Molecular Genetic Analysis of Intravascular Malignant Lymphomatosis (IML)

血管内恶性淋巴瘤(IML)是一种以肿瘤细胞在许多器官的小血管内增殖为特征的疾病，尤其是在大脑。长期以来，人们一直在讨论这些细胞的起源。最近，免疫组织化学研究和Southern杂交分析表明，这些肿瘤细胞具有淋巴细胞性质。然而，肿瘤细胞的遗传特征，包括它们的抗原受体基因和肿瘤抑制基因还没有完全详细。在这项研究中，我们首先检测了重排免疫球蛋白重链(IgH)基因的互补决定区III(CDR-III)。用聚合酶链式反应(PCR)和针对IgH基因可变区和连接区的通用引物扩增CDR III序列。用聚丙烯酰胺凝胶电泳法对扩增产物进行检测。包括IML在内的B细胞淋巴瘤的标本产生了一条单克隆带；这种疾病的单克隆性是特有的。固相萃取…更多来自外周血细胞的Cimen产生了广泛的多克隆物质涂片；而转移性癌症和脑肿瘤的样本要么没有扩增，要么产生了多克隆物质。通过对扩增的CDRⅢ进行克隆和测序，我们确定了IML患者免疫球蛋白基因重组区的核苷酸序列。这项检查有助于早期发现IML中的肿瘤细胞(手稿正在准备中)。聚合酶链式反应-单链构象多态分析显示p53基因外显子5~8和p16基因外显子2(MTSI)无异常迁移。这些结果表明，p53和p16基因突变与IML的发生关系不大。在p21基因外显子2(WAF1)的PCR-SSCP分析中，所有IML病例都出现了异常条带。通过随后的和测序，检测到密码子31处的核苷酸替换。这种核苷酸替换在30%的正常对照组中可见，并被认为是一种多态性。较少

Intravascular malignant lymphomatosis (IML) is a disease characterized by proliferation of neoplastic cells within small vessels in many organs, especially in the brain. The origin of these cells has long been discussed. Recently, immunohistochemical studies and Southern blot analyzes have suggested that these neoplastic cells were of lymphocytic nature. However, the genetic characteristics of the neoplastic cells including their antigen receptor genes and tumor suppressor genes have not yet been fully detailed. In this study, we examined the complementarity-determining region III (CDR-III) of rearranged immunoglobulin heavy chain (IgH) genes, first. CDR III sequences were amplified using the polymerase chain reaction (PCR) and consensus primers for the Variable and Joining regions of the IgH gene. PCR products were examined by polyacrylamide gel electrophoresis. Specimens from B cell lymphomas including IML produced a monoclonal band ; monoclonality was specific for this disorder. Spe … More cimens from peripheral blood cells produced a broad smear of polyclonal material ; and specimens from metastatic carcinomas and brain tumors produced either no amplification or polyclonal material. By cloning and sequencing the amplified CDR III,we have determined nucleotide sequences of rearranged regions of immunoglobulin genes in IML cases. This strafegy should be useful for detecting neoplastic cells in IML at an early stage (manuscript in preparation) . In this study, we also examined tumor suppressor genes in IML.The polymerase chain reaction-single strand conformation polymorphism (PCR-SSCP) analysis revealed no abnormal migration in exons 5 to 8 of the p53 gene and exon 2 of the p16 (MTSI) gene. These findings suggested that mutation of p53 and p16 genes is rarely related with the tumorigenesis of IML.In PCR-SSCP analysis for exon 2 of the p21 (WAF1) , aberrant bands were seen in all of IML cases. By subsequent and sequencing, a nucleotide substitution at codon 31 was detected. This nucleotide substitution was seen in 30% of normal controls and was considered as a kind of polymorphism. Less