Long noncoding RNA CCAT1 promotes cell proliferation and metastasis in human medulloblastoma via MAPK pathway

2018 ◽  
Vol 104 (1) ◽  
pp. 43-50 ◽  
Author(s):  
Ran Gao ◽  
Rui Zhang ◽  
Cuicui Zhang ◽  
Li Zhao ◽  
Yue Zhang

Background: Medulloblastoma is the most common posterior fossa tumor in children and one that easily metastasizes. The mechanisms of how the medulloblastoma develops and progresses remain to be elucidated. The present study aimed to assess the role of long noncoding colon cancer–associated transcript-1 (lncRNA CCAT1) in cell proliferation and metastasis in human medulloblastoma. Methods: Levels of CCAT1 were measured in samples and cell lines of medulloblastoma. Cell cycle progression, cell viability assay, colony formation assay, wound-healing and Transwell assays Corning, Cambridge, MA, USA were used to investigate the viability and motility of cells. Western blot assay was used to investigate the levels of CCAT1 and other proteins. Results: The initial findings indicated that CCAT1 was significantly up-regulated in clinical cancerous tissues and expressed differently in a series of medulloblastoma cell lines. CCAT1 knockdown significantly slowed cell proliferation rates and inhibited cell clonogenic potential in Daoy cells and D283 cells. Cell cycle progression was disrupted with cell proportions in the G0/G1 phase decreased and the proportion in the S phase and G2/M phases increased, in Daoy cells and D283 cells. Concordantly, medulloblastoma tumor cell growth rates were found to be impaired in xenotransplanted mice. After CCAT1 knockdown, cell wound recovery ability was significantly inhibited. Furthermore, the phosphorylated levels of MAPK, ERK and MEK, but not their total levels decreased after the down-regulation of CCAT1 in Daoy and D283 cells. Conclusions: Our results suggested that the lncRNA CCAT1 promotes cell proliferation and metastasis in human medulloblastoma by possibly regulating the MAPK pathway.

Blood ◽  
2010 ◽  
Vol 116 (21) ◽  
pp. 1199-1199
Author(s):  
Tomonari Takemura ◽  
Satoki Nakamura ◽  
Yasuyuki Nagata ◽  
Daisuke Yokota ◽  
Isao Hirano ◽  
...  

Abstract Abstract 1199 [Background and Aims] CABLES1 (cyclin-dependent kinase (CDK)-5 and ABL enzyme 1) is a regulator of cell proliferation, apoptosis, and cell cycle, and it has been reported to be lost in a variety cancers. It has been also reported that knockout of the Cable1 gene has minimal to no effect on hematopoietic stem cells. However, we found that the expression of Cables1 gene and CABLES1 protein was suppressed in CML cells, and its function is little known in CML. In this study, we have investigated the function of CABLES1 in CML cell proliferation. [Methods] The cells used in this study were human CML cell lines, K562, Meg01 and SHG3 cells. Primary CML cells (ALDHhi cells) were obtained from the bone marrow of CML (CP) patients (n=12). Human normal ALDHhi cells were isolated from bone marrow of healthy volunteers after obtaining informed consents. For analysis of Cables1 mRNA expression, quantitative RT-PCR was performed in all cell lines treated with Abl kinase inhibitors (STI571, AMN107, and BMS354825). For cell survival analysis and the levels of p53 and some CDKIs in CML cells, MTT assays, western blot and cell cycle analysis were performed in all cell lines transfected with Cables1 shRNA or cDNA. For colony analysis, the colonies of CFU-GEMM, CFU-GM, and BFU-E were counted in CML stem/progenitor cells transfected with Cables1 cDNA or shiRNA, or treated with Abl kinase inhibitors. [Results] In CML cell lines, the expressions of Cables1 mRNA and CABLES1 protein were significantly increased by treatment with Abl kinase inhibitors or transfection with Bcr-Abl shRNA. In CML cells transfected with the Cables1 cDNA, it is shown that CML cell proliferation was inhibited, and the phosphorylation levels of p53, and the expression of BAX and p21 protein were markedly increased compared to the untransfected cells. In addition, the overexpression of CABLES1 induced G1 cell cycle arrest and reduced the DiOC6 fluorescence, indicating breakdown of the mitochondrial membrane potential in CML cells. On the other hand, the changes of p73 and p27 protein expression were not detected. Moreover, in CML cells transfected with Cables1 shRNA, the inhibition of CML cell proliferation by the Abl kinase inhibitors were weakened. In CML stem/progenitor cells (ALDHhi cells) obtained from patients with CML, the expression of Cables1 mRNA was suppressed, and the transfection with Bcr-Abl shRNA or treatment with Abl kinase inhibitors increased the expression of Cables1 mRNA and CABLES1 protein, and decreased the counts of CFU-GEMM, CFU-GM and BFU-E. [Conclusion] Our results demonstrated that the Bcr-Abl suppressed the expression of CABLES1, and the depletion of CABLES1 promotes cell cycle progression and p53-dependent apoptosis. Moreover, the induction of CABLES1 expression has the potentiality to eradicate CML stem/progenitor cells. Disclosures: No relevant conflicts of interest to declare.


