The results of the present study suggest that PF-2341066 and celecoxib may inhibit the development of cholangiocarcinoma by downregulating the expression of c-Met and COX-2 to inhibit cell proliferation, promote apoptosis and prevent VEGF-mediated tumor angiogenesis.
The significant correlation of VEGF expression with COX-2 expression and MCD may represent the roles of COX-2 and MCD in tumor angiogenesis by modulating VEGF production.
Cyclooxygenase-2 (COX-2) is a critically important mediator of inflammation that significantly influences tumor angiogenesis, invasion, and metastasis.
Cyclooxygenase-2 (COX-2) and 5-lipoxygenase (5-LOX) are the key players in the inflammatory cascade contributing towards the angiogenesis, tumor cell invasiveness, and disruption in the pathways of cellular proliferation/apoptosis.
Because hypoxia-inducible factor-1alpha (HIF-1alpha), its downstream target vascular endothelial growth factor (VEGF), and other angiogenic factors such as interleukin-8 (IL-8) and cyclooxygenase 2 (COX-2) play critical roles in neovascularization, we tested the hypothesis that the inhibitory effect of T3 on tumor angiogenesis is via regulation of these angiogenic factors.
Finally, treatment of glioma cell lines with prostaglandin E2, the predominant product of COX-2 activity, results in increased vascular endothelial growth factor expression, thus potentially linking elevations in COX-2 expression with tumor angiogenesis in malignant gliomas.
Cyclooxygenase-2 (COX-2) affects cell proliferation, apoptosis, and metastasis of breast cancer, and may also be involved in tumor angiogenesis through vascular endothelial growth factor.
Our aim was to study total COX-2 mRNA expression in both cancer cells and surrounding stromal cells and its association with angiogenic factor VEGF mRNA expression, tumor angiogenesis and prognosis in patients with NSCLC.
Whereas COX-2 and PGE(2) are associated with cancer cell survival and tumor angiogenesis, arachidonic acid itself is a strong apoptotic signal that may facilitate cancer cell death.
A papillary thyroid carcinoma cell line TPC-1 was also studied in vitro to determine the role of the specific COX-2 inhibitor NS-398 on COX-2 and vascular endothelial growth factor-A, since COX-2 also has a role in regulating tumor angiogenesis.
Elevated tumor cyclooxygenase 2 (COX-2) expression is associated with increased angiogenesis, tumor invasion, and promotion of tumor cell resistance to apoptosis.
In experimental setting, at low levels NSAIDs downregulate the COX-2 gene in colorectal cancer cells, whereas at clinical relevant concentrations the production of prostaglandin E2 by enzymatic activity of COX-2 is diminished resulting in inhibition of the tumor angiogenesis.
Elevated tumor cyclooxygenase 2 (COX-2) expression is associated with increased angiogenesis, tumor invasion and promotion of tumor cell resistance to apoptosis.