COX-2/EGFR expression and survival among women with adenocarcinoma of the lung

[Survival and epidemiological characteristics of women with lung cancer in Reunion]

Lung cancer is a common disease throughout the world, representing the main cause of death from cancer. Its incidence in the female population is increasing. In metropolitan France and Reunion Island, the main risk factor remains tobacco smoking. However, environmental, genetic and hormonal factors appear to play a role in bronchial oncogenesis and the survival of affected women is better than that of men. We studied retrospectively the survival and characteristics of a cohort in Reunion Island, diagnosed with lung cancer between January 2017 and December 2018. In total, 501 patients were included over the period including 166 women. The median overall survival was 23 months in women against 11 months in men (P<0.0005). Male sex has been identified as a poor prognostic factor for overall survival (HR=1.338; 95% CI=1.007-1.778) regardless of disease stage. Women smoked less often than men 85.4% of them had adenocarcinoma, with more EGFR mutations than men, and their environmental exposures were lower. The female population of Reunion Island in our study had better overall survival than the men. Smoking status, environmental exposures, histological and molecular characteristics varied by sex.

Cyclooxygenase-2 expression in colorectal carcinoma, adenomatous polyps and non-tumour bearing margins of resection tissues in a cohort of black Africans

Background

Emerging data suggest a negative role of cyclooxygenase-2 (COX-2) in colorectal carcinomas (CRC). Investigating this in developing communities such as ours helps to contribute to existing understanding of these lesions.

Methods and findings

Formalin-fixed paraffin-embedded CRC colectomy tissues and their corresponding non-tumour margins of resected tissues were sectioned and stained with COX-2 antibody. Adenomatous polyp tissues from non-cancer bearing individuals were similarly processed for comparison. COX-2 expression was scored for percentage (< 5% = 0; 6%-25% = 1; 26%-50% = 2; 51%-75% = 3; 76%-100% = 4) and intensity (no staining = 0; yellow = 2; yellowish-brown = 3, brown = 4). Total immunoscore (percentage + intensity score) ≥ 2 was regarded as positive COX-2 expression. Outcome was statistically evaluated with clinicopathological data to determine COX-2 expression-associated and predictor variables. Ninety-five CRC cases and 27 matched non-tumour tissues as well as 31 adenomatous polyps met the inclusion criteria. Individuals with CRC had a mean age of 56.1 ± 12.6 years while those with adenomatous polyps had a median age of 65 years (range 43–88). COX-2 was differentially overexpressed in CRCs (69/95; 72.6%) and in adenomatous polyps (17/31; 54.8%) than in non-tumour tissues 5/27 (18.5%); p < 0.001). The difference in COX-2 expression between CRC and polyps was non-significant (p > 0.065). Tumour grade, advanced pT-stage, tumour-infiltrating lymphocytes, and dirty necrosis were also significantly associated with COX-2 expression (p < 0.035; 0.043, 0.035 and 0.004, respectively). Only dirty necrosis and Crohns-like lymphocytic aggregates predicted COX-2 expression (p < 0.05).

Conclusion

This study showed a progressive increase in COX-2 expression from normal to adenomatous polyp and CRC tissues, this being associated with poorer prognostic indicators. Although COX-2 appears early in CRC, it may play a secondary role in promoting tumour growth and invasiveness.

Primary resistance to crizotinib treatment in a non-small cell lung cancer patient with an EML4-ALK rearrangement: a case report

