E2F1 transcriptionally regulates CCNA2 expression to promote triple negative breast cancer tumorigenicity

2021 ◽  
pp. 1-14
Author(s):  
Yongbin Lu ◽  
Fei Su ◽  
Hui Yang ◽  
Yi Xiao ◽  
Xiaobin Zhang ◽  
...  

BACKGROUND: Triple-negative breast cancer (TNBC) is a highly malignant breast cancer subtype with a poor prognosis. The cell cycle regulator cyclin A2 (CCNA2) plays a role in tumor development. Herein, we explored the role of CCNA2 in TNBC. METHODS: We analyzed CCNA2 expression in 15 pairs of TNBC and adjacent tissues and assessed the relationship between CCNA2 expression using the tissue microarray cohort. Furthermore, we used two TNBC cohort datasets to analyze the correlation between CCNA2 and E2F transcription factor 1 (E2F1) and a luciferase reporter to explore their association. Through rescue experiments, we analyzed the effects of E2F1 knockdown on CCNA2 expression and cellular behavior. RESULTS: We found that CCNA2 expression in TNBC was significantly higher than that in adjacent tissues with similar observations in MDA-MB-231 and MDA-MB-468 cells. E2F1 was highly correlated with CCNA2 as observed through bioinformatics analysis (R= 0.80, P< 0.001) and through TNBC tissue verification analysis (R= 0.53, P< 0.001). We determined that E2F1 binds the +677 position within the CCNA2 promoter. Moreover, CCNA2 overexpression increased cell proliferation, invasion, and migration owing to E2F1 upregulation in TNBC. CONCLUSION: Our data indicate that E2F1 promotes TNBC proliferation and invasion by upregulating CCNA2 expression. E2F1 and CCNA2 are potential candidates that may be targeted for effective TNBC treatment.

Oncotarget ◽  
2016 ◽  
Vol 8 (12) ◽  
pp. 19455-19466 ◽  
Author(s):  
Zhishuang Li ◽  
Qingyong Meng ◽  
Aifeng Pan ◽  
Xiaojuan Wu ◽  
Jingjing Cui ◽  
...  

2021 ◽  
Vol 16 (1) ◽  
Author(s):  
Jintao Qian ◽  
Xinhan Lei ◽  
Yue Sun ◽  
Lu Zheng ◽  
Jia Li ◽  
...  

Abstract Background Growing evidence has demonstrated that long non-coding RNAs (lncRNAs) can function as modulators in the development of triple-negative breast cancer (TNBC). However, the function of lncRNA small nucleolar RNA host gene 8 (SNHG8) in TNBC remains unclear. Therefore, our study aimed at investigating the role of SNHG8 in the proliferation and migration of TNBC cells. Methods SNHG8 expression was evaluated using RT-qPCR assay. Cell proliferation and migration were assessed by EdU, colony formation and Transwell assays. The levels of proteins related to EMT process were examined by western blot assay. The interaction among SNHG8, miR-335-5p and pygopus family PHD finger 2 (PYGO2) was detected by RIP assay, RNA pull down assay and luciferase reporter assay. Results SNHG8 expression was significantly up-regulated in TNBC cells. SNHG8 silencing obviously inhibited TNBC cell proliferation, migration and EMT process. Moreover, SNHG8 acted as a sponge to sequester miR-335-5p in TNBC cells. Besides, PYGO2 was proven as a target gene of miR-335-5p, and SNHG8 promoted TNBC cell proliferation, migration and EMT process through regulating miR-335-5p and PYGO2. Conclusions Totally, our study indicated that SNHG8 promoted TNBC cell proliferation and migration by regulating the miR-335-5p/PYGO2 axis.


2020 ◽  
Vol 19 ◽  
pp. 153303382097752
Author(s):  
Lin Gan ◽  
Huachao Yang ◽  
Zhifeng Xiong ◽  
Zailiang Yang ◽  
Ting Wang ◽  
...  

MicroRNAs (miRNAs) are emerging as critical mediators in tumors, including triple-negative breast cancer (TNBC). The role of miR-518a-3p in TNBC was investigated to identify potential therapeutic target. Data from KM Plotter database ( www.kmplot.com ) showed that high miR-518a-3p expression was significantly associated with overall survival of patients with TNBC ( p = 0.04). The expression of miR-518a-3p was dysregulated in TNBC cells. Functional assays revealed that over-expression of miR-518a-3p inhibited cell invasion and migration of TNBC. Additionally, miR-518a-3p could target TMEM2 (transmembrane protein 2), and decreased protein and mRNA expression of TMEM2 in TNBC cells. Knockdown of TMEM2 suppressed cell invasion and migration through inhibiting phospho (p)-JAK1 (Janus kinase 1) and p-STAT (signal transducer and activator of transcription protein) 1/2. Moreover, over-expression of TMEM2 counteracted the suppressive effect of miR-518a-3p on TNBC invasion and migration through promoting the levels of p-JAK1 and p-STAT1/2. In conclusion, miR-518a-3p negatively regulates the JAK/STAT pathway via targeting TMEM2 and suppresses invasion and migration in TNBC, suggesting that miR-518a-3p may be a potential therapeutic target in TNBC.


2020 ◽  
Vol 21 (3) ◽  
pp. 1038
Author(s):  
Jiajia Zhang ◽  
Jiajia Dai ◽  
Qingxuan Zheng ◽  
Shuju Guo ◽  
Yanyan Yu ◽  
...  

