scholarly journals Determination of a Comprehensive Alternative Splicing Regulatory Network and Combinatorial Regulation by Key Factors during the Epithelial-to-Mesenchymal Transition

2016 ◽  
Vol 36 (11) ◽  
pp. 1704-1719 ◽  
Author(s):  
Yueqin Yang ◽  
Juw Won Park ◽  
Thomas W. Bebee ◽  
Claude C. Warzecha ◽  
Yang Guo ◽  
...  
Keyword(s):  
Alternative Splicing ◽  
Regulatory Network ◽  
Posttranscriptional Regulation ◽  
Cancer Metastasis ◽  
Epithelial To Mesenchymal Transition ◽  
Combinatorial Regulation ◽  
Mesenchymal Transition ◽  
Splicing Regulators

The epithelial-to-mesenchymal transition (EMT) is an essential biological process during embryonic development that is also implicated in cancer metastasis. While the transcriptional regulation of EMT has been well studied, the role of alternative splicing (AS) regulation in EMT remains relatively uncharacterized. We previously showed that the epithelial cell-type-specific proteinsepithelialsplicingregulatoryproteins 1 (ESRP1) and ESRP2 are important for the regulation of many AS events that are altered during EMT. However, the contributions of the ESRPs and other splicing regulators to the AS regulatory network in EMT require further investigation. Here, we used a robustin vitroEMT model to comprehensively characterize splicing switches during EMT in a temporal manner. These investigations revealed that the ESRPs are the major regulators of some but not all AS events during EMT. We determined that the splicing factor RBM47 is downregulated during EMT and also regulates numerous transcripts that switch splicing during EMT. We also determined that Quaking (QKI) broadly promotes mesenchymal splicing patterns. Our study highlights the broad role of posttranscriptional regulation during the EMT and the important role of combinatorial regulation by different splicing factors to fine tune gene expression programs during these physiological and developmental transitions.

scholarly journals Novel role of Snail 1 in promoting tumor neoangiogenesis

2019 ◽  
Vol 39 (5) ◽  
Author(s):  
Yi-Kun Zhang ◽  
Hua Wang ◽  
Yu-Wei Guo ◽  
Yang Yue
Keyword(s):  
Tumor Metastasis ◽  
Epithelial To Mesenchymal Transition ◽  
Tube Formation ◽  
Fibroblast Growth ◽  
Quantitative Real Time Pcr ◽  
Potential Therapeutic Target ◽  
Mesenchymal Transition ◽  
Tumor Neoangiogenesis

Abstract Snail1 plays an important role in epithelial to mesenchymal transition (EMT) during tumor metastasis; however, whether Snai1 potentiates the process of neoangiogenesis is completely unknown. In the present study, tube formation assay was used to evaluate neoangiogenesis in vitro. The expression of Snai1 and other pro-neoangiogenic factors was measured by quantitative real time PCR. Tumor derived endothelial cells (TDECs) were stimulated with fibroblast growth factor 1 (FGF1) or VEGF and formed more tubes compared with untreated, whereas cells treated with Sulforaphane had less tube formation. Silencing SNAI1 significantly attenuated tube formation accompanied by decreased CD31, CD34, and VWF expression in TDECs compared with control. In contrast, overexpression of Snai1 led to more CD31, CD34, and VWF expression and tube formation. To determine if the observed effects of SNAI1 on tube formation was a global phenomenon, the same assay was conducted in normal mesenchymal stem cells (MSCs). SNAI1 silencing did not have any effect on tube formation in MSCs. The expression of TIMP2, ENG, and HIF1A was up-regulated 3-fold or higher after silencing SNAI1, and ID1, VEGFA, PLG, LECT1, HPSE were shown down-regulated. Taken together, our study elucidates an important role of EMT inducer Snai1 in regulating tumor neoangiogenesis, suggesting a potential therapeutic target for overcoming tumor EMT.

