8.2.1 Oncogenes and Tumor Suppressor Genes

• Proto-oncogenes are normal genes that regulate cell growth and differentiation
• Tumor suppressor genes prevent uncontrolled cell growth by regulating cell cycle progression and apoptosis
• Tumor suppressor genes are inactivated by a loss-of-function mutation.


  True
• Proto-oncogenes ensure controlled cell division and development.


  True
• Proto-oncogenes are normal genes that regulate cell growth and differentiation
• What is the effect of proto-oncogenes on cell growth?

  Regulated growth
• What type of mutation is associated with oncogenes?

  Gain-of-function
• What are three main mechanisms of oncogene activation?

  Gene amplification, point mutations, chromosomal translocations
• The RAS oncogene is associated with uncontrolled cell growth and inhibited apoptosis
• Oncogenes drive uncontrolled cell growth
• The HER2 oncogene is also known as ERBB2
• The p53 tumor suppressor gene induces apoptosis in damaged cells
• What is the mutation type associated with oncogenes?

  Gain-of-function
• Match the concept with its effect on cell growth and apoptosis:

  Proto-oncogenes ↔️ Regulated growth, normal apoptosis

  Oncogenes ↔️ Uncontrolled growth, inhibited apoptosis
• Proto-oncogenes are normal genes that regulate cell growth and differentiation
• Gene amplification increases the copy number of the gene
• The RAS oncogene drives uncontrolled cell growth
• Mutations in the RAS gene are found in many cancers, including lung, colon, and pancreatic cancer
• The RB tumor suppressor gene controls cell cycle progression from G1 to S phase.
• Which phase of the cell cycle does RB regulate?

  G1 to S phase
• Match the tumor suppressor gene with its function:

  p53 ↔️ Regulates cell cycle and apoptosis

  RB ↔️ Controls G1 to S phase progression
• Oncogenes result from a gain-of-function mutation in a proto-oncogene
• What type of mutation transforms proto-oncogenes into oncogenes?

  Gain-of-function
• Mechanisms of oncogene activation

  1️⃣ Gene amplification

  2️⃣ Point mutations

  3️⃣ Chromosomal translocations
• Which oncogene promotes cell growth through tyrosine kinase receptors?

  HER2/ERBB2
• Match the gene type with its function:

  Proto-oncogenes ↔️ Regulate cell growth

  Oncogenes ↔️ Drive uncontrolled cell growth

  Tumor suppressor genes ↔️ Suppress tumor growth
• Oncogenes require a gain-of-function mutation to become active

  True
• Tumor suppressor genes act as cellular brakes to prevent tumor formation.


  True
• Tumor suppressor genes drive uncontrolled cell growth.

  False
• Which tumor suppressor gene controls the progression from G1 to S phase?

  RB
• What is the function of the RB tumor suppressor gene?

  Controls G1 to S phase
• Oncogenes are mutated proto-oncogenes that result from a gain-of-function
• Tumor suppressor genes are inactivated through loss-of-function mutations, which require both copies of the gene to be mutated
• What are oncogenes?

  Mutated proto-oncogenes
• What are tumor suppressor genes?

  Genes preventing tumor formation
• Steps in the mechanism of oncogene activation

  1️⃣ Gene amplification

  2️⃣ Point mutations

  3️⃣ Chromosomal translocations
• Oncogenes are mutated proto-oncogenes that drive uncontrolled cell growth and inhibit apoptosis
• Match the concept with its effect on cell growth:

  Proto-oncogenes ↔️ Regulated growth

  Oncogenes ↔️ Uncontrolled growth
• Proto-oncogenes are the non-mutated versions of oncogenes.

  True
• Mutated proto-oncogenes lose their regulatory functions, leading to tumor formation.


  True