Triple negative breast cancer (TNBC) is the most aggressive cancer in women, and despite improved treatments, it remains a major cause of morbidity and mortality. We and others have demonstrated that different hybrid compounds targeting PARP/MAPK or other pathways to inhibit cancer progression may lead to promising therapeutic results. We introduced fluorine to alter the physical properties of the compounds. TSC-3C was one of the generated compounds. Upon treatment with TSC-3C, MDA-MB-231 cell proliferation, invasion, and migration were inhibited. TSC-3C induced MDA-MB-231 cell mitochondrial dysfunction and apoptosis, which may be caused by reducing the level of phosphorylated p44/42 MAPK (ERK1/2) and increasing the level of p-JNK. The present study may help to elucidate the role of the MAPK pathway in the development of breast cancer and may promote further research on halogenated heterocyclic compounds for the treatment of breast cancer.


2020 ◽  
Author(s):  
Xiao Luo ◽  
Hui Wang

Abstract Background: Long noncoding RNAs (lncRNAs) have recently identified as essential gene modulators in numerous cancers. Previous studies have confirmed the oncogenic role of long intergenic nonprotein-coding RNA 00514 (LINC00514) in some cancers. Nevertheless, its biological function and mechanism remain elusive in triple-negative breast cancer (TNBC). Methods: Herein, we detected LINC00514 expression level in TNBC tissues and cells via RT-qPCR. The function of LINC00514 in TNBC cellular activities was assessed via colony formation, EdU, wound healing, transwell assays and flow cytometry analysis. Results: The binding between miR-6504-5p/miR-3139 and LINC00514/CCDC71L was validated by luciferase reporter assay. The data indicated that LINC00514 expression was increased in TNBC tissues and cells. Furthermore, it was manifested that silenced LINC00514 restrained cell proliferative, migratory and invasive abilities and accelerated cell apoptosis. In mechanism, LINC00514 was revealed to sequester miR-6504-5p and miR-3139 in TNBC cells. Furthermore, the low level of miR-6504-5p and miR-3139 was discovered in TNBC tissues and cells. Accordingly, we discovered overexpression of miR-6504-5p or miR-3139 retarded cell growth and migration in TNBC. Later, CCDC71L was recognized as a common downstream gene of miR-6504-5p and miR-3139. Rescue assay verified that overexpressed CCDC71L countervailed the inhibitive influence of LINC00514 knockdown in TNBC cellular process. Conclusion: MiR-6504-5p and miR-3139 were involved in LINC00514-mediated cellular activities through regulating CCDC71L expression, which provided a novel LINC00514/miR-6504-5p/miR-3139/CCDC71L axis in TNBC.


2020 ◽  
Vol 10 (1) ◽  
pp. 26-36
Author(s):  
XiaoHu Sun ◽  
Yue Yu ◽  
Jie Ge ◽  
Xin Wang ◽  
XuChen Cao

Protein R-spondin 2, which is known as roof plate-specific spondin 2, is an extracellular matrix secreted protein that participates in a wide range of biological processes. However, the expression of R-spondin 2 in triple negative breast cancer (TNBC) and its specific mechanism have not been reported. In this study, RT-qPCR and western blot were used to detect the expression of R-spondin 2 and Axin2 in cells. Cell transfection techniques were used to overexpress Axin2 and interfere with the expression of R-spondin 2. CCk-8 and clone formation assay were used to detect cell viability. Wound healing and Traswell techniques were used to test the rate of invasion and migration of TNBC cells. Western blot was used to detect the expression of related proteins. The results showed that the expression of R-spondin 2 in TNBC cell lines was significantly increased compared with normal breast cancer cells. After interfering with the expression of R-spondin 2 in TNBC cell lines, the rate of cell viability, invasion and migration were decreased. It was also found that the expressions of Axin2 and β-catenin and Cyclin-D1, which are wnt/β-catenin pathway related proteins, were significantly decreased. Subsequently, the overexpression of Axin2 can inhibit the proliferation, invasion and migration that were ever promoted by R-spondin 2 of TNBC cells. Moreover, the overexpression of Axin2 inhibited the activation of wnt/β-catenin signaling pathway, which was also activated by R-spondin 2 in TNBC cells. In a word, R-spondin 2 promoted proliferation, invasion and migration of triple negative breast cancer cells through activating wnt/β-catenin signaling pathway after Axin2 inhibition.


2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Xiao Luo ◽  
Hui Wang

Abstract Background Long noncoding RNAs (lncRNAs) have recently identified as essential gene modulators in numerous cancers. Previous studies have confirmed the oncogenic role of long intergenic nonprotein-coding RNA 00514 (LINC00514) in some cancers. Nevertheless, its biological function and mechanism remain unclear in triple-negative breast cancer (TNBC). Methods Herein, we detected LINC00514 expression level in TNBC tissues and cells using RT-qPCR. The function of LINC00514 in TNBC cellular activities was assessed by colony formation, EdU, wound healing, transwell assays and flow cytometry analysis. Results The binding between miR-6504-5p/miR-3139 and LINC00514/CCDC71L was validated by luciferase reporter assay. The results indicated that LINC00514 expression was upregulated in TNBC tissues and cells. Furthermore, it was manifested that silenced LINC00514 restrained cell proliferative, migratory and invasive abilities and promoted cell apoptosis. In mechanism, LINC00514 was revealed to sequester miR-6504-5p and miR-3139 in TNBC cells. Furthermore, the low level of miR-6504-5p and miR-3139 was identified in TNBC tissues and cells. Overexpression of miR-6504-5p or miR-3139 inhibited cell growth and migration in TNBC. CCDC71L was recognized as a common downstream gene of miR-6504-5p and miR-3139. Rescue assay verified that overexpressed CCDC71L countervailed the anti-tumor influence of LINC00514 knockdown on TNBC cell proliferation, migration, invasion and apoptosis. Conclusions LINC00514 promote cell proliferation, migration and invasion in triple-negative breast cancer by targeting the miR-6504-5p/miR-3139/CCDC71L axis in TNBC.


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