Combination immunotherapy of the P815 murine mastocytoma with killer cells, IL-2 and anti-estrogens.
BACKGROUND
Lymphokine activated killer (LAK) cells, cytotoxic T lymphocytes (CTL) and interleukin-2 (IL-2) all are being tested in cancer immunotherapy with modest success. The anti-estrogenic drug, toremifene (T0), was found earlier to amplify cancer immunotherapy with killer cells in mice. Here T0 is examined in combination with CTL and IL-2 in immunotherapy experiments.


METHODS
The P815 mastocytoma of DBA/2 mice was treated with combinations of CTL, LAK cells and T0 and combinations of CTL, IL-2 and T0 along with control groups. Tumor growth rate and mortality has been recorded.


RESULTS
Combined treatment with CTL and LAK cells cured 25% of tumor bearing animals, as did treatment with tamoxifen (TX) or T0 alone. When killer cells were given in conjunction with anti-estrogens the cure rate was 75% with both TX and T0. Human recombinant IL-2 significantly inhibited tumor growth but no cures occurred. CTL alone cured 25% of the animals. When CTL and IL-2 treatment was given jointly with T0 75% of tumor bearing animals were cured.


CONCLUSIONS
The results indicate that treatment with anti-estrogens increased the efficiency of immunotherapy by killer cells. This was true also when CTL therapy was supplemented with IL-2 treatment.
Baral
E
E
Manitoba Cancer Treatment and Research Foundation, University of Manitoba, Winnipeg, Canada.
Nagy
E
E
Kangas
L
L
Berczi
I
I
D000818:Animals; D018931:Antineoplastic Agents, Hormonal / Q000627:therapeutic use; D003131:Combined Modality Therapy; D003602:Cytotoxicity, Immunologic; D004965:Estrogen Antagonists / Q000627:therapeutic use*; D005260:Female; D006801:Humans; D007111:Immunity, Cellular; D007167:Immunotherapy; D007376:Interleukin-2 / Q000627:therapeutic use*; D015979:Killer Cells, Lymphokine-Activated / Q000276:immunology; D012515:Mast-Cell Sarcoma / Q000188:drug therapy / Q000628:therapy*; D051379:Mice; D008811:Mice, Inbred DBA; D012513:Sarcoma, Experimental / Q000188:drug therapy / Q000628:therapy; D013602:T-Lymphocytes, Cytotoxic / Q000276:immunology; D013629:Tamoxifen / Q000627:therapeutic use*; D017312:Toremifene / Q000627:therapeutic use*
D018931:Antineoplastic Agents, Hormonal; D004965:Estrogen Antagonists; D007376:Interleukin-2; D013629:Tamoxifen; D017312:Toremifene