基于网络药理学和分子对接的康艾注射液治疗胃癌的分子机制研究

目的:基于网络药理学从靶基因层面研究康艾注射液治疗胃癌的潜在机制。方法:系统检索Pubmed、CNKI等数据库,筛选康艾注射液有效成分;通过PubChem数据库获得所有药物成分的SMILES结构,分别在STITCH、SuperPred及Swiss Target Prediction数据库检索获取药物成分靶基因;通过Disgenet和GeneBank数据库筛选胃癌靶基因;通过R软件取康艾注射液成分及胃癌靶点的交集,根据共同靶点进行GO及KEGG分析,构建药物-疾病-靶点网络药理图;通过分子对接实验验证。结果:共检索到康艾注射液成分相关文献8篇,共筛选到康艾注射液有效成分21种;最终共获得康艾注射液成分靶点155个,胃癌相关靶基因3 720个,共同靶点84个;通过Cytoscape 3.6对STRING数据分析发现Top10-Hub基因分别是TP53、VEGFA、EGFR、TNF、STAT3、ESR1、HSP90AA1、AR、CYP3A4和HDAC1;主要涉及的通路分别是:“Wnt signaling pathway”、“p53 pathway”和“Apoptosis signaling pathway”等;分子对接实验发现VEGFA、EGFR、TNF和STAT3能够与成分稳定结合。结论:康艾注射液通过多基因、多通路发挥治疗胃癌的作用,为中成药临床有效治疗癌症提供客观依据。     

网络药理学与分子对接技术指导下土大黄苷对慢性粒细胞白血病作用机制研究

目的 近年来,蛋白质相互作用网络及分子对接技术成为中药现代化研究领域十分活跃的一部分,逐渐成为链接中药应用与现代化的重要纽带.本研究基于分子对接技术与网络药理学分析,探讨中药大黄活性成分土大黄苷与慢性粒细胞白血病(chronic myelocytic leukemia,CML)相关基因之间的相互作用,寻求土大黄苷作用与CML的可能机制.方法 前期研究中构建了CML蛋白质相互作用网络,并筛选了CML关键靶点蛋白,作为本研究的受体;通过软件Chemoffice 8.0构建土大黄苷的分子结构,导入SYBYL软件中,进行一系列数据处理,作为本研究的配体.利用SYBYL8.1软件的Surflex-Dock模块进行分子对接,用配体-受体亲和力的一致性评分函数进行打分,并对氢键及其结合部位进行观察、分析.进一步对分子对接结果进行文献验证.结果 得到土大黄苷与CML19个相关基因之间的分子对接评分及氢键数,其中与JUN(2G01)受体对接得分及氢键数是最高的,说明土大黄苷与JUN(2G01)结合最好,可以推断JUN(2G01)是土大黄苷优先选择的作用受体.其次,得分较高的还有SRC (SRC)、JAK2 (5AEP)、MAPK14(2YIX)、FRAP1(3OAW)、MAPK8(3PZE)和PARP1(1U5Y)等.结论 大黄活性成分土大黄苷对CML的作用机制是多靶点、多途径相互作用的,其作用受体可能与JUN、SRC、JAK2、MAPK14、FRAP1、MAPK8和PARP1等基因相关.     

