VEGF-A and VEGF-B mRNA expression in gastro-oesophagela cancers

INTRODUCTION: Angiogenesis is essential for the local growth, invasion and metastasis of the tumours. Vascular endothelial growth factors (VEGFs) play a crucial role in tumour angiogenesis. The aim of our study was to quantify the expression of several VEGF family molecules in human gastro-oesophageal cancers and to analyse possible correlations between genes expression and clinico-pathological features. MATERIALS AND METHODS: Gene expression was quantified in 43 gastro-oesophageal paired samples using qRT-PCR with TaqMan probes specific to VEGF-A, including soluble transcript variants and VEGF-B genes. RESULTS: VEGF-A, including the studied splice variants and VEGF-B mRNAs were expressed in both tumour and peritumour mucosa. The expression of VEGF-A and its isoforms was higher in tumour compared with paired peritumour mucosa, while no significant difference was observed in VEGF-B expression. VEGF-A expression tended to correlate with tumour invasion. CONCLUSION: VEGF-A has a tendency to over-express in gastro-oesophageal cancers, while VEGF-B does not seem involved in these tumours. Further studies are required to establish the utility of anti-VEGF-A therapy and to find biomarkers for pathogenesis or response to therapy in gastro-oesophageal tumours (AU)

VEGFR1 and VEGFR2 immunohistochemical expression in oral squamous cell carcinoma: a morphometric study.

Vascular endothelial growth factor (VEGF) is considered one of the main molecules involved in tumor angiogenesis and is largely expressed in oral squamous cell carcinoma (OSCC). His signal is transmitted intracellulary by binding with class III tyrosine kinase receptors, known as VEGF receptor family (VEGFRs). Therefore, we designed this study for quantification of VEGFR1 and VEGFR2 immunohistochemical expression in the tumor cells of OSCC, and compare this expression with clinicopathologic parameters. For this purpose, 46 formalin-fixed, paraffin-embedded tissue blocks of OSCC were processed by immunohistochemistry. The immunohistochemical signal was assessed by estimating the area of the objects and the medium pixel intensity per object, as the integrated optical density (IOD). In our study, VEGFR1 staining intensity was significantly higher for tongue localization, while VEGFR2 was higher for the lip. Both markers were higher expressed in the center of the tumor compared to the tumor front. Moderate differentiated tumors exert higher expression levels for VEGFR1 but lower for VEGFR2. pT1 tumors had higher VEGFR1 levels, and when lymph node involvement was present, this was accompanied by elevated expression levels for VEGFR2 and lower levels for VEGFR1. These results point to an inverse profile of these receptors in OSCC, suggesting their involvement in a sequential manner in VEGF signaling regulation. In conclusion, our study revealed that VEGFR1 and VEGFR2 correlate with tumor localization, tumoral area (front vs. center of the tumor), histological differentiation degree, and lymph node involvement, while only VEGFR1 correlated with pT stage.

Clinical relevance of vascular endothelial growth factor-A in colorectal cancer.

PURPOSE: To study the expression status and clinical relevance of vascular endothelial growth factor-A (VEGF-A) in colorectal cancer (CRC) tissues. EXPERIMENTAL DESIGN: VEGF-A expression was investigated by immunohistochemistry in 89 cases with CRC. Some demographic and histopathological variables were compared with VEGF-A expression to determine the prognostic significance in CRC. RESULTS: VEGF-A (-) was found in 24 cases; (+), (++) and (+++) stainings were detected in 24, 35 and six cases, respectively. VEGF-A (-) was found in 20 of 58 cases with left colon cancer, while only four of 31 cases with right colon cancer were VEGF-A (-) (p=0.024). There was a trend for lower tumor grade and lesser serosal invasion in cases with VEGF-A (-) samples (p=0.07 and p=0.079, respectively). Although the correlation was not statistically significant, there was a trend for lower death rate in cases with VEGF-A (-) tumor (p=0.087). The longest survival was found in cases with VEGF-A (-) tumor and the shortest survival was found in cases with VEGF-A (+++) tumor. Median survival for patients with VEGF-A (-), (+), (++) and (+++) tumors was 59, 47, 35 and 11 months, respectively (p=0.02). The Cox proportional hazards model identified stage IV disease and VEGF-A (+++) tumor as having the most important influences upon overall survival (odds ratio: 5.1, 95% confidence interval: 2.0-13.0 and odds ratio: 3.6, 95% confidence interval: 1.0-12.7, respectively), followed by serosal invasion (odds ratio: 2.4, 95% confidence interval: 1.0-5.9). CONCLUSIONS: This study shows that VEGF-A is a poor prognostic factor in cases with CRC, but the relatively small size of the study group precluded the correlation with the entire known prognostic indicator.

The association of the rs1049353 polymorphism of the CNR1 gene with hypoadiponectinemia.

