Lung Cancer Pathology: Current Concepts

Classification of lung cancer subtypes on CT images with synthetic pathological priors

The accurate diagnosis on pathological subtypes for lung cancer is of significant importance for the follow-up treatments and prognosis managements. In this paper, we propose self-generating hybrid feature network (SGHF-Net) for accurately classifying lung cancer subtypes on computed tomography (CT) images. Inspired by studies stating that cross-scale associations exist in the image patterns between the same case's CT images and its pathological images, we innovatively developed a pathological feature synthetic module (PFSM), which quantitatively maps cross-modality associations through deep neural networks, to derive the "gold standard" information contained in the corresponding pathological images from CT images. Additionally, we designed a radiological feature extraction module (RFEM) to directly acquire CT image information and integrated it with the pathological priors under an effective feature fusion framework, enabling the entire classification model to generate more indicative and specific pathologically related features and eventually output more accurate predictions. The superiority of the proposed model lies in its ability to self-generate hybrid features that contain multi-modality image information based on a single-modality input. To evaluate the effectiveness, adaptability, and generalization ability of our model, we performed extensive experiments on a large-scale multi-center dataset (i.e., 829 cases from three hospitals) to compare our model and a series of state-of-the-art (SOTA) classification models. The experimental results demonstrated the superiority of our model for lung cancer subtypes classification with significant accuracy improvements in terms of accuracy (ACC), area under the curve (AUC), positive predictive value (PPV) and F1-score.

Inhibition of ASAP1 Modulates the Tumor Immune Microenvironment and Suppresses Lung Cancer Metastasis via the p-STAT3 Signaling Pathway

ADP ribosylation factor guanylate kinase 1 (ASAP1), a key protein regulating cell migration and invasion, has attracted extensive attention in oncological research in recent years. This study aims to explore the effects of ASAP1 inhibition on lung cancer metastasis and its potential mechanisms, particularly how it modulates the tumor immune microenvironment through the p-STAT3 signaling pathway. In this study, shRNA technology was employed to specifically inhibit ASAP1 expression in lung cancer cell lines A549, NCI-H1299, and PC-9. The effects of ASAP1 inhibition on lung cancer cell viability, apoptosis, migration, and invasion were evaluated using CCK-8, TUNEL apoptosis detection, and cell migration and invasion assays. Furthermore, animal experiments were conducted to assess the in vivo effects of ASAP1 inhibition on lung cancer metastasis, and immunohistochemical analysis was performed to investigate changes in immune cells in lung metastasis models, further exploring its impact on the tumor immune microenvironment. The experimental results demonstrated that ASAP1 inhibition significantly reduced lung cancer cell viability, induced apoptosis in A549, NCI-H1299, and PC-9 cells, and suppressed the migration and invasion abilities of these cells. In vivo experiments revealed that ASAP1 inhibition effectively suppressed lung cancer metastasis and altered the tumor immune microenvironment by regulating immune cells. Moreover, we found that ASAP1 inhibition could decrease tumor cell proliferation and induce tumor apoptosis in lung metastasis models by inhibiting the p-STAT3 signaling pathway. This study confirms that ASAP1 inhibition can suppress lung cancer metastasis by modulating the tumor immune microenvironment through the inhibition of the p-STAT3 signaling pathway. These findings provide new targets for lung cancer treatment and a theoretical basis for developing novel strategies against lung cancer metastasis. Future research will further explore the mechanisms of ASAP1 in lung cancer metastasis and how to optimize treatment strategies for lung cancer patients by targeting ASAP1.

Impact of treatment interval between neoadjuvant immunochemotherapy and surgery in lung squamous cell carcinoma

OBJECTIVE

The optimal timing for surgery following neoadjuvant immunochemotherapy for lung squamous cell carcinoma appears to be a topic of limited data. Many clinical studies lack stringent guidelines regarding this timing. The objective of this study is to explore the effect of the interval between neoadjuvant immunochemotherapy and surgery on survival outcomes in patients with lung squamous cell carcinoma.

METHODS

This study conducted a retrospective analysis of patients with lung squamous cell carcinoma who underwent neoadjuvant immunochemotherapy between January 2019 and October 2022 at The First Affiliated Hospital, Zhejiang University School of Medicine. Patients were divided into two groups based on the treatment interval: ≤33 days and > 33 days. The primary observational endpoints of the study were Disease-Free Survival (DFS) and Overall Survival (OS). Secondary observational endpoints included Objective response rate (ORR), Major Pathological Response (MPR), and Pathological Complete Remission (pCR).

RESULTS

Using the Kaplan-Meier methods, the ≤ 33d group demonstrated a superior DFS curve compared to the > 33d group (p = 0.0015). The median DFS for the two groups was 952 days and 590 days, respectively. There was no statistical difference in the OS curves between the groups (p = 0.66), and the median OS was not reached for either group. The treatment interval did not influence the pathologic response of the tumor or lymph nodes.

CONCLUSIONS

The study observed that shorter treatment intervals were associated with improved DFS, without influencing OS, pathologic response, or surgical safety. Patients should avoid having a prolonged treatment interval between neoadjuvant immunochemotherapy and surgery.

Usenamine A triggers NLRP3/caspase-1/GSDMD-mediated pyroptosis in lung adenocarcinoma by targeting the DDX3X/SQSTM1 axis

BACKGROUND

Usenamine A (C18H17NO6) is a newly developed, natural anticancer drug that reportedly exerts low toxicity. The therapeutic efficacy and underlying mechanisms of usenamine A in lung adenocarcinoma (LUAD) remain poorly understood. We aimed to explore the therapeutic effects and molecular mechanisms through which usenamine A inhibits LUAD tumorigenesis.

METHODS

We used LUAD cell lines H1299 and A549 in the present study. CCK-8 and colony formation assays were performed to analyze cell proliferation. Cell migration, invasion, and apoptosis were evaluated using wound-healing, transwell, and flow cytometric assays, respectively. Levels of reactive oxygen species were measured using a DCFH-DA probe. Inflammatory factors (lactate dehydrogenase, interleukin [IL]-1β, and IL-18) were detected using enzyme-linked immunosorbent assays. Western blotting was performed to determine the expression of NOD-like receptor pyrin 3 (NLRP3)/caspase-1/gasdermin D (GSDMD) pathway-related proteins. Pyroptosis was detected using transmission electron microscopy. The interaction and co-localization of DDX3X and sequestosome 1 (SQSTM1) were identified using co-immunoprecipitation and immunofluorescence assays, respectively. For in vivo assessment, we established a xenograft model to validate the usenamine A-mediated effects and mechanisms of action in LUAD.

RESULTS

Usenamine A inhibited the proliferation, migration, and invasion of LUAD cells. Furthermore, usenamine A induced NLRP3/caspase-1/GSDMD-mediated pyroptosis in LUAD cells. Usenamine A upregulated DDX3X expression to trigger pyroptosis. DDX3X interacted with SQSTM1, which is responsible for inducing pyroptosis. In vivo, usenamine A suppressed LUAD tumorigenesis by triggering NLRP3/caspase-1/GSDMD-mediated pyroptosis via the upregulation of the DDX3X/SQSTM1 axis.

CONCLUSIONS

Usenamine A was found to induce NLRP3/caspase-1/GSDMD-mediated pyroptosis in LUAD by upregulating the DDX3X/SQSTM1 axis.

G6PD is a prognostic biomarker correlated with immune infiltrates in lung adenocarcinoma and pulmonary arterial hypertension

BACKGROUND

Lung adenocarcinoma (LUAD) with Pulmonary arterial hypertension (PAH) shows a poor prognosis. Detecting related genes is imperative for prognosis prediction.

METHODS

The gene expression profiles of LUAD and PAH were acquired from The Cancer Genome Atlas (TCGA) and the Gene Expression Omnibus (GEO) database, respectively. The co-expression modules associated with LUAD and PAH were evaluated using the Weighted Gene Co-Expression Network Analysis (WGCNA). The relationship between key gene expression with immune-cell infiltration and the tumor immune microenvironment (TIME) was evaluated. We confirmed the mRNA and protein levels in vivo and vitro. G6PD knockdown was used to conduct the colony formation assay, transwell invasion assay, and scratch wound assay of A549 cells. EDU staining and CCK8 assay were performed on G6PD knockdown HPASMCs. We identified therapeutic drug molecules and performed molecular docking between the key gene and small drug molecules.

RESULTS

Three major modules and 52 overlapped genes were recognized in LUAD and PAH. We identified the key gene G6PD, which was significantly upregulated in LUAD and PAH. In addition, we discovered a significant difference in infiltration for most immune cells between high- and low-G6PD expression groups. The mRNA and protein expressions of G6PD were significantly upregulated in LUAD and PAH. G6PD knockdown decreased proliferation, cloning, and migration of A549 cells and cell proliferation in HPASMCs. We screened five potential drug molecules against G6PD and targeted glutaraldehyde by molecular docking.

CONCLUSIONS

This study reveals that G6PD is an immune-related biomarker and a possible therapeutic target for LUAD and PAH patients.

Schizandrin A induces non-small cell lung cancer apoptosis by suppressing the epidermal growth factor receptor activation

OBJECTIVE

The purpose of this study is to explore the biological mechanism of Schizandrin A (SchA) inducing non-small cell lung cancer (NSCLC) apoptosis.

METHODS

The reverse molecular docking tool "Swiss Target Prediction" was used to predict the targets of SchA. Protein-protein interaction analysis was performed on potential targets using the String database. Functional enrichment analyses of potential targets were performed with Gene Ontology and Kyoto Encyclopedia of Genes and Genomes. The conformation of SchA binding to target was simulated by chemical-protein interactomics and molecular docking. The effect of SchA on the expression and phosphorylation level of EGFR was detected by Western blot. Lipofectamine 3000 and EGFR plasmids were used to overexpress EGFR. Apoptosis was tested with Annexin V-FITC and propidium iodide staining, and cell cycle was detected by propidium iodide staining.