Crizotinib, a small molecular tyrosine kinase inhibitor, manifests dramatic responses in patients with non-small cell lung cancer with echinoderm microtubule associated protein like 4-anaplastic lymphoma kinase (EML4-ALK) rearrangements. ALK gene point mutation is the primary mechanism of acquired crizotinib resistance; however, the intrinsic mechanism is not fully understood. Here, we report a patient with a low mutant allele fraction (MAF) of EML4-ALK rearrangement, who experienced primary resistance to crizotinib treatment. The patient was a 66-year-old Chinese man, who had a history of metastatic lung cancer and was treated with first- and third-generation epidermal growth factor receptor tyrosine kinase inhibitors (EGFR TKIs). After 14 months of osimertinib treatment, his disease progressed, and next-generation sequencing was performed from a liquid biopsy of the patient’s blood. An EML4-ALK rearrangement was found and crizotinib was administered. The patient’s lung lesions continued to progress after one month of crizotinib treatment, and pemetrexed-bevacizumab was initiated. After two cycles of chemotherapy, the metastatic cancers shrunk, and the patient maintained stable disease at his last follow-up. EML4-ALK rearrangements can happen in patients with EGFR-positive NSCLC, after acquired resistance to EGFR TKI treatment. The EGFR T790M and C797G mutations occur in cis is a critical mechanism of resistance to osimertinib therapy. The MAF of EML4-ALK rearrangements in cancer cells might be a predictive factor for crizotinib treatment.

Cyclooxygenase-2 is associated with malignant phenotypes in human lung cancer

The objective of the present study was to investigate whether cyclooxygenase-2 (COX-2) is associated with malignancy, and to investigate its molecular mechanisms in human lung cancer tumor malignancy. The present study used RNA interference (RNAi) methodology and celecoxib, a COX-2 inhibitor, to investigate the effect of COX-2 knockdown on the proliferation and invasion abilities of lung cancer cells and the molecular mechanisms involved. Human lung adenocarcinoma A549-si10 and LTEP-A2 cells transfected with a specific small interfering RNA (A549-si10 and LTEP-A2-si10, respectively) grew more slowly compared with parental cell lines and cells transfected with pU6. The colony formation of A549-si10 and LTEP-A2-si10 cells was also reduced. In addition, A549-si10 and LTEP-A2-si10 cells were characterized by decreased metastatic and invasive abilities. The proliferation and invasive potential of parental A549 and LTEP-A2 cells was inhibited following treatment with celecoxib. In vivo, a COX-2 knockdown resulted in a decrease of proliferation and reduction of vascular endothelial growth factor (VEGF), matrix metalloproteinase-2 (MMP-2) and endothelial growth factor receptor (EGFR) expression in A549 xenografts. In conclusion, the present study revealed that COX-2 plays a extremely important role in tumor growth, infiltration and metastasis via the regulation of VEGF, MMP-2 and EGRF expression. Therefore, COX-2 is a potential therapeutic target for lung cancer.

Gene Expression of the EGF System-a Prognostic Model in Non-Small Cell Lung Cancer Patients Without Activating EGFR Mutations

OBJECTIVES: Contradicting results have been demonstrated for the expression of the epidermal growth factor receptor (EGFR) as a prognostic marker in non–small cell lung cancer (NSCLC). The complexity of the EGF system with four interacting receptors and more than a dozen activating ligands is a likely explanation. The aim of this study is to demonstrate that the combined network of receptors and ligands from the EGF system is a prognostic marker. MATERIAL AND METHODS: Gene expression of the receptors EGFR, HER2, HER3, HER4, and the ligands AREG, HB-EGF, EPI, TGF-α, and EGF was measured by quantitative polymerase chain reaction in tumor samples from 100 NSCLC patients without EGFR activating mutations. Results were dichotomized into high or low levels of target expression. Coexpression of the ligands and receptors was observed, and a score was developed based on the summed effect of receptors and ligands. Akaike’s information criteria selected the optimal score. Results were correlated with age, sex, stage, histology, performance status, and overall survival. RESULTS: Patients were randomly split 1:1 to create test and validation cohorts. In multivariate analyses, the only individual prognostic marker was EPI (hazard ratio [HR] 0.38 [0.20-0.72], P = .003). The optimal score in the test cohort was validated as a marker of inferior survival in the validation cohort and by bootstrapping. Multivariate analysis confirmed the combined score as a prognostic marker of inferior survival (HR 3.75 [2.17-6.47], P < .00001). CONCLUSION: Our study has developed a model that takes the complexity of the EGF system into account and shows that this model is a strong prognostic marker in NSCLC patients.

