Update in lung cancer 2008

Plasma cytokines interleukin-18 and C-X-C motif chemokine ligand 10 are indicative of the anti-programmed cell death protein-1 treatment response in lung cancer patients

Background

Although programmed cell death protein-1 (PD-1)/programmed death ligand-1 (PD-L1) checkpoint inhibitors have shown prominent efficacy for treatment of advanced lung cancer, the outcomes of metastatic lung cancer remain poor throughout the world. Although progression-free survival (PFS) and overall survival (OS) have improved in the first- and second-line therapy settings for advanced lung cancer, the response rates to PD-1/PD-L1 inhibition range from 20% to 40%. Furthermore, patients may be at risk for immune-related adverse events (irAEs); hence, appropriate patient selection is crucial. This study aimed to identify a panel of plasma cytokines representing prognostic and predictive biomarkers of the response to anti-PD-1/PD-L1 treatment.

Methods

We prospectively studied 32 lung cancer patients who received anti-PD-1/PD-L1 antibody immunotherapy. Plasma cytokines in peripheral blood samples were evaluated and analyzed using flow cytometry at the time of diagnosis and at 2 months after the initiation of PD-1/PD-L1 inhibition.

Results

The baseline plasma concentrations of interleukin-18 (IL-18) and C-X-C motif chemokine ligand 10 (CXCL10) were correlated with the degree of tumor response. Moreover, the magnitude of plasma IL-18 and CXCL10 level fluctuations were correlated significantly with the objective tumor response to anti-PD-1/PD-L1 immunotherapy, and patients with high CXCL10 expression had significantly shorter PFS than those with low CXCL10 expression. A strong positive correlation between the fluctuation of IL-18 and interleukin-8 (IL-8) levels was detected, as was a negative correlation between the fluctuation of IL-18 and CXCL10 levels. The level of plasma C-C motif chemokine ligand 5 (CCL5) was significantly higher in patients with irAEs than in those without irAEs.

Conclusions

Plasma cytokines are related to the clinical efficacy of PD-1/PD-L1 inhibitors. IL-18 and CXCL10 are potential predictive markers for anti-PD-1/PD-L1 therapy in lung cancer patients and may play an important role in selecting patients who would benefit from PD-1/PD-L1 inhibitors.

Salivary cytokine panel indicative of non-small cell lung cancer

Objective To develop a combinatorial panel of salivary cytokines that manifests the presence of non-small cell lung cancer (NSCLC) that will eventually improve prognosis by facilitating the early diagnosis and management of this common cancer. Methods We performed a case-control study comparing salivary cytokine profiles of 35 adult subjects with NSCLC with those of 35 matched, healthy nonsmokers. Multiplex bead array assays were used to quantify 27 cytokines in saliva, serum, and oral mucosal transudate samples. Logistic regression analysis was used to develop an informative cytokine panel. Receiver operating characteristic (ROC) curves were generated to evaluate the discriminant ability of the panel. Results A combinatorial 12-cytokine panel (interleukin receptor antagonist [IL1RN], IL1B, IL6, IL7, IL8, IL10, C-C motif chemokine ligand 11 [CCL11], tumor necrosis factor, C-X-C motif chemokine ligand 10 [CXCL10], C-C motif chemokine ligand 3, C-C motif chemokine ligand 4, and platelet-derived growth factor-BB) distinguished patients with NSCLC from healthy controls. Further, ROC analysis revealed that a cytokine panel comprising IL10 (odds ratio, 1.156) and CXCL10 (odds ratio, 1.000) discriminated NSCLC with a sensitivity of 60.6% and specificity of 80.8% (area under the ROC curve, 0.701). Conclusion A combinatorial panel of select salivary cytokines indicates the presence of NSCLC.

