Molecular Pathological analyses of aberrant expression of the proteintyrosine phosphatase SHP1 gene in terms of lymphomagenesis/leukemogenesis.

利用cDNA微阵列在基因组水平上研究基因表达，使得一次测量每个基因的转录本变得容易。各种类型的淋巴瘤/白血病已分析与基因芯片或宏阵列研究淋巴瘤/白血病发生的分子基础。本课题组利用cDNA微阵列和组织芯片技术，结合RT-PCR和Western blotting技术，对人NK/T细胞系（NK-YS）基因组的表达模式进行了全面系统的研究。与正常NK细胞或外周血单个核细胞相比，NK-YS细胞系的基因表达发生了显著变化：18个基因表达增加，20个基因表达减少。在这些基因中，我们发现造血细胞特异性蛋白酪氨酸磷酸酶SHP 1 mRNA的cDNA微阵列和RT-PCR的强烈减少。进一步用标准的免疫组织化学和组织芯片分析，其中利用207个石蜡包埋标本的各种大肠杆菌 关于我们 NK/T淋巴瘤100%，各类恶性淋巴瘤95%以上均为阴性。已发现SHP 1基因的启动子区在成人T细胞白血病（甲基化频率90%）、自然杀伤（NK）/T细胞淋巴瘤（91%）、弥漫性大B细胞淋巴瘤（93%）、MALT淋巴瘤（82%）、套细胞淋巴瘤（75%）、浆细胞瘤（100%）和滤泡性淋巴瘤（96%）的患者样本中高度甲基化。甲基化频率在高级别MALT淋巴瘤病例中（100%）显著高于低级别MALT淋巴瘤病例（70%），与SHP 1蛋白在高级别MALT淋巴瘤（80%）和低级别MALT淋巴瘤（54%）中无表达的频率密切相关。提示SHP 1基因沉默与CpG甲基化异常不仅与淋巴瘤的恶性转化有关，还与淋巴瘤的进展有关。此外，SHP 1基因启动子甲基化与临床分期（如完全缓解或复发）明显相关。79%的ALL病例中，SHP 1基因附近的微卫星标记存在杂合性丢失。这些证据表明，SHP 1基因是一个相关的新的生物标志物的广泛的造血系统恶性肿瘤。此外，SHP 1基因表达的丧失被认为在多步骤淋巴瘤/白血病发生中起重要作用。少

The studies of gene expression on a genomic scale with cDNA microarrays make it easy to measure the transcripts for every gene at once. Various types of lymphomas/leukemias have been analyzed with the cDNA microarray or macroarrays to investigate the molecular basis of lymphomagenesis/leukemogenesis. Recently, our group analyzed the expression pattern of the human NK/T cell line (NK-YS) genome by cDNA macroarray and tissue-microarray comprehensively and systematically followed by RT-PCR and Western blotting. The significant changes in the gene expression of NK-YS cell line were detected : increase in 18 and decrease in 20 genes compared to normal NK cells or peripheral blood mononuclear cells. Among these genes, we found a strong decrease in hematopoietic cell specific protein-tyrosine-phosphatase SHP1 mRNA by cDNA-macroarray and RT-PCR. Further analysis with standard immunohistochemistry and tissue-microarray, which utilized 207 paraffin-embedded specimens of various kinds of malignan … More t lymphomas, showed that 100% of NK/T lymphoma specimens and more than 95% of various types of malignant lymphoma were negative for SHP1 protein expression. The promoter region of the SHP1 gene has been revealed to be highly methylated in patient samples of adult T cell leukemia (methylation frequency 90%), natural killer (NK)/T cell lymphoma (91%), diffuse large B-cell lymphoma (93%), MALT lymphoma (82%), mantle cell lymphoma (75%), plasmacytoma (100%) and follicular lymphoma (96%). The methylation frequency was significantly higher in high grade-MALT lymphoma cases (100%) than in low grade- MALT lymphoma cases (70%), correlating well with the frequency of no expression of SHP1 protein in high grade- (80%) and low grade-MALT lymphoma (54%). It suggests that the SHP1 gene silencing with aberrant CpG methylation relates to the lymphoma progression in addition to the malignant transformation. Furthermore, the promoter methylation of the SHP1 gene was clearly correlated with the clinical stage such as complete remission or relapse. Loss of heterozygosity with microsatellite markers near the SHP1 gene was showed in 79% of informative ALL cases. These evidences show that the SHP1 gene is a relevant novel biomarker of the wide range of hematopoietic malignancies. Additionally, the loss of SHP1 gene expression is suggested to play an important role in multistep lymphomagenesis/leukemogenesis. Less