Intragenic amplification and formation of extrachromosomal small circular DNA molecules from the PIP gene on chromosome 7 in primary breast carcinomas.
The PIP gene is expressed in exocrine glands and, in pathologic conditions, in breast cysts and breast cancers exhibiting apocrine features. It is localized on the long arm of chromosome 7, a region frequently alterated in mammary tumors. We previously described an abnormal restriction pattern of the PIP gene in 33% of prostate carcinomas analyzed. Here, we analyze the structure of the PIP gene in primary breast carcinomas. We report that part of the 3' end, including exon 3, intron C, two-thirds of exon 4 and a small portion of intron B, is amplified and involved in the formation of extrachromosomal spcDNA molecules in 3/14 (21.4%) breast cancers analyzed. The involvement of a well-defined intragenic region of a gene in the formation of spcDNA appears to be unprecedented. Since spcDNA has been suggested to serve as an enhancer of genetic instability, the PIP gene may be the target of genomic variability processes in breast cancer.
Autiero
Monica
M
Génétique Moléculaire et Biologie du Développement, Centre National de la Recherche Scientifique, Villejuif, France.
Camarca
Alessandra
A
Ciullo
Marina
M
Debily
Marie-Anne
MA
El Marhomy
Sandrine
S
Pasquinelli
Rosa
R
Capasso
Immacolata
I
D'Aiuto
Giuseppe
G
Anzisi
Anna Maria
AM
Piatier-Tonneau
Dominique
D
Guardiola
John
J
D001053:Apolipoproteins; D053399:Apolipoproteins D; D001483:Base Sequence; D015139:Blotting, Southern; D001943:Breast Neoplasms / Q000235:genetics*; D002352:Carrier Proteins / Q000235:genetics*; D002897:Chromosomes, Human, Pair 7; D004270:DNA, Circular; D004591:Electrophoresis, Polyacrylamide Gel; D005091:Exons; D005260:Female; D014644:Genetic Variation; D006023:Glycoproteins; D006801:Humans; D007438:Introns; D008297:Male; D026901:Membrane Transport Proteins; D008957:Models, Genetic; D008969:Molecular Sequence Data; D010957:Plasmids / Q000378:metabolism; D016133:Polymerase Chain Reaction; D011471:Prostatic Neoplasms / Q000235:genetics
C024328:APOD protein, human; D001053:Apolipoproteins; D053399:Apolipoproteins D; D002352:Carrier Proteins; D004270:DNA, Circular; D006023:Glycoproteins; D026901:Membrane Transport Proteins