Biomedical subjects

Dominique Vidaud

Publications and source records attributed to Dominique Vidaud.

18 recordsLinked to original sources

PubMed2007

Microarray-based identification of tenascin C and tenascin XB, genes possibly involved in tumorigenesis associated with neurofibromatosis type 1.

PURPOSE: Neurofibromatosis type 1 (NF1) is an autosomal dominant disorder with a complex variety of clinical manifestations. The hallmark of NF1 is the onset of heterogeneous (dermal or plexiform) benign neurofibromas. Plexiform neurofibromas can give rise to malignant peripheral nerve sheath tumors, which are resistant to conventional therapies. EXPERIMENTAL DESIGN: To identify new signaling pathways involved in the malignant transformation of plexiform neurofibromas, we applied a 22,000-oligonucleotide microarray approach to a series of plexiform neurofibromas and malignant peripheral nerve sheath tumors. Changes in the expression of selected genes were then confirmed by real-time quantitative reverse transcription-PCR. RESULTS: We identified two tenascin gene family members that were significantly deregulated in both human NF1-associated tumors and NF1-deficient primary cells: Tenascin C (TNC) was up-regulated whereas tenascin XB (TNXB) was down-regulated during tumor progression. TNC activation is mainly due to the up-regulation of large TNC splice variants. Immunohistochemical studies showed that TNC transcripts are translated into TNC protein in TNC-overexpressing tumors. Aberrant transcriptional activation of TNC seems to be principally mediated by activator protein transcription factor complexes. CONCLUSION: TNXB and TNC may be involved in the malignant transformation of plexiform neurofibromas. Anti-TNC antibodies, already used successfully in clinical trials to treat malignant human gliomas, may be an appropriate new therapeutic strategy for NF1.

Alternative Splicing↗

PubMed2006

High predictive value of early viral kinetics in retreatment with peginterferon and ribavirin of chronic hepatitis C patients non-responders to standard combination therapy.

BACKGROUND/AIMS: To evaluate the efficacy of peginterferon alfa-2b and ribavirin in unselected consecutive patients with chronic hepatitis C, treated outside of trials, who were relapsers or non-responders to interferon and ribavirin combination. METHODS: One hundred and fifty-four patients were evaluated. There were 101 non-responders and 53 relapsers to standard combination therapy. Patients were retreated with peginterferon alfa-2b 1.5 microg/kg/wk plus ribavirin 1000-1200 mg/day during 48 weeks. RESULTS: Forty-four patients (28.6%) achieved sustained virological response (SVR). Rapid (week 4) and early (week 12) virological response had high negative predictive values of SVR (94% and 97%, respectively); however positive predictive values were relatively low (52% and 49%, respectively). Relapsers had higher SVR rates (58.5%) than non-responders (13%) p<0.0001. In non-responders, SVR raised to 50% in patients with genotype non-1 and mild or moderate fibrosis. In multivariate analysis, predictors of SVR were: relapse after interferon plus ribavirin combination, mild or moderate fibrosis, genotype non-1 and baseline viral load <2 million copies/ml. CONCLUSIONS: Relapsers to interferon plus ribavirin therapy, and non-responders with genotype non-1 and mild or moderate fibrosis, achieved a relatively high SVR rate following retreatment with peginterferon plus ribavirin. Early viral kinetics had a high negative predictive value of SVR.

Antiviral Agents↗

PubMed2006

Conservation of hotspots for recombination in low-copy repeats associated with the NF1 microdeletion.

Several large-scale studies of human genetic variation have provided insights into processes such as recombination that have shaped human diversity. However, regions such as low-copy repeats (LCRs) have proven difficult to characterize, hindering efforts to understand the processes operating in these regions. We present a detailed study of genetic variation and underlying recombination processes in two copies of an LCR (NF1REPa and NF1REPc) on chromosome 17 involved in the generation of NF1 microdeletions and in a third copy (REP19) on chromosome 19 from which the others originated over 6.7 million years ago. We find evidence for shared hotspots of recombination among the LCRs. REP19 seems to contain hotspots in the same place as the nonallelic recombination hotspots in NF1REPa and NF1REPc. This apparent conservation of patterns of recombination hotspots in moderately diverged paralogous regions contrasts with recent evidence that these patterns are not conserved in less-diverged orthologous regions of chimpanzees.

