[Intraperitoneal injection of human-derived anti-c-Met single-chain antibody inhibits the growth of transplanted tumours in A549 lung adenocarcinoma-loaded mice].

Objective To verify the anti-tumor effect of the mesenchymal-epithelial transition single-chain antibody (Met scFv) on subcutaneously transplanted tumors in nude mice. Methods A tumor model was established in nude mice by subcutaneous injection of A549 lung adenocarcinoma cells. Once the tumors were formed, IRDye680 LT N-hydroxysuccinimide (NHS) ester-labeled Met scFv was administered intraperitoneally. Real-time monitoring was conducted using a small animal imager to observe the dynamic distribution of the antibody in tumor-bearing mice. The affinity between c-Met and the antibody in tumor cells was detected. Tumor volume changes were observed and the tumor growth curve were plotted following regular tail vein injections of Met scFv. Immunohistochemical staining was employed to determine whether Met scFv could effectively bind to the c-Met antigen in tumor tissues. Results The distribution of Met scFv in nude mice showed that it was primarily located in the peritoneal cavity within the first 3 hours. After approximately 48 hours, fluorescent signals began to accumulate in the tumor tissue. Immunohistochemical staining of the tumors revealed high expression of c-Met in the tumor tissues; regular tail vein injections of Met scFv significantly slowed down the growth of tumors in mice. Conclusion Met scFv specifically recognizes tumor cells in vivo and exhibites significant anti-tumor activity.

c-Met specific CAR-T cells as a targeted therapy for non-small cell lung cancer cell A549.

Non-small cell lung cancer (NSCLC) is considered to be one of the most prevalent and fatal malignancies, with a poor survival rate. Chimeric antigen receptor T cell (CAR-T) cell therapy is one of the most exciting directions in the field of Cellular immunotherapy. Therefore, CAR-T cells that target c-Met have been developed for use in NSCLC therapy and might be a potential therapeutic strategy. The anti c-Met scFv structure was fused with the transmembrane and intracellular domains. Using a lentiviral vector to load the c-Met CAR gene, then transfected the c-Met CAR lentiviral into human T cells to obtain the second generation c-Met CAR-T expressing CARs stably. In vitro co-culture, experiments revealed that CAR-T cells have high proliferative activity and the potential to secrete cytokines (IL-2, TNF-α, and IFN-γ). c-Met CAR-T cells showed special cellular cytotoxicity in LDH release assay. A subcutaneous tumor model in nude mice was used to test the anticancer effectiveness of c-met CAR-T cells in vivo. For c-Met positive NSCLC tissue, according to tumor volume, weight, fluorescence intensity, and immunohistochemical detection, c-Met CAR-T cells had stronger tumor growth suppression compared to untransduced T cells. HE staining revealed that c-Met CAR-T cells did not produced side effects in nude mice. Taken together, we provided useful method to generate c-Met CAR- T cells, which exhibit enhanced cytotoxicity against NSCLC cells in vitro and in vivo. Thus, providing a new therapeutic avenue for treating NSCLC clinically.Highlights (1) c-Met CAR-T capable of stably expressing c-Met CARs were constructed.(2) c-Met CAR-T have strong anti-tumor ability and proliferation ability in vitro.(3) c-Met CAR-T can effectively inhibit the growth of A549 cells subcutaneous xenografts.