Anticancer activity of a synthetic peptide derived from harmoniasin, an antibacterial peptide from the ladybug Harmonia axyridis

  • Authors:
    • In-Woo Kim
    • Joon Ha Lee
    • Young-Nam Kwon
    • Eun-Young Yun
    • Sung-Hee Nam
    • Mi-Young Ahn
    • Dong-Chul Kang
    • Jae Sam Hwang
  • View Affiliations

  • Published online on: June 4, 2013     https://doi.org/10.3892/ijo.2013.1973
  • Pages: 622-628
Metrics: Total Views: 0 (Spandidos Publications: | PMC Statistics: )
Total PDF Downloads: 0 (Spandidos Publications: | PMC Statistics: )


Abstract

Harmoniasin is a defensin-like antimicrobial peptide identified from the ladybug Harmonia axyridis. Among the synthetic homodimer peptide analogues derived from harmoniasin, HaA4 has been found to have antibacterial activity without hemolytic activity. In this study, we investigated whether HaA4 has anticancer activity against human leukemia cell lines such as U937 and Jurkat cells. HaA4 manifested cytotoxicity and decreased the cell viability of U937 and Jurkat cells in MTS assay and LDH release assay. We found that HaA4 induced apoptotic and necrotic cell death of the leukemia cells using flow cytometric analysis, acridine orange/ethidium bromide staining and nucleosomal fragmentation of genomic DNA. Activation of caspase-7 and -9 and fragmentation of poly (ADP-ribose) polymerase was detected in the HaA4-treated leukemia cells, suggesting induction of a caspase-dependent apoptosis pathway by HaA4. Caspase-dependent apoptosis was further confirmed by reversal of the HaA4-induced viability reduction by treatment of Z-VAD-FMK, a pan-caspase inhibitor. In conclusion, HaA4 caused necrosis and caspase-dependent apoptosis in both U937 and Jurkat leukemia cells, which suggests potential utility of HaA4 as a cancer therapeutic agent.

Introduction

Living organisms are exposed daily to microbial infections and pathogens. In order to defend themselves against such infectious agents, they have developed potent defensive mechanism, i.e., innate and adaptive immunity. In innate immunity, antimicrobial peptides (AMPs) that possess potent antibiotic activity against bacteria, fungi and even certain viruses play important roles in the host defense mechanisms of most living organisms including plants, insects, amphibians and mammals (13).

Insect AMPs are cationic and amphipathic. Although insect AMPs display variable length, sequences and structures, most AMPs have relatively small (<5 kDa) molecular masses (4,5). In case of insect defensins, that was first isolated from the culture medium of an embryonic cell line of the flesh fly, Sarcophaga peregrine (6), are members of a widely distributed family of AMPs. Insect defensin contains six conserved cysteine residues engaged in three intradisulfide bonds (4,5) and have antimicrobial activity against Gram-positive bacteria and fungi (5,7).

Interestingly, several insect AMPs show cytotoxic effects against a broad range of cancer cell lines such as mouse myeloma, melanoma, lymphomas, leukemia, breast cancer and lung cancer (812). Coprisin belongs to the defensin family of insect AMPs, and has been identified from dung beetle, Copris tripartitus (13) and its analogue CopA3 showing cytotoxicity against cancer cell lines as well as strong antibacterial activity against microbes (1416).

Previously, we characterized the antibacterial activity of the synthetic analogue of harmoniasin, HaA4 that was identified from the ladybug, Harmonia axyridis. Active region of harmoniasin was defined and selected to be modified as a homodimeric peptide. HaA4 displayed more potent antibacterial activity than that of the native peptide (17). HaA4 might also retain cytotoxic effect on cancer cells similarly to some other AMPs. Therefore, we investigated the anticancer activity of the HaA4 peptide against two human leukemia cell types in the present study and report that the anticancer effect of HaA4 is caused by necrosis and apoptosis.

Materials and methods

Peptide synthesis

Harmoniasin is a defensin-like peptide consisting of 50 amino acid residues with three intra-disulfide bonds. Because of the large molecular weight and disulfide bonds, we designed a variety of analogues based on the harmoniasin sequence in a previous study (17). The resulting homodimer peptide, named HaA4, was synthesized and provided by Anygen Co., Ltd. (Gwangju, Korea).

