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Nicholas R Lemoine

Publications and source records attributed to Nicholas R Lemoine.

At least 19 recordsLinked to original sources
PubMed2006

Quantifying the activity of adenoviral E1A CR2 deletion mutants using renilla luciferase bioluminescence and 3'-deoxy-3'-[18F]fluorothymidine positron emission tomography imaging.

The adenoviral E1A CR2 mutant dl922-947 has potent activity in ovarian cancer. We have used Renilla luciferase bioluminescence imaging to monitor viral E1A expression and replication and [18F]fluorothymidine positron emission tomography ([18F]FLT-PET) to quantify the activity of dl922-947 in vivo. We created dlCR2 Ren, with the same E1A CR2 deletion as dl922-947 and the luciferase gene from Renilla reniformis downstream of E1. Light emitted from s.c. and i.p. IGROV1 ovarian carcinoma xenografts was measured following treatment with dlCR2 Ren. Mice bearing s.c. IGROV1 xenografts were injected with 2.96 to 3.7 MBq of [18F]FLT 48 and 168 hours following i.t. injection of dl922-947 or control virus Ad LM-X. The presence of Renilla luciferase in dlCR2 Ren did not reduce in vitro nor in vivo potency compared with dl922-947. Light emission correlated closely with E1A expression in vitro and peaked 48 hours after dlCR2 Ren injection in both s.c. and i.p. IGROV1 xenografts. It diminished by 168 hours in s.c. tumors but persisted for at least 2 weeks in i.p. models. Normalized tumor [18F]FLT uptake at 60 minutes (NUV60), fractional retention, and area under radioactivity curve all decreased marginally 48 hours after dl922-947 treatment and significantly at 168 hours compared with controls. There was a close linear correlation between NUV60 and both tumor proliferation (Ki67 labeling index) and thymidine kinase 1 expression. Renilla luciferase bioluminescence and [18F]FLT-PET imaging are capable of quantifying the activity and effectiveness of E1A CR2-deleted adenoviral mutants in ovarian cancer.

Adenoviridae↗
PubMed2006

Analysis of p53 mutations for a mutational signature in human intrahepatic cholangiocarcinoma.

Cholangiocarcinoma development may be related to cholangiocyte DNA damage from genotoxic compounds in bile. We have previously shown that human biliary tissue is exposed to genotoxic agents, as evidenced by the presence of DNA adducts. Establishing the presence of a 'mutational signature' in tumour suppressor genes from tumour tissue provides a means of linking cause and effect in human cancer. Inactivation of p53, known to have 'hot-spots' for particular chemical carcinogens, has previously been linked to human cholangiocarcinoma. However, previous p53 studies have focused on exons 5-8, potentially missing gene alterations at other sites. This study examined the putative link between environmental carcinogens and intrahepatic cholangiocarcinoma by analysing DNA from 31 patients for complete p53 mutational signatures, using single strand conformational polymorphism and polymerase chain reaction. All mutations found were compared to known p53 mutations in cholangiocarcinoma and to mutations induced by environmental mutagens, as described in p53 databases. Five non-silent p53 mutations were found, including three new frameshift mutations and two new intron mutations which have not previously been reported in cholangiocarcinoma. Two frameshifts were due to deletions and the third due to an insertion in exon 5. There was no predominant mutational spectrum amongst the set of cholangiocarcinoma samples studied, or on combining these mutations with the dataset of known p53 mutations in cholangiocarcinoma. Several reasons may explain this, including lack of data outside exons 5-8, bias in mutation reporting, the involvement of mutations in non-coding regions or genes other than p53, or the possibility that there is no carcinogenic specific agent and therefore no signature.

Base Sequence↗
PubMed2005

Peanut-like 1 (septin 5) gene expression in normal and neoplastic human endocrine pancreas.

