scholarly journals Analysis of co-factor function in a glucocorticoid-resistant small cell carcinoma cell line

2004 ◽  
Vol 183 (2) ◽  
pp. 375-383 ◽  
Author(s):  
C E Waters ◽  
A Stevens ◽  
A White ◽  
D W Ray
Keyword(s):  
Cell Line ◽  
Cell Lines ◽  
Small Cell Lung Carcinoma ◽  
A549 Cells ◽  
Neuroendocrine Differentiation ◽  
Small Cell ◽  
Human Lung Cancer ◽  
Luciferase Reporter ◽  
Cell Lung Carcinoma ◽  
The Impact

Human small cell lung carcinoma (SCLC) tumours exhibit neuroendocrine differentiation, secreting hormones such as ACTH and related peptides. While glucocorticoids inhibit ACTH secretion from the pituitary, this does not occur in SCLC tumours and SCLC cell lines. Failure of glucocorticoids to suppress ACTH peptides is accompanied by a global lack of glucocorticoid action in a number of SCLC cell lines. In the human SCLC cell line, COR L103, activation of a human tyrosine aminotransferase (TAT3)-luciferase reporter gene is resistant to glucocorticoids despite similar glucocorticoid receptor (GR) expression to the glucocorticoid-sensitive A549 human lung cancer cell line; moreover, the GR is free of deleterious mutations. Over-expression of a wild-type GR restores glucocorticoid regulation of TAT3-luciferase, and this is enhanced when the activation function (AF)-2 domain is deleted but much reduced when the AF-1 domain is deleted. This suggests aberrant AF-2 activation domain function. We identified defective steroid receptor co-activator 1 (SRC1) recruitment to the GR AF-2 in COR L103 cells, although SRC1 was successfully recruited to the steroid X receptor with rifampicin, suggesting a defect in the GR. Analysis of other GR C-terminal co-factors identified increased expression of nuclear co-repressor (NCoR) in COR L103 cells. To determine the impact of this, NCoR was over-expressed in A549 cells, where it reduced GR transactivation by 55%. In summary, glucocorticoid resistance is associated with altered SRC protein recruitment and increased expression of NCoR in these SCLC cells, suggesting that glucocorticoid sensitivity may be modified by subtle changes in co-factor recruitment.

scholarly journals Hypoxia-induced Tie1 Drives Stemness and Cisplatin Resistance in Non-small Cell Lung Carcinoma Cells

2020 ◽  
Author(s):  
Chaojie Li ◽  
Nannan Yang ◽  
Zhijin Chen ◽  
Ning Xia ◽  
Qungang Shan ◽  
...  
Keyword(s):  
Cell Lines ◽  
Lung Carcinoma ◽  
Cisplatin Resistance ◽  
Small Cell Lung Carcinoma ◽  
Small Cell ◽  
Nsclc Cell ◽  
Luciferase Reporter ◽  
Small Cell Lung ◽  
Cell Lung Carcinoma

Abstract Background: Drug resistance and metastasis involving hypoxic tumor environment and persistent stem cell populations are detrimental to the survival of patients with non-small cell lung carcinoma (NSCLC). Tie1 is upregulated in hypoxia and is believed to counteract the effectiveness of platinum agents, by promoting the stemness properties in cells. We have investigated the association of Tie1 with HIF-1α and cisplatin resistance in NSCLC cell lines. Methods: Expression of Tie1 in a pulmonary microvascular endothelial cell line (HPMEC) and in NSCLC cell lines was detected using qRT-PCR and western blot. The effect of Tie1 on cell stemness and migration was examined by sphere-forming assay and transwell assay in NSCLC cells with Tie1 silenced. The regulation of Tie1 by HIF-1α was evaluated by a dual-luciferase reporter assay and chromatinImmune precipitation (ChIP) analysis.Results: We found that hypoxia could induce stemness and cisplatin resistance in vitro. Tie1 was expressed at low levels in NSCLC cells when compared with human pulmonary microvascular endothelial cells, however, its expression was increased by hypoxia. Additionally, Tie1 knockdown could reduce the stemness properties and increase sensitivity to cisplatin in vitro and in a xenograft mouse model. The promoter of Tie1 contains two predicted hypoxia-response elements (HREs). We mutated both HRE sites and conducted chromatin immune-precipitation and promoter luciferase reporter assays and were able to conclude that the induction of Tie1 by hypoxia was HIF-1α-dependent. Conclusions: Our findings indicated that Tie1 is upregulated in a hypoxic environment by HIF-1α and contributes to tumorigenesis and cisplatin resistance through the promotion of stemness in NSCLC cells.

