Hypoxia differently regulates the proportion of ALDHhi cells in lung squamous carcinoma H520 and adenocarcinoma A549 cells via the Wnt/β-catenin pathway

BACKGROUND

Cancer stem cells (CSCs) are a specific subpopulation of cancer cells with the ability of self-renewal, infinite proliferation, multidifferentiation and tumorigenicity, and play critical roles in cancer progression and treatment resistance. CSCs are tightly regulated by the tumor microenvironment, such as hypoxia; however, how hypoxia regulates CSCs in non-small cell lung cancer (NSCLC) remains unclear.

METHODS

The proportion of ALDHhi cells was examined using the Aldefluor assay. Tankyrase inhibitor XAV939 and siRNA were used to inhibit β-catenin while pcDNA3-β-catenin (S33Y) plasmid enhanced the expression of β-catenin. Western blot was administered for protein detection. The mRNA expression was measured by quantitative real-time PCR.

RESULTS

We found that hypoxia led to an increase in the proportion of ALDHhi cells in lung squamous carcinoma (LUSC) H520 cells, while causing a decrease in the ALDHhi cell proportion in lung adenocarcinoma (LUAD) A549 cells. Similarly, β-catenin expression was upregulated in H520 cells but downregulated in A549 cells upon exposure to hypoxia. Mechanically, the proportion of ALDHhi cells in both cell lines was decreased by β-catenin inhibitor or siRNA knockdown, whereas increased after β-catenin overexpression. Furthermore, hypoxia treatment suppressed E-cadherin expression in H520 cells and enhanced N-cadherin and β-catenin expression, while this effect was completely opposite in A549 cells.

CONCLUSION

The hypoxia-EMT-β-catenin axis functions as an important regulator for the proportion of CSCs in NSCLC and could potentially be explored as therapeutic targets in the future.

The Evaluation of Prognostic Value and Immune Characteristics of Ferroptosis-Related Genes in Lung Squamous Cell Carcinoma

Background  The purpose of our study was to construct a prognostic model based on ferroptosis-related gene signature to improve the prognosis prediction of lung squamous carcinoma (LUSC). Methods  The mRNA expression profiles and clinical data of LUSC patients were downloaded. LUSC-related essential differentially expressed genes were integrated for further analysis. Prognostic gene signatures were identified through random forest regression and univariate Cox regression analyses for constructing a prognostic model. Finally, in a preliminary experiment, we used the reverse transcription-quantitative polymerase chain reaction assay to verify the relationship between the expression of three prognostic gene features and ferroptosis. Results  Fifty-six ferroptosis-related essential genes were identified by using integrated analysis. Among these, three prognostic gene signatures (HELLS, POLR2H, and POLE2) were identified, which were positively affected by LUSC prognosis but negatively affected by immune cell infiltration. Significant overexpression of immune checkpoint genes occurred in the high-risk group. In preliminary experiments, we confirmed that the occurrence of ferroptosis can reduce three prognostic gene signature expression. Conclusions  The three ferroptosis-related genes could predict the LUSC prognostic risk of antitumor immunity.

Risk stratification and prognosis prediction based on inflammation-related gene signature in lung squamous carcinoma

BACKGROUND

Inflammation is known to have an intricate relationship with tumorigenesis and tumor progression while it is also closely related to tumor immune microenvironment. Whereas the role of inflammation-related genes (IRGs) in lung squamous carcinoma (LUSC) is barely understood. Herein, we recognized IRGs associated with overall survival (OS), built an IRGs signature for risk stratification and explored the impact of IRGs on immune infiltration landscape of LUSC patients.

METHODS

The RNA-sequencing and clinicopathological data of LUSC patients were downloaded from The Cancer Genome Atlas (TCGA) and the Gene Expression Omnibus (GEO) database, which were defined as training and validation cohorts. Cox regression and least absolute shrinkage and selection operator analyses were performed to build an IRG signature. CIBERSORT, microenvironment cell populations-counter and tumor immune dysfunction and rejection (TIDE) algorithm were used to perform immune infiltration analysis.

RESULTS

A two-IRG signature consisting of KLF6 and SGMS2 was identified according to the training set, which could categorize patients into two different risk groups with distinct OS. Patients in the low-risk group had more anti-tumor immune cells infiltrated while patient with high-risk had lower TIDE score and higher levels of immune checkpoint molecules expressed. The IRG signature was further identified as an independent prognostic factor of OS. Subsequently, a prognostic nomogram including IRG signature, age, and cancer stage was constructed for predicting individualized OS, whose concordance index values were 0.610 (95% CI: 0.568-0.651) in the training set and 0.652 (95% CI: 0.580-0.724) in validation set. Time-dependent receiver operator characteristic curves revealed that the nomogram had higher prediction accuracy compared with the traditional tumor stage alone.

CONCLUSION

The IRG signature was a predictor for patients with LUSC and might serve as a potential indicator of the efficacy of immunotherapy. The nomogram based on the IRG signature showed a relatively good predictive performance in survival.

