarkers in "low-risk" patients who were potentially eligible for adjuvant treatments or more intensive follow-up. Methods: We assembled a cohort of ccRCC patients (n = 443) and identified all "low-risk" patients who later developed progressing tumors (n = 8). Subsequently, we performed genome-wide expression profiling from formalin-fixed samples obtained at initial surgery from these "low-risk" patients and 16 matched patients not progressing to recurrence with metastasis. The patients were matched for Leibovich sore, creatinine, age, sex, tumor size and tumor stage. Key results were confirmed with qPCR and external data from The Cancer Genome Atlas. Results: Principal component analysis indicated that systematic transcriptomic differences were already detectable at the time of initial surgery. One thousand one hundred sixty-seven genes, mainly associated with cancer and immune-related pathways, were differentially expressed between progressors and nonprogressors. A search for a classifier revealed that overexpression of AGAP2-AS1, an antisense long noncoding RNA, correctly classified 23 of 24 samples, years (4.5 years average) in advance of the discovery of metastasis and without requiring larger gene panels. Subsequently, we confirmed AGAP2-AS1 gene overexpression by qPCR in the same samples (p < 0.05). Additionally, in external data from The Cancer Genome Atlas, overexpression of AGAP2-AS1 is correlated with overall unfavorable survival outcome in ccRCC, irrespective of other prognostic predictors (p = 2.44E−7). Conclusion: AGAP2-AS1 may represent a novel biomarker identifying high-risk ccRCC patients currently classified as "low risk" at the time of surgery. [ABSTRACT FROM AUTHOR]

Yang Yan,1,* Yiping Wang,1,* Yuxia Liu,2 Tao Chen,3 Yaoli Zhu,4 Huiqing Li,5 Fangen Kong1 1Department of Neurosurgery, The Fifth Affiliated Hospital Sun Yat-Sen University, Zhuhai, Guangdong, People’s Republic of China; 2Department of Gastrointestinal Surgery, The Fifth Affiliated Hospital Sun Yat-Sen University, Zhuhai, Guangdong, People’s Republic of China; 3Department of Spine Surgery, The Fifth Affiliated Hospital Sun Yat-Sen University, Zhuhai, Guangdong, People’s Republic of China; 4Department of Critical Care Medicine, The Fifth Affiliated Hospital Sun Yat-Sen University, Zhuhai, Guangdong, People’s Republic of China; 5Department of Neurology, The Fifth Affiliated Hospital Sun Yat-Sen University, Zhuhai, Guangdong, People’s Republic of China*These authors contributed equally to this workCorrespondence: Fangen Kong Email uyangleyanwlpty@163.comPurpose: Long non-coding RNAs (lncRNAs) have been reported to be involved in a variety of cancers, including glioma. However, the exact role and underlying mechanism of lncRNA AGAP2 antisense RNA 1 (AGAP2-AS1) in glioma have not yet been fully elucidated.Methods: The expression levels of AGAP2-AS1, microRNA-628-5p (miR-628-5p) and pleiotrophin (PTN) were measured by quantitative real-time polymerase chain reaction (qRT-PCR). Cell proliferation, apoptosis, migration and invasion were detected by Cell Counting Kit-8 (CCK-8) assay, flow cytometry, transwell assay, respectively. Western blot assay was used to detect the protein level of PTN. The interaction between miR-628-5p and AGAP2-AS1 or PTN was predicted by bioinformatics software and confirmed by the dual-luciferase reporter and RNA Immunoprecipitation (RIP) assays. Murine xenograft model was established to confirm the role of AGAP2-AS1 in glioma progression in vivo.Results: AGAP2-AS1 expression was upregulated in glioma tissues and cells. Knockdown of AGAP2-AS1 inhibited the proliferation, migration and invasion, but facilitated apoptosis in glioma cells. Moreover, AGAP2-AS1 could directly bind to miR-628-5p and its overexpression reversed the anti-tumor effect of miR-628-5p restoration on the progression of glioma cells. In addition, miR-628-5p directly targeted PTN and its inhibition abolished the inhibitory effect of PTN knockdown on the progression of glioma cells. Furthermore, AGAP2-AS1 functioned as a competing endogenous RNA (ceRNA) by sponging miR-628-5p to modulate PTN expression. Besides, AGAP2-AS1 depletion reduced tumor growth by upregulating miR-628-5p and downregulating PTN.Conclusion: AGAP2-AS1 knockdown suppressed cell proliferation, migration and invasion but promoted cell apoptosis in glioma cells by regulating miR-628-5p/PTN axis, providing novel avenues for treatment of glioma.Keywords: glioma, AGAP2-AS1, miR-628-5p, PTN, cell progression

