scholarly journals GIRK1 triggers multiple cancer-related pathways in the benign mammary epithelial cell line MCF10A

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Gebhard Schratter ◽  
Susanne Scheruebel ◽  
Sonja Langthaler ◽  
Katja Ester ◽  
Brigitte Pelzmann ◽  
...  

AbstractExcessive expression of subunit 1 of GIRK1 in ER+ breast tumors is associated with reduced survival times and increased lymph node metastasis in patients. To investigate possible tumor-initiating properties, benign MCF10A and malign MCF7 mammary epithelial cells were engineered to overexpress GIRK1 neoplasia associated vital parameters and resting potentials were measured and compared to controls. The presence of GIRK1 resulted in resting potentials negative to the controls. Upon GIRK1 overexpression, several cellular pathways were regulated towards pro-tumorigenic action as revealed by comparison of transcriptomes of MCF10AGIRK1 with the control (MCF10AeGFP). According to transcriptome analysis, cellular migration was promoted while wound healing and extracellular matrix interactions were impaired. Vital parameters in MCF7 cells were affected akin the benign MCF10A lines, but to a lesser extent. Thus, GIRK1 regulated cellular pathways in mammary epithelial cells are likely to contribute to the development and progression of breast cancer.

1985 ◽  
Vol 5 (1) ◽  
pp. 268-272
Author(s):  
N E Hynes ◽  
R Jaggi ◽  
S C Kozma ◽  
R Ball ◽  
D Muellener ◽  
...  

A line of mouse mammary epithelial cells (NMuMG) has been characterized for its ability to be stably transfected with exogenous DNA. A transfection frequency of at least 1 cell per 1,000 was obtained with the pSV2neo plasmid. Several thousand G418-resistant NMuMG cell clones can easily be generated in cotransfection of genomic DNA and pSV2neo. The NMuMG cells were isolated from normal mammary glands and do not form malignant lesions when injected into nude mice. We have cotransfected NMuMG cells with pSV2neo and genomic DNA from the human EJ bladder carcinoma line, a cell line which contains an activated c-rasH oncogene. When a pool of 4,700 G418-resistant colonies was injected into nude mice, tumors were obtained. These tumors contain a transfected human rasH gene. Genomic DNA transfection into a line of mouse epithelial cells, in combination with the selection of stable transfectants and tumor induction in nude mice, can be used to screen human tumor DNA for the presence of activated oncogenes.


1985 ◽  
Vol 5 (1) ◽  
pp. 268-272 ◽  
Author(s):  
N E Hynes ◽  
R Jaggi ◽  
S C Kozma ◽  
R Ball ◽  
D Muellener ◽  
...  

A line of mouse mammary epithelial cells (NMuMG) has been characterized for its ability to be stably transfected with exogenous DNA. A transfection frequency of at least 1 cell per 1,000 was obtained with the pSV2neo plasmid. Several thousand G418-resistant NMuMG cell clones can easily be generated in cotransfection of genomic DNA and pSV2neo. The NMuMG cells were isolated from normal mammary glands and do not form malignant lesions when injected into nude mice. We have cotransfected NMuMG cells with pSV2neo and genomic DNA from the human EJ bladder carcinoma line, a cell line which contains an activated c-rasH oncogene. When a pool of 4,700 G418-resistant colonies was injected into nude mice, tumors were obtained. These tumors contain a transfected human rasH gene. Genomic DNA transfection into a line of mouse epithelial cells, in combination with the selection of stable transfectants and tumor induction in nude mice, can be used to screen human tumor DNA for the presence of activated oncogenes.


2008 ◽  
Vol 15 (1) ◽  
pp. 226-237 ◽  
Author(s):  
Beate C. Litzenburger ◽  
Hyun-Jung Kim ◽  
Isere Kuiatse ◽  
Joan M. Carboni ◽  
Ricardo M. Attar ◽  
...  

Toxins ◽  
2020 ◽  
Vol 12 (8) ◽  
pp. 496 ◽  
Author(s):  
Yawang Sun ◽  
Yongjiang Wu ◽  
Zili Wang ◽  
Juncai Chen ◽  
You Yang ◽  
...  

