Cancer Genetics

What are the distinct phases of the eukaryotic cell cycle?

Interphase (G1, S, G2) and Mitosis.

What occurs during the G1 phase of the cell cycle?

The cell has one chromatid per chromosome.

What happens during the S phase of the cell cycle?

DNA replication occurs.

What is the role of checkpoint proteins in the cell cycle?

They prevent progression through the cell cycle if conditions are not favorable.

What is the function of cyclins in cell cycle regulation?

Cyclins promote progression through the cell cycle.

What are cyclin-dependent kinases (CDKs)?

They activate various processes in the cell cycle.

What characterizes cancer?

A failure to regulate the cell cycle, leading to rapid division and lack of inhibition.

What is anchorage dependence?

The requirement for cells to be attached to a surface to grow.

What does density-dependent inhibition refer to?

The cessation of cell division when cells become too crowded.

What are primary tumors?

Initial tumors that form at the site of cancer origin.

What is metastasis?

The process by which cancer cells migrate to other tissues and form secondary tumors.

What is the multistep model of cancer development?

It states that several gene mutations are required for a cell to become cancerous.

What are oncogenes?

Mutated proto-oncogenes that promote excessive cell cycle progression.

What is the function of tumor suppressor genes?

They normally inhibit cell cycle progression.

Give an example of a tumor suppressor gene.

Retinoblastoma (RB) gene.

What role do DNA repair genes play in cancer?

They prevent mutations; loss of function increases mutation rates.

What is the significance of vascularization genes in cancer?

They recruit new blood vessels to supply nutrients to tumors.

What are epigenetic changes in cancer cells?

Defects in histone or DNA methylation affecting gene expression.

What is colorectal cancer characterized by?

A sequence of mutations in different genes leading to cancer from GI epithelial cells.

What chromosomal changes are common in cancer cells?

Aneuploidy, translocations, inversions, and deletions.

How can viruses contribute to cancer?

By inserting their genome, acquiring proto-oncogenes, or interfering with tumor suppressor genes.

What is the Philadelphia chromosome?

A translocation between chromosomes 9 and 22 associated with chronic myelogenous leukemia.