An in vitro model for purging of tumour cells from ovarian tissue

BACKGROUND: Cryopreservation and autografting of ovarian tissue may preserve fertility after cancer treatment, but could be hampered by tumour cell contamination. Epithelial tumour cell lysis can be obtained with cytotoxic T cell retargeting through the bispecific antibody BIS‐1, with combined affinity for the T‐cell receptor and epithelial glycoprotein‐2 (EGP‐2). Our aim was to study the concept of tumour cell purging in the setting of a suspension of ovarian tissue. METHODS: Human ovarian tissue was brought into suspension by mechanical and enzymatic treatment. Cells of the MCF‐7 breast cancer cell line and activated human lymphocytes were co‐ incubated for 4 h with or without BIS‐1 and with or without ovarian suspension. After incubation, MCF‐7 cell death and cell growth were evaluated by fluorescent cell detection and MTT assay, respectively. Ovarian tissue morphology was evaluated immunohistochemically. RESULTS: MCF‐7 cell death and cell growth inhibition increased with increasing ratios of lymphocytes to MCF‐7 cells. BIS‐1 addition gave further augmentation, with a maximum depletion of growing MCF‐7 cells of 89% (SD 11%) versus without BIS‐1, 23% (SD 15%; P