Effects of ranibizumab and amfenac on the functional abilities and radiosensitivity of uveal melanoma cells

Abstract

To evaluate the effects of ranibizumab and amfenac in human uveal melanoma cell lines and to explore the ability of these compounds to sensitize uveal melanoma cells to radiation therapy. Methods: The 92.1 human uveal melanoma cell line was cultured and subjected to the proposed treatment (ranibizumab, amfenac, and a combination of both). Proliferation, migration, and invasion assays of the 92.1 uveal melanoma cell line were assessed after pretreatment with ranibizumab (125 µg/mL), amfenac (150 nM), or a combination of both. In addition, proliferation rates were assessed after treatment with ranibizumab and amfenac, and the cells were subsequently exposed to various radiation doses (0, 4, and 8 Gy). Results: Proliferation assay: cells treated with a combination of ranibizumab and amfenac had lower proliferation rates than controls (p=0.016) and than those treated with only ranibizumab (p=0.033). Migration assay: a significantly lower migration rate was observed in cells treated with amfenac than the control (p=0.014) and than those treated with ranibizumab (p=0.044). Invasion assay: there were no significant differences among the studied groups. Irradiation exposure: in the 4 Gy dose group, there were no significant differences among any groups. In the 8 Gy dose group, treatment with ranibizumab, amfenac, and their combination prior to application of the 8 Gy radiation led to a marked reduction in proliferation rates (p=0.009, p=0.01, and p=0.034, respectively) compared with controls. Conclusion: Combination of ranibizumab and amfenac reduced the proliferation rate of uveal melanoma cells; however, only amfenac monotherapy significantly decreased cell migration. The radiosensitivity of the 92.1 uveal melanoma cell line increased following the administration of ranibizumab, amfenac, and their combination. Further investigation is warranted to determine if this is a viable pretreatment strategy to render large tumors amenable to radiotherapy.

Uptake of Ranibizumab but Not Bevacizumab into Uveal Melanoma Cells Correlates with a Sustained Decline in VEGF-A Levels and Metastatic Activities

“…Yet, in another study, incubation of the UM cell line 92.1 with 100 µg/mL bevacizumab for one day in serum-free medium could suppress the proliferation significantly by 20%, suggesting that certain serum factors may be interfering with the bevacizumab activity [21]. Our findings demonstrating the stronger activity of ranibizumab at the double dose of 250 µg/mL were also supported by an earlier work on ciliary body melanoma cultures, which required this dosage for a significant decline in survival [47], and a very recent study on the proliferation of 92.1 cells, which could not be inhibited by 125 µg/mL ranibizumab [48]. Interestingly, the incubation of six different UM cultures with high concentrations of bevacizumab (above 2 mg/mL) under hypoxia resulted in the striking upregulation of VEGF mRNA levels in four of these cell lines, suggesting that an excessive VEGF inhibition in a hypoxic environment might activate the pro-angiogenic signaling through alternative pathways, which may be one of the reasons underlying the paradoxical effects of bevacizumab [19].…”