PTK7-Targeting CAR T-Cells for the Treatment of Lung Cancer and Other Malignancies.

In spite of impressive success in treating hematologic malignancies, adoptive therapy with chimeric antigen receptor modified T cells (CAR T) has not yet been effective in solid tumors, where identification of suitable tumor-specific antigens remains a major obstacle for CAR T-cell therapy due to the "on target off tumor" toxicity. Protein tyrosine kinase 7 (PTK7) is a member of the Wnt-related pseudokinases and identified as a highly expressed antigen enriched in cancer stem cells (CSCs) from multiple solid tumors, including but not limited to triple-negative breast cancer, non-small-cell lung cancer, and ovarian cancer, suggesting it may serve as a promising tumor-specific target for CAR T-cell therapy. In this study, we constructed three different PTK7-specific CAR (PTK7-CAR1/2/3), each comprising a humanized PTK7-specific single-chain variable fragment (scFv), hinge and transmembrane (TM) regions of the human CD8α molecule, 4-1BB intracellular co-stimulatory domain (BB-ICD), and CD3ζ intracellular domain (CD3ζ-ICD) sequence, and then prepared the CAR T cells by lentivirus-mediated transduction of human activated T cells accordingly, and we sequentially evaluated their antigen-specific recognition and killing activity in vitro and in vivo. T cells transduced with all three PTK7-CAR candidates exhibited antigen-specific cytokine production and potent cytotoxicity against naturally expressing PTK7-positive tumor cells of multiple cancer types without mediating cytotoxicity of a panel of normal primary human cells; meanwhile, in vitro recursive cytotoxicity assays demonstrated that only PTK7-CAR2 modified T cells retained effective through multiple rounds of tumor challenge. Using in vivo xenograft models of lung cancers with different expression levels of PTK7, systemic delivery of PTK7-CAR2 modified T cells significantly prevented tumor growth and prolonged overall survival of mice. Altogether, our results support PTK7 as a therapeutic target suitable for CAR T-cell therapy that could be applied for lung cancers and many other solid cancers with PTK7 overexpression.

Jie Y ，Liu G ，Feng L ，Li Y ，E M ，Wu L ，Li Y ，Rong G ，Li Y ，Wei H ，Gu A ... -  《Frontiers in Immunology》

A novel TREM1/DAP12-based multiple chain CAR-T cell targets PTK7 in ovarian cancer therapy.

While CAR-T cell therapy has shown success against hematological tumors, its effectiveness for solid tumors, including ovarian cancer, remains unsatisfactory. This study aimed to develop and evaluate the efficacy of novel chimeric antigen receptor T (CAR-T) cells targeting PTK7 through TREM1/DAP12 signaling against ovarian cancer. The expression of PTK7 in ovarian cancer tissues and cells was evaluated using immunohistochemical staining and flow cytometric analysis. The anti-tumor effects of PTK7 CAR-T cells were assessed in vitro using real-time cell analysis and enzyme-linked immunosorbent assay, and in vivo using a xenograft tumor model. PTK7 was significantly expressed in ovarian cancer tissues and cells. PTK7-targeting CAR-T cells based on TREM1/DAP12 signaling exhibited potent cytotoxicity against ovarian cancer cells expressing PTK7 in vitro, and effectively eradicated tumors in vivo. Our findings suggest that TREM1/DAP12-based PTK7 CAR-T cells have potential as a treatment strategy for ovarian cancer. Further studies are needed to evaluate the safety and efficacy of this approach in clinical trials.

Xu T ，Wang C ，Wang X ，Wang E ，Wang B ，Sun M ... -  《-》

CAR T Cells Targeting the Tumor MUC1 Glycoprotein Reduce Triple-Negative Breast Cancer Growth.

Zhou R ，Yazdanifar M ，Roy LD ，Whilding LM ，Gavrill A ，Maher J ，Mukherjee P ... -  《-》

Effective Targeting of TAG72(+) Peritoneal Ovarian Tumors via Regional Delivery of CAR-Engineered T Cells.

Murad JP ，Kozlowska AK ，Lee HJ ，Ramamurthy M ，Chang WC ，Yazaki P ，Colcher D ，Shively J ，Cristea M ，Forman SJ ，Priceman SJ ... -  《Frontiers in Immunology》

Chimeric antigen receptor T cell targeting EGFRvIII for metastatic lung cancer therapy.

Zhang Z ，Jiang J ，Wu X ，Zhang M ，Luo D ，Zhang R ，Li S ，He Y ，Bian H ，Chen Z ... -  《-》