Accumulating evidence has indicated that, aberrant lncRNA expression plays essential roles in the colorectal cancer (CRC) tumorigenesis. AGAP2-AS1 is upregulated in some cancers, however, its involvement in the CRC tumorigenesis in the population of North-West of Iran has remained unknown. In this study, we evaluated its deregulation in CRC microarray datasets, colon cell lines, CRC tumor, adenomatous colorectal polyps and their paired normal tissues. The results showed that AGAP2-AS1 is upregulated in CRC and might be considered as a potential biomarker for CRC development. Moreover, our results suggest AGAP2-AS1 promoted CRC progression by sponging the hsa-miR-15/16 family and upregulation of their targets. [ABSTRACT FROM AUTHOR]

Abstract Background Accumulating evidence has highlighted the potential role of long non-coding RNAs (lncRNAs) in the biological behaviors of hepatocellular carcinoma (HCC). Here, we elucidated the function and possible molecular mechanisms of the effect of lncRNA-AGAP2-AS1 on the biological behaviors of HCC. Methods EdU, Transwell and flow cytometry were used to determine proliferation, migration, invasion and apoptosis of HCC cells in vitro. The subcutaneous tumor model and lung metastasis mouse model in nude mice was established to detect tumor growth and metastasis of HCC in vivo. The direct binding of miR-16-5p to 3’UTR of ANXA11 was confirmed by luciferase reporter assay. The expression of AGAP2-AS1 and miR-16-5p in HCC specimens and cell lines were detected by real-time PCR. The correlation among AGAP2-AS1 and miR-16-5p were disclosed by a dual-luciferase reporter assay, RIP assay and biotin pull-down assay. Results Here, we demonstrated that AGAP2-AS1 expression was up-regulated in HCC tissues and cell lines, especially in metastatic and recurrent cases. Gain- and loss-of-function experiments indicated that AGAP2-AS1 promoted cell proliferation, migration, invasion, EMT progression and inhibited apoptosis of HCC cells in vitro and in vivo. Further studies demonstrated that AGAP2-AS1 could function as a competing endogenous RNA (ceRNA) by sponging miR-16-5p in HCC cells. Functionally, gain- and loss-of-function studies showed that miR-16-5p promoted HCC progression and alteration of miR-16-5p abolished the promotive effects of AGAP2-AS1 on HCC cells. Moreover, ANXA11 was identified as direct downstream targets of miR-16-5p in HCC cells, and mediated the functional effects of miR-16-5p and AGAP2-AS1 in HCC, resulting in AKT signaling activation. Clinically, AGAP2-AS1 and miR-16-5p expression were markedly correlated with adverse clinical features and poor prognosis of HCC patients. We showed that hypoxia was responsible for the overexpression of AGAP2-AS1 in HCC. And the promoting effects of hypoxia on metastasis and EMT of HCC cells were reversed by AGAP2-AS1 knockdown. Conclusions Taken together, this research supports the first evidence that AGAP2-AS1 plays an oncogenic role in HCC via AGAP2-AS1/miR-16-5p/ANXA11/AKT axis pathway and represents a promising therapeutic strategy for HCC patients.

Long non-coding RNA (lncRNA) AGAP2-AS1 acts as an oncogene in several types of cancers. However, the role and mechanism of AGAP2-AS1 in papillary thyroid carcinoma (PTC) remain unclear. Thus, in this study, we aimed to explore the role of AGAP2-AS1 in PTC. Our results showed that AGAP2-AS1 was significantly upregulated in PTC tissues. Knockdown of AGAP2-AS1 inhibited the proliferation, migration and invasion of PTC cells. In vivo experiment showed that AGAP2-AS1 knockdown inhibited the tumorigenesis of PTC. MiR-628-5p was found to act as a target miRNA of AGAP2-AS1 in PTC. The expression level of miR-628‐5p in PTC tissues was negatively associated with that of AGAP2-AS1. Inhibition of miR-628-5p attenuated the effects of AGAP2-AS1 knockdown on PTC. Moreover, miR-628-5p directly bound to the 3'UTR of KLF12 and inhibited the expression of KLF12. Knockdown of KLF12 enhanced the inhibitory effects of miR-628-5p on PTC cell proliferation and metastasis. In conclusion, these findings indicated that AGAP2-AS1 exerted an oncogenic role in PTC progression and metastasis. The effects of AGAP2-AS1 might be mediated by the regulation of miR-628-5p/KLF12 axis. [ABSTRACT FROM AUTHOR]

Background: LncRNA can regulate gene at various levels such as apparent genetics, alternative splicing, and regulation of mRNA degradation. However, the molecular mechanism of LncRNA in cholangiocarcinoma is still unclear. This deserves further exploration. Methods: We investigated the expression of AGAP2-AS1 in 32 CCA tissues and two CCA cell lines. We found a LncRNA AGAP2-AS1 which induced by SP1 has not been reported in CCA, and Knockdown and overexpression were used to investigate the biological role of AGAP2-AS1 in vitro. CHIP and RIP were performed to verify the putative targets of AGAP2-AS1. Results: AGAP2-AS1 was significantly upregulated in CCA tumor tissues. SP1 induced AGAP2-AS1 plays an important role in tumorigenesis. AGAP2-AS1 knockdown significantly inhibited proliferation and caused apoptosis in CCA cells. In addition, we demonstrated that AGAP2-AS1 promotes the proliferation of CCA. Conclusions: We conclude that the long non-coding RNA AGAP2-AS1 plays a role in promoting the proliferation of cholangiocarcinoma. [ABSTRACT FROM AUTHOR]

