人工诱导树鼩乳腺肿瘤的病理分析

Pathological analysis of the induced breast tumor models in tree shrew

目的建立树鼩乳腺肿瘤模型。方法用DMBA联合人工合成孕激素MPA的方法,挑选45只雌性树鼩,随机分为3组。(1)DMBA组:连续3次进行DMBA(20 mg/次)灌胃处理,每周1次;(2)DMBA+MPA组:每3周1次,连续3次DMBA灌胃处理之后,于树鼩背部左侧皮下第1次植入MPA缓释片剂(150 mg/片,90 d缓释),间隔3个月,第2次植入MPA片;(3)正常对照组:使用花生油进行灌胃处理,每3周1次,连续3次。实验处理后,每周定期观察肿瘤发生情况,共观察45周。采用HE染色对诱发肿瘤的病理类型进行鉴定。结果 DMBA能单独诱导树鼩特异的产生乳腺肿瘤,诱发率为12%;联合MPA皮下植入可以把DMBA诱导的乳腺肿瘤发病率提高到50%;而对照组没有观察到乳腺肿瘤的发生。诱导的肿瘤主要为导管内乳头状瘤,恶性程度低,仅有一例为恶性程度高的浸润性导管癌。结论所诱导的树鼩导管内乳头状瘤和浸润性导管癌均为人类共有的肿瘤病理类型。诱发肿瘤形态与自发肿瘤相似。

Objective To establish a tree shrew mode of breast tumor. Method Forty-five 3 to 4 month-old female tree shrews were orally gavaged with 20 mg 7,12-dimethylbenz（ a） anthracene（ DMBA） or peanut oil per animal for three times. Following that,fifteen DMBA administrated tree shrews were implanted 90 day-release medroxyprogesterone acetate（ MPA） pellets. The tree shrews were palpated once weekly to detect mammary tumors for 45 weeks after first DMBA administration. Results DMBA were able to induce breast tumors（ 12. 5%） in tree shrews,and MPA increased the tumor incidence（ 50%） while no breast tumors were observed in the control group. Three induced breast tumors were intraductal papillary carcinomas and one was IDC by HE stain. Conclusion All induced tumors are similar with spontaneous tumors in structure and molecular markers.