interleukin-8 and Adrenal-Cortex-Neoplasms

Stimulation of H295R adrenocortical carcinoma cells with angiotensin II or cytokines induces the secretion of the chemokine interleukin-8 (IL-8). Here, we have analyzed the molecular mechanism of stimulus-induced IL-8 expression. IL-8 expression and IL-8 promoter activity increased in H295R cells expressing an activated Gαq-coupled designer receptor. H295R cells stimulated with either interleukin-1β (IL-1β) or phorbol ester also showed elevated IL-8 mRNA levels and higher IL-8 promoter activities. Deletion and point mutations of the IL-8 promoter revealed that the AP-1 binding site within the IL-8 promoter is essential to connect designer receptor stimulation with the transcriptional activation of the IL-8 gene. Expression of a constitutively active mutant of c-Jun, or expression of constitutively active mutants of the protein kinases MEKK1 and MKK6 confirmed that the IL-8 gene is a bona fide target of AP-1 in adrenocortical carcinoma cells. Upregulation of IL-8 expression in IL-1β-treated H295R cells required NF-κB while the phorbol ester TPA used both the AP-1 and NF-κB sites of the IL-8 gene to stimulate IL-8 expression. These data were corroborated in experiments with chromatin-embedded AP-1 or NF-κB-responsive reporter genes. While stimulation of Gαq-coupled designer receptors increased the AP-1 activity in the cells, IL-1β specifically stimulated NF-κB-regulated transcription. Stimulation of the cells with TPA increased both AP-1 and NF-κB activities. We conclude that stimulation of Gαq-coupled designer receptors or IL-1 receptors triggers distinct signaling pathways in H295R cells leading to the activation of either AP-1 or NF-κB. Nevertheless, both signaling cascades converge to the IL-8 gene, inducing IL-8 gene transcription.

Topics: Adrenal Cortex Neoplasms; Adrenocortical Carcinoma; Cell Line, Tumor; Gene Expression Regulation, Neoplastic; Genes, jun; Humans; Interleukin-1beta; Interleukin-8; MAP Kinase Kinase 6; MAP Kinase Kinase Kinase 1; NF-kappa B; Point Mutation; Promoter Regions, Genetic; Sequence Deletion; Tetradecanoylphorbol Acetate; Transcription Factor AP-1; Transcriptional Activation; Up-Regulation

Bacterially derived ligands, Pam3CSK4 and LPS, can directly impact adrenal glands steroidogenesis through microdomain-related TLR1/2 and 4, respectively, and indirectly via immune cell-derived cytokines. The bilateral immunoadrenal relationship plays an important role in the proper functioning of both systems. CXC chemokine-dependent immune cell infiltration into adrenocortical carcinomas (ACC), which correlates with poor prognosis, is a common phenomenon. Recently, IL8 was identified in ACC and NCI-H295R cells, and was found to contribute to ACC tumour growth. The aim of this study was to clarify the role of different TLR ligands in IL8 production in NCI-H295R cells. This is the first study to demonstrate the expression of several TLRs including TLR1, 3, 6, 7 and 9 in human adrenocortical cells by using the RT-PCR approach. Only stimulation with TLR1/6 together with TLR2 ligands resulted in IL8 peptide and mRNA induction in a dose and time-dependent manner. Our data suggest that gram-positive bacteria-related TLR1/2/6 ligands might contribute to adrenal gland tumorigenesis via IL8 production.

Topics: Adrenal Cortex Neoplasms; Humans; Interleukin-8; Ligands; Lipopeptides; Lipopolysaccharides; Peptides; Teichoic Acids; Toll-Like Receptors

A patient with adrenocortical carcinoma presented with fever, leukocytosis, and increased acute phase reactants. The tumor was infiltrated with neutrophils. Immunohistochemical staining of the tumor showed positive signal for epithelial neutrophil-activating protein-78, an angiogenic and chemotactic CXC chemokine. Conditioned medium from tumor-derived cells (RL-251) showed high concentration of IL-8, epithelial neutrophil-activating protein-78, Gro alpha, and Gro gamma, angiogenic CXC chemokines with a potential role in tumorigenesis. An adrenal cancer/severe combined immunodeficiency mouse chimera was developed. Mice grew tumors rapidly, and circulating levels of IL-8 and epithelial neutrophil-activating protein-78 were detected. In contrast, animals transplanted with NCI-H295 cells, a nonchemokine-secreting cell line, grew tumors more slowly and did not have detectable chemokine levels. Similar to the patient, mice with RL-251 tumors developed marked leukocytosis and neutrophilia, and their tumors were infiltrated with neutrophils. Mice were passively immunized with epithelial neutrophil-activating protein-78 antisera. A marked decrease in tumor growth was observed. Potential for chemokine production by other adrenocortical tumors was investigated by RT-PCR in archival material. Six of seven adrenal carcinomas and one of three adenomas had cDNA for IL-8; six of seven carcinomas and the three adenomas had cDNA for epithelial neutrophil-activating protein-78. We concluded that the clinical presentation of this case resulted from increased tumor production of chemotactic chemokines. Through their angiogenic and chemotactic properties these chemokines may play an important role in adrenal tumorigenesis.

Topics: 17-Hydroxycorticosteroids; 17-Ketosteroids; Adenoma; Adrenal Cortex Neoplasms; Adrenocorticotropic Hormone; Aged; Chemokine CXCL5; Chemokines, CXC; Circadian Rhythm; Fever; Humans; Hydrocortisone; Immunohistochemistry; Interleukin-8; Leukocytosis; Male; Neutrophil Activation; Neutrophils; Reverse Transcriptase Polymerase Chain Reaction; Syndrome; Tumor Cells, Cultured