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1.
Cancer-associated fibroblasts (CAFs) play a key role in orchestrating the tumor malignant biological properties within tumor microenvironment and evidences demonstrate that CAFs are a critical regulator of tumoral immunosuppression of the T cell response. However, the functions and regulation of CAFs in the expression of programmed death-ligand 1 (PD-L1) in melanoma and colorectal carcinoma (CRC) are not completely understood. Herein, by scrutinizing the expression of α-SMA and PD-L1 in melanoma and CRC tissues, we found that CAFs was positive correlated with PD-L1 expression. Further analyses showed that CAFs promoted PD-L1 expression in mice tumor cells. By detecting a majority of cytokines expression in normal mice fibroblasts and CAFs, we determined that CXCL5 was abnormal high expression in CAFs and the immunohistochemistry and in situ hybridization confirmed that were CAFs which were expressing CXCL5. In addition, CXCL5 promoted PD-L1 expression in B16, CT26, A375 and HCT116. The silencing of CXCR2, the receptor of CXCL5, inhibited the PD-L1 expression induced by CAFs in turn. Functionally, CXCL5 derived by CAFs promoted PD-L1 expression in mice tumor cells through activating PI3K/AKT signaling. LY294002, the inhibitor of PI3K, confirmed that CXCL5 forested an immunosuppression microenvironment by promoting PD-L1 expression via PI3K/AKT signaling. Meanwhile, the B16/CT26 xenograft tumor models were used and both CXCR2 and p-AKT were found to be positively correlated with PD-L1 in the xenograft tumor tissues. The immunosuppressive action of CAFs on tumor cells is probably reflective of them being a potential therapeutic biomarker for melanoma and CRC.  相似文献   

2.
PD-L1 expression is a feature of Epstein-Barr virus (EBV) associated malignancies such as nasopharyngeal carcinoma (NPC). Here, we found that EBV-induced latent membrane protein 1 (LMP1) and IFN-γ pathways cooperate to regulate programmed cell death protein 1 ligand (PD-L1). Expression of PD-L1 was higher in EBV positive NPC cell lines compared with EBV negative cell lines. PD-L1 expression could be increased by exogenous and endogenous induction of LMP1 induced PD-L1. In agreement, expression of PD-L1 was suppressed by knocking down LMP1 in EBV positive cell lines. We further demonstrated that LMP1 up-regulated PD-L1 through STAT3, AP-1, and NF-κB pathways. Besides, IFN-γ was independent of but synergetic with LMP1 in up-regulating PD-L1 in NPC. Furthermore, we showed that PD-L1 was associated with worse disease-free survival in NPC patients. These results imply that blocking both the LMP1 oncogenic pathway and PD-1/PD-L1 checkpoints may be a promising therapeutic approach for EBV positive NPC patients.  相似文献   

3.
Nasopharyngeal carcinoma (NPC) is a common malignant tumor and a major cause of mortality and morbidity in southern China. However, the mechanism is still elusive. Here, we focused on studying the role of squalene epoxidase (SQLE), a key enzyme of cholesterol biosynthesis, in the progression of NPC. Clinical study revealed that SQLE expression was significantly upregulated in NPC tissues compared to normal tissues from mRNA level and patients with high expression of SQLE showed a poor prognosis. In vitro experiments showed that SQLE overexpression led to a significant proliferation of cells whereas SQLE knockdown showed an opposite result. In vivo studies also showed that SQLE promoted tumor growth in nude mice. Further study revealed that SQLE promoted NPC proliferation by cholesteryl ester accumulation instead of cholesterol. Mechanism studies indicated that cholesteryl ester promoted NPC cell proliferation by activating the PI3K/AKT pathway and inhibition of this pathway in SQLE‐overexpressed or cholesteryl ester‐treated cells resulted in a significant reduction of NPC cell proliferation. These results indicate that the oncogenic effect of SQLE in NPC mainly resulted from cholesteryl ester accumulation and PI3K/AKT is a promising target for NPC with SQLE overexpression.  相似文献   

