Nikolaos Soulitzis

p53 codon 72 polymorphism and its association with bladder cancer.

p53 codon 72 Arg homozygosity has been associated with increased risk of developing cervical cancer. This association has been tested in various human cancers with controversial results. In the present study we investigated the impact of this polymorphism in a population-based case-control study of bladder cancer. Using allele-specific polymerase chain reaction to detect the p53 codon 72 polymorphism, we tested peripheral blood samples from 50 patients with bladder cancer and 99 healthy individuals of similar age and from the same geographical region. Tumor specimens from all bladder cancer patients were examined for the presence of human papilloma virus (HPV). The distribution of p53 alleles in bladder cancer patients and in controls was statistically significant (P<0.002; odds ratio, 2.67; 95% confidence interval, 1.38-5.20), and homozygosity for arginine at residue 72 was associated with an increased risk for bladder cancer (P<0.00002; odds ratio, 4.69; 95% confidence interval, 2.13-10.41). The presence of HPV was found in six of the 50 patients (12%). This is the first study correlating p53 codon 72 polymorphism with bladder cancer. Our results provide evidence that this p53 polymorphism is implicated in bladder carcinogenesis and that individuals harboring the Arg/Arg genotype have an increased risk of developing bladder cancer.

Association of p53 codon 72 polymorphism with advanced lung cancer: the Arg allele is preferentially retained in tumours arising in Arg/Pro germline heterozygotes

The association of p53 codon 72 polymorphism with cancer has been investigated by several scientific groups with controversial results. In the present study, we examined the genotypic frequency of this polymorphism in 54 patients with advanced lung cancer and 99 normal controls from the geographical region of Greece. Sputum and bronchial washing samples from each patient were assayed for the presence of human papillomavirus. Codon 72 heterozygous (Arg/Pro) patients were also analysed for loss of heterozygosity at the TP53 locus, in order to determine the lost p53 allele (Arg or Pro). p53 Arg/Arg genotype was significantly increased in lung cancer patients compared to normal controls (50% vs 24.2%, P<0.002). Human papillomavirus was detected only in two patients (3.7%). Loss of heterozygosity at the TP53 locus was found in 14 out of 27 Arg/Pro patients (51.85%). The Pro allele was lost in 11 cases (78.6%), while the Arg allele was lost in three (21.4%). Our results suggest that p53 codon 72 Arg homozygosity is associated with advanced lung cancer, and that the Arg allele is preferentially retained in patients heterozygous for this polymorphism. On the other hand, human papillomavirus infection does not seem to play an important role in lung carcinogenesis.

Aberrant methylation and deacetylation of Deleted in liver cancer-1 gene in prostate cancer : Potential clinical applications

Purpose: The deleted in liver cancer-1 (DLC-1) gene that encodes a Rho GTPase-activating protein with tumor suppressor function is located on chromosome 8p21-22, a region frequently deleted in prostate carcinomas. This study was designed to determine whether DLC-1 is deregulated in prostate carcinomas and to assess the contribution of DLC-1 alterations to prostate carcinogenesis. Experimental Design: Primary prostate carcinomas, prostate carcinoma cell lines, benign prostatic hyperplasias, and normal prostatic tissues were examined for detection of functional and structural alterations of the DLC-1 gene by real-time PCR, methylation-specific PCR, and Southern and Western blots. Results: Down-regulation or loss of DCL-1 mRNA expression was detected in 10 of 27 (37%) prostate carcinomas, 3 of 5 (60%) prostate carcinoma cell lines, and 5 of 21 (24%) benign prostatic hyperplasias. DLC-1 promoter methylation was identified in 13 of 27 (48%) prostate carcinomas and 2 matching normal tissues and in 15 of 21 (71%) benign prostatic hyperplasias but was absent in 10 normal prostatic tissues from noncancerous individuals. Genomic deletions were found in only 3 prostate carcinomas and 1 benign prostatic hyperplasia. DLC-1 protein was not detected in 8 of 27 (30%) prostate carcinomas and 11 of 21 (52%) benign prostatic hyperplasias. Methylation of DLC-1 correlated with age in prostate carcinoma patients (P = 0.006) and with prostate-specific antigen blood levels in benign prostatic hyperplasia patients (P = 0.029). Treatment of the three prostate carcinoma cell lines (PC-3, LNCaP, and 22Rv1) expressing a low level of DLC-1 transcripts with inhibitors of DNA methyltransferase or histone deacetylase increased DLC-1 expression. Conclusions: These results show that the transcriptional silencing of DLC-1 by two epigenetic mechanisms is common and may be involved in the pathogenesis of prostate carcinomas and benign prostatic hyperplasias and could have potential clinical application in the early detection and gene therapy of prostate cancer.

