scholarly journals Effects of the SUMO Ligase BCA2 on Metabolic Activity, Cell Proliferation, Cell Migration, Cell Cycle, and the Regulation of NF-κB and IRF1 in Different Breast Epithelial Cellular Contexts

Author(s):  
Yuhang Shi ◽  
Sergio Castro-Gonzalez ◽  
Yuexuan Chen ◽  
Ruth Serra-Moreno

Breast cancer-associated gene 2 (BCA2) is an E3 ubiquitin and SUMO ligase with antiviral properties against HIV. Specifically, BCA2 (i) enhances the restriction imposed by BST2/Tetherin, impeding viral release; (ii) promotes the ubiquitination and degradation of the HIV protein Gag, limiting virion production; (iii) down-regulates NF-κB, which is necessary for HIV RNA synthesis; and (iv) activates the innate transcription factor IRF1. Due to its antiviral properties, ectopic expression of BCA2 in infected cells represents a promising therapeutic approach against HIV infection. However, BCA2 up-regulation is often observed in breast tumors. To date, the studies about BCA2 and cancer development are controversial, stating both pro- and anti-oncogenic roles. Here, we investigated the impact of BCA2 on cellular metabolic activity, cell proliferation, cell migration, and cell cycle progression. In addition, we also examined the ability of BCA2 to regulate NF-κB and IRF1 in transformed and non-tumor breast epithelial environments. Despite the fact that BCA2 promotes the transition from G1 to S phase of the cell cycle, it did not increase cell proliferation, migration nor metabolic activity. As expected, BCA2 maintains its enzymatic function at inhibiting NF-κB in different breast cancer cell lines. However, the effect of BCA2 on IRF1 differs depending on the cellular context. Specifically, BCA2 activates IRF1 in ER+ breast cell lines while it inhibits this transcription factor in ER– breast cancer cells. We hypothesize that the distinct actions of BCA2 over IRF1 may explain, at least in part, the different proposed roles for BCA2 in these cancers.

2020 ◽  
Author(s):  
Danahe Mohammed ◽  
Park Young Chan ◽  
Jeffrey J. Fredberg ◽  
David A. Weitz

AbstractThe migration of tumorigenic epithelial cells is a critical step for metastatic breast cancer progression. Although the role of the extracellular matrix in breast cancer cell migration has been extensively described, the effect of osmotic stress on the migration of tumor breast epithelial cohorts remains unclear. Most of our understanding on the effect of osmotic stresses on cell migration comes from studies at the level of the single cell in isolation and does not take into account cell-cell interactions. Here, we study the impact of moderate osmotic stress on the migration of epithelial clusters composed of either non-tumorigenic or tumorigenic epithelial cells. We observe a decrease in migration distance and speed for non-tumorigenic epithelial cells but not for tumorigenic ones. To explain these differences, we investigate how osmotic stress impacts the mechanical properties of cell clusters and affects cell volumes. After application of osmotic stress renal epithelial cells become stiffer whereas non-tumorigenic and tumorigenic breast epithelial cells do not. In addition, tumorigenic cells are shown to be less sensitive to osmotic stress than non-tumorigenic cells, and this difference is associated with lower levels of E-cadherin expression. Using EGTA treatments, we confirm that the establishment of cell-cell adhesive interactions is a key component of the behavior of epithelial clusters in response to osmotic stress. This study provides evidence on the low sensitivity of tumorigenic epithelial clusters to moderate osmotic stress and highlights the importance of cadherin-based junctions in response to osmotic stress.


