MYC-regulated lncRNA NEAT1 promotes B cell proliferation and lymphomagenesis via the miR-34b-5p-GLI1 pathway in diffuse large B-cell lymphoma.
ABSTRACT: Background:LncRNA NEAT1 has been identified as a tumour driver in many human cancers. However, the underlying mechanism of lncRNA NEAT1 in diffuse large B-cell lymphoma (DLBCL) progression is unclear. Methods:The expression levels of NEAT1, GLI1 and miR-34b-5p were detected by RT-qPCR and Western blotting in DLBCL tissues and cell lines. MTT and colony formation assays were performed to examine cell proliferation, while annexin-V staining and TUNEL assays were performed to measure cell apoptosis. The effect of NEAT1, GLI1 and miR-34b-5p on cell cycle-associated proteins was evaluated by Western blotting. Dual-luciferase reporter and RNA immunoprecipitation (RIP) assays were employed to investigate the interaction between NEAT1 and miR-34b-5p or GLI1 and miR-34b-5p. Moreover, chromatin immunoprecipitation (ChIP) was performed to demonstrate the interaction between MYC and NEAT1. Results:NEAT1 and GLI1 were upregulated while miR-34b-5p was downregulated in DLBCL tissues and cell lines compared to normal controls. Knockdown of NEAT1 or overexpression of miR-34b-5p inhibited cell proliferation but promoted cell apoptosis. Overexpression of NEAT1 reversed GLI1-knockdown induced attenuation of cell proliferation. In other words, NEAT1 acted as a competing endogenous RNA (ceRNA), regulating the miR-34b-5p-GLI1 axis, further affecting the proliferation of DLBCL. Moreover, MYC modulated NEAT1 transcription by directly binding to the NEAT1 promoter. Conclusion:We revealed that MYC-regulated NEAT1 promoted DLBCL proliferation via the miR-34b-5p-GLI1 pathway, which could provide a novel therapeutic target for DLBCL.
Project description:Hypoxic-ischemic brain damage (HIBD) is a major cause of fatality and morbidity in neonates. However, current treatment approaches to alleviate HIBD are not effective. Various studies have highlighted the role of microRNAs (miRNAs) in various biological functions in multiple diseases. This study investigated the role of miR-339-5p in HIBD progression. Neonatal HIBD mouse model was induced by ligation of the right common carotid artery. Neuronal cell model exposed to oxygen-glucose deprivation (OGD) was also established. The miR-339-5p expression in mouse brain tissues and neuronal cells was quantified, and the effects of miR-339-5p on neuronal cell activity and apoptosis induced by hypoxia-ischemia were explored. The overexpression or knockdown of long non-coding RNA (lncRNA) nuclear-enriched abundant transcript 1 (NEAT1) in hippocampal neurons was used to determine the effect of lncRNA NEAT1 on the expression of miR-339-5p and homeobox A1 (HOXA1) and apoptosis. Short hairpin RNA targeting lncRNA NEAT1 and miR-339-5p antagomir were used in neonatal HIBD mice to identify their roles in HIBD. Our results revealed that miR-339-5p was downregulated in neonatal HIBD mice and neuronal cells exposed to OGD. Downregulated miR-339-5p promoted neuronal cell viability and suppressed apoptosis during hypoxia-ischemia. Moreover, lncRNA NEAT1 competitively bound to miR-339-5p to increase HOXA1 expression and inhibited neuronal cell apoptosis under hypoxic-ischemic conditions. The key observations of the current study present evidence demonstrating that lncRNA NEAT1 upregulated HOXA1 to alleviate HIBD in mice by binding to miR-339-5p.
