Acetaminophen sensitizing erastin-induced ferroptosis via modulation of Nrf2/heme oxygenase-1 signaling pathway in non-small-cell lung cancer

Growing evidence confirms that ferroptosis plays an important role in tumor growth inhibition. However, some non-small-cell lung cancer (NSCLC) cell lines are less sensitive to erastin-induced ferroptotic cell death. Elucidating the mechanism of resistance of cancer cells to erastin-induced ferroptosis and increasing the sensitivity of cancer cells to erastin need to be addressed. In our experiment, erastin and acetaminophen (APAP) cotreatment inhibited NSCLC cell viability and promoted ferroptosis and apoptosis, accompanied with attenuation of glutathione and ectopic increases in lipid peroxides. Erastin and APAP promoted NSCLC cell death by regulating nucleus translocation of nuclear factor erythroid 2-related factor 2 (Nrf2); and the ferroptosis induced by erastin and APAP was abrogated by bardoxolone methyl (BM) with less generation of reactive oxygen species and malondialdehyde. As a downstream gene of Nrf2, heme oxygenase-1 expression decreased significantly with the cotreatment of erastin and APAP, which could be rescued by BM. In vivo experiment showed that the combination of erastin and APAP had a synergic therapeutic effect on xenograft of lung cancer. In short, the present study develops a new effective treatment for NSCLC by synergizing erastin and APAP to induce ferroptosis.     

Inhibition of tumor propellant glutathione peroxidase 4 induces ferroptosis in cancer cells and enhances anticancer effect of cisplatin

Glutathione peroxidase 4 (GPX4) has been confirmed to inhibit ferroptosis in cancer cells, however, whether GPX4 serves as an oncogene is not clear. In this study, the expression of GPX4 and its influence to survival of patients with cancer were analyzed via public databases. Furthermore, the epigenetic regulation of GPX4 and the relation between GPX4 and chemoresistance of different anticancer drugs was also detected. Most importantly, cytological assays were performed to investigate the function of GPX4 in cancer cells. The results showed that GPX4 was higher expressed in cancer tissues than normal and was negatively associated with prognosis of patients. Furthermore, at upstream of GPX4 there was low DNA methylation sites and enhanced level of H3K4me3 and H3K27ac, indicating that high level of GPX4 in cancer may resulted from epigenetic regulation. Moreover, GPX4 was positively related to chemoresistance of anticancer drugs L-685458, lapatinib, palbociclib, and topotecan. In addition, GPX4 may potentially be involved in translation of protein, mitochondrial respiratory chain complex I assembly, electron transport oxidative phosphorylation, nonalcoholic fatty liver disease, and metabolic pathways. Finally, we detected that GPX4 inhibited ferroptosis in cancer cells, the inhibition of GPX4 via RSL3 could enhance the anticancer effect of cisplatin in vitro and in vivo. In conclusion, GPX4 acts as an oncogene and inhibits ferroptosis in cancer cells, the anticancer effect of cisplatin can be enhanced by GPX4 inhibition.     

Preferential elevation of Prx I and Trx expression in lung cancer cells following hypoxia and in human lung cancer tissues

Transient/chronic microenvironmental hypoxia that exists within a majority of solid tumors has been suggested to have a profound influence on tumor growth and therapeutic outcome. Since the functions of novel antioxidant proteins, peroxiredoxin I (Prx I) and II, have been implicated in regulating cell proliferation, differentiation, and apoptosis, it was of our special interest to probe a possible role of Prx I and II in the context of hypoxic tumor microenvironment. Since both Prx I and II use thioredoxin (Trx) as an electron donor and Trx is a substrate for thioredoxin reductase (TrxR), we investigated the regulation of Trx and TrxR as well as Prx expression following hypoxia. Here we show a dynamic change of glutathione homeostasis in lung cancer A549 cells and an up-regulation of Prx I and Trx following hypoxia. Western blot analysis of 10 human lung cancer and paired normal lung tissues also revealed an elevated expression of Prx I and Trx proteins in lung cancer tissues. Immunohistochemical analysis of the lung cancer tissues confirmed an augmented Prx I and Trx expression in cancer cells with respect to the parenchymal cells in adjacent normal lung tissue. Based on these results, we suggest that the redox changes in lung tumor microenvironment could have acted as a trigger for the up-regulation of Prx I and Trx in lung cancer cells. Although the clinical significance of our finding awaits more rigorous future study, preferential augmentation of the Prx I and Trx in lung cancer cells may well represent an attempt of cancer cells to manipulate a dynamic redox change in tumor microenvironment in a manner that is beneficial for their proliferation and malignant progression.     

