中文摘要：

生命体的遗传物质基础是DNA分子,多种因素可以作用于细胞内的DNA分子,导致多种类型的DNA损伤。若受损的DNA得不到及时和有效的修复,细胞将走向凋亡或发生变异。染色质改构复合物（chromatin remodeling complex）在基因表达调控和DNA复制等方面扮演着重要角色。依赖ATP的染色质改构复合物SWI/SNF的核心亚基Brahma Related Gene1（BRG1）在染色质结构调整和基因转录调控等多个细胞进程中具有重要作用,仅有有限的文献报道BRG1参与到DNA的损伤修复过程。因此,进一步研究与验证BRG1在调控DNA的损伤修复进而挽救细胞凋亡中的作用十分重要。本文通过利用不同强度的UV照射检测细胞凋亡的情况,初步建立了DNA损伤修复的实验体系。将BRG1表达质粒瞬时转染到SW13（BRG1-/-）细胞系中,并利用30J/m2的UV照射,分别在0h、6h和24h检测细胞早期凋亡程度。结果表明,SW13（BRG1-/-）细胞中瞬时表达BRG1可以明显降低由UV照射引起的细胞凋亡,其中UV照射后24h的细胞表现最明显。我们进一步在HeLa细胞中通过瞬时表达BRG1验证了上述结果。由于BRG1通过染色质改构在基因的转录调控、复制和重组等方面起着重要的作用,我们推测BRG1可能通过染色质改构参与了DNA的损伤修复过程,进而影响了细胞凋亡。

英文摘要：

DNA molecules are the basis of the genetic material of lives, a variety of factors act on the DNA molecules within of cells leading to various types of DNA damage. If damaged DNA is not timely and effective repaired, the cell would go toward apoptosis or variation. Chromatin remodeling complex plays an important role in the regulation of gene expression and DNA replication. Brahma related gene 1 （BRG1）, a core subunit of the ATP-dependent chromatin remodeling complex SWI/SNF, plays an important role in adjustment of the chromatin structure, regulation of gene transcription and other cellular processes. It was limited literature to report that BRG1 involved in the process of DNA damage repairing. Therefore, it would be very important to further study and verify the roles of BRG1 in the regulation of DNA damage repairing to rescue the cell apoptosis. In this research, DNA damage repairing model was preliminary established by detecting the cell apoptosis induced with the different intensity of UV radiation. The BRG1 expression plasmids were transiently transfected into SW13 （BRG1-/-） cell lines, and then were exposed under 30 J/m2 of UV irradiation. We detected the degree of the early cell apoptosis for 0 h, 6 h and 24 h, respectively. The results showed that the BRG1 transient expressed in the SW13 （BRG1-/-） cells could significantly reduce cell apoptosis caused by UV irradiation, in which the cells exposed for 24 h after UV irradiation would be the most obvious working. The above results were verified by transiently expressing the BRG1 gene in the HeLa cells. Because BRG1 plays an important role by chromatin remodeling in regulation of gene transcription, replication, recombination, etc., we speculated that BRG1 might involve in the process of DNA damage repairing by chromatin remodeling, thereby leading to affect apoptosis.