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Detection of chromosomal aberrations using premature chromosome condensation in conjunction with chromosome painting
106
Abstracts
DETECTION OF CHROMOSOMAL ABERRATIONS USING PREMATURE CHROMOSOME CONDENSATION IN CONJUNCTION WITH CHROMOSOME PAINTING Ron F. Suiikerbuiik (1), Paula Silva (2), Bert Janssen (1), S~rgio Castedo (2) and Ad Geurts van Kessel (1). (1) Department of Human Genetics, University Hospital Nijmegen, P.O. Box 9101, 6500 HB Nijmegen, The Netherlands; (2) Unit of Genetics IPATIMUP, Hospital S. Jo~io, P-4200 Porto, Portugal.
During recent years evidence has been accumulated indicating that, as in hematopoietic malignancies, solid tumors are accompanied by the occurrence of non-random chromosomal abnormalities, both in number and arrangement. Due to the general scarcity of metaphases and their poor quality, however, cytogenetic analysis of solid tumors has remained a different task to perform. Preferential growth of karyotypically normal cells in a mixed tumor is another problem to be dealt with. Recently, new technical approaches have been developed to overcome some of the limitations of conventional cytogenetic methods. These approaches are based on fluorescent chromosome in situ suppression hybridization using (combinations of) chromosome-specific probes. Since one human chromosome, or a fragment thereof, can be specifically visualized (i.e. chromosome painting), both numerical and structural aberrations can efficiently be detected. In addition, interphase chromosomes of poorly dividing malignant (and normal) cells can be viewed by means of the premature chromosome condensation (PCC) method. In this study both PCC and chromosome painting techniques were combined to achieve detailed karyotypic information of both hematopoietic and solid tumors. Further details of the technique and the results obtained will be presented.
INFLUENCE OF CHOICE OF TISSUE CULTURE TECHNIQUE ON KARYTOTYPIC PATTERN IN HEAD AND NECK SQUAMOUS CELL CARCINOMAS Yueshena Jin, Nils Mandahl, Sverre Heim, Felix Mitelman Department of Clinical Genetics, University Hospital, S-221 85 Lund, Sweden. We have cytogenetically investigated short-term cultures from 112 squamous cell carcinomas (SCC) of the head and neck region. Thirty-six tumors have previously been reported while 76 are new cases. The material was divided into two series based on technique differences. The 80 tumors of series I were cultured in RPMI 1640 medium supplemented with fetal calf serum, glutamine, antibiotics, insulin, cholera toxin, and epidermal growth factor. The 32 tumors of series II were cultured in a chemically defined, serum-free medium with a low calcium concentration, MCDB 153. These culture conditions stimulated epithelial growth while fibroblasts were inhibited. Series II showed a higher proportion of tumors with complex karyotypic changes than series I (31.3% vs 7.5%) and a lower proportion of tumors with pseudo- or near-diploid clones characterized by simple balanced rearrangements (9.4% vs 41.3%). The different karyotypic profile in the two series indicates that the different culture conditions favor growth of different cell populations. The most common structural change was rearrangement of 11q13. This was seen in all six tumors with a complex karyotype in series I, in two of them as a homogeneously staining region (hsr), and in two of 10 tumors with a complex karyotype in series II, in both cases as an hsr. The results indicate that chromosomal band 1lq13 contains loci of importance in SCC tumorigenesis and that amplification of these gene(s) may be an essential pathogenetic mechanism.
Abstracts
DETECTION OF CHROMOSOMAL ABERRATIONS USING PREMATURE CHROMOSOME CONDENSATION IN CONJUNCTION WITH CHROMOSOME PAINTING Ron F. Suiikerbuiik (1), Paula Silva (2), Bert Janssen (1), S~rgio Castedo (2) and Ad Geurts van Kessel (1). (1) Department of Human Genetics, University Hospital Nijmegen, P.O. Box 9101, 6500 HB Nijmegen, The Netherlands; (2) Unit of Genetics IPATIMUP, Hospital S. Jo~io, P-4200 Porto, Portugal.
During recent years evidence has been accumulated indicating that, as in hematopoietic malignancies, solid tumors are accompanied by the occurrence of non-random chromosomal abnormalities, both in number and arrangement. Due to the general scarcity of metaphases and their poor quality, however, cytogenetic analysis of solid tumors has remained a different task to perform. Preferential growth of karyotypically normal cells in a mixed tumor is another problem to be dealt with. Recently, new technical approaches have been developed to overcome some of the limitations of conventional cytogenetic methods. These approaches are based on fluorescent chromosome in situ suppression hybridization using (combinations of) chromosome-specific probes. Since one human chromosome, or a fragment thereof, can be specifically visualized (i.e. chromosome painting), both numerical and structural aberrations can efficiently be detected. In addition, interphase chromosomes of poorly dividing malignant (and normal) cells can be viewed by means of the premature chromosome condensation (PCC) method. In this study both PCC and chromosome painting techniques were combined to achieve detailed karyotypic information of both hematopoietic and solid tumors. Further details of the technique and the results obtained will be presented.
INFLUENCE OF CHOICE OF TISSUE CULTURE TECHNIQUE ON KARYTOTYPIC PATTERN IN HEAD AND NECK SQUAMOUS CELL CARCINOMAS Yueshena Jin, Nils Mandahl, Sverre Heim, Felix Mitelman Department of Clinical Genetics, University Hospital, S-221 85 Lund, Sweden. We have cytogenetically investigated short-term cultures from 112 squamous cell carcinomas (SCC) of the head and neck region. Thirty-six tumors have previously been reported while 76 are new cases. The material was divided into two series based on technique differences. The 80 tumors of series I were cultured in RPMI 1640 medium supplemented with fetal calf serum, glutamine, antibiotics, insulin, cholera toxin, and epidermal growth factor. The 32 tumors of series II were cultured in a chemically defined, serum-free medium with a low calcium concentration, MCDB 153. These culture conditions stimulated epithelial growth while fibroblasts were inhibited. Series II showed a higher proportion of tumors with complex karyotypic changes than series I (31.3% vs 7.5%) and a lower proportion of tumors with pseudo- or near-diploid clones characterized by simple balanced rearrangements (9.4% vs 41.3%). The different karyotypic profile in the two series indicates that the different culture conditions favor growth of different cell populations. The most common structural change was rearrangement of 11q13. This was seen in all six tumors with a complex karyotype in series I, in two of them as a homogeneously staining region (hsr), and in two of 10 tumors with a complex karyotype in series II, in both cases as an hsr. The results indicate that chromosomal band 1lq13 contains loci of importance in SCC tumorigenesis and that amplification of these gene(s) may be an essential pathogenetic mechanism.