Application of proteomics in non-small-cell lung cancer

Non-small-cell lung cancer (NSCLC) is a heterogeneous disease with diverse pathological features. Clinical proteomics allows the discovery of molecular markers and new therapeutic targets for this most prevalent type of lung cancer. Some of them may be used to detect early lung cancer, while others may serve as predictive markers of resistance to different therapies. Therapeutic targets and prognostic markers in NSCLC have also been discovered. These proteomics biomarkers may help to pair the individual NSCLC patient with the best treatment option. Despite the fact that implementation of these biomarkers in the clinic appears to be scarce, the recently launched Precision Medicine Initiative may encourage their translation into clinical practice.     

Molecular mechanisms of ferroptosis and its role in cancer therapy

Ferroptosis is a newly defined programmed cell death process with the hallmark of the accumulation of iron‐dependent lipid peroxides. The term was first coined in 2012 by the Stockwell Lab, who described a unique type of cell death induced by the small molecules erastin or RSL3. Ferroptosis is distinct from other already established programmed cell death and has unique morphological and bioenergetic features. The physiological role of ferroptosis during development has not been well characterized. However, ferroptosis shows great potentials during the cancer therapy. Great progress has been made in exploring the mechanisms of ferroptosis. In this review, we focus on the molecular mechanisms of ferroptosis, the small molecules functioning in ferroptosis initiation and ferroptosis sensitivity in different cancers. We are also concerned with the new arising questions in this particular research area that remains unanswered.     

Identification and validation of key genes associated with non-small-cell lung cancer

Non-small-cell lung cancer (NSCLC) is one of the main causes of death induced by cancer globally. However, the molecular aberrations in NSCLC patients remain unclearly. In the present study, four messenger RNA microarray datasets (GSE18842, GSE40275, GSE43458, and GSE102287) were downloaded from the Gene Expression Omnibus (GEO) database. Differentially expressed genes (DEGs) between NSCLC tissues and adjacent lung tissues were obtained from GEO2R and the overlapping DEGs were identified. Moreover, functional and pathway enrichment were performed by Funrich, while the protein–protein interaction (PPI) network construction were obtained from STRING and hub genes were visualized and identified by Cytoscape software. Furthermore, validation, overall survival (OS) and tumor staging analysis of selected hub genes were performed by GEPIA. A total of 367 DEGs (95 upregulated and 272 downregulated) were obtained through gene integration analysis. The PPI network consisted of 94 nodes and 1036 edges in the upregulated DEGs and 272 nodes and 464 edges in the downregulated DEGs, respectively. The PPI network identified 46 upregulated and 27 downregulated hub genes among the DEGs, and six (such as CENPE, NCAPH, MYH11, LRRK2, HSD17B6, and A2M) of that have not been identified to be associated with NSCLC so far. Moreover, the expression differences of the mentioned hub genes were consistent with that in lung adenocarcinoma and lung squamous cell carcinoma in the TCGA database. Further analysis showed that all the six hub genes were associated with tumor staging except MYH11, while only the upregulated DEG CENPE was associated with the worse OS of patients with NSCLC. In conclusion, the current study showed that CENPE, NCAPH, MYH11, LRRK2, HSD17B6, and A2M might be the key genes contributed to tumorigenesis or tumor progression in NSCLC, further functional study is needed to explore the involved mechanisms.     

