Novel structured ADAM17 small-molecule inhibitor represses ADAM17/Notch pathway activation and the NSCLC cells' resistance to anti-tumour drugs.

Background and aims: The outcomes of current treatment for non-small cell lung cancer (NSCLC) are unsatisfactory and development of new and more efficacious therapeutic strategies are required. The Notch pathway, which is necessary for cell survival to avert apoptosis, induces the resistance of cancer cells to antitumour drugs. Notch pathway activation is controlled by the cleavage of Notch proteins/receptors mediated by A disintegrin and metalloproteinase 17 (ADAM17); therefore, ADAM17 is a reliable intervention target for anti-tumour therapy to overcome the drug resistance of cancer cells. This work aims to develop and elucidate the activation of Compound 2b, a novel-structured small-molecule inhibitor of ADAM17, which was designed and developed and its therapeutic efficacy in NSCLC was assessed via multi-assays. Methods and results: A lead compound for a potential inhibitor of ADAM17 was explored via pharmacophore modelling, molecular docking, and biochemical screening. It was augmented by substituting two important chemical groups [R1 and R2 of the quinoxaline-2,3-diamine (its chemical skeleton)]; subsequently, serial homologs of the lead compound were used to obtain anoptimized compound (2b) with high inhibitory activity compared with leading compound against ADAM17 to inhibit the cleavage of Notch proteins and the accumulation of the Notch intracellular domain in the nuclei of NSCLC cells. The inhibitory activity of compound 2b was demonstrated by quantitative polymerase chain reaction and Western blotting. The specificity of compound 2b on ADAM17 was confirmed via point-mutation. Compound 2b enhanced the activation of antitumor drugs on NSCLC cells, in cell lines and nude mice models, by targeting the ADAM17/Notch pathway. Conclusion: Compound 2b may be a promising strategy for NSCLC treatment.

Molecular characterization based on tumor microenvironment-related signatures for guiding immunotherapy and therapeutic resistance in lung adenocarcinoma.

Background: Although the role of tumor microenvironment in lung adenocarcinoma (LUAD) has been explored in a number of studies, the value of TME-related signatures in immunotherapy has not been comprehensively characterized. Materials and Methods: Consensus clustering was conducted to characterize TME-based molecular subtypes using transcription data of LUAD samples. The biological pathways and immune microenvironment were assessed by CIBERSORT, ESTIMATE, and gene set enrichment analysis. A TME-related risk model was established through the algorithms of least absolute shrinkage and selection operator (Lasso) and stepwise Akaike information criterion (stepAIC). Results: Four TME-based molecular subtypes including C1, C2, C3, and C4 were identified, and they showed distinct overall survival, genomic characteristics, DNA methylation pattern, immune microenvironment, and biological pathways. C1 had the worst prognosis and high tumor proliferation rate. C3 and C4 had higher enrichment of anti-tumor signatures compared to C1 and C2. C4 had evidently low enrichment of epithelial-mesenchymal transition (EMT) signature and tumor proliferation rate. C3 was predicted to be more sensitive to immunotherapy compared with other subtypes. C1 is more sensitive to chemotherapy drugs, including Docetaxel, Vinorelbine and Cisplatin, while C3 is more sensitive to Paclitaxel. A five-gene risk model was constructed, which showed a favorable performance in three independent datasets. Low-risk group showed a longer overall survival, more infiltrated immune cells, and higher response to immunotherapy than high-risk group. Conclusion: This study comprehensively characterized the molecular features of LUAD patients based on TME-related signatures, demonstrating the potential of TME-based signatures in exploring the mechanisms of LUAD development. The TME-related risk model was of clinical value to predict LUAD prognosis and guide immunotherapy.

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.

Novel small molecule inhibitors of the transcription factor ETS-1 and their antitumor activity against hepatocellular carcinoma.

