Pathogenesis Of Non-small Cell Lung Carcinoma Research Articles

RETRACTED ARTICLE: Upregulation of MCL-1 by LUCAT1 through interacting with SRSF1 promotes the migration and invasion in non-small cell lung carcinoma.

The onset of non-small cell lung carcinoma (NSCLC) still be in the fog. LUCAT1 is potentially capable of modulating MCL-1-involved NSCLC pathogenesis via targeting SRSF1. Also, MCL-1 can regulate Wnt/β-catenin pathway to affect the tumorigenesis of NSCLC. Thus, this paper aims to uncover an intriguing and novel role of LUCAT1/SRSF1/MCL-1 axis in NSCLC based on Wnt/β-catenin pathway. A549 and NCI-H1650, two cell lines of NSCLC, were used to mimic NSCLC in vitro. MCL-1 siRNA (si-MCL-1) and LUCAT1 siRNA (si-LUCAT1) were used to downregulate MCL-1 and LUCAT1 in NSCLC cells, respectively. The overexpression vector of SRSF1 based on pcDNA 3.1 was constructed to upregulate SRSF1 expression. 40 μM SKL2001 was used to activate Wnt/β-catenin pathway. Transwell assay was used for migrative and invasive tests. The effect of LUCAT1 on tumor metastasis was verified in nude mice. MCL-1 downregulation led to the decrease of EMT, invasion, and migration in NSCLC, while Wnt/β-catenin pathway agonist partially reversed the effects of MCL-1 downregulation. Mechanistic investigations revealed that LUCAT1 and MCL-1 mRNA were enriched in SRSF1; LUCAT1 silence decreased MCL-1, whereas SRSF1 enhancement elevated MCL-1; Importantly, SRSF1 overexpression significantly reversed MCL-1 alteration due to LUCAT1 silence. In NSCLC cells, SRSF1 overexpression offset the si-LUCAT1-induced changes, and si-MCL-1 reversed the SRSF1-induced cellular changes. Further, LUCAT1 inhibition reduced lung metastasis of cancer cells. LUCAT1 can interact with SRSF1 to regulate MCL-1 expression that targets the Wnt/β-catenin pathway-mediated NSCLC cell migration, invasion, and EMT.

Unique Spectrum of Driver Gene Mutations in Patients with Non-Small Cell Lung Carcinoma (NSCLC) from Coal-manufacturing Districts in Southwest China

IntroductionThe coal-manufacturing districts in the Eastern Yunnan province of Southwest China are the utmost occurrence and death of lung tumors. As previously reported on unique clinical characteristics of non-small cell lung cancer (NSCLC) in patients from these regions without a clear understanding of the aetiology and molecular characteristics. We aim to identify the unique driver gene mutations spectrum.Material and methodsSamples from 1120 NSCLC patients from Eastern Yunnan were gathered for next-generation sequencing. Seventeen gene targets were sequenced. We have compared individuals' medical and genetic features from the coal- and non-coal-manufacturing zones.ResultsThe mutation rates of EGFR (L858R, 19-Del, G719X+L861X, L858R+EGFR amplification) and ERBB2 (20ins) were low in patients from coal-manufacturing regions. Interestingly, EGFR (G719X, S768I, G719X+S768I), KRAS (G12C), TP53 (R158L) and NTRK3 demonstrated a much higher mutation frequency. Furthermore, EGFR compound mutations were linked with the patient's job and TNM staging IIIb-IV. The OncodriverCLUST algorithm authenticated 6 genes (KRAS, EGFR, ROS1, NRAS, BRAF, and ERBB2) as driver genes in patients from coal manufacturing. EGFR with KRAS, BRAF, RET, and TP53 with ALK and KRAS were mutually exclusive. Mutations in the TP53 signaling pathway were the most common in NSCLC patients from the coal-fabricating districts.ConclusionsOur analyses confirmed the unique spectrum of driver genetic mutations and emphasized the potential of future targeted therapy in NSCLC patients from the coal-manufacturing districts of Eastern Yunnan. Our data broaden the view of NSCLC pathogenesis and its relationship with the environmental conditions in coal-producing regions.

