Biology of Cancer Flashcards

*Cancer is derived from healthy cells that have gone crazy. Cancer cells can often be linked back to the cell type that they originated from. Cancer is out of control proliferation of cells.*Metastasis is cancer spreading throughout the body. 90% of cancer deaths are from metastatic tumors, not the original tumor. Common sites of metastasis: Lung, brain, liver, bone.

1) Degree of aggressiveness. Benign means not aggressive, slow growing, not invading nearby tissue. Malignant means aggressive, invading nearby tissue and metastasizing.2) Embryonic origin. During early development there are three cell layers: Ectoderm=Epithelial cells that line the tracts in your body such as respiratory and GI. Mesoderm=Blood cells, muscles, connective tissue. Ectoderm=Skin, nervous system.3) Epithelial versus Nonepithelial Cells. 80% of cancer diagnoses are derived from epithelial cells. Epithelial cells continuously regenerate. Continous but ordered proliferation, replicate DNA, possibility for mutation. Epithelial cells are more exposed to mutagens in your environment.

Carcinoma--Squamous Cell Carcinoma = Cancers derived from epithelial cells that form protective layers between you and the outside world.--Adenocarcinoma = Cancers derived from epithelial cells that are specialized to secrete something. Ex) Mucus, milk.

--Sarcoma = Cancer derived from connective tissue. 1% of tumors.--Leukemia = Derived from white blood cells, many forms depending on the cell type. Flowing in your body.--Lymphoma = Derived from white blood cells, localized to a lympth node.--Neuroectodermal tumors = Derived from cells of the nervous system, 1% of tumors.

--Melanoma = Cancer derived from melanocytes.--Small cell lung carcinoma= Tumor arises in the lung. Look like neural derived cells. Transdifferentiated.--Teratomas = Very rare (around 10,000 cases annually). Derived from germ cells (diploid cells) that migrated to the wrong location and give rise to hair, teeth, bones, etc.

Too many cells but still maintaining tissue architecture.

Wrong cells in wrong place. Ex) In a normal esophagus, mucosal cells line the esophagus. In the metaplastic state, a different kind of epithelial cell starts to move into place.

Individual cells with abnormal appearances.

Cancer that is not yet invading nearby tissues. Macroscopic growth (ex. Lump).

Invading into nearby tissue.

Invading far away tissue.

Normal cell----> Hyperplasia/ Metaplasia-----> Dysplasia-------> Pre-Invasive Cancer------> Invasive Cancer------> Metastic Invasive Cancer/Metastatic Tissue.

Myeloma is a cancer of plasma cells. Plasma cells are antibody producing cells. Each plasma cell produces a unique antibody. Different antibodies are slightly different in size.--Normal-----> Polyclonal plasma cells, different antibody proteins that are different sizes.--Myeloma-----> One size of antibody, one kind of antibody, monoclonal population of plasma cells.Therefore, most tumors are monoclonal.The cancer stem cell is the original cell that proliferates into more cells.

In a normal cell with high oxygen levels, glucose is converted into pyruvate (building block for amino acids and nucleic acids) to produce 2 ATP through glycolysis. Then it goes through the mitochondria citric acid cycle (requires oxygen) to produce 36 more ATP. There are 38 ATP total. In a normal cell with low oxygen levels, the cell can only go through glycolysis so only 2 ATPs are produced.

Usually cancer cells are in hypoxic (no oxygen) conditions so they are not supplied with blood.If oxygen levels were high, the cancer cell would only go through glycolysis and would not go through the citric acid cycle.Less efficient--->Compensate by using more glucose.Why? Possibly make lots of pyruvate to make more nucleic acids and amino acids.