The target-specific fluorochromes allow the sensitive detection of cellular proteins such as cell receptors, which are involved in breast cancer development such as epidermal growth factor (EGF) receptor.
Proteins that had previously been implicated in breast cancer development, such as fibroblast growth factors and wnt proteins, were also highly recurrent in the present screen.
One mechanism for the apparent divergence of PR functions may relate to early events in breast cancer development, such as altered signal transduction.
The cDNA's recovered from the selected cells reveal a high recurrence of genes that have previously been implicated in breast cancer development, such as Wnt and FGF proteins, while at the same time revealing high recurrences of genes that had previously not been directly linked to breast cancer development, such as FGF-binding proteins and paraoxonases.
These findings add to previous findings of differences between mouse and human breast cancer development such as that activation of Wnt and/or its pathway members are commonly found in mouse but not in human spontaneous breast tumors, differences in metastasis patterns, or that few mouse models accurately represent ER positive human breast cancers [ 40].
Some of these genes were already described as involved in stem/progenitor cell-specific functions or in regulation of self-renewal, and abnormal expression of some of the genes has been correlated with breast cancer development such as proliferation, cell survival, and invasion (Table 1).
Among competitors of PVT1 for binding to the mir-200 family in normal breast tissues, there are some important regulators of breast tissue morphogenesis and development, such as CDH1; all the three members of the extended p53 family (i.e., TP53, TP63, and TP73); two members of the mammalian RUNX family (i.e., RUNX1 and RUNX3); and GATA3.
Among PVT1 nearest-neighbors in the normal-MMI-network, we emphasize some important regulators of breast tissue morphogenesis and development, such as: the aforementioned CDH1; all three members of the extended p53 family (i.e., TP53, TP63 and TP73); two members of the mammalian RUNX family (i.e., RUNX1 and RUNX3) and GATA3.
It is well known that bone is the most frequently targeted organ of breast cancer metastasis 7. Growth factors that are involved in bone development, such as TGF-β and BMPs, also play important roles in the breast cancer metastatic process 13, 15.
In most tumor types, HOX genes function as oncogenes to promote cancer development such as HOXA9 in leukemia and HOXB13 in ovarian and breast cancers [ 13, 14].
