趋化因子CX3CL1／CX3CR1生物轴促进铂类药物诱导卵巢癌细胞凋亡的研究

目的 探讨趋化因子CX3CL1及其受体CX3CR1与卵巢癌患者耐药及预后的关系,以及裸鼠耐药模型中CX3CL1、CX3CR1在铂类耐药过程中的变化,分析其表达水平与Fas信号通路的相关性。方法 利用癌症基因图集（TCGA）数据库中卵巢癌患者的全基因组表达谱,分析CX3CL1和CX3CR1在铂类敏感和耐药患者中的表达与临床病理特征的关系。利用已构建的带有绿色荧光标记的卵巢癌SKOV3敏感细胞（SKOV3-GFP）和顺铂耐药细胞（SKOV3-GFP／DDPⅢ）进行裸鼠皮下种植,成瘤后分次给予顺铂体内注射;qRT-PCR检测第0、2、5、8次顺铂注射后移植瘤组织中CX3CL1、CX3CR1与Fas信号通路上基因的表达水平。结果 CX3CL1表达与卵巢癌FIGO分期和铂类耐药产生呈负相关（r=-0.112,P=0.030;r=-0.106,P=0.044）;CX3CR1表达与无进展生存时间呈负相关（r=-0.130,P=0.029）和1年复发率呈正相关（r=0.119,P=0.045）。铂类敏感组卵巢癌患者的卵巢组织中CX3CL1的平均表达量为3.96±0.039,显著高于耐药组的3.64±0.55（P=0.000）。顺铂干预后,裸鼠皮下移植瘤体质量随时间推移而增加,SKOV3-GFP／DDPⅢ组形成的移植瘤体质量始终高于SKOV3-GFP组,在第5次给药后移植瘤开始逐渐变小。顺铂干预后,SKOV3-GFP组CX3CL1、CX3CR1表达水平明显升高（P=0.001,P=0.002）,SKOV3-GFP／DDPⅢ组CX3CL1、CX3CR1基因表达始终处于较低水平。SKOV3-GFP／DDPⅢ组中Fas信号通路上的Fas、FADD的表达较SKOV3-GFP组明显降低（P＜0.001）;而PARP1基因的相对表达较SKOV3 GFP组明显上调（P＜0.001）。CX3CL1和CX3CR1的表达与Fas信传导通路上节点基因Fas、FADD表达呈正相关,与下游PARP1基因的表达呈负相关。结论 CX3CL1、CX3CR1表达下调与铂类耐药形成相关,两者可能具有维持肿瘤细胞对铂类药物敏感性的作用。CX3CL1、CX3CR1在耐药细胞中的低表达可能通过某种机制抑制Fas信号传导通路,使其传导失调,抑制细胞凋亡及诱发卵巢癌对铂类耐药。     

Loss of CX3CR1 increases accumulation of inflammatory monocytes and promotes gliomagenesis

The most abundant populations of non-neoplastic cells in the glioblastoma (GBM) microenvironment are resident microglia, macrophages and infiltrating monocytes from the blood circulation. The mechanisms by which monocytes infiltrate into GBM, their fate following infiltration, and their role in GBM growth are not known. Here we tested the hypothesis that loss of the fractalkine receptor CX3CR1 in microglia and monocytes would affect gliomagenesis. Deletion of Cx3cr1 from the microenvironment resulted in increased tumor incidence and shorter survival times in glioma-bearing mice. Loss of Cx3cr1 did not affect accumulation of microglia/macrophages in peri-tumoral areas, but instead indirectly promoted the trafficking of CD11b⁺CD45^hiCX3CR1^lowLy-6C^hiLy-6G⁻F4/80^−/low circulating inflammatory monocytes into the CNS, resulting in their increased accumulation in the perivascular area. Cx3cr1-deficient microglia/macrophages and monocytes demonstrated upregulation of IL1β expression that was inversely proportional to Cx3cr1 gene dosage. The Proneural subgroup of the TCGA GBM patient dataset with high IL1β expression showed shorter survival compared to patients with low IL1β. IL1β promoted tumor growth and increased the cancer stem cell phenotype in murine and human Proneural glioma stem cells (GSCs). IL1β activated the p38 MAPK signaling pathway and expression of monocyte chemoattractant protein (MCP-1/CCL2) by tumor cells. Loss of Cx3cr1 in microglia in a monocyte-free environment had no impact on tumor growth and did not alter microglial migration. These data suggest that enhancing signaling to CX3CR1 or inhibiting IL1β signaling in intra-tumoral macrophages can be considered as potential strategies to decrease the tumor-promoting effects of monocytes in Proneural GBM.     

