scholarly journals MED28 Over-Expression Shortens the Cell Cycle and Induces Genomic Instability

2019 ◽  
Vol 20 (7) ◽  
pp. 1746 ◽  
Author(s):  
Jin Cho ◽  
Joon-Seok Choi ◽  
Jae-Ho Lee ◽  
Min-Guk Cho ◽  
Hong-Sook Kim ◽  
...  

The mammalian mediator complex subunit 28 (MED28) is overexpressed in a variety of cancers and it regulates cell migration/invasion and epithelial-mesenchymal transition. However, transcription factors that increase MED28 expression have not yet been identified. In this study, we performed a luciferase reporter assay to identify and characterize the prospective transcription factors, namely E2F transcription factor 1, nuclear respiratory factor 1, E-26 transforming sequence 1, and CCAAT/enhancer-binding protein β, which increased MED28 expression. In addition, the release from the arrest at the G1−S or G2−M phase transition after cell cycle synchronization using thymidine or nocodazole, respectively, showed enhanced MED28 expression at the G1−S transition and mitosis. Furthermore, the overexpression of MED28 significantly decreased the duration of interphase and mitosis. Conversely, a knockdown of MED28 using si-RNA increased the duration of interphase and mitosis. Of note, the overexpression of MED28 significantly increased micronucleus and nuclear budding in HeLa cells. In addition, flow cytometry and fluorescence microscopy analyses showed that the overexpression of MED28 significantly increased aneuploid cells. Taken together, these results suggest that MED28 expression is increased by oncogenic transcription factors and its overexpression disturbs the cell cycle, which results in genomic instability and aneuploidy.

2020 ◽  
Vol 21 (19) ◽  
pp. 7388
Author(s):  
Federica Zinghirino ◽  
Xena Giada Pappalardo ◽  
Angela Messina ◽  
Francesca Guarino ◽  
Vito De Pinto

VDACs (voltage-dependent anion-selective channels) are pore-forming proteins of the outer mitochondrial membrane, whose permeability is primarily due to VDACs’ presence. In higher eukaryotes, three isoforms are raised during the evolution: they have the same exon–intron organization, and the proteins show the same channel-forming activity. We provide a comprehensive analysis of the three human VDAC genes (VDAC1–3), their expression profiles, promoter activity, and potential transcriptional regulators. VDAC isoforms are broadly but also specifically expressed in various human tissues at different levels, with a predominance of VDAC1 and VDAC2 over VDAC3. However, an RNA-seq cap analysis gene expression (CAGE) approach revealed a higher level of transcription activation of VDAC3 gene. We experimentally confirmed this information by reporter assay of VDACs promoter activity. Transcription factor binding sites (TFBSs) distribution in the promoters were investigated. The main regulators common to the three VDAC genes were identified as E2F-myc activator/cell cycle (E2FF), Nuclear respiratory factor 1 (NRF1), Krueppel-like transcription factors (KLFS), E-box binding factors (EBOX) transcription factor family members. All of them are involved in cell cycle and growth, proliferation, differentiation, apoptosis, and metabolism. More transcription factors specific for each VDAC gene isoform were identified, supporting the results in the literature, indicating a general role of VDAC1, as an actor of apoptosis for VDAC2, and the involvement in sex determination and development of VDAC3. For the first time, we propose a comparative analysis of human VDAC promoters to investigate their specific biological functions. Bioinformatics and experimental results confirm the essential role of the VDAC protein family in mitochondrial functionality. Moreover, insights about a specialized function and different regulation mechanisms arise for the three isoform gene.


2021 ◽  
Author(s):  
Nabanita Roy ◽  
Mrinmoy Kshattry ◽  
Susmita Mandal ◽  
Mohit Kumar Jolly ◽  
Dhruba Kumar Bhattacharyya ◽  
...  

AbstractGallbladder cancer (GBC) has a lower incidence rate among the population relative to other cancer types but majorly contributes to the total cancer cases of the biliary tract system. GBC is distinguished from other malignancies due to its high mortality, marked geographical variation and poor prognosis. To date no systemic targeted therapy is available for GBC. The main objective of this study is to determine the molecular signatures correlated with GBC development using integrative system level approaches. We performed analysis of publicly available transcriptomic data to identify differentially regulated genes and pathways. Co-expression network analysis and differential regulatory network analysis identified hub genes and hub transcription factors (TFs) associated with GBC pathogenesis and progression. We then assessed the epithelial-mesenchymal transition (EMT) status of the hub genes using a combination of three scoring methods. The hub genes such as; CDC6, MAPK15, CCNB2, BIRC7, L3MBTL1 identified are regulators of cell cycle components which suggests that cell cycle regulatory genes are significantly linked to GBC pathogenesis and progression.