In practical dairy production, cows are frequently subjected to inflammatory diseases, such as high-grain diet-induced subacute ruminal acidosis (SARA) as well as mastitis and metritis. Under the circumstances, lipopolysaccharide (LPS) induces oxidative stress within the cow and in the mammary epithelial cells. It has implications in practical production to alleviate oxidative stress and to optimize the lactational function of the mammary epithelial cells. This study thus aimed to investigate the antioxidative effects of dandelion aqueous extract (DAE) on LPS-induced oxidative stress and the mechanism of DAE as an antioxidant to alleviate oxidative stress through the nuclear factor erythroid 2-related factor 2 (Nrf2) pathway in the bovine mammary epithelial cell line MAC-T cells. The cells were cultured for 48 h in six treatments including control (without LPS and DAE), LPS (100 ng/mL), DAE10 (100 ng/mL LPS and 10 μg/mL DAE), DAE50 (100 ng/mL LPS and 50 μg/mL DAE), DAE100 (100 ng/mL LPS and 100 μg/mL DAE), and DAE200 (100 ng/mL LPS and 200 μg/mL DAE), respectively. The results showed that cell viability was reduced by LPS, and the adverse effect of LPS was suppressed with the supplementation of DAE. Lipopolysaccharide-induced oxidative stress through enhancing reactive oxygen species (ROS) production, resulted in increases in oxidative damage marker concentrations, while 10 and 50 μg/mL DAE alleviated the LPS-induced oxidative stress via scavenging cellular ROS and improving antioxidant enzyme activity. The upregulation of antioxidative gene expression in DAE treatments was promoted through activating the Nrf2 signaling pathway, with DAE at a concentration of 50 μg/mL exhibiting the highest effect. Overall, DAE acted as an effective antioxidant to inhibit LPS-induced oxidative stress and as a potential inducer of the Nrf2 signaling pathway.


2000 ◽  
Vol 113 (5) ◽  
pp. 795-806 ◽  
Author(s):  
P. Schedin ◽  
R. Strange ◽  
T. Mitrenga ◽  
P. Wolfe ◽  
M. Kaeck

Mammary gland form and function are regulated by interactions between epithelium and extracellular matrix. Major glycoprotein components of extracellular matrix have been identified that give survival, proliferation and differentiation signals to mammary epithelial cells. We provide evidence that proteolytic fragments of the extracellular matrix glycoprotein, fibronectin, suppress growth and can promote apoptosis of mouse mammary epithelial cells. During mammary gland involution, total fibronectin and fibronectin fragment levels are increased. The peak levels of fibronectin protein and fragments are observed 4–6 days post-weaning, coincident with the peak in epithelial cell death. Using a model for hormone withdrawal-induced death of mammary epithelium, elevated levels of fibronectin proteolytic fragments were associated with apoptosis in TM-6 cells, a tumorigenic mouse mammary epithelial cell line. Treatment of TM-6 cells with exogenous fibronectin fragments (FN120) reduced cell number, and induced apoptosis and matrix degrading protease activity. Inhibition of matrix protease activity rescued TM-6 cell viability, indicating that FN120-induced cell loss is mediated through matrix protease activity. In a three-dimensional model for mammary gland development, FN120 reduced alveolar-like and promoted ductal-like development by a matrix protease-dependent mechanism. These data suggest that during post-lactational involution, fibronectin fragments may contribute to epithelial cell loss and dissolution of mammary alveoli by inducing matrix degrading proteinases.


1990 ◽  
Vol 1 (11) ◽  
pp. 863-872 ◽  
Author(s):  
N T Telang ◽  
M P Osborne ◽  
L A Sweterlitsch ◽  
R Narayanan

A spontaneously immortalized, nontumorigenic mouse mammary epithelial cell line (MMEC) was transfected with an activated myc construct by electroporation. Constitutive expression of myc in MMEC resulted in anchorage independence in soft agar and tumorigenicity in nude mice. The myc-expressing MMEC showed higher saturation density, faster growth rate, and partial abrogation of serum-derived growth factor(s) requirement compared with parent MMEC. Epidermal growth factor or transforming growth factor alpha stimulated the anchorage-independent growth, but not the anchorage-dependent growth, of MMEC-myc cells. Type 1 transforming growth factor beta, on the other hand, inhibited both the anchorage-independent and anchorage-dependent growth of MMEC-myc cells. These results demonstrate that deregulated expression of myc results in neoplastic transformation iin mammary epithelial cells. Accompanying the transformation is altered sensitivity to polypeptide growth factors.


2021 ◽  
Vol 9 (10) ◽  
pp. 2090
Author(s):  
Yi-Tian Ying ◽  
Wei-Jia Ren ◽  
Xun Tan ◽  
Jing Yang ◽  
Rui Liu ◽  
...  

Background: Staphylococcus aureus is a leading cause of contagious mastitis in dairy cattle. Internalization of S. aureus by bovine mammary gland epithelial cells is thought to be responsible for persistent and chronic intramammary infection, but the underlying mechanisms are not fully understood. Methods: In the present study, we evaluated the role of Annexin A2 (AnxA2), a membrane-binding protein, in S. aureus invasion into bovine mammary epithelial cell line (MAC-T). In vitro binding assays were performed to co-immunoprecipitate the binding proteins of AnxA2 in the lysates of S. aureus. Results: AnxA2 mediated the internalization but not adherence of S. aureus. Engagement of AnxA2 stimulated an integrin-linked protein kinase (ILK)/p38 MAPK cascade to induce S. aureus invasion. One of the AnxA2-precipitated proteins was identified as S. aureus clumping factor B (ClfB) through use of mass spectrometry. Direct binding of ClfB to AnxA2 was further confirmed by using a pull-down assay. Pre-incubation with recombinant ClfB protein enhanced S. aureus internalization, an effect that was specially blocked by anti-AnxA2 antibody. Conclusion: Our results demonstrate that binding of ClfB to AnxA2 has a function in promoting S. aureus internalization. Targeting the interaction of ClfB and AnxA2 may confer protection against S. aureus mastitis.


