Biomedical subjects

Eldon R Jupe

Publications and source records attributed to Eldon R Jupe.

6 recordsLinked to original sources

PubMed2005

Diverse gene expression pattern during 5-fluorouridine-induced apoptosis.

The purpose of this study was to establish experimental conditions to produce apoptosis by the fluorinated pyrimidine 5-fluorouridine and to examine the changes in gene expression that occurred during cell death. HCT-116 colorectal carcinoma cells were exposed to 10 microM 5-fluorouridine alone or in the presence of 1 mM uridine, 30 microM thymidine or both uridine and thymidine. A time-dependent increase in the percentage of apoptotic cells and a decrease in the percentage of viable cells were observed when the cells were treated with 5-fluorouridine in the absence of uridine (p < 0.001) but not in the presence of uridine. cDNA microarray analysis was used to study the expression of 1,200 different genes during apoptosis by 5-flurouridine. The expression of 33 genes was upregulated by 5-fold or greater at 16 and 24 h of 5-fluorouridine exposure. The largest cluster of upregulated genes included a group of genes classified as growth factors, cytokines and chemokines (e.g. interleukin-3, interleukin-4, B-cell growth factor 1 and stem cell growth factor). The expression of MIC-1 increased up to 100-fold during 5-flurouridine exposure. One hundred and twenty-four genes were downregulated by 5-fold or greater following exposure to 5-fluorouridine. The downregulated genes were distributed throughout the six different classifications on the array. Our data demonstrate a diverse pattern of gene expression during the fluorouridine-induced apoptosis and suggest that mechanisms besides a global inhibition of RNA synthesis/ processing contribute to the RNA-directed cytotoxicity of fluoropyrimidines.

Analysis of Variance↗

PubMed2004

Oligogenic combinations associated with breast cancer risk in women under 53 years of age.

Common, but weakly penetrant, functional polymorphisms probably account for most of the genetic risk for breast cancer in the general population. Current polygenic risk models assume that component genes act independently. To test for potential gene-gene interactions, single nucleotide polymorphisms in ten genes with known or predicted roles in breast carcinogenesis were examined in a case-control study of 631 Caucasian women diagnosed with breast cancer under the age of 53 years and 1,504 controls under the age of 53 years. Association of breast cancer risk with individual genes and with two- and three-gene combinations was analyzed. Sixty-nine oligogenotypes from 37 distinct two- and three-gene combinations met stringent criteria for significance. Significant odds ratios (ORs) covered a 12-fold range: 0.5-5.9. Of the observed ORs, 17% differed significantly from the ORs predicted by a model of independent gene action, suggesting epistasis, i.e., that these genes interact to affect breast cancer risk in a manner not predictable from single gene effects. Exploration of the biological basis for these oligogenic interactions might reveal etiologic or therapeutic insights into breast cancer and other cancers.

Adolescent↗

PubMed2004

Expression of prohibitin 3' untranslated region suppressor RNA alters morphology and inhibits motility of breast cancer cells.

The prohibitin 3' untranslated region (3'UTR) belongs to a novel class of non-coding regulatory RNAs. It arrests cell cycle progression by blocking G1-S transition in breast and other cancers. Our previous studies comparing MCF7 derived clones constitutively expressing a common allelic form of prohibitin RNA (UTR/C) to various controls demonstrated that it functions as a tumor suppressor. Here, we further characterized the morphology and motility of these transgenic breast cancer cells when grown in cell culture and on nude mice. In contrast to empty vector (EV) cells, UTR/C cells were observed to grow in an organized manner with more cell-cell contact and differentiate into structures with a duct-like appearance. Computer assisted cytometry to evaluate differences in nuclear morphology was performed on UTR/C and EV tissues from nude mice. Receiver operator curve areas generated using a logistic regression model were 0.8, indicating the ability to quantitatively distinguish UTR/C from EV tissues. Keratinocyte growth factor-induced motility experiments showed that migration of UTR/C cells was significantly reduced (80-90%) compared to EV cells. Together, these data indicate that this novel 3'UTR influences not only the tumorigenic phenotype but also may play a role in differentiation and migration of breast cancer cells.

3' Untranslated Regions↗

PubMed2003

Tumor suppression by the prohibitin gene 3'untranslated region RNA in human breast cancer.

