Detection of chromosome aberrations in metaphase and interphase tumor cells by in situ hybridization using chromosome-specific library probes

Chromosome aberrations in two glioma cell lines were analyzed using
biotinylated DNA library probes that specifically decorate
chromosomes 1, 4, 7, 18 and 22 from pter to qter. Numerical
changes, deletions and rearrangements of these chromosomes were
radily visualized in metaphase spreads, as well as in early
prophase and interphase nuclei. Complete chromosomes, deleted
chromosomes and segments of translocated chromosomes were rapidly
delineated in very complex karyotypes. Simultaneous hybridizations
with additional subregional probes were used to further define
aberrant chromosomes. Digital image analysis was used to quantitate
the total complement of specific chromosomal DNAs in individual
metaphase and interphase cells of each cell line. In spite of the
fact that both glioma lines have been passaged in vitro for many
years, an under-representation of chromosome 22 and an
over-representation of chromosome 7 (specifically 7p) were
observed. These observations agree with previous studies on
gliomas. In addition, sequences of chromosome 4 were also found to
be under-represented, especially in TC 593. These analyses indicate
the power of these methods for pinpointing chromosome segments that
are altered in specific types of tumors.