肺癌与乳房癌病人DNA修复能力及关卡基因蛋白 的研究.ppt

Investigating the genetic instability and expression of four DNA repair related proteins in the peripheral lymphocytes of 36 untreated lung cancer patients Medical school of Zhejiang University He Jiliang Roles 0f DNA damage,DNA repair, Cell cycle arrest and apoptosis in carcinogenesis Genetic instability of cancer One of the main causes of cancer is high genetic change or genetic instability. Genetic instability is a transient or a persistent state that causes a series of mutational events leading to gross genetic alterations. It is now clear that most cancers have altered genomes, and genetic instability has been found in many types of cancers. The question whether genetic instability is a cause or a consequence of tumorigenesis has been debated for years. Genetic instability The term “genetic instability” is generic : nucleotide alteration genomic instability (at the gene level) (chromosomal level ) faulty or leaky (a) microsatellite instability DNA repair pathways (MIN) (b) chromosomal instabilities (CIN) in chromosome structure and number Genetic instability of cancer DNA replication mechanisms : (1)DNA repair pathways: keeping genes and genome intact (2)chromatin epigenetic modification pathways; (B) maintenance of mitotic stability and chromosome integrity DNA repair pathways safeguard the genome from deleterious mutations Main DNA repair mechanisms (a) nucleotide excision repair (NER); (b) base excision repair (BER); (c) homologous recombination repair (HRR); (d) non-homologous end joining (NHEJ); (e) mismatch repair (MMR) Tumor suppressor genes Tumor suppresso