Cancer Genetics

What is a proto-oncogene?

A normal gene that promotes cell growth and division.

What is an oncogene?

A mutated proto-oncogene with gain-of-function that promotes cancer.

What is a tumor suppressor gene?

A gene that suppresses cell growth or triggers apoptosis.

Define driver mutation.

A mutation that directly contributes to cancer progression.

Define passenger mutation.

A mutation that arises during cancer but does not contribute to growth.

Name 4 ways a proto-oncogene becomes an oncogene.

Point mutation, amplification, translocation, insertion near enhancer.

What happens in the Philadelphia chromosome translocation?

BCR-ABL fusion creates a constitutively active tyrosine kinase (CML).

How do tumor suppressor genes become inactive?

Loss-of-function mutations, deletions, or epigenetic silencing.

What gene is mutated in most familial retinoblastomas?

RB1 (Retinoblastoma gene)

Which targeted drug blocks BCR-ABL activity?

Gleevec (Imatinib)

What are two oncogenes often amplified in cancer?

HER2 and Myc

What are the 6 Hallmarks of Cancer (Hanahan & Weinberg)?

Proliferative signaling, evading growth suppressors, resisting death, immortality, angiogenesis, metastasis.

Why are cancer stem cells significant in treatment?

They sustain the tumor and must be targeted to prevent relapse.

What method identifies genes involved in metastasis in mice?

Genome-wide CRISPR screens.