LncRNA LINC00942 promotes chemoresistance in gastric cancer by suppressing MSI2 degradation to enhance c-Myc mRNA stability.

BACKGROUND: Chemoresistance to cisplatin (DDP) remains a major challenge in advanced gastric cancer (GC) treatment. Although accumulating evidence suggests an association between dysregulation of long non-coding RNAs (lncRNAs) and chemoresistance, the regulatory functions and complexities of lncRNAs in modulating DDP-based chemotherapy in GC remain under-investigated. This study was designed to explore the critical chemoresistance-related lncRNAs in GC and identify novel therapeutic targets for patients with chemoresistant GC. METHODS: Chemoresistance-related lncRNAs were identified through microarray and verified through a quantitative real-time polymerase chain reaction (qRT-PCR). Proteins bound by lncRNAs were identified through a human proteome array and validated through RNA immunoprecipitation (RIP) and RNA pull-down assays. Co-immunoprecipitation and ubiquitination assays were performed to explore the molecular mechanisms of the Musashi2 (MSI2) post-modification. The effects of LINC00942 (LNC942) and MSI2 on DDP-based chemotherapy were investigated through MTS, apoptosis assays and xenograft tumour formation in vivo. RESULTS: LNC942 was found to be up-regulated in chemoresistant GC cells, and its high expression was positively correlated with the poor prognosis of patients with GC. Functional studies indicated that LNC942 confers chemoresistance to GC cells by impairing apoptosis and inducing stemness. Mechanically, LNC942 up-regulated the MSI2 expression by preventing its interaction with SCFß-TRCP E3 ubiquitin ligase, eventually inhibiting ubiquitination. Then, LNC942 stabilized c-Myc mRNA in an N6-methyladenosine (m6 A)-dependent manner. As a potential m6 A recognition protein, MSI2 stabilized c-Myc mRNA with m6 A modifications. Moreover, inhibition of the LNC942-MSI2-c-Myc axis was found to restore chemosensitivity both in vitro and in vivo. CONCLUSIONS: These results uncover a chemoresistant accelerating function of LNC942 in GC, and disrupting the LNC942-MSI2-c-Myc axis could be a novel therapeutic strategy for GC patients undergoing chemoresistance.

Knockdown of HCG18 Inhibits Cell Viability, Migration and Invasion in Pediatric Osteosarcoma by Targeting miR-188-5p/FOXC1 Axis.

Understanding the underlying mechanisms of pediatric osteosarcoma (OS) migration and invasion is important for prognosis and treatment. We tried to measure the expression of long non-coding RNA HLA complex group 18 (HCG18) in OS and reveal its function in the malignant behaviors of OS cells. This study detected the expression of HCG18, miR-188-5p and forkhead box C1 (FOXC1) in OS tissues and cell lines by quantitative real-time PCR (qRT-PCR). The relevance between miR-188-5p and HCG18 or FOXC1 was affirmed by dual-luciferase reporter (DLR) assay. Cell viability was analyzed by MTT assay. Transwell assay was utilized to test cell invasion and migration. FOXC1 protein expression was detected by western blot. HCG18 expression was elevated in OS tissues, and enhanced HCG18 expression was related to metastasis. HCG18 silencing repressed the viability, migration and invasion of OS cells. Moreover, HCG18 interacted with miR-188-5p. MiR-188-5p up-regulation repressed cell viability, invasion and migration in OS cells. FOXC1, a known target of miR-188-5p, was negatively modulated by miR-188-5p. Furthermore, miR-188-5p inhibition or FOXC1 over-expression partially abolished the reduced of cell viability, invasion and migration mediated by HCG18 silencing in OS cell lines. This study revealed that HCG18 knockdown repressed the viability, invasion and migration of OS cells by targeting miR-188-5p and regulating FOXC1 expression. Thus, HCG18/ miR-188-5p/FOX may be a hopeful target for OS therapy.

HOXBLINC long non-coding RNA activation promotes leukemogenesis in NPM1-mutant acute myeloid leukemia.

