Mechanism of action of paclitaxel is:
**Core Concept**
Paclitaxel is a chemotherapeutic agent used to treat various cancers, including ovarian, breast, and lung cancer. Its mechanism of action involves stabilizing microtubules and interfering with cell division.
**Why the Correct Answer is Right**
Paclitaxel binds to the beta-subunit of tubulin, preventing the dissociation of tubulin dimers. This results in the formation of stable microtubules, which inhibits the normal dynamic cycle of microtubule assembly and disassembly. As a consequence, the cell is unable to progress through the G2/M phase of the cell cycle, leading to cell cycle arrest and apoptosis. The stabilization of microtubules also prevents the separation of chromosomes during mitosis, ultimately resulting in cell death.
**Why Each Wrong Option is Incorrect**
**Option A:** This option is incorrect because paclitaxel does not work by inhibiting topoisomerase enzymes, which are targeted by other chemotherapeutic agents such as doxorubicin.
**Option B:** This option is incorrect because paclitaxel does not work by inducing DNA damage, which is a mechanism of action of agents such as cisplatin.
**Option C:** This option is incorrect because paclitaxel does not work by inhibiting protein synthesis, which is a mechanism of action of agents such as doxorubicin.
**Clinical Pearl / High-Yield Fact**
Paclitaxel is a taxane, a class of diterpenes derived from the bark of the Pacific yew tree (Taxus brevifolia). This fact is useful to remember when considering the pharmacological properties of paclitaxel.
**Correct Answer:** C. Stabilization of microtubules.