Retraction notice to "Potential of ß-elemene induced ferroptosis through Pole2-mediated p53 and PI3K/AKT signaling in lung cancer cells" [Chem. Biol. Interact. 365 (25 September 2022) 110088].

This article has been retracted: please see Elsevier Policy on Article Withdrawal (https://www.elsevier.com/about/our-business/policies/article-withdrawal). The entire 'Reason' text must be identical to that in the XML version Box 6).

Potential of ß-elemene induced ferroptosis through Pole2-mediated p53 and PI3K/AKT signaling in lung cancer cells.

Ferroptosis is crucial for tumor growth inhibition. Moreover, ferroptosis has been considered as a potential strategy against cancer. The present study focused on the mechanism of ferroptosis induction by ß-elemene during the lung cancer (extracted from the Chinese medicine Curcuma Wen yujin). CCK-8 assay, flow cytometry and biochemical assays including intracellular ROS, MDA, GSH, iron and 8-OHdG level were performed. DNA polymerase epsilon subunit 2 (Pole2) and the ferroptosis-related proteins were studied by utilizing western blotting. The study results showed that the ß-elemene reduced the viability of lung cancer cells via ferroptosis. Furthermore, multiple experiments confirmed that Pole2 knockdown enhanced the production of lipid ROS, MDA and iron, leading to the iron-dependent ferroptosis in lung cancer cells. Overexpression of Pole2 inhibited ß-elemene-induced ferroptosis through reduction of iron-dependent oxidative damage. Mechanically, Pole2 reduced the upregulation of p53 expression, and increased the phosphorylation levels of PI3K and AKT in ß-elemene-induced cells. Overexpression of TP53 or the inhibitor of PI3K/AKT pathway reversed the effects of Pole2. Together, ß-elemene evoked ferroptosis through the Pole2-regulated p53 or PI3K/AKT signalling, and might be an effective therapy for lung carcinogenesis.

1H-NMR-based metabolic profiling of healthy individuals and high-resolution CT-classified phenotypes of COPD with treatment of tiotropium bromide.

BACKGROUND: Heterogeneity of COPD results in different therapeutic effects for different patients receiving the same treatment. COPD patients need to be individually treated according to their own characteristics. The purpose of this study was to explore the differences in different CT phenotypic COPD by molecular metabolites through the use of metabolomics. METHODS: According to the characteristics of CT imaging, 42 COPD patients were grouped into phenotype E (n=20) or phenotype M (n=24). Each COPD patient received tiotropium bromide powder for inhalation for a therapeutic period of 3 months. All subjects were assigned into phenotype E in pre-therapy (EB, n=20), phenotype E in post-therapy (EA, n=20), phenotype M in pre-therapy (MB, n=22), phenotype M in post-therapy (MA, n=22), or normal control (N, n=24). The method of metabolomics based on 1H nuclear magnetic resonance (1H-NMR) was used to compare the changes in serum metabolites between COPD patients and normal controls and between different phenotypes of COPD patients in pre- and post-therapy. RESULTS: Patients with COPD phenotype E responded better to tiotropium bromide than patients with COPD phenotype M in terms of pulmonary function and COPD assessment test scores. There were differences in metabolites in COPD patients vs normal control people. Differences were also observed between different COPD phenotypic patients receiving the treatment in comparison with those who did not receive treatment. The changes of metabolites involved lactate, phenylalanine, fructose, glycine, asparagine, citric acid, pyruvic acid, proline, acetone, ornithine, lipid, pyridoxine, maltose, betaine, lipoprotein, and so on. These identified metabolites covered the metabolic pathways of amino acids, carbohydrates, lipids, genetic materials, and vitamin. CONCLUSION: The efficacy of tiotropium bromide on COPD phenotype E is better than that of phenotype M. Metabolites detected by 1H-NMR metabolomics have potentialities of differentiation of COPD and healthy people, discrimination of different COPD phenotypes, and giving insight into the individualized treatment of COPD.

Relationship between PPARα mRNA expression and mitochondrial respiratory function and ultrastructure of the skeletal muscle of patients with COPD.

Peripheral muscle dysfunction is an important complication in patients with chronic obstructive pulmonary disease (COPD). The objective of this study was to explore the relationship between the levels of peroxisome proliferator-activated receptor α (PPARα) mRNA expression and the respiratory function and ultrastructure of mitochondria in the vastus lateralis of patients with COPD. Vastus lateralis biopsies were performed on 14 patients with COPD and 6 control subjects with normal lung function. PPARα mRNA levels in the muscle tissue were detected by real-time PCR. A Clark oxygen electrode was used to assess mitochondrial respiratory function. Mitochondrial number, fractional area in skeletal muscle cross-sections, and Z-line width were observed via transmission electron microscopy. The PPARα mRNA expression was significantly lower in COPD patients with low body mass index (BMIL) than in both COPD patients with normal body mass index (BMIN) and controls. Mitochondrial respiratory function (assessed by respiratory control ratio) was impaired in COPD patients, particularly in BMIL. Compared with that in the control group, mitochondrial number and fractional area were lower in the BMIL group, but were maintained in the BMIN group. Further, the Z-line became narrow in the BMIL group. PPARα mRNA expression was positively related to mitochondrial respiratory function and volume density. In COPD patients with BMIN, mitochondria volume density was maintained, while respiratory function decreased, whereas both volume density and respiratory function decreased in COPD patients with BMIL. PPARα mRNA expression levels are associated with decreased mitochondrial respiratory function and volume density, which may contribute to muscle dysfunction in COPD patients.