Long non-coding RNA dysregulation is a frequent event in non-small cell lung carcinoma pathogenesis

BackgroundLong non-coding RNAs compose an important level of epigenetic regulation in normal physiology and disease. Despite the plethora of publications of lncRNAs in human cancer, the landscape is still unclear.MethodsMicroarray analysis in 44 NSCLC paired specimens was followed by qPCR-based validation in 29 (technical) and 38 (independent) tissue pairs. Cross-validation of the selected targets was achieved in 850 NSCLC tumours from TCGA datasets.ResultsTwelve targets were successfully validated by qPCR (upregulated: FEZF1-AS1, LINC01214, LINC00673, PCAT6, NUTM2A-AS1, LINC01929; downregulated: PCAT19, FENDRR, SVIL-AS1, LANCL1-AS1, ADAMTS9-AS2 and LINC00968). All of them were successfully cross validated in the TCGA datasets. Abnormal DNA methylation was observed in the promoters of FENDRR, FEZF1-AS1 and SVIL-AS1. FEZF1-AS1 and LINC01929 were associated with survival in the TCGA set.ConclusionsOur study provides through multiple levels of internal and external validation, a comprehensive list of dysregulated lncRNAs in NSCLC. We therefore envisage this dataset to serve as an important source for the lung cancer research community assisting future investigations on the involvement of lncRNAs in the pathogenesis of the disease and providing novel biomarkers for diagnosis, prognosis and therapeutic stratification.

Association of Overexpressed MYC Gene with Altered PHACTR3 and E2F4 Genes Contributes to Non-small Cell Lung Carcinoma Pathogenesis.

SummaryBackgroundC-Myc is one of the major cellular oncogenes overexpressed in non-small cell lung carcinoma (NSCLC). Its deregulated expression is necessary but not sufficient for malignant transformation. We evaluated expression of MYC gene in NSCLC patients and its association with alterations in the genes previously identified to be related to NSCLC pathogenesis, PHACTR3 and E2F4.MethodsWe analyzed MYC gene expression by qRT-PCR in 30 NSCLC patients’ samples and paired normal lung tissue. MYC expression was further statistically evaluated in relation to histopathological parameters, PHACTR3 and E2F4 gene alterations and survival. Alterations in aforementioned genes were previously detected and identified based on AP-PCR profiles of paired normal and tumor DNA samples, selection of DNA bands with altered mobility in tumor samples and their characterization by the reamplification, cloning and sequencing.ResultsMYC expression was significantly increased in NSCLC samples and its overexpression significantly associated with squamous cell carcinoma subtype. Most importantly, MYC overexpression significantly coincided with mutations in PHACTR3 and E2F4 genes, in group of all patients and in squamous cell carcinoma subtype. Moreover, patients with jointly overexpressed MYC and altered PHACTR3 or E2F4 showed trend of shorter survival.ConclusionsOverall, MYC is frequently overexpressed in NSCLC and it is associated with mutated PHACTR3 gene, as well as mutated E2F4 gene. These joint gene alterations could be considered as potential molecular markers of NSCLC and its specific subtypes.

Down-regulation of cytoplasmic PLZF correlates with high tumor grade and tumor aggression in non–small cell lung carcinoma