The endocannabinoid system (ECS) is an important physiological system that modulates appetite, food intake, energy homeostasis, substance addiction. It is comprised of the cannabinoid receptors (CB1 and CB2), the endogenous lipid ligands of these receptors and the enzymes that mediate the endogenous ligands' biosynthesis and degradation. CB1 receptor is expressed in the brain, adipose tissue, liver, skeletal muscle, gastrointestinal tract and pancreas. The CB1 receptor is encoded by CNR1 gene located at 6q14-q15 level. The aim of our study was to investigate the possible correlation between rs1049353 polymorphism of the CNR1 gene with levels of adiponectin in a group of subjects from Romania. The study included 305 subjects divided in two groups according to their fasting adiponectin levels. Fasting adiponectin levels were determined using ELISA technique. The genotyping of the rs1049353 polymorphism of the CNR1 gene was made using the Real-Time PCR technique. The statistical analysis was performed using De Finetti's program. The differences between the allelic frequencies indicated that the presence of G-wild allele seems to confer risk for expressing low levels of adiponectin (OR=1.917; 95%C.I.=1.353-2.715; p=0.00023) and A-mutant allele seems to be protective (OR=0.522; 95%C.I.=0.368-0.739; p=0.00023). At the test of allelic positivity, the presence of the G-allele conferred risk of hypoadiponectinemia (OR=2.113; 95%C.I.=1.324-3.373). In conclusion, this study indicates that the rs1049353 polymorphism of the CNR1 gene is associated with decreased levels of adiponectin. Further research is needed in order to elucidate the link between the polymorphisms of the CNR1 gene and adiponectin levels.

Alterations in expression of cartilage-specific genes for aggrecan and collagen type II in osteoarthritis.

PURPOSE: Osteoarthritis is characterized by a progressive degradation of cartilage structure and function. This study tests the hypothesis that disease severity is characterized by alterations in expression of cartilage-specific genes for aggrecan and collagen type II. EXPERIMENTAL DESIGN: Cartilage, discarded from six subjects undergoing knee replacement, was subdivided into homogeneous portions by the surgeon according to the Outerbridge classification. For four subjects, it was possible to separate the tissue into two or three fractions with different disease severity. Portions of each sample were prepared either for histological analysis and ranking according to the Mankin system or for RNA extraction. Quantitative, competitive RT-PCR assays were used for measurement of mRNA for aggrecan, collagen type II, and glyceraldehyde-3-phosphate dehydrogenase. Clinical grading was correlated with histological score (Spearman r=0.60, p=0.043). RESULTS: There was a striking decrease in expression of aggrecan and collagen II that was correlated with increase in the grade in regions of cartilage within an individual subject. In the series of 12 samples, there was an inverse correlation between aggrecan expression and osteoarthritis grade (Spearman r=-0.59, p=0.042). CONCLUSIONS: In conclusion, there was an inverse relationship between regional disease severity in osteoarthritis and expression of aggrecan. Use of quantitative, competitive RT-PCR is practical for assessment of chondrocyte gene signatures.

Association of +35A/C (intron3/exon3) polymorphism in SOD1-gene with diabetic nephropathy in type 1 diabetes.

Diabetic nephropathy is a major complication of type 1 diabetes whose pathogenesis is insufficiently known, but oxidative stress and genetic susceptibility seem to be involved. The purpose of this study is to assess the possible association of +35A/C (rs2234694) polymorphism in SOD1-gene with advanced stages of diabetic nephropathy in patients with type 1 diabetes in Romania. There have been enrolled 238 unrelated patients, having type 1 diabetes, divided into group A (106 patients) with diabetic nephropathy - macroalbuminuria or ESRD (End Stage Renal Disease) and group B (132 patients) without diabetic nephropathy. The genomic DNA was extracted from the peripheral venous blood and the genotyping of +35A/C (rs2234694) polymorphism has been made using the PCR-RFLP technique. The statistical analysis has been made using De Finetti's program. There has not been a significant deviation from the Hardy-Weinberg equilibrium for any group (p=0.229 and p=0.894, respectively). The data analysis revealed that the presence of a C-allele confers a significant risk (p=0.008) for the advanced diabetes nephropathy (OR=4.940, 95% C.I.=1.341-18.198), and the CA-genotype (p=0.015) confers a little lower risk (OR=4.491, 95% C.I.=1.203-16.766). This study shows the association of a mutant C-allele of rs2234694 polymorphism in SOD1-gene with the advanced stages of diabetic nephropathy in patients with type 1 diabetes in Romania, suggesting the involvement of the defense against oxidative stress, as an important link in the pathogeny of diabetic nephropathy.

[The synthesis and effects of nitric oxide at the retinal level]. / Sinteza si efectele monoxidului de azot la nivelul retinei.

Nitric oxide (NO) is synthetized from L-arginine by the aid of an enzyme--NO synthase (NOS). This enzyme has there isoforms, which are either constitutive; neural NOS (nNOS) and endothelial NOS (eNOS) or inducible (iNOS). These three isoforms are expressed also in the retina. NO produced in small amounts by nNOS and eNOS is involved in neurotransmission in the retina and in the regulation of retinal arteriolar tonicity. NO produced in large quantities by iNOS is a bactericidal agent but can also generate inflammation of the retina and even retinal degeneration.

[The molecular mechanism of visual transduction]. / Mecanismul molecular al transductiei vizuale.

Light absorbtion by the visual pigment rhodopsin triggers, through Gt-protein (transducin) coupling, a cascade of events--in the outer segment of the rod cell of the retina--that results in membrane hyperpolarization and nerve excitation. Activated rhodopsin is removed from the cascade of reactions by rhodopsin kinase and arrestin that stop the visual transduction pathway. Thus, when light stimulation ceases, the transduction system is restored to its resting state.