Tumor necrosis factor is dispensable for the success of immunogenic anticancer chemotherapy

The antineoplastic effects of anthracyclines have been shown to rely, at least in part, on a local immune response that involves dendritic cells (DCs) and several distinct subsets of T lymphocytes. Here, we show that the administration of anthracyclines to mice bearing established neoplasms stimulates the intratumoral secretion of tumor necrosis factor a (TNF α). However, blocking the TNF α/TNF receptor (TNFR) system by three different strategies-namely, (1) neutralizing antibodies, (2) etanercept, a recombinant protein in which TNFR is fused to the constant domain of an IgG₁ molecule, and (3) gene knockout-failed to negatively affect the therapeutic efficacy of anthracyclines in three distinct tumor models. In particular, TNF α-blocking strategies did not influence the antineoplastic effects of doxorubicin (a prototypic anthracycline) against MCA 205 fibrosarcomas growing in C57BL/6 mice, F244 sarcomas developing in 129/Sv hosts and H2N100 mammary carcinomas arising in BALB/c mice. These findings imply that, in contrast to other cytokines (such as interleukin-1β, interleukin-17 and interferon γ), TNFαis not required for anthracyclines to elicit therapeutic anticancer immune responses.