Theodora Kerenidi

Foxp3 expression in human cancer cells

ObjectiveTranscription factor forkhead box protein 3 (Foxp3) specifically characterizes the thymically derived naturally occurring regulatory T cells (Tregs). Limited evidence indicates that it is also expressed, albeit to a lesser extent, in tissues other than thymus and spleen, while, very recently, it was shown that Foxp3 is expressed by pancreatic carcinoma. This study was scheduled to investigate whether expression of Foxp3 transcripts and mature protein occurs constitutively in various tumor types.Materials and methodsTwenty five tumor cell lines of different tissue origins (lung cancer, colon cancer, breast cancer, melanoma, erythroid leukemia, acute T-cell leukemia) were studied. Detection of Foxp3 mRNA was performed using both conventional RT-PCR and quantitative real-time PCR while protein expression was assessed by immunocytochemistry and flow cytometry, using different antibody clones.ResultsFoxp3 mRNA as well as Foxp3 protein was detected in all tumor cell lines, albeit in variable levels, not related to the tissue of origin. This expression correlated with the expression levels of IL-10 and TGFb1.ConclusionWe offer evidence that Foxp3 expression, characterizes tumor cells of various tissue origins. The biological significance of these findings warrants further investigation in the context of tumor immune escape, and especially under the light of current anti-cancer efforts interfering with Foxp3 expression.

VEGF, TNF-α and 8-isoprostane levels in exhaled breath condensate and serum of patients with lung cancer

The aim of the present study was to evaluate the levels of VEGF, 8-isoprostane and TNF-alpha in EBC and serum of patients with primary lung cancer prior to the initiation of any treatment, in order to evaluate their possible diagnostic role. Furthermore, associations between VEGF, 8-isoprostane and TNF-alpha levels in EBC and serum with clinicopathologic factors were investigated. We enrolled 30 patients with lung cancer (mean age 65.2+/-10.5 years) and 15 age and gender-matched healthy smokers as controls. Serum and EBC were collected before any treatment. TNF-alpha, VEGF and 8-isoprostane levels in EBC and serum were analyzed by an immunoenzymatic method (ELISA). A statistically significant difference was observed between lung cancer patients and the control group regarding the values of TNF-alpha, both in EBC (52.9+/-5.0 pg/ml vs. 19.4+/-3.9 pg/ml, p<0.0001) and serum (44.5+/-6.3 pg/ml vs. 22.2+/-4.3 pg/ml, p=0.035). Moreover, EBC VEGF levels were higher in patients with T3-T4 tumor stage compared to T1-T2 (9.3+/-2.8 pg/ml vs. 2.3+/-0.7pg/ml, p=0.047). A statistically significant correlation was also observed between serum and EBC values of VEGF (r=0.52, p=0.019). In addition, serum levels of VEGF were higher in lung cancer patients than in controls (369.3+/-55.1 pg/ml vs. 180.5+/-14.7 pg/ml, p=0.046). VEGF serum levels were also found higher in patients with advanced stage of disease (IIIB-IV) and distant nodal metastasis (N2-N3). No differences were observed in 8-isoprostane in EBC between lung cancer patients and controls. In contrast, serum 8-isoprostane levels were higher in lung cancer patients compared to controls (24.9+/-3.6 pg/ml vs. 12.9+/-1.6 pg/ml, p=0.027) and were higher in patients with advanced disease. All three biomarkers presented acceptable reproducibility in the EBC on two consecutive days. In conclusion, we have shown that TNF-alpha, VEGF and 8-isoprostane are elevated in the serum of lung cancer patients and increased serum VEGF and 8-isoprostane levels are related to advanced disease. In EBC, increased TNF-alpha levels were observed in lung cancer patients, whereas increased VEGF levels were observed in advanced T-stage. Further longitudinal studies are warranted for the evaluation of the prognostic role of these biomarkers in lung cancer.