Peanut-like 1 (PNUTL1) is a septin gene which is expressed at high levels in human brain. There it plays a role in the process of membrane fusion during exocytosis by interacting with syntaxin and synaptophysin. As the secretory apparatus of pancreatic islet cells closely resembles that of neurons, we decided to study the expression of PNUTL1 in the human endocrine pancreas, both in normal islets and in pancreatic endocrine tumors (PETs). Normal pancreatic tissue, purified islets, 11 PETs and two cell lines were used to evaluate the presence of PNUTL1 by RT-PCR and Western blot. The expression of the PNUTL1 protein was also evaluated by immunohistochemistry on normal pancreas, additional 26 PETs, eight pancreatic adenocarcinomas, one mixed endocrine-exocrine pancreatic neoplasm, a specimen of solid papillary pseudomucinous tumor, an adult islet cell hyperplasia and a case of neonatal nesidioblastosis. In addition, a tissue array (LandMark High Density Cancer Tissue MicroArray) comprising 280 various tumor and matched normal specimens was utilized. In PETs, the expression of pancreatic hormones, chromogranin-A, synaptophysin and Ki-67 were also evaluated. In the normal pancreas PNUTL1 expression is almost exclusively confined to the islet cells, weak expression was occasionally seen in some acinar cells, while immunoreactivity was completely absent in the ductal epithelia. PNUTL1 expression is maintained at similar high levels in hyperplastic and neoplastic islet cells, but this did not correlate with any of the clinicopathological data nor with proliferation status in PETs. Weak immunoreactivity was also noted in a proportion of exocrine neoplasms. Our findings describe for the first time the high expression levels of PNUTL1 in human pancreatic endocrine cells that suggests a similar role of this protein in islet cells to that demonstrated in neuronal tissues, and warrants further functional studies of this protein.

Adult↗
PubMed2005

Intrinsic chemoresistance to gemcitabine is associated with decreased expression of BNIP3 in pancreatic cancer.

PURPOSE: Although chemotherapy with gemcitabine is a common mode of treatment of pancreatic cancer, 75% of patients do not benefit from this therapy. It is likely that the sensitivity of cancer cells to gemcitabine is determined by a number of different factors. EXPERIMENTAL DESIGN: To identify genes that might contribute to resistance to gemcitabine, 15 pancreatic cancer cell lines were subjected to gemcitabine treatment. Simultaneously, gene expression profiling using a cDNA microarray to identify genes responsible for gemcitabine sensitivity was performed. RESULTS: The pancreatic cancer cell lines could be classified into three groups: a gemcitabine "sensitive," an "intermediate sensitive," and a "resistant" group. Microarray analysis identified 71 genes that show differential expression between gemcitabine-sensitive and -resistant cell lines including 27 genes relatively overexpressed in sensitive cell lines whereas 44 genes are relatively overexpressed in resistant cell lines. Among these genes, 7 genes are potentially involved in the phosphatidylinositol 3-kinase/Akt pathway. In addition to this major signaling pathway, Bcl2/adenovirus E1B 19 kDa protein interacting protein (BNIP3), a Bcl-2 family proapoptotic protein, was identified as being expressed at lower levels in drug-resistant pancreatic cancer cell lines. In an analysis of 21 pancreatic cancer tissue specimens, more than 90% showed down-regulated expression of BNIP3. When expression of BNIP3 was suppressed using small interfering RNA, gemcitabine-induced cytotoxicity in vitro was much reduced. CONCLUSIONS: These results suggest that BNIP3 and the phosphatidylinositol 3-kinase/Akt pathway may play an important role in the poor response to gemcitabine treatment in pancreatic cancer patients.

Antimetabolites, Antineoplastic↗
PubMed2005

Growth delay of human pancreatic cancer cells by methylase inhibitor 5-aza-2'-deoxycytidine treatment is associated with activation of the interferon signalling pathway.