4.
目的:探讨Ig 样结构域 2 黏附分子(adhesion molecule with Ig like domain 2,AMIGO2)在鼻咽癌(nasopharyngeal carcinoma,NPC)细胞增殖中的作用及其机制。方法: 选用2017年9月至11月福建省肿瘤医院收集的10例NPC组织和10例正常鼻 咽黏膜上皮组织标本,以及NPC细胞系CNE-1、CNE-2、SUNE-1、 6-10B、 C666-1和人永生化鼻咽黏膜上皮细胞株NP69, 用qPCR法 检测NPC组织和细胞中AMIGO2 mRNA的表达。构建慢病毒载体干扰AMIGO2表达, 用qPCR法验证其干扰效率; 用CCK-8 法、克隆形成及流式细胞术检测干扰AMIGO2表达对NPC细胞增殖、克隆形成和凋亡的影响, 用 Western blotting 检测干扰 AMIGO2 表达对 NPC 细胞增殖及 PI3K/AKT/mTOR 信号通路相关标志蛋白表达的影响。结果: AMIGO2在NPC组织和 CNE-2和SUNE-1细胞中高表达(均P<0.01)。慢病毒AMIGO2感染后,CNE-2和SUNE-1细胞的AMIGO2干扰效率均达50%以 上。干扰AMIGO2表达,显著降低CNE-2和SUNE-1细胞增殖及克隆形成能力(均P<0.01)、明显提高细胞的凋亡率(均P<0.01); 降低 SUNE-1 细胞中PI3K、AKT和mTOR磷酸化蛋白的表达水平 (均P<0.01)、下调survivin 和 PCNA 蛋白的表达水平(均P<0.01)。 结论:AMIGO2通过激活PI3K/AKT/mTOR信号通路促进NPC细胞增殖并抑制其凋亡,提示AMIGO2可能是NPC治疗的潜 在靶点。  相似文献   

5.
王静  陈洁  胡春  黄诚 《中国癌症杂志》2020,30(6):419-427
背景与目的:程序性死亡[蛋白]配体-1(programmed death ligand-1,PD-L1)在肿瘤细胞中的表达对肿瘤逃避机体免疫监视具有重要的意义,其表达通常受MAPK、PI3K-AKT或STAT3等多条通路的影响,但这些通路具体经哪个关键环节尚不明确。拟通过PI3K/AKT信号通路对肺癌细胞A549、H460中PD-L1表达的调控具体机制进行探究。方法:使用shRNA技术选择性地沉默A549、H460细胞中的HEB、HTF4、Nrf2及FOXO3a等基因,构建缺陷细胞株;将目的基因PD-L1的3’UTR区域构建至pGL3-basic载体中,通过luciferase双报告基因体系检测PD-L1转录激活情况,并使用实时荧光定量聚合酶链反应(real-time fluorescence quantitative polymerase chain reaction,RTFQ-PCR)技术验证细胞内PD-L1基因转录的情况;通过蛋白质印迹法(Western blot)检测细胞内PD-L1的总表达情况;免疫细胞与肿瘤细胞共培养,检测Nrf2基因敲除前后,人外周血单个核细胞(peripheral blood mononuclear cells,PBMC)对A549、H460细胞株的杀伤效果。结果:经10μg/mL的insulin刺激后,A549、H460细胞株中蛋白激酶B(AKT)基因磷酸化水平显著增强,伴随着PD-L1基因的转录水平和表达水平显著增强(P<0.001),在HEB、HTF4及FOXO3a基因敲除的细胞株中,情况相似,而在Nrf2基因敲除的细胞株A549(A549 Nrf2- )和H460(H460 Nrf2- )细胞株中,PD-L1的转录和表达水平则与阴性对照组一样未见明显变化(P>0.05);活性氧(reactive oxygen species,ROS)诱导剂isoproterenol能提高A549、H460细胞株中PD-L1基因的转录和表达水平,而ROS在被NAC解除后,PD-L1的转录和表达水平显著下调,进一步证明Nrf2对PD-L1基因的转录调控作用;wortmannin能逆转insulin刺激引起的AKT磷酸化水平增加,促进PD-L1基因的转录水平和表达水平下降,表明PD-L1的调控与AKT激活程度相关;在insulin和wortmannin的分别干预下,A549、H460细胞株中的Nrf2磷酸化水平能随着AKT磷酸化水平改变而改变,二者相关系数r分别为0.86和0.93,为强正相关;Nrf2敲除后,A549、H460细胞株与PBMC共培养后凋亡数量显著增加。结论:PI3K/AKT通路对肺癌细胞A549、H460中PD-L1表达具有关键调控作用,该调控是通过磷酸化激活Nrf2而实现的。  相似文献   