scholarly journals Hypoxia-induced Tie1 drives stemness and cisplatin resistance in non-small cell lung carcinoma cells

2020 ◽  
Author(s):  
Chaojie Li ◽  
Nannan Yang ◽  
Zhijin Chen ◽  
Ning Xia ◽  
Qungang Shan ◽  
...  
Keyword(s):  
Cell Lines ◽  
Lung Carcinoma ◽  
Cisplatin Resistance ◽  
Small Cell Lung Carcinoma ◽  
Small Cell ◽  
Nsclc Cell ◽  
Luciferase Reporter ◽  
Small Cell Lung ◽  
Cell Lung Carcinoma

Abstract Background: Drug resistance and metastasis involving hypoxic tumor environments and persistent stem cell populations are detrimental to the survival of patients with non-small cell lung carcinoma (NSCLC). Tie1 is upregulated in hypoxia and is believed to counteract the effectiveness of platinum agents by promoting the stemness properties in cells. We have investigated the association of Tie1 with HIF-1α and cisplatin resistance in NSCLC cell lines.Methods: The expression of Tie1 in a pulmonary microvascular endothelial cell line (HPMEC) and NSCLC cell lines was detected using qRT-PCR and western blotting. The effect of Tie1 on cell stemness and migration was examined by sphere-forming and transwell assays in NSCLC cells with Tie1 silenced. The regulation of Tie1 by HIF-1α was evaluated by a dual-luciferase reporter assay and chromatin immunoprecipitation.Results: We found that hypoxia could induce stemness and cisplatin resistance in vitro. Tie1 was expressed at low levels in NSCLC cells when compared with human pulmonary microvascular endothelial cells, however, its expression was increased by hypoxia. Additionally, Tie1 knockdown could reduce stemness properties and increase sensitivity to cisplatin in vitro and in a xenograft mouse model. The promoter of Tie1 contains two predicted hypoxia-response elements (HREs). We mutated both HRE sites and conducted chromatin immune-precipitation and promoter luciferase reporter assays and were able to conclude that the induction of Tie1 by hypoxia was HIF-1α-dependent.Conclusions: Our findings indicated that Tie1 is upregulated in a hypoxic environment by HIF-1α and contributes to tumorigenesis and cisplatin resistance through the promotion of stemness in NSCLC cells.

scholarly journals Hypoxia-induced Tie1 drives stemness and cisplatin resistance in non-small cell lung carcinoma cells

2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Chaojie Li ◽  
Nannan Yang ◽  
Zhijin Chen ◽  
Ning Xia ◽  
Qungang Shan ◽  
...  
Keyword(s):  
Cell Lines ◽  
Lung Carcinoma ◽  
Cisplatin Resistance ◽  
Small Cell Lung Carcinoma ◽  
Small Cell ◽  
Nsclc Cell ◽  
Luciferase Reporter ◽  
Small Cell Lung ◽  
Cell Lung Carcinoma

