scholarly journals MicroPET/CT Imaging of AXL Downregulation by HSP90 Inhibition in Triple-Negative Breast Cancer

2017 ◽  
Vol 2017 ◽  
pp. 1-11 ◽  
Author(s):  
Wanqin Wang ◽  
Jun Zhao ◽  
Xiaoxia Wen ◽  
Curtis Chun-Jen Lin ◽  
Junjie Li ◽  
...  
Keyword(s):  
Breast Cancer ◽  
Triple Negative Breast Cancer ◽  
Epithelial To Mesenchymal Transition ◽  
Triple Negative ◽  
Hsp90 Inhibition ◽  
Mesenchymal Transition ◽  
Important Regulator ◽  
Axl Receptor Tyrosine Kinase ◽  
Tumor Types

AXL receptor tyrosine kinase is overexpressed in a number of solid tumor types including triple-negative breast cancer (TNBC). AXL is considered an important regulator of epithelial-to-mesenchymal transition (EMT) and a potential therapeutic target for TNBC. In this work, we used microPET/CT with 64Cu-labeled anti-human AXL antibody (64Cu-anti-hAXL) to noninvasively interrogate the degradation of AXL in vivo in response to 17-allylamino-17-demethoxygeldanamycin (17-AAG), a potent inhibitor of HSP90. 17-AAG treatment caused significant decline in AXL expression in orthotopic TNBC MDA-MB-231 tumors, inhibited EMT, and delayed tumor growth in vivo, resulting in significant reduction in tumor uptake of 64Cu-anti-hAXL as clearly visualized by microPET/CT. Our data indicate that 64Cu-anti-hAXL can be useful for monitoring anti-AXL therapies and for assessing inhibition of HSP90 molecular chaperone using AXL as a molecular surrogate.

scholarly journals LncRNA DLX6-AS1 Contributes to Epithelial–Mesenchymal Transition and Cisplatin Resistance in Triple-negative Breast Cancer via Modulating Mir-199b-5p/Paxillin Axis

2020 ◽  
Vol 29 ◽  
pp. 096368972092998 ◽  
Author(s):  
Chuang Du ◽  
Yan Wang ◽  
Yingying Zhang ◽  
Jianhua Zhang ◽  
Linfeng Zhang ◽  
...  
Keyword(s):  
Breast Cancer ◽  
Cell Proliferation ◽  
Drug Resistance ◽  
Triple Negative Breast Cancer ◽  
Triple Negative ◽  
Cisplatin Resistance ◽  
Epithelial Mesenchymal Transition ◽  
Mesenchymal Transition ◽  
Expression Levels

Triple-negative breast cancer (TNBC) is one of the most aggressive cancer types with high recurrence, metastasis, and drug resistance. Recent studies report that long noncoding RNAs (lncRNAs)-mediated competing endogenous RNAs (ceRNA) play an important role in tumorigenesis and drug resistance of TNBC. Although elevated lncRNA DLX6 antisense RNA 1 (DLX6-AS1) has been observed to promote carcinogenesis in various cancers, the role in TNBC remained unclear. In this study, expression levels of DLX6-AS1 were increased in TNBC tissues and cell lines when compared with normal tissues or breast fibroblast cells which were determined by quantitative real-time PCR (RT-qPCR). Then, CCK-8 assay, cell colony formation assay and western blot were performed in CAL-51 cells transfected with siRNAs of DLX6-AS1 or MDA-MB-231 cells transfected with DLX6-AS1 over expression plasmids. Knock down of DLX6-AS1 inhibited cell proliferation, epithelial-mesenchymal transition (EMT), decreased expression levels of BCL2 apoptosis regulator (Bcl-2), Snail family transcriptional repressor 1 (Snail) as well as N-cadherin and decreased expression levels of cleaved caspase-3, γ-catenin as well as E-cadherin, while up regulation of DLX6-AS1 had the opposite effect. Besides, knockdown of DLX6-AS1 in CAL-51 cells or up regulation of DLX6-AS1 in MDA-MB-231 cells also decreased or increased cisplatin resistance of those cells analyzed by MTT assay. Moreover, by using dual luciferase reporter assay, RNA immunoprecipitation and RNA pull down assay, a ceRNA which was consisted by lncRNA DLX6-AS1, microRNA-199b-5p (miR-199b-5p) and paxillin (PXN) was identified. And DLX6-AS1 function through miR-199b-5p/PXN in TNBC cells. Finally, results of xenograft experiments using nude mice showed that DLX6-AS1 regulated cell proliferation, EMT and cisplatin resistance by miR-199b-5p/PXN axis in vivo. In brief, DLX6-AS1 promoted cell proliferation, EMT, and cisplatin resistance through miR-199b-5p/PXN signaling in TNBC in vitro and in vivo.