Diagnostic role of Wnt pathway gene promoter methylation in non small cell lung cancer

Wnt signal pathway genes are known to be involved with cancer development. Here we tested the hypothesis whether DNA methylation of genes part of the Wnt signaling pathway could help the diagnosis of non-small cell lung cancer (NSCLC). The methylation levels of SFRP1, SFRP2, WIF1 and PRKCB in 111 NSCLC patients were evaluated by quantitative methylation-specific PCR (qMSP). Promoter methylation levels of four candidate genes were significantly higher in tumor tissues compared with the adjacent tissues. SFRP1, SFRP2 and PRKCB genes were all shown to be good predictors of NSCLC risk (SFRP1: AUC = 0.711; SFRP2: AUC = 0.631; PRKCB: AUC = 0.650). The combined analysis showed that the methylation status of the four genes had a sensitivity of 70.3% and a specificity of 73.9% in the prediction of NSCLC risk for study cohort. A higher diagnostic value with an AUC of 0.945 (95% CI: 0.923–0.967, sensitivity: 90.6%, specificity: 93.0%) was found in TCGA cohort. In addition, SFRP1 and SFRP2 hypermethylation events were specific to male patients. Further TCGA data mining analysis suggested that SFRP1_cg15839448, SFRP2_cg05774801, and WIF1_cg21383810 were inversely associated with the host gene expression. Moreover, GEO database analysis showed that 5′-Aza-deoxycytidine was able to upregulate gene expression in several lung cancer cell lines. Subsequent dual-luciferase reporter assay showed a crucial regulatory function of PRKCB promoter. In summary, our study showed that a panel of Wnt signal pathway genes (SFRP1, SFRP2, WIF1 and PRKCB) had the potential as methylation biomarkers in the diagnosis of NSCLC.

Insulin receptor substrate-1 deficiency drives a proinflammatory phenotype in KRAS mutant lung adenocarcinoma

Insulin receptor substrate-1 (IRS-1) is a signaling adaptor protein that interfaces with many pathways activated in lung cancer. It has been assumed that IRS-1 promotes tumor growth through its ability to activate PI3K signaling downstream of the insulin-like growth factor receptor. Surprisingly, tumors with reduced IRS-1 staining in a human lung adenocarcinoma tissue microarray displayed a significant survival disadvantage, especially within the Kirsten rat sarcoma viral oncogene homolog (KRAS) mutant subgroup. Accordingly, adenoviral Cre recombinase (AdCre)-treated LSL-Kras/Irs-1(fl/fl) (Kras/Irs-1(-/-)) mice displayed increased tumor burden and mortality compared with controls. Mechanistically, IRS-1 deficiency promotes Janus kinase/signal transducers and activators of transcription (JAK/STAT) signaling via the IL-22 receptor, resulting in enhanced tumor-promoting inflammation. Treatment of Kras/Irs-1(+/+) and Kras/Irs-1(-/-) mice with JAK inhibitors significantly reduced tumor burden, most notably in the IRS-1-deficient group.

Clinical outcomes in patients with small cell lung cancer in a single institute: Comparative analysis of radiographic screening with symptom-prompted patients

OBJECTIVES

The present study was performed to evaluate the differences in clinical characteristics and survival outcomes of patients with small cell lung cancer (SCLC) according to methods used for detecting the disease: radiographic screening or symptomatically prompted.

MATERIALS AND METHODS

The clinical findings and actual treatment outcomes were estimated according to three means of detection of SCLC: computed tomography (CT), radiographic test, and symptom-prompted cases.

RESULTS

We identified 147 patients (male/female ratio: 127/20; mean age: 68.1 years old) between 2000 and 2011. The patients were divided into three categories according to method of detection: chest CT (CT; n=24), radiographic screening (CXR; n=37), and symptom-prompted cases (symptom; n=86). There was no significant shift to early TNM stage distribution in the CT or CXR group compared with the symptom group. However, the rates of limited disease (LD)-SCLC were significantly higher in the CT and CXR groups than the symptom group. Median survival times were 17.0 months (95% confidence interval (CI): 11.6-22.4) in the CT group, 19.0 months (95%CI: 11.7-126.3) in the CXR group, and 12.0 months (95%CI: 9.6-14.4) in the symptom group. There were statistically significant differences in overall survival between CT and symptom groups (P<0.05) and between CXR and symptom groups (P<0.001). However, there was no significant difference in survival between CT and CXR groups.

CONCLUSIONS

Radiographic (CT plus CXR) testing contributes to better clinical outcome in patients with SCLC.