基于网络药理学和分子对接法预测甘草干姜汤抗乳腺癌的主要活性成分及作用机制

目的： 利用网络药理学和分子对接法研究甘草干姜汤（LDGD）可能的抗乳腺癌活性成分及作用机制。方法： 借助TCMSP数据库筛选出复方甘草干姜汤的主要有效成分;利用Genecards人类基因数据库获取乳腺癌的疾病靶点;利用STRING数据库和Cytoscape 3.8.0软件进行蛋白相互作用网络的构建和分析;并通过DAVID数据库进行GO富集分析和KEGG通路富集分析;基于文献检索甘草干姜汤的药效成分并将筛选出的关键靶点进行分子对接。结果： LDGD抗乳腺癌潜在的关键靶点有AKT1、MYC、TP53、EGF等;GO功能富集分析显示与作用靶点有关的生物学过程主要有凋亡信号通路、氧化应激等;细胞成分主要有细胞周期蛋白依赖性激酶、转录因子复合体、丝氨酸/苏氨酸蛋白激酶复合物、膜区、膜微区等;分子功能主要有蛋白质丝氨酸/苏氨酸激酶活性、转录因子活性核受体活性、泛素蛋白连接酶结合等;KEGG通路分析结果显示主要涉及p53、TNF、IL-17、EGFR、细胞凋亡等信号通路;以AKT1为靶点,8种药效成分中与其结合的小分子有甘草苷、6-姜酚、6-姜烯酚、甘草素、异甘草素、异甘草苷,其中甘草苷、6-姜酚、6-姜烯酚、甘草素的打分值大于原配体打分值的80%。结论： 甘草苷、6-姜酚、6-姜烯酚、甘草素可能是甘草干姜汤中抗乳腺癌主要活性成分之一,抗肿瘤作用机制可能涉及细胞增殖、凋亡、氧化应激、炎症等相关通路。     

甘草干姜汤的抗胃癌作用及其机制研究

目的: 采用血清药理学方法探究甘草干姜汤(LDGD)的体外抗胃癌作用,并基于网络药理学和分子对接法探讨其抗胃癌机制。方法: 以不同配比的甘草干姜汤灌胃大鼠后以腹主动脉取血方式提取含药血清,利用四甲基噻唑蓝(MTT)法观察甘草、干姜不同配比LDGD大鼠含药血清对人胃腺癌细胞AGS以及人脐静脉血管内皮细胞HUVEC活力的影响;基于网络药理学构建LDGD抗胃癌的“成分-靶点”网络,通过构建蛋白-蛋白相互作用网络(PPI)筛选出关键靶点,通过GO功能和KEGG通路富集分析探究LDGD抗胃癌可能涉及的生物学功能和信号通路;通过分子对接分析LDGD中文献报道的8种主要成分甘草苷、异甘草苷、甘草素、异甘草素、甘草酸、6-姜酚、6-姜烯酚、8-姜酚和抗胃癌关键靶点的结合情况。结果: 血清药理学实验中不同配比LDGD灌胃大鼠后提取的30%含药血清对人胃腺癌细胞AGS的细胞活力均产生了显著的抑制作用,而对HUVEC无明显抑制作用;通过网络药理学分析得到LDGD有效化学成分101个,抗胃癌关键靶点为VEGFA、TNF-α、CASP3、MYC;富集分析结果表明,LDGD抗胃癌可能主要通过对凋亡信号、氧化应激、活性氧反应等途径的调节,以及对TNF、p53等信号通路发挥作用;分子对接结果表明,甘草酸、甘草苷与VEGFA对接良好,6-姜酚与TNF-α对接良好,且这3种成分在LDGD中含量相对较高。结论: 甘草干姜汤具有一定抗胃癌活性,其机制可能是通过调节氧化应激,作用于TNF、p53等信号通路,其中甘草酸、甘草苷、6-姜酚可能为关键药效成分。     

Ampelopsin Inhibits Breast Cancer Glucose Metabolism Reprogramming Based on Network Pharmacology and Molecular Docking

Background: Breast cancer (BC) is the most frequent type of gynecology tumors with high morbidity and mortality. Ampelopsin, the main active compound of Ampelopsis grossedentata, exerts an anti-tumor effect on a variety of cancers. However, the anti-cancer role of ampelopsin in BC remains unclear. The aim of this study is to explore the mechanism of ampelopsin against breast cancer. Materials and Methods: The target genes of ampelopsin in the treatment of breast cancer were determined and analyzed by network pharmacology and molecular docking. Cytoscape software was used to identify the core target genes and construct a protein–protein interaction (PPI) network. Discovery Studio software was used to perform the molecular docking of ampelopsin and core genes and glycolytic metabolic enzymes. Results: In total, 25 potential target genes of ampelopsin were screened out. The core target genes of ampelopsin against breast cancer were AKT1, ESR1, ESR2, NCOA1, HSP90AA1, NCOA2, BECN1, COMT, HMOX1, and CDK6, with AKT1, ESR1 and ESR2 considered as the key target proteins. Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis showed that ampelopsin inhibited breast cancer via modulating the estrogen signaling pathway, apoptosis regulation, carbohydrate metabolism, and inflammation. Molecular docking analysis showed that ampelopsin possessed a stable binding ability to regulate the three target proteins and glycolytic metabolic enzymes such as ALDOA and LDHA. Conclusions: Ampelopsin may inhibit the proliferation of breast cancer cells by acting on AKT and estrogen-related glucose metabolic pathways and inhibiting the enzymes involved in glycolysis and oxidative phosphorylation.     

