辐射诱发胸腺淋巴瘤中包含易位的染色体畸变

Analysis of initial events in radiation-induced lymphomagenesis:investigation of chromosome aberrations including translocations.

为了研究包含易位的染色体畸变在辐射诱发淋巴瘤过程中的作用，作者分析了供体型Ｔ淋巴瘤细胞的染色体Ｇ带核型．结果观察到，在供体派生的Ｔ细胞淋巴瘤中，有许多数目和结构畸变。有意义的是：几乎在每组淋巴瘤中都发现了含有易位的共同畸变。如：Ｄ组中１１号和１２号染色体的易位；Ｅ组中１２号和１５号染色体的易位；Ｆ组中７号和１０号染色体的易位；Ｇ组中１号和１３号染色体的易位；Ｈ组中６号和Ｘ染色体的易位；Ａ组和Ｆ组中还有共同的１５号染色体三体。这些结果表明：包含易位的染色体畸变在辐射诱发淋巴瘤过程中可能是重要的启动事件。畸变细胞数／总细胞数图６小鼠每条染色体的畸变频率常发生畸变的染色体，畸变类型包括三体和易位，在３４个淋巴瘤中发生频率为５３％。其次１２号染色体的易位发生率为３２％。而１号、１３号和Ｘ染色体也有２０％左右的畸变率。与此相反，２，３，４，８，９，１４，１６，１７和１９号染色体几乎未检出畸变。一般认为，肿瘤的发生过程与原癌基因的激活或抑癌基因的失活有关。在淋巴瘤形成的原发事件中，染色体的某些部位可能含有原癌基因的起动子或操纵子。这些基因片断被射线打断并发生错误重接（表现为染色体的易位），从而启动了肿瘤的多阶段过程。尽?

To investigate the contribution of chromosome aberrations in radiation- induced lymphomagenesis, chromosome G-banding analysis of the lymphoma cells(8 groups and 34 kinds of cells),of which each group was derived from a single donor by intrathymic injection of a limited number of prelymphoma cells, was performed.Many numerical and structural aberrations were observed in the donor-derived T cell lymphomas. Common aberrations including translocations were found almost in the lymphomas of all groups.Translocations between chromosomes 11 and 12,12 and 15,7 and 10,1 and 13, 6 and X were found in D, E, F, G,H groups,respectively.There were also common aberrations such as trisomy 15 in A and F groups.These results indicate that chromosome aberrations including translocations may be important candidates of initiating events in radiation-induced lymphomagenesis.