Targeting LINC00673 expression triggers cellular senescence in lung cancer.

Aberrant expression of noncoding RNAs plays a critical role during tumorigenesis. To uncover novel functions of long non-coding RNA (lncRNA) in lung adenocarcinoma, we used a microarray-based screen identifying LINC00673 with elevated expression in matched tumor versus normal tissue. We report that loss of LINC00673 is sufficient to trigger cellular senescence, a tumor suppressive mechanism associated with permanent cell cycle arrest, both in lung cancer and normal cells in a p53-dependent manner. LINC00673-depleted cells fail to efficiently transit from G1- to S-phase. Using a quantitative proteomics approach, we confirm the modulation of senescence-associated genes as a result of LINC00673 knockdown. In addition, we uncover that depletion of p53 in normal and tumor cells is sufficient to overcome LINC00673-mediated cell cycle arrest and cellular senescence. Furthermore, we report that overexpression of LINC00673 reduces p53 translation and contributes to the bypass of Ras-induced senescence. In summary, our findings highlight LINC00673 as a crucial regulator of proliferation and cellular senescence in lung cancer.

Corrigendum: Pseudomonas aeruginosa Modulates the Antiviral Response of Bronchial Epithelial Cells.

[This corrects the article DOI: 10.3389/fimmu.2020.00096.].

Pseudomonas aeruginosa Modulates the Antiviral Response of Bronchial Epithelial Cells.

Cystic fibrosis (CF) patients frequently acquire Pseudomonas aeruginosa infections that have been associated with a bad prognosis and an increased rate of pulmonary exacerbations. Respiratory viruses can cause exacerbations in chronic pulmonary diseases including COPD or asthma and have been suggested to contribute to exacerbations also in CF. In this study we investigated a possible link between P. aeruginosa infection and susceptibility to respiratory viruses. We show that P. aeruginosa is able to block the antiviral response of airway epithelial cells thereby promoting virus infection and spread. Mechanistically, P. aeruginosa secretes the protease AprA in a LasR dependent manner, which is able of directly degrading epithelial-derived IFNλ resulting in inhibition of IFN signaling. In addition, we correlate the virus infection status of CF patients with the ability of patients' P. aeruginosa isolates to degrade IFNλ. In line with this, the infection status of CF patients correlated significantly with the amount of respiratory viruses in sputum. Our data suggest that the interplay between P. aeruginosa and respiratory virus infections might partially explain the association of increased rates of pulmonary exacerbations and P. aeruginosa infections in CF patients.

Molecular signatures in IASLC/ATS/ERS classified growth patterns of lung adenocarcinoma.

BACKGROUND: The current classification of human lung adenocarcinoma defines five different histological growth patterns within the group of conventional invasive adenocarcinomas. The five growth patterns are characterised by their typical architecture, but also by variable tumor biological behaviour. AIMS: The aim of this study was to identify specific gene signatures of the five adenocarcinoma growth patterns defined by the joint IASLC/ATS/ERS working group. METHODS: Total RNA from microdissected adenocarcinoma tissue samples of ten lepidic, ten acinar, ten solid, nine papillary, and nine micropapillary tumor portions was isolated and prepared for gene expression analysis. Differential expression of genes was determined using the R package "LIMMA". The overall significance of each signature was assessed via global test. Gene ontology statistics were analysed using GOstat. For immunohistochemical validation, tissue specimens from 20 tumors with solid and 20 tumors with lepidic growth pattern were used. RESULTS: Microarray analyses between the growth patterns resulted in numerous differentially expressed genes between the solid architecture and other patterns. The comparison of transcriptomic activity in the solid and lepidic patterns revealed 705 up- and 110 downregulated non-redundant genes. The pattern-specific protein expression of Inositol-1,4,5-trisphosphate-kinase-A (ITPKA) and angiogenin by immunohistochemistry confirmed the RNA levels. The strongest differences in protein expression between the two patterns were shown for ITPKA (p = 0.02) and angiogenin (p = 0.113). CONCLUSIONS: In this study growth pattern-specific gene signatures in pulmonary adenocarcinoma were identified and distinct transcriptomic differences between lung adenocarcinoma growth patterns were defined. The study provides valuable new information about pulmonary adenocarcinoma and allows a better assessment of the five adenocarcinoma subgroups.

CT characteristics in pulmonary adenocarcinoma with epidermal growth factor receptor mutation.

Comprehensively investigate the association of CT morphology and clinical findings of adenocarcinoma with EGFR mutation status. Retrospectively included 282 patients who was pathologically proved as lung adenocarcinoma with known EGFR mutation status (mutations: 138 patients, female: 86, median age: 66 years; wildtype: 144 patients, female: 67, median age: 62 years) and their pre-treatment CT scans were analyzed. CT findings and clinical information were collected. Univariate and multivariable logistic regression analysis were performed. Adjusted for age, gender and smoking history of two groups, significantly more patients with pleural tags, pleural and liver metastases were found in the EGFR mutated group (P = 0.007, 0.004, and 0.043, respectively). Multivariable logistic regression analysis found that the model included age, gender, smoking history, air bronchogram, pleural tags, pleural and liver metastasis had a moderate predictive value for EGFR mutation status (AUC = 0.741, P < .0001). Exon-19 deletion was associated with air bronchogram which adjusted for age, gender and smoking history (P = 0.007, OR: 2.91, 95%CI: 1.25-7.79). The evidence of pleural tags, pleural and liver metastases go along with a higher probability of EGFR mutation in adenocarcinoma patients and air bronchogram is positively associated with Exon-19 deletion mutation.