RESULTS

The "Swiss Target Prediction" database predicted 112 and 111 targets based on the 2D and 3D structures of SchA, respectively, of which kinases accounted for the most, accounting for 24%. Protein interaction network analyses showed that molecular targets such as ERBB family and SRC were at the center of the network. Functional enrichment analyses indicated that ERBB-related signaling pathways were enriched. Compound-protein interactomics and molecular docking revealed that SchA could bind to the ATP-active pocket of the EGFR tyrosine kinase domain. Laboratory results showed that SchA inhibited the phosphorylation of EGFR. Insulin could counteract the cytotoxic effect of SchA. EGFR overexpression and excess EGF or IGF-1 had limited impacts on the cytotoxicity of SchA.

CONCLUSIONS

Network pharmacology analyses suggested that ERBB family members may be the targets of SchA. SchA can inhibit NSCLC at least in part by inhibiting EGFR phosphorylation, and activating the EGFR bypass can neutralize the cytotoxicity of SchA.

FOXM1 and CENPF are associated with a poor prognosis through promoting proliferation and migration in lung adenocarcinoma

Lung adenocarcinoma (LUAD) is a clinically challenging disease due to its poor prognosis and limited therapeutic methods. The aim of the present study was to identify prognosis-related genes and therapeutic targets for LUAD. Raw data from the GSE32863, GSE41271 and GSE42127 datasets were downloaded from the Gene Expression Omnibus database. Following normalization, the data were merged into a matrix, which was first used to identify differentially expressed genes (DEGs). Weighted gene co-expression network analysis (WGCNA) and survival analysis were performed to screen potential prognosis-related genes. Gene overlaps among DEGs, survival-related genes and WGCNA genes were finally constructed to obtain candidate genes. An analysis with the STRING database was performed to construct a protein-protein interaction network and hub genes were selected using Cytoscape. The candidate genes were finally identified by univariate and multivariate Cox regression analysis. Furthermore, in vivo and in vitro experiments, including immunohistochemistry, immunofluorescence, Cell Counting Kit-8, colony-formation and migration assays, were performed to validate the potential mechanism of these genes in LUAD. Two genes, namely forkhead box M1 (FOXM1) and centromere protein F (CENPF), were identified as unfavorable indicators of prognosis in patients with LUAD. High expression of FOXM1 and CENPF were associated with poor survival. Furthermore, LUAD cells with FOXM1 and CENPF knockdown showed a significant reduction in proliferation and migration (P<0.05). FOXM1 and CENPF may have an essential role in the prognosis of patients with LUAD by influencing cell proliferation and migration, and they provide potential molecular targets for LUAD therapy.

Leveraging a disulfidptosis/ferroptosis-based signature to predict the prognosis of lung adenocarcinoma

BACKGROUND

Disulfidptosis and Ferroptosis are two novel forms of cell death. Although their mechanisms differ, research has shown that there is a relationship between the two. Investigating the connection between these two forms of cell death can further deepen our understanding of the development and progression of cancer, and provide better prediction models for accurate prognosis.

METHODS

In this study, RNA sequencing (RNA-seq) data, clinical data, single nucleotide polymorphism (SNP) data, and single-cell sequencing data were obtained from public databases. We used weighted gene co-expression network analysis (WGCNA) and unsupervised clustering to identify new Disulfidptosis/Ferroptosis-Related Genes (DFRG), and constructed a LASSO COX prognosis model that was externally validated. To further explore this novel signature, pathway and function analysis was performed, and differences in gene mutation frequency between high- and low-risk groups were studied. Importantly, we also conducted research on immune checkpoint, immune cell infiltration levels and immune resistance indicators, in addition to analyzing real clinical immunotherapy data.

RESULTS

We have identified four optimal disulfidptosis/ferroptosis-related genes (ODFRGs) that are differentially expressed and associated with the prognosis of Lung Adenocarcinoma (LUAD). These genes include GMPR, MCFD2, MRPL13, and SALL2. Based on these ODFRGs, we constructed a robust prognostic model in this study, and the high-risk group showed significantly lower overall survival (OS) compared to the low-risk group. Furthermore, this model can also predict the immunotherapy outcomes of LUAD patients to some extent.

Silencing of Perilipin 3 Inhibits Lung Adenocarcinoma Cell Immune Resistance by Regulating the Transcription of PD-L1 Through c-Myc

BACKGROUND

Perilipin 3 (PLIN3), a lipid droplet-associated protein, is found to be highly expressed in human cancers. This study aimed to investigate the biological functions and underlying mechanism of PLIN3 in lung adenocarcinoma (LUAD).

METHODS

To analyse PLIN3 expression in normal and cancerous tissues, relevance between PLIN3 expression and survival prognosis, and to predict the pathways related to PLIN3, bioinformatic analysis was performed. In A549 and H1299 cells, qRT-PCR or western blotting was used to determine mRNA/protein expression of PLIN3, PD-L1, and c-Myc. In A549 and H1299 cells, CCK-8 assay, EdU, and flow cytometry were used to assess cell viability, proliferation, and apoptosis. Chip and luciferase reporter assays were performed to verify the binding of PD-L1 with c-Myc. The functions of PLIN3 were examined in vivo in a xenograft tumor model.

RESULTS

In LUAD tissues and cells, PLIN3 expression was downregulated. A shorter survival time was observed in patients with high PLIN3 expression than in patients with low PLIN3 expression. Silencing of PLIN3 inhibited cell proliferation, PD-L1 expression, and Myc pathway, as well as induced apoptosis in LUAD cells. c-Myc acts as a transcription factor of PD-L1. Moreover, the inhibitory actions of PLIN3 silencing on c-Myc and PD-L1 expression as well as cell proliferation and stimulatory action of PLIN3 silencing on cell apoptosis were reversed by c-Myc overexpression. In vivo, PLIN3 silencing inhibited the growth of xenograft tumour and reduced PLIN3, PD-L1, and c-Myc protein expression.

CONCLUSION

Silencing of PLIN3 inhibited tumour growth by regulating the Myc/PD-L1 pathway.

Cucurbitacin E Exerts Anti-Proliferative Activity via Promoting p62-Dependent Apoptosis in Human Non-Small-Cell Lung Cancer A549 Cells

EGFR tyrosine kinase inhibitors (TKIs) are the first-line treatment for advanced EGFR-mutated non-small-cell lung cancer (NSCLC). However, NSCLC patients with wild-type EGFR and KRAS mutation are ineligible for EGFR-TKIs. Therefore, the discovery of new therapeutic agents is urgently needed for NSCLC patients who cannot receive targeted therapies. Natural products possess tremendous chemical diversity and have been extensively investigated for their anticancer activity. In this study, we found that Cucurbitacin E (Cu E), a triterpene of cucurbitacins widely presented in the edible plants of the Cucurbitaceae family, significantly inhibits the viability and proliferation of A549 cells that harbor wild-type EGFR and KRAS mutation. Our results revealed that Cu E increases cell-cycle arrest at G2/M and subG1 phase. Mechanistically, Cu E significantly inhibits the phosphorylation and protein levels of regulatory proteins and hinders G2/M cell-cycle progression. Meanwhile, the treatment of Cu E resulted in DNA damage response and apoptosis. For the first time, we observed that Cu E induces incomplete autophagy as evidenced by increased LC3B-II expression and p62-accumulation. Knockdown of p62 rescued the cells from Cu E-mediated anti-proliferative effect, apoptosis, DNA damage, and ROS production. These findings suggest that Cu E is a promising drug candidate for NSCLC.

Potential roles of exosomes in the initiation and metastatic progression of lung cancer

Lung cancer (LC) incidence and mortality continue to increase annually worldwide. LC is insidious and readily metastasizes and relapses. Except for its early diagnosis and surgical resection, there is no effective cure for advanced metastatic LC, and the prognosis remains dismal. Exosomes, a class of nano-sized extracellular vesicles produced by healthy or diseased cells, are coated with a bilayer lipid membrane and contain various functional molecules such as proteins, lipids, and nucleic acids. They can be used for intracellular or intercellular signaling or the transportation of biological substances. A growing body of evidence supports that exosomes play multiple crucial roles in the occurrence and metastatic progression of many malignancies, including LC. The elucidation of the potential roles of exosomes in the initiation, invasion, and metastasis of LC and their underlying molecular mechanisms may contribute to improved early diagnosis and treatment.

Intratumoral Microbiota-Host Interactions Shape the Variability of Lung Adenocarcinoma and Lung Squamous Cell Carcinoma in Recurrence and Metastasis

Differences in tissue microbiota-host interaction between lung squamous cell carcinoma (LUSC) and lung adenocarcinoma (LUAD) about recurrence and metastasis have not been well studied. In this study, we performed bioinformatics analyses to identify the genes and tissue microbes significantly associated with recurrence or metastasis. All lung cancer patients were divided into the recurrence or metastasis (RM) group and the nonrecurrence and nonmetastasis (non-RM) group according to whether or not they had recurred or metastasized within 3 years after the initial surgery. Results showed that there were significant differences between LUAD and LUSC in gene expression and microbial abundance associated with recurrence and metastasis. Compared with non-RM, the bacterial community of RM had a lower richness in LUSC. In LUSC, host genes significantly correlated with tissue microbe, whereas host-tissue microbe interaction in LUAD was rare. Then, we established a novel multimodal machine learning model based on genes and microbes to predict the recurrence and metastasis risk of a LUSC patient, which achieves an area under the curve (AUC) of 0.81. In addition, the predicted risk score was significantly associated with the patient's survival. IMPORTANCE Our study elucidates significant differences in RM-associated host-microbe interactions between LUAD and LUSC. Besides, the microbes in tumor tissue could be used to predict the RM risk of LUSC, and the predicted risk score is associated with patients' survival.

