lncRNA Biomarkers of Glioblastoma Multiforme.

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.

Identification of long noncoding RNAs downregulated specifically in ovarian high-grade serous carcinoma.

Purpose: To investigate whether long noncoding RNAs (lncRNAs) are involved in the development or malignant behavior of ovarian high-grade serous carcinoma (HGSC), we attempted to identify lncRNAs specific to HGSC. Methods: Total RNAs were isolated from HGSC, normal ovarian, and fallopian tube tissue samples and were subjected to a PCR array that can analyze 84 cancer-associated lncRNAs. The lncRNAs that were upregulated and downregulated in HGSC in comparison to multiple samples of normal ovary and fallopian tube were validated by real-time RT-PCR. To infer the function, ovarian cancer cell lines that overexpress the identified lncRNAs were established, and the activation of cell proliferation, migration, and invasion was analyzed. Results: Eleven lncRNAs (ACTA2-AS1, ADAMTS9-AS2, CBR3-AS1, HAND2-AS1, IPW, LINC00312, LINC00887, MEG3, NBR2, TSIX, and XIST) were downregulated in HGSC samples. We established the cell lines that overexpress ADAMTS9-AS2, CBR3-AS1, or NBR2. In cell lines overexpressing ADAMTS9-AS2, cell proliferation was suppressed, but migration and invasion were promoted. In cell lines overexpressing CBR3-AS1 or NBR2, cell migration tended to be promoted, although cell proliferation and invasion were unchanged. Conclusion: We identified eleven lncRNAs that were specifically downregulated in HGSC. Of these, CBR3-AS1, NBR2, and ADAMTS9-AS2 had unique functions in the malignant behaviors of HGSC.

A review on the role of ADAMTS9-AS2 in different disorders.

Recent decade has seen a tremendous progress in identification of the role of different long non-coding RNAs (lncRNAs) in human pathologies. ADAMTS9-AS2 is an example of lncRNAs with different roles in human disorders. It is mostly acknowledged as a tumor suppressor lncRNA in different types of cancers. However, it has been reported to be up-regulated in tongue squamous cell carcinoma, salivary adenoid cystic carcinoma and glioblastoma. Moreover, ADAMTS9-AS2 is possibly involved in the pathoetiology of pulpitis, acute ischemic stroke, type 2 diabetes and its complications. This lncRNA sponges miR-196b-5p, miR-223-3p, miR-130a-5p, miR-600, miR-223-3p, miR-27a-3p, miR-32, miR-143-3p, miR-143-3p and miR-182-5p in order to regulate downstream mRNAs. This review aims at summarization of the role of ADAMTS9-AS2 in different disorders with a particular focus on its diagnostic and prognostic values.

Melittin inhibits the proliferation migration and invasion of HCC cells by regulating ADAMTS9-AS2 demethylation.

BACKGROUND: Melittin (MEL) has been reported to exhibit anti-cancer effects in vitro against several types of cancer. Long non-coding RNA (lncRNA) ADAMTS9-AS2 can be used as a tumor suppressor. However, there is insufficient data on the potential link between MEL and ADAMTS9-AS2 in hepatocellular carcinoma (HCC). METHODS: RT-qPCR, CCK-8, colony formation, scratch wound healing and transwell assays were used to detect the function of MEL or ADAMTS9-AS2 on HCC cells. Furthermore, Western blot analysis was applied to determine that whether an association existed in MEL or ADAMTS9-AS2 with the PI3K/AKT/mTOR signal pathway. In addition, RT-qPCR and Western blot analysis validated that whether MEL has a demethylation effect. RESULTS: All the experimental data showed that MEL or ADAMTS9-AS2 inhibited the proliferation, migration and invasion of MHCC97-H and HepG2 cells, which may relate to PI3K/AKT/mTOR signal pathway. Moreover, the result showed that MEL treatment inhibited the expression of DNA methyltransferase protein-1 (DNMT1), which acted as the role of demethylation, and then up-regulated the expression of ADAMTS9-AS2, affecting the development of HCC. CONCLUSIONS: ADAMTS9-AS2 played a role in MEL-induced HCC inhibition. This study provided an interesting theoretical basis and further evidence for the potential application of MEL in the treatment of HCC.