There are currently no effective prognostic biomarkers for lung cancer. Promyelocytic leukemia zinc finger (PLZF), a transcriptional repressor, has a role in cell cycle progression and tumorigenicity in various cancers. The expression and value of PLZF in lung carcinoma, particularly in the subclass of non-small cell lung carcinoma (NSCLC), has not been studied. Our aim was to study the immunohistochemical expression of PLZF in lung adenocarcinoma and squamous cell carcinoma and correlate the alteration of PLZF expression with tumor differentiation, lymph node metastasis, tumor stage, and overall survival. A total of 296 NSCLCs being mounted on tissue microarray (181 adenocarcinomas and 91 squamous cell carcinomas) were investigated. Moderate to strong expression of PLZF was found in the cytoplasm of all the nonneoplastic respiratory epithelium and most (89.9%) well-differentiated adenocarcinoma. The proportions of moderately differentiated, poorly differentiated adenocarcinoma, and paired lymph node adenocarcinoma metastases that demonstrated negative or only weak PLZF reactivity were 75.6%, 97.2%, and 89.9%, respectively. The expression of PLZF in squamous cell carcinoma was mostly weak or absent and significantly lower than that in adenocarcinoma of the same grade (P < .0005). The loss of cytoplasmic PLZF strongly correlated with high tumor grade and lymph node metastasis in both squamous carcinoma and adenocarcinoma (P < .0001). Down-regulation of PLZF also correlated with higher tumor stage and shorter overall survival (P < .05). These results support a prognostic value for loss of cytoplasmic PLZF expression in the stratification of NSCLC and a possible role of cytoplasmic shift and down-regulation of PLZF in the pathogenesis of NSCLC.

Association of CCND1 overexpression with KRAS and PTEN alterations in specific subtypes of non-small cell lung carcinoma and its influence on patients' outcome.

Cyclin D1 is one of the major cellular oncogenes, overexpressed in number of human cancers, including non-small cell lung carcinoma (NSCLC). However, it does not exert tumorigenic activity by itself, but rather cooperates with other altered oncogenes and tumor suppressors. Therefore, in the present study, we have examined mutual role of cyclin D1, KRAS, and PTEN alterations in the pathogenesis of NSCLC and their potential to serve as multiple molecular markers for this disease. CCND1 gene amplification and gene expression were analyzed in relation to mutational status of KRAS gene as well as to PTEN alterations (loss of heterozygosity and promoter hypermethylation) in NSCLC patient samples. Moreover, the effect of these co-alterations on patient survival was examined. Amplified CCND1 gene was exclusively associated with increased gene expression. Statistical analyses also revealed significant association between CCND1 overexpression and KRAS mutations in the whole group and in the groups of patients with adenocarcinoma, grade 1/2, and stage I/II. In addition, CCND1 overexpression was significantly related to PTEN promoter hypermethylation in the whole group and in the group of patients with squamous cell carcinoma and lymph node invasion. These joint alterations also significantly shortened patients' survival and were shown to be an independent factor for adverse prognosis. Overall results point that cyclin D1 expression cooperates with KRAS and PTEN alterations in pathogenesis of NSCLC, and they could serve as potential multiple molecular markers for specific subgroups of NSCLC patients as well as prognostic markers for this type of cancer.

Expression and significance of stathmin and peptidyl prolyl cistrans isomerase in non-small cell lung carcinoma

Objective To investigate the expression of stathmin and peptidyl prolyl cistrans isomerase (Pin1) in non-small cell lung carcinoma (NSCLC),and their relation to the clinicopathological features.Methods Envision immunohistochemical method was used to assess the expression of stathmin and Pin1 in 76 cases of human NSCLC tissues and non-cancerous adjacent lung tissues.Results The expression rate of stathmin was 65.79％ (50/76) in NSCLC tissues,and 34.21％ (26/76) in non-cancerous adjacent lung tissues (P ＜ 0.01).The expression levels of stathmin were related with histology grade,TNM stage and lymph node metastasis of NSCLC (P ＜ 0.05).The expression rate of Pin1 was 84.21％ (64/76) in NSCLC tissues,and 27.63％ (21/76) in non-cancerous adjacent lung tissues (P ＜ 0.01).There was a close relation between the expression of Pin1 and TNM stage and lymph node metastasis (P ＜ 0.05).Conclusion Stathmin and Pin1 have important roles in the pathogenesis of NSCLC. Key words: Non-small cell lung carcinoma; Stathmin; Peptidyl prolyl cistrans isomerase; Immunohistochemical method

