scholarly journals Dnmt3a is downregulated by Stat5a and mediates G0/G1 arrest by suppressing the miR-17-5p/Cdkn1a axis in Jak2V617F cells

BMC Cancer ◽  
2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Jie Zhou ◽  
Cheng Guo ◽  
Hao Wu ◽  
Bing Li ◽  
Li-Li Zhou ◽  
...  

Abstract Background Despite of the frequently reported Dnmt3a abormality in classical myeloproliferative neoplasms (cMPNs) patients, few research explores how the Dnmt3a is regulated by Jak2V617F mutation. In this study, we have investigated how the Dnmt3a is regulated by Jak2V617F mutation and its effects on downstream signaling pathways in cMPNs. Methods Specimens of Jak2V617F positive cMPN patients and normal controls were collected. Murine BaF3 cell line was used to construct cell models. Dual-Glo luciferase assays and chromatin immunoprecipitation (ChIP)-qPCR were performed to detect the impact of Stat5a on transcription activity of Dnmt3a. Soft agar colony formation assay and cell counting assay were performed to detect cell proliferation. BrdU staining and flow cytometry were used to investigate cell cycle distribution. Western blotting and quantitative reverse-transcription PCR (qPCR) were performed to detect the expression levels of genes. Results Firstly, the results of western blotting and qPCR revealed that compared with the control samples, Dnmt3a is downregulated in Jak2V617F positive samples. Then we explored the mechanism behind it and found that Dnmt3a is a downstream target of Stat5a, the transcription and translation of Dnmt3a is suppressed by the binding of aberrantly activated Stat5a with Dnmt3a promoter in Jak2V617F positive samples. We further revealed the region approximately 800 bp upstream of the first exon of the Dnmt3a promoter, which includes a gamma-activated sequence (GAS) motif of Stat5a, is the specific site that Stat5a binds to. Soft agar colony formation assay, cell counting assay, and BrdU staining and flow cytometry assay found that Dnmt3a in Jak2V617F-BaF3 cells significantly affected the cell proliferation capacity and cell cycle distribution by suppressing Cdkn1a via miR-17-5p/Cdkn1a axis and mediated G0/G1 arrest. Conclusions Transcription and translation of Dnmt3a is downregulated by the binding of Stat5a with Dnmt3a promoter in Jak2V617F cells. The GAS motif at promoter of Dnmt3a is the exact site where the Stat5a binds to. Dnmt3a conducted G0/G1 arrest through regulating miR-17-5p/Cdkn1a axis. The axis of Stat5a/Dnmt3a/miR-17-5p/Cdkn1a potentially provides a treatment target for cMPNs.

2016 ◽  
Vol 28 (2) ◽  
pp. 194
Author(s):  
S. Gebremedhn ◽  
D. Salilew-Wondim ◽  
M. Hoelker ◽  
F. Rings ◽  
C. Neuhoff ◽  
...  