ADAMTS9-AS2 regulates PPP1R12B by adsorbing miR-196b-5p and affects cell cycle-related signaling pathways inhibiting the malignant process of esophageal cancer.

This study explored the mechanism that ADAMTS9-AS2/miR-196b-5p/PPP1R12B/cell cycle pathway axis in inhibiting the malignant progression of esophageal cancer (EC), providing a new idea for targeted molecular therapy of EC. The expression data of EC tissue were acquired from TCGA database. The target lncRNA, downstream miRNA and its target gene were determined by bioinformatics analysis. ADAMTS9-AS2, miR-196b-5p and PPP1R12B levels in EC tissue and cells were assayed through qRT-PCR. Western blot was applied to assess protein level of PPP1R12B in cells and tissues, as well as protein expression of CDK1, cyclin A2, cyclin B1 and Plk1 in EC cells. Cell proliferation was assayed via CCK-8 assay. Cell cycle distribution was analyzed by flow cytometry. Cell migratory and invasive abilities were measured through scratch healing and transwell assays. Pearson correlation analysis was utilized to analyze relationship among ADAMTS9-AS2, miR-196b-5p and PPP1R12B. RIP was introduced to assess binding among the three. Dual-luciferase assay was utilized to verify targeted binding sites. The tumor formation in nude mice assay was utilized to detect tumorigenesis of EC cells in vivo. ADAMTS9-AS2 was significantly lowly expressed while miR-196b-5p was increased in EC tissue and cells. ADAMTS9-AS2 bound to miR-196b-5p and constrained its expression. Overexpressed ADAMTS9-AS2 inhibited EC cell malignant progression via downregulating miR-196b-5p, while overexpressed miR-196b-5p reversed this inhibitory effect. ADAMTS9-AS2 modulated PPP1R12B level by competitively inhibiting miR-196b-5p. PPP1R12B played a modulatory role in EC by inhibiting cell cycle pathway. Overexpressed ADAMTS9-AS2 regulated the tumor-forming ability of EC cells in vivo through miR-196b-5p/PPP1R12B/cell cycle signaling pathway axis. ADAMTS9-AS2 downregulated PPP1R12B by adsorbing miR-196b-5p, so as to regulate the cell cycle signaling pathway to inhibit EC malignant progression.

ADAMTS9-AS2 Promotes Angiogenesis of Brain Microvascular Endothelial Cells Through Regulating miR-185-5p/IGFBP-2 Axis in Ischemic Stroke.

Ischemic stroke is a common disease threatening human health. ADAMTS9-AS2 is a lncRNA that has been widely studied in tumors, but not in ischemic stroke. The purpose of this study was to investigate the role and potential molecular mechanism of ADAMTS9-AS2 in endothelial cell function after ischemic stroke in vivo and in vitro. The results showed that ADAMTS9-AS2 was decreased in the plasma of acute ischemic stroke (AIS) patients and in the brain tissue and plasma of MCAO mice, and the low expression of ADAMTS9-AS2 was associated with the increase in infarct size. Besides, compared with the control group, MCAO treatment slightly promoted angiogenesis, which was enhanced by the overexpression of ADAMTS9-AS2. Molecular mechanism results indicated that ADAMTS9-AS2 and miR-185-5p affected the pathological process of ischemic stroke through ceRNA mechanism, and IGFBP-2 was a downstream target gene of miR-185-5p. These findings demonstrated that ADAMTS9-AS2 promoted angiogenesis through regulating miR-185-5p/IGFBP-2 axis, suggesting that ADAMTS9-AS2 may be a potential marker for the diagnosis and treatment of neurological diseases.

