Tsai S T, Jin Y T, Leung H W, Wang S T, Tsao C J, Su I J
Department of Otolaryngology, National Cheng Kung University Medical College, Tainan, Taiwan.
Anticancer Res. 1998 Jul-Aug;18(4B):2849-54.
Many anticancer treatments, including radiation therapy, have been demonstrated to work through apoptosis. The treatment of choice on nasopharyngeal carcinoma (NPC), a radiosensitive tumor, is radiotherapy. Apoptosis therefore provides a good model to predict or re-evaluate the therapeutic response in NPC. Cellular genes such as p53 and bcl-2 have been shown to be involved in apoptosis. Proliferating cell nuclear antigen (PCNA) is a useful marker for proliferating cells. This study was designed to investigate whether the expression of p53, bcl-2 and PCNA, evaluated on tumor specimens obtained at diagnosis, is indicative of the subsequent local recurrence and distant metastasis following radiation therapy. We analyzed the expression of p53, bcl-2 and PCNA by immunohistochemical methods from NPC specimens prior to radiation therapy. A total of 63 T3/T4 NPC patients including 10 patients with local relapse (Group I), 19 patients with distant metastasis (Group II), and 34 disease-free patients (Group III) were assessed. Six of the 10 (60%) group I NPC, 4 of the 19 (21.1%) group II NPC, and 13 of the 34 (38.2%) group III NPC exhibited positive p53 expression. For bcl-2 immunostaining, 8 of the 10 (80%) group I NPC, 10 of the 19 (52.6%) group II NPC, and 10 of the 34 (29.4%) group III NPC were positive. High PCNA labelling index was shown in 6 of the 10 (60%) group I NPC, 7 of the 19 (36.8%) group II NPC, and 5 of the 34 (14.7%) group III NPC. The bcl-2 and PCNA reactivity in NPC developing local recurrence after radiation therapy was significantly higher than that in the disease-free NPC (p < 0.05). These findings show that the overexpression of bcl-2 and high PCNA labelling index are probably related to local relapse in NPC patients receiving radiation therapy alone as primary treatment.
许多抗癌治疗方法，包括放射治疗，已被证明是通过细胞凋亡起作用的。鼻咽癌（NPC）是一种对放疗敏感的肿瘤，其首选治疗方法是放射治疗。因此，细胞凋亡为预测或重新评估鼻咽癌的治疗反应提供了一个良好的模型。细胞基因如p53和bcl-2已被证明与细胞凋亡有关。增殖细胞核抗原（PCNA）是增殖细胞的一个有用标志物。本研究旨在调查在诊断时获取的肿瘤标本上评估的p53、bcl-2和PCNA的表达是否表明放疗后随后的局部复发和远处转移。我们通过免疫组化方法分析了放疗前鼻咽癌标本中p53、bcl-2和PCNA的表达。总共评估了63例T3/T4期鼻咽癌患者，包括10例局部复发患者（第一组）、19例远处转移患者（第二组）和34例无病患者（第三组）。第一组10例鼻咽癌中有6例（60%）、第二组19例中有4例（21.1%）、第三组34例中有13例（38.2%）p53表达呈阳性。对于bcl-2免疫染色，第一组10例鼻咽癌中有8例（80%）、第二组19例中有10例（52.6%）、第三组34例中有10例（29.4%）呈阳性。第一组10例鼻咽癌中有6例（60%）、第二组19例中有7例（36.8%）、第三组34例中有5例（14.7%）显示PCNA高标记指数。放疗后发生局部复发的鼻咽癌中bcl-2和PCNA反应性明显高于无病鼻咽癌（p<0.05）。这些发现表明，bcl-2的过表达和高PCNA标记指数可能与仅接受放射治疗作为主要治疗的鼻咽癌患者的局部复发有关。
