凋亡、PCNA及c-myc表达水平与鼻咽癌放射敏感性的相关性研究

The Impact of Apoptosis, PCNA and c-myc Expression on Radiosensitivity in Nasopharyngeal Carcinoma

目的:探讨凋亡、增殖细胞核抗原(PCN A)及c-m yc之间的相互关系以及它们与放射敏感性的相关关系。方法:搜集31例鼻咽癌患者于放疗前及接受放射剂量1520CG y后分别从鼻咽部肿物取活检。应用末端脱氧核苷酸转移酶(TdT)介导的脱氧核苷酸缺口末端标记(TU N EL)技术检测肿瘤细胞的凋亡率(AR),应用S-P免疫组化法检测PCN A、c-m yc,并将它们与放射敏感性进行相关研究。结果:放疗前c-m yc蛋白的表达水平与肿瘤细胞的自发性凋亡呈负相关、与PCN A呈正相关(P<0.01);放疗后c-m yc蛋白的表达水平与放射诱导凋亡呈正相关,与PCN A呈负相关(P<0.01)。肿瘤细胞放射敏感性级别与放疗前PCNA、放疗前凋亡率、放射诱导凋亡、放疗后PCN A下降幅度呈正相关(P<0.01);而与c-m yc无明显相关性(P>0.05)。结论:凋亡及PCNA与鼻咽癌的放射敏感性之间存在密切相关性,而c-m yc对凋亡及细胞增殖有调控作用。

Objective: To study the correlation between apoptosis, proliferating cell nuclear antigen (PCNA) and c-myc expression, and the relationship between they and radionsensitivity in nasopharyngeal carcinoma(NPC). Methods: Thirty-one patients proven to be nasopharyngeal squamous cell carcinoma were eligible to enter into this study. All patients in this study were biopsied from nasopharynx for two times, first biopsy's samples were performed before irradiation,and second ones were taken after receiving radiation dose of 1520CGy. Apoptosis cells were determined by the terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling (TUNEL) method. PCNA and c-myc were determined by immunohistochemical S-P staining technique. Results: The expression of c-myc before radiotherapy was negative relationship with Spontaneous AR of tumor cell, and was positive relationship with PCNA. However, the expression of c-myc after radiotherapy was positive relationship with AR of radiation-induced and was negative relationship with PCNA after radiation(P<0.01). Radiosensitivity of tumor cells was positively associated with the PCNA expression before radiation, spontaneous AR, AR of radiation-induced and down values of PCNA after radiation(P<0.01), and was not associated with and c-myc(P>0.05). Conclusions: The apoptosis and PCNA are closely related with the radiosensitivity in NPC, whereas c-myc expressions plays a modulated role for apoptosis and cell proliferation.