6.
7.
The activation of PI3K further activates subsequent regulatory pathways, which are activated via AKT phosphorylation. AKT is closely related to the Bcl-2 family, a protein known to be involved in cell survival. AKT also has a relationship with inflammatory and glycolytic mediators. The present work aimed to evaluate the relationship between the PI3K/AKT pathway, cell survival/proliferation, inflammatory mediators and the glycolytic pathway in oral squamous cell carcinoma. All experiments were performed in the SCC25 oral squamous cell carcinoma cell line. In the presence or absence of PI3K pathway inhibitors, we analyzed the protein expression of pAKT and AKT; X-linked inhibitor of apoptosis protein; Bcl-2-associated death promoter; Bcl-2-like protein two inhibitor; cyclooxygenase 1; cyclooxygenase-2; and glycoprotein-associated glucose transporter 1. For the functional characterization of treated or untreated cells, we also performed matrix invasion assays, cell migration assays, and cell proliferation assays. Our results demonstrated that activation of the PI3K/AKT pathway is directly related to members of the Bcl-2 family and GLUT1, but not the inflammatory mediators COX1 and COX2. Our data suggest that the PI3K/AKT pathway is related to cell survival and proliferation in oral squamous cell carcinoma through its interaction with Bcl-2 family members.  相似文献   

8.
Nasopharyngeal carcinoma (NPC) is the most prevalent human primary malignancy of the head and neck, and the presence of vasculogenic mimicry (VM) renders anti-angiogenic therapy ineffective and poorly prognostic. However, the underlying mechanisms are unclear. In the present study, we used miR-940 silencing and overexpression for in vitro NPC cell EdU staining, wound healing assay and 3D cell culture assay, and in vivo xenograft mouse model and VM formation to assess miR-940 function. We found that ectopic miR-940 expression reduced NPC cell proliferation, migration and VM, as well as tumorigenesis in vivo. By bioinformatic analysis, circMAN1A2 was identified as a circRNA that binds to miR-940. Mechanistically, we confirmed that circMAN1A2 acts as a sponge for miR-940, impairs the inhibitory effect of miR-940 on target ERBB2, and then activates the PI3K/AKT/mTOR signaling pathway using RNA-FISH, dual luciferase reporter gene and rescue analysis assays. In addition, upregulation of ERBB2 expression is associated with clinical staging and poor prognosis of NPC. Taken together, the present findings suggest that circMAN1A2 promotes VM formation and progression of NPC through miR-940/ERBB2 axis and further activates the PI3K/AKT/mTOR pathway. Therefore, circMAN1A2 may become a biomarker and therapeutic target for anti-angiogenic therapy in patients with nasopharyngeal carcinoma.  相似文献   