Metabolic regulation of ferroptosis in the tumor microenvironment

Ferroptosis is an iron-dependent, nonapoptotic form of regulated cell death triggered by impaired redox and antioxidant machinery and propagated by the accumulation of toxic lipid peroxides. A compendium of experimental studies suggests that ferroptosis is tumor-suppressive. Sensitivity or resistance to ferroptosis can be regulated by cell-autonomous and non-cell-autonomous metabolic mechanisms. This includes a role for ferroptosis that extends beyond the tumor cells themselves, mediated by components of the tumor microenvironment, including T cells and other immune cells. Herein, we review the intrinsic and extrinsic factors that promote the sensitivity of cancer cells to ferroptosis and conclude by describing approaches to harness the full utility of ferroptotic agents as therapeutic options for cancer therapy.     

Nanoparticle-biomolecular corona: A new approach for the early detection of non-small-cell lung cancer

Lung cancer (LC) is the most common type of cancer and the second cause of death worldwide in men and women after cardiovascular diseases. Non-small-cell lung cancer (NSCLC) is the most frequent type of LC occurring in 85% of cases. Developing new methods for early detection of NSCLC could substantially increase the chances of survival and, therefore, is an urgent task for current research. Nowadays, explosion in nanotechnology offers unprecedented opportunities for therapeutics and diagnosis applications. In this context, exploiting the bio-nano-interactions between nanoparticles (NPs) and biological fluids is an emerging field of research. Upon contact with biofluids, NPs are covered by a biomolecular coating referred to as “biomolecular corona” (BC). In this study, we exploited BC for discriminating between NSCLC patients and healthy volunteers. Blood samples from 10 NSCLC patients and 5 subjects without malignancy were allowed to interact with negatively charged lipid NPs, leading to the formation of a BC at the NP surface. After isolation, BCs were characterized by sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE). We found that the BCs of NSCLC patients was significantly different from that of healthy individuals. Statistical analysis of SDS-PAGE results allowed discriminating between NSCLC cancer patients and healthy subjects with 80% specificity, 80% sensitivity and a total discriminate correctness rate of 80%. While the results of the present investigation cannot be conclusive due to the small size of the data set, we have shown that exploitation of the BC is a promising approach for the early diagnosis of NSCLC.     

Deregulation of UCA1 expression may be involved in the development of chemoresistance to cisplatin in the treatment of non-small-cell lung cancer via regulating the signaling pathway of microRNA-495/NRF2

Non-small-cell lung cancer (NSCLC) remains the leading cause of cancer death worldwide. As a platinum-based chemotherapeutic drug, cisplatin has been used for over 30 years in NSCLC treatment while its effects are diminished by drug resistance. Therefore, we aimed to study the potential role of UCA1 in the development of chemoresistance against cisplatin. Real-time polymerase chain reaction, western-blot analysis, and immunofluorescence were used to study the involvement of UCA1, miR-495, and NRF2 in chemoresistance against cisplatin. 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay was performed to determine the effect of cisplatin on cell proliferation. Computational analysis and luciferase assay were carried out to explore the interaction among UCA1, miR-495, and NRF2. The cisplatin-R group exhibited lower levels of UCA1 and NRF2 expression but a higher level of miR-495 expression than the cisplatin-S group. The growth rate and half-maximal inhibitory concentration of cellular dipeptidyl peptidase (cisplatinum) of the cisplatin-R group were much higher than those in the cisplatin-S group. MiR-495 contained a complementary binding site of UCA1, and the luciferase activity of wild-type UCA1 was significantly reduced after the transfection of miR-495 mimics. MiR-495 directly targeted the 3′-untranslated region (3′-UTR) of NRF2, and the luciferase activity of wild-type NRF2 3′-UTR was evidently inhibited by miR-495 mimics. Finally, UCA1 and NRF2 expressions in the effective group were much lower than that in the ineffective group, along with a much higher level of miR-495 expression. We suggested for the first time that high expression of UCA1 contributed to the development of chemoresistance to cisplatin through the UCA1/miR-495/NRF2 signaling pathway.     