Alteration of methylation status has been recognized as a possible epigenetic mechanism of selection during tumorigenesis in pancreatic cancer. This type of cancer is characterized by poor prognosis partly due to resistance to conventional drug treatments. We have used microarray technology to investigate the changes in global gene expression observed after treatment of different pancreatic cancer cell lines with the methylase inhibitor 5-aza-2'-deoxycytidine (5-aza-CdR). We have observed that this agent is able to inhibit to various degrees the growth of three pancreatic cancer cell lines. In particular, this inhibition was associated with induction of interferon (IFN)-related genes, as observed in other tumour types. Thus, expression of STAT1 seems to play a key role in the cellular response to treatment with the cytosine analogue. Moreover, we found increased p21(WAF1) and gadd45A expression to be associated with the efficacy of the treatment; this induction may correlate with activation of the IFN signalling pathway. Expression of the p16(INK) protein was also linked to the ability of cells to respond to 5-aza-CdR. Finally, genome-wide demethylation induced sensitization that significantly increased response to further treatment with various chemotherapy agents.

Antimetabolites, Antineoplastic↗
PubMed2005

Proteomic analysis of chronic pancreatitis and pancreatic adenocarcinoma.

BACKGROUND & AIMS: Markers to differentiate among pancreatic adenocarcinoma, chronic pancreatitis, and normal pancreas would be of significant clinical utility. This study was therefore designed to analyze the proteome of such specimens and identify new candidate proteins for differential diagnosis. METHODS: A PowerBlot analysis with more than 900 well-characterized antibodies was performed with tissue specimens from patients with chronic pancreatitis, pancreatic adenocarcinoma, and normal pancreas. Differential expression of selected proteins was confirmed on a larger scale by quantitative reverse transcription-polymerase chain reaction and immunohistochemistry using tissue arrays. RESULTS: A total of 30 and 102 proteins showed significant deregulation between normal pancreas when compared with chronic pancreatitis and pancreatic adenocarcinoma, respectively, and although a substantial proportion were found similarly dysregulated in both chronic pancreatitis and pancreatic adenocarcinoma, several proteins were identified as potential disease-specific markers. CONCLUSIONS: A large number of proteins are differentially expressed in chronic pancreatitis and pancreatic adenocarcinoma compared with normal pancreas. Among these, expression analysis of UHRF1, ATP7A, and aldehyde oxidase 1 in combination could potentially provide a useful additional diagnostic tool for fine-needle aspirated or cytological specimens obtained during endoscopic investigations.

Adenocarcinoma↗
PubMed2005

Doxazosin induces apoptosis in LNCaP prostate cancer cell line through DNA binding and DNA-dependent protein kinase down-regulation.

Doxazosin is a quinazoline-based compound acting as an alpha-1-adrenergic inhibitor shown to induce apoptosis in prostate cancer cell lines via an alpha-1-adrenergic receptor-independent mechanism. To better understand the mechanism of doxazosin-induced apoptosis in prostate cancer, we performed cDNA microarray to analyze gene expression changes produced by doxazosin in the androgen-dependent human prostate cancer cell line, LNCaP. We found that 70 and 92 genes were deregulated after 8 and 24 h of doxazosin treatment, respectively. These genes are involved in several cellular processes such as cell-cycle regulation, cell adhesion and signal transduction pathways. Strikingly, we found that doxazosin induces deregulation of genes implicated in DNA replication and repair, such as GADD45A, XRCC5 and PRKDC. These facts, together with the demonstration of the ability of doxazosin to bind DNA, allowed us to propose a novel mechanism of action for doxazosin in prostate cancer cells that implies DNA-damage mediated apoptosis by down-regulation of XRCC5 and PRKDC genes.

Adrenergic alpha-Antagonists↗
PubMed2004

Analysis of gene expression in cancer cell lines identifies candidate markers for pancreatic tumorigenesis and metastasis.