2020 ◽  
Vol 2020 ◽  
pp. 1-14
Author(s):  
Xianbao Zhao

Objective. This study is designed to clarify that miR-1258 targets E2F1 to regulate the proliferation and cell cycle of breast cancer (BC) cells and consequently suppress the progression of BC. Methods. Bioinformatics analysis was used to analyze the differentially expressed genes in BC. The expression of miR-1258 and E2F1 mRNA in BC cell lines and immortalized breast epithelial cell lines were detected by qRT-PCR. The proliferation and growth activity of BC cells were detected by MTT and colony formation assays. The apoptosis and cell cycle of BC cells were detected by flow cytometry and the targeting relationship between miR-1258 and E2F1 was identified by dual-luciferase assay. Results. The expression of miR-1258 was decreased while that of E2F1 was increased in BC cells. Overexpression of miR-1258 and silencing E2F1 could inhibit the cell proliferation and growth, block cells in the G0/G1 phase, and promote cell apoptosis. Besides, miR-1258 inhibited cell proliferation and growth, block cells in the G0/G1 phase, and promote cell apoptosis by downregulating E2F1. Conclusion. miR-1258 regulates the proliferation and cell cycle to inhibit the progression of BC by targeting and downregulating E2F1.


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.


2009 ◽  
Vol 27 (15_suppl) ◽  
pp. 2542-2542
Author(s):  
J. Ju ◽  
B. Song ◽  
Y. Wang

2542 Background: Translational control plays a key role in resistance to anti-cancer drug treatment. MicroRNAs regulate gene expression at the post-transcriptional level, mainly by interacting with 3'-UTR of their mRNA targets. Methods: miR-215 was ectopically expressed by transient transfection in both human colon cancer cell lines and osteosarcoma cell lines. The impact of miR-215 on cell proliferation, cell cycle control, chemosensitivity and down stream targets were characterized. The expression of miR-215 in colorectal cancer specimens and normal adjacent tissues was quantified by real time-qRT-PCR analysis. Results: In this study, we discovered that miR-215 down-regulates the expression of both dihydrofolate reductase (DHFR) and thymidylate synthase (TS), two of the most important chemotherapeutic targets, in human osteosarcoma U-2 OS and colon cancer HCT-116 (wt-p53) cell lines. Cells with elevated miR-215 expression are more resistant to DHFR inhibitor methotrexate (MTX) or TS inhibitor Tomudex (TDX) treatment. Ectopically over-expressing miR-215 triggers reduced cell proliferation and increased G2 arrest, at least in part, through the induction of p53 and p21. miR-215 transfected cells with reduced proliferating phenotype were resist to MTX or TDX treatment due to deceased cell cycle in S phase. The expression of endogeneous miR-215 was highly elevated in CD133+/HI CD44+/HI colon cancer stem cells compared to CD133- CD44- colon cancer cells, suggesting that tumor stem cells may be avoiding cellular and DNA damage caused by chemotherapy with a reduced proliferating phenotype mediated by certain miRNAs such as miR-215. The elevated expression of miR-215 in colon cancer stem cells with slow proliferation rate and resistance to chemotherapy further supports the role of miR-215 in cell proliferation and chemotherapy resistance. Conclusions: miR-215 may have a unique potential as a novel therapeutic target and biomarker candidate in cancer. No significant financial relationships to disclose.


2021 ◽  
Author(s):  
Margarite Matossian ◽  
Steven Elliott ◽  
Van T. Hoang ◽  
Hope E. Burks ◽  
Maryl K. Wright ◽  
...  

Abstract Purpose: Breast cancer remains a prominent global disease affecting women worldwide despite the emergence of novel therapeutic regimens. Metastasis is responsible for most cancer-related deaths, and acquisition of a mesenchymal and migratory cancer cell phenotypes contributes to this devastating disease. The utilization of kinase targets in drug discovery have revolutionized the field of cancer research but despite impressive advancements in kinase-targeting drugs, a large portion of the human kinome remains under-studied in cancer. NEK5, a member of the Never-in-mitosis kinase family, is an example of such an understudied kinase. Here, we characterized the function of NEK5 in breast cancer. Methods: Stably overexpressing NEK5 cell lines (MCF-7) and shRNA knockdown cell lines (MDA-MB-231, TU-BcX-4IC) were utilized. Cell morphology changes were evaluated using immunofluorescence and quantification of cytoskeletal components. Cell proliferation was assessed by Ki-67 staining and transwell migration assays tested cell migration capabilities. In vivo experiments with murine models were necessary to demonstrate NEK5 function in breast cancer tumor growth and metastasis. Results: NEK5 activation altered breast cancer cell morphology and promoted cell migration independent of effects on cell proliferation. NEK5 overexpression or knockdown does not alter tumor growth kinetics but promotes or suppresses metastatic potential in a cell type specific manner, respectively. Conclusion: While NEK5 activity modulated cytoskeletal changes and cell motility, NEK5 activity affected cell seeding capabilities but not metastatic colonization or proliferation in vivo. Here we characterized NEK5 function in breast cancer systems and we implicate NEK5 in regulating specific steps of metastatic progression.


