Project description:Anaplastic Lymphoma Kinase (ALK) most frequently mutated in neuroblastoma (NB) and is atractive molecular target for therapy. However, efficacy of the ALK inhibitor against ALK-amplified NB is unclear. To elucidate genetic alterations induced by treatment of the ALK inhibitor, we compared expression profile between ALK inhibitor-treated and DMSO-treated NB39nu cells using Agilent SurePrint G3 Human GE 8x60K V2 Microarray Kit
Project description:High anaplastic lymphoma kinase (ALK) protein levels may be correlated with an unfavorable prognosis in neuroblastoma (NBL) patients, regardless of ALK mutation status. We therefore examined the correlation between levels of ALK, phosphorylated ALK (pALK) and downstream signaling proteins and response to ALK inhibition in a large panel of both ALK mutated (MUT) and wild type (WT) NBL cell lines. Six of the nineteen NBL cell lines had a point mutation and four an amplification of the ALK gene. ALK amplified cell lines showed similar ALK levels and ALK inhibitor sensitivity as WT cell lines and were therefore co-analyzed. The ALK mRNA (p=0.043), ALK 220 kDa (p=0.009) and ALK 140 kDa (p=0.025) protein levels were higher in ALK mutant (n=6) than WT cell lines (n=13). ALK mRNA and protein levels significantly correlated with ERK1 and ERK2 protein levels, and also with PHOX2B mRNA levels, a neural differentiation marker which is mutated in NBL. Response to ALK inhibitor TAE684 was also significantly correlated with ALK levels. ALK mutant cell lines (n=4) demonstrated a higher sensitivity towards ALK inhibitor TAE684 (14.9 fold more sensitive, p=0.004) than eight WT cell lines. These results underline the importance of ALK mutations but also ALK levels for response to ALK inhibitors in NBL cell lines. Furthermore, the strong correlation of PHOX2B and ALK suggests that neural differentiation stage may be correlated with ALK levels in neuroblastoma. These data will enhance understanding of ALK inhibitor response in future patient trials. To study differentially expressed genes in the neuroblastoma cell lines described in the protein analysis study above, 15 cell lines and 2 derivative cell lines were used.
Project description:High anaplastic lymphoma kinase (ALK) protein levels may be correlated with an unfavorable prognosis in neuroblastoma (NBL) patients, regardless of ALK mutation status. We therefore examined the correlation between levels of ALK, phosphorylated ALK (pALK) and downstream signaling proteins and response to ALK inhibition in a large panel of both ALK mutated (MUT) and wild type (WT) NBL cell lines. Six of the nineteen NBL cell lines had a point mutation and four an amplification of the ALK gene. ALK amplified cell lines showed similar ALK levels and ALK inhibitor sensitivity as WT cell lines and were therefore co-analyzed. The ALK mRNA (p=0.043), ALK 220 kDa (p=0.009) and ALK 140 kDa (p=0.025) protein levels were higher in ALK mutant (n=6) than WT cell lines (n=13). ALK mRNA and protein levels significantly correlated with ERK1 and ERK2 protein levels, and also with PHOX2B mRNA levels, a neural differentiation marker which is mutated in NBL. Response to ALK inhibitor TAE684 was also significantly correlated with ALK levels. ALK mutant cell lines (n=4) demonstrated a higher sensitivity towards ALK inhibitor TAE684 (14.9 fold more sensitive, p=0.004) than eight WT cell lines. These results underline the importance of ALK mutations but also ALK levels for response to ALK inhibitors in NBL cell lines. Furthermore, the strong correlation of PHOX2B and ALK suggests that neural differentiation stage may be correlated with ALK levels in neuroblastoma. These data will enhance understanding of ALK inhibitor response in future patient trials.
Project description:The prognosis of advanced stage neuroblastoma patients remains poor and, despite intensive therapy, the 5-year survival rate remains less than 50%. We previously identified histone deacetylase (HDAC) 8 as an indicator of poor clinical outcome and a selective drug target for differentiation therapy in vitro and in vivo. Here we performed kinome-wide RNAi screening to identify genes that are synthetically lethal with HDAC8 inhibitors. These experiments identified the neuroblastoma predisposition gene ALK as a candidate gene. Accordingly, the combination of the ALK/MET inhibitor crizotinib and selective HDAC8 inhibitors (3-6μM PCI-34051 or 10μM 20a) efficiently killed neuroblastoma cell lines carrying wildtype ALK (SK-N-BE(2)-C, IMR5/75), amplified ALK (NB-1), and those carrying the activating ALK F1174L mutation (Kelly), and, in cells carrying the activating R1275Q mutation (LAN-5), combination treatment decreased viable cell count. The effective dose of crizotinib in neuroblastoma cell lines ranged from 0.05μM (ALK-amplified) to 0.8μM (wildtype ALK). The combinatorial inhibition of ALK and HDAC8 also decreased tumor growth in an in vivo zebrafish xenograft model. Bioinformatic analyses revealed that the mRNA expression level of HDAC8 was significantly correlated with that of ALK in two independent patient cohorts, the Academic Medical Center cohort (n=88) and the German Neuroblastoma Trial cohort (n=649), and co-expression of both target genes identified patients with very poor outcome. Mechanistically, HDAC8 and ALK converge at the level of receptor tyrosine kinase (RTK) signaling and their downstream survival pathways, such as ERK signaling. Combination treatment of HDAC8 inhibitor with crizotinib efficiently blocked the activation of growth receptor survival signaling and shifted the cell cycle arrest and differentiation phenotype toward effective cell death of neuroblastoma cell lines, including sensitization of resistant models, but not of normal cells. These findings reveal combined targeting of ALK and HDAC8 as a novel strategy for the treatment of neuroblastoma.
