Abstract
CD133 + cancer stem cells mediate chemoresistance in multiple aggressive cancers, and anti-CD133 chimeric antigen receptor T (CAR-T) cells are designed to selectively target cisplatin-resistant gastric cancer stem cells in this investigation. The relative CD133 expression was detected in gastric cancer patients before and after cisplatin treatment. Anti-CD133 CAR-T cells were incubated with cisplatin-exposed CD133+ BGC-823 cells to evaluate the killing efficacy. At the same time, the canonical T cell activation markers were assayed by fluorescence-activated cell sorting, and the functional cytokine profile was detected with enzyme-linked immunosorbent assays. In addition to the percentage of CD133 positive stem cell-like cells, the volume and weight of subcutaneous tumors in BGC-823, KATO III and MKN-28 xenograft models were measured to evaluate the anti-tumor activity of cisplatin and anti-CD133 CAR-T combination strategy. After cisplatin treatment, both human samples and BGC-823 cells showed up-regulated CD133 expression. Anti-CD133 CAR-T cells exhibited pronounced killing efficiency against cisplatin-exposed CD133+ BGC-823 cells with up-regulated activation markers and cytotoxicity cytokine production. Moreover, cisplatin and anti-CD133 CAR-T combination treatment inhibited tumor progression in three different xenograft models with diminished CD133 positive stem cell-like cell infiltration. These results indicate that cisplatin and anti-CD133 CAR-T combination strategy can simultaneously target normal and stem cell-like gastric cancer cells to improve the treatment outcome.