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Biomedical subjects

Luis Miguel Real

Publications and source records attributed to Luis Miguel Real.

11 recordsLinked to original sources
PubMed2006

Lack of association between NOS3 Glu298Asp and breast cancer risk: a case-control study.

Nitric oxide (NO) plays a central role in the physiololgy and pathology of diverse tissues. Different studies provide data suggesting that the endothelial cell nitric oxide synthase (NOS3) expression in peritumoral microvessels might be a prognostic indicator in breast cancer patients. However, the putative contribution of common NOS3 germline variants to breast cancer risk remained unknown. A recent work comprising 269 breast cancer patients and 244 controls suggested that NOS3 Glu298Asp polymorphism is associated to breast cancer risk (OR=1.9). We performed an independent analysis of these results in 440 unrelated patients and 321 controls from Spanish population. Although our study was 90% powered to detect ORs >/=1.55, did not find any significant difference in the Glu298Asp allele distribution between cases and controls (P > 0.42). These putative reasons for this result are discussed.

Aspartic Acid↗
PubMed2006

Pyrosequencing protocol requiring a unique biotinylated primer.

BACKGROUND: DNA sequencing has markedly changed the nature of biomedical research. Large-scale sequencing projects have generated several millions of potential polymorphisms widespread in the human genome requiring validation and incorporation into screening panels. As a consequence, high-throughput analysis of these variants in different populations of interest is now the cornerstone of structural genomics. Pyrosequencing is a versatile technique allowing an easy 96-well typing format. However, every polymorphism requires a specific labeled primer to generate a single-stranded DNA fragment containing the region of interest. METHODS: We describe how with an adjusted primer stoichiometry we can standardize the labeling of every amplicon with a single biotinylated universal primer (BM13S). RESULTS: We circumvent the need for specific biotinylated primers for each single-nucleotide polymorphism (SNP) under study. As an example, we assessed this novel protocol by genotyping three SNPs mapping calpain-10, caveolin-1 and CYP19A1. CONCLUSION: The present approach represents an alternative to standard pyrosequencing protocols, since it requires a single biotinylated primer that is suitable for each SNP under study.

Biotinylation↗
PubMed2006

Exploring allelic imbalance within paraffin-embedded tumor biopsies using pyrosequencing technology.

BACKGROUND: The comparison of molecular genetic changes in healthy and pathological tissues has historically led to the identification of oncogenes and tumor suppressor genes. It is very common that studies investigating loss of heterozygosity are carried out retrospectively on paraffin-embedded samples. METHODS: In this study, we evaluated the power of pyrosequencing for determining the loss of heterozygotic regions. The present method uses the fact that pyrosequencing is an accurate, sensitive and reproducible technique. The method is also simple to perform, with results available in 96-well format, making the assays amenable to automation. Thus, we analyzed nine single nucleotide polymorphisms along 1 Mb between the EMSY and PAK1 genes on 11q13, a region frequently rearranged in different tumors and cell lines. We assessed the study using samples from breast cancer and thyroid cancer biopsies. RESULTS AND CONCLUSIONS: We conclude that this technique is capable of detecting variations of >10% in allele loss. However, strong allele imbalances were detected, depending on the origin of the sample. Seven out of the nine markers used exhibited differential allele amplification, depending on the DNA quality (p<0.01).

Allelic Imbalance↗
PubMed2006

Genetic analysis of CAV1 gene in hypertension and metabolic syndrome.

Recently, we reported that the polymorphism 1132T>C (GenBank: AF519768.1) of the NOS3 gene was associated with susceptibility to metabolic syndrome (MS) in hypertensive patients. This suggests that other genes such as CAV1, whose product (CAV1) regulates eNOS activity, could also be related to this phenotype. In this work we investigated the following: i) whether CAV1 is a quantitative trait locus of clustering of atherothrombotic traits associated with MS; ii) whether CVA1 is associated with hypertension or MS in hypertensive patients; and iii) whether genetic interaction between NOS3 and CAV1 is involved in the susceptibility or protection to hypertension associated with MS. To carry out the study, we genotyped 285 randomly selected individuals and 175 hypertensive patients, all of them < or = 60 years old, with two polymorphisms of the CAV1 gene: the 22285 C>T and the 22375-22375 del AC (GenBank AF125348), and the 1132T>C polymorphism of the NOS3 gene. To perform sample genotyping, we used pyrosequencing and FRET techniques. The 22285 C-22375-22375 del (Cd) haplotype of CAV1 gene was associated with low levels of blood pressure in the general population. Moreover, it was a genetic protection factor against MS in hypertensive patients. In addition, we found no evidence of gene-gene interaction between NOS3 and CAV1 genes with regard to that phenotype.

