Cancer - Chapter 20

Flashcards on Cancer Biology

Cancer

General name for a group of diseases characterized by uncontrolled cell division, caused by multiple mutations in genes regulating the cell cycle in one cell.

Tumor

Abnormal lump or growth of cells.

Benign tumor

Normal cells that are dividing, do not spread (e.g., Fibroids or lipomas).

Malignant tumor

Abnormal cells that grow uncontrollably and spread to other parts of the body; cancerous cells.

Metastasis

Cancer cells spreading through the body via the lymphatic system or blood vessels.

Tumor

Abnormal mass of tissue, can be benign or malignant.

Hyperplasia

Enlargement of tissue, increase in proliferation of cells.

Dysplasia

Presence of cells of an abnormal type within a tissue.

In Situ Cancer

Contained in the location of origin.

Invasive Cancer

Spread beyond the layer of tissue where it developed.

Metastasis

Secondary malignant sites distant from primary.

Mutations

Mutations are random, but can be selected for or against depending on whether they are beneficial or harmful to the cell (natural selection).

Oncogenes

Normal genes that stimulate the cell cycle. Mutated forms are overly active, increasing stimulation of the cell cycle.

Tumor Suppressors

Normal genes that inhibit the cell cycle. When mutated, they lose their ability to suppress the cell cycle.

Gain-of-function mutations (Oncogenes)

Mutations to turn the protein ON, causing increased cell cycle; only one copy of the gene needs to be mutated to cause dysregulation.

Loss-of-function mutations (Tumor Suppressors)

Mutations turn the protein OFF, preventing the normal inhibition on cell cycle, so cell cycle increases; both copies of the gene must be mutated to fully lose function.

BRCA1/BRCA2

Genes that repair damaged DNA.

Telomeres

Repeating sequences at the ends of chromosomes, shorten every division.

Telomerase

Enzyme that lengthens telomeres (stem cells).

Angiogenesis

New blood vessel growth is required to bring nutrients to the tumor to allow for continued growth.

Driver mutations

Mutations that contribute directly to tumor progression

Passenger mutations

Mutations that arise as result of increased mutation rate, but are not involved in tumor progression.

Single Cell Theory

A single cancer cell (fully transformed) can recapitulate (recreate) the disease of cancer in a new host.

CAR-T cell therapy:

Patient’s T-cells are modified to better recognize and destroy cancer cells. (successful in blood cancers, now being adapted for solid tumors)

ctDNA

circulating tumor DNA, cancer cells die