Genetic and biochemical alterations in non-small cell lung cancer

Genes whose expressions in the primary lung squamous cell carcinoma are able to accurately predict the progression of metastasis through lymphatic system, inferred from a bioinformatics analyses

Lymph node metastasis is the most important prognostic factor in patients with lung squamous cell carcinoma. The current findings show that lymph node metastatic tumor cells can arise by programming metastasis in primary tumor cells. Thereby, the genetic alterations responsible for the metastasis could be detected in the primary tumors. This bioinformatic study aimed to determine novel potential prognostic biomarkers shared between primary lung squamous cell tumors (without lymph node metastasis) and lymphatic metastasis, using the Cancer Genome Atlas database. Differentially expressed genes were screened by limma statistical package in R environment. Gene ontology and biological pathways analyses were performed using Enrichr for up-regulated and down-regulated genes. Also, we selected lymph node metastasis related genes among DEGs using correlation analysis between DEGs and suitable references genes for metastasis. Receiver operating characteristic curves was applied using pROC and R package ggplot2 to evaluate diagnostic value of differentially expressed genes. In addition, survival and drug resistance analyses were performed for differentially expressed genes. The miRNA-mRNA interaction networks were predicted by miRwalk and TargetScan databases and expression levels analysis of the miRNAs which were mainly targeting mRNAs was performed using UALCAN database. Protein-protein interaction network analysis and hub genes identification were performed using FunRich and Cytoscape plugin cytoHubba. In this study, a total of 397 genes were differentially expressed not only with a significant difference between N + vs. normal and N0 vs. normal but also with significant difference between N + vs. N0. Identified GO terms and biological pathways were consistent with DEGs role in the lung squamous cell carcinoma and lymph node metastasis. A significant correlation between 56 genes out of 397 differentially expressed genes with reference genes prompted them being considered for identifying lymph node metastasis of lung squamous cell carcinoma. In addition, SLC46A2, ZNF367, AC107214.1 and NCBP1 genes were identified as survival-related genes of patients with lung squamous cell carcinoma. Moreover, NEDD9, MRPL21, SNRPF, and SCLT1 genes were identified to be involved in lung squamous cell carcinoma drug sensitivity/resistance. We have identified several numbers of miRNAs and their related target genes which could emerge as potential diagnostic biomarkers. Finally, CDK1, PLK1, PCNA, ZWINT and NDC80 identified as hub genes for underlying molecular mechanisms of lung squamous cell carcinoma and lymphatic metastasis. Our study highlights new target genes according to their relation to lymph node metastasis, whose expressions in the primary lung squamous cell carcinoma are able to accurately assess the presence of lymphatic metastasis.

AS-tDR-007872: A Novel tRNA-Derived Small RNA Acts an Important Role in Non-Small-Cell Lung Cancer

tRNA-derived small RNAs (also known as tsRNAs) are novel kinds of non-coding RNAs. Although tsRNAs are aberrantly expressed in different tumor types, there is scanty of research investigating their expression profiling and functions in pulmonary adenocarcinoma (PADC). We identified the expression of AS-tDR-007872 in 30 non-small-cell lung carcinoma (NSCLC) patients' carcinoma tissues and conducted biological function evaluation. We also test the expression levels of AS-tDR-007872 in plasma samples obtained from 35 healthy people and 79 NSCLC cases. The results identified downregulated AS-tDR-007872 in both cancer tissues and plasma samples versus adjacent normal counterparts (p < 0.05) and healthy controls (p < 0.001). The area under the curve of AS-tDR-007872 was identified by receiver operating characteristic curve analysis to be 0.756 (95% CI, 0.663-0.849; p < 0.001). Furthermore, overexpression of AS-tDR-007872 in vitro inhibited tumor cell proliferation, invasion, and migration and promoted apoptosis. The knockdown of AS-tDR-007872 showed the opposite results. Meanwhile, we found significantly downregulated BCL2L11 after overexpressing AS-tDR-007872. From the above, our research suggests that AS-tDR-007872 can be a tumor suppressor and a promising biomarker for diagnosing lung cancer.

MiR-195-3p is a Novel Prognostic Biomarker Associated with Immune Infiltrates of Lung Adenocarcinoma

Background

MicroRNA-195-3p (miR-195-3p) plays an important role in some tumors, but its role in LUAD is unclear. This study explored the expression of miR-195-3p in LUAD and the relationship between the expression of miR-195-3p and the clinical and prognostic characteristics of LUAD patients.

Methods

MiR-195-3p expression and clinical information of LUAD patients were obtained from The Cancer Genome Atlas (TCGA). Kruskal–Wallis test, Wilcoxon signed rank test, logistic regression, and Cox regression were used to assess the relationship between the expression level of miR-195-3p and clinical features in LUAD tissues. Kaplan–Meier survival curves were used to analyze the effect of miR-195-3p expression levels on the prognosis of LUAD patients. Target genes of miR-195-3p were predicted by several software. GO (Gene Ontology), KEGG (Kyoto Encyclopedia of Genes and Genomes), and immune infiltration analysis were used to analyze the possible regulatory network of miR-195-3p.

Results

Compared with normal lung tissue, miR-195-3p is down expressed in LUAD tissue (P < 0.001). The low miR-195-3p expression in LUAD was significantly associated with N stage (P = 0.046), pathologic stage (P = 0.011), and gender (P = 0.010). Low miR-195-3p expression predicted a poorer overall survival (HR: 0.60; 95% CI: 0.45–0.81; P = 0.001) and disease-specific survival (HR: 0.55; 95% CI: 0.37–0.80; P = 0.002). The expression of miR-195-3p (HR: 0.488; 95% CI: 0.304–0.784; P = 0.003) was independently correlated with OS in LUAD patients. High expression of miR-195-3p genes, including ABCC2, AGMAT, ARNTL2, ATP6V0A4, CDC25A, CDK1, FAM111B, GJB2, GRIP1, HMGA2, HOXA9, KIF14, SYT2, and TFAP2A, were associated with poor OS in LUAD. GO and KEGG analysis suggested that miR-195-3p was related to the phagosome pathway. MiR-195-3p may promote the function of B cells, dendritic cells, eosinophils, immature dendritic cells, macrophages, Mast cells, NK cells, plasmacytoid dendritic cells, and follicular helper T cells.

Conclusion

Low miR-195-3p expression is significantly associated with poor survival in LUAD, which may be a promising prognostic biomarker for LUAD.