Background: Glioma (GBM) is the most prevalent malignancy worldwide with high morbidity and mortality. Exosome-mediated transfer of long noncoding RNA (lncRNA) has been reported to be associated with human cancers, containing GBM. Meanwhile, myeloid-derived suppressor cells (MDSCs) play a vital role in mediating the immunosuppressive environments in GBM., Objectives: This study is designed to explore the role and mechanism of exosomal (Exo) lncRNA AGAP2-AS1 on the MDSC pathway in GBM., Methods: AGAP2-AS1, microRNA-486-3p (miR-486-3p), and Transforming growth factor beta-1 (TGF-β1) levels were detected by real-time quantitative polymerase chain reaction (RT-qPCR). Cell proliferation, apoptosis, migration, and invasion were detected by 5-ethynyl-2'-deoxyuridine (EdU), flow cytometry, and Transwell assays. E-cadherin, Vimentin, CD9, CD81, and TGF-β1 protein levels were examined using Western blot. Exosomes were detected by a transmission electron microscope (TEM). Binding between miR-486-3p and AGAP2-AS1 or TGF-β1 was predicted by LncBase or TargetScan and then verified using a dual-luciferase reporter assay., Results: AGAP2-AS1 was highly expressed in GBM tissues and cells. Functionally, AGAP2-AS1 absence or TGF-β1 knockdown repressed tumor cell growth and metastasis. Furthermore, Exo-AGAP2-AS1 from GBM cells regulated TGF-β1 expression via sponging miR-486-3p in MDSCs. Exo-AGAP2-AS1 upregulation facilitated GBM cell growth and metastasis via the MDSC pathway., Conclusion: Exo-AGAP2-AS1 boosted GBM cell development partly by regulating the MDSC pathway, hinting at a promising therapeutic target for GBM treatment., Competing Interests: The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (© 2024 The Authors.)

Background: Colorectal cancer (CRC) is a frequently occurring tumor. Although a number of long noncoding RNAs have been researched in CRC, the expression, function and mechanism of AGAP2‐AS1 remains poorly investigated. Methods: Gene expression was analyzed by a quantitative reverse transcriptase‐polymerase chain rreaction and western blot analyses. Cell counting kit‐8, colony formation and Transwell assays were utilized to explore the functional role of AGAP2‐AS1 in CRC. Luciferase reporter, RNA pull down and RNA immunoprecipitation assays were implemented to verify relationships between RNA molecules. Results: In the present study, AGAP2‐AS1 was unveiled as highly expressed in CRC cell lines compared to normal cells. AGAP2‐AS1 knockdown suppressed cell proliferation, migration, invasion and the epithelial‐to‐mesenchymal transition process. Interestingly, AGAP2‐AS1 sponges miR‐4,668‐3p to release SRSF1 in CRC. Furthermore, in the rescue functional assay, miR‐4,668‐3p down‐regulation exacerbated the malignant behaviors of AGAP2‐AS1‐depleted CRC cells, whereas such effects were further offset by SRSF1 knockdown. Conclusions: AGAP2‐AS1 facilitates cell proliferation, motility and EMT in CRC via targeting the miR‐4,668‐3p/SRSF1 axis. AGAP2‐AS1 or SRSF1 may have potential as underlying therapeutic targets for CRC patients. [ABSTRACT FROM AUTHOR]

Recently, growing evidence has shown that aberrant long non‐coding RNA (lncRNA) expression in conjunction with an impaired trophoblastic phenotype could implicate the pathological process of pre‐eclampsia (PE). However, only a small portion of lncRNAs has been characterized with regard to the function and molecular mechanisms involved in PE. There are still gaps in the available knowledge; as a result, there are currently only a few applicable treatments for PE in the context of lncRNA. Here, we found that lncRNA AGAP2‐AS1 is abnormally down‐regulated in severe PE placenta tissues. Using human trophoblasts, we established that AGAP2‐AS1 knockdown could inhibit trophoblasts proliferation and invasion and promote cell apoptosis. Further, we showed that overexpression of AGAP2‐AS1 substantially stimulated the development of the trophoblastic phenotype. Through high‐throughput sequencing analysis, we demonstrated that silencing of AGAP2‐AS1 favourably regulated various genes which are relevant to trophoblastic growth and invasion. Mechanistically, AGAP2‐AS1 promoted the suppressor protein, Jun dimerization protein 2 (JDP2), by sponging miR‐574‐5p. Resultantly, further impairment of the trophoblastic phenotype was achieved by way of inhibiting cell growth, apoptosis and invasion. We also determined that the expression of AGAP2‐AS1 could be mediated by FOXP1. Our results showed that the down‐regulated expression of lncRNA AGAP2‐AS1 might serve as a key suppressor in PE via inhibition of JDP2 at the post‐transcriptional level by competing for miR‐574; thus, this presents a novel therapeutic strategy for PE. [ABSTRACT FROM AUTHOR]