A nomogram combining thoracic CT and tumor markers to predict the malignant grade of pulmonary nodules ≤3 cm in diameter

Background

With the popularity of computed tomography (CT) of the thorax, the rate of diagnosis for patients with early-stage lung cancer has increased. However, distinguishing high-risk pulmonary nodules (HRPNs) from low-risk pulmonary nodules (LRPNs) before surgery remains challenging.

Methods

A retrospective analysis was performed on 1064 patients with pulmonary nodules (PNs) admitted to the Qilu Hospital of Shandong University from April to December 2021. Randomization of all eligible patients to either the training or validation cohort was performed in a 3:1 ratio. Eighty-three PNs patients who visited Qianfoshan Hospital in the Shandong Province from January through April of 2022 were included as an external validation. Univariable and multivariable logistic regression (forward stepwise regression) were used to identify independent risk factors, and a predictive model and dynamic web nomogram were constructed by integrating these risk factors.

Results

A total of 895 patients were included, with an incidence of HRPNs of 47.3% (423/895). Logistic regression analysis identified four independent risk factors: the size, consolidation tumor ratio, CT value of PNs, and carcinoembryonic antigen levels in blood. The area under the ROC curves was 0.895, 0.936, and 0.812 for the training, internal validation, and external validation cohorts, respectively. The Hosmer-Lemeshow test demonstrated excellent calibration capability, and the fit of the calibration curve was good. DCA has shown the nomogram to be clinically useful.

Conclusion

The nomogram performed well in predicting the likelihood of HRPNs. In addition, it identified HRPNs in patients with PNs, achieved accurate treatment with HRPNs, and is expected to promote their rapid recovery.

Combination Chemotherapy with Selected Polyphenols in Preclinical and Clinical Studies-An Update Overview

This review article describes studies published over the past five years on the combination of polyphenols, which are the most studied in the field of anticancer effects (curcumin, quercetin, resveratrol, epigallocatechin gallate, and apigenin) and chemotherapeutics such as cisplatin, 5-fluorouracil, oxaliplatin, paclitaxel, etc. According to WHO data, research has been limited to five cancers with the highest morbidity rate (lung, colorectal, liver, gastric, and breast cancer). A systematic review of articles published in the past five years (from January 2018 to January 2023) was carried out with the help of all Web of Science databases and the available base of clinical studies. Based on the preclinical studies presented in this review, polyphenols can enhance drug efficacy and reduce chemoresistance through different molecular mechanisms. Considering the large number of studies, curcumin could be a molecule in future chemotherapy cocktails. One of the main problems in clinical research is related to the limited bioavailability of most polyphenols. The design of a new co-delivery system for drugs and polyphenols is essential for future clinical research. Some polyphenols work in synergy with chemotherapeutic drugs, but some polyphenols can act antagonistically, so caution is always required.

Clinical Relevance of Targeted Therapy and Immune-Checkpoint Inhibition in Lung Cancer

Lung cancer (LC) represents the second most diagnosed tumor and the malignancy with the highest mortality rate. In recent years, tremendous progress has been made in the treatment of this tumor thanks to the discovery, testing, and clinical approval of novel therapeutic approaches. Firstly, targeted therapies aimed at inhibiting specific mutated tyrosine kinases or downstream factors were approved in clinical practice. Secondly, immunotherapy inducing the reactivation of the immune system to efficiently eliminate LC cells has been approved. This review describes in depth both current and ongoing clinical studies, which allowed the approval of targeted therapies and immune-checkpoint inhibitors as standard of care for LC. Moreover, the present advantages and pitfalls of new therapeutic approaches will be discussed. Finally, the acquired importance of human microbiota as a novel source of LC biomarkers, as well as therapeutic targets to improve the efficacy of available therapies, was analyzed. Therapy against LC is increasingly becoming holistic, taking into consideration not only the genetic landscape of the tumor, but also the immune background and other individual variables, such as patient-specific gut microbial composition. On these bases, in the future, the research milestones reached will allow clinicians to treat LC patients with tailored approaches.

Primary pulmonary lymphoepithelial-like carcinoma : A rare childhood malignancy

Lymphoepithelial-like carcinoma (LELC) usually presents as a head and neck tumor with a close resemblance to nasopharyngeal carcinoma. We present an extremely rare case of Primary Pulmonary lymphoepithelioma in a 14-year-old female patient. The patient presented with a right-sided lung mass, which on biopsy revealed to be a lymphoepithelioma. There was no evidence of any mass elsewhere in the body, including the nasopharynx, as evidenced by PET CT. The IHC was positive for both cytokeratin and lymphoid cell markers. Hence, we conclude that lymphoepitheliomas can present as a primary lung mass in a young nonsmoking female, of which only two case reports are available from the Indian subcontinent till date.

CRISPRi screening identifies CASP8AP2 as an essential viability factor in lung cancer controlling tumor cell death via the AP-1 pathway

Since lung cancer remains the leading cause of cancer death globally, there is an urgent demand for novel therapeutic targets. We carried out a CRISPR interference (CRISPRi) loss-of-function screen for human lung adenocarcinoma (LUAD) targeting 2098 deregulated genes using a customized algorithm to comprehensively probe the functionality of every resolvable transcriptional start site (TSS). CASP8AP2 was identified as the only hit that significantly affected the viability of all eight screened LUAD cell lines while the viability of non-transformed lung cells was only moderately impacted. Knockdown (KD) of CASP8AP2 induced both autophagy and apoptotic cell death pathways. Systematic expression profiling linked the AP-1 transcription factor to the CASP8AP2 KD-induced cancer cell death. Furthermore, inhibition of AP-1 reverted the CASP8AP2 silencing-induced phenotype. Overall, the tailored CRISPRi screen profiled the impact of over 2000 genes on the survival of eight LUAD cell lines and identified the CASP8AP2 - AP-1 axis mediating lung cancer viability.

[Correlation Analysis of Ki67 Expression and EGFR Mutation on the Risk of Recurrence and Metastasis in Postoperative Patients with Stage I Lung Adenocarcinoma]

BACKGROUND

The prognosis of stage I non-small cell lung cancer (NSCLC) is generally good. However, some of the stage I NSCLC patients still may have early recurrence and metastasis, and there is no standard method to screen this part of the population. The aim of this study is to investigate the relationship between Ki67 expression as well as epidermal growth factor receptor (EGFR) mutation and the risk of recurrence in postoperative patients with stage I lung adenocarcinoma.

METHODS

We retrospectively enrolled 118 postoperative patients with stage I lung adenocarcinoma. EGFR mutation was tested using amplification refractory mutation system polymerase chain reaction (ARMS-PCR) , and Ki67 level was detected by immunohistochemistry (IHC), followed by the collection of the patients' clinical characteristics. Kaplan-Meier method, Log-rank test, and Cox proportional hazards regression model were used for the prognostic statistical analysis.

RESULTS

Among the 118 patients, the rate of high Ki67 expression was 43.22% (51/118), which is related to gender, smoking status, surgical method, differentiation degree, and postoperative stage (P<0.05). Meanwhile, EGFR mutation rate was 61.02% (72/118), of which EGFR exon 19 deletion mutation rate was 19.49% (23/118), and the EGFR exon 21 L858R mutation rate was 41.53% (49/118). However, Ki67 expression was not associated with EGFR mutation status (χ2=1.412, P=0.235). Survival analysis showed that high Ki67 expression was inversely associated with disease-free survival (DFS) and overall survival (OS) in stage I lung adenocarcinoma (P<0.05), but EGFR mutation status was not significantly associated with DFS and OS (P>0.05). In the subgroup analysis, the DFS of the EGFR exon 19 deletion group was significantly decreased compared with the EGFR exon 21 L858R mutation group (P=0.031), but there was no significant difference in OS (P=0.308). Multivariate analysis showed that there was statistical significance between Ki67 expression (P=0.001) and DFS in stage I lung adenocarcinoma; Ki67 expression (P=0.03) and gender (P=0.015) were associated with OS in stage I lung adenocarcinoma.

CONCLUSIONS

Ki67 expression is an independent influencing factor for postoperative recurrence and OS of stage I lung adenocarcinoma and it is not significantly associated with EGFR mutation. There is no significant difference between EGFR mutation status and the prognostis of stage I lung adenocarcinoma. However, the prognosis differed in EGFR mutation types; the patients with EGFR exon 19 deletion are at higher risk of recurrence than EGFR exon 21 L858R mutation.

Curcumin and Its Analogs in Non-Small Cell Lung Cancer Treatment: Challenges and Expectations

Researchers have made crucial advances in understanding the pathogenesis and therapeutics of non-small cell lung cancer (NSCLC), improving our understanding of lung tumor biology and progression. Although the survival of NSCLC patients has improved due to chemoradiotherapy, targeted therapy, and immunotherapy, overall NSCLC recovery and survival rates remain low. Thus, there is an urgent need for the continued development of novel NSCLC drugs or combination therapies with less toxicity. Although the anticancer effectiveness of curcumin (Cur) and some Cur analogs has been reported in many studies, the results of clinical trials have been inconsistent. Therefore, in this review, we collected the latest related reports about the anti-NSCLC mechanisms of Cur, its analogs, and Cur in combination with other chemotherapeutic agents via the Pubmed database (accessed on 18 June 2022). Furthermore, we speculated on the interplay of Cur and various molecular targets relevant to NSCLC with discovery studio and collected clinical trials of Cur against NSCLC to clarify the role of Cur and its analogs in NSCLC treatment. Despite their challenges, Cur/Cur analogs may serve as promising therapeutic agents or adjuvants for lung carcinoma treatment.

