Prime–boost vaccination with plasmid and adenovirus gene vaccines control HER2/neu(+ )metastatic breast cancer in mice

INTRODUCTION: Once metastasis has occurred, the possibility of completely curing breast cancer is unlikely, particularly for the 30 to 40% of cancers overexpressing the gene for HER2/neu. A vaccine targeting p185, the protein product of the HER2/neu gene, could have therapeutic application by controlling the growth and metastasis of highly aggressive HER2/neu(+ )cells. The purpose of this study was to determine the effectiveness of two gene vaccines targeting HER2/neu in preventive and therapeutic tumor models. METHODS: The mouse breast cancer cell line A2L2, which expresses the gene for rat HER2/neu and hence p185, was injected into the mammary fat pad of mice as a model of solid tumor growth or was injected intravenously as a model of lung metastasis. SINCP-neu, a plasmid containing Sindbis virus genes and the gene for rat HER2/neu, and Adeno-neu, an E1,E2a-deleted adenovirus also containing the gene for rat HER2/neu, were tested as preventive and therapeutic vaccines. RESULTS: Vaccination with SINCP-neu or Adeno-neu before tumor challenge with A2L2 cells significantly inhibited the growth of the cells injected into the mammary fat or intravenously. Vaccination 2 days after tumor challenge with either vaccine was ineffective in both tumor models. However, therapeutic vaccination in a prime–boost protocol with SINCP-neu followed by Adeno-neu significantly prolonged the overall survival rate of mice injected intravenously with the tumor cells. Naive mice vaccinated using the same prime–boost protocol demonstrated a strong serum immunoglobulin G response and p185-specific cellular immunity, as shown by the results of ELISPOT (enzyme-linked immunospot) analysis for IFNγ. CONCLUSION: We report herein that vaccination of mice with a plasmid gene vaccine and an adenovirus gene vaccine, each containing the gene for HER2/neu, prevented growth of a HER2/neu-expressing breast cancer cell line injected into the mammary fat pad or intravenously. Sequential administration of the vaccines in a prime–boost protocol was therapeutically effective when tumor cells were injected intravenously before the vaccination. The vaccines induced high levels of both cellular and humoral immunity as determined by in vitro assessment. These findings indicate that clinical evaluation of these vaccines, particularly when used sequentially in a prime–boost protocol, is justified

IFNγ ELISPOT analysis of spleen cells from mice vaccinated with SINCP (prime) and Adeno (boost)

<p><b>Copyright information:</b></p><p>Taken from "Prime–boost vaccination with plasmid and adenovirus gene vaccines control HER2/metastatic breast cancer in mice"</p><p>Breast Cancer Research 2005;7(5):R580-R588.</p><p>Published online 23 May 2005</p><p>PMCID:PMC1242122.</p><p>Copyright © 2005 Wang et al.; licensee BioMed Central Ltd.</p> Naive mice were vaccinated with SINCP-(a plasmid containing Sindbis virus genes and the gene for rat HER2/) and then twice, at 2-week intervals, with Adeno-(an E1,E2a-deleted adenovirus also containing the gene for rat HER2/). Spleen cells were collected 2 weeks after the second Adeno vaccination and were cultured overnight with 5 μg/ml concanavalin A, without stimulation, or with A2L2 cells at three different effector:stimulator ratios. The number of IFNγ-secreting cells was determined using a commercial ELISPOT procedure and antibody pair. Horizontal bars indicate means. IFNγ, interferon γ

Age-Dependent Pancreatic Gene Regulation Reveals Mechanisms Governing Human β Cell Function

Intensive efforts are focused on identifying regulators of human pancreatic islet cell growth and maturation to accelerate development of therapies for diabetes. After birth, islet cell growth and function are dynamically regulated; however establishing these age-dependent changes in humans has been challenging. Here we describe a multimodal strategy for isolating pancreatic endocrine and exocrine cells from children and adults to identify age-dependent gene expression and chromatin changes on a genomic scale. These profiles revealed distinct proliferative and functional states of islet α-cells or β-cells, and histone modifications underlying age-dependent gene expression changes. Expression of SIX2 and SIX3, transcription factors without prior known functions in the pancreas and linked to fasting hyperglycemia risk, increased with age specifically in human islet β-cells. SIX2 and SIX3 were sufficient to enhance insulin content or secretion in immature β-cells. Our work provides a unique resource to study human-specific regulators of islet cell maturation and function