Effect of active immunization against luteinizing hormone-releasing hormone on the androgen-sensitive Dunning R3327-PAP and androgen-independent Dunning R3327-AT2.1 prostate cancer sublines.
BACKGROUND
The objective of this study was to determine the effect of active immunization against LHRH on the growth characteristics and histology of subcutaneously implanted tumors of the androgen-sensitive Dunning R3327-PAP and androgen-independent R3327-AT2.1 rat prostate adenocarcinoma sublines.


RESULTS
We herein demonstrate that 1) active immunization with an LHRH-diphtheria toxoid-conjugate (LHRH-DT) leads to the downregulation of gonadotropins and testosterone and consequently the atrophy of testosterone-dependent organs such as the testes, prostate, and androgen-sensitive Dunning R3327-PAP tumors, 2) growth inhibition of Dunning R3327-PAP tumors is caused by suppression of cell division rather than by an increase in cell death and is associated with an increase of the tumor stroma content, and 3) volume increase of the androgen-independent Dunning R3327-AT2.1 tumor is slightly but significantly reduced, indicating a local stimulatory LHRH loop within this tumor cell line.
Fuerst
J
J
Department of Zoology, University of Salzburg, Austria.
Fiebiger
E
E
Jungwirth
A
A
Mack
D
D
Talwar
P G
PG
Frick
J
J
Rovan
E
E
D000704:Analysis of Variance; D000818:Animals; D019496:Cancer Vaccines; D002455:Cell Division; D002460:Cell Line; D002999:Clone Cells; D004167:Diphtheria Toxin; D005640:Follicle Stimulating Hormone / Q000097:blood; D007987:Gonadotropin-Releasing Hormone / Q000276:immunology*; D007167:Immunotherapy; D008297:Male; D011467:Prostate / Q000473:pathology; D011471:Prostatic Neoplasms / Q000097:blood / Q000276:immunology / Q000473:pathology / Q000628:therapy*; D051381:Rats; D011916:Rats, Inbred F344; D013737:Testis / Q000473:pathology; D013739:Testosterone / Q000097:blood / Q000502:physiology*; D014614:Vaccines, Synthetic
D019496:Cancer Vaccines; D004167:Diphtheria Toxin; D014614:Vaccines, Synthetic; D007987:Gonadotropin-Releasing Hormone; D013739:Testosterone; D005640:Follicle Stimulating Hormone