The Expression of Hypoxia-Related Biomarkers: A Significance of HIF-1α C1772T Polymorphism as Predictor of Laryngeal Carcinoma Relapse.

INTRODUCTION: The association between the expression of HIF-1α in the laryngeal carcinoma and the prognosis of disease is quite well documented, but the significance of HIF-1α C1772T polymorphism and its relation to disease phenotype have to be clarified. The aim of this study was to investigate the influence of C1772T polymorphism on the clinical-pathological characteristics and disease-free survival after initial surgical treatment of patients with laryngeal carcinoma. MATERIALS AND METHODS: The prospective cohort study included 65 patients with laryngeal carcinoma. Two representative tumor tissue specimens were taken in each patient during surgery; 1 specimen was used to asses HIF-1α C1772T polymorphism and the other 1 to determine the immunohistochemical expression of HIF-1α, VEGF, as well as CD 34 proteins. The comparison of polymorphism frequency between study and control population was conducted by collecting a 5 mL of peripheral venous blood samples in each subject. RESULTS: Clinicopathological characteristics of laryngeal carcinoma didn't affect the expression of hypoxia-related biomarkers, such as HIF-1α, VEGF or MVD. The statistically significant association between HIF-1α and VEGF expression was found (P = .034), but not between HIF-1α expression and MVD value (P = .696). The expression of HIF-1α was significantly higher among CT heterozygotes (P = .029). We found a significantly more recurrence among CT heterozygotes compared with patients with CC homozygous alleles (57.10% and 24.30%, respectively; P = .007). Patients with C1772T polymorphic variants had significantly worse disease-free survival compared with patients without polymorphism (Log-rank test, P = .007). CONCLUSION: HIF-1α C1772T polymorphism was significantly associated with worse disease-free survival which nominates it as a predictor of laryngeal carcinoma relapse. The preoperative assessment of hypoxia-related biomarkers should be used in everyday practice in order to determine the treatment modalities for laryngeal carcinoma.

VHL Dependent Expression of REDD1 and PDK3 Proteins in Clear-cell Renal Cell Carcinoma.

BACKGROUND: Sporadic clear-cell renal cell carcinoma (ccRCC) is associated with mutations in the VHL gene, upregulated mammalian target of rapamycin (mTOR) activity and glycolytic metabolism. Here, we analyze the effect of VHL mutational status on the expression level of mTOR, eIF4E-BP1, AMPK, REDD1, and PDK3 proteins. METHODS: Total proteins were isolated from 21 tumorous samples with biallelic inactivation, 10 with monoallelic inactivation and 6 tumors with a wild-type VHL (wtVHL) gene obtained from patients who underwent total nephrectomy. The expressions of target proteins were assessed using Western blot. RESULTS: Expressions of mTOR, eIF4EBP1 and AMPK were VHL independent. Tumors with monoallelic inactivation of VHL underexpressed REDD1 in comparison to wtVHL tumors (P = 0.042), tumors with biallelic VHL inactivation (P < 0.005) and control tissue (P = 0.004). Additionally, REDD1 expression was higher in tumors with VHL biallelic inactivation than in control tissue (P = 0.008). Only in wt tumor samples PDK3 was overexpressed in comparison to tumors with biallelic inactivation of VHL gene (P = 0.012) and controls (P = 0.016). In wtVHL ccRCC, multivariate linear regression analysis revealed that 97.4% of variability in PDK3 expression can be explained by variations in AMPK amount. CONCLUSION: Expressions of mTOR, eIF4EBP1 and AMPK were VHL independent. We have shown for the first time VHL dependent expression of PDK3 and we provide additional evidence that VHL mutational status affects REDD1 expression in sporadic ccRCC.

Correlation of structural defects in the ascending aortic wall to ultrasound parameters: benefits for decision-making process in aortic valve surgery.

BACKGROUND: Histopathological changes in the ascending aorta wall in patients with severe tricuspid aortic valve (TAV) stenosis were graded and correlated to echocardiographic parameters. Objective was to associate threshold echocardiographic values with structural defects in the ascending aorta providing a tool to improve decision-making process in cases when simultaneous aortic valve replacement (AVR) and ascending aorta replacement is considered. METHODS: Biopsies from 108 TAV stenosis patients subjected to AVR were graded into three grades according to severity of aortic wall changes. Echocardiographic parameters obtained preoperatively and correlated to grade, age, gender and risk factors, were diameters of ventriculo-aortic junction (AA), sinus Valsalva (SV), sinotubular junction (STJ), the largest diameter of the visualized ascending aorta (AscA) as well as indexes: sinus Valsalva (SVI), sinotubular junction (STJI), AscA/AA and STJ/AA. RESULTS: Two echocardiographic parameters portrayed grades with statistical significance: STJ (F = 5.417; p = 0.006 (p < 0.05)) and AscA (F = 3.924; p = 0.023 (p < 0.05)). By using multiple predictors in the setting of Regression analysis, statistically significant differences among grades were reached for AA, SV, STJ, AscA and SVI. With further ROC curves analysis, threshold values for different grades were recognized. Grade 2 is identified in patients with AscA > 3.3 cm, while Grade 3 is identified in patients with values of AscA > 3.5 cm, STJ > 2.9 cm and STJI > 1. CONCLUSIONS: Hemodynamic stress induced by TAV stenosis leads to elastic lamellae disruption in the aortic wall. Those changes could be graded and correlated with echocardiographic parameters of the aortic root and ascending aorta, providing a tool for decision to replace ascending aorta concomitantly with AVR.

