Characterization of a fibroblastoid mammary carcinoma cell line (LM2) originated from a mouse adenocarcinoma

We established and characterized a new mammary tumor cell line, LM2, derive d from M2 mammary adenocarcinoma which spontaneously appeared in a BALB/c f emale mouse. The LM2 cell line has been maintained in culture for more than 40 passages and grows as poorly differentiated elongated cells. Ultrastruc tural and immunocytochemistry analysis revealed characteristic features of adenocarcinoma. Cytogenetic studies showed that LM2, cells are fundamentall y hypotetraploid. They express metalloproteinases (MMP) and show high level s of plasminogen activator type urokinase (uPA). They were sensitive to nit ric oxide (NO)-mediated cytotoxicity when NO derived from an exogenous dono r. In vivo, although LM2 cells were able to grow in the lungs, they could n ot metastasize to the same target organ from s.c. primary tumors. The LM2 m ouse mammary adenocarcinoma cell line is a suitable model to examine differ ent aspects of tumor biology, in particular those related to the different pathways involved in the metastatic cascade and in the cytotoxicity mediate d by NO.