Effect of microRNA-202-3p on cell proliferation and targeting of ADP-ribosylation factor-like 5A in human colorectal carcinoma.

2013 ◽  
Vol 31 (15_suppl) ◽  
pp. e14667-e14667
Author(s):  
Qifeng WANG ◽  
Xiang Du

e14667 Background: MicroRNAs (miRNAs) are small, non-coding RNAs that are strongly implicated in cancer and reshaped our understanding of the role of non-protein-coding genes in carcinogenesis. Methods: Quantitative RT-PCR was used to evaluate miR-202-3p expression in 94 pairs of human primary CRC and adjacent noncancerous tissues (NCT) to determine the clinicopathologic significance of miR-202-3p. Cell proliferation analysis and Xenograft analysis was used to investigate miR-202-3p function in vitro and in vivo.It’s direct target ARL5A was confirmed by Luciferase assay and Western blot. Immunochemistry was performed to reveal endogenous protein level of ARL5A and analysis clinical significance. Results: In this study, miR-202-3p was verified significantly down regulated in 46.7% (44/94) of the CRC tissues when compared to the corresponding noncancerous tissues(NCT). Subsequently, DNA copy number deletion of Pre-miR-202 in 63.2%(24/38) CRC tissue was proved(compared with NCT), which was considered as a main cause of the low expression of miR-202-3p. Cell proliferation analysis and colony formation assay showed that overexpression of miR-202-3p inhibit CRC cell growth in vitro. Xenograft analysis revealed that ectopic expression of miR-202-3p decreased the tumorigenicity of CRC cells in vivo. Consistent with these results, silencing of miR-202-3p resulted in a increased growth ratio of the colon cancer cells. In addition, ADP-ribosylation factor-like 5A(ARL5A) was predicted as potential target of miR-202-3p which was confirmed by Luciferase assay and Western blot. Overexpression of miR-202-3p could reduced the endogenous protein level of ARL5A, whereas silencing of miR-202-3p obviously up regulated ARL5A expression. In human CRC tissues, miR-202-3p expression levels correlated inversely with ARL5A protein levels which was identified as an prognostic factor in this study. Furthermore, knockdown of ARL5A phenocopied the proliferation-inhibiting effect of miR-202-3p. Conclusions: These results indicated that miR-202-3p, acting as a new tumor suppressor in CRC, could decrease cell proliferation via directly targeting ARL5A, a first reported gene related to CRC prognosis.

2013 ◽  
Vol 47 (1) ◽  
pp. 42-49 ◽  
Author(s):  
Xinyu Wu ◽  
Daixing Zhong ◽  
Bin Lin ◽  
Wenliang Zhai ◽  
Zhenqi Ding ◽  
...  

Abstract Background. The ether à go-go (Eag) channel has been shown to be overexpressed in a variety of cancers. However, the expression and function of Eag in osteosarcoma are poorly understood. In addition, the molecular mechanisms responsible for Eag overexpression in cancer cells remain unclear. Methods. The expression of Eag in human osteosarcoma cell line MG-63 was detected by reverse transcription polymerase chain reaction (RT-PCR) and Western blot analysis. The effect of Eag inhibition on MG-63 cell proliferation was assessed in vitro. The effect of short hairpin RNA (shRNA) mediated knockdown of Eag on osteosarcoma growth was evaluated in xenograft model in vivo. The activation of mitogen-activated protein kinase (MAPK) pathway and p53 in MG-63 cells was detected by Western blot analysis. Results. Eag was overexpressed in MG-63 cells. Imipramine or Eag shRNA significantly suppressed the proliferation of MG-63 cells in vitro and in vivo. MG-63 cell proliferation was specifically inhibited by p38 MAPK inhibitor SB203580 or small interference RNA (siRNA). The inhibition of p38 MAPK activation by SB203580 or siRNA reduced Eag protein level but increased p53 protein level. Moreover, the activation of p53 by nutlin-3 induced cell growth arrest in MG-63 cells and reduced Eag protein level, while the inactivation of p53 by pifithrin-alpha (PFT-α) promoted MG-63 cell growth and increased Eag protein expression. Conclusions. Eag channel functions as an oncogene to promote the proliferation of human osteosarocma cells. Furthermore, the high expression of Eag in osteosarcoma cells is regulated by p38 MAPK/p53 pathway.


