Kidins220/ARMS depletion is associated with the neural-to Schwann-like transition in a human neuroblastoma cell line model

The Tangential Dialogue Between Science and Medicine: A Case in Point

The road between a hypothesis about a disease or condition and its cure or palliation is never simply linear. There are many tantalizing tangents to be chased and many seemingly obvious truths with countless exceptions; this is usually a feature, not a bug, as they say in computer programming. In the tangents and exceptions are clues and alternative roads to science and medicine that can provide cures and palliative measures, sometimes for diseases or conditions other than the one being studied. The narrative that follows uses the author's scientific experience in childhood nervous system cancer to illustrate the importance of a robust, bidirectional interaction between the laboratory bench and the clinic bedside in the quest for solutions to problems of health, longevity, and quality of life.

STMN2 overexpression promotes cell proliferation and EMT in pancreatic cancer mediated by WNT/β-catenin signaling

STMN2, as a key regulator in microtubule disassembly and dynamics, has recently been shown to participate in cancer development. However, the corresponding role in pancreatic ductal adenocarcinoma (PC), to our knowledge, has not been reported yet. In the current study, we systematically investigate the potential role of STMN2 in the progression of PC in vitro and vivo. Overexpression of STMN2 was prevalently observed in 81 human cases of PC tissues compared with that in the paired adjacent pancreas (54.3% vs 18.5%, P < 0.01), which was positively associated with multiple advanced clinical stages of PC patients (tumor size, T stage, lymph-node metastasis and the poor prognosis). Meanwhile, a close correlation between high STMN2 and cytoplasmic/nuclear β-catenin expression (P = 0.007) was observed in PC tissues and cell lines. STMN2 overexpression induced EMT and cell proliferation in vitro via stimulating EMT-like cellular morphology, cell motility and proliferation, and the change of EMT (Snail1, E-cadherin and Vimentin) and Cyclin D1 signaling. However, XAV939 inhibited STMN2 overexpression-enhanced EMT and proliferation. Conversely, KY19382 reversed STMN2 silencing- inhibited EMT and cell proliferation in vitro. Furthermore, activated STMN2 and β-catenin were co-localized in cytoplasm/nuclear in vitro. β-catenin/TCF-mediated the transcription of STMN2 by the potential binding sites (TTCAAAG). Finally, STMN2 promoted subcutaneous tumor growth following the activation of EMT and Cyclin D1 signaling. STMN2 overexpression promotes the aggressive clinical stage of PC patients and promotes EMT and cell proliferation in vitro and vivo. β-catenin/TCF-mediated the transcription of STMN2.

Kidins220/ARMS controls astrocyte calcium signaling and neuron-astrocyte communication

Through their ability to modulate synaptic transmission, glial cells are key regulators of neuronal circuit formation and activity. Kidins220/ARMS (kinase-D interacting substrate of 220 kDa/ankyrin repeat-rich membrane spanning) is one of the key effectors of the neurotrophin pathways in neurons where it is required for differentiation, survival, and plasticity. However, its role in glial cells remains largely unknown. Here, we show that ablation of Kidins220 in primary cultured astrocytes induced defects in calcium (Ca2+) signaling that were linked to altered store-operated Ca2+ entry and strong overexpression of the transient receptor potential channel TRPV4. Moreover, Kidins220-/- astrocytes were more sensitive to genotoxic stress. We also show that Kidins220 expression in astrocytes is required for the establishment of proper connectivity of cocultured wild-type neurons. Altogether, our data reveal a previously unidentified role for astrocyte-expressed Kidins220 in the control of glial Ca2+ dynamics, survival/death pathways and astrocyte-neuron communication.

Kidins220/ARMS Expression Confers Proliferation But Independent of Self-Renewal in Mouse Embryonic Stem Cells

Embryonic stem cells (ESCs) are characterized by their ability to self-renew and their potential to differentiate into any cell type. Therefore, identification of novel molecular markers to verify the pluripotent status of mouse ESCs (mESCs) is of great significance. Kinase D interacting substrate of 220 kDa (Kidins220)/ankyrin repeat-rich membrane spanning (ARMS) plays a crucial role in the integration of growth factor receptor pathways during embryonic development. However, the role of Kidins220/ARMS in ESCs is still unknown. To elucidate the effects of Kidins220/ARMS on ESCs, we performed a knockdown of the Kidins220/ARMS gene by RNA interference. To our surprise, downregulation of Kidins220/ARMS did not alter the pluripotent state of mESCs. In contrast, it was essential for the proliferation and survival of ESCs. Furthermore, downregulation of the ARMS gene limited the migration of embryoid body cells derived from mESCs. This study indicates novel roles of Kidins220/ARMS in ESCs, which may represent valuable targets for future clinical applications of ESCs.

