Roberto Verna

Plasma oxidative stress biomarkers, nitric oxide and heat shock protein 70 in trained elite soccer players.

The physiological response to the physical exercise involves a number of changes in the oxidative balance and in the metabolism of some important biological molecules, including nitric oxide (NO) and heat shock proteins (Hsp 70). With the aim to optimise previous laboratory diagnostic panels, we measured the plasma concentration of reactive oxygen metabolites (ROMs), total antioxidant status (TAS), glutathione reductase (GR) activity, and NO and Hsp 70 levels in 44 elite, antioxidant-supplemented and trained soccer players and in 15 sedentary controls. Although no statistically significant difference between athletes and controls was detected in the plasma level of ROMs and TAS, soccer players showed a significantly higher plasma GR activity, NO and Hst 70 levels than those of sedentary controls. These findings suggest that the measuring of relatively novel biomarkers in sport medicine, like GR, NO and Hsp 70, in addition to the well-known and reliable assays (d-ROMs test and TAS) may be useful to a clinician to better assess and evaluate the benefits of training and/or supplementation programs.

PON1 L55M polymorphism is not a predictor of coronary atherosclerosis either alone or in combination with Q192R polymorphism in an Italian population

Abstract Background  The present study evaluated the role of the PON1 L55M polymorphism independently and in conjunction with the Q192R polymorphism on the risk of coronary atherosclerosis in an Italian population.

Lack of association of the common TaqIB polymorphism in the cholesteryl ester transfer protein gene with angiographically assessed coronary atherosclerosis

The anti‐atherogenic effect of cholesteryl ester transfer protein (CETP) genetic variants associated with lowered enzyme activity is controversial. Moreover, in a few studies, this effect has been evaluated in the presence of a certain risk factor constellation. We addressed this issue in a case–control study, where 415 subjects with angiographically documented coronary artery disease (CAD+), 397 subjects without CAD (in 215, CAD was excluded by coronarography (CAD−)), and 188 healthy population controls, were screened for the CETP TaqIB polymorphism. The prevalence of the low‐activity TaqIB2 allele was 0.396 in CAD+, and 0.428 and 0.416 in CAD− and population controls, respectively (p=0.40). Its presence was significantly associated with increased high‐density lipoprotein cholesterol (HDL‐C) in population controls (1.40±0.40 mmol/l in B1B1, 1.52±0.39 mmol/l in B1B2 and 1.58±0.46 mmol/l in B2B2; p<0.03 for trend), but not in the other groups. The CETP TaqIB polymorphism accounted for <1% of the HDL‐C variance in the whole cohort (p=0.048). After adjustment for other risk factors, the CETP TaqIB2 allele was found not to be associated with significant changes in CAD risk independently of an assumed either dominant (odds ratio (OR) 0.97; 95% confidence interval (CI) 0.66–1.44; p=0.89) or recessive effect (OR 0.68; 95% CI 0.42–1.12; p=0.13). The CETP TaqIB polymorphism did not show a significant interaction with other risk factors in influencing CAD risk. Our findings do not support the hypothesis that a genetic variant resulting in lowered CETP activity is associated with reduced risk of coronary atherosclerosis.

In situ detection of telomerase catalytic subunit mRNA in glioblastoma multiforme