Nucleophosmin (NPM1) is the most commonly mutated gene in acute myeloid leukemia (AML) resulting in aberrant cytoplasmic translocation of the encoded nucleolar protein (NPM1c+). NPM1c+ maintains a unique leukemic gene expression program, characterized by activation of HOXA/B clusters and MEIS1 oncogene to facilitate leukemogenesis. However, the mechanisms by which NPM1c+ controls such gene expression patterns to promote leukemogenesis remain largely unknown. Here, we show that the activation of HOXBLINC, a HOXB locus-associated long non-coding RNA (lncRNA), is a critical downstream mediator of NPM1c+-associated leukemic transcription program and leukemogenesis. HOXBLINC loss attenuates NPM1c+-driven leukemogenesis by rectifying the signature of NPM1c+ leukemic transcription programs. Furthermore, overexpression of HoxBlinc (HoxBlincTg) in mice enhances HSC self-renewal and expands myelopoiesis, leading to the development of AML-like disease, reminiscent of the phenotypes seen in the Npm1 mutant knock-in (Npm1c/+) mice. HoxBlincTg and Npm1c/+ HSPCs share significantly overlapped transcriptome and chromatin structure. Mechanistically, HoxBlinc binds to the promoter regions of NPM1c+ signature genes to control their activation in HoxBlincTg HSPCs, via MLL1 recruitment and promoter H3K4me3 modification. Our study reveals that HOXBLINC lncRNA activation plays an essential oncogenic role in NPM1c+ leukemia. HOXBLINC and its partner MLL1 are potential therapeutic targets for NPM1c+ AML.

Long non coding RNA SLC26A4-AS1 exerts antiangiogenic effects in human glioma by upregulating NPTX1 via NFKB1 transcriptional factor.

Malignant gliomas are a heterogeneous group of brain tumors with a poor prognosis, which is largely due to its aggressive invasiveness and angiogenesis. In recent years, it has been found that multiple long noncoding RNAs (lncRNAs) participate in a wide range of biological functions including angiogenesis through the regulation of gene expression in cancers. In this study, we investigate and report the novel role of lncRNA SLC26A4-AS1 in gliomas, with a novel mechanism involving transcription factors NFKB1 and NPTX1. We determined that SLC26A4-AS1 was downregulated in human glioma tissues and cells. Furthermore, overexpression of SLC26A4-AS1 or NPTX1 restrained the aggressiveness of glioma cells and their pro-angiogenic ability. SLC26A4-AS1 was also found to upregulate NPTX1 by recruiting NFKB1 into the NPTX1 promoter. Moreover, silencing of either NPTX1 or NFKB1 restored the aggressive and pro-angiogenic properties of glioma cells in the presence of SLC26A4-AS1. Taken together, we demonstrate that SLC26A4-AS1 promotes NPTX1 transcriptional activity by recruiting NFKB1 and thus exerting antiangiogenic effects on glioma cells. This study provides an experimental basis for the intervention of SLC26A4-AS1 in the treatment of gliomas.

Targeting MALAT1 induces DNA damage and sensitize non-small cell lung cancer cells to cisplatin by repressing BRCA1.

PURPOSE: Metastasis-associated lung adenocarcinoma transcript 1 (MALAT1) is a long non-coding RNA which has been identified to be involved in alternative non-homologous end joining (A-NHEJ) pathways by binding with PARP1 and LIG3 in myeloma cells. This study aims to explore the roles of MALAT1 in DNA repair processes in non-small cell lung cancer (NSCLC). METHODS: The interactions between MALAT1 and proteins were identified by co-immunoprecipitation and RNA pulldown. The interactions between MALAT1 and microRNAs (miRNA) were predicted by bioinformatics tools and confirmed by luciferase assay and RNA pulldown. The DNA damages were quantified by comet assay. The cell viability was examined by MTT assay and the cell apoptosis was determined by flow cytometry. RESULTS: MALAT1 is identified to be involved in A-NHEJ pathway in NSCLC cells. However, in LIG3-null cells where A-NHEJ pathway is inactivated, targeting MALAT1 still increases DNA damages, suggesting that MALAT1 participates in other DNA repair pathways. Subsequently, MALAT1 is identified to bind with miR-146a and miR-216b, which directly target the 3'UTR of BRCA1. MALAT1 is confirmed to functions as a competing endogenous RNA (ceRNA) absorbing miR-146a and miR-216b, upregulating BRCA1 expression and protecting Homologous Recombination (HR) pathway in NSCLC cells. Finally, overexpression MALAT1 protects NSCLC cells from the cytotoxic effect of cisplatin. While, targeting MALAT1 in NSCLC cells induces DNA damages by repressing HR pathway and sensitizes NSCLC cells to cisplatin which had the potential for NSCLC treatment. CONCLUSION: MALAT1 is involved in HR pathway by protecting BRCA1 and targeting MALAT1 induces DNA damages in NSCLC.