2021 ◽  
Vol 14 (11) ◽  
pp. 1674-1682
Author(s):  
Xiao-Hui Yu ◽  
◽  
Cheng-Fang Li ◽  

AIM: To explore the regulatory mechanism of nuclear paraspeckle assembly transcript 1 (NEAT1) in the pathogenesis of posterior capsule opacification (PCO). METHODS: Quantitative reverse transcription polymerase chain reaction (RT-qPCR) was executed to analyze NEAT1 and microRNA (miR)-26a-5p expression in transforming growth factor-beta 2 (TGF-β2)-disposed lens epithelial cells (LECs). The proliferation, cell cycle progression, apoptosis, and migration of TGF-β2-disposed LECs were evaluated. The relationship between NEAT1 or fanconi anemia (FA) complementation group E (FANCE) and miR-26a-5p was verified by dual-luciferase reporter assay. RESULTS: TGF-β2 induced NEAT1 expression in LECs. NEAT1 inhibition accelerated apoptosis, cell cycle arrest, decreased proliferation, epithelial-mesenchymal transition (EMT), and migration of TGF-β2-disposed LECs. NEAT1 sponged miR-26a-5p to further regulate FANCE expression. Rescue experiments presented that miR-26a-5p downregulation overturned NEAT1 silencing-mediated impacts on TGF-β2-disposed LEC biological behaviors. Additionally, FANCE overexpression reversed miR-26a-5p mimic-mediated impacts on TGF-β2-disposed LEC biological behaviors. CONCLUSION: TGF-β2-induced NEAT1 facilitates LEC proliferation, migration, and EMT by upregulating FANCE via sequestering miR-26a-5p.


2007 ◽  
Vol 18 (11) ◽  
pp. 4615-4624 ◽  
Author(s):  
Jakob Mejlvang ◽  
Marina Kriajevska ◽  
Cindy Vandewalle ◽  
Tatyana Chernova ◽  
A. Emre Sayan ◽  
...  

Zinc finger transcription factors of the Snail/Slug and ZEB-1/SIP1 families control epithelial-mesenchymal transitions in development in cancer. Here, we studied SIP1-regulated mesenchymal conversion of epidermoid A431 cells. We found that concomitant with inducing invasive phenotype, SIP1 inhibited expression of cyclin D1 and induced hypophosphorylation of the Rb tumor suppressor protein. Repression of cyclin D1 was caused by direct binding of SIP1 to three sequence elements in the cyclin D1 gene promoter. By expressing exogenous cyclin D1 in A431/SIP1 cells and using RNA interference, we demonstrated that the repression of cyclin D1 gene by SIP1 was necessary and sufficient for Rb hypophosphorylation and accumulation of cells in G1 phase. A431 cells expressing SIP1 along with exogenous cyclin D1 were highly invasive, indicating that SIP1-regulated invasion is independent of attenuation of G1/S progression. However, in another epithelial-mesenchymal transition model, gradual mesenchymal conversion of A431 cells induced by a dominant negative mutant of E-cadherin produced no effect on the cell cycle. We suggest that impaired G1/S phase progression is a general feature of cells that have undergone EMT induced by transcription factors of the Snail/Slug and ZEB-1/SIP1 families.


2021 ◽  
Vol 20 ◽  
Author(s):  
Rabih Roufayel ◽  
Rabih Mezher ◽  
Kenneth B. Storey

: Selected transcription factors have critical roles to play in organism survival by regulating the expression of genes that control the adaptations needed to handle stress conditions. The retinoblastoma (Rb) protein coupled with the E2F transcription factor family was demonstrated to have roles in controlling the cell cycle during freezing and associated environmental stresses (anoxia, dehydration). Rb phosphorylation or acetylation at different sites provide a mechanism for repressing cell proliferation that is under the control of E2F transcription factors in animals facing stresses that disrupt cellular energetics or cell volume controls. Other central regulators of the cell cycle including Cyclins, Cyclin dependent kinases (Cdks), and checkpoint proteins detect DNA damage or any improper replication, blocking further progression of cell cycle and interrupting cell proliferation. This review provides an insight into the molecular regulatory mechanisms of cell cycle control, focusing on Rb-E2F along with Cyclin-Cdk complexes typically involved in development and differentiation that need to be regulated in order to survive extreme cellular stress.