2021 ◽  
Author(s):  
Jiantang Yang ◽  
Lili Fu ◽  
Yi Zeng ◽  
Chen Yuan

Abstract Background: Radiation-induced oral mucositis (RIOM) is an adverse reaction in patients of head and neck cancer after radiotherapy. However, the key regulatory factors in the pathogenesis of RIOM remain largely unclear. In this article, we discover a novel role of DNA damage-inducible transcript 4 (DDIT4) in regulating RIOM pathogenesis.Methods: We established RIOM in vitro and in vivo models to mimic the biological processes of RIOM. The level of DDIT4 in RIOM was analyzed by real-time PCR and Western blot. Through the bioinformatics analysis and luciferase assay, the relationship between miR-199b-3p and DDIT4 was performed. The level of mTOR signaling were explored by Western blot. Besides, Clone Formation and EDU assay were performed to investigate the effects of miR-199b-3p/DDIT4 on cell proliferation. H&E and immunohistochemistry experiments examined the effects of miR-199b-3p/DDIT4 on RIOM in vivo. Results: We found that the level of DDIT4 was significantly reduced during the RIOM formation, and up-regulated of DDIT4 suppressed the progression of RIOM in vitro and in vivo. Besides, we found DDIT4 was a direct target of miR-199b-3p. Ectopic expression of miR-199b-3p repressed the level of DDIT4 and activated mTOR signal conduction to promote RIOM progress, whereas the silencing of miR-199b-3p promoted the DDIT4-mediated RIOM regulation both in vitro and in vivo. Conclusion: Collectively, our studies not only identified the novel functional role of DDIT4 in modulating pathogenic processes of RIOM but also provided new directions and ideas for the future treatment of radiotherapy oral mucositis.


2013 ◽  
Vol 24 (2) ◽  
pp. 161-166 ◽  
Author(s):  
Jincheng-Yuan ◽  
Jinhui-Song ◽  
Hailian-Ma ◽  
Xiaoqing-Song ◽  
Huiping-Wei ◽  
...  

1990 ◽  
Vol 10 (12) ◽  
pp. 6690-6699
Author(s):  
T Stearns ◽  
R A Kahn ◽  
D Botstein ◽  
M A Hoyt

ADP ribosylation factor (ARF) is a ubiquitous 21-kDa GTP-binding protein in eucaryotes. ARF was first identified in animal cells as the protein factor required for the efficient ADP-ribosylation of the mammalian G protein Gs by cholera toxin in vitro. A gene (ARF1) encoding a protein homologous to mammalian ARF was recently cloned from Saccharomyces cerevisiae (Sewell and Kahn, Proc. Natl. Acad. Sci. USA, 85:4620-4624, 1988). We have found a second gene encoding ARF in S. cerevisiae, ARF2. The two ARF genes are within 28 centimorgans of each other on chromosome IV, and the proteins encoded by them are 96% identical. Disruption of ARF1 causes slow growth, cold sensitivity, and sensitivity to normally sublethal concentrations of fluoride ion in the medium. Disruption of ARF2 causes no detectable phenotype. Disruption of both genes is lethal; thus, ARF is essential for mitotic growth. The ARF1 and ARF2 proteins are functionally homologous, and the phenotypic differences between mutations in the two genes can be accounted for by the level of expression; ARF1 produces approximately 90% of total ARF. Among revertants of the fluoride sensitivity of an arf1 null mutation were ARF1-ARF2 fusion genes created by a gene conversion event in which the deleted ARF1 sequences were repaired by recombination with ARF2.


