This review presents important information about the current state of the art for vaccine immunotherapy of prostate cancer. It includes important preclinical research for each of the important prostate cancer vaccines to have reached clinical trials. To date, the only prostate cancer vaccine that has completed Phase III trials and has been approved and licensed by the US FDA is Sipuleucel-T, which immunizes patients against the prostate-associated antigen prostatic acid phosphatase. The benefits and concerns associated with the vaccine are presented. A current Phase III trial is currently underway using the vaccinia-based prostate-specific antigen vaccine Prostvac-TRICOM. Other immunotherapeutic vaccines in trials include the Ad/prostate-specific antigen vaccine Ad5-prostate-specific antigen and the DNA/prostatic acid phosphatase vaccine. A cellular vaccine, GVAX, has been in clinical trials but has not seen continuous study. This review also delves into the multiple immune regulatory elements that must be overcome in order to obtain strong antitumor-associated antigen immune responses capable of effectively destroying prostate tumor cells.
"On the other hand, the PAP encoded DNA vaccine is currently undergoing clinical trials that aim to prevent and treat prostate cancer. Ten of twenty-two patients showed antigen-specific T cell proliferation and upregulation of CD8+INFγ (McNeel et al., 2009, Lubaroff, 2012). DNA vaccines encoding PAP are expected to be an effective way to prevent and treat prostate cancer. "
[Show abstract][Hide abstract] ABSTRACT: Prostate cancer is one of the most prevalent non-skin related cancers. It is the second leading cause of cancer deaths among males in most Western countries. If prostate cancer is diagnosed in its early stages, there is a higher probability that it will be completely cured. Prostatic acid phosphatase (PAP) is a non-specific phosphomonoesterase synthesized in prostate epithelial cells and its level proportionally increases with prostate cancer progression. PAP was the biochemical diagnostic mainstay for prostate cancer until the introduction of prostate-specific antigen (PSA) which improved the detection of early-stage prostate cancer and largely displaced PAP. Recently, however, there is a renewed interest in PAP because of its usefulness in prognosticating intermediate to high-risk prostate cancers and its success in the immunotherapy of prostate cancer. Although PAP is believed to be a key regulator of prostate cell growth, its exact role in normal prostate as well as detailed molecular mechanism of PAP regulation is still unclear. Here, many different aspects of PAP in prostate cancer are revisited and its emerging roles in other environment are discussed.
Biomolecules and Therapeutics 01/2013; 21(1):10-20. DOI:10.4062/biomolther.2012.095 · 1.73 Impact Factor
"Since sipuleucel-T (Provenge, Dendreon), an autologous cellular immunotherapy, was approved by the U.S. Food and Drug Administration (FDA), the significant effect of DC-based vaccines on overall survival in metastatic castration-resistant prostate cancer patients has attracted much attention despite a low rate of clinical response
[Show abstract][Hide abstract] ABSTRACT: High-grade gliomas including glioblastoma multiforme (GBM) are among the most malignant and aggressive of tumors, and have a very poor prognosis despite a temozolomide-based intensive treatment. Therefore, a novel therapeutic approach to controlling recurrence is needed. In the present study, we investigated the effect of activated dendritic cell (DC) (α-type-1 polarized DC)-based immunotherapy on high-grade glioma patients with the HLA-A2 or A24 genotype.
Nine patients with recurrent high-grade gliomas including 7 with GBMs who fulfilled eligibility criteria were enrolled into a phase I study of monocyte-derived DC-based immunotherapy. HLA-genotyping revealed 1 case of HLA-A*0201 and 8 cases of A*2402. Enriched monocytes obtained using OptiPrepTM from leukapheresis products on day1, were incubated with GM-CSF and IL-4 in a closed serum-free system, and activated on day6 with TNF-α, IL-1β, IFN-α, IFN-γ, and poly I/C. After pulsing with a cocktail of 5 synthetic peptides (WT-1, HER2, MAGE-A3, and MAGE-A1 or gp100) restricted to HLA-A2 or A24 and KLH, cells were cryopreserved until used. Thawed DCs were injected intradermally in the posterior neck at a dose per cohort of 1.0, 2.0 and 5.0× 107/body.
The frequency of CD14+ monocytes increased to 44.6% from 11.9% after gradient centrifugation. After a 7-day-incubation with cytokines, the mean percentage of DCs rated as lin-HLA-DR+ in patients was 56.2 ± 19.1%. Most DCs expressed high levels of maturation markers, co-stimulatory molecules and type-1 phenotype (CD11c+HLA-DR+) with a DC1/2 ratio of 35.6. The amount of IL-12 produced from activated DCs was 1025 ± 443 pg/ml per 105 cells. All 76 DC injections were well tolerated except for transient liver dysfunction with grade II. Six patients showed positive immunological responses to peptides in an ELISPOT assay, and positive skin tests to peptide-pulsed DC and KLH were recognized in 4 cases. The clinical response to DC injections was as follows :1 SD and 8 PD. Interestingly, the SD patient, given 24 DC injections, showed a long-term recurrence-free and immunological positive response period.
These results indicate peptide cocktail-treated activated α-type-1 DC-based immunotherapy to be a potential therapeutic tool against recurrent high-grade glioma with mainly HLA-A*2402.
Current non-randomized investigational trial UMIN-CTR UMIN ID: 000000914.
BMC Cancer 12/2012; 12(1):623. DOI:10.1186/1471-2407-12-623 · 3.36 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: This study demonstrates the ability to generate antigen-specific cytotoxic T cells (CTLs) against HER2 using a xenoantigenic immune stimulation strategy. Dendritic cells (DCs) were transduced with an adenovirus vector incorporating full-length cDNA for rat (xenoantigen) epidermal growth factor receptor 2 (Adv-HER2). Stimulation of autologous T cells with Adv-HER2 infected DCs led to enhanced HER2-specific reactivity as assessed by quantitative real-time polymerase chain reaction (qRT-PCR) for T cell IFN-γ mRNA. In ELISPOT and intracellular cytokine staining (ICS) assays, CD8+ CTLs induced by Adv-HER2 transduced DCs released IFN-γ following stimulation with irradiated autologous DCs infected with Adv-HER2 or loaded with a human prostate cancer cell line (LNCaP) lysate. DCs pulsed with HER2 peptides were less stimulatory than Adv-HER2 transduced DCs. HER2 DC induced CTL lysed HER2+ HLA-A2+ tumor cells (MCF-7); significantly reduced lysis occurred in HER2+ HLA-A2- tumor cells (SKOV-3), and the NK cell sensitive cell line K-562.
International Journal of Oncology 10/2011; 39(4):907-13. DOI:10.3892/ijo.2011.1124 · 3.03 Impact Factor
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