Project description:Anaplastic thyroid carcinoma (ATC) has a poor prognosis due to its resistance to all conventional treatments. The long non‑coding RNA (lncRNA) nuclear paraspeckle assembly transcript 1 (NEAT1) serves a critical role in cancer chemoresistance; however, whether NEAT1 is associated with chemoresistance of ATC remains unclear. In the present study, reverse transcription‑quantitative PCR assays were performed to detect the expression levels of NEAT1, microRNA (miR)‑9‑5p and sperm‑associated antigen 9 (SPAG9). Western blot analysis was conducted to assess the protein expression levels of p62, microtubule‑associated proteins 1A/1B light chain 3B and SPAG9. Cell proliferation was detected using the Cell Counting kit‑8 assay, and cell apoptosis was determined by flow cytometry. Dual‑luciferase reporter and RNA immunoprecipitation assays were performed to verify the interaction between NEAT1 and miR‑9‑5p, or miR‑9‑5p and SPAG9. Furthermore, an animal model was used to investigate the regulatory effects of NEAT1 on cisplatin (DDP)‑resistance in tumors in vivo. The present results demonstrated that NEAT1 was upregulated in ATC tissues and cell lines, and NEAT1 silencing resulted in decreased DDP‑resistance of ATC cells. In addition, NEAT1 suppressed miR‑9‑5p expression by binding to miR‑9‑5p and SPAG9 was a direct target of miR‑9‑5p. miR‑9‑5p overexpression sensitized ATC cells to DDP. Notably, NEAT1 silencing exerted its inhibitory effect on DDP‑resistance of ATC via the miR‑9‑5p/SPAG9 axis in vitro and in vivo. In conclusion, the present study demonstrated that NEAT1 silencing ameliorated DDP‑resistance of ATC, at least in part by reducing miR‑9‑5p sponging and regulating SPAG5 expression; therefore, NEAT1 may be considered a potential therapeutic target of ATC.
Project description:Background:LncRNAs act as functional regulators in tumor progression through interacting with various signaling pathways in multiple types of cancer. However, the effect of LINC02418 on colorectal cancer (CRC) progression and the underling mechanisms remain unclear. Methods:LncRNA expression profile in CRC tissues was investigated by the TCGA database. The expressional level of LINC02418 in CRC patients was determined by quantitative reverse transcription-polymerase chain reaction (qRT-PCR). Kaplan-Meier analyses was used to investigate the correlation between LINC02418 and overall survival (OS) of CRC patients. Cell proliferative, migratory and invasive abilities were detected by CCK-8 assays, colony formation assays and trans-well assays in HCT116 and LoVo cells which were stably transduced with sh-LINC02418 or sh-NC. The binding between LINC02418 and miR-34b-5p, and the interaction between miR-34b-5p and BCL2 were determined by dual-luciferase assays. Western blot experiments were conducted to further explore the effect of miR-34b-5p on BCL2 signaling pathway. Rescue experiments were performed to uncover the role of LINC02418/miR-34b-5p/BCL2 axis in CRC progression. Results:LINC02418 was upregulated in human colon cancer samples when compared with adjacent tissue, and its high expressional level correlated with poor prognosis of CRC patients. LINC02418 promoted cancer progression by enhancing tumor growth, cell mobility and invasiveness of colon cancer cells. Additionally, LINC02418 could physically bind to miR-34b-5p and subsequently affect BCL2 signaling pathway. Down-regulation of LINC02418 reduced cell proliferation, while transfection of miR-34b-5p inhibitor or BCL2 into LINC02418-silenced CRC cells significantly promoted CRC cells growth. Conclusions:LINC02418 was upregulated in human CRC samples and could be used as the indicator for prediction of prognosis. LINC02418 acted as a tumor driver by negatively regulating cell apoptosis through LINC02418/miR-34b-5p/BCL2 axis in CRC.
Project description:Dysregulation of long non-codng RNA (lncRNA) expression has been found to contribute to tumorigenesis. However, the roles of lncRNAs in BRCA1-related breast cancer remain largely unknown. In this study, we delineate the role of the novel BRCA1/lncRNA NEAT1 signaling axis in breast tumorigenesis. BRCA1 inhibits NEAT1 expression potentially through binding to its genomic binding site upstream of the NEAT1 gene. BRCA1 deficiency in human normal/cancerous breast cells and mouse mammary glands leads to NEAT1 overexpression. Our studies show that NEAT1 upregulation resulting from BRCA1 deficiency stimulates in vitro and in vivo breast tumorigenicity. We have further identified molecular mediators downstream of the BRCA1/NEAT1 axis. NEAT1 epigenetically silences miR-129-5p expression by promoting the DNA methylation of the CpG island in the miR-129 gene. Silencing of miR-129-5p expression by NEAT1 results in upregulation of WNT4 expression, a target of miR-129-5p, which leads to activation of oncogenic WNT signaling. Our functional studies indicate that this NEAT1/miR-129-5p/WNT4 axis contributes to the tumorigenic effects of BRCA1 deficiency. Finally our in silico expression correlation analysis suggests the existence of the BRCA1/NEAT1/miR-129-5p axis in breast cancer. Our findings, taken together, suggest that the dysregulation of the BRCA1/NEAT1/miR-129-5p/WNT4 signaling axis is involved in promoting breast tumorigenesis.
