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Elise C Kohn

Publications and source records attributed to Elise C Kohn.

At least 37 records · Page 2Linked to original sources
PubMed2004

Molecular therapeutics: promise and challenges.

The ability to analyze the genetic and epigenetic aberrations present in a particular patient's tumor on a global basis is rapidly maturing. The emerging fields of functional genomics and functional proteomics offer the opportunity to translate these advances into a full comprehension of the pathophysiology of cancer. Linking these approaches to chemical genomics and molecular therapeutics should provide an expanding repertoire of targeted therapeutics for clinical evaluation. Novel clinical trial designs that can determine the efficacy of targeted therapeutics in patients selected for aberrations in the target are needed to evaluate the wealth of new drugs becoming available. The promise of these technologies and advances in our understanding of cancer is immense, making it our responsibility to see them to fruition. These technologies should lead to a new era of individualized molecular medicine, wherein we will treat each patient with a "prescription" based on the genetic changes in each patient's tumor and their own genetic make-up, resulting in more effective and less toxic therapy.

Animals↗
PubMed2004

Proteomics and ovarian cancer: implications for diagnosis and treatment: a critical review of the recent literature.

PURPOSE OF REVIEW: Epithelial ovarian cancer is the leading cause of death from gynecologic malignancies amongst American women. Emerging proteomic technologies have promise for early diagnosis and in advancing treatment directions. Application of these technologies has produced new biomarkers, diagnostic approaches, and understanding of disease biology. RECENT FINDINGS: Mass spectral blood and tissue analysis has yielded new putative biomarkers that require further validation and assessment of diagnostic specificity and sensitivity. Protein signature patterns derived from mass spectrometry datastreams have been modeled and are moving into validation. Tissue-based protein analysis has led to identification of tumor and stromal protein and signal activation events in ovarian cancer. Clinical trials are now ascertaining tissue samples prior to and during therapy with molecularly targeted agents to evaluate modulation of targeted signaling pathways. Finally, proteomic analysis of tissues and metastases will outline biochemical events underlying the metastatic phenotype of ovarian cancer. SUMMARY: Proteomic approaches are experimental technologies applied to ovarian and other cancers. Proper validation and use of findings may advance our understanding of biochemical events that have complicated successful detection and intervention. This knowledge is the first step in fulfilling the promise of personalized molecular medicine.

Biomarkers, Tumor↗
PubMed2004

CAI is a potent inhibitor of neovascularization and imparts neuroprotection in a mouse model of ischemic retinopathy.

PURPOSE: This study was performed to characterize the effects of an antimetastatic and antiangiogenic molecule, carboxyamido-triazole (CAI), on retinal neovascularization in a mouse model. METHODS: Neonatal mice were subjected to 75% to 85% oxygen from postnatal day (PND)-7 to -12 and then were abruptly placed in room air. CAI (100 mg/kg) or vehicle control polyethylene glycol-400 (PEG-400) was given daily from PND-14 to -16, and mice were killed on PND-17 to form group A. In group B, CAI (100 mg/kg) or PEG-400 was given daily from PND-17 to -19, and mice were killed on PND-20. RESULTS: A 92% inhibition of neovascular cell nuclei on light microscopy was observed in mice treated with CAI in group A (P < 0.0001). Fluorescein-perfusion demonstrated a similar profound inhibition of neovascular frond formation in CAI-treated mice in group A. In group B, after neovascular fronds had already formed, CAI administration reduced neovascular cell nuclei by 72% (P < 0.001). Fluorescein perfusion studies confirmed that CAI induced regression of neovascular fronds. Similar amounts of posterior retinal ischemia were observed in all mice at both PND-17 and -20. In group A and B animals, CAI increased immunoreactivity of a cellular survival factor, Bcl-2, decreased TUNEL-positive cells, and after CAI treatment the normal morphology of the inner retina remained intact. CONCLUSIONS: CAI almost completely abolished retinal neovascularization in group A, and neovascular fronds involuted after treatment with CAI in group B. Thus, CAI is a potent inhibitor of ischemia-induced neovascularization and also imparts retinal neuroprotection after ischemic injury.

Angiogenesis Inhibitors↗
PubMed2003

Phase II trial of carboxyamidotriazole in patients with relapsed epithelial ovarian cancer.