Among other microRNA clusters, we previously showed that the miR-183~96~182 cluster (miR-183, miR-96, and miR-182) is abundantly expressed in bovine granulosa cells (bGC) of preovulatory dominant follicles obtained at the follicular phase of the bovine oestrous cycle. Moreover, this miRNA cluster are validated to coordinately target the Fork head O1 (FOXO1), a subfamily of transcription factors that regulate genes involved in cell proliferation, apoptosis, cell cycle arrest, and metabolism. However, the functional involvement of miR-183~96~182 cluster in bGC function by regulation of FOXO1 is not yet determined. Here, we aimed to investigate the function of miR-183~96~182 cluster in bGC using in vitro cell culture model. For this, bGC were aspirated from ovarian follicles (Ø 3–5 mm) obtained from local abattoir. Cells were plated in 24-well plate (2.5 × 105 cells well–1) in DMEM/F-12 (Sigma, Germany) supplemented with 10% FBS (GIBCO, Grand Island, NY) and 1% penicillin/streptomycin (GIBCO) and incubated at 37°C in 5% CO2. Transfection of bGC with miRNA mimics, inhibitors, FOXO1-siRNA, and appropriate controls (Exiqon, Vedbæk, Denmark) was performed using Lipofectamine 2000 (Invitrogen, Carlsbad, CA, USA). Cell proliferation was determined using Cell Counting Kit-8 (CCK-8; Dojindo Molecular Technology, Kumamoto, Japan). Cell cycle distribution was determined with flow cytometric analysis. Total RNA was isolated using miRNeasy mini kit (Qiagen, Hilden, Germany), quantification of target gene was performed using qPCR, and data were analysed using ΔΔCT method. Differences in the mean expression values between treatments were analysed with two-tailed Student’s t-test and statistical significance was defined at P ≤ 0.05. Results showed that a sponge effect was observed upon inhibition in individual miRNA of the cluster, which could be attributed to the partial sequence similarity among cluster members. Both FOXO1 mRNA and protein expression were significantly reduced upon transfection of bGC with miR-183~96~182 cluster mimics, while miR-183~96~182 cluster inhibition increased both FOXO1 mRNA and protein expression. Transfection of bGC with miR-183~96~182 mimics promoted cell proliferation, while inhibition tends to slow down proliferation. Furthermore, the proportion of bGC under G0/G1 arrest markedly declined (P < 0.05), while the S and G2/M phases increased in response to miR-183~96~182 mimicking. Selective knockdown of FOXO1 with FOXO1-siRNA significantly reduced FOXO1 mRNA and protein expression. Interestingly, knockdown of FOXO1 showed similar phenotypic effects such as that of miR-183~96~182 mimics transfection, which resulted in elevated bGC proliferation and reduction in the proportion of cells under G0/G1 arrest. In conclusion, overexpression of miR-183~96~182 cluster promote bGC proliferation and G0/G1 to S and G2/M cell cycle transition through coordinated regulation of genes in the FOXO1 signaling axis.


2021 ◽  
Vol 21 ◽  
Author(s):  
Tongqing Xue ◽  
Gang Yin ◽  
Weixuan Yang ◽  
Xiaoyu Chen ◽  
Cheng liu ◽  
...  

Background: Dysregulation of microRNAs (miRNAs) figures prominently in radio-sensitivity of non-small cell lung cancer (NSCLC). MiR-129-5p can block the development of a variety of tumors. However, whether miR-129-5p modulates radio-sensitivity of NSCLC cells remains unknown. Objective: This study was aimed to explore the role and the underlying mechanism of miR-129-5p in the radiosensitivity of NSCLC. Methods: Radio-resistant NSCLC cell lines (A549-R and H1299-R) were constructed using A549 and H1299 cells. Quantitative real-time polymerase chain reaction (qRT-PCR) was employed to quantify miR-129-5p, SRY-box transcription factor 4 (SOX4) mRNA, and RUNX family transcription factor 1 (RUNX1) mRNA expression levels. Cell apoptosis and cell cycle were detected by flow cytometry. Cell counting kit-8 (CCK-8) assay and colony formation experiments were used to measure cell proliferation. γ-H2AX was examined by Western blot to confirm DNA injury. Dual-luciferase reporter experiments were applied to analyze the interactions among miR-129-5p, RUNX1, and SOX4. Results: In A549-R and H1299-R cells, compared with the wild type cell lines, miR-129-5p expression was remarkably reduced while SOX4 and RUNX1 expressions were increased. The transfection of miR-129-5p into NSCLC cell lines, markedly induced cell apoptosis, DNA injury, and cell cycle arrest, and inhibited cell proliferation and colony formation. RUNX1 and SOX4 were validated as target genes of miR-129-5p, and the restoration of RUNX1 or SOX4 could counteract the influence of miR-129-5p on A549-R cells. Conclusion: MiR-129-5p sensitizes A549-R and H1299-R cells to radiation by targeting RUNX1 and SOX4.


2018 ◽  
Vol 96 (5) ◽  
pp. 663-671 ◽  
Author(s):  
Teng Lv ◽  
Kejuan Song ◽  
Lili Zhang ◽  
Weihua Li ◽  
Yulong Chen ◽  
...  

