Biomedical subjects

Manuel Hidalgo Pascual

Publications and source records attributed to Manuel Hidalgo Pascual.

3 recordsLinked to original sources

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 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.

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