Prevalence of BK virus and human papillomavirus in human prostate cancer

Polyomaviruses such as the BK virus (BKV), JC virus (JCV) and SV40, as well as the human papillomaviruses (HPV) are frequently detected throughout human populations, causing subclinical persistent infections and inducing oncogenesis in human and other cell lines. To test the involvement of these viruses in prostate tumorigenesis, we investigated the prevalence of BKV, JCV and HPV in a series of human prostatic malignancies. Forty-two samples of diagnosed prostatic malignancies were tested using standard polymerase chain reaction (PCR) protocols. Differentiation between BKV and JCV among the polyomavirus-positive samples was achieved after sequencing analysis of the PCR products. Reconstitution of BKV in vitro was performed and indirect immunofluorescence for the large T-antigen of the virus was applied to confirm the production of progeny virus. Detection and typing of HPV was carried out by PCR. The overall prevalence of polyomaviruses was 19% in the prostate cancer cases. Sequencing analysis of the polyomavirus-positive specimens revealed the presence of BKV in all samples. Reconstitution of the BKV from the BKV-positive prostate samples was successfully achieved in cell culture and progeny viral particles were obtained, confirming the presence of the virus in the human biopsies. HPV was detected in 4.8% of the samples, however, no HPV-11, HPV-16, HPV-18 or HPV-33 types were identified. BKV was frequently detected and could play a relevant role in the development and progression of human prostate cancer, whereas HPV does not seem to be implicated in this type of human neoplasia.

Deregulation of apoptosis mediators' p53 and bcl2 in lung tissue of COPD patients

Abnormal apoptotic events in chronic obstructive pulmonary disease (COPD) subvert cellular homeostasis and may play a primary role in its pathogenesis. However, studies in human subjects are limited.p53 and bcl2 protein expression was measured by western blot on lung tissue specimens from 43 subjects (23 COPD smokers and 20 non-COPD smokers), using beta-actin as internal control. Additionally, p53 and bcl2 expression patterns were evaluated by immunohistochemistry in formalin-fixed, paraffin-embedded lung tissue sections from the same individuals.Western blot analysis showed statistically significant increased p53 protein levels in COPD smokers in comparison with non-COPD smokers (p = 0.038), while bcl2 protein levels were not statistically different between the two groups. Lung immunohistochemistry showed increased ratio of positive p53-stained type II pneumocytes/total type II pneumocytes in COPD smokers compared to non-COPD smokers (p = 0.01), whereas the p53 staining ratio in alveolar macrophages and in lymphocyte-like cells did not differ statistically between the two groups. On the other hand, bcl2 expression did not differ between the two groups in all three cell types.The increased expression of pro-apoptotic p53 in type II pneumocytes of COPD patients not counterbalanced by the anti-apoptotic bcl2 could reflect increased apoptosis in the alveolar epithelium of COPD patients. Our results confirm previous experiments and support the hypothesis of a disturbance in the balance between the pro- and anti-apoptotic mediators in COPD.

YY1 Over-Expression in Human Brain Gliomas and Meningiomas Correlates with TGF-β1, IGF-1 and FGF-2 mRNA Levels

In this study we examined by QRT-PCR the mRNA expression of TGF-β 1, IGF-1, EGF, FGF-2 and YY1 in human brain tumors. Our findings introduce YY1, for the first time, as a novel gene implicated in brain gliomatogenesis and meningioma establishment. We present a positive correlation between the autocrine expression of YY1 and TGF-β 1, IGF-1 and FGF-2, known to be involved in the progression of gliomas and meningiomas. We suggest that mRNA profiling of the above genes in the early stages of disease development could be useful for prognostic purposes, and these genes can be considered as potential targets for therapeutic approaches against brain tumors.

