Objective To establish an appropriate animal model of brain metastases from lung cancer in nude mice by thoracic orthotopic implantation in the chest or left ventricular injection , and to serve further studies on the mechanisms of lung cancer brain metastasis .Methods PC-9 cells (1 ×106/0.1 mL) in logarithmic phase were respectively injected into 18 nude mice by orthotopic implantation in the chest or left ventricular injection ( n=9 each group ) .The statuses of nude mice were observed after implantation .Animals showing clear signs of dyscrasia were killed .At autopsy, the lung, brain, liver and kidney were removed and histological sections were stained with H /E to detect the presence of tumor cells . Results In the thoracic orthotopic implantation group , three weeks after implantation , the number 4, 6, 9 mice showed tumor nodules in the chest wall , they began to lose weight in the fourth to sixth week differently , showing signs of dyscrasia gradually , and were sacrificed at the fifth to seventh week .The thoracotomy revealed that the whole thorax was occupied by many large lung cancer masses , spreading into bilateral ribs , pleura and spinal vertebra , with scarce eroded , compressed , pale and distorted lung tissues left .Histological examination with HE staining showed the presence of neoplasms in their lung tissues but only the number 6 mouse showed metastatic lesions in the brain tissue .In the left ventricular injection group, the mice almost began to lose weight in the third week simultaneously and became moribund slowly , which were all sacrificed at the fourth week .After thoracotomy , the thoraxes were clear except the number 11 and 18 mice which appeared 2-3 tiny tumor foci in the chest wall , with normal lung tissues .Histological examination with HE staining showed the pres-ence of brain metastases in all the nine mice .The rate of brain metastases from lung cancer in the left ventricular injection group was 100%, compared with 11.1% in the thoracic orthotopic implantation group .Conclusions The establishment method of mouse model by left ventricular injection shows significantly higher rate of lung cancer brain metastases than that by thoracic orthotopic implantation .

Objective To establish a mouse model of lung adenocarcinoma brain metastasis with human luc+-PC?9 cells stably expressing luciferase and to compare the evaluation values of bioluminescence imaging and18 F?FDG ( 18 F?flu?orodeoxyglucose) SPECT/CT in these models. Methods Suspension of luc+?PC?9 cells was injected into the left ventri?cle of BALB/c nude mice to establish a mouse model of brain metastasis from lung cancer. Bioluminescence imaging and18 F?FDG SPECT/CT were used to evaluate the metastasis of tumors as compared with HE?staining pathology as a golden standard. Results The success rate of brain metastases was 85% through injecting luc+?PC?9 cells into the left ventricle. The number of tumor cells was positively related to the intensity of light, with a linear correlation (R2 =0. 96). Fluores?cence was observed in the brain, spine and femur by bioluminescence imaging, and the metastases were confirmed by H&E pathological examination. 18 F?FDG SPECT/CT observed abnormal density collective foci in the spine or femur but not in the brain. Conclusions Injection of tumor cell suspension into the mouse left ventricle is a good method to establish a brain metastasis of lung cancer. Bioluminescence has a higher sensitivity and specificity in detecting brain metastasis and bone metastasis, with advantages of real?time, dynamical and non?invasive detection of tumor metastasis growth. 18 F?FDG SPECT/CT does not have superiority in detection of brain metastases but is suitable for detecting bone metastasis.

Objective To observe the ultrastructure of blood-brain barrier in the nude mouse model of brain me-tastases from lung cancer by transmission electron microscopy using lanthanum nitrate tracing.Methods PC-9 cells (1 × 106/0.1 mL) in logarithmic phase were respectively injected into six nude mice ( model group) selected from eight nude mice randomly via the left ventricle, the other two mice without any treatment as the control group.The general status of the mice was observed after implantation.In the fourth week all the mice were sacrificed and brain tissue samples were taken and prepared for transmission electron microscopic observation using lanthanum nitrate tracing.besides, the lung and brain were removed and stained with HE to detect the presence of tumor metastasis.Results Mice in the model group began to lose weight almost simultaneously in the third week and became moribund slowly, and were all sacrificed at the fourth week when showing clear signs of cachexia.At autopsy, the thoraxes were clear, with normal lungs.Histology showed evidence of brain metastasis in all the six mice.The electron microscopy showed that lathanum nitrate tracer was escaped from the capillaries and diffusely or sparsely distributed in the brain tissues of the model group mice, however lathanum nitrate tracer was still confined in the capillary lumen in the mice of control group.Conclusions The diffuse lathanum nitrate tracer in the brain parenchymal tissue indicates the impairment of blood-brain barrier in the nude mouse model of lung cancer brain metastasis and the formation of these metastases is accompanied with the destruction of blood brain barrier.

