Pulmonary adenocarcinoma: a renewed entity in 2011

Decoding Cancer through Silencing the Mitochondrial Gatekeeper VDAC1

Mitochondria serve as central hubs for regulating numerous cellular processes that include metabolism, apoptosis, cell cycle progression, proliferation, differentiation, epigenetics, immune signaling, and aging. The voltage-dependent anion channel 1 (VDAC1) functions as a crucial mitochondrial gatekeeper, controlling the flow of ions, such as Ca2+, nucleotides, and metabolites across the outer mitochondrial membrane, and is also integral to mitochondria-mediated apoptosis. VDAC1 functions in regulating ATP production, Ca2+ homeostasis, and apoptosis, which are essential for maintaining mitochondrial function and overall cellular health. Most cancer cells undergo metabolic reprogramming, often referred to as the "Warburg effect", supplying tumors with energy and precursors for the biosynthesis of nucleic acids, phospholipids, fatty acids, cholesterol, and porphyrins. Given its multifunctional nature and overexpression in many cancers, VDAC1 presents an attractive target for therapeutic intervention. Our research has demonstrated that silencing VDAC1 expression using specific siRNA in various tumor types leads to a metabolic rewiring of the malignant cancer phenotype. This results in a reversal of oncogenic properties that include reduced tumor growth, invasiveness, stemness, epithelial-mesenchymal transition. Additionally, VDAC1 depletion alters the tumor microenvironment by reducing angiogenesis and modifying the expression of extracellular matrix- and structure-related genes, such as collagens and glycoproteins. Furthermore, VDAC1 depletion affects several epigenetic-related enzymes and substrates, including the acetylation-related enzymes SIRT1, SIRT6, and HDAC2, which in turn modify the acetylation and methylation profiles of histone 3 and histone 4. These epigenetic changes can explain the altered expression levels of approximately 4000 genes that are associated with reversing cancer cells oncogenic properties. Given VDAC1's critical role in regulating metabolic and energy processes, targeting it offers a promising strategy for anti-cancer therapy. We also highlight the role of VDAC1 expression in various disease pathologies, including cardiovascular, neurodegenerative, and viral and bacterial infections, as explored through siRNA targeting VDAC1. Thus, this review underscores the potential of targeting VDAC1 as a strategy for addressing high-energy-demand cancers. By thoroughly understanding VDAC1's diverse roles in metabolism, energy regulation, mitochondrial functions, and other cellular processes, silencing VDAC1 emerges as a novel and strategic approach to combat cancer.

Identification of lung adenocarcinoma subtypes and predictive signature for prognosis, immune features, and immunotherapy based on immune checkpoint genes

Background: Lung adenocarcinoma (LUAD) is the most common variant of non-small cell lung cancer (NSCLC) across the world. Recently, the rapid development of immunotherapy has brought a new dawn for LUAD patients. Closely related to the tumor immune microenvironment and immune cell functions, more and more new immune checkpoints have been discovered, and various cancer treatment studies targeting these novel immune checkpoints are currently in full swing. However, studies on the phenotype and clinical significance of novel immune checkpoints in LUAD are still limited, and only a minority of patients with LUAD can benefit from immunotherapy. Methods: The LUAD datasets were downloaded from The Cancer Genome Atlas (TCGA) and the Gene Expression Omnibus (GEO) databases, and the immune checkpoints score of each sample were calculated based on the expression of the 82 immune checkpoints-related genes (ICGs). The weighted gene co-expression network analysis (WGCNA) was used to obtain the gene modules closely related to the score and two different LUAD clusters were identified based on these module genes by the Non-negative Matrix Factorization (NMF) Algorithm. The differentially expressed genes between the two clusters were further used to construct a predictive signature for prognosis, immune features, and the response to immunotherapy for LUAD patients through a series of regression analyses. Results: A new immune checkpoints-related signature was finally established according to the expression of 7 genes (FCER2, CD200R1, RHOV, TNNT2, WT1, AHSG, and KRTAP5-8). This signature can stratify patients into high-risk and low-risk groups with different survival outcomes and sensitivity to immunotherapy, and the signature has been well validated in different clinical subgroups and validation cohorts. Conclusion: We constructed a novel immune checkpoints-related LUAD risk assessment system, which has a good predictive ability and significance for guiding immunotherapy. We believe that these findings will not only aid in the clinical management of LUAD patients but also provide some insights into screening appropriate patients for immunotherapy.

Immune- and Stemness-Related Genes Revealed by Comprehensive Analysis and Validation for Cancer Immunity and Prognosis and Its Nomogram in Lung Adenocarcinoma

Objective

Lung adenocarcinoma (LUAD) is a familiar lung cancer with a very poor prognosis. This study investigated the immune- and stemness-related genes to develop model related with cancer immunity and prognosis in LUAD.

Method

The Cancer Genome Atlas (TCGA) was utilized for obtaining original transcriptome data and clinical information. Differential expression, prognostic value, and correlation with clinic parameter of mRNA stemness index (mRNAsi) were conducted in LUAD. Significant mRNAsi-related module and hub genes were screened using weighted gene coexpression network analysis (WGCNA). Meanwhile, immune-related differential genes (IRGs) were screened in LUAD. Stem cell index and immune-related differential genes (SC-IRGs) were screened and further developed to construct prognosis-related model and nomogram. Comprehensive analysis of hub genes and subgroups, involving enrichment in the subgroup [gene set enrichment analysis (GSEA)], gene mutation, genetic correlation, gene expression, immune, tumor mutation burden (TMB), and drug sensitivity, used bioinformatics and reverse transcription polymerase chain reaction (RT-PCR) for verification.

Results

Through difference analysis, mRNAsi of LUAD group was markedly higher than that of normal group. Clinical parameters (age, gender, and T staging) were ascertained to be highly relevant to mRNAsi. MEturquoise and MEblue were found to be the most significant modules (including positive and negative correlations) related to mRNAsi via WGCNA. The functions and pathways of the two mRNAsi-related modules were mainly enriched in tumorigenesis, development, and metastasis. Combining stem cell index-related differential genes and immune-related differential genes, 30 prognosis-related SC-IRGs were screened via Cox regression analysis. Then, 16 prognosis-related SC-IRGs were screened to construct a LASSO regression model at last. In addition, the model was successfully validated by using TCGA-LUAD and GSE68465, whereas c-index and the calibration curves were utilized to demonstrate the clinical value of our nomogram. Following the validation of the model, GSEA, immune cell correlation, TMB, clinical relevance, etc., have found significant difference in high- and low-risk groups, and 16-gene expression of the SC-IRG model also was tested by RT-PCR. ADRB2, ANGPTL4, BDNF, CBLC, CX3CR1, and IL3RA were found markedly different expression between the tumor and normal group.

Conclusion

The SC-IRG model and the prognostic nomogram could accurately predict LUAD survival. Our study used mRNAsi combined with immunity that may lay a foundation for the future research studies in LUAD.

Effect of prior antibiotic or chemotherapy treatment on immunotherapy response in non-small cell lung cancer

BACKGROUND

Treatment outcomes of advanced non-small cell lung cancer (NSCLC) have substantially improved with immune checkpoint inhibitors (ICI), although only approximately 19% of patients respond to immunotherapy alone, increasing to 58% with the addition of chemotherapy. The gut microbiome has been recognized as a modulator of ICI response via its priming effect on the host immune response. Antibiotics as well as chemotherapy reduce gut microbial diversity, hence altering composition and function of the gut microbiome. Since the gut microbiome may modify ICI efficacy, we conducted a retrospective study evaluating the effects of prior antibiotic or chemotherapy use on NSCLC patient response to ICI.

METHODS

We retrospectively evaluated 256 NSCLC patients treated between 2011-2017 at Moffitt Cancer Center with ICI ± chemotherapy, examining the associations between prior antibiotic or chemotherapy use, overall response rate and survival. Relative risk regression using a log-link with combinatorial expectation maximization algorithm was performed to analyze differences in response between patients treated with antibiotics or chemotherapy versus patients who didn't receive antibiotics or chemotherapy. Cox proportional hazards models were constructed to evaluate associations between risk factors and overall survival.

RESULTS

Only 46 (18% of 256) patients used antibiotics prior to and/or during ICI treatment, and 146 (57%) had prior chemotherapy. Antibiotic users were 8% more likely to have worse overall response rate (RR:1.08; CI:0.93-1.26; p = 0.321), as well as a 35% worse overall survival (HR:1.35; CI:0.91-2.02; p = 0.145), although results were not statistically significant. However, prior use of chemotherapy was significantly associated with poor ICI response (RR:1.24; CI:1.05-1.47; p = 0.013) and worse overall survival (HR:1.47; CI:1.07-2.03; p = 0.018).

CONCLUSIONS

Patients receiving antibiotics prior to and/or during ICI therapy might experience worse treatment outcomes and survival than unexposed patients, although these associations were not statistically significant and hence warrant further prospective study. Prior chemotherapy significantly reduced ICI response and overall survival. Antibiotic or chemotherapy exposure may negatively impact ICI response, perhaps through disruption of the eubiotic gut microbiome.

Computational detection of a genome instability-derived lncRNA signature for predicting the clinical outcome of lung adenocarcinoma

Evidence has been emerging of the importance of long non-coding RNAs (lncRNAs) in genome instability. However, no study has established how to classify such lncRNAs linked to genomic instability, and whether that connection poses a therapeutic significance. Here, we established a computational frame derived from mutator hypothesis by combining profiles of lncRNA expression and those of somatic mutations in a tumor genome, and identified 185 candidate lncRNAs associated with genomic instability in lung adenocarcinoma (LUAD). Through further studies, we established a six lncRNA-based signature, which assigned patients to the high- and low-risk groups with different prognosis. Further validation of this signature was performed in a number of separate cohorts of LUAD patients. In addition, the signature was found closely linked to genomic mutation rates in patients, indicating it could be a useful way to quantify genomic instability. In summary, this research offered a novel method by through which more studies may explore the function of lncRNAs and presented a possible new way for detecting biomarkers associated with genomic instability in cancers.

