Vaccine against LH-releasing fusion protein does not increase prostate cancer.

2004 SEP 1 - (NewsRx.com & NewsRx.net) -- Immunization against luteinizing hormone (LH)-releasing fusion proteins does not increase prostate cancer in the transgenic adenocarcinoma mouse prostate model.

"This study was undertaken to test the effect of immunization against luteinizing hormone-releasing hormone (LHRH) fusion proteins on the development and progression of prostate cancer in the transgenic adenocarcinoma mouse prostate (TRAMP) model. Two LHRH fusion proteins, ovalbumin with seven LHRH peptides (OV-LHRH-7), and thioredoxin with seven LHRH peptides (TH-LHRH-7) were used in a cocktail vaccine. Two groups of male TRAMP mice were immunized with the cocktail. Primary immunizations were at either 4 or 8 weeks of age," scientists in the United States report.

"LHRH immunized mice (n=19) were compared with castrated (n=19) and intact mice (n=18) for testosterone concentration, tumor weight, and lifespan," said Richard E. Hill and collaborators at Washington State University and Baylor College of Medicine. "Immunization against LHRH in the TRAMP mice resulted in significant production of antibodies to LHRH compared with surgically castrated and intact control mice. Testicular weight was significantly reduced in the LHRH immunized groups compared with intact control mice. Serum testosterone was reduced (p <0.05) in the immunized mice compared with intact control mice and was not different from that of castrated mice (p>0.05)."

"Tumor weight was variable and inconsistent throughout all treatment groups," reported Hill and his colleagues. "Lifespan was not increased by immunization against LHRH or castration. Intact control mice (lived the longest (227[+ or -]11 days), whereas immunized mice lived 206[+ or -]11 days and castrated mice lived 213[+ or -]13 days. Tumors from immunized ...