LncRNA ADAMTS9-AS2 is a Prognostic Biomarker and Correlated with Immune Infiltrates in Lung Adenocarcinoma.

BACKGROUND: The role of long noncoding RNA (LncRNA) ADAMTS9 antisense RNA 2 (ADAMTS9-AS2) is unclear in lung adenocarcinoma (LUAD). The aim of this study was to explore the relationship between ADAMTS9-AS2 and LUAD, based on The Cancer Genome Atlas (TCGA) database and bioinformatics analysis. METHODS: Various statistical methods, Kaplan-Meier method, Cox regression analysis, GSEA, and immune infiltration analysis were used to evaluate the relationship between clinical features and ADAMTS9-AS2 expression, prognostic factors, and the significant involvement of ADAMTS9-AS2 in function. RESULTS: In LUAD patients, low expression of ADAMTS9-AS2 was associated with N stage (P=0.011), gender (P=0.002), number of packs smoked (P=0.024) and smoker (P<0.001). Low ADAMTS9-AS2 expression predicted a poorer overall survival (OS) (HR: 0.68; 95% CI: 0.51-0.91; P=0.01). And ADAMTS9-AS2 expression (HR: 0.626; 95% CI: 0.397-0.986; P=0.043) was independently correlated with OS in LUAD patients. Unwinding of DNA, extrinsic pathway, polo-like kinase-mediated events, cori cycle, MCM pathway, proteasome pathway, lagging strand synthesis and PCNA-dependent long patch base excision repair were differentially enriched in ADAMTS9-AS2 high expression phenotype. ADAMTS9-AS2 expression was correlated with certain immune infiltrating cells. CONCLUSION: In LUAD patients, ADAMTS9-AS2 expression was significantly associated with poor survival and immune infiltration. ADAMTS9-AS2 may be a promising biomarker of prognosis and response to immunotherapy for LUAD.

Bioinformatics Analysis and Functional Verification of ADAMTS9-AS1/AS2 in Lung Adenocarcinoma.

Long non-coding RNAs (lncRNAs), as competitive endogenous RNAs (ceRNAs), play a critical role in biological processes of cancer. However, the roles of specific lncRNAs in ceRNA network of lung adenocarcinoma (LUAD) remains largely unclear. Herein, we identified the roles of lncRNA ADAMTS9-AS1/AS2 (ADAMTS-AS1/AS2) in lung adenocarcinoma by bioinformatics analyses and functional verification. First, differentially expressed genes ADAMTS9-AS1, ADAMTS9-AS2 and ADAMTS9 were screened out from GSE130779. Then the expression correlation of these three genes was analyzed. The results showed that ADAMTS9-AS1, ADAMTS9-AS2 and ADAMTS9 were down-regulated in LUAD, and were positively correlated with each other. After that, miRcode was used to find miR-150 which binds to ADAMTS9-AS1/ADAMTS9-AS2/ADAMTS9. Next, co-expression analysis and functional enrichment analyses were performed to further analyze differentially expressed genes. The results showed that the differentially expressed genes were mainly enriched in Beta3 integrin cell surface interactions and epithelial-to-mesenchymal transition. Finally, the cell functions of ADAMTS9-AS1 and ADAMTS9-AS2 in A549 and NCI-H1299 cell lines were verified. In vitro cell studies confirmed that ADAMTS9-AS1 and ADAMTS9-AS2 play an inhibitory role in LUAD cells.

The diagnostic significance of circulating lncRNA ADAMTS9-AS2 tumor biomarker in non-small cell lung cancer among the Egyptian population.