Indoleamine 2,3-dioxygenase (IDO) expression in lung cancer

BACKGROUND: The expression of indoleamine 2,3-dioxygenase (IDO) by tumor cells has been considered as a major tumor immune escape mechanism. The aim of this study was to investigate the expression of IDO in lung cancer cell lines as well as in surgically resected lung cancer specimens comparing the latter, to the expression in autologous sam-ples from the corresponding non malignant lung tissue. Correlations of IDO expression with clinicopathological parameters of the disease were performed. METHODS: Nine human lung cancer cell lines and 28 patients with various types of primary lung cancer were enrolled in the study. IDO expression was determined by quantitative real-time PCR using a sample of lung hamartoma as reference. RESULTS: IDO expression was detected in all but 3 patients’ tumor samples, in all but 4 autologous non malignant lung tissues and in 3 out of the 9 cell lines that were exam-ined. The relative expression of IDO in lung cancer cell lines (4.7±11.1) was significantly lower than that of all patients’ tumor samples (p=0.006) as well as than that of the autologous non affected lung tissues (p=0.027). No statistically significant differences were noted between ADC and SCC regarding either the tumor samples or the autologous non affected samples. No significant correlations between IDO expression and clinico-pathological parameters were found. CONCLUSION: Direct evidence is provided demonstrating that IDO mRNA can be constitutively expressed by lung cancer cells. The higher IDO expression observed in patients’ samples can be attributed to the production of the enzyme by other cells recruited in the tumor microenvironment and the peritumoral lung area and/or to its induction by soluble factors of tumor origin.

Serum vascular endothelial growth factor is related to systemic oxidative stress in patients with lung cancer

Vascular endothelial growth factor (VEGF) is known to play crucial role in tumour angiogenesis. It is demonstrated that VEGF can be up-regulated by oxidative stress. The aim of this study was to determine the serum VEGF levels and oxidative stress in patients with primary lung cancer and to investigate their association with clinicopathologic factors. We measured serum VEGF levels and oxidative stress in 63 patients (age 63.02+/-1.12 S.E.M.) with primary lung cancer before any treatment (39 NSCLC and 24 SCLC; 6 patients stage I, 3 stage II, 25 stage III and 29 stage IV) and 25 normal subjects. The serum VEGF levels were measured with enzyme linked immunosorbent assay. Serum oxidative stress levels were detected by a commercially available assay (D-ROMs test, Diacron, Grossetto, Italy). The levels of oxidative stress in patients were higher than those in normal subjects (555.3+/-30.35 UCarr vs. 360.1+/-17.46 UCarr). Additionally, a significant difference was found in serum VEGF levels between lung cancer patients and healthy control subjects (428.1+/-38.42pg/ml vs. 298.8+/-19.89pg/ml, respectively, p=0.040). Interestingly, serum oxidative stress presented a significant correlation with serum VEGF levels in patients with lung cancer (r=0.542, p=0.002). Serum VEGF levels were significantly associated with the clinical staging (N-stage) of the patients (p=0.023), performance status (p=0.004) and age (p=0.004). In conclusion, oxidative stress and VEGF are significantly increased in patients with primary lung cancer. The correlation between them might implicate new aspects of the mechanisms controlling tumour angiogenesis and may present clinical interest in the future. Further studies are warranted to evaluate the role of oxidative stress and VEGF as possible biomarkers for the diagnosis and follow-up of patients with lung cancer.

Baseline levels of CD8+ T cells against survivin and survivin-2B in the blood of lung cancer patients and cancer-free individuals

Survivin and its variant survivin-2B have been considered as potential candidates for cancer immunotherapy. The magnitude however of spontaneously occurring CD8(+) T cells circulating precursor CTLs (pCTL), has never been evaluated. We set out to measure in 20 patients with lung carcinomas and 5 aged matched healthy male individuals (expressing HLA-A2 and/or -A24), the frequency of pCTLs specific for two naturally processed and presented peptides of survivin (LTLGEFLKL presented by HLA-A2) and survivin-2B (AYACNTSTL presented by HLA-A24) since these peptides are the only ones used in immunotherapeutic trials. The frequency of peptide-specific pCTLs was estimated using a sensitive method that combines HLA-multimer flow cytometric technology with a previous step of in vitro amplification under limiting dilution conditions. Anti-survivin or anti-survivin-2B specific CTL clones were not detected in 17 out of the 21 tested patients, and in none of the healthy individuals. In a number of peripheral blood mononuclear cell microcultures of the remaining 4 patients, diffuse clusters stained weakly by the HLA-multimers were observed which were not amplified after further stimulation and, therefore, they were finally considered as negative. The significance of the levels of spontaneously occurring CTL-responses against survivin and survivin-2B peptides, in cancer patients and cancer-free subjects, remains to be elucidated and it would be interesting to be considered in relation to the clinical efficacy of anti-cancer vaccination protocols.

