Clinical use of streptolysin-O to facilitate antisense oligodeoxyribonucleotide delivery for purging autografts in chronic myeloid leukaemia

Bone Marrow Transplant. 1999 Jun;23(12):1303-8. doi: 10.1038/sj.bmt.1701801.

Abstract

Antisense oligodeoxyribonucleotides (ODN) targeted against the breakpoint in BCR-ABL mRNA will specifically decrease BCR-ABL mRNA, provided cells are first permeabilised with streptolysin-O (SL-O). We used 18-mer chimeric methylphosphonodiester: phosphodiester linked (4-9-4) ODN complementary to 9 bases either side of the BCR-ABL junction to purge harvests ex vivo in three CML patients who remained completely Ph positive after multiple chemotherapy courses. After CD34+ cell selection and SL-O permeabilisation, harvests were purged with 20 microM ODN. After purging, all individual CFU-GM colonies grown from the two b3a2 breakpoint cases remained positive for BCR-ABL mRNA. In contrast, all 24 colonies grown from the b2a2 breakpoint case were BCR-ABL mRNA negative. Patients were conditioned with busulphan 16 mg/kg. The initial post-transplant course was uneventful, although the time to return to 0.5 x 10(9)/l neutrophils was slow at 25-51 days. Both chronic phase patients remain in haematological remission at +724 and +610 days, although each has cytogenetic evidence of relapse. The b2a2 accelerated phase patient died of myeloid blast transformation at day +91. The present SL-O-facilitated ODN purging strategy appears to be without significant toxicity, and offers considerable improvements in ODN delivery to the cytosol.

Publication types

  • Clinical Trial
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Antigens, CD34
  • Fusion Proteins, bcr-abl / genetics*
  • Hematopoietic Stem Cell Mobilization
  • Hematopoietic Stem Cell Transplantation / methods*
  • Humans
  • Leukapheresis
  • Leukemia, Myelogenous, Chronic, BCR-ABL Positive / therapy*
  • Oligonucleotides, Antisense / administration & dosage
  • Oligonucleotides, Antisense / therapeutic use*
  • Outcome Assessment, Health Care
  • Sequence Analysis, DNA
  • Transplantation Conditioning / methods*

Substances

  • Antigens, CD34
  • Oligonucleotides, Antisense
  • Fusion Proteins, bcr-abl