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Carmen Alonso

Publications and source records attributed to Carmen Alonso.

26 records · Page 2Linked to original sources
PubMed2004

Kinetics and immunophenotypic characterization of circulating hematopoietic progenitor cells after peripheral blood stem cell transplantation.

BACKGROUND AND OBJECTIVES: Hematopoietic progenitor cells (HPC) circulate in the peripheral blood (PB) before and after engraftment following autologous or allogeneic peripheral blood stem cell transplantation (PBSCT), although the characteristics of these cells are not known. CD34 protein is a reliable marker for identifying the fraction of hematopoietic cells in which HPC are contained. The CD34(+) cells represent a heterogeneous cell population consisting of both primitive uncommitted as well as pluripotent committed progenitors. The aim of this study was to investigate the kinetics and immunophenotypic characteristics of these post-transplant circulating progenitor cells. DESIGN AND METHODS: Forty-seven auto-PBSCT and nine allo-PBSCT recipients were selected for this study. Samples of PB were taken from each patient 4, 9, 11, 14, 16 and 18 days after the transplant. Cells were incubated with the following combinations of monoclonal antibodies: CD34-FITC/CD90-PE/CD38-CyCrome; CD34-FITC/CD117-PE/HLA-DR-PerCP; CD34-FITC/CD13-PE/CD33-CyCrome and the cells were then analyzed by flow cytometry. RESULTS: CD34(+) cells were undetectable on day +4; they reappeared from day +9 to day +18 along with neutrophil and platelet recovery. Subsets of CD34(+) HPC enriched in pluripotent stem cells (CD90(+)/CD38(low) or HLADR-) were hardly detected during the very early post-transplant period. HPC that expressed myeloid associated antigens (CD33, CD13, and CD117) increased after engraftment and constituted the largest proportion of the hematopoietic progenitor cells. INTERPRETATION AND CONCLUSIONS: Circulating HPC could be detected in the early period after PBSCT. The qualitative and quantitative composition of these cells is similar to that found among HPC from mobilized PB.

Adolescent↗
PubMed2003

Immunohistochemical characteristics defined by tissue microarray of hereditary breast cancer not attributable to BRCA1 or BRCA2 mutations: differences from breast carcinomas arising in BRCA1 and BRCA2 mutation carriers.

PURPOSE: Most familial breast cancers are not associated with BRCA1 or BRCA2 germ-line mutations. Therefore, it is of major importance to define the morphological, immunohistochemical, and molecular features of this group of tumors to improve genetic testing and also gain further insight into the biological characteristics of tumors. EXPERIMENTAL DESIGN: We evaluated the morphological characteristics of 37 tumors arising in women without BRCA1 or BRCA2 mutations, 20 tumors from BRCA1 mutation carriers, and 18 from BRCA2 mutation carriers, all of which were from index patients from breast cancer families. In addition, a tissue microarray was constructed with all tumoral samples to evaluate the immunohistochemical expression of a wide panel of antibodies (11 antibodies) and the amplification of HER-2 and c-MYC genes by fluorescence in situ hybridization. An age-matched group with 50 sporadic breast cancers as controls for non-BRCA1/2 was also included. RESULTS: Non-BRCA1/2 infiltrating ductal carcinomas (IDCs) showed specific differences from BRCA1 tumors. They were of lower grade (1 and 2); more frequently estrogen receptor, progesterone receptor, BCL2 positive, and p53 negative; had a low proliferation rate (Ki-67 immunostaining < 5%); and did not express P-cadherin. With respect to BRCA2 IDCs and control group, non-BRCA1/2 tumors were of lower grade and had a lower proliferation rate. No cases of HER-2 amplification and/or overexpression were observed except in the control group ( approximately 20%). In contrast, c-MYC amplification was present in 18.2, 62.5, and 12.5% of BRCA1, BRCA2, and non-BRCA1/2 IDCs, respectively, and 31% in the control group. CONCLUSIONS: This study thus reveals distinct morphological and immunohistochemical features in non-BRCA1/2 and BRCA1 tumors, whereas BRCA2 tumors present characteristics intermediate between the two phenotypes. In addition, the study also demonstrates the usefulness of tissue microarray technology in the evaluation of the immunophenotypic features of hereditary breast cancer.

Adult↗
PubMed2003

Analysis of BRCA1 and BRCA2 genes in Spanish breast/ovarian cancer patients: a high proportion of mutations unique to Spain and evidence of founder effects.

We screened index cases from 410 Spanish breast/ovarian cancer families and 214 patients (19 of them males) with breast cancer for germ-line mutations in the BRCA1 and BRCA2 genes, using SSCP, PTT, CSGE, DGGE, and direct sequencing. We identified 60 mutations in BRCA1 and 53 in BRCA2. Of the 53 distinct mutations observed, 11 are novel and 12 have been reported only in Spanish families (41.5%). The prevalence of mutations in this set of families was 26.3%, but the percentage was higher in the families with breast and ovarian cancer (52.1%). The lowest proportion of mutations was found in the site-specific female breast cancer families (15.4%). Of the families with male breast cancer cases, 59.1% presented mutations in the BRCA2 gene. We found a higher frequency of ovarian cancer associated with mutations localized in the 5' end of the BRCA1 gene, but there was no association between the prevalence of this type of cancer and mutations situated in the ovarian cancer cluster region (OCCR) region of exon 11 of the BRCA2 gene. The mutations 187_188delAG, 330A>G, 5236G>A, 5242C>A, and 589_590del (numbered after GenBank U14680) account for 46.6% of BRCA1 detected mutations whereas 3036_3039del, 6857_6858del, 9254_9258del, and 9538_9539del (numbered after GenBank U43746) account for 56.6% of the BRCA2 mutations. The BRCA1 330A>G has a Galician origin (northwest Spain), and BRCA2 6857_6858del and 9254_9258del probably originated in Catalonia (northeast Spain). Knowledge of the spectrum of mutations and their geographical distribution in Spain will allow a more effective detection strategy in countries with large Spanish populations.

