scholarly journals Constitutive activation of NF-kappaB during progression of breast cancer to hormone-independent growth.

1997 ◽  
Vol 17 (7) ◽  
pp. 3629-3639 ◽  
Author(s):  
H Nakshatri ◽  
P Bhat-Nakshatri ◽  
D A Martin ◽  
R J Goulet ◽  
G W Sledge

Breast cancers often progress from a hormone-dependent, nonmetastatic, antiestrogen-sensitive phenotype to a hormone-independent, antiestrogen- and chemotherapy-resistant phenotype with highly invasive and metastatic growth properties. This progression is usually accompanied by altered function of the estrogen receptor (ER) or outgrowth of ER-negative cancer cells. To understand the molecular mechanisms responsible for metastatic growth of ER-negative breast cancers, the activities of the transcription factor NF-kappaB (which modulates the expression of genes involved in cell proliferation, differentiation, apoptosis, and metastasis) were compared in ER-positive (MCF-7 and T47-D) and ER-negative (MDA-MB-231 and MDA-MB-435) human breast cancer cell lines. NF-kappaB, which is usually maintained in an inactive state by protein-protein interaction with inhibitor IkappaBs, was found to be constitutively active in ER-negative breast cancer cell lines. Constitutive DNA binding of NF-kappaB was also observed with extracts from ER-negative, poorly differentiated primary breast tumors. Progression of the rat mammary carcinoma cell line RM22-F5 from an ER-positive, nonmalignant phenotype (E phenotype) to an ER-negative, malignant phenotype (F phenotype) was also accompanied by constitutive activation of NF-kappaB. Analysis of individual subunits of NF-kappaB revealed that all ER-negative cell lines, including RM22-F5 cells of F phenotype, contain a unique 37-kDa protein which is antigenically related to the RelA subunit. Cell-type-specific differences in IkappaB alpha, -beta, and -gamma were also observed. In transient-transfection experiments, constitutive activity of an NF-kappaB-dependent promoter was observed in MDA-MB-231 and RM22-F5 cells of F phenotype, and this activity was efficiently repressed by cotransfected ER. Since ER inhibits the constitutive as well as inducible activation function of NF-kappaB in a dose-dependent manner, we propose that breast cancers that lack functional ER overexpress NF-kappaB-regulated genes. Furthermore, since recent data indicate that NF-kappaB protects cells from tumor necrosis factor alpha-, ionizing radiation-, and chemotherapeutic agent daunorubicin-mediated apoptosis, our results provide an explanation for chemotherapeutic resistance in ER-negative breast cancers.

2015 ◽  
Vol 8 (6) ◽  
Author(s):  
Mahdieh Shokrollahi Barough ◽  
Hadi Hasanzadeh ◽  
Mehdi Barati ◽  
Fatemeh Pak ◽  
Parviz Kokhaei ◽  
...  

Endocrinology ◽  
2000 ◽  
Vol 141 (12) ◽  
pp. 4357-4364 ◽  
Author(s):  
Jennifer L. Sanders ◽  
Naibedya Chattopadhyay ◽  
Olga Kifor ◽  
Toru Yamaguchi ◽  
Robert R. Butters ◽  
...  

Abstract Metastasis of breast cancer to bone occurs with advanced disease and produces substantial morbidity. Secretion of PTH-related peptide (PTHrP) from breast cancer cells is thought to play a key role in osteolytic metastases and is increased by transforming growth factor-β (TGFβ), which is released from resorbed bone. Elevated extracellular calcium (Cao2+) also stimulates PTHrP secretion from various normal and malignant cells, an action that could potentially be mediated by the Cao2+-sensing receptor (CaR) originally cloned from the parathyroid gland. Indeed, we previously showed that both normal breast ductal epithelial cells and primary breast cancers express the CaR. In this study we investigated whether the MCF-7 and MDA-MB-231 human breast cancer cell lines express the CaR and whether CaR agonists modulate PTHrP secretion. Northern blot analysis and RT-PCR revealed bona fide CaR transcripts, and immunocytochemistry and Western analysis with a specific anti-CaR antiserum demonstrated CaR protein expression in both breast cancer cell lines. Furthermore, elevated Cao2+ and the polycationic CaR agonists, neomycin and spermine, stimulated PTHrP secretion dose dependently, with maximal, 2.1- to 2.3-fold stimulation. In addition, pretreatment of MDA-MB-231 cells overnight with TGFβ1 (0.2, 1, or 5 ng/ml) augmented both basal and high Cao2+-stimulated PTHrP secretion. Thus, in PTHrP-secreting breast cancers metastatic to bone, the CaR could potentially participate in a vicious cycle in which PTHrP-induced bone resorption raises the levels of Cao2+ and TGFβ within the bony microenvironment, which then act in concert to evoke further PTHrP release and worsening osteolysis.