Project description:The aberrant expression and dysfunction of long non-coding RNAs (lncRNAs) have been identified as critical factors governing the initiation and progression of different human cancers, including diffuse large B-cell lymphoma (DLBCL). LncRNA small nucleolar RNA host gene 16 (SNHG16) has been recognized as a tumour-promoting factor in various types of cancer. However, the biological role of SNHG16 and its underlying mechanism are still unknown in DLBCL. Here we disclosed that SNHG16 was overexpressed in DLBCL tissues and the derived cell lines. SNHG16 knockdown significantly suppressed cell proliferation and cell cycle progression, and it induced apoptosis of DLBCL cells in vitro. Furthermore, silencing of SNHG16 markedly repressed in vivo growth of OCI-LY7 cells. Mechanistically, SNHG16 directly interacted with miR-497-5p by acting as a competing endogenous RNA (ceRNA) and inversely regulated the abundance of miR-497-5p in DLBCL cells. Moreover, the proto-oncogene proviral integration site for Moloney murine leukaemia virus 1 (PIM1) was identified as a novel direct target of miR-497-5p. SNHG16 overexpression rescued miR-497-5p-induced down-regulation of PIM1 in DLBCL cells. Importantly, restoration of PIM1 expression reversed SNHG16 knockdown-induced inhibition of proliferation, G0/G1 phase arrest and apoptosis of OCI-LY7 cells. Our study suggests that the SNHG16/miR-497-5p/PIM1 axis may provide promising therapeutic targets for DLBCL progression.
Project description:BACKGROUND:Long noncoding RNAs (lncRNA) are important in the growth and metastasis of colon cancer. The objective of this study was to describe the potential role of lncRNA NEAT1 in the progression of colon cancer. METHODS:Quantitative real-time polymerase chain reaction was used for detecting NEAT1, miR-185-5p, and IGF2 in colon cancer cells and tissues. The potential diagnostic value of NEAT1 in colon cancer was analyzed with the receiver operating characteristic curve. Kaplan-Meier method was applied for evaluating the association between NEAT1 expression and the overall survival of osteosarcoma patients, whereas Transwell assay was introduced to examine the potential invasion and migration of colon cancer cells. In addition, the binding of NEAT1/IGF2 to miR-185-5p was confirmed by RNA pull-down and RNA-binding protein immunoprecipitation assays and dual-luciferase reporter gene assay. Finally, rescue experiments were conducted to confirm the role of NEAT1/miR-185-5p/IGF2 axis in colon cancer. RESULTS:Colon cancer patients with low NEAT1 expression presented with longer overall survival than those with high expression. The migration and invasion of colon cancer cells were considerably promoted by overexpressed NEAT1. Both NEAT1 and IGF2 bound to miR-185-5p. CONCLUSION:NEAT1 upregulate IGF2 expression through absorbing miR-185-5p to enhances the migration and invasion of colon cancer cells.
Project description:As key post-transcriptional regulators, microRNAs (miRNAs) play an indispensable role in skeletal muscle development. Our previous study suggested that miR-34b-5p and IGFBP2 could have a potential role in skeletal muscle growth. Our goal in this study is to explore the function and regulatory mechanism of miR-34b-5p and IGFBP2 in myogenesis. In this study, the dual-luciferase reporter assay and Western blot analysis showed that IGFBP2 is a direct target of miR-34b-5p. Flow cytometric analysis and EdU assay showed that miR-34b-5p could repress the cell cycle progression of myoblasts, and miR-34b-5p could promote the formation of myotubes by promoting the expression of MyHC. On the contrary, the overexpression of IGFBP2 significantly facilitated the proliferation of myoblasts and hampered the formation of myotubes. Together, our results indicate that miR-34b-5p could mediate the proliferation and differentiation of myoblasts by targeting IGFBP2.
