[show abstract][hide abstract] ABSTRACT: The aim of this study was to analyze whether tyrosine phosphorylation in tumoral arteries may modulate their vascular response. To do this, mesenteric arteries supplying blood flow to colorectal tumors or to normal intestine were obtained during surgery and prepared for isometric tension recording in an organ bath. Increasing tyrosine phosphorylation with the phosphatase inhibitor, sodium orthovanadate produced arterial contraction which was lower in tumoral than in control arteries, whereas it reduced the contraction to noradrenaline in tumoral but not in control arteries and reduced the relaxation to bradykinin in control but not in tumoral arteries. Protein expression of VEGF-A and of the VEGF receptor FLT1 was similar in control and tumoral arteries, but expression of the VEGF receptor KDR was increased in tumoral compared with control arteries. This suggests that tyrosine phosphorylation may produce inhibition of the contraction in tumoral mesenteric arteries, which may increase blood flow to the tumor when tyrosine phosphorylation is increased by stimulation of VEGF receptors.
BioMed research international. 01/2013; 2013:545983.
[show abstract][hide abstract] ABSTRACT: Amino-terminal procollagen propeptide of type I collagen (P1NP) and cross-linked C-terminal telopeptide of type I collagen (βCTX) are two of the more sensitive bone markers for reflecting and monitoring patients with an increased bone turnover as observed in primary hyperparathyroidism (PHPT) patients.
The present study was performed to evaluate the trend of type I collagen markers one year after parathyroidectomy (PTX) and to examine the relationships between serum P1NP and βCTX levels and bone mineral density (BMD) change after PTX in PHPT Spanish patients.
Fifty-three PHPT patients were enroled and were followed for one year by measuring lumbar BMD, lumbar t-score, lumbar z-score, PTH, calcium, phosphorus, P1NP and βCTX.
Pre-surgery concentrations of both markers were elevated (P1NP: 90.71±5.03; βCTX: 1.52±0.44). A significant decrease was observed in mean post-operative βCTX and P1NP concentrations (p<0.0001). Levels of BMD, t-score and z-score at lumbar spine were relatively low (BMD: 0.75±0.16; z-score -0.90±0.23; t-score -2.51±0.32); after PTX a significant increase was observed in the levels of these three parameters. P1NP and βCTX were correlated with lumbar BMD change one year after PTX (P1NP: r=0.79, p=0.016; βCTX: r=0.89, p=0.003).
Pre-surgery concentrations of both bone markers were elevated and a significant decrease after PTX was found. Serum βCTX and P1NP levels were potently related to lumbar BMD changes over one year after PTX. The measurement of βCTX and P1NP would be useful to predict long-term changes in lumbar BMD after PTX.
Journal of endocrinological investigation 09/2011; 35(7):640-4. · 1.65 Impact Factor
[show abstract][hide abstract] ABSTRACT: Colorectal cancer (CRC) has become a highly relevant condition nowadays. In this respect, advances in the understanding of its molecular basis are key for an adequate management. From the time when the adenoma-carcinoma sequence was formulated as a carcinogenesis model to this day, when -among other things- three major carcinogenic pathways have been identified, the CRC concept has evolved from that of a single disease to the notion that each CRC is a differentiated condition in itself. The suppressor or chromosome instability pathway, the mutator or microsatellite instability pathway, and the methylator or CpG island methylation pathway allow various phenotypes to be identified within CRC. Similarly, the presence of different changes in certain genes confers several behaviors on CRC from both the prognostic and responsive standpoints to specific therapies. However, this apparent complexity does help develop the clinical management of this disease through the identification of novel, more specific therapy targets, and also markers for various behaviors within the condition, which will most likely lead us to an individualized management for these patients.
Revista espanola de enfermedades digestivas: organo oficial de la Sociedad Espanola de Patologia Digestiva 01/2011; 103(1):29-35. · 1.65 Impact Factor
[show abstract][hide abstract] ABSTRACT: The importance of colorectal cancer (CRC) is increasing. A proportion show a hereditary component, as in Lynch syndrome and Familial Adenomatous Polyposis, and a recently defined entity as well, namely, Familial Colorectal Cancer type X. The high probability to develop CRC in these groups may, at the time of recognition, change surgical management, including its timing or even the surgical technique. In some cases prophylactic surgery can play an important role. The possibility of using tools that allow recognition of the aforementioned syndromes, including microsatellite instability, immunohistochemistry for DNA mismatch repair system proteins, and especially their mutations, is on the basis of therapeutic strategies that differ from those employed in sporadic CRC cases.
