Tumor-targeting Salmonella typhimurium A1-R prevents experimental human breast cancer bone metastasis in nude mice

Bone metastasis is a lethal and morbid late stage of breast cancer that is currently treatment resistant. More effective mouse models and treatment are necessary. High bone-metastatic variants of human breast cancer cells were selected in nude mice by cardiac injection. After cardiac injection of a high bone-metastatic variant of breast cancer, all untreated mice had bone metastases compared to only 20% with parental cells. Treatment with tumor-targeting Salmonella typhimurium A1-R completely prevented the appearance of bone metastasis of the high metastatic variant in nude mice (P < 0.001). After injection of the highly bone-metastatic breast cancer variant to the tibia of nude mice, S. typhimurium A1-R treatment significantly reduced tumor growth in the bone (P < 0.001). These data indicated that S. typhimurium A1-R is useful to prevent and inhibit breast cancer bone metastasis and should be of future clinical use for breast cancer in the adjuvant setting.     

Intraperitoneal administration of tumor-targeting Salmonella typhimurium A1-R inhibits disseminated human ovarian cancer and extends survival in nude mice

Peritoneal disseminated cancer is highly treatment resistant. We here report the efficacy of intraperitoneal (i.p.) administration of tumor-targeting Salmonella typhimurium A1-R in a nude mouse model of disseminated human ovarian cancer. The mouse model was established by intraperitoneal injection of the human ovarian cancer cell line SKOV3-GFP. Seven days after implantation, mice were treated with S. typhimurium A1-R via intravenous (i.v.) or i.p. administration at the same dose, 5×10⁷ CFU, once per week. Both i.v. and i.p. treatments effected prolonged survival compared with the untreated control group (P=0.025 and P<0.001, respectively). However, i.p. treatment was less toxic than i.v. treatment. Tumor-specific targeting of S. typhimurium A1-R was confirmed with bacterial culture from tumors and various organs and tumor or organ colony formation after i.v. or i.p. injection. Selective tumor targeting was most effective with i.p. administration. The results of the present study show S. typhimurium A1-R has promising clinical potential for disseminated ovarian cancer, especially via i.p. administration.     

Tumor-targeting Salmonella typhimurium A1-R arrests growth of breast-cancer brain metastasis

Brain metastasis is a morbid, treatment-resistant, end-stage frequent occurrence in breast cancer patients. The aim of this study was to evaluate the efficacy of tumor-targeting Salmonella typhimurium A1-R on breast cancer brain metastases. High brain-metastatic variants of murine 4T1 breast cancer cells expressing red fluorescent protein (RFP) were injected orthotopically in the mammary fat pad in non-transgenic nude mice or in the left ventricle of non-transgenic nude mice and transgenic nude mice expressing nestin-driven green fluorescent protein (ND-GFP). ND-GFP mice express GFP in nascent blood vessels. In the orthotopically-injected mice, the primary tumor was surgically-resected in order to allow brain metastasis to develop. At various time points, the tumors and vasculature in the brain were imaged by confocal and stereo fluorescence microscopy. Some of the breast cancer cells that reached the brain extravasated and grew perivascularly and some of the cells proliferated within the vasculature. S. typhimurium A1-R significantly inhibited brain metastasis in both metastatic models and increased survival of the orthotopically-transplanted, primary-tumor-resected mice (p<0.05). The results of the present study suggest the clinical potential of bacterial therapy of breast cancer brain metastasis.     

Tumor-specifically hypoxia-induced therapy of SPRY1/2 displayed differential therapeutic efficacy for melanoma

