Which of the following is characteristic of cytotoxic antibiotics?

Cytotoxic antibiotics are a class of chemotherapy drugs that have a key characteristic of inhibiting DNA and RNA synthesis. These agents, which include drugs like doxorubicin and bleomycin, work by intercalating into the DNA strands or through direct interaction with the enzymes involved in DNA replication and transcription. This ability disrupts the normal functioning of DNA and RNA, ultimately leading to cell death, particularly in rapidly dividing cancer cells.

The design of cytotoxic antibiotics isn't limited by the specific types of cancer, nor do they operate solely in particular phases of the cell cycle, which differentiates them from other classes of chemotherapy that target specific cell cycle phases. They do not function as oncogene inhibitors either, as their primary mechanism revolves around affecting nucleic acids rather than inhibiting oncogenic pathways directly. Thus, the ability of cytotoxic antibiotics to hinder DNA and RNA synthesis is a defining trait that illustrates their mechanism of action in combating cancer.