PURPOSE: Carboxyamidotriazole (CAI) is a cytostatic inhibitor of nonvoltage-operated calcium channels and calcium channel-mediated signaling pathways. It inhibits angiogenesis, tumor growth, invasion, and metastasis. We hypothesized that CAI would promote disease stabilization lasting >/= 6 months in patients with relapsed ovarian cancer. PATIENTS AND METHODS: Patients with epithelial ovarian cancer, good end-organ function, measurable disease, and three or fewer prior regimens were eligible. Oral CAI was given daily using a pharmacokinetic-dosing approach to maintain plasma concentrations between 2 and 4 microg/mL. Radiographic imaging to assess response was performed every 8 weeks. Positive outcome included stabilization or improvement of disease lasting >/= 6 months. Plasma vascular endothelial growth factor (VEGF), interleukin (IL)-8, and matrix metalloproteinase (MMP)-2 were measured. RESULTS: Thirty-six patients were assessable for primary end point analysis, and 38 were assessable for toxicity. Forty-four percent of patients had three prior regimens, more than 50% had four or more disease sites, and 48% had liver metastases. Thirty-three patients reached the targeted concentration range during the first cycle. Eleven patients (31%) attained the >/= 6-month outcome end point, with one partial response (8 months) and three minor responses (8, 12+, and 13 months). Median time to progression was 3.6 months (range, 1.6 to 13.3 months). CAI was well tolerated, with mostly grade 1 to 2 toxicity. Grade 3 events included fatigue (5%), vomiting (2%), neutropenic fever (2%), and neutropenia (2%). There were no grade 4 adverse events. No associations between VEGF, IL-8, and MMP-2 with CAI concentration or clinical outcome were observed. CONCLUSION: CAI is a potential agent for additional study in the stabilization of relapsed ovarian cancer. Given a limited toxicity profile, it may have utility as a maintenance therapeutic agent for this disease.

Administration, Oral↗
PubMed2003

CAIR-1/BAG-3 abrogates heat shock protein-70 chaperone complex-mediated protein degradation: accumulation of poly-ubiquitinated Hsp90 client proteins.

BAG family proteins are regulatory co-chaperones for heat shock protein (Hsp) 70. Hsp70 facilitates the removal of injured proteins by ubiquitin-mediated proteasomal degradation. This process can be driven by geldanamycin, an irreversible blocker of Hsp90. We hypothesize that CAIR-1/BAG-3 inhibits Hsp-mediated proteasomal degradation. Human breast cancer cells were engineered to overexpress either full-length CAIR-1 (FL), which binds Hsp70, or a BAG domain-deletion mutant (dBAG) that cannot bind Hsp70. FL overexpression prevented geldanamycin-mediated loss of total and phospho-Akt and other Hsp client proteins. dBAG provided no protection, indicating a requirement for Hsp70 binding. Ubiquitinated Akt accumulated in FL-expressing cells, mimicking the effect of lactacystin proteasomal inhibition, indicating that CAIR-1 inhibits proteasomal degradation distal to protein ubiquitination in a BAG domain-dependent manner. Protein protection in FL cells was generalizable to downstream Akt targets, GSK3beta, P70S6 kinase, CREB, and other Hsp client proteins, including Raf-1, cyclin-dependent kinase 4, and epidermal growth factor receptor. These findings suggest that Hsp70 is a chaperone driving a multiprotein degradation complex and that the inhibitory co-chaperone CAIR-1 functions distal to client ubiquitination. Furthermore, poly-ubiquitination is not sufficient for efficient proteasomal targeting of Hsp client proteins.

Acetylcysteine↗
PubMed2003

Regulation of the pro-angiogenic microenvironment by carboxyamido-triazole.

Anti-angiogenic agents regulate tumor growth by inhibiting endothelial cell proliferation and invasion. Carboxyamido-triazole (CAI), an inhibitor of non-voltage-operated calcium entry and calcium influx-mediated pathways, has angiogenesis and invasion inhibitory activity. We hypothesized that CAI may express its anti-angiogenic effects through negative regulation of pro-angiogenic cytokine production and/or function. In vivo, orally administered CAI prevented A2058 human melanoma xenograft growth and concomitantly resulted in a marked reduction in circulating vascular endothelial growth factor (VEGF) and interleukin-8 (IL-8). In vitro, A2058 cell secretion of VEGF was inhibited by CAI treatment under limiting micronutrient conditions that approximate the tumor microenvironment, media restriction, and acidification to pH 6.8 (P=0.0003 and P=0.0006, respectively). VEGF and HIF-1alpha message and protein were also reduced by CAI treatment. Oral CAI treatment reduced vascular ingrowth in vivo into VEGF-containing Matrigel plugs. Commensurate with those findings, human umbilical vein endothelial cell (HUVEC) migration towards VEGF was reduced below background by exposure to CAI in the migration chamber (P<0.0001). An 88% reduction in circulating IL-8 concentration was measured in CAI-treated animals. However, IL-8 protein secretion and gene expression were increased by CAI treatment in culture (P< or =0.01), where CAI caused a dose-dependent acidification of the culture milieu (P< or =0.005). This paradox suggests that IL-8 production in vitro may be more sensitive to ambient pH than cytosolic calcium. These observations suggest that CAI inhibition of tumor cell VEGF production and endothelial cell response to VEGF results in disruption of signaling between the tumor and its microenvironment, causing a net anti-angiogenic effect.

