Dataset Information

Phosphoproteomics of induced and inhibited early Hh signaling in human medulloblastoma cells

ABSTRACT: Aberrant sonic hedeghog signaling is implicated in the development of various cancer entities such as medulloblastoma. The canonical signaling cascade has been studied for years. Activation of GLI transcription factors was revealed as the driving force upon pathway activation. Phosphorylation by Proteinkinase A, Casein Kinase 1 and Glycogen Synthase Kinase 3 β has been found to influence the degradation of the GLI transcription factors. However, the deeper role of phosphorylation in the signal transduction remains unclear. We, therefore, applied comprehensive HPLC-MS/MS based phosphoproteomics to reveal phosphorylation dynamics underlying the chemical activation and inhibition of sonic hedgehog signaling in human medulloblastoma cells. Human medulloblastoma cells were treated with SAG (Hh pathway induction) and Vismodegib (Hh pathway inhibition) for 5 and 15 minutes. Our phosphoproteomic profiling revealed a central role of phosphorylation in the regulation of ciliary assembly, trafficking and signal transduction after 5 minutes treatment. ERK/MAPK signaling besides protein kinase A signaling and mTOR signaling were differentially regulated. Activation of Polo-like kinase 1 and inhibtion of Caseinkinase 2A1 was characteristic for Vismodegib treatment while SAG treatment induced Aurora kinase A activity. Distinctive phosphorylation of central players of sonic Hh signaling such as Smoothened, SUFU, Gli2 and Gli3 was obtained after 15 minutes treatment.

INSTRUMENT(S):

ORGANISM(S): Homo Sapiens (human)

TISSUE(S): Epithelial Cell, Cell Culture

DISEASE(S): Medulloblastoma,Brain Cancer

SUBMITTER: Tamara Scheidt

LAB HEAD: Christian G. Huber

PROVIDER: PXD013408 | Pride | 2021-09-08

REPOSITORIES: Pride

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Dataset's files

Source:

			Action	DRS
	15min_HILIC_final.mzTab	Mztab
	15min_HILIC_final_extractPH.csv	Csv
	15min_pH8_PQ_final.csv	Csv
	15min_pH8_final.mzTab	Mztab
	5min_HILIC_final.mzTab	Mztab

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Publications

Phosphoproteomics of short-term hedgehog signaling in human medulloblastoma cells.

Scheidt Tamara T Alka Oliver O Gonczarowska-Jorge Humberto H Gruber Wolfgang W Rathje Florian F Dell'Aica Margherita M Rurik Marc M Kohlbacher Oliver O Zahedi René P RP Aberger Fritz F Huber Christian G CG

Cell communication and signaling : CCS 20200623 1

<h4>Background</h4>Aberrant hedgehog (HH) signaling is implicated in the development of various cancer entities such as medulloblastoma. Activation of GLI transcription factors was revealed as the driving force upon pathway activation. Increased phosphorylation of essential effectors such as Smoothened (SMO) and GLI proteins by kinases including Protein Kinase A, Casein Kinase 1, and Glycogen Synthase Kinase 3 β controls effector activity, stability and processing. However, a deeper and more com ...[more]

PMID: 32576205

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Project description:Aberrant activation of Hedgehog (HH) signaling has been identified as a key etiologic factor of many human malignancies. Signal strength, target gene specificity, and oncogenic activity of HH signaling profoundly depend on interactions with other pathways such as epidermal growth factor receptor-mediated signaling which has been shown to cooperate with HH/GLI in basal cell carcinoma and pancreatic cancer. We demonstrate that the human medulloblastoma cell line Daoy possesses a fully inducible endogenous HH pathway. Treatment of Daoy cells with Sonic Hedgehog or Smoothened agonist induced expression of GLI1 protein and prevented processing of GLI3 to its repressor form. To study interactions between HH- and EGF-induced signaling in greater detail, time-resolved measurements were carried out and analyzed on the transcriptomic as well as proteomic level. Daoy cells responded to the co-treatment by downregulating GLI1, PTCH, and HHIP on the transcript level which was also seen when Amphiregulin (AREG) was used instead of EGF. The finding that EGFR signaling silences proteins acting as negative regulators of HH signaling is firstly described here as a novel crosstalk mechanism. Furthermore, combined EGFR/HH signaling maintains high GLI1 protein levels contrasting its downregulation on the transcript level. On the other hand, high level synergism was observed with respect to a strong and significant upregulation of numerous canonical EGF-targets with putative tumor-promoting properties such as MMP7, VEGFA, and IL-8. In conclusion, synergistic effects between EGFR and HH signaling can selectively induce a switch from a canonical HH/GLI profile to a modulated specific target gene profile pointing to more wide-spread, yet context-dependent, interactions between HH/GLI and growth factor receptor signaling in human malignancies. To study interactions between HH- and EGF-induced signaling, time-resolved measurements were carried out over a period of 24 h at 14 different time points after stimulation by EGF with and without additional stimulation by SHH. Furthermore, as a control, cells without any stimulation by EGF and SHH (control) and cells in the presents of SHH were analyzed. Overall, three biological replicates of 60 different treatment/timepoints were analyzed yielding 180 different samples.