The long non-coding RNA (lncRNA) AGAP2-AS1 was implicated in tumorigenesis, yet with unclear mechanism in the development of Bladder Cancer (BCa). We collected the clinicopathological features and tissue samples of 45 patients with BCa in Xiangya Hospital. Expressions of AGAP2-AS1 and LRG1 were detected by RT-qPCR in BCa tissues and normal tissues as well as in BCa cells. The roles of AGAP2-AS1 and LRG1 were investigated by CCK-8, colony formation assay, transwell assays and tube formation assay. The subcellular localization of AGAP2-AS1 was detected by Fluorescence in situ hybridization. Bioinformatics method, RNA immunoprecipitation, RNA pull-down assay and Actinomycin D test were used to predict and identify the relationships between AGAP2-AS1, LRG1 and IGF2BP2. Xenografted tumors were produced to explore the function of AGAP2-AS1 in BCa in vivo. AGAP2-AS1 and LRG1 were highly upregulated in BCa. AGAP2-AS1 positively correlated with T stage, grade and vascular invasion, but negatively correlated with the survival of patients. Overexpressions of AGAP2-AS1 promoted proliferation, migration, invasion, tumor angiogenesis in vitro and tumor growth, metastasis in vivo, knockdown of AGAP2-AS1 exhibited the opposite effects. AGAP2-AS1 localized mainly in the cytoplasm. AGAP2-AS1 directly bound to IGF2BP2 protein to enhance LRG1 mRNA stability. Inhibition of BCa progression by AGAP2-AS1 knockdown may be reversed by LRG1 overexpression. AGAP2-AS1 can promote BCa progression and metastasis by recruiting IGF2BP2 to stabilize LRG1. LncRNA AGAP2-AS1 enhanced the stability of the LRG1 mRNA by recruiting the RNA-binding protein IGF2BP2 to the target gene LRG1 mRNA in the cytoplasm, so as to promot the proliferation, migration, invasion and angiogenesis of bladder cancer cells. [Display omitted] • We found AGAP2-AS1 was overexpressed in BCa, the high expression of AGAP2-AS1 was positively correlated with high pathological T stage, high grade and vascular invasion, but negatively correlated with the survival prognosis. High expression of AGAP2-AS1 and LRG1 promoted proliferation, migration, invasion of BCa cells and angiogenesis of tumor in vitro. AGAP2-AS1 also promoted tumor growth and metastasis in vivo. AGAP2-AS1 promoted the stability of LRG1 mRNA by recruiting the RNA binding protein IGF2BP2 to LRG1 mRNA. Morever, AGAP2-AS1 promoted uncontrolled proliferation, migration, invasion and angiogenesis of BCa cells in an LRG1-dependent manner, thereby accelerating the malignant progression of BCa. • According 45 BCa patients' tissues in our hospital, AGAP2-AS1 and LRG1 are upregulated in bladder cancer (BCa), pathological features such as pathological T stage, high grade, especially vascular infiltration were related to the level of AGAP2-AS1. • AGAP2-AS1 recruits IGF2BP2 to stabilize LRG1 mRNA in BCa, the co-localization of AGAP2-AS1, IGF2BP2 and LRG1 was confirmed by IF-FISH. • In addition to using bioinformatics methods to predict target genes, we employed a number of experimental methods to verify our conclusions. [ABSTRACT FROM AUTHOR]