SOX2 regulates paclitaxel resistance of A549 non‑small cell lung cancer cells via promoting transcription of ClC‑3

Paclitaxel (PTX) is widely used in the treatment of non‑small cell lung cancer (NSCLC). However, acquired PTX drug resistance is a major obstacle to its therapeutic efficacy and the underlying mechanisms are still unclear. The present study revealed a novel role of the SRY‑box transcription factor 2 (SOX2)‑chloride voltage‑gated channel‑3 (ClC‑3) axis in PTX resistance of A549 NSCLC cells. The expression levels of SOX2 and ClC‑3 were upregulated in PTX‑resistant A549 NSCLC cells by RT‑qPCR and western blotting. The drug resistance to PTX of A549 NSCLC cells were measured by detecting the cell viability and the expression of drug resistance markers. Knockdown of SOX2 or ClC‑3 effectively decreased PTX resistance of A549 NSCLC cells, whereas SOX2 or ClC‑3 overexpression promoted PTX resistance. Mechanistically, SOX2 bound to the promoter of ClC‑3 and enhanced the transcriptional activation of ClC‑3 expression by CUT&Tag assays, CUT&Tag qPCR and luciferase reporter. In summary, the present findings defined ClC‑3 as an important downstream effector of SOX2 and ClC‑3 and SOX2 contributed to PTX resistance. Targeting SOX2 and its downstream effector ClC‑3 increased the sensitivity of NSCLC cells to PTX treatment, which provided potential therapeutic strategies for patients with NSCLC with PTX resistance.

Exploration and validation of hub genes in lung adenocarcinoma based on bioinformatics analysis

BACKGROUND

Genomic abnormality is a crucial factor for lung cancer development. This study used bioinformatics analysis to explore the hub genes involved in lung adenocarcinoma.

METHODS

The GeneCards, Comparative Toxicogenomics Database (CTD), and DISEASES databases were used to screen the genes associated with lung adenocarcinoma. The hub genes were then identified using WebGestalt. The Cancer Genome Atlas (TCGA), UALCAN, and the Human Protein Atlas (HPA) were used to validate the expression of hub genes. The predictive effects of hub genes on the risk of lung adenocarcinoma were evaluated using receiver operating characteristic (ROC) curve analysis. The Tumor-Immune System Interaction Database (TISIDB) was used to estimate the correlation between hub genes and immune infiltration.

RESULTS

A total of 21 genes were defined as common genes associated with lung adenocarcinoma, and from these, AKT1, CD44, and CDKN2A were identified as hub genes. Significant differences in the hub gene mRNA and protein expression were observed between lung adenocarcinoma samples and normal samples derived from the TCGA and UALCAN databases. The area under the ROC curve (AUC) for AKT1, CD44, and CDKN2A in predicting lung adenocarcinoma risk was 0.847, 0.880, and 0.805, respectively, with sensitivity of 89.8%, 93.2%, and 94.9%, respectively. TISIDB analysis indicated that AKT1, CD44, and CDKN2A expression had a strong relationship with immune infiltration in lung adenocarcinoma.

CONCLUSIONS

These hub genes, AKT1, CD44, and CDKN2A, may represent tumor biomarkers that may contribute to the understanding, diagnosis, and treatment of lung adenocarcinoma.

Handling and standardization of EBUS needle aspiration in NSCLC patients: The value of the cell block, a monoinstitutional experience

BACKGROUND

Lung cancer is the main cause of cancer-related death worldwide, and 85% of all lung tumors are non-small cell lung cancers (NSCLC). More than 60% of all lung tumors are diagnosed at an advanced stage, leading to poor prognosis. Given the growing demand for NSCLC profiling for selection of the most appropriate therapy, the acquisition of adequate tumor samples has become increasingly crucial, mostly in advanced NSCLC patients due to old age and/or comorbidities. Being a mini-invasive sampling technique, endobronchial ultrasound-guided transbronchial needle aspiration (EBUS-TBNA) represents a valuable alternative to traditional transthoracic or surgical sampling in these patients, and perfoming cell block (CB) could be crucial to maximize the potential biological information. The aim of this study is to describe a monoinstitutional interprofessional experience in handling EBUS-TBNA and CB in 464 patients.

METHODS

We retrospectively collected all the consecutive CBs obtained from EBUS TBNA performed between 2014 and 2021 on the lung lesions or mediastinal lymph nodes. All the CBs were handled in a standardized method.

RESULTS

A total of 95.5% (448/464 samples) of adequacy for site and 92.6% (430/464) of adequacy for diagnosis were observed. Moreover, in the adenocarcinoma histotype, ALK, ROS1 and tumor proportion score (TPS) PD-L1 assessment by IHC was possible in 96% (140/146) of cases, and molecular profile was obtained in 93.8% (137/146) of cases. In the squamous cell carcinoma histotype, TPS PD-L1 assessment was possible in 81% (13/16) of cases. All four CB results obtained from carcinoma NOS were adequate for ALK, ROS1 and PD-L1 assessment and molecular profiling. All 39 metastatic samples from extra-pulmonary primary were adequate for immunohistochemical characterization and molecular profiling. Finally, reporting of the tumor sample adequacy to the clinicians took a median time of about 30 h (range: 24-80 h).

CONCLUSION

Careful cytological smear management together with the handling and standardization of CB obtained from EBUS-TBNA could represent an effective method to increase the adequacy of the tumor specimen for both diagnosis and molecular profile.

The Change in Paradigm for NSCLC Patients with EML4–ALK Translocation

The severe prognosis linked with a lung cancer diagnosis has changed with the discovery of oncogenic molecularly driven subgroups and the use of tailored treatment. ALK-translocated advanced lung cancer is the most interesting model, having achieved the longest overall survival. Here, we report the most important paradigmatic shifts in the prognosis and treatment for this subgroup population occurred among lung cancer.

QKI-6 Suppresses Cell Proliferation, Migration, and EMT in Non-Small Cell Lung Cancer

The RNA-binding protein quaking homolog 6 (QKI-6) is a tumor-suppressor gene in several cancers. However, its role in non-small cell lung cancer (NSCLC) is unclear. In this study, we aimed to determine the association between QKI-6 expression and survival and clinicopathological features in patients with NSCLC and identify the related mechanisms. Western blot and immunohistochemistry (IHC) were used to detect QKI-6 expression in NSCLC. The effect of QKI-6 on NSCLC cells was determined by overexpression and knockdown assays, and label-free quantitative proteomics and Western blot were used to identify the underlying mechanisms. Low QKI-6 expression level was positively correlated with poor overall survival in patients with NSCLC. Furthermore, QKI-6 overexpression inhibited NSCLC cell proliferation and migration and induced a block in the G0/G1 phase, and QKI-6 downregulation increased proliferation and migration. QKI-6 inhibited EMT processes via EGFR/SRC/STAT3 signaling by upregulating AGR2. In conclusion, QKI-6 could be used to develop novel strategies for the treatment of NSCLC.

TXNDC9 knockdown inhibits lung adenocarcinoma progression by targeting YWHAG

Lung adenocarcinoma (LUAD) is the most common form of lung cancer and with the highest mortality rate. Therefore, the identification and development of effective methods for the treatment of LUAD is of great importance. The present study aimed to investigate the role of thioredoxin domain-containing protein 9 (TXNDC9) and tyrosine 3-monooxygenase/tryptophan 5-monooxygenase activation protein γ (YWHAG; also known as 14-3-3γ) in the progression of LUAD. The expression of TXNDC9 and its association with the survival of patients with LUAD was analyzed using Encyclopedia of RNA Interactomes. Reverse transcription-quantitative PCR and western blot analysis were used to detect TXNDC9 mRNA and protein expression levels, respectively, in in vitro studies. To investigate the role of TXNDC9 in the progression of LUAD, TXNDC9 was silenced using small interfering RNA transfection. Furthermore, the viability, proliferation, migration, invasiveness and apoptosis of TXNDC9-silenced A549 cells were detected using Cell Counting Kit (CCK)-8, colony formation, wound healing, Transwell and TUNEL assays, respectively. The association between TXNDC9 and YWHAG was analyzed using STRING and Gene Expression Profiling Interactive Analysis databases, as well as co-immunoprecipitation assays. Subsequently, YWHAG was overexpressed to similarly determine effects of YWHAG on viability, proliferation, migration, invasiveness and apoptosis of A549 cells. TXNDC9 expression was markedly upregulated in lung cancer cells, particularly A549 cells, and silencing of TXNDC9 expression suppressed the viability of the lung cancer cells. The results also revealed that TXNDC9 silencing exerted inhibitory effects on the viability, proliferation, migration and invasiveness of A549 cells, whereas the apoptotic rate was increased. Similar to TXNDC9, YWHAG expression was also upregulated in the A549 cells. Furthermore, TXNDC9 was demonstrated to bind to YWHAG and was positively associated with YWHAG. YWHAG overexpression reversed the inhibitory effects of TXNDC9 silencing on LUAD, as evidenced by increased viability, proliferation, migration and invasiveness, and decreased apoptosis, of A549 cells. The present study demonstrated that the knockdown of TXNDC9 exerted suppressive effects on LUAD, whereas YWHAG overexpression reversed the inhibitory effects of TXNDC9 silencing on LUAD. Therefore, TXNDC9 silencing may exert protective effects against LUAD by targeting YWHAG.

Based on SEER Database: Population Distribution, Survival Analysis, and Prognostic Factors of Organ Metastasis of Lung Large Cell Neuroendocrine Carcinoma

Background

The incidence rate of lung large cell neuroendocrine carcinoma (LCNEC) in lung cancer is low, but the malignancy is high and the prognosis is poor. We used the Surveillance, Epidemiology, and End Results (SEER) database to determine the population distribution of organ metastasis in LCNEC, conduct survival analysis, judge prognostic factors, and provide direction for follow-up diagnosis and treatment.

