Objective: To detect and delineate 6q deletions in ten breast carcinoma cell lines.
Methods: Fluorescence in situ hybridization(FISH) with 37 YAC probes hybridizing from 6q12 to 6q27 and a centromeric probe of chromosome 6 as internal control.
Results: In five cell lines, large deletions extending from 6q12 to 6q27 were found, while a small deletion involving 6q25-6q27 was identified in one cell line. In two cell lines containing different cell populations, deletions of 6q occurred in cells with polysomy 6, but not in cells with disomy 6. In addition, an overpresentation of 6q21-q22.2 was detected in one cell line.
Conclusion: 6q25-q27 seems to be the commonly deleted region in breast cancers and 6q deletions might be secondary changes.