Heterogeneous pattern of gene expression driven by TTN mutation is involved in the construction of a prognosis model of lung squamous cell carcinoma

Objective

To investigate the impact that TTN mutation had on the gene heterogeneity expression and prognosis in patients with lung adenocarcinoma.

Methods

In this study, the Cancer Genome Atlas (TCGA) dataset was used to analyze the TTN mutations in lung adenocarcinoma. Lung adenocarcinoma data was collected from the TCGA database, clinical information of patients was analyzed, and bioinformatics statistical methods were applied for mutation analysis and prognosis survival analysis. The results were verified using the GEO dataset.

Results

The incidence of TTN mutations in lung adenocarcinoma was found to be 73%, and it was related to the prognosis of lung adenocarcinoma. Ten genes were screened with significant contributions to prognosis. A prognosis model was constructed and verified by LASSO COX analysis in the TCGA and GEO datasets based on these ten beneficial factors. The independent prognostic factor H2BC9 for TTN mutation-driven gene heterogeneity expression was screened through multi-factor COX regression analysis.

Conclusion

Our data showed that the gene heterogeneity expression, which was driven by TTN mutations, prolonged the survival of lung adenocarcinoma patients and provided valuable clues for the prognosis of TTN gene mutations in lung adenocarcinoma.

Chromium (VI)-induced ALDH1A1/EGF axis promotes lung cancer progression

Cr(VI) is broadly applied in industry. Cr(VI) exposure places a big burden on public health, thereby increasing the risk of lung squamous cell carcinoma (LUSC). The mechanisms underlying Cr(VI)-induced LUSC remain largely elusive. Here, we report that the cancer stem cell (CSC)/tumour-initiating cell (TIC)-like subgroup within Cr(VI)-transformed bronchial epithelial cells (CrT) promotes lung cancer tumourigenesis. Mechanistically, Cr(VI) exposure specifically increases the expression levels of aldehyde dehydrogenase 1A1 (ALDH1A1), a CSC marker, through KLF4-mediated transcription. ALDH1A1 maintains self-renewal of CrT/TICs and facilitates the expression and secretion of EGF from CrT/TICs, which subsequently promotes the activation of EGFR signalling in differentiated cancer cells and tumour growth of LUSC. In addition, the ALDH1A1 inhibitor A37 and gemcitabine synergistically suppress LUSC progression. Importantly, high ALDH1A1 expression levels are positively correlated with advanced clinical stages and predict poor survival in LUSC patients. These findings elucidate how ALDH1A1 modulates EGF secretion from TICs to facilitate LUSC tumourigenesis, highlighting new therapeutic strategies for malignant lung cancers.

Assessing the efficacy of immunotherapy in lung squamous carcinoma using artificial intelligence neural network

Background

At present, immunotherapy is a very promising treatment method for lung cancer patients, while the factors affecting response are still controversial. It is crucial to predict the efficacy of lung squamous carcinoma patients who received immunotherapy.

Methods

In our retrospective study, we enrolled lung squamous carcinoma patients who received immunotherapy at Beijing Chest Hospital from January 2017 to November 2021. All patients were grouped into two cohorts randomly, the training cohort (80% of the total) and the test cohort (20% of the total). The training cohort was used to build neural network models to assess the efficacy and outcome of immunotherapy in lung squamous carcinoma based on clinical information. The main outcome was the disease control rate (DCR), and then the secondary outcomes were objective response rate (ORR), progression-free survival (PFS), and overall survival (OS).

Results

A total of 289 patients were included in this study. The DCR model had area under the receiver operating characteristic curve (AUC) value of 0.9526 (95%CI, 0.9088-0.9879) in internal validation and 0.9491 (95%CI, 0.8704-1.0000) in external validation. The ORR model had AUC of 0.8030 (95%CI, 0.7437-0.8545) in internal validation and 0.7040 (95%CI, 0.5457-0.8379) in external validation. The PFS model had AUC of 0.8531 (95%CI, 0.8024-0.8975) in internal validation and 0.7602 (95%CI, 0.6236-0.8733) in external validation. The OS model had AUC of 0.8006 (95%CI, 0.7995-0.8017) in internal validation and 0.7382 (95%CI, 0.7366-0.7398) in external validation.

Conclusions

The neural network models show benefits in the efficacy evaluation of immunotherapy to lung squamous carcinoma patients, especially the DCR and ORR models. In our retrospective study, we found that neoadjuvant and adjuvant immunotherapy may bring greater efficacy benefits to patients.

Shared network pattern of lung squamous carcinoma and adenocarcinoma illuminates therapeutic targets for non-small cell lung cancer

Background

Non-small cell lung cancer (NSCLC) is a malignant tumor with high mortality. Lung squamous carcinoma (LUSC) and lung adenocarcinoma (LUAD) are the common subtypes of NSCLC. However, how LUSC and LUAD are compatible remains to be elucidated.

