Inhibition of RPMI8226 myeloma cell xenografted tumor angiogenesis by downregulation of Notch1

doi:10.3760/cma.j.issn.1673422X.2015.09.006

Abstract

Abstract: ObjectiveTo investigate the effects of Notch1 siRNA on VEGF and angiogenesis of myeloma cell line RPMI8226 in vitro and in vivo. MethodsIn vitro, Notch siRNA was transfected into RPMI8226 cells, and then cell supernatant VEGF secretion was detected using ELISA method. Expression levels of Notch1 and VEGF proteins were assayed by Western blotting. RPMI8226 cells were subcutaneously transplanted in NOD/SCID mice, and then the tumor mice were divided into three groups randomly: NS group (Notch1 siRNAtransfected group), CS group (Control siRNAtransfected group) and UN group (Untransfected group), and the changes of tumor volume were observed. Immunohistochemical staining was used to detect the changes in expression levels of Notch1, VEGF and CD34. ResultsNotch1 and VEGF proteins expressions of RPMI8226 cells were significantly decreased by Notch1 siRNA. At 48 h and 72 h, VEGF secretion level in NS group was significantly different with CS group ［（120±25）ng/L∶（175±15）ng/L, t＝3.27, P＜0.05; （145±24）ng/L∶（295±17）ng/L, t＝8.83, P＜0.01］. At 13 d, 17 d and 21 d, tumor volume in NS group was significantly reduced, that was significantly different with CS group ［（1 548±218）mm3∶（1 820±64）mm3, t＝2.68, P＜0.05; （1 200±75）mm3∶（2 180±84）mm3, t＝19.46, P＜0.01; （1 150±88）mm3∶（2 250±145）mm3, t＝14.50, P＜0.01］. The expression levels of Notch1 and VEGF protein were decreased by Notch1 siRNA. The expression levels of Notchl and VEGF in NS group were different with CS group ［（16.33±2.52）%∶（75.33±2.52）%, t＝28.71, P＜0.01; （5.00±1.00）%∶29.67±2.08 %, t＝18.50, P＜0.01］. Notch1 siRNA reduced the number of transplanted tumor neovascularization in NS group. Microvascular density in NS group was significantly less than that in CS group ［(14.67±2.52)∶(30.00±5.00), t＝4.74, P＜0.01］. ConclusionIn vitro, Notch siRNA reduces human myeloma cell RPMI8226 cell supernatant VEGF secretion. In vivo, Notch siRNA can reduce tumor volume and the number of new blood vessels in transplantedmultiple myeloma mice. Thus, Notch1 is an effective molecular target for antiangiogenesis in myeloma.

LI Chun-Pu, WANG Jing, LIU Yan, WANG Ling, LI Ban-Ban, ZHANG Kai-Gang, GUO Dong-Mei. Inhibition of RPMI8226 myeloma cell xenografted tumor angiogenesis by downregulation of Notch1[J]. Journal of International Oncology, 2015, 42(8): 661-.

References

［1］ Abraham J, Salama NN, Azab AK. The role of Pglycoprotein in drug resistance in multiple myeloma［J］. Leuk Lymphoma, 2015, 56(1): 2633. ［2］ Podar K, Anderson KC. Emerging therapies targeting tumor vasculature in multiple myeloma and other hematologic and solid malignancies［J］. Curr Cancer Drug Targets, 2011, 11(9): 10051024. ［3］ Guo D, Li C, Teng Q, et al. Notch1 overexpression promotes cell growth and tumor angiogenesis in myeloma［J］. Neoplasma, 2013, 60(1): 3340. ［4］李斑斑, 郭冬梅, 滕清良. 乏氧及Notch1在多发性骨髓瘤中作用的研究进展［J］. 国际肿瘤学杂志, 2013, 40(7): 542546. ［5］冀俊琴, 周建华. 血管内皮生长因子和Dll4Notch信号通路在肿瘤血管发生中的作用［J］. 国际肿瘤学杂志, 2011, 38(5): 323326. ［6］ Brito AB, Loureno GJ, Oliveira GB, et al. Associations of VEGF and VEGFR2 polymorphisms with increased risk and aggressiveness of multiple myeloma［J］. Ann Hematol, 2014, 93(8): 13631369. ［7］ Liu Z, Fan F, Wang A, et al. Dll4Notch signaling in regulation of tumor angiogenesis［J］. J Cancer Res Clin Oncol, 2014, 140(4): 525536. ［8］ Hernandez SL, Banerjee D, Garcia A, et al. Notch and VEGF pathways play distinct but complementary roles in tumor angiogenesis［J］. Vasc Cell, 2013, 5(1): 17. ［9］ Lin W, Zhao J, Cao Z, et al. Livistona chinensis seeds inhibit hepatocellular carcinoma angiogenesis in vivo via suppression of the Notch pathway［J］. Oncol Rep, 2014, 31(4): 17231728. ［10］ Patenaude A, Fuller M, Chang L, et al. Endothelialspecific Notch blockade inhibits vascular function and tumor growth through an eNOSdependent mechanism［J］. Cancer Res, 2014, 74(9): 24022411. ［11］ Liu Z, Fan F, Wang A, et al. Dll4Notch signaling in regulation of tumor angiogenesis［J］. J Cancer Res Clin Oncol, 2014, 140(4): 525536. ［12］ Ridgway J, Zhang G, Wu Y, et al. Inhibition of Dll4 signalling inhibits tumour growth by deregulating angiogenesis［J］. Nature, 2006, 444(7122): 10831087. ［13］刘琰，李纯璞，刘双，等. Notch1 siRNA对骨髓瘤细胞硼替佐米药物敏感性的影响［J］. 中华临床医师杂志(电子版), 2014, 8(19): 34773482. ［14］陈海涛, 蔡全才, 李兆申. 抗血管内皮生长因子药物治疗肿瘤的耐药机制［J］. 国际肿瘤学杂志, 2011, 38(4): 261262.