Molecular biologic characteristics of seven new cell lines of squamous cell carcinomas of the head and neck and comparison to fresh tumor tissue.

Background: Squamous cell carcinoma (SCC) is the most frequent malignant tumor of the upper aerodigestive tract. Cell lines of these tumors facilitate the investigation of various tumor biological parameters. This study was conducted to compare molecular biologic characteristics between cell lines and fresh tumor tissue.
Methods: In seven SCC-derived cell lines, cytokeratin 5/6 and cytokeratin 19 expression, DNA content, chromosome aberrations and tumorigenicity were assessed in nude rats. Unbalanced numerical and structural chromosomal aberrations were investigated by comparative genomic hybridization (CGH), and results were compared to those obtained in fresh tumor tissues of the same patients.
Results: All cell lines expressed cytokeratins 5/6 and 19, indicating their epidermoid origin. Tumor growth after transplantation into nude rats occurred in five of seven cell lines. Routine histology and immunohistochemical examinations confirmed SCC. Aneuploidy was detected in all cell lines, with a 2c deviation index ranging from 1.9 through 9.5 and a 5c exceeding rate ranging from 2.6 through 36.7%. The most frequent chromosomal aberrations in cell lines were overrepresentations of chromosomal material on chromosomes 15q, 7p (5 cases each), 3q, 5p (4 cases each), and 11q and 17q (3 cases each) and losses of chromosomal material on chromosomes 3p, 18q (3 cases each), and 19p and 7q (2 cases each). Comparing these results to CGH analysis of fresh tumor tissue from the same patients, overrepresentations of chromosomal material on 10q, 20q and 21q, along with loss of chromosomal material on 4q was detected more frequently in primary tumors, whereas overrepresentations on 7p and loss of chromosomal material on 7q were more frequently detected in cell lines. Nevertheless, there was a high degree of similarity of chromosomal alterations in cell lines and corresponding fresh tumor tissue.
Conclusion: The data suggest a high degree of genetic similarity between tumor cells of cell lines and the tumors from which they were derived. Therefore, these cell lines can serve as an accurate model to investigate cell biology of SCC in vitro.
(Copyright 2003 S. Karger AG, Basel)