Open AccessGiant Subependymoma Developed in a Patient with Aniridia: Analyses of PAX6 and Tumor‐relevant Genes
Author(s) -
Maekawa Motoko,
Fujisawa Hironori,
Iwayama Yoshimi,
Tamase Akira,
Toyota Tomoko,
Osumi Noriko,
Yoshikawa Takeo
Publication year - 2010
Publication title -
brain pathology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.986
H-Index - 132
eISSN - 1750-3639
pISSN - 1015-6305
DOI - 10.1111/j.1750-3639.2010.00406.x
Subject(s) - pax6 , biology , loss of heterozygosity , aniridia , exon , gene , carcinogenesis , tumor suppressor gene , cancer research , intron , genetics , microbiology and biotechnology , allele , transcription factor
We observed an unusually large subependymoma in a female patient with congenital aniridia. To analyze the genetic mechanisms of tumorigenesis, we first examined the paired box 6 ( PAX6 ) gene using both tumor tissue and peripheral lymphocytes. Tumor suppressor activity has been proposed for PAX6 in gliomas, in addition to its well‐known role in the eye development. Using genomic quantitative PCR and loss of heterozygosity analysis, we identified hemizygous deletions in the 5′‐region of PAX6 . In lymphocytes, the deletion within PAX6 spanned from between exons 6 and 7 to the 5′‐upstream region of the gene, but did not reach the upstream gene, RNC1 , which is reported to be associated with tumors. The subependymoma had an additional de novo deletion spanning from the intron 4 to intron 6 of PAX6 , although we could not completely determine whether these two deletions are on the same chromosome or not. We also examined other potentially relevant tumor suppressor genes: PTEN , TP53 and SOX2 . However, we detected no exonic mutations or deletions in these genes. Collectively, we speculate that the defect in PAX6 may have contributed to the extremely large size of the subependymoma, due to a loss of tumor suppressor activity in glial cell lineage.