碩士 / 國立宜蘭大學 / 生物技術研究所碩士班 / 98 / Resistance is a very disturbing problem during cancer treatment, so the development of new agents with new modes of action attracts a great deal of interest. Recent studies have reported that certain cationic amphipathic antimicrobial peptide (AMPs) have selective toxicity toward various cancer cells. Most antibacterial and anticancer AMPs share a common membranolytic mode of action that results either in the selective disruption of the cancer cell membrane or permeation and swelling of mitochondria. The electrostatic attraction between the negatively charged membrane components of bacterial and cancer cells and AMPs is believed to play a crucial role in the disruption of bacterial and cancer cell membranes. In the current study, we use a series of synthetic AMPs designed by our own laboratory and a C-terminal modified naturally occurring AMP, Pleurocidine-amide (PleA) to test their cytotoxicity toward A549 human lung adenocarcinoma cells. PleA is a 23-mer AMP having selective toxicity toward cancer cells with no hemolytic activity. MTT assay revealed that PleA reduced viability of A549 cells and the IC50 value was 42 μM. In addition, western blot analysis showed that PleA could inhibit autophagy of A549 cells, and induce apoptosis 48-hrs after treatment. Flowcytometic analysis also demonstrated that PleA induced cancer cells to increase their sub-G1 population. Ultimately, confocal microscopy using AO and MDC staining also confirmed that PleA inhibited autophagy and induced apoptosis of A549. Proteomic approaches were also applied to further investigate the anticancer mechanism of PleA against A549 cells. Image analysis of 2-DE gels revealed 10 protein spots with significant differences and 6 of them were identified by LC-ESI-Q-TOF MS/MS to be Phosphoglycerate kinase 1、Poly(rC)-binding protein 2、Retinal dehydrogenase 1、Alpha-enolase Aldose reductase and Partner and localizer of BRCA2. More detailed investigations in the future will help us to know the anticancer mechanism of PleA.
| Identifer | oai:union.ndltd.org:TW/098NIU07108006 |
| Date | January 2010 |
| Creators | Ming-lung Yeh, 葉明龍 |
| Contributors | Wei-Jung Chen, Hui-chen Hsu, 陳威戎, 許惠貞 |
| Source Sets | National Digital Library of Theses and Dissertations in Taiwan |
| Language | zh-TW |
| Detected Language | English |
| Type | 學位論文 ; thesis |
| Format | 104 |
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