Abstract
BackgroundGastric cancer is a deadly malignancy and is a prognostically unfavorable entity with restricted therapeutic strategies available. Prostate stem cell antigen (PSCA) is a glycosylphosphatidylinositol (GPI)-anchored cell surface protein widely expressed in bladder, prostate, and pancreatic cancers. Existing studies have thoroughly recognized the availability of utilizing anti-PSCA CAR-T cells in the treatment of metastatic prostate cancer and non-small-cell lung cancer. However, no previous study has investigated the feasibility of using anti-PSCA CAR-T cells to treat gastric cancer, irrespective of the proven expression of PSCA on the gastric cancer cell surface.MethodsWe determined the expression of PSCA in several primary tumor tissues and constructed third-generation anti-PSCA CAR-T cells. We then incubated anti-PSCA CAR-T cells and GFP-T cells with target tumor cell lines at E:T ratios of 2:1, 1:1, 1:2, and 1:4 to evaluate the therapeutic efficacy of anti-PSCA CAR-T cells in vitro. We also assayed canonical T cell activation markers after coculturing anti-PSCA CAR-T cells with target cell lines by flow cytometry. The detection of a functional cytokine profile was carried out via enzyme-linked immunosorbent assays. We then evaluated the antitumor activity of anti-PSCA CAR-T cells in vivo by establishing two different xenograft GC mouse models.ResultsAnti-PSCA CAR-T cells exhibited upregulated activation markers and increased cytokine production profiles related to T cell cytotoxicity in an antigen-dependent manner. Moreover, anti-PSCA CAR-T cells exhibited robust anti-tumor cytotoxicity in vitro. Importantly, we demonstrated that anti-PSCA CAR-T cells delivered by peritumoral injection successfully stunted tumor progression in vivo. However, intravenous administration of anti-PSCA CAR-T cells failed to reveal any therapeutic improvements.ConclusionsOur findings corroborated the feasibility of anti-PSCA CAR-T cells and their efficacy against gastric cancer, implicating the potential of applying anti-PSCA CAR-T cells to treat GC patients in the clinic.
Highlights
Gastric cancer is a significant public health issue, as the fourth most common cancer and the third leading cause of cancer death worldwide [1]
Generation and expansion of Chimeric antigen receptor (CAR)-T cells Peripheral blood mononuclear cells mononuclear cells (PBMC) were extracted from whole blood obtained from healthy donors through Ficoll-Hypaque density gradient centrifugation (Fresenius Kabi Norge, AS, Berg i Østfold, Norway), while primary human T cells were isolated from PBMCs by means of negative selection with the Pan-T Isolation Kit (Miltenyi Biotec, Germany) and activated by microbeads coated with anti-human CD3, antihuman CD2, and anti-human CD28 antibodies (Miltenyi Biotec, Germany) at a 1:1 ratio for 48 h
Prostate stem cell antigen (PSCA) expression in patient tissues and gastric cancer cell lines To evaluate the potential of the tumor antigen PSCA as an immunotherapeutic target, we immunohistochemically detected its presence and abundance in eight primary gastric cancer samples (Fig. 1a)
Summary
Gastric cancer is a significant public health issue, as the fourth most common cancer and the third leading cause of cancer death worldwide [1]. Chimeric antigen receptors (CARs) are genetically modified receptors that redirect T cells to various tumor surface antigens [3]. Despite the characterization of EpCAM and claudin as new target antigens in gastric cancer [12, 13], disease heterogeneity remains a substantial obstacle for solid tumor immunotherapy [14], necessitating the identification of alternative antigens. Prostate stem cell antigen (PSCA) is a glycosylphosphatidylinositol (GPI)-anchored cell surface protein widely expressed in bladder, prostate, and pancreatic cancers. Existing studies have thoroughly recognized the availability of utilizing anti-PSCA CAR-T cells in the treatment of metastatic prostate cancer and nonsmall-cell lung cancer. No previous study has investigated the feasibility of using anti-PSCA CAR-T cells to treat gastric cancer, irrespective of the proven expression of PSCA on the gastric cancer cell surface
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
