Anti cancer drugs Flashcards
Name two different anti-cancer drugs that has been derived from natural products and explain their mechanism of action.
Paclitaxel (Taxol): Paclitaxel is a chemotherapeutic drug derived from the bark of the Pacific yew tree. It is used to treat several types of cancer, including ovarian, breast, and lung cancers. Paclitaxel works by stabilizing microtubules, which are essential for the proper division of cells during mitosis. By stabilizing microtubules, paclitaxel prevents the proper separation of chromosomes during cell division, leading to cell death. Additionally, paclitaxel can also induce apoptosis (programmed cell death) in cancer cells.
Vinblastine: Vinblastine is another chemotherapeutic drug that is derived from the Madagascar periwinkle plant. It is used to treat various types of cancers, including Hodgkin’s lymphoma and testicular cancer. Vinblastine works by binding to tubulin, a protein that makes up microtubules, which are essential for cell division. By binding to tubulin, vinblastine prevents the formation of microtubules, leading to the disruption of the mitotic spindle and preventing the separation of chromosomes during cell division. As a result, the cancer cells cannot divide and eventually die.
There are several different groups of anti-cancer drugs used to treat tumors. Antimetabolites are a specific class of drugs used after initial diagnosis.
What is the mechanism of acrtion and in which cell phase do they act
They act in the S phase and can inhibit nucleotide synthesis, incorperate themselves as nucleotides causing faults and destruction or inhibit DNA polymerase.
a) What are these two main groups of mitosinhibitors called?
b) Explain how the drugs affects the balance between free tubulin heterodimers and microtubule? If you add another drug that promotes/enhances microtubule formation, is the drug effect enhanced or decreased for the two groups of mitosinhibitors?
c) When treating the cells with each type of mitosinhibitors what is the result of the inhibition on the cells?
a) The two main groups of mitosis inhibitors are microtubule-destabilizing agents and microtubule-stabilizing agents.
b) Microtubule-destabilizing agents, such as vinca alkaloids (e.g. vincristine, vinblastine) and colchicine, bind to the beta subunit of tubulin and prevent the formation of microtubules. This results in an increase in the concentration of free tubulin heterodimers in the cytoplasm, which are unable to polymerize into microtubules. As a consequence, the balance between free tubulin heterodimers and microtubules is shifted towards the former, leading to a disruption of the mitotic spindle and arrest of the cell cycle in the metaphase.
On the other hand, microtubule-stabilizing agents, such as taxanes (e.g. paclitaxel, docetaxel) and epothilones (e.g. ixabepilone), bind to the microtubules and stabilize them, preventing their depolymerization. This results in the accumulation of microtubules in the cell, which interferes with the normal dynamics of the mitotic spindle and leads to cell cycle arrest in the metaphase.
If another drug that promotes/enhances microtubule formation, such as the microtubule-stabilizing agent, is added to the cells treated with microtubule-destabilizing agents, the effect of the mitosinhibitors is decreased. This is because the microtubule-stabilizing agent counters the effect of the microtubule-destabilizing agent by promoting the formation of microtubules.
c) When cells are treated with mitosinhibitors, their cell division is inhibited, leading to cell cycle arrest in the metaphase. This can ultimately lead to apoptosis or cell death if the cells are unable to exit the mitotic phase and complete the cell division process. Mitosinhibitors are widely used in cancer therapy, as cancer cells divide more rapidly than normal cells and are therefore more sensitive to mitotic inhibitors. However, these drugs can also affect normal cells that divide rapidly, such as cells in the bone marrow, gastrointestinal tract, and hair follicles, leading to various side effects.
There are several different groups of anti-cancer drugs used to treat tumors. Anti-metabolites are a specific class of drugs used after initial diagnosis.
What is the mechanism of action of anti-metabolites, and in which phase of the cell cycle do the mainly exert their action? (3p)
They act in the S phase and can inhibit nucleotide synthesis, incorperate themselves as nucleotides causing faults and destruction or inhibit DNA polymerase.