Project description:Neuroblastoma is an embryonal neoplasm that remains of dramatic prognosis in its aggressive forms. Activating mutations of the ALK tyrosine kinase receptor have been identified in sporadic and familial cases of this cancer. We generated knock-in mice carrying the two most frequent Alk mutations observed in neuroblastoma patients. We used microarrays to detail the global programme of gene expression underlying the impact of ALK mutations on neuroblastoma formation in a MYCN amplified background. We selected several murine neuroblastoma tumors for RNA extraction and hybridization on Affymetrix microarrays. We generated three groups of tumors: 10 MYCN amplified tumors, 11 MYCN amplified/ALK F1174L tumors and 10 MYCN amplified/ALK R1275Q tumors.
Project description:We used mass spectrometry-based proteomics to unravel anaplastic lymphoma kinase (ALK) signaling in the ALK and MYCN amplified neuroblastoma cell line, NB1. We specifically measured the ALK phosphoproteome upon siRNA depletion of ALK and upon ALK inhibition using the ALK-targeting small-molecule inhibitor lorlatinib. For quantitative phosphoproteomics we used a tandem mass tag (TMT)-based approach. Conditions for the TMT 11-plex setup is specified below. For each siRNA depletion experiment, NB1 cells were treated with siRNA (80 nM; as specified below) for 48 hours prior to stimulation with 0.1% DMSO for 30 minutes. For inhibitor treatment, NB1 cells were treated for 30 minutes with either 10 microM or 10 nM lorlatinib. The experimental treatment conditions and TMT11-plex labeling are specified below: 126: siControl replicate 1, 0.1% DMSO 127N: siControl replicate 2, 0.1% DMSO 127C: siControl replicate 3, 0.1% DMSO 128N: siALK sequence 1, 0.1% DMSO 128C: siALK sequence 2, 0.1% DMSO 129N: siALK mix of sequence 1 and 2, 0.1% DMSO 129C: 10 microM lorlatinib replicate 1 130N: 10 microM lorlatinib replicate 2 130C: 10 microM lorlatinib replicate 3 131N: 10 nM lorlatinib replicate 1 131C: 10 nM lorlatinib replicate 2
Project description:Neuroblastoma is an embryonal neoplasm that remains of dramatic prognosis in its aggressive forms. Activating mutations of the ALK tyrosine kinase receptor have been identified in sporadic and familial cases of this cancer. We generated knock-in mice carrying the two most frequent Alk mutations observed in neuroblastoma patients. We used microarrays to detail the global programme of gene expression underlying the impact of ALK mutations on neuroblastoma formation in a MYCN amplified background.
Project description:To understand the in vivo transcriptomic response to ATR inhibition, RNA-Seq was performed 3 days after treatment of a previously developed neuroblastoma mouse model (Alk-F1178S;Th-MYCN; see Borenas et al., EMBO J, 2021) with the ATR inhibitor ceralasertib.
Project description:High-risk neuroblastoma (NB) currently presents significant clinical challenges. MYCN and ALK, which are often involved in high-risk NB, lead to increased replication stress in cancer cells, providing options for therapeutic exploitation. We previously identified an ATR/ALK inhibitor combination as an effective therapeutic approach in two independent genetically modified mouse NB models. Here, we identify an underlying molecular mechanism, in which ALK signalling leads to phosphorylation of ATR and CHK1, supporting an effective DNA damage response. The importance of ALK inhibition is supported by mouse data, in which monotreatment with ATRi resulted in a robust initial response, but subsequent relapse, in contrast to a 14-day ALKi/ATRi combination treatment that resulted in robust and sustained responses. Finally, we show that the remarkable response to the 14-day combined ATR/ALK inhibition protocol reflects a robust differentiation response in the tumour, reprogramming tumour cells to a neuronal/Schwann cell lineage identity. Our results identify a unique ability of ATR inhibition to trigger neuroblastoma differentiation and underscore the importance of further exploring combined ALK/ATR inhibition in NB, particularly in high-risk patient groups with oncogene-induced replication stress.