Animals↗

PubMed2006

Liver fibrosis in women with chronic hepatitis C: evidence for the negative role of the menopause and steatosis and the potential benefit of hormone replacement therapy.

BACKGROUND AND AIMS: The rates of fibrosis progression in chronic hepatitis C are significantly different between males and females. The antifibrogenic effect of oestrogen has been proposed, possibly via inhibition of stellate cells. The aim of this study was to evaluate the severity of chronic hepatitis C in women, in relation to the menopause, steatosis and hormone replacement therapy (HRT). METHODS: From November 2003 to October 2004, women with chronic hepatitis C were enrolled prospectively. A questionnaire was completed prospectively and a blood sample was obtained on the day of biopsy. We identified characteristics associated with moderate/severe fibrosis using univariate and multivariate analysis. RESULTS: 251 women were included in the study. 122 women (52%) were menopausal and 65 were receiving HRT. 61 (24%) women with moderate/severe fibrosis (F2-F4, Metavir score) had a longer known duration of infection (>15 years), a higher body mass index and presented with steatosis more frequently than 190 (76%) women with mild fibrosis (F0-F1). Women with F2-F4 were more often menopausal (67% v 47%). The probability of fibrosis F2-F4 was lower for menopausal women receiving HRT (p = 0.012). Steatosis was more frequent and more severe in menopausal women. CONCLUSIONS: Severity of fibrosis was associated with a longer duration of infection (>15 years), a higher body mass index, advanced steatosis and the menopause. Menopausal women receiving HRT presented with a lower stage fibrosis. These results reinforce the hypothesis of a protective role of oestrogens in the progression of fibrosis. Steatosis may be implicated in the progression of fibrosis after the menopause.

Adolescent↗

PubMed2006

Global proteomic analysis of microdissected cirrhotic nodules reveals significant biomarkers associated with clonal expansion.

Cirrhosis is a heterogeneous tissue composed of polyclonal regenerative and monoclonal neoplastic, potentially malignant nodules from which hepatocellular carcinoma (HCC) might develop. The aim of this study was to investigate proteomic profile changes associated with clonal expansion of cirrhotic nodules and malignant transformation of monoclonal nodules. Seventy-one cirrhotic nodules from 10 female patients with six HCC were dissected from liver surgical specimen by laser capture microdissection. Clonal status of each nodule was assessed by the study of X-chromosome inactivation pattern using the human androgen receptor. Protein profiles were determined by surface-enhanced laser desorption ionisation-time-of-flight technology using Q10 arrays (Cyphergen ProteinChip). Molecular weight of differentially expressed protein peaks was assessed. An average of 50 protein peaks was obtained for each nodule's profile. Comparison of protein profiles in polyclonal (n=45) and monoclonal cirrhotic nodules (n=26) identified three differentially expressed protein peaks (10,092, 54,025 and 62,133 Da). All were upregulated in monoclonal nodules. Twelve peaks were differentially expressed between monoclonal nodules and HCC with nine proteins upregulated in cancer samples. This study confirms that proteome analysis can be achieved from a limited number of microdissected cells, and provides further insight into the process of clonal expansion and malignant transformation of cirrhotic nodules.

Adult↗

PubMed2006

Genetic polymorphisms in antioxidant enzymes modulate hepatic iron accumulation and hepatocellular carcinoma development in patients with alcohol-induced cirrhosis.

