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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 & FGF: Growing,See also: Current opinion in cell biology, 13: 662-665, 2001,Production of differentiated cells from mouse ES cells in culture.,Stem cells migrate to sites of organ damage and differentiate to cell types competent to participate in tissue regeneration.,利用
11、干细胞可塑性,Regeneration of new tissues from our own cells will not be far behind Science, December 6, 2002: 1901,Cancer: Cells proliferate uncontrollably,Tumor,Benign tumors: Do not spread,Malignant tumors Cancers: Metastasize,Benign tumor,Malignant tumor,1. The biology characteristics of cancer,(1) Cel
12、l proliferate uncontrollably,(2) Invade and metastasize,(3) Less well differentiated than normal cells or benign tumor cells,(4) Have highly aberrant chromosome complements Aneuploidy,Pancreas cancer,(5) Lose Contact inhibition in vitro,2. The causes of cancer,Carcinogenic chemicals and UV,DNA and R
13、NA tumor viruses,Alter the genome,SV40, Adenovirus,HIV,Benign tumor,Malignant tumor,Normal cell,3. Caner: As a result of the accumulation of mutation and natural selection,Cancer-inducing mutation genes,Proto-oncogenes,Tumor-suppressor genes,癌基因（oncogenes）：v-onc and c-onc 抑癌基因（tumor-suppressor gene）
14、Rb p53 特 点 原癌基因 抑癌基因 基因属性 细胞增殖必需 细胞分化必需 致癌方式 基因突变激活、异常表达 基因缺失或失活,Rous(1910)发现鸡的致癌RNA病毒； 1963年发现RSV突变株： tsRSV 鸡成纤维细胞,40C,37C,细胞正常,病毒正常繁殖,细胞癌变,病毒正常繁殖,tdRSV,鸡成纤维细胞,40C,37C,细胞正常,细胞正常,病毒正常繁殖,病毒正常繁殖,v-oncogene,tdRSV3端缺失15002000bp; 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（protoonco
15、gene）,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RSV,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
16、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-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,C