Evaluation of KRAS Concomitant Mutations in Advanced Lung Adenocarcinoma Patients

Background and Objectives: One of the most frequently mutated oncogenes in cancer belongs to the Ras family of proto-oncogenes, which encode distinct key signaling events. RAS gain-of-function mutations are present in ~30% of all human cancers, with KRAS being the most frequently mutated isoform showing alterations in different cancer types including lung cancer. This study aimed to investigate the incidence of KRAS mutations, and concomitant mutations, in advanced non-small cell lung adenocarcinoma patients. Materials and Methods: This was a retrospective study, where genomic DNA extracted from paraffin-embedded tumor tissues from 121 Brazilian advanced non-small cell lung adenocarcinoma patients were analyzed to evaluate via Next Generation Sequencing (NGS) the incidence of KRAS mutations and co-occurring mutations and correlate, when possible, to clinicopathological characteristics. Statistical analyses were performed to calculate the prevalence of mutations and to investigate the association between mutational status, mutation type, and sex. Results: The results showed a prevalence of male (N = 63; 54.8%) compared to female patients (N = 52, 45.2%), and mutant KRAS was present in 20.86% (24/115) of all samples. Interestingly, 33.3% of the mutant KRAS samples showed other mutations simultaneously. Conclusions: This study revealed the presence of rare KRAS concomitant mutations in advanced lung adenocarcinoma patients. Further investigation on the importance of these genomic alterations in patient prognosis and treatment response is warranted.

Inhibitors Targeting CDK9 Show High Efficacy against Osimertinib and AMG510 Resistant Lung Adenocarcinoma Cells

Simple Summary

Non-small cell lung cancer accounts for 80% of all lung cancer cases. While a subset of non-small cell lung cancer patients respond to immunotherapy, those who are treated with chemotherapy or targeted therapy develop resistance to the drugs. Thus, novel therapeutic strategies are needed to combat this disease. Here we show that inhibitors of the cyclin-dependent kinase 9 are highly effective in preventing the growth of a variety of lung cancer cell lines and lung cancer organoids with high potency. These inhibitors suppressed the expression of several genes like Sox2, Sox9, and Mcl1 that promote tumor growth, facilitating growth arrest. Since inhibitors of cyclin-dependent kinase 9 are undergoing clinical trials for hematological malignancies, our studies suggest that these inhibitors would be attractive candidates to combat non-small cell lung cancer.

Abstract

Non-small cell lung cancer has a 5-year survival rate of less than 12–15%, calling for the development of additional therapeutic strategies to combat this disease. Here we tested the efficacy of inhibiting cyclin-dependent kinase 9 (CDK9) on lung cancer cell lines with K-Ras and EGFR mutations and on lung cancer organoids. Three different CDK9 inhibitors reduced the viability and anchorage-independent growth of lung cancer cell lines at very low nanomolar to micromolar concentrations. CDK9 inhibition suppressed the expression of the anti-apoptotic protein, Mcl1, as well as the embryonic stem cell transcription factors, Sox2 and Sox9, which are pro-tumorigenic. In contrast, treatment with CDK9 inhibitors increased the levels of WT p53 and its downstream target p21 in K-Ras mutant cell lines. Furthermore, the CDK9 inhibitors could markedly reduce the viability of Osimertinib-resistant PC9 and AMG510-resistant H23 and H358 cells with comparable efficacy as the parental cells. CDK9 inhibitors could also significantly reduce the growth and viability of lung cancer organoids with high potency. Taken together, the data presented here strongly suggest that CDK9 inhibitors would be efficacious against K-Ras mutant and EGFR mutant NSCLCs, including those that develop resistance to targeted therapies.

Design, synthesis and assessment of new series of quinazolinone derivatives as EGFR inhibitors along with their cytotoxic evaluation against MCF7 and A549 cancer cell lines

New acetamide (IV a-e) and 1,3-thiazolidinone derivatives (VII a-e) were designed, synthesized and assessed for their cytotoxic activity against MCF-7 and A549 cell lines along with their lead compounds (erlotinib and gefitinib). The newly designed compounds were prepared according to the adopted procedures in schemes 1 and 2 from their quinazolinone parents. 3D QSAR pharmacophore and docking molecular modeling protocols were conducted using Discovery Studio program, beside a full biological assay for these compounds. The cytotoxicity evaluation demonstrated that compounds IVb, IVc, VIIa, VIIb, VIId exhibited potent cytotoxic activities against both MCF-7 and A549 cell lines. Moreover, the molecular modeling studies corroborated to the affinity of the compounds towards EGFR. Consequently, these five compounds were then screened for their EGFR inhibition and evaluated as well for their toxicity to normal cells, which revealed that the acetamide derivative IVc and the thiazolidinone derivative VIIa were the most potent and least toxic. DNA flow cytometry analysis was conducted for compounds IVc and VIIa, which indicated that they both induced arrest at G2/M phase of the cell cycle.

DNA repair pathways and their roles in drug resistance for lung adenocarcinoma

Lung cancer is the leading cancer type of death rate. The lung adenocarcinoma subtype is responsible for almost half of the total lung cancer deaths. Despite the improvements in cancer treatment in recent years, lung adenocarcinoma patients' overall survival rate remains poor. Immunetherapy and chemotherapy are two of the most widely used options for the treatment of cancer. Although many cancer types initially respond to these treatments, the development of resistance is inevitable. The rapid development of drug resistance mainly characterizes lung adenocarcinoma. Despite being the subject of many studies in recent years, the resistance initiation and progression mechanism is still unclear. In this review, we have examined the role of the primary DNA repair pathways (non-homologous end joining (NHEJ) pathway, homologous-recombinant repair (HR) pathway, base excision repair (BER) pathway, and nucleotide excision repair (NER) pathway and transactivation mechanisms of tumor protein 53 (TP53) in drug resistance development. This review suggests that mentioned pathways have essential roles in developing the resistance against chemotherapy and immunotherapy in lung adenocarcinoma patients.

Analysis of Expression and Its Clinical Significance of the Secreted Phosphoprotein 1 in Lung Adenocarcinoma

Objective

To explore the expression of secreted phosphoprotein 1 (SPP1) in lung adenocarcinoma (LUAD), and evaluate its relationship with clinicopathological characteristics and prognosis of LUAD, and analyze the advantages of SPP1 as a potential prognostic marker in LUAD.

Methods

The expression of SPP1 in normal lung tissue and LUAD was analyzed from the Cancer Cell Line Encyclopedia (CCLE), Gene Expression Omnibus (GEO), and Human Protein Atlas (HPA) databases. GSE68465 was used to explore the relationship between the SPP1 expression and clinicopathological characteristics and the prognosis of LUAD patients. The relationship between SPP1 and immune infiltration in LUAD was analyzed by the Tumor Immune Estimation Resource (TIMER) database. Gene enrichment analysis was performed in GSEA. The Cancer Genome Atlas (TCGA)-LUAD data was used to verify the results.

