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Putative Biomarker (putative + biomarker)
Selected AbstractsReduced expression of alpha-1,2-mannosidase I extends lifespan in Drosophila melanogaster and Caenorhabditis elegansAGING CELL, Issue 4 2009Ya-Lin Liu Summary Exposure to sub-lethal levels of stress, or hormesis, was a means to induce longevity. By screening for mutations that enhance resistance to multiple stresses, we identified multiple alleles of alpha-1,2-mannosidase I (mas1) which, in addition to promoting stress resistance, also extended longevity. Longevity enhancement is also observed when mas1 expression is reduced via RNA interference in both Drosophila melanogaster and Caenorhabditis elegans. The screen also identified Edem1 (Edm1), a gene downstream of mas1, as a modulator of lifespan. As double mutants for both mas1 and Edm1 showed no additional longevity enhancement, it appeared that both mutations function within a common pathway to extend lifespan. Molecular analysis of these mutants revealed that the expression of BiP, a putative biomarker of dietary restriction (DR), is down-regulated in response to reductions in mas1 expression. These findings suggested that mutations in mas1 may extend longevity by modulating DR. [source] Imaging the proliferative status of tumors with PET ,JOURNAL OF LABELLED COMPOUNDS AND RADIOPHARMACEUTICALS, Issue 5-6 2007Robert H. Mach Abstract The development of radiotracers for imaging solid tumors has recently focused on measuring a tumor's proliferative status. Two different strategies have emerged: (1) radiolabeled DNA precursors that measure DNA synthesis; and (2) radiotracers that label the sigma-2 receptor, a putative biomarker of proliferation. This paper provides a brief description of these two different methods of imaging tumor proliferation that are currently being developed in the field of positron emission tomography (PET). Copyright © 2007 John Wiley & Sons, Ltd. [source] Pilot study of capillary electrophoresis coupled to mass spectrometry as a tool to define potential prostate cancer biomarkers in urineELECTROPHORESIS, Issue 14 2005Dan Theodorescu Dr. Abstract We describe the use of capillary eletrophoresis (CE) coupled with mass spectrometry (MS) to identify single polypeptides and patterns of polypeptides specific for prostate cancer (CaP) in human urine. Using improved sample preparation methods that enable enhanced comparability between different samples, we examined samples from 47,patients who underwent prostate biopsy. Of this group, 21,patients had benign pathology and 26 with,CaP, and these were used to define potential biomarkers, which allow discrimination between these two states. In addition, CE-MS data from these 47,urine samples were compared to that of 41,young men (control) without known or suspected clinical CaP to further confirm the polypeptides indicative for CaP. Upon crossvalidation of the same samples, several polypeptides were selected that enabled correct classification of the CaP patients with 92% sensitivity and 96% specificity. We then examined an additional 474,samples from patients with renal disease enrolled in other studies and found that 14 (3%) had polypeptides suggestive of CaP possibly indicating that they harbor clinical CaP. In conclusion, this early pilot study suggests that CE-MS of urine warrants further investigation as a tool that can identify putative biomarkers for CaP. [source] Cancer biomarker discovery via low molecular weight serum proteome profiling , Where is the tumor?PROTEOMICS - CLINICAL APPLICATIONS, Issue 12 2007Michael T. Davis Abstract Time-course analyses of rapidly processed serum performed in parallel by SELDI and nanoscale LC-MS/MS have revealed the temporal correlation of several literature-based disease markers with ex vivo driven events such that their in vivo existence in healthy subjects is questionable. Identification by MS/MS reveals these putative biomarkers to be byproducts of the coagulation cascade and platelet activation and suggests plasmatic analysis may be preferred. In a pilot plasmatic study, a cohort of naïve prostate cancer (PCa) samples were uniformly distinguished from their age-matched controls (n,=,20) on the basis of multiple peptidic components; most notably by a derivative of complement C4 at 1863,m/z (GLEEELQFSLGSKINVK, C41353,1369). The fully tryptic nature of this and other putative PCa discriminants is consistent with the cleavage specificity of common blood proteases and questions the need for tumor-derived proteolytic activities as has been proposed. In light of the known correlation of disregulated hemostasis with malignant disease, we suggest the underlying differentiating phenomena in these types of analyses may lie in the temporal disparity of sample activation such that the case (patient) samples are preactivated while the control samples are not. [source] | ||||||||||