BACKGROUND: Long non-coding RNA ADAM metallopeptidase with thrombospondin type 1 motif, 9 antisense RNA 2 (ADAMTS9-AS2) was recognized as a novel tumor suppressor and plays an important role in the initiation and progression of malignant behavior in human cancers, although its plasma expression and clinical value in patients with non-small cell lung cancer (NSCLC) remain unknown. We aimed to analyze the diagnostic role of ADAMTS9-AS2 and cytokeratin 19 fragmentation antigen (CYFRA 21-1) in NSCLC. METHODS: The present study included 80 control subjects, 80 patients with benign lung lesion and 80 NSCLC patients. The expression of ADAMTS9-AS2 in the tissue and plasma was detected by a real-time polymerase chain reaction. Serum CYFRA 21-1 was analyzed using an enzyme-linked immunosorbent assay. RESULTS: In comparison with benign lung lesion and controls, tissue and plasma ADAMTS9-AS2 expression were significantly down-regulated in NSCLC (p < 0.001). Decreased ADAMTS9-AS2 expression was associated with TNM stages in NSCLC patients (p < 0.001). Up-regulation of CYFRA 21-1 was reported among NSCLC patients and it was associated with TNM staging. Tissue and plasma ADAMTS9-AS2 expression levels were the predicting factors for NSCLC and they both correlated negatively with CYFRA 21-1 levels. Plasma ADAMTS9-AS2 levels had a significant positive correlation with their tumor tissue levels. Plasma ADAMTS9-AS2 showed a higher sensitivity (95%) and specificity (99.1%) in the diagnosis of NSCLC than CYFRA 21-1 (61.3% sensitivity and 60% specificity). CONCLUSIONS: Our results suggested that decreased plasma ADAMTS9-AS2 expression might act as a novel non-invasive tumor biomarker in NSCLC diagnosis. Furthermore, plasma ADAMTS9-AS2 might predict aggressive tumor behavior.

The lncRNA ADAMTS9-AS2 Regulates RPL22 to Modulate TNBC Progression via Controlling the TGF-ß Signaling Pathway.

BACKGROUND: Long non-coding RNAs (lncRNAs) are key regulators of triple-negative breast cancer (TNBC) progression, but further work is needed to fully understand the functional relevance of these non-coding RNAs in this cancer type. Herein, we explored the functional role of the lncRNA ADAMTS9-AS2 in TNBC. METHODS: Next-generation sequencing was conducted to compare the expression of different lncRNAs in TNBC tumor and paracancerous tissues, after which ADAMTS9-AS2differential expression in these tumor tissues was evaluated via qPCR. The functional role of this lncRNA was assessed by overexpressing it in vitro and in vivo. FISH and PCR were used to assess the localization of ADAMTS9-AS2within cells. Downstream targets of ADAMTS9-AS2 signaling were identified via RNA pulldown assays and transcriptomic sequencing. RESULTS: The expression ofADAMTS9-AS2 was decreased in TNBC tumor samples (P < 0.05), with such downregulation being correlated with TNM stage, age, and tumor size. Overexpressing ADAMTS9-AS2 promoted the apoptotic death and cell cycle arrest of tumor cells in vitro and inhibited tumor growth in vivo. From a mechanistic perspective, ADAMTS9-AS2 was found to control the expression of RPL22 and to thereby modulate TGF-ß signaling to control TNBC progression. CONCLUSION: ADAMTS9-AS2 controls the expression of RPL22 and thereby regulates TNBC malignancy via the TGF-ß signaling pathway.

Long non-coding RNA ADAMTS9-AS2 inhibits liver cancer cell proliferation, migration and invasion.

