| 2. |
- Qundos, Ulrika, 1983-
(författare)
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Antibody based plasma protein profiling
- 2013
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- This thesis is about protein profiling in serum and plasma using antibody suspension bead arrays for the analysis of biobanked samples and in the context of prostate cancer biomarker discovery. The influence of sample preparation methods on antibody based protein profiles were investigated (Papers I-III) and a prostate cancer candidate biomarker identified and verified (Papers III-V). Furthermore, a perspective on the research area affinity proteomics and its’ employment in biomarker discovery, for improved understanding and potentially improved disease diagnosis, is provided.Paper I presents the results of a comparative plasma and serum protein profiling study, with a targeted biomarker discovery approach in the context of metabolic syndrome. The study yielded a higher number of significant findings and a low experimental variability in blood samples prepared as plasma. Paper II investigated the effects from post-centrifugation delays at different temperatures prior sample storage of serum and plasma samples. Minor effects were found on the detected levels of more than 300 predicted or known plasma proteins. In Paper III, the detectability of proteins in plasma was explored by exposing samples to different pre-analytical heat treatments, prior target capture. Heat induced epitope retrieval was observed for approximately half of the targeted proteins, and resulted in the discovery of different candidate markers for prostate cancer. Several antibodies towards the prostate cancer candidate biomarker CNDP1 were generated, epitope mapped and evaluated in a bead based sandwich immunoassay, as presented in Papers IV and V. Furthermore, the developed sandwich immunoassay targeting multiple distinct CNDP1 epitopes in more than 1000 samples, confirmed the association of CNDP1 levels to aggres- sive prostate cancer and more specifically to prostate cancer patients with regional lymph node metastasis (Paper V).As an outcome of the present investigations and in parallel to studies within the Biobank profiling research group, valuable lessons from study design and multiplex antibody analysis of plasma within biomarker discovery to experimental, technical and biological verifications have been collected.
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| 3. |
- von der Heyde, Silvia, et al.
(författare)
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Boolean ErbB network reconstructions and perturbation simulations reveal individual drug response in different breast cancer cell lines
- 2014
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Ingår i: BMC Systems Biology. - : Springer Science and Business Media LLC. - 1752-0509. ; 8:1, s. 75-
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Tidskriftsartikel (refereegranskat)abstract
- Background: Despite promising progress in targeted breast cancer therapy, drug resistance remains challenging. The monoclonal antibody drugs trastuzumab and pertuzumab as well as the small molecule inhibitor erlotinib were designed to prevent ErbB-2 and ErbB-1 receptor induced deregulated protein signalling, contributing to tumour progression. The oncogenic potential of ErbB receptors unfolds in case of overexpression or mutations. Dimerisation with other receptors allows to bypass pathway blockades. Our intention is to reconstruct the ErbB network to reveal resistance mechanisms. We used longitudinal proteomic data of ErbB receptors and downstream targets in the ErbB-2 amplified breast cancer cell lines BT474, SKBR3 and HCC1954 treated with erlotinib, trastuzumab or pertuzumab, alone or combined, up to 60 minutes and 30 hours, respectively. In a Boolean modelling approach, signalling networks were reconstructed based on these data in a cell line and time course specific manner, including prior literature knowledge. Finally, we simulated network response to inhibitor combinations to detect signalling nodes reflecting growth inhibition. Results: The networks pointed to cell line specific activation patterns of the MAPK and PI3K pathway. In BT474, the PI3K signal route was favoured, while in SKBR3, novel edges highlighted MAPK signalling. In HCC1954, the inferred edges stimulated both pathways. For example, we uncovered feedback loops amplifying PI3K signalling, in line with the known trastuzumab resistance of this cell line. In the perturbation simulations on the short-term networks, we analysed ERK1/2, AKT and p70S6K. The results indicated a pathway specific drug response, driven by the type of growth factor stimulus. HCC1954 revealed an edgetic type of PIK3CA-mutation, contributing to trastuzumab inefficacy. Drug impact on the AKT and ERK1/2 signalling axes is mirrored by effects on RB and RPS6, relating to phenotypic events like cell growth or proliferation. Therefore, we additionally analysed RB and RPS6 in the long-term networks. Conclusions: We derived protein interaction models for three breast cancer cell lines. Changes compared to the common reference network hint towards individual characteristics and potential drug resistance mechanisms. Simulation of perturbations were consistent with the experimental data, confirming our combined reverse and forward engineering approach as valuable for drug discovery and personalised medicine.
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