Ifosfamide induced stress response in human lymphocytes

Area of Science:

• Oncology
• Cell Biology
• Immunology

Background:

• Ifosfamide is an effective antineoplastic agent for human malignancies.
• Intracellular glutathione (GSH) status modulates ifosfamide cytotoxicity.
• Human peripheral blood lymphocytes (PBL) are critical for immune function.

Purpose of the Study:

• To investigate the effects of 4-hydroperoxy-ifosfamide (4-OOH-IF) on human PBL proliferation and intracellular GSH content.
• To assess the sensitivity of PBL to 4-OOH-IF compared to other cell types.
• To explore the cellular stress response and potential for GSH reconstitution in PBL.

Main Methods:

• Exposure of interleukin-2 (IL-2) expanded PBL to 4-OOH-IF.
• Measurement of [3H]-thymidine incorporation to assess proliferation.
• Quantification of intracellular GSH content.
• Analysis of heat shock protein 27 (HSP27) phosphorylation.
• GSH reconstitution using GSH-monoethylester and mesna.

Main Results:

• 4-OOH-IF significantly inhibited [3H]-thymidine incorporation in PBL.
• PBL exhibited substantial depletion of intracellular GSH following 4-OOH-IF exposure.
• PBL demonstrated greater sensitivity to 4-OOH-IF compared to Ewing sarcoma and Chinese hamster ovary cells.
• 4-OOH-IF induced rapid phosphorylation of HSP27, indicating a stress response.
• GSH levels were successfully reconstituted in PBL post-treatment within 24 hours.

Conclusions:

• Human lymphocytes are sensitive targets to ifosfamide-induced metabolic stress.
• The depletion of GSH in lymphocytes may impact their proliferation and function.
• Understanding these effects is crucial for managing ifosfamide therapy and preserving immunological function.