MiR‐503 targets PI3K p85 and IKK‐β and suppresses progression of non‐small cell lung cancer

A microRNA usually has the ability to coordinately repress multiple target genes and therefore are associated with many pathological conditions such as human cancer. Our understanding of the biological roles of microRNAs in lung cancer, however, remains incomplete. In this study, we identified miR-503 as a tumor-suppressive microRNA in human non-small cell lung carcinoma (NSCLC), whose expression level correlates inversely with overall survival in NSCLC patients. Ectopic expression of miR-503 suppressed tumor cell proliferation and metastasis-related traits in vitro as well as in vivo, supporting a anti-cancer role of the microRNA in NSCLC progression. Mechanistic study revealed that oncogenic PI3K p85 and IKK-β were direct targets of miR-503. Overexpression of either PI3K p85 or IKK-β partially restored the malignant properties of NSCLC cells in the presence of miR-503. Taken together, our data demonstrate miR-503 inhibits the malignant phenotype of NSCLC by targeting PI3K p85 and IKK-β and might play a suppressive role in the pathogenesis of NSCLC, thus providing new insights in developing novel diagnostic and therapeutic approaches.

Level of plasmacytoid dendritic cells is increased in non-small cell lung carcinoma

In non-small cell lung carcinoma (NSCLC), the immune system fails to eradicate established tumors partly due to the induction of immune tolerance within the tumor microenvironment. Plasmacytoid dendritic cells (pDCs) play critical roles in regulating the immune system. In this study, we investigated pDCs in the peripheral blood of NSCLC. CD4 + CD123 + BDCA2+ pDCs were tested from peripheral blood mononuclear cells in 52 NSCLC patients and 52 healthy controls by flow cytometry. Results revealed that proportion of pDCs was significantly increased in cases than in controls (0.52 ± 0.07% versus 0.21 ± 0.02%, p < 0.001), whereas myeloid dendritic cells (mDCs) did not present any obvious difference between patients and healthy donors (0.25 ± 0.04 % versus 0.18 ± 0.02%, p = 0.120). We further studied pDCs in NSCLC patients with different clinical stages. Data showed that cases with higher stages (III/IV) had elevated level of pDCs than those with lower stages (I/II) (0.65 ± 0.09% versus 0.25 ± 0.07%, p = 0.006). In addition, the amount of pDCs was identified to be associated with squamous cell carcinoma, one of the major subtypes of NSCLC. Interestingly, we observed that smoking patients presented significantly elevated pDCs than those non-smokers (0.63 ± 0.09% versus 0.22 ± 0.05%, p = 0.008). These data suggested that pDCs may be closely involved in the pathogenesis of NSCLC and may predict the progression of the disease.

Allelic imbalance in 1p, 7q, 9p, 11p, 12q and 16q regions in non-small cell lung carcinoma and its clinical association: a pilot study

In lung cancer pathogenesis, genetic instability, i.e., loss of heterozygosity (LOH) and microsatellite instability (MSI) is a frequent molecular event, occurring at an early stage of cancerogenesis. The presence of LOH/MSI in non-small cell lung carcinoma (NSCLC) was found in many chromosomal regions, but exclusive of 3p their diagnostic value remains controversial. In this study we focused on other than 3p regions—1p31.2, 7q32.2, 9p21.3, 11p15.5, 12q23.2 and 16q22—the loci of many oncogenes and tumour suppressor genes. To analyze the potential role of LOH/MSI involved in NSCLC pathogenesis we allelotyped a panel of 13 microsatellite markers in a group of 56 cancer specimens. Our data demonstrate the presence of allelic loss for all (13) analyzed markers. Total LOH/MSI frequency in NSCLC was the highest for chromosomal region 11p15.5 (25.84 %), followed by 9p21.3 and 1p31.2 (19.87 and 16.67 % respectively). A statistically significant increase of total LOH/MSI frequency was detected for the 11p15.5 region (p = 0.0301; χ2 test). The associations of total LOH/MSI frequency: 1) increase in 11p15.5 region (p = 0.047; χ2 test) and 2) decrease in 7q32.2 region (p = 0.037; χ2 test) have been statistically significant in AJCC III (American Joint Committee on Cancer Staging). In Fractional Allele Loss (FAL) index analysis, the correlation with cigarette addiction has been statistically significant. The increased amount of cigarettes smoked (pack years) in a lifetime correlates with increasing FAL (p = 0.024; Kruskal–Wallis test). These results demonstrate that LOH/MSI alternation in studied chromosomal regions is strongly influenced by tobacco smoking but do not seem to be pivotal NSCLC diagnostic marker with prognostic impact.

