Crest Cell Migration Research Articles

Neural crest cells and their potential therapeutic applications

Neural crest (NC) is a population of cells, formed at the intersection between non-neural ectoderm and neural tube. Neural crest progenitors are multipotent, have capacity to extensive migration and self-renewal. They can be differentiated into various cells types from craniofacial skeletal tissues to components of peripheral nervous system. Influence of signaling molecules and transcription factors, which are expressed at the different stages regulate development of NC. The regulatory network of genes determines the processes of induction, specification, migration and differentiation of neural crest cells (NCC). The purpose of this article is to compare the characteristics of NCC, obtained from tissues of the embryo, fetus and adult; experimental strategies for obtaining NCC from embryonic stem cells, induced pluripotent stem cells, skin fibroblasts; comparison of the potential of different cell types for therapeutic use in a clinical setting. Embryonic stem NCC are differentiated to the trunk, cranial, cardiac, circumpharyngeal and vagal according to the area of their initial migration. Mature stem NCC can be obtained from the dorsal root ganglia, red bone marrow, hair follicle, skin, intestines, carotid body, heart, cornea, iris, dental pulp, hard palate and oral mucosa. Genetic mutations may lead to failure of regulation of NC development, which leads to many congenital human diseases such as cardiovascular defects, craniofacial abnormalities and intestinal aganglionosis, collectively known as neurocristopathies. The identification and isolation of multipotent stem NCC derived from adult tissues, embryonic stem cells, and induced pluripotent stem cells are promising source for regenerative medicine.

Draxin inhibits chick trunk neural crest delamination and migration by increasing cell adhesion.

The neural crest is a multipotent cell population that migrates extensively to play important roles during embryonic development. After acquiring motility, trunk neural crest cells delaminate from the spinal cord and migrate to various regions of the body. Several cellular adhesion molecules, such as vinculin, are involved in the regulation of neural crest delamination and migration. In the present study, we found that draxin could inhibit delamination and migration of neural crest cells from the chick spinal cord and abnormal aggregation of the migrating neural crest cells. In the presence of draxin, the resuspended neural crest regained its adhesive ability such that it was significantly increased. Overexpression of draxin caused increased vinculin expression in vivo. Our data indicate that draxin might control delamination and migration of chick trunk neural crest by increasing cell adhesion.

Msx1 haploinsufficiency modifies the Pax9-deficient cardiovascular phenotype

BackgroundSuccessful embryogenesis relies on the coordinated interaction between genes and tissues. The transcription factors Pax9 and Msx1 genetically interact during mouse craniofacial morphogenesis, and mice deficient for either gene display abnormal tooth and palate development. Pax9 is expressed specifically in the pharyngeal endoderm at mid-embryogenesis, and mice deficient for Pax9 on a C57Bl/6 genetic background also have cardiovascular defects affecting the outflow tract and aortic arch arteries giving double-outlet right ventricle, absent common carotid arteries and interruption of the aortic arch.ResultsIn this study we have investigated both the effect of a different genetic background and Msx1 haploinsufficiency on the presentation of the Pax9-deficient cardiovascular phenotype. Compared to mice on a C57Bl/6 background, congenic CD1-Pax9–/– mice displayed a significantly reduced incidence of outflow tract defects but aortic arch defects were unchanged. Pax9–/– mice with Msx1 haploinsufficiency, however, have a reduced incidence of interrupted aortic arch, but more cases with cervical origins of the right subclavian artery and aortic arch, than seen in Pax9–/– mice. This alteration in arch artery defects was accompanied by a rescue in third pharyngeal arch neural crest cell migration and smooth muscle cell coverage of the third pharyngeal arch arteries. Although this change in phenotype could theoretically be compatible with post-natal survival, using tissue-specific inactivation of Pax9 to maintain correct palate development whilst inducing the cardiovascular defects was unable to prevent postnatal death in the mutant mice. Hyoid bone and thyroid cartilage formation were abnormal in Pax9–/– mice.ConclusionsMsx1 haploinsufficiency mitigates the arch artery defects in Pax9–/– mice, potentially by maintaining the survival of the 3rd arch artery through unimpaired migration of neural crest cells to the third pharyngeal arches. With the neural crest cell derived hyoid bone and thyroid cartilage also being defective in Pax9–/– mice, we speculate that the pharyngeal endoderm is a key signalling centre that impacts on neural crest cell behaviour highlighting the ability of cells in different tissues to act synergistically or antagonistically during embryo development.