Pancreatic cancer is a highly aggressive type of malignancy and the prognosis for disease presenting typically at a late stage is extremely poor. A comprehensive understanding of its molecular genetics is required in order to develop new approaches to clinical management. To date, serial analysis of gene expression and more recently oligo/cDNA microarray technologies have been employed in order to identify genes involved in pancreatic neoplasia that can be developed as diagnostic markers and drug targets for this dismal disease. This study describes the expression profile obtained from 20 pancreatic cell lines using cDNA microarrays containing 9,932 human gene elements. Numerous genes were identified as being differentially expressed, some of which have been previously implicated in pancreatic adenocarcinoma (S100P, S100A4, prostate stem cell antigen, lipocalin 2, claudins 3 and 4, trefoil factors 1 and 2) as well as several novel genes. The differentially expressed genes identified are involved in a variety of cellular functions, including control of transcription, regulation of the cell cycle, proteolysis, cell adhesion and signaling. Validation of our array results was performed by exploring the SAGEmap database and by immunohistochemistry for a selection of 4 genes that have not previously been studied in pancreatic cancer: anterior gradient 2 homologue (Xenopus laevis), insulin-like growth factor binding protein 3 and 4 and Forkhead box J1. Immunostaining was performed using pancreas-specific tissue microarrays containing core biopsies from 305 clinical specimens. In addition, using statistical group comparison and hierarchical clustering, a selection of genes was identified that may be linked to the site of metastasis from which these cell lines were isolated.

Biomarkers, Tumor↗
PubMed2004

Silencing of androgen-regulated genes using a fusion of AR with the PLZF transcriptional repressor.

The androgen receptor (AR) is a member of the nuclear receptor superfamily of ligand-activated transcription factors and plays a key role in the development and progression of prostate cancer. Current therapies include the use of antiandrogens aimed at inhibiting the transcriptional activation of AR-regulated genes by AR. Here, we explore a strategy aimed at obtaining silencing of AR-regulated genes, based on the properties of the transcriptional repressor promyelocytic leukamia zinc-finger protein (PLZF). In order to do this, we have made a fusion protein between PLZF and AR, named PLZF-AR, and show that PLZF-AR is able to bring about silencing of genomically encoded AR-regulated genes and inhibit the androgen-regulated growth of LNCaP prostate cancer cells. Together, our results show that this strategy is able to bring about potent repression of AR-regulated responses and, therefore, could be of value in the development of new therapies for prostate cancer.

Androgens↗
PubMed2004

Noninvasive imaging of the transcriptional activities of human telomerase promoter fragments in mice.

We have assessed the feasibility of positron emission tomography (PET) and ex vivo gamma-counting to measure the pattern of expression of telomerase promoter fragments in vivo. Promoter fragments from either the RNA [human telomerase RNA (hTR)] or the catalytic components [human telomerase reverse transcriptase (hTERT)] of the telomerase genes were used to drive the expression of the sodium iodide symporter PET reporter gene in recombinant adenoviruses. Both promoter fragments provided cancer-selective expression that could be visualized and quantitated by PET. The transcriptional activity of the hTR promoter was found to be consistently stronger than that of the hTERT promoter. Both promoters appear therefore to be good candidates for safe use in gene therapy, and PET imaging can be used to assess the selectivity of promoters in vivo. Given that this methodology is directly scalable to humans, imaging gene expression using the sodium iodide symporter PET reporter gene could be applied to measure telomerase promoter activity in humans.

Adenoviridae↗
PubMed2004

Low molecular weight heparin, therapy with dalteparin, and survival in advanced cancer: the fragmin advanced malignancy outcome study (FAMOUS).