Life ◽  
2021 ◽  
Vol 11 (12) ◽  
pp. 1425
Author(s):  
Arshad Ali ◽  
Ayaz Ali ◽  
Shaker Khan ◽  
Muhammad Ibrahim ◽  
Mohammed Ali Alshehri ◽  
...  

(1) Background: Gastric cancer (GC) is the most common high death-rate cancer type worldwide, with an enhanced prevalence and increased rate of mortality. Although significant evidence on surgery strategy has been generated for the treatment of GC, conclusions are still uncertain regarding profound metastatic or persevering gastric cancer. Therefore, it is essential to develop novel and effective biomarkers or therapeutic targets for the diagnosis of GC. Histone deacetylations (HDACs) are important epigenetic regulators that control the aberrant transcription of critical genes that are mainly involved in cell proliferation, cell migration, regulation of the cell cycle, and different signal pathways. (2) Methods: Expression analysis of HDACs family members and E2F5 in gastric cancer cell lines was determined by RT-PCR and Western blotting. The cell proliferation was determined through an MTT assay. Cell migration was determined using a wound-healing assay. Flow cytometry experiments were used to determine cell-cycle analysis. The statistical software OriginPro 2015 (OriginLab, Northampton, MA, USA) was used to analyze data. A p value of < 0.05 was regarded as significant. (3) Results: The present study shows that E2F5 expression is upregulated in GC cancer cell lines compared to normal cell lines, and is positively associated with the level of HDACs and BCL2. HDACi and knocking down of E2F5 as tumor suppressors inhibited cell proliferation, migration invasion, and blocked the cell cycle in gastric cancer cells by suppressing BCL2. The results conclude that the anticancer mechanism of HDACi was determined by regulating E2F5 via targeting BCL2. (4) Conclusions: Our results suggest that the HDAC–E2F5–BCL2 signaling axis might be a novel potential biomarker in gastric cancer.


Cancers ◽  
2021 ◽  
Vol 13 (12) ◽  
pp. 2920
Author(s):  
Nayoung Kim ◽  
Solbi Kim ◽  
Myung-Won Lee ◽  
Heung-Jin Jeon ◽  
Hyewon Ryu ◽  
...  

Microphthalmia-associated transcription factor (MITF) is a basic helix-loop-helix leucine zipper transcription factor involved in the lineage-specific regulation of melanocytes, osteoclasts and mast cells. MITF is also involved in the progression of melanomas and other carcinomas, including the liver, pancreas and lung. However, the role of MITF in clear cell renal cell carcinoma (ccRCC) is largely unknown. This study investigates the functional role of MITF in cancer and the molecular mechanism underlying disease progression in ccRCC. MITF knockdown inhibited cell proliferation and shifted the cell cycle in ccRCC cells. In addition, MITF knockdown reduced wound healing, cell migration and invasion compared with the controls. Conversely, MITF overexpression in SN12C and SNU482 cells increased cell migration and invasion. Overexpression of MITF activated the RhoA/YAP signaling pathway, which regulates cell proliferation and invasion, and increased YAP signaling promoted cell cycle-related protein expression. Additionally, tumor formation was impaired by MITF knockdown and enhanced by MITF overexpression in vivo. In summary, MITF expression was associated with aggressive tumor behavior, and increased the migratory and invasive capabilities of ccRCC cells. These effects were reversed by MITF suppression. These results suggest that MITF is a potential therapeutic target for the treatment of ccRCC.