Case-Control Studies↗
PubMed2006

Genetic analysis of caveolin-1 and eNOS genes in colorectal cancer.

Caveolae are involved in physical compartmentalization between different groups of signaling events. Its main component, CAV1, modulates different pathways in cellular physiology. The emerging evidence pointing to the role of CAV1 in cancer led us to study whether different alleles of this gene are associated with colorectal cancer (CRC). Since one of the most characterized enzymes regulated by CAV1 is eNOS, we decided to include both genes in this study. We analyzed five SNPs in 360 unrelated CRC patients and 550 controls from the general population. Two of these SNPs were located within eNOS and three within the CAV1 gene. Although haplotype distribution was not associated with CRC, haplotype TiA (CAV1) was associated with familiar forms of CRC (p<0.05). This was especially evident in CRC antecedents and nuclear forms of CRC. If both CG (eNOS) and TiA (CAV1) haplotypes were taken together, this association increased in significance. Thus, we propose that CAV1, either alone or together with eNOS alleles, might modify CRC heritability.

Aged↗
PubMed2005

Preliminary molecular genetic analysis of the Receptor Interacting Protein 140 (RIP140) in women affected by endometriosis.

BACKGROUND: Endometriosis is a complex disease affecting 10-15% of women at reproductive age. Very few genes are known to be altered in this pathology. RIP140 protein is an important cofactor of oestrogen receptor and many other nuclear receptors. Targeting disruption experiments of nrip1 gene in mice have demonstrated that nuclear receptor interacting protein 1 gene (nrip1), the gene encoding for rip140 protein, is essential for female fertility. Specifically, mice null for nrip1 gene are viable, but females are infertile because of complete failure of mature follicles to release oocytes at ovulation stage. The ovarian phenotype observed in mice devoid of rip140 closely resembles the luteinized unruptured follicle (LUF) syndrome that is observed in a high proportion of women affected of endometriosis or idiopathic infertility. Here we present a preliminary work that analyses the role of NRIP1 gene in humans. METHODS: We have sequenced the complete coding region of NRIP1 gene in 20 unrelated patients affected by endometriosis. We have performed genetic association studies by using the DNA variants identified during the sequencing process. RESULTS: We identified six DNA variants within the coding sequence of NRIP1 gene, and five of them generated amino acid changes in the protein. We observed that three of twenty sequenced patients have specific combinations of amino-acid variants within the RIP140 protein that are poorly represented in the control population (p = 0.006). Moreover, we found that Arg448Gly, a common polymorphism located within NRIP1 gene, is associated with endometriosis in a case-control study (59 cases and 141 controls, Pallele positivity test = 0.027). CONCLUSION: Our results suggest that NRIP1 gene variants, separately or in combinations, might act as predisposing factors for human endometriosis.

Journal Article↗
PubMed2004

Association of NOS3 gene with metabolic syndrome in hypertensive patients.

Recent data from animal models indicate that the eNOS null mice present a phenotype that resemble the human metabolic syndrome (hypertension, insulin resistance and hypertriglyceridemia). In this work, we have studied whether NOS3 gene, previously related to endothelial dysfunction, might have a role in metabolic syndrome susceptibility in hypertensive patients. To carry out the study, we genotyped 105 hypertensive patients < or = 60 years old with two polymorphisms of NOS3 gene: 1132 T>C and 7164 G>T (GeneBank:AF519768.1). To check the allelic frequency of these polymorphisms in our geographical area, we also genotyped 94 unselected healthy controls (control group). To perform sample genotyping, we designed a novel FRET system coupled to real time PCR. There were no differences in genotypic distribution or allelic frequency between hypertensive patients and the control group. However, we observed that 786CC genotype was significantly more frequent in hypertensive patients with metabolic syndrome than in those without the syndrome (p=0.0022). When both polymorphisms were analyzed, we identified the 786C894G as the risk haplotype for metabolic syndrome susceptibility (p=0.011). These data suggest a role of the NOS3 gene in the pathogenesis of metabolic syndrome in hypertensive patients.