Abstract Background Long noncoding RNAs (lncRNAs) have emerged as important regulators of tumorigenesis and cancer progression. Recently, the lncRNA AGAP2-AS1 was identified as an oncogenic lncRNA in human non-small cell lung cancer (NSCLC) and its elevated expression was linked to NSCLC development and progression. However, the expression pattern and molecular mechanism of AGAP2-AS1 in gastric cancer (GC) have not been characterized. Methods Bioinformatic analysis was performed to determine AGAP2-AS1 expression levels in the GC and normal tissues using gene profiling data from the Gene Expression Omnibus. Quantitative real-time polymerase chain reaction was used to validate AGAP2-AS1 expression in the GC tissues/cell lines compared with that in the adjacent nontumorous tissues/normal epithelial cells. Loss- and gain-of-function approaches were performed to investigate the effect of AGAP2-AS1 on GC cell phenotypes. The effect of AGAP2-AS1 on cell proliferation was evaluated by MTT, colony formation, flow cytometry, and in vivo tumor formation assays. The effects of AGAP2-AS1 on cell migration and invasion were examined using Transwell assays. Chromatin immunoprecipitation, luciferase reporter assays, RNA pull-down, and RNA immunoprecipitation were used to investigate the factors involved in AGAP2-AS1 dysregulation and the mechanism of action of AGAP2-AS1 in the GC cells. Results AGAP2-AS1 was highly expressed in the GC tissues and cell lines, and patients with higher AGAP2-AS1 expression had a poorer prognosis and shorter overall survival. Furthermore, knockdown of AGAP2-AS1 significantly inhibited GC cell proliferation, migration, and invasion in vitro and tumor growth in vivo. AGAP2-AS1 overexpression promoted cell growth and invasion. In addition, the transcription factor SP1 activated AGAP2-AS1 expression in the GC cells. AGAP2-AS1 functions as an oncogenic lncRNA by interacting with LSD1 and EZH2 and suppressing CDKN1A (P21) and E-cadherin transcription. Conclusions Taken together, these findings imply that AGAP2-AS1 upregulated by SP1 plays an important role in GC development and progression by suppressing P21 and E-cadherin, which suggests that AGAP2-AS1 is a potential diagnostic marker and therapeutic target for GC patients.

Abstract Glioma is a kind of malignant brain tumor which damages the central nervous system of adults. Recent years, the molecular mechanism involved in the initiation and progression of glioma has been widely reported. Long non-coding RNAs (lncRNAs) have been proved to be significant modulators in the biological processes of glioma. In this study, we found that lncRNA AGAP2-AS1 was differentially expressed in glioma tissue samples and cell lines. Kaplan-Meier method was used to analyze the correlation between AGAP2-AS1 expression and the overall survival of glioma patients. Higher expression of AGAP2-AS1 was correlated with the lower overall survival of glioma patients. Functionally, AGAP2-AS1 knockdown inhibited glioma cell proliferation and accelerated glioma cell apoptosis. Mechanistically, AGAP2-AS1 upregulated HDGF by sponging miR-15a/b-5p. The function of AGAP2-AS1-miR-15a/b-5p-HDGF axis was confirmed by performing rescue assays. Experimental results suggested that miR-15a/b-5p and HDGF involved in AGAP2-AS1-mediated glioma cell proliferation. Moreover, AGAP2-AS1 and HDGF were found to activate Wnt/β-catenin signaling pathway in glioma cell lines. In summary, this study demonstrated that AGAP2-AS1 promoted glioma cell proliferation by sponging miR-15a/b-5p to upregulate the expression of HDGF. [ABSTRACT FROM AUTHOR]

OBJECTIVE: The purpose of this study was to explore whether long non-coding RNA AGAP2-AS1 (AGAP2-AS1) could serve as a novel biomarker for non-small-cell lung cancer (NSCLC). PATIENTS AND METHODS: Cancer and matched normal lung tissues were collected from 198 patients. AGAP2-AS1 levels were examined by RT-PCR, and the associations of AGAP2-AS1 levels with clinicopathological characteristics evaluated. Overall survival was evaluated using the Kaplan-Meier method. Cox proportional hazard modeling was performed for univariate and multivariate analysis to determine the effects of variables on survival. Receiver-operating characteristic. Besides, the receiver operating characteristic (ROC) curve analysis were applied to analyze its diagnostic value. RESULTS: Expression of AGAP2-AS1 was up-regulated in the NSCLC tissues compared with the adjacent normal tissues (p < 0.01). Furthermore, The level of AGAP2-AS19 in NSCLC was strongly correlated with tumor stage (p = 0.001) and lymph nodes metastasis (p = 0.005). Kaplan-Meier analysis demonstrated patients with higher AGAP2-AS1 expression had a shorter overall survival time than those with lower AGAP2-AS1 expression (p < 0.0001). The multivariate analysis showed that AGAP2-AS1 expression is an independent prognostic factor of overall survival in patients with NSCLC. The results of ROC curve analysis showed that AGAP2-AS1 might be a promising diagnostic marker of NSCLC with an AUC of 0.846. CONCLUSIONS: Our findings revealed that AGAP2-AS1 might be a potential biomarker for the diagnosis and prognosis of NSCLC. However, to completely elucidate its role as a biomarker, further studies are required. [ABSTRACT FROM AUTHOR]

