腫瘤學(xué)基礎(chǔ)及實(shí)踐：信號傳導(dǎo)與疾病

1、信號傳導(dǎo)與疾?。⊿ignal transduction and disease）,The Hallmarks of Cancer,Cell-to-cell communication by extracellular signaling usually involves six steps,synthesis of signaling molecule by signaling cell,release of the signaling molecule by the signaling cell,transport of the signal to the target cell,Chang

2、es in targeted gene expression triggered by the receptor-signal complex,removal of the signal, which usually terminates the cellular response,detection of the signal by a specific receptor protein,細(xì)胞外因子通過與受體（膜受體或核受體）結(jié)合，引發(fā)細(xì)胞內(nèi)的一系列生物化學(xué)反應(yīng)，直至細(xì)胞生理反應(yīng)所需基因的轉(zhuǎn)錄表達(dá)開始的過程。,“wiring” of cell regulatory circuits,Inte

3、rcellular Signaling:how cells communicate with one another,Examples of Signaling,SYNAPTIC,PARACRINE,ENDOCRINE,Extracellular Signals Bind to Different Types of Receptors,1951年，第一個(gè)生長因子神經(jīng)生長因子 NGF發(fā)現(xiàn) Rita Levi-Montalcini 420-430 (2002); TARGETING DEATH AND DECOY RECEPTORS OF THE TUMOUR-NECROSIS FACTOR SU

4、PERFAMILY,TNF- and NF-B,cell surface TNF- receptor NF-B inactive in cytoplasm with IB kinase removes IB NF-B trans-locates to nucleus,NF-kappa B is an anti-apoptotic factor,Via NF-kappaB TNF blocks its own cell death potential,chemotherapy activates NF-kB within tumor cells,NF-kB inhibitors augment

5、chemotherapy,many common synthetic (e.g., aspirin), and traditional (e.g., green tea, curcumin) remedies target, at least in part, the NF-kB signaling pathway,The Wnt signaling pathway,Integrin 傳導(dǎo)通路,Networks of Signal Transduction,600 G protein-coupled receptors,+,Multiple gene families and combinat

6、ions of G protein subunits 20G isoforms 6 G isoforms 12 G isoforms,+,Multiple gene families for selected effector proteins,Adenylyl cyclases Phospholipases Ion channels,The phenomenon of crosstalk increases the complexity and variety of signal transduction pathways in a cell. The net result is that

7、a single cellular response may be sensitive to several different extracellular stimuli. Crosstalk is, in part, a reflection of multiple gene families for all major protein components of signal transduction pathways.,The magnitude of amplification within this cellular cascade structure often exceeds

8、10+4. That is, the binding of one molecule of ligand to a cell-surface receptor leads a change of 10,000-fold in the intracellular concentration of a metabolic product.,腫瘤臨床中的信號傳導(dǎo),信號傳導(dǎo)異常與腫瘤發(fā)生 腫瘤治療,增殖失控： 生長因子： c-Sis 生長因子受體: HER-2 蛋白激酶: c-Src G蛋白: c-Ras 細(xì)胞周期調(diào)控因子: Rb 凋亡受阻 TNF Fas/FasL Bcl/Bax p53 侵襲與轉(zhuǎn)移

9、 Integrin E-Cadherin VEGF,信號傳導(dǎo)異常與腫瘤發(fā)生,腫瘤發(fā)生與發(fā)展是多因素作用、多基因參與、經(jīng)過多個(gè)階段形成。,腫瘤中常見的信號傳導(dǎo)異常,Familial adenomatosis polyposis coli （FAP,APC),Based on genetic analysis, at least two pathways are characterized in detail, which lead to colon cancer development. One pathway (indicated with red arrows) initiates with

10、 mutations in the APC gene followed by mutations in K-ras, deleted in colorectal cancer (DCC) and p53 genes. The second pathway (indicated with blue arrows) is initiated by mutations in the MMR genes (hMSH3, hMSH) and other genes (TGFbetaIIR, IGFIIR, PTEN, BLM, Tcf-4, Bax and E2F4). Beside these the