Clinical significance of aberrant Wnt7a promoter methylation in human non-small cell lung cancer in Koreans

The Wnt signaling pathway has regulatory roles in cell proliferation, differentiation, and polarity. Aberrant Wnt pathway regulation can lead to abnormal cell proliferation and cancer, and loss of Wnt7a expression has been demonstrated in lung cancer cell lines. E-cadherin keeps intercellular integrity and prevents metastasis. Therefore, E-cadherin has been known as a prognostic factor in cancer. In the present study, we investigated the E-cadherin expression status by immunohistochemical stain and the Wnt7a promoter methylation status in human non-small cell lung carcinoma (NSCLC) by methylation-specific PCR. We also analyzed their correlations with clinicopathological factors. Methylation of the Wnt7a gene promoter was detected in the lung tissues of 32 of 121 (26.4%) patients with NSCLC. Wnt7a promoter methylation was correlated with advanced tumor stage (P = 0.036) and distant metastasis (P = 0.037). In addition, Wnt7a promoter methylation showed correlation with loss of E-cadherin expression (P < 0.001). However, Wnt7a promoter methylation was not closely related with gender, age, histological type, or smoking habit. Even though Wnt7a methylation could not show significant correlation with the long term survival of the patients with limited follow up data, these findings suggest that loss of the Wnt7a gene induced by promoter methylation might be another prognostic factor for NSCLC and that restoration of Wnt7a may be a promising treatment for NSCLC.

SIAH2 antagonizes TYK2-STAT3 signaling in lung carcinoma cells

The Janus tyrosine kinases JAK1-3 and tyrosine kinase-2 (TYK2) are frequently hyperactivated in tumors. In lung cancers JAK1 and JAK2 induce oncogenic signaling through STAT3. A putative role of TYK2 in these tumors has not been reported. Here, we show a previously not recognized TYK2-STAT3 signaling node in lung cancer cells. We reveal that the E3 ubiquitin ligase seven-in-absentia-2 (SIAH2) accelerates the proteasomal degradation of TYK2. This mechanism consequently suppresses the activation of STAT3. In agreement with these data the analysis of primary non-small-cell lung cancer (NSCLC) samples from three patient cohorts revealed that compared to lung adenocarcinoma (ADC), lung squamous cell carcinoma (SCC) show significantly higher levels of SIAH2 and reduced STAT3 phosphorylation levels. Thus, SIAH2 is a novel molecular marker for SCC. We further demonstrate that an activation of the oncologically relevant transcription factor p53 in lung cancer cells induces SIAH2, depletes TYK2, and abrogates the tyrosine phosphorylation of STAT1 and STAT3. This mechanism appears to be different from the inhibition of phosphorylated JAKs through the suppressor of cytokine signaling (SOCS) proteins. Our study may help to identify molecular mechanisms affecting lung carcinogenesis and potential therapeutic targets.

TEGS-CN: A Statistical Method for Pathway Analysis of Genome-wide Copy Number Profile

The effects of copy number alterations make up a significant part of the tumor genome profile, but pathway analyses of these alterations are still not well established. We proposed a novel method to analyze multiple copy numbers of genes within a pathway, termed Test for the Effect of a Gene Set with Copy Number data (TEGS-CN). TEGS-CN was adapted from TEGS, a method that we previously developed for gene expression data using a variance component score test. With additional development, we extend the method to analyze DNA copy number data, accounting for different sizes and thus various numbers of copy number probes in genes. The test statistic follows a mixture of X² distributions that can be obtained using permutation with scaled X² approximation. We conducted simulation studies to evaluate the size and the power of TEGS-CN and to compare its performance with TEGS. We analyzed a genome-wide copy number data from 264 patients of non-small-cell lung cancer. With the Molecular Signatures Database (MSigDB) pathway database, the genome-wide copy number data can be classified into 1814 biological pathways or gene sets. We investigated associations of the copy number profile of the 1814 gene sets with pack-years of cigarette smoking. Our analysis revealed five pathways with significant P values after Bonferroni adjustment (<2.8 × 10⁻⁵), including the PTEN pathway (7.8 × 10⁻⁷), the gene set up-regulated under heat shock (3.6 × 10⁻⁶), the gene sets involved in the immune profile for rejection of kidney transplantation (9.2 × 10⁻⁶) and for transcriptional control of leukocytes (2.2 × 10⁻⁵), and the ganglioside biosynthesis pathway (2.7 × 10⁻⁵). In conclusion, we present a new method for pathway analyses of copy number data, and causal mechanisms of the five pathways require further study.

