L-BLP25 Vaccine plus Letrozole Induces a TH1 Immune Response and Has Additive Antitumor Activity in MUC1-Expressing Mammary Tumors in Mice

• DOI: 10.1158/1078-0432.ccr-12-0168
• Publication Date: 2012-03-22T16:06:56Z
• Authors: Neelima R. Mehta; Gregory T. Wurz; Rebekah A. Burich; Brittany E. Green...; Stephen Griffey; Audrey Gutierrez; Katie E. Bell; Jamie L. McCall; Michael Wolf; Michael DeGregorio
• Keywords: Letrozole; Antiestrogen

In this study, we examine the immunomodulatory effects and antitumor activity of tamoxifen letrozole when combined with human epithelial mucin (hMUC1)-specific vaccine, L-BLP25, in hMUC1-expressing mammary tumor (MMT) mouse model.Dose-finding studies were conducted for both letrozole. Letrozole L-BLP25 combination used 69 MMT female mice assigned to five groups: untreated, cyclophosphamide + placebo, 0.8 mg/kg, Tamoxifen 48 treatment 50 mg/kg group. Mice injected subcutaneously (10 μg) weekly 8 weeks. Serum cytokines serially measured using a Luminex assay, whereas splenocytes at termination analyzed by ELISpot determine T-helper (T(H))1/T(H)2 polarization immune response.Daily oral doses letrozole, respectively, resulted significant survival advantage over controls (P < 0.05). A predominant T(H)1-polarized response vaccinated was seen or without treatments. plus group, statistically 0.05) additive observed, not significantly different > 0.05).The results study show that hormonal therapy does interfere L-BLP25-induced T(H)1 response, has model.