1999 ◽  
Vol 112 (23) ◽  
pp. 4193-4205 ◽  
Author(s):  
J. Huang ◽  
J.D. Hardy ◽  
Y. Sun ◽  
J.E. Shively

Normal mammary epithelial cells express the cell surface protein biliary glycoprotein (BGP or CD66a) in a polarized manner, suggesting that this protein may play a role in the formation of mammary acini. In order to test this hypothesis, we interrupted the expression of BGP in the mammary epithelial line MCF10F when cultured in or on Matrigel, a source of extracellular matrix (ECM). When analyzed by immunofluorescence confocal microscopy, the BGP staining is confined to the lumenal surface and colocalizes with actin. Sequential scanning electron microscopy demonstrates that the MCF10F cells migrate to form clusters, followed by apoptotic cell death within the center, resulting in lumen formation. Transmission electron micrographs reveal the presence of tight junctions and desmosomes between the cells, microvilli along the lumenal surface, and typical apoptotic bodies within the lumen. When the MCF10F cells are transfected with the BGP antisense gene and grown in Matrigel, they exhibit reduced acini formation (12% and 20%) compared to untransfected cells (52%) or to cells transfected with vector only (62%). Acini formation is also significantly reduced when MCF10F cells grown in Matrigel are treated with anti-BGP antibody (18% at 100 microgram/ml), or recombinant soluble BGP (18% at 0.4 microM). In contrast, the BGP-negative MCF7 breast tumor cell line, which does not form acini when grown in matrigel, exhibits >60% cell death with the occasional formation of acini, when transfected with the BGP sense gene and grown in Matrigel. These results support the hypothesis that BGP plays a role in the normal differentiation program of mammary epithelial cells, indicating that its expression is essential to the formation of the lumen. Furthermore, and as shown by others, the differentiation program depends on the presence of ECM. The lack of expression of BGP in the MCF7 breast cancer cell line suggests that the downregulation of BGP expression confers a growth advantage to these cells in ECM. In addition, we found that the MCF10F cells could be separated into a BGP-positive epithelial fraction (MCF10F-e), and a BGP-negative myoepithelial fraction (MCF10F-m). When the myoepithelial cell-enriched fraction is grown on Matrigel, web-like structures are formed. These cells have a typical spindle shape cell morphology and express keratin, alpha-smooth muscle actin and vimentin, markers of the myoepithelial cell phenotype. When MCF10F-m cells are treated with IFNgamma, they express CEA (carcinoembryonic antigen) but not BGP. Since breast carcinomas, especially in situ carcinomas, express CEA, this finding may suggest a heretofore unappreciated relationship between myoepithelial cells and breast cancer.


Author(s):  
Anna Acheva ◽  
Tytti Kärki ◽  
Niccole Schaible ◽  
Ramaswamy Krishnan ◽  
Sari Tojkander

In postmenopausal women, a major risk factor for the development of breast cancer is obesity. In particular, the adipose tissue-derived adipokine leptin has been strongly linked to tumor cell proliferation, migration, and metastasis, but the underlying mechanisms remain unclear. Here we show that treatment of normal mammary epithelial cells with leptin induces EMT-like features characterized by higher cellular migration speeds, loss of structural ordering of 3D-mammo spheres, and enhancement of epithelial traction forces. Mechanistically, leptin triggers the phosphorylation of myosin light chain kinase-2 (MLC-2) through the interdependent activity of leptin receptor and Ca2+ channels. These data provide evidence that leptin-activated leptin receptors, in co-operation with mechanosensitive Ca2+ channels, play a role in the development of breast carcinomas through the regulation of actomyosin dynamics.


1993 ◽  
Vol 4 (8) ◽  
pp. 849-858 ◽  
Author(s):  
J Kirjavainen ◽  
S Leppä ◽  
N E Hynes ◽  
M Jalkanen

A cell surface proteoglycan, syndecan-1, has been shown to participate in the maintenance of the epithelial cell morphology. A point mutated activated c-Ha-ras gene under the control of the glucocorticoid inducible MMTV-LTR promoter was transfected into the mouse mammary epithelial cell line, NOG-8. The NOG-8 ras cells were used to study changes in syndecan-1 expression during epithelial transformation. NOG-8 ras cells, when induced to express Ha-ras, transformed and formed foci in monolayer cultures and colonies in suspension cultures. Expression of syndecan-1 at the cell surface was markedly reduced in cells showing the transformed phenotype. The accumulation of newly synthesized core protein of syndecan-1 was suppressed in these cells, whereas mRNA levels remained unchanged. This novel finding indicates that syndecan-1 expression is translationally suppressed in the Ha-ras-transformed epithelial cells. Hence, syndecan-1 loss during epithelial transformation could take place without altering syndecan gene transcription and, on the other hand, could be one of the critical events involved in malignant transformation.


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