中国医科大学病理学英文课件8

nullSection 8. Etiology and pathogenesis of tumor Section 8. Etiology and pathogenesis of tumor nullnull8.1 Molecular basis of oncogenesis8.1 Molecular basis of oncogenesis8.1.1 Oncogene 1. Protooncogene , oncogene and products (1) Protooncogene: cellular genes that promote normal cell growth and differentiation, exist in normal cells, in the form of inactivity. (2) Oncogene: derived from protooncogene promote abnormal growth .null (3) Mode of protooncogenes activation Point mutation Chromosomal rearrangement Gene amplification promoter insertion(4) Products and functions of protooncogenes(4) Products and functions of protooncogenesGrowth factors: PDGF,FGF, EGF Growth factor receptors Signal- transducing proteins: ras Nuclear regulatory proteins: myc Cell cycle regulatory proteins: cyclinsnull8.1.2 Tumor suppressor gene8.1.2 Tumor suppressor gene1.Concept: cellular genes that exist in normal cells inhibit normal growth and cause cells to malignant transform when they become inactive. 2. Examples: Rb , p53 , P16,TGF-β, BRCA-1 , BRCA-2 3. mechanism: allele mutation, deletion, methylation8.1.3 Genes that regulate apoptosis and DNA repair 8.1.3 Genes that regulate apoptosis and DNA repair Genes that regulate apoptosis Bcl (B-cell lymphoma)family: Bcl-2: inhibit apoptosis Bax: induce apoptosis 2. Genes that regulate DNA repair: null8.1.4 Telomeres, telomerase and cancer8.1.4 Telomeres, telomerase and cancer1.Telomeres shorting is believed to be a clock that counts cell division, is a tumor-suppressive mechanism. 2.Telomerase: Sustain the function of telomeres Absent from most somatic cell Increased activity of it tumor8.1.5 Molecular basis of multistep carcinogenesis 8.1.5 Molecular basis of multistep carcinogenesis null8.2 Environmental factors and their mechanism 8.2 Environmental factors and their mechanism 8.2.1 Cheminal carcinogenic agents Indirect-acting agent Polycyclic hydrocarbons:in fossil fuel or combustion of tabacco in smoking ,relate to the development of skin, lung, stomach carcinoma (2) Aromatic amines and azo dyes: bladder, hepatocellular carcinoma (3) Aflatoxin: potent hepatocarcinogen (4)Nitrosamines:lung, gastric, esophagus, null2. Direct-acting agents (1) Alkylatingand acylating agents: anticancer drugs – cyclophosphamide (2) Others arsenic—skin carcinoma chromium—lung carcinoma cadmium—prostate carcinoma nickel—lung carcinoma null8.2.2 Physical carcinogenic factors8.2.2 Physical carcinogenic factors1. Ionizing radiation: X-ray, γ-ray related to leukemia , carcinoma of skin, lung, breast,colon. 2. UV: skin carcinoma 3. Others: asbestos mesothelioma artificial mammary carcinoma8.2.3 Biologic carcigenic agents8.2.3 Biologic carcigenic agents1. RNA virus: Transduction/ insertional mutagenesis HTLV-1 : human T cell leukemia/ lymphoma 2. DNA virus: (1) HPV:cervical squamous cell carcinoma (2) Epstein-Barr virus :nasopharyngeal carcinoma (3) HBV: hepatocyte carcinoma 3. Helicobacter pylori: chronic gastritis, B lymphoma of stomachnullnull8.3 Internal factors and its mechanism8.3 Internal factors and its mechanism8.3.1 Inherited predisposition to carcinogens 1. Inherited cancer syndrome (Autosomal dominant) Familial retinoblastoma 2. Autosomal recessive syndromes: Bloom syndrome, fanconi anemia 3. Familial cancer: breast,ovary,colonnull8.3.2 Tumor immunity8.3.2 Tumor immunity1.Tumor antigen: Tumor specific Ag :only in neoplastic Tumor associated Ag: CEA, AFP 2. Antitumor immunity: mainly cell immunity T cell: lymphotoxin NK cell, Macrophage :ADCC 3. Immunesurveilance: Immunodificient host/ immunosuppressed 4. Immunotherapy: stimulate the endogenous reaction, increase the function of antitumornullnullnullnullnull复习思考题 1.比较良、恶性肿瘤的区别？ 2.高分化鳞癌的结构特点？ 3.何谓实性癌？简述其病理特点？ 4.异型性、分化程度及与肿瘤良恶性的关系？ 5.肿瘤性增生与炎症性增生的区别？ 6.恶性肿瘤对机体的影响？ 7.何谓癌前病变，请列举5种癌前病变或癌前疾病，并说明应如何正确对待癌前病变。 8.腺上皮可形成哪几种类型的恶性肿瘤，并简述各自的形态特点？ 9.试述转移瘤的形成过程及其形态特点？ 10.举例说明为什么说良恶性肿瘤的区别是相对的？ null