Expression of angiogenic factors vascular endothelial growth factor and interleukin-8/CXCL8 is highly responsive to ambient glutamine availability: role of nuclear factor-kappaB and activating protein-1

• Published in: Cancer research (Chicago, Ill.) Vol. 64; no. 14; pp. 4858 - 4869
• Main Authors: Bobrovnikova-Marjon, Ekaterina V, Marjon, Philip L, Barbash, Olena, Vander Jagt, David L, Abcouwer, Steve F
• Format: Journal Article
• Language: English
• Published: United States 15.07.2004
• Subjects: Breast Neoplasms - genetics; Breast Neoplasms - metabolism; Cell Line, Tumor; Chemokine CXCL1; Chemokines, CXC - biosynthesis; Chemokines, CXC - genetics; Chemokines, CXC - physiology; Curcumin - pharmacology; DNA, Neoplasm - genetics; DNA, Neoplasm - metabolism; Gene Expression Regulation, Neoplastic; Glutamine - deficiency; Glutamine - metabolism; Humans; Intercellular Signaling Peptides and Proteins - biosynthesis; Intercellular Signaling Peptides and Proteins - genetics; Intercellular Signaling Peptides and Proteins - physiology; Interleukin-8 - biosynthesis; Interleukin-8 - genetics; NF-kappa B - antagonists & inhibitors; NF-kappa B - metabolism; NF-kappa B - physiology; Oligonucleotide Array Sequence Analysis; RNA, Messenger - biosynthesis; RNA, Messenger - genetics; RNA, Messenger - metabolism; Transcription Factor AP-1 - antagonists & inhibitors; Transcription Factor AP-1 - metabolism; Transcription Factor AP-1 - physiology; Transcription, Genetic; Up-Regulation; Vascular Endothelial Growth Factor A - biosynthesis; Vascular Endothelial Growth Factor A - genetics
• ISSN: 0008-5472

Vascular endothelial growth factor (VEGF) and interleukin-8/CXCL8 (IL-8) are prominent pro-angiogenic and pro-metastatic proteins that represent negative prognostic factors in many types of cancer. Hypoxia is thought to be the primary environmental cause of VEGF and IL-8 expression in solid tumors. We hypothesized that a lack of nutrients other than oxygen could stimulate the expression of these factors and previously demonstrated that expression of VEGF and IL-8 is responsive to amino acid deprivation. In the present study, we examined the effect of glutamine availability on the expression of these factors as well as the role of transcription factors NFkappaB and activating protein-1 (AP-1) in the response of TSE human breast carcinoma cells to glutamine deprivation. VEGF and IL-8 secretion and mRNA levels were dramatically induced by glutamine deprivation. mRNA stabilization contributed to this response. Glutamine deprivation increased NFkappaB (p65/p50) and AP-1 (Fra-1/c-Jun+JunD) DNA-binding activities. Blocking NFkappaB and AP-1 activation with curcumin as well as expression of dominant inhibitors, inhibitor of nuclear factor-kappaB (IkappaB) super repressor (IkappaBM), and a mutant form of c-Fos (A-Fos) demonstrated that the activation of NFkappaB and AP-1 transcription factors was necessary for the induction of IL-8 expression but dispensable for the induction of VEGF expression. A macro-array containing 111 NFkappaB target genes identified a total of 17 that were up-regulated 2-fold or more in response to glutamine deprivation. These included growth regulated oncogene alpha (GROalpha/GRO1/CXCL1), another neutrophil chemoattractant implicated in tumor angiogenesis and metastasis.