Cancers ◽  
2021 ◽  
Vol 13 (12) ◽  
pp. 3089
Author(s):  
Chuan Zhang ◽  
Mandy Berndt-Paetz ◽  
Jochen Neuhaus

Background: A hallmark of Notch signaling is its variable role in tumor biology, ranging from tumor-suppressive to oncogenic effects. Until now, the mechanisms and functions of Notch pathways in bladder cancer (BCa) are still unclear. Methods: We used publicly available data from the GTEx and TCGA-BLCA databases to explore the role of the canonical Notch pathways in BCa on the basis of the RNA expression levels of Notch receptors, ligands, and downstream genes. For statistical analyses of cancer and non-cancerous samples, we used R software packages and public databases/webservers. Results: We found differential expression between control and BCa samples for all Notch receptors (NOTCH1, 2, 3, 4), the delta-like Notch ligands (DLL1, 3, 4), and the typical downstream gene hairy and enhancer of split 1 (HES1). NOTCH2/3 and DLL4 can significantly differentiate non-cancerous samples from cancers and were broadly altered in subgroups. High expression levels of NOTCH2/3 receptors correlated with worse overall survival (OS) and shorter disease-free survival (DFS). However, at long-term (>8 years) follow-up, NOTCH2 expression was associated with a better OS and DFS. Furthermore, the cases with the high levels of DLL4 were associated with worse OS but improved DFS. Pathway network analysis revealed that NOTCH2/3 in particular correlated with cell cycle, epithelial–mesenchymal transition (EMT), numbers of lymphocyte subtypes, and modulation of the immune system. Conclusions: NOTCH2/3 and DLL4 are potential drivers of Notch signaling in BCa, indicating that Notch and associated pathways play an essential role in the progression and prognosis of BCa through directly modulating immune cells or through interaction with cell cycle and EMT.


2021 ◽  
Vol 20 ◽  
pp. 153303382198981
Author(s):  
Xin-bo Sun ◽  
Yong-wei Chen ◽  
Qi-sheng Yao ◽  
Xu-hua Chen ◽  
Min He ◽  
...  

Background: Prostate cancer is a common malignant tumor with a high incidence. MicroRNAs (miRNAs) have been shown to be important post-transcriptional regulators during tumorigenesis. This study aimed to explore the effect of miR-144 on PCa proliferation and apoptosis. Material and Methods: The expression of miR-144 and EZH2 were examined in clinical PCa tissues. PCa cell line LNCAP and DU-145 was employed and transfected with miR-144 mimics or inhibitors. The correlation between miR-144 and EZH2 was verified by luciferase reporter assay. Cell viability, apoptosis and migratory capacity were detected by CCK-8, flow cytometry assay and wound healing assay. The protein level of EZH2, E-Cadherin, N-Cadherin and vimentin were analyzed by western blotting. Results: miR-144 was found to be negatively correlated to the expression of EZH2 in PCa tissues. Further studies identified EZH2 as a direct target of miR-144. Moreover, overexpression of miR-144 downregulated expression of EZH2, reduced cell viability and promoted cell apoptosis, while knockdown of miR-144 led to an inverse result. miR-144 also suppressed epithelial-mesenchymal transition level of PCa cells. Conclusion: Our study indicated that miR-144 negatively regulate the expression of EZH2 in clinical specimens and in vitro. miR-144 can inhibit cell proliferation and induce cell apoptosis in PCa cells. Therefore, miR-144 has the potential to be used as a biomarker for predicting the progression of PCa.


2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Kejun Liu ◽  
Xianwen Chen ◽  
Ligang Wu ◽  
Shiyuan Chen ◽  
Nianxin Fang ◽  
...  

