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Raymond B Nagle

Publications and source records attributed to Raymond B Nagle.

At least 19 recordsLinked to original sources
PubMed2006

Role of c-Myc in intestinal tumorigenesis of the ApcMin/+ mouse.

The c-MYC oncogene plays an important role in tumorigenesis and is commonly highly expressed in gastrointestinal cancers. In colon cells, c-MYC is regulated by the adenomatous polyposis coli (Apc) tumor suppressor gene. Multiple intestinal neoplasia (ApcMin/+ or Min) mice are heterozygous for a truncating Apc mutation and serve as a model of familial adenomatous polyposis (FAP) disease. To study the role of c-Myc in the mutant Apc-mediated colon tumorigenesis, we have developed a transgenic mouse with the conditional deletion of the floxed c-Myc alleles in the intestinal crypts of ApcMin/+ mice (ApcMin/+; c-Mycfl/fl). The floxed c-Myc deletion was initiated via a Cre recombinase controlled by the intestine-specific transcriptional regulatory elements of the liver fatty acid-binding protein gene (Fabpl4xat-132). Fabpl4xat-132-mediated Cre expression and recombination resulted in a two-fold decrease in c-MYC protein expression with no effect on intestinal tract morphology. Small intestinal tumorigenesis was significantly suppressed throughout the small intestinal tract of ApcMin/+; c-Mycfl/fl mice compared to c-Myc wild type littermates. In ApcMin/+; c-Mycfl/fl mice, the intestinal apoptosis was higher in the areas of the small intestine with the decreased c-Myc protein expression (P=0.0016, compared to their littermates with the wild type c-Myc). Thus, conditional inactivation of c-Myc, mediated by Fabpl4xat-132-driven Cre-recombinase, suppresses Apc-dependent intestinal tumorigenesis in adult ApcMin/+ mice, without apparent effect on normal intestinal mucosa.

Animals↗
PubMed2006

Human laminin-5 and laminin-10 mediated gene expression of prostate carcinoma cells.

In prostate cancer progression, the basal lamina switches from predominantly laminin-5 to laminin-10. DU-145 prostate cancer cells were treated with either soluble laminin-5 (20 ng/ml) or laminin-10 (1 microg/ml) for 6, 24, and 48 hr. Total RNA was harvested for a 7,500 human cDNA microarray. Hybridizations were carried out in accordance with a 10 sample analysis of variance (ANOVA) statistical model. One thousand one hundred sixteen genes had measurable expression 2 standard deviations above background and 50% of spots for any given sample for all hybridizations were positive. Expression values of significantly varying genes were clustered and a list of 408 genes (P < 0.05) with a 1.5 or greater fold change in at least one time point were chosen for further analysis. Seventy eight changed in a time-dependent manner with laminin-10 treatment, 85 changed with laminin-5, and 13 showed changes with both treatments. The 408 genes that passed a paired t-test in at least one time-dependent category were further analyzed using Pathway Miner. One of the largest gene association networks involved signal transduction in the growth factor-MAP kinase pathways. EGFR was validated by real-time PCR and laminin-10 mediated cell adhesion activated EGFR in DU-145 cells. Both laminins appear to be important signal transducers in prostate cancer.

Calpain↗
PubMed2006

Expression of mTOR signaling pathway markers in prostate cancer progression.

BACKGROUND: The PI3K/AKT/mTOR pathway is central to prostate cancer progression. A preliminary investigation of immuno-histochemical expression of mammalian target of rapamycin (mTOR) pathway markers was undertaken to identify patterns of expression in prostate tissue. METHODS: Immunohistochemistry was performed on a custom-made prostate tissue array. Mean long scores and variability of long scores for each marker were recorded for normal lumenal cells, prostate intraepithelial neoplasia (PIN), and cancer. RESULTS: Expression of PTEN decreased and mTOR signaling pathway markers increased in PIN and in cancer as compared to normal cells in the majority of samples. Overexpression of 4E-BP1 and p-4E-BP1 was observed in PIN and cancer. However, in cancer, the overexpression of 4E-BP1 was significantly higher than with any other marker. DISCUSSION: Results suggest that 4E-BP1 overexpression is strongly associated with prostate cancer, especially when combined with PTEN and mTOR expression data. Hierarchical clustering analysis utilizing PTEN, mTOR, and 4E-BP1 separated normal from cancer cell populations in most cases.

