Anticaner Therapy I

Question 0

What are the three cell proliferation checkpoints in the cell cycle?

Answer 0

1. Cell Growth Checkpoint, which occurs toward the end of the growth phase G1, indicating whether the cell can transition into the synthesis phase.
2. DNA Synthesis Checkpoint, which occurs during the S phase, which ensures DNA has been replicated correctly.
3. Mitosis Checkpoint, which checks whether mitosis is complete.

Question 1

What are the hallmarks of cancer?

Answer 1

1. Sustained angiogenesis
2. Self-sufficiency in growth signals
3. Insensitivity to antigrowth signals
4. Evasion of apoptosis
5. Limitless replicative potential
6. Tissue invasion and metastasis

Question 2

Describe the general features of apoptosis.

Answer 2

A highly organized process where the internal structures condense and the nucleus fragments. The plasma membrane blebs outward but stays intact and the cell breaks into apoptotic bodies. No inflammation occurs and it is triggered by pro-apoptotic stimuli, such as cytotoxic drugs.

Question 3

Describe the general features of necrosis.

Answer 3

Highly disorganized process of uncontrolled cell lysis, where there is complete plasma membrane disruption leading to the damage of neighbouring cells and an inflammatory response. Necrosis is triggered by cellular injury, such as blunt trauma or ischemia.

Question 4

What are some common toxicities of cytotoxic therapy?

Answer 4

1. Bone marrow suppression.
2. Gastrointestinal
3. Cardiotoxicity
4. Hair loss
5. Infertility
6. Secondary cancers

Question 5

What are the manifestations of bone marrow suppression as a result of cytotoxic therapy toxicity?

Answer 5

Neutropenia and thrombocytopenia.

Question 6

How is neutropenia treated?

Answer 6

Filgrastin, which stimulates bone marrow to produce more neutrophils.

Question 7

What are the three types of cytotoxic anticancer targets?

Answer 7

1. Inhibition of DNA synthesis & repair.
2. DNA damaging agents.
3. Inhibitors of microtubule function.

Question 8

What are the categories of DNA damaging agents?

Answer 8

1. Alkylating agents.
2. Platinums
3. Anthracyclines

Question 9

What are the categories of inhibitors of DNA synthesis and repair?

Answer 9

1. Topoisomerase Inhibitors

2. Antimetabolites

Question 10

What are the categories of inhibitors of microtubule function?

Answer 10

1. Taxanes

2. Vinca Alkaloids

Question 11

What is an example of a drug that is an alkylating agent?

Answer 11

Cyclophosphamide

Question 12

What is an example of a platinum compound?

Answer 12

Cisplatin

Question 13

What is an examples of an anthracycline?

Answer 13

Doxorubicin

Question 14

What are the effects of doxorubicin?

Answer 14

1. Reacts with molecular oxygen to produce free radicals that damage DNA (creates breaks).
2. Inhibits topoisomerase.
3. Intercalates between base pairs to inhibit DNA synthesis.

Question 15

What is an example of a topoisomerase inhibitor?

Answer 15

Etoposide

Question 16

What is the function of etoposide?

Answer 16

Etoposide stabilizes the topoisomerase enzyme after it induces a strand break, preventing the strand from rejoining and inhibiting DNA synthesis, leading to apoptosis.

Question 17

What is an antimetabolite drug that is an example of a folate analogue?

Answer 17

Methotrexate

Question 18

How does methotrexate work?

Answer 18

As a folate analogue, it inhibits dihydrofolate reductase, which depetes the cell of reduced folate needed for the production of purines and thymidine. This blocks synthesis of DNA, RNA and protein, which arrests the cell in the S phase and leads to apoptosis.

Question 19

What a pyrimidine analogue that is an example of an antimetabolite for cancer therapy?

Answer 19

5-Fluorouracil

Question 20

How does 5-Fluorouracil work?

Answer 20

Inhibits thymidylate synthase that depletes the cell of thymidine, blocking downstream DNA synthesis, arresting cell in S phase leading to apoptosis.

Question 21

What is an example of an antimitotic agent that is a taxane?

Answer 21

Paclitaxel

Question 22

How do taxanes function?

Answer 22

Taxanes, such as paclitaxel, bind microtubules in a way that stabilizes them in the polymerized state, inhibiting depolymerization which is necessary for cell division. This arrests the cell in mitosis and leads to apoptosis.

Question 23

How do vinca alkaloids function?

Answer 23

Vinca alkaloids bind cytoplasmic tubulin, which prevents microtubule polymerization, disrupting microtubule assembly necessary for cell division. The cell arrests in mitosis and apoptosis results.

Question 24

What is an example of a vinca alkaloid?

Answer 24

Vincristine

Question 25

How can the growth of cancer that are derived from hormone-responsive tissues be inhibited?

Answer 25

Inhibiting hormone production or using hormone antagonists.

Question 26

What is an example of an aromatase inhibitor?

Answer 26

Anastrozole

Question 27

What is an example of an anti-estrogen?

Answer 27

Tamoxifen

Question 28

What are the two types of hormone therapies?

Answer 28

1. Surgical Castration

2. Medical Castration

Question 29

What is the function of orchiectomy?

Answer 29

Removal of tests blocks testosterone production.

Question 30

What is the function of leutenizing hormone releasing hormone analogues?

Answer 30

Blocks testosterone production via the pituitary.

Question 31

What are two examples of LHRH analogues?

Answer 31

Goserelin and Leuprolide

Question 32

What is an example of an anti-androgen?

Answer 32

Flutamide

Question 33

What is the function of flutamide?

Answer 33

Blocks the action of testosterone in prostate cells.