Activation of receptor tyrosine kinase (RTK) signalling pathways is frequently correlated to cancer cell proliferation, angiogenesis and cell survival. Sprouty (SPRY) proteins function as a physiological endogenous inhibitor of RTK signalling pathways, have been shown to be deregulated in most cancer cells. Here, we demonstrated that over-expression of SPRY1 and SPRY2 inhibited B16F10 cell proliferation through G1 phase arrest in vitro, and SPRY2 showed more potent inhibitory effects than SPRY1. In order to tumor-specific delivery of SPRY1/2 in vivo, two strains of attenuated Salmonella typhimurium VNP20009 (VNP-PQE-SPRY1 and VNP-PQE-SPRY2) were constructed to specifically express SPRY1 or SPRY2 under the control of a hypoxia-induced nirB promoter. The efficiency and specificity of the recombinant strains were validated in both bacteria and animal tumor models. SPRY1 and SPRY2 gene could be specifically driven by the nirB promoter under hypoxia, but not normoxia conditions. In addition, the tumor-targeting ability of VNP-PQE-SPRY1 or VNP-PQE-SPRY2 was similar with VNP. VNP-PQE-SPRY2 significantly suppressed melanoma growth in vivo, suggesting that SPRY2 is a more efficient agent for melanoma therapy. Moreover, the antitumor effect of VNP-SPRY2 is mainly mediated through the inhibition of ERK1/2 phosphorylation, which leads to the inhibition of proliferation in melanoma. Taken together, our results indicated that SPRY2 displayed more potent melanoma suppression than SPRY1 both in vitro and in vivo, and the hypoxia-induced tumor-specific gene therapy of SPRY2 delivered by VNP20009 is a promising strategy for melanoma therapy.     

Therapeutic efficacy of tumor-targeting Salmonella typhimurium A1-R on human colorectal cancer liver metastasis in orthotopic nude-mouse models

Liver metastasis is the most frequent cause of death from colon and other cancers. Generally, liver metastasis is recalcitrant to treatment. The aim of this study is to determine the efficacy of tumor-targeting Salmonella typhimurium A1-R on liver metastasis in orthotopic mouse models. HT-29 human colon cancer cells expressing red fluorescent protein (RFP) were used in the present study. S. typhimurium A1-R infected HT-29 cells in a time-dependent manner, inhibiting cancer-cell proliferation in vitro. S. typhimurium A1-R promoted tumor necrosis and inhibited tumor growth in a subcutaneous tumor mouse model of HT-29-RFP. In orthotopic mouse models, S. typhimurium A1-R targeted liver metastases and significantly reduced their growth. The results of this study demonstrate the future clinical potential of S. typhimurium A1-R targeting of liver metastasis.     

Tumor-targeting Salmonella typhimurium A1-R inhibits human prostate cancer experimental bone metastasis in mouse models

Bone metastasis is a frequent occurrence in prostate cancer patients and often is lethal. Zoledronic acid (ZOL) is often used for bone metastasis with limited efficacy. More effective models and treatment methods are required to improve the outcome of prostate cancer patients. In the present study, the effects of tumor-targeting Salmonella typhimurium A1-R were analyzed in vitro and in vivo on prostate cancer cells and experimental bone metastasis. Both ZOL and S. typhimurium A1-R inhibited the growth of PC-3 cells expressing red fluorescent protien in vitro. To investigate the efficacy of S. typhimurium A1-R on prostate cancer experimental bone metastasis, we established models of both early and advanced stage bone metastasis. The mice were treated with ZOL, S. typhimurium A1-R, and combination therapy of both ZOL and S. typhimurium A1-R. ZOL and S. typhimurium A1-R inhibited the growth of solitary bone metastases. S. typhimurium A1-R treatment significantly decreased bone metastasis and delayed the appearance of PC-3 bone metastases of multiple mouse models. Additionally, S. typhimurium A1-R treatment significantly improved the overall survival of the mice with multiple bone metastases. The results of the present study indicate that S. typhimurium A1-R is useful to prevent and inhibit prostate cancer bone metastasis and has potential for future clinical use in the adjuvant setting.     

Adjuvant treatment with tumor-targeting Salmonella typhimurium A1-R reduces recurrence and increases survival after liver metastasis resection in an orthotopic nude mouse model

Colon cancer liver metastasis is often the lethal aspect of this disease. Well-isolated metastases are candidates for surgical resection, but recurrence is common. Better adjuvant treatment is therefore needed to reduce or prevent recurrence. In the present study, HT-29 human colon cancer cells expressing red fluorescent protein (RFP) were used to establish liver metastases in nude mice. Mice with a single liver metastasis were randomized into bright-light surgery (BLS) or the combination of BLS and adjuvant treatment with tumor-targeting S. typhimurium A1-R. Residual tumor fluorescence after BLS was clearly visualized at high magnification by fluorescence imaging. Adjuvant treatment with S. typhimurium A1-R was highly effective to increase survival and disease-free survival after BLS of liver metastasis. The results suggest the future clinical potential of adjuvant S. typhimurium A1-R treatment after liver metastasis resection.     