PURPOSE: In experimental systems, interference with coagulation can affect tumor biology. Furthermore, it has been suggested that low molecular weight heparin therapy may prolong survival in patients with cancer. The primary aim of this study was to assess survival at 1 year of patients with advanced cancer. PATIENTS AND METHODS: Patients with advanced malignancy (N = 385) were randomly assigned to receive either a once-daily subcutaneous injection of dalteparin (5,000 IU), a low molecular weight heparin, or placebo for 1 year. RESULTS: The Kaplan-Meier survival estimates at 1, 2, and 3 years after randomization for patients receiving dalteparin were 46%, 27%, and 21%, respectively, compared with 41%, 18%, and 12%, respectively, for patients receiving placebo (P =.19). In an analysis not specified a priori, survival was examined in a subgroup of patients (dalteparin, n = 55; and placebo, n = 47) who had a better prognosis and who were alive 17 months after randomization. In these patients, Kaplan-Meier survival estimates at 2 and 3 years from randomization were significantly improved for patients receiving dalteparin versus placebo (78% v 55% and 60% v 36%, respectively, P =.03). The rates of symptomatic venous thromboembolism were 2.4% and 3.3% for dalteparin and placebo, respectively, with bleeding rates of 4.7% and 2.7%, respectively. CONCLUSION: Dalteparin administration did not significantly improve 1-year survival rates in patients with advanced malignancy. However, the observed improved survival in a subgroup of patients with a better prognosis suggests a potential modifying effect of dalteparin on tumor biology.

Aged↗
PubMed2004

A multicenter Phase I gene therapy clinical trial involving intraperitoneal administration of E1A-lipid complex in patients with recurrent epithelial ovarian cancer overexpressing HER-2/neu oncogene.

PURPOSE: HER-2/neu oncogene is overexpressed in 10-30% of epithelial ovarian cancers and is associated with a poor prognosis. The E1A gene product of adenovirus type 5 down-regulates HER-2/neu and causes tumor regression in animal models. In the current study, we sought to determine the toxicity and biological activity of E1A-lipid complex in ovarian cancer patients. EXPERIMENTAL DESIGN: A Phase I trial involving intraperitoneal (i.p.) administration of E1A-lipid complex was initiated in ovarian cancer patients to assess biological activity (E1A gene transfer/transcription/translation and HER-2/neu expression) and to determine the maximum tolerated dose. Successive cohorts received E1A-lipid complex at doses of 1.8, 3.6, and 7.2 mg DNA/m(2), given as weekly i.p. infusions for 3 of 4 weeks (each cycle) up to a maximum of six cycles. Peritoneal fluid was sampled at baseline and twice monthly for cellularity, cytology, CA-125, and biological activity RESULTS: Fifteen patients, with a median age of 57 years (range, 43-81) were recruited. Three (1.8 mg DNA/m(2)), 4 (3.6 mg DNA/m(2)), and 8 patients (7.2 mg DNA/m(2)) received i.p. E1A. A total of 91 infusions (range, 1-18) was administered. Abdominal pain was the dose-limiting toxicity, and the maximum-tolerated dose was 3.6 mg DNA/m(2). E1A gene transfer and expression was observed in all of the patients and at all of the dose levels. HER-2/neu down-regulation could be demonstrated in the tumor cells of 2 patients (18%). There was no correlation between dose and biological activity. CONCLUSIONS: I.P. EIA-lipid complex gene therapy is feasible and safe. Future studies, either alone or in combination with chemotherapy, particularly in patients with minimal residual disease, should be evaluated.

Abdominal Pain↗
PubMed2004

Role of Bim in the survival pathway induced by Raf in epithelial cells.

Selective and sustained activation of the Raf/MAP kinase pathway in MCF-10A Delta Raf-ER cells, a spontaneously immortalized human mammary epithelial cell line, was previously shown to protect these cells from suspension-induced cell death, a critical feature of the Ras-transformed phenotype. Although autocrine signalling through the EGF receptor is crucial for the protection induced by Raf in these cells, we report here the existence of an additional, more direct survival mechanism, linking Raf activation to the inhibition of a proapoptotic member of the Bcl-2 family, Bim. While detachment from the matrix results in transcriptional induction of two variants of this BH3-only protein, BimEL and BimL, activation of the Raf/ERK signalling both prevents Bim upregulation specifically and leads to phosphorylation and degradation of the BimEL isoform. This represents an important route to protect epithelial cells from the proapoptotic effect of Bim.

