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Fluorescence in situ hybridization characterization of complex karyotypes in glioblastomas
168
Abstracts
FLUORESCENCE IN SITU HYBRIDIZATION CHARACTERI Z A T I O N OF COMPLEX KARYOTYPES I N GLIOBLASTOMAS CB Lozzio, N Cacheiro, E Bamberger, N Fuller and AB Kliefoth, Univ o t TN Medical Ctr Knoxville TN Complex structural chromosome rearrangements and numerical abnormalities are frequently observed in malignant glioblastomas and other solid tumors. Identification of the chromosomes involved is diftlcuIt when the cytogenetic analyses i s limited to banding techniques. We have used alpha satellite specific centromere probes and whole chromosome (painted) probes in both metaphases and intcrphases. These studies identified the origin ot these complex rearrangements and ot the gene amplification associated with the presence of double minutes (DHs). In one astrocytoma grade II-III with pseudodiploid karyotype the following rearrangements were tound:der(1)t(l;6)(p32;q21)/der(6)t(l;6;7)(p32; q23;q32)/der(6)t(6;16)(q21;qll)/der(7)t(l;7)(p36-1; q32)/der(lO)t(lO;?)(qll;?). The DMs were painted with the chromosome 7 probe. Both interphase and metaphase studies confirmed the presence of trisomy 7. Interphase studies revealed two centromeres for chromosome i0 and only one for chromosome 16. H e taphase studies showed that one of the centromere lO's was present in the der(10)t(10;?) marker. The painted chromosome I0, showed that one ot the arms of this marker was the short arm of chromosome I0, and the long arm of I 0 was d e l e t e d . The other arm of the marker has not been identified and chromosomes 19,16,17,18 and 22 have already been ruled out with painted probes. The DHs derived from chromosome 7 may represent chromosomal expression of EGFR gene amplification. This gene located on 7p13-p12 has been found to be amplified in adult glioblasto~as. Preliminary FISH studies in other gliob[astomas have shown several copies of various chromosomes including numbers 7,11, and 22. We conclude that FISH studies are needed to characterize complex chromosome aberrations.
B37
B39 Generation of a chromosome 22 specific c-DNA as confirmed by FISH analysis E. Moose, H-W. M011er, K.D. Zang, K Overmyer, E. G0ttert, Department of Human Genetics, University of Saar, Homurg / Saar, Germany Genomic DNA free hnRNA was isolated from a hybrid cell line whose only human component is chromosome 22. A human specific Alu primer (A1) directed the selective conversion of human RNA sequences into eDNA. FISH analysis showed the majority of cDNA priming events were human chromosome 22 specific and not the result of snapback or other random sell priming. Rather than direct cDNA cloning cDNA was probed against a human fetal brain library to identify chromosome specific transcribed sequences. Since there is a bias for repetitive transcripts positive clones were screened with total human DNA. Single copy clones of the fetal brain library were reconfirmed on chromosome 22 by FISH.
B38 Tumor marker BCBI e x p r c • s l o n cerci~a•
NikolsU•
Blin,
Corneliu•
in glsndular
Welt•r,
celia
of ademo~s
Gerhard Seitz
Th• b r • e s t c • n c e r - a s • o c l a t e d p r o t e i n hCEI ( ~ r • a s t L a n c e r , ! • t r o g e n ~ n d u e c d ) i • a l s o p r e s e n t ~n many human g • e t r o l n t e • t l n • 1 tumors. I n d u c t i o n o f t h e BCEI t r • n s c r £ p t t o n , however, i s n o t dependent on e s t r o g e n r e c e p t o r • i n t h e s e t e l l e r • , ~n c o n t r a s t ¢ 0 b r e a s t c • n c • r . To c l • r i f y the activation • n d f u n c t i o n o f BOB; we • n • l y s e d i t • e x p r e s s i o n i n 14 • d v • n c • d adwnoequmnous c a r c i n o m a s o f t h e human geetrotnteetin•l tr•ct. The s t u d y wee aimed s t t h e c e l l t y p e • pacific loceltz•tion o t BCEI t o d e t e r m i n e i f t h i s a c t i v i t y is l i m i t e d t o t h • glendu%u¢ p a r t . The d • t • c l e a r l y c o n f i r m such a specific compertieent•tion of the gene's activity, •ugge•tiug s f u n c t i o n • • • s e c r e t e d p r o t e i n . Due t o t h e s p e c i f i c e x p r • • s i o n , BCKZ may become • now and u s e f u l d i e g t s o s t i c m a r k e r o f e d e n o carcinoma.