DNA methylome and transcriptome landscapes of cancer-associated fibroblasts reveal a smoking-associated malignancy index

Unlike the better-studied aberrant epigenome in the tumor, the clinicopathologic impact of DNA methylation in the tumor microenvironment (TME), especially the contribution from cancer-associated fibroblasts (CAFs), remains elusive. CAFs exhibit profound patient-to-patient tumorigenic heterogeneity. We asked whether such heterogeneity may be exploited to quantify the level of TME malignancy. We developed a robust and efficient methylome/transcriptome co-analytical system for CAFs and paired normal fibroblasts (NFs) from non-small-cell lung cancer patients. We found 14,781 CpG sites of CAF/NF differential methylation, of which 3,707 sites showed higher methylation changes in ever-smokers than in nonsmokers. Concomitant CAF/NF differential gene expression analysis pointed to a subset of 54 smoking-associated CpG sites with strong methylation-regulated gene expression. A methylation index that summarizes the β values of these CpGs was built for NF/CAF discrimination (MIND) with high sensitivity and specificity. The potential of MIND in detecting premalignancy across individual patients was shown. MIND succeeded in predicting tumor recurrence in multiple lung cancer cohorts without reliance on patient survival data, suggesting that the malignancy level of TME may be effectively graded by this index. Precision TME grading may provide additional pathological information to guide cancer prognosis and open up more options in personalized medicine.

LINC01089 suppresses lung adenocarcinoma cell proliferation and migration via miR-301b-3p/STARD13 axis

Background

Lung adenocarcinoma (LUAD) is one of the most common cancers with high morbidity and mortality worldwide. Long non-coding RNAs (lncRNAs) serve as tumor promoters or suppressors in the development of various human malignancies, including LUAD. Although long intergenic non-protein coding RNA 1089 (LINC01089) suppresses the progression of breast cancer, its mechanism in LUAD requires further exploration. Thus, we aimed to investigate the underlying function and mechanism of LINC01089 in LUAD.

Methods

The expression of LINC01089 in LUAD and normal cell lines was detected. Functional assays were applied to measure cell proliferation, apoptosis and migration. Besides, mechanism experiments were employed for assessing the interplay among LINC01089, miR-301b-3p and StAR related lipid transfer domain containing 13 (STARD13). Data achieved in this study was statistically analyzed with Student’s t test or one-way analysis of variance.

Results

LINC01089 expression was significantly down-regulated in LUAD tissues and cells and its overexpression could reduce cell proliferation and migration. Moreover, LINC01089 could regulate STARD13 expression through competitively binding to miR-301b-3p in LUAD. Additionally, rescue assays uncovered that STARD13 depletion or miR-301b-3p overexpression could countervail the restraining effect of LINC01089 knockdown on the phenotypes of LUAD cells.

Conclusion

LINC01089 served as a tumor-inhibitor in LUAD by targeting miR-301b-3p/STARD13 axis, providing an innovative insight into LUAD therapies.

Trial registration Not applicable.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12890-021-01568-6.

Varied clinical significance of ATP-binding cassette C sub-family members for lung adenocarcinoma

Lung adenocarcinoma (LUAD) is a lethal malignancy worldwide and a major public health concern. We explored the potential clinical significance for LUAD of ATP-binding cassette (ABC), sub-family C, consisting of ABCC1-6, 8-12, and cystic fibrosis transmembrane conductance regulator (CFTR).Five hundred LUAD patients from The Cancer Genome Atlas database were used for analysis, including differential expression and diagnostic and prognostic significance. Oncomine and MERAV databases were used to validate differential expression and diagnostic significance. A risk score model was constructed using prognosis-related ABCC members. Prognosis-related genes were further explored to correlate their expression with tumor stage progression. Interaction networks, including biological processes and metabolic pathways, were constructed using Cytoscape software and STRING website.ABCC1-3 consistently showed high expression in tumor tissues (all P ≤ 0.05). Most datasets indicated that ABCC5, 10, and 11 were highly expressed in tumor tissues whereas ABCC6, 9, and CFTR were highly expressed in nontumor tissues (all P ≤ 0.05). Diagnostic significance of ABCC3 and ABCC5 was consistently assessed and validated in three datasets (all area under the curve > 0.700) whereas ABCC6, 8, 10, 11, and CFTR were assessed in The Cancer Genome Atlas dataset and validated in one dataset (all area under the curve > 0.700). Prognostic analysis indicated that ABCC2, 6, and 8 mRNA expression was associated with survival of LUAD (all adjusted P ≤ .037). The risk score model constructed using ABCC2, 6, and 8 suggested prognostic significance for survival predictions. ABCC2 expression was associated with tumor stage, whereas ABCC6 and 8 were not. Interaction networks indicated that they were involved in establishment of localization, ion transport, plasma membrane, apical plasma membrane, adenylyl nucleotide binding, ABC transporters, ABC transporter disorders, ABC-family-protein-mediated transport, and bile secretion.Differentially expressed ABCC2 and ABCC5 might be diagnostic whereas ABCC2, 6, and 8 may be prognostic biomarkers for LUAD, possibly through ABC-family-mediated transporter disorders.

Development of an Oncogenic Driver Alteration Associated Immune-Related Prognostic Model for Stage I-II Lung Adenocarcinoma

Lung adenocarcinoma (LUAD) needs to be stratified for its heterogeneity. Oncogenic driver alterations such as EGFR mutation, ALK translocation, ROS1 translocation, and BRAF mutation predict response to treatment for LUAD. Since oncogenic driver alterations may modulate immune response in tumor microenvironment that may influence prognosis in LUAD, the effects of EGFR, ALK, ROS1, and BRAF alterations on tumor microenvironment remain unclear. Immune-related prognostic model associated with oncogenic driver alterations is needed. In this study, we performed the Cox-proportional Hazards Analysis based on the L1-penalized (LASSO) Analysis to establish an immune-related prognostic model (IPM) in stage I-II LUAD patients, which was based on 3 immune-related genes (PDE4B, RIPK2, and IFITM1) significantly enriched in patients without EGFR, ALK, ROS1, and BRAF alterations in The Cancer Genome Atlas (TCGA) database. Then, patients were categorized into high-risk and low-risk groups individually according to the IPM defined risk score. The predicting ability of the IPM was validated in GSE31210 and GSE26939 downloaded from the Gene Expression Omnibus (GEO) database. High-risk was significantly associated with lower overall survival (OS) rates in 3 independent stage I-II LUAD cohorts (all P < 0.05). Moreover, the IPM defined risk independently predicted OS for patients in TCGA stage I-II LUAD cohort (P = 0.011). High-risk group had significantly higher proportions of macrophages M1 and activated mast cells but lower proportions of memory B cells, resting CD4 memory T cells and resting mast cells than low-risk group (all P < 0.05). In addition, the high-risk group had a significantly lower expression of CTLA-4, PDCD1, HAVCR2, and TIGIT than the low-risk group (all P < 0.05). In summary, we established a novel IPM that could provide new biomarkers for risk stratification of stage I-II LUAD patients.

Systemic analyses of expression patterns and clinical features for GIMAPs family members in lung adenocarcinoma

GTPase of immunity-associated proteins (GIMAPs) are frequently prescribed as important components of immune regulation complexes, which were known to play key roles in lung adenocarcinoma. However, little is known about the function of distinct GIMAPs in lung adenocarcinoma. To address this issue, this study investigated the biological function and pathway of GIMAPs in lung adenocarcinoma using multiple public databases. Absent expression of GIMAPs was found in lung adenocarcinoma at mRNA and protein levels. While a purity-corrected value uncovered that all GIMAPs were positively associated with the immune infiltration of lung adenocarcinoma. Furthermore, the expressions of GIMAPs were considered to be negatively associated with clinical cancer stages, patient’s gender and pathological tumor grades in patients with lung adenocarcinoma. Besides, higher mRNA expression of GIMAPs was significantly associated with longer overall survival of patients with lung adenocarcinoma. Taken together, these results may enable GIMAPs family members as diagnostic and survival biomarker candidates or even potential therapeutic targets for patients with lung adenocarcinoma.

Sodium Butyrate Combined with Docetaxel for the Treatment of Lung Adenocarcinoma A549 Cells by Targeting Gli1

Purpose

This study is aimed to investigate the combined treating efficacy of sodium butyrate and docetaxel on proliferation and apoptosis of the lung adenocarcinoma A549 cell line based on Gli1 regulation in vitro and in vivo.

Materials and Methods

RNA interference method was used to overexpress Gli1 in A549 cells. Cells were treated with varying concentrations of sodium butyrate, docetaxel or both in combination. CCK-8, colony formation assay, Hoechst 33258 staining, flow cytometry and TUNEL assay were employed to detect proliferation, cell cycle and apoptosis. qRT-PCR and Western blot analysis were applied to detect the mRNA and protein expression of Gli1. In vivo tumorigenicity was detected by tumor transplantation in nude mice. Downstream protein levels of Gli1 were detected using Western blot assay.

Results

It was found that sodium butyrate or docetaxel alone, respectively, inhibited proliferation and promoted apoptosis of A549 cells in vitro and in vivo, while the combination of the two generated significantly higher responses, which were also effective in another lung adenocarcinoma cell line H1299. Furthermore, the combined therapy had an additive effect in suppressing Gli1 expression and regulating the expression of its downstream proteins that involve in proliferation, cell cycle and apoptosis of A549 cells in vitro and in vivo, including decreased protein expression of Ki-67, CDK1, CDK2, Cyclin D1, Bcl-2 and Survivin, and increased protein expression of Cyclin A, p21, Bax and cleaved-Caspase 3. On the other hand, Gli1 overexpression perceptibly reversed the above-mentioned additive effect in vitro and in vivo.

