【作者】 戴爱丽；

【导师】 陈灵；

【作者基本信息】 上海交通大学 ， 生物化工， 2010， 硕士

【摘要】 抑癌基因的鉴定和功能研究一直以来都是研究的热点。本实验以MB1-Cre-LoxP为基础建立PTEN和(或)INK4a/ARF基因组织特异性敲除模型小鼠共三组。实验发现,PTEN和INK4a/ARF都敲除的模型小鼠肿瘤发生率为100%,肿瘤分为三种:胸腔内、腹腔内和肠道肿瘤,流式细胞仪分析结果显示:各淋巴组织B细胞发育受到影响,主要为Mac-1+,肿瘤细胞具有Mac-1+/B220+,具体为何种造血细胞系肿瘤还需进一步确认。而PTEN或者INK4a/ARF单独缺失的小鼠并未发现类似的肿瘤。对于三组模型小鼠的B细胞发育研究分析表明,单独PTEN缺失组别以及PTEN和INK4a/ARF都缺失的组别在pre-pro-B或更早阶段就已经阻断B细胞发育,而单独INK4a/ARF缺失的模型小鼠B细胞发育没有明显变化。说明PTEN和INK4a/ARF在限制肿瘤生成上具有一定的协同作用,PTEN缺失的小鼠中INK4a/ARF的缺失促进病变进展,其作用机制仍需要深入研究。本论文另一部分重点在于对急性髓样白血病(Acute myeloid leukemia,AML)中甲基化基因的研究,以寻找潜在的抑癌基因。实验通过COBRA和MSP等方法分析研究得到了以ALOX12为代表的一系列潜在抑癌基因。甲基化程度和mRNA表达水平呈负相关,经过去甲基化处理后能恢复表达水平。各潜在抑癌基因的功能分析仍在进行中。更多还原

【Abstract】 The identification and functional validation of tumor suppressor gene have been a research hotspot. Here, we have established three groups of tissue-specific mouse models of PTEN and (or) INK4a/ARF gene based on MB1-Cre-LoxP model. Tumor incidence in PTEN and INK4a/ARF double knockout mouse was 100%, including tumor in the pleural cavity, abdomen, and tumor linked with intestine. Flow cytometry analysis demonstrated that cells of lymphoid tissues were mainly Mac-1+, and tumor cells were Mac-1 and B220 double positive. The characteristics of this hematopoietic neoplasm still need to be studied. However, mice deficient for either PTEN or INK4a/ARF did not show the occurrence of similar tumors. B cell development was blocked in the pre-pro-B stage or earlier in either PTEN or compound PTEN & INK4a/ARF deficient mice, while there were no such changes in INK4a/ARF null mice. Thus, PTEN and INK4a/ARF show synergy in constraining tumorigenesis. INK4a/ARF deficiency likely facilitates tumor development in PTEN null mice, although the mechanism of which remains undetermined. Additional aspect of this thesis focused on identifying potential tumor suppressors that are methylated in acute myeloid leukemia. Using the method of COBRA and MSP, we have identified a few potential tumor suppressors such as ALOX12. The methylation status around the ALOX12 CpG-island inversely correlated with the expression levels of mRNA. On the other hand, its expression was restored by demethylation reagent such as 5-aza treatment. Further functional studies are undertaken.更多还原