Numerical aberrations of chromosomes 1 and 17 in tumor cell lines of the exocrine pancreas as determined by fluorescence in situ hybridization

The relationship between the copy numbers of chromosomes 1 and 17 and characteristics related to aggressiveness, histological grade, and doubling time was studied in 10 cell lines from pancreatic carcinomas (7 from primary tumors, 2 from ascites, and 1 from a liver metastasis). Fluorescence in situ hybridization with, respectively, the (peri-)centromeric pUC 1.77 (chromosome 1), and D17Z1 (chromosome 17) probes was applied to interphase nuclei. The results showed that most of these cell lines were hyperploid for both chromosomes studied in accordance with their chromosome counts in metaphase; moreover, there existed a statistically significant positive correlation between the results for both probes. Two of these cell lines had a higher mean copy number for chromosome 17 than for chromosome 1 (PaCa 44 and PaTu 2); two of them had a higher mean copy number for chromosome 1 than for chromosome 17 (Panc 1 and PSN 1). Although only a weak correlation was observed between the number of signals for either chromosomes 1 or 17 and the doubling time, lines of grade 1 and 2 showed a lower average number of spots per nucleus than grade 3 cell lines for both chromosomes studied.