Objective: To examine the effects and mechanisms of AGAP2 Antisense RNA 1 (AGAP2-AS1) in progression of skin cutaneous melanoma (SKCM)., Methods: AGAP2-AS1 expression and SKCM survival outcomes were assessed using bioinformatics analysis. In vitro and in vivo assays, including cell proliferation, colony formation, migration, and tumor formation assays, were performed to detect AGAP2-AS1 oncogenic effects in SKCM. RNA pull-down, RNA immunoprecipitation (RIP), and co-immunoprecipitation were used to evaluate the mechanism of AGAP2-AS1 in SKCM progression., Results: AGAP2-AS1 was upregulated in human SKCM tissues and cells and predicted a worse prognosis. AGAP2-AS1 silencing in two SKCM cell lines inhibited cell proliferation, as well as colony formation and migration both in vitro and in vivo. The RNA pull-down assay and RIP analysis results indicated that AGAP2-AS1 interacted with bromodomain containing 7 (BRD7). AGAP2-AS1 knockdown attenuated the BRD7 and c-Myc interaction, which reduced c-Myc expression. The altered phenotypes found in AGAP2-AS1- and BRD7-deficient cells were rescued by overexpression of c-Myc., Conclusions: AGAP2-AS1 participated in oncogenesis in SKCM via the BRD7/c-Myc signaling pathway. These results suggest a molecular mechanism for AGAP2-AS1 in the carcinogenesis of SKCM., Competing Interests: None., (AJTR Copyright © 2023.)

Background: LncRNA has been found to participate in a variety of biological processes and play an important role in the occurrence and development of tumors. Therefore, it is of vital clinical value to study the relationship between lncRNA and tumor. It has been confirmed that lncRNA affects tumor progression through sponge mRNA, regulation of signal pathways and activity of oncogenes. Recent studies have shown that LncRNA AGAP2-AS1 is closely related to tumor, because this review focuses on the molecular mechanism of LncRNA AGAP2-AS1 affecting tumor progression., Methods: The role of LncRNAAGAP2-AS1 in tumor was summarized by searching the literature related to LncRNAAGAP2-AS1 from PubMed in recent years., Results: LncRNA AGAP2-AS1 is abnormally expressed as an oncogene in tumors, which participates in biological processes such as tumor proliferation, migration, invasion and autophagy. LncRNA AGAP2-AS1 plays an important role in tumorigenesis and development by binding to mRNA, regulating signal pathway and affecting protein activity, which suggests that AGAP2- AS1 may play a great potential value in the treatment of human cancer., Conclusion: The abnormal expression of LncRNAAGAP2-AS1 plays an important role in the progression of tumor and has a promising value in the treatment of tumor. Exploring the molecular mechanism of lncRNA AGAP2-AS1 is of indispensable significance for tumor treatment., (Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.net.)

Trastuzumab has been widely used for treatment of HER-2-positive breast cancer patients, however, the clinical response has been restricted due to emergence of resistance. Recent studies indicate that long noncoding RNA AGAP2-AS1 (lncRNA AGAP2-AS1) plays an important role in cancer resistance. However, the precise regulatory function and therapeutic potential of AGAP2-AS1 in trastuzumab resistance is still not defined. In this study, we sought to reveal the essential role of AGAP2-AS1 in trastuzumab resistance. Our results suggest that AGAP2-AS1 disseminates trastuzumab resistance via packaging into exosomes. Exosomal AGAP2-AS1 induces trastuzumab resistance via modulating ATG10 expression and autophagy activity. Mechanically, AGAP2-AS1 is associated with ELAVL1 protein, and the AGAP2-AS1-ELAVL1 complex could directly bind to the promoter region of ATG10, inducing H3K27ac and H3K4me3 enrichment, which finally activates ATG10 transcription. AGAP2-AS1-targeting antisense oligonucleotides (ASO) substantially increased trastuzumab-induced cytotoxicity. Clinically, increased expression of serum exosomal AGAP2-AS1 was associate with poor response to trastuzumab treatment. In conclusion, exosomal AGAP2-AS1 increased trastuzumab resistance via promoting ATG10 expression and inducing autophagy. Therefore, AGAP2-AS1 may serve as predictive biomarker and therapeutic target for HER-2+ breast cancer patients., Competing Interests: None., (AJCR Copyright © 2021.)

