Cancer =Uncontrolled cell growth due to gene mutations -Cancer is always genetic, but it is not necessarily inherited

Cancer = series of unfortunate events Most environmen tal factors said to cause cancer are really just risk factors (another mutation)

Not All Mutations are Created Equally Mutation = change in the DNA sequence of a cell Cancer occurs (in contrast to other types of mutations we’ve discussed) when the mutations that occur lead to changes in the proteins involved in regulating the cell cycle Therefore, all mutations are not cancerous nor are all mutations related to cell cycle

I. What are the two types of tumors? Benign (noncancerous): does not spread Malignant (cancerous): can spread into other parts of body (spreading process is called metastasis; new tumors=metastases)

Benign vs. Malignant

Benign does not always mean not harmful

How do cancer cells travel?

II. Why are tumors harmful? Mutated cells can’t carry out normal functions of that type of cell Mutated cells crowd out normal cells Mutated cells steal nutrients from normal cells

Angiogenesis= formation of new blood vessels Blood vessels = nutrients

Angiogenesis Inhibitors to Treat Cancer

Why does the number of new cases not correlate to the number of deaths

Review of Day #1 How does cancer begin? What type of DNA sequences must be mutated? Cancer prevalence vs. death rates How does the body prevent must mutations that could become cancers from occurring Benign vs. malignant? metastasis angiogenesis

Why Smoking is Silly

Causes of Cancer/Risk Factors Biological (genetics) Only 10% of cancer is directly inherited Inherited= if you have the “cancer gene”, you will get cancer no matter what Environmental Chemicals Diet bacteria/viruses Age

III. What are carcinogens? They are chemical, physical, or biological agents that cause cancer by mutating genes. UV radiation Tobacco Some viruses HPV– Cervical cancer Some toxins Others?

Treatment Prevention Don’t do things that increase risk factor for cancer Early detection Late detection

Late Detection Treatment Surgery Radiation Chemotherapy

Radiation -DNA damage (increased p53)

Chemotherapy

IV. What types of genes do carcinogens mutate? Growth Promoting Genes Stimulate cell division Mutation can lead to gene being permanently ‘turned on’- cells divide too often Tumor Suppressor Genes Block cell growth and division Mutation leads to inability to turn off cell division; cells therefore divide too often p53 is an example

p53 gene is mutated in about 50% of human tumor cells NORMAL FUNCTION OF p53 PROTEIN

Another benefit of Apoptosis– AKA Why Humans Don’t Look Like Ducks

Cancer versus Normal Cells Normal Cells Divide limited number of times Fussy about nutrients Cell division highly controlled Cancer Cells Immortal-can divide forever Easily grown Divide rapidly and randomly