Manganese superoxide dismutase (MnSOD) converts the superoxide anion into H(2)O(2), which, unless it is detoxified by glutathione peroxidase 1 (GPx1), can increase hepatic iron and can react with iron to form genotoxic compounds. We investigated the role of Ala/Val-MnSOD and Pro/Leu-GPx1 polymorphisms on hepatic iron accumulation and hepatocellular carcinoma development in patients with alcoholic cirrhosis. Genotypes were determined in 162 alcoholic patients with cirrhosis but without hepatocellular carcinoma initially, who were prospectively followed up for hepatocellular carcinoma development. We found that patients with two Val-MnSOD alleles (slow H(2)O(2) production) and two Pro-GPx1 alleles (presumably quick H(2)O(2) detoxification) had a lower risk of hepatocellular carcinoma development than other patients (chi(2) trend test, P = 0.001; log-rank, P = 0.0009). Indeed, hepatocellular carcinoma percentage was 0% in subjects with this "2Val-MnSOD/2Pro-GPx1" genotype versus 16%, 27%, and 32% in "2Val-MnSOD/1or2Leu-GPx1," "1or2Ala-MnSOD/2Pro-GPx1," and "1or2Ala-MnSOD/1or2Leu-GPx1" patients, respectively. The percentage of patients with stainable hepatic iron increased progressively with these genotypic associations: 22%, 28%, 50%, and 53%, respectively (chi(2) trend test, P = 0.005). Stainable iron was a risk factor for hepatocellular carcinoma (log-rank, P = 0.0002; relative risk, 3.40). In conclusion, polymorphisms in antioxidant enzymes modulate hepatic iron accumulation and hepatocellular carcinoma development in French alcoholic patients with cirrhosis.

Alleles↗

PubMed2006

Prothrombin Saint-Denis: a natural variant with a point mutation resulting in Asp to Glu substitution at position 552 in prothrombin.

A new prothrombin variant, with a point mutation at nucleotide 20 029 resulting in Asp 552 to Glu substitution (prothrombin numbering), has been identified in a male newborn. Plasma prothrombin level was <3%, 16% and 60% when measured by clotting, chromogenic and immunological assays respectively. The substitution did not affect the rate of prothrombin conversion to thrombin but altered thrombin activity. Amino acid 552 has been reported to be involved in the allosteric transition, which is induced by sodium binding to thrombin. This is the first known amino acid substitution at this site to result in dysprothrombinaemia.

Base Sequence↗

PubMed2005

Molecular profiling of early stage liver fibrosis in patients with chronic hepatitis C virus infection.

The molecular mechanisms of acute hepatitis C virus (HCV) infection, end-stage hepatitis (cirrhosis), and hepatocellular carcinoma have been extensively studied, but little is known of the changes in liver gene expression during the early stages of liver fibrosis associated with chronic HCV infection, that is, the transition from normal liver (NL) of uninfected patients to the first stage of liver fibrosis (F1-CH-C). To obtain insight into the molecular pathogenesis of F1-CH-C, we used real-time quantitative reverse transcriptase-polymerase chain reaction (RT-PCR) to study the mRNA expression of 240 selected genes in liver tissue with F1-CH-C, in comparison with NL. The expression of 54 (22.5%) of the 240 genes was significantly different between F1-CH-C and NL; 46 genes were upregulated and 8 were downregulated in F1-CH-C. The most noteworthy changes in gene expression mainly affected the transcriptional network regulated by interferons (IFNs), including both IFN-alpha/beta-inducible genes (STAT1, STAT2, ISGF3G/IRF9, IFI27, G1P3, G1P2, OAS2, MX1) and IFN-gamma-inducible genes (CXCL9, CXCL10, CXCL11). Interesting, upregulation of IFN-alpha/beta-inducible genes (but not IFN-gamma-inducible genes) was independent of histological scores (grade and stage of fibrosis) and HCV characteristics (hepatic HCV mRNA levels and the HCV genotype), and was specific to HCV (as compared to hepatitis B virus (HBV)). Other genes dysregulated in F1-CH-C, albeit less markedly than IFN-alpha/beta- and IFN-gamma-inducible genes, were mainly involved in the activation of lymphocytes infiltrating the liver (IFNG, TNF, CXCL6, IL6, CCL8, CXCR3, CXCR4, CCR2), cell proliferation (p16/CDKN2A, MKI67, p14/ARF), extracellular matrix remodeling (MMP9, ITGA2), lymphangiogenesis (XLKD1/LYVE), oxidative stress (CYP2E1), and cytoskeleton microtubule organization (STMN2/SCG10). Thus, a limited number of signaling pathways, and particularly the transcriptional network regulated by interferons, are dysregulated in the first stage of HCV-induced liver fibrosis. Some of the genes identified here could form the basis for new approaches aimed at refining IFN-based therapies for chronic HCV infection.