Decreased Annexin A5 mRNA placental expression in pregnancies complicated by fetal growth restriction

BACKGROUND The placental anticoagulant protein Annexin A5 (ANXA5) is highly expressed on the apical surfaces of syncytiotrophoblasts and plays an important role in maintaining blood fluidity in the placental circulation. We investigated the mRNA and protein expression of ANXA5 in placentas from pregnancies complicated by fetal growth restriction (FGR) compared with uncomplicated pregnancies. MATERIALS AND METHODS Placental tissue was collected from 18 pregnancies complicated by FGR and 16 pregnancies with a normal outcome. ANXA5 mRNA expression was quantified by Real-Time PCR (RT-PCR), and protein concentrations were measured by an enzyme-linked immunosorbent assay (ELISA). RESULTS A decreased ANXA5 mRNA expression was observed in placenta samples from FGR-affected pregnancies compared to those from uncomplicated pregnancies. However, similar ANXA5 protein levels were measured in both specimen groups. No correlation was observed between ANXA5 mRNA and protein levels. CONCLUSIONS Transcriptional ANXA5 down-regulation was demonstrated in FGR-affected pregnancies, although protein levels were similar in FGR-related placentas and controls. We can speculate that either recruitment of the protein from the bloodstream or increased apoptosis or post-transcriptional modifications occur, which affect ANXA5 protein levels in FGR-related placentas. Further studies are required to reveal the role of ANXA5 in FGR pathology.

Molecular profiling of EGFR family in chronic obstructive pulmonary disease: correlation with airway obstruction.

Growth factors mediate various cellular responses to environmental stimuli. Specifically, exposure of lung epithelium to oxidative stress induced by cigarette smoke stimulates aberrant epidermal growth factor receptor (ERBB) family activation. This studys objective was to evaluate the expression of ERBB1–4 receptors in the lung tissue of smokers with or without chronic obstructive pulmonary disease (COPD).

Reduced placental prolyl hydroxylase 3 mRNA expression in pregnancies affected by fetal growth restriction

Please cite this paper as: Gourvas V, Sifakis S, Dalpa E, Soulitzis N, Koukoura O, Spandidos D. Reduced placental prolyl hydroxylase 3 mRNA expression in pregnancies affected by fetal growth restriction. BJOG 2010;117:1635–1642.

Downregulation of notch signaling pathway in late preterm and term placentas from pregnancies complicated by preeclampsia.

Preeclampsia (PE) is a major cause of maternal mortality and morbidity, affecting 3–5% of all pregnancies. The Notch signaling pathway plays an important role during placental development, activating several target genes. Defects in the Notch pathway have adverse effect on placentation. The aim of this study was to investigate the expression of receptors NOTCH1,-2,-3,-4, ligands DLL1,-3,-4, JAG1,-2 and target genes HEY1,-2 in placental tissue samples from 20 late preterm or term pregnancies complicated by PE versus 20 normal pregnancies. mRNA levels of the studied molecules were measured by quantitative Real-Time PCR (qRT-PCR), while the protein expression of the intracellular domain of NOTCH2 (NICD2) and NOTCH3 (NICD3) was measured by Western Blot (WB). qRT-PCR analysis revealed that NOTCH1, NOTCH4 and DLL1 were not expressed in the placenta. On the contrary, NOTCH2, NOTCH3, DLL3, DLL4, JAG1, JAG2, HEY1 and HEY2 mRNA levels were downregulated in PE samples vs. controls (p<0.01). WB confirmed that NICD2 (p = 0.014) and NICD3 (p<0.001) protein levels were also lower in PE specimens. Statistical analysis revealed several significant associations: of NOTCH3 mRNA expression with smoking during pregnancy (p = 0.029), of NICD3 protein levels (p = 0.028) and DLL3 mRNA levels (p = 0.041) with birth weight centile, and of HEY2 transcript levels with parity (p = 0.034) and mode of delivery (p = 0.028). Our results suggest that Notch pathway downregulation is associated with PE. Further studies are required in order to determine the role of these molecules in PE pathogenesis and to evaluate their potential use for the early detection and treatment of PE.