Narrowing of the region of allelic loss in 21q11-21 in squamous non-small cell lung carcinoma and cloning of a novel ubiquitin-specific protease gene from the deleted segment.
We examined 42 fresh non-small cell lung carcinomas for allelic loss using 4 microsatellite markers located in a 4.5 Mb region in 21q11-21, a gene-poor interval recently found by others to be homozygously deleted and exhibiting frequent allelic loss in lung cancer. We found allelic loss across the entire segment in 13/34 informative squamous carcinomas, with 2 cases showing loss in only part of the region. Analysis by fluorescence in situ hybridization of P1-derived artificial chromosomes from the region directly on paraffin sections of the tumor is in concordance with the loss of heterozygosity (LOH) results, and tentatively excludes a 2 Mb segment bearing 2 of the only 3 known genes in the area. Exon trapping in the remaining segment of loss led to identification and cloning of a novel gene spanning 150 kb within the deletion. The full-length gene encodes a protein of 1,055 amino acids with homology to ubiquitin-specific proteases across the eukaryotic evolutionary spectrum. The expressed protein acts as a de-ubiquitinating enzyme as proved by the ability to cleave ubiquitin from a model fusion protein. We found no mutations in the sequence of the functional domains of this gene in any of the LOH-exhibiting tumor DNA samples. It is, however, interesting that genes of the same superfamily have been reported on 3p21, a locus showing the most frequent allelic instability and deletions in lung cancer. Genes Chromosomes Cancer 27:153-161, 2000.
Groet
J
J
Centre for Applied Molecular Biology, School of Pharmacy, University of London, London, United Kingdom.
Ives
J H
JH
Jones
T A
TA
Danton
M
M
Flomen
R H
RH
Sheer
D
D
Hrascan
R
R
Pavelic
K
K
Nizetic
D
D
D000595:Amino Acid Sequence; D002289:Carcinoma, Non-Small-Cell Lung / Q000235:genetics*; D002294:Carcinoma, Squamous Cell / Q000235:genetics*; D002891:Chromosomes, Human, Pair 21 / Q000235:genetics*; D003001:Cloning, Molecular; D004247:DNA / Q000737:chemistry / Q000235:genetics; D010450:Endopeptidases / Q000235:genetics* / Q000378:metabolism; D005091:Exons; D005822:Genetic Vectors; D006801:Humans; D017404:In Situ Hybridization, Fluorescence; D019656:Loss of Heterozygosity; D008175:Lung Neoplasms / Q000235:genetics*; D018895:Microsatellite Repeats; D008969:Molecular Sequence Data; D011993:Recombinant Fusion Proteins / Q000235:genetics / Q000378:metabolism; D017422:Sequence Analysis, DNA; D017384:Sequence Deletion; D017386:Sequence Homology, Amino Acid; D064570:Ubiquitin-Specific Proteases; D014452:Ubiquitins / Q000235:genetics / Q000378:metabolism
D011993:Recombinant Fusion Proteins; D014452:Ubiquitins; D004247:DNA; D010450:Endopeptidases; D064570:Ubiquitin-Specific Proteases