CX3CR1/CX3CL1 axis negatively controls glioma cell invasion and is modulated by transforming growth factor-beta1

The chemokine CX3CL1 is constitutively expressed in the central nervous system by neurons and astrocytes controlling neuronal survival and neurotransmission. In this work, we analyzed the expression and function of the chemokine CX3CL1 and its receptor, CX3CR1, by human glioma cells. We show that both molecules are expressed on the tumor cell plasma membrane and that soluble CX3CL1 accumulates in the culture supernatants, indicating that the chemokine is constitutively released. We found that CX3CR1 is functional, as all the cell lines adhered to immobilized recombinant CX3CL1 and migrated in response to the soluble form of this chemokine. In addition, the blockade of endogenous CX3CL1 function by means of a neutralizing monoclonal antibody markedly delayed tumor cell aggregation and increased their invasiveness. We also show that CX3CL1 expression is potently modulated by the transforming growth factor-beta1 (TGF-beta1), a key regulator of glioma cell invasiveness. Indeed, both the treatment of glioma cells with recombinant TGF-beta1 and the inhibition of its endogenous expression by siRNA showed that TGF-beta1 decreases CX3CL1 mRNA and protein expression. Overall, our results indicate that endogenously expressed CX3CL1 negatively regulates glioma invasion likely by promoting tumor cell aggregation, and that TGF-beta1 inhibition of CX3CL1 expression might contribute to glioma cell invasive properties.     

CAVEOLIN-1 expression in brain metastasis from lung cancer predicts worse outcome and radioresistance,irrespective of tumor histotype

Brain metastases develop in one-third of patients with non-small-cell lung cancer and are associated with a dismal prognosis, irrespective of surgery or chemo-radiotherapy. Pathological markers for predicting outcomes after surgical resection and radiotherapy responsiveness are still lacking. Caveolin 1 has been associated with chemo- and radioresistance in various tumors, including non-small-cell lung cancer. Here, caveolin 1 expression was assessed in a series of 69 brain metastases from non-small-cell lung cancer and matched primary tumors to determine its role in predicting survival and radiotherapy responsiveness. Only caveolin 1 expression in brain metastasis was associated with poor prognosis and an increased risk of death (log rank test, p = 0.015). Moreover, in the younger patients (median age of <54 years), caveolin 1 expression neutralized the favorable effect of young age on survival compared with the older patients. Among the radiotherapy-treated patients, an increased risk of death was detected in the group with caveolin 1-positive brain metastasis (14 out of 22 patients, HR=6.839, 95% CI 1.849 to 25.301, Wald test p = 0.004). Overall, caveolin 1 expression in brain metastasis from non-small-cell lung cancer is independently predictive of worse outcome and radioresistance and could become an additional tool for personalized therapy in the critical subset of brain-metastatic non-small-cell lung cancer patients.     

GIT1 promotes lung cancer cell metastasis through modulating Rac1/Cdc42 activity and is associated with poor prognosis

G-protein-coupled receptor kinase interacting protein 1 (GIT1) is participated in cell movement activation, which is a fundamental process during tissue development and cancer progression. GIT1/PIX forming a functional protein complex that contributes to Rac1/Cdc42 activation, resulting in increasing cell mobility. Although the importance of Rac1/Cdc42 activation is well documented in cancer aggressiveness, the clinical importance of GIT1 remains largely unknown. Here, we investigated the clinical significance of GIT1 expression in non-small-cell lung cancer (NSCLC) and also verified the importance of GIT1-Rac1/Cdc42 axis in stimulating NSCLC cell mobility. The result indicated higher GIT1 expression patients had significantly poorer prognoses in disease-free survival (DFS) and overall survival (OS) compared with lower GIT1 expression patients. Higher GIT1 expression was an independent prognostic factor by multivariate analysis and associated with migration/invasion of NSCLC cells in transwell assay. In vivo studies indicated that GIT1 promotes metastasis of NSCLC cells. Finally, GIT1 was found to stimulate migration/invasion by altering the activity of Rac1/Cdc42 in NSCLC cells. Together, the GIT1 expression is associated with poor prognosis in patients with NSCLC. GIT1 is critical for the invasiveness of NSCLC cells through stimulating the activity of Rac1/Cdc42.     