Loss of Integrin-Linked Kinase Leads to Dysplasia of the Colon in Mice

Normal development of the colon is essential for well-being during the life span. Integrin linked kinase (ILK), which is a key part of the integrin signaling pathway, connects intracellular and extracellular signaling pathways and is evolutionally conserved. It has been shown that ILK knockouts can lead to abnormal formation of various organs. In our study, we found that deletion of ILK by platelet-derived growth factor receptor B (PDGFR[Formula: see text]-Cre leads to the abnormal migration of neural crest cells (NCCs) and the shortening of the gastrointestinal tract, along with the expansion of the colon cavity and dysplasia of the intestinal nerve fibers. In conclusion, ILK is required for normal colon development.

Current concepts on ocular vascular abnormalities in the phakomatoses

ABSTRACT Background: Neurofibromatosis, Von Hippel Lindau disease, and tuberous sclerosis complex are classified under the term phakomatoses. They are characterized by ocular vascular abnormalities such as vascular tortuosity, corkscrew retinal vessel configuration, moyamoya-like aspect, microaneurysms, hemangioblastomas, and focal sheathing of retinal arteries, possibly due to abnormal formation, migration, and differentiation of neural crest cells. These alterations can be the first sign or the hallmark of disease and can be related to vasoproliferative tumors. Purpose: Novel imaging technologies in ophthalmology, such as near-infrared reflectances and spectral domain optical coherence tomography, have improved our knowledge in the diagnosis of these pathologies. Previously undetected macular vascular alterations have been reported in phakomatoses using optical coherence tomography angiography. This review will summarize the ophthalmic vascular abnormalities and novel imaging methods in the phakomatoses. Conclusion: Active research is being led into the ophthalmic management of these conditions and their complications, and owing to elevated vascular endothelial growth factor production from hemangioblastoma, hamartoma, and retinal vascular proliferative tumors, increasing interest in this line of therapy has been conducted although research is still ongoing in this area.

Correlation of Peritumoral Edema and Microvessel Density with Tissue Expression of VEGF, Semaphorins 3A and 3C in Patients with Meningioma

Background: Several angiogenic factors correlate with angiogenesis in meningioma while their exact role is yet to be identified. Semaphorins are described with a variety of physiological functions including angiogenesis and migration of neural crest cells. Objective: We aimed to determine the correlation of semaphorin 3A, 3C (Sema 3A and 3C) and vascular endothelial growth factor (VEGF) expression with microvessel density (MVD) and peritumoral brain edema (PTBE) in meningioma.Methods: In this study 21 patients with grade I meningioma were included. PTBE was measured on axial and coronal brain MRI. Tissue expression of semaphorin 3A, 3C and VEGF were determined using quantitative real-time PCR (qRT-PCR). Result: We found that mean vascular density and tumor edema index were negatively associated with tissue expression of semaphorin 3A and 3C, respectively (p=0.029 and p=0.048). VEGF did not show statistically significant correlation with tumor characteristics studied (p> 0.05). We also found that the mean vascular density of the menigiomas was positively associated with intra operative blood loss (r=0.503, p=0.010). Conclusion: Our data indicates an inverse correlation of Sema3A and Sema3C with vascular density and peritumoral edema, respectively, while no correlation could be shown for VEGF. Thus, Sema3A and 3C may be identified as appropriate inhibitors of pathological angiogenesis in human meningioma. However, confirmation of this finding in a larger dataset is warranted.

ZnO NPs exposure impairs cranial neural crest development by inducing excessive oxidant stress level during chick embryogenesis

Introduction: Zinc oxide Nanoparticles (ZnO NPs) could lead to defects in chick craniofacial skeleton during embryogenesis, but the further mechanism is still not clear. In this study, we found ZnO NPs exposure cause craniofacial development defect, including shorten coracoids, curved coracoids and impaired parietal bone, which is derived from the cranial neural crest cells. we observed that ZnO NPs could inhibit the production and migration of cranial neural crest cells, which mainly caused by altering expression of epithelial-mesenchymal transitions-related adhesion molecules. Moreover, we observed that ZnO NPs significantly induced the extent apoptosis in cranial neural crest cells but not affect the cell proliferation. Then, the level of oxidant stress of cranial neural crest cells is elevated by ZnO NPs treatment.