2018 ◽  
Vol 2018 ◽  
pp. 1-15 ◽  
Author(s):  
Ning Li ◽  
Haiming Wu ◽  
Rongxin Geng ◽  
Qizhu Tang

Diabetic cardiomyopathy (DCM) is a disorder of the myocardium in diabetic patients, which is one of the critical complications of diabetes giving rise to an increased mortality. However, the underlying mechanisms of DCM remain incompletely understood presently. This study was designed to screen the potential molecules and pathways implicated with DCM. GSE26887 involving 5 control individuals and 7 DCM patients was selected from the GEO database to identify the differentially expressed genes (DEGs). DAVID was applied to perform gene ontology (GO) and the Kyoto Encyclopedia of Genes and Genomes (KEGG) analyses. A protein-protein interaction (PPI) network was also constructed to visualize the interactions among these DEGs. To further validate significant genes and pathways, quantitative real-time PCR (qPCR) and Western blot were performed. A total of 236 DEGs were captured, including 134 upregulated and 102 downregulated genes. GO, KEGG, and the PPI network disclosed that inflammation, immune disorders, metabolic disturbance, and mitochondrial dysfunction were significantly enriched in the development of DCM. Notably, IL6 was an upregulated hub gene with the highest connectivity degree, suggesting that it may interact with a great many molecules and pathways. Meanwhile, SOCS3 was also one of the top 15 hub genes in the PPI network. Herein, we detected the protein level of STAT3 and SOCS3 in a mouse model with DCM. Western blot results showed that the protein level of SOCS3 was significantly lower while phosphorylated-STAT3 (P-STAT3) was activated in mice with DCM. In vitro results also uncovered the similar alterations of SOCS3 and P-STAT3 in cardiomyocytes and cardiac fibroblasts induced by high glucose (HG). However, overexpression of SOCS3 could significantly reverse HG-induced cardiomyocyte hypertrophy and collagen synthesis of cardiac fibroblasts. Taken together, our analysis unveiled potential biomarkers and molecular mechanisms in DCM, which could be helpful to the diagnosis and treatment of DCM.


2000 ◽  
Vol 149 (5) ◽  
pp. 1087-1096 ◽  
Author(s):  
Arunashree Bhamidipati ◽  
Sally A. Lewis ◽  
Nicholas J. Cowan

The ADP ribosylation factor-like proteins (Arls) are a family of small monomeric G proteins of unknown function. Here, we show that Arl2 interacts with the tubulin-specific chaperone protein known as cofactor D. Cofactors C, D, and E assemble the α/β- tubulin heterodimer and also interact with native tubulin, stimulating it to hydrolyze GTP and thus acting together as a β-tubulin GTPase activating protein (GAP). We find that Arl2 downregulates the tubulin GAP activity of C, D, and E, and inhibits the binding of D to native tubulin in vitro. We also find that overexpression of cofactors D or E in cultured cells results in the destruction of the tubulin heterodimer and of microtubules. Arl2 specifically prevents destruction of tubulin and microtubules by cofactor D, but not by cofactor E. We generated mutant forms of Arl2 based on the known properties of classical Ras-family mutations. Experiments using these altered forms of Arl2 in vitro and in vivo demonstrate that it is GDP-bound Arl2 that interacts with cofactor D, thereby averting tubulin and microtubule destruction. These data establish a role for Arl2 in modulating the interaction of tubulin-folding cofactors with native tubulin in vivo.


2020 ◽  
Vol 20 (1) ◽  
Author(s):  
Xinyue Du ◽  
Shuangmiao Wang ◽  
Xingyan Liu ◽  
Tao He ◽  
Xiangui Lin ◽  
...  