Co-expression patterns of tumor-associated antigen genes by non-small cell lung carcinomas: Implications for immunotherapy

Background: Polyvalent vaccination represents a recent attempt to improve the effectiveness of lung cancer immunotherapy. This study aimed to investigate whether a gene expression pattern of tumor-associated antigens (TAA) would exist indicating that their use will be most appropriate for the polyvalent vaccination of Caucasian non-small cell lung carcinoma (NSCLC) patients. We examined the concomitant expression of genes belonging to different TAA families for which expression frequencies either have never been detected in NSCLC or vary widely in the literature.Methods: Tumor material from 23 patients with NSCLC (12 adenocarcinomas, 8 squamous cell carcinomas, 3 bronchiolo - carcinomas) was examined. mRNA transcripts were detected for 5 genes of the survivin family, 5 MAGE-A genes as well as the genes of human telomerase reverse transcriptase (hTERT) and p53, by the use of quantitative real-time reverse-transcription polymerase chain reaction (RT-PCR) or semi-quantitative RT-PCR. Results: 15/23 (65%) and 8/23 (35%) tumor samples were found expressing 6-11 and 2-5 out of the 12 examined TAAs, respectively, at levels >1% of the testis reference sample. The most prevalent TAA patterns observed were those of survivin standard (survivin-std)/survivin-2B expressed by 22/23 (95.5%) tumor samples and of survivin-std/survivin-2B/hTERT expressed by 19/23 (82.5%) tumor samples. The expression levels of the survivin-std gene strongly positively correlated to those of the survivin-2B (p=0.001) and the hTERT genes (p=0.031). The number of concomitantly expressed genes was found to be positively correlated to the age of the patients (p=0.001) and the tumor size (p=0.048).Conclusion: This study provides evidence that, in Caucasian patients with NSCLC, highly prevalent expression patterns of TAA genes, predominantly of overexpressed TAAs, do exist. This result implies that the combined use of these TAA could help in designing more effective NSCLC immunotherapeutic protocols.

Anti-survivin antibody responses in lung cancer

Existing evidence regarding spontaneous anti-survivin humoral responses in lung cancer is inconclusive. Moreover, despite that cancer cell death elicited by radiotherapy and some chemotherapeutic agents seems to be immunogenic, information about the possible effect of treatment on these responses, is lacking. Serum samples from 33 small cell lung cancer (SCLC) and 117 non-small cell lung cancer (NSCLC) patients upon diagnosis, and from 100 controls, were tested by ELISA for anti-survivin antibodies. Cutoff was set to the mean+2SD of controls. 7.7% of NSCLC, none of the SCLC patients and 2% of the controls appeared with elevated antibody levels (OR 3.6, 95% CI 0.7-17.3 for NSCLC, OR 0.6, 95% CI 0.03-12.6 for SCLC). Measurement of antibodies in 76 NSCLC patients post therapies and during their follow-up, revealed that in 12 NSCLC patients the antibody levels increased up to 2-38 times, and in seven others, they decreased by 2-8 times. No significant correlation was uncovered between either the antibody levels upon diagnosis or their changes post therapies and during follow-up, and any clinicopathological parameter, their response to therapy and survival. Survivin does not induce considerable humoral responses in lung cancer. Potentially, however, strong anti-survivin antibody responses can be elicited during the post therapy and follow-up of the patients, whose clinical significance remains to be elucidated. These findings, together with our previous data concerning survivin expression and the related cytolytic T cell responses in lung cancer, signify a high tolerogenic potential of this tumor-associated antigen.

Systemic oxidative stress in patients with pulmonary sarcoidosis.

BACKGROUND A local redox imbalance has been reported in pulmonary sarcoidosis. However, so far no study has described a systemic redox imbalance in this context. The aim of the present study was to evaluate the systemic oxidative stress in patients with sarcoidosis and determine its relationship to treatment and indices of disease severity. METHODS 35 patients with histologically proven pulmonary sarcoidosis and 13 healthy volunteers were included in the study. All patients were studied during a stable phase of their disease. Systemic oxidative stress was quantified in serum with the use of a commercially available spectrophotometric method (D-ROM test) which determines overall oxidative stress, by measuring total hydroperoxides. Oxidative stress was expressed in conventional units, i.e. Carratelli Units (UCarr), where 1 UCarr corresponds to 0.8 mg/L H(2)O(2). RESULTS Serum oxidative stress levels were significantly higher in patients with sarcoidosis compared to those of normal subjects (390+/-25 vs 300+/-18 UCarr respectively, p=0.04). Patients not receiving systemic corticosteroids had higher levels of oxidative stress compared to steroid-treated patients (461.5+/-38 vs 315+/-20, p<0.01) and compared to controls (461.5+/-38 vs 300+/-18 UCarr, p<0.01). Oxidative stress did not correlate with diffusion lung capacity (DLCO), partial arterial oxygen tension (PaO(2)), MRC dyspnoea scale or chest X-ray stage. CONCLUSIONS Systemic oxidative stress is increased in patients with stable pulmonary sarcoidosis who do not receive systemic corticosteroids. This finding suggests a sustained oxidative burden even when clinical, functional and radiological criteria indicate disease stability.