Materials and methods

By logging into the SEER database, the data of lung LCNEC were retrieved and the target population was selected. According to the presence or absence of organ metastasis (bone, brain, liver, and lung), we divided the target population into the no organ metastasis group (n = 1,202) and the organ metastasis group (n = 870). By analyzing the clinicopathological data of patients and using the survival function, the corresponding median survival time was obtained, and the influencing factors of each group were analyzed. Then, the significant influencing factors were analyzed by multivariate Cox regression analysis to screen out the independent influencing factors.

Result

In the overall sample group, multivariate Cox regression analysis showed that sex, age, primary site surgery, bone metastasis, brain metastasis, liver metastasis, radiotherapy, and chemotherapy were independent prognostic factors. The 1-year survival rate was 13.8% in the bone metastasis group, 19.1% in the brain metastasis group, 13.8% in the liver metastasis group, and 20.3% in the intrapulmonary metastasis group. In the organ metastasis group, multivariate Cox regression analysis showed that sex, chemotherapy, radiotherapy sequence with surgery, primary site surgery, liver metastasis, and age at diagnosis were independent factors affecting the prognosis.

Conclusion

In the overall sample of LCNEC, bone metastasis, brain metastasis, and liver metastasis all reduced the overall survival time, while the effect of intrapulmonary metastasis on the overall survival time was not statistically significant. Sex, chemotherapy, radiotherapy sequence with surgery, primary site surgery, liver metastasis, and age were independent factors affecting the prognosis of the LCNEC organ metastasis group. Women, chemotherapy, and radiotherapy sequence with surgery were favorable factors, while old age, liver metastasis, and male were unfavorable factors.

Parameters of Dual-Layer Spectral Detector CT could be Used to Differentiate Non-Small Cell Lung Cancer from Small Cell Lung Cancer

BACKGROUND AND OBJECTIVE

Differentiating non-small cell lung cancer (NSCLC) from small cell lung cancer (SCLC) remains a substantial challenge. This study aimed at evaluating the performance of dual-layer spectral detector CT (DLCT) in differentiating NSCLC from SCLC.

METHODS

Spectral images of 247 cancer patients confirmed by pathology were retrospectively analyzed in both the arterial phase (AP) and the venous phase (VP), which includes 197 cases of NSCLC and 50 cases of SCLC. Effective atomic umber (Z-eff), Spectral CT-Mono Energetic (MonoE [40keV~90keV]), iodine density (ID) and thoracic aorta iodine density (IDaorta) in contrast-enhanced images were calculated and compared between the SCLC and NSCLC subgroups of tumors. Slope of spectral curve (λ, interval of 10 keV) and normalized iodine density (NID) was calculated between the SCLC and NSCLC too. Through statistical analysis, the diagnostic efficiency of each spectral parameter was calculated, and the difference of their efficiency was analyzed.

RESULTS

Both in NSCLS and SCLC, all parameters in VP were significantly higher than those in AP (p<0.001), except for λ90. There were significant differences in all spectral parameters between NSCLS and SCLC, both in AP and VP (p < 0.001). Except VP-λ90, there was no significant difference in ROC curves of all spectral parameters. VP-NID has the best diagnostic performance with AUC value of 0.917 (95%[CI]: 0.870~0.965), sensitivity and specificity of 92.9%, 80%, and diagnostic threshold of 0.217.

CONCLUSION

All parameters of DLCT have high diagnostic efficiency in differentiating NSCLC from SCLC except for VP-λ90, and VP-NID has the highest diagnostic efficiency.

Notch3 regulates ferroptosis via ROS-induced lipid peroxidation in NSCLC cells

Ferroptosis is type of programmed cell death (PCD), which is known to be involved in certain cancers. Notch3 signaling is reported to be involved in the tumorigenesis of non-small cell lung cancer (NSCLC) and regulates iron metabolism, lipid synthesis and oxidative stress in some tissues. However, whether Notch3 signaling regulates ferroptosis is unclear. In this study, we found that ferroptosis inhibitors, ferrostatin-1 and liproxstatin-1, protected against cell death induced by Notch3 knockdown and that Notch3 knockdown initiated ferroptosis in NSCLC cells by increasing reactive oxygen species (ROS) levels, lipid peroxidation, and Fe²⁺ levels, accompanied by downregulation of glutathione4 (GPX4) and peroxiredoxin6 (PRDX6). Conversely, Notch3 intracellular domain (NICD3) overexpression suppressed erastin-induced ferroptosis, which was synergistically enhanced by MJ33 in H1299 cells via a decrease in ROS levels and lipid peroxidation, accompanied by upregulation of GPX4 and PRDX6. Moreover, Notch3 knockdown decreased tumorigenesis in vivo with downregulation of GPX4 and PRDX6. In summary, here we have identified Notch3 as a potential negative regulator of ferroptosis in NSCLC.

Construction and validation of a novel prognostic model for lung squamous cell cancer based on N6-methyladenosine-related genes

Background

N6-methyladenosine (m6A) is the most prevalent modification in mRNA in biological processes and associated with various malignant tumor initiation and progression. The present study aimed to construct a prognostic risk model based on m6A-related genes (the downstream genes influenced by m6A modulators) for LUSC.

Methods

Based on TCGA, we stratified LUSC patients with and without genetic alteration of m6A modulators into altered and unaltered groups. Using univariate Cox and Lasso regression analyses, we identified prognostic m6A-related genes to construct a prognostic risk model. We then applied a multivariate Cox proportional regression model and the survival analysis to evaluate the risk model. Moreover, we performed the Receiver operating characteristic curve to assess the efficiency of the prognostic model based on TCGA and GSE43131. We analyzed the characteristics of tumor-associated immune cell infiltration in LUSC through the CIBERSORT method.

Results

Three m6A-related genes (FAM71F1, MT1E, and MYEOV) were identified as prognostic genes for LUSC. A novel prognostic risk model based on the three m6A-related genes was constructed. The multivariate Cox analysis showed that the prognostic risk model was an independent risk factor (HR = 2.44, 95% CI = 1.21~3.56, p = 0.029). Patients with a high-risk group had worse overall survival both in TCGA (p = 0.018) and GSE43131 (p = 0.00017). The 1, 2, and 3-year AUC value in TCGA was 0.662, 0.662, and 0.655, respectively; The 1, 2, and 3-year AUC value in GSE43131 was 0.724, 0.724, and 0.722, respectively. The proportion of infiltrated neutrophils in the high-risk group was higher than that in the low-risk group (p = 0.028), whereas that of resting NK cells (p = 0.002) was lower.

Conclusion

A novel prognostic risk model based on three m6A-related genes for LUSC was generated in this study.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12957-022-02509-1.

A two-phase comprehensive NSCLC prognostic study identifies lncRNAs with significant main effect and interaction

Long noncoding RNA (lncRNA) are involved in regulating physiological behaviors for various malignant tumors, including non-small-cell lung cancer (NSCLC). However, few studies comprehensively evaluated both lncRNA-lncRNA interaction effects and main effects of lncRNA on overall survival of NSCLC. Hence, we performed a two-phase designed study of lncRNA expression in tumor tissues using 604 NSCLC patients from The Cancer Genome Atlas as the discovery phase and 839 patients from Gene Expression Omnibus as the validation phase. In the discovery phase, we adopted a two-step strategy, Screening before Testing, for dimension reduction and signal detection. These candidate lncRNAs first screened out by the weighted random forest (Ranger), were then tested through the Cox proportional hazards model adjusted for covariates. Significant lncRNAs with either type of effects aforementioned were carried forward into the validation phase to confirm their significances again. As a result, in the discovery phase, 19 lncRNAs were identified by Ranger, among which five lncRNAs and one pair of lncRNA-lncRNA interaction exhibited significant effects (FDR-q ≤ 0.05) main and interaction effects on NSCLC survival, respectively, through Cox model. After the independent validation, we finally observed that one lncRNA (ENSG00000227403.1) with main effect was robustly associated with NSCLC prognosis (HR_discovery = 0.90, P = 1.20 × 10^-3; HR_validation = 0.94, P = 4.11 × 10^-3) and one pair of lncRNAs (ENSG00000267121.4 and ENSG00000272369.1) had significant interaction effect on NSCLC survival (HR_discovery = 1.12, P = 3.07 × 10^-4; HR_validation = 1.11, P = 0.0397). Our comprehensive NSCLC prognostic study of lncRNA provided population-level evidence for further functional study.

METTL14-Mediated miR-30c-1-3p Maturation Represses the Progression of Lung Cancer via Regulation of MARCKSL1 Expression

Lung cancer (LC) is a pulmonary malignant tumor with extremely low 5-year survival rate. N6-methyladenosine (m6A) is confirmed to regulate diverse pathophysiological processes including cancers. Methyltransferase-like 14 (METTL14) is an important RNA methyltransferase in m6A modification. However, researches on the regulatory mechanism of METTL14 on LC progression are relatively rare. Tumor xenograft experiment was conducted to investigate the effect of METTL14 on LC in vivo. The relative expression of METTL14, miR-30c-1-3p, and myristoylated alanine-rich C kinase substrate-like protein-1 (MARCKSL1) in LC tissues and/or cell lines was determined using qRT-PCR. Western blot assay was used to measure the protein levels of METTL14 and MARCKSL1 in tumor xenograft model and/or LC cell lines. MTT, wound healing, and transwell assays were performed to detect LC cell viability and metastasis. RNA immunoprecipitation assay and qRT-PCR were used to verify the effects of METTL14 on pri-miR-30c-1-3p. The relationship between miR-30c-1-3p and MARCKSL1 was confirmed by the dual-luciferase reporter assay. METTL14 was remarkably downregulated in LC tissues and cell lines. METTL14 mediated the maturation of miR-30c-1-3p. The overexpressed METTL14 and overexpressed miR-30c-1-3p suppressed the cell viability and metastasis in LC. Meanwhile, the increased METTL14 also repressed the growth of tumor xenograft in vivo. In addition, MARCKSL1 was confirmed to be the target gene of miR-30c-1-3p. High expression of MARCKSL1 and low expression of miR-30c-1-3p reversed the suppressive effects of METTL14 overexpression on cell viability and metastasis. METTL14 promoted the maturation of miR-30c-1-3p and mediated MARCKSL1 expression to inhibit the progression of LC. This study may provide a new insight for the LC clinical therapy.

