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Background The role of cancer cell FOXP3 in tumorigenesis is conflicting. We aimed to study FOXP3 expression and regulation, function and clinical implication in human non-small cell lung cancer (NSCLC). Methods One hundred and six patients with histologically-confirmed NSCLC who underwent surgery were recruited for the study. Tumor samples and NSCLC cell lines were used to examine FOXP3 and its related molecules. Various cell functions related to tumorigenesis were performed. In vivo mouse tumor xenograft was used to confirm the in vitro results. Results NSCLC patients with the high level of FOXP3 had a significant decrease in overall survival and recurrence-free survival. FOXP3 overexpression significantly induced cell proliferation, migration, and invasion, whereas its inhibition impaired its oncogenic function. In vivo studies confirmed that FOXP3 promoted tumor growth and metastasis. The ectopic expression of FOXP3 induced epithelial–mesenchymal transition (EMT) with downregulation of E-cadherin and upregulation of N-cadherin, vimentin, snail, slug, and MMP9. The oncogenic effects by FOXP3 could be attributed to FOX3-mediated activation of Wnt/β-catenin signaling, as FOXP3 increased luciferase activity of Topflash reporter and upregulated Wnt signaling target genes including c-Myc and Cyclin D1 in NSCLC cells. Co-immunoprecipitation results further indicated that FOXP3 could physically interacted with β-catenin and TCF4 to enhance the functions of β-catenin and TCF4, inducing transcription of Wnt target genes to promote cell proliferation, invasion and EMT induction. Conclusions FOXP3 can act as a co-activator to facilitate the Wnt-b-catenin signaling pathway, inducing EMT and tumor growth and metastasis in NSCLC.

Background Epidemiological observations have demonstrated that ambient fine particulate matter with d p  < 2.5 μm (PM 2.5 ) as the major factor responsible for the increasing incidence of lung cancer in never-smokers. However, there are very limited experimental data to support the association of PM 2.5 with lung carcinogenesis and to compare PM 2.5 with smoking carcinogens. Methods To study whether PM 2.5 can contribute to lung tumorigenesis in a way similar to smoking carcinogen 4-methylnitrosamino-l-3-pyridyl-butanone (NNK) via 15-lipoxygenases (15-LOXs) reduction, normal lung epithelial cells and cancer cells were treated with NNK or PM 2.5 and then epigenetically and post-translationally examined the cellular and molecular profiles of the cells. The data were verified in lung cancer samples and a mouse lung tumor model. Results We found that similar to smoking carcinogen NNK, PM2.5 significantly enhanced cell proliferation, migration and invasion, but reduced the levels of 15-lipoxygenases-1 (15-LOX1) and 15-lipoxygenases-2 (15-LOX2), both of which were also obviously decreased in lung cancer tissues. 15-LOX1/15-LOX2 overexpression inhibited the oncogenic cell functions induced by PM2.5/NNK. The tumor formation and growth were significantly higher/faster in mice implanted with PM2.5- or NNK-treated NCI-H23 cells, accompanied with a reduction of 15-LOX1/15-LOX2. Moreover, 15-LOX1 expression was epigenetically regulated at methylation level by PM2.5/NNK, while both 15-LOX1 and 15-LOX2 could be significantly inhibited by a set of PM2.5/NNK-mediated microRNAs. Conclusion Collectively, PM2.5 can function as the smoking carcinogen NNK to induce lung tumorigenesis by inhibiting 15-LOX1/15-LOX2.

Background: Early data showed that FOXP3 could induce epithelial-mesenchymal transition by stimulating the Wnt/β-catenin signaling pathway in non-small cell lung cancer (NSCLC). However, how the expression of FOXP3 is regulated in NSCLC remains unknown. We thus explored the impacts of the long noncoding RNA EGFR antisense RNA 1 (EGFR-AS1) and hypoxia-inducible factor-2A (HIF2A) on FOXP3 expression and the cancer stemness of NSCLC. Methods: Lung tissues samples from 87 patients with NSCLC and two NSCLC cell lines were used in this study. The regulation of FOXP3 and lung cancer cell stemness by EGFR-AS1 and HIF2A was determined at molecular levels in NSCLC tissue samples and cultured cells in the presence/absence of the smoking carcinogen, 4-(N-methyl-N-nitrosamino)-1-(3-pyridyl)-1-butanone (NNK) (also known as nicotine-derived nitrosamine ketone). The results were confirmed in tumor xenograft models. Results: We found that NNK decreased the expression of EGFR-AS1 in the long term, but increased the expression of HIF2A and FOXP3 to stimulate lung cancer cell stemness. EGFR-AS1 significantly inhibited FOXP3 expression and NSCLC cell stemness, whereas HIF2A obviously promoted both. The enhancement of lung cancer stemness by FOXP3 was, at least partially, via stimulating Notch1, as the inhibition of Notch1 could markedly diminish the effect of FOXP3. Conclusions: FOXP3, the expression of which is under the fine control of EGFR-AS1, is a critical molecule that promotes NSCLC cancer cell stemness through stimulating the Notch1 pathway.