miR-409-3 p调控靶基因Beclin-1抑制小细胞肺癌细胞的自噬进而抑制其生长和转移

目的:探究miR-409-3p及其靶基因对小细胞肺癌细胞自噬、生长和转移的影响.方法:qRT-PCR检测miR-409-3p在HPAEpiC、SBC-5、NCI-H446、HOP-92细胞中的表达,SBC-5细胞中转染miR-409-3p mimic和miR-NC,CCK8法检测转染后细胞增殖,Transwell小室法...     

NOX4 promotes non-small cell lung cancer cell proliferation and metastasis through positive feedback regulation of PI3K/Akt signaling

NADPH oxidase 4 (NOX4) is deregulated in various cancers and involved in cancer proliferation and metastasis. However, what the role of NOX4 plays during malignant progression of non-small cell lung cancer (NSCLC) remains unknown. Our results show that NOX4 was upregulated in NSCLC cell lines and samples from patients, compared with controls; NOX4 protein levels were closely correlated with clinical disease stage and survival time. Overexpression of NOX4 in A549 and H460 NSCLC cells enhanced cell proliferation and invasion in vitro, and produced larger tumors, shorter survival time, and more lung metastasis in nude mice than control cells. On the contrary, NOX4 depletion inhibited NSCLC cell aggressiveness. Inhibition of PI3K/Akt pathway could sufficiently block the cellular effects of NOX4 overexpression in NSCLC cells both in vitro and in vivo. Specifically, we demonstrated that PI3K/Akt pathway also positively regulated NOX4 expression via NF-κB-mediated manner. Therefore, there existed a mutual positive regulation between NOX4 and PI3K/Akt signaling in NSCLC cells, and NOX4 was confirmed to functionally interplay with PI3K/Akt signaling to promote NSCLC cell proliferation and invasion. In conclusion, the positive feedback loop between NOX4 and PI3K/Akt signaling contributes to NSCLC progression.     

PP4R1 interacts with HMGA2 to promote non-small-cell lung cancer migration and metastasis via activating MAPK/ERK-induced epithelial-mesenchymal transition

Protein phosphatase 4 regulatory subunit 1 (PP4R1) has been shown to play a role in the regulation of centrosome maturation, apoptosis, DNA repair, and tumor necrosis factor signaling. However, the function of PP4R1 in non-small-cell lung cancer remains unclear. In this study, we identify PP4R1 as an oncogene through Oncomine database mining and immunohistochemical staining, and we showed that PP4R1 is upregulated in lung cancer tissues as compared with that in normal lung tissues and correlated with a poor prognosis in lung cancer patients. Furthermore, in vitro study by wound-healing and Transwell assay showed that PP4R1 could promote migration and invasion of lung cancer cells. Mechanistic investigations revealed that PP4R1 could cooperate with high mobility group AT-hook 2 and thereby promotes epithelial-mesenchymal transition via MAPK/extracellular receptor kinase activation. Taken together, our study provides a rich resource for understanding PP4R1 in lung cancer and indicates that PP4R1 may serve as a potential biomarker in lung cancer therapies.     

