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.

Effect of combined adoptive immunotherapy and radiotherapy on tumor growth.

Advanced squamous cell carcinomas of the head and neck are difficult to control despite optimal surgery, radiotherapy and/or chemotherapy, and the tumors are usually not immunogenic. Because of the anatomic accessibility of the tumors, local adoptive immunotherapy of these tumors is feasible and may interact with radiotherapy to retard tumor growth. It is hypothesized that antigens released from tumor cells injured by radiation may stimulate, in the presence of interleukin-2, an enhanced immunocytodestruction of live tumor cells by adoptively transferred lymphokine activated killer cells and recruited tumor cytotoxic cells.

Supplementation with selenium augments the functions of natural killer and lymphokine-activated killer cells.

This study examined the effects of dietary (2.0 ppm for 8 wk) and in vitro (1 x 10(-7)M) supplementation with selenium (Se, as sodium selenite) on the activity of spleen natural killer (NK) cells and plastic-adherent lymphokine-activated killer (A-LAK) cells from C57B1/6J male mice. Dietary supplementation with Se resulted in a significant increase in the lytic activity of activated NK cells, and cells from these highly lytic effector cell populations expressed significantly higher numbers of intermediate affinity interleukin-2 receptors (II-2R)/cell.

Supplementation with selenium restores age-related decline in immune cell function.

This study examined the effect of dietary (2.00 ppm for 8 weeks) supplementation with selenium (as sodium selenite) on the ability of lymphocytes from aged (24-month-old), male, C57BL/6JNIA mice to respond to: (i) stimulation with mitogen (phytohemagglutinin) or alloantigen; (ii) develop into cytotoxic effector cells; and (iii) destroy tumor cells. Supplementation with selenium resulted in a significant increase in the ability of spleen lymphocytes from aged animals to undergo blastogenesis, as indicated by significantly higher amounts of nuclear incorporation of 3H-thymidine after stimulation with mitogen.

Supplementation with selenium and human immune cell functions. II. Effect on cytotoxic lymphocytes and natural killer cells.

This study examined the effect of dietary (200 micrograms/d for 8 wk) supplementation with selenium (as sodium selenite) on the ability of human peripheral blood lymphocytes to respond to stimulation with alloantigen, develop into cytotoxic lymphocytes, and to destroy tumor cells, and on the activity of natural killer cells. The participants in the study were randomized for age, sex, weight, height, and nutritional habits and given selenite or placebo tablets; all participants had a selenium replete status as indicated by their plasma Se levels prior to supplementation. The data indicated that the supplementation regimen resulted in 118% increase in cytotoxic lymphocyte-mediated tumor cytotoxicity and 82.