Long non‑coding RNA LINC01748 exerts carcinogenic effects in non‑small cell lung cancer cell lines by regulating the microRNA‑520a‑5p/HMGA1 axis

The important functions of long non‑coding RNAs in the malignancy of non‑small cell lung cancer (NSCLC) has been increasingly highlighted. However, whether LINC01748 functions in a crucial regulatory role still requires further research. The aim of the present study was to investigate the biological roles of LINC01748 in NSCLC. Furthermore, different experiments were utilized to investigate the mechanism of action of LINC01748 in 2 NSCLC cell lines. Reverse transcription‑quantitative PCR was used to measure mRNA expression levels. Cell Counting Kit‑8 assay, flow cytometry analysis and Transwell and Matrigel assays were also used to analyze, cell viability, apoptosis, and migration and invasion, respectively. A tumor xenograft model was used for in vivo experiments. RNA immunoprecipitation experiments, luciferase reporter assays and rescue experiments were used to investigate the mechanisms involved. Data from The Cancer Genome Atlas dataset and patients recruited into the present study showed that LINC01748 was overexpressed in NSCLC. Patients with high LINC01748 mRNA expression level had shorter overall survival rate compared with that in patients with low LINC01748 mRNA expression level. Then, knockdown of LINC01748 mRNA expression level reduced cell proliferation, migration and invasion, but increased cell apoptosis in vitro. Knockdown of LINC01748 also reduced tumor growth in vivo. Mechanistically, LINC01748 could act as a competing endogenous (ce)RNA to sponge microRNA(miR)‑520a‑5p, to increase the expression level of the target gene, high mobility group AT‑hook 1 (HMGA1) in the NSCLC cell lines. Furthermore, rescue experiments illustrated that the functions exerted by LINC01748 knockdown were negated by miR‑520a‑5p inhibition or HMGA1 overexpression. In summary, LINC01748 acted as a ceRNA by sponging miR‑520a‑5p, leading to HMGA1 overexpression, thus increasing the aggressiveness of the NSCLC cells. Accordingly, targeting the LINC01748/miR‑520a‑5p/HMGA1 pathway may benefit NSCLC therapy.

GATA binding protein 5 (GATA5) induces Rho GTPase activating protein 9 (ARHGAP9) to inhibit the malignant process of lung adenocarcinoma cells

Lung adenocarcinoma is the main cause of the excessive mortality for patients who lives with lung cancers. According to the GEPIA database analysis, GATA5 and ARHGAP9 were found to be low expressed in lung adenocarcinoma, and they were positively correlated, and in addition ARHGAP9 low expression was associated with poor prognosis in lung adenocarcinoma. Therefore, the present study focused on the effect of promoting GATA5 to induce ARHGAP9 on the malignant process of lung adenocarcinoma cells. The expressions of GATA5 and ARHGAP9 were measured with Western blot and RT-qPCR. With the adoption of CCK-8, EDU staining, transwell and colony formation, the cell viability, proliferation, invasion and tumorigenesis ability were detected, respectively. In addition, the wound healing and Western blot were employed to evaluate migration and metastasis-related proteins individually. Moreover, the luciferase activity as well as the binding of GATA5 and ARHGAP9 promoters were detected by luciferase report and ChIP. After further comprehensive assessments, the results confirmed that GATA5 could successfully activate ARHGAP9. Moreover, ARHGAP9 upregulation remarkably inhibited lung adenocarcinoma cell proliferation, invasion and migration as compared to the control group. More importantly, GATA5 silencing reversed the inhibitory effect of ARHGAP9 upregulation on the malignant progression of lung adenocarcinoma cells. To conclude, the present study successfully demonstrated for the first time that GATA5-induced ARHGAP9 upregulation has a protective effect on lung adenocarcinoma cells.

LncRNA ADAMTS9-AS2 is a Prognostic Biomarker and Correlated with Immune Infiltrates in Lung Adenocarcinoma

Background

The role of long noncoding RNA (LncRNA) ADAMTS9 antisense RNA 2 (ADAMTS9-AS2) is unclear in lung adenocarcinoma (LUAD). The aim of this study was to explore the relationship between ADAMTS9-AS2 and LUAD, based on The Cancer Genome Atlas (TCGA) database and bioinformatics analysis.

Methods

Various statistical methods, Kaplan–Meier method, Cox regression analysis, GSEA, and immune infiltration analysis were used to evaluate the relationship between clinical features and ADAMTS9-AS2 expression, prognostic factors, and the significant involvement of ADAMTS9-AS2 in function.

Results

In LUAD patients, low expression of ADAMTS9-AS2 was associated with N stage (P=0.011), gender (P=0.002), number of packs smoked (P=0.024) and smoker (P<0.001). Low ADAMTS9-AS2 expression predicted a poorer overall survival (OS) (HR: 0.68; 95% CI: 0.51–0.91; P=0.01). And ADAMTS9-AS2 expression (HR: 0.626; 95% CI: 0.397–0.986; P=0.043) was independently correlated with OS in LUAD patients. Unwinding of DNA, extrinsic pathway, polo-like kinase-mediated events, cori cycle, MCM pathway, proteasome pathway, lagging strand synthesis and PCNA-dependent long patch base excision repair were differentially enriched in ADAMTS9-AS2 high expression phenotype. ADAMTS9-AS2 expression was correlated with certain immune infiltrating cells.

Conclusion

In LUAD patients, ADAMTS9-AS2 expression was significantly associated with poor survival and immune infiltration. ADAMTS9-AS2 may be a promising biomarker of prognosis and response to immunotherapy for LUAD.

A narrative review of prognosis prediction models for non-small cell lung cancer: what kind of predictors should be selected and how to improve models?

Objective

To discover potential predictors and explore how to build better models by summarizing the existing prognostic prediction models of non-small cell lung cancer (NSCLC).

Background

Research on clinical prediction models of NSCLC has experienced explosive growth in recent years. As more predictors of prognosis are discovered, the choice of predictors to build models is particularly important, and in the background of more applications of next-generation sequencing technology, gene-related predictors are widely used. As it is more convenient to obtain samples and follow-up data, the prognostic model is preferred by researchers.

Methods

PubMed and the Cochrane Library were searched using the items “NSCLC”, “prognostic model”, “prognosis prediction”, and “survival prediction” from 1 January 1980 to 5 May 2021. Reference lists from articles were reviewed and relevant articles were identified.

Conclusions

The performance of gene-related models has not obviously improved. Relative to the innovation and diversity of predictors, it is more important to establish a highly stable model that is convenient for clinical application. Most of the prevalent models are highly biased and referring to PROBAST at the beginning of the study may be able to significantly control the bias. Existing models should be validated in a large external dataset to make a meaningful comparison.

Precise pathological classification of non-small cell lung adenocarcinoma and squamous carcinoma based on an integrated platform of targeted metabolome and lipidome

BACKGROUND

Non-small cell lung cancer (NSCLC) is the leading cause of cancer-related death worldwide. Lung adenocarcinoma (LUAD) and squamous cell carcinoma (LUSC) are the most common subtypes of NSCLC. Despite genetic differences between LUAD and LUSC have been clarified in depth, the metabolic differences of these two subtypes are still unclear.

METHODS

Totally, 128 plasma samples of NSCLC patients were collected before initial treatments, followed by determination of LC-ESI-Q TRAP-MS/MS. Differentially expressed metabolites were screened based on a strict standard.

RESULTS

Based on the integrated platform of targeted metabolome and lipidome, a total of 1141 endogenous metabolites (including 809 lipids) were finally detected in the plasma of NSCLC patients, including 16 increased and 3 decreased endogenous compounds in LUAD group when compared with LUSC group. Thereafter, a logistic regression model integrating four differential metabolites [2-(Methylthio) ethanol, Cortisol, D-Glyceric Acid, and N-Acetylhistamine] was established and could accurately differentiate LUAD and LUSC with an area under the ROC curve of 0.946 (95% CI 0.886-1.000). The cut-off value showed a satisfactory efficacy with 92.0% sensitivity and 92.9% specificity. KEGG functional enrichment analysis showed these differentially expressed metabolites could be further enriched in riboflavin metabolism, steroid hormone biosynthesis, prostate cancer, etc. The endogenous metabolites identified in this study have the potential to be used as novel biomarkers to distinguish LUAD from LUSC.

CONCLUSIONS

Our research might provide more evidence for exploring the pathogenesis and differentiation of NSCLC. This research could promote a deeper understanding and precise treatment of lung cancer.

Prognostic Value of Ki-67 Expression in Advanced Lung Squamous Cell Carcinoma Patients Treated with Chemotherapy

Background

The relationship between the Ki-67 expression level and chemotherapy response and survival prognosis in advanced lung squamous cell carcinoma (SCC) remains unclear.

Methods

A total of 101 patients were included in the study. All patients received systemic first-line platinum-based chemotherapy. The Ki-67 expression level was determined by immunohistochemistry analysis.

Results

The Ki-67 expression level was positively correlated with an increase in tumor T stage (P = 0.0140), N stage (P < 0.0001), and M stage (P < 0.0001) in advanced lung SCC. High Ki-67 expression could predict chemotherapy response (area under the curve = 0.7524, P < 0.0001). Patients with tumors that expressed high levels of Ki-67 had shorter overall survival (OS) (18.8 months vs 25.5 months, P = 0.0002) and progression-free survival (PFS) (4.8 months vs 6.7 months, P < 0.0001). Cox analysis found Ki-67 expression to be an independent prognostic biomarker of shortened OS (P = 0.009) and PFS (P = 0.008).