Functions of the multi-interacting protein KIDINS220/ARMS in cancer and other pathologies

Development of an organ and subsequently the whole system from an embryo is a highly integrated process. Although there is evidence that different systems are interconnected during developmental stages, the molecular understanding of this relationship is either not known or only to a limited extent. Nervous system development, amongst all, is maybe the most crucial and complex process. It relies on the correct distribution of specific neuronal growth factors and hormones to the specific receptors. Among the plethora of proteins that are involved in downstream signalling of neuronal growth factors, we find the kinase-D interacting substrate of 220 kDa (KIDINS220), also known as ankyrin-rich repeat membrane spanning (ARMS) protein. KIDINS220 has been shown to play a substantial role in the nervous system and vascular system development as well as in neuronal survival and differentiation. It serves as a downstream regulator for many important neuronal and vascular growth factors such as vascular endothelial growth factor (VEGF), the neurotrophin family, glutamate receptors and ephrin receptors. Moreover, activation and differentiation of B- and T-cells, as well as tumour cell proliferation has also shown to be related to KIDINS220. This review comprehensively summarises the existing research data on this protein, with a particular interest in its role in cancer and in other pathologies.

Using Chemistry to Target Neuroblastoma

Neuroblastoma is a cancer of the neural crest almost exclusively seen in childhood. While children with single, small primary tumors are often cured with surgery alone, the 65% of children with neuroblastoma whose disease has metastasized have less than a 50% chance of surviving five years after diagnosis. Innovative pharmacological strategies are critically needed for these children. Efforts to identify novel targets that afford ablation of neuroblastoma with minimal toxicity to normal tissues are underway. Developing approaches to neuroblastoma include those that target the catecholamine transporter, ubiquitin E3 ligase, the ganglioside GD2, the retinoic acid receptor, the protein kinases ALK and Aurora, and protein arginine N-methyltransferases. Here, as examples of the use of chemistry to combat neuroblastoma, we describe targeting of the protein arginine N-methyltransferases and their role in prolonging the half-life of the neuroblastoma oncoprotein N-Myc, redox signaling in neuroblastoma, and developmentally regulated proteins expressed in primitive neuroblastoma cells but not in mature neural crest elements.

Kidins220 and tumour development: Insights into a complexity of cross-talk among signalling pathways (Review)

The mechanistic complexes of kinase D-interacting substrate of 220 kDa/ankyrin repeat-rich membrane spanning (Kidins220/ARMS) bind and integrate a variety of cellular cues to mediate neuronal activities such as neuronal differentiation, survival, and cytoskeleton remodelling by interacting with a variety of binding partners. Accumulated evidence has also indicated its role in the regulation of vascular development. Mice with Kidins220 knockdown phenotypically present with cardiovascular abnormalities. Kidins220 also contributes to immunomodulation in combination with B cells and T cells. Moreover, emerging evidence has revealed that this protein regulates many crucial cellular processes and thus has been implicated in an increasing number of malignancies. Here, we review recent advances in our understanding of Kidins220 and its role in cancer development. Further investigation is warranted to shed light on the role played by Kidins220 in the dynamic arrangement of the cytoskeleton and epithelial–mesenchymal transition, and its implication in tumourigenesis and cancer progression.

The "neuro" of neuroblastoma: Neuroblastoma as a neurodevelopmental disorder

Neuroblastoma is a childhood cancer derived from cells of neural crest origin. The hallmarks of its enigmatic character include its propensity for spontaneous regression under some circumstances and its association with paraneoplastic opsoclonus, myoclonus, and ataxia. The neurodevelopmental underpinnings of its origins may provide important clues for development of novel therapeutic and preventive agents for this frequently fatal malignancy and for the associated paraneoplastic syndromes. Ann Neurol 2016;80:13-23.

