Mechanism of lnRNA-ICL involved in lung cancer development in COPD patients through modulating microRNA-19-3p/NKRF/NF-κB axis

The incidence of lung cancer (LC) in chronic obstructive pulmonary disease (COPD) patients is dozens of times higher than that in patients without COPD. Elevated activity of nuclear factor-k-gene binding (NF-κB) was found in lung tissue of patients with COPD, and the continuous activation of NF-κB is observed in both malignant transformation and tumor progression of LC, suggesting that NF-κB and its regulators may play a key role in the progression of LC in COPD patients. Here, we report for the first time that a key long non-coding RNA (lncRNA)-ICL involved in the regulation of NF-κB activity in LC tissues of COPD patients. The analyses showed that the expression of ICL significantly decreased in LC tissues of LC patients with COPD than that in LC tissues of LC patients without COPD. Functional experiments in vitro showed that exogenous ICL only significantly inhibited the proliferation, invasion and migration in primary tumor cells of LC patients with COPD compared to LC patients without COPD. Mechanism studies have shown that ICL could suppress the activation of NF-κB by blocking the hsa-miR19-3p/NKRF/NF-κB pathway as a microRNA sponge. Furthermore, In vivo experiments showed that exogenous ICL effectively inhibited the growth of patient-derived subcutaneous tumor xenografts (PDX) of LC patients with COPD and significantly prolonged the survival time of tumor-bearing mice. In a word, our study shows that the decrease of ICL is associated with an increased risk of LC in patients with COPD, ICL is not only expected to be a new therapeutic target for LC in COPD patients, but also has great potential to be used as a new marker for evaluating the occurrence, severity stratification and prognosis of LC in patients with COPD.