Pro-apoptotic effect of cecropin AD on nasopharyngeal carcinoma cells.

Biotechnology Research Center, Key Laboratory of Gene Engineering, Ministry of Education, Sun Yat-sen University, Guangzhou 510275, China.
Chinese medical journal (Impact Factor: 1.05). 07/2006; 119(12):1042-6.
Source: PubMed


Summarily, antibacterial peptide Cad was able to express in the eukaryotic cells. Its transient expression significantly suppressed the growth of tumor cells and induced cells apoptosis. But it had no effect on the general eukaryotic cells. Most importantly, our data suggested the possibility of delivering and expressing such antimicrobial peptides to tumor cells in vivo. In the future, more work should be done on screening the stable expression of cell lines, performing experiments on animals, and practical clinical research.

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    ABSTRACT: Four enantiomeric 9-mer peptides named d-peptide A, B, C and D were designed and synthesized on the basis of 43-mer insect defensins from two beetles. The d-9-mer peptides maintained bacterial membrane disruptive activity similar to the original peptides and also showed various extents of growth inhibitory activity against different cancer cell lines. Of these peptides, d-peptide B exhibited the highest selective cancer cell cytotoxicity against the mouse myeloma cell line, P3-X63-Ag8.653. Flow cytometric and scanning electron microscopic analysis revealed d-peptide B disrupts mouse myeloma membrane construction, whereas no cytotoxic effect on normal leukocytes was observed. Moreover, a strong correlation between negatively charged phosphatidylserine (PS) density in cancer cell membrane surface and sensitivity to d-9-mer peptides were observed in various cancer cell lines. These results suggest that d-9-mer peptides have negative charge-dependent selective cancer cell cytotoxicity targeting PS in the cancer cell membrane. In addition, synergic growth inhibitory activity against mouse myeloma was observed in combinations of d-peptide B and dexamethasone. These results suggest d-9-mer peptides are promising candidates for novel anticancer drugs.
    No preview · Article · Apr 2009 · Peptides
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    ABSTRACT: Cecropin AD, a chimeric antimicrobial peptide obtained from cecropins, is effective at killing specific microorganisms. However, a highly efficient expression system is still needed to allow for commercial application of cecropin AD. For the exogenous expression of cecropin AD, we fused the cecropin AD gene with a small ubiquitin-like modifier (SUMO) gene and a signal peptide of SacB, while a Bacillus subtilis expression system was constructed based on Bacillus subtilis cells genetically modified by the introduction of an operon including an isopropyl-β-d-thiogalactopyranoside (IPTG)-inducible Spac promoter, a signal peptide of amyQ, and the SUMO protease gene. The recombinant cecropin AD was expressed, and 30.6 mg of pure recombinant protein was purified from 1 liter of culture supernatant. The purified cecropin AD displayed antimicrobial activity against some pathogens, such as Staphylococcus aureus and Escherichia coli, and was especially effective toward Staphylococcus aureus, with MICs of <0.05 μM (0.2 μg/ml). Stability analysis results showed that the activity of cecropin AD was not influenced by temperatures as high as 55°C for 20 min; however, temperatures above 85°C (for 20 min) decreased the antimicrobial activity of cecropin AD. Varying the pH from 4.0 to 9.0 did not appear to affect the activity of cecropin AD, but some loss of potency was observed at pH values lower than pH 4.0. Under the challenge of several proteases (proteinase K, trypsin, and pepsin), cecropin AD maintained functional activity. The results indicated that the recombinant product expressed by the designed Bacillus subtilis expression system was a potent antimicrobial agent and could be applied to control infectious diseases of farm animals or even humans.
    Preview · Article · Jun 2009 · Antimicrobial Agents and Chemotherapy

  • No preview · Article · Jan 2012 · Journal of Microbiology and Biotechnology
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