拷贝数变异对多发骨肉瘤临床分型与耐药机制的影响

摘要

Objective To study the clinical significance of copy number variation (CNV) and driver gene in multiple osteosarcoma (MOS) for the diagnosis,classification,clinical features and difference of chemo-drug sensitivity,and to discuss the applications of exons group sequencing technology in tumor research.Methods 2 cases of multiple osteosarcoma patients diagnosed from January 2014 to October 2014 were collected.The exome of each patient's normal tissue and multiple lesions was sequenced in accordance with the unified standards.After filtering the sequencing data,the sequence of mutation gene and its type was confirmed.Highlight the single nucleotide mutation/SNV and CNV.Analyze the similarities and differences of genetic variations between multiple lesions of each patient,and the gene variants that are shared by the all four tumor lesions.Finally,analyze the molecular targeted drug sensitive gene about the similarities and differences between different lesions.Results The sequencing results showed that all specimens of each patient had vast majority of the same part,which confirmed they were obtained from a single patient at the genetic level firstly.Then,through the SNV analysis of both tumor tissues,the final data showed that there was highly overlap between them.We found PIK3 and HNRNPA2B1,both drive gene variants played an important role in the process of tumor when analyzing one patient's SNV.The anti-oncogene TP53 was found with CNV between multiple lesions of the 2 cases,while the CNV mutation got the same variation trend but different range.The CNV mutation of the molecular targeted drug sensitive gene was found to have significant differences between the tumor sites of both patients.By analyzing the patients' somatic SNV and CNV globally,the results indicated that the enrolled two patients were all metastasis MOS that with only one primary lesion.Conclusion CNV is one of the significant features of genetic abnormality of MOS.%目的 探讨多发骨肉瘤体细胞拷贝数变异(copy number variation,CNV)及驱动基因在该病诊断、分型、化疗药物敏感性差异分析中的意义.方法 2014年1月至2014年10月收治多发骨肉瘤患者2例,按照统一标准采集每例患者的正常组织及所有骨肉瘤病灶组织进行全外显子组测序,分析基因序列发生的变异及类型.重点观察体细胞单核苷酸变异(single nucleotide variation,SNV)及CNV,对比分析每例患者多发病灶之间基因变异的异同,提取各病灶间共有的变异基因.分析分子靶向药物敏感基因在不同病灶之间的异同.结果 测序结果显示,同一例患者所测序组织的单核苷酸多态性完全一致,在基因层面证实了所分析的每组标本均来自同一个体;且2例患者两处肿瘤组织的SNV重叠部分较多(分别为64％和54％),其中1例患者的SNV识别到PIK3及HNRNPA2B1两个驱动基因变异.2例患者TP53等抑癌基因所处片段均识别到CNV,初步判断2例患者均为胫骨近端病灶单中心起源的转移性多发骨肉瘤.总体上,2例患者多发病灶组织间的大片段CNV具有相同的变异趋势,但变异幅度不同.对患者各肿瘤病灶间分子靶向药物敏感基因CNV分析显示,变异的差异有统计学意义.结论 拷贝数变异是多发骨肉瘤基因异常的表征之一.