Long non-coding RNAs engender drug resistance to different subtypes of treatments of breast cancers and may provide a "next generation" therapy option.

The dysfunction of long non-coding RNAs (lncRNAs), without protein-coding potential, has been implicated in drug resistance against treatment in various human diseases, especially in malignant tumors. As the most common-diagnosed female malignancy worldwide, breast cancer is also the second-leading cause of cancer-related mortality in women. Despite the improvement in neo-adjuvant therapy, endocrine therapy, molecular-targeted treatment, and chemotherapy, drug resistance to various treatment regimens is still quite prevalent. This article focused on the lncRNAs and their functions in drug resistance against breast cancer therapeutic agents, in order to develop new precise treatment strategies for patients with breast cancers. The discovery of lncRNA opened new doors to the molecular mechanisms of the biological processes, and has provided new pathways to regulate biochemical events. Thus, lncRNAs may be developed as a biomarker for the detection and/or prevention of breast cancer. Additionally, lncRNA-based approaches may provide an additional treatment modality in personalized medicine alone or in combination with existing tumor-directed interventions to improve patient outcomes. In conclusion, lncRNAs molecules may represent the "next generation" therapy option for breast cancer patients.

lncRNA LA16c­313D11.11 modulates the development of endometrial cancer by binding to and inhibiting microRNA­205­5p function and indirectly increasing PTEN activity.

The aim of the present study was to determine the competitive endogenous RNA (ceRNA) network associated with long­coding RNA (lncRNA) LA16c­313D11.11 in endometrial cancer (EC). Initially, the expression levels of LA16c­313D11.11 in 60 EC tissues, 20 atypical hyperplasia endometrium (EAH) tissues and 20 normal endometrium tissues was determined. MicroRNA (miRNA/miR)­205­5p mimics and LA16c­313D11.11 mimics were transfected into HEC­1A and Ishikawa cells. The expression levels of miR­205­5p, LA16c­313D11.11 and their target proteins were assessed using reverse transcription­quantitative PCR or western blot analysis. Flow cytometry, Cell Counting kit­8 assays, Transwell migration assays and wound healing assays were performed to assess the effects of LA16c­313D11.11 and miR­205­5p on the migration and proliferation of tumor cells in vitro. The expression levels of LA16c­313D11.11 and phosphatase and tensin homolog deleted on chromosome ten (PTEN) in human EAH and EC tissues were significantly decreased, whereas the expression levels of miR­205­5p in EAH and EC tissues were significantly increased, compared with the normal endometrium tissues. The expression of LA16c­313D11.11 in human EC tissues negatively correlated with the expression of miR­205­5p. Additionally, the overexpression of LA16c­313D11.11 significantly reduced the invasion, migration and viability of HEC­1A and Ishikawa cells in vitro. LA16c­313D11.11 was shown to regulate the expression of PTEN, and the invasion, migration and viability of HEC­1A and Ishikawa cells, through its microRNA response element to compete for microRNA­205­5p. LA16c­313D11.11 was also shown to modulate the PI3K/AKT signaling pathway. Therefore, LA16c­313D11.11 acts as an effective ceRNA associated with a microRNA­205­5p­PTEN axis. LA16c­313D11.11 may inhibit the development and progression of EC by acting as a sponge of miR­205­5p, thus indirectly increasing the expression of PTEN.

Long noncoding RNA MALAT-1 inhibits apoptosis and matrix metabolism disorder in interleukin-1ß-induced inflammation in articular chondrocytes via the JNK signaling pathway.