RhoC和Ki67在非小细胞肺癌中的表达及意义

目的探讨RhoC、Ki67在非小细胞肺癌中的表达状况及其与临床病理学参数间的关系。方法利用免疫组织化学(ElivisionTMplus法),检测肺癌组织芯片中151例非小细胞肺癌患者RhoC、Ki67的表达情况。结果肺癌组织的RhoC蛋白阳性表达率为59.60%(90/151),相应癌旁组织RhoC阳性表达率为32.7%(16/49),差别有显著意义(P<0.05)。RhoC在TNMIII/IV期的NSCLC组织中阳性表达率为68.9%(51/74),明显高于在Ⅰ/II期NSCLC组织中阳性表达率50.6%(39/77,P<0.05);RhoC在出现淋巴结转移的表达率为49.2%(32/65),显著高于没有淋巴结转移的阳性表达率67.4%(58/86,P<0.05);非小细胞肺癌中RhoC高表达同Ki-67高表达呈显著正相关关系(χ2=21.634,r=0.377,P<0.01)。结论RhoC的高表达与非小细胞肺癌的分期,淋巴结转移及增殖有关。     

AIM2 promotes non-small-cell lung cancer cell growth through inflammasome-dependent pathway

The human absent in melanoma 2 (AIM2) is considered as a DNA recognizer. AIM2 has been described as a tumor suppressor gene in the early years. But recent studies suggested that it functions as an oncogene in several cancers. However, its roles in non-small-cell lung cancer (NSCLC) remain unclear. Here we reported that AIM2 highly expressed in NSCLC cells and exhibited a tumor-promoting property both in vitro and in vivo. Besides, AIM2 short hairpin RNA (shRNA)-mediated suppression of cell proliferation was triggered by the accumulation of cells at the G2/M phase. Knockdown of AIM2 reduced the inflammasome formation, while overexpression of AIM2 or stimulation by poly(dA:dT) induced the inflammasome formation. Interestingly, blockade of the inflammasome by caspase-1 inhibitor VX-765 or ASC small interfering RNA (siRNA) abolished the effects brought by AIM2 shRNA and AIM2 plasmid. In summary, our results revealed that AIM2 functioned as an oncogene in NSCLC in an inflammasome-dependent way.     

Construction of a prognostic model for non-small-cell lung cancer based on ferroptosis-related genes

We wished to construct a prognostic model based on ferroptosis-related genes and to simultaneously evaluate the performance of the prognostic model and analyze differences between high-risk and low-risk groups at all levels. The gene-expression profiles and relevant clinical data of patients with non-small-cell lung cancer (NSCLC) were downloaded from public databases. Differentially expressed genes (DEGs) were obtained by analyzing differences between cancer tissues and paracancerous tissues, and common genes between DEGs and ferroptosis-related genes were identified as candidate ferroptosis-related genes. Next, a risk-score model was constructed using univariate Cox analysis and least absolute shrinkage and selection operator (Lasso) analysis. According to the median risk score, samples were divided into high-risk and low-risk groups, and a series of bioinformatics analyses were conducted to verify the predictive ability of the model. Single-sample gene set enrichment analysis (ssGSEA) was used to investigate differences in immune status between high-risk and low-risk groups, and differences in gene mutations between the two groups were investigated. A risk-score model was constructed based on 21 ferroptosis-related genes. A Kaplan–Meier curve and receiver operating characteristic curve showed that the model had good prediction ability. Univariate and multivariate Cox analyses revealed that ferroptosis-related genes associated with the prognosis may be used as independent prognostic factors for the overall survival time of NSCLC patients. The pathways enriched with DEGs in low-risk and high-risk groups were analyzed, and the enriched pathways were correlated significantly with immunosuppressive status.     

