Expression of Vascular Endothelial Growth Factor and Interleukin-6 in Multiple Myeloma

Park, Sa Yong; Im, Seock Ah; Nam, Eun Mi; Kim, Do Yeun; Choi, Young Ah; Lee, Kyung Eun; Seong, Chu Myoung; Lee, Soon Nam; Koo, Hea Soo; Kim, Sung Sook

Abstract

BACKGROUND: Vascular endothelial growth factor (VEGF) is a multifunctional cytokine involved in angiogenesis as selective mitogen for endothelial cells as well as potent permeability factor. And interleukin-6 (IL-6) is also known to be a growth factor of myeloma cells. To determine the role of angiogenesis, VEGF and IL-6 in the patients with multiple myeloma, the relationship between the level of VEGF expression, microvessel count (MVC), IL-6 expression in the bone marrow specimen of multiple myeloma patients and stage, response, survival duration were evaluated in 18 patients with multiple myeloma who underwent bone marrow biopsy.
METHODS
VEGF expression, MVC and IL-6 expression were assessed by immunohistochemical stain with polyclonal antibody to VEGF, factor VIII related antigen and IL-6 respectively.
RESULTS
VEGF expression was higher in multiple myeloma than that of control (61.4+/-34.4% vs 19.0+/-25.9%, P<0.001), and MVC was also higher in multiple myeloma than that of control (11.7+/-6.1 vs 6.2+/-3.8, P=0.005). IL-6 was expressed in 66.7% of multiple myeloma but not in control (P<0.001). Between high VEGF expression group and low VEGF expression group, there were no significant differences in the stage, response or survival. There were no significant differences between hypervascular group and hypovascular group. Also IL-6 expression was not a prognostic indicator. After treatment, VEGF expression, MVC and IL- 6 expression were decreased in the responder, but these differences were not statistically significant (P=0.23, P=0.07, P=0.06), probably due to limited number of cases.
CONCLUSION
VEGF, angiogenesis and IL-6 can play a role in the pathogenesis of multiple myeloma. But we cannot confirm the prognostic role of those parameters. Further study with more cases in longer duration as well as prospective study would be necessary for the establishment of relationship between VEGF expression, neovascularization, IL-6 expression and disease severity and prognosis of multiple myeloma.