Open AccessITCH is a putative target for a novel 20q11.22 amplification detected in anaplastic thyroid carcinoma cells by array‐based comparative genomic hybridization
Author(s) -
Ishihara Takaya,
Tsuda Hitoshi,
Hotta Akiko,
Kozaki Kenichi,
Yoshida Akira,
Noh Jaeduk Yoshimura,
Ito Koichi,
Imoto Issei,
Inazawa Johji
Publication year - 2008
Publication title -
cancer science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.035
H-Index - 141
eISSN - 1349-7006
pISSN - 1347-9032
DOI - 10.1111/j.1349-7006.2008.00900.x
Subject(s) - thyroid carcinoma , comparative genomic hybridization , cancer research , gene duplication , gene knockdown , ectopic expression , biology , thyroid , thyroid cancer , pathology , cell culture , gene , medicine , endocrinology , genetics , genome
Anaplastic thyroid carcinoma (ATC) is one of the most virulent of all human malignancies, with a mean survival time among patients of less than 1 year after diagnosis. To date, however, cytogenetic information on this disease has been very limited. During the course of a program to screen a panel of ATC cell lines for genomic copy‐number aberrations using array‐based comparative genomic hybridization, we identified a high‐level amplification of the ITCH gene, which is mapped to 20q11.22 and belongs to the homologous to the E6‐associated protein carboxylterminus ubiquitin ligase family. The expression of ITCH was increased in 4 of 14 ATC cell lines (28.6%), including 8305C in which there was a copy‐number amplification of this gene, and six of seven primary cases (85.7%). Among the primary thyroid tumors, a considerable number of ITCH high expressers was found in ATC (40/45, 88.9%), papillary thyroid carcinoma (25/25, 100%), and papillary microcarcinoma (25/25, 100%). Furthermore, knockdown of ITCH by specific small interfering RNA significantly inhibited the growth of ITCH‐overexpressing cells, whereas ectopic overexpression of ITCH promoted growth of ATC cell lines with relatively weak expression. These observations indicate ITCH to be the most likely target for 20q11.22 amplification and to play a crucial role in the progression of thyroid carcinoma. ( Cancer Sci 2008; 99: 1940–1949)