LB52
FGF-2 expression is altered in myoepithelial cells from cancer-containing breasts
Vasileios Modes, Charlene Rodrigues, Nora Nyquist, Jacqueline Shaw, Rosemary Walker
University of Leicester, UK
Myoepithelial cells form the outer layer of the epithelial bi-layer of the lobular and ductal system of the breast. They have important roles in the regulation of growth, apoptosis, differentiation and polarity of luminal epithelial cells.
Fibroblast growth factor-2 (FGF-2) is a pleiotropic polypeptide involved in the control of cellular proliferation, differentiation, survival and migration and in breast it has been shown to be expressed exclusively in myoepithelial cells. Given the potential of myoepithelial cell-derived FGF-2 as a paracrine factor controlling epithelial cell survival and growth, we compared FGF-2 levels in non-involved tissue from cancer- containing breast (NTCCB) and normal breast from age-matched women without cancer, using both immunohistochemistry and molecular biology techniques.
Immunohistochemical analysis was performed using fixed tissue from 188 cases (89 NTCCB and 99 normal). Staining was observed in the nuclei of myoepithelial cells. Higher levels of FGF-2 were found in tissue from cancer containing breast (p=0.012), particularly in age group ≤39 yrs (p=0.001).
Primary myoepithelial cells were isolated from fresh breast from 5 NTCCB and 6 normal controls using positive selection and cultured for up to 3 passages; mRNA and protein was extracted. FGF-2 expression was measured using RT qPCR and found to be higher in myoepithelial cells from NTCCB (p=0.021), as was FGF-2 protein by immunoblotting.
Our data show that expression of FGF-2 by myoepithelial cells is altered in the normal tissue of breasts in which cancer develops. Since it is a factor in controlling cell survival this supports our hypothesis that altered myoepithelial cell function may contribute or predispose to breast cancer development.
Acknowledgements
This work is supported by Breast Cancer Campaign