Rapid Induction of Lung Adenocarcinoma by Fibroblast Growth Factor 9 Signaling through FGF Receptor 3

Fibroblast growth factors (FGF) are expressed in many non-small cell lung carcinoma (NSCLC) primary tumors and derived cell lines, and mutations in FGF receptor 3 (FGFR3) have been identified in human lung adenocarcinoma. FGF9 has been implicated in the pathogenesis of NSCLC by synergizing with EGFR pathways or by providing an escape pathway mediating resistance to EGFR inhibition. To model pathogenic mechanisms mediated by FGF signals, we have established a mouse model in which FGF9 expression can be induced in adult lung epithelium. Here, we show that induced expression of FGF9 in adult lung leads to the rapid proliferation of distal airway epithelial cells that express the stem cell marker, Sca-1, and the proximal and distal epithelial markers, Sftpc and CC10, the rapid formation of Sftpc-positive adenocarcinomas, and eventual metastasis in some mice. Furthermore, we have identified FGFR3 as the obligate receptor mediating the FGF9 oncogenic signal. These results identify an FGF9-FGFR3 signal as a primary oncogenic pathway for lung adenocarcinoma and suggest that this pathway could be exploited for customized therapeutic applications for both primary tumors and those that have acquired resistance to inhibition of other signaling pathways.

Concurrent alteration of p16 and PTEN tumor suppressor genes could be considered as potential molecular marker for specific subgroups of NSCLC patients

p16 and PTEN are tumor suppressors that are commonly inactivated in human cancers. Loss of each of these molecules is widely studied in lung cancer, including non-small cell lung carcinoma (NSCLC), its most common clinical form. However, the importance of their mutual alterations for NSCLC pathogenesis has been barely examined so far. In this study we tested hypothesis that aberrant p16 might cooperate with inactive PTEN during pathogenesis of NSCLC, particularly in promoting tumor aggressiveness and invasiveness. Initially, we screened NSCLC tumor samples from patients for the presence of the most common genetic and epigenetic alterations of p16 and further correlated them with previously detected aberrations in PTEN gene. Statistical analyses showed that aberrant p16 directly correlated with altered PTEN. Such significant correlation was also observed in groups of patients with high genomic instability, with squamocellular histological subtype, with disease grade 2 and with lymph node invasion. Finally, survival analyses revealed dramatic decrease in survival rate of patients with mutual alterations of p16 and PTEN, but without prognostic significance. Overall results implicate cooperation between aberrant p16 and PTEN in pathogenesis of NSCLC and suggest that their combination might be considered as potential molecular marker for specific subgroups of NSCLC patients.

Critical Role of VCP/p97 in the Pathogenesis and Progression of Non-Small Cell Lung Carcinoma