Abstract 5832: Rho-associated kinase is a therapeutic target in neuroblastoma

Abstract Background: Neuroblastoma is a peripheral neural system tumor that originates from the neural crest and is the most common and deadly tumor of infancy. The non-canonical Wnt/planar cell polarity (PCP) signaling pathway regulates cytoskeletal organization, migration and maturation of neural crest cells during neuritogenesis. Here we show that neuroblastoma harbors frequent mutations of genes controlling the PCP signaling pathway and Rac/Rho signaling cascade important for proper migration and differentiation of neural crest cells during neuritogenesis. The majority of these mutations were detected in GTPase activating proteins and guanine nucleotide exchange factors genes, which may result in inhibition of Rac and activation of Rho and was associated with aggressive high-stage neuroblastomas. Methods: We performed whole-exome sequencing of neuroblastoma samples of all clinical subgroups to search for mutations and genetic aberrations. Cytotoxic activity of Rho-associated kinases (ROCK) inhibitors was studied in cell viability assays. Morphology and invasion were studied with microscopy. The molecular mechanisms were characterized using cell- and molecular biology techniques. In vivo studies (xenografts and the transgenic mouse model TH-MYCN) in mice were carried out to validate the therapeutic effects and toxicity. Results: Exome sequencing detected frequent mutations and gene aberrations in genes controlling the activity of PCP signaling. Analysis of gene signatures and immunohistochemistry showed that high expression of ROCK1 and ROCK2 correlated with poor patient survival. Several mediators of Rac/Rho were differentially expressed in cell lines and patient samples. Pharmacological or genetic inhibition of ROCK, a key molecule in Rac/Rho signaling resulted in differentiation, inhibition of neuroblastoma cell growth and migration and degradation of MYCN protein. Finally, ROCK inhibition reduced the growth of established neuroblastoma xenografts in nude mice and repressed tumor progression in a MYCN-driven mouse model of neuroblastoma (T-MYCN) Conclusions: These results provide evidence that inhibition of the non-canonical/PCP signaling cascade using ROCK inhibitors suppress the growth of neuroblastoma in preclinical models and suggest possibilities for improved treatment of high-risk neuroblastomas. Citation Format: Cecilia H. Dyberg, Susanne Fransson, Teodora Andonova, Baldur Sveinbjörnsson, Jessika Lännerholm-Palm, David Forsberg, Eric Herlenius, Tommy Martinsson, Per Kogner, John Inge Johnsen, Malin Wickström. Rho-associated kinase is a therapeutic target in neuroblastoma [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 5832. doi:10.1158/1538-7445.AM2017-5832

A rare combination of Tessier 2 cleft with Goldenhar syndrome

The incidence of rare craniofacial clefts ranges from 1.43 to 4.85/100,000 live births. Most craniofacial centers report an incidence of 9.4-34 cases of rare clefts for every 1000 clefts. Among these Tessier clefts, the number 2 cleft is the rarest. We report one such case of complete number 2 nasal cleft in a 3-year-old boy, with features of Goldenhar syndrome, such as preauricular tags, epibulbar dermoid, and coloboma of middle one-third of the upper eyelid. This combination is extremely rare and has only been reported once before in literature. Reconstruction of the nasal cleft was carried out using a modification of Denonvilliers Z-plasty along with a composite graft from the right helix and rotation of dorsal nasal skin. Rare facial cleft combinations reinforce the embryological basis that they are likely to result from the disruption in migration of neural crest cells from rhombomeres to branchial arches by genetic manipulation by teratogens, rather than other simplistic theories.

Abstract 3266: Inhibition of Rho-associated kinase 2 suppresses MYCN expression and induces differentiation of neuroblastoma

