In vitro studies on potentiation of cytotoxic effects of anticancer drugs by interferon on a human neoplastic cell line (HeLa)

Abstract

Experiments were performed to ascertain whether the antitumor effect of various anticancer drugs might be enhanced by interferon, using cultures of HeLa cells originating from a human carcinoma of the uterine cervix. The effects of drugs were assessed by counting cell colonies formed in culture. The drugs studied included 4 metabolic antagonists: cytosine arabinoside (Ara-C), 5-fluorouracil (5-FU), 6-mercaptopurine (6-MP) and methotrexate (MTX), 7 antibiotics: aclacinomycin (ACM), adriamycin (ADM), actinomycin D (ACD), cycloheximide, mitomycin C (MMC), peplomycin (PEP) and puromycin; 2 alkylating agents: nimustine hydrochloride (ACNU) and melphalan, and 3 other drugs, vincristine (VCR), cisplatin (CDDP) and hydroxyurea (HU). Interferon was a preparation of the β-type produced by human fibroblasts. A specific additive or synergistic potentiation of the cytotoxic effect by concomitant application of interferon was observed with PEP, ACNU, ACN, CDDP, 5-FU and ADM; the drug concentration given a 50% inhibition of cell growth was reduced by one-half or more in cultures with the combination of interferon and these drugs. The treatment of cells with interferon alone caused only 10–30% inhibition of cell proliferation.