title: Application of thermally responsive elastin-like polypeptide fused to a lactoferrin-derived peptide for treatment of pancreatic cancer.
abstract: A well characterized, peptide derivative of bovine lactoferrin, L12, has been shown to possess anticancer properties in multiple cell lines. However, adverse side effects in normal tissues and poor plasma kinetics that hinder the clinical effectiveness of current chemotherapeutics also deter the potential for effective delivery of this L12 peptide. To overcome these limitations, we have developed an Elastin-like polypeptide (ELP) carrier that has the potential to thermally target therapeutic peptides and chemotherapeutics to a tumor site. The coding sequence of ELP was modified with the L12 peptide at the C-terminus and a membrane transduction domain derived from the HIV-1 Tat protein at the N-terminus (Tat-ELP-L12). The thermally responsive Tat-ELP1-L12 is soluble in aqueous solutions at 37 degrees C but aggregates near 41 degrees C, which makes Tat-ELP1-L12 ideal for targeting to solid tumors on application of focused hyperthermia. We observed that under hyperthermia conditions at 42 degrees C, Tat-ELP1-L12 mediated cytotoxicity in MIA PaCa-2 pancreatic adenocarcinoma cells was enhanced by nearly thirty-fold. We investigated the mechanisms of cell death and found evidence of mitochondrial membrane depolarization and caspase activation, which are characteristic of apoptosis, as well as, increased membrane permeability, as shown by LDH release. These results suggest that Tat-ELP1-L12 possesses cytotoxic properties to cancer cells in vitro and may have the potential to provide an effective vehicle to thermally target solid tumors.
authors.affiliation: Department of Biochemistry, University of Mississippi Medical Center 2500 N. State Street Jackson, MS 39216, USA.
authors.forename: Iqbal
authors.initials: I
authors.lastname: Massodi
authors.forename: Emily
authors.initials: E
authors.lastname: Thomas
authors.forename: Drazen
authors.initials: D
authors.lastname: Raucher
mesh_terms: D000818:Animals; D000970:Antineoplastic Agents / Q000138:chemical synthesis / Q000737:chemistry / Q000494:pharmacology / Q000627:therapeutic use*; D002417:Cattle; D045744:Cell Line, Tumor; D049109:Cell Proliferation / Q000187:drug effects; D004337:Drug Carriers / Q000138:chemical synthesis* / Q000737:chemistry; D006461:Hemolysis / Q000187:drug effects; D006801:Humans; D007770:L-Lactate Dehydrogenase / Q000378:metabolism; D007781:Lactoferrin / Q000138:chemical synthesis / Q000737:chemistry / Q000627:therapeutic use*; D053078:Membrane Potential, Mitochondrial / Q000187:drug effects; D010190:Pancreatic Neoplasms / Q000188:drug therapy*; D010455:Peptides / Q000138:chemical synthesis / Q000737:chemistry / Q000627:therapeutic use*; D051381:Rats; D013696:Temperature
chemical_list: D000970:Antineoplastic Agents; D004337:Drug Carriers; D010455:Peptides; D007770:L-Lactate Dehydrogenase; D007781:Lactoferrin