Abstract Background: Neuroblastoma is an embryonic tumor of the peripheral sympathetic nervous system that originates from cells within the neural crest. The non-canonical Wnt/planar cell polarity (PCP) signaling pathway regulates cytoskeletal organization, migration and maturation of neural crest cells during neuritogenesis. We and others have shown that high-risk neuroblastoma exhibit frequent mutations of genes controlling the activity of the Wnt/PCP signaling cascade leading to inhibition of Rac and activation of Rho resulting in downstream activation of the serine/threonine kinases Rho-Associated Coiled-Coil Containing Protein Kinases (ROCK1 and ROCK2) Methods: We performed whole-exome sequencing for 33 neuroblastoma samples of all clinical subgroups to search for mutations and genetic aberrations. Cytotoxic activity of ROCK inhibitors was studied in cell viability assays. Morphology and invasion were studied with microscopy. The molecular mechanisms were characterized using cell- and molecular biology techniques. In vivo studies (xenografts and the transgenic mouse model TH-MYCN) in mice were carried out to validate the therapeutic effects and toxicity. Results: Exome sequencing detected frequent mutations and gene aberrations in genes controlling the activity of PCP signalling. Analysis ofgene signatures and immunohistochemistry showed that high expression of ROCK1 and ROCK2 correlated with poor patient survival. Several mediators of Rho/Rac were differentially expressed in cell lines and patient samples. Using compounds blocking ROCK1 and ROCK2 activity revealed that the ROCK2 inhibitor HA-1077 effectively repressed proliferation and reduced cell viability in neuroblastoma. HA-1077 inhibited migration and induced differentiation through inhibition of neural outgrowth and inhibited MYCN protein expression, effects that were mimicked using siRNA against ROCK. Finally, HA-1077 reduced the growth of established neuroblastoma xenografts in nude mice and repressed tumor progression in a MYCN-driven mouse model of neuroblastoma (T-MYCN) Conclusions: Our results show the significance of the non-canonical/PCP signaling cascade in neuroblastoma development and progression. Furthermore, ROCK inhibition suppress the growth of neuroblastoma in preclinical models and provide a novel option for improved treatment of high-risk neuroblastoma. Citation Format: Cecilia Dyberg, David Forsberg, Susanne Fransson, Jessika Lännerholm Palm, Bjorn Helge Haug, Baldur Sveinbjornsson, Tommy Martinsson, Per Kogner, John Inge Johnsen, Malin Wickstrom. Inhibition of Rho-associated kinase 2 suppresses MYCN expression and induces differentiation of neuroblastoma. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 3266. doi:10.1158/1538-7445.AM2015-3266

Fibronectin and Craniofacial Surgery

Fibronectin is an essential component of the extracellular matrix. The role of fibronectin in craniofacial surgery has not been previously reviewed. Fibronectin mediates bone differentiation and development of the skull. Studies have shown that normal development of the skull requires a specific pattern of expression around the epithelial-mesenchymal interface of the neurocranium. Fibronectin is also essential in mediating the migration of neural crest cells to form the facial skeleton. The calvaria of patients with Apert and Crouzon syndromes have an abnormally elevated collagen level. However, fibronectin levels are elevated in the former syndrome and decreased in the latter syndrome. The significance of this requires further research. Fibronectin gene expression is increased in port wine-derived fibroblasts in patients with Sturge-Weber syndrome. Normal palatogenesis also requires a specific pattern of expression of fibronectin around the maxillary process as well as the roof of the stomodeum, and several studies have linked the development of cleft lip/palate to an imbalance of fibronectin content of the extracellular matrix. Fibronectin mediates cell-to-cell attachment during repair of calvarial defects; hence, fibronectin has been used as a carrier for bone morphogenetic proteins to treat calvarial defects. Finally, fibronectin is now an essential component in stem cell technology related to craniofacial surgery.

Enteric nervous system cell replacement therapy for Hirschsprung disease: beyond tissue-engineered intestine.

Hirschsprung disease (HD), a neurocristopathy characterized by failed migration of neural crest cells to the distal colon, requires surgical resection of the aganglionic segment. Advances in stem cell and regenerative medicine research have opened the possibility to treat HD less invasively using enteric nervous system (ENS) cell replacement therapy. This article reviews the progress to date of culturing and delivering ENS stem cells in various in vitro and in vivo models, as well as review the available evidence of functionality of the transplant-derived cells. Potential areas of future study are identified, and application of conditions other than HD is briefly discussed.

