Choi S H, Kong X T, Taki T, Tsuchida Y, Kawaguchi H, Kato H, Hanada R, Look A T, Hayashi Y
Department of Pediatrics, Faculty of Medicine, University of Tokyo, Tokyo, Japan.
Int J Mol Med. 2000 Oct;6(4):463-7. doi: 10.3892/ijmm.6.4.463.
Genetic alterations occurring in various chromosomes have been described in many human tumors. The DCC gene was originally identified in colorectal cancer and was reported as a tumor suppressor gene that might be related to tumor metastasis. We investigated 10 cell lines and 15 fresh tumors of childhood rhabdomyosarcoma, 7 cell lines of Ewing's sarcoma, and 4 cell lines of primitive neuroectodermal tumor (PNET) for the expression and mutation of DCC gene by RT-PCR analysis and PCR-single stranded conformation polymorphism (SSCP) analysis. Twenty-five pairs of primers were used for PCR-SSCP. Six of ten (60%) cell lines of rhabdomyosarcoma and 3 of 7 (43%) cell lines of Ewing's sarcoma showed reduced or absent expression of DCC gene. There was no mobility shift within 24 exons by SSCP analysis, although 3 types of polymorphism were found at codon 201 in exon 3. Direct sequencing of different bands showed types I, II, and I/II representative of codon 201Gly, codon 201Arg, and codon 201Gly/Arg, respectively. The proportion of type I between fresh rhabdomyosarcoma and normal controls was not significant. Our results suggested that the inactivation of DCC gene may play a role in the pathogenesis of a subset of rhabdomyosarcoma and Ewing's sarcoma.
在许多人类肿瘤中已描述了发生在各种染色体上的基因改变。DCC基因最初是在结直肠癌中被鉴定出来的，并被报道为一个可能与肿瘤转移有关的肿瘤抑制基因。我们通过逆转录聚合酶链反应（RT-PCR）分析和聚合酶链反应-单链构象多态性（PCR-SSCP）分析，研究了10个儿童横纹肌肉瘤细胞系、15个新鲜肿瘤，7个尤因肉瘤细胞系和4个原始神经外胚层肿瘤（PNET）细胞系中DCC基因的表达和突变情况。使用25对引物进行PCR-SSCP。横纹肌肉瘤的10个细胞系中有6个（60%）、尤因肉瘤的7个细胞系中有3个（43%）显示DCC基因表达降低或缺失。尽管在第3外显子的密码子201处发现了3种多态性，但通过SSCP分析在24个外显子内未发现迁移率改变。对不同条带进行直接测序显示，I型、II型和I/II型分别代表密码子201甘氨酸、密码子201精氨酸和密码子201甘氨酸/精氨酸。新鲜横纹肌肉瘤与正常对照之间I型的比例无显著差异。我们的结果表明，DCC基因的失活可能在一部分横纹肌肉瘤和尤因肉瘤的发病机制中起作用。