Proinflammatory cytokine such as interleukin (IL)-1ß causes inflammation of articular cartilage. In this current study, we explored the chondroprotective effects of long noncoding RNA (lncRNA) MALAT-1 on cell proliferation, apoptosis, and matrix metabolism in IL-1ß-induced inflammation in articular chondrocytes. Articular chondrocytes from knee joints of normal rats were isolated and cultured, followed by identification through observation of toluidine blue and COL II immunocytochemical stainings. The proliferation of chondrocytes at passage 2 was detected by the 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2H-tetrazolium bromide (MTT) assay. The inflammatory chondrocytes induced by 10 ng/mL IL-1ß were observed and identified by toluidine blue and COL II immunocytochemical stainings. pcDNA 3.1 and pcDNA-MALAT-1 were transfected in the chondrocytes. Ultrastructure of chondrocytes was observed by using a transmission electron microscope. The MTT assay was carried out to evaluate chondrocyte viability. Hoechst 33258 staining and flow cytometry were adopted to assess chondrocyte apoptosis. The chondrocytes at passage 2 with the biological characteristics of chondrocytes were used for subsequent experiments. In IL-1ß-treated chondrocytes, the growth rate of chondrocytes slowed down, the cells became narrow and long, the vacuoles were seen in the cells, and the morphology of the chondrocytes was irregular. The toluidine blue staining and the immunohistochemical staining of COL II became weaker. In response to IL-1ß induction, articular chondrocytes showed reduced MALAT-1 expression; moreover, obvious cartilage injury was observed with decreased chondrocyte viability and Col II expression and elevated chondrocyte apoptosis, MMP-13 expression, and p-JNK expression. With the treatment of pcDNA-MALAT-1, the cartilage injury was alleviated with increased chondrocyte viability and type II collagen (Col II) expression and reduced chondrocyte apoptosis, MMP-13 expression and p-JNK expression. Taken together these results, lncRNA MALAT-1 blocked the activation of the JNK signaling pathway; thereby, IL-1ß-induced inflammation in articular chondrocytes was reduced with enhanced chondrocyte proliferation and suppressed chondrocyte apoptosis and extracellular matrix degradation.

HCP5 is a SMAD3-responsive long non-coding RNA that promotes lung adenocarcinoma metastasis via miR-203/SNAI axis.

Introduction: Transforming growth factor-beta (TGFß) signaling plays a vital role in lung adenocarcinoma (LUAD) progression. However, the involvement of TGFß-regulated long non-coding RNAs (lncRNAs) in metastasis of LUAD remains poorly understood. Methods: We performed bioinformatic analyses to identify putative lncRNAs regulated by TGF-ß/SMAD3 and validated the results by quantitative PCR in LUAD cells. We performed luciferase reporter and chromatin immunoprecipitation assays to demonstrate the transcriptional regulation of the lncRNA histocompatibility leukocyte antigen complex P5 (HCP5) we decided to focus on. Stable HCP5 knockdown and HCP5-overexpressing A549 cell variants were generated respectively, to study HCP5 function and understand its mechanism of action. We also confirmed our findings in mouse xenografts and metastasis models. We analyzed the correlation between the level of lncRNA expression with EGFR, KRAS mutations, smoke state and prognostic of LUAD patients. Results: We found that the lncRNA HCP5 is induced by TGFß and transcriptionally regulated by SMAD3, which promotes LUAD tumor growth and metastasis. Moreover, HCP5 is overexpressed in tumor tissues of patients with LUAD, specifically in patients with EGFR and KRAS mutations and current smoker. HCP5 high expression level is positively correlated with poor prognosis of patients with LUAD. Finally, we demonstrated that upregulation of HCP5 increases the expression of Snail and Slug by sponging the microRNA-203 (miR-203) and promoting epithelial-mesenchymal transition (EMT) in LUAD cells. Conclusions: Our work demonstrates that the lncRNA HCP5 is transcriptionally regulated by SMAD3 and acts as a new regulator in the TGFß/SMAD signaling pathway. Therefore, HCP5 can serve as a potential therapeutic target in LUAD.

Novel lncRNA-IUR suppresses Bcr-Abl-induced tumorigenesis through regulation of STAT5-CD71 pathway.

BACKGROUND: Long noncoding RNAs (lncRNAs), defined as the transcripts longer than 200 nt without protein-coding capacity, have been found to be aberrantly expressed in diverse human diseases including cancer. A reciprocal translocation between chromosome 9 and 22 generates the chimeric Bcr-Abl oncogene, which is associated with several hematological malignancies. However, the functional relevance between aberrantly expressed lncRNAs and Bcr-Abl-mediated leukemia remains obscure. METHODS: LncRNA cDNA microarray was used to identify novel lncRNAs involved in Bcr-Abl-mediated cellular transformation. To study the functional relevance of novel imatinib-upregulated lncRNA (IUR) family in Abl-induced tumorigenesis, Abl-transformed cell survival and xenografted tumor growth in mice was evaluated. Primary bone marrow transformation and in vivo leukemia transplant using lncRNA-IUR knockdown (KD) transgenic mice were further conducted to corroborate the role of lncRNA-IUR in Abl-induced tumorigenesis. Transcriptome RNA-seq, Western blot, RNA pull down and RNA Immunoprecipitation (RIP) were employed to determine the mechanisms by which lncRNA-IUR-5 regulates Bcr-Abl-mediated tumorigenesis. RESULTS: We identified a conserved lncRNA-IUR family as a key negative regulator of Bcr-Abl-induced tumorigenesis. Increased expression of lncRNA-IUR was detected in both human and mouse Abl-transformed cells upon imatinib treatment. In contrast, reduced expression of lncRNA-IUR was observed in the peripheral blood lymphocytes derived from Bcr-Abl-positive acute lymphoblastic leukemia (ALL) patients compared to normal subjects. Knockdown of lncRNA-IUR remarkably promoted Abl-transformed leukemic cell survival and xenografted tumor growth in mice, whereas overexpression of lncRNA-IUR had opposite effects. Also, silencing murine lncRNA-IUR promoted Bcr-Abl-mediated primary bone marrow transformation and Abl-transformed leukemia cell survival in vivo. Besides, knockdown of murine lncRNA-IUR in transgenic mice provided a favorable microenvironment for development of Abl-mediated leukemia. Finally, we demonstrated that lncRNA-IUR-5 suppressed Bcr-Abl-mediated tumorigenesis by negatively regulating STAT5-mediated expression of CD71. CONCLUSIONS: The results suggest that lncRNA-IUR may act as a critical tumor suppressor in Bcr-Abl-mediated tumorigenesis by suppressing the STAT5-CD71 pathway. This study provides new insights into functional involvement of lncRNAs in leukemogenesis.