Results

In the cell line level, non-small cell lung cancer ranked ninth among cancer cell lines based on SPP1 expression. In the messenger RNA (mRNA) and protein levels, SPP1 expression was higher in LUAD tissues than that in normal control. SPP1 expression was related to gender, N stage, histological grade, and progression or relapse. In men, SPP1 expression were higher compared to that in women. The higher the N stage, the higher the SPP1 expression level. As LUAD progresses or relapses, SPP1 expression could increase. In the pathological grade, the SPP1 expression was higher in LUAD samples with moderate differentiation. In addition, the overall 5-year survival rates of the SPP1 high and low expression groups were 50.574 and 59.181% [P = 0.008; hazard ratio (HR) = 0.7057; 95% CI, 0.5467-0.9109], indicating that SPP1 had an impact on overall survival for LUAD patients. The relationship between SPP1 expression and CD4⁺ T cell, macrophage, neutrophil, and dendritic cell infiltration was weak in LUAD. SPP1 could be considered as an independent prognostic marker in LUAD (P = 0.003; HR = 1.150; 95% CI, 1.048-1.261) by multivariate Cox regression analysis. The results of GSEA indicated that samples with high SPP1 expression were enriched in protein secretion, mTORC1 signaling, angiogenesis, and glycolysis pathway. The analysis results obtained by TCGA-LUAD data were basically consistent with the results obtained by GSE68465.

Conclusions

SPP1 can not only affect the occurrence and development of LUAD but also may be an independent prognostic marker of LUAD. SPP1 is expected to be a new target for molecular targeted therapy.

Mitofusin1 Is a Major Mediator in Glucose-Induced Epithelial-to-Mesenchymal Transition in Lung Adenocarcinoma Cells

Background

Epithelial-to-mesenchymal transition (EMT) has been considered a latent mediator of diverse biological processes in cancer. However, the mechanisms involved in high glucose-associated EMT in lung adenocarcinoma (LAD) have not been fully clarified. In this study, we aimed to investigate whether mitofusin1 (MFN1) is involved in the EMT of LAD cells induced by glucose and to identify the molecular mechanism involved in this process.

Materials and Methods

The expression of specific proteins was analysed by Western blotting, immunohistochemistry, co-immunoprecipitation and immunofluorescence analysis. The proliferation, migration and invasion of cells were assessed by Cell Counting Kit-8, bromodeoxyuridine incorporation, wound-healing and transwell assays. Lung tissues of adjacent normal regions and lung tissues from patients with LAD and LAD combined with diabetes mellitus were collected to determine the expression and significance of MFN1.

Results

Here, we showed that the expression of MFN1 was increased in LAD tissues compared with adjacent normal tissues and expression was even higher in lung tissues from patients with LAD combined with diabetes. In the lung cancer cell line A549, increased cell proliferation, invasion and EMT induced by high glucose were inhibited by MFN1 silencing. Mechanistic studies demonstrated that inhibiting autophagy reversed the abnormal EMT triggered by high glucose conditions. In addition, our data provide novel evidence demonstrating that PTEN-induced kinase (Pink) is a potential regulator involved in MFN1-mediated cell autophagy, which eventually leads to high glucose-induced proliferation, invasion and EMT of A549 cells.

Conclusion

Taken together, our data show that MFN1 interacts with Pink to induce the autophagic process and that the abnormal occurrence of autophagy ultimately contributes to glucose-induced pathological EMT in LAD.

Comparison of Clinical Characteristics and Outcomes in Relapsed Versus De Novo Metastatic Non-Small Cell Lung Cancer

OBJECTIVES

To compare the clinical characteristics and outcomes between relapsed and de novo metastatic non-small cell lung cancer (NSCLC).

MATERIALS AND METHODS

We reviewed all NSCLC diagnoses between January 1999 and December 2013 in the institutional Glans-Look Lung Cancer Database, which contains demographic, clinical, pathologic, treatment, and outcome information. Patients with distant metastasis at diagnosis (American Joint Committee on Cancer [AJCC] eighth edition, stage IV), the "de novo" cohort, were compared with the "relapsed" cohort, consisting of patients diagnosed with early stage disease (stage I/II) undergoing curative intent treatment and subsequently experiencing metastatic relapse. Survival analysis, along with univariate and multivariable analysis was performed.

RESULTS

A total of 185 relapsed and 3039 de novo patients were identified. Significantly different patterns of smoking history, histology, systemic therapy use, and disease extent were observed between the relapsed and de novo cohorts. Median overall survival from time of metastasis was significantly longer in relapsed than in de novo disease (8.9 vs. 3.7 mo, P<0.001). Relapsed patients demonstrated significant improvements in outcomes over time. In multivariate analysis, de novo metastatic disease continued to bode a worse prognosis (adjusted hazard ratio [HR], 1.4) as did male sex (HR, 1.2), never-smoking history (HR, 1.2), and presence of extrapulmonary metastases (HR, 1.3). Systemic therapy receipt conferred better outcome (HR, 0.4), although the impact of relapsed versus de novo disease on outcomes persisted regardless of systemic therapy receipt.

CONCLUSIONS

Relapsed and de novo patients represent significantly different subpopulations within metastatic NSCLC with the latter exhibiting poorer survival. This information facilitates discussions about prognosis with patients and supports screening initiatives aimed at reducing de novo disease.

The association of HLA/KIR genes with non-small cell lung cancer (adenocarcinoma) in a Han Chinese population

The host immune system plays a crucial role in the surveillance, recognition and elimination of tumor cells. Recent studies found that Human lymphocyte antigen class I (HLA I) genes, Killer cell immunoglobulin-like receptor (KIR) genes and HLA/KIR combinations play a role in the defense against tumor cells. To evaluated the associations between HLA I genes, KIR genes and HLA/KIR combinations and non-small cell lung cancer (NSCLC) in a Chinese Han population, a total of 229 patients with NSCLC (adenocarcinoma) and 217 healthy individuals were studied. Our results showed that the HLA-C*08:01 allele occurred at a significantly higher frequency in the NSCLCs compared with the controls (P=0.034). The HLA haplotype frequencies bearing HLA-A, -B, and -C loci between the NSCLC and control groups were not different (P>0.05). And there were no differences in the KIR gene, genotype and haplotype frequencies between the NSCLC and control groups (P>0.05). Also, there were no differences between the HLA/KIR combinations in the KIR3D genes and HLA-A3/A11, HLA-Bw4 ligands and KIR2D genes and HLA-C1/C2 ligands between the NSCLC and control groups (P>0.05). Our results indicate that the HLA-C*08:01 allele could be a risk factor for NSCLC (adenocarcinoma) in the Chinese Han population (OR=2.395; 95% CI: 1.359-4.221).

Genetic polymorphisms in the TERT gene and susceptibility to non-small cell lung cancer in a Chinese Han population

Background

Recent studies have revealed that the TERT gene plays crucial roles in cancer initiation and development. Genome-wide analysis studies and case-control studies have demonstrated that polymorphisms in the TERT gene are associated with various cancers.

