癌症通史---南京大学幻灯片.ppt

* * National Cancer Institute Understanding Cancer and Related Topics Understanding Cancer NCI Web site: /cancertopics/understandingcancer * One group of genes implicated in the development of cancer are damaged genes, called “oncogenes.” Oncogenes are genes whose PRESENCE in certain forms and/or overactivity can stimulate the development of cancer. When oncogenes arise in normal cells, they can contribute to the development of cancer by instructing cells to make proteins that stimulate excessive cell growth and division. 原癌基因是细胞内与细胞增殖相关的基因，是维持机体正常生命活动所必须的，在进化上高度保守。 当原癌基因的结构或调控区发生变异，基因产物增多或活性增强时，原癌基因转化成为癌基因。 * 原癌基因是细胞内与细胞增殖相关的基因，是维持机体正常生命活动所必须的，在进化上高度保守。 当原癌基因的结构或调控区发生变异，基因产物增多或活性增强时，原癌基因转化成为癌基因。 * National Cancer Institute Understanding Cancer and Related Topics Understanding Cancer NCI Web site: /cancertopics/understandingcancer * Tumor suppressor genes are a family of normal genes that instruct cells to produce proteins that restrain cell growth and division. Since tumor suppressor genes code for proteins that slow down cell growth and division, the loss of such proteins allows a cell to grow and divide in an uncontrolled fashion. Tumor suppressor genes are like the brake pedal of an automobile. The loss of a tumor suppressor gene function is like having a brake pedal that does not function properly, thereby allowing the cell to grow and divide continually. National Cancer Institute Understanding Cancer and Related Topics Understanding Cancer NCI Web site: /cancertopics/understandingcancer * A second group of genes implicated in cancer are the “tumor suppressor genes.” Tumor suppressor genes are normal genes whose ABSENCE can lead to cancer. In other words, if a pair of tumor suppressor genes are either lost from a cell or inactivated by mutation, their functional absence might allow cancer to develop. Individuals who inherit an increased risk of developing cancer often are born with one defective copy of a tumor suppressor gene. Because genes come in pai