Naturally occurring tumor-specific CD8+ T-cell precursors in individuals with and without cancer.

Boosting pre‐existing, naturally occurring cytolytic CD8+ T‐cell (CTLs) responses directed against class‐I MHC‐restricted peptides of tumor antigens, represents a primary goal of cancer immunotherapy. The number of pre‐existing antitumor CTLs and their impaired function has been incriminated as the most likely candidates for the reduced clinical efficacy of these trials. This study was scheduled to determine possible differences in the frequency and the function of naturally occurring CTL precursors (pCTLs) against multiple peptides derived from the cancer‐testis antigens MAGE‐A1 and MAGE‐A3, and the overexpressed antigen hTERT, in newly diagnosed lung cancer patients as compared with aged‐matched healthy individuals. The cumulative frequency of circulating peptide‐specific pCTLs was found significantly higher in the cancer patients, varied widely and was not affected by radiotherapy and chemotherapy. Furthermore, this frequency was greatly different between the various tumor‐antigen peptides. Under the light of recent evidence provided from animal models, these results indicate that the peptide‐specific pCTL frequency might represent an important determinant for the fate of cancer immunotherapy. In addition, our results show that tumor‐specific pCTLs of cancer patients can present functional differences regarding their proliferative capacity, intensity of multimer staining and lytic capacity, when compared with those of healthy individuals. Hence, our findings could have an important role for the design of improved immunotherapeutic approaches for lung cancer.

Poly(A)-specific ribonuclease and Nocturnin in squamous cell lung cancer: prognostic value and impact on gene expression

BackgroundLung cancer is the leading cause of cancer mortality worldwide, mainly due to late diagnosis, poor prognosis and tumor heterogeneity. Thus, the need for biomarkers that will aid classification, treatment and monitoring remains intense and challenging and depends on the better understanding of the tumor pathobiology and underlying mechanisms. The deregulation of gene expression is a hallmark of cancer and a critical parameter is the stability of mRNAs that may lead to increased oncogene and/or decreased tumor suppressor transcript and protein levels. The shortening of mRNA poly(A) tails determines mRNA stability, as it is usually the first step in mRNA degradation, and is catalyzed by deadenylases. Herein, we assess the clinical significance of deadenylases and we study their role on gene expression in squamous cell lung carcinoma (SCC).MethodsComputational transcriptomic analysis from a publicly available microarray was performed in order to examine the expression of deadenylases in SCC patient samples. Subsequently we employed real-time PCR in clinical samples in order to validate the bioinformatics results regarding the gene expression of deadenylases. Selected deadenylases were silenced in NCI-H520 and Hep2 human cancer cell lines and the effect on gene expression was analyzed with cDNA microarrays.ResultsThe in silico analysis revealed that the expression of several deadenylases is altered in SCC. Quantitative real-time PCR showed that four deadenylases, PARN, CNOT6, CNOT7 and NOC, are differentially expressed in our SCC clinical samples. PARN overexpression correlated with younger patient age and CNOT6 overexpression with non-metastatic tumors. Kaplan-Meier analysis suggests that increased levels of PARN and NOC correlate with significantly increased survival. Gene expression analysis upon PARN and NOC silencing in lung cancer cells revealed gene expression deregulation that was functionally enriched for gene ontologies related to cell adhesion, cell junction, muscle contraction and metabolism.ConclusionsOur results highlight the clinical significance of PARN and NOC on the survival in SCC diagnosed patients. We demonstrate that the enzymes are implicated in important phenotypes pertinent to cancer biology and provide information on their role in the regulation of gene expression in SCC. Overall, our results support an emerging role for deadenylases in SCC and contribute to the understanding of their role in cancer biology.