scholarly journals MicroRNA in Lung Cancer Metastasis

Cancers ◽  
2019 ◽  
Vol 11 (2) ◽  
pp. 265 ◽  
Author(s):  
Shang-Gin Wu ◽  
Tzu-Hua Chang ◽  
Yi-Nan Liu ◽  
Jin-Yuan Shih
Keyword(s):  
Lung Cancer ◽  
Targeted Therapy ◽  
Cancer Metastasis ◽  
Epithelial To Mesenchymal Transition ◽  
Cancer Treatments ◽  
Mesenchymal Transition ◽  
Lung Cancer Metastasis ◽  
Targeted Treatments

Tumor metastasis is a hallmark of cancer, with distant metastasis frequently developing in lung cancer, even at initial diagnosis, resulting in poor prognosis and high mortality. However, available biomarkers cannot reliably predict cancer spreading sites. The metastatic cascade involves highly complicated processes including invasion, migration, angiogenesis, and epithelial-to-mesenchymal transition that are tightly controlled by various genetic expression modalities along with interaction between cancer cells and the extracellular matrix. In particular, microRNAs (miRNAs), a group of small non-coding RNAs, can influence the transcriptional and post-transcriptional processes, with dysregulation of miRNA expression contributing to the regulation of cancer metastasis. Nevertheless, although miRNA-targeted therapy is widely studied in vitro and in vivo, this strategy currently affords limited feasibility and a few miRNA-targeted therapies for lung cancer have entered into clinical trials to date. Advances in understanding the molecular mechanism of metastasis will thus provide additional potential targets for lung cancer treatment. This review discusses the current research related to the role of miRNAs in lung cancer invasion and metastasis, with a particular focus on the different metastatic lesions and potential miRNA-targeted treatments for lung cancer with the expectation that further exploration of miRNA-targeted therapy may establish a new spectrum of lung cancer treatments.

The Role of Calcium Signaling in Regulation of Epithelial-Mesenchymal Transition

2020 ◽  
pp. 1-23
Author(s):  
Divya Adiga ◽  
Raghu Radhakrishnan ◽  
Sanjiban Chakrabarty ◽  
Prashant Kumar ◽  
Shama Prasada Kabekkodu
Keyword(s):  
Cancer Metastasis ◽  
Epithelial To Mesenchymal Transition ◽  
Epithelial Mesenchymal Transition ◽  
Critical Role ◽  
Cancer Therapeutics ◽  
Growth And Survival ◽  
Mesenchymal Transition ◽  
Microenvironmental Factors ◽  
Favorable Clinical Outcome

Despite substantial advances in the field of cancer therapeutics, metastasis is a significant challenge for a favorable clinical outcome. Epithelial to mesenchymal transition (EMT) is a process of acquiring increased motility, invasiveness, and therapeutic resistance by cancer cells for their sustained growth and survival. A plethora of intrinsic mechanisms and extrinsic microenvironmental factors drive the process of cancer metastasis. Calcium (Ca<sup>2+</sup>) signaling plays a critical role in dictating the adaptive metastatic cell behavior comprising of cell migration, invasion, angiogenesis, and intravasation. By modulating EMT, Ca<sup>2+</sup> signaling can regulate the complexity and dynamics of events leading to metastasis. This review summarizes the role of Ca<sup>2+</sup> signal remodeling in the regulation of EMT and metastasis in cancer.

scholarly journals PRPF6 Induces the Alternative Splicing of lncRNA SNHG16 To Promote Progression and Paclitaxel Resistance of Ovarian Cancer via Regulating GATA3 Transcription

2021 ◽  
Author(s):  
Han Wang ◽  
Yingying Zhou ◽  
Siyang Zhang ◽  
Ya Qi ◽  
Min Wang
Keyword(s):  
Ovarian Cancer ◽  
Alternative Splicing ◽  
Epithelial To Mesenchymal Transition ◽  
Binding Protein ◽  
Luciferase Reporter ◽  
Luciferase Reporter Gene ◽  
Mesenchymal Transition ◽  
Gene Assay