Long non-coding RNA GBCDRlnc1 induces chemoresistance of gallbladder cancer cells by activating autophagy.

BACKGROUND: Gallbladder cancer is the most common biliary tract malignancy and not sensitive to chemotherapy. Autophagy is an important factor prolonging the survival of cancer cells under chemotherapeutic stress. We aimed to investigate the role of long non-coding RNAs (lncRNAs) in autophagy and chemoresistance of gallbladder cancer cells. METHODS: We established doxorubicin (Dox)-resistant gallbladder cancer cells and used microarray analysis to compare the expression profiles of lncRNAs in Dox-resistant gallbladder cancer cells and their parental cells. Knockdown or exogenous expression of lncRNA combined with in vitro and in vivo assays were performed to prove the functional significance of lncRNA. The effects of lncRNA on autophagy were assessed by stubRFP-sensGFP-LC3 and western blot. We used RNA pull-down and mass spectrometry analysis to identify the target proteins of lncRNA. RESULTS: The drug-resistant property of gallbladder cancer cells is related to their enhanced autophagic activity. And we found a lncRNA ENST00000425894 termed gallbladder cancer drug resistance-associated lncRNA1 (GBCDRlnc1) that serves as a critical regulator in gallbladder cancer chemoresistance. Furthermore, we discovered that GBCDRlnc1 is upregulated in gallbladder cancer tissues. Knockdown of GBCDRlnc1, via inhibiting autophagy at initial stage, enhanced the sensitivity of Dox-resistant gallbladder cancer cells to Dox in vitro and in vivo. Mechanically, we identified that GBCDRlnc1 interacts with phosphoglycerate kinase 1 and inhibits its ubiquitination in Dox-resistant gallbladder cancer cells, which leads to the down-regulation of autophagy initiator ATG5-ATG12 conjugate. CONCLUSIONS: Our findings established that the chemoresistant driver GBCDRlnc1 might be a candidate therapeutic target for the treatment of advanced gallbladder cancer.

Exosomal FMR1-AS1 facilitates maintaining cancer stem-like cell dynamic equilibrium via TLR7/NFκB/c-Myc signaling in female esophageal carcinoma.

BACKGROUND: Though esophageal cancer is three to four times more common among males than females worldwide, this type of cancer still ranks in the top incidence among women, even more than the female specific cancer types. The occurrence is currently attributed to extrinsic factors, including tobacco use and alcohol consumption. However, limited attention has been given to gender-specific intrinsic genetic factors, especially in female. METHODS: We re-annotated a large cohort of microarrays on 179 ESCC patients and identified female-specific differently expressed lncRNAs. The associations between FMR1-AS1 and the risk and prognosis of ESCC were examined in 206 diagnosed patients from eastern China and validated in 188 additional patients from southern China. The effects of FMR1-AS1 on the malignant phenotypes on female ESCC cells were detected in vitro and in vivo. ChIRP-MS, reporter gene assays and EMSA were conducted to identify the interaction and regulation among FMR1-AS1, TLR7 and NFκB. RESULTS: We found FMR1-AS1 expression is exclusively altered and closely associated with the level of sXCI in female ESCC patients, and its overexpression may correlate to poor clinical outcome. ChIRP-MS data indicate that FMR1-AS1 could be packaged into exosomes and released into tumor microenvironment. Functional studies demonstrated that FMR1-AS1 could bind to endosomal toll-like receptor 7 (TLR7) and activate downstream TLR7-NFκB signaling, promoting the c-Myc expression, thus inducing ESCC cell proliferation, anti-apoptosis and invasion ability. Exosome incubation and co-xenograft assay indicate that FMR1-AS1 exosomes may secreted from ESCC CSCs, transferring stemness phenotypes to recipient non-CSCs in tumor microenvironment. Furthermore, we also found a correlation between the serum levels of FMR1-AS1 and the overall survival (OS) of the female ESCC patients. CONCLUSIONS: Our results highlighted exosomal FMR1-AS1 in maintaining CSC dynamic interconversion state through the mechanism of activating TLR7-NFκB signaling, upregulating c-Myc level in recipient cells, which may be taken as an attractive target approach for advancing current precision cancer therapeutics in female patients.