Conclusion

This study demonstrates that the combined therapy of sodium butyrate and docetaxel additively inhibits proliferation and promotes apoptosis of A549 lung adenocarcinoma cells via suppressing Gli1 expression in vitro and in vivo. Targeting Gli1 by the combined therapy may provide new insights into the therapeutic management of patients with lung adenocarcinoma.

Kank1 and Ki67 expression are associated with poor prognosis in human pulmonary adenocarcinoma

KN motif and ankyrin repeat domains 1 (Kank1) and ki67 are associated with tumorigenesis and progression. This paper researched the expression of Kank1 and Ki67 and their clinicopathologic significance in pulmonary adenocarcinoma (PA). We monitored the expression of KanK1 and ki67 in 94 cases of human PA and 31 cases of paracancerous tissue by the immunohistochemical method. The results showed that Kank1 protein was detected in 74.2% (41/94) of PA tissues, and they were associated with differentiation (P = 0.025) and lymphatic metastasis (P = 0.002). Kaplan-Meier analysis suggested that patients with low Kank1 expression had shorter overall survival in PA (P = 0.020). Ki67 protein was detected in 79.8% (75/94) of PA tissues, and they were associated with differentiation (P < 0.001), TNM classification (P = 0.007), and lymphatic metastasis (P = 0.044). Furthermore, Kaplan-Meier analysis showed that patients with overexpression of Ki67 had shorter overall survival (P = 0.014). Cox multivariate analysis showed that tumor differentiation, TNM classification, lymphatic metastasis, Kank1, and ki67 expression were independent factors for prognosis of PA (P = 0.012, 0.016, 0.007, 0.021 and P = 0.003 respectively). In conclusion, compared with paracancerous tissues, Kank1 had low expression, while Ki67 was overexpressed in PA. They are closely related to its occurrence and development, and the prognosis of patients with low expression of Kank1 or overexpression of ki67 was poor in PA. Kank1 and Ki67 can be helpful for diagnosing and detecting the prognosis of patients with PA.

Nucleophosmin 1 overexpression correlates with 18F-FDG PET/CT metabolic parameters and improves diagnostic accuracy in patients with lung adenocarcinoma

PURPOSE

This study investigated the correlation of nucleophosmin 1 (NPM1) expression with ¹⁸F-fluorodeoxyglucose (¹⁸F-FDG) positron emission tomography/computerised tomography scan (PET/CT)-related parameters and compared the diagnostic value of NPM1 with that of the positive biomarker TTF1 in lung adenocarcinoma patients.

METHODS

Forty-six lung adenocarcinoma patients who underwent ¹⁸F-FDG PET/CT before pulmonary surgery were retrospectively analysed. Metabolic parameters including SUV_max, SUV_mean, metabolic tumour volume (MTV) and total lesion glycolysis (TLG) were calculated from ¹⁸F-FDG PET imaging data. The expression levels of NPM1 and TTF1 were assessed using The Cancer Genome Atlas (TCGA) database and immunohistochemistry of tumour tissues and adjacent normal lung tissues. We examined the association between the frequency of NPM1 and TTF1 expression and the metabolic parameters.

RESULTS

Lung adenocarcinoma samples expressed higher levels of NPM1 than adjacent normal lung epithelial tissues. NPM1 showed higher specificity and sensitivity for lung adenocarcinoma compared with TTF1 (p < 0.001). SUV_max, SUV_mean and TLG correlated with NPM1 expression (p < 0.001). MTV was inversely correlated with TTF1 (p < 0.01). SUV_max was the primary predictor of NPM1 expression by lung adenocarcinoma (p < 0.01). A cutoff value for the SUV_max of 3.93 allowed 90.9% sensitivity and 84.6% specificity for predicting NPM1 overexpression in lung adenocarcinoma.

CONCLUSION

NPM1 overexpression correlated with ¹⁸F-FDG PET/CT metabolic parameters and improved diagnostic accuracy in lung adenocarcinoma. SUV_max on ¹⁸F-FDG PET/CT may estimate NPM1 expression for targeted therapy of lung adenocarcinoma.

LINC02418 promotes malignant behaviors in lung adenocarcinoma cells by sponging miR-4677-3p to upregulate KNL1 expression

Background

Lung adenocarcinoma (LAD) is a prevalent type of bronchogenic malignant tumor and one of the most critical factors related to human death. Long noncoding RNAs (lncRNAs) are involved in many complex biological processes and have been emerged as extremely important regulators of various cancers. LINC02418, a novel lncRNA, hasn’t been mentioned in previous studies on cancer development. Therefore, it’s important to define the potential function of LINC02418 in LAD.

Methods

Gene expression was examined by RT-qPCR or western blot. CCK-8, colony formation, TUNEL, and transwell assays were utilized to study the role of LINC02418 in LAD. The interaction of miR-4677-3p with LINC02418 (or KNL1) was verified through luciferase reporter, RIP and RNA pull-down assays.

Results

High expression of LINC02418 was observed in LAD specimens and cells. Downregulation of LINC02418 obstructed the proliferation and motility of LAD cells. Moreover, LINC02418 negatively modulated miR-4677-3p expression and miR-4677-3p overexpression could repress cell proliferation and migration. Moreover, kinetochore scaffold 1 (KNL1) expression was negatively modulated by miR-4677-3p but positively regulated by LINC02418. Furthermore, miR-4677-3p could bind with LINC02418 (or KNL1). Finally, KNL1 overexpression reversed the inhibitory function of LINC02418 deficiency in the malignant behaviors of LAD cells.

Conclusions

LINC02418 contributes to the malignancy in LAD via miR-4677-3p/KNL1 signaling, providing a probable therapeutic direction for LAD.

Support Vector Machine for Lung Adenocarcinoma Staging Through Variant Pathways

Lung adenocarcinoma (LUAD) is one of the most common malignant tumors. How to effectively diagnose LUAD at an early stage and make an accurate judgement of the occurrence and progression of LUAD are still the focus of current research. Support vector machine (SVM) is one of the most effective methods for diagnosing LUAD of different stages. The study aimed to explore the dynamic change of differentially expressed genes (DEGs) in different stages of LUAD, and to assess the risk of LUAD through DEGs enriched pathways and establish a diagnostic model based on SVM method. Based on TMN stages and gene expression profiles of 517 samples in TCGA-LUAD database, coefficient of variation (CV) combined with one-way analysis of variance (ANOVA) were used to screen out feature genes in different TMN stages after data standardization. Unsupervised clustering analysis was conducted on samples and feature genes. The feature genes were analyzed by Pearson correlation coefficient to construct a co-expression network. Fisher exact test was conducted to verify the most enriched pathways, and the variation of each pathway in different stages was analyzed. SVM networks were trained and ROC curves were drawn based on the predicted results so as to evaluate the predictive effectiveness of the SVM model. Unsupervised hierarchical clustering analysis results showed that almost all the samples in stage III/IV were clustered together, while samples in stage I/II were clustered together. The correlation of feature genes in different stages was different. In addition, with the increase of malignant degree of lung cancer, the average shortest path of the network gradually increased, while the closeness centrality gradually decreased. Finally, four feature pathways that could distinguish different stages of LUAD were obtained and the ability was tested by the SVM model with an accuracy of 91%. Functional level differences were quantified based on the expression of feature genes in lung cancer patients of different stages, so as to help the diagnosis and prediction of lung cancer. The accuracy of our model in differentiating between stage I/II and stage III/IV could reach 91%.

Analysis of genes associated with prognosis of lung adenocarcinoma based on GEO and TCGA databases

BACKGROUNDS

Lung adenocarcinoma (LUAD) is one of the most common malignancies, and is a serious threat to human health. The aim of the present study was to assess potential biomarkers for the prognosis of LUAD through the analysis of gene expression microarrays.

METHODS

The gene expression data for GSE118370 was downloaded from the Gene Expression Omnibus (GEO) database. Differentially expressed genes (DEGs) between normal lung and LUAD samples were screened using the R language. The DAVID database was used to analyze the functions and pathways of DEGs. The STRING database was used to the map protein-protein interaction (PPI) networks, and these were visualized with the Cytoscape software. Finally, the prognostic analysis of the hub gene in the PPI network was performed using the Kaplan-Meier tool.

RESULTS

A total of 406 downregulated and 203 upregulated DEGs were identified. The GO analysis results revealed that downregulated DEGs were significantly enriched in angiogenesis, calcium ion binding and cell adhesion. The upregulated DEGs were significantly enriched in the extracellular matrix disassembly, collagen catabolic process, chemokine-mediated signaling pathway and endopeptidase inhibitor activity. The KEGG pathway analysis revealed that downregulated DEGs were enriched in neuroactive ligand-receptor interaction, hematopoietic cell lineage and vascular smooth muscle contraction, while upregulated DEGs were enriched in phototransduction. In addition, the top 10 hub genes and the most closely interacting modules of the top 3 proteins in the PPI network were screened. Finally, the independent prognostic value of each hub gene in LUAD patients was analyzed through the Kaplan-Meier plotter. Seven hub genes (ADCY4, S1PR1, FPR2, PPBP, NMU, PF4, and GCG) were closely correlated to overall survival time.

CONCLUSION

The discovery of these candidate genes and pathways reveals the etiology and molecular mechanisms of LUAD, providing ideas and guidance for the development of new therapeutic approaches to LUAD.

Identification of Three Differentially Expressed miRNAs as Potential Biomarkers for Lung Adenocarcinoma Prognosis

OBJECTIVE

The aim of this study areto screen MicroRNAs (miRNAs) related to the prognosis of lung adenocarcinoma (LUAD) and to explore the possible molecular mechanisms.