Author(s):  
Chen-Long Wang ◽  
Jing-Chi Li ◽  
Ci-Xiang Zhou ◽  
Cheng-Ning Ma ◽  
Di-Fei Wang ◽  
...  

Abstract Purpose Tumor metastasis is the main cause of death from breast cancer patients and cell migration plays a critical role in cancer metastasis. Recent studies have shown long non-coding RNAs (lncRNAs) play an essential role in the initiation and progression of cancer. In the present study, the role of an LncRNA, Rho GTPase Activating Protein 5- Antisense 1 (ARHGAP5-AS1) in breast cancer was investigated. Methods RNA sequencing was performed to find out dysregulated LncRNAs in MDA-MB-231-LM2 cells. Transwell migration assays and F-actin staining were utilized to estimate cell migration ability. RNA pulldown assays and RNA immunoprecipitation were used to prove the interaction between ARHGAP5-AS1 and SMAD7. Western blot and immunofluorescence imaging were used to examine the protein levels. Dual luciferase reporter assays were performed to evaluate the activation of TGF-β signaling. Results We analyzed the RNA-seq data of MDA-MB-231 and its highly metastatic derivative MDA-MB-231-LM2 cell lines (referred to as LM2) and identified a novel lncRNA (NR_027263) named as ARHGAP5-AS1, which expression was significantly downregulated in LM2 cells. Further functional investigation showed ARHGAP5-AS1 could inhibit cell migration via suppression of stress fibers in breast cancer cell lines. Afterwards, SMAD7 was further identified to interact with ARHGAP5-AS1 by its PY motif and thus its ubiquitination and degradation was blocked due to reduced interaction with E3 ligase SMURF1 and SMURF2. Moreover, ARHGAP5-AS1 could inhibit TGF-β signaling pathway due to its inhibitory role on SMAD7. Conclusion ARHGAP5-AS1 inhibits breast cancer cell migration via stabilization of SMAD7 protein and could serve as a novel biomarker and a potential target for breast cancer in the future.


2021 ◽  
Vol 13 (1) ◽  
pp. 17-29
Author(s):  
Emann M Rabie ◽  
Sherry X Zhang ◽  
Andreas P Kourouklis ◽  
A Nihan Kilinc ◽  
Allison K Simi ◽  
...  

Abstract Metastasis, the leading cause of mortality in cancer patients, depends upon the ability of cancer cells to invade into the extracellular matrix that surrounds the primary tumor and to escape into the vasculature. To investigate the features of the microenvironment that regulate invasion and escape, we generated solid microtumors of MDA-MB-231 human breast carcinoma cells within gels of type I collagen. The microtumors were formed at defined distances adjacent to an empty cavity, which served as an artificial vessel into which the constituent tumor cells could escape. To define the relative contributions of matrix degradation and cell proliferation on invasion and escape, we used pharmacological approaches to block the activity of matrix metalloproteinases (MMPs) or to arrest the cell cycle. We found that blocking MMP activity prevents both invasion and escape of the breast cancer cells. Surprisingly, blocking proliferation increases the rate of invasion but has no effect on that of escape. We found that arresting the cell cycle increases the expression of MMPs, consistent with the increased rate of invasion. To gain additional insight into the role of cell proliferation in the invasion process, we generated microtumors from cells that express the fluorescent ubiquitination-based cell cycle indicator. We found that the cells that initiate invasions are preferentially quiescent, whereas cell proliferation is associated with the extension of invasions. These data suggest that matrix degradation and cell proliferation are coupled during the invasion and escape of human breast cancer cells and highlight the critical role of matrix proteolysis in governing tumor phenotype.


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