Overexpression of long non-coding RNA TUG1 alleviates TNF-α-induced inflammatory injury in interstitial cells of Cajal.

OBJECTIVE: Irritable bowel syndrome (IBS) is a common functional disorder in the gastrointestinal tract. Inflammatory response has been found to participate in the pathogenesis of IBS. This study aimed to explore the effects of long non-coding RNA taurine upregulated gene 1 (TUG1) on tumor necrosis factor alpha (TNF-α)-induced interstitial cells of Cajal (ICC) inflammatory injury, which was relevant to the pathogenesis of IBS. PATIENTS AND METHODS: The expression levels of TUG1 and microRNA-127 (miR-127) were analyzed by qRT-PCR. Viability, apoptosis and the expression of apoptosis-associated factors were analyzed by CCK-8 assay, flow cytometry and Western blot, respectively. The mRNA and protein levels of pro-inflammatory cytokines were detected by qRT-PCR and Western blot, respectively. Finally, activations of nuclear factor kappa-B (NF-κB) and Notch pathways were evaluated by Western blot. RESULTS: TNF-α treatment inhibited ICC viability, induced ICC apoptosis and promoted an inflammatory response in ICC. TUG1 was downregulated in TNF-α-treated ICC. TUG1 overexpression protected ICC from TNF-α-induced apoptosis and pro-inflammatory cytokines expression. TUG1 suppression showed opposite effects. MiR-127 was negatively regulated by TUG1 and implicated in the action of TUG1 in ICC. MiR-127 up-regulation largely reversed the effects of TUG1 on TNF-α-treated ICC. Mechanistically, TUG1 inhibited TNF-α-induced activation of NF-κB and Notch pathways in ICC by down-regulating miR-127. CONCLUSIONS: TUG1 attenuated TNF-α-caused apoptosis and inflammatory response in ICC by down-regulating miR-127 and then inactivating NF-κB and Notch pathways.

Long noncoding RNA HAGLROS regulates apoptosis and autophagy in colorectal cancer cells via sponging miR-100 to target ATG5 expression.

The aim of this study was to explore the relationship between the expression of HOXD antisense growth-associated long noncoding RNA (HAGLROS) and prognosis of patients with colorectal cancer (CRC), as well as the roles and regulatory mechanism of HAGLROS in CRC development. The HAGLROS expression in CRC tissues and cells was detected. The correlation between HAGLROS expression and survival time of CRC patients was investigated. Moreover, HAGLROS was overexpressed and suppressed in HCT-116 cells, followed by detection of cell viability, apoptosis, and the expression of apoptosis-related proteins and autophagy markers. Furthermore, the association between HAGLROS and miR-100 and the potential targets of miR-100 were investigated. Besides, the regulatory relationship between HAGLROS and PI3K/AKT/mTOR pathway was elucidated. The results showed that HAGLROS was highly expressed in CRC tissues and cells. Highly expression of HAGLROS correlated with a shorter survival time of CRC patients. Moreover, knockdown of HAGLROS in HCT-116 cells induced apoptosis by increasing the expression of Bax/Bcl-2 ratio, cleaved-caspase-3, and cleaved-caspase-9, and inhibited autophagy by decreasing the expression of LC3II/LC3I and Beclin-1 and increasing P62 expression. Furthermore, HAGLROS negatively regulated the expression of miR-100, and HAGLROS controlled HCT-116 cell apoptosis and autophagy through negatively regulation of miR-100. Autophagy related 5 (ATG5) was verified as a functional target of miR-100 and miR-100 regulated HCT-116 cell apoptosis and autophagy through targeting ATG5. Besides, HAGLROS overexpression activated phosphatidylinositol-3-kinase/protein kinase B/mammalian target of rapamycin (PI3K/Akt/mTOR) pathway. In conclusion, a highly expression of HAGLROS correlated with shorter survival time of CRC patients. Downregulation of HAGLROS may induce apoptosis and inhibit autophagy in CRC cells by regulation of miR-100/ATG5 axis and PI3K/AKT/mTOR pathway.