High expression of cellular retinol binding protein-1 in lung adenocarcinoma is associated with poor prognosis

Purpose

Adenocarcinoma, the most common non-small cell lung cancer is a leading cause of death worldwide, with a low overall survival (OS) despite increasing attempts to achieve an early diagnosis and accomplish surgical and multimodality treatment strategies. Cellular retinol binding protein-1 (CRBP-1) regulates retinol bioavailability and cell differentiation, but its role in lung cancerogenesis remains uncertain.

Experimental design

CRBP-1 expression, clinical outcome and other prognostic factors were investigated in 167 lung adenocarcinoma patients. CRBP-1 expression was evaluated by immunohistochemistry of tissue microarray sections, gene copy number analysis and tumor methylation specific PCR. Effects of CRBP-1 expression on proliferation/apoptosis gene array, protein and transcripts were investigated in transfected A549 lung adenocarcinoma cells.

Results

CRBP-1^High expression was observed in 62.3% of adenocarcinomas and correlated with increased tumor grade and reduced OS as an independent prognostic factor. CRBP-1 gene copy gain also associated with tumor CRBP-1^High status and dedifferentiation. CRBP-1-transfected (CRBP-1⁺) A549 grew more than CRBP-1⁻ A549 cells. At >1μM concentrations, all trans-retinoic acid and retinol reduced viability more in CRBP-1⁺ than in CRBP-1⁻ A549 cells. CRBP-1⁺ A549 cells showed up-regulated RARα/ RXRα and proliferative and transcriptional genes including pAkt, pEGFR, pErk1/2, creb1 and c-jun, whereas RARβ and p53 were strongly down-regulated; pAkt/pErk/ pEGFR inhibitors counteracted proliferative advantage and increased RARα/RXRα, c-jun and CD44 expression in CRBP-1⁺ A549 cells.

Conclusion

CRBP-1^High expression in lung adenocarcinoma correlated with increased tumor grade and reduced OS, likely through increased Akt/Erk/EGFR-mediated cell proliferation and differentiation. CRBP-1^High expression can be considered an additional marker of poor prognosis in lung adenocarcinoma patients.

Epigenetic profiling of gallbladder cancer and gall stone diseases: Evaluation of role of tumour associated genes

BACKGROUND

As on today, the global mortality rate of gallbladder cancer is still very high. Both genetic and epigenetic alterations play pivotal roles in the development of cancer. We selected seven tumour associated genes, implicated in other cancers, to assess their methylation status in gallbladder cancer and gallstone diseases.

AIM OF STUDY

To study the promoter methylation of certain tumour associated genes in the molecular pathogenesis of gallbladder cancer and gall stone diseases.

MATERIALS AND METHODS

Methylation specific PCR for seven tumour associated genes, viz., MASPIN, 14-3-3 sigma gene, THBS1, FLNC, HLTF, COX-2 and SOCS1, was performed in 50 gallbladder cancer (GBC), 30 gall stone diseases (GSD) and their respective adjacent control tissues. Semi-quantitative PCR and immunohistochemistry was carried out to check the expression level. Student's t-test was carried out to compare the differences in the methylation and expression patterns between cases and control tissues.

RESULTS

We observed methylation of CpG islands in seven of the studied markers, but, the frequency of methylation was found varying among different samples. Of them, 14-33 sigma showed methylation in 45 GBC (90%; p=0.0001) and 25 GSD (86.66%; p=0.001), MASPIN in 35 GBC (70%; p=0.0008) and 18 GSD (51.43%; p=0.040), FLNC in 16 GBC (32%; p=0.0044) and 9 GSD (25.71%; p=ns), THBS1 in 26 GBC (52%; p=0.0009) and 10 GSD (28.57%; p=0.0505), HLTF in 8 GBC (16%; p=ns) and 2 GSD (5.71%; p=ns), COX2 in 10 GBC (20%; p=ns) and 6 GSD (17.14%; p=ns) and SOCS-1 in 3 GBC samples only (6%; p=ns), but not in GSD. Semi-quantitative PCR revealed down regulation in MASPIN, 14-3-3 sigma, THBS1, HLTF, COX2 and SOCS1 in advanced gallbladder cases. Immunohistochemistry further confirmed the down-regulation of SOCS1 in GBC.

