Journal of Surgical Oncology 62:288-297 (1996) Characterization of F311, a Sarcomatoid Mammary Carcinoma Cell Line Originated From a Clonal Subpopulation of a Mouse Adenocarcinoma

We characterized a new mammary tumor cell line, F311, previously estab-lished in vitro from a clonal subpopulation of the BALB/c transplantable mammary adenocarcinoma M3, moderately metastatic to lung. The F31I cell line has been passaged>50 times. It has grown as elongated cells adherent to the bottom of the flask. Cytogenetic studies showed that F3II cultures were nearly triploid. Tumor cells expressed fibronectin and showed high levels of cell-surface urokinase, a key protease in invasion and metas-tasis. F3II cells grew as poorly differentiated, spindle-cell carcinoma tu-mors (sarcomatoid carcinomas) with a prominent local invasiveness, a high angiogenic response, and a 90-100 % incidence of lung metastases when inoculated S.C. into syngeneic mice. Ultrastructural and immunocyto-chemical analysis revealed characteristic features of carcinomas. Our data suggest that F3II is less differentiated and more aggressive than the original tumor line, supporting the notion that mammary carcinomas are heteroge-neous neoplasms and contain subpopulations with diverse biologic behav-ior. The F3II mouse mammary sarcomatoid carcinoma line is a suitable model to examine antiinvasive, antiangiogenic, and antimetastatic agents. 0 1996 Wiley-Liss, Inc