scholarly journals CD73 facilitates EMT progression and promotes lung metastases in triple-negative breast cancer

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Nataliia Petruk ◽  
Sanni Tuominen ◽  
Malin Åkerfelt ◽  
Jesse Mattsson ◽  
Jouko Sandholm ◽  
...  
Keyword(s):  
Breast Cancer ◽  
Triple Negative Breast Cancer ◽  
Triple Negative ◽  
Epithelial Mesenchymal Transition ◽  
Lung Metastases ◽  
Vimentin Expression ◽  
Mesenchymal Transition ◽  
Cell Protrusion

AbstractCD73 is a cell surface ecto-5′-nucleotidase, which converts extracellular adenosine monophosphate to adenosine. High tumor CD73 expression is associated with poor outcome among triple-negative breast cancer (TNBC) patients. Here we investigated the mechanisms by which CD73 might contribute to TNBC progression. This was done by inhibiting CD73 with adenosine 5′-(α, β-methylene) diphosphate (APCP) in MDA-MB-231 or 4T1 TNBC cells or through shRNA-silencing (sh-CD73). Effects of such inhibition on cell behavior was then studied in normoxia and hypoxia in vitro and in an orthotopic mouse model in vivo. CD73 inhibition, through shRNA or APCP significantly decreased cellular viability and migration in normoxia. Inhibition of CD73 also resulted in suppression of hypoxia-induced increase in viability and prevented cell protrusion elongation in both normoxia and hypoxia in cancer cells. Sh-CD73 4T1 cells formed significantly smaller and less invasive 3D organoids in vitro, and significantly smaller orthotopic tumors and less lung metastases than control shRNA cells in vivo. CD73 suppression increased E-cadherin and decreased vimentin expression in vitro and in vivo, proposing maintenance of a more epithelial phenotype. In conclusion, our results suggest that CD73 may promote early steps of tumor progression, possibly through facilitating epithelial–mesenchymal transition.

scholarly journals CircNR3C2 promotes HRD1-mediated tumor-suppressive effect via sponging miR-513a-3p in triple-negative breast cancer

2021 ◽  
Vol 20 (1) ◽  
Author(s):  
Ya Fan ◽  
Jia Wang ◽  
Wen Jin ◽  
Yifei Sun ◽  
Yuemei Xu ◽  
...  
Keyword(s):  
Breast Cancer ◽  
Rna Sequencing ◽  
Cancer Progression ◽  
Triple Negative Breast Cancer ◽  
Triple Negative ◽  
Proteasomal Degradation ◽  
Circular Rnas ◽  
Mesenchymal Transition

