BackgroundImmune system evasion, distance tumor metastases, and increased cell proliferation are the main reasons for the progression of non-small cell lung cancer (NSCLC) and the death of NSCLC patients. Dysregulation of circular RNAs plays a critical role in the progression of NSCLC; therefore, further understanding the biological mechanisms of abnormally expressed circRNAs is critical to discovering novel, promising therapeutic targets for NSCLC treatment.MethodsThe expression of circular RNA fibroblast growth factor receptor 1 (circFGFR1) in NSCLC tissues, paired nontumor tissues, and cell lines was detected by RT-qPCR. The role of circFGFR1 in NSCLC progression was assessed both in vitro by CCK-8, clonal formation, wound healing, and Matrigel Transwell assays and in vivo by a subcutaneous tumor mouse assay. In vivo circRNA precipitation, RNA immunoprecipitation, and luciferase reporter assays were performed to explore the interaction between circFGFR1 and miR-381-3p.ResultsHere, we report that circFGFR1 is upregulated in NSCLC tissues, and circFGFR1 expression is associated with deleterious clinicopathological characteristics and poor prognoses for NSCLC patients. Forced circFGFR1 expression promoted the migration, invasion, proliferation, and immune evasion of NSCLC cells. Mechanistically, circFGFR1 could directly interact with miR-381-3p and subsequently act as a miRNA sponge to upregulate the expression of the miR-381-3p target gene C-X-C motif chemokine receptor 4 (CXCR4), which promoted NSCLC progression and resistance to anti-programmed cell death 1 (PD-1)- based therapy.ConclusionTaken together, our results suggest the critical role of circFGFR1 in the proliferation, migration, invasion, and immune evasion abilities of NSCLC cells and provide a new perspective on circRNAs during NSCLC progression.

Purpose: The aim of our study is to elucidate whether T cells expressing GPC3-targeted chimeric antigen receptor (CAR) can efficiently eliminate GPC3-positive HCC cells and their potential in the treatment of HCC. Experimental Design: T cells expressing a first-generation and third-generation GPC3-targeted CAR were prepared using lentiviral vector transduction. The in vitro and in vivo cytotoxic activities of the genetically engineered CAR T cells were evaluated against various HCC cell lines. Results: GPC3-targeted CAR T cells could efficiently kill GPC3-positive HCC cells but not GPC3-negative cells in vitro. These cytotoxic activities seemed to be positively correlated with GPC3 expression levels in the target cells. In addition, T cells expressing the third-generation GPC3-targeted CAR could eradicate HCC xenografts with high level of GPC3 expression and efficiently suppress the growth of HCC xenografts with low GPC3 expression level in vivo. The survival of the mice bearing established orthotopic Huh-7 xenografts was significantly prolonged by the treatment with the third-generation GPC3-targeted CAR T cells. Conclusions: GPC3-targeted CAR T cells could potently eliminate GPC3-positive HCC cells, thereby providing a promising therapeutic intervention for GPC3-positive HCC. Clin Cancer Res; 20(24); 6418–28. ©2014 AACR.

Adoptive immunotherapy leveraging chimeric antigen receptor-modified T (CAR-T) cells holds great promise for the treatment of cancer. However, tumor-associated antigens often have low expression levels in normal tissues, which can cause on-target, off-tumor toxicity. Recently, we reported that GPC3-targeted CAR-T cells could eradicate hepatocellular carcinoma (HCC) xenografts in mice. However, it remains unknown whether on-target, off-tumor toxicity can occur. Therefore, we proposed that dual-targeted CAR-T cells co-expressing glypican-3 (GPC3) and asialoglycoprotein receptor 1 (ASGR1) (a liver tissue-specific protein)-targeted CARs featuring CD3ζ and 28BB (containing both CD28 and 4-1BB signaling domains), respectively, may have reduced on-target, off-tumor toxicity. Our results demonstrated that dual-targeted CAR-T cells caused no cytotoxicity to ASGR1GPC3 tumor cells, but they exhibited a similar cytotoxicity against GPC3ASGR1 and GPC3ASGR1 HCC cells in vitro. We found that dual-targeted CAR-T cells showed significantly higher cytokine secretion, proliferation and antiapoptosis ability against tumor cells bearing both antigens than single-targeted CAR-T cells in vitro. Furthermore, the dual-targeted CAR-T cells displayed potent growth suppression activity on GPC3ASGR1 HCC tumor xenografts, while no obvious growth suppression was seen with single or double antigen-negative tumor xenografts. Additionally, the dual-targeted T cells exerted superior anticancer activity and persistence against single-targeted T cells in two GPC3ASGR1 HCC xenograft models. Together, T cells carrying two complementary CARs against GPC3 and ASGR1 may reduce the risk of on-target, off-tumor toxicity while maintaining relatively potent antitumor activities on GPC3ASGR1 HCC.