Question

Which of the following anticancer drugs are competitive inhibitors of tyrosine kinase ?

• A. Imatinib and sunitinib
• B. Letrozole
• C. Bicalutamide
• D. Fulvestrant

Answer 1

The Correct Option is A

In pharmacology, tyrosine kinase inhibitors are a type of anticancer drug that specifically target cancer cells by inhibiting the enzyme tyrosine kinase, which plays a crucial role in signaling pathways for cell division and survival. Competitive inhibitors bind to the active site of the enzyme, competing with the natural substrate and effectively blocking the enzyme's activity.

The question asks which of the given options are competitive inhibitors of tyrosine kinase. Let's evaluate each:

• Imatinib and sunitinib: These drugs are well-known competitive inhibitors of tyrosine kinase. They work by binding to the kinase active sites and are used in cancer treatments, particularly for chronic myeloid leukemia and renal cell carcinoma, respectively.
• Letrozole: This is an aromatase inhibitor, not a tyrosine kinase inhibitor, used primarily in the treatment of breast cancer by reducing estrogen levels.
• Bicalutamide: This is a non-steroidal anti-androgen used in the treatment of prostate cancer, which works by blocking the action of androgens and does not involve tyrosine kinase inhibition.
• Fulvestrant: This is an estrogen receptor antagonist used in hormone receptor-positive metastatic breast cancer and does not inhibit tyrosine kinase either.

From the analysis above, the correct choice is Imatinib and sunitinib as they are the only options that competitively inhibit tyrosine kinase activity in cancer cells.