Stepping Out of the Shade: Control of Neuronal Activity by the Scaffold Protein Kidins220/ARMS

The correct functioning of the nervous system depends on the exquisitely fine control of neuronal excitability and synaptic plasticity, which relies on an intricate network of protein-protein interactions and signaling that shapes neuronal homeostasis during development and in adulthood. In this complex scenario, Kinase D interacting substrate of 220 kDa/ankyrin repeat-rich membrane spanning (Kidins220/ARMS) acts as a multi-functional scaffold protein with preferential expression in the nervous system. Engaged in a plethora of interactions with membrane receptors, cytosolic signaling components and cytoskeletal proteins, Kidins220/ARMS is implicated in numerous cellular functions including neuronal survival, neurite outgrowth and maturation and neuronal activity, often in the context of neurotrophin (NT) signaling pathways. Recent studies have highlighted a number of cell- and context-specific roles for this protein in the control of synaptic transmission and neuronal excitability, which are at present far from being completely understood. In addition, some evidence has began to emerge, linking alterations of Kidins220 expression to the onset of various neurodegenerative diseases and neuropsychiatric disorders. In this review, we present a concise summary of our fragmentary knowledge of Kidins220/ARMS biological functions, focusing on the mechanism(s) by which it controls various aspects of neuronal activity. We have tried, where possible, to discuss the available evidence in the wider context of NT-mediated regulation, and to outline emerging roles of Kidins220/ARMS in human pathologies.

Ankyrin repeat-rich membrane spanning (ARMS)/Kidins220 scaffold protein regulates neuroblastoma cell proliferation through p21

Cell proliferation is tightly controlled by the cell-cycle regulatory proteins, primarily by cyclins and cyclin-dependent kinases (CDKs) in the G1 phase. The ankyrin repeat-rich membrane spanning (ARMS) scaffold protein, also known as kinase D-interacting substrate of 220 kDa (Kidins 220), has been previously identified as a prominent downstream target of neurotrophin and ephrin receptors. Many studies have reported that ARMS/Kidins220 acts as a major signaling platform in organizing the signaling complex to regulate various cellular responses in the nervous and vascular systems. However, the role of ARMS/Kidins220 in cell proliferation and cell-cycle progression has never been investigated. Here we report that knockdown of ARMS/Kidins220 inhibits mouse neuroblastoma cell proliferation by inducing slowdown of cell cycle in the G1 phase. This effect is mediated by the upregulation of a CDK inhibitor p21, which causes the decrease in cyclin D1 and CDK4 protein levels and subsequent reduction of pRb hyperphosphorylation. Our results suggest a new role of ARMS/Kidins220 as a signaling platform to regulate tumor cell proliferation in response to the extracellular stimuli.

Neurogenic maturation of human dental pulp stem cells following neurosphere generation induces morphological and electrophysiological characteristics of functional neurons

Cell-based therapies are emerging as an alternative treatment option to promote functional recovery in patients suffering from neurological disorders, which are the major cause of death and permanent disability. The present study aimed to differentiate human dental pulp stem cells (hDPSCs) toward functionally active neuronal cells in vitro. hDPSCs were subjected to a two-step protocol. First, neuronal induction was acquired through the formation of neurospheres, followed by neuronal maturation, based on cAMP and neurotrophin-3 (NT-3) signaling. At the ultrastructural level, it was shown that the intra-spheral microenvironment promoted intercellular communication. hDPSCs grew out of the neurospheres in vitro and established a neurogenic differentiated hDPSC culture (d-hDPSCs) upon cAMP and NT-3 signaling. d-hDPSCs were characterized by the increased expression of neuronal markers such as neuronal nuclei, microtubule-associated protein 2, neural cell adhesion molecule, growth-associated protein 43, synapsin I, and synaptophysin compared with nondifferentiated hDPSCs. Enzyme-linked immunosorbent assay demonstrated that the secretion of brain-derived neurotrophic factor, vascular endothelial growth factor, and nerve growth factor differed between d-hDPSCs and hDPSCs. d-hDPSCs acquired neuronal features, including multiple intercommunicating cytoplasmic extensions and increased vesicular transport, as shown by the electron microscopic observation. Patch clamp analysis demonstrated the functional activity of d-hDPSCs by the presence of tetrodotoxin- and tetraethyl ammonium-sensitive voltage-gated sodium and potassium channels, respectively. A subset of d-hDPSCs was able to fire a single action potential. The results reported in this study demonstrate that hDPSCs are capable of neuronal commitment following neurosphere formation, characterized by distinct morphological and electrophysiological properties of functional neuronal cells.

Aiming at neuroblastoma and hitting other worthy targets

Neuroblastoma is, at once, the most common and deadly extracranial solid tumor of childhood. Efforts aimed at targeting the neural characteristics of these tumors have taught us much about neural crest cell biology, apoptosis induction in the nervous system, and neurotrophin receptor signaling and intracellular processing. But neuroblastoma remains a formidable enemy to the oncologist and an enigmatic target to the neuroscientist.