[The Construction of ROR1 Targeting Chimeric Antigen Receptor Modified T Cells and Its Killing Effect for ROR1-positive Tumor Cells].

OBJECTIVE: To test the killing effect of type Ⅰ receptor tyrosine kinase-like orphan receptor (ROR1) chimeric antigen receptor T cell (CAR-T) on several ROR1-expressing tumor cells in vitro. METHODS: The CAR gene was designed and synthesized by constructing the lentiviral vector plasmid, and BamHⅠ/EcoRⅠ was used to identify the plasmid. The expression levels of ROR1 among a variety of tumor cell lines were compared using flow cytometry (FCM). The killing effect of CAR-T on positive cells was detected by FCM, the LDH assay and ELISA. RESULTS: The double enzyme digestion identified CAR gene was successfully constructed to the lentivirus vector plasmid. FCM detection showed that the efficiency of CAR-T infection was about 47.23%. Multiple tumor cells expressed ROR1 in varying degrees. The FCM and the LDH assay indicated that CAR-T specifically killed ROR1-positive tumor cells. On positive target cells, more interferonI-γ (FN-γ) could be released during the CAR-T killing process than control T (P<0.05). CONCLUSION: We successfully constructed ROR1 CAR-T. CAR-T can specifically kill ROR1-positive tumor cells and cause the release of large amounts of IFN-γ, providing an experimental basis for clinical application.

Hurdles of CAR-T cell-based cancer immunotherapy directed against solid tumors.

Recent reports on the impressive efficacy of chimeric antigen receptor (CAR)-modified T cells against hematologic malignancies have inspired oncologists to extend these efforts for the treatment of solid tumors. Clinical trials of CAR-T-based cancer immunotherapy for solid tumors showed that the efficacies are not as remarkable as in the case of hematologic malignancies. There are several challenges that researchers must face when treating solid cancers with CAR-T cells, these include choosing an ideal target, promoting efficient trafficking and infiltration, overcoming the immunosuppressive microenvironment, and avoiding associated toxicity. In this review, we discuss the obstacles imposed by solid tumors on CAR-T cell-based immunotherapy and strategies adopted to improve the therapeutic potential of this approach. Continued investigations are necessary to improve therapeutic outcomes and decrease the adverse effects of CAR-T cell therapy in patients with solid malignancies in the future.