Activation of telomerase may allow unlimited cell proliferation and immortalization. One of the telomerase protein subunits has a reverse transcriptase (hTERT) activity that is essential for telomerase function and regulation. In human gliomas, telomerase is frequently associated with malignant tumor progression. In our study, we investigated the expression of hTERT at the cellular level in 34 primary de novo glioblastoma multiforme (GBM) by in situ hybridization ( ISH ). The expression of hTERT in tumor tissue was also assessed by RT‐PCR. In addition, telomerase activity measured by telomeric repeat amplification protocol (TRAP) and telomere length polymorphism assayed by telomere restriction fragment (TRF) Southern blot were investigated. We found that all GBM, including those with negative TRAP reaction, contained abundant amounts of cytoplasmic hTERT mRNA. Interestingly, the ISH analysis revealed that the hTERT mRNA was homogeneously expressed by the whole tumor cell population in about 60% of the GBM. In the remaining cases, hTERT was absent in subsets of tumor cells. TRF analysis, which shows that both TRAP‐positive and TRAP‐negative de novo GBM have elongated telomeres, further supports that telomerase activity is present in all de novo GBM. Correlations with tumor size and extent of necrosis suggest that hTERT reactivation is an early event in GBM development and that telomerase activity may be lost in subpopulations of neoplastic cells during tumor progression. Finally, ISH analysis of hTERT mRNA seems to provide a prognostic parameter for primary de novo GBM. Int. J. Cancer 88:895–901, 2000.

Regulatory Cytokine Gene Polymorphisms and Risk of Colorectal Carcinoma

Abstract:  It is well established that cancer arises in chronically inflamed tissue, and this is particularly notable in the gastrointestinal tract. Classic examples include Helicobacter pylori–associated gastric cancer, hepatocellular carcinoma, and inflammatory bowel disease–associated colorectal cancer. Growing evidence suggests that these associations might be not casual findings. Focusing on individual cytokines has generated evidence that anti‐inflammatory cytokine interleukin (IL)‐10 and transforming growth factor‐beta1 (TGF‐β1) may have a complex role in gastrointestinal carcinogenesis. As an example, IL‐10‐deficient mice develop severe atrophic gastritis and a chronic enterocolitis, developing colorectal cancer similar to human inflammatory bowel disease–associated neoplasia. TGF‐β1 is a multifunctional signaling molecule with a wide array of roles. Animal experiments suggest that TGF‐β1 plays a biphasic role in carcinogenesis by protecting against the early formation of benign epithelial growths, but promoting a significant stimulation of tumor growth invasion and metastasis during tumor progression. We assessed association of functional polymorphisms (–1082G/A; –592C/A) and TGF‐β1 (–509C/T; +869C/T) influencing the IL‐10 production to colorectal cancer risk in a case–control study of 62 patients and 124 matched controls. No significant differences were observed among cancer patients and controls for IL‐10 –1082G/A; –592C/A genotype frequencies. Evaluation of odds ratios (OR) for the TGF‐β1 +869C/T genotypes showed a significant increased risk for individuals bearing +869CC genotype compared to +869CT‐ and +869TT‐positive individuals. These results suggest that the +869C allele, responsible for a Leu→Pro substitution in the signal peptide sequence of the TGF‐β1 protein, may have a predisposing role in the development of colorectal cancer.

Cytokine gene polymorphisms and breast cancer susceptibility

Abstract:  Human breast cancer (BC) is characterized by a considerable clinical heterogeneity. Steroid hormone receptor expression and growth factor receptor expression have been considered suitable diagnostic and prognostic markers, whereas mutations of oncosuppressor and gatekeeper genes have been found associated with an increased risk for this malignancy. To evaluate the role that polymorphisms of genes involved in the regulation of inflammatory response might play in BC susceptibility, we investigated associations between cytokine functionally relevant polymorphisms in 84 BC patients compared to 110 age‐ and sex‐matched controls. TNF‐α (‐308G/A), TGF‐β1 (+869C/T), IL‐10 (−1117G/A; −854C/T; −627C/A), and IFN‐γ (874T/A) single nucleotide polymorphisms (SNPs) were identified by sequence‐specific primers (SSP)‐PCR or restriction fragment length polymorphism (RFLP)‐PCR. Genotype or haplotype distributions for each polymorphisms were consistent with the HWE in these populations. We were unable to demonstrate differences in genotype or allele frequencies between patient and control groups. Data obtained in this study indicate that none of the cytokine SNPs studied is likely to have predisposing or protective effects on BC susceptibility. On the other hand, both positive and negative association with BC have been reported for some of the studied genotypes by different research groups. In conclusion, further studies involving larger numbers of subjects are required.