Adaptor Proteins, Signal Transducing↗
PubMed2006

90K/Mac-2 binding protein is expressed in prostate cancer and induces promatrilysin expression.

BACKGROUND: 90K/Mac-2 binding protein is a cell adhesive protein whose level of expression has been correlated with metastatic potential in many different tumor types. The purpose of this investigation was to examine 90K expression in prostate cancer and to determine a possible role for 90K in cancer progression. METHODS: 90K expression in prostate cell lines and tissue samples was evaluated by immunohistochemistry. Expression in cell lines was also evaluated by Western blot analysis and real-time RT-PCR. Induction of promatrilysin by 90K was evaluated by ELISA. RESULTS: Some of the human prostate cell lines studied expressed 90K. 90K was over-expressed in 38.8% of prostate cancer tumor samples, 7.14% of PIN lesions, and 18.6% of normal tissue. 90K was also shown to induce promatrilysin expression in the prostate cell line, LNCaP. CONCLUSIONS: These data demonstrate that 90K is over-expressed in a large fraction of malignant tumors. The fact that 90K can induce expression of promatrilysin indicates a possible role for 90K in cancer progression and metastasis. This suggests that 90K over-expression may be a useful marker for examining prostate cancer progression.

Antigens, Neoplasm↗
PubMed2005

Aurora-A over-expression in high-grade PIN lesions and prostate cancer.

BACKGROUND: Over-expression of Aurora-A (Aurora 2 kinase, STK-15), a protein found in centrosomes thought to be associated with genetic instability, has been previously documented in prostate cancer [Pihan et al.: Cancer Res 61(5):2212-2219, 2001]. It is unknown if this protein is also over-expressed in high-grade prostatic intraepithelial neoplasia (PIN) lesions. METHODS: PIN lesions were examined for increased Aurora-A using immunohistochemical staining on archival paraffin embedded prostatectomy tissue. Aurora-A expression was scored using size, number, and staining intensity. Protein expression was examined and compared between stromal cells, normal glands, high-grade PIN lesions, and invasive cancer. RESULTS: Immunohistochemistry shows an increased expression of Aurora-A in 96% of high-grade PIN cases, and 98% in cancer lesions. Twenty-nine percent of cases of normal glands from cancerous prostates also showed increased Aurora-A expression. CONCLUSIONS: Over-expression of Aurora-A is present in some normal and the majority of high-grade PIN lesions indicating that this may be an early event that leads to the genetic instability seen in prostate carcinogenesis.

Aurora Kinases↗
PubMed2005

Membrane type 1 matrix metalloprotease cleaves laminin-10 and promotes prostate cancer cell migration.

Disruption of the extracellular matrix by proteases is crucial for tumor invasion. Laminin-10 (Ln-10) has previously been identified as a substrate for cell migration and cell adhesion, and is present in the basal lamina (BL) of both normal prostate and prostate cancer. Here, we investigate a role for membrane type 1 matrix metalloprotease (MT1-MMP) in modifying this Ln-10-rich BL. MT1-MMP is a transmembrane member of the MMP family that has been demonstrated to be upregulated as prostate cancer progresses from normal to prostate intraepithelial neoplasia to invasive cancer, suggesting a role for MT1-MMP in the invasion of prostate cancer. We show that MT1-MMP cleaves the alpha5 chain of purified human Ln-10 from its 350-kDa form into 310-, 190-, 160-, and 45-kDa fragments. This cleavage causes a decrease in DU-145 prostate cancer cell adhesion to purified Ln-10, and an increase in transmigration of DU-145 cells through cleaved Ln-10. We also show that prostate cancer cells expressing membrane-bound MT1-MMP cleave the alpha5 chain of Ln-10. Ln alpha5-chain cleavage is also observed in human prostate cancer tissues. These findings suggest that prostate cancer cells expressing high levels of MT1-MMP have increased invasive potential through their ability to degrade and invade Ln-10 barriers.