Abstract Background E3 ubiquitin ligase HRD1 (HMG-CoA reductase degradation protein 1, alias synoviolin with SYVN1 as the official gene symbol) was found downregulated and acting as a tumor suppressor in breast cancer, while the exact expression profile of HRD1 in different breast cancer subtypes remains unknown. Recent studies characterized circular RNAs (circRNAs) playing an regulatory role as miRNA sponge in tumor progression, presenting a new viewpoint for the post-transcriptional regulation of cancer-related genes. Methods Examination of the expression of HRD1 protein and mRNA was implemented using public microarray/RNA-sequencing datasets and breast cancer tissues/cell lines. Based on public RNA-sequencing results, online databases and enrichment/clustering analyses were used to predict the specific combinations of circRNA/miRNA that potentially govern HRD1 expression. Gain-of-function and rescue experiments in vitro and in vivo were executed to evaluate the suppressive effects of circNR3C2 on breast cancer progression through HRD1-mediated proteasomal degradation of Vimentin, which was identified using immunoblotting, immunoprecipitation, and in vitro ubiquitination assays. Results HRD1 is significantly underexpressed in triple-negative breast cancer (TNBC) against other subtypes and has an inverse correlation with Vimentin, inhibiting the proliferation, migration, invasion and EMT (epithelial-mesenchymal transition) process of breast cancer cells via inducing polyubiquitination-mediated proteasomal degradation of Vimentin. CircNR3C2 (hsa_circ_0071127) is also remarkably downregulated in TNBC, negatively correlated with the distant metastasis and lethality of invasive breast carcinoma. Overexpressing circNR3C2 in vitro and in vivo leads to a crucial enhancement of the tumor-suppressive effects of HRD1 through sponging miR-513a-3p. Conclusions Collectively, we elucidated a bona fide circNR3C2/miR-513a-3p/HRD1/Vimentin axis that negatively regulates the metastasis of TNBC, suggesting that circNR3C2 and HRD1 can act as potential prognostic biomarkers. Our study may facilitate the development of therapeutic agents targeting circNR3C2 and HRD1 for patients with aggressive breast cancer.

MALT1 is a Targetable Driver of Epithelial-to-Mesenchymal Transition in Claudin-low, Triple-Negative Breast Cancer

2021 ◽  
pp. molcanres.0208.2021
Author(s):  
Jia-Ying (Lloyd) Lee ◽  
Prasanna Ekambaram ◽  
Neil M. Carleton ◽  
Dong Hu ◽  
Linda R. Klei ◽  
...  
Keyword(s):  
Breast Cancer ◽  
Triple Negative Breast Cancer ◽  
Epithelial To Mesenchymal Transition ◽  
Triple Negative ◽  
Mesenchymal Transition

scholarly journals Interferon-beta represses cancer stem cell properties in triple-negative breast cancer

2017 ◽  
Vol 114 (52) ◽  
pp. 13792-13797 ◽  
Author(s):  
Mary R. Doherty ◽  
HyeonJoo Cheon ◽  
Damian J. Junk ◽  
Shaveta Vinayak ◽  
Vinay Varadan ◽  
...  
Keyword(s):  
Breast Cancer ◽  
Gene Expression ◽  
Triple Negative Breast Cancer ◽  
Epithelial To Mesenchymal Transition ◽  
Triple Negative ◽  
Mammary Epithelial Cells ◽  
Gene Expression Signature ◽  
Tumor Infiltrating Lymphocytes ◽  
Gene Signature ◽  
Mesenchymal Transition