Deregulation of serum microRNA expression is associated with cigarette smoking and lung cancer

Lung cancer is the leading cause of cancer-related death and cigarette smoking is the main risk factor for lung cancer. Circulating microRNAs (miRNAs) are considered potential biomarkers of various cancers, including lung cancer. However, it is unclear whether changes in circulating miRNAs are associated with smoking and smoking-related lung cancer. In this study, we determined the serum miRNA profiles of 10 nonsmokers, 10 smokers, and 10 lung-cancer patients with miRCURY LNA microRNA arrays. The differentially expressed miRNAs were then confirmed in a larger sample. We found that let-7i-3p and miR-154-5p were significantly downregulated in the sera of smokers and lung-cancer patients, so the serum levels of let-7i-3p and miR-154-5p are associated with smoking and smoking-related lung cancer. The areas under receiver operating characteristic curves for let-7i-3p and miR-154-5p were approximately 0.892 and 0.957, respectively. In conclusion, our results indicate that changes in serum miRNAs are associated with cigarette smoking and lung cancer and that let-7i-3p and miR-154-5p are potential biomarkers of smoking-related lung cancer.

Gene expression profiles on predicting protein interaction network and exploring of new treatments for lung cancer

In the present study, we aimed to explore disease-associated genes and their functions in lung cancer. We downloaded the gene expression profile GSE4115 from Gene Expression Omnibus (GEO) database. Total 97 lung cancer and 90 adjacent non-tumor lung tissue (normal) samples were applied to identify the differentially expressed genes (DEGs) by paired t test and variance analysis in spectral angle mapper (SAM) package in R. Gene Ontology (GO) functional enrichment analysis of DEGs were performed with Database for Annotation Visualization and Integrated Discovery, followed by construction of protein-protein interaction (PPI) network from Human Protein Reference Database (HPRD). Finally, network modules were analyzed by the MCODE algorithm to detect protein complexes in the PPI network. Total 3,102 genes were identified as DEGs at FDR < 0.05, including 1,146 down-regulated and 1,956 up-regulated DEGs. GO functional enrichment analysis revealed that up-regulated DEGs mainly participated in cell cycle and intracellular related functions, and down-regulated DEGs might influence cell functions. There were 39,240 pairs of PPIs in human obtained from HPRD databases, 3,102 DEGs were mapped to this PPI network, in which 2,429 pairs of PPIs and 1,342 genes were identified. With MCODE algorithm, 48 modules were selected, including five corresponding modules and three modules with differences in gene expressing profiles. In addition, three DGEs, FXR2, ARFGAP1 and ELAVL1 were discovered as potential lung cancer related genes. The discovery of featured genes which were probably related to lung cancer, has a great significance on studying mechanism, distinguishing normal and cancer tissues, and exploring new treatments for lung cancer.

Myasthenia gravis-like syndrome presenting as a component of the paraneoplastic syndrome of lung adenocarcinoma in a nonsmoker

Adenocarcinoma of the lung is the most common form of lung cancer in nonsmokers. It is commonly seen in the periphery of the lungs. Myasthenia gravis is generally associated with mediastinal malignancies and rarely associated with adenocarcinoma of the lung. We present a case of a 38-year-old male nonsmoker with rapidly progressive adenocarcinoma of the lung associated with myasthenia gravis, a patient whom expired within 27 days of hospital admission and diagnosis.

The role of vimentin intermediate filaments in the progression of lung cancer

There is an accumulation of evidence in the literature demonstrating the integral role of vimentin intermediate filaments (IFs) in the progression of lung cancers. Vimentin IF proteins have been implicated in many aspects of cancer initiation and progression, including tumorigenesis, epithelial-to-mesenchymal transition (EMT), and the metastatic spread of cancer. Specifically, vimentin IFs have been recognized as an essential component regulating EMT, major signal transduction pathways involved in EMT and tumor progression, cell migration and invasion, the positioning and anchorage of organelles, such as mitochondria, and cell-cell and cell-substrate adhesion. In tumorgenesis, vimentin forms a complex with 14-3-3 and beclin 1 to inhibit autophagy via an AKT-dependent mechanism. Vimentin is a canonical marker of EMT, and recent evidence has shown it to be an important regulator of cellular motility. Transcriptional regulation of vimentin through hypoxia-inducible factor-1 may be a potential driver of EMT. Finally, vimentin regulates 14-3-3 complexes and controls various intracellular signaling and cell cycle control pathways by depleting the availability of free 14-3-3. There are many exciting advances in our understanding of the complex role of vimentin IFs in cancer, pointing to the key role vimentin IFs may play in tumor progression.