Inhibition of spontaneous and experimental lung metastasis of soft-tissue sarcoma by tumor-targeting Salmonella typhimurium A1-R

Prognosis of patients with lung metastases of soft-tissue sarcoma is still poor. Therefore, novel systemic therapy is needed to improve the survival of soft-tissue sarcoma. In the present study, tumor-targeting therapy with a genetically-modified auxotrophic strain of Salmonella typhimurium, termed A1-R, was evaluated. Mouse models of primary soft tissue sarcoma and spontaneous lung metastasis were obtained by orthotopic intra-muscular injection of HT1080-RFP human fibrosarcoma cells. S. typhimurium A1-R was administered from day 14, once a week for two weeks. On day 28, lung samples were excised and observed with a fluorescence imaging system. The number of lung metastasis was 8.8 ± 3.4 in the untreated group and 0.8 ± 0.8 in the treated group (P = 0.024). A mouse model of experimental lung metastasis was obtained by tail vein injection of HT1080-RFP cells. The mice were treated with S. typhimurium A1-R (i.v.) on day 7, once a week for three weeks. S. typhimurium A1-R significantly reduced lung metastases and improved overall survival (P = 0.004). S. typhimurium A1-R bacterial therapy has future potential for treating advanced soft tissue sarcoma and improving prognosis of patients with lung metastasis.     

Determination of the optimal route of administration of Salmonella typhimurium A1-R to target breast cancer in nude mice

We have developed the genetically-modified Salmonella typhimurium A1-R strain that selectively targets tumors. S. typhimurium A1-R is auxotrophic for Leu and Arg, which precludes it from growing continuously in normal tissues but allows high tumor virulence. We report here the efficacy and safety of three different routes of S. typhimurium A1-R administration: oral (p.o.), intravenous (i.v.), and intra-tumoral (i.t.) in nude mice with orthotopic human breast cancer. Nude mice with MDA-MB-435 human breast cancer, expressing red fluorescent protein (RFP), were administered S. typhimurium A1-R by one of the three routes: [p.o.: 2×10(8) colony forming units (CFU)/200 μl; i.v.: 2.5×10(7) CFU/100 μl; i.t.: 2.5×10(7) CFU/50 μl] twice a week. Tumor growth was monitored by fluorescence imaging and caliper measurement in two dimensions. S. typhimurium A1-R targeted tumors at much higher levels than normal organs after all three routes of administration. The fewest bacteria were detected in normal organs after p.o. administration, which suggests that p.o. administration has the highest safety. The i.v. route had the greatest antitumor efficacy. There were no obvious toxic effects on the host with any of the routes of administration. The results of this study suggest that p.o. administration was the most safe to the host and the i.v. route was most effective for tumor targeting with S. typhimurium A1-R.     

口服VEGFR2 DNA疫苗抗小鼠Lewis肺癌血管生成的实验研究

背景与目的血管内皮生长因子(VEGF)及其主要受体血管内皮生长因子受体-2(VEGFR2)在肿瘤新生血管和肿瘤基质形成过程中起着重要作用。本研究的目的是观察口服VEGFR2 DNA疫苗抗C57BL/6小鼠Lewis肺癌皮下移植瘤生长的作用,并探讨其可能的作用机制。方法将重组DNA疫苗对小鼠进行免疫,通过观察小鼠Lewis肺癌皮下移植瘤大小,记录各组小鼠离体肿瘤湿重,检测移植瘤微血管密度(MVD)及血液CD3 、CD8 T细胞水平,评价重组疫苗的抑瘤作用。结果疫苗组、空质粒组、生理盐水组的MVD分别为1.75±1.07、6.89±2.52、7.57±3.75,肿瘤湿重分别为(2.05±1.32)、(4.83±1.47)、(5.12±1.02)g,疫苗组与其它两组比较,差异均有统计学意义(P<0.05)。接种肿瘤后,疫苗组CD3 T细胞仍维持较高水平,其它两组明显下降(P<0.05);疫苗组CD8 T细胞水平较其它两组明显升高(P<0.05)。结论口服VEGFR2DNA疫苗对小鼠Lewis肺癌皮下移植瘤的生长具有较强的抑制作用。该疫苗可能是通过杀伤肿瘤内皮细胞、抑制血管生成而起到抗肿瘤生长的作用。     