[Abstract] Objective: To investigate the influences of human lung adenocarcinoma PC-9 cells on tight junction proteins of blood brain barrier (BBB) under CXCR4/SDF-1 axis by establishing a model of BBB in vitro. Methods: The immortalized mouse brain microvascular endothelial Bends cells were used to establish a model of BBB in vitro by monolayer culture; Subsequently, transendothelial electric resistance (TEER) and fluorescein sodium permeability experiment were used to detect the function of in vitro BBB model and observe the effect of PC-9 cells on the function of BBB model, respectively. Western blotting was used to detect the effect of PC-9 cells on function of BBB model and expressions of endothelial tight junction proteins under the treatment of single or combined AMD3100 and SDF-1 (1 μg/ml AMD3100,100 ng/ml SDF-1, AMD3100+SDF-1). Transwell assay was used to detect the influence of CXCR4/SDF-1 axis on the ability of PC-9 cells transmigrating the cell layer of BBB model. Results: Monolayer culture of Bends cells can form tightly connected BBB withhighTEER,which reached (182.13±5.19) Ω.cm2 at the 96 h; in the meanwhile, fluorescein sodium permeability experiment showed that BBB had significantly lower permeability than that of control group ([40.31±2.43]% vs [150.10±3.17]%, P<0.05). The TEER of BBB decreased to (46.7±4.35) Ω·cm2 after coculture with PC-9 cells for 24 h, and at the same time the sodium fluorescein permeability of BBB significantly increased than that of pre-treatment ([136.32±4.93]% vs [50.24±6.21]%, P<0.05). PC-9 cells up-regulated the expressions of tight junction proteins of Bends cells under the treatment of AMD3100 (P<0.05). The number of PC-9 cells transmigrating the BBB inAMD3100 treatment group was significantly lower than that of CON group (43±2 vs 81±2, P<0.05). Conclusion: AMD3100 can reduce the ability of PC-9 cells destroying the tight junction of the BBB model established in vitro by Bends cells.

[Abstract] Objective: To investigate he effect of tetracycline- (Tet-on) mediated livin RNA interference on growth of lung carcinoma xenegrafts, and find a better regulatory way to interfere the development on lung cancer. Methods: livin shRNA lentiviral vectors were constructed; and the lung cancerA549 cells were subcutaneously injected into right upper back of nude mice to establish xenegraft model. The livin shRNAlentiviral vectors were injected into xenografts to interfere the expression of livin, then tetracycline was injected intraperitoneally for the induction. The suppressive effect of Tet-on mediated livin RNA interference efficiency was investigated and lung cancer xenograft development was observed. Results: After the induction with Tet-on, livin gene expression was significantly inhibited by livin shRNAcompared with the control group and Tet-on-NC group; the xenograft volume in Tet-on- livin shRNAgroup was significantly smaller than that in control group and Tet-on-NC group ([5.31±0.86]g vs [8.22±0.63]g and [7.17±0.54] g, P<0.05). Moreover, little body toxicity was observed and no nude mice died in this study. Conclusion: The Tet-on mediated livin shRNA could suppress the growth of lung cancer development with good targeting and controllable characteristics, which might provide a potent tool for treating lung cancer with livin protein as target.

[摘 要] 目的：探讨表皮生长因子受体（epidermal growth factor receptor，EGFR）基因突变与非小细胞肺癌（non-small cell lung cancer，NSCLC）伴脑转移患者预后的相关性，为改善NSCLC合并脑转移患者预后、指导个体化治疗提供临床依据。方法：回顾性分析福建省立医院2013年1月1日至2018年9月30日期间收治的88例NSCLC合并脑转移患者的临床资料，随访取得患者的死亡时间，随访截止日期为2019年10月31日。收集和分析的临床资料包括性别、年龄、吸烟史、病理类型、基因检测、治疗情况、无进展生存期（progression free survival，PFS）、总生存期（overall survival，OS）等。运用生存分析（Kaplan-Meier生存时间曲线）评价EGFR突变型患者的预后，以单因素分析（log-rank检验）预测影响EGFR-TKI治疗效果的因素。结果：88例NSCLC脑转移患者有57例为EGFR突变型，其中位PFS（MPFS）为13.0个月（95%CI：11.951~14.049），明显高于EGFR野生型患者（P=0.003），患者中位生存期（median survival time，MST）为29.0个月（95%CI：20.531~37.468），明显高于EGFR野生型（P=0.001）。EGFR突变型中，Exon19-del突变组患者较Exon21 L858R突变组患者OS有延长趋势（P=0.05），Exon19-del+Exon20T790M突变组患者OS较Exon21 L858R突变组有延长趋势（P=0.077）。结论：EGFR突变组较野生型组NSCLC脑转移患者预后相对好些，且携带19外显子单一缺失突变的患者预后最好。