Ch7.9 TSGs and Prs

Question 1

What is the primary function of tumor suppressor genes?

Answer 1

umor suppressor genes reduce the likelihood of cancer development.

Question 2

How do tumor suppressor genes block cancer development?

Answer 2

They act through diverse mechanisms, such as suppressing cell proliferation or responding to genomic damage.

Question 3

What unites all tumor suppressor genes?

Answer 3

The common feature is their role in reducing cancer risk, despite their diverse mechanisms of action.

Question 4

What signals can tumor suppressor genes respond to?

Answer 4

Some respond to growth-inhibitory and differentiation-inducing signals.

Question 5

How do some tumor suppressor genes respond to cellular conditions?

Answer 5

They respond to metabolic imbalances and genomic damage to inhibit proliferation.

Question 6

Which two tumor suppressor genes are most commonly studied?

Answer 6

Rb (retinoblastoma gene) and p53 (also known as TP53 or Trp53).

Question 7

What is the function of the Rb gene?

Answer 7

The Rb gene governs the progress of cells through their growth-and-division cycles.

Question 8

Why is the Rb circuit significant in cancer?

Answer 8

Growth control via the Rb circuit is disrupted in most, if not all, human tumors.

Question 9

Why is p53 important in cancer?

Answer 9

The p53 gene and its product play a central role in preventing cancer by regulating the cell death program.

Question 10

What tumor suppressor genes are part of the Rb and p53 pathways?

Answer 10

Genes such as p16INK4A, p15INK4B, and p19ARF are part of these pathways.

Question 11

Why is the Rb and p53 pathway disruption critical for cancer development?

Answer 11

These pathways control key aspects of cell cycle regulation and apoptosis, which, when disrupted, lead to uncontrolled proliferation.

Question 12

What role do other tumor suppressor genes play besides Rb and p53?

Answer 12

They send their gene products to various intracellular sites to suppress cell proliferation.

Question 13

How do tumor suppressor proteins affect cell proliferation and survival?

Answer 13

They interact with and control various circuits responsible for regulating cell growth and survival.

Question 14

What challenges are faced in studying tumor suppressor genes?

Answer 14

The biochemical and biological actions of many tumor suppressor proteins are difficult to determine.

Question 15

Why are examples of tumor suppressor gene mechanisms valuable?

Answer 15

They demonstrate the diverse ways cells prevent uncontrolled proliferation and the complexity of these mechanisms.

Question 16

What is the significance of understanding the mechanisms of tumor suppressor genes?

Answer 16

It reveals how cells maintain control over proliferation and how disruptions can lead to cancer.

Question 17

How well are the actions of tumor suppressor genes understood?

Answer 17

While some are well understood, others remain obscure or only partially elucidated.

Question 18

Why are p16INK4A, p15INK4B, and p19ARF significant?

Answer 18

They are important components of the Rb and p53 regulatory pathways, which are critical for controlling cell cycle progression and apoptosis.

Question 19

What do tumor suppressor gene examples illustrate?

Answer 19

They highlight the diversity of cellular strategies to prevent excessive cell proliferation and the complexity of cancer suppression mechanisms.