Synergistic effects of arsenic trioxide combined with Salmonella typhimurium in treating the advanced hepatocellular carcinoma in rat models

BackgroundTo evaluate the safety and efficacy of arsenic trioxide (ATO) combined with {"type":"entrez-protein","attrs":{"text":"VNP20009","term_id":"1666609276","term_text":"VNP20009"}}VNP20009 in treating the advanced hepatocellular carcinoma (HCC).MethodsThe proliferation assay, migration assay and real-time PCR analyses were performed to assess the impact of ATO combined with {"type":"entrez-protein","attrs":{"text":"VNP20009","term_id":"1666609276","term_text":"VNP20009"}}VNP20009 on the McA-RH7777 cells. Forty Buffalo rats were orthotopically implanted with HCC in the livers and randomly divided into four groups: (A) ATO plus {"type":"entrez-protein","attrs":{"text":"VNP20009","term_id":"1666609276","term_text":"VNP20009"}}VNP20009; (B) ATO; (C) {"type":"entrez-protein","attrs":{"text":"VNP20009","term_id":"1666609276","term_text":"VNP20009"}}VNP20009; and (D) control. ATO (2 mg/kg) was administered by peritoneal injection once a day and continued for five days. {"type":"entrez-protein","attrs":{"text":"VNP20009","term_id":"1666609276","term_text":"VNP20009"}}VNP20009 (about 1×10⁷ CFU) was directly injected into the tail vein. MRI examinations were performed to access the tumor responses one and 2 weeks later, respectively. Micro CT scans of chest were performed to assess the lung metastases. Hematoxylin-eosin (HE) staining and immunohistochemical analyses were performed to analyze the tumor tissues.ResultsIn the in vitro experiments, {"type":"entrez-protein","attrs":{"text":"VNP20009","term_id":"1666609276","term_text":"VNP20009"}}VNP20009 suppressed the proliferation of McA-RH7777 cells, attenuated their migration ability, and weakened the potential of metastases. MRI examinations showed that the mean residual tumor volumes of ATO plus {"type":"entrez-protein","attrs":{"text":"VNP20009","term_id":"1666609276","term_text":"VNP20009"}}VNP20009 group on the 7th day and 14th day after the administration of ATO combined with {"type":"entrez-protein","attrs":{"text":"VNP20009","term_id":"1666609276","term_text":"VNP20009"}}VNP20009 were significantly smaller than those of other groups. Micro CT scans revealed that the lung metastases rates of ATO plus {"type":"entrez-protein","attrs":{"text":"VNP20009","term_id":"1666609276","term_text":"VNP20009"}}VNP20009 group and {"type":"entrez-protein","attrs":{"text":"VNP20009","term_id":"1666609276","term_text":"VNP20009"}}VNP20009 group were significantly lower than those of other groups. Immunohistochemical analyses displayed that the levels of VEGF and Vimentin in the tumors of ATO plus {"type":"entrez-protein","attrs":{"text":"VNP20009","term_id":"1666609276","term_text":"VNP20009"}}VNP20009 group were obviously lower than those of other groups. The median survival of rats in the ATO plus {"type":"entrez-protein","attrs":{"text":"VNP20009","term_id":"1666609276","term_text":"VNP20009"}}VNP20009 group was longer than those of other groups.ConclusionsThe strategy of ATO combined with {"type":"entrez-protein","attrs":{"text":"VNP20009","term_id":"1666609276","term_text":"VNP20009"}}VNP20009 was safe and had a potential to inhibit tumor growth, decrease the lung metastases, and prolong the overall survival in treating the advanced HCC. The two complementary interventions may have synergistic effects.     