Cell culture

Raw 264.7, Jurkat and U937 cells were maintained in DMEM and RPMI-1640 medium containing 10% FBS, penicillin G (100 U/ml) and streptomycin (100 μg/ml) (Invitrogen, Carlsbad, CA, USA), respectively. Cells were cultured at 37°C in a humidified incubator with 5% CO2.

Cell viability assay

Cells were plated into 96-well tissue culture plates (2×104 cells/well) and treated with various concentrations (50, 100, 150 and 200 μg/ml) of HaA4 or without HaA4. After incubation for 24 h, viability of the cancer cells was measured using the CellTiter 96 AQueous One Solution Cell Proliferation Assay according to the manufacturer's protocol (Promega, Madison, WI, USA). Optical density was measured at 490 nm with a microplate reader (Beckman DTX 8800 multi detector). Reversal of viability reduction by HaA4 was attempted by treatment with Z-VAD-FMK (Promega), a broad-spectrum caspase inhibitor at indicated concentration.

LDH release assay

Cell membrane integrity was analyzed by measuring LDH activity. LDH activity was measured using a Cytotoxicity Detection kit (Roche Applied Science). In brief, the cells were seeded at 1×104 cells/well into a 96-well tissue culture plate in assay medium (RPMI-1640 containing 1% FBS). The cells were treated with different doses of HaA4. After 24 h of incubation, 5 μl of lysis solution was added to high control samples as a positive control and the plate incubated for an additional 15 min. Then, 100 μl reaction mixture was added to each well on the 96-well plate and incubated for 15 min. Finally, 50 μl stop solution was added to each well on the plate and the absorbance at 490 nm was measured using a microplate reader. The percent cytotoxicity was calculated by the following equation: Cytotoxicity (%) = (exp. value − low control)/(high control − low control) × 100.

Annexin V/propidium iodide (PI) staining

Jurkat and U937 cells were plated into 6-well tissue culture plates (1×106 cells/well) and treated with various concentrations (50, 100, 150 and 200 μg/ml) of HaA4 or without HaA4. After incubation for 4 h, cells were harvested and washed twice with cold PBS and once with 1X binding buffer (0.01 M HEPES/NaOH (pH 7.4), 0.14 M NaCl, 2.5 mM CaCl2). Cells were prepared in 100 μl of the binding buffer (1×105 cells) and then, added with 5 μl of FITC Annexin V and PI. The cells were gently mixed by vortex and incubated for 15 min at room temperature in the dark. After the incubation, 400 μl of 1X binding buffer was added to each tube. Stained cells were measured by flow cytometry with a BD FACSCalibur cytometer (BD Biosciences) and CellQuest software (BD Biosciences) was used for analysis of the results.

Acridine orange/ethidium bromide staining

Cells were seeded in 6-well tissue culture plates (1×106 cells/well), treated without or with HaA4 (50, 100 and 150 μg/ml) for 24 h and the cells were washed with PBS. Then, the cells were stained with mixture of acridine orange (3 μg/ml) and ethidium bromide (10 μg/ml) and observed immediately using AxioImager Z1 fluorescence microscope (Carl Zeiss, Germany).

DNA fragmentation assay

For the DNA fragmentation assay, 2×106 cells were seeded into 6-well plates and treated with 200 μg/ml HaA4 or without HaA4 for 24 h. Cells were collected, washed once with PBS, lysed in a solution containing 10 mM Tris-HCl (pH 7.4), 10 mM EDTA (pH 8.0) and 0.5% Triton X-100 on ice for 30 min and then centrifuged at 15,000 rpm for 5 min. The supernatant was digested with 0.1 mg of RNase A/ml and 1 mg of proteinase K/ml for 1 h at 55°C in the presence of 1% sodium dodecyl sulfate (SDS). DNA was extracted from the digested supernatant with phenol and chloroform, precipitated in cold ethanol and subjected to electrophoresis on 2% agarose gels containing ethidium bromide. DNA fragments were visualized by UV light.

Terminal deoxynucleotidyl transferase-mediated dUTP nick-end labeling (TUNEL assay)

Jurkat and U937 cells were plated into 6-well plates (2×106/ml) and treated with or without HaA4 (200 μg/ml) for 24 h. TUNEL assay was performed with DeadEnd™ Fluorometric TUNEL system according to the manufacturer's instructions (Promega) to determine apoptotic cells.