This study aimed to explore the roles of miRNA-34a (miR-34a) in ovarian cancer (OC) cells and uncover possible mechanisms. The proliferation of OC cells was measured with an MTT assay and soft agar colony formation assay. TargetScan analysis, real-time PCR, and a luciferase reporter assay were used to demonstrate the downstream target of miR-34a in OC cells. HDAC1 expression levels were detected by immunoblot analysis. miR-34a inhibited the proliferation of SKOV3 and OVCA433 cells and enhanced cisplatin sensitivity in cisplatin-resistant SKOV3cp cells. The results of TargetScan analysis, real-time PCR, and luciferase reporter assay confirmed that miR-34a downregulated HDAC1 expression by directly targeting the 3′-UTR of HDAC1 mRNA. The overexpression of HDAC1 decreased cisplatin sensitivity and promoted proliferation in OC cells. MTT assay and soft agar colony formation assay showed that HDAC1 overexpression blocked the suppressive effects of miR-34a on SKOV3 cell proliferation. In addition, treatment with the miR-34a mimic partially recovered the cisplatin sensitivity of SKOV3cp cells, whereas HDAC1 overexpression blocked the above phenomena caused by treatment with the miR-34a mimic. miR-34a exhibited suppressive effects on OC cells via directly binding and downregulating HDAC1 expression, which subsequently decreased the resistance to cisplatin and suppressed proliferation in OC cells.


2021 ◽  
Vol 49 (2) ◽  
pp. 030006052199221
Author(s):  
Haitian He ◽  
Jianhua Li ◽  
Mayao Luo ◽  
Qiang Wei

Objective Circular RNAs (circRNAs) are non-coding RNAs with high cancer-specific expression and the potential for regulating tumorigenesis. CircRNA_100395 is expressed at low levels in many cancers and is involved in the regulation of tumor cell proliferation and metastasis. However, its expression and function in prostate cancer remain unclear. Methods Endogenous expression levels of circRNA_100395 and microRNA-1228 (miR-1228) in prostate cancer tissue samples and cell lines were detected by quantitative reverse transcription-polymerase chain reaction. Cell proliferation, invasion, and migration, cell cycle distribution, and epithelial–mesenchymal transition (EMT) were analyzed in circRNA_100395-overexpressing prostate cancer cells by Cell Counting Kit-8, flow cytometry, Transwell assay, and western blotting, respectively. Results CircRNA_100395 expression was downregulated in cancerous prostate tissues relative to adjacent normal tissues. CircRNA_100395 expression was negatively correlated with tumor size, Gleason score, tumor stage, and lymph node metastasis. Moreover, circRNA_100395 overexpression inhibited cell proliferation, altered cell cycle distribution, reduced cell migration and invasion abilities, and suppressed EMT in prostate cancer cells. Moreover, miR-1228 was a direct downstream target of circRNA_100395, and the anti-tumor ability of circRNA_100395 was significantly reversed by miR-1228. Conclusion This study identified circRNA_100395 as an anti-tumor circRNA and a potential therapeutic target for prostate cancer.


2020 ◽  
Vol 48 (10) ◽  
pp. 030006052096401
Author(s):  
Guoliu Ye ◽  
Lingling Wang ◽  
Kang Yang ◽  
Caizhi Wang

