Noninvasive identification of lineage-specific circular RNA for ER-positive breast cancer.

2020 ◽  
Vol 38 (15_suppl) ◽  
pp. 3543-3543 ◽  
Author(s):  
Jason Brown ◽  
Palak Shah ◽  
Josh Vo ◽  
Lanbo Xiao ◽  
Yashar Niknafs ◽  
...  
Keyword(s):  
Breast Cancer ◽  
Cancer Cells ◽  
Cancer Patients ◽  
Breast Cancer Cells ◽  
Circular Rna ◽  
Breast Cancer Cell Lines ◽  
Breast Cancer Patients ◽  
Non Invasive ◽  
Er Positive ◽  
Positive Breast Cancer

3543 Background: Non-invasive testing in plasma using RNA biomarkers has been limited by exoribonuclease-mediated degradation of RNA. Circular RNA (circRNA) are covalently closed RNA structures that resist this degradation due to their circular structure. Therefore circRNA are more stable than their linear counterparts. CircRNA are formed by alternative backsplicing of the 3’ end of a downstream exon to the 5’ end of an upstream exon. Here, we propose a novel method for non-invasive identification of circRNA and demonstrate circularized forms of several lineage and cancer specific targets for estrogen receptor-positive breast cancer. Methods: Capture RNA sequencing on cancer tissue was previously performed to determine the relative expression of potential circRNA isoforms in breast cancer patients. These isoforms as well as those predicted by intron length were screened using a quantitative PCR-based assay on ER-positive breast cancer cells. RNA extracted from breast cancer cells are exposed to ribonuclease R to demonstrate stability of circRNA. CircRNA derived from targets with known universal expression are used as positive controls as well as for analysis on plasma. Results: We identify the circRNA isoforms with highest expression for five genes, including ESR1, that are differentially expressed in ER-positive breast cancer compared to other cancers and normal breast tissue. We determine that the circRNA corresponding to all five targets is specifically expressed in breast cancer cell lines with at least 1000-fold higher expression than in non-ER positive breast cancer cell lines. We demonstrate that the highest expressing circRNA isoforms are resistant to degradation by ribonuclease R, whereas corresponding linear mRNA is susceptible. We also demonstrate the presence and stability of positive control circRNA in plasma from patients without cancer. Conclusions: CircRNA are promising biomarkers for early non-invasive detection of cancer due to their stability in plasma. This assay reliably detects ER-positive breast cancer specific circRNA, and exoribonuclease resistance has been validated. Application of this diagnostic assay to plasma from breast cancer patients is underway.

scholarly journals Extracellular vesicles from young women’s breast cancer patients drive increased invasion of non-malignant cells via the Focal Adhesion Kinase pathway: a proteomic approach

2020 ◽  
Vol 22 (1) ◽  
Author(s):  
Kimberly R. Jordan ◽  
Jessica K. Hall ◽  
Troy Schedin ◽  
Michelle Borakove ◽  
Jenny J. Xian ◽  
...  
Keyword(s):  
Breast Cancer ◽  
Cancer Patients ◽  
Cancer Progression ◽  
Focal Adhesion ◽  
Invasive Breast Cancer ◽  
Breast Cancer Cells ◽  
Breast Cancer Cell Lines ◽  
Breast Cancer Patients ◽  
Non Invasive ◽  
Healthy Donors

