Abstract 5030: Vitamin D exhibits therapeutic anti-tumor and anti-angiogenic potential by reducing VEGF levels and altering TIMP/MMP system in breast cancer

Abstract

Abstract Background: Clinical and experimental observations suggest that Vitamin D deficiency associates with increased risk of breast cancer. Furthermore, studies concluded that Vitamin D precipitates in significant anti-neoplastic effects against breast, and inducing apoptosis and affecting angiogenesis in other types of cancer. However, the exact mechanism underlying this anti-angiogenic effect of Vitamin D is still elusive. This study aims to investigate the anti-cancer role of Vitamin D anti-cancer and its association with modulation of major factors involved in angiogenesis and metastasis in breast cancer cell lines. Experimental methods: The hormonally active form of vitamin D, 1α,25-dihydroxyvitamin D3 (calcitriol), was used to evaluate anti-proliferative effect, inhibition of cell cycle progression and apoptosis induction in two breast cancer cell lines, MCF-7 and MDA-MB-231. Furthermore, impact of calcitriol on expression and activity of tissue inhibitors of metalloproteinases (TIMP), major groups of the matrix metalloproteinases (MMPs), vascular endothelial growth factor (VEGF), and tumor growth factor (TGF-β1) among others involved in tumor progression and angiogenesis were also examined. Results and Discussions: Calcitriol treatment (10 µM) significantly inhibited cell proliferation in a timely dependent manner. Both cell lines showed G1 cell cycle arrest, decreased levels of the cell death inhibitor, survivin, and apoptosis induction in response to calcitriol treatment. Proteome Profiler array analysis revealed that calcitriol resulted in reducing the levels of major pro-angiogenesis regulators, especially VEGF, TGF-β1, Urokinase-type plasminogen activator (uPA), and Amphiregulin. Analysis of mRNA and proteins expression upon calcitriol exposure showed an increase of TIMP1, TIMP2 and a decrease in MMP 2, 3 and 9 levels. Finally, quantitative analysis using ELISA revealed that calcitriol treatment reduced MMP2 and MMP9 activities. Conclusion: Our study demonstrates potential therapeutic property of calcitriol through inhibiting of pro-angiogenetic markers in breast cancer. Citation Format: Khuloud Bajbouj, Jasmin Shafarin, Ahmad Sawan, Ahmed Shehada, Walaa Eldin Elkhalifa. Vitamin D exhibits therapeutic anti-tumor and anti-angiogenic potential by reducing VEGF levels and altering TIMP/MMP system in breast cancer [abstract]. In: Proceedings of the Annual Meeting of the American Association for Cancer Research 2020; 2020 Apr 27-28 and Jun 22-24. Philadelphia (PA): AACR; Cancer Res 2020;80(16 Suppl):Abstract nr 5030.