Modulation of the airway smooth muscle phenotype in a murine asthma model and effects of nuclear factor-κB inhibition.

Objective: Phenotype modulation of airway smooth muscle (ASM) is a unique characteristic of asthma and is considered to regulate airway remodeling, airway hyperresponsiveness (AHR) and inflammation. The nuclear factor-κB (NF-κB) signaling pathway plays a crucial role in phenotypic modulation. Thus, models of acute and chronic asthma were established and pyrrolidine dithiocarbamate (PDTC), an NF-κB inhibitor was delivered by intraperitoneal injection. Methods: The Penh value was measured using the BUXCO WBP system. Lung tissues were subjected to histologic analysis. Phenotypic markers of ASM and COL1A1 mRNA levels were measured by RT-PCR. Expression levels of phosphorylated p65 (pP65) and α-SMA were detected by Western blot. Serum cytokine levels were quantified by RayBiotech ELISA array. Results: PDTC intervention decreased the Penh values in both the acute and chronic models. The ASM area and the airway collagen area were decreased in the PDTC intervention group. A decrease in phenotypic markers were detected in both the acute and chronic models in time-dependent manner, and PDTC intervention partially reversed the phenotypic modulation. The effect of PDTC intervention on systemic inflammation was also verified. Conclusion: These results revealed the existence of a dynamic ASM phenotype modulation procedure in asthma development and that targeting NF-κB by PDTC was effective to mitigate ASM phenotype modulation and major asthmatic pathological features.

Inhibition of TRPC3 downregulates airway hyperresponsiveness, remodeling of OVA-sensitized mouse.

Airway hyperresponsiveness (AHR), airway remodeling and inflammation are the fundamental pathological alterations that occur in asthma. Transient receptor potential canonical 3 (TRPC3) has been implicated in diverse functions of airway smooth muscle cells (ASMCs) in asthma. However, the underlying mechanisms remain incompletely understood. We investigated the mRNA and protein expression of TRPC3 in ASMCs from normal and OVA-sensitized mouse. And the effects of inhibition or knockdown of TRPC3 with Ethyl-1- (4- (2,3,3-trichloroacrylamide) phenyl) -5 - (trifluoromethyl) -1H -pyrazole -4-carboxylate (Pyr3) and lentiviral shRNA on OVA-sensitized mouse AHR, airway remodeling, circulating inflammatory cytokines, cell proliferation and migration. We found that TRPC3 mRNA and protein expression levels were significantly increased in ASMCs from OVA-sensitized mouse. Inhibiting TRPC3 with continuous subcutaneous administration of Pyr3 decreased enhanced pause (Penh) of OVA-sensitized mouse. Meanwhile, both Pyr3 and lentiviral shRNA treatment of ASMCs in OVA-sensitized mouse significantly decreased their proliferation and migration. These results suggest that TRPC3 plays a critical role in asthma and represents a promising new target for asthma treatment.

Hypoxic stress suppresses lung tumor-secreted exosomal miR101 to activate macrophages and induce inflammation.

Hypoxia promotes inflammation in the tumor microenvironment. Although hypoxia-inducible factor 1α (HIF1α) is a master modulator of the response to hypoxia, the exact mechanisms through which HIF1α regulates the induction of inflammation remain largely unclear. Using The Cancer Genome Atlas Lung Squamous Cell Carcinoma (TCGA-LUSC) database, we divided patients with LUSC into two groups based on low or high HIF1α expression. After analyzing the differentially expressed genes in these two groups, we found that HIF1α was positively correlated with interleukin 1A (IL1A) and IL6 expression. Our in vitro study showed that hypoxic stress did not induce IL1A or IL6 expression in tumor cells or macrophages but dramatically enhanced their expression when co-cultured with tumor cells. We then investigated the effect of tumor-derived exosomes on macrophages. Our data suggested that the changes in miR101 in the tumor-derived exosomes played an important role in IL1A and IL6 expression in macrophages, although the hypoxic stress did not change the total amount of exosome secretion. The expression of miR101 in exosomes was suppressed by hypoxic stress, since depletion of HIF1α in tumor cells recovered the miR101 expression in both tumor cells and exosomes. In vitro, miRNA101 overexpression or uptake enriched exosomes by macrophages suppressed their reprogramming into a pro-inflammatory state by targeting CDK8. Injection of miR101 into xenografted tumors resulted in the suppression of tumor growth and macrophage tumor infiltration in vivo. Collectively, this study suggests that the HIF1α-dependent suppression of exosome miR101 from hypoxic tumor cells activates macrophages to induce inflammation in the tumor microenvironment.

Complete response associated with immune checkpoint inhibitors in advanced non-small-cell lung cancer: a meta-analysis of nine randomized controlled trials.

PURPOSE: The purposes of this study were to investigate whether the use of immune checkpoint inhibitors (ICIs) in advanced non-small-cell lung cancer (NSCLC) would increase the possibility of archiving complete response (CR) and assess the surrogate end points for overall survival (OS). METHODS: We calculated the incidence and relative risk (RR) of CR events in patients assigned to ICIs compared to that in controls. Simple linear regression models were fitted for median OS and each surrogate (median progression-free survival [PFS], CRs, and objective response rate [ORR]). RESULTS: A total of 4,803 NSCLC patients from nine randomized controlled trials (RCTs) were included for analysis. The incidence of CR in NSCLC patients treated with ICIs was 1.5% (95% CI: 0.8-3.0) compared to 0.7% (95% CI: 0.4-1.2) in chemotherapy (CT) groups. The use of ICIs in advanced NSCLC significantly improved the possibility of archiving CR (RR 2.89, 95% CI: 1.44-5.81, P=0.003) compared to CT. Subgroup analysis according to ICIs showed that the use of atezolizumab (RR 3.26, P=0.01) and nivolumab (RR 4.83, P=0.042) in advanced NSCLC significantly improved the CR rate in comparison with CT alone, but not pembrolizumab and ipilimumab. We also found that the use of ICIs as first-line (RR 2.39, 95% CI: 1.08-5.3, P=0.032) or second-line (RR 4.99, 95% CI: 1.10-22.66, P=0.038) therapy significantly increased the change in obtaining a CR. In addition, correlation analysis indicates that PFS was strongly correlated with OS in NSCLC patients who received ICIs (r=0.89 for PFS, P=0.017). No marked correlation was found between OS and CR (r=0.19, P=0.75) and OS and ORR (r=0.52, P=0.28). CONCLUSION: The CR is a rate event in advanced NSCLC, but the use of ICIs significantly increases the possibility of archiving CR in comparison with CT. PFS is significantly correlated with OS and could be used as a surrogate end point, but not for CRs and ORRs.