%0 Journal Article
%T The plasticity of human breast carcinoma cells is more than epithelial to mesenchymal conversion
%A Ole William Petersen
%A Helga Lind Nielsen
%A Thorarinn Gudjonsson
%A Ren¨¦ Villadsen
%A Lone R£¿nnov-Jessen
%A Mina J Bissell
%J Breast Cancer Research
%D 2001
%I BioMed Central
%R 10.1186/bcr298
%X Human breast cancer cells are generally believed to originate from the luminal epithelial lineage of terminal duct lobular units [1]. Accordingly, the phenotype of most breast cancer cell lines is luminal, and they express sialomucin and keratin K19 [2,3] as well as other epithelial markers. In recent years, however, there has been an increasing appreciation of human breast carcinoma cells being more flexible in their differentiation program. Intra-tumor and inter-tumor heterogeneity of human breast cancer should no longer be viewed as a consequence of phenotypic drifting due to genetic instability, but also from the point of view of different differentiation repertoires available to the neoplastic cells in response to the tumor microenvironment, including reversion to a 'normal' phenotype (for an overview, see [4]). This is important because it allows for possible strategies to influence the breast cancer cells towards a more differentiated state (for a review, see [5]). We recently showed that the myoepithelial lineage is derived directly from the normal luminal epithelial lineage [6]. It has been observed previously that the luminal epithelial lineage of breast cancer was defective in its ability to differentiate along the myoepithelial differentiation program [7]. The growing number of myoepithelial markers is similarly providing evidence that neoplastic breast cancer cells frequently exhibit at least a partial myoepithelial differentiation program [8,9,10]. If the normal myoepithelial differentiation program is indeed tumor suppressive [5,11,12], then defining these traits becomes rather important for diagnosis and therapy. Furthermore, recent data based on loss of heterozygosity suggest that the neoplastic and mesenchymal compartments, of which the latter contain the myofibroblasts, are directly evolutionarily connected [13,14,15]. It has also been shown that loss of differentiation in breast cancer, invasion and metastasis both in vivo and in culture concur w
%K breast cancer
%K differentiation programs
%K epithelial to mesenchymal transition
%K myoepithelial cells
%K myofibroblasts
%U http://breast-cancer-research.com/content/3/4/213