Altered expression of microRNA-365 is related to the occurrence and development of non-small-cell lung cancer by inhibiting TRIM25 expression

The purpose of this current study is to elucidate whether altered microRNA-365 (miR-365) has an association with the initiation and development of non-small-cell lung cancer (NSCLC) by targeting TRIM25 expression. The expression of miR-365 and TRIM25 in NSCLC tissues, adjacent normal tissues, and NSCLC cell lines were detected. The relationship between miR-365 expression and TRIM25 with the clinicopathological characteristics of NSCLC was analyzed. The putative binding site between miR-365 and TRIM25 was determined by luciferase activity assay. miR-365 inhibitors and miR-365 mimics were transfected to human NSCLC A549 cells, and the cell viability was detected by cell counting kit-8 assay; flow cytometry was carried out to determine cell cycle and apoptosis rate. Poorly expressed miR-365 and overexpressed TRIM25 was found in NSCLC tissues. TRIM25 was determined as a target gene of miR-365. The miR-365 and TRIM25 expression were related to the clinicopathological features of NSCLC, such as pathological classification, differentiation degree, TNM stage as well as lymph node metastasis. miR-365 suppressed the expression of TRIM25 and elevated the expression of the proapoptotic protein in NSCLC cells. Our study demonstrates that altered expression of miR-365 has a close association with the occurrence and development of NSCLC by inhibiting TRIM25 expression.     

Effect of Smac and Taxol on non-small-cell lung cancer

A series of structurally unique second mitochondria-derived activator of caspases （Smacs） that act as antagonists of the inhibitor of apoptosis proteins （IAPs） directly have been discovered. They play crucial roles in mitochondrial apoptosis pathways and promote chemotherapy-induced apoptosis. In this study, we constructed a eukaryotic expression vector pcDNA3.1/Smac and transfected it into A549 human lung cancer cells. Then we analyzed the cell invasive and cloning ability, as well as cell apoptosis induced by Taxol. The results showed that over-expressed Smac significantly inhibited A549 cell invasive and cloning ability and promoted apoptosis following Taxol treatment. This finding provides a potential approach for the biological therapy of lung cancer.     

Preoperative albumin-to-globulin ratio predicts survival in patients with non-small-cell lung cancer after surgery

The prognostic value of the preoperative albumin-to-globulin ratio (AGR) has not been investigated in non-small-cell lung cancer (NSCLC). Therefore, we aimed to assess the clinical applicability of the preoperative AGR to predict the prognosis in patients with NSCLC. We retrospectively enrolled 545 patients with stage I/II/III NSCLC who underwent surgery at our institution. The cutoff value for preoperative AGR was calculated by using a receiver operating characteristic curve analysis. A low AGR was associated with several clinicopathological variables related to tumor progression. In the multivariate analyses, the preoperative AGR was identified as an independent prognostic factor for disease-free survival (DFS; P = 0.003) and overall survival (OS; P = 0.005). For patients with stage II and III with a preoperative AGR ≤ 1.43, the surgery plus chemotherapy group had a significantly longer DFS and OS than the surgery alone group (P = 0.002 and P = 0.001, respectively); however, a significant difference in DFS and OS between these two groups was not observed in patients with stage II and III with an AGR > 1.43 (P = 0.808 and P = 0.842, respectively). The preoperative AGR is an independent, significant predictor of DFS and OS in patients with NSCLC. Our results also demonstrate that the preoperative AGR might be a predictive marker of the therapeutic effect of postoperative chemotherapy in patients with stage II and III NSCLC.     

RING finger protein 38 induces the drug resistance of cisplatin in non-small-cell lung cancer

Cisplatin resistance of non-small-cell lung cancer (NSCLC) needs to be well elucidated. RING finger protein (RNF38) has been proposed as a biomarker of NSCLC poor prognosis. However, its role in drug resistance in NSCLC is poorly understood. RNF38 expression was detected in normal lung epithelial cell and four NSCLC cell lines. RNF38 was stably overexpressed in A549 and H460 cells or silenced in H1975 and cisplatin-resistant A549 cells (A549-CDDP resistant) using lentiviral vectors. RNF38 expression levels were determined using quantitative real-time polymerase chain reaction and western blotting analysis. Cell viability in response to different concentrations of cisplatin was evaluated by Cell Counting Kit-8 assay. RNF38 expression levels were markedly elevated in NSCLC cells and cells harboring high RNF38 were less sensitive to cisplatin. Overexpression of RNF38 reduced, while RNF38 silencing increased the drug sensitivity of cisplatin in NSCLC cells. Cisplatin-resistant cells expressed high RNF38 level. RNF38 silencing promoted cell apoptosis and enhanced the drug sensitivity of cisplatin in cisplatin-resistant NSCLC cells. These findings indicate that RNF38 might induce cisplatin resistance of NSCLC cells via promoting cell apoptosis and RNF38 could be a novel target for rectify cisplatin resistance in NSCLC cases.     