The transcription factor ETS-1 (E26 transformation specific sequence 1) is the key regulator for malignant tumor cell proliferation and invasion by mediating the transcription of the invasion/migration related factors, e.g. MMPs (matrix metalloproteinases). This work aims to identify the novel small molecule inhibitors of ETS-1 using a small molecule compound library and to study the inhibitors' antitumor activity against hepatocellular carcinoma (HCC). The luciferase reporter is used to examine the inhibition and activation of ETS-1's transcription factor activity in HCC cells, including a highly invasive HCC cell line, MHCC97-H, and five lines of patient-derived cells. The inhibition of the proliferation of HCC cells is examined using the MTT assay, while the invasion of HCC cells is examined using the transwell assay. The anti-tumor activity of the selected compound on HCC cells is also examined in a subcutaneous tumor model or intrahepatic tumor model in nude mice. The results show that for the first time, four compounds, EI1~EI-4, can inhibit the transcription factor activation of ETS-1 and the proliferation or invasion of HCC cells. Among the four compounds, EI-4 has the best activation. The results from this paper contribute to expanding our understanding of ETS-1 and provide alternative, the safer and more effective, HCC molecular therapy strategies.

Slug Is Associated With Tumor Metastasis and Angiogenesis in Ovarian Cancer.

Ovarian cancer is the most lethal gynecologic malignancy among women and usually initiated by the malignant transformation of epithelial cells. The progression of ovarian cancer involves a cascade of events, including tumor cell epithelial-mesenchymal transition (EMT), invasion, migration, and angiogenesis. Slug plays vital roles in the development of motile and invasive manner of cancer cells via EMT progression. The present work is devoted to investigate the effect of slug on the invasion and angiogenesis in ovarian cancer. The findings reveal that tumors with high expression of slug (44 of 60) represent higher tumor grade, lymph node metastasis, and worse prognosis than those with low expression (16 of 60; P < .05). We also identified a significant correlation between the slug and the microvessel density (MVD). Results of transwell migration assay showed that decreased slug induced by short hairpin RNA contributed to the repressed invasion and migration of SKOV3 cells. Additionally, the migration and tube formation capacity of human umbilical vein endothelial cells were markedly decreased in SKOV3-sh-conditioned medium compared to SKOV3 and SKOV3-NC. Furthermore, xenograft mouse models (SKOV3/SKOV3-sh cells injection into BALB/c nude mice) were developed to validate the effects of slug. The data confirmed that inhibited expression of slug extensively decreased the growth of tumor and MVD in vivo. Moreover, knockdown of slug can significantly reduce tumor angiogenesis of SKOV3 cells via ccn1/vascular endothelial growth factor. Thus, our present study demonstrates that slug is closely associated with tumor metastasis and angiogenesis in ovarian cancer.

RhNRG-1ß Protects the Myocardium against Irradiation-Induced Damage via the ErbB2-ERK-SIRT1 Signaling Pathway.

Radiation-induced heart disease (RIHD), which is a serious side effect of the radiotherapy applied for various tumors due to the inevitable irradiation of the heart, cannot be treated effectively using current clinical therapies. Here, we demonstrated that rhNRG-1ß, an epidermal growth factor (EGF)-like protein, protects myocardium tissue against irradiation-induced damage and preserves cardiac function. rhNRG-1ß effectively ameliorated irradiation-induced myocardial nuclear damage in both cultured adult rat-derived cardiomyocytes and rat myocardium tissue via NRG/ErbB2 signaling. By activating ErbB2, rhNRG-1ß maintained mitochondrial integrity, ATP production, respiratory chain function and the Krebs cycle status in irradiated cardiomyocytes. Moreover, the protection of irradiated cardiomyocytes and myocardium tissue by rhNRG-1ß was at least partly mediated by the activation of the ErbB2-ERK-SIRT1 signaling pathway. Long-term observations further showed that rhNRG-1ß administered in the peri-irradiation period exerts continuous protective effects on cardiac pump function, the myocardial energy metabolism, cardiomyocyte volume and interstitial fibrosis in the rats receiving radiation via NRG/ErbB2 signaling. Our findings indicate that rhNRG-1ß can protect the myocardium against irradiation-induced damage and preserve cardiac function via the ErbB2-ERK-SIRT1 signaling pathway.