Conclusion

Ki-67 expression may affect chemotherapy response and thus has prognostic value. Ki-67 expression may be a promising prognostic biomarker for advanced lung SCC.

NCAPG promotes the progression of lung adenocarcinoma via the TGF-β signaling pathway

Background

Lung cancer has the highest case fatality rate among cancers because of uncontrolled proliferation and early metastasis of cancer cells in the lung tissue. This study aimed to clarify the role of the non-SMC condensin I complex, subunit G (NCAPG) in lung adenocarcinoma (LUAD), explore the mechanisms of its progression, and lay the foundation for the search for new biological markers.

Methods

We analyzed overlapping differentially expressed genes (DEGs) from three datasets; a protein–protein interaction (PPI) network was subsequently constructed and analyzed using Cytoscape. We then selected NCAPG for validation because of its poor prognosis and because it has not been sufficiently studied in the context of LUAD. Immunohistochemical analysis was used to detect the expression of NCAPG in LUAD tissues, and the relationships between NCAPG and clinical parameters were analyzed. In vitro and in vivo experiments were conducted to verify the role of NCAPG in LUAD. Finally, we studied the specific mechanism of action of NCAPG in LUAD.

Results

Through comprehensive analysis of the GSE43458, GSE75037, and The Cancer Genome Atlas databases, we identified 517 overlapping DEGs. Among them, NCAPG was identified as a hub gene. Immunohistochemical analysis revealed that NCAPG was strongly associated with the clinical stage, M-classification, and N-classification. Univariate and multivariate Cox regression analyses indicated that NCAPG was a prognostic risk factor for LUAD, while the in vitro experiments showed that NCAPG overexpression promoted proliferation, migration, invasion, and epithelial-mesenchymal transition. Furthermore, knockdown of NCAPG inhibited LUAD progression, both in vitro and in vivo. Mechanistically, NCAPG overexpression increased p-Smad2 and p-Smad3 expressions in the transforming growth factor β (TGF-β) signaling pathway. Additionally, rescue experiments indicated that TGF-β signaling pathway inhibitors could restore the effect of NCAPG overexpression in LUAD cells.

Conclusions

NCAPG may promote proliferation and migration via the TGF-β signaling pathway in LUAD.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12935-021-02138-w.

Recommendations for immunocytochemistry in lung cancer typing: An update on a resource-efficient approach with large-scale comparative Bayesian analysis

OBJECTIVES

The majority of lung cancer cases are of advanced stage and diagnosis is usually made using minimally invasive small biopsies and cytological specimens. The WHO 2015 classification recommends limiting immunocytochemistry (ICC) to lung cancer typing and molecular testing drives for personalised therapies. An algorithm using Bayes' theorem could be useful for defining antibody profiles. This study aims to assess the impact of different antibody profiles for cytological samples on the accuracy of lung cancer typing with a large-scale Bayesian analysis.

METHODS

A retrospective examination of 3419 consecutive smears and/or cytospins diagnosed over 2011-2016 found 1960 primary lung cancer tumours: 972 adenocarcinomas (ADC), 256 squamous carcinomas (SQC), 268 neuroendocrine tumours (NET), and 464 non-small cell cancer-not otherwise specified (NSCC-NOS). The a priori and a posteriori probabilities, before and after ICC using antibodies singly or in combination, were calculated for different lung cancer types.

RESULTS

TTF-1 or CK7 alone improved the a posteriori probabilities of correct cytological typing for ADC to 86.5% and 95.8%, respectively. For SQC, using p40 (∆Np63) or CK5/6 together with CK5/14 led to comparable results (78.3% and 90.3%). With synaptophysin or CD56 alone, improvements in a posteriori probabilities to 87.5 and 90.3% for the correct recognition of NET could be achieved.

CONCLUSIONS

Based on morphological and clinical data, the use of two antibodies appears sufficient for reliable detection of the different lung cancer types. This applies to diagnoses that were finalised following ICC both on a clinical or cytological basis and on a histological basis.

GPC3 affects the prognosis of lung adenocarcinoma and lung squamous cell carcinoma

Background

Glypican 3 (GPC3) is a heparin sulphate proteoglycan whose expression is associated with several malignancies. However, its expression in non-small-cell lung carcinoma (NSCLC) is limited and ambiguous. This study aimed to comprehensively evaluate the expression of GPC3 in NSCLC and develop a risk-score model for predicting the prognosis of NSCLC.

Methods

The gene expression profiles of lung adenocarcinoma (LUAD) and lung squamous cell carcinoma (LUSC) were downloaded from the UCSC Xena database. Using the limma package, the differentially expressed genes (DEGs) between different comparison groups were analysed and the differential expression of GPC3 was calculated. A functional enrichment analysis was conducted for GPC3-associated genes using the DAVID tool. For the GPC3-associated genes shared by the four comparison groups, a protein–protein interaction network was built using the Cytoscape software. After conducting a survival analysis and a Cox regression analysis, the genes found to be significantly correlated with prognosis were selected to construct a risk-score model. Besides, the gene and protein levels of GPC3 were examined by quantitative reverse transcriptase-PCR (qRT-PCR) and immunohistochemistry (IHC) in LUSC tissues and paracancer tissues.

Results

The differential expression of GPC3 was significant (adjusted P < 0.05) in the NSCLC vs. normal, LUAD vs. normal, LUSC versus normal, and LUAD versus. LUSC comparison groups. GPC3 directly interacted with SERPINA1, MFI2, and FOXM1. Moreover, GPC3 expression was significantly correlated with pathologic N, pathologic T, gender, and tumour stage in LUAD samples. Finally, the risk-score model (involving MFI2, FOXM1, and GPC3) for LUAD and that (involving SERPINA1 and FOXM1) for LUSC were established separately. The qRT-PCR result showed that GPC3 expression was much higher in the LUSC tissues than that in the normal group. The IHC results further showed that GPC3 is highly expressed in LUSC tissues, but low in paracancer tissues.

Conclusion

The three-gene risk-score model for LUAD and the two-gene risk-score model for LUSC might be valuable in improving the prognosis of these carcinomas.

Spatial distribution of immune checkpoint proteins in histological subtypes of lung adenocarcinoma

The most prevalent histological type of non-small cell lung cancer (NSCLC) is adenocarcinoma. The WHO classifies this tumor into subtypes according to the predominant growth pattern such as lepidic, acinar, papillary, solid or micropapillary, each harboring specific molecular features. NSCLC adenocarcinoma heterogeneity is discussed to be a reason for therapy failure using targeted therapy or immune checkpoint inhibitors. For successful therapy of immune checkpoint inhibitors the expression and distribution of the involved immune checkpoint proteins is essential. Therefore, we aimed to investigate the distribution of five prominent immune checkpoint proteins in regard of the histological growth patterns of lung adenocarcinoma. We performed immunohistochemical staining of 84 tumor segments from 22 resected tumor samples to evaluate the expression of PD-L1, PD-1, Nectin-2, PVR, and TIGIT in distinct growth patterns of lung adenocarcinoma. We determined a distinct heterogeneity between and within different tumor segments regarding morphological growth patterns. Furthermore, expression of immune checkpoint proteins varied between different growth pattern areas as well as within one distinct growth pattern. Expression of PVR was significantly higher in solid compared to acinar growth pattern (p= 0.00736). Of note, we detected TIGIT not only on tumor infiltrating lymphocytes but also on tumor cells, whereas non-neoplastic lung tissue was consistently TIGIT-negative. The immune checkpoint protein distribution in histologic subtypes of pulmonary adenocarcinoma displays an considerable intra- and intertumoral heterogeneity implying the requirement of either a multiregion or an adjusted analysis when determining the expression status of PD-1:PD-L1 and the TIGIT:PVR/Nectin-2 checkpoint proteins as predictive markers.

Differential MUC22 expression by epigenetic alterations in human lung squamous cell carcinoma and adenocarcinoma

Disruption in mucins (MUCs) is involved in cancer development and metastasis and is thus used as a biomarker. Non‑small cell lung carcinoma (NSCLC) is characterized by heterogeneous genetic and epigenetic alterations. Lung adenocarcinoma (LUAD) and squamous cell carcinoma (LUSC) are the two primary subtypes of NSCLC that require different therapeutic interventions. Here, we report distinct expression and epigenetic alterations in mucin 22 (MUC22), a new MUC family member, in LUSC vs. LUAD. In lung cancer cell lines and tissues, MUC22 was downregulated in LUSC (MUC22Low) but upregulated in LUAD (MUC22High) with co‑expression of MUC21. The aberrant expression of MUC22 was inversely correlated with its promoter hypermethylation in LUSC and hypomethylation in LUAD cells and tissues, respectively. Decreased MUC22 expression in NSCLC cell lines was restored upon treatment with epigenetic modifiers 5‑aza‑2'‑deoxycytidine (5‑Aza) or trichostatin A (TSA), accompanied by reduction in global protein level of histone deacetylase 1 (HDAC1) but increased enrichment of histone H3 lysine 9 acetylation (H3K9ac) specifically in the MUC22 promoter in the SK‑MES‑1 cell line. MUC22 knockdown increased the growth and motility of lung cancer cells and an immortalized human bronchial epithelial BEAS‑2B cell line via NF‑κB activation. Clinically, MUC22Low in LUSC and MUC22High in LUAD were shown to be indicators of unfavorable overall survival for patients with early cancer stages. Our study reveals that changes in MUC22 expression due to epigenetic alterations in NSCLC may have important biological significance and prognostic potential in LUSC when compared to LUAD. Thus, MUC22 expression and epigenetic alterations may be used for molecular subtyping of NSCLC in precision medicine.

