We have identified a mutation in KIAA0196 as the cause of the form of RSS characterised in our cohort. The ubiquitous expression and highly conserved nature of strumpellin, the product of KIAA0196, is consistent with the complex and multisystem nature of this disorder.
Purpose
Using prostatic fluids rich in glycoproteins like prostate specific antigen (PSA) and prostatic acid phosphatase (PAP) , the goal of this study was to identify the structural types and relative abundance of glycans associated with prostate cancer status for subsequent use in emerging mass spectrometry-based glycopeptide analysis platforms.
Experimental Design
A series of pooled samples of expressed prostatic secretions (EPS) and exosomes reflecting different stages of prostate cancer disease were used for N-linked glycan profiling by three complementary methods, MALDI-TOF profiling, normal-phase HPLC separation, and triple quadropole MS analysis of PAP glycopeptides.
Results
Glycan profiling of N-linked glycans from different EPS fluids indicated a global decrease in larger branched tri- and tetra-antennary glycans. Differential exoglycosidase treatments indicated a substantial increase in bisecting N-acetylglucosamines correlated with disease severity. A triple quadrupole MS analysis of the N-linked glycopeptides sites from PAP in aggressive prostate cancer pools was done to cross-reference with the glycan profiling data.
Conclusion and clinical relevance
Changes in glycosylation as detected in EPS fluids reflect the clinical status of prostate cancer. Defining these molecular signatures at the glycopeptide level in individual samples could improve current approaches of diagnosis and prognosis.
Prostate cancer is a clinically heterogeneous disease, ranging from indolent asymptomatic disease to very aggressive metastatic and life threatening forms of the disease. Distant metastasis represents the major lethal cause of prostate cancer. The most critical clinical challenge in the management of the patients is identifying those individuals at risk of developing metastatic disease. To understand the molecular mechanisms of prostate cancer metastasis and identify markers with metastatic potential, we have analyzed protein expression in two syngeneic prostate cancer cells lines PC3-N2 and PC3-ML2 using isobaric tags for relative and absolute quantitation labeling and multi-dimensional protein identification technology liquid chromatography matrix assisted laser desorption ionization tandem mass spectrometry. PC3-N2 is lowly metastatic while PC3-ML2 highly metastatic. A total of 1,756 proteins were identified in the analyses with 130 proteins showing different expression levels (p<0.01) in the two cell lines. Out of these, 68 proteins were found to be significantly up-regulated while 62 are significantly down-regulated in PC3-ML2 cells compared with PC3-N2 cells. The upregulation of plectin and vimentin which were the most significantly differentially expressed were validated by Western blot and their functional relevance with respect to invasion and migration was determined by siRNA gene silencing. To our knowledge, this study is the first to demonstrate that up-regulation of vimentin and plectin expression positively correlates with the invasion and metastasis of androgen-independent PCA.
Background
Enteroviruses (EVs) have been linked to the pathogenesis of several diseases and there is a collective need to develop improved methods for the detection of these viruses in tissue samples.
Objectives
This study evaluates the relative sensitivity of immunohistochemistry (IHC), proteomics, in situ hybridization (ISH) and RT-PCR to detect one common EV, Coxsackievirus B1 (CVB1), in acutely infected human A549 cells in vitro.
Study design
A549 cells were infected with CVB1 and diluted with uninfected A549 cells to produce a limited dilution series in which the proportion of infected cells ranged from 10−1 to 10−8. Analyses were carried out by several laboratories using IHC with different anti-EV antibodies, ISH with both ViewRNA and RNAScope systems, liquid chromatography multiple reaction monitoring mass spectrometry (LC/MRM/MS/MS), and two modifications of RT-PCR.
Results
RT-PCR was the most sensitive method for EV detection yielding positive signals in the most diluted sample (10−8). LC/MRM/MS/MS detected viral peptides at dilutions as high as 10−7. The sensitivity of IHC depended on the antibody used, and the most sensitive antibody (Dako clone 5D8/1) detected virus proteins at a dilution of 10−6, while ISH detected the virus at dilutions of 10−4.
Conclusions
All methods were able to detect CVB1 in infected A549 cells. RT-PCR was most sensitive followed by LC/MRM/MS/MS and then IHC. The results from this in vitro survey suggest that all methods are suitable tools for EV detection but that their differential sensitivities need to be considered when interpreting the results from such studies.
The composition of N-linked glycans that are conjugated
to the
prostate-specific membrane antigen (PSMA) and their functional significance
in prostate cancer progression have not been fully characterized.
PSMA was isolated from two metastatic prostate cancer cell lines,
LNCaP and MDAPCa2b, which have different tissue tropism and localization.
Isolated PSMA was trypsin-digested, and intact glycopeptides were
subjected to LC-HCD-EThcD-MS/MS analysis on a Tribrid Orbitrap Fusion
Lumos mass spectrometer. Differential qualitative and quantitative
analysis of site-specific N-glycopeptides was performed using Byonic
and Byologic software. Comparative quantitative analysis demonstrates
that multiple glycopeptides at asparagine residues 51, 76, 121, 195,
336, 459, 476, and 638 were in significantly different abundance in
the two cell lines (
p
< 0.05). Biochemical analysis
using endoglycosidase treatment and lectin capture confirm the MS
and site occupancy data. The data demonstrate the effectiveness of
the strategy for comprehensive analysis of PSMA glycopeptides. This
approach will form the basis of ongoing experiments to identify site-specific
glycan changes in PSMA isolated from disease-stratified clinical samples
to uncover targets that may be associated with disease progression
and metastatic phenotypes.
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