2016 ◽  
Vol 65 (1) ◽  
pp. 82-87 ◽  
Author(s):  
Haihao Wang ◽  
Qiannan Guo ◽  
Peiwen Yang ◽  
Guoxian Long

Adult T-cell leukemia/lymphoma (ATL) is a highly aggressive T-cell malignancy. This study was designed to explore the expression and functional significance of microRNA (miR)-212 in ATL. The expression of miR-212 in human ATL tissues and cell lines were investigated. Gain-of-function experiments were carried out to determine the roles of miR-212 in cell proliferation, tumorigenesis, cell cycle progression, and apoptosis. We also identified and functionally characterized the target genes of miR-212 in ATL cells. Compared with normal lymph node biopsies, lymphoma samples from ATL patients displayed underexpression of miR-212 (p=0.0032). Consistently, miR-212 was downregulated in human ATL cell lines, compared with normal T lymphocytes. Restoration of miR-212 significantly (p<0.05) inhibited ATL cell proliferation and tumorigenesis in mice. Overexpression of miR-212 led to an accumulation of G0/G1-phase cells and a concomitant reduction of S-phase cells. Moreover, enforced expression of miR-212-induced significant apoptosis in ATL cells. CCND3, which encodes a cell cycle regulator cyclin D3, was identified as a direct target of miR-212 in ATL cells. Rescue experiments with a miR-212-resistant variant of CCND3 demonstrated that overexpression of CCND3 restored cell-cycle progression and attenuated apoptotic response in miR-212-overexpressing ATL cells. Taken together, miR-212 exerts growth-suppressive effects in ATL cells largely by targeting CCND3 and may have therapeutic potential in ATL.


2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Jian Zhang ◽  
Jiaojiao Zhang ◽  
Wenli Liu ◽  
Rui Ge ◽  
Tianyuan Gao ◽  
...  

Abstract Background UBTF is an HMGB-box DNA binding protein and a necessary Pol I/Pol II basal transcription factor. It has been found that UBTF involves in carcinogenesis and progression of a few cancers. Nevertheless, the the biological function and potential molecular mechanism of UBTF in melanoma are still not clear and need to be clarified. Methods UBTF and GIT1 expressions in melanoma specimens and cell lines were examined by quantitative real-time PCR (qRT-PCR) and Western blot. MTT and colony formation assays were used to investigate the effects of UBTF and GIT1 on melanoma cell proliferation. Cell cycle and apoptosis assays were detected by flow cytometry. Tumor formation assay was used to analyze the effect of UBTF on melanoma growth. Bioinformatics predicting, chromatin immunoprecipitation (ChIP)-qRT-PCR and reporter gene assay were fulfilled for verifing GIT1 as UBTF targeting gene. Results Here we reported that UBTF mRNA and protein expressions were upregulated in primary melanoma specimens and cell lines. UBTF overexpression facilitated melanoma cell proliferation and cell cycle progression and restrained. Silencing UBTF suppressed cell multiplication, cell cycle progression and tumor growth, and promoted apoptosis. UBTF expression was positively related with GIT1 expression in human melanoma tissues. It was verified that UBTF promoted GIT1 transcription in melanoma cells through binding to the promoter region of GIT1. Furthermore, GIT1 overexpression promoted melanoma cell growth and suppressed apoptosis. Knockdown of GIT1 inhibited cell multiplication and induced apoptosis. Overexpression of GIT1 eliminated the effects of silencing UBTF on melanoma cells. Importantly, UBTF activated MEK1/2-ERK1/2 signalling pathways by upregulating GIT1 expression. Conclusions Our study demonstrates that UBTF promotes melanoma cell proliferation and cell cycle progression by promoting GIT1 transcription, thereby activating MEK1/2-ERK1/2 signalling pathways. The findings indicate that UBTF plays a crucial function in melanoma and may be a potential therapeutic target for the treatment of this disease.


Author(s):  
Haixia Li ◽  
Xuefei Tian ◽  
Paoqiu Wang ◽  
Mao Huang ◽  
Ronghua Xu ◽  
...  

