Effect of interleukin-2 and selenium on the growth of squamous cell carcinoma cells.

Objectives: The objectives of this study were to determine whether the expression of the interleukin-2 (IL-2) receptors on squamous cell carcinoma cells can be enhanced in the presence of selenium (Se) and contribute to a greater retardation of tumor growth after locoregional therapy with IL-2.

Study Design: The growth of the cells was studied after in vitro or dietary supplementation with Se in a murine model.

Results: Treatment of established tumors in hosts supplemented with Se with peritumoral injections of IL-2 resulted in 50% reduction of tumor size, whereas treatment of early tumors resulted in 72.4% reduction. The effect was most likely related to a combination of enhanced immune responsiveness and enhanced IL-2 receptor expression on the tumor cells.

Conclusions And Significance: The data suggested that local immunotherapy with IL-2 in hosts supplemented with Se may represent an effective modality of treatment for the prevention of recurrences at the site of conventionally treated primary tumors, including tumors that do not express IL-2 receptors.