Acute urinary retention from coprostatic colon: an unusual presentation of 'adult Hirschsprung's disease'

Hirschsprung disease (HD), or congenital intestinal aganglionosis, is characterized by absence of neurons in the distal colon resulting from a lack of migration of neural crest cells to the large intestine during fetal development.1 HD typically manifests in early childhood, but very rarely the diagnosis may be delayed for several years when ‘adult HD’ patients present with refractory constipation, intestinal obstruction, sigmoid volvulus or colonic perforation.2 While co-existing congenital genitourinary anamolies have been reported in ∼6% of HD cases, …

Annexin A6 Modulates Chick Cranial Neural Crest Cell Emigration

The vertebrate neural crest is a population of migratory cells that originates in the dorsal aspect of the embryonic neural tube. These cells undergo an epithelial-to-mesencyhmal transition (EMT), delaminate from the neural tube and migrate extensively to generate an array of differentiated cell types. Elucidating the gene regulatory networks involved in neural crest cell induction, migration and differentiation are thus crucial to understanding vertebrate development. To this end, we have identified Annexin A6 as an important regulator of chick midbrain neural crest cell emigration. Annexin proteins comprise a family of calcium-dependent, membrane-binding molecules that mediate a variety of cellular and physiological processes including cell adhesion, migration and invasion. Our data indicate that Annexin A6 is expressed in the proper spatio-temporal pattern in the chick midbrain to play a potential role in neural crest cell ontogeny. To investigate Annexin A6 function, we have depleted or overexpressed Annexin A6 in the developing midbrain neural crest cell population. Our results show that knock-down or overexpression of Annexin A6 reduces or expands the migratory neural crest cell domain, respectively. Importantly, this phenotype is not due to any change in cell proliferation or cell death but can be correlated with changes in the size of the premigratory neural crest cell population and with markers associated with EMT. Taken together, our data indicate that Annexin A6 plays a pivotal role in modulating the formation of cranial migratory neural crest cells during vertebrate development.

The p21-activated kinase Pak1 regulates induction and migration of the neural crest in Xenopus

Pak1 is a member of the PAK family of serine/threonine kinases that are downstream effectors of Rac1 and Cdc42 small GTPases and are implicated in cytoskeleton reorganization. Early expression of Pak1 in Xenopus embryos is tissue restricted, suggesting a role in organogenesis and in cranial neural crest (CNC) cell migration. By observing CNC in vivo and after transplantation, we show that a dominant-negative (DN) Pak1 inhibits its migration. DN-Pak1 also specifically modified the expression of several NC markers. Twist expression was decreased and Snail1 expression posteriorized, but Snail2 (Slug), Sox9 and AP2 were unaffected. DN-Pak1 inhibition of CNC migration could be rescued with Snail1 but not with Twist, which, in fact, cooperated with DN-Pak1 in inhibiting migration. The data confirm that neither Snail1 nor Snail2 expression alone is sufficient for Xenopus CNC migration. Furthermore, they show that, in this tissue, Snail1 and Snail2 expression is not interdependent, nor are these factors subject to obligatory co-regulation, and that their expression depends on signal transduction. Our results also represent the first evidence that Pak1 links extracellular signals to the genetic cascade of transcription factors necessary for CNC specification.

Complement, Attraction, and Collective Migration

Complement factor C3a and its receptor are required for the mutual attraction and collective migration of neural crest cells.

Highlights in basic autonomic neuroscience: Development of autonomic neurons — From the neural crest to circuit formation

Neural crest cells arise fromdorsal regions of the neural tube, delaminate and migrate to many target sites. In the trunk, neural crest cells follow distinct pathways to form multiple derivatives, including neurons and glia in sympathetic and dorsal root ganglia and melanocytes in the skin. The earliest migrating cells proceed ventrally to the sympathetic ganglia, while later migrating cells populate the dorsal root ganglia, and last of all, pre-specified melanoblasts migrate along a dorsolateral pathway. Multiple molecular differences have been identified between neural crest following the dorsolateral pathway compared to those migrating ventrally. Krispin and colleagues examined in detail the emergence of neural crest cells from the dorsal region of the neural tube by labeling and lineage tracing small numbers of cells in the dorsal neural tube (by electroporating a GFP construct or with DiI) at a specified axial level at defined stages of development in chick embryos. Following labeling of dorsal neural tube cells shortly prior to the initial migration of neural crest cells, all of the labeled cells exited the neural tube in ~90% of the experiments. This suggested a ventral to dorsal relocation of cells in the dorsal neural tube, rather than asymmetric cell division in which one daughter cell emigrated as a neural crest cell while the other daughter cell remained within the neural tube. Time lapse imaging of the neural tube opened along themiddle and flattened into a hemi-tube showed movement of labeled cells from ventral to dorsal. When cells at distinct sites within the dorsal 30% of the neural tube were labeled shortly prior to initial migration, a strong correlation was observed between the dorsoventral positionwithin the neural tube and the final localization of the labeled cells. These results suggest that within the neural tube there is a progressive ventral to dorsal relocation of cells prior to neural crest cell delamination, and that the roof plate is formed from the cells that have relocated dorsally after the dorsolaterally migrating melanoblasts have exited the neural tube. The authors concluded that there is a dynamic spatiotemporal fate map in the dorsal neural tube shortly prior to and during neural crest emigration. Finally,

