title: Growth inhibition of SK-MEL-30 human melanoma cells by antisense c-myc oligonucleotides delivered by poly(N-isopropylacrylamide)/ poly(ethyleneimine) copolymer.
abstract: The c-myc oncogene has been shown to be overexpressed in a number of malignancies and plays a key role in the abnormal growth regulation of melanoma cells. This study aimed to provide an efficient system for the in vitro manipulation of c-myc expression by antisense oligonucleotides. Therefore, we used poly(NIPA)/PEI2B copolymer as vector in order to improve the intracellular availability and stability of AS ODNs. We targeted oligonucleotide sequences within the human c-myc mRNA as free AS ODNs or conjugated with a thermosensitive copolymer, in an effort to inhibit the growth of human melanoma cells. The conjugates adopted more positive charge and smaller size at 37 degrees C and they had no toxic effects on human fibroblast cells. The conjugated AS ODNs showed increased antiproliferative effect on melanoma cells as compared to free AS ODNs. At a concentration of 100 ng, AS ODNs inhibited SK-MEL 30 human melanoma cell line proliferation maximally by 18.6%, whereas the same amount of conjugated AS ODN provided 52% inhibition. The greatest inhibition was obtained by conjugates having a polymer:AS ODN ratio of 9. Greatest inhibition was detected at 48 h and decreased after 96 h, which may be due to the depletion of AS ODNs. The results confirm the enhanced antiproliferative effects of poly(NIPA)/PEI2B-conjugated AS ODNs, which may provide improved intracellular availability for c-myc-directed antisense strategies.
authors.affiliation: Bioengineering Department, Yildiz Technical University, Davutpasa, Istanbul, Turkey.
authors.forename: S
authors.initials: S
authors.lastname: Dinçer
authors.forename: E K
authors.initials: EK
authors.lastname: Oskay
authors.forename: A K
authors.initials: AK
authors.lastname: Piskin
authors.forename: N D
authors.initials: ND
authors.lastname: Zeybek
authors.forename: E
authors.initials: E
authors.lastname: Pişkin
mesh_terms: D000180:Acrylic Resins; D016923:Cell Death / Q000187:drug effects; D045744:Cell Line, Tumor; D049109:Cell Proliferation / Q000187:drug effects; D004337:Drug Carriers; D006801:Humans; D008545:Melanoma / Q000235:genetics / Q000378:metabolism / Q000473:pathology* / Q000628:therapy; D016376:Oligonucleotides, Antisense / Q000494:pharmacology*; D010316:Particle Size; D011094:Polyethyleneimine / Q000031:analogs & derivatives*; D016271:Proto-Oncogene Proteins c-myc / Q000096:biosynthesis / Q000235:genetics*; D013696:Temperature
chemical_list: D000180:Acrylic Resins; D004337:Drug Carriers; D016376:Oligonucleotides, Antisense; D016271:Proto-Oncogene Proteins c-myc; C552303:poly(N-isopropylacrylamide)-poly(ethyleneimine) copolymer; D011094:Polyethyleneimine