Alleles↗
PubMed2003

Scanning of Y-chromosome azoospermia factors loci using real-time polymerase chain reaction and melting curve analysis.

OBJECTIVE: To develop a novel method to scan AZF loci looking for microdeletions. DESIGN: Molecular method development. SETTING: Men undergoing reproductive techniques in a private fertility unit. Molecular methods were performed in a private center for biomedical research. PATIENT(S): : Fifty-eight men divided in two groups depending on seminal analyses. A group of 19 women were also included as positive controls (absence of amplification). INTERVENTION(S): Peripheral blood extraction and DNA purification. MAIN OUTCOME MEASURE(S): Our method is based on real-time polymerase chain reaction (PCR) and melting curve analysis. We performed the screening of 16 selected sequence tagged sites (STS) within AZF loci, and we also calculated the mean, range, and standard deviation for melting temperature patterns and the crossing points values for each STS tested. RESULT(S): We detected one azoospermic patient with several STS deleted within the AZFc region. No deletions were detected in a group of 13 healthy men, and no amplification for any of the STS tested were observed in the positive control group (19 healthy women). CONCLUSION(S): We have developed a novel method based on real-time PCR and melting curve analysis to scan AZF loci looking for microdeletions This method is fast and reliable and permits the scanning of DNA from one patient per hour, minimizing the risk of cross contamination, and false-positive and false-negative results.

Adult↗
PubMed2003

Specific CAPN10 gene haplotypes influence the clinical profile of polycystic ovary patients.

Recently, several research groups have evaluated CAPN10 gene in polycystic ovarian syndrome (PCOS) patients and other phenotypes, including hirsutism or intermediate phenotypes of PCOS. Molecular genetic analysis of CAPN10 gene indicates that different alleles may play a role in PCOS susceptibility and could be associated with idiopathic hirsutism. However, these observations are not exempt from controversy, because independent studies cannot replicate these preliminary findings. We present a haplotype-phenotype correlation study of CAPN10 haplotypes in 148 women showing ecographically detected polycystic ovaries (PCO) combined with one or more of these clinical symptoms: amenorrhea or severe oligomenorrhea, hyperandrogenism, and anovulatory infertility, as well as 93 unrelated controls. We have reconstructed and analyzed 482 CAPN10 haplotypes in patients and controls. We detected the association of UCSNP-44 allele with PCO phenotype in the Spanish population (P = 0.02). In addition, we identified several CAPN10 alleles associated to phenotypic differences observed between PCO patients, such as the presence of hypercholesterolemia (haplotype 1121, P = 0.005), presence of hyperandrogenic features (P = 0.05), and familial cancer incidence (haplotype 1111, P = 0.0005). Our results confirm the association of UCSNP-44 allele with PCO phenotype in the Spanish population. Moreover, we have identified novel candidate risk alleles and genotypes, within CAPN10 gene, that could be associated with important phenotypic and prognosis differences observed in PCOS patients.

Amenorrhea↗
PubMed2002

Comment: CAPN10 alleles are associated with polycystic ovary syndrome.

Polycystic ovary syndrome (PCOS) is characterized by chronic anovulation infertility, hyperandrogenemia, and frequently insulin resistance. This study investigated whether polymorphisms in the CAPN10 gene are related with PCOS etiology. The allelic frequencies and genotypes of CAPN10 polymorphisms UCSNP-44, 43, 19, and 63 were determined in 55 well characterized women with polycystic ovaries and 93 unrelated healthy controls using spectrofluorimetric analyses and real-time PCR. Our data indicate that CAPN10 UCSNP-44 allele is associated with PCOS in the Spanish population (P = 0.01). These results support a role of Calpain 10 gene in PCOS susceptibility in humans.

Calpain↗