Yoo E K, Rook A H, Elenitsas R, Gasparro F P, Vowels B R
Department of Dermatology, School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, U.S.A.
J Invest Dermatol. 1996 Aug;107(2):235-42. doi: 10.1111/1523-1747.ep12329711.
The anti-tumor action of many chemotherapeutic agents has recently been attributed to the induction of apoptosis in the malignant cell population. In this study, we investigated the ability of extracorporeal photopheresis (ExP) and in vitro PUVA (8-methoxy-psoralen + ultraviolet A) therapy to induce apoptosis in peripheral blood mononuclear cells from Sezary syndrome patients and normal controls. Flow cytometric analysis of ExP- or PUVA-treated peripheral blood lymphocytes demonstrated two distinct cell populations within 24 h of treatment. One population was similar to untreated controls with the other exhibiting characteristics of apoptotic cell death, i.e., a loss of cell volume and an accompanying increase in cell density. This latter population was comprised of cells with DNA strand breaks as determined by the Tdt-mediated deoxyuridine triphosphate-biotin nick end labeling assay. Apoptosis was also confirmed morphologically by fluorescent and electron microscopy as well as by demonstration of characteristic DNA strand breaks (laddering) using gel electrophoresis. Apoptosis was not observed with 8-methoxypsoralen (< or = 300 ng per ml) alone; however, ultraviolet A alone at doses > or = 2 J per cm2 induced apoptosis in lymphocytes. Peripheral blood T-cell subpopulations of Sezary syndrome patients, including the malignant clone, were equally susceptible to apoptosis subsequent to either photopheresis or PUVA treatment. In contrast, monocytes (CD14+/CD45+) appear to be resistant to apoptosis induction by ExP or PUVA treatment. Moreover, ExP-treated and untreated monocytes phagocytized apoptotic, but not untreated, peripheral blood mononuclear cells. ExP and PUVA have been shown to be efficacious and well-tolerated therapies in the treatment of dermatologic diseases and transplant rejection. These data suggest that induction of apoptosis may be an important event for therapeutic efficacy.
许多化疗药物的抗肿瘤作用最近被认为是由于诱导恶性细胞群体发生凋亡。在本研究中，我们调查了体外光化学疗法（ExP）和体外补骨脂素加长波紫外线（PUVA，8-甲氧基补骨脂素 + 紫外线A）疗法诱导蕈样肉芽肿综合征患者和正常对照者外周血单个核细胞凋亡的能力。对经ExP或PUVA处理的外周血淋巴细胞进行流式细胞术分析显示，处理后24小时内有两个不同的细胞群体。一个群体与未处理的对照相似，另一个表现出凋亡细胞死亡的特征，即细胞体积减小并伴随细胞密度增加。通过末端脱氧核苷酸转移酶介导的生物素化脱氧尿苷三磷酸缺口末端标记试验确定，后一个群体由具有DNA链断裂的细胞组成。通过荧光显微镜和电子显微镜以及使用凝胶电泳证明特征性DNA链断裂（梯状条带），也从形态学上证实了凋亡。单独使用8-甲氧基补骨脂素（≤300 ng/ml）未观察到凋亡；然而，单独使用剂量≥2 J/cm² 的紫外线A可诱导淋巴细胞凋亡。蕈样肉芽肿综合征患者的外周血T细胞亚群，包括恶性克隆，在光化学疗法或PUVA治疗后同样容易发生凋亡。相比之下，单核细胞（CD14⁺/CD45⁺）似乎对ExP或PUVA治疗诱导的凋亡具有抗性。此外，经ExP处理和未处理的单核细胞吞噬凋亡的外周血单个核细胞，但不吞噬未处理的外周血单个核细胞。ExP和PUVA已被证明在治疗皮肤病和移植排斥反应方面是有效且耐受性良好的疗法。这些数据表明，诱导凋亡可能是治疗效果的一个重要事件。