Endoplasmic Reticulum Stress Is a Danger Signal Promoting Innate Inflammatory Responses in Bronchial Epithelial Cells.

Endoplasmic reticulum (ER) stress is associated with chronic pulmonary inflammatory diseases. We hypothesized that the combined activation of both Toll-like receptor (TLR) signaling and ER stress might increase inflammatory reactions in otherwise tolerant airway epithelial cells. Indeed, ER stress resulted in an increased response of BEAS-2B and human primary bronchial epithelial cells to pathogen-associated molecular pattern stimulation with respect to IL6 and IL8 production. ER stress elevated p38 and ERK MAP kinase activation, and pharmacological inhibition of these kinases could inhibit the boosting effect. Knockdown of unfolded protein response signaling indicated that mainly PERK and ATF6 were responsible for the synergistic activity. Specifically, PERK and ATF6 mediated increased MAPK activation, which is needed for effective cytokine secretion. We conclude that within airway epithelial cells the combined activation of TLR signaling and ER stress-mediated MAPK activation results in synergistic proinflammatory activity. We speculate that ER stress, present in various chronic pulmonary diseases, boosts TLR signaling and therefore proinflammatory cytokine production, thus acting as a costimulatory danger signal.

Three-Year Follow-Up of a Randomized Phase II Trial on Refinement of Early-Stage NSCLC Adjuvant Chemotherapy with Cisplatin and Pemetrexed versus Cisplatin and Vinorelbine (the TREAT Study).

INTRODUCTION: Adjuvant chemotherapy in non-small cell lung cancer (NSCLC) improves survival but is associated with significant toxicity. The Randomized Phase II Trial on Refinement of Early-Stage NSCLC Adjuvant Chemotherapy with Cisplatin and Pemetrexed versus Cisplatin and Vinorelbine (TREAT study) was designed to test the hypothesis that a protocol with reduced toxicity might improve feasibility of postoperative delivery of adjuvant chemotherapy drugs to patients with NSCLC, thereby improving compliance and, potentially, survival. METHODS: Two adjuvant regimens were evaluated for feasibility in 132 patients with NSCLC: the standard regimen of cisplatin and vinorelbine (CVb) (cisplatin 50 mg/m(2) on day 1 and day 8 and vinorelbine 25 mg/m(2) on days 1, 8, 15, and 22 every 4 weeks) and a regimen consisting of cisplatin and pemetrexed (CPx) (cisplatin 75 mg/m(2) and pemetrexed 500 mg/m(2) on day 1 every 3 weeks). The primary end-point analysis showing that CPx is safe and feasible with dose delivery superior to that of CVb has already been published. Here we report the 3-year follow-up results of the secondary efficacy end points-overall, relapse-free, distant metastasis-free, and local relapse-free survival-also with regard to histologic diagnosis. RESULTS: After a median of 39 months, no significant differences in any of the outcome parameters between CVb and CPx were observed. Also, histologic diagnosis and tumor size in stage IB did not influence survival in the CPx-treated patients. Yet, Cox regression analyses showed that overall survival at 3 years was significantly correlated with feasibility and the occurrence of dose-limiting toxicity. CONCLUSIONS: Although adjuvant chemotherapy with CPx is safe and characterized by less toxicity and better dose delivery than CVb, overall survival was not influenced by treatment arm in the context of this phase II trial.

Quantitative volumetric CT-histogram analysis in N-staging of 18F-FDG-equivocal patients with lung cancer.

UNLABELLED: Lung cancer often coexists with acute and chronic lung diseases such as chronic obstructive pulmonary disease. Therefore, mediastinal lymph nodes may be false-positive on (18)F-FDG PET because of the inflammatory disease alone. Nevertheless, (18)F-FDG PET/CT is the primary imaging modality used for staging patients with lung cancer, including nodal status. The purpose of this study was to evaluate whether volumetric CT histogram analysis can improve the characterization of lymph nodes on PET/CT staging of patients with lung cancer. METHODS: Sixty histologically proven lymph nodes of 45 patients aged 43-76 y diagnosed with lung cancer were investigated. (18)F-FDG PET/CT, contrast-enhanced CT, and nonenhanced CT were performed before surgery or biopsy as part of the clinical staging procedure. Lymph nodes were analyzed on the basis of the (18)F-FDG standardized uptake value and volumetric CT histogram analysis. These findings were correlated to the gold standard of histopathology. RESULTS: Histologic examination revealed 36 positive and 24 negative lymph nodes, which were also successfully analyzed by volumetric CT histogram. Median CT density was significantly higher for histologically positive lymph nodes (33.2 Hounsfield units [HU]; range, -29.8 to 59.1) than for histologically negative lymph nodes (10.1 HU; range, -21.0 to 87.4; P = 0.002). The incidence of malignancy was 88% above a cutoff value of 20 HU in the ten (18)F-FDG-equivocal lymph nodes; the incidence of benign findings was 100% in the interval between -20 and +20 HU. Visual- and density-based analysis on contrast-enhanced CT failed to differentiate affected from nonaffected lymph nodes. CONCLUSION: Three-dimensional histogram analysis is a promising and potentially valuable imaging surrogate for N-stage stratification in patients with lung cancer with unclear glucose uptake during (18)F-FDG PET imaging. In cases of equivocal (18)F-FDG PET status, this technique might potentially bridge the diagnostic gap between noninvasive techniques and invasive lymph node sampling and could help improve the yield of core biopsies.