LncRNA HCG11 通过调控miR-144-3p/ZEB1 分子轴影响直肠癌的发生及转移

[摘要] 目的：探究lncRNA HCG11 通过调控miR-144-3p 上调锌指蛋白E-盒结合同源异形盒-1（zine finger E box binding homeobox 1, ZEB1）基因的表达促进结直肠癌（colorectal cancer,CRC）发生及转移的分子机制。方法：收集2013 年1 月至2018 年1月云南省肿瘤医院结直肠外科手术切除的78 例CRC组织标本及其癌旁组织标本,采用qPCR检测HCG11 在CRC癌组织及细胞系中表达情况,以构建的HCG11 敲降载体、miR-144-3p 模拟物及抑制剂转染CRC细胞株SW480 及SW620,CCK-8 法及克隆形成实验检测细胞的增殖情况,Transwell 实验检测细胞的迁移及侵袭情况。通过Wb及免疫荧光实验检测ZEB1 及上皮间质特异蛋白（E-cadherin、Vimentin、ɑ-catenin、Sox2、Nestin、Oct4 及Nanog）的表达,通过双荧光素酶报告基因检测HCG11、miR-144-3p 及ZEB1 的靶向调控关系。建立小鼠移植瘤模型验证敲降HCG11 后对小鼠移植瘤生长的抑制作用。结果：HCG11 在CRC癌组织的表达显著高于癌旁组织（P<0.01）,其在多种CRC细胞系中表达水平明显高于正常肠上皮细胞（均P<0.05）;HCG11 的表达与CRC患者肿瘤转移、临床分期及预后密切相关（P<0.05 或P<0.01）。敲降HCG11 后显著抑制CRC细胞的增殖、迁移、侵袭、上皮间质转化及干细胞转化（均P<0.05）。敲降HCG11 显著上调miR-144-3p 的表达水平（P<0.05）,过表达miR-144-3p 可显著抑制ZEB1基因的表达（P<0.05）及明显降低双荧光素酶活性（P<0.05）。结论：HCG11 通过调控miR-144-3p 上调ZEB1 的表达,从而促进CRC的发生及转移,HCG11可作为CRC诊断及治疗的靶点。     

The effects of combined antioxidant (beta-carotene, alpha-tocopherol and ascorbic acid) supplementation on antioxidant capacity, DNA single-strand breaks and levels of insulin-like growth factor-1/IGF-binding protein 3 in the ferret model of lung cancer

Insulin-like growth factor 1 (IGF-1) and its major binding protein, IGF binding protein 3 (IGFBP-3) are implicated in lung cancer and other malignancies. We have previously shown that the combination of three major antioxidants [beta-carotene (BC), alpha-tocopherol (AT) and ascorbic acid (AA)] can prevent lung carcinogenesis in a 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone (NNK)-treated and smoke-exposed (SM) ferret model, which is highly analogous to humans. The present study is aimed at determining the effect of the combination of BC, AT and AA on antioxidant capacity, lymphocyte DNA damage, plasma IGF-1 and IGFBP-3 concentrations, as well as on IGF-1/IGFBP-3 mRNA expression in the tissues (lung and liver) of the ferrets. Ferrets were treated with or without combined antioxidant (BC, AT and AA) supplementation (AOX) for 6 months in the following 4 groups: (i) control; (ii) SM+NNK; (iii) AOX; and (iv) SM+NNK+AOX. Combined AOX supplementation significantly attenuated SM+NNK induced lymphocyte DNA damage in the ferret, while increasing resistance to oxidative damage when challenged with H(2)O(2) in vitro. Ferrets treated with SM+NNK had significantly lower IGFBP-3 mRNA expression in lungs, whereas there was significantly higher IGFBP-3 mRNA expression in the liver, as well as higher circulating IGFBP-3 concentrations. Combined AOX supplementation did not affect the plasma or tissue (lung and liver) ratio of IGF-1/IGFBP-3. Combined antioxidant supplementation provides protection against smoke-induced oxidative DNA damage, but does not affect the IGF-1/IGFBP-3 system. Differential expression of IGFBP-3 in different tissues indicates that caution should be taken when using plasma IGFBP-3 as a biomarker of tissue status.     

