利用比较基因组杂交技术分析横纹肌肉瘤中染色体基因组的变化特征

目的 探讨横纹肌肉瘤(RMS)基因组DNA的变化特征.方法 在一步法RT-PCR检测所有标本PAX3/PAX7-FKHR mRNA融合基因表达情况的基础上,应用比较基因组杂交技术分析25例原发性RMS患者,其中腺泡状横纹肌肉瘤(ARMS)10例,胚胎性横纹肌肉瘤(ERMS)12例,多形性横纹肌肉瘤(PRMS)3例.根据融合基因表达情况、组织学分型、临床分期、组织学分级、性别和年龄进行分组比较.同时收集RMS细胞株A204(腺泡型)、RD(胚胎型)作为对照.结果 25例RMSCGH分析结果显示:(1)RMS中发生DNA拷贝数扩增最常见的部位是2p和12q,其他依次为6p、9q、10q、1p、2q、6q、8q、15q和18q(30%),发生DNA拷贝数丢失最常见的部位是3p、11P和6p(30%).(2)ARMS扩增最常见的染色体臂是12q、2p、6、2q、4q、10q和15q(30%),缺失最常见的染色体臂是3p、6p、1q、5q(30%);ERMS扩增最常见的染色体臂是7p、9q、2p、18q和1 p、8q(30%),缺失最常见的染色体臂是11p.基因组变化在不同的组织学分类中差异无统计学意义(P0.05).(3)伴有融合基因组扩增最常见的染色体臂是12q、2、6、10q、4q和15q(30%),缺失最常见的染色体臂是3 p、6p、5q(30%);不伴有融合基因组扩增最常见的染色体臂是2p、9q、18q(30%),基因组缺失最常见的染色体臂是11p和14q(30%).12q扩增在这两组间的差异有统计学意义(P<0.05),并多见于伴有融合基因的RMS.(4)在临床分期分组中,9q扩增在Ⅱ期和Ⅲ～Ⅳ期间差异有统计学意义(P<0.05),且多见于Ⅱ期患者.结论 (1)2p、12q、6p、9q、10q、lp、2q、6q、8q、15q、18q扩增及3p、11p、6p缺失可能与RMS发病相关;(2)12q扩增可能与融合基因相关;(3)9q扩增可能与RMS发病早期有关.

Comparative genomic hybridization: the profile of chromosomal imbalances in rhabdomyosarcoma

Objective To characterize the profile of chromosomal imbalances of rhabdomyosarcoma (RMS). Methods Comparative genomic hybridization (CGH) was used to investigate genomic imbalances in 25 cases of primary RMS including 10 cases of alveolar rhabdomyosarcoma (ARM), 12 cases of embryonic rhabdomyosarcoma (ERMS), 3 cases of polymorphic rhabdomyosarcoma (PRMS) and 2 RMScell lines (A240 originated from ARMS and RD from PRMS), with correlation to histological type,pathologic grading, clinical staging, gender and age, respectively. Results All twenty-five rhabdomyosarcomas showed evidence of increased or decreased DNA sequence copy numbers involving one or more regions of the genome. (1) The frequently gained chromosome regions in RMS were 2p, 12q, 6p, 9q,10q, 1p, 2q, 6q, 8q, 15q, 18q, and the frequently lost chromosome regions were 3p, 11p,6p. (2) The frequently gained chromosome arms in ARMS were 12q, 2p, 6, 2q,4q, 10q, 15q. The frequently lost chromosome arms were 3p, 6p, 1q,5q. The frequently gained chromosome regions in ERMS were 7p, 9q,2p,18q,1p,8q. The frequently lost chromosome arms in ERMS were 11p. (3) The frequently gained chromosome arms in translocation associated RMS were 12q, 2, 6, 10q, 4q and 15q(>30%), 3p,6p, 5q (>30%)were the frequently loss chromosome arms. The frequently gained chromosome regions in non-translocation associated RMS were 2p,9q, 18q(>30%), and 11p,14q(>30%) were the frequently loss chromosome regions. Gain of 12q was significantly correlated with the translocation-associated tumors (P<0.05). (4) Gains of 9q was significantly correlated with clinical staging (P<0.05). Conclusions Gain of 2p, 12q,6p ,9q, 10q, 1 p,2q,6q, 8q, 15q, 18q and loss of 3p, 11p,6p may be involved in the tumorigenesis of RMS. Gains of 12q may be correlated with gene fusion/chromosomal translocation in ARMS. Gains of 9q may be correlated with an early tumor stage of RMS.