Vimentin (VIM) is a mesenchymal marker which is expressed in some cancer types including breast cancer. A long non-coding RNA (lncRNA) has been identified to be transcribed from VIM gene locus and positively regulate expression of VIM. This lncRNA has been named as VIM-antisense 1 (VIM-AS1). Expression of VIM is also regulated by another lncRNA namely AGAP2-antisense RNA 1 (AGAP2-AS1). In the current study, we aimed at identification of the expression pattern of VIM , VIM-AS1 , AGAP2 and AGAP2-AS1 in 78 breast cancer samples and their paired adjacent non-cancerous tissues (ANCTs) by means of real time PCR. All mentioned genes were significantly down-regulated in tumoral tissues compared with ANCTs (P values less than 0.000). Relative expression of VIM-AS1 in tumoral tissues versus ANCTs was associated with menopause age (P =.02) in a way that this gene was down-regulated in most of patients whose menopause age was between 40 and 50 years. Moreover, AGAP2–AS1 relative expression was associated with patients' body mass index (P =.03). There were trends toward association between VIM relative expression and tumor size (P =.07) and association between VIM-AS1 relative expression and obesity (P =.06). Expression of VIM was significantly higher in tumoral tissues of patients who had history of hormone replacement therapy compared with those without such history (P =.03). Moreover, expression levels of both VIM and AGAP2-AS1 were lower in patients whose menarche age was between 10 and 12 years old compared with those whose menarche age was between 13 and 15 years old (P values =.01 and 0.04, respectively). Transcript quantities of VIM , VIM-AS1 , AGAP2 and AGAP2-AS1 were correlated with each other both in tumoral tissues and in ANCTs. Among four assessed genes, AGAP2 had the best diagnostic power for discrimination of tumoral tissues from ANCTs (AUC value = 0.87). Combination of four genes led to enhancement of AUC value to 0.94. The current study shows the importance of VIM and its associated lncRNAs in breast cancer and potentiates these genes as biomarkers for this malignancy. Moreover, these lncRNAs might be regarded as therapeutic targets in breast cancer. [ABSTRACT FROM AUTHOR]

Cancer remains the second leading life-threatening disease worldwide. Increasing evidence indicates that long non-coding RNAs (lncRNAs) play an important role in multiple physiological and pathological processes, including gene amplification, mutation, rearrangement, and overexpression regulations. In this review, we comprehensively summarize the current knowledge of lncRNA AGAP2-AS1 from a cancer perspective. As a member of the lncRNA family, lncRNA AGAP2-AS1 is upregulated in solid tumor malignancies, functions as an oncogene, and plays a key role in tumorigenesis and tumor progression. AGAP2-AS1 expression is significantly increased in clinical cancer tissue samples, cell lines, and in vivo, and is closely related to an unfavorable prognosis in several cancers. Upregulated lncRNA AGAP2-AS1 binds with microRNAs (miRNAs) and promotes activation of downstream genes. This aberrant regulation induces carcinogenesis and tumorigenesis. Here we provide a comprehensive overview of AGAP2-AS1 in cancer progression that leads to an improved understanding of the effects of AGAP2-AS1 on early detection and therapeutic approaches. This information is essential for the future development of lncRNA AGAP2-AS1 as a potential therapy against these devastating cancers., Competing Interests: None., (AJTR Copyright © 2021.)

Papillary thyroid cancer (PTC) is considered a low hazard endocrine system cancer, but a considerable number of patients have poor prognosis because of lymph node metastasis and invasion of surrounding tissues. In this study, we analyzed the expression and function of the long non-coding RNA (lncRNA) AGAP2-AS1 in PTC. We found that AGAP2-AS1 expression was significantly higher in human PTC tissues than adjacent noncancerous tissues (n=110; p<0.01) and correlated with lymph node metastasis (p=0.01) and tumor-node-metastasis stage (p=0.006). AGAP2-AS1 downregulation decreased migration and invasion by PTC cells, and reduced expression of matrix metalloproteinase-2 (MMP2). AGAP2-AS 1 upregulated MMP2 expression by competitively binding to microRNA-425-5p. In addition, miR-424-5p expression was decreased in PTC tissues and correlates negatively with the AGAP2-AS1 levels. These results demonstrate that AGAP2-AS1 expression is significantly elevated in PTC tissues and that, by binding to miRNA-425-5p, it upregulates the MMP2 expression, thereby increasing the invasiveness and migration capacity of PTC cells.

Antisense long noncoding RNAs serve as important regulators of protein-coding genes and contribute to tumorigenesis and metastasis. AGAP2-AS1, an antisense lncRNA transcribed from AGAP2, is involved in various cancer types. However, the clinical significance, biological roles and regulatory mechanisms of AGAP2-AS1 in epithelial ovarian cancer (EOC) have not been thoroughly elucidated to date. In this study, we demonstrated the expression pattern and biological roles of AGAP2-AS1 in EOC. Clinically, AGAP2-AS1 expression was decreased in EOC tissues compared to that in the controls. Low expression of AGAP2-AS1 was associated with advanced FIGO stage, high histological grade, serous subtype and lymph node metastasis in patients with EOC. AGAP2-AS1 inhibited cell migration, invasion and proliferation in vitro . AGAP2-AS1 suppressed tumor growth in vivo . Mechanistically, AGAP2-AS1 inhibited cell metastasis and proliferation by downregulating KRAS, FGFR4, and CTSK and suppressing epithelial-mesenchymal transition. In conclusion, we provide the first evidence for the tumor-suppressing effect of AGAP2-AS1 in EOC and demonstrate that AGAP2-AS1 may represent a promising therapeutic target for EOC patients., Competing Interests: Competing Interests: The authors have declared that no competing interest exists., (© The author(s).)