低剂量辐射对Lewis肺癌小鼠肿瘤微环境的影响

目的 探讨低剂量辐射(LDR)对Lewis肺癌小鼠肿瘤微环境(TME)的影响,以及高剂量辐射(HDR)前LDR预处理在TME中发挥的效应机制.方法 接种Lewis肺癌细胞(1×106)于雄性C57BL/6小鼠左侧腋下,待小鼠肿瘤直径1 cm左右(12 d),随机分为假手术Sham(1)组、LDR(2)组、HDR(3)组...     

裸鼠肺癌移植瘤中NRP-1的表达及其意义

Objective:To establish angiogenesis model of xenografts of lung cancer cell in nude mouse and investigate the expression of the neuropilin-1 (NRP-1) protein in tumors and its role in progression and angiogenesis of lung cancer.Methods:Human lung adenocarcinoma cells A549 were analyzed for the expression of vascular endothelial growth factor165(VEGF165)mRNA using RT-PCR in vitro.TWo groups of nude mice were subcutaneously inoculated with A549 at different tumor-loading time.Two groups of xenografts were jdentified by hematoxylin and eosin (HE) staining.their microvessel density (MVD) were analyzed meanwhile.Two groups were analyzed for the expression of NRP-1 protein and their mean absorbency by using immunohistochemistry and automatic image analysis system respectively.Results:A549 expressed VEGF165 mRNA,and xenografts of A549 in nude mice were successfully established and confirmed by HE staining.The atypia of cancer cells and angiogenesis were occurred in two groups.Two groups of MVD were 13.06±1158.23.61±3.11(vessels/mm2)(P＜0.01).NRP-1 protein was expressed in cytoplasm of vascular endothelium cells and partial tumor cells.Two groups of mean absorbency of NRP-1 were 0.1095±O.0228,0.1784±0.0151 (P＜0.01).Conclusion:The angioqenesis models of xenografts in nude mice with lung cancer cell A549 expressing VEGF165 mRNA at different tumor-loading times were established successfully.The expression of NRP-1 protein and MVD were increased with the tumor progression.Our results demonstrate that NRP-1 protein in lung cancer is related to angiogenesis.     

自噬基因Beclin1对肺癌A549细胞裸鼠移植瘤生长的影响

目的:探讨自噬基因Beclin1在裸鼠体内对人肺腺癌A549细胞成瘤性的影响。方法:将重组质粒pRNAT-U6.2/Lenti-si423和pLenex-Beclin1通过脂质体介导的方法分别转染到A549细胞中。采用实时荧光定量PCR(real-time fluorogenic quantitative-PCR,RFQ-PCR)和蛋白质印迹法分别检测转染细胞中Beclin1mRNA和蛋白的表达;MTT法检测转染细胞在体外的增殖能力。将过表达或沉默Beclin1基因的A549细胞株分别接种于裸鼠右侧腋部皮下,观察瘤体的生长速度和大小,并采用RFQ-PCR和免疫组织化学法检测瘤体组织中Beclin1mRNA和蛋白的表达。结果:转染重组质粒pLenex-Beclin1的A549细胞中Beclin1mRNA和蛋白表达量显著增加,而体外增殖能力被明显降低;转染重组质粒pRNAT-U6.2/Lenti-si423的A549细胞中Beclin1mRNA和蛋白表达量显著减少。过表达Beclin1组的裸鼠皮下移植瘤生长缓慢,肿瘤体积明显缩小、质量明显减轻,移植瘤组织中Beclin1mRNA以及蛋白的相对表达量增加;而Beclin1基因沉默组的移植瘤组织中Beclin1mRNA及其蛋白的相对表达量降低。结论:自噬基因Beclin1的过表达可以抑制A549细胞在裸鼠体内的生长,有望成为肿瘤治疗的一个新靶点。     