Methods

We used a network approach to find highly interconnected genes shared with LUSC and LUAD, and we then built modules to assess the degree of preservation between them. To quantify this result, Z-scores were used to summarize the interrelationships between LUSC and LUAD. Furthermore, we correlated network hub genes with patient survival time to identify risk factors.

Results

Our findings provided a look at the regulatory pattern for LUSC and LUAD. For LUSC, several genes, such as AKR1C1, AKR1C2, and AKR1C3, play key roles in regulating network modules of cell growth pathways. In addition, CCL19, CCR7, CCL21, and LY9 are enriched in LUAD network modules of T lymphocyte-related pathways. LUSC and LUAD have similar expressed gene expression patterns. Their networks share 46 hub genes with connectivity greater than 0.9. These genes are correlated with patient survival time. Among them, the expression level of COL5A2 in LUSC and LUAD is higher than that in normal tissues, which is closely related to the poor prognosis of LUSC and LUAD patients.

Conclusion

LUSC and LUAD share a network pattern. COL5A2 may be a risk factor in poor prognosis in LUSC and LUAD. The common landscape of LUSC and LUAD will help better define the regulation of NSCLC candidate genes and achieve the goals of precision medicine.

A novel diagnostic model for predicting immune microenvironment subclass based on costimulatory molecules in lung squamous carcinoma

There is still no ideal predictive biomarker for immunotherapy response among patients with non-small cell lung cancer. Costimulatory molecules play a role in anti-tumor immune response. Hence, they can be a potential biomarker for immunotherapy response. The current study comprehensively investigated the expression of costimulatory molecules in lung squamous carcinoma (LUSC) and identified diagnostic biomarkers for immunotherapy response. The costimulatory molecule gene expression profiles of 627 patients were obtained from the The Cancer Genome Atlas, GSE73403, and GSE37745 datasets. Patients were divided into different clusters using the k-means clustering method and were further classified into two discrepant tumor microenvironment (TIME) subclasses (hot and cold tumors) according to the immune score of the ESTIMATE algorithm. A high proportion of activated immune cells, including activated memory CD4 T cells, CD8 T cells, and M1 macrophages. Five CMGs (FAS, TNFRSF14, TNFRSF17, TNFRSF1B, and TNFSF13B) were considered as diagnostic markers using the Least Absolute Shrinkage and Selection Operator and the Support Vector Machine-Recursive Feature Elimination machine learning algorithms. Based on the five CMGs, a diagnostic nomogram for predicting individual tumor immune microenvironment subclasses in the TCGA dataset was developed, and its predictive performance was validated using GSE73403 and GSE37745 datasets. The predictive accuracy of the diagnostic nomogram was satisfactory in all three datasets. Therefore, it can be used to identify patients who may benefit more from immunotherapy.

Transcriptome Analyses Identify a Metabolic Gene Signature Indicative of Antitumor Immunosuppression of EGFR Wild Type Lung Cancers With Low PD-L1 Expression

Purpose

With the development and application of targeted therapies like tyrosine kinase inhibitors (TKIs) and immune checkpoint inhibitors (ICIs), non-small cell lung cancer (NSCLC) patients have achieved remarkable survival benefits in recent years. However, epidermal growth factor receptor (EGFR) wild-type and low expression of programmed death-ligand 1 (PD-L1) NSCLCs remain unmanageable. Few treatments for these patients exist, and more side effects with combination therapies have been observed. We intended to generate a metabolic gene signature that could successfully identify high-risk patients and reveal its underlying molecular immunology characteristics.

Methods

By identifying the bottom 50% PD-L1 expression level as PD-L1 low expression and removing EGFR mutant samples, a total of 640 lung adenocarcinoma (LUAD) and lung squamous carcinoma (LUSC) tumor samples and 93 adjacent non-tumor samples were finally extracted from The Cancer Genome Atlas (TCGA). We identified differentially expressed metabolic genes (DEMGs) by R package limma and the prognostic genes by Univariate Cox proportional hazards regression analyses. The intersect genes between DEMGs and prognostic genes were put into the least absolute shrinkage and selection operator (LASSO) penalty Cox regression analysis. The metabolic gene signature contained 18 metabolic genes generated and successfully stratified LUAD and LUSC patients into the high-risk and low-risk groups, which was also validated by the Gene Expression Omnibus (GEO) database. Its accuracy was proved by the time-dependent Receiver Operating Characteristic (ROC) curve, Principal Components Analysis (PCA), and nomogram. Furthermore, the Single-sample Gene Set Enrichment Analysis (ssGSEA) and diverse acknowledged methods include XCELL, TIMER, QUANTISEQ, MCPcounter, EPIC, CIBERSORT-ABS, and CIBERSORT revealed its underlying antitumor immunosuppressive status. Besides, its relationship with somatic copy number alterations (SCNAs) and tumor mutational burden (TMB) was also discussed.

Results

It is noteworthy that metabolism reprogramming is associated with the survival of the double-negative LUAD and LUSC patients. The SCNAs and TMB of critical metabolic genes can inhibit the antitumor immune process, which might be a promising therapeutic target.

