Establishment and characterisation of a new tumorigenic cell line with a normal karyotype derived from a human breast adenocarcinoma.

A new cell line (CAL51) was isolated from a malignant pleural effusion of a woman with metastatic breast cancer. These cells grow in continuous culture and exhibit the morphological, ultrastructural and immunohistochemical features of epithelial cells of mammary origin. They are tumorigenic in nude mice and clone in soft agar. Oestrogen receptors are not detected. CAL51 consists of a homogeneous population of cells with normal chromosomes even after the use of high resolution banding. Cytogenetic analysis of the cells from the tumour induced by CAL51 in the nude mouse confirmed the normality and the stability of the karyotype. All breast cancer cell lines established to date present abnormal karyotypes; CAL51 cell line may be more informative than cell lines with aberrant karyotypes for investigating essential genetic differences between normal and malignant mammary gland cells.