2020 ◽  
Vol 22 (1) ◽  
Author(s):  
Jessica Finlay-Schultz ◽  
Britta M. Jacobsen ◽  
Duncan Riley ◽  
Kiran V. Paul ◽  
Scott Turner ◽  
...  

Abstract Background Breast cancer is a highly heterogeneous disease characterized by multiple histologic and molecular subtypes. While a myriad of breast cancer cell lines have been developed over the past 60 years, estrogen receptor alpha (ER)+ disease and some mutations associated with this subtype remain underrepresented. Here we describe six breast cancer cell lines derived from patient-derived xenografts (PDX) and their general characteristics. Methods Established breast cancer PDX were processed into cell suspensions and placed into standard 2D cell culture; six emerged into long-term passageable cell lines. Cell lines were assessed for protein expression of common luminal, basal, and mesenchymal markers, growth assessed in response to estrogens and endocrine therapies, and RNA-seq and oncogenomics testing performed to compare relative transcript levels and identify putative oncogenic drivers. Results Three cell lines express ER and two are also progesterone receptor (PR) positive; PAM50 subtyping identified one line as luminal A. One of the ER+PR+ lines harbors a D538G mutation in the gene for ER (ESR1), providing a natural model that contains this endocrine-resistant genotype. The third ER+PR−/low cell line has mucinous features, a rare histologic type of breast cancer. The three other lines are ER− and represent two basal-like and a mixed ductal/lobular breast cancer. The cell lines show varied responses to tamoxifen and fulvestrant, and three were demonstrated to regrow tumors in vivo. RNA sequencing confirms all cell lines are human and epithelial. Targeted oncogenomics testing confirmed the noted ESR1 mutation in addition to other mutations (i.e., PIK3CA, BRCA2, CCND1, NF1, TP53, MYC) and amplifications (i.e., FGFR1, FGFR3) frequently found in breast cancers. Conclusions These new generation breast cancer cell lines add to the existing repository of breast cancer models, increase the number of ER+ lines, and provide a resource that can be genetically modified for studying several important clinical breast cancer features.


2007 ◽  
Vol 25 (18_suppl) ◽  
pp. 14129-14129
Author(s):  
K. Sakaguchi ◽  
H. Nakajima ◽  
I. Fujiwara ◽  
N. Mizuta ◽  
J. Magae

14129 Background: While agents targeting estrogen receptors are the most effective in adjuvant therapy for human breast cancers expressing estrogen receptor(ER), breast cancers lacking ER are clinically serious, because they are highly malignant and exhibit resistance to the usual anti-cancer drugs, including estrogen receptor-antagonists and DNA breaking agents. Although a transcription factor, AP-1, is known to be related to tumor malignancy including metastasis, invasion and drug-resistance, it remains to be elucidated how AP-1 plays in development and expression of malignant characters of human breast cancers. Methods and Results: Here, we used MX-1, a human breast cancer cell line lacking ER and several ER positive cell lines, to clarify the roles of AP-1 and the therapeutic efficacy of ascochlorin, a newly developed prenylphenol antibiotic on ER-negative breast cancer. We found that MX-1 exhibited higher AP-1 activity and expressed higher levels of c-Jun, c-Fos and Fra-1 when compared with conventional ER-positive human breast cancer cell lines. Consistent with this study in vitro, histological study on human breast cancer tissues suggests that ER-negative cancers express high Fra-1 protein, and that paclitaxel- sensitive cancers express low Fra-1 protein. The ascochlorin, which inhibits AP-1 through the Erk signaling pathway, suppressed the AP-1 activity of MX-1 cells, and selectively killed MX-1 cells, partly due to induction of apoptosis. Moreover, administration of ascochlorin elongated life span of mice intraperitoneally implanted with murine mammary carcinoma cells. Conclusions: Our results suggest that AP-1 is an effective clinical target molecule for the treatment of ER-negative human breast cancer, and that ascochlorin is promising therapeutic agent for these refractory breast cancers. No significant financial relationships to disclose.


1995 ◽  
Vol 2 (4) ◽  
pp. 293-309
Author(s):  
L E Yaich ◽  
N Roodi ◽  
L R Bailey ◽  
C S Verrier ◽  
C J Yee ◽  
...  

