miR-29a靶向调控CLDN1抑制肝癌细胞增殖的实验研究

目的:探讨miR-29a在肝癌组织中的表达水平，及其对人肝癌细胞增殖能力的影响。方法:通过RT-PCR测定肝癌组织及非肝癌组织中miR-29a的表达水平；将携带miR-29a的脂质体miR-29a mimic、空载体miR-NC以及miR-29a抑制剂anti-miR-29a转染入肝癌细胞系HepG2和HLE，通过RT-PCR方法检测miR-29a对肝癌细胞系HepG2、HLE增殖能力影响；通过Targetscan软件预测miR-29a靶基因，采用Western blot及荧光素酶实验验证。结果:与非肝癌组织比较，miR-29a在肝癌组织中表达下调，MTT实验提示:miR-29a高表达组肝癌细胞增殖能力较弱，miR-29a低表达组肝癌细胞增殖能力提高。Targetscan软件提示:CLDN1可能为miR-29a靶基因，Western blot及荧光素酶实验提示:与阴性对照组相比，miR-29a高表达组内CLDN1表达下降，相反miR-29a低表达组内CLDN1表达增加。结论:miR-29a在肝癌细胞及组织中表达下调，并且可能通过调控CLDN1影响肝癌细胞增殖能力。     

miR-149与肿瘤关系的研究进展

miRNAs是一类长度约为20~25个核苷酸，参与基因调控表达的内源性非编码RNA。miR-149作为miRNAs的重要成员，在多种肿瘤中表达异常，其表达水平与肿瘤细胞增殖、转移、凋亡、耐药、患者的早期诊断及预后密切相关。因此，miR-149有望成为新一类抗肿瘤治疗的靶点。     

The role of lncRNA MSC-AS1/miR-29b-3p axis-mediated CDK14 modulation in pancreatic cancer proliferation and Gemcitabine-induced apoptosis

Pancreatic ductal adenocarcinoma (PDAC) remains a leading cause of cancer-related death due to the failure of traditional therapies. In the present study, we attempted to construct a lncRNA-miRNA-mRNA network which may modulate PDAC cell proliferation and Gemcitabine-induced cell apoptosis starting from CDK14, a new member of the CDK family and an oncogene in many cancers. Based on TCGA data, a significant positive correlation was observed between lncRNA MSC-AS1 and CDK14. Moreover, MSC-AS1 expression was upregulated in PDAC tissues. Higher MSC-AS1 expression was correlated with poorer prognosis in patients with PDAC. MSC-AS1 knockdown in Panc-1 and BxPC-3 cells significantly inhibited the cell proliferation. Moreover, miR-29b-3p, which has been reported to act as a tumor suppressor, was predicted to bind to both MSC-AS1 and CDK14. Contrary to MSC-AS1, higher miR-29b-3p expression was correlated to better prognosis in patients with PDAC. In both PDAC cell lines, miR-29b-3p negatively regulated MSC-AS1 and CDK14. As confirmed using luciferase reporter gene and RIP assays, MSC-AS1 served as a ceRNA for miR-29b-3p to counteract miR-29b-mediated CDK14 repression. MSC-AS1 knockdown inhibited CDK14 protein levels and PDAC proliferation and enhanced gemcitabine-induced cell death and apoptosis while miR-29b-3p inhibition exerted an opposing effect; the effect of MSC-AS1 knockdown was partially attenuated by miR-29b-3p inhibition. Taken together, we demonstrated that MSC-AS1/miR-29b-3p axis modulates the cell proliferation and GEM-induced cell apoptosis in PDAC cell lines through CDK14. We provided a novel experimental basis for PDAC treatment from the perspective of lncRNA-miRNA-mRNA network.     