Association between the hOGG1 Ser326Cys polymorphism and lung cancer susceptibility: a meta-analysis based on 22,475 subjects

Objectives

The Ser326Cys polymorphism in the human 8-oxogunaine glycosylase (hOGG1) gene with lung cancer susceptibility had been investigated, but results were inconsistent and underpowered. The aim of this study was to conduct a meta-analysis assessing the association of hOGG1 Ser326Cys polymorphism with risk of lung cancer.

Materials and methods

Relevant studies were identified through a search of MEDLINE, PubMed, Web of Science, EMBASE, and Chinese Biomedical Literature database (CBM) using terms “lung cancer”, “hOGG1” or “OGG1”, “polymorphism” or “variation” and the last search updated on May 1, 2013. In this meta-analysis, we assessed 30 published studies involving 22,475 subjects that investigated the association between the hOGG1 Ser326Cys polymorphism and lung cancer susceptibility.

Results

Overall, the hOGG1 Ser326Cys polymorphism was not associated with lung cancer susceptibility in different genetic models (dominant model comparison: OR = 0.133; 95% CI = 0.111–0.161; P_{heterogeneity} = 0.000), and recessive model: OR = 0.543; 95% CI = 0.399–0.739; P_{heterogeneity} = 0.000). Similarly, in the stratified analyses by ethnicity, significantly increased risks were found among Asians for homozygote comparison (OR = 0.850; 95% CI = 0.732 0.986; P_{heterogeneity} = 0.064), and dominant model (OR = 0.160; 95% CI = 0.137–0.187; P_{heterogeneity} = 0.001), and Caucasians for dominant model (OR = 1.35; 95% CI = 1.03–1.77; P_{heterogeneity} = 0.015), and recessive model (OR = 1.35; 95% CI = 1.03–1.77; P_{heterogeneity} = 0.015). In population-based populations, marginally significant increased risks were found in dominant model (OR = 0.143; 95% CI = 0.111 0.184; P_{heterogeneity} = 0.000) and recessive model (OR = 0.429; 95% CI = 0.261–0.705; P_{heterogeneity} = 0.000). We also found a significant difference between hOGG1 Ser326Cys genotype and lung cancer susceptibility in studies with hospital-based controls for homozygote model (OR = 0.798; 95% CI = 0.649–0.982; P_{heterogeneity} = 0.007),dominant model (OR = 0.122; 95% CI = 0.091–0.163; P_{heterogeneity} = 0.000).

Conclusion

Our data showed that the hOGG1 Ser326Cys polymorphism contributed to the risk of lung cancer.

Virtual slides

The virtual slides for this article can be found here: http://www.diagnosticpathology.diagnomx.eu/vs/3842531131031605

Clinical characteristics and outcomes of patients with small cell lung cancer detected by CT screening

The present study was performed to evaluate the clinical characteristics and survival outcomes in patients with small cell lung cancer (SCLC) detected by low-dose computed tomography (CT). We retrospectively reviewed clinical records of patients with SCLC treated at our hospital between 1997 and 2011 and selected patients with SCLC detected by CT screening. We identified 12 patients (male/female 11/1; mean age 67.8 years old. Nine patients had limited disease (LD), and 3 had extensive disease (ED). Five LD patients underwent thoracic surgery, and the pathological staging information included stage IA (n = 1), IB (n = 1), IIA (n = 1), and IIIB (n = 2). Although 2 patients with pathological stages IA and IB had >10-year survival, the median survival times (MST) in LD and ED were 25 months (95 % CI 17.0-32.9) and 16 months (95 % CI; not evaluated), respectively. In addition, MST in 12 patients was not significantly different from that in SCLC patients in general care in our hospital. This analysis suggested that CT screening contributes to the detection of early-stage SCLC in patients that are potentially suitable for surgery, but it remains unclear how to improve clinical outcome in patients with SCLC.

Mayak Worker Dosimetry System 2008 (MWDS-2008): assessment of internal dose from measurement results of plutonium activity in urine

A new modification of the prior human lung compartment plutonium model, Doses-2005, has been described. The modified model was named "Mayak Worker Dosimetry System-2008" (MWDS-2008). In contrast to earlier models developed for workers at the Mayak Production Association (Mayak PA), the new model more correctly describes plutonium biokinetics and metabolism in pulmonary lymph nodes. The MWDS-2008 also provides two sets of doses estimates: one based on bioassay data and the other based on autopsy data, where available. The algorithm of internal dose calculation from autopsy data will be described in a separate paper. Results of comparative analyses of Doses-2005 and MWDS-2008 are provided. Perspectives on the further development of plutonium dosimetry are discussed.