2021 ◽  
Author(s):  
Niantao Deng ◽  
Andre Minoche ◽  
Kate Harvey ◽  
Meng Li ◽  
Juliane Winkler ◽  
...  

Abstract Background: Breast cancer cell lines (BCCLs) and patient-derived xenografts (PDX) are the most frequently used models in breast cancer research. Despite their widespread usage, genome sequencing of these models is incomplete, with previous studies only focusing on targeted gene panels, whole exome or shallow whole genome sequencing. Deep whole genome sequencing is the most sensitive and accurate method to detect single nucleotide variants and indels, gene copy number and structural events such as gene fusions.Results: Here we describe deep whole genome sequencing (WGS) of commonly used BCCL and PDX models using the Illumina X10 platform with an average ~ 60x coverage. We identify novel genomic alterations, including point mutations and genomic rearrangements at base-pair resolution, compared to previously available sequencing data. Through integrative analysis with publicly available functional screening data, we annotate new genomic features likely to be of biological significance. CSMD1, previously identified as a tumor suppressor gene in various cancer types, including head and neck, lung and breast cancers, has been identified with deletion in 50% of our PDX models, suggesting an important role in aggressive breast cancers. Conclusions: Our WGS data provides a comprehensive genome sequencing resource of these models.


2021 ◽  
Vol 17 (2) ◽  
pp. e1008608
Author(s):  
Shay Ben-Elazar ◽  
Miriam Ragle Aure ◽  
Kristin Jonsdottir ◽  
Suvi-Katri Leivonen ◽  
Vessela N. Kristensen ◽  
...  

Different miRNA profiling protocols and technologies introduce differences in the resulting quantitative expression profiles. These include differences in the presence (and measurability) of certain miRNAs. We present and examine a method based on quantile normalization, Adjusted Quantile Normalization (AQuN), to combine miRNA expression data from multiple studies in breast cancer into a single joint dataset for integrative analysis. By pooling multiple datasets, we obtain increased statistical power, surfacing patterns that do not emerge as statistically significant when separately analyzing these datasets. To merge several datasets, as we do here, one needs to overcome both technical and batch differences between these datasets. We compare several approaches for merging and jointly analyzing miRNA datasets. We investigate the statistical confidence for known results and highlight potential new findings that resulted from the joint analysis using AQuN. In particular, we detect several miRNAs to be differentially expressed in estrogen receptor (ER) positive versus ER negative samples. In addition, we identify new potential biomarkers and therapeutic targets for both clinical groups. As a specific example, using the AQuN-derived dataset we detect hsa-miR-193b-5p to have a statistically significant over-expression in the ER positive group, a phenomenon that was not previously reported. Furthermore, as demonstrated by functional assays in breast cancer cell lines, overexpression of hsa-miR-193b-5p in breast cancer cell lines resulted in decreased cell viability in addition to inducing apoptosis. Together, these observations suggest a novel functional role for this miRNA in breast cancer. Packages implementing AQuN are provided for Python and Matlab: https://github.com/YakhiniGroup/PyAQN.


Nutrients ◽  
2019 ◽  
Vol 11 (2) ◽  
pp. 237 ◽  
Author(s):  
Sylvain Lecomte ◽  
Florence Demay ◽  
Thu Ha Pham ◽  
Solenn Moulis ◽  
Théo Efstathiou ◽  
...  

The flavone apigenin and the mycotoxin zearalenone are two major compounds found in the human diet which bind estrogen receptors (ERs), and therefore influence ER activity. However, the underlying mechanisms are not well known. To unravel the molecular mechanisms that could explain the differential effect of zearalenone and apigenin on ER-positive breast cancer cell proliferation, gene-reporter assays, chromatin immunoprecipitation (ChIP) experiments, proliferation assays and transcriptomic analysis were performed. We found that zearalenone and apigenin transactivated ERs and promoted the expression of estradiol (E2)-responsive genes. However, zearalenone clearly enhanced cellular proliferation, while apigenin appeared to be antiestrogenic in the presence of E2 in both ER-positive breast cancer cell lines, MCF-7 and T47D. The transcriptomic analysis showed that both compounds regulate gene expression in the same way, but with differences in intensity. Two major sets of genes were identified; one set was linked to the cell cycle and the other set was linked to stress response and growth arrest. Our results show that the transcription dynamics in gene regulation induced by apigenin were somehow different with zearalenone and E2 and may explain the differential effect of these compounds on the phenotype of the breast cancer cell. Together, our results confirmed the potential health benefit effect of apigenin, while zearalenone appeared to be a true endocrine-disrupting compound.


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