Quadruple-editing of the MAPK and PI3K pathways effectively blocks the progression of KRAS-mutated colorectal cancer cells

Mutated KRAS promotes the activation of the MAPK pathway and the progression of colorectal cancer (CRC) cells. Aberrant activation of the PI3K pathway strongly attenuates the efficacy of MAPK suppression in KRAS-mutated CRC. The development of a novel strategy targeting a dual pathway is therefore highly essential for the therapy of KRAS-mutated CRC. In this study, a quadruple-depleting system for the KRAS, MEK1, PIK3CA, and MTOR genes based on CRISPR/SaCas9 was developed. Adenovirus serotype 5 (ADV5) was integrated with two engineered proteins, an adaptor and a protector, to form ADV-protein complex (APC) for systemic delivery of the CRISPR system. Quadruple-editing could significantly inhibit the MAPK and PI3K pathways in CRC cells with oncogenic mutations of KRAS and PIK3CA or with KRAS mutation and compensated PI3K activation. Compared with MEK and PI3K/MTOR inhibitors, quadruple-editing induced more significant survival inhibition on primary CRC cells with oncogenic mutations of KRAS and PIK3CA. The adaptor specifically targeting EpCAM and the hexon-shielding protector could dramatically enhance ADV5 infection efficiency to CRC cells and significantly reduce off-targeting tropisms to many organs except the colon. Moreover, quadruple-editing intravenously delivered by APC significantly blocked the dual pathway and tumor growth of KRAS-mutated CRC cells, without influencing normal tissues in cell- and patient-derived xenograft models. Therefore, APC-delivered quadruple-editing of the MAPK and PI3K pathways shows a promising therapeutic potential for KRAS-mutated CRC.     

基于网络药理学-分子对接技术研究贞芪扶正颗粒治疗大肠癌相关性疲乏的作用机制

目的：探讨贞芪扶正颗粒治疗大肠癌相关性疲乏的作用机制。方法：通过中药系统药理学数据库与分析平台(TCMSP)获取黄芪、女贞子的主要化学成分及靶点,根据ADME筛选中药活性组分;通过GeneCards、OMIM等数据库获取大肠癌相关性疲乏的主要靶点,利用String平台进行蛋白质相互作用分析,构建蛋白互作网络(PPI)并使用CytoScape 3.7.2中的MCODE插件挖掘网络中潜在的蛋白质功能模块。采用Metascape平台分析“药物-成分-靶点”及其参与的生物过程及通路,然后采用Cytoscape 3.7.2软件构建“贞芪扶正颗粒成分-大肠癌相关性疲乏靶点-通路”网络,最后通过AutoDock Vina1.1.2进行分子对接验证。结果：贞芪扶正颗粒治疗大肠癌相关性疲乏的核心活性成分为槲皮素、木犀草素、山柰酚、β-谷甾醇、毛蕊异黄酮等,核心靶点有 AKT1、JUN、MMP9、VEGFA等,分子对接结果亦证明以上核心成分与核心靶点结合活性较好。贞芪扶正颗粒治疗大肠癌相关性疲乏的生物学通路主要作用于癌症通路、PI3K-AKT信号通路等。结论：贞芪扶正颗粒治疗大肠癌相关性疲乏的机制具有多成分、多靶点、多通路的特点,本研究为进一步研究贞芪扶正颗粒治疗大肠癌相关性疲乏的机制及临床应用提供了依据。     