Immunoblot analysis

Cells were washed with cold PBS and lysed in buffer [150 mM NaCl, 50 mM Tris-HCl (pH 8.0), 5 mM EDTA and 1% Nonidet P-40]. Equal amount of protein was separated by SDS-polyacrylamide gel electrophoresis (12% SDS-PAGE) and transferred onto a nitrocellulose membrane. The antigen-antibody complexes were detected using FluorChem (Alpha Innotech, USA). Polyclonal antibodies against caspase-7, -9, PARP and AIF were obtained from Cell Signaling Technology (MA, USA). The β-actin antibody was purchased from Sigma-Aldrich (St. Louis, MO, USA) and the broad-spectrum caspase inhibitor, Z-VAD-FMK, was obtained from Promega.

Results and Discussion

The peptide

The primary amino acid sequence of the synthetic harmoniasin analogues are shown in Table I. HaA4 peptide was used in this study. Dimerized peptides by disulfide bond such as magainin 2 and melittin analogues showed stronger antimicrobial activity than the monomeric forms (18,19). Moreover, halocidin dimer congeners derived from halocidin, a dimeric α-helical structure peptide that was purified from the tunicate Halocynthia aurantium showed more potent antibacterial activity than the its monomer forms (20). Therefore, dimerization of the AMPs is suggested to potentiate their biological activity in an undefined way.

Table I.

Sequence of harmoniasin analogues.

Table I.

Sequence of harmoniasin analogues.

PeptideAmino acid sequenceMass (Da)
MeasuredTheoretical
HaNP ijo-43-02-0622i1.gif2134.82134.4
HaA4 ijo-43-02-0622i2.gif2330.22330.8

[i] Vertical bar represents a disulfide linkage between cysteine residues in the sequence. Substituted residues are underlined.

HaA4 markedly decreases cell viability of leukemia cell lines

Recently, we showed that synthetic HaA4 exerts antibacterial effect without hemolytic activities (17). We attempted to determine the effect of the synthetic peptide HaA4 on cell growth and survival of human leukemia cells (Jurkat and U937) in this study. Cancer cells were treated with various concentrations (50, 100, 150 and 200 μg/ml) of HaA4 for 24 h and the cell viability was measured by MTS assay. As shown in Fig. 1, HaA4 decreased the viability of the leukemia cells in a dose-dependent manner. In particular, viability of the cells precipitated by >70% at 200 μg/ml of HaA4, while >70% of Raw 264.7 cells remained viable. Therefore, our results suggest that HaA4 should exert a potent anticancer activity against human leukemia cells.

Effect of HaA4 on the integrity of cancer cell membrane

We attempted to characterize the effects of HaA4 on the integrity of cancer cell membranes by detecting the LDH activity. As shown in Fig. 2, the amount of LDH release increased in a dose-dependent manner in both cancer cell types and the percentage of cytotoxicity appeared to reach plateau with the elevation of the peptide concentration. Although level of LDH release from both was similar, LDH release from U937 was a little higher than that from Jurkat. Maximal cytotoxicity at 200 μg/ml HaA4 was 43.3 and 55.7% for Jurkat and U937 cells, respectively. However, HaA4 showed cytotoxic activity against Raw 264.7 cells and the LDH release was similar to Jurkat cells. Base on the results, we surmised that lytic activity of HaA4 is influenced by the presence of serum. Although HaA4 had no hemolytic activity in our previous report (17), cell selectivity of HaA4 including serum stability needs to be examined further. Finally, when compared to the results from the MTS assay, the reduction in cell viability was 30–40% higher than expected from cytotoxicity. The observed discrepancy suggested that additional factors including apoptosis and growth inhibition as well as necrosis could play a critical role in the viability reduction by HaA4.