Abstracts
FLUORESCENCE IN SITU HYBRIDIZATION CHARACTERI Z A T I O N OF COMPLEX KARYOTYPES I N GLIOBLASTOMAS CB Lozzio, N Cacheiro, E Bamberger, N Fuller and AB Kliefoth, Univ o t TN Medical Ctr Knoxville TN Complex structural chromosome rearrangements and numerical abnormalities are frequently observed in malignant glioblastomas and other solid tumors. Identification of the chromosomes involved is diftlcuIt when the cytogenetic analyses i s limited to banding techniques. We have used alpha satellite specific centromere probes and whole chromosome (painted) probes in both metaphases and intcrphases. These studies identified the origin ot these complex rearrangements and ot the gene amplification associated with the presence of double minutes (DHs). In one astrocytoma grade II-III with pseudodiploid karyotype the following rearrangements were tound:der(1)t(l;6)(p32;q21)/der(6)t(l;6;7)(p32; q23;q32)/der(6)t(6;16)(q21;qll)/der(7)t(l;7)(p36-1; q32)/der(lO)t(lO;?)(qll;?). The DMs were painted with the chromosome 7 probe. Both interphase and metaphase studies confirmed the presence of trisomy 7. Interphase studies revealed two centromeres for chromosome i0 and only one for chromosome 16. H e taphase studies showed that one of the centromere lO's was present in the der(10)t(10;?) marker. The painted chromosome I0, showed that one ot the arms of this marker was the short arm of chromosome I0, and the long arm of I 0 was d e l e t e d . The other arm of the marker has not been identified and chromosomes 19,16,17,18 and 22 have already been ruled out with painted probes. The DHs derived from chromosome 7 may represent chromosomal expression of EGFR gene amplification. This gene located on 7p13-p12 has been found to be amplified in adult glioblasto~as. Preliminary FISH studies in other gliob[astomas have shown several copies of various chromosomes including numbers 7,11, and 22. We conclude that FISH studies are needed to characterize complex chromosome aberrations.
B37
B39 Generation of a chromosome 22 specific c-DNA as confirmed by FISH analysis E. Moose, H-W. M011er, K.D. Zang, K Overmyer, E. G0ttert, Department of Human Genetics, University of Saar, Homurg / Saar, Germany Genomic DNA free hnRNA was isolated from a hybrid cell line whose only human component is chromosome 22. A human specific Alu primer (A1) directed the selective conversion of human RNA sequences into eDNA. FISH analysis showed the majority of cDNA priming events were human chromosome 22 specific and not the result of snapback or other random sell priming. Rather than direct cDNA cloning cDNA was probed against a human fetal brain library to identify chromosome specific transcribed sequences. Since there is a bias for repetitive transcripts positive clones were screened with total human DNA. Single copy clones of the fetal brain library were reconfirmed on chromosome 22 by FISH.
B38 Tumor marker BCBI e x p r c • s l o n cerci~a•
NikolsU•
Blin,
Corneliu•
in glsndular
Welt•r,
celia
of ademo~s
Gerhard Seitz
Th• b r • e s t c • n c e r - a s • o c l a t e d p r o t e i n hCEI ( ~ r • a s t L a n c e r , ! • t r o g e n ~ n d u e c d ) i • a l s o p r e s e n t ~n many human g • e t r o l n t e • t l n • 1 tumors. I n d u c t i o n o f t h e BCEI t r • n s c r £ p t t o n , however, i s n o t dependent on e s t r o g e n r e c e p t o r • i n t h e s e t e l l e r • , ~n c o n t r a s t ¢ 0 b r e a s t c • n c • r . To c l • r i f y the activation • n d f u n c t i o n o f BOB; we • n • l y s e d i t • e x p r e s s i o n i n 14 • d v • n c • d adwnoequmnous c a r c i n o m a s o f t h e human geetrotnteetin•l tr•ct. The s t u d y wee aimed s t t h e c e l l t y p e • pacific loceltz•tion o t BCEI t o d e t e r m i n e i f t h i s a c t i v i t y is l i m i t e d t o t h • glendu%u¢ p a r t . The d • t • c l e a r l y c o n f i r m such a specific compertieent•tion of the gene's activity, •ugge•tiug s f u n c t i o n • • • s e c r e t e d p r o t e i n . Due t o t h e s p e c i f i c e x p r • • s i o n , BCKZ may become • now and u s e f u l d i e g t s o s t i c m a r k e r o f e d e n o carcinoma.