Peripheral Lung Squamous Carcinoma With ROS1 Rearrangement Sensitive to Crizotinib: A Case Report

ROS1 rearrangements have been identified as driver mutations, accounting for 1–2% of lung adenocarcinoma, but are extremely rare in case of lung squamous cell carcinoma. In this work, we report a lung squamous cell carcinoma in a patient with peripheral lung cancer radiological manifestation, harboring ROS1 rearrangement, with high sensitivity to crizotinib. Our findings suggest that clinicians should pay more attention toward the occurrence of ROS1 rearrangements and the application of crizotinib for lung squamous cell carcinoma treatment.

Next-generation sequencing revealed synchronous double primary lung squamous carcinoma: a case report

Synchronous double primary lung squamous carcinoma (sDPLSCC) is rare and difficult to distinguish from metastatic disease, histopathologically. Owing to the heterogeneity of cancer, it is also difficult to select the optimal therapeutic strategy for patients with multiple primary lung cancer (MPLC). The present study reports a rare case of a 61-year-old male patient with sDPLSCC diagnosed using histology and genetic profiling. LSCC-related driver mutations were detected in this patient, and we reported the TP53 c.475G>C mutation, which has been detected in both breast cancer and hepatocellular carcinoma, but not previously in lung squamous carcinoma. Our findings provide further evidence supporting the necessity of genetic testing for primary tumor diagnosis.

Molecular characterization of lung squamous cell carcinoma tumors reveals therapeutically relevant alterations

INTRODUCTION

Unlike lung adenocarcinoma patients, there is no FDA-approved targeted-therapy likely to benefit lung squamous cell carcinoma patients.

MATERIALS AND METHODS

We performed survival analyses of lung squamous cell carcinoma patients harboring therapeutically relevant alterations identified by whole exome sequencing and mass spectrometry-based validation across 430 lung squamous tumors.

RESULTS

We report a mean of 11.6 mutations/Mb with a characteristic smoking signature along with mutations in TP53 (65%), CDKN2A (20%), NFE2L2 (20%), FAT1 (15%), KMT2C (15%), LRP1B (15%), FGFR1 (14%), PTEN (10%) and PREX2 (5%) among lung squamous cell carcinoma patients of Indian descent. In addition, therapeutically relevant EGFR mutations occur in 5.8% patients, significantly higher than as reported among Caucasians. In overall, our data suggests 13.5% lung squamous patients harboring druggable mutations have lower median overall survival, and 19% patients with a mutation in at least one gene, known to be associated with cancer, result in significantly shorter median overall survival compared to those without mutations.

CONCLUSIONS

We present the first comprehensive landscape of genetic alterations underlying Indian lung squamous cell carcinoma patients and identify EGFR, PIK3CA, KRAS and FGFR1 as potentially important therapeutic and prognostic target.

A novel immunogenomic prognostic signature in lung squamous carcinoma

Lung squamous carcinoma (LUSC) is a common subtype of lung cancer with limited available therapy and is thus associated with poor survival. Immune infiltrating cells and immune-related genes (IRGs) play a key role in the clinical outcomes of LUSC. In the present study, we aimed to develop a potential immunogenomic prognostic signature for patients with LUSC. The transcriptional profiles of 501 LUSC samples from The Cancer Genome Atlas (TCGA) and 2498 IRGs from the ImmPort database were used to develop the signature by Cox regression analysis. Ten differentially expressed and survival-associated IRGs were used to develop the risk signature, which could serve as an independent prognostic and predictive factor for patients with LUSC. Furthermore, this risk signature correlated with overall survival and clinical features, including age, in patients with LUSC. In addition, we identified 25 transcription factors that may regulate 15 survival-associated IRGs, using a regulatory network. Collectively, this immunogenomic signature could be a robust prognostic tool for patients with LUSC and holds great promise as individualized immunotherapy for LUSC.

Four hub genes regulate tumor infiltration by immune cells, antitumor immunity in the tumor microenvironment, and survival outcomes in lung squamous cell carcinoma patients

In this study, we performed bioinformatics analyses to identify hub genes that regulate tumor infiltration by immune cells and antitumor immunity in the lung squamous cell carcinoma (LUSC). We identified 1738 robust and stable differentially expressed genes (DEGs) in the LUSC tissues based on robust rank aggregation (RRA) analysis of RNA-sequencing data from 5 GEO-LUSC datasets. We then classified TCGA-LUSC patients based on ssGSEA and ESTIMATE analyses of LUSC tissues into high, medium and low immunity subgroups showing significant differences in tumor purity. Weighted gene co-expression network analysis of the robust DEGs revealed five immunity-related modules, including the brown module with 762 DEGs and 30 hub genes showing the highest correlation with the immunity-related LUSC patient subgroups and their clinicopathological characteristics. We selected four hub genes, LAPTM5, C1QC, CSF1R and SLCO2B1, for validation of the immunity status and prognosis of LUSC patients. High expression of these four genes correlated with increased infiltration of immune cell types, upregulation of the immunosuppressive TOX pathway genes, CD8⁺ T cell exhaustion, and shorter overall survival of LUSC patients. These findings demonstrate that four hub genes regulate tumor infiltration of immune cells, anti-tumor immunity, and survival outcomes in LUSC patients.