HaA4 induces apoptosis and necrosis in leukemia cells

In order to further characterize mechanism of the viability reduction, we assessed the involvement of apoptosis. Apoptosis (programmed cell death) is a pivotal physiological process that is required for the normal development and maintenance of tissue homeostasis in multicellular organisms (21). During apoptosis, certain morphological characteristics are involved, such as membrane blebbing, phosphatidyl inositol exposure, nuclear and cytoplasmic shrinkages, chromatic condensation and DNA fragmentation (22). Apoptosis was examined by Annexin V/PI staining of the HaA4-treated leukemic cells. Annexin V binding to the HaA4-treated leukemia cells was gradually increased as the peptide concentration elevated. Annexin V-positive cell population reached maximum at 150 μg/ml HaA4, while Annexin V/PI-positive at 200 μg/ml HaA4 (Fig. 3). These results indicated that HaA4 should induce both apoptosis and necrosis depending on the concentration of HaA4. Necrosis appeared prevailing over apoptosis at higher concentration of HaA4.

Previously it has been reported that piscidin-1, a cationic peptide isolated from the mast cells of hybrid striped bass (23), also causes apoptosis and necrosis at a low concentration and necrotic effect at a high concentration for a short period in HT1080 cells (24). Piscidin-1 has a net charge of +3 and HaA4 has a net charge of +2 at pH 7.0, which might function in the anticancer activity. Net charge of a peptide is an important parameter for antitumor activity (25). Thus, it is supposed that the positively charged cationic peptide could interact with anionic cancer cell membrane electrostatically and damage the membrane integrity.

Acridine orange/ethidium bromide staining

To verify Annexin V/PI assay results, HaA4-treated Jurkat cells were stained with acridine orange/ethidium bromide. After HaA4 treatment for 24 h, majority of cells exhibited green fluorescence in control, while diffused or orange-colored nuclei were increased in HaA4-treated cells with increase of HaA4 concentration. The cells treated with 150 μg/ml HaA4 developed orange and orange-red fluorescence, indicating membrane disruption (Fig. 4). U937 cells presented similar results (data not shown). These results support that HaA4 could induce both apoptosis and necrosis at high concentrations.

HaA4-induced DNA fragmentation

In order to further determine whether apoptosis is involved in the viability reduction of the leukemia cells, we performed TUNEL assay and agarose gel electrophoresis for chromosomal DNA after treating these cells with 200 μg/ml of HaA4 for 24 h. As shown in Fig. 5A, the number of TUNEL-positive apoptotic cells was significantly increased in Jurkat and U937 cells treated with HaA4 when compared with the untreated cells. In agreement with the results, the chromosomal DNA of Jurkat and U937 cells was fragmented in nucleosomal ladder by HaA4 (Fig. 5B). Based on these results, we assured that such pro-apoptotic effects of HaA4 should contribute to the viability reduction of the leukemia cells.

HaA4 induces apoptosis in the leukemia cells via a caspase-dependent pathway

Since apoptosis can proceed via either caspase-dependent or -independent signaling pathways (26,27), the involvement of caspases in HaA4-induced leukemia cell apoptosis was assessed. As shown in Fig. 6, a marked increase in the cleavage of caspase-7, -9 and PARP was observed. Subsequently, the potential role of apoptosis inducing factor (AIF), a caspase-independent apoptosis regulator on HaA4-induced apoptosis was investigated. However, we could not observe converted mature form of AIF (Fig. 6). These results suggest that HaA4-mediated leukemia cell apoptosis might be associated with the activation of caspase. Moreover, the decreased cell viability by HaA4 treatment in the MTS assay recovered in the presence of Z-VAD-FMK, a pan-caspase inhibitor (Fig. 7), demonstrating that HaA4-induced leukemia cell apoptosis is dependent on the activation of the caspase family proteins.

Most antibacterial and anticancer peptides employ cell membrane disruption by lytic activity, or some peptides employ apoptosis in cancer cells through mitochondrial damage. It is believed that the mode of action originates from electrostatic interaction between cationic peptides and anionic cell wall components of bacterial and cancer cells. To date, there are four possible different models (toroidal, carpet, barrel-stave and aggregate channel) of AMP action mechanisms for membrane permeabilization (28). In previous studies, α-helical peptides were shown to need more than 20 amino acid residues to span the entire thickness of the eukaryotic cell membranes for the barrel-stave mechanism (29,30). Thus, the relatively small size of HaA4 along with aurein 1.2 (31) and citropin 1.1 (32), isolated from frogs suggest that these AMPs mediate their membranolytic effect through the carpet mechanism (33). In addition, it has been reported that bovine lactoferricin binds to the cell membrane and causes cell membrane disruption followed by entry of the peptide to the cytoplasm of Jurkat T-leukemia cells and damage to mitochondrial membrane (34). Based on the results of our previous study (17), it was postulated that HaA4 acts on anticancer activity similar to bovine lactoferricin, although the exact mechanism of HaA4 has to be elucidated.

