Characterization of plasma protein profiles from patients with neurofibromatosis I

Background: Neurofibromatosis type I (NF1) is a common autosomal dominant disorder, affecting approximately one in every 3500 individuals. Early diagnosis of NF1 can be ambiguous, and clinical symptoms are diverse. We compared plasma protein profiles between normal controls and NF1 patients for yielding important insights into the mechanisms underlying NF1 related tumor formation and diagnostic biomarkers to classify the diverse clinical symptoms. Methods: MALDI-TOF mass spectrometry was used to identify plasma proteins. Prior to that, a micro-solution isoelectric focusing (μsol-IEF) pre-fractionation combined with two-dimensional gel electrophoresis (2-DE) using the narrow pH range strip was applied to enhance the resolution and sensitivity. Results: There was a significant increase in fibrinogen level in patients with NF1. This increase in fibrinogen expression was subsequently confirmed by Western blotting assay. Furthermore, the effect of fibrinogen on cell growth was tested on PC12 cells. Conclusion: Fibrinogen is the central protein associated with angiogenesis; a process which modulates tumor growth, the up-regulation of fibrinogen may help explain the development of neurofibromas in NF1 patients.