Xiaohua Wang1, Cheng Chen2, Guoren Zhou1, Jinjun Ye2, Rong Yin3, Dongjie Feng3, Shuai Zhang3, Xiaojun Wang3, Xin Zhao4, Zhi Zhang3. 1. Department of chemotherapy, Nanjing Medical University Affiliated Cancer Hospital, Cancer Institute of Jiangsu Province, Jiangsu Cancer Hospital, Nanjing, China. 2. Department of Radiotherapy, Nanjing Medical University Affiliated Cancer Hospital, Cancer Institute of Jiangsu Province, Jiangsu Cancer Hospital, Nanjing, China. 3. Department of Thoracic Surgery, Nanjing Medical University Affiliated Cancer Hospital, Cancer Institute of Jiangsu Province, Jiangsu Cancer Hospital, Nanjing, China. 4. Department of Respiratory and Critical Care Medicine, The First Affiliated Hospital of Nanjing Medical University, Nanjing, China.
Abstract
BACKGROUND/AIMS: Our previous study suggested the anti-tumor activity of sepia ink oligopeptide (SIO). Here we sought to investigate the underlying molecular mechanism. METHODS: Cell proliferation was evaluated by cell counting kit-8 (CCK-8) assay. Cell apoptosis was determined by Annexin V/Propidium Iodide (PI) staining. The mitochondria pathway was characterized by quantification of Bcl-2, Bax, Caspase-9 and Cyto-C. The death receptor pathway was analyzed by determinement of Fas, Caspase-8 and NIK. The endoplasmic reticulum (ER)-dependent pathway was determined by measurement the expression of CHOP, Caspase-12, GRP78 and Calpain. The associated gene expression was quantified by RT-PCR and protein level was determined by immunoblotting. RESULTS: We demonstrated treatment with structurally modified SIO (CSIO, 5 µM) significantly inhibited cell proliferation and induced apoptosis in lung cancer cell line A549. The mitochondrial pathway, death receptor pathway and ER stress induced apoptosis were stimulated upon CSIO treatment. The administration with respective inhibitors including midiv-1 (50 µM for 2 h), PDTC (20 µM PDTC for 30 min) and ALLN (20 mM ALLN for 5 h) readily reversed the apoptosis inducing effect of CSIO. CONCLUSION: Our data demonstrates that CSIO is capable of induction apoptosis in lung cancer cell line, which is mediated by all three classical apoptotic pathways. Our results warrant further in vivo investigations of the anti-tumor potential of CSIO.
BACKGROUND/AIMS: Our previous study suggested the anti-tumor activity of sepia ink oligopeptide (SIO). Here we sought to investigate the underlying molecular mechanism. METHODS: Cell proliferation was evaluated by cell counting kit-8 (CCK-8) assay. Cell apoptosis was determined by Annexin V/Propidium Iodide (PI) staining. The mitochondria pathway was characterized by quantification of Bcl-2, Bax, Caspase-9 and Cyto-C. The death receptor pathway was analyzed by determinement of Fas, Caspase-8 and NIK. The endoplasmic reticulum (ER)-dependent pathway was determined by measurement the expression of CHOP, Caspase-12, GRP78 and Calpain. The associated gene expression was quantified by RT-PCR and protein level was determined by immunoblotting. RESULTS: We demonstrated treatment with structurally modified SIO (CSIO, 5 µM) significantly inhibited cell proliferation and induced apoptosis in lung cancer cell line A549. The mitochondrial pathway, death receptor pathway and ER stress induced apoptosis were stimulated upon CSIO treatment. The administration with respective inhibitors including midiv-1 (50 µM for 2 h), PDTC (20 µM PDTC for 30 min) and ALLN (20 mM ALLN for 5 h) readily reversed the apoptosis inducing effect of CSIO. CONCLUSION: Our data demonstrates that CSIO is capable of induction apoptosis in lung cancer cell line, which is mediated by all three classical apoptotic pathways. Our results warrant further in vivo investigations of the anti-tumor potential of CSIO.