Two Candidate Tumor Suppressor Genes, MEOX2 and SOSTDC1, Identified in a 7p21 Homozygous Deletion Region in a Wilms Tumor
GENES CHROMOSOMES & CANCER
Authors: Ohshima, Junjiro; Haruta, Masayuki; Arai, Yasuhito; Kasai, Fumio; Fujiwara, Yuiko; Ariga, Tadashi; Okita, Hajime; Fukuzawa, Masahiro; Hata, Jun-Ichi; Horie, Hiroshi; Kaneko, Yasuhiko
Abstract
A SNP-based array analysis of 100 Wilms tumors (WT) from 97 patients identified 7p alterations (hemizygous and homozygous deletions and uniparental disomy) in nine tumors. The homozygous deletion (HD) region of 7p21 found in one tumor partially overlapped with another HD region reported previously, and was narrowed down to a 2.1-Mb region. Based on an expression analysis of 10 genes located in the HD region in 3 WT lines and previous studies on tumorigenic roles of MEOX2 and SOSTDC1, we further analyzed these two genes. Sequencing showed no mutation in MEOX2, but two missense mutations (L50F and Q129L) in SOSTDC1 in four tumors; L50F in two tumors was of germline origin. Expression levels (0, 1+ and 2+) of MEOX2 were lower in four tumors with 7p alterations than in 18 tumors with no 7p alterations (P = 0.017), and those of SOSTDC1 tended to be lower in five tumors with 7p alterations or SOSTDC1 mutation than in 17 tumors with no 7p alterations or SOSTDC1 mutation (P = 0.056). There were no significant differences in clinical characteristics between nine patients with 7p alterations and 88 patients with no 7p alterations; however, there was a difference in the status of IGF2 (uniparental disomy, loss of imprinting, or retention of imprinting) between the two patient groups (P = 0.028). Losses of MEOX2 and SOSTDC1 may accelerate angiogenesis and augment signals in the Writ pathway, respectively. Both genes may be prime candidates for 7p tumor suppressor genes, which may have a role in the progression of Wilms tumorigenesis. (C) 2009 Wiley-Liss, Inc.
SHH signaling directed by two oral epithelium-specific enhancers controls tooth and oral development
SCIENTIFIC REPORTS
Authors: Sagai, Tomoko; Amano, Takanori; Maeno, Akiteru; Kiyonari, Hiroshi; Seo, Hyejin; Cho, Sung-Won; Shiroishi, Toshihiko
Abstract
Interaction between the epithelium and mesenchyme coordinates patterning and differentiation of oral cavity structures including teeth, palatal rugae and tongue papillae. SHH is one of the key signaling molecules for this interaction. Epithelial expression of Shh in the tooth buds and tongue papillae is regulated by at least two enhancers, MRCS1 and MFCS4. However, it is unclear how the two enhancers cooperate to regulate Shh. Here, we found that simultaneous deletion of MRCS1 and MFCS4 results in the formation of a supernumerary tooth in front of the first molar. Since deletion of either single enhancer barely affects tooth development, MRCS1 and MFCS4 evidently act in a redundant fashion. Binding motifs for WNT signaling mediators are shared by MRCS1 and MFCS4, and play a central role in regulating Shh expression, indicating that the two redundant enhancers additively exert their Shh regulation by responding to WNT signal input.