METHODS

The data for a total of 535 patients with LUAD data were downloaded from The Cancer Genome Atlas (TCGA) database. The miRNAs for LUAD prognosis were screened by both Cox risk proportional regression model and Last Absolute Shrinkage and Selection Operator (LASSO) regression model. The performances of the models were verified by time-dependent Receiver Operating Characteristic (ROC) curve. The possible biological processes linked to the miRNAs' target genes were analyzed by Gene Ontology (GO), Kyoto gene and genome encyclopedia (KEGG).

RESULTS

Among 127 differentially expressed miRNAs identified from the screening analysis, there are 111 up-regulated and 16 down-regulated miRNAs. Three of them, hsa-miR-1293, hsa-miR-490 and hsa-miR- 5571, were also significantly associated with the survival of the LUAD patients. The targets of the three miRNAs are significantly enriched in systemic lupus erythematosus pathways.

CONCLUSION

Hsa-miR-1293, hsa-miR-490 and hsa-miR-5571 can be potentially used as novel biomarkers for the prognosis prediction of LUAD.

Micropapillary pattern is associated with the development of brain metastases and the reduction of survival time in EGFR-mutation lung adenocarcinoma patients with surgery

OBJECTIVE

The role of micropapillary pattern (MIP) in EGFR-mutated NSCLC patients with brain metastases (BM) after complete surgical resection still remains unclear. Therefore, a retrospective study was conducted to evaluate the role of MIP in those patients.

METHODS

This study included 332 stage I-III patients with EGFR-mutant lung adenocarcinoma and complete resection. Patients were classified in four groups: the MIP-positive patients without BM development, the MIP-negative patients without BM development, the MIP-positive patients with BM development and the MIP-negative patients with BM development. Intracranial disease-free survival (iDFS), systemic disease-free survival (DFS) and overall survival (OS) were evaluated.

RESULTS

The median OS in the whole group was 70 months. The patients with MIP show inferior DFS (13 months vs. 22 months; P < 0.001) and OS (56 months vs. 74 months; P < 0.001). Furthermore, BM development was more likely to be found in patients with MIP (P = 0.001). In addition, the MIP-positive patients showed a significantly shorter iDFS compared with MIP-negative patients (14.5 months vs. 26 months; P < 0.001). Furthermore, the MIP-positive patients had significantly inferior iDFS in both BM as first line development groups (13 months vs. 19 months; P < 0.001) and BM as non-first line development groups (18 months vs. 33 months; P = 0.007).

CONCLUSIONS

MIP was related to the earlier recurrence and shortened survival time. In addition, MIP was an independent poor prognostic factor for the increase of BM rate and the shortened time of BM development after surgery.

Correlation between 18F-FDG maximum standardized uptake value with CD147 expression in lung adenocarcinomas: a retrospective study

Background

The pro-tumoral action of the cluster of differentiation 147 (CD147), which is associated with the chemotherapy resistance of lung adenocarcinoma, is partly due to accelerated tumor cell glycolysis. ¹⁸F-fluorodeoxyglucose positron emission tomography (¹⁸F-FDG PET) metabolic parameters included maximal standardized uptake value (SUVmax), mean standardized uptake value (SUVmean), metabolic tumor volume (MTV), and total lesion glycolysis (TLG), which are non-invasive markers of the glucose metabolism of tumor cells in vivo. This study aimed to clarify the correlation between PET metabolic parameters and CD147 expression, and to evaluate the prognostic value of CD147 expression in resectable lung adenocarcinoma patients.

Methods

A total of 89 lung adenocarcinoma chemotherapy-naive patients who underwent ¹⁸F-fluorodeoxyglucose positron emission tomography and computerized tomography scan before pulmonary surgery were retrospectively analyzed. The PET metabolic parameters were calculated by ¹⁸F-FDG PET imaging, and CD147 expression was analyzed by immunohistochemistry. SUVmax, SUVmean, MTV, and TLG compared for their performance in predicting the expression of CD147 were illustrated with statistical analysis. All patients were then followed-up for survival analysis.

Results

The SUVmax was significantly correlated with the CD147 expression and was the primary predictor for the CD147 expression of lung adenocarcinoma. A cut-off value of the SUVmax, 9.77 allowed 85.1% sensitivity and 64.3% specificity for predicting the CD147 positive lung adenocarcinoma. CD147 expression was correlated with tumor differentiation and metastasis. Univariate survival analysis showed that CD147 expression was significantly associated with a shorter overall survival (OS) time. Multivariate analysis revealed that CD147 was an independent prognostic factor of lung adenocarcinoma patients.

Conclusion

The SUVmax of a primary tumor measured with ¹⁸F-FDG PET may be a simple and non-invasive marker for predicting CD147 expression in lung adenocarcinoma. CD147 is an independent prognostic factor related to OS of postoperative lung adenocarcinoma patients.

LncRNA TP73-AS1 promoted the progression of lung adenocarcinoma via PI3K/AKT pathway

Lung adenocarcinoma (LAD) is one of the most common malignancies that threats human health worldwide. Long non-coding RNAs (lncRNAs) have been reported to play significant roles in tumorigenesis and might be novel biomarkers and targets for diagnosis and treatment of cancers. TP73-AS1 is a newly discovered lncRNA involved in the tumorigenesis and development of several cancers. However, its role in LAD has not been investigated yet. In the present study, we first found that TP73-AS1 expression was markedly increased in LAD tissues and cell lines and its overexpression was strongly associated with poor clinical outcomes. Then the loss/gain-of-function assays elucidated that TP73-AS1 contributed to cell proliferation, migration, and invasion in vitro, and the in vivo experiments illustrated that its knockdown inhibited tumor growth and metastasis. What was more, we discovered that phosphoinositide 3-kinase and AKT (PI3K/AKT) pathway was activated both in LAD tissues and cell lines but inactivated under TP73-AS1 silence. Moreover, the activation of this pathway could rescue the inhibitory effects of TP73-AS1 suppression on LAD cellular processes partially. These data suggested that TP73-AS1 served as an oncogene in LAD partially through activating PI3K/AKT pathway and it could be a potential target for diagnosis and treatment of LAD.

Sodium-glucose transporter 2 is a diagnostic and therapeutic target for early-stage lung adenocarcinoma

The diagnostic definition of indeterminate lung nodules as malignant or benign poses a major challenge for clinicians. We discovered a potential marker, the sodium-dependent glucose transporter 2 (SGLT2), whose activity identified metabolically active lung premalignancy and early-stage lung adenocarcinoma (LADC). We found that SGLT2 is expressed early in lung tumorigenesis and is found specifically in premalignant lesions and well-differentiated adenocarcinomas. SGLT2 activity could be detected in vivo by positron emission tomography (PET) with the tracer methyl 4-deoxy-4-[18F] fluoro-alpha-d-glucopyranoside (Me4FDG), which specifically detects SGLT activity. Using a combination of immunohistochemistry and Me4FDG PET, we identified high expression and functional activity of SGLT2 in lung premalignancy and early-stage/low-grade LADC. Furthermore, selective targeting of SGLT2 with FDA-approved small-molecule inhibitors, the gliflozins, greatly reduced tumor growth and prolonged survival in autochthonous mouse models and patient-derived xenografts of LADC. Targeting SGLT2 in lung tumors may intercept lung cancer progression at early stages of development by pairing Me4FDG PET imaging with therapy using SGLT2 inhibitors.

The upregulation of TMPRSS4, partly ascribed to the downregulation of miR‑125a‑5p, promotes the growth of human lung adenocarcinoma via the NF‑κB signaling pathway

In this study, with the aid of microarray technology, transmembrane protease serine 4 (TMPRSS4), a novel member of the serine protease family, was found to be upregulated in the majority of lung adenocarcinoma (LUAD) tissues compared to normal lung tissues. Of note, the clinical significance of TMPRSS4 in LUAD has not yet been reported, at least to the best of our knowledge. Through immunohistochemistry assays, we found that TMPRSS4 was overexpressed in LUAD tissues and that the TMPRSS4 expression level was also proportionally associated with the AJCC clinical stage, T stage and pathological grade. Moreover, a high expression of TMPRSS4 was found to be associated with adverse outcomes and was a significant independent factors predicting a poor prognosis. To elucidate the possible mechanisms responsible for the overexpression of TMPRSS4, we examined at microRNAs (miRNAs or miRs), which are small non-coding RNAs commonly dysregulated in human malignancies and are known to promote carcinogenesis by interacting with other types of RNAs. By means of bioinformatics analysis, a miRNA potentially targeting TMPRSS4 mRNA, namely miR-125a-5p, was selected. Dual luciferase reporter gene assays were then performed to verify the interaction. The results of MTT assays and apoptotic assays revealed that miR-125a-5p significantly inhibited cell growth and enhanced apoptosis, and the silencing of TMPRSS4 had similar effects. Furthermore, we observed that either the overexpression of miR-125a-5p or the silencing of TMPRSS4 prevented the activation of the nuclear factor (NF)-κB signaling pathway. On the whole, our findings illustrate that TMPRSS4 may be a candidate oncogene and may thus serve as a prognostic biomarker for LUAD, and its overexpression may be partly ascribed to the downregulation of miR-125a-5p. The dysregulation of miR-125a-5p and TMPRSS4 affect the biological function of LUAD cells via the NF-κB signaling pathway. The miR-125a-5p/TMPRSS4/NF-κB axis may thus provide novel insight into the pathogenic mechanisms of LUAD and may be used in the development of novel treatment strategies for LUAD.