Gene Expression↗

PubMed2005

Noonan syndrome type I with PTPN11 3 bp deletion: structure-function implications.

Noonan syndrome was recently reported to be caused by mutations in the PTPN11 gene in 40% of the cases. This gene encodes the nonreceptor-type protein tyrosine phosphatase SHP-2 and has been shown to be self down-regulated with the concurrency of two SH2 domains. Insertion of a specific loop (D'EF) from N-terminal SH2 domain into the SHP-2 active-site is responsible for the reversible inhibition of the phosphatase activity. Here we report the first in frame trinucleotide deletion resulting in the removal of Aspartate 61 (D61del), a key residue of the N-terminal SH2 D'EF loop. Energetic-based structural analysis and electrostatic calculations carried out on the wild-type and mutant proteins predict lower stability of the D'EF loop for the D61del variant as compared to the wild type indicating better access to the active site and most likely an enzyme activated for longer extent. Similar computations were performed on the previously functionally characterized gain-of-function D61Y mutant and similar behaviors were observed. The simulation data for the D61del and D61Y mutants suggest that both variants could yield more catalytic cycles than the wild-type molecule in the same timespan because of the opening of the active site. It also supports the notion that D61 plays a major role for proper down-regulation of the protein tyrosine phosphatase activity of SHP-2.

Adult↗

PubMed2005

[Mutation mechanisms and their consequences].

The identification of mutations leading to human genetic diseases has grown into an intensive research field during the last few years. Through novel DNA analysis progress, it is now possible to determine the mutational spectrum for a given genetic disease and international databases are now available online. Genetic diagnosis of hereditary diseases has become an essential tool in genetic counselling and prenatal diagnosis. The knowledge of the deleterious mutation type and the molecular associated mechanism is fundamental in order to devise the optimal molecular diagnosis strategy. This review aims to present the various mutation categories involved in genetic diseases (single base-pair substitutions, small deletions or insertions, dynamic mutations, gross DNA lesions...) and to summarize our current knowledge about the main molecular mechanisms responsible for these mutations. Their deleterious consequences on gene expression, including transcription and transcript maturation, and protein loss or gain of function are also discussed in this review.

Chromosome Inversion↗

PubMed2005

Liver gene expression signature of mild fibrosis in patients with chronic hepatitis C.

BACKGROUND & AIMS: The molecular mechanisms of hepatocellular carcinoma have been studied, but little is known of the changes in liver gene expression during the different stages of chronic hepatitis C virus (HCV) infection, in particular the transition from mild to moderate fibrosis. METHODS: We used real-time quantitative RT PCR to study the messenger RNA expression of 240 selected genes in 2 pools of liver specimens according to the stages of fibrosis (Metavir score; mild fibrosis = F1 and septal fibrosis = F2). Genes whose expression differed between pools (F2 vs F1) by at least 2-fold were selected. In addition, the expression level of these selected genes then was assessed in each of the 62 individual samples (F4, n = 6; F3, n = 17; F2, n = 21; vs F1, n = 18). RESULTS: The 22 genes that were up-regulated in the 21 F2 samples relative to the 18 F1 samples mainly encoded genes involved in cytoskeleton (KRT 19 and SCG 10), growth factors/cytokines (CXCL6, interleukin 8 [IL8], IL1A, IL2, and CXCL10), or growth factor receptors (CCR2, CXCR3, and CXCR4), or were involved in extracellular matrix production (COL1A1, CHI3L, and SPP1), in extracellular matrix remodeling (TIMP1, MMP7, and MMP9), and in cell junction (ITGA2 and CLDN 4). When hierarchically clustering the F2 and F1 samples according to the expression of the 11 most discriminatory genes (KRT 19, COL1A1, STMN2, CXCL6, CCR2, TIMP1, IL8, IL1A, ITGA2, CLDN 4, and IL2), the patient population was categorized into 2 subgroups: F1 and F2. Specifically, 15 of 18 F1 (83%) and 19 of 21 F2 (90%) were classified correctly (P < 10(-5)). We also studied the messenger RNA expression of these 240 selected genes in normal liver in comparison with F1. Genes dysregulated in the transition from normal liver to F1 mainly were interferon-inducible genes, and therefore were very different from those dysregulated in the transition from F1 to F2. CONCLUSIONS: Genes involved in extracellular matrix turnover and immune response are implicated in the transition from mild to moderate fibrosis. Eleven of the genes could form the basis for the gene expression signature of mild versus moderate fibrosis in patients with chronic hepatitis C.