A novel role for MuSK and non-canonical Wnt signaling during segmental neural crest cell migration

Trunk neural crest cells delaminate from the dorsal neural tube as an uninterrupted sheet; however, they convert into segmentally organized streams before migrating through the somitic territory. These neural crest cell streams join the segmental trajectories of pathfinding spinal motor axons, suggesting that interactions between these two cell types might be important for neural crest cell migration. Here, we show that in the zebrafish embryo migration of both neural crest cells and motor axons is temporally synchronized and spatially restricted to the center of the somite, but that motor axons are dispensable for segmental neural crest cell migration. Instead, we find that muscle-specific receptor kinase (MuSK) and its putative ligand Wnt11r are crucial for restricting neural crest cell migration to the center of each somite. Moreover, we find that blocking planar cell polarity (PCP) signaling in somitic muscle cells also results in non-segmental neural crest cell migration. Using an F-actin biosensor we show that in the absence of MuSK neural crest cells fail to retract non-productive leading edges, resulting in non-segmental migration. Finally, we show that MuSK knockout mice display similar neural crest cell migration defects, suggesting a novel, evolutionarily conserved role for MuSK in neural crest migration. We propose that a Wnt11r-MuSK dependent, PCP-like pathway restricts neural crest cells to their segmental path.

Progress on the etiology of the Hirschsprung's disease

The major progress on the study of etiology of the Hirschsprung's disease is the genetic factots and the aherations of microenvironment in primarily embryogenic period.The genetic factors comprise of RETGDNF system.EDNRB.EDN3 system,and many other genes involving in the formulation of the tormer two svstems.such as SOX10,NRG-1, FoxD3,PHOX2B,HOXB5,ZFHXIB,all of which file essencial for the migration and differentiation of neural crest cells(NCC).The alterations of microenvironment in primarily embryogenic period include interstitial ceLls of cajal(ICC),cell adhesion molecules(CAMLl),Ca2+ and so on.Definitely,CAML1 plays as the basis of NCC's migration and differentiation,and the decline of the Ca2+dependent channel's expression brings about the anolnaloug contraction of smooth muscle. Key words: Hirschsprung's disease; Genetic factors; Microenvironment in primarily embryogenic period

Abstract 4873: Protein complexes in cancer: A novel strategy to identify protein complexes through reduction of false discovery rate

Abstract Most cellular processes are controlled by protein-protein interactions, and aberrant protein-protein interactions can lead to human diseases such as cancer. Hence a comprehensive understanding of a protein interaction network and its dynamics response to different physiological conditions is essential for understanding a protein's function and may reveal novel therapeutic opportunities for fighting cancer. Affinity purification coupled with mass spectrometry has become the method of choice to study in vivo protein interactions and formation of protein complexes. However, the methodology has some limitations that reduce it application such as, under sampling of low abundant proteins and high background leading to an elevated false discovery rate (FDR). Herein we describe a strategy utilizing differential expression of the target protein followed by analysis using quantitative proteomics. By performing affinity purification on cells expressing increasing amounts of the polycomb complex protein Bmi-1, we show that known interacting proteins could be distinguished very efficiently from the background proteins based on their abundance profile. Applying this method to the data set significantly reduced the FDR and allowed us to identify potentially new interacting proteins for Bmi-1 that otherwise would have been considered non-specifically bound proteins. The method was also applied to characterize the interactome for Snail I, II and III a family of Zn-finger proteins thought to be involved in transcriptional repression. These proteins have been implicated in diverse biological function such as regulation of epithelial to mesenchymal transition, formation and maintenance of embryonic mesoderm, generation and migration of neural crest cells and metastasis. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 4873. doi:10.1158/1538-7445.AM2011-4873