Outline. What is cancer? How do people know they have cancer? How do tumors develop and cancer spread? Why are older people more likely to get cancer? What regulations do cells have that help prevent cancer? What are some of the causes of cancer?
How do people find out if they have cancer?
Cells that have gone awry, because the genes that help cells “follow the rules” have mutated. Thus they can divide rapidly, start acting like other cells and move from where they are supposed to stay.
Cancer develops step-by-step, across time, as an accumulation of many molecular changes, each contributing some of the characteristics that eventually produce cancer cells.
We have genes in our DNA called tumor suppressor genes that code for proteins that interact with the molecules cyclin and CDK which are controlling the cell cycle at certain checkpoints to determine if the DNA is good enough shape to proceed to division. If the DNA is damaged in anyway it is either repaired or the cell undergoes programmed cell death.
A cell with to much DNA material does not behave correctly so DNA must only replicate once with each cycle and each daughter cell must have the correct amount of genetic material.
To prevent a cell from having the ability to become cancerous, damage must be repaired.
It will undergo programmed cell death, also known as apoptosis. This prevents damaged cells from dividing and leading to cancerous cells.
environment (ex: sun), chemicals, infection, genes, toxins etc.
-mutated tumor suppressor genes
-mutated cell cycle regulators
-mutated repair proteins
-mutated receptor signaling constant division, etc.
How can one’s environment affect their chances of getting cancer?Example: UVA and UVB light exposureBy damaging the skin’s cellular DNA, excessive UV radiation produces genetic mutations that can lead to skin cancer.
Viruses insert their own DNA into our cells so our cells will make more viruses. The viral genes that cause cancer activate or over express similar human genes that cause the cells to exhibit uncontrolled cell divison.
One way viruses have been found to cause cancer is through mutated receptors on the cell surface. What might the receptor be for?
Heredity-This is the process by which an offspring cell or organism acquires or becomes predisposed to the characteristics of its parent cell or organism.
Autosomal recessive disorder caused by mutations in genes that code for DNA repair proteins
Retinoblastoma is a form of cancer that young children usually get because of one mutated copy of a protein called RB1. What must happen for retinoblastoma to occur?
With only one good copy of the gene, all it takes is one hit on that gene for the stage to be set for retinoblastoma to occur.
Antioxidants are substances that may protect your cells against the effects of free radicals. Free radicals can damage cells, and may play a role in heart disease, cancer and other diseases.
The Immune System
It uses the body's immune system, either directly or indirectly, to fight cancer or to lessen the side effects that may be caused by some cancer treatments.
Surgery may be used for cancer prevention to remove tissue before cancer develops, diagnosis to determine if tumor is cancerous or not, staging to see how advanced the cancer is, and primary treatment to remove cancerous tumors.
It uses drugs to destroy cancer cells, stop cancer cells from spreading, and slow the growth of cancer cells. It can be given through an IV, a shot into part of the body, a pill or liquid to swallow, or a cream to rub on skin.
It uses high powered x-rays or radioactive seeds to damage the DNA and kill cancer cells. Other rapidly growing cells may also be damaged in the process.