Abstract 3862: In vivo chemopreventive of pseudosemiglabrin via inhibition of tumor angiogenesis and manipulation of hormones in estrogen-responsive breast cancer

Abstract

Breast cancer is the most frequently diagnosed form of malignancy and the second leading cause of death in Western women. Mortality and most of the complications associated with breast cancer are due to metastasis developing in regional lymph nodes and in distant organs, including bone, lung, liver and brain. Chemopreventive is administration of chemical agents to prevent the initiational and promotional events associated with carcinogenesis. Some chemopreventive agents can prevent reaction or attacking molecules by different ways, these agents can suppress growth factors or signaling pathway. On this study we examined (-)-Pseudosemiglabrin (SSG) a natural compound extracted from Tephrosia apollinea on breast cancer cells and tumor vascularization in vitro and in vivo. Hormone sensitive breast cancer cell MCF-7 was found subtitle susceptible to SSG, it showed profound antitumorgeneis via inhibiting breast cancer cell migration, invasion and colony formation in vitro settings. In silico investigation of potential PARP inhibitor, SSG showed high binding affinity comparable to Rucaparib (standard PARP inhibitor). The natural compound significantly inhibited the sprouting of new blood vessels in ex vivo rat aorta ring assay; the antiangiogenic efficacy is perturbed by targeting VEGF expression and VEGFR phosphorylation. SSG completely inhibited the onset of breast cancer in animals pretreated with the compound. Molecular docking study showed that SSG binds to active site of Aromatase (the enzyme responsible for a key step in the biosynthesis of estrogens) with binding affinity better than standard aromatase inhibitor (Arimidex), moreover the compound has inhibitory activity against estrogen receptor in the breast cancer cells comparable to Tamoxifen. Our findings reveal that (-)-Pseudosemiglabrin can potentially be beneficial in preventing breast cancer in high-risk women or it can be adjuvant therapy with standard chemotherapy or even can be used for the treatment of women who have been diagnosed with breast cancer.

Note: This abstract was not presented at the meeting.

Citation Format: Loiy E. Ahmed Hassan. In vivo chemopreventive of pseudosemiglabrin via inhibition of tumor angiogenesis and manipulation of hormones in estrogen-responsive breast cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 3862. doi:10.1158/1538-7445.AM2017-3862