An antibiotic is a chemical made by a microbe that antagonizes the growth of other cells.  Most of the natural product antibiotics use in medicine come from the bacteria of the genus Streptomyces.  Can antibiotics be used to treat cancer?  By the traditional definition of antibiotic, no, but some chemotherapy drugs are often called antibiotics,

Usually antibiotic is used to refer to chemical compounds originally produced by fungi that are used to kill bacteria, or perhaps other fungi.  That’s why you see reports of antibiotics being discovered in soil, where fungi naturally occur.  The first antibiotic was penicillin, discovered in 1928.

Antitumor antibiotics are not the same as the ones used to fight bacterial infections.  These drugs were often originally discovered in soil, which is perhaps why they get the antibiotic label.  Antineoplastic antibiotics bind with DNA, causing these famously coiled molecules to uncoil, thereby preventing RNA synthesis, a key step in protein synthesis.   They also oxidize critical compounds the cells need.   In this they are like many chemotherapy medicines. The origins of the antibiotics are microorganisms (bacteria or fungi) but once they get discovered as effective drugs, their chemical structure is elucidated and they are made by chemical synthesis without biotechnology.

Antibiotics work throughout the cell cycle.  They are classified as cell cycle nonspecific.    Antibiotics are used against leukemia, bladder cancer, testicular cancer, and sarcomas.

See our page on anthracyclines for information on antibiotics in that class, including Doxorubicin, Daunorubicin, Epirubicin, Valrubicin, and Idarubicin.  Mitoxantrone, which this site classifies as a topoisomerase inhibitor, can also be considered an antibiotic.

Other antibiotics in use for cancer treatment include:

Actinomycin-D

Brand/Trade Names: Act-D, Cosmegen, Dactinomycin

Formula: C₆₂H₈₆N₁₂O₁₆

Manufacturers: Asia Pioneer Pharmaceuticals, Concord Biotech, SAFC, Zhejiang Hisun Pharmaceutical

Class: Polypeptide Antibiotic

Administration: Intravenous

Notes: First antibiotic used against cancer.  Approved by the FDA in 1964.  Used in treatment of many sarcomas and some carcinomas.  This is sometimes put in the classification chromomycin.  Another chromomycin, Plicamycin, was used to treat cancer in the past.

Bleomycin

Brand/Trade Names: Blenoxanen

Formula: C₅₅H₈₄N₁₇O₂₁S₃

Mechanism:

Class: Glycopeptide Antibiotic

Administration: Intravenous, subcutaneous, intramuscular

Notes:  Approved by the FDA in 1973.  Used in treatment of lymphoma, melanoma, sarcoma, ovarian cancer, and testicular cancer.

Mitomycin

Brand/Trade Names: Mutamycin, MTC

Formula: C₁₅H₁₈N₄O₅

Manufacturers: ChemWerth Inc, Concord Biotech, HUBEI HONCH PHARMACEUTICAL CO., Hanways Chempharm Co.

Class: Antibiotic

Administration: Intravenous

Notes: First discovered as a product of bacteria.  Approved by the FDA in 1974.  Used for treatment of stomach cancer and pancreas cancer.

Page on salinomycin.