Surgical outcomes in patients with small cell lung cancer: comparative analysis of computed tomograpy-detected patients with others

Background

It is shown that low-dose computed tomography (CT) screening is useful for a reduction in lung-cancer-specific mortality in heavy smokers. However, the information about effectiveness according to the histological types of lung cancer has not been adequately investigated especially small cell lung cancer (SCLC). The present study was performed to see the clinical benefit of CT screening in patients with SCLC following thoracotomy.

Methods

We retrospectively reviewed the outcome in patients with early stage SCLC who initially underwent thoracotomy. The clinical stages and actuarial survival were estimated according to the three means of detection of SCLC: chest CT, radiographic screen, and symptomatically prompted cases.

Results

Sixty-nine patients (men/women, 63/6; mean age, 70 years) with SCLC underwent thoracotomy between 1991 and 2010 including chest CT (n = 13), radiographic screening (n = 39), and symptomatically prompted cases (n = 17). Pathological staging information included stage IA (n = 25), IB (n = 8), IIA (n = 13), IIB (n = 5), IIIA (n = 11), and IIIB (n = 7). Median survival time was 30.0 (95% confidence interval (CI): 22.0 to 57.0) months, with overall survival at 5 years of 34.3% (95% CI, 23.47 to 47.3). Nine patients (69%) with stage I were detected by CT which was significantly higher than those in other detection arms. However, there were no significant differences in the survival between CT and other detection arms.

Conclusions

CT examination may be useful for detection in early stage SCLC potentially suitable for surgery, but the contribution to better clinical outcome in patients with SCLC remains unclear.

Study on invadopodia formation for lung carcinoma invasion with a microfluidic 3D culture device

Invadopodia or invasive feet, which are actin-rich membrane protrusions with matrix degradation activity formed by invasive cancer cells, are a key determinant in the malignant invasive progression of tumors and represent an important target for cancer therapies. In this work, we presented a microfluidic 3D culture device with continuous supplement of fresh media via a syringe pump. The device mimicked tumor microenvironment in vivo and could be used to assay invadopodia formation and to study the mechanism of human lung cancer invasion. With this device, we investigated the effects of epidermal growth factor (EGF) and matrix metalloproteinase (MMP) inhibitor, GM6001 on invadopodia formation by human non-small cell lung cancer cell line A549 in 3D matrix model. This device was composed of three units that were capable of achieving the assays on one control group and two experimental groups' cells, which were simultaneously pretreated with EGF or GM6001 in parallel. Immunofluorescence analysis of invadopodia formation and extracellular matrix degradation was conducted using confocal imaging system. We observed that EGF promoted invadopodia formation by A549 cells in 3D matrix and that GM6001 inhibited the process. These results demonstrated that epidermal growth factor receptor (EGFR) signaling played a significant role in invadopodia formation and related ECM degradation activity. Meanwhile, it was suggested that MMP inhibitor (GM6001) might be a powerful therapeutic agent targeting invadopodia formation in tumor invasion. This work clearly demonstrated that the microfluidic-based 3D culture device provided an applicable platform for elucidating the mechanism of cancer invasion and could be used in testing other anti-invasion agents.

N-methylpurine DNA glycosylase and OGG1 DNA repair activities: opposite associations with lung cancer risk

Only a minority of smokers develop lung cancer, possibly due to genetic predisposition, including DNA repair deficiencies. To examine whether inter-individual variations in DNA repair activity of N-methylpurine DNA glycosylase (MPG) are associated with lung cancer, we conducted a blinded, population-based, case–control study with 100 lung cancer case patients and 100 matched control subjects and analyzed the data with conditional logistic regression. All statistical tests were two-sided. MPG enzyme activity in peripheral blood mononuclear cells from case patients was higher than in control subjects, results opposite that of 8-oxoguanine DNA glycosylase (OGG1) DNA repair enzyme activity. For lung cancer associated with one standard deviation increase in MPG activity, the adjusted odds ratio was 1.8 (95% confidence interval [CI] = 1.2 to 2.6; P = .006). A combined MPG and OGG1 activities score was more strongly associated with lung cancer risk than either activity alone, with an odds ratio of 2.3 (95% CI = 1.4 to 3.6; P < .001). These results form a basis for a future panel of risk biomarkers for lung cancer risk assessment and prevention.

