| 1. |
- Darmanis, Spyros, et al.
(författare)
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Multiplexed solid-phase proximity ligation assays: Highly specific and parallel protein measurements with DNA sequencing readout
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Annan publikation (övrigt vetenskapligt/konstnärligt)abstract
- Identification and validation of protein biomarkers is a very important step towards the understanding of the underlying mechanisms of disease, early diagnosis and efficient patient treatment. To carry out this task, methods are needed that would allow us to mine the proteome with sufficient sensitivity and specificity in large sets of samples. We present herein the development of a Multiplexed Proximity Ligation Assay (MultiPLAy), to facilitate efficient protein profiling in a parallel, sensitive and specific manner. We showed that for the simultaneous analysis of 35 proteins MultiPLAy exhibited an improved sensitivity over conventional sandwich assays as well as a smaller susceptibility to background signal increase in the transition from singleplex to multiplex. We used MultiPLAy to identify putative biomarkers in two separate sample cohorts of colorectal cancer (CRC) and cardiovascular disease (CVD) and with the use a novel multivariate analysis approach were able to identify new, as well as already known diagnostic biomarkers. Furthermore we were able to combine MultiPLAy with the use of next-generation sequencing allowing for the first time digital recording of protein profiles in blood. We demonstrated good reproducibility of MultiPLAy coupled to next-generation sequencing, as well as a satisfactory correlation to standard real-time PCR readout. We conclude that MultiPLAy has great potential as a basis for highly multiplexed protein detection assays that can be utilized for the identification of large numbers of proteins or protein variants. This will allow extensive validation of protein expression patterns in biobanked samples and in prospective studies, and can provide a much-needed platform for efficient validation of diagnostic markers for clinical use.
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| 2. |
- Ghanipour, Lana, et al.
(författare)
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Detection of prognostic biomarkers with solid-phase proximity ligation assay in patients with colorectal cancer
- 2016
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Ingår i: Translational Oncology. - : Elsevier BV. - 1944-7124 .- 1936-5233. ; 9:3, s. 251-255
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Tidskriftsartikel (refereegranskat)abstract
- Background: In the search for prognostic biomarkers a significant amount of precious biobanked blood samples is needed if conventional analyses are used. Solid-phase proximity ligation assay (SP-PLA) is an analytic method with the ability to analyse many proteins at the same time in small amounts of plasma. The aim of this study was to explore the potential use of SP-PLA in patients with colorectal cancer (CRC).Material and methods: Plasma from patients with stage I-IV CRC, with (n=31) and without (n=29) disease dissemination at diagnosis or later, was analysed with SP-PLA using 35 antibodies targeting an equal number of proteins in 5 ml plasma. Carcinoembryonic antigen (CEA), analysed earlier on this cohort, was used as a reference.Results: A total of 21 of the 35 proteins were detectable with SP-PLA. Patients in stage II-III with disseminated disease had lower plasma concentrations of HCC-4 (p=0.025). Low plasma levels of TIMP-1 were seen in patients with disseminated disease stage II (p=0.003). The level of CEA was higher in patients with disease dissemination compared to those without (p=0.007).Conclusion: SP-PLA has the ability to analyse many tumour markers simultaneously in a small amount of blood. However, none of the markers selected for the present SP-PLA analyses gave better prognostic information compared with CEA.
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| 3. |
- Wallin, Ulrik, et al.
(författare)
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Growth differentiation factor 15 : a prognostic marker for recurrence in colorectal cancer
- 2011
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Ingår i: British Journal of Cancer. - : Springer Science and Business Media LLC. - 0007-0920 .- 1532-1827. ; 104:10, s. 1619-1627
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: Growth differentiation factor 15 (GDF15) belongs to the transforming growth factor beta superfamily and has been associated with activation of the p53 pathway in human cancer. The aim of this study was to assess the prognostic value of GDF15 in patients with colorectal cancer (CRC). METHODS: Immunohistochemistry and tissue microarrays were used to analyse GDF15 protein expression in 320 patients with CRC. In a subgroup of 60 patients, the level of GDF15 protein in plasma was also measured using a solid-phase proximity ligation assay. RESULTS: Patients with CRC with moderate to high intensity of GDF15 immunostaining had a higher recurrence rate compared with patients with no or low intensity in all stages (stages I-III) (HR, 3.9; 95% CI, 1.16-13.15) and in stage III (HR, 10.32; 95% CI, 1.15-92.51). Patients with high plasma levels of GDF15 had statistically shorter time to recurrence (P = 0.041) and reduced overall survival (P = 0.002). CONCLUSION: Growth differentiation factor 15 serves as a negative prognostic marker in CRC. High expression of GDF15 in tumour tissue and high plasma levels correlate with an increased risk of recurrence and reduced overall survival.
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