Abstract Background MicroRNAs (miRNAs) function as post-transcriptional gene expression regulators. Some miRNAs, including the recently discovered miR-582–3p, have been implicated in leukemogenesis. This study aimed to reveal the biological function of miR-582–3p in acute myeloid leukemia (AML), which is one of the most frequently diagnosed hematological malignancies. Methods The expression of miR-582–3p was determined using quantitative real-time PCR in blood samples from leukemia patients and in cell lines. Cell proliferation and cell cycle distribution were analyzed using the CCK-8, colony formation and flow cytometry assays. The target gene of miR-582–3p was verified using a dual-luciferase reporter assay. The G2/M phase arrest-related molecule contents were measured using western blotting analysis. Results We found miR-582–3p was significantly downregulated in the blood samples from leukemia patients and in the cell lines. MiR-582–3p overexpression significantly impaired cell proliferation and induced G2/M cell cycle arrest in THP-1 cells. Furthermore, cyclin B2 (CCNB2) was confirmed as a target gene of miR-582–3p and found to be negatively regulated by miR-582–3p overexpression. More importantly, CCNB2 knockdown showed suppressive effects on cell proliferation and cell cycle progression similar to those caused by miR-582–3p overexpression. The inhibitory effects of miR-582–3p overexpression on cell proliferation and cell cycle progression were abrogated by CCNB2 transfection. Conclusion These findings indicate new functions and mechanisms for miR-582–3p in AML development. Further study could clarify if miR-582–3p and CCNB2 are potential therapeutic targets for the treatment of AML.


PPAR Research ◽  
2019 ◽  
Vol 2019 ◽  
pp. 1-9 ◽  
Author(s):  
Ping-Li Yang ◽  
Jia-Shun Wang ◽  
Xiao-Mei Cheng ◽  
Jing-Cai Chen ◽  
Hui Zhu ◽  
...  

Purpose. Peroxisome proliferator-activated receptor-γ (PPAR-γ) is a nuclear hormone receptor with a key role in lipid metabolism. Previous studies have identified various roles of PPAR-γ in cell cycle progression, cellular proliferation, and tumor progression. However, no report has described a role for PPAR-γ in human nasopharyngeal carcinoma (NPC). Notably, some studies have reported a relationship between PPAR-γ and E2F transcription factor 2 (E2F2), which has been identified as a regulator of cell cycle, apoptosis, and the DNA damage response. Notably, E2F2 has also been reported to correlate with a poor prognosis in patients with various malignancies. Methods. We used immunohistochemical (IHC) and western blot methods to evaluate PPAR-γ and E2F2 expression and function in nonkeratinizing NPC and nasopharyngitis (NPG) tissue samples, as well as western blotting and CCK8 analyses in the NPC cell lines, CNE1 and CNE2. Results. We observed lower levels of PPAR-γ expression in nonkeratinizing NPC tissues compared with NPG tissues and determined an association between a low level of PPAR-γ expression with a more advanced tumor stage. Furthermore, strong E2F2 expression was detected in nonkeratinizing NPC tissues. We further demonstrated that rosiglitazone, a PPAR-γ agonist, reduced E2F2 expression and proliferation in NPC cell lines. Conclusions. Our study results revealed a novel role for the PPAR-γ–E2F2 pathway in controlling NPC cell proliferation and metastasis.


Oncotarget ◽  
2016 ◽  
Vol 7 (37) ◽  
pp. 59287-59298 ◽  
Author(s):  
Yan-Li Li ◽  
Ju Wang ◽  
Cai-Yan Zhang ◽  
Yu-Qing Shen ◽  
Hui-Min Wang ◽  
...  

2016 ◽  
Vol 36 (23) ◽  
pp. 2903-2917 ◽  
Author(s):  
Baolei Yuan ◽  
Xingshun Wang ◽  
Chunyan Fan ◽  
Jin You ◽  
Yuchu Liu ◽  
...  

The RNA helicase DHX33 has been shown to be a critical regulator of cell proliferation and growth. However, the underlying mechanisms behind DHX33 function remain incompletely understood. We present original evidence in multiple cell lines that DHX33 transcriptionally controls the expression of genes involved in the cell cycle, notably cyclin, E2F1, cell division cycle (CDC), and minichromosome maintenance (MCM) genes. DHX33 physically associates with the promoters of these genes and controls the loading of active RNA polymerase II onto these promoters. DHX33 deficiency abrogates cell cycle progression and DNA replication and leads to cell apoptosis. In zebrafish, CRISPR-mediated knockout of DHX33 results in downregulation of cyclin A2, cyclin B2, cyclin D1, cyclin E2, cdc6, cdc20, E2F1, and MCM complexes in DHX33 knockout embryos. Additionally, we found the overexpression of DHX33 in a subset of non-small-cell lung cancers and in Ras-mutated human lung cancer cell lines. Forced reduction of DHX33 in these cancer cells abolished tumor formation in vivo . Our study demonstrates for the first time that DHX33 acts as a direct transcriptional regulator to promote cell cycle progression and plays an important role in driving cell proliferation during both embryo development and tumorigenesis.


