The Role of Cell Lines in the Study of Neuroendocrine Tumors

Grozinsky‐Glasberg, Simona; Shimon, Ilan; Rubinfeld, Hadara

doi:10.1159/000338793

Cited by 49 publications

(42 citation statements)

References 190 publications

(105 reference statements)

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“…TGF-β1 can act as either promoter, via EMT activation, or suppressor of tumor progression, depending on the degree of tumor malignancy [26]. In this context [3], we have reported its protective role in low-to-intermediate grade carcinoids, but the higher malignancy of NET cell lines is well documented [27, 28]. Therefore, here we used TGF-β1 as positive regulator of EMT and observed that this cytokine induced the transcriptional signature of EMT in all NET cell lines, with modifications similar to those caused by CXCL12 in CXCR4 high /CXCL12 low NET cells.…”

Section: Discussionmentioning

confidence: 99%

Osteotropism of neuroendocrine tumors: role of the CXCL12/CXCR4 pathway in promoting EMT in vitro

et al. 2017

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Neuroendocrine tumors (NETs) metastasize to the skeleton in approximately 20% of patients. We have previously shown that the epithelial-mesenchymal transition (EMT) regulates the NET osteotropism and that CXCR4 overexpression predicts bone spreading. Here, we unravel the molecular mechanisms linking the activation of the CXCL12/CXCR4 axis to the bone colonization of NETs using cell lines representative of pancreatic (BON1, CM, QGP1), intestinal (CNDT 2.5), and bronchial origin (H727). By combining flow cytometry and ELISA, BON1, CM and QGP1 cells were defined as CXCR4high/CXCL12low, while H727 and CNDT 2.5 were CXCR4low/CXCL12high. CXCL12 was inert on cell proliferation, but significantly increased the in vitro osteotropism of CXCR4high/CXCL12low cells, as assessed by transwell assays with or without Matrigel membranes. In these cells, CXCL12 induced in vitro a marked EMT-like transcriptional shift with acquirement of a mesenchymal shape. The nuclei of CXCR4high/CXCL12low NET cells were typically enriched in non-phosphorylated CXCR4, particularly upon agonist stimulation. Silencing of CXCR4 via siRNA prevented the CXCL12-induced EMT in CXCR4high/CXCL12low NET cell lines resulting in the abrogation of both migration and transcriptional mesenchymal patterns. Our data suggest that CXCL12 conveys EMT-promoting signals in NET cells through CXCR4, which in turn regulates transcriptional, morphologic and functional modifications resulting in enhanced in vitro osteotropism of NET cells. Unique functions of CXCR4 may be segregated in relation to its subcellular localization and may acquire potential relevance in future in vivo studies.

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Section: Discussionmentioning

confidence: 99%

Osteotropism of neuroendocrine tumors: role of the CXCL12/CXCR4 pathway in promoting EMT in vitro

et al. 2017

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“…In our study we used the well-known and highly proliferative BON1 cell line of human pancreatic carcinoid origin as a NET in vitro model [49]; whereas the important antiproliferative effect of CQ demonstrated here in BON1 cells may not be directly applicable to in vivo grade 1 or grade 2 (well-differentiated) NET models, they are probably suggestive for the possible efficacy of autophagy inhibition as a therapeutic target also in NET models with a lower proliferation rate. Indeed, the main limitation of our study is that all of the experiments were done on a cell line, and further experiments using primary tumors in mouse models are needed before human studies can be contemplated; however, these results are encouraging and suggest that lysosomal inhibitors, such as CQ, may become a new therapeutic approach for patients with metastatic NETs treated with or without mTORi.…”

Section: Discussionmentioning

confidence: 99%

Abrogation of Autophagy by Chloroquine Alone or in Combination with mTOR Inhibitors Induces Apoptosis in Neuroendocrine Tumor Cells