Project description:Background:Long noncoding RNAs play essential roles in regulating drug resistance in cancers. However, how and whether lncRNA nuclear paraspeckle assembly transcript 1 (NEAT1) could mediate cisplatin resistance in ovarian cancer remain poorly understood. Patients and Methods:Eighteen cisplatin-sensitive and 19 cisplatin-resistant patients with ovarian cancer were recruited. Cisplatin-resistant ovarian cancer cells were used for this study. The expression levels of NEAT1, microRNA (miR)-770-5p and poly adenosine diphosphate-ribose polymerase 1 (PARP1) were detected by quantitative real-time polymerase chain reaction or Western blot. Cisplatin resistance was assessed by the half-maximal inhibitory concentration (IC50) of cisplatin, cell viability and apoptosis using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl-tetrazolium bromide, flow cytometry and Western blot, respectively. The target association between miR-770-5p and NEAT1 or PARP1 was investigated by dual-luciferase reporter assay. The xenograft model was used to investigate cisplatin resistance in vivo. Results:NEAT1 expression is elevated in cisplatin-resistant ovarian cancer tissues and cells. Knockdown of NEAT1 repressed cisplatin resistance by decreasing the IC50 of cisplatin, cell viability and increasing apoptosis. MiR-770-5p was bound to NEAT1 and PARP1 was confirmed as a target of miR-770-5p. MiR-770-5p inhibition or PARP1 restoration could abate the effect of NEAT1 silencing on cisplatin resistance in cisplatin-resistant ovarian cancer cells. Moreover, NEAT1 knockdown reduced PARP1 expression by increasing miR-770-5p. Interference of NEAT1 decreased xenograft tumor growth by regulating miR-770-5p and PARP1. Conclusion:Knockdown of NEAT1 inhibited cisplatin resistance in ovarian cancer cells by up-regulating miR-770-5p and down-regulating PARP1, providing a new target for improving the efficacy of cisplatin-based therapy in ovarian cancer.
Project description:OBJECTIVES:MiR-34 is a tumour suppressor in breast cancer. Neurokinin-1 receptor (NK1R), which is the predicted target of the miR-34 family, is overexpressed in many cancers. This study investigated the correlation and clinical significance of miR-34 and NK1R in breast cancer. MATERIALS AND METHODS:Western blotting, quantitative reverse transcription-PCR (qRT-PCR) and luciferase assays were conducted to analyse the regulation of NK1R by miR-34 in MDA-MB-231, MCF-7, T47D, SK-BR-3 and HEK-293 T cells. MiR-34b/c-5p, full-length NK1R (NK1R-FL) and truncated NK1R (NK1R-Tr) expression in fifty patients were quantified by qRT-PCR and correlated with their clinicopathological parameters. CCK-8 assays, colony formation assays and flow cytometry were used to measure cell proliferation and apoptosis in MDA-MB-231 and MCF-7 cells transfected with miR-34b/c-5p or NK1R-siRNA and before treatment with or without Substance P (SP), an endogenous peptide agonists of NK1R. The effect of NK1R antagonist aprepitant was also investigated. In vivo xenograft models were used to further verify the regulation of NK1R by miR-34b/c-5p. RESULTS:Expression levels of miR-34b/c-5p and NK1R-Tr, but not NK1R-FL, were associated with enhanced malignant potential, such as tumour stage and Ki67 expression. The overexpression of miR-34b/c-5p or NK1R silencing potently suppressed cell proliferation and induced G2/M phase arrest and the apoptosis of MDA-MB-231 and MCF-7 cells. The NK1R antagonist aprepitant had similar effects. In vivo studies confirmed that miR-34b/c-5p overexpression or NK1R silencing reduced the tumorigenicity of breast cancer. In addition, SP rescued the effects of miR-34b/c-5p overexpression or NK1R silencing on cell proliferation and apoptosis in vitro and in vivo assays. CONCLUSIONS:MiR-34b/c-5p and NK1R contribute to breast cancer cell proliferation and apoptosis and are potential targets for breast cancer therapeutics.
Project description:Platinum-based drugs are the firstline of treatment for non-small cell lung cancer (NSCLC), but resistance to these drugs is a major obstacle to effective chemotherapy. Our previous study revealed that the green tea polyphenol, EGCG, induced cisplatin transporter CTR1 (copper transporter 1) and enhanced cisplatin sensitivity in ovarian cancer. In this study, we found that EGCG upregulated CTR1 and increased platinum accumulation in NSCLC (A549, H460 and H1299) cells, cDDP-resistant A549 cells and a nude mouse xenograft model. Cisplatin-induced inhibition of cell growth was enhanced by EGCG treatment in vitro and in vivo. MicroRNA hsa-mir-98-5p appears to suppress CTR1 gene expression, while long non-coding RNA (lncRNA) nuclear enriched abundant transcript 1 (NEAT1) appears to enhance it. Bioinformatics analysis showed that hsa-mir-98-5p has specific complementary binding sites for NEAT1. In addition, hsa-mir-98-5p was predicted to be a putative CTR1 target. NEAT1 may act as a competing endogenous lncRNA to upregulate EGCG-induced CTR1 by sponging hsa-mir-98-5p in NSCLC. Our findings reveal a novel mechanism how NEAT1 upregulates EGCG-induced CTR1 and enhances cisplatin sensitivity in vitro and in vivo, and suggest EGCG could serve as an effective adjuvant chemotherapeutic in lung cancer treatment.