Abstract Background Extracellular vesicles (EVs) are small membrane particles that contribute to cancer progression and metastases by transporting biologically significant proteins and nucleic acids. They may also serve as biomarkers of various disease states or important therapeutic targets. Breast cancer EVs have the potential to change the behavior of other cells in their microenvironment. However, the proteomic content of EVs isolated from young women’s breast cancer patients and the mechanisms underlying the influence of EVs on tumor cell behavior have not yet been reported. Methods In our current translational studies, we compared the proteomic content of EVs isolated from invasive breast cancer cell lines and plasma samples from young women’s breast cancer (YWBC) patients and age-matched healthy donors using mass spectrometry. We analyzed the functionality of EVs in two dimensional tumor cell invasion assays and the gene expression changes in tumor cells after incubation with EVs. Results We found that treatment with EVs from both invasive breast cancer cell lines and plasma of YWBC patients altered the invasive properties of non-invasive breast cancer cells. Proteomics identified differences between EVs from YWBC patients and healthy donors that correlated with their altered function. Further, we identified gene expression changes in non-invasive breast cancer cells after treatment with EVs that implicate the Focal Adhesion Kinase (FAK) signaling pathway as a potential targetable pathway affected by breast cancer-derived EVs. Conclusions Our results suggest that the proteome of EVs from breast cancer patients reflects their functionality in tumor motility assays and may help elucidate the role of EVs in breast cancer progression.

scholarly journals Hyperglycaemia-induced chemoresistance in breast cancer cells: role of the estrogen receptor

2015 ◽  
Vol 23 (2) ◽  
pp. 125-134 ◽  
Author(s):  
L Zeng ◽  
H A Zielinska ◽  
A Arshad ◽  
J P Shield ◽  
A Bahl ◽  
...  
Keyword(s):  
Breast Cancer ◽  
Estrogen Receptor ◽  
Cancer Cells ◽  
Cancer Patients ◽  
Breast Cancer Cells ◽  
Diabetic Patients ◽  
Breast Cancer Patients ◽  
Patients With Diabetes ◽  
The Impact ◽  
Positive Breast Cancer

Breast cancer patients with diabetes respond less well to chemotherapy; in keeping with this we determined previously that hyperglycaemia-induced chemoresistance in estrogen receptor (ERα) positive breast cancer cells and showed that this was mediated by fatty acid synthase (FASN). More recent evidence suggests that the effect of metabolic syndrome and diabetes is not the same for all subtypes of breast cancer with inferior disease-free survival and worse overall survival only found in women with ERα positive breast cancer and not for other subtypes. Here we examined the impact of hyperglycaemia on ERα negative breast cancer cells and further investigated the mechanism underlying chemoresistance in ERα with a view to identifying strategies to alleviate hyperglycaemia-induced chemoresistance. We found that hyperglycaemia-induced chemoresistance was only observed in ERα breast cancer cells and was dependent upon the expression of ERα as chemoresistance was negated when the ERα was silenced. Hyperglycaemia-induced an increase in activation and nuclear localisation of the ERα that was downstream of FASN and dependent on the activation of MAPK. We found that fulvestrant successfully negated the hyperglycaemia-induced chemoresistance, whereas tamoxifen had no effect. In summary our data suggests that the ERα may be a predictive marker of poor response to chemotherapy in breast cancer patients with diabetes. It further indicates that anti-estrogens could be an effective adjuvant to chemotherapy in such patients and indicates the importance for the personalised management of breast cancer patients with diabetes highlighting the need for clinical trials of tailored chemotherapy for diabetic patients diagnosed with ERα positive breast cancers.

scholarly journals miR-200 affects tamoxifen resistance in breast cancer cells through regulation of MYB

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Yu Gao ◽  
Wenzhi Zhang ◽  
Chengwen Liu ◽  
Guanghua Li
Keyword(s):  
Breast Cancer ◽  
Cancer Cells ◽  
Breast Cancer Cells ◽  
Tamoxifen Resistance ◽  
Breast Cancer Patients ◽  
Over Expression ◽  
Er Positive ◽  
Emt Markers ◽  
Mcf 7 ◽  
Positive Breast Cancer