Long non-coding RNAs (LncRNAs) have attracted increasing attention for their important regulation functions in a wide range of malignancies. AGAP2-AS1 was demonstrated as an oncogene in several cancers, including glioblastoma (GBM). However, the biological mechanisms of AGAP2-AS1 in GBM progression are still unclear. Herein, we found that AGAP2-AS1 expression was up-regulated in GBM tissues and cells. High AGAP2-AS1 expression may predict a poor prognosis in GBM patients. Functionally, silencing of AGAP2-AS1 suppressed proliferation and invasion, while enhanced apoptosis in GBM cells. Overexpression of AGAP2-AS1 promoted cell proliferation and invasion. Mechanically, AGAP2-AS1 could interact with EZH2 and LSD1, recruiting them to TFPI2 promoter region to inhibit its transcription. Moreover, TFPI2 overexpression decreased proliferation and invasion, and facilitated apoptosis in GBM cells. Furthermore, the tumor-suppressive effects mediated by AGAP2-AS1 knockdown were greatly reversed following down-regulation of TFPI2. Also, suppression of AGAP2-AS1 impaired tumor growth of GBM in vivo . In summary, AGAP2-AS1 exerts oncogenic functions in GBM by epigenetically silencing TFPI2 expression through binding to EZH2 and LSD1, illuminating a novel mechanism of AGAP2-AS1 in GBM development and furnishing a prospective therapeutic method to combat GBM.

Long noncoding RNA (lncRNA) AGAP2 antisense RNA 1 (AGAP2-AS1) has been suggested to function as an oncogenic lncRNA in lung cancer, breast cancer, and anaplastic glioma. However, the expression pattern and molecular mechanism of AGAP2-AS1 in glioblastoma multiforme (GBM) remains unknown. The purpose of this study is to present more evidence about the clinical and biological function of AGAP2-AS1 in GBM. In our results, we found AGAP2-AS1 expression was increased in GBM compared with adjacent normal brain tissues or low-grade glioma tissues, and there was no significantly different between low-grade glioma tissues and normal tissues. Kaplan-Meier survival analysis indicated patients with GBM having high-expression of AGAP2-AS1 had shorter overall survival time than those with low expression of AGAP2-AS1. The loss-of-function studies showed that downregulation of AGAP2-AS1 depressed cell proliferation, migration, and invasion, and promoted cell apoptosis in GBM. In summary, AGAP2-AS1 is a prognostic biomarker for patients with GBM, and functions as an oncogenic lncRNA to modulate GBM cell proliferation, apoptosis, migration, and invasion, which suggests that AGAP2-AS1 is potential therapeutic target for GBM., (© 2018 Wiley Periodicals, Inc.)

Background: Long noncoding RNAs (lncRNAs) have emerged as important regulators of tumorigenesis and cancer progression. Recently, the lncRNA AGAP2-AS1 was identified as an oncogenic lncRNA in human non-small cell lung cancer (NSCLC) and its elevated expression was linked to NSCLC development and progression. However, the expression pattern and molecular mechanism of AGAP2-AS1 in gastric cancer (GC) have not been characterized., Methods: Bioinformatic analysis was performed to determine AGAP2-AS1 expression levels in the GC and normal tissues using gene profiling data from the Gene Expression Omnibus. Quantitative real-time polymerase chain reaction was used to validate AGAP2-AS1 expression in the GC tissues/cell lines compared with that in the adjacent nontumorous tissues/normal epithelial cells. Loss- and gain-of-function approaches were performed to investigate the effect of AGAP2-AS1 on GC cell phenotypes. The effect of AGAP2-AS1 on cell proliferation was evaluated by MTT, colony formation, flow cytometry, and in vivo tumor formation assays. The effects of AGAP2-AS1 on cell migration and invasion were examined using Transwell assays. Chromatin immunoprecipitation, luciferase reporter assays, RNA pull-down, and RNA immunoprecipitation were used to investigate the factors involved in AGAP2-AS1 dysregulation and the mechanism of action of AGAP2-AS1 in the GC cells., Results: AGAP2-AS1 was highly expressed in the GC tissues and cell lines, and patients with higher AGAP2-AS1 expression had a poorer prognosis and shorter overall survival. Furthermore, knockdown of AGAP2-AS1 significantly inhibited GC cell proliferation, migration, and invasion in vitro and tumor growth in vivo. AGAP2-AS1 overexpression promoted cell growth and invasion. In addition, the transcription factor SP1 activated AGAP2-AS1 expression in the GC cells. AGAP2-AS1 functions as an oncogenic lncRNA by interacting with LSD1 and EZH2 and suppressing CDKN1A (P21) and E-cadherin transcription., Conclusions: Taken together, these findings imply that AGAP2-AS1 upregulated by SP1 plays an important role in GC development and progression by suppressing P21 and E-cadherin, which suggests that AGAP2-AS1 is a potential diagnostic marker and therapeutic target for GC patients.