Anticancer I Flashcards

(57 cards)

1
Q

What are the 7 classes of anticancer agents?

A
Alkylating agents
Antimetabolite and nucleoside analogs
Antitumor antibiotics
Antimitotic agents
Miscellaneous antineoplastics
Hormonal therapy
Combination therapy
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

What are the different alkylating agents?

A
Nitrogen mustards
Phosphoamide mustards
Nitrosoureas
Platins
Other alkylating agents
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

What is the main MOA of alkylating agents?

A

React with DNA, preferentially alkylating the N-7 position of guanine (most common)
Bifunctional alkylating agents product inter- or intra-strand crosslinks preventing DNA separation

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

What is the MOA of nitrogen mustards?

A

They activate the chloride

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

What are some nitrogen mustards?

A
Melphalan
Cyclophosphamide
Ifosfamide
Chlorambucil
Estramustine phosphate
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

What are some other alkylating anticancer agents?

A

Busulfan (Myleran)
Thiopeta
Procarbazine (Matulane)
Dacarbazine

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

What is the MOA of nitrosureas?

A

Urea NH is deprotonated and the negatively charged oxygen displaces chloride to give a cyclic oxazolidine, which fragments to give 2-chloroethylisocyanate and vinyl diazohydroxide, which decomposes to give electrophilic vinyl cation

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

What are some nitrosureas?

A

Carmustine (BiCNU)
Lomustine (CeeNU)
Streptozin (Zanosar)

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

What are some platins?

A

Cisplatin

Carboplatin

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

What is the MOA of antimetabolites?

A

They care closely related to cellular precursors and thus they prevent use or formation of normal cellular products.

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

What are the MOAs of pyrimidine-based antimetabolites?

A

Inhibition of kinases
Inhibition of enzymes involved in pyrimidine biosynthesis
Incorporation into RNA or DNA, causes misreading
Inhibition of DNA polymerase

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

What is the role of folate?

A

DNA synthesis
DNA repair
DNA methylation
Cofactor

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

What are the active forms of folate?

A

Tetrahydrofolate and dihydrofolate

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

What do dihydrofolate reductase (DHFR) inhibitors do?

A

They inhibit DHFR, which leads to:
Decreased levels of FH2 and FH4
Decreased conversion of dUMP into dTMP
Decreased DNA synthesis

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

What are some DHFR inhibitors?

A

Methotrexate
Pemetrexed (Alimta)
Pralatrexate (Folotyn)

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

What does pralatrexate do?

A

Inhibits enzymes used in purine and pyrimidine synthesis:
thymidylate synthase
dihydrofolate reductase
glycinamide ribonucleotide formyltransferase

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

What does folinic acid do?

A

Adjuvant used in cancer chemotherapy to “rescue” bone marrow and GI mucosa cells from methotrexate

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

What is 5-fluorouracil?

A

“Mechanism-based” prodrug that acts as a suicide substrate and directly inhibits the thymidylate synthase

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

What are the 3 main active metabolites of 5-fluorouracil?

A
Fluorodeoxyuridine monophosphate (FdUMP)
Fluorodeoxyuridine triphosphate (FdUTP)
Fluorouridine triphosphate (FUTP)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

What is the MOA of 5-FU (specifically, it’s active metabolite FdUMP)?

A

Direct inhibition of TS via the formation of a ternary complex in the nucleotide-binding site. This blocks dUMP from accessing the binding site.
This leads to an increase in dUTP, which causes DNA damage

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

What are some other pyrimidine-based antimetabolites?

A

Cytarabine (ARA-C)

Gemcitabine

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

What are some purine-based antimetabolites?

A

6-mercaptopurine
6-thioguanine
Fludarabbine phoshpate (Fludara)
Cladribine

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

What is the MOA of 6-mercaptopurine?

A

Blocks the synthesis of PRA and PRPP

24
Q

What are some antitumor antibiotics?