Abstract Background ID1 is associated with resistance to the first generation of EGFR tyrosine kinase inhibitors (EGFR-TKIs) in non-small cell lung cancer (NSCLC). However, the effect of ID1 expression on osimertinib resistance in EGFR T790M-positive NSCLC is not clear. Methods We established a drug-resistant cell line, H1975/OR, from the osimertinib-sensitive cell line H1975. Alterations in ID1 protein expression and Epithelial–mesenchymal transition (EMT)-related proteins were detected with western blot analysis. RT-PCR was used to evaluate the differences of gene mRNA levels. ID1 silencing and overexpression were used to investigate the effects of related gene on osimertinib resistance. Cell Counting Kit-8 (CCK8) was used to assess the proliferation rate in cells with altered of ID1 expression. Transwell assay was used to evaluate the invasion ability of different cells. The effects on the cell cycle and apoptosis were also compared using flow cytometry. Results In our study, we found that in osimertinib-resistant NSCLC cells, the expression level of the EMT-related protein E-cadherin was lower than that of sensitive cells, while the expression level of ID1 and vimentin were higher than those of sensitive cells. ID1 expression levels was closely related to E-cadherin and vimentin in both osimertinib-sensitive and resistant cells. Alteration of ID1 expression in H1975/OR cells could change the expression of E-cadherin. Downregulating ID1 expression in H1975/OR cells could inhibit cell proliferation, reduce cell invasion, promote cell apoptosis and arrested the cell cycle in the G1/G0 stage phase. Our study suggests that ID1 may induce EMT in EGFR T790M-positive NSCLC, which mediates drug resistance of osimertinib. Conclusions Our study revealed the mechanism of ID1 mediated resistance to osimertinib in EGFR T790M-positive NSCLC through EMT, which may provide new ideas and methods for the treatment of EGFR mutated NSCLC after osimertinib resistance.


2021 ◽  
Vol 12 (2) ◽  
Author(s):  
Yawei Wang ◽  
Yingying Sun ◽  
Chao Shang ◽  
Lili Chen ◽  
Hongyu Chen ◽  
...  

AbstractRing1b is a core subunit of polycomb repressive complex 1 (PRC1) and is essential in several high-risk cancers. However, the epigenetic mechanism of Ring1b underlying breast cancer malignancy is poorly understood. In this study, we showed increased expression of Ring1b promoted metastasis by weakening cell–cell adhesions of breast cancer cells. We confirmed that Ring1b could downregulate E-cadherin and contributed to an epigenetic rewiring via PRC1-dependent function by forming distinct complexes with DEAD-box RNA helicases (DDXs) or epithelial-mesenchymal transition transcription factors (EMT TFs) on site-specific loci of E-cadherin promoter. DDXs-Ring1b complexes moderately inhibited E-cadherin, which resulted in an early hybrid EMT state of epithelial cells, and EMT TFs-Ring1b complexes cooperated with DDXs-Ring1b complexes to further repress E-cadherin in mesenchymal-like cancer cells. Clinically, high expression of Ring1b with DDXs or EMT TFs predicted low levels of E-cadherin, metastatic behavior, and poor prognosis. These findings provide an epigenetic regulation mechanism of Ring1b complexes in E-cadherin expression. Ring1b complexes may be potential therapeutic targets and biomarkers for diagnosis and prognosis in invasion breast cancer.


2021 ◽  
Vol 12 (7) ◽  
Author(s):  
Peng Li Zhou ◽  
Zhengyang Wu ◽  
Wenguang Zhang ◽  
Miao Xu ◽  
Jianzhuang Ren ◽  
...  

AbstractGrowing evidence has indicated that circular RNAs (circRNAs) play a pivotal role as functional RNAs in diverse cancers. However, most circRNAs involved in esophageal squamous cell carcinoma (ESCC) remain undefined, and the underlying molecular mechanisms mediated by circRNAs are largely unclear. Here, we screened human circRNA expression profiles in ESCC tissues and found significantly increased expression of hsa_circ_0000277 (termed circPDE3B) in ESCC tissues and cell lines compared to the normal controls. Moreover, higher circPDE3B expression in patients with ESCC was correlated with advanced tumor-node-metastasis (TNM) stage and dismal prognosis. Functional experiments demonstrated that circPDE3B promoted the tumorigenesis and metastasis of ESCC cells in vitro and in vivo. Mechanistically, bioinformatics analysis, a dual-luciferase reporter assay, and anti-AGO2 RNA immunoprecipitation showed that circPDE3B could act as a competing endogenous RNA (ceRNA) by harboring miR-4766-5p to eliminate the inhibitory effect on the target gene laminin α1 (LAMA1). In addition, LAMA1 was significantly upregulated in ESCC tissues and was positively associated with the aggressive oncogenic phenotype. More importantly, rescue experiments revealed that the oncogenic role of circPDE3B in ESCC is partly dependent on the miR-4766-5p/LAMA1 axis. Furthermore, bioinformatics analysis combined with validation experiments showed that epithelial-mesenchymal transition (EMT) activation was involved in the oncogenic functions of the circPDE3B–miR-4766-5p/LAMA1 axis in ESCC. Taken together, we demonstrate for the first time that the circPDE3B/miR-4766-5p/LAMA1 axis functions as an oncogenic factor in promoting ESCC cell proliferation, migration, and invasion by inducing EMT, implying its potential prognostic and therapeutic significance in ESCC.


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