Prohibitin is a candidate tumor suppressor gene located on human chromosome 17q21, a region of frequent loss of heterozygosity in breast cancers. We showed previously that microinjection of RNA encoded by the prohibitin gene 3'untranslated region (3'UTR) blocks the G(1)-S transition causing cell cycle arrest in several human cancer cell lines, including MCF7. Two allelic forms (C versus T) of the prohibitin 3'UTR exist, and carriers of the less common variant (Tallele) with a family history of breast cancer exhibited an increased risk of breast cancer. In the present study, we examined the tumor suppressor activity of the prohibitin 3'UTR in human breast cancer cells. Stable clones of MCF7 cells expressing either the C allele or the T allele RNA under the control of the cytomegalovirus promoter were isolated and compared with empty vector clones. Clones expressing the C allele RNA (UTR/C) exhibited significant suppression of growth in cell proliferation assays, inhibition of colony formation in soft agar assays, and suppression of xenograft tumor growth when implanted on nude mice, compared with either T allele expressing or empty vector clones. Immunohistochemical analyses with Ki67 staining confirmed a significant reduction in proliferation of UTR/C tumors. Thus, the C allele of prohibitin 3'UTR produces a functional RNA, whereas a single nucleotide polymorphism creates a null allele (T allele) of which the RNA product has lost activity. Our data demonstrate for the first time that an RNA molecule functions as a tumor suppressor in human breast cancer.

3' Untranslated Regions↗

PubMed2002

Increased expression of alpha-1-antitrypsin, glutathione S-transferase pi and vascular endothelial growth factor in human pancreatic adenocarcinoma.

BACKGROUND: This study was designed to investigate abnormalities in gene expression in ductal adenocarcinoma of the pancreas using cDNA arrays. METHODS: Gene expression in pancreatic ductal adenocarcinoma was compared with normal pancreatic tissue controls. Specimens from 5 patients with pancreatic adenocarcinoma were taken fresh at operation and analyzed using commercially prepared cDNA arrays evaluating approximately 2,000 genes. Immunohistochemical staining was used to confirm protein expression of selected genes. RESULTS: Alpha-1-antitrypsin (A1AT) and glutathione S-transferase pi (GSTP) were significantly up-regulated in all 5 tumors. Vascular endothelial growth factor (VEGF) was up-regulated in 4 of the 5 patients. Immunohistochemical staining verified the overexpression of each of these genes. CONCLUSIONS: A1AT, GSTP, and VEGF are overexpressed in human pancreatic adenocarcinoma specimens taken fresh at operation. To our knowledge, this is the first study of human pancreatic ductal adenocarcinoma demonstrating the up-regulation of these genes using gene expression arrays.

Adenocarcinoma↗

PubMedDate not supplied

Enhanced motility of KGF-transfected breast cancer cells.

BACKGROUND: In a previous study, we reported that keratinocyte growth factor (KGF) produced a rapid increase in the motility of ER-positive breast cancer cells. Others have demonstrated that KGF treatment in rodent species produces rapid mammary ductal hyperplasia. Epithelial cells do not produce KGF; thus, in the present study, MCF-7 cells were stably transfected with a KGF-expressing vector and the motility and morphology of the transfected, non-transfected and empty vector cell lines compared. MATERIALS AND METHODS: A mammalian expression vector containing a KGF cDNA was transfected into MCF-7/beta cells, and two stable clones (MCF-7/beta/KGF-T8 and MCF-7/beta/KGF-T9) were identified. Western blotting of conditioned medium from these clones was used to confirm the expression of KGF. The motility of wild-type and KGF-transfected MCF-7 cells was compared using time-lapse videomicroscopy and a cell culture wounding model which examined cell migration over a period of 1-3 days. RESULTS: The Western blots demonstrated that the expression of KGF in both the MCF-7/beta/KGF-T8 and MCF-7/beta/KGF-T9 cell lines was higher than the wild-type and MCF-7/beta cell lines. The cell proliferation and migration distance was significantly greater for both KGF-transfected MCF-7 cell lines than the wild-type and MCF-7/beta cell lines under the same experimental conditions. Further, changes in motile morphology were observed in both the MCF-7/beta/KGF-T8 and MCF-7/beta/KGF-T9 cell lines. In addition, the MCF-7/beta/KGF-T8 clone was found to produce much larger tumors than both the MCF-7/beta/KGF-T9 and EV clones in mouse xenografts. These results indicated that autocrine production of KGF in the KGF-transfected MCF-7 cell lines enhanced cell migration, migration-related morphology and xenograft tumor growth. CONCLUSION: KGF-transfected MCF-7 cells displayed a much greater motility than non-transfected cells, confirming the KGF motility enhancement effect which we previously reported. The use of KGF-transfected breast cancer cells in the xenograft model may help to study the mechanism of KGF-mediated cell motility and to identify specific KGF antagonists that may be used to prevent or impede KGF-mediated metastatic progression.

Animals↗