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Elise C Kohn

Publications and source records attributed to Elise C Kohn.

46 records · Page 3Linked to original sources
PubMed2002

Use of proteomic patterns in serum to identify ovarian cancer.

BACKGROUND: New technologies for the detection of early-stage ovarian cancer are urgently needed. Pathological changes within an organ might be reflected in proteomic patterns in serum. We developed a bioinformatics tool and used it to identify proteomic patterns in serum that distinguish neoplastic from non-neoplastic disease within the ovary. METHODS: Proteomic spectra were generated by mass spectroscopy (surface-enhanced laser desorption and ionisation). A preliminary "training" set of spectra derived from analysis of serum from 50 unaffected women and 50 patients with ovarian cancer were analysed by an iterative searching algorithm that identified a proteomic pattern that completely discriminated cancer from non-cancer. The discovered pattern was then used to classify an independent set of 116 masked serum samples: 50 from women with ovarian cancer, and 66 from unaffected women or those with non-malignant disorders. FINDINGS: The algorithm identified a cluster pattern that, in the training set, completely segregated cancer from non-cancer. The discriminatory pattern correctly identified all 50 ovarian cancer cases in the masked set, including all 18 stage I cases. Of the 66 cases of non-malignant disease, 63 were recognised as not cancer. This result yielded a sensitivity of 100% (95% CI 93--100), specificity of 95% (87--99), and positive predictive value of 94% (84--99). INTERPRETATION: These findings justify a prospective population-based assessment of proteomic pattern technology as a screening tool for all stages of ovarian cancer in high-risk and general populations.

CA-125 Antigen↗
PubMed2002

Genomics and proteomics: application of novel technology to early detection and prevention of cancer.

Advances in molecular biology over the past decade have helped to enhance our understanding of the complex interplay between genetic, transcriptional and translational alterations in human cancers. These molecular changes are the basis for an evolving field of high-throughput cancer discovery techniques using microscopic amounts of patient-based materials. Laser capture microdissection allows pure populations of cells to be isolated from both the tumor and stroma in order to identify subtle differences in RNA and protein expression. Comparative analysis of these alterations between normal, pre-invasive, and invasive tissue using powerful bioinformatics programs has allowed us to identify novel tumor markers, profile complex protein pathways, and develop new molecular-based therapies. Continued refinement of such high-throughput microtechnologies will enable us to rapidly query patient specimens to identify novel methods for early detection, treatment, and follow-up of a wide array of human cancers.

Genomics↗
PubMed2002

Signal transduction targets in invasion.

The processes of physiologic and malignant invasion use the same cellular pathways, albeit under differential regulation. Critical signaling messages can be initiated through cell-cell and cell-substratum contact, as well as using autocrine and paracrine activation. Cancer cells are known for their flexibility and autocrine functions, however, they still rely on a battery of important signaling events. The interaction between the tumor cell and the stroma provides an important signaling milieu and target zone for molecular therapeutic intervention. It is now recognized that malignant invasion requires that interaction for optimal signaling and function. New technologies are now available to allow more rapid dissection of these pathways and characterization of unique regulatory sites for therapeutic gain.

Animals↗
PubMed2002

Clinical proteomics: translating benchside promise into bedside reality.

The ultimate goal of proteomics is to characterize the information flow through protein networks. This information can be a cause, or a consequence, of disease processes. Clinical proteomics is an exciting new subdiscipline of proteomics that involves the application of proteomic technologies at the bedside, and cancer, in particular, is a model disease for studying such applications. Here, we describe proteomic technologies that are being developed to detect cancer earlier, to discover the next generation of targets and imaging biomarkers, and finally to tailor the therapy to the patient.

Female↗
PubMed2002

Proteomic analysis and identification of new biomarkers and therapeutic targets for invasive ovarian cancer.

Epithelial ovarian cancer kills almost 16 000 women each year in part due to late stage of presentation and lack of reliable biomarkers for disease detection. CA-125, the currently accepted serum marker, alone lacks the sensitivity for early stage diagnosis, as only 50% of early stage cases are detected with this marker. Although more early stage cases may be detected by lysophosphatidic acid, this marker is also elevated in other cancers. One major objective of the NCI-FDA Tissue Proteomics Initiative has been to combine the technique of laser capture microdissection (LCM) of epithelial tumor cells in human tissue specimens with two-dimensional gel electrophoresis (2-D PAGE) to identify proteins that may serve as invasive ovarian cancer-specific biomarkers for early detection and/or new therapeutic targets. We performed 2-D PAGE on lysates from five microdissected ovarian tumors (three invasive ovarian cancers and two noninvasive, low malignant potential (LMP) ovarian tumors). We then compared silver stained 2-D gels created from microdissected lysates with SYPRO-Ruby stained 2-D PAGE profiles of the patient-matched undissected bulk tumor lysates from all five patients. Twenty-three proteins were consistently differentially expressed between both the LMP and three invasive ovarian tumors in the limited study set. Thirteen were uniquely present in all three of the invasive ovarian cancer cases and absent or underexpressed in the two LMP cases. Ten were uniquely present in the LMP cases but absent or underexpressed in all invasive ovarian cancer cases. Credentialing and preliminary target validation of the mass spectrometry identified proteins cut from the Ruby-red stained gels was performed by LCM coupled Western blot and reverse-phase array technology in a study set of six cases (the aforementioned five cases used in the 2-D PAGE profiling component of the study plus one additional LMP case). The analysis revealed that the 52 kDa FK506 binding protein, Rho G-protein dissociation inhibitor (RhoGDI), and glyoxalase I are found to be uniquely overexpressed in invasive human ovarian cancer when compared to the LMP form of this cancer. The direct comparison of LCM generated proteomic profiles of invasive vs. LMP ovarian cancer may more directly generate important markers for early detection and/or therapeutic targets unique to the invasive phenotype.