Cell Adhesion↗
PubMed2004

Mutations in the G-quadruplex silencer element and their relationship to c-MYC overexpression, NM23 repression, and therapeutic rescue.

We have demonstrated that a parallel G-quadruplex structure in the c-MYC promoter functions as a transcriptional repressor element. Furthermore, a specific G-to-A mutation in this element results in destabilization of the G-quadruplex repressor element and an increase in basal transcriptional activity. To validate this model in an in vivo context, we have examined the sequence of this region in human colorectal tumors and the surrounding normal tissue. We have found that approximately 30% of tumors contain one of two specific G-to-A mutations, not present in the surrounding normal tissue, that destabilize the parallel G-quadruplex, which would be expected to give rise to abnormally high expression of c-MYC in these cells. In contrast, G-quadruplex-disruptive mutations were absent in 20 colon adenomas, suggesting that these mutations occur late in tumorigenesis. We have also demonstrated that these same mutations are found in established colorectal cell lines. NM23-H2 levels are lower in cancer tissues and cell lines that harbor these mutations. In cells with repressed levels of NM23-H2, the mutated and destabilized G-quadruplex silencer element can be reinstated by the addition of G-quadruplex-stabilizing compounds, providing an opportunity for therapeutic intervention for patients carrying these mutations.

Base Sequence↗
PubMed2004

Extracellular alpha 6 integrin cleavage by urokinase-type plasminogen activator in human prostate cancer.

During human prostate cancer progression, the integrin alpha6beta1 (laminin receptor) is expressed on the cancer cell surface during invasion and in lymph node metastases. We previously identified a novel structural variant of the alpha6 integrin called alpha6p. This variant was produced on the cell surface and was missing the beta-barrel extracellular domain. Using several different concentrations of amiloride, aminobenzamidine and PAI-1 and the urokinase-type plasminogen activator (uPA) function-blocking antibody (3689), we showed that uPA, acting as a protease, is responsible for production of alpha6p. We also showed that addition of uPA in the culture media of cells that do not produce alpha6p, resulted in a dose-dependent alpha6p production. In contrast, the addition of uPA did not result in the cleavage of other integrins. Using alpha2-antiplasmin and plasmin depleted media, we observed that uPA cleaves the alpha6 integrin directly. Further, 12-o-tetradecanoyl-phorbol-13-acetate (TPA) induced the production of alpha6p, and this induction was abolished by PAI-1 but not alpha2-antiplasmin. Finally, the alpha6p integrin variant was detected in invasive human prostate carcinoma tissue indicating that this is not a tissue culture phenomenon. These data, taken together, suggest that this is a novel function of uPA, that is, to remove the beta-barrel ligand-binding domain of the integrin while preserving its heterodimer association.

Antibodies↗
PubMed2004

Fibroblast growth factor-1 transcriptionally induces membrane type-1 matrix metalloproteinase expression in prostate carcinoma cell line.