Silencing of Btbd7 Inhibited Epithelial-Mesenchymal Transition and Chemoresistance in CD133+ Lung Carcinoma A549 Cells.

Cancer stem cells (CSCs) are responsible for tumorigenesis and recurrence, so targeting CSCs is an effective method to potentially cure cancer. BTB/POZ domain-containing protein 7 (Btbd7) has been found in various cancers, including lung cancer and liver cancer, but the role of Btbd7 in non-small cell lung cancer (NSCLC), CSC self-renewal, and chemoresistance is still unknown. Therefore, in this study we found that the ratio of tumor sphere formation and stem cell transcription factors in CD133+ cells was dramatically enhanced compared to parental cells, which indicated successful sorting of CD133+ cells from A549. Meanwhile, Btbd7 and the markers of the epithelial-mesenchymal transition (EMT) process were more highly expressed in CD133+ cells than in parental cells. Silencing of Btbd7 significantly inhibited the self-renewal and EMT process in CD133+ cells. Furthermore, we found that downregulation of Btbd7 promoted cell apoptosis and increased the sensitivity to paclitaxel in CD133+ and parental cells. In conclusion, our results suggest that Btbd7 is a promising agent for the inhibition of survival and chemoresistance of cancer stem-like cells of NSCLC, which may act as an important therapeutic target in NSCLC.

Effect of N-acetylcysteine in COPD patients with different microsomal epoxide hydrolase genotypes.

BACKGROUND: The role of the antioxidant N-acetylcysteine (NAC) in the treatment of chronic obstructive pulmonary disease (COPD) has not been clarified as yet. In early studies, we found that the proportion of smokers with COPD having extremely slow/slow microsomal epoxide hydrolase (EPHX1) enzyme activity is significantly higher than that in healthy smokers. The purpose of this study was to evaluate whether different EPHX1 enzyme activity is related to differential therapeutic effects of treatment with NAC in COPD. METHODS: A total of 219 patients with COPD were randomly allocated to an extremely slow/slow EPHX1 enzyme activity group (n=157) or a fast/normal EPHX1 enzyme activity group (n=62) according to their EPHX1 enzyme activity. Both groups were treated with NAC 600 mg twice daily for one year. The main study parameters, including forced expiratory volume in one second (FEV1), St George's Respiratory Questionnaire (SGRQ), and yearly exacerbation rate, were measured at baseline and at 6-month intervals for one year. RESULTS: Both FEV1 and SGRQ symptom scores were improved after treatment with NAC in the slow activity group when compared with the fast activity group. Further, changes in FEV1 and SGRQ symptom score in patients with mild-to-moderate COPD were more significant than those in patients with severe-to-very severe COPD. The yearly exacerbation rates were reduced in both groups, but the reduction in the slow activity group was significantly lower than in the fast activity group. CONCLUSION: NAC treatment in COPD patients with extremely slow/slow EPHX1 enzyme activity improves FEV1 and the SGRQ symptom score, especially in those with mild-to-moderate COPD, and polymorphism in the EPHX1 gene may have a significant role in differential responses to treatment with NAC in patients with COPD.

Relationship between polymorphisms in the 5' leader cistron, positions 16 and 27 of the adrenergic ß2 receptor gene and asthma in a Han population from southwest China.

BACKGROUND AND OBJECTIVE: Adrenergic ß2 receptors (ADRB2) play an important role in regulating pulmonary function. Many previous studies have investigated possible associations between polymorphisms in the ADRB2 gene and asthma, but have yielded conflicting results. Furthermore, little is known regarding the possible role of the Arg19Cys polymorphism in susceptibility to asthma among Chinese. METHODS: This case-control association study involved 238 patients with asthma and 265 healthy subjects from a Han population in southwest China. For all subjects, the 5' leader cistron Arg19Cys, Arg16Gly and Gln27Glu polymorphisms in the ADRB2 gene were characterized by direct sequencing. Genotype, allele and haplotype frequencies were determined. In addition, to evaluate the association between the ADRB2 polymorphisms and lung function, bronchodilator response to inhaled ß2 agonists (400 µg of albuterol) was assessed in the asthmatic patients. RESULTS: There were no significant differences in genotype or allele frequencies for the three ADRB2 polymorphisms between the two cohorts. The Arg19/Arg16/Gln27 haplotype was more frequent among asthmatic patients than control subjects (odds ratio 2.24, 95% confidence interval (CI): 1.05-4.73, P=0.04). Moreover, the Arg19/Cys19 genotype was associated with a lower FEV1% (mean difference -4.5, 95% CI: -12.5 to 3.6, P=0.02) and FEV1/FVC (mean difference 8.9, 95% CI: 8.5-9.4, P=0.01). The bronchodilator response to albuterol was also marginally lower in individuals who were homozygous for the Arg19 genotype (mean difference 4.2, 95% CI: 3.7-4.8, P=0.03). CONCLUSIONS: The Arg19/Cys19 genotype was an independent risk factor for lower FEV1% and FEV1/FVC. Asthmatic patients with the Arg19/Arg19 genotype showed decreased responsiveness to albuterol. Furthermore, the Arg19/Arg16/Gln27 haplotype may contribute to increased susceptibility to asthma in the Chinese population.