Project description:Background. Primary cilia (PC) are solitary antennae present at the cell surface. These non-motile cilia play an important role in organ development and tissue homeostasis through the transduction of the Hedgehog (Hh) signaling pathway. We recently revealed the presence of PC in the epithelium of the developing epididymis, an organ of the male reproductive system whose dysfunction triggers male infertility. Acknowledging that systemic blockade of the Hh pathway trigger epididymal dysfunctions in vivo, our main goals were 1) to portray the epididymal Hh environment, 2) to determine the direct responsiveness of epididymal epithelial cells to Hh, and 3) to define the contribution of PC to the transduction of this pathway. Results. The Hh ligands Indian and Sonic hedgehog (Ihh and Shh) were respectively located in principal and clear cells of the mouse epididymis by immunofluorescent staining. The propensity of epididymal principal cells to respond to Hh signaling was assessed on immortalized epididymal DC2 cells by western-blot, confocal imaging and 3D-reconstruction. Our results indicate that epididymal principal cells secrete Ihh and expose PC that co-localize with the conventional acetylated tubulin/Arl13b ciliary markers, as well as with GLI3 Hh signaling factor. Gene expression microarray profiling indicated that the expression of 43 and 248 genes was respectively and significantly modified following pharmacological treatment of DC2 cells with the Hh agonist SAG (250 nM) or the Hh antagonist cyclopamine (20 µM) compared with the control. Among Hh target genes identified, 6.7 % presented perfect matches for GLI-transcription factor consensus sequences, and the majority belonged to interferon-dependent immune response and lipocalin 2 pathways. Finally, the contribution of epididymal PC to the transduction of canonical Hh pathway was validated by ciliobrevinD treatment, which induced a significant decrease of PC length and the expressional reduction of Hh signalling targets. Conclusions. All together our data indicate that PC from epithelial principal cells regulate gene expression profile through a possible autocrine Hh signaling. This provides new hypotheses regarding the potential contribution of PC and Hh signaling in intercellular cross-talk and immunological regulation of the epididymis.

Project description:Mutations in Hedgehog (Hh) pathway genes, leading to constitutive activation of Smoothened (Smo), occur in sporadic medulloblastoma, the most common brain cancer in children. Antagonists of Smo induce tumor regression in mouse models of medulloblastoma and hold great promise for targeted therapy for this tumor. However, acquired resistance has emerged as one of the major challenges of targeted cancer therapy. Here, we describe novel mechanisms of acquired resistance to Smo antagonists in medulloblastoma. NVP-LDE225, a potent and selective Smo antagonist, inhibits Hh signaling and induces tumor regressions in allograft models of medulloblastoma that are driven by mutations of Patched (Ptch), a tumor suppressor in the Hh pathway. However, after long-term treatment, evidence of acquired resistance was observed. Genome-wide profiling of resistant tumors revealed distinct mechanisms to evade the inhibitory effects of Smo antagonists. Chromosomal amplification of Gli2, a downstream effector of Hh signaling, reactivated Hh signaling and restored tumor growth. Analysis of pathway gene-expression signatures selectively deregulated in resistant tumors identified increased phosphoinosite-3-kinase (PI3K) signaling as another potential resistance mechanism. Probing the functional relevance of increased PI3K signaling, we showed that the combination of NVP-LDE225 with the dual PI3K/mTOR inhibitor NVP-BEZ235 markedly delayed the development of resistance. Our findings have important clinical implications for future treatment strategies in medulloblastoma. mRNA profiling: RNA was prepared from tumours from vehicle or NVP-LDE225 treated nude mice allografted with medulloblastoma tumors derived from Ptch+/-p53-/- transgenic mouse and hybridized on Affymetrix Mouse Genome 430 2.0 RNA expression array. The dosage terminology (BID & QD) reflects the dosing schedule, where BID = twice a day, QD = once a day. aCGH: DNA was prepared from tumors from vehicle or NVP-LDE225 treated nude mice allografted with medulloblastoma tumors derived from Ptch+/-p53-/- transgenic mouse and hybridized on Agilent mouse CGH 244K Array.