BACKGROUND: We and others have shown that the matrix metalloproteinases, MT1-MMP is overexpressed in human prostate PIN lesions and invasive cancers compared to normal prostate epithelium. However, the mechanism for this overexpression is not understood. Evidence from our laboratory and others has indicated that fibroblast growth factors (FGFs) can regulate the expression of certain matrix metalloproteinase. In addition, human prostate fibroblasts are known to express certain FGFs, including FGF-1. The purpose of the work in this paper was to determine the mechanism involved in FGF-1 induced MT1-MMP expression in prostate carcinoma cells. METHODS: We tested the ability of recombinant FGF-1 to induce MT1-MMP expression in prostate carcinoma cell line, LNCaP cells. We measured the MT1-MMP message by using Northern analyses and protein levels by Western analysis after FGF-1 treatment. Downstream signaling was investigated using dominant negative constructs for FGFR-1 and signal transducer and activator of transcription-3 (STAT3). Transient transfection was performed using reporter plasmids of the MT1-MMP gene promoter region (7.2 kb) linked to the firefly luciferase gene in the pGL3-Basic vector. For dominant negative studies FGFR-1 dominant negative plasmid in PCEP4 vector or STAT3 dominant negative plasmid in pCMV-1 vector was co-transfected with the MT1-MMP reporter plasmid. RESULTS: Recombinant FGF-1 significantly induced MT1-MMP expression in LNCaP prostate carcinoma cells. MT1-MMP message increased with FGF-1 treatment compared to that of untreated control LNCaP cells. Quantitation by digital image analysis revealed that this increase was twofold over untreated LNCaP cells. Treatment of pGL3-MT1-MMP-luciferase transfected cells with FGF-1 resulted in a twofold to fourfold increase in luciferase enzyme activity compared with untreated cells. Co-transfection of LNCaP with human MT1-MMP reporter construct and a dominant negative FGFR1 mutant showed that FGF-1-induced MT1-MMP expression in LNCaP cells was completely inhibited by the mutated FGFR-1, indicating that FGF receptor (FGFR) activation is necessary for induction of MT1-MMP. Further, expression of dominant negative STAT3 inhibited the FGF-1-induced transactivation of the human MT1-MMP 7.2-kb promoter. CONCLUSIONS: From these data, we conclude that FGF-1 induces MT1-MMP expression in prostate carcinoma cells through a transcriptional mechanism mediated through the FGFR and the transcription factor, STAT3. These results confirm earlier data indicating that acidic FGF and STAT3 are involved in the signaling leading to the expression of a MMP. Our findings support the idea that paracrine and autocrine factors play an important role in the regulation of MT1-MMP in human prostate carcinoma cells.

Blotting, Northern↗
PubMed2004

Selenium and selenomethionine levels in prostate cancer patients.

OBJECTIVE: Selenium (Se) and selenomethionine (Se-Met) have been identified as potential chemopreventive agents of prostate cancer. Using an assay for the speciation (separation and identification) and quantification of selenoamino acids, Se-Met was profiled in serum and prostate tissue from prostate cancer patients. Total Se was measured also. METHODS: Serum and prostate tissue samples were analyzed using high performance liquid chromatography ion channel plasma-mass spectrometry (HPLC ICP-MS). Samples were provided by 25 subjects undergoing radical prostatectomy for the treatment of prostate cancer. RESULTS: The mean serum Se-Met concentration was 59.4 +/- 19.5 ng/ml. Mean total serum Se levels were 133.8 +/- 29.2 ng/ml. Total Se levels in paired samples from the transitional and peripheral zones of the prostate were also compared. Total mean Se levels in peripheral zone tissue was higher than in transitional zone tissue (0.432 +/- 0.212 microg/g versus 0.293 +/- 0.172 microg/g, P = 0.01). Se-Met was detected in the majority of prostate tissues. CONCLUSION: This group of prostate cancer patients had total Se levels in serum and in prostate tissue in a range expected for normal Se intake. There was a significantly higher total Se level found in peripheral versus transitional zone tissues. This is the first time that Se-Met has been detected in prostate tissue.

Aged↗
PubMed2004

Immunohistochemical comparison of vascular and sinusoidal adherens junctions in cavernosal endothelium.

