Active immunization against LHRH alone or combined with LHRH-analogue treatment impedes growth of androgen-dependent prostatic carcinoma.
OBJECTIVE
To determine whether active immunization against LHRH can serve as treatment for androgen-dependent prostatic carcinoma.


METHODS
Male rats of Copenhagen X Fisher strain, implanted with Dunning R-3327 prostatic carcinoma cells were either immunized against LHRH, treated with LHRH-antagonist, or received a combined treatment of active immunization against LHRH and LHRH-antagonist.


RESULTS
Testicular histology was consistent with infertility in all treatment groups. The rate of tumor growth was inhibited by all three treatment regimens. Tumor size increased by 3.8 +/- 1.4 cm2 in the LHRH-antagonist group, 3.2 +/- 1.1 cm2 in the immunized group, and 1.0 +/- 0.4 cm2 in the combined treatment group, as compared to 8.2 +/- 2.6 cm2 in non-treated control group.


CONCLUSIONS
LHRH-antagonist administration combined with immunization against LHRH appeared to exert a synergistic effect. This may be due to the blockade of prostatic LHRH-like receptors by the antagonist, while androgen depletion was rapidly achieved by LHRH-antagonist, and maintained by continued gonadotropin suppression caused by active immunization against LHRH once antagonist treatment had been discontinued.
Ladd
A
A
Population Council, Center for Biomedical Research, New York, New York, USA.
Walfield
A
A
Tsong
Y Y
YY
Thau
R
R
D000726:Androgen Antagonists / Q000627:therapeutic use; D000728:Androgens / Q000502:physiology*; D000818:Animals; D000906:Antibodies / Q000097:blood; D002277:Carcinoma / Q000276:immunology / Q000473:pathology / Q000628:therapy*; D002455:Cell Division / Q000187:drug effects; D004359:Drug Therapy, Combination; D007987:Gonadotropin-Releasing Hormone / Q000031:analogs & derivatives / Q000276:immunology* / Q000627:therapeutic use; D007110:Immunity, Active; D007167:Immunotherapy / Q000379:methods; D000922:Immunotoxins / Q000627:therapeutic use; D008297:Male; D009929:Organ Size / Q000187:drug effects; D011471:Prostatic Neoplasms / Q000276:immunology / Q000473:pathology / Q000628:therapy*; D051381:Rats; D013737:Testis / Q000187:drug effects; D013739:Testosterone / Q000097:blood; D013745:Tetanus Toxoid / Q000627:therapeutic use
D000726:Androgen Antagonists; D000728:Androgens; D000906:Antibodies; D000922:Immunotoxins; D013745:Tetanus Toxoid; D007987:Gonadotropin-Releasing Hormone; D013739:Testosterone