Genetics of Cancer Chapter 23

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What determines the presence of each type of CDK-cyclin complex?

Stimulation of apoptosis

Synthesis of specific cyclins at certain times (correct)

Inhibition of CDK activity

Destruction of cyclins that are needed

Which CDK-cyclin complex is involved in the transition from the G1 to the S phase of the cell cycle?

Cyc D-CDK4/6

CycB-Cdk1

CDK2-cyclin E (correct)

Cyc A-CDK1

What is the role of CycB-Cdk1 in the cell cycle?

Phosphorylating lamin and leading to nuclear envelope breakdown during early mitosis (correct)

Promoting G1 progression

Initiating apoptosis

Regulating S-phase

What is the purpose of the G1-to-S checkpoint?

To arrest the cell cycle in response to DNA damage Signup and view all the answers

What happens to cells producing p53 in response to DNA damage?

They undergo apoptosis Signup and view all the answers

What is the primary function of checkpoints in cell division?

To prevent the transmission of genomic instability Signup and view all the answers

What is the outcome of apoptosis?

DNA degradation and nucleus condensation Signup and view all the answers

What is the result of gene amplification in tumor cells?

Formation of homogenously staining regions (HSRs) or double minutes Signup and view all the answers

What is the characteristic of oncogenes?

They have the capacity to convert a normal cell into a cancer cell Signup and view all the answers

What is the effect of mutations in tumor-suppressor genes?

They can cause dominantly inherited predispositions to cancer Signup and view all the answers

What is the main difference between proto-oncogenes and tumor-suppressor genes?

Proto-oncogenes have the capacity to convert a normal cell into a cancer cell, while tumor-suppressor genes suppress tumor formation Signup and view all the answers

What is the consequence of cells with defective checkpoints?

They are more vulnerable to DNA damage Signup and view all the answers

What is the main function of CDKs in the cell cycle?

To phosphorylate other proteins Signup and view all the answers

What happens to lamins during mitosis?

They are phosphorylated and become soluble Signup and view all the answers

How many cyclins have been identified in mammals?

29 Signup and view all the answers

What type of mutation results in increased proliferation in oncogenes?

Gain-of-function mutation Signup and view all the answers

What is the role of cyclins in the cell cycle?

To activate CDKs Signup and view all the answers

What is the significance of studying cell-cycle mutants in yeast?

To identify cell division genes Signup and view all the answers

What is the role of tumor suppressor genes?

To slow down the cell cycle Signup and view all the answers

How do retroviruses contribute to the formation of oncogenes?

By integrating into the host genome and activating a proto-oncogene Signup and view all the answers

What is the result of CDKs phosphorylating proteins?

Either activation or inactivation of the protein Signup and view all the answers

What is the characteristic of oncogenes in terms of their action?

They act dominantly to promote cancer Signup and view all the answers

What is the role of proto-oncogenes?

They encode proteins needed for cell cycle progression Signup and view all the answers

What is the result of loss-of-function mutations in both copies of a tumor suppressor gene?

Increased cell proliferation Signup and view all the answers

What type of kinases are Cyclin-Dependent Kinases (CDKs)?

Ser/Thr kinases Signup and view all the answers

What is the role of cyclins in the regulation of cell cycle progression?

To act as regulatory subunits Signup and view all the answers

How many CDKs are involved in cell cycle progression, according to the text?

6 Signup and view all the answers

What is the condition for CDKs to be active?

When bound to cyclins Signup and view all the answers

What is the purpose of CDK7, 8, 9, 11, and 12?

Transcription regulation Signup and view all the answers