Question

Cancer and Gene Regulation Why is a cell cycle control system needed for cell division? What happens when cells do NOT respond to the cell cycle control system and divide excessively? Tumor Proto-oncogeno (for protein that stimulates coll division) 6 Y DNA Benign Tumor= Mutation withln a control region of DNA Malignant Tumor Mutated promoter Metastasis Normal growth-stimulating protein in excess Oncogene Tumor-Suppressor Genes Proto-oncogene utled tara gese Samor-auppresr gane Many proto-oncogenes code for growth factors /Deletive nonimenig Normel grewt inhblin proain Call diviaion ander cenirel Celldivisles nd contrel Tumor-Suppressor Genes oesetroed oell grewth ancer) Nomal cel grwl Accumulated mutations in proto-oncogenes and tumor-suppressor genes alters gene expression and aids in the development of malignant (cancerous) tumors. Mutations in proto-oncogenes converts them to over-active oncogenes. Explain how this alters the regulation of growth factors and leads to the development of cancer: Mutations in tumor-suppressor genes cause these genes to be inactivated. Explain how this alters the regulation of growth-inhibiting proteins and leads to the development of cancer:

Answer 1

Cancer and Gene Regulation Why is a cell cycle control system needed for cell division? Cell division involves duplication of the genetic material also. So if anything goes wrong in copying the genetic material, the cell cycle cotrol system helps to identify the mistake, try to rectify it and if not possible, terminates the cell division what happens when cells do NOT respond to the cell cycle control system and divide excessively? Proto-oncogene - DHA Tumor - Undesired accumulation of abnormal cells Tumor which is not dangerous and does not invade Benign Tumor = nearby tissues/organs. Tumor that invades the nearby tissues/organs, Malignant Tumor = i.e, dangerous When cancer cells spread from the place of its origin totated pro Metastasis = other tissues/organs, it is called metastasis. Mutation within a control region of DNA Oncogene = gene having the potential of causing cancer Normal growth-stimulating protein in excess A normal gene which mutates to Proto-oncogene = become an oncogene Tumor-Suppressor Genes Sarregue Sandvik Many proto-oncogenes code for growth factors True, they even code for DNA-binding proteins, cell cycle regulators, kinases involved in cell signalling, TFs, etc Tumor-Suppressor Genes = They control cell growth and cell division, so that the cells do m a celo not lead to cancer. These are also called antioncogenes. Accumulated mutations in proto-oncogenes and tumor-suppressor genes alters gene expression and aids in the development of malignant (cancerous) tumors. Mutations in proto-oncogenes converts them to over-active oncogenes. Explain how this alters the regulation of growth factors and leads to the development of cancer: Mutations affect the genes that code for growth factors. Now, growth factors are secreted without any control and this gives the perfect opportunity to the cancer cells to grow without any limitation and perform metastasis. Mutations in tumor-suppressor genes cause these genes to be inactivated. Explain how this alters the regulation of growth-inhibiting proteins and leads to the development of cancer: when the tumor suppressor genes are inactivated, the tumor supressing proteins are no more produced. This affects the cell cycle control mechanism and the cells divide without any limit thereby leading to development of cancer.