Overview of Cancer and Treatments and Therapies - CHEMOTHERAPY

Chemotherapeutic drugs are designed to target where?

various aspects of all the cell cycle

What does Chemotherapeutic drugs mainly affect?

mitosis, but some target S-phase processes, while others directly damage DNA

What do Chemotherapeutic drugs do not specifically recognize what?

neoplastic cells (what cancer is/isn't)

Majority of cells in many tissues are non-cycling, so cancer cells in these tissues are favorably targeted why?

to their HIGH rate of mitosis

What tissues what have high turnover?

GI tract, hair follicles, and germ cells

What is essential for producing healthy daughter cells?

mitosis

What are the 5 distinct phases of mitosis?

1. Prophase

2. Metaphase

3. Anaphase

4. Telophase

5. Cytogenesis

What are mitotic inhibitors?

Drugs that kill cells as the process of mitosis begins

What are the 2 mitotic inhibitors?

1. Vinca Alkaloids

2. Taxanes

Vinca Alkaloids (mitotic inhibitor)

microtubule destabilizers and inhibit their growth

- binds to free tubulin dimers, preventing them from being incorporated into microtubule polymers

- NO GROWTH

What are examples of Vinca Alkaloids?

vincristine and vinblastine

What are Vinca Alkaloids used to treat?

breast cancers, lung cancer, myelomas, lymphomas, and leukemias

Taxanes (mitotic inhibitor)

microtubule stablizers

- bind to the cap on the plus end of the microtubule and prevent GTP to GDP conversion, INHIBITING the shrinkage of the microtubule

- NO SHRINK

What are examples of taxanes?

Paclitaxel and Docetaxel

Anti-Metabolites

1. Methotrexate

2. Fluorouracil

Methotrexate (Anti-Metabolites)

analogue of folic acid

What does Methotrexate inhibit?

DHFR

When methotrexate inhibits DHFR, what does this mean?

no synthesis of thymidine

Fluorouracil - 5-FU (Anti-Metabolites)

prevents the synthesis of thymidine

What are Anti-Metabolites commonly used to treat?

leukemias, breast, overian, and GI cancers

Why do both Anti-Metabolite drugs result in Thymineless death of cells?

its due to the absence of dTTPs and inability to replicate DNA

What does DNA Damaging agents have?

cytotoxic activity

DNA Damaging agents cytotoxic activity is due to what?

the induction of DNA damage

What are 3 examples of DNA Damaging agents?

1. Doxorubicin

2. Dactinomycin (actinomycin D)

3. Alkylating Agents

Doxorubicin (DNA Damaging Agents)

induces free radical species

Dactinomycin (DNA Damaging Agents)

intercalates into the minor groove of the DNA double helix structure

Alklaying Agents (DNA Damaging Agents)

can also be used to induce DNA damage

- Streptozocin

- Busulfan