Prostate stem cell antigen (PSCA) has been considered a potentially worthwhile target for prostate cancer therapy with its overexpression in both androgen-dependent and androgen-independent prostate cancers.
However, PSCA is an autoantigen that can evoke immunological tolerance and hardly incite effective immunologic response. In this study, we sought to construct the fusion protein vaccines based on PSCA and heat shock protein 70 (HSP70) and to evaluate their immune responses and therapeutic efficacy. A series of recombinant proteins were prepared, and then, the male C57BL/6 mice were immunized subcutaneously by inoculation with RM-PSCA/Luc cells. The PSCA-specific cellular immune responses were monitored with ELISPOT and intracellular cytokines staining assay, and ELISA assay was used to detect humoral immune responses. The tumor growth was observed by in vivo bioluminescence imaging. The results showed that the mice vaccinated with PSCA-HSP could induce the PSCA-specific cellular and humoral immune responses. Tumor progression could be quantitatively monitored by in vivo bioluminescence imaging. Animal experiments showed that PSCA-HSP could inhibit the growth of PSCA-expressing tumors and prolong the survival time of vaccinated mice. This study supported and confirmed the potential of HSP70 as a chaperone for protein vaccines, and PSCA-HSP could be of potential value for prostate cancer treatment.
Written by:
Dong L, Zhang X, Ren J, Wu S, Yu T, Hou L, Fu L, Yi S, Yu C. Are you the author?
Clinical Laboratory Center, PLA Air Force General Hospital, Beijing, China.
Reference: Cancer Biother Radiopharm. 2013 Jun;28(5):391-7.
doi: 10.1089/cbr.2012.1357
PubMed Abstract
PMID: 23701419
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