Amino Acid Motifs↗
PubMed2004

Quantitative imaging of Na/I symporter transgene expression using positron emission tomography in the living animal.

Transgene expression can be measured in living animals by positron emission tomography (PET) using reporter genes associated with radiolabeled substrates or ligands. We examined here whether PET images obtained with a new reporter gene system (sodium/iodide symporter (NIS) and [124I]iodide) could provide quantitative information on gene expression in mice. Mice received various doses of recombinant adenovirus in which the expression of the NIS cDNA was driven by the CMV promoter and subsequently [124I]iodide. Postmortem gamma counting of liver biopsies was correlated to the adenovirus dose and with NIS mRNA concentration. In addition, immunohistochemically NIS-positive cells increased with higher tissue activities. Finally, a linear relationship existed between the postmortem gamma counting in liver tissues and that calculated from images obtained through small animal PET scanning (r = 0.9581), although there was a bias at high and low specific values. This systematic study on 35 animals demonstrates that quantitative information on gene expression can be obtained from PET images using the NIS reporter system. This new methodology of quantitative imaging of gene expression presents the advantage of avoiding extensive radiochemistry, an important step for more disseminated use of this emerging technology. In addition, this work supports further development of the NIS system for noninvasive assessment of gene delivery in preclinical and clinical studies.

Adenoviridae↗
PubMed2004

Salmonella enterica serovar Typhimurium interaction with dendritic cells: impact of the sifA gene.

Salmonella enterica serovar Typhimurium (S. Typhimurium) and several mutant derivatives were able to enter efficiently murine bone marrow-derived dendritic cells using mechanisms predominantly independent of the Salmonella pathogenicity island 1 type III secretion system. The levels of intracellular bacteria did not increase significantly over many hours after invasion. Using fluid endocytic tracers and other markers, S. Typhimurium-containing vacuoles (SCVs) were physically distinguishable from early endocytic compartments. Fifty to eighty per cent of SCVs harbouring wild-type S. Typhimurium or aroA, invH and ssaV mutant derivatives were associated with late endosome markers. In contrast, S. Typhimurium sifA was shown to escape the SCVs into the cytosol of infected dendritic cells. S. Typhimurium aroC sifA was more efficient than S. Typhimurium aroC in delivering a eukaryotic promoter-driven green fluorescent protein reporter gene for expression in dendritic cells. In contrast, S. Typhimurium aroC sifA did not detectably increase the efficiency of MHC class I presentation of the model antigen ovalbumin to T cells compared to a similar aroC derivative. Mice infected with the S. Typhimurium aroC sifA expressing ovalbumin did not develop detectably enhanced levels of cytotoxic T cell or interferon-gamma production compared to S. Typhimurium aroC derivatives.

Animals↗
PubMed2004

Interleukin-1beta and tumour necrosis factor-alpha promote the transformation of human immortalised mesothelial cells by erionite.

Asbestos fails to induce the transformation of human mesothelial cells in vitro although it has been known as a potential carcinogen to human mesothelial cells. Interleukin-1beta (IL-1beta) and tumour necrosis factor-alpha (TNF-alpha) are major cytokines released by macrophages after inhalation of asbestos. These cytokines can regulate mesothelial cell proliferation both in vitro and in vivo. In the present study, we used the growth in soft agar as an index of transformation and investigated the role of IL-1beta and TNF-alpha during the process of human mesothelial cell carcinogenesis. Both IL-1beta and TNF-alpha were demonstrated to enhance erionite-induced transformation of the immortalised, non-tumorigenic human mesothelial cell line (MeT-5A) in vitro. The MeT-5A cells could only be transformed when the cells were exposed to a combination of cytokines and erionite, or at least two cytokines together without erionite, for at least 4 months in vitro. The findings presented here suggest that IL-1beta and TNF-alpha play a significant role in the pathogenesis of mesothelioma, and that it might be desirable to block or inhibit cytokine secretion in high risk populations to prevent mesothelioma.

Cell Line, Transformed↗