A prospective cohort study of 13,862 patients showed that among those who underwent isolated coronary-artery bypass grafting or aortic-valve replacement or repair, the threshold high-sensitivity cardiac troponin I level (within 1 day after surgery) associated with an adjusted hazard ratio for death within 30 days of more than 1.00 was 5670 ng per liter — 218 times the upper reference limit.

Intraoperative hyperglycemia in cardiac and neurosurgical patients is significantly associated with morbidity. Little is known about the perioperative glycemic profile or its impact in other surgical populations or in nondiabetic patients. A systematic review of blood glucose values during major general surgical procedures reported since 1980 was conducted. Data extracted included blood glucose measures, study sample size, gender distribution, age grouping, study purpose, surgical procedure, anesthetic details, and infusion regime. Excluded studies were those with subjects with diabetes insipidus, insulin-treated diabetes, renal or hepatic failure, adrenal gland tumors or dysfunction, pregnancy, and emergency or trauma surgery. Blood glucose levels rose significantly with the induction of anesthesia ( P < .001) in nondiabetic patients. At incision, 2 hours, 4 hours, and 6 hours, 30%, 40%, 38%, and 40% of studies, respectively, reported hyperglycemia. Factors that confound or protect against significant rises in perioperative glycemic levels in nondiabetic patients were identified. The findings facilitate investigating the impact of hyperglycemia on general surgical outcomes.

The mechanism responsible for the apoptotic effect induced by ent-11α-hydroxy-15-oxo-kaur-16-en-19-oic-acid (5F) is not fully understood and its in vivo effect has not been tested. In this study, the effect and mechanism of 5F was investigated in cigarette smoking carcinogen 4-methylnitrosamino-1-3-pyridyl-butanone (NNK)-induced mouse lung tumor model and in cultured lung cancer cells NCI-H23 and CRL-2066. 5F were given to mice after they were treated with NNK for 18 weeks. The effect of 5F on the lung tumor formation was examined, and its side effect was monitored. Cell proliferation and apoptosis were determined through expression of PCNA, Bcl-2, Bax, and TUNEL assay in in vivo animal model. 5F significantly inhibited the NNK-induced lung tumors by inducing apoptosis and suppressing cell proliferation in vivo with minimal side effects. Cell culture experiments showed that 5F translocated Bax into the mitochondria, downregulated Bcl-2, activated caspase-9 and caspase-3, released cytochrome c into the cytosol, and translocated AIF from the mitochondria to the nucleus, which leading to G2-M cell cycle arrest and cell apoptosis. 5F also activated ERK1/2 and the inhibition of ERK1/2 suppressed 5F-mediated changes in apoptotic molecules. In addition to ERK1/2, 5F activated Akt. The inhibition of Akt further facilitated the apoptosis induced, suggesting that Akt activation was anti-apoptotic rather than pro-apoptotic. Collectively, 5F is effective against lung cancer in vivo with minimal side effects. It induces apoptosis in lung cancer through the mitochondrial-mediated pathway, in which the activation of ERK is critical.

Background15-S-Hydroxyeicosatetraenoic acid (15(S)-HETE) and 13-S-hydroxyoctadecadienoic acid (13(S)-HODE), both of which are metabolites of 15-lipoxygenases (15-LOXs), are endogenous ligands for peroxisome proliferator-activated receptor gamma (PPARγ). The activation of PPARγ inhibits cell growth and induces apoptosis in some cancers. The role of 15(S)-HETE) and 13(S)-HODE in the development of lung cancer is not clear.Methods15-LOXs, 15(S)-HETE and 13(S)-HODE were monitored during the development of mouse lung tumours induced by the tobacco smoke carcinogen 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone (NNK) and the levels of these markers were determined in 54 human non-small cell lung cancers.Results15-LOXs, 15(S)-HETE and 13(S)-HODE levels were significantly reduced in human lung cancer tissue compared with non-tumour lung tissue (p=0.011 and p=0.022, respectively). In mouse experiments, 15(S)-HETE and 13(S)-HODE started to reduce at 26 and 30 weeks, respectively, after NNK treatment. The time frame of 15(S)-HETE reduction was in line with the decrease in 12/15-LOX mRNA and protein. A significant difference in the number of tumours in NNK-treated mice and controls was not observed until week 34 (p<0.05) and week 38 (p<0.01). The reduction in 12/15-LOX and 15(S)-HETE therefore predated the appearance of lung tumour. Furthermore, PPARγ activity was decreased in NNK-treated mouse lungs compared with the control, and the decreased PPARγ activity occurred at the same time points as the reduction in 12/15-LOX and 15(S)-HETE.ConclusionThese findings indicate that the reduction in 15-LOX, 15(S)-HETE and 13(S)-HODE results in the decreased PPARγ activity seen in lung tumours and contributes to the development of lung tumours induced by tobacco smoking.

