Cancer

1. Cancer By: Aujan M., Zach J., Aditya P.

3. Genetic disease that results in uncontrolled growth. • Mutation in genetic code results in failure of cell division control. • ~90% of time, cancer mutation due to external environmental factors. Cancer due to inherited mutations ~10% of time. Overview

5. Deletion or duplication of nucleotides in genetic sequence can lead to mutation. • Once cell’s life cycle is disrupted, cancerous cells begin to grow at rapid rate, forming a neoplasm. Overview

7. Cell undergoes cell division before cell is fully mature. Since they divide at a rapid rate, successive cancer cells will be immature and dysfunctional. • Mutations occur after birth, not a hereditary disease. Genetic Basis

8. Genes that inhibit cell division are proto-oncogenes. These can mutate and become oncogenes. • Oncogenes – mutations causes constant production of proteins/enzymes stimulating unrestrained cytokinesis. Genetic Basis

10. Majority of genetic mutations occur during S phase. • Result of 3 major mechanisms: • 1.) Carcinogens – cancer causing agents that cause mutation to cell’s DNA (anti-oncogenes). i.e.- chemicals and radiation. • 2.) Viruses – viruses insert their fragment of DNA into genetic material of cells they infect. DNA can compromise proto-oncogenes of cell. • 3.) Replicative Mutations – during replication, mutations can affect proto-oncogenes turning them into oncogenes. Causes of Cancer

12. Changes to a specific portion of a gene. • May be transmitted to offspring, allowing it to be found in successive generations. Types of Mutations:Point Mutations

13. Base Pair Substitution – replacement of one nucleotide and complimentary base with another complimentary pair. • Missense Mutation – altered codon still codes for amino acid, but amino acid doesn’t make sense with function of protein. • Nonsense Mutation – causes production of stop codon. Types of Mutations:Substitutions

14. Substitution

15. Adding/Losing Nucleotide Pairs – more harmful than substitutions because mRNA coded in series of triplets. Loss/gain causes entire sequence to shift over, resulting in shift in reading frame. • Frameshift Mutation – nucleotides inserted/deleted don’t come in multiple of three. Alters reading frame. Produces useless protein. Types of Mutations:Insertions/Deletions

16. Insertion/Deletion

17. Benign Neoplasm – mass of cells whose cellular compositions is same as cells of surrounding tissues. • Surrounded by connective tissue, so metastasis doesn’t occur. • Nuclear fission similar to that of normal cells. • Since rate of division slightly higher than that of normal cells, tumor will grow slowly. Types of Neoplasms:Benign

18. Neoplasms whose DNA has mutated. Different from surrounding tissues. • Resemble immature and undifferentiated cells. • Growth is greatly accelerated and can become detrimental to surrounding tissue. • Neoplasm then breaks out of connective tissue capsule and can metastasize. • Usually contain degraded chromosomes joined incorrectly to another gene. Types of Neoplasms:Malignant

19. Benign (top) and Malignant (bottom) Tumors

20. Apoptosis- programmed cell death • Inhibit the expression of Apaf-1 • Secrete elevated levels of decoy soluble molecule that binds to Fas-L • Utilization of human proto-oncogene Bcl-2 How do cells avoid death?

24. Inhibit cell division • Contains p53 gene which binds DNA and stops it from allowing damaged DNA to divide Tumor Suppressor Genes

26. Stimulates the cell cycle • Ras is a gene turns on other genes through the signal transduction cascade which tells the cell cycle to go Proto-Oncogene

30. Divisions determined by telomeres • Cancer cells turn on telomerase • Cancer cells now divide without any limits Why do cancer cells grow uncontrollably?

32. Cancer cells need nutrients • Blood vessels nourish the tumor • angiogenesis Processing Nutrients

33. Invading tissues and disrupting functions • metastasizing Invading Tissues

35. There are no cures for cancer but treatment options do exist. • Chemotherapy- poison cancer cells • Radiation- uses x-rays and radio isotopes to destroy cancer causing cells • Surgery- removes neoplasm and surrounding tissues Treatments