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


KILIÇ SÜLOĞLU A. , KARACAOĞLU E. , SELMANOĞLU G. , Akel H. , KARAASLAN İ. Ç.

TURKISH JOURNAL OF BIOLOGY, cilt.40, sa.3, ss.539-546, 2016 (SCI İndekslerine Giren Dergi) identifier identifier

  • Cilt numarası: 40 Konu: 3
  • Basım Tarihi: 2016
  • Doi Numarası: 10.3906/biy-1504-6
  • Dergi Adı: TURKISH JOURNAL OF BIOLOGY
  • Sayfa Sayıları: ss.539-546

Özet

Hypericin (HYP)-mediated photodynamic therapy (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 (survivin, caspase-3, caspase-9, Bcl-2, and Bax) at the mRNA level using real-time polymerase chain reaction (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.