Tuberous sclerosis complex protein 1 expression is affected by VHL Gene alterations and HIF-1α production in sporadic clear-cell renal cell carcinoma.

Alterations in von Hippel-Lindau gene (VHL) do not determine deregulation of hypoxia-inducible factors (HIFs) in clear-cell renal carcinoma (ccRCC). Their effects on tuberous sclerosis proteins (TSC1/2) and heat shock protein 90 (Hsp90) expressions in sporadic ccRCC are unknown. Therefore, we analyze the impact of VHL alterations and HIF-α production on the expression of TSC proteins and Hsp90 in these tumors. Alterations in VHL gene region exhibited 37/47 (78.7%) tumors. Monoallelic inactivation (intragenic mutation or LOH) was found in 10 (21.3%) and biallelic inactivation (intragenic mutation plus LOH) in 27 (57.4%) ccRCCs. Tumorous expression of HIF-α mRNAs, HIF-α, Hsp90 and TSC2 were VHL independent; TSC2 was underexpressed in all tumors by immunostaining (P<0.001). Immunoblotting revealed that TSC1 production was lower in tumors with monoallelic VHL inactivation than in control (P=0.01) and tissues with biallelic VHL inactivation (P=0.019), while tumors lacking HIF-1α (16/47) concurrently overexpressed HIF-2α and underexpressed TSC1 in comparison to controls (P=0.01 for both) and HIF-1α positive tumors (P=0.015 and P=0.050). Significant portion of variability (56.4%) in tumor diameter was explained by oscillations in nuclear grade, and TSC1 and HIF-2α expression in VHL altered tumors. In conclusion, while TSC2 is broadly downregulated in sporadic ccRCC, TSC1 expression is reduced in two subsets of these tumors, those with monoallelic VHL gene inactivation and those with concurrent low HIF-1α and high HIF-2α expression. Hence, the involvement of nuclear grade, TSC1 and HIF-2α in the progression of VHL altered tumors, implies the interplay between pVHL and TSC1.

Glucocorticoid receptor and molecular chaperones in the pathogenesis of adrenal incidentalomas: potential role of reduced sensitivity to glucocorticoids.

Glucocorticoid (GC) sensitivity depends on glucocorticoid receptor (GR) and heat shock proteins (Hsps). We investigated whether common GR genes (ER22/23EK, N363S, Bcl I, and 9ß) and adrenocorticotropin receptor promoter polymorphisms influence susceptibility for unilateral adrenal incidentaloma (AI), plus GR and Hsp expression in tumorous (n = 19), peritumorous (n = 13) and normal adrenocortical (n = 11) tissues. Patients (n = 112), population-matched controls (n = 100) and tumor tissues (n = 32) were genotyped for these polymorphisms. Postdexamethasone serum cortisol was higher in patients (p < 0.001). GR gene variants, larger allele of Bcl I (odds ratio [OR] 2.9; 95% confidence interval [CI] 1.7-5.1; p < 0.001] and minor allele of 9ß (OR 3.0; 95% CI 1.6-5.7; p < 0.001) were independent predictors of AI. In patients, the first allele is linked with larger tumors (p = 0.002) and the latter with higher postdexamethasone cortisol levels (p = 0.025). Both allele carriers had lesser waist circumference (p = 0.02), similar adrenocorticotropin and higher basal (p = 0.024) and postdexamethasone cortisol concentrations (p < 0.001). Tumorous and constitutional genotypes were similar. GR-D is the major receptor isoform in normal adrenal cortex by Western blotting. Loss of other receptor isoforms, decrease in immunostaining for GR (p < 0.0001), underexpression of chaperones (p ≤ 0.01) and the presence of inducible Hsp70 were found in adenomas. In conclusion, GR gene variants, C allele of Bcl I and minor allele of 9ß, are associated with AIs. Their concurrent presence in patients reduces GC sensitivity. Normal adrenal cortex preferentially expresses GR-D. In adenomas, the lack of other GR isoforms and underexpression of heat shock proteins perhaps permanently impair GC signaling, which could promote dysregulated cortisol production and tumor growth. The innate GC sensitivity probably modifies these effects.