Epigenetic biomarkers in cancer epidemiology

Biochemical, epigenetic, genetic, and imaging biomarkers are used to identify people at high risk for developing cancer. In cancer epidemiology, epigenetic biomarkers offer advantages over other types of biomarkers because they are expressed against a person's genetic background and environmental exposure, and because epigenetic events occur early in cancer development. This chapter describes epigenetic biomarkers that are being used to study the epidemiology of different types of cancer. Because epigenetic alterations can be reversed by chemicals and activate gene expression, epigenetic biomarkers potentially have numerous clinical applications in cancer intervention and treatment and significant implications in public health. This review discusses cancer biomarkers, the characteristics of an ideal biomarker for cancer, and technologies for biomarker detection.

Transbronchial biopsy using endobronchial ultrasonography with a guide sheath increased the diagnostic yield of peripheral pulmonary lesions

OBJECTIVE

The advantage of transbronchial biopsy (TBB) using endobronchial ultrasonography (EBUS) with a guide sheath (GS) over TBB without EBUS guidance was investigated in this study.

MATERIALS AND METHODS

A retrospective chart review was conducted at Nagasaki University Hospital, Japan. Data were collected from all cases of peripheral pulmonary lesions (PPLs) undergoing either EBUS-GS-guided TBB or TBB without EBUS guidance in our department from December 2003 through November 2009. The diagnostic yield in each group was compared, after adjustment for other factors.

RESULTS

In total 110 PPLs were investigated in 102 patients: 65 (59.1%) were examined with EBUS-GS-guided TBB (EBUS-GS group) and 45 (40.9%) were TBB without EBUS guidance (non-EBUS group). Both procedures were performed under x-ray fluoroscopy. Basic characteristics were similar between the two groups. Of all EBUS examined lesions, 53 (81.5%) were visualized by EBUS. The diagnostic yields in EBUS-GS group and non-EBUS group were 64.6% and 46.7%, respectively (p=0.08). Adjusting for size and location of lesions, the yield of EBUS-GS guidance was 1.46 (95% confidence interval 1.03 to 2.05) times higher than without EBUS guidance. When the lesion was visualized by EBUS, the diagnostic yield ratio was further increased to 1.63 (95% CI 1.16 to 2.27).

CONCLUSION

EBUS-GS-guided TBB demonstrates a higher diagnostic yield than TBB without EBUS guidance.

Cigarette smoking increases copy number alterations in nonsmall-cell lung cancer

Cigarette smoking has been a well-established risk factor of lung cancer for decades. How smoking contributes to tumorigenesis in the lung remains not fully understood. Here we report the results of a genome-wide study of DNA copy number and smoking pack-years in a large collection of nonsmall-cell lung cancer (NSCLC) tumors. Genome-wide analyses of DNA copy number and pack-years of cigarette smoking were performed on 264 NSCLC tumors, which were divided into discovery and validation sets. The copy number-smoking associations were investigated in three scales: whole-genome, chromosome/arm, and focal regions. We found that heavy cigarette smokers (>60 pack-years) have significantly more copy number gains than non- or light smokers (≤60 pack-years) (P = 2.46 × 10(-4)), especially in 8q and 12q. Copy number losses tend to occur away from genes in non/light smokers (P = 5.15 × 10(-5)) but not in heavy smokers (P = 0.52). Focal copy number analyses showed that there are strong associations of copy number and cigarette smoking pack-years in 12q23 (P = 9.69 × 10(-10)) where IGF1 (insulin-like growth factor 1) is located. All of the above analyses were tested in the discovery set and confirmed in the validation set. DNA double-strand break assays using human bronchial epithelial cell lines treated with cigarette smoke condensate were also performed, and indicated that cigarette smoke condensate leads to genome instability in human bronchial epithelial cells. We conclude that cigarette smoking leads to more copy number alterations, which may be mediated by the genome instability.