Long noncoding RNA PVT1 promotes laryngeal squamous cell carcinoma development by acting as a molecular sponge to regulate miR-519d-3p.

OBJECTIVE: This study was designed to investigate the effects and mechanism of long noncoding RNA (lncRNA) PVT1 on cell migration, proliferation, and apoptosis of laryngeal squamous cell carcinoma (LSCC). METHODS: We screened lncRNAs expression profiles in four pair LSCC and matched noncancerous tissues by microarray assay. The messenger RNA levels of PVT1 in tissues and cells were evaluated by quantitative real-time polymerase chain reaction analysis. StarBase website was used to predict the target miRNAs for PVT1. And the interaction between PVT1 and target miRNA-519d-3p in LSCC cells was analyzed using dual-luciferase reporter assay. MTT assay was used to investigate the cell viability. Cell counting assay was used to explore the cell proliferation. Annexin-V propidium iodide flow cytometry was used to examine the cell apoptosis, and transwell assay was used to investigate the effects of lncRNA PVT1 on cell migration. RESULTS: PVT1 was significantly overexpressed in human LSCC tissues and several LSCC cell lines. Upregulation of lncRNA PVT1 markedly facilitated proliferation suppressed apoptosis and promoted cell migration in LSCC cells. We further demonstrated that silencing PVT1 strikingly suppressed proliferation, promoted apoptosis, and reduced migration in LSCC cells. Further bioinformatic analysis and dual-luciferase reporter assay revealed that PVT1 could function as an oncogenic transcript partly through sponging miR-519d-3p. Besides, mechanistic investigations indicated that PVT1 could promote cell and migration through interacting with miR-519d-3p. CONCLUSION: LncRNA PVT1 is consistently overexpressed in human LSCC, and overexpression of lncRNA PVT1 contributes to the proliferation and migration of LSCC through inhibiting miR-519d-3p expression.

Long non-coding RNA C5orf66-AS1 promotes cell proliferation in cervical cancer by targeting miR-637/RING1 axis.

Long non-coding RNA (lncRNA) plays an important role in the development of human malignant tumours. Recently, an increasing number of lncRNAs have been identified and investigated in a variety of tumours. However, the expression pattern and biological function of lncRNAs in cervical cancer still remain largely unexplored. Differentially expressed lncRNAs in cervical cancer and para-carcinoma tissues were identified by screening using The Cancer Genome Atlas (TCGA), and candidate lncRNAs were verified by quantitative real-time PCR. We found that lncRNAC5orf66-AS1 was significantly upregulated in cervical cancer tissues and cells. Over-expression of C5orf66-AS1 promoted the proliferation of cervical cancer cells, while downregulation of C5orf66-AS1 promoted the apoptosis of cervical cancer cells. C5orf66-AS1 was identified as the sponge of miR-637 by RNA immunoprecipitation (RIP) and luciferase reporter assays. Exogenous miR-637 and RING1 interventions could reverse the proliferation ability mediated by C5orf66-AS1 in cervical cancer cells. In vivo experiments also confirmed that downregulation of C5orf66-AS1 inhibited the tumour growth. LncRNA C5orf66-AS1, as a competitive endogenous RNA (ceRNA), regulated the effect of RING1 on the proliferation, apoptosis and cell cycle of cervical cancer cells through adsorbing miR-637. Taken together, our findings provided a new theoretical and experimental basis for investigating the pathogenesis and exploring effective therapeutic targets for cervical cancer.

LncRNA H19 promotes the proliferation of pulmonary artery smooth muscle cells through AT1R via sponging let-7b in monocrotaline-induced pulmonary arterial hypertension.