CONCLUSION

The present study infers that accumulation of epigenetic alterations increases poor prognosis of GBC patients. Out of seven genes, MASPIN and THBS1 play key epigenetic role in GBC, but not in GSD. The reason for downregulation of SOCS1 only in GBC, and unaltered expression of 14-3-3 sigma protein in all the GBC and GSD tissue samples is not clear. Further investigation on the expression pattern of these genes in GBC cell lines may elucidate their likely functional role in in association with gallbladder cancer.

Prognostic impact of COX-2 in non-small cell lung cancer: a comprehensive compartment-specific evaluation of tumor and stromal cell expression

Cyclooxygenase-2 (COX-2) is an enzyme that has been extensively investigated as a prognostic marker in cancer. In non-small cell lung cancer (NSCLC) previous results regarding the prognostic impact of COX-2 expression are inconsistent. Therefore we evaluated the association between transcript levels and overall survival in nine publicly available gene expression data sets (total n = 1337) and determined in situ compartment-specific tumor and stromal cell protein expression in two independent cohorts (n = 616). Gene expression did not show any correlation with clinical parameters or with overall survival. Protein expression in tumor and stromal cells did not correlate with any clinical parameter or with overall survival in one of the analyzed cohorts, while a significant association of high stromal expression with longer survival was observed in both univariate and multivariate analysis in the other cohort. Stromal expression of COX-2 has not been separately evaluated in NSCLC previously and may be a subject of further investigation, whereas the presented findings from this comprehensive compartment specific evaluation clearly reject the hypothesis of COX-2 tumor cell expression having a prognostic value in NSCLC.

COX-2 overexpression and -8473 T/C polymorphism in 3' UTR in non-small cell lung cancer

A new class of compounds targeting cyclooxygenase 2 (COX-2) together with other different clinically used therapeutic strategies has recently shown a promise for the chemoprevention of several solid tumors including lung cancer. The aim was to study the possible role of COX-2 -8473 T/C NP and its expression in the pathogenesis of non-small cell lung cancer. One hundred ninety non-small cell lung cancer (NSCLC) patients and 200 healthy age-, sex-, and smoking-matched controls were used for polymorphic analysis, and 48 histopathologically confirmed NSCLC patients were analyzed for COX-2 messenger RNA (mRNA) and protein expression. Our results showed that the frequencies of variant genotypes 8473 CT/CC were significantly less common in the cases (30.0%) than in the controls (36%), suggesting that the 8473 C variant allele is related with lower susceptibility in NSCLC (OR = 0.79, 95% CI 0.54-1.4). However, the frequency of COX-2 -8473 TC and CC genotypes were significantly associated with age in NSCLC (P = 0.02). Quantitative real-time expression analysis showed a significant increase in the COX-2 mRNA in tumor tissues as compared to their adjacent normal tissues [delta cycle threshold (ΔCT) = 9.25 ± 4.67 vs 5.63 ± 3.85, P = 0.0001]. Multivariate logistic regression analyses revealed that the COX-2 expression was associated significantly with age (P = 0.044). Also, an increasing trend was observed in stages I and II and in female patients compared to stages III and IV and male patients, respectively, but no statistical significance was observed. However, COX-2 mRNA expression shown no association with the -8473 C variant allele. Our findings indicate that the COX-2 T8473C polymorphism may contribute to NSCLC cancer susceptibility in the Kashmiri population, while our expression analysis revealed a significant increase of COX-2 in tumor tissues as compared to their adjacent normal tissues, suggesting that it could become an important therapeutic marker in NSCLC in the future.

Women and lung cancer: what is new?