Animals↗
PubMed2003

Mitochondrial proteome: altered cytochrome c oxidase subunit levels in prostate cancer.

Laser capture microdissection was combined with reverse phase protein lysate arrays to quantitatively analyze the ratios of mitochondrial encoded cytochrome c oxidase subunits to nuclear encoded cytochrome c oxidase subunits, and to correlate the ratios with malignant progression in human prostate tissue specimens. Cytochrome c oxidase subunits I-III comprise the catalytic core of the enzyme and are all synthesized from mitochondrial DNA. The remaining subunits (IV-VIII) are synthesized from cellular nuclear DNA. A significant (P < 0.001, 30/30 prostate cases) shift in the relative concentrations of nuclear encoded cytochrome c oxidase subunits IV, Vb, and VIc compared to mitochondrial encoded cytochrome c oxidase subunits I and II was noted during the progression of prostate cancer from normal epithelium through premalignant lesions to invasive carcinoma. Significantly, this shift was discovered to begin even in the premalignant stage. Reverse phase protein lysate array-based observations were corroborated with immunohistochemistry, and extended to a few human carcinomas in addition to prostate. This analysis points to a role for nuclear DNA encoded mitochondrial proteins in carcinogenesis; underscoring their potential as targets for therapy while highlighting the need for full characterization of the mitochondrial proteome.

Blotting, Western↗
PubMed2003

CAI inhibits the growth of small cell lung cancer cells.

The effects of carboxyamido-triazole (CAI) on small cell lung cancer (SCLC) cells were investigated. Using SCLC cell lines NCI-H209 or H345, 20 micro M CAI had little effect on basal cytosolic Ca(2+) but inhibited the ability of 10 nM bombesin (BB) or 1 nM neurotensin (NT) to elevate cytosolic Ca(2+). Also, CAI, impaired the ability of BB or NT to cause tyrosine phosphorylation of focal adhesion kinase. In contrast, CAI did not affect the ability of (125I-Tyr(4))BB or 125I-NT to bind with high affinity to NCI-H345 cells. These results indicate that CAI impairs SCLC second messenger activation, but not neuropeptide receptor binding. Using a MTT growth assay, CAI inhibited the proliferation of NCI-H209 or H345 cells in a concentration-dependent manner with little proliferation occurring using 100 micro M CAI. Also, CAI inhibited colony formation of NCI-H209 or H345 cells in a dose-dependent manner in vitro. In vivo, CAI (2 mg/day by gavage) inhibited significantly NCI-H209 xenograft proliferation in nude mice. Animals treated daily with CAI had significantly reduced CD31 immunostaining of microvessels in the tumor. Also, CAI inhibited the increase in vascular endothelial cell growth factor (VEGF) mRNA after addition of BB to SCLC cells. These results suggest that CAI inhibits the growth of SCLC cells as well as the angiogenesis of SCLC tumors in a VEGF-dependent manner.

Animals↗
PubMed2003

Calcium as a molecular target in angiogenesis.

The plethora of cellular pathways and events involved in angiogenesis are a prime example of the widespread role of calcium ion flux in biological functions. Indeed, calcium is a main point of intersection for many distinct molecular signaling pathways that promote and modulate angiogenesis. Here, we illustrate some of the important aspects of calcium induction, function, downstream effects, and resulting cellular changes that ensue. We describe some of the main mechanisms of calcium regulation in cells as well as intracellular and cross-membrane flux, highlighting key players that are known to facilitate these events. We review some of the major signaling pathways that tie into angiogenesis, and also describe how cellular phenotypic changes that occur during angiogenesis require processes rich in calcium ion stimulation of gradient shifts. Lastly, we hypothesize on current thinking of the role of calcium as a whole in angiogenic cellular function and propose new insight into calcium as a universal effector molecule and a prime target for therapeutic intervention.

Calcium↗
PubMed2003

The granulin-epithelin precursor/PC-cell-derived growth factor is a growth factor for epithelial ovarian cancer.

