scholarly journals Endotoxin Triggers Tumor Initiation Events in Nontumorigenic Breast Epithelial Cells and Enhances Invasion-Related Phenotype in Pretumorigenic and Tumorigenic Breast Epithelial Cells

2021 ◽  
Vol 2021 ◽  
pp. 1-13
Author(s):  
Farah Yassine ◽  
Sabreen F. Fostok ◽  
Nataly Naser Al Deen ◽  
Rabih S. Talhouk

Inflammation is associated with the development of several cancers, including breast cancer. However, the molecular mechanisms driving breast cancer initiation or enhancement by inflammation are yet to be deciphered. Hence, we opted to investigate the role of inflammation in initiating and enhancing tumor-like phenotypes in nontumorigenic, pretumorigenic, and tumorigenic breast epithelial cells. Noncytotoxic endotoxin (ET) concentrations capable of inducing an inflammatory phenotype were determined for the different cell lines. Results showed that short-term ET exposure upregulated matrix metalloproteinase-9 (MMP-9) activity in nontumorigenic mammary epithelial cells of mouse (SCp2) and human origins (HMT-3522 S1; S1) and upregulated inflammatory mediators including nitric oxide (NO) and interleukin 1-β in tumorigenic human breast cells (MDA-MB-231), all in a dose-dependent manner. Long-term ET treatment, but not short-term, triggered the migration of SCp2 cells, and proliferation and migration of tumorigenic human breast cells MCF-7 and MDA-MB-231. Both short- and long-term ET exposures preferentially enhanced the invasion of pretumorigenic S1-connexin 43 knockout (Cx43-KO S1) cells compared to their nontumorigenic S1 counterparts. Moreover, both ET exposures disrupted lumen formation and apicolateral distribution of β-catenin in 3D cultures of S1 cells. In conclusion, ET treatment at concentrations that elicited inflammatory phenotype triggered tumor initiation events in nontumorigenic and pretumorigenic breast cells, and increased tumorigenicity of breast cancer cells. Our findings highlight the role of inflammation in enhancing migration, invasion, and loss of normal 3D morphology and suggest that such inflammatory insults can “add injury” to pretumorigenic and tumorigenic breast epithelial cells.

Author(s):  
Harald Seeger ◽  
Xiangjan Ruan ◽  
Hans Neubauer ◽  
Alfred O. Mueck

AbstractProliferation of human breast epithelial cells is regulated by sex hormones. Epidemiological studies indicate that progestogen addition to estrogen therapy can increase breast cancer risk. However, it remains unclear if all progestogens react in a similar manner. Here, the new progestogen drospirenone (DRSP) was compared to progesterone and other synthetic progestins.Human benign epithelial breast cells (HMECs) were incubated for 7 days with DRSP, progesterone (P), medroxyprogesterone acetate (MPA) and levonorgestrel (LNG) in the presence of a growth factor mixture (GF). HCC1500 and T-47D cells (human estrogen and progesterone receptor-positive primary breast cancer cells) were also incubated with the progestogens, but in the presence of estradiol (E2). The proliferation rate was measured by the MTT assay.DRSP and P elicited a similar significant inhibition of proliferation of HMECs in combination with GFs. LNG and MPA had no effect. DRSP, P, MPA and LNG were able to significantly inhibit the proliferation of HCC1500 and T-47D cells in combination with E2. No significant difference between the progestogens was observed in HCC1500 cells, whereas in T-47D cells both DRSP and P were significantly more effective at 10 μM than LNG and MPA.Because different results were found in the same experimental model, it appears that progestogens do not react similarly on the proliferation of human breast epithelial cells. However, for assessment of breast cancer risk different models should be used, because various mechanism(s) might be involved. It is also important to use benign as well as cancerous cell lines. The choice of progestogen could be of significance in terms of breast cancer risk under hormone therapy.


Cancers ◽  
2019 ◽  
Vol 11 (9) ◽  
pp. 1240 ◽  
Author(s):  
Vasudeva Bhat ◽  
Alison L. Allan ◽  
Afshin Raouf

The epithelial cells in an adult woman’s breast tissue are continuously replaced throughout their reproductive life during pregnancy and estrus cycles. Such extensive epithelial cell turnover is governed by the primitive mammary stem cells (MaSCs) that proliferate and differentiate into bipotential and lineage-restricted progenitors that ultimately generate the mature breast epithelial cells. These cellular processes are orchestrated by tightly-regulated paracrine signals and crosstalk between breast epithelial cells and their tissue microenvironment. However, current evidence suggests that alterations to the communication between MaSCs, epithelial progenitors and their microenvironment plays an important role in breast carcinogenesis. In this article, we review the current knowledge regarding the role of the breast tissue microenvironment in regulating the special functions of normal and cancer stem cells. Understanding the crosstalk between MaSCs and their microenvironment will provide new insights into how an altered breast tissue microenvironment could contribute to breast cancer development, progression and therapy response and the implications of this for the development of novel therapeutic strategies to target cancer stem cells.


2020 ◽  
Author(s):  
Lin Cao ◽  
Xin Wang ◽  
Juhong Yang ◽  
Jia Guo ◽  
Xiang Li ◽  
...  

Abstract Background Neural cell adhesion molecule (NCAM), a common mammalian cell surface glycoprotein, is the major substrate of polysialic acid (polySia). Polysialylated NCAM occurs in many types of cancer, but rarely in normal adult tissues. Epithelial-mesenchymal transition (EMT) is an important process contributing to tumor metastasis. The functional role of NCAM hypersialylation in EMT is unclear. Method Expression of NCAM and polysialylated NCAM in breast cancer progression were evaluated by western blot (WB), immunohistochemistry, semi-quantitative PCR and immunoprecipitation (IP). Overexpression of NCAM-140 and ST8SiaII were performed to assess the functional role of NCAM hypersialylation by liposome transfection. Cell proliferation ability was investigated with MTT assay. Transwell and wound closure assay were conducted to evaluate cell migratory ability. Phagokinetic gold sol assay and cell adhesion assay were performed to assess cell motility ability and cell adhesion ability, respectively. Furthermore, WB and IP were used to reveal the activated signaling pathway. Results The present study indicates that NCAM and attached polysialic acid affect behaviors of breast epithelial cells through differential signaling pathways, based on the following observations: (i) NCAM and polysialylated NCAM were aberrantly regulated in breast cancer cells; (ii) NCAM and polysialylated NCAM expression were upregulated in normal breast epithelial cells undergoing EMT; (iii) NCAM overexpression induced EMT in breast epithelial cells; (iv) NCAM promoted cell proliferation and migration through activation of a β-catenin/slug signaling pathway; (v) modification of polySia attached to NCAM inhibited cell adhesion and promoted cell motility through activation of an EGFR/STAT3 pathway. Conclusion This study demonstrates that NCAM and polysialylated NCAM facilitate different signaling pathway and affect different cell behaviors. Switching between the NCAM-mediated pathways appeared to depend on polySia decoration.


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