Long non-coding RNA (lncRNA) ADAM metallopeptidase with thrombospondin type 1 motif 9 antisense RNA 2 (ADAMTS9-AS2) is involved in various types of cancer, such as ovarian cancer, lung cancer and clear cell renal cell carcinoma. However, the roles of ADAMTS9-AS2 in liver cancer are not completely understood. The present study aimed to determine the functional role of ADAMTS9-AS2 in human liver cancer and investigate the potential underlying molecular mechanisms. The expression levels of ADAMTS9-AS2 and ADAMTS9 were determined following ADAMTS9-AS2 overexpression and knockdown. The results indicated that ADAMTS9-AS2 overexpression and knockdown increased and decreased ADAMTS9 mRNA and protein expression levels, respectively, indicating that alterations in ADAMTS9 expression corresponded with ADAMTS9-AS2 expression. Subsequently, the effects of ADAMTS9-AS2 on liver cancer cell proliferation, migration and invasion were analyzed by performing Cell Counting Kit-8, wound healing and Transwell assays, respectively. The results demonstrated that ADAMTS9-AS2 inhibited liver cancer cell proliferation, migration and invasion. Finally, the effect of ADAMTS9 on PI3K/AKT/mTOR signaling pathway-associated proteins [AKT, phosphorylated-AKT, phosphatidylinositol-4, 5-bisphosphate 3-kinase catalytic subunit ß (PIK3CB), mTOR and phosphorylated-mTOR], several key autophagy-related proteins [light chain 3-I/II (LC3-I/II), beclin 1 (BECN1) and sequestosome 1 (SQSTM1)] and apoptosis-related proteins (Bax and Bcl-2) was detected via western blotting. The results suggested that ADAMTS9-AS2 downregulated the phosphorylation of AKT and mTOR, the protein expression level of PIK3CB, as well as the expression levels of autophagy protein SQSTM1 and antiapoptotic protein Bcl-2. By contrast, ADAMTS9-AS2 upregulated the expression levels of autophagy proteins LC3-II and BECN1, and the proapoptotic protein Bax. Collectively, ADAMTS9-AS2 inhibited liver cancer cell proliferation, migration and invasion via inhibiting the PI3K/AKT/mTOR signaling pathway. The present study provided a novel insight into the role of ADAMTS9-AS2 in liver cancer.

ADAMTS9-AS2: A Functional Long Non-coding RNA in Tumorigenesis.

BACKGROUND: Long non-coding RNAs (lncRNA) have been identified as novel molecular regulators in cancers. LncRNA ADAMTS9-AS2 can mediate the occurrence and development of cancer through various ways, such as regulating miRNAs, activating the classical signaling pathways in cancer, and so on, which have been studied by many scholars. In this review, we summarize the molecular mechanisms of ADAMTS9-AS2 in different human cancers. METHODS: Through a systematic search of PubMed, lncRNA ADAMTS9-AS2 mediated molecular mechanisms in cancer are summarized inductively. RESULTS: ADAMTS9-AS2 aberrantly expression in different cancers is closely related to cancer proliferation, invasion, migration, and inhibition of apoptosis. The involvement of ADAMTS9-AS2 in DNA methylation, mediating PI3K / Akt / mTOR signaling pathways, and regulating miRNAs and proteins, shows its significant potential as a therapeutic cancer target. CONCLUSION: LncRNA ADAMTS9-AS2 can become a promising biomolecular marker and a therapeutic target for human cancer.

Long-Chain Noncoding RNA ADAMTS9-AS2 Regulates Proliferation, Migration, and Apoptosis in Bladder Cancer Cells Through Regulating miR-182-5p.

The long-chain noncoding RNA ADAMTS9-AS2 functions as a tumor suppressor gene in many cancers. However, the underlying mechanism remains to be fully elucidated in bladder cancer (BC). ADAMTS9-AS2 exhibited a lower expression level in BC samples and cell lines. In addition, overexpression of ADAMTS9-AS2 obviously suppressed proliferation and migration, and induced apoptosis of T24 cells, while transfection with the ADAMTS9-AS2 inhibitor had opposite results in 5637 cells. Furthermore, miR-182-5p was the target microRNA of ADAMTS9-AS2 and was negatively correlated with ADAMTS9-AS2 expression. Upregulation of miR-182-5p reversed the effects of ADAMTS9-AS2 overexpression on biological function in T24 cells. ADAMTS9-AS2 was a tumor suppressor that inhibited BC cell proliferation and induced cellular apoptosis by targeting miR-182-5p, and it could be a promising target for BC treatment.

