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单击此处编辑母版标题样式,单击此处编辑母版文本样式,第二级,第三级,第四级,第五级,*,单击此处编辑母版标题样式,单击此处编辑母版文本样式,第二级,第三级,第四级,第五级,*,Genetic Variability,Genetic Variability,1,Roles 0f DNA damage,DNA repair, Cell cycle arrest and apoptosis in carcinogenesis,Roles 0f DNA damage,DNA repair,2,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 of cancer,3,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,The term “genetic instability”,4,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,Mechanisms maintaining chromosome integrity,Genetic instability of cancerD,5,(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,),Main DNA repair mechanisms,(a) nucleotide excision repair,6,Tumor suppressor genes,(targets for many genetic changes),gatekeeper genes caretaker genes,act directly to regulate do not directly regulate,cell proliferation proliferation,but regulate cell-cycle,checkpoints,DNA repair,and,apoptosis,Tumor suppressor genes,Tumor suppressor genes Tumor s,7,ATM,gene is a caretaker gene (,a checkpoint gene),.,ATM,protein is a large serine/threonine protein kinase and,has more than,15,known substrates.,After activation by ionizing radiation, ATM kinase initiates a cascade of signaling pathways and culminates in cell cycle arrest, apoptosis,and DNA repair.,ATM plays a key role in safeguarding genome integrity.,ATM,gene,and,ATM protein,ATM gene is a caretaker gene (,8,肺癌与乳房癌病人DNA修复能力及关卡基因蛋白的研究课件,9,肺癌与乳房癌病人DNA修复能力及关卡基因蛋白的研究课件,10,肺癌与乳房癌病人DNA修复能力及关卡基因蛋白的研究课件,11,The aims of present study,Chromosomal instability may be one of the primary causes of tumor cell evasion of therapy,understanding of biologic basis of chromosomal instability is critical for effective diagnostic and prognostic evaluation and therapeutic intervention of cancer.,The aims of present study Chro,12,(A) To,observe,whether the,genetic instability,occurs in peripheral lymphocytes of lung cancer patients with MN assay and comet assay.,(B) To,observe,the genetic instability is associated with,four DNA repair related proteins,(ATM, DNA ligase , DNA ligase and XPF) in lung cancer patients,As,markers of susceptibility,were measured using west blotting.,(A) To observe whether the gen,13,1.The blood samples,(1) 36 untreated lung cancer patients,(15 females and 21 males, mean age 60.42 years old),(2) 30 controls,(16 females and 14 males, mean age 55.83 years old),(3) Each sample was divided into two parts:,(a),irradiated sample,(exposed to 3 Gy X-ray),(b),non-irradiated sample,(not exposed to 3 Gy X-ray),Materials and Methods,1.The blood samplesMaterials a,14,2. Detecting Methods,(1) Chromosomal Damage,Micronucleus (,MN,) assay can be used to detect,(,chromosome loss and chromosome breakage,),(2) DNA Damage,Comet assay,can be used to detect,(,various forms of DNA damage,),(3) Protein expression,West blotting,was used to detected:,ATM,XPF,Ligase,and,Ligase,Materials and Methods,2. Detecting MethodsMaterials,15,Blood Samples,Part 1 Part 2,(,Irradiated samples,) (,non-irradiated samples,),Comet assay Comet assay,MN assay MN assay,West blotting,Chromosomal Damage Chromosomal Damage,DNA Damage DNA Damage,Protein expression,Blood Samples,16,Results 1 (comet assay),Patients,Controls,Non-irradiated,Samples,irradiated,Samples,Non-irradiated,Samples,irradiated,Samples,MTL,(m),1.88,0.05,1.45,0.16,1.78,0.11,1.16,0.11,MTM,0.84,0.07,b,1.090.11,b,0.60,0.05,0.70,0.10,Results 1 (comet assay)Patient,17,Fig.1. Spontaneous (MTL0 and MTM0) and IR-induced (IR-MTL and IR- MTM) genetic damage in lung cancer patients and controls was detected by comet assay. MTL=mean tail length, MTM=mean tail moment, IR=ionizing radiation, *,P,0.05,.,Fig.1. Spontaneous (MTL0 and M,18,Results 2 (MN assay),Patients,Controls,Non-irradiated,Samples,irradiated,Samples,Non-irradiated,Samples,irradiated,Samples,MCF,(,),9.250.58,b,66.142.07,a,6.100.65,60.501.71,MNF,(,),10.170.72,b,75.642.34,a,6.600.74,67.602.13,Results 2 (MN assay) PatientsC,19,Fig.2. Spontaneous (MCF0 and MNF0) and IR-induced (IR-MCF and IR- MNF) genetic damage in lung cancer patients and controls was detected by MN assay. MCF=micronucleated cell frequency, MNF=micronucleus frequency,IR=ionizing radiation, *,P,0.05,.,Fig.2. Spontaneous (MCF0 and M,20,Results 3 (West blotting),ATM,Ligase,Ligase,XPF,Patients,0.750.08,a,0.590.07,a,0.540.05,a,0.840.07,Controls,1.630.39,1.000.17,0.810.09,1.200.21,Results 3 (West blotting)ATMLi,21,Fig.3. Four DNA repair related proteins expression levels in DNA of lymphocytes collected from lung cancer patients and controls were measured by west blotting.,*,P,0.05,.,Fig.3. Four DNA repair related,22,Fig.1 shows:,Four DNA related proteins and,loading control (GAPDH),Results 4,Fig.1 shows:Results 4,23,Fig.4.Four DNA related proteins and loading control (GAPDH) were detected by west blotting. A: ATM protein, B: Ligase protein，C: Ligase protein，D: XPF protein. No. 1, 3 were,from control group, No. 2, 4 were from lung cancer patient group,Fig.4.Four DNA related protein,24,(1) The genetic instability in peripheral lymphocytes of 36 lung cancer patients was significantly higher than that of controls,(2) The increased genetic instability in peripheral lymphocytes of lung cancer patients may be associated with the reduced expression of DNA repair related proteins,.,Conclusion,(1) The genetic instability in,25,Official Journal of the British,Toxicology Society,Official Journal of the German,Toxicology Society,Impact Factor: 2.584 in 2019,I am a member of Editorial Board,I wish Chinese Scientists to submit your manuscripts to,The Journal of Toxicology,The Journal of Toxicology,Official Journal of the Britis,26,Thanks,Thanks,27,谢谢你的阅读,知识就是财富,丰富你的人生,谢谢你的阅读知识就是财富,28,肺癌与乳房癌病人DNA修复能力及关卡基因蛋白的研究课件,29,
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