title: Chemosensitization of Prostate Carcinoma Cells with a Receptor-directed Smac Conjugate.
abstract: BACKGROUND
  Second mitochondrial activator of caspase (Smac) is a short mitochondrial peptide. When released from the mitochondria into the cytoplasm, it binds to inhibitor of apoptotic proteins (IAPs) within the cytoplasm and prevents them from inhibiting apoptosis.
  
  
  OBJECTIVE
  Delivery of external synthetic Smac peptide into the cytoplasm of malignant cells could greatly improve the efficiency of apoptosis-inducing chemotherapeutic agents.
  
  
  METHODS
  In our study different conjugates based on the seven N-terminal amino acids AVPIAQK of Smac (SmacN7) were produced to obtain a cytoplasm-directed Smac variant. SmacN7 and a point mutant (AVPKAQK) were coupled either to rhodamine alone or to both rhodamine and undecylic aldehyde, which is an antagonist of the Lily-of-the-valley fragrance receptor. The fifth conjugate consisted of rhodamine coupled only to undecylic aldehyde, without SmacN7. The uptake of these five conjugates into three different human cell lines was characterized and quantified by confocal laser scanning microscopy and flow cytometry. A caspase apoptosis assay was performed for cells incubated with the five different conjugates after induction of apoptosis.
  
  
  RESULTS
  The coupling of undecylic aldehyde to SmacN7 increased the cellular uptake of the correct and mutant conjugates.
  
  
  CONCLUSIONS
  Caspase 3/7 apoptosis tests after induction of apoptosis with staurosporine or UV irradiation showed that the coupling of SmacN7 with undecylic aldehyde resulted in a greatly increased adjuvant pro-apoptotic effect compared to the separate components and a mutant SmacN7 peptide sequence in the LNCaP prostate carcinoma cells compared to the benign prostate hyperplasia (BPH) cells and the human embryonal kidney (HEK) cells.
authors.forename: Alexander
authors.initials: A
authors.lastname: Sturzu
authors.affiliation: Department of Neuroradiology University of Tübingen Hoppe-Seyler-Str.3 72076 Tübingen, Germany. sumblafarooq@yahoo.com.
authors.forename: Sumbla
authors.initials: S
authors.lastname: Sheikh
authors.forename: Hartmut
authors.initials: H
authors.lastname: Echner
authors.forename: Martin
authors.initials: M
authors.lastname: Deeg
authors.forename: Thomas
authors.initials: T
authors.lastname: Nägele
authors.forename: Christopher
authors.initials: C
authors.lastname: Weidenmaier
authors.forename: Christian
authors.initials: C
authors.lastname: Schwentner
authors.forename: Marius
authors.initials: M
authors.lastname: Horger
authors.forename: Ulrike
authors.initials: U
authors.lastname: Ernemann
authors.forename: Stefan
authors.initials: S
authors.lastname: Heckl
mesh_terms: D000277:Adjuvants, Pharmaceutic / Q000138:chemical synthesis / Q000737:chemistry / Q000494:pharmacology*; D000447:Aldehydes / Q000138:chemical synthesis / Q000737:chemistry / Q000494:pharmacology*; D000970:Antineoplastic Agents / Q000138:chemical synthesis / Q000737:chemistry / Q000494:pharmacology*; D017209:Apoptosis / Q000187:drug effects / Q000528:radiation effects; D053148:Caspase 3 / Q000378:metabolism; D053179:Caspase 7 / Q000378:metabolism; D045744:Cell Line, Tumor; D004354:Drug Screening Assays, Antitumor; D005456:Fluorescent Dyes / Q000138:chemical synthesis / Q000737:chemistry; D006801:Humans; D008297:Male; D009842:Oligopeptides / Q000138:chemical synthesis / Q000737:chemistry / Q000494:pharmacology*; D011471:Prostatic Neoplasms / Q000188:drug therapy*; D018035:Receptors, Odorant / Q000037:antagonists & inhibitors*; D012235:Rhodamines / Q000138:chemical synthesis / Q000737:chemistry; D019311:Staurosporine / Q000494:pharmacology; D014466:Ultraviolet Rays
chemical_list: D000277:Adjuvants, Pharmaceutic; D000447:Aldehydes; D000970:Antineoplastic Agents; D005456:Fluorescent Dyes; D009842:Oligopeptides; D018035:Receptors, Odorant; D012235:Rhodamines; C000621018:SmacN7 peptide; C533561:olfactory receptor 17-4, human; C479548:undecanal; C027755:rhodamine isothiocyanate; D053148:Caspase 3; D053179:Caspase 7; D019311:Staurosporine