Cancers, Vol. 11, Pages 868: Uptake of Ranibizumab but Not Bevacizumab into Uveal Melanoma Cells Correlates with a Sustained Decline in VEGF-A Levels and Metastatic Activities

Cancers, Vol. 11, Pages 868: Uptake of Ranibizumab but Not Bevacizumab into Uveal Melanoma Cells Correlates with a Sustained Decline in VEGF-A Levels and Metastatic Activities Cancers doi: 10.3390/cancers11060868 Authors: Tura Pawlik Rudolf Ernesti Stutzer Grisanti Ranjbar Despite the implication of vascular endothelial growth factor-A (VEGF-A) in the pathophysiology of uveal melanoma (UM), the anti-VEGF-A antibody bevacizumab yielded conflicting results on UM growth. Here, we evaluated whether bevacizumab and ranibizumab, a humanized Fab-fragment against VEGF-A, can enter UM cells and induce a sustained physiological response. The primary and metastatic UM cell lines Mel-270 and OMM-2.5 were exposed to bevacizumab or ranibizumab for one day and were maintained further in untreated medium for a total of three days. Both antibodies significantly reduced the levels of extracellular VEGF-A and the angiogenic potential of the conditioned medium after one day. These inhibitory effects of bevacizumab diminished by day three. Ranibizumab suppressed the viability, proliferation, and intracellular VEGF-A levels in a cell-type and concentration-dependent manner, whereas bevacizumab exerted no effect. Both drugs were detected inside early endosomes within the UM cells, with the stronger and sustained colocalization of ranibizumab. Our results therefore demonstrated the more potent and persistent suppressive activity of ranibizumab on the UM cells, possibly due...
Source: Cancers - Category: Cancer & Oncology Authors: Tags: Article Source Type: research