Human breast cancers respond to growth factors in vivo but not in vitro.
Growth response of human breast cancer cells to epidermal growth factor (EGF) and transforming growth factor-alpha (TGF-alpha) was tested both in culture and in vivo in nude mice. Human breast cancer cells were obtained from palpable tumors resulting from xenografted primary breast cancers in nude mice. In collagen gel culture, the breast cancer cells grew autonomously as expanding spherical masses of loosely adherent cells in the basal medium and the supplementation of growth factors had no additional stimulatory effect. To determine whether this in vitro response is reflected in vivo, the collagen gel embedded human breast cancer cells were transplanted into athymic nude mice and the growth response to EGF was studied in vivo. In contrast to the situation in vitro, exogenous EGF was growth promoting in vivo. Our results demonstrate the importance of the combined in vitro-in vivo approach in studying physiologically relevant growth regulation. In addition, the use of collagen gel embedded human breast cancer cells for transplantation studies may more closely model the clinical situation in view of the close histopathological resemblance of the recovered gels to the surgical breast specimens.
Yang
J
J
Cancer Research Laboratory, University of California, Berkeley 94720.
Popnikolov
N K
NK
Sakthivel
R
R
Nandi
S
S
D000818:Animals; D001943:Breast Neoplasms / Q000473:pathology*; D002455:Cell Division / Q000187:drug effects; D003094:Collagen; D003470:Culture Media; D004815:Epidermal Growth Factor / Q000494:pharmacology*; D005782:Gels; D006801:Humans; D051379:Mice; D008819:Mice, Nude; D009368:Neoplasm Transplantation; D013268:Stimulation, Chemical; D016211:Transforming Growth Factor alpha / Q000494:pharmacology*; D014183:Transplantation, Heterologous; D014407:Tumor Cells, Cultured / Q000187:drug effects
D003470:Culture Media; D005782:Gels; D016211:Transforming Growth Factor alpha; D004815:Epidermal Growth Factor; D003094:Collagen