Identification of Potential Long Non-coding RNA Expression Quantitative Trait Methylations in Lung Adenocarcinoma and Lung Squamous Carcinoma

There are associations between DNA methylation and the expression of long non-coding RNA (lncRNA), also known as lncRNA expression quantitative trait methylations (lnc-eQTMs). Lnc-eQTMs may induce a wide range of carcinogenesis pathways. However, lnc-eQTMs have not been globally identified and studied, and their roles in lung adenocarcinoma (LUAD) and lung squamous carcinoma (LUSC) are largely unknown. In the present study, we identified some differential methylation sites located in genes of long intergenic non-coding RNAs (lincRNAs) and other types of lncRNAs in LUAD and LUSC. An integrated pipeline was established to construct two global cancer-specific regulatory networks of lnc-eQTMs in LUAD and LUSC. The associations between eQTMs showed common and specific features between LUAD and LUSC. Some lnc-eQTMs were also related with survival in LUAD- and LUSC-specific regulatory networks. Lnc-eQTMs were associated with cancer-related functions, such as lung epithelium development and vasculogenesis by functional analysis. Drug repurposing analysis revealed that these lnc-eQTMs may mediate the effects of some anesthesia-related drugs in LUAD and LUSC. In summary, the present study elucidates the roles of lnc-eQTMs in LUAD and LUSC, which could improve our understanding of lung cancer pathogenesis and facilitate treatment.

miRNA-9 Inhibits Proliferation and Migration of Lung Squamous Cell Carcinoma Cells by Regulating NRSF/EGFR

Background:

To investigate the mechanism of microRNA9 in inhibiting proliferation and migration of lung squamous cell carcinoma cells via neuron-restricted silencing factor/epidermal growth factor receptor.

Material and Methods:

Detection of microRNA9, neuron-restricted silencing factor, and epidermal growth factor receptor expression levels in lung cancer patients’ tissues and lung cancer cells by Western blotting and quantitative polymerase chain reaction. Detection of cell proliferation by colony formation assay and cell counting kit-8 assay. Detection of cell migration by wound-healing assay and Transwell assay. And detection of the regulatory effect between neuron-restricted silencing factor and epidermal growth factor receptor by Luciferase reporter gene system. Subcutaneous implantation mouse models of NCI-H520 cells were constructed to detect cell proliferation in vivo, and Kaplan–Meier method calculated patient survival.

Results:

The expression of microRNA9 and epidermal growth factor receptor was higher in lung cancer tissues than in normal lung tissues, while the expression of neuron-restricted silencing factor was lower in lung cancer tissues than in normal lung tissues. MicroRNA9 higher expression was strongly related to tumor size, and TNM stage and predicted showed reduced overall survival in patients with lung cancer. Further loss of function and enhancement experiments revealed that inhibition of microRNA9 could significantly inhibit lung squamous carcinoma cell proliferation and migration. Luciferase reporter assay demonstrated that microRNA9 could bind to NRSF messenger RNA and inhibit its expression, neuron-restricted silencing factor overexpression also exerted inhibitory effects on cell proliferation and migration. Moreover, Luciferase reporter assay showed that neuron-restricted silencing factor downregulate epidermal growth factor receptor expression levels by binding to epidermal growth factor receptor promoter regions, and Pearson’s correlation analysis indicated that the levels of microRNA9 in lung cancer tissues were correlated with neuron-restricted silencing factor and epidermal growth factor receptor. Combined microRNA9 with neuron-restricted silencing factor or epidermal growth factor receptor to predict the prognosis of patients with lung cancer may be more accurate.

Conclusion:

MicroRNA9 inhibits proliferation and migration of lung squamous cell carcinoma cells by inhibiting neuron-restricted silencing factor/epidermal growth factor receptor axis. MicroRNA9 can be a new prognostic marker and therapeutic target for lung squamous cell carcinoma.

Identification of Key Genes Related to Lung Squamous Cell Carcinoma Using Bioinformatics Analysis

Lung squamous cell carcinoma (LUSC) is often diagnosed at the advanced stage with poor prognosis. The mechanisms of its pathogenesis and prognosis require urgent elucidation. This study was performed to screen potential biomarkers related to the occurrence, development and prognosis of LUSC to reveal unknown physiological and pathological processes. Using bioinformatics analysis, the lung squamous cell carcinoma microarray datasets from the Gene Expression Omnibus (GEO) and The Cancer Genome Atlas (TCGA) databases were analyzed to identify differentially expressed genes (DEGs). Furthermore, PPI and WGCNA network analysis were integrated to identify the key genes closely related to the process of LUSC development. In addition, survival analysis was performed to achieve a prognostic model that accomplished good prediction accuracy. Three hundred and thirty–seven up–regulated and 119 down-regulated genes were identified, in which four genes have been found to play vital roles in LUSC development, namely CCNA2, AURKA, AURKB, and FEN1. The prognostic model contained 5 genes, which were all detrimental to prognosis. The AUC of the established prognostic model for predicting the survival of patients at 1, 3, and 5 years was 0.692, 0.722, and 0.651 in the test data, respectively. In conclusion, this study identified several biomarkers of significant interest for additional investigation of the therapies and methods of prognosis of lung squamous cell carcinoma.

