Isolation and characterization of murine mammary cell lines with differentiated aggressive phenotype

Abstract

Breast cancer is the first cause of death from female cancer. The recurrence of the disease originated at the level of secondary organs, or metastasis, is responsible for 90% of deaths from cancer. The factors that endow these cells with metastatic functions are largely unknown. One of the limitations in the study of tumor cells with metastatic phenotypes is that cell lines maintained in culture lose this ability to invade and colonize tissues. On the other hand, it has been shown that reinjection of cells in animals can lead to their enrichment with aggressive phenotypes. The aim of this work was the isolation and characterization of different cell populations with differentiated metastatic capacities. Following inoculation of the F3II murine mammary carcinoma cell lines, we established cell populations in vitro, one from the primary tumor and another from a metastatic nodule, F3II TP and F3II NM cell lines respectively. To determine their aggressiveness, a series of additional characteristics were compared between these lines and F3II. The three lines showed variations in morphology in culture and a different doubling time, with F3II NM having the highest one. Moreover, F3II NM presented major adhesion capacity and lower clonogenic potential. This could be explained by the differential expression of cell adhesion molecules, such as integrins or cadherins analyzed by flow cytometry. In addition, the migration capacity was analyzed by transwell assay and the results showed differences in this process. Finally, we compared the behavior in vivo and we detected variations in tumor progression such as latency, frequency of ulceration, tumor growth and the presence of pulmonary nodules. All things considered, the establishment and characterization of these two new different cell lines with differentiated metastatic capacities will allow us to determine molecular differences involved in the metastatic process.