环孢菌素A联合顺铂对Lewis肺癌裸鼠移植瘤的协同抑制作用

目的：探讨亲环蛋白A（cyclophiline A, CyPA）抑制剂环孢菌素A（cyclosporine A, CsA）联合顺铂（Cisplatin,DDP）化疗提高肺癌细胞对DDP的敏感性。方法： C57BL/6裸鼠随机分为4组：空白对照组、DDP组、CsA组和联合组（DDP+CsA）,每组各10只。裸鼠左侧腋部皮下注射100 μl细胞密度为5×106/ml的小鼠Lewis肺癌细胞株（3LL）细胞悬液,接种2 d后开始腹腔给药,DDP给药剂量为2 mg/kg,每3 d 1次,共3次;CsA给药剂量5 mg/kg,隔天1次,共3次;此后实验组每周1次,维持血药浓度。空白对照组不给药。接种后每3天观察一次肿瘤生长情况,绘制肿瘤生长曲线。接种35 d后处死裸鼠取出瘤块,H-E染色观察组织形态学变化,免疫组化法观察移植瘤中Ki-67蛋白的表达情况。结果：联合组裸鼠的移植瘤体积（P<0.01）、移植瘤质量（P<0.05）、肿瘤细胞密度（P<0.05）、核分裂象（P<0.05）均较其余3组显著降低;DDP组和CsA组裸鼠移植瘤体积、瘤质量、肿瘤细胞密度和核分裂象均较空白对照组低（均P<0.05）。免疫组化观察联合组移植瘤组织的Ki-67表达水平明显降低。结论：免疫抑制剂CsA与DDP联合用药可提高肺癌细胞对DDP的敏感性,协同抑制肺癌细胞移植瘤的生长。     

裸鼠肺癌移植瘤中NRP-1的表达及其意义

目的:探讨非小细胞肺癌(non-smallcelllungcancer,NSCLC)中神经纤毛蛋白-1(neuropilin-1,NRP-1)的表达与肿瘤发展及血管新生的关系。方法:用RT-PCR方法体外检测人肺腺癌细胞株A549中血管内皮生长因子(vascularendo-thelialgrowthfactor-165,VEGF165)mRNA的表达。此细胞株皮下接种裸鼠,建立两组荷瘤时间不同的肺癌移植瘤模型,两组移植瘤块均经常规HE染色鉴定。用免疫组化S-P法检测两组移植瘤块中NRP-1的表达,并用全自动图像分析系统分析其平均吸光度,同时对两组移植瘤内微血管密度(microvesseldensity,MVD)值进行测定。结果:A549细胞株表达VEGF165mRNA,经常规HE染色鉴定裸鼠肺癌皮下移植瘤模型建立成功。NRP-1在瘤内血管内皮细胞及部分A549细胞的胞浆中有表达。两组移植瘤中NRP-1的平均吸光度分别为0·11±0·02,0·18±0·02(P<0·05),MVD值分别为13±1·58,24±2·92(vessels/mm2)(P<0·05),且NRP-l的平均吸光度与MVD值呈线性正相关(Pearson相关系数r=0·92,P=0·0002)。结论:两组荷瘤时间不同的裸鼠肺癌皮下移植瘤中NRP-1的表达及MVD值随时间进展增加,肿瘤中NRP-1的表达与血管新生有关。     

白细胞介素-18通过诱导肿瘤细胞凋亡抑制人肺腺癌细胞皮下移植瘤的生长

目的：探讨白细胞介素-18（IL-18）对人肺癌裸鼠皮下移植瘤生长的影响及抗肿瘤机制。方法：采用荷人肺腺癌A549细胞的裸鼠皮下移植瘤模型,不同剂量（5μg/100μl、50μg/100μl）的IL-18进行腹腔内注射,对照组为磷酸盐缓冲液（PBS溶液）,观察瘤细胞生长能力和裸鼠生存期,应用光学显微镜观察肿瘤组织形态学变化,TUNEL法观察肿瘤细胞凋亡情况。结果：与对照组比较,IL-18高剂量组和IL-18常规剂量组明显抑制了皮下移植瘤生长（P〈0.05）。IL-18常规剂量组生存期（63±8天）明显延长（P〈0.05）,IL-18高剂量组（44±5天）与空白对照组（42±6天）生存期无明显差异（P〉0.05）。IL-18常规剂量治疗组和IL-18高剂量治疗组肿瘤组织内见大量淋巴细胞及炎细胞浸润,可见肿瘤细胞点、片状坏死;IL-18高剂量组和IL-18常规剂量组的凋亡细胞数均明显高于空白对照组（P〈0.01）。结论：IL-18在裸鼠体内具有明显的抗肿瘤作用,其机制可能是刺激淋巴细胞、NK细胞和吞噬细胞等炎细胞分泌各种细胞因子,诱导肿瘤细胞凋亡,发挥抗肿瘤作用。     