Adult↗

PubMed2005

FAS promoter polymorphisms correlate with activity grade in hepatitis C patients.

OBJECTIVE: Hepatocytes are susceptible to FAS-mediated apoptosis. The impact of polymorphisms in the FAS gene on histopathological features of HCV infection was therefore investigated. DESIGN/METHODS: Three single-nucleotide polymorphisms in the FAS promoter were assessed in 190 patients with chronic hepatitis C. Associations between FAS haplotypes and fibrosis stage and activity grade were tested by univariate and multivariate analyses. RESULTS: While there was no correlation between FAS promoter genotype and fibrosis stage, patients carrying the GCA haplotype (P=0.03, Fisher's exact test) and those homozygous for the GTG haplotype (P = 0.06) tended to have lower activity scores. Logistic regression showed that these associations were independent of patient age, sex and alcohol consumption. In a logistic regression model incorporating only male gender (odds ratio 2.1, 95% confidence interval 1.1-4.1 P = 0.04), the presence of the GCA haplotype (OR 0.31 95% CI 0.13-0.78 P = 0.01), and GTG homozygosity (OR 0.26 95% CI 0.08-0.83 P = 0.02), all three factors were independently correlated with activity grade. Furthermore, the GTG haplotype appeared to have lower promoter activity than the wild type GTA haplotype in a hepatocellular carcinoma cell line. CONCLUSIONS: Genetic polymorphism in the FAS gene may account for some of the histopathological variability in chronic hepatitis C.

Adult↗

PubMed2004

Human chorionic gonadotrophin beta expression in malignant Barrett's oesophagus.

BACKGROUND: Human chorionic gonadotrophin beta (hCGbeta) is expressed in several non-trophoblastic tumours, and this is usually associated with aggressive behaviour. Little is known about hCGbeta expression in Barrett's adenocarcinoma. MATERIALS AND METHODS: We determined the hCGbeta profile in a large series of surgically resected Barrett's adenocarcinoma (a) at mRNA level using real-time quantitative reverse-transcription polymerase chain reaction analysis and (b) at protein level using immunohistochemistry with a polyclonal antibody and with a monoclonal antibody specific for free hCGbeta. We then sought links between the hCGbeta protein expression pattern and clinical and pathological parameters, including patient outcome as well as vascular endothelial growth factor (VEGF) expression. RESULTS: hCGbeta protein expression was observed in 43 of 76 (57%) Barrett's adenocarcinomas. We showed a strong correlation between hCGbeta protein abundance and CGB mRNA level. We observed a statistical link between hCGbeta protein expression and infiltrative tumour type ( P=0.023), perineural neoplastic invasion ( P=0.007) and VEGF protein expression ( P=0.016). hCGbeta expression tended to be associated with a poor outcome (16% versus 36% survival 8 years after resection). CONCLUSION: Expression of hCGbeta correlates with specific infiltrative characteristics and is associated with higher VEGF expression. Both molecules may play a co-ordinated role in the development of Barrett's adenocarcinomas.