BACKGROUND: Pulmonary arterial hypertension (PAH) is related to inflammation, and the lncRNA H19 is associated with inflammation. However, whether PDGF-BB-H19-let-7b-AT1R axis contributes to the pathogenesis of PAH has not been thoroughly elucidated to date. This study investigated the role of H19 in PAH and its related mechanism. METHODS: In the present study, SD rats, C57/BL6 mice and H19-/- mice were injected with monocrotaline (MCT) to establish a PAH model. H19 was detected in the cytokine-stimulated pulmonary arterial smooth muscle cells (PASMCs), serum and lungs of rats/mice. H19 overexpression and knockdown experiments were also conducted. A dual luciferase reporter assay was used to explore whether let-7b is a sponge miRNA of H19, and AT1R is a novel target of let-7b. A CCK-8 assay and flow cytometry were used to analyse cell proliferation. RESULTS: The results showed that H19 was highly expressed in the serum and lungs of MCT-induced rats/mice, and H19 was upregulated by PDGF-BB in vitro. H19 upregulated AT1R expression via sponging miRNA let-7b following PDGF-BB stimulation. AT1R is a novel target of let-7b. Moreover, the overexpression of H19 and AT1R could facilitate PASMCs proliferation in vitro. H19 knockout protected mice from pulmonary artery remodeling and PAH following MCT treatment. CONCLUSION: Our study showed that H19 is highly expressed in MCT-induced rodent lungs and upregulated by PDGF-BB. The H19-let-7b-AT1R axis contributed to the pathogenesis of PAH by stimulating PASMCs proliferation. The H19 knockout had a protective role in the development of PAH. H19 may be a potential tar-get for the treatment of PAH.

Up-regulation of inflammation-related LncRNA-IL7R predicts poor clinical outcome in patients with cervical cancer.

The long-term chronic inflammation of cervical intraepithelial neoplasia (CIN) induces the initiation and progression of cervical cancer. Long non-coding RNAs (LncRNAs) are being identified to be involved into inflammation and carcinogenesis and could function as cancer biomarkers in clinical. However, the significance of inflammation-related LncRNA (e.g. LncRNA-IL7R) in cervical cancer is limited. We, here, investigated the clinical role of inflammation-related LncRNA-IL7R (Lnc-IL7R) in healthy cervical tissue (n=15), CIN 1/2/3 (n=35), cervical cancer (n=70), and clarified its function via knockdown in vitro and in vivo The results showed that the expression of Lnc-IL7R was increased from normal tissues to neoplastic lesions and cervical cancer. Up-regulated Lnc-IL7R positively correlated to tumor size, International Federation of Gynaecology and Obstetrics (FIGO) stage, and lymph node metastasis (LNM). Patients with high expression of Lnc-IL7R had poor prognosis with short overall survival (OS) time, and Cox regression analysis revealed that Lnc-IL7R could be independent prognostic factor for cervical cancer. Moreover, knockdown of Lnc-IL7R by two different siRNAs in cervical cancer cell lines Hela and SiHa induced impaired cell vitality and caspase-3-dependent apoptosis in vitro Furthermore, inhibition of Lnc-IL7R in vivo significantly restricted the tumor growth with decreased expressions of proliferation index Ki-67 and Lnc-IL7R These data indicated that Lnc-IL7R predicts a poor clinical outcome of cervical cancer patients, and knockdown of Lnc-IL7R is amenable to the treatment of cervical cancer.

Long non-coding RNA CASP5 promotes the malignant phenotypes of human glioblastoma multiforme.

BACKGROUND: Long non-coding RNAs (lncRNAs) have been demonstrated to be intensively involved in the development of various carcinomas, including glioblastoma multiforme (GBM). However, only a few of them have been well characterized. LncRNA CASP5 have been found to be up-regulated in GBM tissues compared with normal tissues in a microarray-based lncRNA profiling study. In the present study, we further explored the biological role of lncRNA CASP5 in GBM. METHODS: We examined the expression level of lncRNA CASP5 in GBM tissues as well as GBM cell lines. CCK-8 assay, flow cytometric analysis, western blotting, orthotopic GBM model as well as transwell assay were performed to investigate the biological role of CASP5. RESULTS: We observed that lncRNA CASP5 was highly expressed in GBM tissues and cell lines. Knockdown of CASP5 greatly inhibited GBM proliferation and resulted in G1 cell cycle arrest along with higher apoptosis ratios in vitro and in vivo, while overexpression led to the opposite phenomenon. Furthermore, the migration and invasion ability of GBM cells were significantly decreased after CASP5 down-regulation, while increased migration and invasion can be observed after CASP5 up-regulation. CONCLUSION: We demonstrate for the first time the potential oncogenic role of lncRNA CASP5 which may be helpful for identifying novel therapeutic targets in GBM.