9.
The cyclin-dependent kinase inhibitor p21WAF1/CIP1/SD11 (p21) plays a crucial role in DNA repair, cell differentiation, and apoptosis through regulation of the cell cycle. A2780 human ovarian carcinoma cells, which are sensitive to cisplatin and paclitaxel, express wild-type p53 and exhibit a p53-mediated increase in p21 in response to the chemotherapeutic agents. Here, we demonstrate that phosphatidylinositol 3-kinase (PI3K) and its downstream targets serine/threonine kinases AKT1 and AKT2 (AKT), are required for the full induction of p21 in A2780 cells treated with cisplatin or paclitaxel. Inactivation of the PI3K/AKT signal transduction pathway either by its specific inhibitor LY294002 or by expression of dominant negative AKT inhibited p21 expression but had no inhibitory effect on the expression of the proapoptotic protein BAX by cisplatin and paclitaxel treatment. In addition, overexpression of wild-type or constitutively active AKT in A2780 cells sustained the regulation of p21 induction or increased the level of p21 expression, respectively. Experiments with additional ovarian carcinoma cell lines revealed that PI3K is involved in the expression of p21 induced by cisplatin or paclitaxel in OVCAR-10 cells, which have wild-type p53, but not in OVCAR-5 cells, which lack functional p53. These data indicate that the PI3K/AKT signal transduction pathway mediates p21 expression and suggest that this pathway contributes to cell cycle regulation promoted by p53 in response to drug-induced stress. However, inactivation of PI3K/AKT signaling did not result in significant alteration of the drug sensitivity of A2780 cells, suggesting that the cell death induced by cisplatin or paclitaxel proceeds independently of cell protective effects of PI3K and AKT.  相似文献   

10.
目的:动力相关蛋白-1(MRP-1/CD9)是四跨膜蛋白超家庭(transmetubrane 4,stperfanily,TM4SF)成员之一,参与调控细胞的生长,分化,细胞间粘附和迁移,本实验旨在研究MRP-1 CD9对人卵巢癌SKON-3细胞株体外增殖和运动能力的影响并探讨其与PI4K/AKT信号通路的相关性,方法:应用RT-PCR获得CD9全长cDNA片段,正向插入pcDNA3.1表达载体,将重组质粒导入SKOV-3细胞中,应用RT-PCR efse一流式细胞测定和单层伤口愈合实验等方法观察梁前后SKOV-3细胞PI4K和AKTmRNA表达水平,细胞增殖及其运动能力变化,结果:成功构建正义全长CD9真核表达载体,获得稳定表达CD9的SKOV-3克隆株,与穿空质粒转染和不转染的SKON-3细胞相比,SKON-3/CD9细胞PI4KmRNA的表达明显被抑制,抵制率为40%;AKTmRNA的表达水平上调3.13倍,细胞增殖和运动能力均有明显升高.结论:CD9促进人卵巢癌SKOV-3细胞的体外增殖 和运动能力,可能是通过PI4K/AKT信号通路发挥作用的,对卵巢癌恶性进展发挥重要作用.  相似文献   

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12.
A high frequency of somatic mutations has been found in breast cancers within the gene encoding the catalytic p110α subunit of PI3K, PIK3CA. Using isogenic human breast epithelial cells, we have previously demonstrated that oncogenic PIK3CA "hotspot" mutations predict for response to the toxic effects of lithium. However, other somatic genetic alterations occur within this pathway in breast cancers, and it is possible that these changes may also predict for lithium sensitivity. We overexpressed the epidermal growth factor receptor (EGFR) into the non-tumorigenic human breast epithelial cell line MCF-10A, and compared these cells to isogenic cell lines previously created via somatic cell gene targeting to model Pten loss, PIK3CA mutations, and the invariant AKT1 mutation, E17K. EGFR overexpressing clones were capable of cellular proliferation in the absence of EGF and were sensitive to lithium similar to the results previously seen with cells harboring PIK3CA mutations. In contrast, AKT1 E17K cells and PTEN -/- cells displayed resistance or partial sensitivity to lithium, respectively. Western blot analysis demonstrated that lithium sensitivity correlated with significant decreases in both PI3K and MAPK signaling that were observed only in EGFR overexpressing and mutant PIK3CA cell lines. These studies demonstrate that EGFR overexpression and PIK3CA mutations are predictors of response to lithium, whereas Pten loss and AKT1 E17K mutations do not predict for lithium sensitivity. Our findings may have important implications for the use of these genetic lesions in breast cancer patients as predictive markers of response to emerging PI3K pathway inhibitors.  相似文献   