Materials and methods

In the current study, we analyzed the associations of eight single nucleotide polymorphisms (SNPs) in the TERT gene with non-small cell lung cancer (NSCLC) in a Chinese Han population. A total of 467 NSCLC patients and 526 healthy individuals were recruited for SNP genotyping using a TaqMan assay.

Results

Our results revealed that the allelic frequencies of rs2853677 and rs2853691 were significantly different between the NSCLC and control groups (P=0.004 and 0.001, respectively). Moreover, the T allele of rs2853677 and the A allele of rs2853691 might be the protective factors against NSCLC (OR=0.766; 95%CI: 0.639–0.918 and OR=0.714; 95%CI: 0.584–0.875, respectively). Additionally, stratified association analysis of the eight SNPs with the different pathological NSCLC stages (I+II and III+IV) and different pathological types (adenocarcinoma and squamous cell carcinoma) revealed that none of the SNPs were significantly different between patients with different pathological stages and pathological types.

Conclusion

Our results indicated that rs2853677 and rs2853691 in the TERT gene might be associated with NSCLC in this Chinese Han population.

Cigarette smoke enhances oncogene addiction to c-MET and desensitizes EGFR-expressing non-small cell lung cancer to EGFR TKIs

Cigarette smoking is one of the leading risks for lung cancer and is associated with the insensitivity of non‐small cell lung cancer (NSCLC) to epidermal growth factor receptor (EGFR) tyrosine kinase inhibitors (TKIs). However, it remains undetermined whether and how cigarette smoke affects the therapeutic efficacy of EGFR TKIs. In this study, our data showed that chronic exposure to cigarette smoke extract (CSE) or tobacco smoke‐derived carcinogen benzo[α]pyrene, B[α]P, but not nicotine‐derived nitrosamine ketone (NNK), reduced the sensitivity of wild‐type EGFR‐expressing NSCLC cells to EGFR TKIs. Treatment with TKIs almost abolished EGFR tyrosine kinase activity but did not show an inhibitory effect on downstream Akt and ERK pathways in B[α]P‐treated NSCLC cells. CSE and B[α]P transcriptionally upregulate c‐MET and activate its downstream Akt pathway, which is not inhibited by EGFR TKIs. Silencing of c‐MET reduces B[α]P‐induced Akt activation. The CSE‐treated NSCLC cells are sensitive to the c‐MET inhibitor crizotinib. These findings suggest that cigarette smoke augments oncogene addiction to c‐MET in NSCLC cells and that MET inhibitors may show clinical benefits for lung cancer patients with a smoking history.

Honokiol suppresses lung tumorigenesis by targeting EGFR and its downstream effectors

Since epidermal growth factor receptor (EGFR) is commonly deregulated in pre-malignant lung epithelium, targeting EGFR may arrest the development of lung cancer. Here, we showed that honokiol (2.5–7.5 μM), a bioactive compound of Magnolia officinalis, differentially suppressed proliferation (up to 93%) and induced apoptosis (up to 61%) of EGFR overexpressing tumorigenic bronchial cells and these effects were paralleled by downregulation of phospho-EGFR, phospho-Akt, phospho-STAT3 and cell cycle-related proteins as early as 6–12 h post-treatment. Autocrine secretion of EGF sensitized 1170 cells to the effects of honokiol. Molecular docking studies indicated that honokiol binds to the tyrosine kinase domain of EGFR although it was less efficient than erlotinib. However, the anti-proliferative and pro-apoptotic activities of honokiol were stronger than those of erlotinib. Upon combinatory treatment, honokiol sensitized bronchial cells and erlotinib resistant H1650 and H1975 cells to erlotinib. Furthermore, in a mouse lung tumor bioassay, intranasal instillation of liposomal honokiol (5 mg/kg) for 14 weeks reduced the size and multiplicity (49%) of lung tumors and the level of total- and phospho-EGFR, phospho-Akt and phospho-STAT3. Overall, our results indicate that honokiol is a promising candidate to suppress the development and even progression of lung tumors driven by EGFR deregulation.

Addressing the elephant in the room, therapeutic resistance in non-small cell lung cancer, with epigenetic therapies

Like Chinese boxes nesting inside each other, the classification of non-small cell lung cancer (NSCLC) is subdivided into smaller and smaller subtypes on the basis of histological and molecular attributes. The latter characterizes NSCLC by its molecular alterations and the identification of inhibitors that target these cancer-specific "driver" mutations. Despite the initial promise of precision-guided therapies to inhibit a finer and finer array of molecular subcategories, despite even the curative potential of immunotherapeutic checkpoint blockade, in particular, casualties still abound and true clinical success stories are few and far between; the ever-present, if sometimes unmentioned, "elephant in the room", is the acquisition of resistance, which, sooner or later, rears its ugly head to undermine treatment success and shorten survival. Emerging data suggests that epigenetic therapies are able to reprogram the aberrant tumor-associated epigenome and 'tame the beast of resistance', thereby prolonging survival. This article reviews the role of epigenetic dysregulation in NSCLC, explores PFS2 as a possible surrogate endpoint, briefly mentions possible biomarkers and highlights combinatorial treatment epigenetic strategies to "prime" tumors and reverse resistance.

Upregulation of long intergenic noncoding RNA 00673 promotes tumor proliferation via LSD1 interaction and repression of NCALD in non-small-cell lung cancer

Despite improvements in diagnostics and treatment of non-small cell lung cancer (NSCLC), it remains the leading causes of cancer-related mortality worldwide. In more recent years, mutiple lines of evidence have highlighted long noncoding RNAs (lncRNAs) serve as novel class of regulators of cancer biological processes, including proliferation, apoptosis and metastasis. LncRNAs serve as a novel class of regulators of cancer biological processes in cancer, but little is known of their expression and potential functions in NSCLC. We identified an oncogene, linc00673, whose expression level was upregulated by bioinformatics analyses and qRT-PCR analyses in NSCLC. The effects of linc00673 on tumor progression were investigated in vitro and in vivo. Linc00673 knockdown significantly inhibited cell proliferation and colony-forming ability, and suppressed S-phase entry in vitro and shRNA linc00673 mediated knockdown significantly inhibit tumor growth in vivo, meanwhile, linc00673 overexpression increased tumor cell growth. Analysis of RNAseq data revealed linc00673 could modulate the transcription of a large amount of genes including oncogene and tumor suppressor gene, so we investigated the role and regulatory mechanism of linc00673 in NSCLC proliferation. Further mechanistic analyses indicated that the oncogenic activity of linc00673 is partially attributable to its repression of NCALD through association with the epigenetic repressor LSD1. Taken together, these findings suggested that linc00673 could play crucial role in NSCLC progression and might be a potential therapeutic target for patients with NSCLC.

