细胞分化与基因表达调控.ppt

1、Cell differentiation and Cancer cells,Cell differentiation,Chapter 12,1. About the concept of cell differentiation,The process that a cell changes to carry out a specialized function: Marked by: Morphology / Structure / Function,The different cell types of a multicellular organism contain the same D

2、NA. A cell can change the expression of its genes in response to external signals. Differences in mRNA expression patterns among different cell types. Different cell types synthesize different sets of proteins. Gene expression can be regulated at many of the steps in the pathway from DNA to RNA to p

3、rotein.,The four essential processes by which a multicellular organism is made: Cell proliferation, Cell specialization, Cell interaction, and Cell movement.,Cell differentiation occurs in multicellular organisms,Human: 1014 cells, 200 cell types,2. Why a fertilized egg can develop into different ce

4、lls: Gene differentiated express,分子杂交技术检测基因及其表达,3. Combinational control and Gene differentiated express pp.416: 12-1: 2n (n=3, A,B,C),4. House-keeping genes and luxury genes,House-keeping genes: Expressed in all cell types, essential for all cells,Luxury genes: Tissue-specific genes, expressed in s

5、pecial cells,Sequential expression of various genes in early Drosophila embryo,5. Transdifferentiation: From one type of cell into another type,Includes: Dedifferentiation-Redifferentiation,去分化,再分化,Cell totipotency (细胞全能性),1. Plant cells,The ability of a cell develops into a complete organism,植物细胞具有

6、全能性，在适宜条件下可培育成完整植株，已广泛应用,2. Animal cloning,Transplantation of frog red cell nucleus indicated the nucleus of animal is totipotency(全能性),A new organism created by the process of nuclear transplantation,Dolly: A lamb with no father,c,The sheep star: Dolly,克隆能给人类带来什么？,克隆动物是未来的制药厂,克隆的爱因斯坦会懂“相对论”吗,Stem c

7、ell and its differentiation potential,1. What is a stem cell ?,Has two abilities: (1)Self-renewing (2)Differentiating,2. Where to get the stem cells?,(1) Embryonic stem cells,(2) Adult stem cells,(3) Umbilical cord blood stem cells,(4) Fetal stem cells,3. Types of stem cells: differentiation potenti

8、al,(1) Monopotential stem cell,(2) Pluripotent stem cells,(3) Embryonic stem cells,Two ways for a stem cell to produce daughters with different fates,4.Why do researchers study stem cells ?,For repairing tissue damage caused by disease or injury, including: Diseases that impair brain function, such

9、as Alzheimers disease and Parkinsons disease Spinal cord injuries Blood diseases, including leukemias Burns,5. Stem cell plasticity,Adult stem cells can differentiate into a large number of different cell types.,Turning blood into brain: Science, 2000, 290: 1779-1782,Turning brain into blood: Scienc

10、e, 1999, 283: 534-535,NSC+EGF 不影响病毒复制，但影响细胞转化,1976年发现，正常鸡细胞核DNA中，具有与V-onc的同源序列，称正常细胞中的同源序列为原癌基因（protooncogene）,或C-oncogene. v-onc和c-onc的关系：c-onc来自v-onc. 理由如下: 1、v-onc对病毒复制和生存都是不必要的；而c-onc对细胞重要功能和活动不可缺少；提示c-onc是进化中保存下来的细胞重要结构元件。 2、发现的30种c-onc是依靠病毒的v-onc探针找到的；并不是所有c-onc都有对应的同源v-onc。 3、v-src缺失3/4不能致癌的R

11、SV,注入鸡体内，发现缺失的v-src与c-src发生重组，v-src回复并致癌。,抑癌基因（tumor suppressor gene） Harris(1968):癌细胞系与同组织正常细胞融合杂交细胞无恶性表型，也不致癌； 随着染色体丢失则可能恢复致癌（Rb13q14.1）.,Proto-oncogenes,(1) Proto-oncogens: Gain-of-function mutations,Ras oncogene: Retain bind GTP,Bcl-2 oncogene: Prevent apoptosis,(2) Tumor suppressor genes: Loss-

12、of-function mutations,Rb gene: The first tumor suppressor gene in patient with retinoblastoma,p53: Guardian of the genome,Because the accumulation of gene mutation and Natural selection, so the patient is aged,Chart of the major signaling pathways relevant to cancer in human cells, indicating the ce

13、llular locations of some of the proteins modified by mutation in cancers.,Can we treat cancer?,1. Conventional approaches to combating cancer,Surgery Chemotherapy/Radiation,Can not rid of all cancer cells,2. Gene therapy,Tumor cells lack functional tumor-suppressor genes,p53-bearing viruses,Engineered adenovirus,Immune response,3. Inhibiting the formation of blood vessels,Angiogenesis: Cancer cells growth factors endothelial cells form new v