Cancer Chemotherapy Flashcards Preview

MD2002 > Cancer Chemotherapy > Flashcards

Flashcards in Cancer Chemotherapy Deck (26):
1

Give three examples of how cancer can arise.

Genetic predisposition
(Ionising) radiation
Chemical carcinogens

2

Name the three approaches a consultant will consider regarding cancer treatment.

Surgical excision
Radiotherapy
Chemotherapy

3

List the three major differences that exist in cancer cells by comparison to normal body cells.

Uncontrolled proliferation
Invasiveness
Metastasis

4

Name the four type of (traditional) chemotherapy agent.

Alkylating Agent
Antimetabolites
Cytotoxic Antibodies
Plant Derivatives

5

Outline the primary way in which alkylating agents work.

INTRASTRAND CROSS LINKING OF DNA

6

How does intrastrand cross linking of DNA prevent cancer cell division

The drug binds to two places on the cancer cell's DNA, inhibiting cell division and cell proliferation

7

Where specifically on DNA does the drug bind to?

To the 7 nitrogen of guanine residues and alkylates them

8

What effect does alkylating the residues have and what does this lead to?

Makes them more acidic, leading to the formation of ENOL TAUTOMERS, allowing guanine to mis-pair with thymine residues during DNA synthesis, leading to DNA damage being recognised by apoptotic factors and apoptosis being initiated

9

What are the three major sub-groups of the alkylating agents?

Nitrogen Mustards
Nitrosoureas
Platinum Based Compounds

10

Name all the examples possible of the nitrogen mustards.

CYCLOPHOSPHAMIDE
Chlorambucil
Uramustine
Ifostamide
Melphalan
Bendumustine

11

What is cyclophosphamide activated by and where is it activated?

P450 mixed function oxidases
The liver

12

What is special about phosphoramide?

It is cytotoxic

13

What is the function of mesna?

Counteracts the effects of acrolein (propana)

14

Outline how nitrosoureas are used and what property they possess that makes them so appropriate for this task.

Nitrosoureas are lipophilic so can cross the blood-brain barrier, making them viable for use against tumours of the brain and the meninges

15

Name all the examples possible of the nitrosoureas.

LOMUSTINE
CARMUSTINE
Semustine
Ethylnitrosourea
Streptozocin

16

Outline how platinum based compounds act.

Cl- dissociates upon entry to cell allowing remaining reactive complex to react with water and interact with DNA causing intrastrand cross-linking between N7 & O6 of adjacent guanine molecules. This leads to local denaturation of DNA chain

17

What is the structure of cisplatin?

Central platinum atom surrounded by 2 chlorine atoms and 2 ammonia groups

18

List the three main groups of

Antifolates
Antipyramidines
Antipurines

19

Give examples of antifolates.

METHOTREXATE

20

Give examples of antipyramidines.

5-FU (fluorouracil)
GEMCITABINE

21

Give examples of antipurines.

MERCAPTOPURINE
THIOGUANINE
FLUDARABINE

22

Give an example of a platinum based compound.

CISPLATIN

23

How do antifolates such as methotrexate act?

Blocks the metabolism of folic acid via inhibition of the DHFR enzyme (similar structure to folic acid)

24

Describe the action of antipyramidines.

Interferes with DTMP (thymidylate synthesis) which is used in DNA synthesis during the S phase. Thymine is a DNA base of the nucleotide thymidylate so the blocking of the production of this inhibits DNA replication and thus cell proliferation

25

Which compound, similar in structure to a nucleotide, does gemcitabine have a similar structure to?

Cytaradine

26

What is the nucleotide that cytaradine is similar in structure to and how is it slightly different?

Cytosine - slightly different in that cytaradine has arabinose and not ribose attached