GATA3-induced vWF upregulation in the lung adenocarcinoma vasculature

Lung adenocarcinoma (LAC) is the leading cause of cancer-related death worldwide. Aberrant expression of genes expressed preferentially in the lung tumor vasculature may yield clues for prognosis and treatment. Von Willebrand factor (vWF) is a large multifunctional glycoprotein with a well-known function in hemostasis. However, vWF has been reported to exert an anti-tumor effect, independent of its role in hemostasis. We investigated the expression of vWF in LAC through immunohistochemical staining of tumor tissue microarrays (TMAs). We found that vWF was overexpressed preferentially in the tumor vasculature of LAC compared with the adjacent tissue vasculature. Consistently, elevated vWF expression was found in endothelial cells (ECs) of fresh human LAC tissues and transplanted mouse LAC tissues. To understand the mechanism underlying vWF up-regulation in LAC vessels, we established a co-culture system. In this system, conditioned media (CM) collected from A549 cells increased vWF expression in human umbilical vein endothelial cells (HUVECs), suggesting enhanced expression is regulated by the LAC secretome. Subsequent studies revealed that the transcription factor GATA3, but not ERG, a known regulator of vWF transcription in vascular cells, mediated the vWF elevation. Chromatin immunoprecipitation (ChIP) assays validated that GATA3 binds directly to the +220 GATA binding motif on the human vWF promoter and A549 conditioned media significantly increases the binding of GATA3. Taken together, we demonstrate that vWF expression in ECs of LAC is elevated by the cancer cell-derived secretome through enhanced GATA3-mediated transcription.

TBX2 subfamily suppression in lung cancer pathogenesis: a high-potential marker for early detection

The TBX2 subfamily (TBXs 2, 3, 4 and 5) transactivates or represses genes involved in lung organogenesis. Yet TBX2 subfamily expression in pathogenesis of non-small cell lung cancer (NSCLC), the most common lung malignancy, remains elusive. We sought to probe the expression profile of the TBX2 subfamily in early phases of NSCLC. Expression of TBX2 subfamily was analyzed in datasets of pan-normal specimens as well as NSCLCs and normal lung tissues. TBX2 subfamily expression in matched normal lungs, premalignant hyperplasias and NSCLCs was profiled by transcriptome sequencing. TBX2 subfamily expression was evaluated in the cancerization field consisting of matched NSCLCs and adjacent cytologically-normal airways relative to distant normal lungs and in a dataset of normal bronchial samples from smokers with indeterminate nodules suspicious for malignancy. Statistical analysis was performed using R. TBX2 subfamily expression was markedly elevated in normal lungs relative to other organ-specific normal tissues. Expression of the TBXs was significantly suppressed in NSCLCs relative to normal lungs (P < 10⁻⁹). TBX2 subfamily was significantly progressively decreased across premalignant lesions and NSCLCs relative to normal lungs (P < 10⁻⁴). The subfamily was significantly suppressed in NSCLCs and adjacent normal-appearing airways relative to distant normal lung tissues (P < 10⁻¹⁵). Further, suppressed TBX2 subfamily expression in normal bronchi was associated with lung cancer status (P < 10⁻⁵) in smokers. Our findings suggest that the TBX2 subfamily is notably suppressed in human NSCLC pathogenesis and may serve as a high-potential biomarker for early lung cancer detection in high-risk smokers.

Whole-exome sequencing and immune profiling of early-stage lung adenocarcinoma with fully annotated clinical follow-up

Background

Lung adenocarcinomas (LUADs) lead to the majority of deaths attributable to lung cancer. We performed whole-exome sequencing (WES) and immune profiling analyses of a unique set of clinically annotated early-stage LUADs to better understand the pathogenesis of this disease and identify clinically relevant molecular markers.

Methods

We performed WES of 108 paired stage I-III LUADs and normal lung tissues using the Illumina HiSeq 2000 platform. Ten immune markers (PD-L1, PD-1, CD3, CD4, CD8, CD45ro, CD57, CD68, FOXP3 and Granzyme B) were profiled by imaging-based immunohistochemistry (IHC) in a subset of LUADs (n = 92). Associations among mutations, immune markers and clinicopathological variables were analyzed using ANOVA and Fisher's exact test. Cox proportional hazards regression models were used for multivariate analysis of clinical outcome.

Results

LUADs in this cohort exhibited an average of 243 coding mutations. We identified 28 genes with significant enrichment for mutation. SETD2-mutated LUADs exhibited relatively poor recurrence- free survival (RFS) and mutations in STK11 and ATM were associated with poor RFS among KRAS-mutant tumors. EGFR, KEAP1 and PIK3CA mutations were predictive of poor response to adjuvant therapy. Immune marker analysis revealed that LUADs in smokers and with relatively high mutation burdens exhibited increased levels of immune markers. Analysis of immunophenotypes revealed that LUADs with STK11 mutations exhibited relatively low levels of infiltrating CD4+/CD8+ T-cells indicative of a muted immune response. Tumoral PD-L1 was significantly elevated in TP53 mutant LUADs whereas PIK3CA mutant LUADs exhibited markedly down-regulated PD-L1 expression. LUADs with TP53 or KEAP1 mutations displayed relatively increased CD57 and Granzyme B levels indicative of augmented natural killer (NK) cell infiltration.

Conclusion(s)

Our study highlights molecular and immune phenotypes that warrant further analysis for their roles in clinical outcomes and personalized immune-based therapy of LUAD.

Overexpression of miR-519d in lung adenocarcinoma inhibits cell proliferation and invasion via the association of eIF4H

Lung cancer is one of the deadliest types of cancer worldwide due to its high mortality rate. Adenocarcinoma constitutes 20%-30% of all lung cancers. In recent years, studies on the mechanisms of lung tumorigenesis and development have in part focused on the microRNAs for their crucial role in the progress of different cancers. As for our study, we demonstrated that miR-519d was differently downregulated and eIF4H was significantly overexpressed in lung adenocarcinoma via the detection of quantitative real-time polymerase chain reaction compared with the adjacent normal tissues. Furthermore, Cell Counting Kit-8 assay, colony formation assay, xenograft tumor experiment, Ki67 immunohistochemistry assay and transwell assay were performed to explain that the upregulated miR-519d could inhibit the proliferation and invasion of A549 and H1299 cells. To further advance our understanding of the mechanisms of miR-519d, we performed the bioinformatics analysis and the luciferase report assay. The results from these procedures revealed eIF4H to be one of the targets of miR-519d. Downregulated eIF4H was analogous to the overexpressed miR-519d obtained from miR-519d agomir and si-eIF4H transfection. In summary, it can be concluded that miR-519d targets eIF4H in lung adenocarcinoma to inhibit cell proliferation and invasion. This mechanism may offer new insights into the tumorigenesis and development of lung adenocarcinoma.

CD147 promotes the proliferation, invasiveness, migration and angiogenesis of human lung carcinoma cells

Cluster of differentiation (CD) 147 is a transmembrane glycoprotein that is highly expressed at the tumor cell surface, which stimulates fibroblasts to produce a large number of matrix metalloproteinases and promotes tumor invasion and metastasis and tumor-induced angiogenesis. The present study investigated the functions and the role of CD147 in the human lung carcinoma A549 cell line. The present study constructed expression and interference [small interfering (si) RNA] lentiviral vectors of CD147, which established stable overexpression and low expression of CD147 in the A549 cell line, named A549-CD147 and A549-siCD147, respectively. The differences in biological features between various levels of CD147 expression in A549 cells was investigated by cell counting kit-8 (CCK-8), Transwell, scratch and lumen formation assays. The results of the CCK-8 assay revealed that A549-CD147 cell proliferation was significantly increased and A549-siCD147 cell proliferation was decreased compared with the control groups. The A549-CD147 cells had the largest number of cells penetrating the Matrigel in the Transwell assay, which indicates that upregulation of CD147 expression increases the infiltration capacity of cells. The scratch assay revealed that A549-CD147 cells have the highest capacity for migration, while A549-siCD147 cells have the lowest. Quantitative polymerase chain reaction and western blot analysis demonstrated that vascular endothelial growth factor (VEGF) expression was proportional to the expression level of CD147 at the mRNA and protein level. The lumen formation assay revealed that the number of vessel lumens that human umbilical vein endothelial cells formed in the A549-CD147 cell supernatant was increased compared with the A549-siCD147 cells. Collectively, the present results suggest that CD147 is important in the promotion of lung carcinoma cell proliferation, invasion and metastasis and the upregulation of VEGF, which stimulates the angiogenesis of lung carcinoma. In conclusion, CD147 may be a potential target in the treatment of lung carcinoma.

Effect of silencing SATB1 on proliferation, invasion and apoptosis of A549 human lung adenocarcinoma cells

The present study aimed to explore the clinical characteristics of special adenine-thymine-rich sequence-binding protein 1 (SATB1) in lung adenocarcinoma and its role in the proliferation, invasion, migration and apoptosis of the lung adenocarcinoma cell line A549. The expression of SATB1 was first studied in tumor tissues of lung adenocarcinoma and adjacent non-tumor tissues. The siRNA green fluorescent protein expression vector of SATB1 was constructed and transfected into the lung adenocarcinoma cell line A549, then a fluorescence microscope was used to study the transfection efficiency. Western blot analysis was adopted to measure the silencing efficiency. 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT), Transwell and scratch assays were used to study cell proliferation, invasion and migration activity, and the apoptosis rate was tested by flow cytometry. SATB1 expression was low in the adjacent non-tumor tissues but high in lung adenocarcinoma tissues, and it was reversely proportional to the differentiation degree. Following transfection with SATB1-siRNA, the expression of SATB1 in A549 cells was blocked (P<0.01). In addition, the proliferation, invasion and migration abilities of cells decreased significantly while the apoptosis rate increased significantly (P<0.01). In conclusion SATB1 is closely associated with the pathogenesis and development of lung adenocarcinoma.

