Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

MD2002 > Cancer Chemotherapy > Flashcards

Cancer Chemotherapy Flashcards

1
Q

what are the 3 main approaches to dealing with established cancers?

A
  1. surgical excision
  2. radiotherapy
  3. chemotherapy
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

what are the 4 types of traditional agent?

A
  • alkylating agents
  • antimetabolites
  • cytotoxic antibiotics
  • plant derivatives
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

what are the major groups of alkylating agents?

A
  1. nitrogen mustards
  2. ethylemimines
  3. alkylsulphonates
  4. hydrazines and triazines
  5. nitrosoureas
  6. platinum based compounds
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

what is an example of a nitrogen mustard?

A

cyclophosphamide

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

what is an example of alkylsulphonates?

A

busulphan

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

what are features of busulphan?

A
  • has a selective effect on bone marrow, depressing formation of granulocytes and platelets in low dosage and red cells in higher dosage
  • little or no effect in lymphoid tissue or GIT
  • used in chronic granulocytic leukaemia
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

what type of cancer is busulphan used against?

A

chronic granulocytic leukaemia

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

what are examples of nitrosoureas?

A
  • lomustine

- carmustine

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

what are features of lomustine and carmustine?

A
  • lipid soluble
  • can cross blood-brain barrier
  • used against tumours of brain and meninges
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

what type of cancer are lomustine and carmustine used against?

A

tumours of brain and meninges

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

what is an example of a platinum based compound?

A

cisplatin

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

what are features of cisplatin?

A
  • water soluble, planar

- containing central platinum atom surrounded by 2 chlorine atoms and 2 ammonia groups

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

how does cisplatin work?

A
  • action analogous to alkylating agents: when enters cell Cl- dissociates leaving reactive complex that reacts with water and then interacts with DNA
  • it causes intrastrand cross-linking which results in local denaturation of DNA chain
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

what are the major groups of metabolites?

A
  1. antifolates
  2. antipyrimidines
  3. antipurines
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

what is an example of an antifolate?

A

methotrexate

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

what are features of methotrexate?

A
  • folate analogue
  • usually given orally, can be given IM, IV or intrathecally
  • low lipid solubility so does not cross blood-brain barrier easily
  • polyglutamated, can be retained within cells for weeks
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

what are some examples of antipyrimidines?

A
  • fluorouracil
  • cytarabine
  • gemcitabine
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

what are features of fluorouracil?

A
  • 5-FU
  • interferes with thymudylate synthesis (DTMP)
  • converted to fraudulent nucleotide FDUMP, cannot be converted into DTMP
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

what are features of cytarabine?

A
  • analogue of cytosine but has arabinose and not ribose attached
  • undergoes phosphorylation to give cytosine arabinoside triphosphate which inhibits DNA polymerase
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

what are features of gemcitabine?

A

an analogue of cytarabine

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

what are examples of antipurines?

A
  • mercaptopurine
  • thioguanine
  • fludarabine
22
Q

what are features of mercaptopurine?

A

converted to 6-mercaptopurine-ribose phosphate called “Lethal Synthesis”:

  • inhibits a number of enzymes in de novo synthesis of purines
  • fraudulent nucleotide
23
Q

what are features of fludarabine?

A

in triphosphate form inhibits DNA polymerase

24
Q

cytotoxic antibiotics

A
  • anti-tumour antibiotics

- produce their effects mainly by direct action on DNA

25
Q

what are examples of types of cytotoxic antibiotics?

A
  • anthracyclines
  • dactinomycin
  • bleomycin
  • mitomycin
26
Q

what is the main anti-cancer anthracycline antibiotic?

A

doxorubicin

27
Q

how does doxorubicin work?

A
  • binds to DNA and inhibits both DNA and RNA synthesis
  • main cytotoxic action appears mediated through an effect on topoisomerase II (whose activity markedly increases in proliferating cells)
28
Q

what are features of dactinomycin?

A
  • intercalates in minor groove of DNA between adjacent guanosine and cytosine pairs, interfering with movement of RNA polymerase along gene, thus preventing transcription
  • similar action anthracyclines on topoisomerase II
29
Q

what are features of bleomycins?

A
  • metal-chelating glycopeptide antibiotics that degrade preformed DNA, causing chain fragmentation
  • most effective in G2 phase and mitosis
30
Q

what are features of mitomycin?

A
  • after enzymic activation functions as bifunctional alkylating agent
  • cross-links DNA
  • may also degrade DNA through generation of free radicals
31
Q

what are examples of plant derivatives?

A
  • spindle poisons
  • vinca alkaloids
  • taxanes
  • camptothecins
  • etoposide
32
Q

what do spindle poisons do?

A

affect microtubule function and prevent mitotic spindle formation

33
Q

what are examples of vinca alkaloids?

A
  • vincristine

- vinblastine

34
Q

what do vinca alkaloids do?

A
  • bind tubulin

- prevent polymerisation into microtubules

35
Q

what are examples of taxanes?

A
  • paclitaxel (taxol)

- docetaxel

36
Q

what do taxanes do?

A

stabilise (freeze) microtubules

37
Q

what are examples of camptothecins?

A

irinotecan

38
Q

what do camptothecins do?

A

bind to and inhibit topoisomerase I

39
Q

what do etoposides do?

A

inhibits mitochondrial function, nucleoside transport and topoisomerase II

40
Q

what are the main drawbacks of current cancer chemotherapy?

A
  • target cell proliferation, not more lethal properties of invasiveness and metastasis
  • non-specific cell killers rather than being aimed at particular changes which make a cell malignant
  • development of resistance to anticancer drugs (esp. multidrug resistance)
  • some remaining cells (tumour stem), total elimination of malignant cells not possible using therapeutic doses, and host immune response often not adequate to deal with remainder
  • patient compliance due to side effects, not completing therapy regimen
41
Q

what are alternative approaches to cancer therapy?

A
  • kill or remove malignant cells
  • targeted cytotoxic agents
  • specifically inactivate components of oncogene signalling pathway
  • employ tissue-specific proliferation inhibitors
  • enhance host immune response
  • reverse drug resistance
  • antisense oligonucleotides
  • restore function of tumour suppressor genes
  • inhibit tumour growth, invasion, metastasis
  • inhibitors of anti-apoptotic factors
42
Q

what anticancer drugs are used for B cell lymphomas?

A

rituximab

- targets B cell surface protein

43
Q

what anticancer drug is used for breast cancer?

A

trastuzumab (herceptin)

- targets epidermal growth factor receptor

44
Q

what anticancer drug is used for chronic myeloid leukaemia?

A

imatinib (gleevec)

- inhibits bcr-abl gene signalling pathways

45
Q

what causes cancer?

A
  1. mutations in DNA resulting in production of altered cells which have changes in proliferating mechanisms
  2. changes in the DNA caused by covalent modification:
    - spontaneous or genetic predisposition
    - ionising radiation or UV radiation
    - chemical carcinogens
46
Q

what is replaced in the structure of the antimetabolite, fludaribine?

A
  • F replaces H of adenosine

- arabinose replaces ribose

47
Q

what is replaced in the structure of the antimetabolite, 5-FU?

A

F replaces H of uracil

48
Q

what is replaced in the structure of the antimetabolite, gemcitabine?

A

F replaces H and OH on ribose ring

49
Q

what is replaced in the structure of the antimetabolite, 6-mercaptopurine?

A

S substitute in purine

50
Q

when are bleomycins most effective in the cell cycle?

A

G2

MD2002 (85 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions