Biomedical subjects

Cécile Le Page

Publications and source records attributed to Cécile Le Page.

11 recordsLinked to original sources

PubMed2006

SET complex in serous epithelial ovarian cancer.

With low cure rates but increasing diverse treatment options that provide variable remission times, ovarian cancer is increasingly being recognized as a chronic disease. This reality indicates the need for a better understanding of factors influencing disease progression. In a previous global analysis of gene expression, we identified genes differentially expressed when comparing serous epithelial ovarian tumors of low and high malignant potential (grade 0 vs grade 3). In this analysis, 4 out of 5 members of the SET complex, SET, APE1, NM23 and HMGB2, were highly expressed in invasive grade 3 tumors. To further investigate the expression of these genes and the fifth member of the SET complex (pp32), we performed immunohistochemistry, on a tissue array composed of 235 serous tumors of different grades and disease stages. A significant correlation between expression of all SET complex proteins and the tumor differentiation was observed (p < 0.05). When combining all tumors, overexpression of Nm23 (p = 0.04), Set (p = 0.004) and Ape1 (p = 0.004) was associated with the clinical stage of the disease. No marker by itself was associated with prognosis. The combination of a high level of Nm23 in the context of a low level of Set compared to all other combinations of these markers did confer a better prognosis (p = 0.03). When combined, high expression of Hmgb2 and low expression of Ape1 was also associated with patient prognosis (p = 0.05). These findings suggest that a strategy that sums the activities of different partners within a pathway may be more appropriate in designing nomograms for patient stratification.

Adult↗

PubMed2006

An androgen-independent androgen receptor function protects from inositol hexakisphosphate toxicity in the PC3/PC3(AR) prostate cancer cell lines.

BACKGROUND: Inositol hexakisphosphate (IP6) is a phytochemical exhibiting anticancer activity. Because few prostate cancer (PCa) cell lines have been used to study IP6, we assessed its efficacy in a panel of PCa cell lines. METHODS AND RESULTS: Using WST-1 assays we observed that, although androgens did not modulate its efficacy, IP6 was more active in androgen receptor (AR) negative cells than in AR-positive cells. Stable expression of the AR in PC3 cells (PC3(AR)) decreased the response to IP6, which was reversed by an AR-targeting siRNA. Furthermore, AR expression in PC3 cells resulted in significantly reduced caspase-3 activation (P < 0.001) and DNA fragmentation (P < 0.05) in response to IP6. Similarly, although treatment with IP6 caused the upregulation of NF-kappaB-responsive (IkappaB-alpha, IRF-2) and p53/E2F-responsive genes (Puma, Noxa) in PC3 cells, this increase was reduced in PC3AR cells (P < 0.01). CONCLUSION: We conclude that resistance to IP6 can be linked to a ligand-independent AR function.

Androgens↗

PubMed2006

Tissue array analysis of expression microarray candidates identifies markers associated with tumor grade and outcome in serous epithelial ovarian cancer.

Molecular profiling is a powerful approach to identify potential clinical markers for diagnosis and prognosis as well as providing a better understanding of the biology of epithelial ovarian cancer. On the basis of the analysis of HuFL expression data, we have previously identified genes that distinguish low malignant potential and invasive serous epithelial ovarian tumors. In this study, we used immunohistochemistry to monitor a subset of differently expressed candidates (Ahr, Paep, Madh3, Ran, Met, Mek1, Ccne1, Ccd20, Cks1 and Cas). A tissue array composed of 244 serous tumors of different grades (0-3) and stages (I-IV) was used in this analysis. All markers assayed presented differential protein expression between serous tumors of low and high grade. Significant differences in Ccne1 and Ran expression were observed in a comparison of low malignant potential and grade 1 tumor samples (p<0.01). In addition, irrespective of the grade, Ccne1, Ran, Cdc20 and Cks1 showed significant differences of expression in association with the clinical stage of disease. While high level of Ccne1 have previously been associated with poor outcomes, here we found that high level of either Ran or Cdc20 appear to be more tightly associated with a poor prognosis (p<0.001, 0.03, respectively). The application of these biomarkers in both the initial diagnosis and prognostic attributes of patients with epithelial ovarian tumors should prove to be useful in patient management.

Basic Helix-Loop-Helix Proteins↗

PubMed2006

Expression and nuclear localization of ErbB3 in prostate cancer.

PURPOSE: The ErbB1 and ErbB2 receptors have been implicated in prostate cancer progression, but less is known about the role and biology of other ErbB receptor family members in prostate cancer. The aim of this study was to analyze the expression and localization of ErbB3 in prostate tissues and prostate cancer cell lines. EXPERIMENTAL DESIGN: Immunohistochemistry of ErbB3 was done on prostate cancer tissue sections from 143 patients and on a tissue microarray containing 390 cores of radical prostatectomy-derived specimens representing normal, prostatic intraepithelial neoplasia, and malignant tissues from 81 patients. ErbB3 subcellular localization was studied by Western blot analysis in LNCaP, 22Rv1, PC-3, and DU145 prostate cancer cell lines. RESULTS: Immunohistochemistry analysis of prostate cancer tissues revealed that >90% of prostate cancer tissues displayed cytoplasmic ErbB3 staining. Minimal ErbB3 nuclear staining was observed in normal prostate tissues and benign prostatic hyperplasia tissues; in contrast, ErbB3 was frequently localized in the nucleus of cancerous tissues. This nuclear localization was more frequent (P < 0.001) in hormone-refractory tissues (17 of 17, 100%) compared with hormone-sensitive samples (37 of 92, 40.2%). Additionally, in the tissue microarray, increased nuclear ErbB3 was associated with increasing Gleason grade. Interestingly, Western blot analysis of cytoplasmic and nuclear subcellular fractions showed that ErbB3 nuclear localization was more prevalent in hormone-sensitive prostate cancer cell lines (LNCaP and 22Rv1) compared with hormone-insensitive cell lines (PC-3 and DU145). CONCLUSIONS: ErbB3 nuclear localization discriminates normal from malignant prostate tissues and between tumors from hormone-sensitive versus hormone-refractory prostate cancer. ErbB3 nuclear staining seems to be associated with risk of disease progression. The high frequency of ErbB3 nuclear localization in hormone-refractory tissues indicates that ErbB3 warrants further study to understand its association with prostate cancer disease progression.

Cell Nucleus↗

PubMed2006

From gene profiling to diagnostic markers: IL-18 and FGF-2 complement CA125 as serum-based markers in epithelial ovarian cancer.

We used an oligonucleotide-based DNA microarray to identify potential markers in 39 primary cultures of ovarian cancer specimens compared with 11 primary cultures of normal ovarian epithelia. Differential gene expression of IL-18 and FGF-2 was validated on a subset of samples by quantitative PCR and by IHC, using an independent tissue array of 90 cores of 20 normal ovarian surface epithelia and 70 EOCs representing different grades and pathologies of ovarian disease. We further compared, by ELISA, these two markers with CA125 in sera from 25 cancer-free and 47 ovarian cancer patients. IL-18 and FGF-2 proteins were significantly elevated in tumor tissues (p<0.04) and sera (p<0.05) from patients with ovarian cancer. In combination, the three markers (IL-18, FGF-2, and CA125) showed similar sensitivity in scoring for ovarian cancer (35/45 patients) compared to that of CA125 alone (37/45) and significantly improved the specificity of detection (20/25 patients) compared to each marker individually (15/25 for CA125; 18/25 FGF-2; 16/25 for IL-18). In conclusion we show that a combination of the three serum markers (IL-18, FGF-2 and CA125) is associated with EOC, with higher specificity than CA125 alone. Prospective studies with a large cohort of susceptible ovarian cancer patients will be required to expand these findings.

Biomarkers, Tumor↗

PubMed2005

Independent role of phosphoinositol-3-kinase (PI3K) and casein kinase II (CK-2) in EGFR and Her-2-mediated constitutive NF-kappaB activation in prostate cancer cells.

BACKGROUND: Recent research has highlighted the potential role of EGFR and Her-2 in the constitutive activation of NF-kappaB (NF-kappaB) in prostate cancer cells, although the mechanism by which these receptors activate NF-kappaB in these cells remains unclear. METHODS AND RESULTS: Using pharmacological and genetic approaches we show that in PC-3 cells, EGFR and Her-2 are involved in the constitutive activation of NF-kappaB through two different mechanisms. EGFR activates NF-kappaB through the PI3K/Akt pathway that leads to the phosphorylation of IkappaBalpha on serines 32 and 36, thereby promoting the nuclear translocation of the p65 subunit. In contrast, Her-2 activates NF-kappaB through Casein Kinase II (CK-2) activation independently of IkappaBalpha phosphorylation on serines 32 and 36. CONCLUSIONS: Our study not only directly clarifies the signaling pathways involved in NF-kappaB activation in prostate cancer cell lines and but also provides a framework for further studies in the clinical characterization and management of prostate cancer.

Blotting, Western↗

PubMed2005

EGFR and Her-2 regulate the constitutive activation of NF-kappaB in PC-3 prostate cancer cells.

BACKGROUND: The mechanism through which NF-kappaB (NF-kappaB) is constitutively activated in prostate cancer cells remains unclear. We investigated whether members of the ErbB family of epidermal growth factor receptors (EGFR) are involved in the constitutive activation of NF-kappaB in prostate cancer cell lines. METHODS AND RESULTS: EGFR, Her-2, and ErbB3 are expressed and constitutively activated in PC-3, DU145, and LNCaP prostate cancer cells lines. Using several pharmacological ErbB inhibitors, we demonstrate that EGFR and Her-2 are involved in the constitutive activation of NF-kappaB in PC-3 cells through two different mechanisms. EGFR activates NF-kappaB through the phosphorylation of IkappaBalpha on serines 32/36 thereby influencing the nuclear translocation of the p65 subunit. In contrast, Her-2 activates NF-kappaB independently of IkappaBalpha phosphorylation on serines 32/36. CONCLUSION: This study directly implicates ErbB receptors in the activation of NF-kappaB in PC-3 prostate cancer cells.

ErbB Receptors↗

PubMed2005

Discrimination between serous low malignant potential and invasive epithelial ovarian tumors using molecular profiling.

Tumors of low malignant potential (LMP) represent 20% of epithelial ovarian cancers (EOCs) and are associated with a better prognosis than the invasive tumors (TOV). Defining the relationship between LMPs and TOVs remains an important goal towards understanding the molecular pathways that contribute to prognosis, as well as providing molecular markers, for these EOCs. To this end, DNA microarray analyses were performed either in a primary culture or a tumor tissue model system and selected candidate genes showing a distinctive expression profile between LMPs and TOVs were identified using a class prediction approach based on three statistical methods of analysis. Both model systems appear relevant as candidate genes identified by either model allowed the proper reclassification of samples as either LMPs or TOVs. Selected candidate genes (CAS, CCNE1, LGALS8, ITGbeta3, ATP1B1, FLIP, KRT7 and KRT19) were validated by real-time quantitative PCR analysis and show differential expression between LMPs and TOVs. Immunohistochemistry analyses showed that the two tumor classes were distinguishable by their expression of CAS, TNFR1A, FLIP, CKS1 and CCNE1. These results define signature patterns for gene expression of LMPs and TOVs and identify gene candidates that warrant further study to deepen our understanding of the biology of EOC.

Diagnosis, Differential↗

PubMed2005

Proteome profiling of human epithelial ovarian cancer cell line TOV-112D.

A proteome profiling of the epithelial ovarian cancer cell line TOV-112D was initiated as a protein expression reference in the study of ovarian cancer. Two complementary proteomic approaches were used in order to maximise protein identification: two-dimensional gel electrophoresis (2DE) protein separation coupled to matrix assisted laser desorption/ionisation time-of-flight mass spectrometry (MALDI-TOF MS) and one-dimensional gel electrophoresis (1DE) coupled to liquid-chromatography tandem mass spectrometry (LC MS/MS). One hundred and seventy-two proteins have been identified among 288 spots selected on two-dimensional gels and a total of 579 proteins were identified with the 1DE LC MS/MS approach. This proteome profiling covers a wide range of protein expression and identifies several proteins known for their oncogenic properties. Bioinformatics tools were used to mine databases in order to determine whether the identified proteins have previously been implicated in pathways associated with carcinogenesis or cell proliferation. Indeed, several of the proteins have been reported to be specific ovarian cancer markers while others are common to many tumorigenic tissues or proliferating cells. The diversity of proteins found and their association with known oncogenic pathways validate this proteomic approach. The proteome 2D map of the TOV-112D cell line will provide a valuable resource in studies on differential protein expression of human ovarian carcinomas while the 1DE LC MS/MS approach gives a picture of the actual protein profile of the TOV-112D cell line. This work represents one of the most complete ovarian protein expression analysis reports to date and the first comparative study of gene expression profiling and proteomic patterns in ovarian cancer.

Cell Line, Transformed↗

PubMed2004

Signature of a silent killer: expression profiling in epithelial ovarian cancer.

With the sequencing of the human genome and the simultaneous development of high-throughput strategies, cancer biologists have entered an exciting new area for gene expression analysis, with the ability to glimpse higher order patterns of genetic and epigenetic alterations in complex diseases. Ovarian cancer biologists are rising to the challenge of applying these new technologies to this silent killer, with the eventual goal of improving the quality of life and long-term survival of patients. This review provides a summary of the disease, a description of available technologies and their application to the ovarian cancer problem, as well as a discussion on the challenges and opportunities related to DNA microarray expression profiling-based research, including downstream clinical applications.

Biomarkers, Tumor↗

PubMedDate not supplied

Modulation of the activation of extracellular signal-regulated kinase (ERK) and the production of inflammatory mediators by ADP-ribosylation inhibitors.

ADP-ribosylation is involved in nuclear factor kappaB (NF-kappaB)-dependent gene expression induced by lipopolysaccharide in murine macrophages. Here we have investigated the mechanism by which ADP-ribosylation inhibitors block signaling pathways induced in macrophages. In RAW264.7 macrophages the inducers of NF-kappaB activate the production of reactive oxygen species and three mitogen-activated protein kinases (MAPK), the extracellular signal regulated kinase (ERK), the c-jun N-terminal kinase/stress-activated protein kinase (JNK), and p38. We demonstrate that ADP-ribosylation inhibitors specifically inhibit ERK MAPK activation and reduce the release of inflammatory mediators such as tumor necrosis factor alpha (TNF-alpha), IL-6 and nitrite.

3-Iodobenzylguanidine↗