In the last 20 years, there has been an increased focus on gender differences in health and disease. The earliest studies of lung cancer enrolled mainly men, as the incidence of lung cancer among women was exceedingly low. As social patterns changed around World War II and women began to smoke more, the epidemiology of lung cancer has changed. The higher percentage of lung cancer in nonsmoking women as compared with nonsmoking men suggests that lung cancer behaves differently in women. Studies of lung cancer in women indicate that there are differences in risk factors, histology, pathophysiology, treatment outcomes, and prognosis as compared with men. The purpose of this review is to provide a concise summary of the literature on lung cancer as it pertains to women, with an emphasis on new areas of research and treatment options.

Cox-2 in non-small cell lung cancer: a meta-analysis

BACKGROUND

We investigated the prognostic value of cyclooxygenase-2 (COX-2) for survival of patients with non-small cell lung cancer (NSCLC).

METHODS

We performed a meta-analysis of literature to aggregate the available survival results, using studies published in English until June 2012. Eligible studies dealt with COX-2 protein assessment in NSCLC patients on primary lesions and reported survival data according to COX-2 expression.

RESULTS

Nineteen trials, comprising 2651 patients, provided sufficient information for the meta-analysis. Overall combined hazard ratio (HR) was 1.86 (95% CI: 1.58-2.20); it was calculated using a random-effects model, and associates high COX-2 expression with poor survival in all NSCLC patients. Aggregate survival data showed poor survival for patients with adenocarcinoma (ADC), squamous cell cancer (SCC) and Stage I NSCLC with high COX-2 expression, at 2.00 (95% CI: 1.38-2.88), 2.29 (95% CI: 1.58-3.33) and 1.95 (95% CI: 1.31-2.91) respectively.

CONCLUSIONS

Our meta-analysis shows that the COX-2 expression status is an independent prognostic factor in NSCLC, and this tendency applies to SCC, ADC and stage I NSCLC.

Concomitant overexpression of EGFR and CXCR4 is associated with worse prognosis in a new molecular subtype of non-small cell lung cancer

Although the relationships between CXCR4 and EGFR expression and survival in non‑small cell lung cancer (NSCLC) have been studied independently, dual CXCR4/EGFR tumor status and its relationship with survival has not been previously investigated. In the present study, we examined the relationship between CXCR4 expression, EGFR expression and dual CXCR4/EGFR expression and survival in patients with NSCLC (n=125) using immunohistochemical techniques. Overall survival was estimated using Kaplan-Meier and Cox proportional hazards models adjusting for patient age, tumor stage and type of treatments. Patients with CXCR4-positive tumors were significantly associated with distant metastasis and tended to have poorer prognosis compared to patients with CXCR4-negative tumors (HR=2.172, 95% CI=1.229‑3.839). No significant association between EGFR expression and survival was found; however co-expression of CXCR4/EGFR was a significant prognostic factor of worse overall survival (HR=2.741, 95% CI=1.330‑5.741). Furthermore, we showed that EGF enhanced the expression of CXCR4 in NSCLC cells through the PI-3K pathway, and treatment of NSCLC cells with EGFR phosphorylation inhibitor, AG1478, resulted in downregulation of the expression of CXCR4. These results suggest an important interaction between CXCR4 and EGFR intra-cellular pathways that may activate signals of tumor progression and may provide a valid explanation for the poor overall survival rate of patients whose co-expression of CXCR4 and EGFR is detected in tissue sections. Based on EGFR and CXCR4 expression, new molecular subtypes of NSCLC established in the present study can be used for customization of NSCLC treatment. Our results also showed that EGFR and CXCR4 are potential therapeutic targets for NSCLC and that simultaneous inhibition of EGFR and CXCR4 in NSCLC patients with concomitant expression of both CXCR4 and EGFR may be an effective treatment strategy.

