201. Aberrant activation of NF-κB signaling in mammary epithelium leads to abnormal growth and ductal carcinoma in situ
- Author
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Whitney Barham, Oleg Tikhomirov, Linda A. Gleaves, Thomas Stricker, Timothy S. Blackwell, Lianyi Chen, Fiona E. Yull, and Halina Onishko
- Subjects
Pathology ,medicine.medical_specialty ,Cancer Research ,Mammary gland ,Gene Expression ,Breast Neoplasms ,Mice, Transgenic ,Tumor initiation ,Biology ,Epithelium ,Mice ,Breast cancer ,medicine ,Genetics ,Animals ,Humans ,skin and connective tissue diseases ,Cell Proliferation ,Mammary ,Inflammation ,Hyperplasia ,Carcinoma in situ ,Carcinoma, Ductal, Breast ,Ductal carcinoma in situ ,NF-kappa B ,Ductal carcinoma ,medicine.disease ,3. Good health ,I-kappa B Kinase ,Enzyme Activation ,Disease Models, Animal ,medicine.anatomical_structure ,Cell Transformation, Neoplastic ,Mammary Epithelium ,Oncology ,Organ Specificity ,Mucin 1 ,Female ,Inflammation Mediators ,Neoplasm Grading ,Nuclear factor kappa-B ,Biomarkers ,Carcinoma in Situ ,Research Article ,Signal Transduction - Abstract
Background Approximately 1 in 5 women diagnosed with breast cancer are considered to have in situ disease, most often termed ductal carcinoma in situ (DCIS). Though recognized as a risk factor for the development of more invasive cancer, it remains unclear what factors contribute to DCIS development. It has been shown that inflammation contributes to the progression of a variety of tumor types, and nuclear factor kappa B (NF-κB) is recognized as a master-regulator of inflammatory signaling. However, the contributions of NF-κB signaling to tumor initiation are less well understood. Aberrant up-regulation of NF-κB activity, either systemically or locally within the breast, could occur due to a variety of commonly experienced stimuli such as acute infection, obesity, or psychological stress. In this study, we seek to determine if activation of NF-κB in mammary epithelium could play a role in the formation of hyperplastic ductal lesions. Methods Our studies utilize a doxycycline-inducible transgenic mouse model in which constitutively active IKKβ is expressed specifically in mammary epithelium. All previously published models of NF-κB modulation in the virgin mammary gland have been constitutive models, with transgene or knock-out present throughout the life and development of the animal. For the first time, we will induce activation at later time points after normal ducts have formed, thus being able to determine if NF-κB activation can promote pre-malignant changes in previously normal mammary epithelium. Results We found that even a short pulse of NF-κB activation could induce profound remodeling of mammary ductal structures. Short-term activation created hyperproliferative, enlarged ducts with filled lumens. Increased expression of inflammatory markers was concurrent with the down-regulation of hormone receptors and markers of epithelial differentiation. Furthermore, the oncoprotein mucin 1, known to be up-regulated in human and mouse DCIS, was over-expressed and mislocalized in the activated ductal tissue. Conclusions These results indicate that aberrant NF-κB activation within mammary epithelium can lead to molecular and morphological changes consistent with the earliest stages of breast cancer. Thus, inhibition of NF-κB signaling following acute inflammation or the initial signs of hyperplastic ductal growth could represent an important opportunity for breast cancer prevention. Electronic supplementary material The online version of this article (doi:10.1186/s12885-015-1652-8) contains supplementary material, which is available to authorized users.
- Published
- 2015