What is the mechanism of action of alkylating agents?

Alkylating agents are a class of chemotherapy drugs that function by damaging the DNA of cancer cells. Their primary mechanism of action involves the addition of alkyl groups to the DNA molecule, which leads to cross-linking of DNA strands. This cross-linking prevents the DNA from unwinding and replicating, thereby hindering the cancer cells' ability to divide and grow.

When alkylating agents bind to DNA, they create lesions that can result in errors during DNA replication or trigger cellular mechanisms that lead to programmed cell death, or apoptosis. Because cancer cells typically divide more rapidly than normal cells, they are particularly susceptible to the effects of alkylating agents, which makes these drugs effective in treating a variety of cancers.

The other options describe different mechanisms that do not apply to alkylating agents. For example, blocking protein synthesis pertains more to antimetabolite drugs, while inhibiting new blood vessel formation relates to anti-angiogenic agents. Stimulating the immune system to attack cancer cells is characteristic of immunotherapy strategies, which also do not align with the action of alkylating agents. Thus, the focus on DNA damage and prevention of cell division is central to understanding how alkylating agents work in oncology.