In this report, we have shown that HaA4 is a good candidate for a new anticancer therapeutic agent as described above. As a consequence, we could identify necrotic effects of HaA4 via LDH activity detection (Fig. 2) and Annexin V and PI staining (Fig. 3) and we also observed that HaA4 indicates apoptotic effects. Additionally, apoptosis of the leukemic cells by HaA4 was dependent on the activation of caspase (Figs. 6 and 7), a regulator of a caspase-dependent pathway. Overall, our present study revealed that HaA4 should retain anticancer activity against human leukemia cells (Jurkat and U937) and the activity might ascribe to necrosis and apoptosis of the leukemia cells.

Acknowledgements

This study was supported by a grant from the Next-Generation BioGreen 21 Program (no. PJ008158) and partially supported by a grant (no. PJ008706) from the Agenda Program, Rural Development Administration, Republic of Korea.

References

1. 

Lehrer RI, Lichtenstein AK and Ganz T: Defensins: antimicrobial and cytotoxic peptides of mammalian cells. Annu Rev Immunol. 11:105–128. 1993. View Article : Google Scholar : PubMed/NCBI

2. 

Zasloff M: Antimicrobial peptides of multicellular organisms. Nature. 415:389–395. 2002. View Article : Google Scholar : PubMed/NCBI

3. 

Koczulla AR and Bals R: Antimicrobial peptides: current status and therapeutic potentials. Drugs. 63:389–406. 2003. View Article : Google Scholar : PubMed/NCBI

4. 

Bulet P, Hetru C, Dimarcq JL and Hoffmann D: Antimicrobial peptides in insects; structure and function. Dev Comp Immunol. 23:329–344. 1999. View Article : Google Scholar : PubMed/NCBI

5. 

Bulet P and Stocklin R: Insect antimicrobial peptides: structures, properties and gene regulation. Protein Pept Lett. 12:3–11. 2005. View Article : Google Scholar : PubMed/NCBI

6. 

Matsuyama K and Natori S: Purification of 3 antibacterial proteins from the culture medium of NIH-Sape-4, an embryonic cell line of Sarcophaga peregrina. J Biol Chem. 263:17112–17116. 1988.PubMed/NCBI

7. 

Bulet P, Cociancich S, Reuland M, Sauber F, Bischoff R, Hegy G, Van Dorsselaer A, Hetru C and Hoffmann JA: A novel insect defensin mediates the inducible antibacterial activity in larvae of the dragonfly Aeschna cyanea (Paleoptera, Odonata). Eur J Biochem. 209:977–984. 1992. View Article : Google Scholar : PubMed/NCBI

8. 

Baker MA, Maloy WL, Zasloff M and Jacob LS: Anticancer efficacy of Magainin2 and analogue peptides. Cancer Res. 53:3052–3057. 1993.PubMed/NCBI

9. 

Moore AJ, Devine DA and Bibby MC: Preliminary experimental anticancer activity of cecropins. Pept Res. 7:265–269. 1994.PubMed/NCBI

10. 

Soballe PW, Maloy WL, Myrga ML, Jacob LS and Herlyn M: Experimental local therapy of human melanoma with lytic magainin peptides. Int J Cancer. 60:280–284. 1995. View Article : Google Scholar : PubMed/NCBI

11. 

Xiao YC, Huang YD, Xu PL, Zhou ZQ and Li XK: Pro-apoptotic effect of cecropin AD on nasopharyngeal carcinoma cells. Chin Med J (Engl). 119:1042–1046. 2006.PubMed/NCBI

12. 

Iwasaki T, Ishibashi J, Tanaka H, Sato M, Asaoka A, Taylor D and Yamakawa M: Selective cancer cell cytotoxicity of enantiomeric 9-mer peptides derived from beetle defensins depends on negatively charged phosphatidylserine on the cell surface. Peptides. 30:660–668. 2009. View Article : Google Scholar : PubMed/NCBI

13. 