OBJECTIVES: To characterize endothelial cell-to-cell junctions in the sinusoids and microvasculature of the corpus cavernosum. METHODS: Corporal tissue was obtained from 6 potent human subjects, cut into 5-microm cryosections, and double-labeled with consecutive applications of primary and secondary antibodies. Laser scanning confocal microscopy identified subcellular localization of endothelial anchoring and adhesion molecules. Fluorescence intensity was rated as strong, weak, or absent by two observers. RESULTS: The cavernosal endothelial adherens junction was composed of vascular endothelial cadherin, alpha-catenin, plakoglobin, vinculin, and the regulatory proteins beta-catenin and ZO-1. Adherens junctions in sinusoids were elongated, redundant, and narrow versus short, dense, linear cell-to-cell contacts in small arterioles and venules. Vinculin expression along the basal interface of the endothelium and stroma was weak in the sinusoids and strong in the arterioles. Definite sinusoidal expression of CD31 and CD34 was noted. P-selectin was only expressed within the cavernosal microvessels. CONCLUSIONS: The regulatory and structural proteins extending from vascular endothelial cadherin provide immunohistochemical evidence of a role for adherens junctions in cavernosal endothelial barrier function and cellular homeostasis. The sinusoidal endothelium has a unique junctional phenotype consistent with its blood trapping function. Differential expression of functional proteins in sinusoidal and microvascular endothelium may reflect segmental variation in hemodynamic exposure to pressure, stretch, or flow.

Adherens Junctions↗
PubMed2003

Membrane type-1-matrix metalloproteinase expressed by prostate carcinoma cells cleaves human laminin-5 beta3 chain and induces cell migration.

Degradation of the extracellular matrix by proteolytic enzymes is a central aspect of physiological and pathologic tissue-remodeling processes such as trophoblastic implantation, wound healing, and tumor invasion. We have hypothesized that prostate adenocarcinoma cell invasion through the normal basal lamina is attributable in part to metalloproteinase-induced cleavage of laminin-5 (Ln-5) and enhanced motility of the cancer cells. We studied the role of membrane type-1-matrix metalloproteinase (MT1-MMP) expressed on the surface of prostate tumor cells in cleaving Ln-5 and enhancing the migration of prostate tumor cells. We also determined the nature of the MT1-MMP cleavage of human Ln-5 and how this altered Ln-5 changes the migration of prostate carcinoma cells. We found that human MT1-MMP cleaves purified human Ln-5 to an 80-kDa fragment. Mass spectrometry analyses of the 80-kDa cleaved product by trypsin and chymotrypsin gave 14 and 9 different peptide sequences, respectively, that were identical to the expected amino acid sequence of the Ln-5-beta3 chain. The recovered peptides represent 14.4% (trypsin) and 10.3% (chymotrypsin) of Ln-5-beta3 chain by amino acid count. Both trypsin and chymotrypsin digestion of MT1-MMP-cleaved product of Ln-5 did not show any other peptides that were identical to the other chains of Ln-5. Using a linear migration assay we found that the Ln-5 cleaved by MT1-MMP enhanced the migration of DU-145 prostate carcinoma cells by 2-fold compared with uncleaved Ln-5. The use of blocked antisense MT1-MMP oligonucleotides inhibited the migration of DU-145 cells on Ln-5. We also found that the prostate carcinoma cells expressing high levels of MT1-MMP, such as PC3N and PPC, demonstrated enhanced migration on human Ln-5-coated substrate, and this migration was inhibited using blocked antisense MT1-MMP oligonucleotides. In conclusion, this is a novel and important finding where we have shown that beta3-chain is cleaved by MT1-MMP, and this cleavage enhances migration of prostate cancer cells.

Amino Acid Sequence↗
PubMed2003

Laminin alpha-1, alpha-3, and alpha-5 chain expression in human prepubertal [correction of prepubetal] benign prostate glands and adult benign and malignant prostate glands.

