Lázcoz Ripoll, Paula

Profile Picture

Email Address

person.page.identifierURI

https://academica-e.unavarra.es/handle/2454/49387

Birth Date

Job Title

Last Name

Lázcoz Ripoll

First Name

Paula

person.page.departamento

Ciencias de la Salud

person.page.instituteName

ORCID

person.page.observainves

1172611

person.page.upna

7324

Name

Filters

2006 - 200912010 - 20121
Reset filters

Settings

Author: Muñoz, Jorge × End date: 2019 ×

Search Results

Now showing 1 - 2 of 2
  • Thumbnail Image
    PublicationOpen Access
    Promoter methylation of RASSF1A associates to adult secondary glioblastomas and pediatric glioblastomas
    (Hindawi / Wiley, 2012) Muñoz, Jorge; Inda, María del Mar; Lázcoz Ripoll, Paula; Zazpe Cenoz, Idoya; Fan, Xing; Alfaro, Jorge; Tuñón Álvarez, Teresa; Rey, Juan A.; Castresana, Javier S.; Ciencias de la Salud; Osasun Zientziak; Gobierno de Navarra / Nafarroako Gobernua; Universidad Pública de Navarra / Nafarroako Unibertsitate Publikoa
    While allelic losses and mutations of tumor suppressor genes implicated in the etiology of astrocytoma have been widely assessed, the role of epigenetics is still a matter of study. We analyzed the frequency of promoter hypermethylation by methylation-specific PCR (MSP) in five tumor suppressor genes (PTEN, MGMT, RASSF1A, p14ARF, and p16INK4A), in astrocytoma samples and cell lines. RASSF1A was the most frequently hypermethylated gene in all grades of astrocytoma samples, in cell lines, and in adult secondary GBM. It was followed by MGMT. PTEN showed a slight methylation signal in only one GBM and one pilocytic astrocytoma, and in two cell lines; while p14ARF and p16INK4A did not show any evidence of methylation in primary tumors or cell lines. In pediatric GBM, RASSF1A was again the most frequently altered gene, followed by MGMT; PTEN, p14 and p16 showed no alterations. Lack or reduced expression of RASSF1A in cell lines was correlated with the presence of methylation. RASSF1A promoter hypermethylation might be used as a diagnostic marker for secondary GBM and pediatric GBM. Promoter hypermethylation might not be an important inactivation mechanism in other genes like PTEN, p14ARF and p16INK4A, in which other alterations (mutations, homozygous deletions) are prevalent.
  • Thumbnail Image
    PublicationOpen Access
    Frequent promoter hypermethylation of RASSF1A and CASP8 in neuroblastoma
    (BioMed Central, 2006) Lázcoz Ripoll, Paula; Muñoz, Jorge; Nistal, Manuel; Pestaña, Ángel; Encío Martínez, Ignacio; Sáez Castresana, Javier; Ciencias de la Salud; Osasun Zientziak
    Background: Epigenetic alterations and loss of heterozygosity are mechanisms of tumor suppressor gene inactivation. A new carcinogenic pathway, targeting the RAS effectors has recently been documented. RASSF1A, on 3p21.3, and NORE1A, on 1q32.1, are among the most important, representative RAS effectors. Methods: We screened the 3p21 locus for the loss of heterozygosity and the hypermethylation status of RASSF1A, NORE1A and BLU ( the latter located at 3p21.3) in 41 neuroblastic tumors. The statistical relationship of these data was correlated with CASP8 hypermethylation. The expression levels of these genes, in cell lines, were analyzed by RT-PCR. Results: Loss of heterozygosity and microsatellite instability at 3p21 were detected in 14% of the analyzed tumors. Methylation was different for tumors and cell lines (tumors: 83% in RASSF1A, 3% in NORE1A, 8% in BLU and 60% in CASP8; cell lines: 100% in RASSF1A, 50% in NORE1A, 66% in BLU and 92% in CASP8). In cell lines, a correlation with lack of expression was evident for RASSF1A, but less clear for NORE1A, BLU and CASP8. We could only demonstrate a statistically significant association between hypermethylation of RASSF1A and hypermethylation of CASP8, while no association with MYCN amplification, 1p deletion, and/or aggressive histological pattern of the tumor was demonstrated. Conclusion: 1) LOH at 3p21 appears in a small percentage of neuroblastomas, indicating that a candidate tumor suppressor gene of neuroblastic tumors is not located in this region. 2) Promoter hypermethylation of RASSF1A and CASP8 occurs at a high frequency in neuroblastomas.