Abstract Background Drug resistance and metastasis involving hypoxic tumor environments and persistent stem cell populations are detrimental to the survival of patients with non-small cell lung carcinoma (NSCLC). Tie1 is upregulated in hypoxia and is believed to counteract the effectiveness of platinum agents by promoting the stemness properties in cells. We have investigated the association of Tie1 with HIF-1α and cisplatin resistance in NSCLC cell lines. Methods The expression of Tie1 in a pulmonary microvascular endothelial cell line (HPMEC) and NSCLC cell lines was detected using qRT-PCR and western blotting. The effect of Tie1 on cell stemness and migration was examined by sphere-forming and transwell assays in NSCLC cells with Tie1 silenced. The regulation of Tie1 by HIF-1α was evaluated by a dual-luciferase reporter assay and chromatin immunoprecipitation. Results We found that hypoxia could induce stemness and cisplatin resistance in vitro. Tie1 was expressed at low levels in NSCLC cells when compared with human pulmonary microvascular endothelial cells, however, its expression was increased by hypoxia. Additionally, Tie1 knockdown could reduce stemness properties and increase sensitivity to cisplatin in vitro and in a xenograft mouse model. The promoter of Tie1 contains two predicted hypoxia-response elements (HREs). We mutated both HRE sites and conducted chromatin immune-precipitation and promoter luciferase reporter assays and were able to conclude that the induction of Tie1 by hypoxia was HIF-1α-dependent. Conclusions Our findings indicated that Tie1 is upregulated in a hypoxic environment by HIF-1α and contributes to tumorigenesis and cisplatin resistance through the promotion of stemness in NSCLC cells.

scholarly journals Hypoxia-induced Tie1 drives stemness and cisplatin resistance in non-small cell lung carcinoma cells

2020 ◽  
Author(s):  
Chaojie Li ◽  
Nannan Yang ◽  
Zhijin Chen ◽  
Ning Xia ◽  
Qungang Shan ◽  
...  
Keyword(s):  
Cell Lines ◽  
Lung Carcinoma ◽  
Cisplatin Resistance ◽  
Small Cell Lung Carcinoma ◽  
Small Cell ◽  
Nsclc Cell ◽  
Luciferase Reporter ◽  
Small Cell Lung ◽  
Cell Lung Carcinoma

Abstract Background: Drug resistance and metastasis involving hypoxic tumor environments and persistent stem cell populations are detrimental to the survival of patients with non-small cell lung carcinoma (NSCLC). Tie1 is upregulated in hypoxia and is believed to counteract the effectiveness of platinum agents by promoting the stemness properties in cells. We have investigated the association of Tie1 with HIF-1α and cisplatin resistance in NSCLC cell lines.Methods: The expression of Tie1 in a pulmonary microvascular endothelial cell line (HPMEC) and NSCLC cell lines was detected using qRT-PCR and western blotting. The effect of Tie1 on cell stemness and migration was examined by sphere-forming and transwell assays in NSCLC cells with Tie1 silenced. The regulation of Tie1 by HIF-1α was evaluated by a dual-luciferase reporter assay and chromatin immunoprecipitation.Results: We found that hypoxia could induce stemness and cisplatin resistance in vitro. Tie1 was expressed at low levels in NSCLC cells when compared with human pulmonary microvascular endothelial cells, however, its expression was increased by hypoxia. Additionally, Tie1 knockdown could reduce stemness properties and increase sensitivity to cisplatin in vitro and in a xenograft mouse model. The promoter of Tie1 contains two predicted hypoxia-response elements (HREs). We mutated both HRE sites and conducted chromatin immune-precipitation and promoter luciferase reporter assays and were able to conclude that the induction of Tie1 by hypoxia was HIF-1α-dependent.Conclusions: Our findings indicated that Tie1 is upregulated in a hypoxic environment by HIF-1α and contributes to tumorigenesis and cisplatin resistance through the promotion of stemness in NSCLC cells.

Expression of the Vasopressin and Gastrin-Releasing Peptide Genes in Small Cell Lung Carcinoma Cell Lines

Pathobiology ◽  
1992 ◽  
Vol 60 (3) ◽  
pp. 136-142 ◽  
Author(s):  
Marleen A.E. Verbeeck ◽  
Jack P.M. Elands ◽  
Lou F.M.H. de Leij ◽  
Charles H.C.M. Buys ◽  
Desmond N. Carney ◽  
...  
Keyword(s):  
Cell Lines ◽  
Lung Carcinoma ◽  
Carcinoma Cell ◽  
Small Cell Lung Carcinoma ◽  
Small Cell ◽  
Small Cell Lung ◽  
Cell Lung Carcinoma ◽  
Gastrin Releasing Peptide ◽  
Carcinoma Cell Lines ◽  
Lung Carcinoma Cell
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