Cyclooxygenase-2 expression in lung cancer cells evaluated by immunocytochemistry

Cyclooxygenase-2 (COX-2) expression may be a prognostic factor in lung cancer. In previous studies, COX-2 expression has almost exclusively been evaluated with immunohistochemical methods performed on histology sections of tissue biopsies. However, in clinical practice, lung cancer is often diagnosed with cytological techniques only. We present methodology and results from analysis of COX-2 expression with immunochemistry on cytological material in 53 patients with lung cancer. Preparation and staining with the method established at our laboratory were easy to perform and resulted in good quality slides. The percentage COX-2-stained cells and the intensity of staining varied widely between and within the different cases. The proportion of positively stained tumor cells was as follows: <1% in 20 patients, 1-10% in 7 patients, 11-50% in 17 patients, and more than 50% in 9 patients. In 17 cases, groups of cells with different intensity of COX-2 staining were found in the same slide. In conclusion, immunocytochemical analysis of COX-2 expression is technically easy to perform with routine diagnostic procedures. There is a great variation in the proportion of COX-2-positive cells among patients and in the intensity of staining among individual cells in many single cases.

EGFR and COX-2 protein expression in non-small cell lung cancer and the correlation with clinical features

Background

To evaluate the expression of EGFR and COX-2 and their correlation with prognosis in NSCLC

Methods

The paraffin embedded tumor samples of 50 NSCLC patients receiving radical resection were analyzed immunohistochemically for EGFR and COX-2 expression and their prognostic values were explored.

Results

The positive rate of EGFR protein in NSCLC tumor cells was 46%, which was significantly higher than its expression in normal lung (p = 0.0234) and paracancerous tissues (p = 0.020). EGFR expression was significantly higher in nodal positive than in nodal negative patients (p = 0.04). The mean survival time for EGFR positive patients (31 months) was significantly lower than that for patients with EGFR negative expression (48 months) (p = 0.008,). In patients receiving post-operation thoracic irradiation, the mean survival time for EGFR positive patients was significantly lower than that for patients without EGFR positive expression (25 vs. 48 months, P = 0.004). The positive rate of COX-2 protein expression in NSCLC tumor cells was 90%, which was significantly higher than that in normal tissue(p = 0.00) and paracancerous tissue (p = 0.00). There was no correlation between COX-2 expression and patient survival, and no correlation between COX-2 and EGFR protein expression (P = 0.555).

Conclusions

COX-2 and EGFR are over-expressed in NSCLC. EGFR is an independent prognostic factor and a predictive factor for radiotherapy response in NSCLC.

Expressions of COX-2 and VEGF-C in gastric cancer: correlations with lymphangiogenesis and prognostic implications

Background

Cyclooxygenase-2 (COX-2) has recently been considered to promote lymphangiogenesis by up-regulating vascular endothelial growth factor-C (VEGF-C) in breast and lung cancer. However, the impact of COX-2 on lymphangiogenesis of gastric cancer remains unclear. This study aims to test the expression of COX-2 and VEGF-C in human gastric cancer, and to analyze the correlation with lymphatic vessel density (LVD), clinicopathologic features and survival prognosis.

Methods

Using immunohistochemistry, COX-2, VEGF-C and level of LVD were analyzed in 56 R0-resected primary gastric adenocarcinomas, while paracancerous normal mucosal tissues were also collected as control from 25 concurrent patients. The relationships among COX-2 and VEGF-C expression, LVD, and clinicopathologic parameters were analyzed. The correlations of COX-2, VEGF-C and level of LVD with patient prognosis were also evaluated by univariate tests and multivariate Cox regression.

Results

The expression rates of COX-2 and VEGF-C were 69.64% and 55.36%, respectively, in gastric carcinoma. Peritumoral LVD was significantly higher than that in both normal and intratumoral tissue (P < 0.05). It was significantly correlated with lymph node metastasis and invasion depth (P = 0.003, P = 0.05). VEGF-C was significantly associated with peritumoral LVD (r = 0.308, P = 0.021). However, COX-2 was not correlated with VEGF-C (r = 0.110, P = 0.419) or LVD (r = 0.042, P = 0.758). Univariate analysis showed that survival time was impaired by higher COX-2 expression and higher peritumoral LVD. Multivariate survival analysis showed that age, COX-2 expression and peritumoral LVD were independent prognostic factors.

