title: MAZ-binding G4-decoy with locked nucleic acid and twisted intercalating nucleic acid modifications suppresses KRAS in pancreatic cancer cells and delays tumor growth in mice.
abstract: KRAS mutations are primary genetic lesions leading to pancreatic cancer. The promoter of human KRAS contains a nuclease-hypersensitive element (NHE) that can fold in G4-DNA structures binding to nuclear proteins, including MAZ (myc-associated zinc-finger). Here, we report that MAZ activates KRAS transcription. To knockdown oncogenic KRAS in pancreatic cancer cells, we designed oligonucleotides that mimic one of the G-quadruplexes formed by NHE (G4-decoys). To increase their nuclease resistance, two locked nucleic acid (LNA) modifications were introduced at the 3'-end, whereas to enhance the folding and stability, two polycyclic aromatic hydrocarbon units (TINA or AMANY) were inserted internally, to cap the quadruplex. The most active G4-decoy (2998), which had two para-TINAs, strongly suppressed KRAS expression in Panc-1 cells. It also repressed their metabolic activity (IC50 = 520 nM), and it inhibited cell growth and colony formation by activating apoptosis. We finally injected 2998 and control oligonucleotides 5153, 5154 (2 nmol/mouse) intratumorally in SCID mice bearing a Panc-1 xenograft. After three treatments, 2998 reduced tumor xenograft growth by 64% compared with control and increased the Kaplan-Meier median survival time by 70%. Together, our data show that MAZ-specific G4-decoys mimicking a KRAS quadruplex are promising for pancreatic cancer therapy.
authors.affiliation: Department of Medical and Biological Sciences, School of Medicine, P.le Kolbe 4, 33100 Udine, Italy.
authors.forename: Susanna
authors.initials: S
authors.lastname: Cogoi
authors.forename: Sonia
authors.initials: S
authors.lastname: Zorzet
authors.forename: Valentina
authors.initials: V
authors.lastname: Rapozzi
authors.forename: Imrich
authors.initials: I
authors.lastname: Géci
authors.forename: Erik B
authors.initials: EB
authors.lastname: Pedersen
authors.forename: Luigi E
authors.initials: LE
authors.lastname: Xodo
mesh_terms: D000818:Animals; D000970:Antineoplastic Agents / Q000737:chemistry / Q000494:pharmacology / Q000627:therapeutic use*; D017209:Apoptosis; D001665:Binding Sites; D001667:Binding, Competitive; D045744:Cell Line, Tumor; D004247:DNA / Q000737:chemistry; D004268:DNA-Binding Proteins / Q000378:metabolism*; D054856:G-Quadruplexes; D006801:Humans; D051379:Mice; D016513:Mice, SCID; D009841:Oligonucleotides / Q000737:chemistry; D010190:Pancreatic Neoplasms / Q000188:drug therapy* / Q000235:genetics / Q000473:pathology; D011401:Promoter Regions, Genetic; D011518:Proto-Oncogene Proteins / Q000037:antagonists & inhibitors* / Q000235:genetics / Q000378:metabolism; D016283:Proto-Oncogene Proteins p21(ras); D014157:Transcription Factors / Q000378:metabolism*; D015533:Transcriptional Activation; D018631:ras Proteins / Q000037:antagonists & inhibitors* / Q000235:genetics / Q000378:metabolism
chemical_list: D000970:Antineoplastic Agents; D004268:DNA-Binding Proteins; C117307:KRAS protein, human; D009841:Oligonucleotides; D011518:Proto-Oncogene Proteins; D014157:Transcription Factors; C076035:c-MYC-associated zinc finger protein; C477371:locked nucleic acid; D004247:DNA; D016283:Proto-Oncogene Proteins p21(ras); D018631:ras Proteins