LncRNA-ATB Promotes Lung Squamous Carcinoma Cell Proliferation, Migration, and Invasion by Targeting microRNA-590-5p/NF90 Axis

Lung cancer with highest morbidity and mortality seriously threatens human health worldwide. Long noncoding RNAs (lncRNAs) exert important biological functions by acting as microRNA, which is implicated in tumorigenesis and cancer development. Previous work has reported that lncRNA-ATB expression was significantly upregulated in lung adenocarcinoma tissues and promoted tumor progression; however, the mechanisms of lncRNA-ATB in lung squamous carcinoma (LSC) are still fairly elusive. In our study, lncRNA-ATB expression also markedly increases in LSC tissues and cell lines in comparison to the adjacent normal tissues and normal lung epithelial cells, respectively. Functional experiments indicate that lncRNA-ATB overexpression improves the proliferative, migratory, and invasive capabilities of normal lung epithelial cells compared with control group. Furthermore, the migratory and invasive abilities are strikingly inhibited in lncRNA-ATB silenced LSC cells. Mechanistically, lncRNA-ATB directly binds to microRNA-590-5p and downregulates microRNA-590-5p level, leading to the upregulation of NF-90 expression. In addition, lncRNA-ATB overexpression promotes the epithelial-mesenchymal transition process, where lncRNA-ATB overexpression facilitates the expression of mesenchymal phenotype related molecules N-cadherin and vimentin, while restrains the expression of epithelial phenotype related proteins E-cadherin and CK-19, compared to the control. Conversely, microRNA-590-5p mimics can reverse the results caused by lncRNA-ATB overexpression. Taken together, our initial data suggest that lncRNA-ATB overexpression may promote the progression of LSC by modulating the microRNA-590-5p/NF-90 axis.

Functional Variant in 3'UTR of FAM13A Is Potentially Associated with Susceptibility and Survival of Lung Squamous Carcinoma

FAM13A is associated with aging lung disease (primarily chronic obstructive pulmonary disorder and pulmonary fibrosis) and shows stable expression throughout lung development. However, a few systematic studies of FAM13A have been conducted to assess the pathogenesis of lung cancer, particularly susceptibility. We predicted that single-nucleotide polymorphisms (SNPs) in FAM13A may be associated with lung cancer development. We systematically selected five functional SNPs (rs2602120, rs3017895, rs9224, rs7657817, and rs3756050) and genotyped them with the Genesky proprietary improved Multiligase Detection Reaction multiplex SNP genotyping system in a case-control study of 626 lung cancer cases and 667 cancer-free controls. The functional effects of FAM13A and specific miRNAs (miRNA-22-5p and miRNA-1301-3p) were evaluated based on The Cancer Genome Atlas database. We found that rs9224 in the 3' untranslated region (UTR) of FAM13A was potentially associated with an increased risk of lung squamous carcinoma (LUSQ) (additive model: odds ratio = 1.47, 95% confidence interval = 1.04-2.07, p = 0.028). In addition, the results of expression quantitative trait loci analysis suggested that the rs9224 polymorphism affects the expression of FAM13A (p = 0.050) and miRNA-22-5p (p = 0.031) in LUSQ. Further, survival analysis indicated decreased overall survival in the presence of the variant alleles of rs9224 (p = 0.048). The present results indicate that variant genotypes of rs9224 in the FAM13A 3'UTR may modify LUSQ susceptibility by affecting the binding of miRNA-22-5p and predict a poor prognosis of patients with LUSQ.

Upregulation of OTUD7B (Cezanne) Promotes Tumor Progression via AKT/VEGF Pathway in Lung Squamous Carcinoma and Adenocarcinoma

OTUD7B, a multifunctional deubiquitinylase, plays an essential role in inflammation and proliferation signals. However, its function in lung cancer remains largely unknown. The aim of this study was to evaluate the prognostic significance of OTUD7B in patients with lung adenocarcinoma and squamous carcinoma and to characterize its molecular mechanisms in lung cancer progression and metastasis. Two tissue microarrays containing 150 pairs of lung squamous carcinoma and matched adjacent non-cancer tissues, and one tissue microarray containing 75 pairs of lung adenocarcinoma and adjacent non-cancer tissues were included, and immunohistochemical staining was performed to assess the clinical relevance of OTUD7B in non-small cell lung cancer. OTUD7B is highly expressed in both lung squamous carcinoma and adenocarcinoma and correlates with a worse prognosis. MTT proliferation, colony formation, migration and invasion assays and immunoblotting assay in NCI-H358 and A549 cell lines suggested that OTUD7B enhances EGF-induced Akt signal transduction and promotes lung cancer cell proliferation and migration. Immunohistochemical staining of large-scale lung cancer subjects (171 cases) revealed positive correlation of OTUD7B and VEGF expression. ELISA and tube formation assay revealed OTUD7B promotes VEGF production and angiogenesis. NCI-H358 tumor model demonstrated OTUD7B is required for lung tumor progression by facilitating activation of Akt signaling. These findings collectively identified OTUD7B as an independent predictive factor for the prognosis of non-small cell lung cancer and revealed OTUD7B promotes lung cancer cell proliferation and metastasis via Akt/VEGF signal pathway.