2005 ◽  
Vol 25 (11) ◽  
pp. 4335-4348 ◽  
Author(s):  
Florence Gizard ◽  
Romain Robillard ◽  
Olivier Barbier ◽  
Brigitte Quatannens ◽  
Anne Faucompré ◽  
...  

ABSTRACT The transcriptional regulating protein of 132 kDa (TReP-132) has been identified in steroidogenic tissues, where it acts as a coactivator of steroidogenic factor 1 (SF-1). We show here that TReP-132 plays a role in the control of cell proliferation. In human HeLa cells, TReP-132 knockdown by using small interfering RNA resulted in increased G1→S cell cycle progression. The growth-inhibitory effects of TReP-132 was further shown to be mediated by induction of G1 cyclin-dependent kinase inhibitors p21WAF1 (p21) and p27KIP1 (p27) expression levels. As a consequence, G1 cyclin/cyclin-dependent kinase activities and pRB phosphorylation were markedly reduced, and cell cycle progression was blocked in the G1 phase. The stimulatory effect of TReP-132 on p21 and p27 gene transcription involved interaction of TReP-132 with the transcription factor Sp1 at proximal Sp1-binding sites in their promoters. Moreover, in different breast tumor cell lines, endogenous TReP-132 expression was positively related with a lower proliferation rate. In addition, TReP-132 knockdown resulted in enhanced cell proliferation and lowered p21 and p27 mRNA levels in the steroid-responsive and nonresponsive T-47D and MDA-MB-231 cell lines, respectively. Finally, a statistic profiling of human breast tumor samples highlighted that expression of TReP-132 is correlated with p21 and p27 levels and is associated with lower tumor incidence and aggressiveness. Together, these results identify TReP-132 as a basal cell cycle regulatory protein acting, at least in part, by interacting with Sp1 to activate the p21 and p27 gene promoters.


2021 ◽  
Vol 22 (1) ◽  
Author(s):  
Lionel Condé ◽  
Yulemi Gonzalez Quesada ◽  
Florence Bonnet-Magnaval ◽  
Rémy Beaujois ◽  
Luc DesGroseillers

AbstractBackgroundStaufen2 (STAU2) is an RNA binding protein involved in the posttranscriptional regulation of gene expression. In neurons, STAU2 is required to maintain the balance between differentiation and proliferation of neural stem cells through asymmetric cell division. However, the importance of controlling STAU2 expression for cell cycle progression is not clear in non-neuronal dividing cells. We recently showed that STAU2 transcription is inhibited in response to DNA-damage due to E2F1 displacement from theSTAU2gene promoter. We now study the regulation of STAU2 steady-state levels in unstressed cells and its consequence for cell proliferation.ResultsCRISPR/Cas9-mediated and RNAi-dependent STAU2 depletion in the non-transformed hTERT-RPE1 cells both facilitate cell proliferation suggesting that STAU2 expression influences pathway(s) linked to cell cycle controls. Such effects are not observed in the CRISPR STAU2-KO cancer HCT116 cells nor in the STAU2-RNAi-depleted HeLa cells. Interestingly, a physiological decrease in the steady-state level of STAU2 is controlled by caspases. This effect of peptidases is counterbalanced by the activity of the CHK1 pathway suggesting that STAU2 partial degradation/stabilization fines tune cell cycle progression in unstressed cells. A large-scale proteomic analysis using STAU2/biotinylase fusion protein identifies known STAU2 interactors involved in RNA translation, localization, splicing, or decay confirming the role of STAU2 in the posttranscriptional regulation of gene expression. In addition, several proteins found in the nucleolus, including proteins of the ribosome biogenesis pathway and of the DNA damage response, are found in close proximity to STAU2. Strikingly, many of these proteins are linked to the kinase CHK1 pathway, reinforcing the link between STAU2 functions and the CHK1 pathway. Indeed, inhibition of the CHK1 pathway for 4 h dissociates STAU2 from proteins involved in translation and RNA metabolism.ConclusionsThese results indicate that STAU2 is involved in pathway(s) that control(s) cell proliferation, likely via mechanisms of posttranscriptional regulation, ribonucleoprotein complex assembly, genome integrity and/or checkpoint controls. The mechanism by which STAU2 regulates cell growth likely involves caspases and the kinase CHK1 pathway.


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