Characterization of cancer cell lines established from two human metastatic breast cancers.

Cell lines are valuable resources for the study of the malignancy and potential therapy of human breast cancer. A major problem with adapting fresh breast tumor specimens to grow in vitro is contamination by fibroblasts. Previously, we have reported a technique to overcome this problem (Nayak, S. K; Dillman, R. O. Clin. Biotechnol. 3:237-242; 1991). We have recently established two new breast cancer cell lines, HH315 and HH375, that were derived from abdominal and supraclavicular lymph node metastases from two patients. They were characterized by (1) growth kinetics; (2) staining with monoclonal antibodies (MoAbs) to cytokeratin-19, epithelial membrane antigen (EMA), anticarcinoembryonic antigen (CEA), breast cancer antigen 1 (BRST-1), breast cancer antigen 2 (BRST-2), Her2/neu, and p53; (3) expression of domains of urinary plasminogen activator (uPA), neural cell adhesion molecule (NCAM), and haptoglobin (Hp) (Harvey et al., 1997); and (4) karyotypic analysis. Growth kinetic studies showed that doubling times for both lines ranged from 48 to 96 h. These two cell lines were found to have characteristics of the metastatic breast cancer cells. Both lines stained positive with MoAbs to cytokeratin-19 and EMA, thus confirming their epithelial origin. They also strongly reacted with the pan-breast carcinoma MoAbs BRST-1 and BRST-2, and carcinoembryonic CEA MoAb. Both cell lines overexpressed the oncogene proteins Her2/neu and p53. The tumor cells were negative for estrogen and progesterone receptors. HH315 cells were poorly differentiated, whereas the HH375 cells exhibited adenocarcinoma morphology. Both cell lines showed intense cell surface and some cytoplasmic staining for uPA, NCAM, and Hp domains, which is a characteristic of malignant neoplasms (Harvey et al., 1997). The HH375 cell line showed two cell types, of which 60% were hyperdiploids with 60-70 chromosomes and 5-10 marker chromosomes. The remaining cells were polyploid with more than 200 chromosomes. Cell line HH315 consisted of only a polyploid population. These cell lines may be useful in breast cancer research.