Abstract Background Small nucleolar RNA host gene 16 (SNHG16) and pre-mRNA processing factor 6(PRPF6) play vital roles in regulatory mechanisms of multiple cancers, but the mechanisms in ovarian cancer (OC) remains poorly understood. Methods The expression of SNHG16 transcripts-SNHG16-L/S in OC tissues were analyzed by real-time PCR (RT-PCR). The expression of PRPF6 in OC tissues were detected by Immunohistochemistry (IHC). Tumorigenesis, epithelial-to-mesenchymal transition (EMT) and PTX-resistance were detected by western blot, transwell, CCK-8 assays, colony formation assays and flow cytometry analyses. Molecular interactions were examined by dual-luciferase reporter gene assay, RNA immunoprecipitation (RIP) and chromatin immunoprecipitation (ChIP). Results The results indicated the expression of SNHG16-L/S was opposite in chemo-resistance and chemo-sensitivity tissues of OC. And SNHG16-L/S had different effects on the progression and PTX-resistance of OC cells. SNHG16-L inhibited GATA binding protein 3 (GATA3) transcription through CCAAT/enhancer-binding protein b (CEBPB) to further promote tumorigenesis, EMT and PTX-resistance of OC. Moreover, PRPF6 was upregulated in chemo-resistance tissues of OC. PRPF6 promoted tumorigenesis and PTX-resistance in vitro and in vivo. Mechanistically, PRPF6 induced the alternative splicing of SNHG16 to downregulate SNHG16-L, which further mediated progression and PTX-resistance through upregulating GATA3 in OC. Conclusions Totally, the results demonstrated that PRPF6 promoted progression and PTX-resistance in OC through SNHG16-L/CEBPB/GATA3 axis. Thus, PRPF6 may become a valuable target for OC therapy.

scholarly journals Extracellular HSP90α-LRP1 Signaling Promote Pancreatic Cancer Metastasis and Chemoresistance Via Regulating Epithelial-To-Mesenchymal Transition

2021 ◽  
Author(s):  
Nina Xue ◽  
Tingting Du ◽  
Fangfang Lai ◽  
Jing Jin ◽  
Ming Ji ◽  
...  
Keyword(s):  
Pancreatic Cancer ◽  
Cancer Metastasis ◽  
Epithelial To Mesenchymal Transition ◽  
Epithelial Mesenchymal Transition ◽  
Critical Role ◽  
Density Lipoprotein ◽  
Underlying Mechanism ◽  
Migration And Invasion ◽  
Mesenchymal Transition

Abstract Extracellular heat shock protein 90α (HSP90α) has been reported to promote cancer cell invasion and migration. However, whether pancreatic cancer (PC) cells expressed membrane-bound or secreted HSP90α and its underlying mechanism for PC progression were still unclear. Our study pointed out that highly invasive Capan2 cells has a higher level of secreted HSP90α, rather than membrane HSP90α, compared with those of less invasive PL45 cells. The conditioned medium of Capan2 cells or recombinant HSP90α protein was able to stimulate the migration and invasion of PL45 or capan2 cells, which could be prevented by a neutralizing anti-HSP90α antibody. Furthermore, secreted HSP90α promoted elements of epithelial-mesenchymal transition (EMT) in PL45 cells, including increases in vimentin and snail expressions, decreases in E-cadherin expression and changes in cell shape towards a mesenchymal phenotype, but these phenomena were reversed by anti-HSP90α antibody in Capan2 cells. In addition, high levels of low-density lipoprotein receptor-related protein 1 (LRP1) mRNA were associated with worsened patient survival in pancreatic adenocarcinoma. LRP1 as a receptor of eHSP90α for its stimulatory role of PC cells EMT and metastasis by activating AKT signaling. Down-regulation of LRP1 could promote chemosensitivity to gemcitabine and doxorubicin, but not to topotecan and paclitaxel in Capan2 cells. Therefore, our study reveals a critical role of secreted HSP90α on EMT events and suggests blocking secreted HSP90α underlies an aspect of metastasis and chemoresistance.

scholarly journals Isoliquiritigenin Inhibits Ovarian Cancer Metastasis by Reversing Epithelial-to-Mesenchymal Transition

