2.Molecular Biology B.Mutations and Cancer Gene Mutations and Cancer Genes Implicated in Cancer Mutations in genes that control normal cell proliferation can lead to cancer. ·Oncogenes These mutations can be .Tumor suppressor genes created by DNA-damaging carcinogens致癌物质 and ·DNA repair genes radiation. However, some cancer-causing mutations are simply spontaneous errors that The mutations of these appear in normal DNA molecules three general classes of when cells duplicate their DNA gene contribute to the prior to cell division. develop-ment of cancer
Gene Mutations and Cancer Mutations in genes that control normal cell proliferation can lead to cancer. These mutations can be created by DNA-damaging carcinogens 致癌物质 and radiation. However, some cancer-causing mutations are simply spontaneous errors that appear in normal DNA molecules when cells duplicate their DNA prior to cell division. The mutations of these three general classes of gene contribute to the develop-ment of cancer. 2. Molecular Biology B. Mutations and Cancer
2.Molecular Biology B.Mutations and Cancer Oncogenes3致癌基因 Normal cell Oncogenes are damaged genes whose PRESENCE in Normal genes certain forms and/or regulate overactivity can stimulate cell growth the development of cancer. It is the first group of mutated/damaged genes s implicated in the oncogene development of cancer. When oncogenes arise in Oncogenes accelerate normal cells,they instruct cell growth cells to make proteins that and division stimulate excessive cell growth and division. Cancer cell
Oncogenes致癌基因 Oncogenes are damaged genes whose PRESENCE in certain forms and/or overactivity can stimulate the development of cancer. It is the first group of genes implicated in the development of cancer. When oncogenes arise in normal cells, they instruct cells to make proteins that stimulate excessive cell growth and division. 2. Molecular Biology B. Mutations and Cancer
2.Molecular Biology B.Mutations and Cancer Proto-Oncogenes and Normal Cell Normal growth-control pathway Growth Oncogenes are related to normal GROWTH genes called proto-oncogenes which FACTOR are a family of normal genes that code for proteins involved in a normal cell growth-control pathway. SIGNALING Cell growth and division is RECEPTOR ENZYMES normally controlled by proteins called growth factors,which bind to TRANSCRIPTION FACTORS receptors on the cell surface. CELL- This binding activates a series of NUCLEUS VOOOOOOOOW DNA enzymes inside the cell,which in turn activate special proteins called CELL PROLIFERATION transcription factors复制因子inside the cell's nucleus. The activated transcription factors turn on genes required for cell growth and proliferation.Many components of this pathway,for example,growth factors signaling enzymes,receptors,and transcription factors,are encoded by proto- oncogenes
Proto-Oncogenes and Normal Cell Growth Oncogenes are related to normal genes called proto-oncogenes which are a family of normal genes that code for proteins involved in a normal cell growth-control pathway. Cell growth and division is normally controlled by proteins called growth factors, which bind to receptors on the cell surface. This binding activates a series of enzymes inside the cell, which in turn activate special proteins called transcription factors复制因子 inside the cell's nucleus. The activated transcription factors turn on genes required for cell growth and proliferation. Many components of this pathway, for example, growth factors signaling enzymes, receptors, and transcription factors, are encoded by protooncogenes. 2. Molecular Biology B. Mutations and Cancer
2.Molecular Biology B.Mutations and Cancer Oncogenes are Mutant Forms of Proto-Oncogenes Proto-oncogene Oncogenes arise from t the 00000N00M mutation of proto-oncogenes. Since they are mutant forms of proto-oncogenes,oncogenes MUTATION resemble proto-oncogenes in that they code for the production of proteins involved in growth control.However, oncogenes code for an altered V00000个0N0 version (or excessive quantities) of these growth-control Oncogene proteins,thereby disrupting a cell's growth-signaling pathway
Oncogenes are Mutant Forms of Proto-Oncogenes Oncogenes arise from the mutation of proto-oncogenes. Since they are mutant forms of proto-oncogenes, oncogenes resemble proto-oncogenes in that they code for the production of proteins involved in growth control. However, oncogenes code for an altered version (or excessive quantities) of these growth-control proteins, thereby disrupting a cell's growth-signaling pathway. 2. Molecular Biology B. Mutations and Cancer
2.Molecular Biology B.Mutations and Cancer Oncogenes Act Like an Hyperactive growth-control pathway Accelerator By producing abnormal GROWTH FACTOR versions or quantities of cellular growth-control proteins,oncogenes cause a cell's growth-signaling SIGNALING RECEPTOR ENZYMES pathway to become hyperactive活动亢进.A simple metaphor: the TRANSCRIPTION FACTORS CELL- growth-control pathway is NUCLEUS VOOOOOOOO0 DNA like the gas pedal of an automobile.The more EXCESSIVE active the pathway,the CELL PROLIFERATION faster cells grow and divide, A cancer cell may contain one or more oncogenes
Oncogenes Act Like an Accelerator By producing abnormal versions or quantities of cellular growth-control proteins, oncogenes cause a cell‘s growth-signaling pathway to become hyperactive 活动亢进 . A simple metaphor: the growth-control pathway is like the gas pedal of an automobile. The more active the pathway, the faster cells grow and divide. A cancer cell may contain one or more oncogenes. 2. Molecular Biology B. Mutations and Cancer