Genetic variation in CDH13 gene was associated with non-small cell lung cancer (NSCLC): A population-based case-control study

Cadherin 13 (CDH13, T-cadherin, H-cadherin) has been identified as an anti-oncogene in various cancers. Recent studies have reported that downregulation of H-cadherin in cancers is associated with CDH13 promoter hypermethylation, which could be affected by the single nucleotide polymorphisms (SNPs) near CpG sites in the CDH13 promoter. In the current study, we investigated and analyzed the association of seven SNPs (rs11646213, rs12596316, rs3865188, rs12444338, rs4783244, rs12051272 and rs7195409) with non-small cell lung cancer (NSCLC) using logistic regression analysis. SNPs rs11646213, rs12596316, rs3865188 and rs12444338 are located in the promoter region, rs4783244 and rs12051272 are located in intron 1, and rs7195409 is located in intron 7. A total of 454 patients with NSCLC were placed into a NSCLC group and 444 healthy controls were placed into a control group, all participants were recruited to genotype the SNPs using Taqman assay. Our results showed that the allelic frequencies of rs11646213 were significantly different between NSCLC and control groups (P = 0.006). In addition, the association analysis of these SNPs stratified into NSCLC pathologic stages I+II and III+IV showed that the allelic frequencies rs7195409 had a significant difference between NSCLC pathologic stages I+II and III+IV (P = 0.006). Our results indicated that the rs11646213 and rs7195409 in CDH13 could be associated with NSCLC or its pathologic stages in the Chinese Han population.

lncRNA-HIT promotes cell proliferation of non-small cell lung cancer by association with E2F1

Lung cancer is the leading cause of cancer-related death around the world. Long noncoding RNA (lncRNA) has pivotal roles in cancer occurrence and development. However, only a few lncRNAs have been functionally characterized. In the present study, we investigated the effects of lncRNA-HIT (HOXA transcript induced by TGFβ) expression on non-small cell lung cancer (NSCLC) cell phenotype with the gain-of-function and loss-of-function assays. We found that ectopic expression or knockdown of lncRNA-HIT markedly increased or decreased NSCLC cell proliferation, respectively. Moreover, we also showed that lncRNA-HIT interacted with E2F1 to regulate its target genes, such as Survivin, FOXM1, SKP2, NELL2 and DOK1. Collectively, our findings indicated that lncRNA-HIT affected the proliferation of NSCLC cells at least in part via regulating the occupancy of E2F1 in the promoter regions of its target genes. The lncRNA-HIT-E2F1 complex may be a potential target for NSCLC treatment.

ABCB1 and ABCG2 drug transporters are differentially expressed in non-small cell lung cancers (NSCLC) and expression is modified by cisplatin treatment via altered Wnt signaling

BACKGROUND

Lung cancer (LC) is still the most common cause of cancer related deaths worldwide. Non-small cell lung cancer (NSCLC) accounts for 85% of all LC cases but is not a single entity. It is now accepted that, apart from the characteristic driver mutations, the unique molecular signatures of adeno- (AC) and squamous cell carcinomas (SCC), the two most common NSCLC subtypes should be taken into consideration for their management. Therapeutic interventions, however, frequently lead to chemotherapy resistance highlighting the need for in-depth analysis of regulatory mechanisms of multidrug resistance to increase therapeutic efficiency.

METHODS

Non-canonical Wnt5a and canonical Wnt7b and ABC transporter expressions were tested in primary human LC (n = 90) resections of AC and SCC. To investigate drug transporter activity, a three dimensional (3D) human lung aggregate tissue model was set up using differentiated primary human lung cell types. Following modification of the canonical, beta-catenin dependent Wnt pathway or treatment with cisplatin, drug transporter analysis was performed at mRNA, protein and functional level using qRT-PCR, immunohistochemistry, immune-fluorescent staining and transport function analysis.

RESULTS

Non-canonical Wnt5a is significantly up-regulated in SCC samples making the microenvironment different from AC, where the beta-catenin dependent Wnt7b is more prominent. In primary cancer tissues ABCB1 and ABCG2 expression levels were different in the two NSCLC subtypes. Non-canonical rhWnt5a induced down-regulation of both ABCB1 and ABCG2 transporters in the primary human lung aggregate tissue model recreating the SCC-like transporter pattern. Inhibition of the beta-catenin or canonical Wnt pathway resulted in similar down-regulation of both ABC transporter expression and function. In contrast, cisplatin, the frequently used adjuvant chemotherapeutic agent, activated beta-catenin dependent signaling that lead to up-regulation of both ABCB1 and ABCG2 transporter expression and activity.

CONCLUSIONS

The difference in the Wnt microenvironment in AC and SCC leads to variations in ABC transporter expression. Cisplatin via induction of canonical Wnt signaling up-regulates ABCB1 and ABCG2 drug transporters that are not transporters for cisplatin itself but are transporters for drugs that are frequently used in combination therapy with cisplatin modulating drug response.

LIM and SH3 protein 1 promotes tumor proliferation and metastasis in lung carcinoma

Lung cancer is the most frequently diagnosed cancer and the leading cause of cancer-related mortality worldwide. In the present study, we focused on LIM and SH3 protein 1 (LASP-1), a key molecule involved in the development of multiple cancers, and attempted to elucidate its effect on the oncogenesis of lung cancer. We determined the expression level of LASP-1 in lung cancer using reverse transcription-quantitative polymerase chain reaction and western blot analysis, and also studied the potential function of LASP-1 in lung cancer cell growth, apoptosis and migration by small interfering RNA transfection. The results revealed that the levels of LASP-1 mRNA and protein were abnormally high in lung cancer cells. Following RNA interference of LASP-1, the proliferation and migration ability of the human cancer cell line A549 were significantly decreased. In addition, fluorescence-activated cell sorting analysis indicated that the apoptotic process in the A549 cell line was induced by the silencing of LASP-1. Our study is the first to investigate the potential of LASP-1 in lung cancer, and revealed its significant role in regulating the growth and metastasis of lung cancer cells. The present study suggests that LASP-1 has potential as a therapeutic target in the treatment of lung cancer in the clinic.

Functional role of lncRNA DB327252 in lung cancer

BACKGROUND

Lung cancer becomes a concerning health issue and is considered one of the most deadly cancers in the worldwide. Most recently, long non-coding RNAs (lncRNAs) are newfound non-coding RNAs that are thought as one of the major players in a range of biological processes of human diseases. Although lncRNAs are involved in numerous cancer types, the precise understandings of lncRNAs' functional roles and mechanisms in lung cancer are limited. In this study, we looked for lung cancer related lncRNAs.