Biomarkers, Tumor↗
PubMed2002

Both protein activation and gene expression are involved in early vascular tube formation in vitro.

PURPOSE: Gene expression and protein translation regulate and direct endothelial cell proliferation and differentiation. We initiated an unbiased global search for transcriptional changes occurring during endothelial cell vascular differentiation in vitro, focusing on genes not previously implicated in vascularization and angiogenesis. EXPERIMENTAL DESIGN: cDNA and protein from human umbilical vein endothelial cells forming vascular tubes on the basement membrane surrogate, Matrigel, were collected and subjected to a global unbiased search for alterations in expression of genes not previously linked to angiogenesis. RESULTS: Transcriptional inhibitors blocked vascular tube formation only when present within the first hour of incubation (P < 0.05). cDNA array analysis yielded 31 differentially regulated transcripts (of 5100 queried; false positive rate, 0.4%) from gene classes representing transcription, translational regulation, cell structure, and cell adhesion. mRNA levels of caldesmon, a cytoskeleton-associated protein not previously linked to angiogenesis, were markedly reduced during early tube formation. Caldesmon protein quantity was also markedly decreased as demonstrated by laser capture microdissection of tubule cells followed by immunoblotting. Strikingly, no significant changes in transcription of genes previously demonstrated to contribute to angiogenesis, invasion, or signal transduction contained on the array were observed. To investigate the possibility that posttranslational rather than transcriptional changes were involved in facilitating tube formation, we evaluated the activation status of two dominant signal pathways, RAS/mitogen-activated protein kinase and phosphatidylinositol 3-kinase/AKT. A net 3-fold reduction in phospho-AKT and a 4-fold reduction in phospho-extracellular signal-regulated kinase-1/2 occurred in a transcription-independent fashion. CONCLUSIONS: These data suggest that both changes in gene expression and transcription-independent activation of signal transduction pathways may be involved in vascular tube formation. A combination of transcriptional and proteomic analysis has the potential to identify novel transcription-dependent and -independent molecular targets of angiogenesis.

Calmodulin-Binding Proteins↗
PubMedDate not supplied

Carboxyamido-triazole (CAI), a signal transduction inhibitor induces growth inhibition and apoptosis in bladder cancer cells by modulation of Bcl-2.

Pro- and anti-apoptotic factors and intracellular signaling pathways are targets for therapeutic development of anticancer agents. Carboxyamido-triazole (CAI) is an inhibitor of transmembrane calcium influx and intracellular calcium-requiring signal transduction pathways. The present study investigates the effects of CAI on human transitional cancer cell (TCC) viability and apoptosis, and evaluates whether apoptotic resistance may be overcome pharmacologically. Both well-differentiated (RT4, RT112/grade 1) and poorly-differentiated (T24/grade 3; SUP/grade 4) human TCC lines were shown to express Fas. Upon exposure to agonistic monoclonal Fas antibody, only well-differentiated TCC lines underwent apoptotic cell death. CAI exposure reduced cell viability and caused an at least additive anti-apoptotic effect in combination with the Fas antibody in the Fas-insensitive TCC lines. Under the same conditions under which CAI treatment augmented Fas-mediated apoptosis, it was shown to reduce intracellular bcl-2 quantity. This response to CAI indicates that apoptotic cell death is enhanced by the reduction of bcl-2 protein expression. We suggest that the antitumor effect of CAI is at least partially based on restoring a pathway of apoptosis. It may cause transformation of cell homeostasis that leads to the alteration of apoptotic mechanisms, thus allowing highly malignant tumor cells to re-enter the physiological course of cell elimination.

Antibodies, Monoclonal↗
PubMedDate not supplied

Carboxyamido-triazole (CAI) reverses the balance between proliferation and apoptosis in a rat bladder cancer model.

Carboxyamido-triazole (CAI) is an orally bioavailable calcium influx and signal transduction inhibitor that has been shown to be anti-invasive, anti-angiogenic and anti-metastatic in different human tumors including transitional cell carcinoma. This study was undertaken to further evaluate the activity of CAI in a rat bladder cancer model. A transitional cell carcinoma (TCC) was chemically induced by intravesical installation of methyl-nitrosurea (MNU) in the bladder of female Fischer 344 rats. First, a toxicity study was performed which revealed no side-effects of CAI in the animals up to a dose of 250 mg/kg CAI. For treatment, a dose of 100 mg/kg CAI dissolved in PEG-400 vehicle was chosen. Oral administration of CAI continuously daily for 4 weeks (group A), 3 days/week over 6 weeks (group B), or intravesically twice a week for 6 weeks (group C) caused a reduction of spontaneous development of TCC. Lower stage and grade of tumors were seen in all CAI-treated animals. Under CAI treatment, the apoptotic rate in tumors increased, whereas the proliferation rate decreased, as shown by TUNEL assay and KI-67-immunhistochemistry, respectively. The highest efficacy was seen in group B, with 5 out of 10 animals tumor-free. Intravesical application (group C) resulted in 3 out of 10 animals tumor-free. Normal urothelium was not affected by CAI. This animal model confirms the anti-tumor effect of CAI and shows induction of apoptosis and growth inhibition in bladder cancer by the drug.

Animals↗