A 16-gene expression signature to distinguish stage I from stage II lung squamous carcinoma

The present study aimed to perform screening of a gene signature for the discrimination and prognostic prediction of stage I and II lung squamous carcinoma. A microarray meta‑analysis was performed to identify differentially expressed genes (DEGs) between stage I and II lung squamous carcinoma samples in seven microarray datasets collected from the Gene Expression Omnibus database via the MetaQC and MetaDE package in R. The important DEGs were selected according to the betweenness centrality value of the protein‑protein interaction (PPI) network. Support vector machine (SVM) analysis was performed to screen the feature genes for discrimination and prognosis. One independent dataset downloaded from The Cancer Genome Atlas was used to validate the reliability. Pathway enrichment analysis was also performed for the feature genes. A total of 924 DEGs were identified to construct a PPI network consisting of 392 nodes and 686 edges. The top 100 of the 392 nodes were selected as crucial genes to construct an SVM classifier, and a 16‑gene signature (caveolin 1, eukaryotic translation elongation factor 1γ, casein kinase 2α1, tyrosine 3-monooxygenase/tryptophan 5-monooxygenase activation η, tyrosine 3‑monooxygenase/tryptophan 5‑monooxygenase activation θ, pleiotrophin, insulin receptor, insulin receptor substrate 1, 3‑phosphoinositide‑dependent protein kinase‑1, specificity protein 1, COP9 signalosome subunit 6, N‑myc downstream regulated gene 1, retinoid X receptor α, heat shock protein 90α A1, karyopherin subunit β1 and erythrocyte membrane protein band 4.1) with high discrimination accuracy was identified. This 16‑gene signature had significant prognostic value, and patients with stage II lung squamous carcinoma exhibited shorter survival rates, compared with those with stage I disease. Seven DEGs of the 16-gene signature were significantly involved in the phosphoinositide 3‑kinase‑Akt signaling pathway. The 16‑gene signature identified in the present study may be useful for stratifying the patients with stage I or II lung squamous carcinoma and predicting prognosis.

EGFR with TKI-sensitive mutations in exon 19 is highly expressed and frequently detected in Chinese patients with lung squamous carcinoma

Recently, tyrosine kinase inhibitors (TKIs) have been recommended as a first-line treatment for advanced non-small cell lung cancer (NSCLC), significantly improving the treatment outcomes of lung adenocarcinoma patients with the EGFR mutation. However, the application of TKIs for lung squamous cell carcinoma (SCC), the second largest pathological subtype of NSCLC, remains controversial because available data for the EGFR mutation profile and frequency in SCC patients are limited. In this study, 89 bronchoscopic-biopsy specimens from Chinese SCC male patients were assayed for EGFR exon 19 mutation, using improved polymerase chain reaction-denature gel gradient electrophoresis. EGFR exon 19 mutations were detected in 77 of 89 (86.5%) patients, and included six kinds of point mutations (11.6%) and two deletions (Del_747-751 [64.9%] and Del_746-751 [23.3%]). We found that the proportion of mutated EGFR varied from 0.98% to 100% in positive specimens and increased with the development of the disease. The difference of proportion between Stage IV patients and Stage II patients or Stage III patients was significant (P<0.001). These results provided valuable clues to explain the reason why patients harboring the same mutation responded distinctly to TKI treatment. Del_747-751 and Del_746-751 were the dominant mutations in the assayed SCC patients (76.4%), and both belong to the EGFR-TKI-sensitive mutation. Recently research demonstrated that Del_746-751 patients have better response to EGFR-TKI than Del_L747-751 patients. However, our study indicated that majority of SCC patients (55.5%) carried Del_ L747-751. We suggest that the unique clinic features of SCC should be further studied to reveal the mechanism of poorer treatment outcome of EGFR-TKI therapy, and that a better treatment plan and more specific, potent targeted drugs for lung SCC need to be developed.