Conclusions

Although COX-2 expression was associated with survival time, it was not correlated with VEGF-C and peritumoral LVD. Our data did not show that overexpression of COX-2 promotes tumor lymphangiogenesis through an up-regulation of VEGF-C expression in gastric carcinoma. Age, COX-2 and peritumoral LVD were independent prognostic factors for human gastric carcinoma.

Cigarette smoke and increased COX-2 and survivin levels in exhaled breath condensate of lung cancer patients: how hot is the link?

One of the most current intriguing hypotheses on lung cancerogenesis envisages a role for inflammation as a possible trigger of both epithelial-mesenchymal transition and cancer development. Cigarette smoke has been suggested to be the main factor underlying the inflammation of the airways described in lung cancer patients. Cycloxygenase and survivin, a COX-2 dependent factor of apoptosis resistance, seem to play a key role in this regard.

PURPOSE

The aim of this study was to study COX-2 and survivin in the airways of lung cancer patients and in those of a group of smokers in a view to increasing our understanding of the link between smoking, airway inflammation and lung cancer.

PATIENTS AND METHODS

70 NSCLC patients (28 smokers, 26 ex-smokers and 16 non-smokers) and 30 healthy subjects (20 smokers and 10 non-smokers) were enrolled in the study. Both COX-2 and survivin concentrations were measured in the exhaled breath condensates of all the subjects under study using EIA kits.

RESULTS

Higher levels of exhaled survivin and COX-2 were found in NSCLC patients compared to healthy smokers and non-smokers. These levels were observed to be significantly elevated in smokers (patients with lung cancer and healthy) and ex-smokers compared to non-smokers and exhibited a positive correlation with the number of cigarettes smoked expressed as pack/year. A correlation was also found between exhaled COX-2 and survivin and the progression of cancer.

CONCLUSIONS

We support the hypothesis that cigarette smoke be strongly connected to the inflammation of the airways observed in lung cancer patients. On the basis of the results obtained the use of exhaled breath condensate COX-2 and survivin levels could be suggested as two potential markers within an early non-invasive screening of populations of smokers at risk of lung cancer.

Cyclooxygenase-2 is a novel transcriptional target of the nuclear EGFR-STAT3 and EGFRvIII-STAT3 signaling axes

Emerging evidence indicates a novel mode of epidermal growth factor receptor (EGFR) signaling, notably, one involves EGFR nuclear translocalization and subsequent gene activation. To date, however, the significance of the nuclear EGFR pathway in glioblastoma (GBM) is unknown. Here, we report that EGFR and its constitutively activated variant EGFRvIII undergo nuclear translocalization in GBM cells, in which the former event requires EGF stimulation and the latter is constitutive. To gain insights into the effect of nuclear EGFR on gene expression in GBM, we created isogenic GBM cell lines, namely, U87MG-vector, U87MG-EGFR, and U87MG-EGFRdNLS that, respectively, express the control vector, EGFR, and nuclear entry-defective EGFR with a deletion of the nuclear localization signal (NLS). Microarray analysis shows that 19 genes, including cyclooxygenase-2 (COX-2), to be activated in U87MG-EGFR cells but not in U87MG-EGFRdNLS and U87MG-vector cells. Subsequent validation studies indicate that COX-2 gene is expressed at higher levels in cells with EGFR and EGFRvIII than those with EGFRdNLS and EGFRvIIIdNLS. Nuclear EGFR and its transcriptional cofactor signal transducer and activator of transcription 3 (STAT3) associate with the COX-2 promoter. Increased expression of EGFR/EGFRvIII and activated STAT3 leads to the synergistic activation of the COX-2 promoter. Promoter mutational analysis identified a proximal STAT3-binding site that is required for EGFR/EGFRvIII-STAT3-mediated COX-2 gene activation. In GBM tumors, an association exists between levels of COX-2, EGFR/EGFRvIII, and activated STAT3. Together, these findings indicate the existence of the nuclear EGFR/EGFRvIII signaling pathway in GBM and its functional interaction with STAT3 to activate COX-2 gene expression, thus linking EGFR-STAT3 and EGFRvIII-STAT3 signaling axes to proinflammatory COX-2 mediated pathway.