1. CANCER

2. General A general grouping of all diseases related to unregulated cell growth Cancers generally develop by an accumulation of mutations of the DNA Begin at the DNA level

3. Multi-hit hypothesis All cancers appear to be the result of multiple DNA damage events Each event causes that cell, and its descendents, to lose more and more control over the cell cycle Eventually, a tumor may form Then, if the cancer begins to leave, survive, and populate other regions of the body, we have metastasis - the growth of the tumor in other regions - this is cancer!

4. DNA damage Number of forms can lead to cancer 1.Direct changes to the DNA 1.Point mutations 2.Insertions and Deletions 2.Relocation of DNA 1.Translocation of chromosomes 2.Loss of chromosomes 3.Duplication of chromosomes 3.Viral and Transposon agents 1.Viruses can insert into critical genes 2.So may transposones

5. 21_42_metastasis.jpg Two mechanisms of action - 1) disruption of function, as shown here, or 2) disruption of homeostasis - bone cancer and Ca2+

6. 21_43_Cancer_chromos.jpg

7. 21_44_Tumors.jpg

8. Common feature of cancer cells Reduced dependence of extracellular signals Less likely to undergo apoptosis Unregulated cell division Unstable - high mutation rate Invasive - they lack cell-adhesion molecules Survive in foreign tissues

9. 21_45_proto_oncogenes.jpg

10. 21_46_oncogene.jpg

11. 21_47_cancer_pathways.jpg

12. 21_48_Colorectal_cancer.jpg

13. 21_49_APC_gene_mutat.jpg

14. 21_50_APC_Wnt.jpg

15. 21_51_tumor_cells.jpg

16. 21_52_Gleevec.jpg