Salivary gland carcinosarcoma: oligonucleotide array CGH reveals similar genomic profiles in epithelial and mesenchymal components.
In this study, we present a case of parotid gland de novo carcinosarcoma. Salivary gland carcinosarcoma (or true malignant mixed tumor) is a rare biphasic neoplasm, composed of both malignant epithelial and malignant mesenchymal components. It is yet unclear whether these two phenotypes occur by collision of two independent tumors or if they are of clonal origin. To analyze the clonality of the different morphologic tumor components, oligonucleotide microarray-based comparative genomic hybridization (oaCGH) was performed on the carcinoma and the sarcoma entity separately. This technique enables a high-resolution, genome-wide overview of the chromosomal alterations in the distinct tumor elements. Analysis of both fractions showed a high number of DNA copy number changes. Losses were more prevalent than gains (82 and 49, respectively). The carcinomatous element displayed more chromosomal aberrations than the sarcomatous component. Specific amplifications of MUC20 (in mesenchymal element) and BMI-1 (in both elements) loci were observed. Overall homology between the two genomic profiles was 75%. DNA copy number profiles of the epithelial and mesenchymal components in this salivary gland carcinosarcoma displayed extensive overlap, indicating a monoclonal origin. Since losses are shared to a larger extent than gains, they seem to be more essential for initial oncogenic events. Furthermore, specific amplifications of a mucin and a Polycomb group gene imply these proteins in the tumorigenesis of carcinosarcomas.
Vékony
Hedy
H
Department of Oral and Maxillofacial Surgery/Oral Pathology, Academic Centre for Dentistry (ACTA), VU University medical center (VUmc), Amsterdam, The Netherlands. hedyvekony@hotmail.com
Leemans
C René
CR
Ylstra
Bauke
B
Meijer
Gerrit A
GA
van der Waal
Isaäc
I
Bloemena
Elisabeth
E
D002296:Carcinosarcoma / Q000235:genetics* / Q000378:metabolism; D055028:Comparative Genomic Hybridization / Q000379:methods; D056915:DNA Copy Number Variations; D005260:Female; D042822:Genomic Instability; D006801:Humans; D008875:Middle Aged; D009077:Mucins / Q000235:genetics*; D009687:Nuclear Proteins / Q000235:genetics; D020411:Oligonucleotide Array Sequence Analysis / Q000379:methods; D010307:Parotid Neoplasms / Q000235:genetics* / Q000378:metabolism; D063150:Polycomb Repressive Complex 1; D063146:Polycomb-Group Proteins; D011518:Proto-Oncogene Proteins / Q000235:genetics; D012097:Repressor Proteins / Q000235:genetics*
C069077:BMI1 protein, human; C490965:MUC20 protein, human; D009077:Mucins; D009687:Nuclear Proteins; D063146:Polycomb-Group Proteins; D011518:Proto-Oncogene Proteins; D012097:Repressor Proteins; D063150:Polycomb Repressive Complex 1