Triple-negative breast cancer (TNBC), the deadliest form of this disease, lacks a targeted therapy. TNBC tumors that fail to respond to chemotherapy are characterized by a repressed IFN/signal transducer and activator of transcription (IFN/STAT) gene signature and are often enriched for cancer stem cells (CSCs). We have found that human mammary epithelial cells that undergo an epithelial-to-mesenchymal transition (EMT) following transformation acquire CSC properties. These mesenchymal/CSCs have a significantly repressed IFN/STAT gene expression signature and an enhanced ability to migrate and form tumor spheres. Treatment with IFN-beta (IFN-β) led to a less aggressive epithelial/non–CSC-like state, with repressed expression of mesenchymal proteins (VIMENTIN, SLUG), reduced migration and tumor sphere formation, and reexpression of CD24 (a surface marker for non-CSCs), concomitant with an epithelium-like morphology. The CSC-like properties were correlated with high levels of unphosphorylated IFN-stimulated gene factor 3 (U-ISGF3), which was previously linked to resistance to DNA damage. Inhibiting the expression of IRF9 (the DNA-binding component of U-ISGF3) reduced the migration of mesenchymal/CSCs. Here we report a positive translational role for IFN-β, as gene expression profiling of patient-derived TNBC tumors demonstrates that an IFN-β metagene signature correlates with improved patient survival, an immune response linked with tumor-infiltrating lymphocytes (TILs), and a repressed CSC metagene signature. Taken together, our findings indicate that repressed IFN signaling in TNBCs with CSC-like properties is due to high levels of U-ISGF3 and that treatment with IFN-β reduces CSC properties, suggesting a therapeutic strategy to treat drug-resistant, highly aggressive TNBC tumors.

scholarly journals The oncogenic kinase NEK2 regulates an RBFOX2-dependent pro-mesenchymal splicing program in triple-negative breast cancer cells

2021 ◽  
Vol 40 (1) ◽  
Author(s):  
Chiara Naro ◽  
Monica De Musso ◽  
Francesca Delle Monache ◽  
Valentina Panzeri ◽  
Pierre de la Grange ◽  
...  
Keyword(s):  
Breast Cancer ◽  
Cancer Cells ◽  
Triple Negative Breast Cancer ◽  
Epithelial To Mesenchymal Transition ◽  
Triple Negative ◽  
Splice Variants ◽  
The Cancer Genome Atlas ◽  
Mesenchymal Transition ◽  
Tnbc Cell ◽  
Tnbc Cell Line

Abstract Background Triple-negative breast cancer (TNBC) is the most heterogeneous and malignant subtype of breast cancer (BC). TNBC is defined by the absence of expression of estrogen, progesterone and HER2 receptors and lacks efficacious targeted therapies. NEK2 is an oncogenic kinase that is significantly upregulated in TNBC, thereby representing a promising therapeutic target. NEK2 localizes in the nucleus and promotes oncogenic splice variants in different cancer cells. Notably, alternative splicing (AS) dysregulation has recently emerged as a featuring trait of TNBC that contributes to its aggressive phenotype. Methods To investigate whether NEK2 modulates TNBC transcriptome we performed RNA-sequencing analyses in a representative TNBC cell line (MDA-MB-231) and results were validated in multiple TNBC cell lines. Bioinformatics and functional analyses were carried out to elucidate the mechanism of splicing regulation by NEK2. Data from The Cancer Genome Atlas were mined to evaluate the potential of NEK2-sensitive exons as markers to identify the TNBC subtype and to assess their prognostic value. Results Transcriptome analysis revealed a widespread impact of NEK2 on the transcriptome of TNBC cells, with 1830 AS events that are susceptible to its expression. NEK2 regulates the inclusion of cassette exons in splice variants that discriminate TNBC from other BC and that correlate with poor prognosis, suggesting that this kinase contributes to the TNBC-specific splicing program. NEK2 elicits its effects by modulating the expression of the splicing factor RBFOX2, a well-known regulator of epithelial to mesenchymal transition (EMT). Accordingly, NEK2 splicing-regulated genes are enriched in functional terms related to cell adhesion and contractile cytoskeleton and NEK2 depletion in mesenchymal TNBC cells induces phenotypic and molecular traits typical of epithelial cells. Remarkably, depletion of select NEK2-sensitive splice-variants that are prognostic in TNBC patients is sufficient to interfere with TNBC cell morphology and motility, suggesting that NEK2 orchestrates a pro-mesenchymal splicing program that modulates migratory and invasive properties of TNBC cells. Conclusions Our study uncovers an extensive splicing program modulated by NEK2 involving splice variants that confer an invasive phenotype to TNBCs and that might represent, together with NEK2 itself, valuable therapeutic targets for this disease.

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