PURPOSE: The role of growth factors in ovarian cancer development and progression is complex and multifactorial. We hypothesized that new growth factors may be identified through the molecular analysis of ovarian tumors as they exist in their native environment. EXPERIMENTAL DESIGN: RNA extracted from microdissected serous low malignant potential (LMP) and invasive ovarian tumors was used to construct cDNA libraries. A total of 7300 transcripts were randomly chosen for sequencing, and those transcripts were statistically evaluated. Reverse transcription-PCR and immunohistochemistry were used to validate the findings in tumor tissue samples. Ovarian cancer cell lines were used to test gene effects on monolayer growth, proliferative capacity, and density-independent growth. RESULTS: Analysis of the pooled library transcripts revealed 26 genes differentially expressed between LMP and invasive ovarian cancers. The granulin-epithelin precursor [GEP/PC-cell derived growth factor (PCDGF)] was expressed only in the invasive ovarian cancer libraries (P < 0.028) and was absent in the LMP libraries (0 of 2872 clones). All of the invasive tumor epithelia, 20% of the LMP tumor epithelia, and all of the stroma from both subsets expressed GEP by reverse transcription-PCR. Immunohistochemical staining for GEP was diffuse and cytosolic in invasive ovarian cancer tumor cells compared with occasional, punctate, and apical staining in LMP tumor epithelia. Antisense transfection of GEP into ovarian cancer cell lines resulted in down-regulation of GEP production, reduction in cell growth (P < 0.002), decrease in the S-phase fraction (P < 0.04), and loss of density-independent growth potential (P < 0.01). CONCLUSION: cDNA library preparation from microdissected tumor epithelium provided a selective advantage for the identification of growth factors for epithelial ovarian cancer. Differential granulin expression in tumor samples and the antiproliferative effects of its antisense down-regulation suggest that GEP may be a new autocrine growth factor and molecular target for epithelial ovarian cancer.

Cell Division↗
PubMed2002

What's in the 'BAG'?--A functional domain analysis of the BAG-family proteins.

Bcl-2-associated athanogene (BAG)-family proteins are BAG domain-containing proteins that interact with the heat shock proteins 70, both constitutive Hsc70 and inducible Hsp70. BAG-family proteins bind through the BAG domain to the ATPase domain of Hsc70/Hsp70. The BAG domain, approximately 110 amino acids in length, is a conserved region at the carboxyl terminus and consists of three anti-parallel alpha helices based on X-ray crystallography and NMR studies. The second and third alpha-helices of the BAG domain interact with the ATP-binding pocket of Hsc70/Hsp70. Currently, six human BAG proteins have been reported, four of which have been shown to functionally bind Hsc70/Hsp70. BAG-family proteins regulate chaperone protein activities through their interaction with Hsc70/Hsp70. Over-expression of BAG-family proteins is found in several cancers and has been demonstrated in the laboratory to enhance cell survival and proliferation. The anti-apoptotic activities of BAG-family proteins may be dependent on their interactions with Hsc70/Hsp70 and/or binding to Bcl-2. Both BAG-1 and BAG-3/CAIR-1 interact with Bcl-2 and have been shown to have a supra-additive anti-apoptotic effect with Bcl-2. Several N-terminal domains or motifs have been identified in BAG-family proteins as well. These domains enable BAG-family proteins to partner with other proteins and potentially alter the activity of those target proteins by recruiting Hsc70/Hsp70. BAG-family proteins participate in a wide variety of cellular processes including cell survival (stress response), proliferation, migration and apoptosis.

Amino Acid Sequence↗
PubMed2002

Serum proteomic patterns for detection of prostate cancer.

Pathologic states within the prostate may be reflected by changes in serum proteomic patterns. To test this hypothesis, we analyzed serum proteomic mass spectra with a bioinformatics tool to reveal the most fit pattern that discriminated the training set of sera of men with a histopathologic diagnosis of prostate cancer (serum prostate-specific antigen [PSA] > or =4 ng/mL) from those men without prostate cancer (serum PSA level <1 ng/mL). Mass spectra of blinded sera (N = 266) from a test set derived from men with prostate cancer or men without prostate cancer were matched against the discriminating pattern revealed by the training set. A predicted diagnosis of benign disease or cancer was rendered based on similarity to the discriminating pattern discovered from the training set. The proteomic pattern correctly predicted 36 (95%, 95% confidence interval [CI] = 82% to 99%) of 38 patients with prostate cancer, while 177 (78%, 95% CI = 72% to 83%) of 228 patients were correctly classified as having benign conditions. For men with marginally elevated PSA levels (4-10 ng/mL; n = 137), the specificity was 71%. If validated in future series, serum proteomic pattern diagnostics may be of value in deciding whether to perform a biopsy on a man with an elevated PSA level.

Biomarkers, Tumor↗