AbstractResistance to tamoxifen is a major clinical challenge. Research in recent years has identified epigenetic changes as mediated by dysregulated miRNAs that can possibly play a role in resistance to tamoxifen in breast cancer patients expressing estrogen receptor (ER). We report here elevated levels of EMT markers (vimentin and ZEB1/2) and reduced levels of EMT-regulating miR-200 (miR-200b and miR-200c) in ER-positive breast cancer cells, MCF-7, that were resistant to tamoxifen, in contrast with the naïve parental MCF-7 cells that were sensitive to tamoxifen. Further, we established regulation of c-MYB by miR-200 in our experimental model. C-MYB was up-regulated in tamoxifen resistant cells and its silencing significantly decreased resistance to tamoxifen and the EMT markers. Forced over-expression of miR-200b/c reduced c-MYB whereas reduced expression of miR-200b/c resulted in increased c-MYB We further confirmed the results in other ER-positive breast cancer cells T47D cells where forced over-expression of c-MYB resulted in induction of EMT and significantly increased resistance to tamoxifen. Thus, we identify a novel mechanism of tamoxifen resistance in breast tumor microenvironment that involves miR-200-MYB signaling.

scholarly journals Pim1 Kinase Inhibitors Exert Anti-Cancer Activity Against HER2-Positive Breast Cancer Cells Through Downregulation of HER2

2021 ◽  
Vol 12 ◽  
Author(s):  
Bo-Wei Wang ◽  
Chih-Hao Huang ◽  
Liang-Chih Liu ◽  
Fang-Ju Cheng ◽  
Ya-Ling Wei ◽  
...  
Keyword(s):  
Breast Cancer ◽  
Cancer Cells ◽  
Cancer Patients ◽  
Breast Cancer Cells ◽  
Breast Cancer Patients ◽  
Her2 Positive ◽  
Her2 Positive Breast Cancer ◽  
Pim1 Kinase ◽  
Anti Cancer ◽  
Positive Breast Cancer

The proviral integration site for moloney murine leukemia virus 1 (Pim1) is a serine/threonine kinase and able to promote cell proliferation, survival and drug resistance. Overexpression of Pim1 has been observed in many cancer types and is associated with the poor prognosis of breast cancer. However, it remains unclear whether Pim1 kinase is a potential therapeutic target for breast cancer patients. In this study, we found that Pim1 expression was strongly associated with HER2 expression and that HER2-overexpressing breast cancer cells were more sensitive to Pim1 inhibitor-induced inhibitions of cell viability and metastatic ability. Mechanistically, Pim1 inhibitor suppressed the expression of HER2 at least in part through transcriptional level. More importantly, Pim1 inhibitor overcame the resistance of breast cancer cells to HER2 tyrosine kinase inhibitor lapatinib. In summary, downregulation of HER2 by targeting Pim1 may be a promising and effective therapeutic approach not only for anti-cancer growth but also for circumventing lapatinib resistance in HER2-positive breast cancer patients.

scholarly journals Inducible upregulation of oestrogen receptor-β1 affects oestrogen and tamoxifen responsiveness in MCF7 human breast cancer cells

2005 ◽  
Vol 34 (2) ◽  
pp. 553-566 ◽  
Author(s):  
L C Murphy ◽  
B Peng ◽  
A Lewis ◽  
J R Davie ◽  
E Leygue ◽  
...  
Keyword(s):  
Breast Cancer ◽  
Cancer Cells ◽  
Oestrogen Receptor ◽  
Breast Cancer Cells ◽  
Breast Cancer Patients ◽  
Growth Responses ◽  
Over Expression ◽  
Er Positive ◽  
Positive Breast Cancer ◽  
Tamoxifen Sensitivity