Molecules ◽  
2019 ◽  
Vol 24 (20) ◽  
pp. 3725 ◽  
Author(s):  
Chen Chen ◽  
Shuang Huang ◽  
Chang-Liang Chen ◽  
Sing-Bing Su ◽  
Dong-Dong Fang
Keyword(s):  
Ovarian Cancer ◽  
Cancer Metastasis ◽  
Epithelial To Mesenchymal Transition ◽  
Tumor Development ◽  
Skov3 Cell ◽  
Anticancer Activities ◽  
Mesenchymal Transition ◽  
Epithelial Phenotype ◽  
Ovary Tumor

The epithelial-to-mesenchymal transition (EMT) plays a prominent role in cancer metastasis. Isoliquiritigenin (ISL), one of the flavonoids in licorice, has been shown to exhibit anticancer activities in many cancer types through various mechanisms. However, it is unknown whether ISL impacts the EMT process. Here, we show that ISL is able to suppress mesenchymal features of ovarian cancer SKOV3 and OVCAR5 cells, evidenced by an apparent morphological change from a mesenchymal to an epithelial phenotype and reduced levels of mesenchymal markers accompanied by the gain of E-cadherin expression. The suppression of EMT is also supported by the observed decrease in cell migration and in vitro invasion upon ISL treatment. Moreover, we show that ISL effectively blocks the intraperitoneal xenograft development of the SKOV3 cell line and prolonged the survival of tumor-bearing mice. These data suggest that ISL inhibits intraperitoneal ovary tumor development through the suppression of EMT, indicating that ISL may be an effective therapeutic agent against ovarian cancer.

Role of E2F3 and shugoshin I in epithelial-to-mesenchymal transition and cell invasion in breast cancer.

2020 ◽  
Vol 38 (15_suppl) ◽  
pp. e13100-e13100
Author(s):  
Shirley Jusino ◽  
Srikumar P. Chellappan ◽  
Harold I. Saavedra
Keyword(s):  
Breast Cancer ◽  
Cell Invasion ◽  
Cancer Metastasis ◽  
Epithelial To Mesenchymal Transition ◽  
Cellular Proliferation ◽  
Protein Localization ◽  
Breast Cancer Metastasis ◽  
Mrna Levels ◽  
Mesenchymal Transition

e13100 Background: Triple-negative breast cancer (TNBC) is the most aggressive and poorly prognostic breast cancer subtype, yet there are currently no biological therapies against this subtype. Our laboratory is finding the sources of novel biological targets in TNBC by studying the E2F transcription factors, which are essential for cellular proliferation and maintenance of genomic stability. While the deregulated Rb/E2F pathway signals the epithelial-to-mesenchymal transition (EMT), the underlining mechanism of how E2Fs drive EMT in TNBC remains unknown. We recently published that the E2F transcriptional activators (E2Fs) are overexpressed in the vast majority of TNBC and that their overexpression upregulates mitotic kinases such as TTK, which we have shown to induce EMT and invasion in TNBC cells. We also demonstrated that the E2Fs maintain genomic integrity in part through Shugoshin I (SGO1), which normally controls chromosome cohesion; however, the role of SGO1 in EMT in breast cancer is unknown. Our hypothesis is that E2F3 and SGO1 are highly expressed in TNBC and that their overexpression modulates EMT genes, thus promoting cell invasion. Methods: To test our hypothesis, we conducted siRNA transfection to knockdown E2F3 and SGO1 in MDA-MB-231 and Hs578t, which are TNBC cells. After 48 hours, we evaluated mRNA levels of EMT-related genes after E2F3 or SGO1 depletion using RT-PCR analysis. We also evaluated the effects of SGO1 depletion in protein localization by immunofluorescence. Furthermore, we evaluated the invasive behavior of MDA-MB-231 and Hs578t cells after SGO1 depletion using a Boyden Chamber Assay. Results: Our results demonstrate that E2F3 and SGO1 depletion decrease MMP3 mRNA levels. Moreover, E2F3 and SGO1 depletion restore E-cadherin expression and localization. Furthermore, E2F3 and SGO1 depletion significantly reduce cell invasion in MDA-MB-231 and Hs578t cells. Conclusions: Our results suggest that SGO1 is a promising drug target for breast cancer metastasis since EMT and invasion are essential early steps in breast cancer metastasis and E2F3 is presently undruggable.

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