Hwang JS, Lee J, Kim YJ, Bang HS, Yun EY, Kim SR, Suh HJ, Kang BR, Nam SH, Jeon JP, Kim I and Lee DG: Isolation and characterization of a defensin-like peptide (Coprisin) from the dung beetle, Copris tripartitus. Int J Pept. View Article : Google Scholar : 2009.PubMed/NCBI

14. 

Kang JK, Hwang JS, Nam HJ, Ahn KJ, Seok H, Kim SK, Yun EY, Pothoulakis C, Lamont JT and Kim H: The insect peptide coprisin prevents Clostridium difficile-mediated acute inflammation and mucosal damage through selective antimicrobial activity. Antimicrob Agents Chemother. 55:4850–4857. 2011.PubMed/NCBI

15. 

Kim IW, Kim SJ, Kwon YN, Yun EY, Ahn MY, Kang DC and Hwang JS: Effects of the synthetic coprisin analog peptide, CopA3 in pathogenic microorganisms and mammalian cancer cells. J Microbiol Biotechnol. 22:156–158. 2012. View Article : Google Scholar : PubMed/NCBI

16. 

Kang BR, Kim H, Nam SH, Yun EY, Kim SR, Ahn MY, Chang JS and Hwang JS: CopA3 peptide from Copris tripartitus induces apoptosis in human leukemia cells via a caspase-independent pathway. BMB Rep. 45:85–90. 2012.

17. 

Kim IW, Lee JH, Park HY, Kwon YN, Yun EY, Nam SH, Kim SR, Ahn MY and Hwang JS: Characterization and cDNA cloning of a defensin-like peptide, harmoniasin, from Harmonia axyridis. J Microbiol Biotechnol. 22:1588–1590. 2012. View Article : Google Scholar : PubMed/NCBI

18. 

Hara T, Kodama H, Kondo M, Wakamatsu K, Takeda A, Tachi T and Matsuzaki K: Effects of peptide dimerization on pore formation: antiparallel disulfide-dimerized magainin 2 analogue. Biopolymers. 58:437–446. 2001. View Article : Google Scholar : PubMed/NCBI

19. 

Takei J, Remenyi A, Clarke AR and Dempsey CE: Self-association of disulfide-dimerized melittin analogues. Biochemistry. 37:5699–5708. 1998. View Article : Google Scholar : PubMed/NCBI

20. 

Jang WS, Kim CH, Kim KN, Park SY, Lee JH, Son SM and Lee IH: Biological activities of synthetic analogs of halocidin, an antimicrobial peptide from the tunicate Halocynthia aurantium. Antimicrob Agents Chemother. 47:2481–2486. 2003. View Article : Google Scholar : PubMed/NCBI

21. 

Wyllie AH: Apoptosis: An overview. Br Med Bull. 53:451–465. 1997. View Article : Google Scholar

22. 

Raff M: Cell suicide for beginners. Nature. 396:119–122. 1998. View Article : Google Scholar : PubMed/NCBI

23. 

Silphaduang U and Noga EJ: Peptide antibiotics in mast cells of fish. Nature. 414:268–269. 2001. View Article : Google Scholar : PubMed/NCBI

24. 

Lin HJ, Huang TC, Muthusamy S, Lee JF, Duann YF and Lin CH: Piscidin-1, an antimicrobial peptide from fish (hybrid striped bass Morone saxatilis x M. chrysops), induces apoptotic and necrotic activity in HT1080 cells. Zoolog Sci. 29:327–332. 2012. View Article : Google Scholar : PubMed/NCBI

25. 

Diao Y, Han W, Zhao H, Zhu S, Liu X, Feng X, Gu J, Yao C, Liu S, Sun C and Pan F: Designed synthetic analogs of the α-helical peptide temporin-La with improved antitumor efficacies via charge modification and incorporation of the integrin αvβ3 homing domain. J Pept Sci. 18:476–486. 2012.

26. 