MicroRNA-145增强非小细胞肺癌细胞对吉非替尼敏感性及其机制探讨

目的:探讨微小RNA-145（microRNA-145，miR-145）对非小细胞肺癌细胞系吉非替尼耐药的作用及其可能的潜在机制。方法:实时荧光定量PCR（Q-PCR）方法检测正常细胞及非小细胞肺癌细胞中miR-145的表达差异；不同时间5 μmol/L吉非替尼干预肺癌细胞SPC-A-1和A549后，Q-PCR检测miR-145表达变化；miR-145 mimics和miR-145 inhibitors分别转染SPC-A-1和A549肺癌细胞后，CCK8检测细胞活力变化;双荧光素酶报告系统检测miR-145与ADAM19的靶向结合；miR-145 mimics转染SPC-A-1和A549肺癌细胞，Western blot检测ADAM19蛋白表达；Western blot检测5 μmol/L吉非替尼干预后，SPC-A-1和A549肺癌细胞中ADAM19蛋白的表达；miR-145 mimics转染SPC-A-1和A549肺癌细胞，再用5 μmol/L吉非替尼干预，Western blot检测ADAM19蛋白的表达；采用siRNA抑制ADAM19表达，再用5 μmol/L吉非替尼干预，CCK8检测细胞活力；采用BALB/C雌性裸鼠皮下接种肿瘤细胞的方法，观察上述效应。结果:Q-PCR结果显示，与正常肺上皮细胞系BEAS-2B相比较，肺癌细胞SPC-A-1和A549中miR-145表达明显降低；5 μmol/L吉非替尼干预SPC-A-1和A549细胞后，miR-145表达显著上调；转染miR-145 mimics后,CCK8结果显示两种细胞细胞活力下降；双荧光素酶报告系统结果显示，miR-145靶向结合ADAM19基因的3'-UTR区；Western blot结果显示，5 μmol/L吉非替尼诱导SPC-A-1和 A549细胞后，两种细胞中ADAM19蛋白表达均降低；miR-145 mimics转染SPC-A-1和A549细胞，之后给予5 μmol/L吉非替尼治疗，ADAM19蛋白表达下调；siRNA抑制SPC-A-1和A549细胞中ADAM19表达，再给予5 μmol/L吉非替尼治疗，CCK8结果显示，两种细胞的细胞活力显著降低；过表达BALB/C雌性裸鼠的miR-145后，显著抑制皮下肿瘤生长，并且增强吉非替尼的抗肿瘤效果。结论:miR-145显著增强肺癌细胞SPC-A-1和A549对吉非替尼的敏感性，其机制可能是通过靶向结合AMDM19基因的3'-UTR区域，从而抑制其表达。miR-145有可能成为治疗非小细胞肺癌吉非替尼耐药的有效靶点。     

PD-L1高表达晚期非小细胞肺癌患者单纯免疫治疗与免疫联合化疗疗效比较

背景与目的以免疫检查点抑制剂（immune checkpoint inhibitors, ICIs）为代表的免疫治疗越来越广泛地应用于肺癌治疗。然而，对于程序性死亡受体配体1（programmed cell death-ligand 1, PD-L1）高表达，即肿瘤比例评分（tumor proportion score, TPS）≥50%的晚期非小细胞肺癌（non-small cell lung cancer, NSCLC）患者，采用单纯免疫治疗还是免疫联合化疗在临床上仍存争议。本研究旨在评估PD-L1高表达的晚期NSCLC患者接受单纯免疫治疗与免疫联合化疗的疗效。方法本研究回顾性分析了49例PD-L1高表达晚期NSCLC患者的临床资料。PD-L1表达采用22C3抗体行免疫组化染色，按TPS判读PD-L1表达水平。比较不同临床特征分组患者的客观缓解率（objective response rate，ORR）和无进展生存时间（progression free survival, PFS）。结果免疫单药与免疫联合化疗组的ORR分别为47.1%（8/17）和43.8%（14/32），差异无统计学意义（P=0.825）。免疫单药与免疫联合化疗组的中位PFS分别为8.0个月和6.8个月，差异无统计学意义（P=0.502）。并对本组PD-L1高表达患者免疫治疗的预测因素进行了分析，结果显示，一线免疫治疗ORR（12/19, 63.2%）显著优于二线及以上免疫治疗（10/30, 33.3%），差异有统计学意义（P=0.041），二者间PFS无差异。年龄、性别、吸烟史、功能状态评分（performance status, PS）、病理类型、肿瘤大小、肿瘤淋巴结转移（tumor node metastasis, TNM）分期与ORR和PFS不相关。结论PD-L1高表达的晚期NSCLC患者接受免疫单药和免疫联合化疗的疗效相近。PD-L1高表达患者一线免疫治疗的ORR更佳。对此类人群的最佳治疗方案有待于前瞻性临床研究进一步探索。     

IL‐17A synergistically enhances TLR3‐mediated IL‐36γ production by keratinocytes: A potential role in injury‐amplified psoriatic inflammation

Skin injury can trigger formation of new lesions in psoriasis (Koebner phenomenon). The mechanisms through which injury exacerbates psoriasis are unclear. During wound repair, epidermal keratinocytes are activated and produce abundant IL‐36γ, further promoting the skin inflammation. IL‐17A is the cornerstone cytokine in the pathogenesis of psoriasis. We sought to investigate the effects of IL‐17A on injury‐induced keratinocyte activation and IL‐36γ production. Here, we demonstrated that dsRNA released from necrotic keratinocytes induced the expression of IL‐36γ. Silencing of TLR3 by siRNA decreased the IL‐36γ induction by necrotic keratinocyte supernatant. Co‐stimulation with dsRNA and IL‐17A synergistically increased the expression of IL‐36γ and other proinflammatory mediators (CCL20, CXCL8, DEFB4 and LCN2) in keratinocytes. The synergistic effects were not dependent on TLR3 upregulation, TNF receptor signalling and mRNA stabilization. Co‐stimulation with dsRNA and IL‐17A resulted in an accumulation of IκBζ. The synergistic upregulation of IL‐36γ and proinflammatory mediators were inhibited by IκBζ siRNA. Co‐stimulation with IL‐17A and poly(I:C) markedly activated the p38 MAPK and NF‐κB pathway, compared with poly(I:C). Blockade of p38 MAPK and NF‐κB suppressed dsRNA/IL‐17A–mediated IκBζ and IL‐36γ induction. These findings demonstrated that IL‐17A synergistically enhanced the dsRNA‐mediated IL‐36γ production through a p38 MAPK‐, NF‐κB–, and IκBζ‐dependent mechanism.     