METHODS

The quantitative reverse transcriptase polymerase chain reaction (qRT-PCR) technique was utilized to investigate the lncRNA DB327252 expression in 91 paired clinical lung cancer tissues and related cell lines. Moreover, its biological functions were also evaluated in the development of lung cancer.

RESULTS

The results indicated that the expression of DB327252 was up-regulated in lung cancer tissues compared to the cancer-adjacent normal tissues (P<0.05); and the up-regulated expression is likely to relate to those with bigger tumor size, adenocarcinoma and advanced TNM stage (P<0.05). In addition, the knockdown of DB327252 inhibited the growth and proliferation of tumor cell in vitro and in vivo. According to the observation from our study, we found that the knockdown of the DB327252 expression, led to G0/G1 phase cell-cycle arrested, colony formation suppressed in vitro, and tumor growth inhibited in a nude mouse xenograft model. Our experimental results also suggest that lncRNA DB327252 may be a lncRNA related to lung cancer and acts an important role in A549 and 16HBE-T cancer cells, which provides evidence that DB327252 has an oncogene-like function in lung cancer.

CONCLUSIONS

The lncRNA DB327252 is up-regulated in lung cancer, and its expression implies that it was probable related to biologic functions of lung cancer.

Regulatory single nucleotide polymorphisms at the beginning of intron 2 of the human KRAS gene

There are two regulatory single nucleotide polymorphisms (rSNPs) at the beginning of the second intron of the mouse K-ras gene that are strongly associated with lung cancer susceptibility. We performed functional analysis of three SNPs (rs12228277: T greater than A, rs12226937: G greater than A, and rs61761074: T greater than G) located in the same region of human KRAS. We found that rs12228277 and rs61761074 result in differential binding patterns of lung nuclear proteins to oligonucleotide probes corresponding two alternative alleles; in both cases, the transcription factor NF-Y is involved. G greater than A substitution (rs12226937) had no effect on the binding of lung nuclear proteins. However, all the nucleotide substitutions under study showed functional effects in a luciferase reporter assay. Among them, rs61761074 demonstrated a significant correlation with allele frequency in non-small-cell lung cancer (NSCLC). Taken together, the results of our study suggest that a T greater than G substitution at nucleotide position 615 in the second intron of the KRAS gene (rs61761074) may represent a promising genetic marker of NSCLC.

MicroRNA-186 suppresses cell proliferation and metastasis through targeting MAP3K2 in non-small cell lung cancer

MicroRNAs are a class of small endogenous non-coding RNAs that play crucial roles in the initiation and progression of human cancers. miR-186 was found decreased in various human malignancies and function as a tumor suppressor. However, the regulating mechanism of miR-186 in growth and metastasis of human non-small cell lung cancer (NSCLC) is still poorly understood. We investigated the role of miR-186 in the growth and metastasis of human NSCLC. In the present study, we found that miR-186 was significantly decreased in lung cancer tissues and cells. Furthermore, overexpression of miR-186 suppressed lung cancer cell proliferation, migration and invasion, and induced cell apoptosis. Moreover, we found that confirmed mitogen-activated protein kinase kinase kinase 2 (MAP3K2) protein was increased in lung cancer tissues and confirmed that MAP3K2 is a target gene of miR-186. In addition, knockdown of MAP3K2 by RNA interference inhibited lung cancer cell proliferation, migration and invasion, and promoted cell apoptosis in vitro. Furthermore, we observed tthat the overexpression of MAP3K2 partially reversed the inhibitory effect of miR-186 on the proliferation and metastasis of A549 and HCC827 cell lines. Taken together, our data indicated that miR-186 regulates lung cancer growth and metastasis through suppressing MAP3K2 expression, at least partly. Therefore, miR-186-MAP3K2 may represent a new and useful potential clinical treatment and diagnosis target for NSCLC.

The association of adiponectin gene promoter variations with non-small cell lung cancer in a Han Chinese population

Recently, in vitro studies have demonstrated that adiponectin has antiangiogenic and tumor growth-limiting properties. Additionally, serum adiponectin levels have been associated with the risk of several cancers; specifically, serum adiponectin was significantly lower in lung cancer patients with advanced-stage disease. In this study, we examined the association of adiponectin gene promoter variations associated with adiponectin gene expression and plasma levels in non-small cell lung cancer (NSCLC) in a Han Chinese population. A total of 319 patients with NSCLC and 489 healthy individuals were recruited to evaluate the association of four adiponectin gene promoter single-nucleotide polymorphisms (SNPs) (SNP-12140G>A, SNP-11426A>G, SNP-11391G>A and SNP-11377C>G) with NSCLS risk. Additionally, we constructed haplotypes of these four SNPs and evaluated the association of these haplotypes with NSCLS risk. Our results showed that among these four SNPs, only SNP-12140G>A was associated with NSCLC risk (P<0.05). The haplotype analysis showed that no haplotype was associated with NSCLC after performing a Bonferroni correction (P>0.05). Additionally, an association analysis of the four SNPs stratified into pathologic stages I+II and III+IV showed that these SNPs did not exhibit significant differences between pathologic stages I+II and III+IV. Moreover, we did not observe any differences in allele and genotype frequency for these SNPs between adenocarcinoma and squamous cell carcinoma. Our results indicated that the G allele of SNP-12140 may be a risk factor for NSCLC (OR = 1.516; 95% CI: 1.098-2.094) in this Han Chinese population.

Clinical outcome and expression of mutant P53, P16, and Smad4 in lung adenocarcinoma: a prospective study

BACKGROUND

Whole-exome sequencing has shown that lung adenocarcinoma (LAC) can be driven by mutant genes, including TP53, P16, and Smad4. The aim of this study was to clarify protein alterations of P53, P16, and Smad4 and to explore their correlations between the protein alterations and clinical outcome.

METHODS

We investigated associations among P53 mutant (P53(Mut)) expression, and P16 and Smad4 loss-of-expression, with clinical outcome in 120 LAC patients who underwent curative resection, using immunohistochemical (IHC) methods.

RESULTS

Of the 120 patients, 76 (63.3%) expressed P53(Mut) protein, whereas 54 (45.0%) loss of P16 expressed and 75 (62.5%) loss of Smad4 expressed. P53(Mut) expression was associated with tumor size (P = 0.041) and pathological stage (P = 0.025). Loss of P16 expression was associated with lymph node metastasis (P = 0.001) and pathological stage (P < 0.001). Loss of Smad4 expression was associated with tumor size (P = 0.033), lymph node metastasis (P = 0.014), pathological stage (P = 0.017), and tumor differentiation (P = 0.022). Kaplan-Meier survival analysis showed that tumor size (P = 0.031), lymph node metastasis (P < 0.001), pathological stage (P < 0.001), P53(Mut) protein expression (P = 0.038), and loss of p16 or Smad4 expression (P < 0.001) were significantly associated with shorter overall survival(OS), whereas multivariate analysis indicated that lymph node metastasis (P = 0.014) and loss of p16 or Smad4 expression (P < 0.001) were independent prognostic factors. Analysis of protein combinations showed patients with more alterations had poorer survival (P < 0.001). Spearman correlation analysis showed that loss of Smad4 expression inversely correlated with expression of P53(Mut) (r = (-)0.196, P = 0.032) and positively with lost P16 expression (r =0.182, P = 0.047).