Chronic obstructive pulmonary disease and lung cancer: new molecular insights

Both chronic obstructive pulmonary disease (COPD) and lung cancer are major causes of death worldwide. In most cases this reflects cigarette smoke exposure which is able to induce an inflammatory response in the airways of smokers. Indeed, COPD is characterized by lower airway inflammation, and importantly, the presence of COPD is by far the greatest risk factor for lung cancer amongst smokers. Cigarette smoke induces the release of many inflammatory mediators and growth factors including TGF-β, EGFR, IL-1, IL-8 and G-CSF through oxidative stress pathways and this inflammation may persist for decades after smoking cessation. Mucus production is also increased by these inflammatory mediators, further linking airway inflammation to an important mechanism of lung cancer. A greater understanding of the molecular and cellular pathobiology that distinguishes smokers with lung cancer from smokers with and without COPD is needed to unravel the complex molecular interactions between COPD and lung cancer. By understanding the common signalling pathways involved in COPD and lung cancer the hope is that treatments will be developed that not only treat the underlying disease process in COPD, but also reduce the currently high risk of developing lung cancer in these patients.

CLEFMA-an anti-proliferative curcuminoid from structure-activity relationship studies on 3,5-bis(benzylidene)-4-piperidones

3,5-Bis(benzylidene)-4-piperidones are being advanced as synthetic analogs of curcumin for anti-cancer and anti-inflammatory properties. We performed structure-activity relationship studies, by testing several synthesized 3,5-bis(benzylidene)-4-piperidones for anti-proliferative activity in lung adenocarcinoma H441 cells. Compared to the lead compound 1, or 3,5-bis(2-fluorobenzylidene)-4-piperidone, five compounds were found to be more potent (IC(50) < 30 microM), and 16 compounds possessed reduced cell-killing efficacy (IC(50) > 50 microM). Based on the observations, we synthesized 4-[3,5-bis(2-chlorobenzylidene-4-oxo-piperidine-1-yl)-4-oxo-2-butenoic acid] (29 or CLEFMA) as a novel analog of 1. CLEFMA was evaluated for anti-proliferative activity in H441 cells, and was found to be several folds more potent than compound 1. We did not find apoptotic cell population in flow cytometry, and the absence of apoptosis was confirmed by the lack of caspase cleavage. The electron microscopy of H441cells indicated that CLEFMA and compound 1 induce autophagic cell death that was inhibited by specific autophagy inhibitor 3-methyladenine. The results suggest that the potent and novel curcuminoid, CLEFMA, offers an alternative mode of cell death in apoptosis-resistant cancers.

Complement activation mediates cetuximab inhibition of non-small cell lung cancer tumor growth in vivo

Background

Cetuximab, an antibody targeting the epidermal growth factor receptor (EGFR), increases survival in patients with advanced EGFR-positive non-small cell lung cancer when administrated in combination with chemotherapy. In this study, we investigated the role of complement activation in the antitumor mechanism of this therapeutic drug.

Results

EGFR-expressing lung cancer cell lines were able to bind cetuximab and initiate complement activation by the classical pathway, irrespective of the mutational status of EGFR. This activation led to deposition of complement components and increase in complement-mediated cell death. The influence of complement activation on the activity of cetuximab in vivo was evaluated in xenografts of A549 lung cancer cells on nude mice. A549 cells express wild-type EGFR and have a KRAS mutation. Cetuximab activity against A549 xenografts was highly dependent on complement activation, since complement depletion completely abrogated the antitumor efficacy of cetuximab. Moreover, cetuximab activity was significantly higher on A549 cells in which a complement inhibitor, factor H, was genetically downregulated.

Conclusions

We demonstrate for the first time that the in vivo antitumor activity of cetuximab can be associated with a complement-mediated immune response. These results may have important implications for the development of new cetuximab-based therapeutic strategies and for the identification of markers that predict clinical response.

Detection of lung cancer by oral examination

Lung cancer continues to be the leading cause of cancer deaths worldwide. Cigarette smoking is the predominant cause of lung cancer. Researchers found that tobacco-induced molecular changes in the oral epithelium are similar to those in the lung epithelium. Furthermore, there has been considerable progress in investigating the tumorigenesis of oral epithelium using molecular markers. These results offer hope that we can predict lung cancer in smokers by oral examination, which is much easier and more practical than lung biopsy. The hypothesis is to collect oral epithelial cells by gently scraping the oral mucosa, and analyze the DNA variation in these cells using molecular biological methods. Therefore, the oral epithelium is serving as a surrogate tissue for assessing smoking-induced molecular damage to the lungs and thus have important implications for early detection of lung cancer.