A bioactive peptide analogue for myxoma virus protein with a targeted cytotoxicity for human skin cancer in vitro.
BACKGROUND
Cancer is an international health problem, and the search for effective treatments is still in progress. Peptide therapy is focused on the development of short peptides with strong tumoricidal activity and low toxicity. In this study, we investigated the efficacy of a myxoma virus peptide analogue (RRM-MV) as a candidate for skin cancer therapy. RRM-MV was designed using the Resonant Recognition Model (RRM) and its effect was examined on human skin cancer and normal human skin cells in vitro.


METHODS
Cell cultures were treated with various concentrations of the peptides at different incubation intervals. Cellular morphological changes (apoptosis and necrosis) were evaluated using confocal laser scanning microscopy. The cytotoxic effects of RRM-MV on human skin cancer and normal human skin cells were quantitatively determined by cytotoxicity and cell viability assays. The effect on human erythrocytes was also determined using quantitative hemolysis assay. DNA fragmentation assay was performed to detect early apoptotic events in treated cancer cells. Furthermore, to investigate the possible cell signalling pathway targeted by the peptides treatment, the levels of p-Akt expression in skin cancer and normal cells were detected by immunoblotting.


RESULTS
Our results indicate that RRM-MV has a dose-dependent toxic effect on cancer cells only up to 18 h. The immunoblotting results indicated that the RRM-MV slightly increased p-Akt expression in melanoma and carcinoma cells, but did not seem to affect p-Akt expression in normal skin cells.


CONCLUSIONS
RRM-MV targets and lethally harms cancer cells and leaves normal cells unharmed. It is able to reduce the cancer cell viability, disrupting the LDH activity in cancer cells and can significantly affect cancer progression. Further investigation into other cell signalling pathways is needed in the process leading to the in vivo testing of this peptide to prove its safety as a possible effective treatment for skin cancer.
Biotechnology and Environmental Biology, School of Applied Sciences, Science Engineering and Health College, RMIT University, Bundoora, VIC 3083, Australia.
Nahlah M
NM
Almansour
Elena
E
Pirogova
Peter J
PJ
Coloe
Irena
I
Cosic
Taghrid S
TS
Istivan
D017209:Apoptosis / Q000187:drug effects; D002294:Carcinoma, Squamous Cell / Q000235:genetics / Q000628:therapy; D045744:Cell Line, Tumor; D002470:Cell Survival / Q000187:drug effects; D053938:DNA Fragmentation / Q000187:drug effects; D006801:Humans; D066298:In Vitro Techniques; D008545:Melanoma / Q000235:genetics / Q000628:therapy; D009233:Myxoma virus / Q000737:chemistry; D009336:Necrosis; D010455:Peptides / Q000008:administration & dosage / Q000737:chemistry; D051057:Proto-Oncogene Proteins c-akt / Q000378:metabolism; D015398:Signal Transduction / Q000187:drug effects; D012878:Skin Neoplasms / Q000235:genetics / Q000628:therapy
D010455:Peptides; D051057:Proto-Oncogene Proteins c-akt