Development of a database system and image viewer to assist in the correlation of histopathologic features and digital image analysis with clinical and molecular genetic information

Pathologists are required to integrate data from multiple sources when making a diagnosis. Furthermore, whole slide imaging (WSI) and next generation sequencing will escalate data size and complexity. Development of well-designed databases that can allow efficient navigation between multiple data types is necessary for both clinical and research purposes. We developed and evaluated an interactive, web-based database that integrates clinical, histologic, immunohistochemical and genetic information to aid in pathologic diagnosis and interpretation with nine lung adenocarcinoma cases. To minimize sectioning artifacts, representative blocks were serially sectioned using automated tissue sectioning (Kurabo Industries, Osaka Japan) and selected slides were stained by multiple techniques, (hematoxylin and eosin [H&E], immunohistochemistry [IHC] or fluorescence in situ hybridization [FISH]). Slides were digitized by WSI scanners. An interactive relational database was designed based on a list of proposed fields covering a variety of clinical, pathologic and molecular parameters. By focusing on the three main tasks of 1.) efficient management of textual information, 2.) effective viewing of all varieties of stained whole slide images (WSI), and 3.) assistance in evaluating WSI with computer-aided diagnosis, this database prototype shows great promise for multi-modality research and diagnosis.

LAPTM4B is associated with poor prognosis in NSCLC and promotes the NRF2-mediated stress response pathway in lung cancer cells

We recently demonstrated that lysosomal protein transmembrane 4 beta (LAPTM4B) is elevated in non-small cell lung cancers (NSCLCs) and in the surrounding premalignant airway field of cancerization. In the present study, we sought to begin to understand the relevance of LAPTM4B expression and signaling to NSCLC pathogenesis. In situ hybridization analysis of LAPTM4B transcript in tissue microarrays comprised of 368 NSCLCs demonstrated that LAPTM4B expression was significantly increased in smoker compared to non-smoker lung adenocarcinoma tumors (P < 0.001) and was significantly associated with poor overall survival (P < 0.05) in adenocarcinoma patients. Knockdown of LAPTM4B expression inhibited cell growth, induced cellular apoptosis and decreased cellular autophagy in serum starved lung cancer cells. Expression profiling coupled with pathways analysis revealed decreased activation of the nuclear factor erythroid 2-like 2 (NRF2) stress response pathway following LAPTM4B knockdown. Further analysis demonstrated that LAPTM4B augmented the expression and nuclear translocation of the NRF2 transcription factor following serum deprivation as well as increased the expression of NRF2 target genes such as heme oxygenase 1/HMOX1). Our study points to the relevance of LAPTM4B expression to NSCLC pathogenesis as well as to the probable role of LAPTM4B/NRF2 signaling in promoting lung cancer cell survival.

Low-Dose Cadmium Upregulates VEGF Expression in Lung Adenocarcinoma Cells

Cadmium (Cd) is a heavy metal and environmental toxin. Exposure to Cd has been associated with a variety of human cancers. In this study, we performed in vitro assays to examine the effects of cadmium chloride (CdCl₂) on A549 cells, a human lung adenocarcinoma cell line. Cd does not affect proliferation, migration, or apoptosis of A549 cells at concentrations of 0.1-10 μM. At 0.5 and 1 μM, Cd increases the expression of vascular endothelial growth factor (VEGF) (p < 0.05, p < 0.01, respectively), but not basic fibroblast growth factor (b-FGF) in A549 cells. The conditioned media were collected from the A549 cells treated with 1 μM Cd and were co-cultured with human umbilical vein endothelial cells (HUVECs). Upon treatment with the conditioned media, the proliferation and migration of HUVECs significantly increased (p < 0.01, p < 0.05, respectively), while apoptosis remained unchanged. In addition, 1 μM Cd increases the level of hypoxia inducible factor 1-α (HIF1-α), which is a positive regulator of VEGF expression. Although low-dose Cd does not directly affect the growth of lung adenocarcinoma cells, it might facilitate the development of tumors through its pro-angiogenic effects.

Chronic inorganic arsenic exposure in vitro induces a cancer cell phenotype in human peripheral lung epithelial cells

Inorganic arsenic is a human lung carcinogen. We studied the ability of chronic inorganic arsenic (2 μM; as sodium arsenite) exposure to induce a cancer phenotype in the immortalized, non-tumorigenic human lung peripheral epithelial cell line, HPL-1D. After 38 weeks of continuous arsenic exposure, secreted matrix metalloproteinase-2 (MMP2) activity increased to over 200% of control, levels linked to arsenic-induced cancer phenotypes in other cell lines. The invasive capacity of these chronic arsenic-treated lung epithelial (CATLE) cells increased to 320% of control and colony formation increased to 280% of control. CATLE cells showed enhanced proliferation in serum-free media indicative of autonomous growth. Compared to control cells, CATLE cells showed reduced protein expression of the tumor suppressor gene PTEN (decreased to 26% of control) and the putative tumor suppressor gene SLC38A3 (14% of control). Morphological evidence of epithelial-to-mesenchymal transition (EMT) occurred in CATLE cells together with appropriate changes in expression of the EMT markers vimentin (VIM; increased to 300% of control) and e-cadherin (CDH1; decreased to 16% of control). EMT is common in carcinogenic transformation of epithelial cells. CATLE cells showed increased KRAS (291%), ERK1/2 (274%), phosphorylated ERK (p-ERK; 152%), and phosphorylated AKT1 (p-AKT1; 170%) protein expression. Increased transcript expression of metallothioneins, MT1A and MT2A and the stress response genes HMOX1 (690%) and HIF1A (247%) occurred in CATLE cells possibly in adaptation to chronic arsenic exposure. Thus, arsenic induced multiple cancer cell characteristics in human peripheral lung epithelial cells. This model may be useful to assess mechanisms of arsenic-induced lung cancer.

Cigarette smoke induces the expression of Notch3, not Notch1, protein in lung adenocarcinoma

The aim of the present study was to determine the effect of cigarette smoke on the expression of Notch proteins in lung adenocarcinoma (LAC). Protein expression levels of Notch1 and Notch3 were analyzed using immunohistochemistry in 102 human LAC specimens. Of these, 52 were obtained from smokers and 50 from non-smokers. In addition, cigarette smoke extract (CSE) at varying concentrations (1, 2.5 and 5%) was administered to A549 cells. The expression of Notch1 and Notch3 protein was then detected by western blot analysis at different time points (0, 8, 24 and 48 h). Of the 102 LAC specimens, 42 (41.2%) were positive for Notch1 and 63 (61.8%) were positive for Notch3. There was no significant difference in the level of Notch1 expression between smokers and non-smokers with LAC (P>0.05). The positive rate and staining intensity of Notch3 expression were increased in the smokers compared with the non-smokers (P<0.05). The expression of Notch3 protein in A549 cells increased in a time- and dose-dependent manner following treatment with CSE, whilst the expression of Notch1 protein appeared stable. The results suggested that cigarette smoke was able to induce the expression of Notch3, not Notch1, protein in LAC. The data revealed an upregulation of Notch3 in LAC following cigarette smoke exposure. Such findings may provide a novel therapeutic target for the treatment of LAC.

Identification of lung adenocarcinoma mutation status based on histologic subtype: Retrospective analysis of 269 patients

BACKGROUND

To evaluate differences in the clinical characteristics and molecular pathology of lung adenocarcinoma subtypes as defined by the new International Association for the Study of Lung Cancer/American Thoracic Society/European Respiratory Society international histological classification.

METHODS

We retrospectively reviewed 269 patients with initial primary lung adenocarcinoma who had undergone complete resection at our department from August 2013 to December 2014, focusing on the new histologic subtype classification, clinical characteristics, and molecular pathology.

RESULTS

All specimens were invasive adenocarcinoma, and were lepidic (13.0%), papillary (19.7%), acinar (51.7%), solid (8.6%), micropapillary (1.1%) or mucinous predominant (5.9%). Epidermal growth factor receptor (EGFR) mutations were detected in 132 cases (60.3%). Female patients and non-smokers had higher EGFR mutation rates (P = 0.022 and 0.026, respectively). The lepidic, papillary, acinar, solid, micropapillary, and mucinous predominant patterns had EGFR mutation rates of 70.6%, 64.8%, 72.5%, 33.3%, 100%, and 5.9%, respectively. The exon mutation distribution differed according to serum carcinoembryonic antigen (CEA) levels (P = 0.018). v-Ki-ras2 Kirsten rat sarcoma viral oncogene homolog (KRAS) mutations were detected in 20 cases (9.2%), and were frequently found in the mucinous and solid predominant subtypes. The serum CEA levels differed among the subtypes.

CONCLUSIONS

In China, there are significant differences between lung adenocarcinoma histologic subtypes. The presence of well-differentiated components in lung adenocarcinoma indicates higher EGFR mutation rates; the presence of solid or mucinous components indicates higher KRAS mutation rates. Serum CEA levels are associated with histologic subtype and EGFR exon mutations.

Identification of stage-specific biomarkers in lung adenocarcinoma based on RNA-seq data

Tumorigenesis is a multistep process that attributes to the sequential accumulation of abnormal expression in key oncogenes or tumor suppressors. We aimed to identify stage-specific biomarkers to distinguish lung adenocarcinoma (LAC) stages in cancer progression. RNA-sequencing data of LAC and matched adjacent non-cancer tissues were downloaded from the Cancer Genome Atlas, including 29 pairs of samples from LAC at stage I, 14 from LAC at stage II, 13 from LAC at stage III, and 1 from LAC at stage IV. Differentially expressed genes (DEGs) were analyzed for each case at different stages of LAC. DEGs were further annotated based on transcription factor data information, tumor-associated gene database, and protein-protein interaction database. Functional annotation was performed for genes in PPI network by DAVID online tool. Our analysis identified 11 high-frequency DEGs in the stage I, 29 in the stage II, and 90 in the stage III of LAC. Among them, eight genes were significantly correlated with LAC stages and identified as biomarkers in LAC progression. ANGPTL5, C7orf16, EDN3, LOC150622, HOXA11AS, IL1F5, and USH1G significantly distinguished stage III from stages I and II. GJB6 was significantly enriched in the gap junction trafficking pathway, while C7orf16 and EDN3 were enriched in Wnt signaling pathway, cell cycle, and G protein-coupled receptor (GPCR) signaling. Up-regulated GJB6 especially in LAC stage II and down-regulated C7orf16 and EDN3 specifically in stage III were identified as biomarkers for distinguishing cancer stage in tumor progression through dysregulating gap junction, Wnt signaling, and GPCR signaling pathways.