13.
Microsatellite instability (MSI), high tumor mutation burden (TMB-H) and programmed cell death 1 ligand 1 (PD-L1) expression are hot biomarkers related to the improvement of immunotherapy response. Two cohorts of non-small-cell lung cancer (NSCLC) were collected and sequenced via targeted next-generation sequencing. Drug analysis was then performed on the shared genes using three different databases: Drugbank, DEPO and DRUGSURV. A total of 27 common genes were mutated in at least two groups of TMB-H-, MSI- and PD-L1-positive groups. AKT1, SMAD4, SCRIB and AXIN2 were severally involved in PI3K-activated, transforming growth factor beta (TGF-β)-activated, Hippo-repressed and Wnt-repressed pathways. This study provides an understanding of the mutated genes related to the immunotherapy biomarkers of NSCLC.  相似文献   

14.
Evasion of apoptosis plays a key role in cancer development, drug resistance, and recurrence. The BRCA1 locus product protein BRCA1-IRIS is overexpressed in several cisplatin-resistant ovarian cancer cell lines, but its relationship to resistance is uncertain. Here, we show that in human ovarian surface epithelial (HOSE) cells, overexpression of BRCA1-IRIS triggers expression of the antiapoptotic protein survivin. Negative modulation of phosphatidylinositol 3-kinase (PI3K) signaling or AKT silencing reduced survivin expression in this setting. Conversely, silencing BRCA1-IRIS in ovarian cancer cell lines derepressed PTEN expression along with the antiapoptotic AKT targets FOXO1 and FOXO3a, suppressing survivin expression. Cisplatin (≤50 μmol/L) exposure was sufficient to activate expression of the BRCA1-IRIS-AKT-survivin cascade in HOSE cells, whereas under similar conditions cisplatin failed to induce apoptosis in ovarian cancer cell lines expressing this regulatory cascade. Mechanistic investigations indicated that BRCA1-IRIS triggers survivin expression through a PI3K/AKT-dependent pathway involving NF-κB, but also through a PI3K/AKT-independent pathway involving PTEN, FOXO1, and FOXO3a. Our findings indicate how BRCA1-IRIS overexpression prevents chemotherapy-induced cell death by upregulating expression of survivin, and they highlight this regulatory cascade as a candidate focus to improve treatment of advanced drug-resistant ovarian cancers.  相似文献   

15.
[摘要] 目的:探讨miR-103 靶向PTEN并激活PI3K/AKT信号通路促进肺癌细胞对达沙替尼(dasatinib,DASA)耐药的机制。方法:收集2014 年4 月至2018 年1 月昆明医科大学第一附属医院胸外科收治的资料完整的肺癌DASA耐药组织和不耐药组织各35 例。采用qPCR实验检测miR-103 在肺癌DASA耐药组织和细胞中的表达水平,同时,采用CCK-8、Transwell 和Wb实验检测敲降miR-103 对A549/DASA细胞增殖、迁移和上皮间质转化(EMT)的影响,双荧光素酶报告基因验证miR-103 与PTEN的靶向关系。进一步采用CCK-8、Transwell 和Wb实验检测miR-103 通过PTEN-PI3K/AKT信号通路对A549/DASA细胞恶性生物学行为的影响。结果:miR-103 在肺癌DASA 耐药组织和A549/DASA 细胞中均高表达(均P<0.01)。敲降miR-103 可显著抑制A549/DASA细胞的增殖、迁移和EMT(P<0.05 或P<0.01)。此外,双荧光素酶报告基因证实miR-103 靶向作用PTEN并下调其表达水平(P<0.01)。进一步实验显示,过表达miR-103 通过靶向下调PTEN并激活PI3K/AKT信号通路进而显著促进A549/DASA细胞增殖、迁移和EMT(P<0.05 或P<0.01),从而上调A549/DASA细胞对DASA的耐药性。结论:miR-103/PTEN/PI3K/AKT信号通路与肺癌DASA耐药性存在调控关系,敲降miR-103 可逆转A549/DASA对DASA耐药。  相似文献   

