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Updated: Aug 9, 2026
Mammary Transplantation of Stromal Cells and Carcinoma Cells in C57BL/6J Mice
Published on: August 12, 2011
Immortalized bovine mammary epithelial cells express stem cell markers and differentiate in vitro
Han Hu1,2, Nan Zheng1, Haina Gao2
1Ministry of Agriculture-Milk Risk Assessment Laboratory, State Key Laboratory of Animal Nutrition, Institute of Animal Science, Chinese Academy of Agricultural Sciences, Beijing, 100193, China.
Insights
Researchers immortalized bovine mammary epithelial cells (CMEC) using SV40 large T antigen, creating CMEC-H. This cell line self-renews, differentiates, and maintains milk protein synthesis, offering a valuable tool for mammary gland research.
Area of Science:
- Veterinary Science
- Cell Biology
- Biotechnology
Background:
- Bovine mammary epithelial cells (CMEC) are crucial for milk production.
- Cell number and secretory activity of CMEC directly impact milk yield.
- Primary CMEC have limited lifespan in vitro.
Purpose of the Study:
- To establish a stable, immortalized bovine mammary epithelial cell line.
- To characterize the properties of the immortalized cell line.
- To assess its utility as a research tool for mammary gland physiology.
Main Methods:
- Immortalization of primary Chinese Holstein CMEC using SV40 large T antigen gene via retrovirus.
- In vitro culture and characterization of the cell line (CMEC-H).
- Assessment of cell morphology, telomerase activity, tumor formation in nude mice, marker expression (epithelial, mesenchymal, stem/progenitor), and milk protein synthesis.
Main Results:
- Successfully established an immortalized bovine mammary epithelial cell line (CMEC-H) that surpassed 50 passages.
- CMEC-H cells exhibited cobblestone morphology, sustained telomerase activity, and did not form tumors in nude mice.
- The cell line expressed epithelial, mesenchymal, and stem/progenitor markers, and induced expression of key milk proteins (caseins, butyrophilin).
Conclusions:
- The immortalized CMEC-H cell line possesses characteristics of self-renewal and differentiation.
- CMEC-H maintains the synthetic function of mammary epithelial cells.
- This cell line serves as a valuable reagent for studying mammary gland physiology and milk production mechanisms.
Abstract:
The bovine mammary epithelial cell is a secretory cell, and its cell number and secretory activity determine milk production. In this study, we immortalized a bovine mammary epithelial cell line by SV40 large T antigen gene using a retrovirus based on Chinese Holstein primary mammary epithelial cells (CMEC) cultured in vitro. An immortalized bovine mammary epithelial cell line surpassed the 50-passage mark and was designated the CMEC-H. The immortalized mammary epithelial cells grew in close contact with each other and exhibited the typical cobblestone morphology characteristic with obvious boundaries. The telomerase expression of CMEC-H has consistently demonstrated the presence of telomerase activity as an immortalized cell line, but the cell line never induced tumor formation in nude mice. CMEC-H expressed epithelial (cytokeratins CK7, CK8, CK18, and CK19), mesenchymal (vimentin), and stem/progenitor (CD44 and p63) cell markers. The induced expression of milk proteins, αS1 -casein, β-casein, κ-casein, and butyrophilin, indicated that CMEC-H maintained the synthesis function of the mammary epithelial cells. The established immortalized bovine mammary epithelial cell line CMEC-H is capable of self-renewal and differentiation and can serve as a valuable reagent for studying the physiological mechanism of the mammary gland.
