Recent studies, investigating the composition and therapeutic potential of leech saliva have identified many peptides and proteins with multiple therapeutic properties including anti-thrombotic, antimicrobial and anti-metastatic. In vitro anti-cancer effects were shown in breast, prostate and lung cells lines. In vivo anticancer activity of the extract was shown in multiple breast and prostate cancer xenografts studied by our lab. In our previous studies, BPS-001 was non-toxic and demonstrated various activities including pro-apoptotic properties, inhibition of cellular adhesion, angiogenesis and downregulation of AR expression. To investigate the affected pathways, mechanistic studies were carried out using in vivo and in vitro treated samples. Protein expression in samples was determined by Western blotting of in vitro and in vivo samples. AR expression was measured using an eGFP reporter assay in LNCaP cells, with PSA also measured in the media using cobas e 411 analyzer. BPS-001 inhibited Proteinase Activated Receptor 1 (PAR-1) which is responsible for hormone like cellular signals in different cancer cells including those of the breast and prostate. Moreover, in LNCaP cells AR activation and PSA expression were significantly inhibited after treatment with BPS-001. Inhibition of PI3K and PLCG2 were also observed. It has been found that BPS-001 modulates a plethora of pathways which makes it a very promising candidate for treatment of cancer with an important advantage of low toxicity and potential resistance.

Citation Format: Amr Ammar, Emma Guns, Omer Kucuk, Abdualrahman Abdualkader, Mohamed Alaama, A.B.M. Helal Uddin, Abbas Ghawi, Mohamed Hassona. Mechanism of anticancer activity of BPS-001 (lyophilized leech saliva extract) [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 107. doi:10.1158/1538-7445.AM2017-107