Buthionine sulfoximine and myeloablative concentrations of melphalan overcome resistance in a melphalan-resistant neuroblastoma cell line

J Pediatr Hematol Oncol. 2001 Nov;23(8):500-5. doi: 10.1097/00043426-200111000-00007.


Background: Alkylator resistance contributes to treatment failure in high-risk neuroblastoma. Buthionine sulfoximine (BSO) can deplete glutathione and synergistically enhance in vitro sensitivity to the alkylating agent melphalan (L-PAM) for many neuroblastoma cell lines, but optimal use of this combination needs to be defined because clinical responses have been less frequent and not durable.

Patients and methods: The authors established and characterized a neuroblastoma cell line (CHLA-171) from a patient who died of progressive disease after treatment with BSO and low-dose L-PAM.

Results: CHLA-171 lacks MYCN amplification, expresses PGP (P-glycoprotein) 9.5 RNA, and shows cell surface antigen expression (human leukocyte antigen class I weakly positive, but HSAN 1.2 (hybridoma, SAN 1.2) and anti-GD2 (anti-ganglioside GD2 antibody) strongly positive) characteristic of neuroblastoma cell lines. Twenty-four hours of BSO treatment (0-1,000 micromol/L) maximally depleted CHLA-171 glutathione to 36% of baseline. The cytotoxic response of CHLA-171 to BSO and L-PAM, alone and in combination, was measured by digital image microscopy (DIMSCAN) over a range of drug concentrations and compared with drug levels obtained in the patient during BSO/L-PAM therapy. As single agents, CHLA-171 was highly resistant to L-PAM (LD90 = 42 micromol/L; peak plasma concentration in the patient equals 3.9 micromol/L) and moderately resistant to BSO (LD90 = 509 micromol/L; steady-state concentration in the patient equals 397 micromol/L). Treatment with a 10:1 (BSO:L-PAM) fixed ratio combination synergistically overcame resistance (3-4 logs of cell kill, combination index <1) at clinically achievable levels of BSO (100-400 micromol/L) and levels of L-PAM (10-40 micromol/L) clinically achievable only with hematopoietic stem cell support.

Conclusions: The in vitro results obtained for CHLA-171 suggest that BSO/L-PAM therapy may be optimally effective for drug-resistant neuroblastoma using myeloablative doses of L-PAM.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Antimetabolites, Antineoplastic / therapeutic use*
  • Antineoplastic Agents, Alkylating / therapeutic use*
  • Apoptosis / drug effects
  • Buthionine Sulfoximine / blood
  • Buthionine Sulfoximine / therapeutic use*
  • Cell Survival / drug effects
  • Child
  • Dose-Response Relationship, Drug
  • Drug Resistance, Neoplasm*
  • Drug Therapy, Combination
  • Female
  • Glutathione / metabolism
  • Humans
  • Melphalan / therapeutic use*
  • Neuroblastoma / drug therapy*
  • Neuroblastoma / metabolism
  • Polymerase Chain Reaction
  • Reverse Transcriptase Polymerase Chain Reaction
  • Tumor Cells, Cultured / drug effects


  • Antimetabolites, Antineoplastic
  • Antineoplastic Agents, Alkylating
  • Buthionine Sulfoximine
  • Glutathione
  • Melphalan