Peroxisome proliferator-activated receptor (PPAR)-α and PPARγ participate in cell proliferation and apoptosis. Few studies have simultaneously investigated both PPARα and PPARγ in lung cancers in vivo. The roles of PPARα and -γ were investigated in the development of pulmonary tumors induced in the adult A/J mouse by treatment with 4-(methylnitrosamino)-l-(3-pyridyl)-lbutanone (NNK). Compared with the normal lung tissues, PPARγ expression was much higher in the NNK-induced lung tumor tissues. However, PPARγ transcriptional activity, and the levels of two major endogenous PPARγ ligands, 13-hydroxyoctadecadienoic acid and 15-hydroxyeicosatetraenoic acid, were significantly lower in the NNK-treated lung tissues. The ligand changes in mice were confirmed in human lung cancer tissues. Along with the alteration of PPARγ and its endogenous ligands, the level of PPARα and its activity were increased in the NNK-induced mouse lung tumors. Treatment of mice with the synthetic PPARγ ligand, pioglitazone, significantly inhibited the formation of mouse lung tumors induced by NNK. Our study demonstrated that the reduction of endogenous PPARγ ligands and increased PPARα occurred before the formation of lung tumors, indicating that the molecular changes play a role in lung carcinogenesis. The results suggest that the enhancement of PPARγ activity with its ligands, and the suppression of PPARα with its inhibitors, may prevent the formation of lung tumors, as well as accelerate the therapy of lung cancer. Our findings may also reveal the possibility of using the level of endogenous PPARγ ligands and the activities of PPARγ or PPARα as tumor markers for lung cancer.

Smoking carcinogen N-nitrosamines such as 4-methylnitrosamino-l-3-pyridyl-butanone (NNK) require metabolic activation to exert their genotoxicity. The first activation step is mainly catalyzed by cytochrome P450 (CYP) family. Estrogen receptor α (ERα) plays a role in lung pathology. The association between them is unknown. In this study, we explored the relationship and function of CYP1B1 and ERα in NNK-induced lung tumorigenesis. CYP1B1 and ERα expression was analyzed in human lung cancer tissues and NNK-induced lung tumor of A/J mice. Cell lines NCI-H23 and NCI-H460 were employed to further study the responsible mechanisms using various cellular and molecular approaches. Our in vivo experiments demonstrated that CYP1B1 and ERα were over-expressed at the early stage of NNK-induced lung tumorigenesis. Microarray analysis found that ERα was involved in the extracellular-signal-regulated kinase (ERK)/MAPK pathway. NNK activated RAS/ERK/AP1 as it remarkably increased the levels of p-ERK, c-Fos, and c-Jun but inhibited multiple negative regulators of Ras/ERK/AP1, Pdcd4, Spry1, Spry2, and Btg2 through up-regulating miR-21. Both CYP1B1 siRNA and ERK-specific inhibitor U0126 suppressed NNK-mediated ERα up-regulation, suggesting that ERα was downstream of CYP1B1 and ERK. ERK inactivation led to the accumulation of CYP1B1, indicating that CYP1B1 was upstream of ERK activation. Inhibition of ERK or ERα decreased NNK-induced cell proliferation. Blockage of CYP1B1 or ERα induced apoptosis of lung cancer cells. Collectively, NNK-mediated ERα induction is via CYP1B1 and ERK and contributes to the lung carcinogenesis. The inhibition of CYP1B1, ERK, or ERα may arrest the lung cancer cell growth, implicating a pivotal strategy for the treatment of lung cancer. Key messages Smoking carcinogen NNK requires metabolic activation to exert their genotoxicity. CYP1B1 is the enzyme to catalyze NNK. NNK activates CYP1B1 and ERK to induce ERα. Inhibition of CYP1B1, ERK, or ERα arrests the lung cancer cell growth.

The role of cancer cell FOXP3 in tumorigenesis is conflicting. We aimed to study FOXP3 expression and regulation, function and clinical implication in human non-small cell lung cancer (NSCLC). One hundred and six patients with histologically-confirmed NSCLC who underwent surgery were recruited for the study. Tumor samples and NSCLC cell lines were used to examine FOXP3 and its related molecules. Various cell functions related to tumorigenesis were performed. In vivo mouse tumor xenograft was used to confirm the in vitro results. NSCLC patients with the high level of FOXP3 had a significant decrease in overall survival and recurrence-free survival. FOXP3 overexpression significantly induced cell proliferation, migration, and invasion, whereas its inhibition impaired its oncogenic function. In vivo studies confirmed that FOXP3 promoted tumor growth and metastasis. The ectopic expression of FOXP3 induced epithelial-mesenchymal transition (EMT) with downregulation of E-cadherin and upregulation of N-cadherin, vimentin, snail, slug, and MMP9. The oncogenic effects by FOXP3 could be attributed to FOX3-mediated activation of Wnt/[beta]-catenin signaling, as FOXP3 increased luciferase activity of Topflash reporter and upregulated Wnt signaling target genes including c-Myc and Cyclin D1 in NSCLC cells. Co-immunoprecipitation results further indicated that FOXP3 could physically interacted with [beta]-catenin and TCF4 to enhance the functions of [beta]-catenin and TCF4, inducing transcription of Wnt target genes to promote cell proliferation, invasion and EMT induction. FOXP3 can act as a co-activator to facilitate the Wnt-b-catenin signaling pathway, inducing EMT and tumor growth and metastasis in NSCLC.