Avelumab in non-small-cell lung cancer

Circ-FOXM1 knockdown suppresses non-small cell lung cancer development by regulating the miR-149-5p/ATG5 axis

Circular RNAs (circRNAs) have been reported to be related to the development of human cancers. However, the function of circ-FOXM1 in non-small cell lung cancer (NSCLC) was largely unknown. Here, we revealed the role and functional mechanism of circ-FOXM1 in NSCLC progression. The relative expression of circ-FOXM1, microRNA-149-5p (miR-149-5p), and autophagy-related 5 (ATG5) was determined by quantitative real-time polymerase chain reaction (RT-qPCR). Cell Counting Kit-8 (CCK-8), flow cytometry, and transwell assay were employed to assess cell viability, apoptosis, and migration, respectively. The relative protein expression was detected by western blot. Furthermore, mouse xenograft was carried out to analyze the effect of circ-FOXM1 on tumor growth in vivo. In addition, the interaction between miR-149-5p and circ-FOXM1 or ATG5 was predicted by Starbase3.0 and confirmed by the dual-luciferase reporter assay and RNA pull-down assay. Circ-FOXM1 and ATG5 levels were upregulated, while the miR-149-5p level was downregulated in NSCLC tissues and cells. Circ-FOXM1 knockdown suppressed NSCLC cell viability, migration, and autophagy, and induced cell apoptosis. Interestingly, circ-FOXM1 targeted miR-149-5p to upregulate the ATG5 level. Moreover, circ-FOXM1 exerted function through repressing miR-149-5p expression, and miR-149-5p exerted function via inhibiting ATG5 expression. Our results suggested that circ-FOXM1 knockdown attenuated the development of NSCLC through modulating the miR-149-5p/ATG5 axis, providing a theoretical basis for the therapy of NSCLC.

Circular RNA circ-CPA4/ let-7 miRNA/PD-L1 axis regulates cell growth, stemness, drug resistance and immune evasion in non-small cell lung cancer (NSCLC)

BACKGROUND

Non-small cell lung cancer (NSCLC) cells derived intracellular and extracellular programmed cell death ligand 1 (PD-L1) promoted cancer progression and drug resistance, and facilitated tumor immune evasion. However, the detailed molecular mechanisms are still largely unknown. In the present study, we aimed to explore the role of circular RNA circ-CPA4/let-7 miRNA/PD-L1 axis in the regulation of NSCLC progression, drug resistance and tumor immune microenvironment.

METHODS

Real-Time qPCR and Western Blot analysis were conducted to examine gene expressions at transcriptional and translated levels, respectively. The regulatory mechanisms of circ-CPA4, let-7 miRNA and PD-L1 were validated by dual-luciferase reporter gene system and RNA pull-down assay. Cell growth and apoptosis were determined by CCK-8 assay, colony formation assay and Annexin V-FITC/PI double staining assay. Cell mobility was evaluated by transwell assay.

RESULTS

Circ-CPA4 and PD-L1 were high-expressed, while let-7 miRNA was low-expressed in NSCLC cells and cancer tissues compared to the human bronchial epithelial (HBE) cells and their paired clinical normal adjacent tissues, respectively. Besides, knock-down of circ-CPA4 inhibited cell growth, mobility and epithelial-mesenchymal transition (EMT), and promoted cell death in NSCLC cells by downregulating PD-L1 through serving as a RNA sponge for let-7 miRNA. In addition, the NSCLC cells derived PD-L1-containing exosomes promoted cell stemness and increased resistance of NSCLC cells to cisplatin. Notably, by co-culturing the NSCLC cells with CD8+ T cells isolated from human peripheral blood mononuclear cells (hPBMCs) in a transwell co-culturing system, we found that NSCLC cells inactivated CD8+ T cells in a secreted PD-L1-dependent manner. Further results suggested that circ-CPA4 also positively regulated exosomal PD-L1, and the NSCLC cells with circ-CPA4 ablation re-activated CD8+ T cells in the co-culturing system.

CONCLUSION

Taken together, circ-CPA4 regulated cell growth, mobility, stemness and drug resistance in NSCLC cells and inactivated CD8+ T cells in the tumor immune microenvironment through let-7 miRNA/PD-L1 axis.

The Role of the Lymphocyte Functional Crosstalk and Regulation in the Context of Checkpoint Inhibitor Treatment-Review

During the last decade, the dynamics of the cellular crosstalk have highlighted the significance of the host vs. tumor interaction. This resulted in the development of novel immunotherapeutic strategies in order to modulate/inhibit the mechanisms leading to escape of tumor cells from immune surveillance. Different monoclonal antibodies directed against immune checkpoints, e.g., the T lymphocyte antigen 4 and the programmed cell death protein 1/ programmed cell death ligand 1 have been successfully implemented for the treatment of cancer. Despite their broad activity in many solid and hematologic tumor types, only 20–40% of patients demonstrated a durable treatment response. This might be due to an impaired T cell tumor interaction mediated by immune escape mechanisms of tumor and immune cells as well as alterations in the composition of the tumor microenvironment, peripheral blood, and microbiome. These different factors dynamically regulate different steps of the cancer immune process thereby negatively interfering with the T cell –mediated anti-tumoral immune responses. Therefore, this review will summarize the current knowledge of the different players involved in inhibiting tumor immunogenicity and mounting resistance to checkpoint inhibitors with focus on the role of tumor T cell interaction. A better insight of this process might lead to the development of strategies to revert these inhibitory processes and represent the rational for the design of novel immunotherapies and combinations in order to improve their efficacy.

lncRNA HNF1A-AS1 modulates non-small cell lung cancer progression by targeting miR-149-5p/Cdk6

Growing evidence have shown the important regulation of lncRNAs (long noncoding RNAs) in non-small cell lung cancer (NSCLC). lncRNA hepatocyte nuclear factor 1 homeobox A (HNF1A)-antisense RNA 1 (AS1), an "oncogene", was reported to regulate human tumors progression. However, the molecular mechanism of HNF1A-AS1 involved in the development of NSCLC is still under investigation. In the current study, we found that HNF1A-AS1 was relatively upregulated in both NSCLC patient tissues and cell lines. Functional studies established that overexpression of HNF1A-AS1 promoted cell proliferation, cell cycle, invasion, and migration of NSCLC cells in vitro. The promotion abilities of HNF1A-AS1 on NSCLC cell progression were suppressed via knockdown of HNF1A-AS1. miR-149-5p was then proved to be a novel target of HNF1A-AS1, whose expression was negatively correlated with HNF1A-AS1 in NSCLC patient tissues and cell lines. HNF1A-AS1 increased the expression of cyclin-dependent kinase 6 (Cdk6) via sponging with miR-149-5p. Gain- and loss-of-functional studies indicated that HNF1A-AS1 promoted NSCLC progression partially through inhibition of miR-363-3p and induction of Cdk6. Subcutaneous xenotransplanted tumor model confirmed that interference of HNF1A-AS1 suppressed the tumorigenic ability of NSCLC via upregulation of miR-149-5p and downregulation of Cdk6 in vivo. In conclusion, our findings clarified the biologic significance of the HNF1A-AS1/miR-149-5p/Cdk6 axis in NSCLC progression and provided novel evidence that HNF1A-AS1 may be a new potential therapeutic target for the treatment of NSCLC.