BACKGROUND: Laminins (Lns) are a family of extracellular matrix glycoproteins located in the basement membrane (BM) of epithelial cells. They exist as heterotrimers composed of an alpha, beta, and gamma chain. Presently, five alpha (alpha1-5), three beta (beta1-3), and three gamma (gamma1-3) chains have been identified with different combinations of these chains resulting in 14 laminin heterotrimers thus far identified (1, 3-5). METHODS: In this study, using immunohistochemistry with chain-specific antibodies, we characterized the expression of the alpha1 (Lns-1/3), alpha3 (Lns 5,6,7), and alpha5 (Lns 10/11) chains in fetal, newborn, infant, prepubertal, and adult benign and malignant prostate glands. RESULTS: In general, alpha1 expression was higher in normal fetal prostate glands and declined by full-term birth, whereas the alpha3 and alpha5 chains remained highly expressed in the adult normal glands. In carcinoma alpha1 (Lns 1/3) and alpha5 (Lns 5,6,7) are lost, whereas alpha5 (Lns 10/11) persists. CONCLUSIONS: Alpha 1 (Lns 1/3) is prominent in BM, but is replaced by a laminin matrix rich in alpha3 (Lns 5,6,7) and alpha5 (Lns 10/11) in benign adult prostate glands. In carcinoma, both alpha1 (Lns-1/3) and alpha3 (Lns 5,6,7) are not expressed with persistence of a BM rich in alpha5 (Lns 10/11).

Adult↗
PubMed2003

Pharmacological inhibition of FGF receptor signaling inhibits LNCaP prostate tumor growth, promatrilysin, and PSA expression.

Previously we have shown that the matrix metalloproteinase matrilysin (MMP-7) is overexpressed in human prostate cancers compared with normal epithelium. However, the mechanism for this overexpression is not understood. Human prostate fibroblasts have been shown to express certain fibroblast growth factors (FGFs), including FGF-1. Evidence from our laboratory and others has indicated that FGFs can regulate the expression of certain matrix metalloproteinases, including matrilysin. The goal of this study was to determine whether pharmacological inhibition of FGFR signaling would alter LNCaP tumor growth as well as expression of promatrilysin when LNCaP cells were co-injected subcutaneously with human prostate fibroblasts into athymic nude mice. For these inhibitor studies, AG1-X2 beads were coated with the pharmacological FGFR inhibitor SU5402 and were co-injected along with LNCaP and human prostate fibroblast cells (PF). Mice injected with LNCaP/PF and LNCaP/PF/beads alone demonstrated significant tumor growth, whereas mice injected with LNCaP/PF/SU5402-coated beads showed a significant decrease in tumor volume and weight. Immunohistochemical analysis showed that significant promatrilysin expression in tumors was inhibited by the FGFR inhibitor SU5402. Serum prostate-specific antigen (PSA) and promatrilysin levels were measured by enzyme-linked immunosorbent assay. The mice injected with LNCaP/PF and LNCaP/PF/beads expressed promatrilysin and serum PSA levels that were inhibited by co-injecting with SU5402. Therefore, pharmacological inhibition of FGF receptor signaling results in a decrease in the growth of LNCaP tumors generated subcutaneously by co-injecting LNCaP cells and human prostate fibroblasts. The inhibition in tumor growth was correlated with a decrease in tumor promatrilysin expression and a decrease in serum promatrilysin and PSA.

Animals↗
PubMed2002

Androgens block interleukin-1 beta-induced promatrilysin expression in prostate carcinoma cells.