Inhibition of livin expression suppresses cell proliferation and enhances chemosensitivity to cisplatin in human lung adenocarcinoma cells

Livin is a novel member of the inhibitor of apoptosis protein family that has been reported to be overexpressed in various types of human malignancy. Although several studies have demonstrated that livin may be used as an effective target for tumor therapy, few studies have investigated its role in human lung adenocarcinoma. In the present study, two different methods were used in order to investigate the tumor‑suppressing effect of livin in human lung adenocarcinoma cells. Firstly, small interfering (si)RNA technology was used to down regulate livin expression; siRNA-mediated knockdown of livin was confirmed using reverse transcription quantitative polymerase chain reaction and western blot analysis, and cell proliferations was assessed using an MTT assay in vitro. Secondly, inhibition of livin expression was induced through the synergistic inhibitory effect between flavopiridol and tumor necrosis factor‑related apoptosis-inducing ligand (TRAIL). Experimental results revealed that, following transfection of the livin gene-silencing vector, the gene expression of livin was markedly decreased, SPC-A1 cell proliferation was significantly reduced and the therapeutic effect of the chemotherapy drug cisplatin was markedly improved. This growth inhibitory effect was also observed in the flavopiridol and TRAIL combination treatment group. In the flavopiridol and TRAIL combination treatment group, the protein expression of livin was significantly reduced and the survival rate of SPC‑A1 cells was significantly lower than the flavopiridol and TRAIL single operation group. In conclusion, the RNA silencing and the synergistic inhibitory effect between flavopiridol with TRAIL was able to effectively inhibit the expression of livin, significantly decrease SPC-A1 tumor cell proliferation and significantly enhance sensitivity to the chemotherapy drug cisplatin. These findings suggest that livin may be used as a novel target for tumor gene therapy.

Epidemiological and clinicopathological characteristics of lung cancer in a teaching hospital in Iran

BACKGROUND

Lung cancer is one of the most commonly diagnosed cancers and the most frequent cause of cancer-related death worldwide. In Iran, it ranks second and third as the cancer-causing death in men and women, respectively. We carried out this study to find out the demographic, clinical, and histological characteristics and risk factors of lung cancer in a referral tertiary center in Iran.

MATERIALS AND METHODS

A retrospective study was conducted on cases of primary lung cancer based on the results of registered cancer reports of cytological and pathological specimens between March 2001 and March 2012. Demographic variables, clinical manifestations, histology and location of tumors were determined based on the data found in the medical records of each patient. Definite or probable etiologic factors were identified. Data analysis was performed with SPSS version 16 and a p-value ≤ 0.05 was considered as significant.

RESULTS

A total of 203 patients, with a mean age of 65.7 years (SD=11.2), with primary lung cancer were identified, 81.3% being men. Of the total, 110 cases (54.2%) were living in urban areas. In 53.2% of cases, the site of tumor was on the right side and in 72.9% of cases the lesion was centrally located. The histological types of lung cancer were squamous cell carcinoma (SCC) in 107 cases (52.7%), adenocarcinoma (AC) in 30 cases (14.8%), and small cell carcinoma (SC) in 27 cases (13.3%). Significant correlations between the gender and residence, smoking, and the histological type and location (central or peripheral) of tumor were found. The percentage of smokers was 75.2% in men and 15.8% in women.

CONCLUSIONS

Smoking was the most important risk factor and squamous cell carcinoma the most common histological type of lung cancer in our study. Male sex and being a smoker was associated with histological types of SCC while being nonsmoker had relationship with adenocarcinoma.

Clinical investigation into the initial diagnosis and treatment of 1,168 lung cancer patients

The aim of the present study was to analyse clinical data obtained from lung cancer patients, including the initial clinical symptoms upon diagnosis, duration of patient delay in presenting to a doctor, lung cancer stage, treatment strategy and prognosis. A retrospective analysis was conducted of the clinical features of 1,168 lung cancer patients who were initially diagnosed and treated at the Tumor Hospital of Shandong Province (Jinan, China) in 2009. The Kaplan-Meier method and multivariate Cox regression analysis were performed to analyse the influence of gender, age, predominant symptoms, histopathological or cytological type and clinical staging on the overall patient survival. The follow-up rate of the present study was 92.4%, and the 1-, 2- and 3-year survival rates were 80.4, 44.9 and 15.8%, respectively. Multivariate analysis demonstrated that the patient age, extent of the tumour (T stage), extent of lymph node spread (N stage), overall clinical stage and treatment strategy were independent risk factors associated with patient survival. The present study identified that the initial symptoms of lung cancer varied, patient delay was long, the lung cancer cases were diagnosed in late clinical stages and the prognosis was poor.

Genomic and transcriptional alterations in lung adenocarcinoma in relation to smoking history

PURPOSE

Cigarette smoking is the major pathogenic factor for lung cancer. The precise mechanisms of tobacco-related carcinogenesis and its effect on the genomic and transcriptional landscape in lung cancer are not fully understood.

EXPERIMENTAL DESIGN

A total of 1,398 (277 never-smokers and 1,121 smokers) genomic and 1,449 (370 never-smokers and 1,079 smokers) transcriptional profiles were assembled from public lung adenocarcinoma cohorts, including matched next-generation DNA-sequencing data (n = 423). Unsupervised and supervised methods were used to identify smoking-related copy-number alterations (CNAs), predictors of smoking status, and molecular subgroups.

RESULTS

Genomic meta-analyses showed that never-smokers and smokers harbored a similar frequency of total CNAs, although specific regions (5q, 8q, 16p, 19p, and 22q) displayed a 20% to 30% frequency difference between the two groups. Importantly, supervised classification analyses based on CNAs or gene expression could not accurately predict smoking status (balanced accuracies ∼60% to 80%). However, unsupervised multicohort transcriptional profiling stratified adenocarcinomas into distinct molecular subgroups with specific patterns of CNAs, oncogenic mutations, and mutation transversion frequencies that were independent of the smoking status. One subgroup included approximately 55% to 90% of never-smokers and approximately 20% to 40% of smokers (both current and former) with molecular and clinical features of a less aggressive and smoking-unrelated disease. Given the considerable intragroup heterogeneity in smoking-defined subgroups, especially among former smokers, our results emphasize the clinical importance of accurate molecular characterization of lung adenocarcinoma.

CONCLUSIONS

The landscape of smoking-related CNAs and transcriptional alterations in adenocarcinomas is complex, heterogeneous, and with moderate differences. Our results support a molecularly distinct less aggressive adenocarcinoma entity, arising in never-smokers and a subset of smokers.

Activated K-RAS and its effect on morphological appearance

RAS genes are frequently mutated in various human tumours. These mutations cause GTPase RAS to remain locked in constitutively active signals through the downstream cascades leading to proliferation. A series of earlier studies reported on the morphological appearance of cells upon RAS activation. Classically, morphologic changes of fibroblasts have been used to confirm the oncogenic activity of RAS. Recent works found that the active RAS induces benign and malignant morphological changes in organoids, which are an in vitro model system for epithelial tissue. The studies of animal models support the basic oncogenic features of RAS revealed in vitro, while also providing evidence that the effects of RAS activation in vivo are different from those in vitro. The pathological observation of the various human materials indicates that the oncogenic RAS participates in metaplasia, which occurs before proliferation, and that RAS promotes mucin production in various organs. These morphological analyses may shed light on important signalling pathways that merit investigation in vitro.

Epigenetic clustering of lung adenocarcinomas based on DNA methylation profiles in adjacent lung tissue: Its correlation with smoking history and chronic obstructive pulmonary disease

The aim of this study was to clarify the significance of DNA methylation alterations during lung carcinogenesis. Infinium assay was performed using 139 paired samples of non-cancerous lung tissue (N) and tumorous tissue (T) from a learning cohort of patients with lung adenocarcinomas (LADCs). Fifty paired N and T samples from a validation cohort were also analyzed. DNA methylation alterations on 1,928 probes occurred in N samples relative to normal lung tissue from patients without primary lung tumors, and were inherited by, or strengthened in, T samples. Unsupervised hierarchical clustering using DNA methylation levels in N samples on all 26,447 probes subclustered patients into Cluster I (n = 32), Cluster II (n = 35) and Cluster III (n = 72). LADCs in Cluster I developed from the inflammatory background in chronic obstructive pulmonary disease (COPD) in heavy smokers and were locally invasive. Most patients in Cluster II were non-smokers and had a favorable outcome. LADCs in Cluster III developed in light smokers were most aggressive (frequently showing lymphatic and blood vessel invasion, lymph node metastasis and an advanced pathological stage), and had a poor outcome. DNA methylation levels of hallmark genes for each cluster, such as IRX2, HOXD8, SPARCL1, RGS5 and EI24, were again correlated with clinicopathological characteristics in the validation cohort. DNA methylation profiles reflecting carcinogenetic factors such as smoking and COPD appear to be established in non-cancerous lung tissue from patients with LADCs and may determine the aggressiveness of tumors developing in individual patients, and thus patient outcome.

Identification of mutant genes with high-frequency, high-risk, and high-expression in lung adenocarcinoma

BACKGROUND

To identify mutant genes with high-frequency-risk-expression between lung adenocarcinoma and normal samples.

METHODS

The ribonucleic acid RNA-Seq data GSE34914 and GSE37765 were downloaded from the Gene Expression Omnibus database, including 12 lung adenocarcinoma samples and six controls. All RNA-Seq reads were processed and the gene-expression level was calculated. Single nucleotide variation (SNV) was analyzed and the locations of mutant sites were recorded. In addition, the frequency and risk-level of mutant genes were calculated. Gene Ontology (GO) functional analysis was performed. The reported cancer genes were searched in tumor suppressor genes, Cancer Genes, and the Catalogue of Somatic Mutations in Cancer (COSMIC) database.