X射线对人肺癌A549细胞Bmi-1表达的影响

目的：研究X射线照射对人肺癌A549细胞株中Bmi-1 mRNA和蛋白表达的影响。方法：用不同剂量（0、2、4、6Gy）的X射线照射体外培养的人肺癌A549细胞株,分别采用实时荧光定量PCR和Western blot技术检测照射0、6、12、24、48和72 h后Bmi-1 mRNA和蛋白的表达水平。结果：与对照组比较,2、4、6 Gy X射线照射A549细胞后48 h内Bmi-1 mRNA表达升高,差异均有统计学意义（P〈0.05）;（2 Gy 48 h组除外）,2 Gy组照射后6 h、4 Gy组12 h、6 Gy组24 h升高最显著（P〈0.05）。照射后48 h内蛋白表达升高（4Gy除外）,48 h后蛋白表达逐渐下降,至72 h时接近未照射组水平。各时间点（除4 Gy 48 h和72 h外）的蛋白表达与对照组相比差异均有统计学意义（P〈0.05）。结论：在本实验条件下,2～6 Gy剂量X射线照射48 h内可使人肺癌A549细胞Bmi-1表达升高,之后表达逐渐降低。     

UGTIA1基因多态性与IP方案治疗小细胞肺癌毒性和疗效相关性分析

目的：探讨尿苷二磷酸葡萄糖转移酶1A1（UGTIA1）基因多态性与伊立替康联合顺铂（IP方案）治疗广泛期小细胞肺癌的不良反应和疗效相关性。方法：选取中国医学科学院肿瘤医院2009-01-01-2012-12-31初治广泛期小细胞肺癌患者48例,采用伊立替康联合顺铂化疗方案,分析其临床治疗效果和不良反应及其与UGT1A1基因多态性的相关性。结果：48例小细胞肺癌患者IP方案化疗后CR3例,PR32例,SD4侧,PD9例,总有效率为73．0％,疾病控制率为81．3％。主要毒副作用为中性粒细胞减少34例,贫血29例,血小板减少14例,恶心呕吐38例,迟发性腹泻26例,便秘15例,脱发5例,乏力38例,转氨酶升高14例,心电图异常9例。UGT1A1＊28基因多态性的分布为TA6／6野生型基因34例,TA6／7杂合突变型基因11例,TA7／7纯合突变型基因3例;UGT1A1＊6基因多态性的分布为G／C野生型基因33例,A／G杂合突变型基因13例,A／A纯合突变型基因2例。UGT1A1基因多态性与临床疗效无明显相关性,P〉0．05。提示UGT1A1突变型基因可增加患者发生迟发性腹泻的风险,而对中性粒细胞减少无影响。Logistic多因素回归分析结果显示,UGT1A1＊28、UGT1A1＊6、ECOG评分和治疗周期数对迟发性腹泻有明显影响;同时ECOG评分和治疗周期数对中性粒细胞减少存在影响。结论：UGT1A1突变基因对患者迟发性腹泻有明显影响,UGT1A1基因多态性检测可为临床应用伊立替康联合顺铂相关不良反应的预测提供依据,对临床用药安全具有重要意义。     

Lewis肺癌小鼠体内PTHrP表达与癌细胞衰老的关系

目的:建立Lewis肺癌荷瘤小鼠动物模型,研究肺癌细胞中.PTHrP、MCT1表达的相关性及与癌细胞衰老的关系和意义.方法:C57 BL/6小鼠共30只,随机分三组:正常小鼠组(第1组)、早期肿瘤组(第2组)、晚期肿瘤组(第3组).免疫组织化学法检测三组中PTHrP、MCT1的表达.结果:三组动物细胞PTHrP蛋白的分泌及MCT1的阳性表达率高度一致,且与衰老相关指标βGal的表达成明显负相关性;两个指标在第3组的表达较在第2组和第1组中的表达明显升高,结果有统计学意义(P＜0.05);在第2组的表达较在第1组中的表达明显升高,结果有统计学意义(P＜0.05).结论:晚期肿瘤组织PTHrP、MCT1的表达具有显著正相关性,且与衰老相关指标βGal的表达成明显负相关性.