11、re are many other less characterized pathways with a high degree of overlapping among them. At least, seven gene mutations are needed to develop a normal epithelial cell into carcinoma. Frontiers in Bioscience 10, 1118-1134, May 1, 2005,Model for genetic alterations in the development of colorectal

12、cancer,結(jié)腸癌、胰腺癌等,colorectal carcinomas 30-60%, K-ras,non-melanoma skin cancer 30-50%, H-ras,hematopoietic neoplasia of myeloid origin 18-30%, K-and N-ras,Seminoma 25-40%, K-ras,In other tumors, a mutant ras gene is found at a lower frequency: for example, in breast carcinoma (0-12%, K-ras), Neuroblas

13、toma (0-10%, K- and N-ras),Wnt-1 was found as an oncogene activated by the Mouse Mammary Tumor Virus in murine breast cancer. APC was first isolated as a tumor suppressor gene in human colon cancer. After establishing that APC and beta-catenin bind to each other activating mutations in the human bet

14、a-catenin gene were found in human colon cancer and melanomas .These mutations alter specific beta-catenin residues important for GSK3 phosphorylation and stability . The role for Frat/GBP in cancer is illustrated by its activation by proviral insertion in mouse lymphomas . A recent example of the l

15、ink between cancer and Wnt signaling comes from the identification of the Drosophila gene legless as a homolog of Bcl-9 a gene implicated in B cell malignancies.Interestingly, mutations in the human AXIN1 gene were reported in human hepatocellular carcinomas. TCF1 can also act as a tumor suppressor

16、gene , as Tcf1 mutant mice develop adenomas in the gut and mammary glands,Several components of the Wnt signaling pathway have been implicated in human tumors or experimental cancer models.,EMT : epithelial-mesenchymal transition,腫瘤的轉(zhuǎn)移及EMT （Epithelial-Mesenchymal Transition）,Different types of EMT,J

17、. Clin. Invest. 119:14201428 (2009). doi:10.1172/JCI39104,Contribution of EMT to cancer progression,Science Vol 331,Mar25, 2011; Cell 147,Oct14, 2011,Biphasic activities of the TGF- signaling pathway during tumorigenesis: from the tumour suppressor to the tumour promoter,腫瘤治療,腫瘤治療,單克隆抗體Herceptin: HE

18、R-2 STI571(Gleevec): Bcr-Abl,May 2001,magic bullet,Hematopoietic stem cell,Mature Blood Cells,Leukemia,Cytogenetic Abnormality of CML:The Philadelphia Chromosome,Chronic Myelogenous Leukemia (CML). The Leukemia 22) Translocation,22,bcr,abl,Ph,bcr-abl,FUSION PROTEINWITH TYROSINEKINASE ACTIVITY,9,9+,S

19、tructure of BCR-ABL Fusion Proteins,Bcr-Abl Signal Transduction Pathways,Gleevec-Tyrosine Kinase Inhibitor,Goldman JM. Lancet. 2000;355:1031-1032.,Bcr-Abl,ATP,Substrate,STI571,Y = Tyrosine P = Phosphate,Bcr-Abl,Substrate,P,P,P,P,Structure of Gleevec (Imatinib Mesylate),Class: Phenylaminopyrimidines,

20、 589.7 mw,CH3SO3H,O,Conclusions,CML is a result of a single genetic mutation termed the Philadelphia Chromosome Gleevec is a Tyrosine Kinase Inhibitor that targets the protein product of the mutation Ongoing trials show Gleevec to be effective in Chronic Phase CMLAcceleratedBlast Crisis Response to

21、therapy is generally seen in 1 month Gleevec is generally well-tolerated,chemist Nicholas Lydon, a former researcher for Novartis, oncologist Brian Druker of Oregon Health and Science University (OHSU), Charles Sawyers of Memorial Sloan-Kettering Cancer Center Lasker-DeBakey Clinical Medical Researc

22、h Award converting a fatal cancer into a manageable chronic condition.,Forward,Add one compound/well,Select compound that produces phenotype of interest,identify protein target,Reverse,Chemical Biology,MicroRNAs in caner: tiny players in big disease,Zhao Qian Department of Pathophysiology Shanghai J

