Vascular endothelial growth factor A

About: Vascular endothelial growth factor A is a research topic. Over the lifetime, 15203 publications have been published within this topic receiving 1271498 citations. The topic is also known as: vascular endothelial growth factor A & vascular endothelial growth factor A165.

Wild-Type p53 and v-Src Exert Opposing Influences on Human Vascular Endothelial Growth Factor Gene Expression

Abstract: Angiogenesis, the development of new capillaries, is tightly controlled by the balance of positive and negative regulatory pathways. A newly described angiogenic factor, vascular endothelial growth factor/vascular permeability factor (VEGF/VPF), binds exclusively to endothelial cells and promotes their proliferation. Here we have studied the role of p53, a tumor suppressor, and v-Src, an oncogene on VEGF regulation. Wild-type p53 down-regulated endogenous VEGF mRNA level, as well as VEGF promoter activity, in a dose-dependent manner, whereas mutant forms of p53 had no effect. Overexpression of v-Src, known to up-regulate VEGF expression, activated a VEGF promoter-luciferase construct in a dose-dependent manner. Moreover, v-Src, in the presence of wt-p53, was unable to activate transcription of the VEGF promoter. Collectively, these data suggest that wild-type p53 may play a role in suppressing angiogenesis.

Akt1 regulates pathological angiogenesis, vascular maturation and permeability in vivo

Abstract: Akt kinases control essential cellular functions, including proliferation, apoptosis, metabolism and transcription, and have been proposed as promising targets for treatment of angiogenesis-dependent pathologies, such as cancer and ischemic injury. But their precise roles in neovascularization remain elusive. Here we show that Akt1 is the predominant isoform in vascular cells and describe the unexpected consequences of Akt1 knockout on vascular integrity and pathological angiogenesis. Angiogenic responses in three distinct in vivo models were enhanced in Akt1−/− mice; these enhanced responses were associated with impairment of blood vessel maturation and increased vascular permeability. Although impaired vascular maturation in Akt1−/− mice may be attributed to reduced activation of endothelial nitric oxide synthase (eNOS), the major phenotypic changes in vascular permeability and angiogenesis were linked to reduced expression of two endogenous vascular regulators, thrombospondins 1 (TSP-1) and 2 (TSP-2). Re-expression of TSP-1 and TSP-2 in mice transplanted with wild-type bone marrow corrected the angiogenic abnormalities in Akt1−/− mice. These findings establish a crucial role of an Akt-thrombospondin axis in angiogenesis.

Gemcitabine sensitivity can be induced in pancreatic cancer cells through modulation of miR-200 and miR-21 expression by curcumin or its analogue CDF.

Abstract: Curcumin induces cancer cell growth arrest and apoptosis in vitro , but its poor bioavailability in vivo limits its antitumor efficacy. We have previously evaluated the bioavailability of novel analogues of curcumin compared with curcumin, and we found that the analogue CDF exhibited greater systemic and pancreatic tissue bioavailability. In this study, we evaluated the effects of CDF or curcumin alone or in combination with gemcitabine on cell viability and apoptosis in gemcitabine-sensitive and gemcitabine-resistant pancreatic cancer (PC) cell lines. Mechanistic investigations revealed a significant reduction in cell viability in CDF-treated cells compared with curcumin-treated cells, which were also associated with the induction of apoptosis, and these results were consistent with the downregulation of Akt, cyclooxygenase-2, prostaglandin E 2 , vascular endothelial growth factor, and NF-κB DNA binding activity. We have also documented attenuated expression of miR-200 and increased expression of miR-21 (a signature of tumor aggressiveness) in gemcitabine-resistant cells relative to gemcitabine-sensitive cells. Interestingly, CDF treatment upregulated miR-200 expression and downregulated the expression of miR-21, and the downregulation of miR-21 resulted in the induction of PTEN. These results prompt further interest in CDF as a drug modality to improve treatment outcome of patients diagnosed with PC as a result of its greater bioavailability in pancreatic tissue. Cancer Res; 70(9); 3606–17. ©2010 AACR.

Transcriptional regulation of the Vascular Endothelial Growth Factor gene--a concert of activating factors.

Abstract: The vascular endothelial growth factor A (VEGF-A) is essential during embryonic development as inactivation of only one allele of its gene results in embryonic lethality. Up-regulation of VEGF under physiological situations allows for adaptation to hypoxic stress, to transient inflammatory processes, and to wounding. Its expression also increases all along the process of neovascularization of solid and hematological tumors. The object of this article is to focus on the transcriptional regulation of its gene. The major cis-acting sequences and trans-activating factors will be described as well as the physiological and pathological situations leading to the intervention of such sequences and factors. We will also focus on two transcription factors essential to VEGF gene transcription: the hypoxia-inducible factor-1, which is responsible for its increased by hypoxia, as well as Sp1, which is implicated in the response to various extracellular stimuli.