Testing the Effect of Bevacizumab Treatment on VEGF Signaling in Vitro
Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
Introduction: Bevacizumab (Avastin; Genentech/Roche) was the first anti-angiogenesis agent approved by the FDA. Angiogenesis is the process of creating new blood vessels. Bevacizumab is a monoclonal antibody against vascular endothelial growth factor (VEGF), a key protein modulating angiogenesis. By inhibiting VEGF, the growth of new blood vessels that can supply tumors with oxygen and nutrients is prevented. Since approval, the treatment has been effective in many patients. Up to 18% of patients experience severe high blood pressure as an adverse reaction, which can make patients discontinue treatment that otherwise may be beneficial. The mechanism of bevacizumab-induced hypertension is not well understood and with a growing use of anti-angiogenesis agents there is an increased need in understanding the toxicities associated with the treatment. The hypothesis is that disruption of VEGF signaling in endothelial cells by bevacizumab causes high blood pressure. The hypothesis was examined in this study using an in vitro model with Human Umbilical Vascular Endothelial Cells (HUVECs). Aim: The aim of this study was to investigate the effects of bevacizumab treatment on VEGF signaling in HUVECs. In order to explore how VEGF and bevacizumab affects phosphorylation of ERK1/2, Akt and P38 under different conditions and is a first step in establishing an integrated endothelial cell-smooth muscle cell system to study the effects of bevacizumab on vascular reactivity. Materials and Methods: HUVECs were grown to confluence in 6-well plates, then exposed to VEGF and bevacizumab at different conditions. Following treatment, the cells were lysed and proteins extracted for detection of ERK1/2, Akt and P38 by Western blot. Results: VEGF induced time- and dose-dependent phosphorylation of ERK1/2 and this response was greatly attenuated by bevacizumab treatment. VEGF-dependent Akt and P38 signaling was not detectable in this experimental system. Conclusions: This study demonstrates that bevacizumab has an inhibitory effect on VEGF-signaling in HUVECs, specifically on phosphorylation of ERK1/2. The contribution of ERK1/2 signaling to effects on adjacent smooth muscle cells and blood pressure regulation requires further study.
Place, publisher, year, edition, pages
2015. , 22 p.
Bevacizumab, hypertension, HUVEC
IdentifiersURN: urn:nbn:se:uu:diva-258704OAI: oai:DiVA.org:uu-258704DiVA: diva2:842285
Master of Science Programme in Pharmacy