CONCLUSIONS

The findings indicate that IHC status of P53(Mut), P16, and Smad4 may predict patient outcomes in LAC.

Circulating antibodies to p16 protein-derived peptides in breast cancer

Overexpression of the p16 protein has been reported in breast cancer and may trigger the secretion of antibodies against itself. Circulating anti-p16 antibodies that were detected with a recombinant protein have been reported in breast cancer. The present study was designed to determine whether the levels of circulating IgG antibody to p16 protein-derived linear antigens are altered in breast cancer. An enzyme-linked immunosorbent assay (ELISA) was developed in-house to determine circulating IgG against peptide antigens derived from the p16 protein in 152 female breast cancer patients and 160 healthy female subjects. The Student's T-test revealed that breast cancer patients exhibited significantly higher levels of anti-p16 IgG antibody compared to control subjects (T=2.02, P=0.045). In addition, ductal cancer appeared to be the main type contributing to the increased levels of circulating anti-p16 antibodies (T=2.08, P=0.038). Of all four stages of breast cancer, stage I was associated with the highest levels of IgG antibody (T=2.02, P=0.045) and receiver operating characteristic (ROC) analysis demonstrated that the area under the ROC curve was 0.74 (95% confidence interval: 0.65-083) and that the sensitivity against a specificity of 90% was 30.3%. Therefore, the levels of circulating IgG antibody to the p16 protein may be a potential biomarker for early diagnosis of breast cancer.

P7170, a novel inhibitor of mTORC1/mTORC2 and Activin receptor-like Kinase 1 (ALK1) inhibits the growth of non small cell lung cancer

BACKGROUND

Lung cancer is the major cause of cancer-related deaths and many cases of Non Small Cell Lung Cancer (NSCLC), a common type of lung cancer, have frequent genetic/oncogenic activation of EGFR, KRAS, PIK3CA, BRAF, and others that drive tumor growth. Some patients though initially respond, but later develop resistance to erlotinib/gefitinib with no option except for cytotoxic therapy. Therefore, development of novel targeted therapeutics is imperative to provide improved survival benefit for NSCLC patients. The mTOR cell survival pathway is activated in naïve, or in response to targeted therapies in NSCLC.

METHODS

We have discovered P7170, a small molecule inhibitor of mTORC1/mTORC2/ALK1 and investigated its antitumor efficacy using various in vitro and in vivo models of human NSCLC.

RESULTS

P7170 inhibited the phosphorylation of AKT, S6 and 4EBP1 (substrates for mTORC2 and mTORC1) levels by 80-100% and growth of NSCLC cells. P7170 inhibited anchorage-independent colony formation of NSCLC patient tumor-derived cells subsistent of disease sub-types. The compound also induced apoptosis in NSCLC cell lines. P7170 at a well-tolerated daily dose of 20 mg/kg significantly inhibited the growth of NSCLC xenografts independent of different mutations (EGFR, KRAS, or PIK3CA) or sensitivity to erlotinib. Pharmacokinetic-pharmacodynamic (PK-PD) analysis showed sub-micro molar tumor concentrations along with mTORC1/C2 inhibition.

CONCLUSIONS

Our results provide evidence of antitumor activity of P7170 in the erlotinib -sensitive and -insensitive models of NSCLC.

Molecular understanding of lung cancers-A review

Lung cancer is considered to be the most common cancer in the world. The purpose of this paper is to review scientific evidence, particularly epidemiologic evidence of overall lung cancer burden in the world. And molecular understanding of lung cancer at various levels by dominant and suppressor oncogenes.

Cytology specimens offer an effective alternative to formalin-fixed tissue as demonstrated by novel automated detection for ALK break-apart FISH testing and immunohistochemistry in lung adenocarcinoma

BACKGROUND

Minimally invasive sampling by cytology or core needle biopsy often provides an initial diagnosis for treatment in patients with lung nodules. From these limited specimens, multiple molecular studies are frequently requested. Current guidelines from the US Food and Drug Administration recommend using formalin-fixed paraffin-embedded tissue sections for the detection of anaplastic lymphoma kinase (ALK) gene rearrangement by fluorescence in situ hybridization (FISH). The authors compared alcohol-fixed and formalin-fixed cytology specimens using a novel automated detection for ALK rearrangements by FISH and immunohistochemistry (IHC).

METHODS

ALK FISH testing was performed on 129 lung adenocarcinomas from 71 cytology cases and 58 biopsy/resection specimens using Papanicolaou staining with integrated cytomorphology. IHC with the ALK D5F3 antibody was performed on cases with residual material (88 of 129 cases).

RESULTS

The mean age of the patients was 66 years; there were 62 women and 67 men. ALK gene rearrangement was present in 4% of cytology specimens (3 of 71 specimens) and 7% of surgical specimens (4 of 58 specimens). FISH in 13 cases was technically unsuccessful. Of the 7 FISH-positive cases, only 2 cytology cases (4%) and 2 surgical cases (6%) were found to be positive with the ALK antibody, demonstrating 80% concordance. The one case found to be negative for ALK by IHC demonstrated a variant rearrangement of the ALK 2p23 gene locus by FISH.

CONCLUSIONS

The results of the current study validate the usefulness of alcohol-fixed and/or formalin-fixed cytology specimens for ALK rearrangement by a novel automated FISH method. IHC using the D5F3 antibody for ALK is specific in this limited cohort. The authors also demonstrated that alcohol-fixed cytology specimens can be used for ALK rearrangement by automated FISH, alone or in conjunction with IHC.

KPT-330 has antitumour activity against non-small cell lung cancer

BACKGROUND

We investigated the biologic and pharmacologic activities of a chromosome region maintenance 1 (CRM1) inhibitor against human non-small cell lung cancer (NSCLC) cells both in vitro and in vivo.

METHODS

The in vitro and in vivo effects of a novel CRM1 inhibitor (KPT-330) for a large number of anticancer parameters were evaluated using a large panel of 11 NSCLC cell lines containing different key driver mutations. Mice bearing human NSCLC xenografts were treated with KPT-330, and tumour growth was assessed.