Adenocarcinoma↗

PubMed2004

Molecular profiling of malignant peripheral nerve sheath tumors associated with neurofibromatosis type 1, based on large-scale real-time RT-PCR.

BACKGROUND: Neurofibromatosis type 1 (NF1) is an autosomal dominant disorder with a complex range of clinical symptoms. The hallmark of NF1 is the onset of heterogeneous (dermal or plexiform) benign neurofibromas. Plexiform neurofibromas can give rise to malignant peripheral nerve sheath tumors (MPNSTs), and the underlying molecular mechanisms are largely unknown. RESULTS: To obtain further insight into the molecular pathogenesis of MPNSTs, we used real-time quantitative RT-PCR to quantify the mRNA expression of 489 selected genes in MPNSTs, in comparison with plexiform neurofibromas. The expression of 28 (5.7%) of the 489 genes was significantly different between MPNSTs and plexiform neurofibromas; 16 genes were upregulated and 12 were downregulated in MPNSTs. The altered genes were mainly involved in cell proliferation (MKI67, TOP2A, CCNE2), senescence (TERT, TERC), apoptosis (BIRC5/Survivin, TP73) and extracellular matrix remodeling (MMP13, MMP9, TIMP4, ITGB4). More interestingly, other genes were involved in the Ras signaling pathway (RASSF2, HMMR/RHAMM) and the Hedgehog-Gli signaling pathway (DHH, PTCH2). Several of the down-regulated genes were Schwann cell-specific (L1CAM, MPZ, S100B, SOX10, ERBB3) or mast cell-specific (CMA1, TPSB), pointing to a depletion and/or dedifferentiation of Schwann cells and mast cells during malignant transformation of plexiform neurofibromas. CONCLUSION: These data suggest that a limited number of signaling pathways, and particularly the Hedgehog-Gli signaling pathway, may be involved in malignant transformation of plexiform neurofibromas. Some of the relevant genes or their products warrant further investigation as potential therapeutic targets in NF1.

Adolescent↗

PubMed2004

Molecular profiles of neurofibromatosis type 1-associated plexiform neurofibromas: identification of a gene expression signature of poor prognosis.

PURPOSE: Neurofibromatosis type 1 (NF1) is an autosomal dominant disorder with a complex variety of clinical symptoms. The hallmark of NF1 is the development of heterogeneous benign neurofibromas, which may appear as dermal neurofibromas or plexiform neurofibromas. NF1 patients with plexiform neurofibromas are at risk of developing malignant peripheral nerve sheath tumors. EXPERIMENTAL DESIGN: To obtain additional insight into the molecular pathogenesis of plexiform neurofibromas, we used real-time quantitative reverse transcription-PCR assays to quantify the mRNA expression of 349 selected genes in plexiform neurofibromas in comparison with dermal neurofibromas and patient-matched malignant peripheral nerve sheath tumors. RESULTS: Thirty genes were significantly up-regulated in plexiform neurofibromas compared with dermal neurofibromas. None were down-regulated. The up-regulated genes mainly encoded transcription factors and growth factors and secreted proteins, cytokines, and their receptors, pointing to a role of paracrine and autocrine signaling defects in the genesis of plexiform neurofibromas. We also identified a gene expression profile, based on MMP9, FLT4/VEGFR3, TNFRSF10B/TRAILR2, SHH, and GLI1, which discriminated those plexiform neurofibromas most likely to undergo malignant transformation. CONCLUSION: Our study has identified a limited number of signaling pathways that could be involved, when altered, in plexiform neurofibroma development. Some of the up-regulated genes could be useful diagnostic or prognostic markers or form the basis of novel therapeutic strategies.

Adolescent↗

PubMed2003

Quantitative RT-PCR reveals a ubiquitous but preferentially neural expression of the KIS gene in rat and human.

