1-palmitoyl-2-oleoylphosphatidylcholine and Pancreatic-Neoplasms

KRAS is mutated in >90% of pancreatic ductal adenocarcinomas. As its inactivation leads to tumour regression, mutant KRAS is considered an attractive target for anticancer drugs. In this study we report a new delivery strategy for a G4-decoy oligonucleotide that sequesters MAZ, a transcription factor essential for KRAS transcription. It is based on the use of palmitoyl-oleyl-phosphatidylcholine (POPC) liposomes functionalized with lipid-modified G4-decoy oligonucleotides and a lipid-modified cell penetrating TAT peptide. The potency of the strategy in pancreatic cancer cells is demonstrated by cell cytometry, confocal microscopy, clonogenic and qRT-PCR assays.

Topics: Adenocarcinoma; Cell Line, Tumor; Cell-Penetrating Peptides; Humans; Lipids; Liposomes; Nanoparticles; Oligonucleotides; Pancreatic Neoplasms; Phosphatidylcholines; Promoter Regions, Genetic; Proto-Oncogene Proteins p21(ras)

Significant differences in biochemical parameters between normal and tumor tissues offer an opportunity to chemically design drug carriers which respond to these changes and deliver the drugs at the desired site. For example, overexpression of the matrix metalloproteinase-9 (MMP-9) enzyme in the extracellular matrix of tumor tissues can act as a trigger to chemically modulate the drug delivery from the carriers. In this study, we have synthesized an MMP-9-cleavable, collagen mimetic lipopeptide which forms nanosized vesicles with the POPC, POPE-SS-PEG, and cholesteryl-hemisuccinate lipids. The lipopeptide retains the triple-helical conformation when incorporated into these nanovesicles. The PEG groups shield the substrate lipopeptides from hydrolysis by MMP-9. However, in the presence of elevated glutathione levels, the PEG groups are reductively removed, exposing the lipopeptides to MMP-9. The resultant peptide-bond cleavage disturbs the vesicles' lipid bilayer, leading to the release of encapsulated contents. These PEGylated nanovesicles are capable of encapsulating the anticancer drug gemcitabine with 50% efficiency. They were stable in physiological conditions and in human serum. Effective drug release was demonstrated using the pancreatic ductal carcinoma cells (PANC-1 and MIAPaCa-2) in two-dimensional and three-dimensional "tumor-like" spheroid cultures. A reduction in tumor growth was observed after intravenous administration of the gemcitabine-encapsulated nanovesicles in the xenograft model of athymic, female nude mice.

Topics: Animals; Antineoplastic Agents; Carcinoma, Pancreatic Ductal; Cell Line, Tumor; Deoxycytidine; Drug Carriers; Drug Delivery Systems; Extracellular Matrix; Female; Gemcitabine; Glutathione; Humans; Hydrolysis; Lipid Bilayers; Lipopeptides; Matrix Metalloproteinase 9; Mice; Mice, Nude; Nanoparticles; Pancreatic Neoplasms; Phosphatidylcholines; Polyethylene Glycols; Transport Vesicles