title: The proliferation of malignant melanoma cells could be inhibited by ranibizumab via antagonizing VEGF through VEGFR1.
abstract: OBJECTIVE
  Angiogenesis is an important mediator in tumor progression. Vascular endothelial growth factor (VEGF) is one of the major cytokines that can influence angiogenesis. However, the potential mechanism of tumor growth inhibition through anti-VEGF agents is still unclear. This study was performed to examine whether ranibizumab could inhibit malignant melanoma growth in vitro and to determine the safety of ranibizumab on human adult retinal pigment epithelium cell line (ARPE-19 cells).
  
  
  METHODS
  Malignant melanoma cells obtained from a clinic were cultured in vitro. VEGF concentrations secreted by malignant melanoma cells and the ARPE-19 cells were examined by enzyme-linked immunosorbent assay (ELISA). The two kinds of cells were both treated with VEGF and its antagonist, ranibizumab. The dynamic changes of the two types of cells were monitored by real-time cell electronic sensing (RT-CES) assay. The effect of ranibizumab on both types of cells was verified by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl (MTT) assay. The expression of VEGF receptor 1 (VEGFR1) RNA in uveal melanoma was further investigated through the PCR technique.
  
  
  RESULTS
  The levels of VEGF secreted by malignant melanoma cells were much higher than those of ARPE-19 cells, and were markedly decreased in the action of 0.1 mg/ml ranibizumab. However, there was no obvious reduction of VEGF in the presence of ranibizumab for ARPE-19 (p>0.05). Meanwhile, RT-CES showed that the viability of malignant melanoma cells increased greatly in the presence of VEGF. When VEGF was 20 ng/ml, viability of the malignant melanoma cells increased by 40% compared with the negative control. There was no evident effect on proliferation of ARPE-19 (p>0.05). Furthermore, the growth of malignant melanoma cells was obviously inhibited after ranibizumab intervention. When ranibizumab was administered at 0.25 mg/ml, the survival rate of the malignant melanoma cells decreased to 57.5%. Nevertheless, low-dose exposure to ranibizumab had only a slight effect on the growth of ARPE-19, and PCR result demonstrated that VEGFR1 plays a role in this tumor tissue rather than VEGFR2.
  
  
  CONCLUSIONS
  Ranibizumab can selectively inhibit malignant melanoma cell proliferation by decreasing the expression of VEGF; the possible mechanism of the inhibitory effect may involve VEGFR1 antagonism.
authors.affiliation: Affiliated Eye Hospital of Shandong University of Traditional Chinese Medicine, Jinan, Shandong, Peoples' Republic of China.
authors.forename: Jiao
authors.initials: J
authors.lastname: Li
authors.affiliation: Eye Institute of Shandong University of TCM, Jinan, Shandong, Peoples' Republic of China.
authors.forename: Yan
authors.initials: Y
authors.lastname: Cui
authors.affiliation: People's Hospital of Rizhao, Rizhao, Shandong, Peoples' Republic of China.
authors.forename: Qin
authors.initials: Q
authors.lastname: Wang
authors.affiliation: Eye Institute of Shandong University of TCM, Jinan, Shandong, Peoples' Republic of China.
authors.forename: Dadong
authors.initials: D
authors.lastname: Guo
authors.affiliation: Affiliated Eye Hospital of Shandong University of Traditional Chinese Medicine, Jinan, Shandong, Peoples' Republic of China.
authors.forename: Xuemei
authors.initials: X
authors.lastname: Pan
authors.affiliation: Affiliated Eye Hospital of Shandong University of Traditional Chinese Medicine, Jinan, Shandong, Peoples' Republic of China.
authors.forename: Xingrong
authors.initials: X
authors.lastname: Wang
authors.affiliation: Affiliated Eye Hospital of Shandong University of Traditional Chinese Medicine, Jinan, Shandong, Peoples' Republic of China.
authors.forename: Hongsheng
authors.initials: H
authors.lastname: Bi
authors.affiliation: Affiliated Eye Hospital of Shandong University of Traditional Chinese Medicine, Jinan, Shandong, Peoples' Republic of China.
authors.forename: Wei
authors.initials: W
authors.lastname: Chen
authors.affiliation: Shandong University of Traditional Chinese Medicine, Jinan, Shandong, Peoples' Republic of China.
authors.forename: Zhengfeng
authors.initials: Z
authors.lastname: Liu
authors.affiliation: Affiliated Eye Hospital of Shandong University of Traditional Chinese Medicine, Jinan, Shandong, Peoples' Republic of China.
authors.forename: Shengya
authors.initials: S
authors.lastname: Zhao
mesh_terms: D000328:Adult; D061067:Antibodies, Monoclonal, Humanized / Q000494:pharmacology / Q000627:therapeutic use*; D016923:Cell Death / Q000187:drug effects; D002460:Cell Line; D049109:Cell Proliferation / Q000187:drug effects; D002924:Ciliary Body / Q000187:drug effects / Q000473:pathology; D003199:Computer Systems; D006801:Humans; D007150:Immunohistochemistry; D008545:Melanoma / Q000188:drug therapy / Q000378:metabolism* / Q000473:pathology*; D000069579:Ranibizumab; D055213:Retinal Pigment Epithelium / Q000378:metabolism / Q000473:pathology; D014604:Uveal Neoplasms / Q000188:drug therapy / Q000473:pathology; D042461:Vascular Endothelial Growth Factor A / Q000037:antagonists & inhibitors* / Q000378:metabolism; D040281:Vascular Endothelial Growth Factor Receptor-1 / Q000378:metabolism*; D000098943:Uveal Melanoma
chemical_list: D061067:Antibodies, Monoclonal, Humanized; D042461:Vascular Endothelial Growth Factor A; D040281:Vascular Endothelial Growth Factor Receptor-1; D000069579:Ranibizumab