Construction of a novel ceRNA network and identification of lncRNA ADAMTS9-AS2 and PVT1 as hub regulators of miRNA and coding gene expression in gastric cancer.

BACKGROUND: Studies on the interactions of single long non-coding RNA, microRNA, and mRNA have many limitations; therefore, it is necessary to study the complex regulatory network of gastric cancer (GC) pathogenesis systematically. METHODS: In this study, gene and miRNA expression data for GC were downloaded from The Cancer Genome Atlas and used for transcriptome profiling, differential gene analysis, and construction of an lncRNA-miRNA-mRNA regulatory network in conjunction with an online database to identify the key genes and subnetworks in GC pathogenesis. Real-time quantitative polymerase chain reaction was used to detect the expression of hub lncRNAs in 54 paired GC and matched normal mucosal tissues. RESULTS: We constructed an lncRNA-miRNA-mRNA competitive endogenous RNA regulatory network containing 1,626 network nodes and 2,704 interactions. LncRNA ADAMTS9-AS2 and PVT1 were identified as key node genes in this competitive endogenous RNA network. Quantitative reverse transcription-polymerase chain reaction revealed ADAMTS9-AS2 downregulation and PVT1 upregulation in 54 pairs of GC and normal tissues adjacent to the cancer tissues. CONCLUSIONS: This study systematically analysed the lncRNA-miRNA-mRNA regulatory network in GC and identified ADAMTS9-AS2 and PVT1 as key regulatory genes in this network, providing new understanding of GC pathogenesis and insights for its early diagnosis and treatment.

Exosome-derived long non-coding RNA ADAMTS9-AS2 suppresses progression of oral submucous fibrosis via AKT signalling pathway.

Oral submucosal fibrosis (OSF) is one of the pre-cancerous lesions of oral squamous cell carcinoma (OSCC). Its malignant rate is increasing, but the mechanism of malignancy is not clear. We previously have elucidated the long non-coding RNA (lncRNA) expression profile during OSF progression at the genome-wide level. However, the role of lncRNA ADAMTS9-AS2 in OSF progression via extracellular communication remains unclear. lncRNA ADAMTS9-AS2 is down-regulated in OSCC tissues compared with OSF and normal mucous tissues. Low ADAMTS9-AS2 expression is associated with poor overall survival. ADAMTS9-AS2 is frequently methylated in OSCC tissues, but not in normal oral mucous and OSF tissues, suggesting tumour-specific methylation. Functional studies reveal that exosomal ADAMTS9-AS2 suppresses OSCC cell growth, migration and invasion in vitro. Mechanistically, exosomal ADAMTS9-AS2 inhibits AKT signalling pathway and regulates epithelial-mesenchymal transition markers. Through profiling miRNA expression profile regulated by exosomal ADAMTS9-AS2, significantly enriched pathways include metabolic pathway, PI3K-Akt signalling pathway and pathways in cancer, indicating that exosomal ADAMTS9-AS2 exerts its functions through interacting with miRNAs during OSF progression. Thus, our findings highlight the crucial role of ADAMTS9-AS2 in the cell microenvironment during OSF carcinogenesis, which is expected to become a marker for early diagnosis of OSCC.

ADAMTS9-AS2 and CADM2 expression and association with the prognosis in esophageal squamous cell carcinoma.

