Establishment, growth and in vivo differentiation of a new clonal human cell line, EM-G3, derived from breast cancer progenitors.
A new clonal cell line, EM-G3, was derived from a primary lesion of human infiltrating ductal breast carcinoma. The line consisted of cuboidal cells with occasional appearance of more differentiated branched cells apparently involved in cell-to-cell communication. The EM-G3 cells, population doubling time 34 h, are dependent on the epidermal growth factor. Multicolor fluorescence in situ hybridization (mFISH) analysis demonstrated a stable diploid genome with several genetic changes. Immunocytochemical analysis of EM-G3 in vitro revealed positivity for keratins (K) K5, K14, K18, nuclear protein p63, epithelial membrane antigen (EMA) and other proteins indicative of a pattern of mammary epithelium bipotent progenitors. Detection of integrins alpha-6, beta-1, and protein CD44 by cDNA array also pointed to the character of basal/stem cells. In contrast, dominant cells in the human original tumor showed the luminal character (K18+, K19+, K5-, K14-, and p63-). However, cells with the immunocytochemical profile similar to that of cultured EM-G3 cells were found in minor clusters in the patient's tumor sections. The EM-G3 cells formed limited tumors in nu/nu mice. The cells in mouse tumors were organized in primitive ductal-like structures consisting of 1-3 large central luminal-like cells (EMA+) surrounded by peripheral myoepithelial-like cells (p63+/EMA-). The large central cells gradually disintegrated, forming a pseudolumen. Apparently, EM-G3 cells are able to partially differentiate in vivo as well as in vitro. Our results indicate that EM-G3 cells were derived from a premalignant population of common progenitors of luminal and myoepithelial cells that were immortalized in an early stage of tumorigenesis.
Brozova
Marketa
M
Department of Cell Biology, Institute of Molecular Genetics, Academy of Sciences of the Czech Republic, Flemingovo nam. 2, Prague 6, Czech Republic.
Kleibl
Zdenek
Z
Netikova
Irena
I
Sevcik
Jan
J
Scholzova
Eva
E
Brezinova
Jana
J
Chaloupkova
Alena
A
Vesely
Pavel
P
Dundr
Pavel
P
Zadinova
Marie
M
Krasna
Luboslava
L
Matouskova
Eva
E
D000818:Animals; D001943:Breast Neoplasms / Q000235:genetics / Q000473:pathology*; D002454:Cell Differentiation; D045744:Cell Line, Tumor; D005260:Female; D006801:Humans; D007150:Immunohistochemistry; D017404:In Situ Hybridization, Fluorescence; D007621:Karyotyping; D051379:Mice; D008819:Mice, Nude; D009154:Mutation; D014411:Neoplastic Stem Cells / Q000473:pathology*; D020411:Oligonucleotide Array Sequence Analysis