Revista espanola de enfermedades digestivas: organo oficial de la Sociedad Espanola de Patologia Digestiva 08/2009; 101(8):536-40. · 1.65 Impact Factor
[show abstract][hide abstract] ABSTRACT: To examine the reaction of tumour arteries to endothelin-1, we obtained arteries supplying blood flow to colorectal tumours from patients, as well as mesenteric arteries supplying the normal colon tissue from the same patients and mesenteric arteries from patients without a colorectal tumour pathology. The contraction in response to endothelin-1 and the relaxation produced by bradykinin was recorded in each of these arteries. Accordingly, the sensitivity to endothelin-1 but not the maximal response, was higher in the arteries supplying colorectal tumours than in mesenteric arteries supplying normal colon or in mesenteric arteries from patients with no tumour pathology. The contraction produced by endothelin-1 was not modified by exposure to L-NAME or meclofenamate in arteries supplying both the tumour and the normal colon. The endothelin ET(A) andET(B) receptors were expressed similarly in arteries supplying the tumour or normal colon. However, the antagonist of the endothelin ET(B) receptors BQ788 (10(-6) M) decreased the contractions in the arteries supplying the tumour but not in those supplying the normal colon. By contrast, the antagonist of endothelin ET(A) receptors BQ123 (10(-6) M) reduced the contraction equally in both these types of arteries. Likewise, in arteries precontracted with U46619, the relaxation in response to bradykinin was similar in all three types of arteries. Together, these results suggest that the arteries supplying human colorectal tumours are more sensitive to endothelin-1, which could be due to the enhanced activity of endothelin ET(B) receptors in the absence of any change in the modulatory effect of nitric oxide or prostanoids in the arterial response to this peptide.
Experimental Biology and Medicine 11/2008; 233(12):1602-7. · 2.80 Impact Factor
[show abstract][hide abstract] ABSTRACT: Papillary thyroid cancer (PTC) accounts for 80% of all thyroid malignancies, and genetic alterations associated to its etiology remain largely unknown. Chromosomal band 11q13 seems to be one of the most frequently amplified regions in human cancer, providing several candidate genes that need detailed characterization. The aim of our study was to investigate the existence of allelic imbalance at EMSY, CAPN5, and PAK1, as candidate genes within 11q13.5-q14 region using a single nucleotide polymorphism-based analysis. We selected a panel of 9 polymorphisms that were analyzed in 41 thyroid carcinoma samples, their contralateral non-pathological tissue and 178 controls from the general population. We did not detect allelic imbalance at these loci in our series. However, we observed a difference in the EMSY-haplotype distribution among PTC patients when compared to controls (odds ratio=2.00; p=0.02). We conclude that 11q13.5-q14 is not imbalanced in PTC, but there is evidence suggesting that EMSY might be of relevance in PTC etiology.
Journal of endocrinological investigation 08/2008; 31(7):618-23. · 1.65 Impact Factor
[show abstract][hide abstract] ABSTRACT: On its physiological cellular context, PTTG1 controls sister chromatid segregation during mitosis. Within its crosstalk to the cellular arrest machinery, relies a checkpoint of integrity for which gained the over name of securin. PTTG1 was found to promote malignant transformation in 3T3 fibroblasts, and further found to be overexpressed in different tumor types. More recently, PTTG1 has been also related to different processes such as DNA repair and found to trans-activate different cellular pathways involving c-myc, bax or p53, among others. PTTG1 over-expression has been correlated to a worse prognosis in thyroid, lung, colorectal cancer patients, and it can not be excluded that this effect may also occur in other tumor types. Despite the clinical relevance and the increasing molecular characterization of PTTG1, the reason for its up-regulation remains unclear.
We analysed PTTG1 differential expression in PC-3, DU-145 and LNCaP tumor cell lines, cultured in the presence of the methyl-transferase inhibitor 5-Aza-2'-deoxycytidine. We also tested whether the CpG island mapping PTTG1 proximal promoter evidenced a differential methylation pattern in differentiated thyroid cancer biopsies concordant to their PTTG1 immunohistochemistry status. Finally, we performed whole-genome LOH studies using Affymetix 50 K microarray technology and FRET analysis to search for allelic imbalances comprising the PTTG1 locus.
Our data suggest that neither methylation alterations nor LOH are involved in PTTG1 over-expression. These data, together with those previously reported, point towards a post-transcriptional level of misregulation associated to PTTG1 over-expression.
[show abstract][hide abstract] ABSTRACT: DNA sequencing has markedly changed the nature of biomedical research, identifying millions of polymorphisms along the human genome that now require further analysis to study the genetic basis of human diseases. Among the DNA-sequencing platforms available, Pyrosequencing has become a useful tool for medium-throughput single nucleotide polymorphism (SNP) genotyping, mutation detection, copy-number studies and DNA methylation analysis. Its 96-well genotyping format allows reliable results to be obtained at reasonable costs in a few minutes. However, a specific biotinylated primer is usually required for each SNP under study to allow the capture of single-stranded DNA template for the Pyrosequencing assay. Here, we present an alternative to the standard labeling of PCR products for analysis by Pyrosequencing that circumvents the requirement of specific biotinylated primers for each SNP of interest. This protocol uses a single biotinylated primer that is simultaneously incorporated into all M13-tagged PCR products during the amplification reaction. The protocol covers all steps from the PCR amplification and capture of single-stranded template, its preparation, and the Pyrosequencing assay itself. Once the correct primer stoichiometry has been determined, the assay takes around 2 h for PCR amplification, followed by 15-20 min (per plate) to obtain the genotypes.