There are several different types of class of groups of anti-cancer drugs used to treat tumors. They have both similarities and differences in their mechanisms of action. Below you will find several statements. Mark the statement/s that are true (none to all). The answer must be correct to get points (applies to each sub-question). (6p)
10:1 Anthracyclines
a) binds to DNA and inhibits DNA-synthesis
b) inhibits the topoisomerases and induce DNA-breaks
c) are mitosis inhibitors
d) inhibits the proteasome, creating unfavorable conditions
a) True - Anthracyclines are a class of anti-cancer drugs that bind to DNA and inhibit DNA synthesis. They can intercalate into the DNA double helix, leading to DNA damage and the inhibition of DNA replication.
b) True - Anthracyclines can also inhibit the action of topoisomerases, which are enzymes involved in DNA replication and repair. This leads to DNA breaks and further exacerbates the DNA damage caused by the drugs.
c) False - Anthracyclines are not mitosis inhibitors. They do not specifically target the process of mitosis but instead act by causing DNA damage and inhibiting DNA synthesis.
d) False - Anthracyclines do not inhibit the proteasome. The proteasome is a complex of enzymes involved in the degradation of cellular proteins, and its inhibition can create unfavorable conditions in cells. However, this is not a direct effect of anthracyclines.
Question 13
There are several different types of class of groups of anti-cancer drugs used to treat tumors. They have both similarities and differences in their mechanisms of action. Below you will find several statements. Mark the statement/s that are true (none to all). The answer must be correct to get points (applies to each sub-question).
10:4 PD-1 inhibitors
a) They inhibit the topoisomerases and induce DNA-breaks
b) They are usually antibodies
c) They are mitosis inhibitors
d) They reactivates T-cell mediated tumor cell killing
a) False - PD-1 inhibitors are not inhibitors of topoisomerases or inducers of DNA breaks. They are a type of immunotherapy that targets the PD-1 receptor on the surface of T cells.
b) True - PD-1 inhibitors are usually antibodies that bind to the PD-1 receptor and block its interaction with PD-L1, a ligand that is expressed on tumor cells. By blocking this interaction, PD-1 inhibitors can enhance T-cell function and reactivate T-cell-mediated tumor cell killing.
c) False - PD-1 inhibitors are not mitosis inhibitors. They do not directly target the process of cell division but instead enhance T-cell function and reactivate T-cell-mediated tumor cell killing.
d) True - By blocking the interaction between the PD-1 receptor and PD-L1, PD-1 inhibitors can enhance T-cell function and reactivate T-cell-mediated tumor cell killing. This makes them an important tool in the treatment of cancer, particularly in the setting of tumor-induced immune suppression.
There are several different types of class of groups of anti-cancer drugs used to treat tumors. They have both similarities and differences in their mechanisms of action. Below you will find several statements. Mark the statement/s that are true (none to all). The answer must be correct to get points (applies to each sub-question).
10:3 Vinca alkaloids
a) It binds to tubulin and inhibit depolymerization of microtubules
b) They are mitosis inhibitors
c) It binds to tubulin and inhibit polymerization of microtubules
d) They have the same pharmacodynamic target as tamoxifen
a) True - Vinca alkaloids are a class of anti-cancer drugs that bind to tubulin, a protein that makes up microtubules. They inhibit the depolymerization of microtubules, which are important components of the mitotic spindle that separate chromosomes during cell division. This leads to the inhibition of cell division and the induction of apoptosis in rapidly dividing cancer cells.
b) True - Vinca alkaloids are mitosis inhibitors. By binding to tubulin and inhibiting the depolymerization of microtubules, they interfere with the process of cell division and induce apoptosis in rapidly dividing cancer cells.
c) False - Vinca alkaloids do not inhibit the polymerization of microtubules. They bind to tubulin and inhibit the depolymerization of microtubules, which are important components of the mitotic spindle. This leads to the inhibition of cell division and the induction of apoptosis in rapidly dividing cancer cells.
d) False - Vinca alkaloids do not have the same pharmacodynamic target as tamoxifen. Tamoxifen is a selective estrogen receptor modulator that acts on the estrogen receptor, whereas vinca alkaloids bind to tubulin and inhibit the depolymerization of microtubules. The mechanism of action of these two classes of drugs is different, and they are used to treat different types of cancers.