et al. 2015

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Background: Everolimus (RAD001), an mTORC1 inhibitor, demonstrated promising, but limited, anticancer effects in neuroendocrine tumors (NETs). Torin1 (a global mTOR inhibitor) and NVP-BEZ235 (a PI3K/mTOR inhibitor) seem to be more effective than RAD001. Autophagy, a degradation pathway that may promote tumor growth, is regulated by mTOR; mTOR inhibition results in stimulation of autophagy. Chloroquine (CQ) inhibits autophagy. Aim: To explore the effect of CQ alone or in combination with RAD001, Torin1 or NVP-BEZ235 on autophagy and on NET cell viability, proliferation and apoptosis. Methods: The NET cell line BON1 was treated with CQ with or without different mTOR inhibitors. siRNA against ATG5/7 was used to genetically inhibit autophagy. Cellular viability was examined by XTT, proliferation by Ki-67 staining and cell cycles by flow cytometry. Apoptosis was analyzed by Western blotting for cleaved caspase 3 and staining for annexin V; autophagy was evaluated by Western blotting and immunostaining for LC3. Results: RAD001, Torin1, NVP-BEZ235 and CQ all decreased BON1 cell viability. The effect of RAD001 was smaller than that of the other mTOR inhibitors or CQ. Torin1 and NVP-BEZ235 markedly inhibited cell proliferation, without inducing apoptosis. CQ similarly decreased cell proliferation, while robustly increasing apoptosis. Treatment with Torin1 or NVP-BEZ235 together with CQ was additive on viability, without increasing CQ-induced apoptosis. Inhibition of autophagy by ATG5/7 knockdown increased apoptosis in the presence or absence of mTOR inhibitors, mimicking the CQ effects. Conclusion: CQ inhibits NET growth by inducing apoptosis and by inhibiting cell proliferation, probably via inhibition of autophagy. CQ may potentiate the antitumor effect of mTOR inhibitors.

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“…GEPNET cell lines have been used to study selected inhibitors for their efficacy and mechanism of action (Grozinsky-Glasberg et al 2012). No comprehensive screening for effective inhibitors of GEPNETs has however been reported.…”

Section: Pannet and Sinet Cells Are Sensitive To Inhibitors Of Mek Anmentioning

confidence: 99%

The neuroendocrine phenotype, genomic profile and therapeutic sensitivity of GEPNET cell lines

Hofving¹,

Arvidsson²,

Almobarak³

et al. 2018

Endocrine-Related Cancer

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Experimental models of neuroendocrine tumour disease are scarce, and no comprehensive characterisation of existing gastroenteropancreatic neuroendocrine tumour (GEPNET) cell lines has been reported. In this study, we aimed to define the molecular characteristics and therapeutic sensitivity of these cell lines. We therefore performed immunophenotyping, copy number profiling, whole-exome sequencing and a large-scale inhibitor screening of seven GEPNET cell lines. Four cell lines, GOT1, P-STS, BON-1 and QGP-1, displayed a neuroendocrine phenotype while three others, KRJ-I, L-STS and H-STS, did not. Instead, these three cell lines were identified as lymphoblastoid. Characterisation of remaining authentic GEPNET cell lines by copy number profiling showed that GOT1, among other chromosomal alterations, harboured losses on chromosome 18 encompassing the SMAD4 gene, while P-STS had a loss on 11q. BON-1 had a homozygous loss of CDKN2A and CDKN2B, and QGP-1 harboured amplifications of MDM2 and HMGA2. Whole-exome sequencing revealed both disease-characteristic mutations (e.g. ATRX mutation in QGP-1) and, for patient tumours, rare genetic events (e.g. TP53 mutation in P-STS, BON-1 and QGP-1). A large-scale inhibitor screening showed that cell lines from pancreatic NETs to a greater extent, when compared to small intestinal NETs, were sensitive to inhibitors of MEK. Similarly, neuroendocrine NET cells originating from the small intestine were considerably more sensitive to a group of HDAC inhibitors. Taken together, our results provide a comprehensive characterisation of GEPNET cell lines, demonstrate their relevance as neuroendocrine tumour models and explore their therapeutic sensitivity to a broad range of inhibitors.

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The Role of Cell Lines in the Study of Neuroendocrine Tumors

Cited by 49 publications

References 190 publications

Osteotropism of neuroendocrine tumors: role of the CXCL12/CXCR4 pathway in promoting EMT in vitro

Osteotropism of neuroendocrine tumors: role of the CXCL12/CXCR4 pathway in promoting EMT in vitro

Abrogation of Autophagy by Chloroquine Alone or in Combination with mTOR Inhibitors Induces Apoptosis in Neuroendocrine Tumor Cells

The neuroendocrine phenotype, genomic profile and therapeutic sensitivity of GEPNET cell lines

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