RESULTS

KPT-330 inhibited proliferation and induced cell cycle arrest and apoptosis-related proteins in 11 NSCLC cells lines. Moreover, the combination of KPT-330 with cisplatin synergistically enhanced the cell kill of the NSCLC cells in vitro. Human NSCLC tumours growing in immunodeficient mice were markedly inhibited by KPT-330. Also, KPT-330 was effective even against NSCLC cells with a transforming mutation of either exon 20 of EGFR, TP53, phosphatase and tensin homologue, RAS or PIK3CA, suggesting the drug might be effective against a variety of lung cancers irrespective of their driver mutation.

CONCLUSIONS

Our results support clinical testing of KPT-330 as a novel therapeutic strategy for NSCLC.

Rapamycin prevents the development and progression of mutant epidermal growth factor receptor lung tumors with the acquired resistance mutation T790M

Lung cancer in never-smokers is an important disease often characterized by mutations in epidermal growth factor receptor (EGFR), yet risk reduction measures and effective chemopreventive strategies have not been established. We identify mammalian target of rapamycin (mTOR) as potentially valuable target for EGFR mutant lung cancer. mTOR is activated in human lung cancers with EGFR mutations, and this increases with acquisition of T790M mutation. In a mouse model of EGFR mutant lung cancer, mTOR activation is an early event. As a single agent, the mTOR inhibitor rapamycin prevents tumor development, prolongs overall survival, and improves outcomes after treatment with an irreversible EGFR tyrosine kinase inhibitor (TKI). These studies support clinical testing of mTOR inhibitors in order to prevent the development and progression of EGFR mutant lung cancers.

Overexpression of G protein-coupled receptor 87 correlates with poorer tumor differentiation and higher tumor proliferation in non-small-cell lung cancer

G protein-coupled receptor 87 (GPR87) is a newly deorphanized member of the transmembrane G protein-coupled receptor family. Recently, GPR87 was suggested to contribute to the viability of human tumor cells and overexpression of GPR87 mRNA was detected in a number of malignant tumors, including lung cancer. We performed a retrospective study of GPR87 expression in association with clinical characteristics and biological markers in non-small-cell lung cancer (NSCLC). We investigated a total of 123 patients with NSCLC who underwent surgery between 1999 and 2004 (58 adenocarcinomas, 53 squamous cell carcinomas and 12 others). Immunohistochemistry was used to evaluate the intratumoral expression of GPR87 and the Ki-67 proliferation index. The TUNEL method was also used to investigate tumor apoptosis. A total of 63 tumors (51.2%) were found to be GPR87-positive. These tumors were more frequently encountered among squamous cell carcinomas rather than among adenocarcinomas (62.3 vs. 43.1%, respectively; P=0.044) and were significantly more frequently poorly and moderately differentiated rather than well differentiated (P=0.029). Moreover, the Ki-67 index was significantly higher in GPR87-positive compared to GPR87-negative tumors (57.0 vs. 40.0%, respectively; P=0.002). The overall survival was significantly worse for patients with GPR87-positive compared to those with GPR87-negative tumors (P=0.029). The Cox regression analyses also demonstrated that the GPR87 status was a significant prognostic factor for NSCLC patients [hazard ratio=2.053; P=0.018). The present study demonstrated that in NSCLC, the overexpression of GPR87 is significantly associated with poorer differentiation and higher proliferation. During the progression of NSCLC, GPR87 overexpression may be associated with the acquisition of a more aggressive phenotype and, therefore, is a potentially useful target for prognostication and treatment.

BMP-4 genetic variants and protein expression are associated with platinum-based chemotherapy response and prognosis in NSCLC

To explore the role of genetic polymorphisms of bone morphogenic proteins 4 (BMP-4) in the response to platinum-based chemotherapy and the clinical outcome in patients with advanced nonsmall cell lung cancer (NSCLC), 938 patients with stage III (A+B) or IV NSCLC were enrolled in this study. We found that the variant genotypes of 6007C > T polymorphisms significantly associated with the chemotherapy response. The 6007CC genotype carriers had a higher chance to be responder to chemotherapy (adjusted odd ratio = 2.77; 95% CI: 1.83–4.18; adjusted < 0.001). The 6007C > T polymorphisms and BMP-4 expression also affect the prognosis of NSCLC. Patients with high BMP-4 expression had a significantly higher chance to be resistant to chemotherapy than those with low BMP-4 expression (OR = 2.81; 95% CI: 1.23–6.44; P = 0.01). The hazard ratio (HR) for 6007TT was 2.37 times higher than 6007CC (P = 0.003). In summary, the 6007C > T polymorphism of BMP-4 gene and BMP-4 tissue expression may be used as potential predictor for the chemotherapy response and prognosis of advanced NSCLC.

A critical role for the long non-coding RNA GAS5 in proliferation and apoptosis in non-small-cell lung cancer

In more recent years, long non-coding RNAs (lncRNAs) have been investigated as a new class of regulators of cellular processes, such as cell growth, apoptosis, and carcinogenesis. Although lncRNAs are dysregulated in numerous cancer types, limited data are available on the expression profile and functional role of lncRNAs in non-small cell lung cancer (NSCLC). In the present study, we determined the expression pattern of the growth arrest-specific transcript 5 (GAS5) in 72 NSCLC specimens by qRT-PCR and assess its biological functions in the development and progression of NSCLC. The results revealed that GAS5 expression was down-regulated in cancerous tissues compared to adjacent noncancerous tissues (P < 0.05) and was highly related to tumor size and TNM stage (P < 0.05). This correlation between GAS5 and clinicopathological parameters indicates that GAS5 might function as a tumor suppressor. Furthermore, GAS5 overexpression increased tumor cell growth arrest and induced apoptosis in vitro and in vivo. Meanwhile, siRNA-mediated knockdown of GAS5 promoted tumor cell growth. Importantly, through western blot analysis, we found that ectopic expression of GAS5 significantly up-regulated p53 expression and down-regulated transcription factor E2F1 expression. Taken together, these findings suggest that GAS5 is a tumor suppressor in NSCLC, and the action of GAS5 is mediated by p53-dependent and p53-independent pathways. GAS5 could serve as a potential diagnostic marker for NSCLC and may be a novel therapeutic target in patients with NSCLC.

Biomarkers and molecular testing for early detection, diagnosis, and therapeutic prediction of lung cancer

The search for biomarkers in the management of lung cancer involves the use of multiple platforms to examine changes in gene, protein, and microRNA expression. Multiple studies have been published in an attempt to describe early detection, diagnostic, prognostic, and predictive biomarkers using chiefly tissues and blood elements. Studies are characterized by a lack of commonality of specific biomarkers, and a lack of validated, clinically useful markers. The future of biomarker discovery as a means of tailoring therapy for patients with lung cancer will involve next-generation sequencing along with collaborative efforts to integrate and validate candidate markers.