Base Sequence↗
PubMed2003

Haplotype analysis of the BRCA2 9254delATCAT recurrent mutation in breast/ovarian cancer families from Spain.

A frame-shift 9254del5 mutation was independently identified in 12 families, eleven of them with Spanish ancestors, in a BRCA2 screening performed in 841 breast and/or ovarian cancer families and in 339 women with breast cancer diagnosed before the age of 40 at different centers in France and Spain. We sought to analyze in detail the haplotype and founder effects of the 9254del5 and to estimate the time of origin of the mutation. Eight polymorphic microsatellite markers and two BRCA2 polymorphisms were used for the haplotype analyses. The markers were located flanking the BRCA2 gene spanning a region of 6.1 cM. Our results suggest that these families shared a common ancestry with BRCA2 9254del5, which is a founder mutation originating in the Northeast Spanish, with an estimated age of 92 (95% CI 56-141) generations.

Adult↗
PubMed2003

RNA analysis of eight BRCA1 and BRCA2 unclassified variants identified in breast/ovarian cancer families from Spain.

Germ-line mutations in the breast cancer susceptibility genes BRCA1 and BRCA2 account for a large proportion of hereditary breast/ovarian cancer families. A large number of disease-causing germ-line mutations and variants of unknown pathological significance have been identified in both genes. The majority of these variants have been studied only in genomic DNA and their effects at the mRNA level have not been reported. Our aim was to ascertain the pathological effect of six BRCA1 and two BRCA2 sequence unclassified variants by RNA analysis. Three of the BRCA1 variants are novel: IVS18+5G>A, IVS20-6_IVS20-4del and IVS22-2A>G. Three BRCA1 mutations showed aberrant splicing: Ala1693del, IVS18+5G>A and IVS22-2A>G. The variants G1706A, S1715N and IVS20-6_IVS20-4del in BRCA1, and T2515I and IVS25+9A>C in BRCA2 led to normal transcripts. We compared these RNA results with those obtained from two theoretical splicing prediction methods. The consensus values for the splice sequences (Shapiro and Senapathy 1987) involved in three of the BRCA1 splicing site variants agreed with the RNA results, lending support to the validity of this model. Moreover, we used previously established exonic splicing enhancer (ESE) sequences to ascertain whether the four exonic variants studied fell within predicted ESE motifs and whether they would disrupt ESE functions. Our results suggest that the splicing predictions based on this method are not definitive and should be considered with caution. This work highlights the importance of studying mutations at DNA and RNA levels in order to clarify their pathological effect. This information is essential for providing efficient counseling for breast/ovarian cancer families.

BRCA1 Protein↗
PubMed2002

[Description of a new TP53 gene germline mutation in a family with the Li-Fraumeni syndrome. Genetic counselling to healthy mutation carriers].

BACKGROUND: Li-Fraumeni syndrome is a dominantly inherited disorder characterized by early-onset breast cancer, soft-tissue sarcomas and osteosarcomas, acute leukemia, adrenocortical neoplasms and central nervous system tumors. Germline mutations in gene TP53 are identified in a percentage of affected families. PATIENTS AND METHOD: Eight families with aggregation of childhood sarcomas, brain tumors, breast cancers in pre-menopausal women, and renal tumors were screened for TP53 germ-line mutations. SSCP and posterior direct sequencing were performed for genetic analysis. We also report a previously undescribed family with the Li-Fraumeni syndrome carrying a germline mutation. RESULTS: Seven families fulfilled so-called Li-Fraumeni like criteria and one fulfilled classical criteria. A new germ-line mutation in codon 238 at exon 7 of the gene TP53 was identified in the family fulfilling classical criteria. This mutation has not been previously reported. CONCLUSIONS: The clinical heterogeneity as well as the molecular complexity and consequences of mutation analysis and genetic counseling make it necessary to develop protocols in this area. A multidisciplinary approach is needed; this approach should be coordinated by a Familial Cancer Genetic Counseling Unit.

Adolescent↗
PubMed2002

Nongenomic regulation of the kinetics of exocytosis by estrogens.

The role of nongenomic action of estrogens on elicited catecholamine secretion and exocytosis kinetics was studied in perfused rat adrenals and in cultured bovine chromaffin cells. 17beta-Estradiol as well as the estrogen receptor modulators raloxifene and LY117018, but not 17alpha-estradiol, inhibited at the micromolar range the catecholamine output elicited by acetylcholine or high potassium. However, these agents failed to modify the secretion elicited by high Ca(2+) in glands treated with the ionophore A-23187 (calcimycin), suggesting that estrogens did not directly act on the secretory machinery. At the single cell level, estrogens modified the kinetics of exocytosis at nanomolar range. All of the drugs tested except 17alpha-estradiol produced a profound slowing down of the exocytosis as measured by amperometry. LY117018 also reduced the granule content of catecholamines. 17beta-Estradiol reduced the intracellular free Ca(2+) but only at micromolar concentrations, whereas nanomolar concentrations increased the cAMP levels. These effects were reproduced with the nonpermeable drug 17beta-estradiol-horseradish peroxidase and antagonized with nanomolar concentrations of the antiestrogen ICI 182,780 (fulvestrant). Our data suggest the presence of membrane sites that regulate both the exocytotic phenomenon and the total catecholamine release with high and low affinity, respectively.

Adrenal Glands↗