23、iaoTong University School of Medicine,Cell, Vol 75, 843-854, 3 December 1993The C. elegans Heterochronic Gene lin-4 Encodes Small RNAs with Antisense Complementarity to lin-14 Rosalind C. Lee, Rhonda L. Feinbaum, and Victor Ambros,endogenous 1925nt non-protein-coding RNAs up to 1000 human miRNAs con

24、servatism, tissue specificity and time-ordered in expression are the obvious characteristics of miRNA negatively regulate the expression of genes at the posttranscriptional level by blocking translation or/and degrading target mRNAs each microRNA regulates 100-200 target genes microRNAs have been sh

25、own to control a wide range of biological functions such as stem cell development, cellular proliferation, differentiation and apoptosis.,Marilena V. Iorio and Carlo M. Croce J Clin Oncol .2009.24.0317,Biogenesis, processing, and maturation of microRNAs,Mechanisms of microRNA regulation,About half o

26、f the annotated human miRNAs map within fragile regions of chromosomes, which are areas of the genome that are associated with various human cancers different miRNAs are deregulated in primary human tumors tumor suppressor gene: let-7d, miR-15a, miR-16-1, et al. oncomirs : miR-155, miR-17-92 cluster

27、, et al.,B cell lymphoma,CLL,tumor suppressor gene,oncomir,目前發(fā)現(xiàn)與乳腺癌發(fā)生和發(fā)展密切相關(guān)的癌基因和抑癌基因有： c-myc基因 HER2基因 (C-erbB-2) RAS基因 MTDH基因 EZH2基因 BRCA1 BRCA2 P53 P21 P16.,與乳腺癌發(fā)生和發(fā)展密切相關(guān)microRNAs: miR-21 miR-29 miR-155 miR-27a miR-25 miR-10b miR-125a/b miR-145 miR-17-5P miR-26a. MiR-200,miRNAs as prognostic tools

28、,miRNAs as therapeutic molecules and targets,Cell. 2009 Jun 12;137(6):1005-17,miRNAs as therapeutic molecules and targets,The miR-34 Family as Mediator of Tumor Suppression by p53,p53 Enters the MicroRNA World,miR-26a miR-26b,Breast cancer,Breast normal,Stefano Volinia et al , PNAS February 14, 2006

29、 vol. 103 no. 7,The expression of miR-26a/b decrease in breast caner VS breast normal in microarray,miR-26a/b expression decrease in Human breast cancer,NC,26A,26B,96h,MiR-26a impairs viability and initiates apoptosis of MCF-7 cells in vitro.,Percentage of TUNEL positive cells,MiR-26a impairs viabil

30、ity and initiates apoptosis of MCF-7 cells in vitro.,MDA-MB-435S,72h,96h,NC-435s,mir-26a-435s,mir-26b-435s,MDA-MB-435S cell transfected with miR-26a/b mimics,Negative control,miR-26a,MCF-7 cell colony formation in soft agar,Total colonies,Negative control,miR-26a,miR-26b,Negative control,miR-26a,miR

31、-26b,Delivery of miR-26a suppress the MCF-7 cell tumorigenesis in vivo,EZH2 (enhancer of zeste homolog 2),AEG-1 (astrocyte elevated gene-1),Validate potential miR-26a/b targets via reporter gene assay in 293T cells,AEG-1 and EZH2 are direct targets of miR-26a and negatively correlate with miR-26a ex

32、pression in breast cancer,AEG-1 and EZH2 knockdown phenocopy miR-26a mediating phenotype in MCF-7 cells,Zhang B et al, Carcinogenesis,2010,AEG-1 can partially reverse miR-26a imposing apoptosis in MCF-7 cells,Zhang B et al, Carcinogenesis,2010,MiR-26a is downregulated in breast cancer specimens and

33、cell lines MiR-26a impairs viability and initiates apoptosis of MCF-7 cells in vitro Retrovirus delivered miR-26a impairs the in vitro colony-forming and in vivo tumor-loading ability of MCF7 cells AEG-1 and EZH2 are direct targets of miR-26a and negatively correlate with miR-26a expression in breast cancer,Conclusion,Composition of RNAs,Nature Review (2011),Non-coding RNAS,John L. Rinn & Howard Y. Chang, Annu Rev Biochem. 2012,Timeline of discoveries of RNA