BackgroundValosin-containing protein (VCP)/p97 is an AAA ATPase molecular chaperone that regulates vital cellular functions and protein-processing. A recent study indicated that VCP expression levels are correlated with prognosis and progression of non-small cell lung carcinoma (NSCLC). We not only verified these findings but also identified the specific role of VCP in NSCLC pathogenesis and progression.Methodology/Principal FindingsOur results show that VCP is significantly overexpressed in non-small cell lung carcinoma (NSCLC) as compared to normal tissues and cell lines (p<0.001). Moreover, we observed the corresponding accumulation of ubiquitinated-proteins in NSCLC cell lines and tissues as compared to the normal controls. VCP inhibition by si/shRNA or small-molecule (Eeyarestatin I, EerI) significantly (p<0.05, p<0.00007) suppressed H1299 proliferation and migration but induced (p<0.00001) apoptosis. Cell cycle analysis by flow cytometry verified this data and shows that VCP inhibition significantly (p<0.001, p<0.003) induced cell cycle arrest in the G0/G1 phases. We also found that VCP directly regulates p53 and NFκB protein levels as a potential mechanism to control tumor cell proliferation and progression. Finally, we evaluated the therapeutic potential of VCP inhibition and observed significantly reduced NSCLC tumor growth in both in vitro and xenograft murine (athymic-nude) models after EerI treatment (p<0.05).Conclusions/SignificanceThus, targeting VCP in NSCLC may provide a novel strategy to restore p53 and NFκB levels and ameliorate the growth and tumorigenicity, leading to improved clinical outcomes.

Coalterations of p53 and PTEN tumor suppressor genes in non–small cell lung carcinoma patients

The inactivation of p53 and PTEN tumor suppressor genes is a common genetic event in lung cancer. However, data on the effect of the joint inactivation of tumor-suppressor genes in non-small cell lung carcinoma (NSCLC) are lacking. The purpose of this study was to investigate the alterations in PTEN and p53 genes, as well as to evaluate their mutual role in NSCLC pathogenesis and their impact on survival rate. To that end, polymerase chain reaction single-strand conformational polymorphism (PCR-SSCP), sequencing, methylation-specific PCR, and fragment analysis were used. The results obtained were correlated with clinicopathologic parameters, the level of genomic instability, and patient survival. Overall, 13% of specimens had aberrant p53 only, 13% had inactive PTEN only, and 50% of samples had both genes altered. Correlation analyses showed that the mutual inactivation of p53 and PTEN was a frequent event that was associated significantly with the increased level of genomic instability and lymph node invasion implying their synergistic effect in promoting metastatic phenotype of this kind of cancer. In addition, our results revealed a significant association of joint alterations of these genes with dramatically shortened survival indicating that aberrant p53 and PTEN could be used as an adverse prognostic factor for NSCLC patients' outcome. Our findings established the relevance of the combinatorial inactivation of p53 and PTEN in NSCLC progression and identified a subgroup of patients with a particularly aggressive disease.

Abstract B55: The impact of inactivation of p53 and PTEN tumor suppressors on promotion and progression of human non-small cell lung carcinoma

Abstract Lung cancer is the major cause of cancer-related death worldwide and the five-year survival rate is not improving significantly, remaining at about 15% for all stages. Inactivation of p53 and PTEN (phosphatase and tensin homolog deleted on chromosome 10) tumor suppressors are molecular events highly related to the pathogenesis of lung cancer, particularly to non-small cell lung carcinoma (NSCLC). However, we still do not have clear image of the sequence of events in NSCLC promotion and progression, that is, whether inactivation of either of these tumor suppressors is early or late event and what the impact of these events is on NSCLC pathogenesis and patients survival. Therefore, we analyzed mutational inactivation of p53 and inactivation of PTEN by loss of heterozygosity (LOH) in 30 NSCLC patients and correlated obtained data with histopathological parameters that are indicators of initiation and progression of the disease: histological subtype, tumor grade, tumor stage, lymph node invasion and necrosis. PCR-single strand conformation polymorphism (PCR-SSCP) analyses revealed and sequencing procedures confirmed that 33.3% of patients had mutationaly inactivated p53 while fragment analysis of PTEN showed that 43.3% had inactivated PTEN by LOH. In total population of analyzed patients, 13.3% of them carried inactivated p53 only, 23.3% had inactivated PTEN only, while 20.0% of patients had inactivated both tumor suppressors. These data suggest that inactivation of PTEN, either alone or in combination with the inactivation of p53, prevalently occurs in NSCLC. Correlation analyses imply that inactivation of either p53 or PTEN is an early event in pathogenesis of NSCLC, while inactivation of both tumor-suppressors contributes to further tumor progression. In addition, correlation analysis of inactivated PTEN and p53 with the degree of genomic instability of each patient (obtained in previous study) disclosed that mutated p53 is associated with high genomic instability while inactivated PTEN was more frequent in patients with low genomic instability confirming important role of p53 in maintaining the stability of the genome. Finally, Kaplan &amp; Meyer survival analyses revealed that patients with inactivated p53 have much worse prognoses. In order to conclude the study of p53 and PTEN inactivation, analyses of hypermetylation of PTEN promoter and LOH of p53 gene are underway. Citation Information: Cancer Res 2009;69(23 Suppl):B55.

