Molecular mapping of 12q22 deletions in male germ cell tumors

Journal Article · Thu Sep 01 04:00:00 EDT 1994 · American Journal of Human Genetics

OSTI ID:133546

Murty, V V.V.S.; Bosl, G; Chaganti, R S.K. ^[1]

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1. Memorial Sloan-Kettering Cancer Center, New York, NY (United States); and others

Germ cell tumors (GCTs) arise in young males from mid-meiotic germ cells. A subset of GCTs display embryonal-like as well as extra-embryonal-like histologic differentiation, and thus provide unique opportunities to study malignant transformation and in vivo differentiation. Cytogenetically, GCTs are characterized by 2 nonrandom abnormalities involving chromosome 12. One is i(12p), seen in >80% of tumors, and tandem duplications of 12p in the remaining. The other is deletion or monosomy of 12q in >30% of tumors. Recently, we have identified 2 sites for candidate tumor suppressor genes (TSGs), at 12q13 and 12q22, by analysis of loss of heterozygosity (LOH). At 12q22, a high frequency of LOH at the loci D12S7 and D12S12 and homozygous deletions in one tumor at the D12S7 and MGF loci were observed. In the present study, we further characterize the 12q22 deletion by analysis of 5 polymorphic (CA){sub n} markers D12S81, D12S101, D12S206, D12S218, and D12S234 in a panel of 66 tumor DNA samples derived from tumor specimens or cell lines and their corresponding normal cells. Sixty four of these were informative for at least one locus and 24 (41.4%) showed LOH at one or more loci. The frequency of LOH was 31.3% for D12S81, 28% for D12S101, 24.2% for D12S206, 37.0% for D12S218, and 25.7% for D12S234. In an attempt to physically map the markers, we employed pulsed-field gel electrophoresis and found that MGF and D12S12 probes co-hybridized to a 700 kb fragment with BssHII digestion, suggesting that these two loci are within a 700 kb region of 12q22. In view of homozygous deletion of MGF, and high frequency of LOH at D12S12 (47%) and D12S218 (37%), we suggest that the putative TSG may lie in the vicinity of these loci.

• OSTI ID: 133546
• Report Number(s): CONF-941009--
• Journal Information: American Journal of Human Genetics, Journal Name: American Journal of Human Genetics Journal Issue: Suppl.3 Vol. 55; ISSN AJHGAG; ISSN 0002-9297
• Country of Publication: United States
• Language: English

Related Subjects

55 BIOLOGY AND MEDICINE
BASIC STUDIES
BIOLOGICAL MARKERS
CHROMOSOMAL ABERRATIONS
DNA HYBRIDIZATION
ELECTROPHORESIS
GENES
GENETIC MAPPING
GERM CELLS
HUMAN CHROMOSOME 12
MALES
MEIOSIS
NEOPLASMS
PROBES
STATISTICS