Where are we now in Cancer Research?
Vaccination against cancer testis antigen (Sp17 in an OC mouse model) significantly controlled tumor growth.[1] The magnitude of antigen-specific IFN-γ-secreting cells, as measured by ELISpot, trended towards survival after the administration of a prostate-specific antigen vaccine in prostate cancer patients.[2] In ELISpot assays Targeting SHP2 against HNC cells could enhance T-cell-based cancer immunotherapy.[3] Addition of IFN-α significantly improved the frequency of p53-specific T cells in IFN-γ ELISpot assay.
In breast cancer, the release of cytokeratin-19 (CK19) and mucin-1 (MUC1) in single epithelial cancer cells are measured using ELISpot demonstrating that many patients harbored viable disseminated tumor cells, even in patients with apparently localized tumors.[5] Tumor specific effector T cells were detected in most patients with prostate cancer, especially those with castration resistant prostate cancer. Since effector T-cell responses against prostate specific antigens strongly increased after regulatory T-cell depletion, our results indicate that immunotherapy efficacy could be enhanced by decreasing regulatory T cells.[6]
ELISpot (Cancer) Reference:
[1] Chiriva IM, et al., Cancer testis antigen vaccination affords long-term protection in a murine model of ovarian cancer, PLoS One, 2010, 5(5):e10471;
[2] Gulley JL, et al., Immunologic and prognostic factors associated with overall survival employing a poxviral-based PSA vaccine in metastatic castrate-resistant prostate cancer, Cancer Immunol Immunother. 2010, 59(5):663-674;
[3] Leibowitz MS, etal., SHP2 Is Overexpressed and Inhibits pSTAT1-Mediated APM Component Expression, T-cell Attracting Chemokine Secretion, and CTL Recognition in Head and Neck Cancer Cells, Clin Cancer Res. 2013, 19(4):798-808;
[4] Zeestraten EC, et al., Addition of interferon-α to the p53-SLP® vaccine results in increased production of interferon-γ in vaccinated colorectal cancer patients: A phase I/II clinical trial, Int J Cancer, 2013, 132(7):1581-1591;
[5] Alix-Panabières C, EPISPOT assay: detection of viable DTCs/CTCs in solid tumor patients, Recent Results Cancer Res. 2012, 195:69-76.
[6] Hadaschik B, et al., Antigen specific T-cell responses against tumor antigens are controlled by regulatory T cells in patients with prostate cancer, J Urol, 2012, 187(4):1458-1465.