To investigate the effect of altered oestrogen receptor (ER)α and ERβ expression on oestrogen and anti-oestrogen action in breast cancer, we have stably expressed an inducible ERβ1 in MCF7 breast cancer cells. Stably expressing clones were isolated and over-expression of ERβ1 correlated with increased levels of specific radiolabelled oestradiol (E2) binding. Increased ERβ1 did not affect endogenous levels of ERα but increased progesterone receptor (PR) levels. Over-expression of ERβ1 reduced growth responses to E2 in contrast to little if any effect of over-expression of ERα. In oestrogen-replete conditions, over-expression of ERβ1 but not ERα reduced proliferation. Over-expression of ERβ1 did not result in anti-oestrogen resistance but was associated with increased sensitivity to 4-hydroxytamoxifen. Our results suggested that over-expression of ERβ1 in the presence of an endogenously expressed ERα was associated with tamoxifen sensitivity but may negatively modulate ERα-mediated growth. However, not all ERα activities were inhibited since endogenous PR expression was increased by both ERα and ERβ1 over-expression. These data paralleled those seen in some in vivo studies showing a relationship between PR and ERβ expression as well as ERβ expression and tamoxifen sensitivity of ER-positive breast cancer patients. These models are relevant and will be useful for dissecting the role of ERβ1 expression in ER-positive breast cancer.

scholarly journals Reduced IQGAP2 expression promotes EMT and inhibits apoptosis by modulating the MEK-ERK and p38 signaling in breast cancer irrespective of ER status

2021 ◽  
Vol 12 (4) ◽  
Author(s):  
Dinesh Kumar ◽  
Saket Awadesbhai Patel ◽  
Md. Khurshidul Hassan ◽  
Nachiketa Mohapatra ◽  
Niharika Pattanaik ◽  
...  
Keyword(s):  
Breast Cancer ◽  
Cancer Cells ◽  
Cancer Patients ◽  
Breast Cancer Cells ◽  
Xenograft Model ◽  
Breast Cancer Cell Lines ◽  
Dependent Manner ◽  
Breast Cancer Patients ◽  
Mesenchymal Transition ◽  
Erk Activation

AbstractIQGAP2, a member of the IQGAP family, functions as a tumor suppressor in most of the cancers. Unlike IQGAP1 and IQGAP3, which function as oncogenes in breast cancer, the role of IQGAP2 is still unexplored. Here we report a reduced expression of IQGAP2, which was associated with lymph node positivity, lymphovascular invasion, and higher age in breast cancer patients. We found an inverse correlation of IQGAP2 expression levels with oncogenic properties of breast cancer cell lines in estrogen receptor (ER) independent manner. IQGAP2 expression enhanced apoptosis via reactive oxygen species (ROS)-P38-p53 pathway and reduced epithelial–mesenchymal transition (EMT) in a MEK-ERK-dependent manner. IQGAP2-IQGAP1 ratio correlated negatively with phospho-ERK levels in breast cancer patients. Pull-down assay showed interaction of IQGAP1 and IQGAP2. IQGAP2 overexpression rescued, IQGAP1-mediated ERK activation, suggesting the possibility of IQGAP1 sequestration by IQGAP2. IQGAP2 depletion, in a tumor xenograft model, increased tumor volume, tumor weight, and phospho-ERK expression. Overall, our findings suggest that IQGAP2 is negatively associated with proliferative and metastatic abilities of breast cancer cells. Suppression of IQGAP1-mediated ERK activation is a possible route via which IQGAP2 restricts oncogenic properties of breast cancer cells. Our study highlights the candidature of IQGAP2 as a potent target for therapeutic intervention.

scholarly journals MMP1 and MMP11 Expression in Peripheral Blood Mononuclear Cells upon Their Interaction with Breast Cancer Cells and Fibroblasts

2020 ◽  
Vol 22 (1) ◽  
pp. 371
Author(s):  
Noemi Eiro ◽  
Sandra Cid ◽  
Nuria Aguado ◽  
María Fraile ◽  
Nagore de Pablo ◽  
...  
Keyword(s):  
Breast Cancer ◽  
Gene Expression ◽  
Cancer Cells ◽  
Cancer Patients ◽  
Breast Cancer Cells ◽  
Mononuclear Cells ◽  
Breast Cancer Cell Lines ◽  
Breast Cancer Patients ◽  
Peripheral Blood Mononuclear ◽  
The Impact