RESULTS

The SNV annotations of somatic mutation sites showed that 70% of mutation sites in the exon region occurred in the coding sequence (CDS). Thyroid hormone receptor interactor (TRIP)12 was identified with the highest frequency. A total of 118 mutant genes with high frequency and high-risk were selected and significantly enriched into several GO terms. No base mutation of cyclin C (CCNC) or RAB11A was recorded. At fragments per kilobase per million reads (FPKM) ≥ 56.5, reported tumor suppressor genes catenin (cadherin-associated protein), delta (CTNND)1, dual specificity phosphatase (DUSP)6, malate dehydrogenase (MDH)1 and RNA binding motif protein (RBM)5, were identified. Notably, signal transducer and activator of transcription 2 (STAT2) was the only transcription factor (TF) with high-risk mutation and its expression was detected.

CONCLUSION

For the mutant genes with high-frequency-risk-expression, CTNND1, DUSP6, MDH1 and RBM5 were identified. TRIP12 might be a potential cancer-related gene, and expression of TF STAT2 with high-risk was detected. These mutant gene candidates might promote the development of lung adenocarcinoma and provide new diagnostic potential targets for treatment.

Spectrum of somatic EGFR, KRAS, BRAF, PTEN mutations and TTF-1 expression in Brazilian lung cancer patients

Lung cancer is the leading global cause of cancer-related mortality. Inter-individual variability in treatment response and prognosis has been associated with genetic polymorphisms in specific genes: EGFR, KRAS, BRAF, PTEN and TTF-1. Somatic mutations in EGFR and KRAS genes are reported at rates of 15-40% in non-small cell lung cancer (NSCLC) in ethnically diverse populations. BRAF and PTEN are commonly mutated genes in various cancer types, including NSCLC, with PTEN mutations exerting an effect on the therapeutic response of EGFR/AKT/PI3K pathway inhibitors. TTF-1 is expressed in approximately 80% of lung adenocarcinomas and its positivity correlates with higher prevalence of EGFR mutation in this cancer type. To determine molecular markers for lung cancer in Brazilian patients, the rate of the predominant EGFR, KRAS, BRAF and PTEN mutations, as well as TTF-1 expression, was assessed in 88 Brazilian NSCLC patients. EGFR exon 19 deletions (del746-750) were detected in 3/88 (3·4%) patients. Activating KRAS mutations in codons 12 and 61 were noted in five (5·7%) and two (2·3%) patients, respectively. None of the common somatic mutations were detected in either the BRAF or PTEN genes. TTF-1 was overexpressed in 40·7% of squamous-cell carcinoma (SCC). Our findings add to a growing body of data that highlights the genetic heterogeneity of the abnormal EGFR pathway in lung cancer among ethnically diverse populations.

Estrogen receptor beta and CXCR4/CXCL12 expression: differences by sex and hormonal status in lung adenocarcinoma

BACKGROUND AND AIMS

Studies have reported differences in lung cancer behavior between sex and hormonal status that suggest a role of estrogens and estrogen receptor beta (ERβ) in lung carcinogenesis. In some types of hormone-dependent cancer, estrogens may regulate CXCL12/CXCR4 expression through ERβ signaling. High expression of CXCL12/CXCR4 is associated with poor prognosis in lung cancer because it promotes tumor growth and metastasis. Therefore, in this study we investigated whether lung adenocarcinoma tissues from pre- and postmenopausal women and from men exhibit different ERβ, CXCR4/CXCL12 expression and whether this expression is associated with clinicopathological features.

METHODS

Sixty primary tumor samples of lung adenocarcinoma from pre- and postmenopausal women and from men were collected for this study. Thirty samples of healthy lung tissue adjacent to the tumor site were used as controls. ERβ and CXCL12/CXCR4 expression was analyzed by immunohistochemistry. Expression of these proteins was measured by digital image software and compared between sex and hormonal status.

RESULTS

Lung adenocarcinomas overexpressed ERβ, CXCR4 and CXCL12 compared to normal lung. Moreover, lung adenocarcinomas from premenopausal women exhibited higher signals for ERβ, CXCL12 and CXCR4 compared to postmenopausal women and to men, who showed lower signals for these proteins. A multivariate analysis revealed a strong association between the immunoreactivity level of ERβ, CXCL12/CXCR4 and both sex and hormonal status, but not with tumor stage and smoking.

CONCLUSION

These results demonstrated that ERβ and CXCL12/CXCR4 expression in lung adenocarcinoma depends on sex and hormonal status, which may partly explain the sex and hormonal differences in lung cancer behavior.

HIF-1α silencing suppresses growth of lung adenocarcinoma A549 cells through induction of apoptosis

Lung adenocarcinoma (AC) is one of the most deadly malignancies. The disease has a low five-year survival rate; therefore, the identification of novel therapeutic agents is required. This study aimed to investigate the effect of small interfering RNA (siRNA) targeting hypoxia‑inducible factor 1α (HIF‑1α) on the growth of AC A549 cells. A549 cells were transfected with various concentrations of HIF‑1α or control siRNA, and the effect on HIF‑1α expression was analyzed using quantitative polymerase chain reaction and western blot analysis. The effects of HIF-1α siRNA on growth inhibition and apoptosis were then assessed using standard methods. HIF‑1α siRNA treatment significantly reduced HIF‑1α mRNA and protein expression in A549 cells. Furthermore, the downregulation of HIF-1α expression inhibited the growth of A549 cells and induced apoptosis of A549 cells by upregulating caspase-3 expression. The present in vitro study demonstrates that the downregulation of HIF‑1α is capable of suppressing AC A549 cell growth, through the induction of apoptosis. This suggests that HIF‑1α inhibition may represent a promising strategy for the treatment of AC.

[Construction of a CD147 lentiviral expression vector and establishment of its stably transfected A549 cell line]

BACKGROUND AND OBJECTIVE

CD147, a type of transmembrane glycoprotein embedded on the surface of tumor cells, can promote tumor invasion and metastasis. This aim of this study is to construct a CD147 lentiviral expression vector, establish its stably transfected A549 cell line, and observe the effect of CD147 on MMP-9 proliferation as well as on the invasive ability of human lung adenocarcinoma cells.

METHODS

Full-length CD147 gene was amplified by real-time polymerase chain reaction (RT-PCR), inserted into a pEGFP vector to construct pEGFP-CD147 and pEGFP vectors, and then transfected into 293FT cells to precede the lentivirus equipment package. Subsequently, we collected the lentivirus venom to infect the A549 cells and establish a stable, overexpressed cell line named A549-CD147. The mRNA expression of MMP-9 was examined by RT-PCR. The proliferation and invasive ability of the human lung cancer cells before and after transfection were examined by the CCK-8 and Transwell methods.

RESULTS

A CD147 lentiviral expression vector (pEGFP-CD147) was successfully constructed by restrictive enzyme digestion and plasmid sequencing. RT-PCR and Western blot analyses revealed increased mRNA and protein expression of CD147 gene in cells transfected with pEGFP-CD147 compared with the control groups. Therefore, the A549-CD147 cell line was successfully established through the experiment. The mRNA expression of MMP-9 also significantly increased after the upregulation of CD147 expression. Meanwhile, CCK-8 and Transwell assays indicated that the proliferation and invasive ability significantly increased in the A549-CD147 cells.

CONCLUSIONS

A lentiviral CD147 expression vector and its A549 cell line (A549-CD14) were successfully constructed. CD147 overexpression upregulated the protein expression of MMP-9, and strengthened the proliferation and invasive ability of human lung adenocarcinoma cells.

Genomic and transcriptional alterations in lung adenocarcinoma in relation to EGFR and KRAS mutation status

Introduction

In lung adenocarcinoma, the mutational spectrum is dominated by EGFR and KRAS mutations. Improved knowledge about genomic and transcriptional alterations in and between mutation-defined subgroups may identify genes involved in disease development or progression.

Methods

Genomic profiles from 457 adenocarcinomas, including 113 EGFR-mutated, 134 KRAS-mutated and 210 EGFR and KRAS-wild type tumors (EGFRwt/KRASwt), and gene expression profiles from 914 adenocarcinomas, including 309 EGFR-mutated, 192 KRAS-mutated, and 413 EGFRwt/KRASwt tumors, were assembled from different repositories. Genomic and transcriptional differences between the three mutational groups were analyzed by both supervised and unsupervised methods.

Results

EGFR-mutated adenocarcinomas displayed a larger number of copy number alterations and recurrent amplifications, a higher fraction of total loss-of-heterozygosity, higher genomic complexity, and a more distinct expression pattern than EGFR-wild type adenocarcinomas. Several of these differences were also consistent when the three mutational groups were stratified by stage, gender and smoking status. Specific copy number alterations were associated with mutation status, predominantly including regions of gain with the highest frequency in EGFR-mutated tumors. Differential regions included both large and small regions of gain on 1p, 5q34-q35.3, 7p, 7q11.21, 12p12.1, 16p, and 21q, and losses on 6q16.3-q21, 8p, and 9p, with 20-40% frequency differences between the mutational groups. Supervised gene expression analyses identified 96 consistently differentially expressed genes between the mutational groups, and together with unsupervised analyses these analyses highlighted the difficulty in broadly resolving the three mutational groups into distinct transcriptional entities.

Conclusions

We provide a comprehensive overview of the genomic and transcriptional landscape in lung adenocarcinoma stratified by EGFR and KRAS mutations. Our analyses suggest that the overall genomic and transcriptional landscape of lung adenocarcinoma is affected, but only to a minor extent, by EGFR and KRAS mutation status.