亚硝基吡啶对人乳头状瘤病毒诱导的食管上皮永生化细胞的促癌作用

The promotive effects of N-nitrosopiperidine on the malignant transformation of the immortalized esophageal epithelium induced by human papillomavirus

目的 观察亚硝基吡啶在细胞恶性转化过程中的促癌作用.方法 用HPV18E6E7诱导食管上皮细胞永生化细胞系SHEE,第17代细胞培养在50 ml培养瓶.加入亚硝基吡啶（Nnitrosopiperidine,NPIP）0,2,4,8 mmol/L作用3周.用相差显微镜检查细胞形态,流式细胞仪检测细胞增殖和凋亡;染色体常规制样,检查染色体众数;细胞软琼脂集落形成及接种裸小鼠检查成瘤性;用Western blot检测HPV18表达.结果 当细胞暴露在8 mmol/L NPIP时细胞死亡增加,只剩少量活细胞.换正常培基代替NPIP,经4周后细胞进入增殖状态,细胞出现增生和异型增生.第8周末细胞软琼脂培养有大集落形成,接种裸小鼠成瘤.2,4 mmol/L组细胞倍增时间延长,细胞未能成瘤.8 mmol/L NPIP组染色体众数61～65,对照组56～61.实验组和对照组HPV阳性.结论 NPIP促进人乳头状瘤病毒诱导人胚食管永生化上皮恶性转化,HPV18E6E7和NPIP能协同作用加速食管上皮恶性转化.

Objective Study on the promotive effects of N-nitrosopiperidine on carcinogenesis process was performed, based on the immortalization of human fetal esophageal epithelium induced by human papillomavirus （HPV） 18E6E7 genes. Methods The immortalized esophageal epithelium SHEE was induced by HPV18E6E7. The ceils at 17th passages were cultured in 50 ml flasks. The N-nitrosopiperidine （NPIP） 0, 2, 4, 8 mmol/L added to the cultured medium of SHEE cells for 3 weeks. The morphology, proliferation and apaptosis of the ceils were studied by phase contrast microscopy and flow cytometry. Modal number of chromosomes was analyzed by standard method. Tumorigenicity of the ceils was assessed by soft agar colony formation and by transplantation of ceils into nude mice. Expression of HPV was detected by Western blot. Results When ceils were exposed to high concentration （8 mmol/L） of NPIP, cell death was increased, leaving a few live ceils. In normal cultural medium instead of NPIP proliferative status of the ceils restored after 4 weeks and the ceils progressed to the proliferation stage with continuous replication and atypical hyperplasia. At the end of the 8th week, the cells appeared with large colonies in sofi-agar and tumor formation in transplanted nude mice. When the cells were cultured in 2, 4 mmol/L NPIP the doubling passage was delayed and without tumor formation in nude mice. Modal number of chromosomes was 61-65, in 8 mmol/L NPIP group and control group, 56-61. Expression of HPV18 appeared in experimental and control groups. Conclusion NPIP promotes malignant change of the immortalized esophageal epithelial cells induced by HPV18E6E7 . HPV18E6E7 synergy with NPIP will accelerate malignant transformation in esophageal epithelium.