Cell Cycle and Cancer Regulation

These flashcards cover key terms and concepts related to the cell cycle and its regulation, particularly in the context of cancer.

G1 checkpoint

The first checkpoint in the cell cycle that checks for cell size, nutrients, growth factors, and DNA damage.

G2 checkpoint

The second checkpoint in the cell cycle that ensures DNA replication is complete and checks for DNA damage.

M checkpoint (spindle checkpoint)

The final checkpoint in the cell cycle that verifies that chromosomes are properly attached to the spindle before division.

MPF (maturation promoting factor)

A complex of cyclin B and CDK that is crucial for passing the G2 checkpoint and initiating mitosis.

Cyclins

Proteins that regulate the cell cycle by increasing concentrations at different stages.

CDK (cyclin-dependent kinase)

An enzyme that, when bound to a cyclin, becomes activated to phosphorylate target proteins in the cell cycle.

Proto-oncogenes

Normally harmless genes that can become cancerous when mutated.

Tumor suppressor genes

Genes that prevent uncontrolled cell division and can lead to cancer when mutated.

p53

A critical tumor suppressor gene that halts the cell cycle in response to DNA damage.

BRCA1 and BRCA2

Genes that code for proteins involved in DNA repair; mutations increase the risk of breast and ovarian cancers.

Benign tumors

Noncancerous growths that grow slowly and have even borders.

Malignant tumors

Cancerous tumors that grow rapidly, invade surrounding tissues, and may spread to other parts of the body.

Positive regulators

Molecules like cyclins and CDKs that promote progression through the cell cycle.

Negative regulators

Proteins that halt the cell cycle, often in response to DNA damage or overcrowding, such as p21 and RB.

Phosphorylation

The process of adding a phosphate group to a molecule, crucial for activating or deactivating proteins in the cell cycle.

Restriction point

A checkpoint during the G1 phase where the cell decides whether to proceed with division.

DNA replication

The process of copying DNA before a cell divides, critical for maintaining genetic integrity.