BACKGROUND: We have shown previously that interleukin (IL) -1 beta- and IL-6-induced promatrilysin expression is mediated by an indirect pathway that requires NF kappa B-dependent synthesis of IL-6 and STAT3 signaling. We now demonstrate that IL-1 beta-induced but not IL-6-induced promatrilysin expression can be blocked by androgens in the prostate carcinoma cell line LNCaP (lymph node-derived carcinoma cells of the prostate). METHODS: By using enzyme-linked immunosorbent assay analyses, promatrilysin was measured in LNCaP cells stimulated with IL-1 beta or IL-6 LNCaP-treated cells pretreated with testosterone. In addition, promatrilysin message was measured by using Northern analyses after IL-6-treated cells pretreated with testosterone. RESULTS: In LNCaP treated with testosterone before IL-1 beta stimulation induced promatrilysin expression was completely abrogated. Furthermore, testosterone completely abrogated NF kappa B transactivation activity and induction of IL-6 protein expression and mRNA. Testosterone and 5 alpha-dihydrotestosterone did not have an inhibitory effect on IL-6-induced promatrilysin expression. Testosterone also had no effect on basal promatrilysin expression or basal NF kappa B transactivation activity. CONCLUSION: From these data, we conclude that testosterone blocks IL-1 beta-induced promatrilysin expression by inhibition of NF kappa B transactivation activity, which in turn, blocks IL-6 expression. These data suggest a mechanism in vivo by which invasive and metastatic prostatic carcinoma cell clones refractory to hormone ablation therapy may develop after chemical or surgical castration. Furthermore, these data suggest that, perhaps, upstream targets such as the cytokines IL-1 beta and IL-6 may provide alternative drug targets for inhibiting prostate cancer progression.

Blotting, Northern↗
PubMed2002

Identification of differentially expressed genes in pancreatic cancer cells using cDNA microarray.

To identify new diagnostic markers and drug targets for pancreatic cancer, we compared the gene expression patterns of pancreatic cancer cell lines growing in tissue culture with those of normal pancreas using cDNA microarray analysis. Fluorescently (cyanine 5) labeled cDNA probes, made individually from mRNA samples of nine pancreatic cell lines, were each combined with fluorescently (cyanine 3) labeled universal reference mRNA. The mixed probes of each sample were then hybridized with 5760 cDNA arrays (5289 unique cDNA sequences) printed on individual microscope slides. Fluorescently (cyanine 5) labeled normal pancreas mRNA was also compared with the same universal reference mRNA reference pool. The expression ratios of neoplastic versus normal pancreas cells were then calculated by multiplying the ratio of cancer versus the universal reference mRNA and the ratio of the universal reference mRNA cell versus normal pancreas. For 5289 different genes interrogated by the arrays, 30 of them showed an expression ratio 2 SD from the mean in at least three of the nine pancreatic cell lines studied. To confirm the expression profiles of these genes, quantitative reverse transcription-PCR and Northern blot were carried out for 25 of the overexpressed genes. To verify the overexpression in patient samples, two of the overexpressed genes, c-Myc and Rad51, were selected to undergo analysis by reverse transcription-PCR in frozen tumor tissues and by immunostaining in paraffin-embedded tissue section microarrays. The results of these experiments are in agreement with the microarray data. Potential up-regulated targets of note from this study include urokinase-type plasminogen activator receptor, serine/threonine kinase 15, thioredoxin reductase, and CDC28 protein kinase 2, as well as several others.

Biomarkers, Tumor↗
PubMed2002

Angiogenesis and neovascularization associated with extracellular matrix-modified porous implants.

Therapies directed toward stimulation of angiogenesis seek to accelerate the development of new blood vessels in tissues rendered dysfunctional because of an insufficient microvascular supply. The goal of the current study was the stimulation of an angiogenic response around and within porous biomedical implants, such as vascular grafts, constructed from a base polymer composed of expanded polytetrafluoroethylene (ePTFE). Similar to many biomaterials, ePTFE does not elicit a significant angiogenic response and the porous interstices of this material remain avascular after implantation. Studies were performed to evaluate the ability of a tumorigenic cell line, the 804-G rat kidney cell to secrete an angiogenic extracellular matrix on and within the porous structures of ePTFE. A rat model was used to evaluate and compare implant-associated healing responses between nonmodified materials and extracellular matrix-modified ePTFE. Results demonstrated that, in contrast to untreated ePTFE, the matrix-modified ePTFE stimulated both angiogenesis in implant-associated tissue and neovascularization of the pores within the ePTFE interstices. Deposition of an insoluble matrix stimulates an angiogenic response and has a potential application for the improvement of medical device function.

Adipose Tissue↗