16.
Ovarian cancer is the major cause of death from gynecological malignancy, and there is an urgent need for new therapeutic targets. The phosphatidylinositol 3-kinase (PI3K)/AKT pathway has been strongly implicated in the genesis of ovarian cancer. However, to identify and evaluate potential targets for therapeutic intervention, it is critical to understand the mechanism by which the PI3K/AKT pathway facilitates ovarian carcinogenesis. Here, we show that AKT3 is highly expressed in 19 of 92 primary ovarian tumors. Strikingly, purified AKT3 exhibited up to 10-fold higher specific activity than AKT1, potentially amplifying the effects of AKT3 overexpression. Consistent with this finding, AKT3 levels in a range of ovarian cancer cell lines correlated with total AKT activity and proliferation rates, implicating AKT3 as a key mediator of ovarian oncogenesis. Specific silencing of AKT3 using short hairpin RNA markedly inhibited proliferation of the two cell lines with highest AKT3 expression and total AKT activity, OVCA429 and DOV13, by slowing G(2)-M phase transition. These findings are consistent with AKT3 playing a key role in the genesis of at least one subset of ovarian cancers.  相似文献   

17.
18.
任凯  丁岩  成凡  任立刚 《现代肿瘤医学》2013,(12):2666-2669
目的:探讨Saposin C促进PC3细胞抑癌基因p27KIP1蛋白泛素化降解,刺激细胞增殖,以及与PI3K/AKT信号通路的关系。方法:利用含有Saposin C的真核表达载体转染PC3细胞,检测Saposin C对PC3细胞Skp2、抑癌基因p27KIP1蛋白水平的调节以及对细胞增殖的影响。结果:Saposin C通过激活PI3K/AKT信号途径上调细胞内Skp2的蛋白含量,下调抑癌基因p27KIP1的蛋白水平,其机制是加速p27KIP1的蛋白降解,促进PC3细胞增殖。结论:Saposin C在PC3细胞中通过激活PI3K/AKT信号途径促进抑癌基因p27KIP1的蛋白泛素化降解,刺激细胞增殖。  相似文献   

19.
肿瘤细胞利用免疫检查点通路来逃避宿主免疫系统并抑制免疫细胞功能.癌细胞表达程序性细胞死亡蛋白配体1/2(programmed death-ligand 1/2,PD-L1/PD-L2)与细胞毒性 T 细胞上存在的程序性细胞死亡蛋白 1(programmed cell death protein-1,PD-1)结合,触发...  相似文献   

20.
Although preclinical and clinical studies on poly-(adenosine diphosphate ribose) polymerase (PARP) inhibitor alone or in combination with DNA-damaging agents have shown promising results, further research to improve and broaden the application scope of this therapeutic approach is needed. The main aim of this study was to evaluate whether overexpressing inositol polyphosphate 4-phosphatase type II (INPP4B) gene, a novel tumor suppressor gene negatively regulating the phosphatidylinositol 3-kinase (PI3K)/AKT signaling pathway, could enhance the antitumor efficacy of PARP inhibitor AG014699 used in the treatment of triple-negative breast cancer (TNBC). Here in this report, we used a TNBC cell line MDA-MB-231 without expression of INPP4B as the study model and a lentiviral system to stably overexpress INPP4B gene in MDA-MB-231 cells. We detected that the overexpression of INPP4B could significantly suppress cell proliferation and block cell cycle progression in G1 phase via decreasing the protein level of phosphorylated AKT. It is further revealed that PARP inhibitor AG014699 induced DNA damage conferring a G2/M arrest and decreased cell viability, which is paralleled by the induction of apoptosis. However, PARP inhibitor AG014699 could activate the PI3K/AKT signaling pathway activity and partially offset its therapeutic efficacy. In our study, a significant enhancement of proliferation inhibition was observed when INPP4B overexpression was combined with PARP inhibitor AG014699 in comparison with either single treatment. The suppression of PI3K/AKT pathway caused by the overexpression of INPP4B contributed to the enhanced antitumor efficacy of the combined therapy. Our in vitro results indicated that this experimental therapeutic strategy combining INPP4B overexpression and PARP inhibitor AG014699 might be of potential therapeutic value as a new strategy for the treatment of patients with TNBC and is worthy of further study.  相似文献   

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