A
Bleomycins
Anthracyclines
Etoposide and teniposide
Camptothecins
Actinomycins
Mitomycins
25
What are bleomycins?
Cytotoxic glycopeptides
26
What is the MOA of bleomycins?
Chelates metail ions (Fe, Cu) producing a pseudo enzyme that reacts with oxygen to produce free radicals, causing DNA strand breaks
27
What is required for bleomycin DNA strand breaking? How is this achieved?
Reactivation and reorganization of bleomycin | The key to reorganization is the linker and the flexibility of the bithiazole tail
28
What are some topoisomerase poisons?
Amsacrine Etoposide Doxorubicin Mitoxantrone
29
What are the functions of DNA topoisomerase?
DNA replication DNA recombination Chromosome condensation/decondensation Segregation of sister chromatids
30
What do topoisomerase II poisons do?
Cause single and double strand DNA breaks Increase in topoisomerase II levels - renders cell hypersensitive (more enzyme, more DNA breaks) Stabilize topoisomerase II-DNA covalent complexes
31
What does topoisomerase II catalytic inhibitors do (...not do)?
Do not cause DNA strand breaks | Do not stabilize topoisomerase II-DNA cleavable complexes (and may destabilize them)
32
What is the MOA of anthracyclines?
intercalation followed by inhibition of topoisomerase II leading to DNA strand breakage and apoptosis Additional mechanism: generation of free radicals
33
What are the 5 clinically useful anthracyclines?
``` Doxorubicin Daunorubicin Epirubicin Idarubicin Valrubicin ```
34
What limits the use of doxorubicin?
Cardiotoxicity; doxorubicin is a quinone and can be reduced to a semiquinone. The semiquinone reacts with oxygen to reform the quinone (redox cycling) Doxorubicin also forms a strong complex with Fe3+, which can be reduced to Fe2+, which can form free radicals
35
What limits the use of etoposide?
Myelosuppression
36
What is the MOA of camptothecins?
Inhibitor of topoisomerase I (prevents realignment and resealing); leads to double stranded DNA breaks and cell death
37
What is increases the water solubility of campothecins to create topotecan and Irinotecan?
Addition of basic amine side chains
38
What's the difference between topoisomerase I and II?
Top. I: single strand break | Top. II: double strand break
39
What are some antimitotic compounds?
Vinca alkaloids Taxanes Epothilones IXA
40
What are the two conjoined groups of vinca alkaloids?
``` Catharanthine moiety (indole, azonine, piperidine ring systms) Vindoline moiety (dihydroindole, cyclohexane, pyrrolidine, piperidine) ```
41
What is the MOA of vinca alkaloids?
Disrupt formation of mitotic spindles, inhibiting microtubule assembly
42
What are some vinca alkaloids?
Vinblastine Vincristine Vinorelbine
43
What is the MOA of taxenes?
They bind to tubular at a different site than vinca alkaloids This stabilizes microtubules and prevent depolymerization, blocking mitosis
44
What are some taxanes?
Paclitaxel (Taxol) | Docetaxel (Taxotere)
45
What does vinblastine bind to the microtubule? What does paclitaxel bind?
Vinblastine binds to the plus end | Paclitexel binds on the interior surface
46
What are epothilones?
They are macrocyclic lactones that have a MOA similar to taxanes but offer several advantages (don't require Cremophor EL for water solubility)
47
What is IXA used for?
Taxane-resistant breast cancer
48
What growth factors do we often target with several drugs and monoclonal antibodies to control overgrowth of cells/tissues?
``` Epidermal GF Platelet-derived GF Nerve GF Vascular endothelial GF Stem cell F ```
49
What is the MOA of protein tyrosine kinase inhibitors
Kinase inhibitors mimic ATP to inhibit tyrosine kinases
50
What is the first protein tyrosine kinase inhibitor on the market?
Imatinib (Gleevec) for chronic myelogenous leukemia
51
What are other protein tyrosine kinase inhibitors?
Nilotinib Dasatinib Bosutinib Ponatinib
52
How do type I kinase inhibitors bind?
They bind to the active conformation of the kinase with the aspartate residue and the DFG motif pointing into the ATP-binding pocket
53
How do the type II kinase inhibitors bind?
They bind and stabilize the inactive conformation of the kinase with the flipped aspartate residue facing outward of the binding pocket
54
What are the limitations of kinase inhibitors?
Cardiotoxicity (CHF, decreased ejection fraction, ischemia, infarction)
55
What are some anticancer monoclonal antibodies?
``` Bevacizumab Cetuximab Ipilimumab Nivolumab Ofatumumab Paitumumab Rituximab ```
56
What is the MOA of Bortezomib?
Inhibits proteosomes
57
What is the MOA of dactinomycin?
Binds to DNA by intercalation, inhibiting DNA function