Recent advances and current controversies in lung neuroendocrine neoplasms✰

In the lung, neuroendocrine tumors (NETs), namely typical and atypical carcinoids, and neuroendocrine carcinomas (NECs), grouping small cell carcinoma (SCLC) and large cell neuroendocrine carcinoma (LCNEC), make up for distinct tumor entities according to epidemiological, genetic, pathologic and clinical data. The proper classification is essential in clinical practice for diagnosis, prognosis and therapy purposes. Through an extensive literature survey, three perspectives on lung NENs have been revised: i) criteria and terminology on biopsy or cytology samples of primaries or metastases; ii) carcinoids with elevated mitotic counts and/or Ki-67 proliferation rates; iii) relevance of molecular landscape to identify new tumor entities and therapeutic targets. Furthermore, a dispute about lung NEN development has been raised according to emerging molecular models. We herein provide a pathology update on practical topics in the setting of lung NENs according to the current classification (recent advances). We have also reappraised the development of these tumors by modeling risk factors and natural history of disease (recent controversies). Combining recent advances and controversies may help clarify our biological understanding of lung NENs and give practical information for the clinical decision-making process.

Nuclear export protein CSE1L interacts with P65 and promotes NSCLC growth via NF-κB/MAPK pathway

Non-small cell lung cancer (NSCLC) is characterized with high morbidity and mortality, mainly due to frequent recurrence and metastasis. However, the underlying molecular mechanisms of NSCLC tumorigenesis are largely unclear. Through data mining in the ONCOMINE and Gene Expression Omnibus (GEO) databases, the expression of CSE1L (chromosome segregation like 1 protein/CAS), an exportin, was identified to be significantly upregulated in NSCLC and positively associated with poor prognosis of patients. By use of in vitro and in vivo gain- and loss-of-function experiments, we found that CSE1L can promote NSCLC cell proliferation while inhibiting cell apoptosis. Through immunoprecipitation and mass spectrometry experiments, we demonstrated that CSE1L interacted with RELA (named as P65) and affected its location in the nucleus. Moreover, we found that one of the mechanisms by which CSE1L promotes proliferation and inhibits apoptosis is through activating the nuclear factor-κB (NF-κB)/mitogen-activated protein kinase (MAPK) signaling pathway. In summary, our findings indicated an oncogenic role of CSE1L in NSCLC tumorigenesis.

Comprehensive Profiling of Genomic and Transcriptomic Differences between Risk Groups of Lung Adenocarcinoma and Lung Squamous Cell Carcinoma

Lung cancer is the second most frequently diagnosed cancer type and responsible for the highest number of cancer deaths worldwide. Lung adenocarcinoma (LUAD) and lung squamous cell carcinoma (LUSC) are subtypes of non-small-cell lung cancer which has the highest frequency of lung cancer cases. We aimed to analyze genomic and transcriptomic variations including simple nucleotide variations (SNVs), copy number variations (CNVs) and differential expressed genes (DEGs) in order to find key genes and pathways for diagnostic and prognostic prediction for lung adenocarcinoma and lung squamous cell carcinoma. We performed a univariate Cox model and then lasso-regularized Cox model with leave-one-out cross-validation using The Cancer Genome Atlas (TCGA) gene expression data in tumor samples. We generated 35- and 33-gene signatures for prognostic risk prediction based on the overall survival time of the patients with LUAD and LUSC, respectively. When we clustered patients into high- and low-risk groups, the survival analysis showed highly significant results with high prediction power for both training and test datasets. Then, we characterized the differences including significant SNVs, CNVs, DEGs, active subnetworks, and the pathways. We described the results for the risk groups and cancer subtypes separately to identify specific genomic alterations between both high-risk groups and cancer subtypes. Both LUAD and LUSC high-risk groups have more downregulated immune pathways and upregulated metabolic pathways. On the other hand, low-risk groups have both up- and downregulated genes on cancer-related pathways. Both LUAD and LUSC have important gene alterations such as CDKN2A and CDKN2B deletions with different frequencies. SOX2 amplification occurs in LUSC and PSMD4 amplification in LUAD. EGFR and KRAS mutations are mutually exclusive in LUAD samples. EGFR, MGA, SMARCA4, ATM, RBM10, and KDM5C genes are mutated only in LUAD but not in LUSC. CDKN2A, PTEN, and HRAS genes are mutated only in LUSC samples. The low-risk groups of both LUAD and LUSC tend to have a higher number of SNVs, CNVs, and DEGs. The signature genes and altered genes have the potential to be used as diagnostic and prognostic biomarkers for personalized oncology.

Elevated NSD3 histone methylation activity drives squamous cell lung cancer

Amplification of chromosomal region 8p11-12 is a common genetic alteration that has been implicated in the aetiology of lung squamous cell carcinoma (LUSC)^1-3. The FGFR1 gene is the main candidate driver of tumorigenesis within this region⁴. However, clinical trials evaluating FGFR1 inhibition as a targeted therapy have been unsuccessful⁵. Here we identify the histone H3 lysine 36 (H3K36) methyltransferase NSD3, the gene for which is located in the 8p11-12 amplicon, as a key regulator of LUSC tumorigenesis. In contrast to other 8p11-12 candidate LUSC drivers, increased expression of NSD3 correlated strongly with its gene amplification. Ablation of NSD3, but not of FGFR1, attenuated tumour growth and extended survival in a mouse model of LUSC. We identify an LUSC-associated variant NSD3(T1232A) that shows increased catalytic activity for dimethylation of H3K36 (H3K36me2) in vitro and in vivo. Structural dynamic analyses revealed that the T1232A substitution elicited localized mobility changes throughout the catalytic domain of NSD3 to relieve auto-inhibition and to increase accessibility of the H3 substrate. Expression of NSD3(T1232A) in vivo accelerated tumorigenesis and decreased overall survival in mouse models of LUSC. Pathological generation of H3K36me2 by NSD3(T1232A) reprograms the chromatin landscape to promote oncogenic gene expression signatures. Furthermore, NSD3, in a manner dependent on its catalytic activity, promoted transformation in human tracheobronchial cells and growth of xenografted human LUSC cell lines with amplification of 8p11-12. Depletion of NSD3 in patient-derived xenografts from primary LUSCs containing NSD3 amplification or the NSD3(T1232A)-encoding variant attenuated neoplastic growth in mice. Finally, NSD3-regulated LUSC-derived xenografts were hypersensitive to bromodomain inhibition. Thus, our work identifies NSD3 as a principal 8p11-12 amplicon-associated oncogenic driver in LUSC, and suggests that NSD3-dependency renders LUSC therapeutically vulnerable to bromodomain inhibition.

Silencing of LOC389641 impairs cell proliferation and induces autophagy via EGFR/MET signaling in lung adenocarcinoma

High-throughput RNA-sequencing studies of tumor samples have identified a large number of long non-coding RNAs (lncRNAs) which are associated with various types of cancer. LncRNAs play key roles in regulating chromatin dynamics, gene expression, growth, differentiation and development. However, the role of LOC389641 in non-small cell lung cancer (NSCLC) tumorigenesis is not clear. Here, we investigated the expression pattern, roles and mechanism of LOC389641 in lung cancer. LOC389641 expressions in tumor tissues and cell lines were measured by qRT-PCR. Functional studies including colony formation, cell proliferation and invasion were performed in lung cancer cell lines and Western blot was used to exam the protein changes upon siRNA treatment. We found that LOC389641 was highly expressed in lung adenocarcinomas and was associated with poor patient survival. Silencing of LOC389641 reduced colony formation, cell proliferation and invasion, as well as induced autophagy and apoptosis of lung adenocarcinoma cell lines in vitro. Mechanistically, downregulation of LOC389641 was found to decrease EGFR, MET and STAT3 proteins expression in lung cancer cells. LOC389641 is highly expressed and plays an oncogenic role in this type of NSCLC. Because of its specificity, LOC389641 may be a potential biomarker for prognosis and a possible target for lung adenocarcinoma.

Identification of a six-gene metabolic signature predicting overall survival for patients with lung adenocarcinoma

Background

Lung cancer is the leading cause of cancer-related deaths worldwide. Lung adenocarcinoma (LUAD) is one of the main subtypes of lung cancer. Hundreds of metabolic genes are altered consistently in LUAD; however, their prognostic role remains to be explored. This study aimed to establish a molecular signature that can predict the prognosis in patients with LUAD based on metabolic gene expression.

Methods

The transcriptome expression profiles and corresponding clinical information of LUAD were obtained from The Cancer Genome Atlas and Gene Expression Omnibus databases. The differentially expressed genes (DEGs) between LUAD and paired non-tumor samples were identified by the Wilcoxon rank sum test. Univariate Cox regression analysis and the lasso Cox regression model were used to construct the best-prognosis molecular signature. A nomogram was established comprising the prognostic model for predicting overall survival. To validate the prognostic ability of the molecular signature and the nomogram, the Kaplan-Meier survival analysis, Cox proportional hazards model, and receiver operating characteristic analysis were used.

Results

The six-gene molecular signature (PFKP, PKM, TPI1, LDHA, PTGES, and TYMS) from the DEGs was constructed to predict the prognosis. The molecular signature demonstrated a robust independent prognostic ability in the training and validation sets. The nomogram including the prognostic model had a greater predictive accuracy than previous systems. Furthermore, a gene set enrichment analysis revealed several significantly enriched metabolic pathways, which suggests a correlation of the molecular signature with metabolic systems and may help explain the underlying mechanisms.

Conclusions

Our study identified a novel six-gene metabolic signature for LUAD prognosis prediction. The molecular signature could reflect the dysregulated metabolic microenvironment, provide potential biomarkers for predicting prognosis, and indicate potential novel metabolic molecular-targeted therapies.