KIS is the only known protein kinase that possesses an RNA recognition motif. This original structure indicates a role for KIS in the maturation of RNAs possibly by phosphorylating and regulating the activities of RNA associated factors. Another function of KIS has recently been unravelled--it negatively regulates the cdk inhibitor p27Kip1 and thus promotes cell cycle progression through G1. In order to explore the functional expression of this kinase, we quantified its mRNA in a wide range of rat and human tissues, during development and in tumors. In both species, the highest level of KIS gene expression was in adult neural tissues. Interestingly, within the adult rat brain, KIS mRNA is enriched in several areas including the substantia nigra compacta and nuclei of the brain stem. Furthermore, KIS gene expression increases dramatically during brain development. Altogether our results point to a ubiquitous function for KIS together with a particular implication during neural differentiation or in the function of mature neural cells. No dysregulation of KIS gene expression was detected in human tumors from breast, bladder, prostate, liver and kidney origins. On the other hand, the KIS gene was overexpressed in NF1-associated plexiform neurofibromas and malignant peripheral nerve sheath tumors (MPNSTs) as compared to dermal neurofibroma which suggests a possible implication of KIS in the genesis of NF1-associated tumors.

Age Factors↗

PubMed2003

CFTR mutations in patients from Colombia: implications for local and regional molecular diagnosis programs.

Cystic Fibrosis is a worldwide distributed hereditary disease. The incidence of the main (p.F508del) and other frequent mutations has been determined in a great number of countries and ethnic groups, but its incidence in most Latin American countries has remained unknown until recently. It is now beginning to be recognized as a frequent cause of infant mortality, and some countries report the incidence of their mutations. Colombia started several years ago a concerted program of molecular study of patients which were clinically diagnosed as probable cystic fibrosis. We screened the whole CFTR (ABCC7) coding sequence in 92 patients from 6 different geographic regions, using conventional PAGE analyses and DGGE followed by sequencing. Additionally, we established the frequency of the p.F508del mutation in 130 unrelated healthy controls. The results of this pilot study in Colombian patients from various ethnic admixture show six main mutations: p.F508del (41.8%), c.1811+1.6kbA>G (6.5%), p.G542X (3.8%), p.S549R (2.2%), p.W1282X (1.1%) and p.R1162X (1.1%). Thirteen other rare mutations, including three novel, were detected, accounting for a total of 63.6% known mutations. There is a great variability between the geographic regions, both in the frequency of the p.F508del mutation and non-p.F508del CF chromosomes. Our results point to a varied origin of the disease genes. These results also show that careful scrutiny of the mutations is needed in each part of Latin America in order to establish priority-screening protocols adapted to each country and region.

Adult↗

PubMed2002

CGA gene (coding for the alpha subunit of glycoprotein hormones) overexpression in ER alpha-positive prostate tumors.

OBJECTIVE: The precise role of estrogen, estrogen receptor (ER) and ER-responsive genes in prostate carcinogenesis is unclear. Paradoxically, estrogens and antiestrogens are used in the treatment of advanced metastatic prostate cancers. Recently, we identified CGA gene coding for the alpha subunit of glycoprotein hormones as a new ER alpha-responsive gene in human breast cancer cells. The aim of this study was to explore the role of CGA in the second major hormone-related cancer, i.e. prostate cancer. PATIENTS AND METHODS: We quantified CGA mRNA in nine cases of benign prostatic hyperplasia (BPH) and 23 sporadic prostate tumors (TP) by using a real-time quantitative reverse transcriptase-polymerase chain reaction (RT-PCR) assay. RESULTS: CGA overexpression (> 10 S.D. above the mean in normal prostate tissues (NP)) was observed in 39% of the TP (ranging from 4.4 to 174.5 times the level in NP) and in none of the BPH samples. CGA overexpression was not accompanied by overexpression of the CGB, LHB, TSHB or FSHB genes to produce ectopic glycoprotein hormones. CGA gene overexpression correlated with ER alpha normal expression (P = 0.016), but not with ER beta or androgen receptor (AR) expression status. CONCLUSION: These results point to CGA gene as a member of a novel dysregulated pathway in prostate cancer. CGA should therefore be considered for investigation as possible novel molecular marker in clinical applications and as possible new potential therapeutic target.

Breast Neoplasms↗