Objective To investigate the role of fucoxanthin, reported to have significant anticancer effects, and histone Cluster 1 H3 Family Member D (HIST1H3D; implicated in tumorigenesis) in cervical cancer. Methods The half maximal inhibitory concentration (IC50) of fucoxanthin against HeLa and SiHa cervical cancer cells was determined. Differentially expressed genes (DEGs) in SiHa cells treated with IC50 fucoxanthin were screened by high-throughput techniques and subjected to signal enrichment. Following identification of HIST1H3D as a candidate gene, HIST1H3D-knockdown models were created via transfection with a short hairpin HIST1H3D payload. Impacts on cell proliferation, cell-cycle distribution, colony formation, and apoptosis were studied. Results The fucoxanthin IC50 was 1 445 and 1 641 µM (Hela and SiHa cells, respectively). Chip results revealed 2 255 DEGs, including 943 upregulated and 1 312 downregulated genes, in fucoxanthin-treated versus untreated SiHa cells. Disease and function analysis indicated that these DEGs are primarily associated with cancer and organismal injuries and abnormalities, and online integrated pathway analysis showed that the DEGs were mainly enriched in p53 signalling. HIST1H3D was significantly downregulated in response to fucoxanthin. Inhibition of HIST1H3D mRNA significantly reduced cell proliferation and colony formation, significantly augmented the percentage of apoptotic HeLa and SiHa cells, and cells were arrested in G0/G1 cell cycle phase. Conclusion The results suggest that HIST1H3D may be an oncogene in cervical carcinogenesis and a potential fucoxanthin target in treating cervical cancer.


2018 ◽  
Vol 18 (2) ◽  
pp. 210-215 ◽  
Author(s):  
Mona Diab-Assaf ◽  
Josiane Semaan ◽  
Marwan El-Sabban ◽  
Soad K. Al Jaouni ◽  
Rania Azar ◽  
...  

Introduction: Adult T-cell leukemia (ATL) is an aggressive form of malignancy caused by human T- cell lymphotropic virus 1 (HTLV-1). Currently, there is no effective treatment for ATL. Thymoquinone has been reported to have anti-cancer properties. Objective: The aim of this study is to investigatthe effects of TQ on proliferation, apoptosis induction and the underlying mechanism of action in both HTLV-1 positive (C91-PL and HuT-102) and HTLV-1 negative (CEM and Jurkat) malignant T-lymphocytes. Materials and Methods: Cells were incubated with different thymoquinone concentrations for 24h. Cell cytotoxicity was assayed using the CytoTox 96® Non-Radioactive Cytotoxicity Assay Kit. Cell proliferation was determined using CellTiter 96® Non-Radioactive Cell Proliferation. Cell cycle analysis was performed by staining with propidium iodide. Apoptosis was assessed using cell death ELISA kit. The effect of TQ on p53, p21, Bcl-2 protein expression was determined using Western blot analysis while TGF mRNA expression was determined by RT-PCR. Results: At non-cytotoxic concentrations of TQ, it resulted in the inhibition of proliferation in a dose dependent manner. Flow cytometric analysis revealed a shift in the cell cycle distribution to the PreG1 phase which is a marker of apoptosis. Also TQ increase DNA fragmentation. TQ mediated its anti-proliferative effect and apoptosis induction by an up-regulation of TGFβ1, p53 and p21 and a down-regulation of TGF-α and Bcl-2α. Conclusion: Thymoquinone presents antiproliferative and proapoptotic effects in ATL cells. For this reason, further research is required to investigate its possible application in the treatment of ATL.


1996 ◽  
Vol 84 (5) ◽  
pp. 831-838 ◽  
Author(s):  
Xiao-Nan Li ◽  
Zi-Wei Du ◽  
Qiang Huang

✓ The modulation effects of hexamethylene bisacetamide (HMBA), a differentiation-inducing agent, on growth and differentiation of cells from human malignant glioma cell line SHG-44 were studied. At cytostatic doses (2.5 mM, 5 mM, 7.5 mM, and 10 mM for 15 days), HMBA exerted a marked inhibitory effect on cell proliferation. Exposure to HMBA (5 mM and 10 mM for 12 days) also resulted in an accumulation of cells in G0/G1 phase and a decrease of cells in S phase as analyzed by flow cytometry. The reversible effects of 7.5 mM HMBA and 10 mM HMBA on cell proliferation and 10 mM HMBA on disruption of cell cycle distribution were observed when HMBA was removed from culture media on Day 6 and replaced with HMBA-free media. Colony-forming efficiency (CFE) in soft agar was remarkably decreased by HMBA (2.5 mM, 5 mM, 7.5 mM, and 10 mM for 14 days), and in 7.5 mM HMBA— and 10 mM HMBA—treated cells, the CFEs were reduced to 25% and 12.5%, respectively, of that in untreated cells. Cells treated with HMBA (5 mM and 10 mM for 15 days) remained tumorigenic in athymic nude mice, but the growth rates of the xenografts were much slower than those in the control group. The effects of HMBA on cell proliferation, cell cycle distribution, CFE, and growth of xenografts were dose dependent. A more mature phenotype was confirmed by the morphological changes from spindle shape to large polygonal stellate shape and remarkably elevated expression of glial fibrillary acidic protein in cells exposed to HMBA (5 mM, 10 mM for 15 days). Our results showed that a more differentiated phenotype with marked growth arrest was induced in SHG-44 cells by HMBA.