Background: We investigated whether ADAMTS9-AS2 and CADM2 were related to esophageal squamous cell carcinoma (ESCC). Methodology: ESCC microarray datasets and reverse transcriptase qualitative PCR were used to analyze ADAMTS9-AS2 and CADM2 expression. Results: The GSE120356 and GSE33810 datasets identified ADAMTS9-AS2 and CADM2 as the candidates and ADAMTS9-AS2 and CADM2 expression was downregulated in ESCC. ADAMTS9-AS2 and CADM2 were positively correlated with ESCC. ADAMTS9-AS2 and CADM2 expression could discriminate ESCC from normal tissue. Five-year overall survival was shorter in underexpressed ADAMTS9-AS2 patients, and CADM2 expression level was related to 5-year overall survival. ADAMTS9-AS2 and CADM2 expression were independent prognosis indicators in ESCC patients. Conclusion: Our findings shed new light on the clinical significance of ADAMTS9-AS2 and CADM2 in ESCC carcinogenesis.

Long Noncoding RNA ADAMTS9-AS2 Inhibits the Proliferation, Migration, and Invasion in Bladder Tumor Cells.

BACKGROUND: Bladder tumor is the fifth most prevalent tumor in men, yet its pathogenesis remains to be fully identified. Albeit a host of long noncoding RNAs (lncRNA) are emerging as new players involved in bladder tumor, the functions of many lncRNAs are still enigmatic. Reports on the deluge of studies on lncRNA ADAMTS9-AS2 have been convincingly associated with various tumors, but without mention of its roles in bladder tumor. Therefore, the roles of ADAMTS9-AS2 in bladder tumor cells were explored in our study. MATERIALS AND METHODS: Quantitative real-time PCR assays and bioinformatic tools were applied in bladder tumor cells to identify the ADAMTS9-AS2 and ADAMTS9 expression. Western blot assays were performed to obtain the protein levels of bladder tumor related key molecules. CCK8, clonogenic assay, scratch wound healing, and transwell assays were separately applied to identify the functional roles of ADAMTS9-AS2 on proliferation, migration, and invasion in bladder tumor cells. RESULTS: First, ADAMTS9-AS2 downregulation in bladder tumor cells was identified. Overexpression and knockdown experiments showed that ADAMTS9-AS2 expression was positively related to ADAMTS9, which is in accordance with the results from GEO database. Second, ADAMTS9-AS2 contributed to the inhibition of proliferation, migration, and invasion in bladder tumor cells. Third, ADAMTS9-AS2 was linked with PI3K/AKT/mTOR pathway related-molecules, several key autophagy, and apoptotic proteins. CONCLUSION: Conjointly, our findings suggested that ADAMTS9-AS2 might function as a tumor suppressor to restrain the proliferation, migration, and invasion in bladder tumor cells. The potential mechanism of ADAMTS9-AS2 related to PI3K/AKT/mTOR signal pathway was further identified. Of note, we found that ADAMTS9-AS2 has a significant effect on several key autophagy and apoptotic proteins. Therefore, these observations will provide supportive evidence to ADAMTS9-AS2 as a potential biomarker in patients with bladder tumor.

LncRNA ADAMTS9-AS2 inhibits gastric cancer (GC) development and sensitizes chemoresistant GC cells to cisplatin by regulating miR-223-3p/NLRP3 axis.

The role of LncRNA ADAMTS9-AS2 in the regulation of chemoresistance of gastric cancer (GC) is largely unknown. Here we found that LncRNA ADAMTS9-AS2 was low-expressed in GC tissues and cells compared to their normal counterparts. In addition, LncRNA ADAMTS9-AS2 inhibited miR-223-3p expressions in GC cells by acting as competing endogenous RNA, and the levels of LncRNA ADAMTS9-AS2 and miR-223-3p showed negative correlations in GC tissues. Of note, overexpression of LncRNA ADAMTS9-AS2 inhibited GC cell viability and motility by sponging miR-223-3p. In addition, the levels of LncRNA ADAMTS9-AS2 were lower, and miR-223-3p was higher in cisplatin-resistant GC (CR-GC) cells than their parental cisplatin-sensitive GC (CS-GC) cells. LncRNA ADAMTS9-AS2 overexpression enhanced the cytotoxic effects of cisplatin on CR-GC cells, which were reversed by overexpressing miR-223-3p. Furthermore, LncRNA ADAMTS9-AS2 increased NLRP3 expressions by targeting miR-223-3p, and upregulation of LncRNA ADAMTS9-AS2 triggered pyroptotic cell death in cisplatin treated CR-GC cells by activating NLRP3 inflammasome through downregulating miR-223-3p. Finally, the promoting effects of LncRNA ADAMTS9-AS2 overexpression on CR-GC cell death were abrogated by pyroptosis inhibitor Necrosulfonamide (NSA). Collectively, LncRNA ADAMTS9-AS2 acted as a tumor suppressor and enhanced cisplatin sensitivity in GC cells by activating NLRP3 mediated pyroptotic cell death through sponging miR-223-3p.

