光卟啉-光照选择性杀灭白血病细胞株K_(562)的研究

SELECTIVE KILLING OF HUMAN LEUKEMIA CELL LINE K 562 BY YHPD MEDIATED PHOTOSENSITIZATION

为研究光卟啉（ＹＨＰＤ）加光照对白血病细胞株Ｋ５６２的杀伤作用及对正常造血祖细胞的影响，通过细胞体外液体培养活细胞计数、体外半固体培养集落测定，以探讨该法用于体外净化自体移植骨髓中残留的白血病细胞的可能性。观察不同光敏剂剂量和光照时间的变化对杀伤白血病细胞作用的影响，结果表明，单用ＹＨＰＤ或单独日光荧光照射对Ｋ５６２细胞和正常人造血祖细胞均无明显杀伤作用。二者联合使用表现光敏效应。细胞存活率的对数与ＹＨＰＤ剂量、光照时间呈线性相关。ＹＨＰＤ加光照对Ｋ５６２细胞具有强大杀伤作用，对正常造血祖细胞影响较小，在能够杀伤白血病细胞大于５个对数级，其体外已不能形成集落的情况下，正常人骨髓－巨噬细胞集落形成单位（ＣＦＵ－ＧＭ）尚有１５．９７％。

To assess the potential of photochemotherapy for the in vitro purging of residual leukemia cells from autologous bone marrow transplants ,we studied the effect of YHPD combined with light irradiation on human leukemia cell line K 562 and normal human hematopoietic progenitor cells by using the methods of trypan blue exclusion test and colony assay. We also investigated the influence of YHPD dose and light exposed time on this photosensitivity of K 562 cells. It was found that YHPD or light irradiation alone had no apparent cytotoxicity while the application of YHPD plus light exposure showed the photosensitization. Decrease in cell viability was linear when plotted on a logarithmic scale from 0 to 5 min (light irradiation) or 0 to 5 mg/L(YHPD). YHPD plus light irradiation was selectively more efficient for killing K 562 cells than normal human marrow progenitors. Under the condition of a 5log reduction in the survival of K 562 cells, 15.97% of normal human CFU GM survived. These results indicate that the photochemotherapy mediated by YHPD might be used for purging bone marrow in vitro.