2014 ◽  
Vol 99 (7) ◽  
pp. E1163-E1172 ◽  
Author(s):  
Wei Qiang ◽  
Yuan Zhao ◽  
Qi Yang ◽  
Wei Liu ◽  
Haixia Guan ◽  
...  

Context: ZIC1 has been reported to be overexpressed and plays an oncogenic role in some brain tumors, whereas it is inactivated by promoter hypermethylation and acts as a tumor suppressor in gastric and colorectal cancers. However, until now, its biological role in thyroid cancer remains totally unknown. Objectives: The aim of this study is to explore the biological functions and related molecular mechanism of ZIC1 in thyroid carcinogenesis. Setting and Design: Quantitative RT-PCR (qRT-PCR) was performed to evaluate mRNA expression of investigated genes. Methylation-specific PCR was used to analyze promoter methylation of the ZIC1 gene. The functions of ectopic ZIC1 expression in thyroid cancer cells were determined by cell proliferation and colony formation, cell cycle and apoptosis, as well as cell migration and invasion assays. Results: ZIC1 was frequently down-regulated by promoter hypermethylation in both primary thyroid cancer tissues and thyroid cancer cell lines. Moreover, our data showed that ZIC1 hypermethylation was significantly associated with lymph node metastasis in patients with papillary thyroid cancer. Notably, restoration of ZIC1 expression in thyroid cancer cells dramatically inhibited cell proliferation, colony formation, migration and invasion, and induced cell cycle arrest and apoptosis by blocking the activities of the phosphatidylinositol-3-kinase (PI3K)/Akt and RAS/RAF/MEK/ERK (MAPK) pathways, and enhancing FOXO3a transcriptional activity. Conclusions: Our data demonstrate that ZIC1 is frequently inactivated by promoter hypermethyaltion and functions as a tumor suppressor in thyroid cancer through modulating PI3K/Akt and MAPK signaling pathways and transcription factor FOXO3a.


2021 ◽  
Author(s):  
Bin Tie ◽  
Zheng Guo ◽  
Li Li ◽  
Wenhui Wang ◽  
Rong Liu ◽  
...  

Abstract Background: MicroRNAs (miRNAs) are dysregulated in hypoxia-induced hepatocellular carcinoma (HCC). This study probed the regulatory mechanism of miR-3156-5p on HCC under hypoxia. Methods: HCC cells (HepG2) were exposed to normoxia or hypoxia, and the conditioned medium (CM) of HepG2 was applied. Quantitative reverse transcription PCR (qRT-PCR) was implemented to analyze the miR-3156-5p profile. The cell counting kit-8 (CCK-8) assay and the colony formation experiment were conducted to measure cell proliferation, colony formation, and angiogenesis. Results: The results manifested that miR-3156-5p was up-regulated in HCC cells and endothelial cells under hypoxia, and up-regulating miR-3156-5p boosted HCC cell proliferation, endothelial cell angiogenesis, and HIF-1α/VEGF expression. Conclusions: miR-3156-5p activates the HIF-1α/VEGF pathway by hampering SOCS5, thereby enhancing the angiogenic potential of hypoxia-induced endothelial cells in HCC cells.


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