LncRNA ADAMTS9-AS2 suppresses the proliferation of gastric cancer cells and the tumorigenicity of cancer stem cells through regulating SPOP.

Nowadays, research on CSCs is still in an initial stage, and there are few studies reporting the successful isolation and identification of CSCs. In the present study, we attempted to isolate CSCs through cultivating the cell line MKN45 in defined serum-free medium and study the expression of stem cell markers or related proteins (Oct3/4, Sox2, Nanog and CD44) in CSCs. Moreover, immunofluorescence staining was performed to validate the stem cell markers of spheroid body-forming cells. Further experiments were used to evaluate the SPOP expression in tumorsphere cells. In addition, ADAMTS9-AS2 is a lncRNA that contributes to the genesis and development of many cancers, including gastric cancer (GC). We found ADAMTS9-AS2 functioned as an anti-oncogene and positively correlated with the expression of SPOP in GC tissues by combining bioinformatics analyses. Furthermore, we reported that ADAMTS9-AS2 regulated the expression of SPOP in GC cells and tumorsphere cells to inhibit GC progression. Together, our results demonstrated that SPOP and ADAMTS9-AS2 can be potential targets for GC treatment.

Long noncoding RNA ADAMTS9-AS2 suppresses the progression of esophageal cancer by mediating CDH3 promoter methylation.

Long noncoding RNAs (lncRNAs) have been implicated in the biology of esophageal cancer via mRNA degradation or translational inhibition. CDH3 is also aberrantly expressed in numerous cancers. This study was conducted with the hypothesis that ADAMTS9-AS2 or CDH3 methylation plays a role in esophageal cancer cell activity and in vivo development. Firstly, mRNA levels of ADAMTS9-AS2 and CDH3 in esophageal cancer tissues and cells were detected by reverse-transcription quantitative polymerase chain reaction. Afterward, esophageal cancer OE21 cells were treated with overexpression of ADAMTS9-AS2, siRNA against ADAMTS9-AS2, overexpression of CDH3 and demethylating agent 5-aza-dc. The biological functions of esophageal cancer OE21 cells were assayed to define the regulatory mechanisms of ADAMTS9-AS2 in esophageal cancer. The interactions among ADAMTS9-AS2, DNMT1/DNMT3 (A/B) and CDH3 were detected by MSP, RNA pull-down, RIP, and ChIP assays. The in vitro findings were reproduced in nude mice to explore the role of ADAMTS9-AS2 in the development of esophageal cancer in vivo. Esophageal cancers expressed low levels of ADAMTS9-AS2 and high levels of CDH3. Methylation of CDH3 promoter was induced by ADAMTS9-AS2 via DNMT1/DNMT3 (A/B). Furthermore, proliferation, invasion, and migration of esophageal cancer cells were inhibited by ADAMTS9-AS2 via downregulation of CDH3. Suppressed esophageal cancer development in vivo was also detected after ADAMTS9-AS2 overexpression. Overexpressed ADAMTS9-AS2 aids in the suppression of esophageal cancer development, which is achieved via inducing CDH3 promoter methylation.