Targeting protein for Xenopus kinesin-like protein 2 knockdown enhances radiation sensitivity of human lung squamous carcinoma cell

The targeting protein for Xenopus kinesin-like protein 2 (TPX2) has been demonstrated to be associated with the tumourigenesis of many cancers. In the present study, we investigated the role and preliminary mechanism of TPX2 in the resistance of lung squamous carcinoma to radiation therapy. The results showed that SK-MES-1R and NCI-H226R cells were more resistant to X-ray irradiation than the parental cells (SK-MES-1 and NCI-H226). Moreover, TPX2 was upregulated in the radioresistant cells compared with the parental cells. TPX2 knockdown significantly decreased TPX2 expression in SK-MES-1 cells, while TPX2 overexpression increased TPX2 expression in NCI-H226 cells compared with the corresponding control cells. TPX2 knockdown enhanced the radiosensitivity of SK-MES-1 and promoted cell apoptosis following exposure to irradiation, whereas TPX2 overexpression decreased the radiosensitivity of NCI-H226 and inhibited cell apoptosis. In in vivo studies, the combination of TPX2 knockdown and irradiation significantly inhibited tumour growth, decreased tumour weight, downregulated TPX2 expression in tumour tissue and induced cell apoptosis in nude mice, while TPX2 overexpression exerted an opposite effect. Our results indicated that TPX2 was correlated with cell radioresistance and it might be served as a therapeutic target to enhance cell radiosensitivity in the radiation therapy of lung squamous carcinoma.

Sequential measurements of serum matrix metalloproteinase 9 to monitor chemotherapy responses in patients with advanced non-small-cell lung cancer

Background

Matrix metalloproteinase 9 (MMP-9) plays an important role in tumor invasion and metastasis, including lung cancer. However, whether variations in serum MMP-9 levels can serve as a biomarker for monitoring chemotherapy curative effect remains unclear. This study was designed to investigate the association between variations in serum MMP-9 levels and chemotherapy curative effect in patients with lung cancer.

Patients and methods

A total of 82 patients with advanced lung cancer were included. All newly diagnosed patients were treated with platinum-based doublet chemotherapy. Serial measurements of serum MMP-9 levels were performed by enzyme-linked immunosorbent assay. In this manner, we chose four time points to examine the association, including before chemotherapy, and 3 weeks after the beginning of the first, second, and fourth cycles of chemotherapy.

Results

Compared with the serum level of MMP-9 before progressive disease, patients with progressive disease had elevated serum levels of MMP-9. Compared with the previous time point of collecting specimens, the serum levels of MMP-9 in the patients with a complete response/partial response/stable disease decreased or were maintained stable. The differences of variation in serum MMP-9 levels in patients with different chemotherapy curative effects were all statistically significant after one cycle, two cycles, and four cycles (after one cycle: P<0.001; after two cycles: P<0.001; after four cycles: P=0.01). However, patients with small-cell lung cancer did not exhibit similar test results.

Conclusion

The variation in serum MMP-9 levels in patients with non-small-cell lung cancer during chemotherapy was closely related to chemotherapy curative effect and could be useful to monitor chemotherapy curative effect for a small portion of patients.

A network-based method for identifying prognostic gene modules in lung squamous carcinoma

Similarities in gene expression between both developing embryonic and precancerous tissues and cancer tissues may help identify much-needed biomarkers and therapeutic targets in lung squamous carcinoma. In this study, human lung samples representing ten successive time points, from embryonic development to carcinogenesis, were used to construct global gene expression profiles. Differentially expressed genes with similar expression in precancerous and cancer samples were identified. Using a network-based greedy searching algorithm to analyze the training cohort (n = 69) and three independent testing cohorts, we successfully identified a significant 22-gene module in which expression levels were correlated with overall survival in lung squamous carcinoma patients.

Lung squamous carcinoma with two paraneoplastic syndromes: dermatomyositis and Lambert-Eaton myasthenic syndrome

BACKGROUND AND AIM

Paraneoplastic syndrome is a disease or symptom that is the consequence of cancer in the body but, unlike mass effect, is not due to the local presence of cancer cells. An overlap of two paraneoplastic syndromes secondary to lung cancer in a patient is very rare. In order to improve the diagnosis of two paraneoplastic syndromes secondary to lung cancer, we reported an overlap of two paraneoplastic syndromes secondary to lung squamous carcinoma in a patient.

METHODS

We reported a case of a 60-year-old male smoker who presented multiple erythematous lesions for 6 months with progressive proximal muscular weakness, and developed to dysphonia in 2 months. His chest computed tomography showed a spiculate pulmonary nodule near the hilar in the right upper lobe and mediastinal lymph nodes enlargement. Lung biopsy showed squamous cell carcinoma. The patient's blood test revealed elevated creatine kinase levels. Electromyography results were consistent with moderate myopathy accompanied with a pattern suggestive of Lambert-Eaton myasthenic syndrome.

RESULTS

So we made the diagnosis of an overlap of two paraneoplastic syndromes (dermatomyositis and Lambert-Eaton myasthenic syndrome) secondary to lung squamous carcinoma.

CONCLUSION

Recognition of paraneoplastic syndrome is crucial for early diagnosis of lung cancer because up to 80% of patients may present paraneoplastic syndromes before any other direct indication of malignancy. Early diagnosis and treatment of paraneoplastic syndrome is also important because delayed diagnosis may result in rapid disease progression and irreversible neurological damage.