Tumor-infiltrating immune cells phenotype is associated with tumor progression. However, little is known about the phenotype of the peripheral blood mononuclear cells (PBMC) from breast cancer patients. We investigated MMP1 and MMP11 expression in PBMC from breast cancer patients and we analyzed gene expression changes upon their interaction with cancer cells and cancer-associated fibroblasts (CAF). We measured the impact of PBMC on proinflammatory gene expression in breast cancer cells, normal fibroblast (NF), and CAF and the impact on proliferation and invasiveness capacity of breast cancer cells. Gene expression of MMP1 and MMP11 in PBMC from breast cancer patients (n = 54) and control (n = 28); expression of IL1A, IL6, IL17, IFNβ, and NFĸB in breast cancer cell lines (MCF-7 and MDA-MB-231); and, additionally, IL10 and MMP11 in CAF and NF were analyzed by qRT-PCR before and after co-culture. Our results show the existence of a subpopulation of breast cancer patients (25.9%) with very high levels of MMP11 gene expression in PBMC. Also, gene expression of MMP1 and MMP11 increases in PBMC after co-culture with breast cancer cell lines, NF or CAF. PBMC from healthy or breast cancer patients induce an increased proliferation rate on MCF-7 and an increased invasiveness capacity of MDA-MB-231. Finally, we show a differential expression profile of inflammatory genes in NF and CAF when co-cultured with control or breast cancer PBMC. We have observed that MMPs’ expression in PBMC is regulated by the microenvironment, while the expression of inflammatory genes in NF or CAF is differentially regulated by PBMC. These findings confirm the importance of the crosstalk between stromal cells and suggest that PBMC would play a role in promoting aggressive tumor behavior.

scholarly journals Antiplatelet Therapy Combined with Anastrozole Induces Features of Partial EMT in Breast Cancer Cells and Fails to Mitigate Breast-Cancer Induced Hypercoagulation

2021 ◽  
Vol 22 (8) ◽  
pp. 4153
Author(s):  
Kutlwano R. Xulu ◽  
Tanya N. Augustine
Keyword(s):  
Breast Cancer ◽  
Cancer Cells ◽  
Cancer Patients ◽  
Antiplatelet Therapy ◽  
Cell Lines ◽  
Cancer Cell ◽  
Breast Cancer Cell ◽  
Breast Cancer Cells ◽  
Cancer Cell Lines ◽  
Breast Cancer Cell Lines

Thromboembolic complications are a leading cause of morbidity and mortality in cancer patients. Cancer patients often present with an increased risk for thrombosis including hypercoagulation, so the application of antiplatelet strategies to oncology warrants further investigation. This study investigated the effects of anastrozole and antiplatelet therapy (aspirin/clopidogrel cocktail or atopaxar) treatment on the tumour responses of luminal phenotype breast cancer cells and induced hypercoagulation. Ethical clearance was obtained (M150263). Blood was co-cultured with breast cancer cell lines (MCF7 and T47D) pre-treated with anastrozole and/or antiplatelet drugs for 24 h. Hypercoagulation was indicated by thrombin production and platelet activation (morphological and molecular). Gene expression associated with the epithelial-to-mesenchymal transition (EMT) was assessed in breast cancer cells, and secreted cytokines associated with tumour progression were evaluated. Data were analysed with the PAST3 software. Our findings showed that antiplatelet therapies (aspirin/clopidogrel cocktail and atopaxar) combined with anastrozole failed to prevent hypercoagulation and induced evidence of a partial EMT. Differences in tumour responses that modulate tumour aggression were noted between breast cancer cell lines, and this may be an important consideration in the clinical management of subphenotypes of luminal phenotype breast cancer. Further investigation is needed before this treatment modality (combined hormone and antiplatelet therapy) can be considered for managing tumour associated-thromboembolic disorder.

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