三氧化二砷诱导人鼻咽低分化鳞癌裸鼠移植瘤细胞分化的研究

背景与目的:既往研究发现三氧化二砷(As2O3)可诱导白血病细胞的分化,但对实体瘤细胞的诱导分化作用报道甚少。本实验拟探讨As2O3对人鼻咽低分化鳞癌可移植瘤在BALB/C裸鼠体内生长的影响,重点观察其诱导鼻咽癌细胞分化的作用。方法:以人鼻咽低分化鳞癌鼠移植癌细胞株CSNE-1为研究对象,观察腹腔注射As2O3(5mg·kg-1·d-1连续10天后,每周给药3次,连续3周)对人鼻咽癌移植瘤在BALB/C裸鼠体内生长情况的影响。用光学显微镜和电子显微镜观察移植瘤细胞形态变化,用免疫组化法检测瘤组织中增殖细胞核抗原(PCNA)的表达情况。结果:腹腔注射As2O3后,人鼻咽癌BALB/C裸鼠移植瘤生长被抑制,抑瘤率为75.4%。同时,瘤组织中癌细胞密度减少,细胞皱缩,胞浆红染,瘤组织分化渐成熟,出现角化细胞和角化珠;间质结缔组织增多。透射电镜下肿瘤细胞出现成熟分化及明显角质化,细胞表面微小突起增多,细胞间桥粒增多并以桥粒互相连接,细胞核浆比例减少,胞浆中出现大量张力原纤维并围绕核周。癌细胞PCNA在阴性对照组呈高表达,PI(PCNA阳性细胞指数)为(95.2±5.0)%,而As2O3组癌细胞PCNA表达明显减少,PI为(53.6±7.0)%(P<0.001)。结论:As2O3抑制人鼻咽低分化鳞癌BALB/C裸鼠移植瘤的生长,这种抑制作用可能与其诱导癌细胞向成熟方向分化有关

Arsenic trioxide induces differentiation of human nasopharyngeal carcinoma in BALB/C nude mice xenograft model

BACKGROUND & OBJECTIVE: There is evidence that arsenic trioxide (AS2O3) induce differentiation of leukemia cells; however, little is known about its effect on solid tumors. The aim of this study was to investigate whether AS2O3 can induce cell differentiation and its association with growth inhibition in human nasopharyngeal carcinoma using BALB/C nude mice xenograft model. METHODS: Poorly differentiated human nasopharyngeal squamous carcinoma cells from CSNE-1 cell strain were transplanted subcutaneously to BALB/C nude mice to produce tumors. AS2O3 at a dose of 5 mg.(kg.d)-1 was given intraperitoneally for 10 consecutive days, and then 3 times a week for the following 3 weeks. The xenograft tumor growth in mice was observed after drug administration. The morphological changes of the tumors were examined under light and electron microscopy. Proliferating cell nuclear antigen (PCNA) expression was determined by immunohistochemistry. RESULTS: AS2O3 at dose of 5 mg.(kg.d)-1 significantly inhibited the tumor growth in vivo, with a inhibitory rate of 75.4%. Remarkable cell differentiation induced by AS2O3 was observed under light microscope and transmission electron microscope, which was characterized by keratinization of tumor cells, decreased nuclear/cytoplasm ratio, increased cytoplasmic organelles and rich tonofibrils in cytoplasm. Desmosomes and micro-processes were much more frequently observed in tumors treated with AS2O3. Significantly decreased PCNA expression was observed in AS2O3-treated tumor cells. The PCNA-positive cell index (PI) was 53.6 +/- 7.0% in AS2O3-treated mice, and 95.2 +/- 5.0% in control, respectively (P < 0.001). CONCLUSION: The growth of human nasopharyngeal carcinoma xenograft in BALB/C nude mice can be significantly inhibited by AS2O3, which might be related to the cell differentiation induced by AS2O3.