SDF-1α/CXCR4 信号通路在轴向应力刺激促进骨再生中的作用研究

目的通过轴向应力刺激促进骨再生，观察基质细胞衍生因子 1α/趋化因子 CXC 亚族受体 4（stromal cell-derived factor 1α/cysteine X cysteine receptor 4，SDF-1α/CXCR4）信号通路变化，探讨轴向应力刺激促进骨再生的机制。方法取 72 只雄性新西兰大白兔，于右后肢胫骨近端内侧制备直径 8 mm 圆形皮质骨缺损并脱蛋白松质骨支架修复模型，随机分为 3 组（n=24）。A 组腹腔注射 PBS，B 组术肢给予应力刺激治疗+腹腔注射 PBS，C 组术肢给予应力刺激治疗+腹腔注射 CXCR4 拮抗剂（AMD3100）。术后 2、4、8、12 周，摄 X 线片并采用 Lane-Sandhu X 线评分标准评价骨愈合情况，取标本行 HE 染色观察新生骨组织及支架降解，免疫组织化学染色观察 VEGF、CXCR4 表达水平；4、8 周取标本 Western blot 检测 SDF-1α 及 CXCR4 蛋白表达水平；12 周行 Micro-CT 检查，计算新生骨体积及新生骨密度。 结果X 线片检查示，除术后 2 周各组骨缺损区及支架无明显变化外，4、8 及 12 周时 B 组骨愈合评分均高于 A、C 组（P<0.05）。12 周时 Micro-CT 扫描可见 B 组骨缺损修复、髓腔再通，新生骨体积及骨密度均高于 A、C 组（P<0.05）。HE 染色显示，术后 4 周开始 B 组骨再生及支架降解均明显快于 A、C 组。免疫组织化学染色示，各组 VEGF 及 CXCR4 阳性表达均在 4 周达峰值；各时间点 B 组 VEGF 及 CXCR4 表达量均显著高于 A、C 组（P<0.05）。Western blot 检测显示，4、8 周时 B 组 SDF-1α 与 CXCR4 表达量均显著高于 A、C 组（P<0.05）。 结论轴向应力刺激促进骨再生可能与其促进骨缺损区组织高表达 SDF-1α，激活与其下游调控 BMSCs 募集的 CXCR4 信号有关。     

Melatonin safeguards against fatty liver by antagonizing TRAFs‐mediated ASK1 deubiquitination and stabilization in a β‐arrestin‐1 dependent manner

Melatonin has been previously shown to prevent nonalcoholic fatty liver disease (NAFLD), yet the underlying mechanisms are poorly understood. Here, we identified a previously unknown regulatory action of melatonin on apoptosis signal‐regulating kinase 1 (ASK1) signaling pathway in the pathogenesis and development of NAFLD. Although melatonin administration did not alter food intake, it significantly alleviated fatty liver phenotypes, including the body weight gain, insulin resistance, hepatic lipid accumulation, steatohepatitis, and fibrosis in a high‐fat diet (HFD)‐induced NAFLD mouse model (in vivo). The protection of melatonin against NAFLD was not affected by inactivation of Kupffer cell in this model. In NAFLD mice liver, ASK1 signal cascade was substantially activated, evidence by the enhancement of total ASK1, phospho‐ASK1, phospho‐MKK3/6, phospho‐p38, phospho‐MKK4/7, and phospho‐JNK. Melatonin treatment significantly suppressed the ASK1 upregulation and the phosphorylation of ASK1, MKK3/6, MKK4/7, p38, and JNK. Mechanistically, we found that lipid stress triggered the interaction between ASK1 and TNF receptor‐associated factors (TRAFs), including TRAF1, TRAF2, and TRAF6, which resulted in ASK1 deubiquitination and thereby increased ASK1 protein stability. Melatonin did not alter ASK1 mRNA level; however, it activated a scaffold protein β‐arrestin‐1 and enabled it to bind to ASK1, which antagonized the TRAFs‐mediated ASK1 deubiquitination, and thus reduced ASK1 protein stability. Consistent with these findings, knockout of β‐arrestin‐1 in mice partly abolished the protection of melatonin against NAFLD. Taken together, our results for the first time demonstrate that melatonin safeguards against NAFLD by eliminating ASK1 activation via inhibiting TRAFs‐mediated ASK1 deubiquitination and stabilization in a β‐arrestin‐1 dependent manner.     

MicroRNA-214 promotes chronic kidney disease by disrupting mitochondrial oxidative phosphorylation

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