Evaluation of apoptotic cell death mechanisms induced by hypericin-mediated photodynamic therapy in colon cancer cells

Authors : AYSUN KILIÇ SÜLOĞLU, ELİF KARACAOĞLU, Güldeniz SELMANOĞLU, Hayriye AKEL, İbrahim Çağatay KARAASLAN

Pages : 539-546

View : 23 | Download : 7

Publication Date : 2016-12-01

Article Type : Research Paper

Abstract :Hypericin insert ignore into journalissuearticles values(HYP);-mediated photodynamic therapy insert ignore into journalissuearticles values(PDT); is a new alternative treatment strategy for colon cancer inducing various cell-death pathways. Apoptotic cell death is the desired cellular fate in cancer cells. Therefore, we investigated the apoptotic pathways by determining apoptosis-related proteins insert ignore into journalissuearticles values(survivin, caspase-3, caspase-9, Bcl-2, and Bax); at the mRNA level using real-time polymerase chain reaction insert ignore into journalissuearticles values(qPCR);, and the percentage of survivin was determined by survivin ELISA in HT-29 and Caco-2 colon cancer cell lines. The downregulation of survivin was significant 16 h after PDT for both cells, while caspase-3 upregulation was apparent 24 h after PDT. Caspase-9 and caspase-3 upregulations were parallel to each other. There was no Bcl-2 expression in HT-29 cells, but we observed downregulation in Bcl-2 expression in Caco-2 cells after HYP photoactivation. The Bax expression downregulated significantly after 24 h incubation in HT-29 cells, while it was upregulated after 16 h incubation in Caco-2 cells. The present study provides evidence that HYP-induced alterations in apoptosis-related protein expression ended in different responses in HT-29 and Caco-2 colon cancer cells, and these may be used in the treatment of chemotherapy-resistant cancer types.
Keywords : Hypericin, PDT, survivin, apoptosis, HT 29 cells, Caco 2 cells