A novel double nucleotide substitution in the HMG box of the SRY gene associated with Swyer syndrome

Abstract We describe a novel double nucleotide substitution in the SRY gene of a 46,XY female with gonadal dysgenesis or Swyer syndrome. The SRY sequence was analysed by both the single-strand conformational polymorphism assay and direct DNA sequencing of products from the polymerase chain reaction. A double nucleotide substitution was identified at codon 18 of the conserved HMG box motif, causing an arginine to asparagine amino-acid substitution. The altered residue is situated in the high mobility group (HMG)-related box of the SRY protein, a potential DNA-binding domain. Since the mutation abolishes one HhaI recognition site, the results were confirmed by HhaI restriction mapping. No other mutations were found in the remaining regions of the gene. The corresponding DNA region from the patient’s brother was analysed and found to be normal. We conclude that the SRY mutation in the reported XY female occurred de novo and is associated with sex reversal.

Absence of Association between a Variant of the Mast Cell Chymase Gene and Atopic Dermatitis in an Italian Population

Atopic dermatitis (AD) is a chronic dermatitis which belongs to the group of atopy-related diseases together with asthma and rhinitis. IgE and mast cell chymase (MCC) play a key role in atopic or allergic inflammation of the skin. An association between AD and a genetic variant of the MCC has been reported in a Japanese population, but failure of confirmation has rendered this association questionable. We have tested for genetic association to an MCC variant in relation to AD in an Italian population. No significant association was found between AD and MCC genotypes. These data suggest that BstXI MCC polymorphism may not be involved in AD.

C242T Polymorphism of NADPH Oxidase p22phox and Recurrence of Cardiovascular Events in Coronary Artery Disease

Objectives—The common C242T polymorphism in the gene for the p22phox subunit of NADPH oxidase has been reported to be negatively associated with oxidative stress, but whether it confers prognostic information is not yet clear. Methods and Results—The incidence of major adverse cardiovascular events (MACE) were determined in 237 patients with coronary stenosis during a median follow-up of 7.8 years. The p22phox genotypes were evaluated in 213 patients (89.9%) by polymerase chain reaction and RsaI. digestion. Plasma levels of 8-hydroxy-2′-deoxyguanosine (8-OHdG), a marker of oxidative stress, were also measured. In the univariate analysis, patients with CT/TT genotypes showed reduced recurrence of cardiovascular deaths, nonfatal MI, and revascularization procedures compared with homozygous carriers of the C allele. After controlling for confounders, a significantly lower risk of new revascularization procedures (HR=0.31, 95% CI 0.12 to 0.70; P=0.014) remained associated with the T allele. The Kaplan–Meier analysis showed a longer survival free from fatal and nonfatal MI in carriers of T allele (P<0.001). The presence of the 242T allele was associated with significantly reduced plasma concentrations of 8-OHdG. Conclusions—The 242T allele was a predictor of lower risk of recurrence of cardiovascular events in high-risk patients and was associated with reduced systemic oxidative stress.

Induction of telomerase activity in v-myc-transformed avian cells

Telomerase activity is detectable in the majority of tumors or immortalized cell lines, but is repressed in most normal human somatic cells. It is generally assumed that reactivation of telomerase prevents the erosion of chromosome ends which occurs in cycling cells and, hence, hinders cellular replicative senescence. Here, we show that the expression of v-Myc oncoprotein by retroviral infection of telomerase-negative embryonal quail myoblasts and chicken neuroretina cells is sufficient for reactivating telomerase activity, earlier than telomere shortening could occur. Furthermore, the use of a conditional v-Myc-estrogen receptor protein (v-MycER) causes estrogen-dependent expression of detectable levels of telomerase activity in recently infected chick embryo fibroblasts and neuroretina cells. We conclude that the high levels of telomerase activity in v-Myc-expressing avian cells are not the mere consequence of transformation or of a differentiative block, since v-Src tyrosine kinase, which prevents terminal differentiation and promotes cell transformation, fails to induce telomerase activity.