Vinblastin and vincristin inhibit growth of cancer cells by

Options

A. Inducing contact inhibition
B. Arresting cell division through inhibition of spindle formation
C. Suppression of oncogenes
D. Activating protooncogenes

Answer

**Step-by-Step Solution:**

1. **Identify the Compounds**: Vinblastine and vincristine are alkaloids derived from the plant Catharanthus roseus. They are known for their effectiveness in treating cancer.

2. **Mechanism of Action**: These compounds inhibit the growth of cancer cells primarily by interfering with cell division. They specifically target the process of mitosis, which is crucial for cell division.

3. **Role of Spindle Formation**: During mitosis, spindle fibers are essential for separating chromosomes. Vinblastine and vincristine inhibit the formation of these spindle fibers, which prevents the cancer cells from successfully dividing.

4. **Conclusion**: By arresting cell division through the inhibition of spindle formation, vinblastine and vincristine effectively stop the abnormal growth of cancer cells.

5. **Correct Option**: Among the given options, the correct one is "arresting cell division through inhibition of spindle formation."

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