4T1乳腺癌细胞株接种联合慢性束缚应激诱导乳腺癌合并抑郁小鼠模型构建探索

Exploration of mouse model of breast cancer complicated with depression induced using 4T1 breast cancer cell inoculation combined with chronic restraint stress

目的研究4T1乳腺癌细胞株接种联合慢性束缚应激方法构建乳腺癌合并抑郁症小鼠模型核心行为症状、生物学指标、病理学等改变。方法BABL/c小鼠随机分为正常(Control)组、束缚(Stress)组、移植瘤(Tumor)组和束缚移植瘤(Stress+Tumor,S+T)组,将4T1细胞株接种于Tumor和S+T组小鼠腋下,待成瘤后,给予Stress和S+T组小鼠束缚应激21 d。造模期间监测各组小鼠体重、摄食量。实验结束后,采用糖水偏好、旷场、高架十字迷宫、强迫游泳等试验评价各组小鼠抑郁样行为。小鼠处死后,测量小鼠瘤体重量和体积;采用ELISA方法检测各组小鼠血清肿瘤标志物糖类抗原(CA199)、癌胚抗原(CEA)、血管内皮生长因子(VEGF)以及相关神经递质5-羟色胺(5-HT)、去甲肾上腺素(NE)、皮质酮(CORT)的含量;运用HE染色法观察小鼠肿瘤和海马组织病理学改变。结果S+T组小鼠体重、摄食量显著降低,瘤体重量和体积明显增大,血清肿瘤标志物(CA199、CEA、VEGF)水平显著升高,快感和对新环境的探索欲望减弱,紧张和绝望行为显著增强,血清神经递质5-HT和NE水平显著降低,CORT水平显著升高;另外肿瘤组织细胞排列松散,间质减少,病理性核分裂象增多,海马CA3区神经元细胞排列和形态紊乱,核内空泡化样改变明显。结论4T1乳腺癌细胞株接种联合慢性束缚应激诱导的乳腺癌合并抑郁小鼠模型出现了乳腺癌和抑郁症双重典型症状和生物学指标改变,可为乳腺癌合并抑郁实验研究提供较好的模型参考。

Objective To study the core behavioral symptoms,biological indicators,and pathological changes of a mouse model of breast cancer complicated with depression induced using 4T1 breast cancer cell inoculation combined with chronic restraint stress(CRS).Methods BABL/c mice were randomly divided into Control,Stress,Tumor,and stress combined with tumor(S+T)groups.Mice in the tumor and S+T groups were inoculated under the front legs with breast cancer 4T1 cells.After tumor formation,mice in the stress and S+T groups were subjected to CRS for 21 days.The body weight and food intake of each group were monitored during modeling.After the experiment,the occurrence of depression-like behavior of mice in each group was evaluated by sucrose preference test,open field test,elevated plus-maze test,and forced swimming test.After the mice were decapitated,the weights and volumes of the tumors were measured.Concentrations of serum tumor markers,including carbohydrate antigen(CA199),carcinoembryonic antigen(CEA),and vascular endothelial growth factor(VEGF),and related neurotransmitters,including 5-hydroxytryptamine(5-HT),norepinephrine(NE),and corticosterone(CORT),were determined using ELISA.HE staining was used to observe histopathological changes to the hippocampus and tumor.Results In S+T group mice,body weight and food intake were significantly decreased,tumor weight and volume were significantly increased,serum tumor marker(CA199,CEA,VEGF)levels were significantly increased,enthusiasm and desire to explore a new environment were reduced,stress and despair behaviors were significantly increased,and levels of the serum neurotransmitters 5-HT and NE and levels of CORT were significantly increased.In addition,the cell arrangement in the tumor tissue was loose,the amount of intercellular substance decreased,the pathological nuclear classification phase was increased,the arrangement and morphology of neurons in the CA3 region of the hippocampus were disordered,and there were obvious nuclear vacuolation-like changes.Conclusions A mouse model of breast cancer complicated with depression induced by 4T1 breast cancer cell inoculation combined with CRS showed the typical dual symptoms and biological indicators of breast cancer and depression and can be used as a good reference model for experimental studies of breast cancer complicated with depression.