Cytoglobin promotes sensitivity to ferroptosis by regulating p53-YAP1 axis in colon cancer cells

Ferroptosis is an iron-dependent mode of non-apoptotic cell death characterized by accumulation of lipid reactive oxygen species (ROS). As a regulator of ROS, cytoglobin (CYGB) plays an important role in oxygen homeostasis and acts as a tumour suppressor. However, the mechanism by which CYGB regulates cell death is largely unknown. Here, we show that CYGB overexpression increased ROS accumulation and disrupted mitochondrial function as determined by the oxygen consumption rate and membrane potential. Importantly, ferroptotic features with accumulated lipid ROS and malondialdehyde were observed in CYGB-overexpressing colorectal cancer cells. Moreover, CYGB significantly increased the sensitivity of cancer cells to RSL3- and erastin-induced ferroptotic cell death. Mechanically, both YAP1 and p53 were significantly increased based on the RNA sequencing. The knock-down of YAP1 alleviated production of lipid ROS and sensitivity to ferroptosis in CYGB overexpressed cells. Furthermore, YAP1 was identified to be inhibited by p53 knock-down. Finally, high expression level of CYGB had the close correlation with key genes YAP1 and ACSL4 in ferroptosis pathway in colon cancer based on analysis from TCGA data. Collectively, our results demonstrated a novel tumour suppressor role of CYGB through p53-YAP1 axis in regulating ferroptosis and suggested a potential therapeutic approach for colon cancer.     

Comprehensive serum N-glycan profiling identifies a biomarker panel for early diagnosis of non-small-cell lung cancer

Aberrant serum N-glycan profiles have been observed in multiple cancers including non-small-cell lung cancer (NSCLC), yet the potential of N-glycans in the early diagnosis of NSCLC remains to be determined. In this study, serum N-glycan profiles of 275 NSCLC patients and 309 healthy controls were characterized by MALDI-TOF-MS. The levels of serum N-glycans and N-glycosylation patterns were compared between NSCLC and control groups. In addition, a panel of N-glycan biomarkers for NSCLC diagnosis was established and validated using machine learning algorithms. As a result, a total of 54 N-glycan structures were identified in human serum. Compared with healthy controls, 29 serum N-glycans were increased or decreased in NSCLC patients. N-glycan abundance in different histological types or clinical stages of NSCLC presented differentiated changes. Furthermore, an optimal biomarker panel of eight N-glycans was constructed based on logistic regression, with an AUC of 0.86 in the validation set. Notably, this model also showed a desirable capacity in distinguishing early-stage patients from healthy controls (AUC = 0.88). In conclusion, our work highlights the abnormal N-glycan profiles in NSCLC and provides supports potential application of N-glycan biomarker panel in clinical NSCLC detection.     

Targeting epidermal growth factor receptors inhibition in non-small-cell lung cancer: a computational approach

Epidermal growth factor receptors (EGFRs) are transmembrane receptors present on cell membranes, play an important role in controlling cell growth, apoptosis and other cellular functions. They have an extracellular binding moiety, a transmembrane component and an intracellular tyrosine kinase unit. Mutations of EGFRs can lead to continual or abnormal activation of the receptors causing unregulated cell division, causing cancer such as non-small-cell lung cancer (NSCLC). Hence, the objective is to recognise the potential drug targets through generating pharmacophoric pattern, identifying and building suitable ligands and docking studies with dynamics applications. The pharmacophore of these compounds explains about physicochemical properties required for designing new compounds which provides the design to develop desired targeted drug therapy. The simulation uncovers changes in the width of the essential channel to the active site, extensive to concede substrates. This study concludes the interaction of EGFRs with its inhibitors through computational modelling which can be important initial steps toward the development of novel pharmaceuticals in the fight against NSCLC.