Abstract Background Non-small cell lung cancer (NSCLC) includes lung adenocarcinoma (LUAD) and lung squamous cell carcinoma (LUSC). MicroRNA (miRNA) plays an important role in the regulation of post-transcriptional gene expression in animals and plants, especially in lung adenocarcinoma. Methods MiR-1307-5p is an miRNA with significant differences screened by the second generation of high-throughput sequencing in the early stage of our research group. In the current study, a series of in vitro and in vivo experiments were carried out. MiR-1307-5p mimic, miR-1307-5p inhibitor, and NC were transfected into A549 and H1299 lung adenocarcinoma cells. The correlation between miR-1307-5p and clinicopathological features in pathological samples was analyzed using a lung adenocarcinoma tissue microarray, and miR-1307-5p expression was detected by qPCR. CCK-8, EdU, colony formation, scratch test, and Transwell assays were used to observe cell proliferation and migration. Double luciferase assay, western blot, qPCR, and immunohistochemistry were employed in confirming the target relationship between miR-1307-5p and TRAF3. Western blotting was used to analyze the relationship between miR-1307-5p and the NF-κB/MAPK pathway. Finally, the effect of miR-1307-5p on tumor growth was studied using a subcutaneous tumorigenesis model in nude mice. Results Increased miR-1307-5p expression was significantly related to decreased overall survival rate of lung adenocarcinoma patients, revealing miR-1307-5p as a potential oncogene in lung adenocarcinoma. MiR-1307-5p mimic significantly promoted while miR-1307-5p inhibitor reduced the growth and proliferation of A549 and H1299 cells. MiR-1307-5p overexpression significantly enhanced the migration ability while miR-1307-5p inhibition reduced the migration ability of A549 and H1299 cells. Target binding of miR-1307-5p to TRAF3 was confirmed by double luciferase assay, western blot, qPCR, and immunohistochemistry. miR-1307-5p caused degradation of TRAF3 mRNA and protein. MiR-1307-5p targeted TRAF3 and activated the NF-κB/MAPK pathway. TRAF3 colocalized with p65 and the localization of TRAF3 and p65 changed in each treatment group. Tumor volume of the lv-miR-1307-5p group was significantly larger than that of the lv-NC group, and that of the lv-miR-1307-5p-inhibitor group was significantly smaller than that of the lv-NC group. Conclusion In conclusion, miR-1307-5p targets TRAF3 and activates the NF-κB/MAPK pathway to promote proliferation in lung adenocarcinoma.


1997 ◽  
Vol 138 (3) ◽  
pp. 505-515 ◽  
Author(s):  
Victor Faúndez ◽  
Jim-Tong Horng ◽  
Regis B. Kelly

Carrier vesicle generation from donor membranes typically progresses through a GTP-dependent recruitment of coats to membranes. Here we explore the role of ADP ribosylation factor (ARF) 1, one of the GTP-binding proteins that recruit coats, in the production of neuroendocrine synaptic vesicles (SVs) from PC12 cell membranes. Brefeldin A (BFA) strongly and reversibly inhibited SV formation in vivo in three different PC12 cell lines expressing vesicle-associated membrane protein–T Antigen derivatives. Other membrane traffic events remained unaffected by the drug, and the BFA effects were not mimicked by drugs known to interfere with formation of other classes of vesicles. The involvement of ARF proteins in the budding of SVs was addressed in a cell-free reconstitution system (Desnos, C., L. Clift-O'Grady, and R.B. Kelly. 1995. J. Cell Biol. 130:1041–1049). A peptide spanning the effector domain of human ARF1 (2–17) and recombinant ARF1 mutated in its GTPase activity, both inhibited the formation of SVs of the correct size. During in vitro incubation in the presence of the mutant ARFs, the labeled precursor membranes acquired different densities, suggesting that the two ARF mutations block at different biosynthetic steps. Cell-free SV formation in the presence of a high molecular weight, ARF-depleted fraction from brain cytosol was significantly enhanced by the addition of recombinant myristoylated native ARF1. Thus, the generation of SVs from PC12 cell membranes requires ARF and uses its GTPase activity, probably to regulate coating phenomena.


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