低表达DJ-1调控PI3K/AKT通路对肺癌细胞增殖、凋亡的影响

目的:探讨低表达DJ-1对肺癌细胞增殖凋亡及PI3K/AKT通路的影响。方法:采用Western blot检测肺癌细胞系中DJ-1蛋白的表达;以脂质体法转染干扰SK-MES-1细胞中DJ-1蛋白的表达后,MTT法检测细胞的增殖变化,流式细胞仪检测细胞的凋亡情况,Western blot检测细胞中p-AKT和AKT蛋白的表达水平;将PI3K/AKT通路抑制剂LY294002处理SK-MES-1细胞48 h后,MTT法和流式细胞仪分别检测细胞的增殖和凋亡情况,Western blot检测细胞中p-AKT和AKT蛋白的表达。结果:与正常肺上皮BEAS-2B细胞相比,肺腺癌A549细胞和肺鳞癌SK-MES-1细胞中DJ-1蛋白的相对表达量均显著升高,且SK-MES-1细胞中DJ-1蛋白的表达量高于A549细胞,差异均有统计学意义（P＜0.05）。转染后siRNA DJ-1组细胞中DJ-1蛋白的表达量明显低于对照组（P＜0.05）;与对照组相比,转染24 h后siRNA DJ-1组细胞的吸光值（OD值）变化不显著（P＞0.05）,而转染48 h和72 h后细胞的OD值明显降低（P＜0.05）;转染48 h后,与对照组相比,siRNA DJ-1组细胞的凋亡率显著升高（P＜0.05）,p-AKT/AKT值显著降低（P＜0.05）。SK-MES-1细胞经抑制剂LY294002处理48 h后,细胞的增殖凋亡趋势与下调DJ-1表达的结果相一致。结论:DJ-1在肺癌细胞中高表达,下调其表达能够抑制细胞增殖,促进细胞凋亡,其作用机制可能与PI3K/AKT信号通路有关。     

苍术素通过激活RIPK1/RIPK3/MLKL 信号通路诱导非小细胞肺癌A549细胞程序性坏死并抑制裸鼠移植瘤生长

目的：探讨苍术素（ATR）通过调节受体相互作用蛋白激酶（RIPK）1/RIPK3/混合谱系激酶结构域样（MLKL）信号通路对非小细胞肺癌（NSCLC）A549 细胞程序性死亡及裸鼠移植瘤生长的影响。方法：使用0~160 μmol/L 的ATR 处理A549 细胞, MTT 法检测细胞存活率以确定后续实验给药浓度。使用ATR 和/或RIPK1 抑制剂Nec-1（necrostatin-1）、caspase 抑制剂Z-VAD-FMK处理A549 细胞,验证ATR是否诱导A549 细胞发生程序性坏死。将A549 细胞分为对照组、ATR-L 组、ATR-M 组、ATR-H 组（分别用0、10、20、40 μmol/L ATR 处理）、ATR+Nec-1 组（40 μmol/L ATR+50 μmol/L Nec-1 处理）,处理24 h 后,采用PI 单染及Hoechst33342/PI 双染法检测细胞死亡情况、透射电镜观察细胞死亡形态、DCFH-DA 荧光探针法检测细胞内ROS水平、JC-1染色法检测线粒体膜电位、WB法检测细胞中RIPK1/RIPK3/MLKL 信号通路相关蛋白质的表达水平。构建A549 细胞裸鼠移植瘤模型,用10 mg/kg ATR（溶于玉米油中）对裸鼠灌胃给药5 周,观察ATR 对移植瘤生长的影响,WB 法检测移植瘤组织中RIPK1/RIPK3/MLKL信号通路相关蛋白质的表达水平。结果：10~160 μmol/L的ATR可显著抑制A549细胞增殖,选择10、20、40 μmol/L的ATR进行后续实验。ATR组A549 细胞存活率显著低于对照组（P<0.01）和ATR+Nec-1组（P<0.01）,而ATR+z-VAD组细胞存活率显著低于z-VAD组（P<0.01）,说明ATR可诱导A549 细胞发生程序性坏死而非凋亡。与对照组比较,ATR处理组A549 细胞发生肿胀,线粒体内脊消失呈空泡化,细胞内容物向外泄漏,细胞核聚集,表现为坏死特征,ATR-L 组、ATR-M组、ATR-H 组A549 细胞死亡率、ROS水平及p-RIPK1、p-RIPK3、p-MLKL表达水平均显著升高,线粒体膜电位显著降低（均P<0.01）,且呈药物浓度依赖性;与ATR-H 组比较,ATR+Nec-1 组细胞死亡率、ROS 及p-RIPK1、p-RIPK3、p-MLKL 表达水平降低,线粒体膜电位显著升高（均P<0.01）。裸鼠移植瘤实验结果显示,与对照组比较,ATR 组裸鼠移植瘤体积、移植瘤质量均降低（P<0.05,或P<0.01）,而与瘤组织中p-RIPK1、p-RIPK3、p-MLKL 蛋白表达水平均显著升高（均P<0.01）。结论：ATR可能通过激活RIPK1/RIPK3/MLKL信号通路诱导A549细胞发生程序性坏死,抑制A549细胞及其裸鼠移植瘤的生长。