Loss and Reduction of Fus1 Protein Expression is a Frequent Phenomenon in the Pathogenesis of Lung Cancer

FUS1, a novel tumor-suppressor gene located in the chromosome 3p21.3 region, may play an important role in lung cancer development. Currently, FUS1-expressing nanoparticles have been developed for treating patients with lung cancer. However, the expression of Fus1 protein has not been examined in a large series of lung cancers and their sequential preneoplastic lesions. Using tissue microarrays, we examined Fus1 immunohistochemical expression in 281 non-small cell lung carcinoma (NSCLC) and 22 small cell lung carcinoma tissue specimens and correlated the findings with patients' clinicopathologic features. To investigate the expression of Fus1 in the early sequential pathogenesis of NSCLC, we studied Fus1 expression in 211 histologically normal and mildly abnormal bronchial epithelia, and 118 bronchial and alveolar preneoplastic lesions obtained from patients with lung cancer. Loss and reduction of expression was detected in 82% of NSCLCs and 100% of small cell lung carcinomas. In NSCLCs, loss of Fus1 immunohistochemical expression was associated with significantly worse overall survival. Bronchial squamous metaplastic and dysplastic lesions expressed significantly lower levels of Fus1 compared with normal (P = 0.014 and 0.047, respectively) and hyperplastic (P = 0.013 and 0.028, respectively) epithelia. Our findings show a high frequency of Fus1 protein loss and reduction of expression in lung cancer, and suggests that this reduction may play an important role in the early pathogenesis of lung squamous cell carcinoma. These findings support the concept that FUS1 gene and Fus1 protein abnormalities could be used to develop new strategies for molecular cancer therapy for a significant subset of lung tumors.

Frequent genetic and epigenetic abnormalities contribute to the deregulation of cytoglobin in non-small cell lung cancer

Lung cancer demonstrates the highest mortality in the UK. Previous studies have implicated allelic loss at chromosome 17q in the development of non-small cell lung carcinoma (NSCLC), and a number of known and putative tumour-suppressor genes reside within this region. One candidate tumour-suppressor gene is cytoglobin (CYGB), which is contained entirely within the 42.5 kb tylosis with oesophageal cancer (TOC) minimal region. CYGB abnormalities have been demonstrated only in sporadic head and neck cancers. In this study, we investigated the expression, promoter methylation and allelic imbalance status of this gene in 52 paired (normal/tumour) surgically excised lung tissue samples from patients with NSCLC. CYGB expression in tumour tissue was significantly reduced compared with corresponding adjacent normal in 54% of the examined cases (paired t-test, P<0.001). The CYGB promoter was shown by pyrosequencing to be significantly hypermethylated [2-fold increase of methylation index (MtI) in tumours] in 25/52 (48%) tumour samples compared with normal samples. MtI of the CYGB promoter was associated with CYGB mRNA expression (linear regression analysis, P=0.009), suggesting a primary role for the epigenetic events in CYGB silencing. In addition, frequent LOH was detected at the locus 17q25 in 32/48 (67%) tumours examined. It is of note that the loss of expression intensified when both LOH and hypermethylation coincided in samples (Mann-Whitney, P=0.049). These findings provide the first evidence to suggest the implication of CYGB in the pathogenesis of NSCLCs.