Zeuner A, Eramo A, Testa U, Felli N, Pelosi E, Mariani G, Srinivasula SM, Alnemri ES, Condorelli G, Peschle C and De Maria R: Control of erythroid cell production via caspase-mediated cleavage of transcription factor SCL/Tal-1. Cell Death Differ. 10:905–913. 2003. View Article : Google Scholar : PubMed/NCBI

27. 

Kitanaka C, Kato K and Tanaka Y: Ras protein expression and autophagic tumor cell death in neuroblastoma. Am J Surg Pathol. 31:153–155. 2007. View Article : Google Scholar : PubMed/NCBI

28. 

Li Y, Xiang Q, Zhang Q, Huang Y and Su Z: Overview on the recent study of antimicrobial peptides: origins, functions, relative mechanisms and application. Peptides. 37:207–215. 2012. View Article : Google Scholar : PubMed/NCBI

29. 

Shai YC: Molecular recognition between membrane-spanning peptides. Trends Biochem Sci. 20:460–464. 1995. View Article : Google Scholar

30. 

Epand RM, Shai YC, Segrest JP and Anantharamaiah GM: Mechanisms for the modulation of membrane bilayer properties by amphipathic helical peptides. Biopolymers. 37:319–338. 1995. View Article : Google Scholar : PubMed/NCBI

31. 

Rozek T, Wegener KL, Bowie JH, Olver IN, Carver JA, Wallace JC and Tyler MJ: The antibiotic and anticancer active aurein peptides from the Australian Bell Frogs Litoria aurea and Litoria raniformis the solution structure of aurein 1.2. Eur J Biochem. 267l:5330–5341. 2000. View Article : Google Scholar : PubMed/NCBI

32. 

Doyle J, Brinkworth CS, Wegener KL, Carver JA, Llewellyn LE, Olver IN, Bowie JH, Wabnitz PA and Tyler MJ: nNOS inhibition, antimicrobial and anticancer activity of the amphibian skin peptide, citropin 1.1 and synthetic modifications. The solution structure of a modified citropin 11 Eur J Biochem. 270:1141–1153. 2003.PubMed/NCBI

33. 

Hoskin DW and Ramamoorthy A: Studies on anticancer activities of antimicrobial peptides. Biochim Biophys Acta. 1778:357–375. 2008. View Article : Google Scholar : PubMed/NCBI

34. 

Mader JS, Richardson A, Salsman J, Top D, de Antueno R, Duncan R and Hoskin DW: Bovine lactoferricin causes apoptosis in Jurkat T-leukemia cells by sequential permeabilization of the cell membrane and targeting of mitochondria. Exp Cell Res. 313:2634–2650. 2007. View Article : Google Scholar : PubMed/NCBI

Related Articles

Journal Cover

August 2013
Volume 43 Issue 2

Print ISSN: 1019-6439
Online ISSN:1791-2423

Sign up for eToc alerts

Recommend to Library

Copy and paste a formatted citation
x
Spandidos Publications style
Kim I, Lee JH, Kwon Y, Yun E, Nam S, Ahn M, Kang D and Hwang JS: Anticancer activity of a synthetic peptide derived from harmoniasin, an antibacterial peptide from the ladybug Harmonia axyridis. Int J Oncol 43: 622-628, 2013
APA
Kim, I., Lee, J.H., Kwon, Y., Yun, E., Nam, S., Ahn, M. ... Hwang, J.S. (2013). Anticancer activity of a synthetic peptide derived from harmoniasin, an antibacterial peptide from the ladybug Harmonia axyridis. International Journal of Oncology, 43, 622-628. https://doi.org/10.3892/ijo.2013.1973
MLA
Kim, I., Lee, J. H., Kwon, Y., Yun, E., Nam, S., Ahn, M., Kang, D., Hwang, J. S."Anticancer activity of a synthetic peptide derived from harmoniasin, an antibacterial peptide from the ladybug Harmonia axyridis". International Journal of Oncology 43.2 (2013): 622-628.
Chicago
Kim, I., Lee, J. H., Kwon, Y., Yun, E., Nam, S., Ahn, M., Kang, D., Hwang, J. S."Anticancer activity of a synthetic peptide derived from harmoniasin, an antibacterial peptide from the ladybug Harmonia axyridis". International Journal of Oncology 43, no. 2 (2013): 622-628. https://doi.org/10.3892/ijo.2013.1973