[Leukemia SH-1 cells purged by ZnPcH(1)-based photodynamic therapy]

The objective of this study was to investigate the effect of a novel Zinc phthalocyanine (ZnPcH(1)) based photodynamic therapy (PDT) on acute monocytic leukemia cell lines SHI-1 and its mechanism, so as to provide theory basis for bone marrow purging in vitro for patients with leukemia. The killing effect of ZnPcH(1)-PDT on SHI-1 cells were assessed by MTT method; the SHI-1 cell death patterns were analyzed by AO/EB fluorescence staining, TdT-mediated dUTP nick end labeling (TUNEL), DNA ploidy analysis, and Annexin V-FITC/PI double staining.Cell mixture was established by integrating SHI-1 cells with normal bone marrow MNC (by 1:100-1:10 000). Purging effect of ZnPcH(1)-PDT against SHI-1 mixed into normal MNC was assessed by analyzing the expression of fusion gene MLL/AF6 mRNA using nested RT-PCR. The results showed that ZnPcH(1)-PDT could effectively inhibit SHI-1 cell proliferation in dose-dependent manner, and ZnPcH(1)-PDT could induce cell apoptosis in time-dependent manner. 0.5 µmol/L ZnPcH(1)-PDT could completely photoinactivated kill SHI-1 cells in the simulated remission bone marrow. It concluded that ZnPcH(1)-PDT may be a effective and convenient promising purging technique for leukemia.