Reduced Expression of E-cadherin in Human Non-small Cell Lung Carcinoma

E-cadherin, a calcium-dependent cell to cell adhesion molecule, plays a key role in the maintenance of tissue integrity. Reduction or loss of E-cadherin has been reported to have a role in the development of human malignancies. The expression of E-cadherin was analyzed in human non-small cell lung carcinoma (NSCLC) to elucidate the role in pulmonary carcinogenesis and determine the relationship with several clinicopathological factors and the prognosis. Sixty five human cases of NSCLC were evaluated by immunohistochemical analysis for the expression of E-cadherin. The immunostaining results for E-cadherin were semiquantitatively interpreted, as preserved and reduced, in the tumor tissues. The E-cadherin expression was analyzed in relation to several clinicopathological data and the survival. The cell proliferation index of the tumors was evaluated by immunostaining with the Ki-67 antigen. Reduced E-cadherin expression was found in 51 cases of NSCLC tissues (78.4%) compared to that in the normal controls. Reduced E-cadherin expression was significantly correlated with male smokers and squamous cell type of the cancer, but not with histological grade, TNM stage and survival. The E-cadherin expression showed a weak inverse relationship with the proliferative activity of tumor cells, which was measured using the Ki-67 antigen. Our data support the hypothesis that reduced E-cadherin expression may play a role in the pathogenesis of human NSCLC, which might be associated with the control for cell proliferation.

Differential expression of inducible nitric oxide synthase and peroxisome proliferator-activated receptor gamma in non-small cell lung carcinoma

Both inducible nitric oxide synthase (iNOS) and peroxisome proliferator-activated receptor gamma (PPARγ) are closely associated with the development of human cancer. Although the expression of iNOS has been studied in non-small cell lung carcinoma (NSCLC), the level of PPARγ has not been examined in tumorous and non-tumorous tissues from NSCLC. The present study analysed the levels of both iNOS and PPARγ in NSCLC tissues and in lung cell lines. The possible role of these two molecules in the carcinogenesis of lung cancer was investigated. The expression of iNOS was significantly higher in the tumorous tissues than in the non-tumorous ones. In contrast to this pattern of iNOS protein expression, the level of PPARγ was much lower in the tumorous tissues than in the non-tumorous samples. A similar result was also obtained in vitro using human lung cancer cell lines and normal lung cells. Immunohistochemical examination revealed that PPARγ expression in the non-tumorous tissues was more likely to be located in the nucleus whereas it was present in both the nucleus and cytoplasm of the tumorous tissues. The intensity of iNOS expression was stronger in the nucleus than in the cytoplasm of the tumorous tissues. More than 50% of the cases tested did not express iNOS protein in the non-tumorous tissues. Statistical analysis indicated a negative correlation between iNOS and PPARγ levels in the NSCLC tissues. In conclusion, this study demonstrated differing expressions for iNOS and PPARγ in NSCLC tissues. Since activated PPARγ is able to inhibit the expression of iNOS and the generation of iNOS is particularly associated with the inflammatory and environmental factors of lung cancer risk, this discrepant expression pattern may be associated with the pathogenesis of NSCLC.

Relationship between Apoptosis and Fas/FasL Expression in Non-small Cell Lung Carcinoma

To study Fas/FasL expression in non-small cell lung carcinoma(NSCLC)and its association with apoptosis and clinicopathological characteristics.Methods Fas and FasL protein expression and apoptotic cells in situ in 45 NSCLC and 38 paracancerous tissues were detected using immunohistochemical staining and terminal deoxynucleotidyl transferase mediated nick end labeling(TUNEL)technique. Results The AI in NSCLC was significantly lower than that in paracancerous tissues,and the AI of NSCLC was closely related to lymph node metastasis and TNM stages,but no close relation was observed among histological types,cell differentation and sex,age of patients.The AI in the Fas positive group was higher than that in the Fas negtive group.Conclusion The abnormal regulation of apoptosis may play an important role in the pathogenesis of NSCLC.