基于网络药理学的防己黄芪汤治疗乳腺癌机制探讨

目的:对防己黄芪汤进行网络药理学分析，探讨该方治疗乳腺癌的潜在靶点及作用机制。方法:通过TCMSP等数据库建立防己黄芪汤有效成分和靶点数据集，利用GeneCards数据库及OMIM数据库建立乳腺癌相关靶点数据集，并与中药靶点数据相匹配。通过STRING数据库分析关键靶点蛋白间的相互作用关系，并利用生物学信息注释数据库进行靶点基因本体（GO）生物过程分析以及京都基因与基因组百科全书（KEGG）信号通路富集分析，运用Cytoscape 3.6.0软件进行活性成分-疾病靶点的网络分析。结果:共发现防己黄芪汤治疗乳腺癌有108个可能的重要靶点，包括IL-6、ALB、CASP3、VEGFA、EGFR等；GO富集分析得到与乳腺癌相关的118个细胞生物学过程（P＜0.05）；KEGG富集分析得到与乳腺癌相关的113条通路（P＜0.05），包括细胞凋亡、TNF信号通路等。体外实验表明防己黄芪汤具有诱导乳腺癌MDA-MB-231细胞凋亡的作用，部分验证了网络药理学的预测结果。结论:防己黄芪汤对乳腺癌的治疗作用可能是多靶点、多途径、多机制的，本研究结果为防己黄芪汤的临床应用提供了更多证据支持。     

Mutations and Deregulation of Ras/Raf/MEK/ERK and PI3K/PTEN/Akt/mTOR Cascades Which Alter Therapy Response

The Ras/Raf/MEK/ERK and PI3K/PTEN/Akt/mTOR cascades are often activated by genetic alterations in upstream signaling molecules such as receptor tyrosine kinases (RTK). Certain components of these pathways, RAS, NF1, BRAF, MEK1, DUSP5, PP2A, PIK3CA, PIK3R1, PIK3R4, PIK3R5, IRS4, AKT, NFKB1, MTOR, PTEN, TSC1, and TSC2 may also be activated/inactivated by mutations or epigenetic silencing. Upstream mutations in one signaling pathway or even in downstream components of the same pathway can alter the sensitivity of the cells to certain small molecule inhibitors. These pathways have profound effects on proliferative, apoptotic and differentiation pathways. Dysregulation of components of these cascades can contribute to: resistance to other pathway inhibitors, chemotherapeutic drug resistance, premature aging as well as other diseases. This review will first describe these pathways and discuss how genetic mutations and epigenetic alterations can result in resistance to various inhibitors.     

Oncogenic PI3K and its role in cancer

PURPOSE OF REVIEW: The purpose of this review is to examine the contribution of the PI3K signaling pathway to the development of human tumors and to propose further studies to elucidate how to develop therapeutics for patients with mutations in this pathway. RECENT FINDINGS: More than 30% of various solid tumor types were recently found to contain mutations in PIK3CA, the catalytic subunit of PI3K. Further analysis of key genes in this pathway identified an additional eight genes altered in tumors. These were generally found to be mutated in a mutually exclusive manner, thus increasing the mutation frequency of the pathway to 40% in colorectal cancers and emphasizing the importance of the PI3K pathway in tumorigenesis. Functional analyses of PIK3CA mutations revealed that they increase its enzymatic activity, stimulate AKT signaling, allow growth factor-independent growth as well as increasing cell invasion and metastasis. SUMMARY: The PI3K signaling pathway is dysregulated by a variety of mechanisms in a large fraction of human tumors. Both mutational and functional analyses have shown that PIK3CA is an oncogene that plays an important role in tumor progression. Mutant members of the PI3K pathway, including PIK3CA, are good targets for therapeutic intervention because most of them are kinases, making them attractive for drug development. Gaining further insights into PIK3CA oncogenic mechanisms may produce new biomarkers and help the development of targeted therapeutics.     

Co-activation of PIK3CA and Yap promotes development of hepatocellular and cholangiocellular tumors in mouse and human liver

Activation of the PI3K and Yes-associated protein (Yap) signaling pathways has been independently reported in human hepatocellular carcinoma (HCC). However, the oncogenic interactions between these two cascades in hepatocarcinogenesis remain undetermined. To assess the consequences of the crosstalk between the PI3K and Yap pathways along liver carcinogenesis, we generated a mouse model characterized by combined overexpression of activated mutant forms of PIK3CA (PIK3CAH1047R) and Yap (YapS127A) in the mouse liver using hydrodynamic transfection (PIK3CA/Yap). In addition, suppression of PI3K and Yap pathways was conducted in human HCC and cholangiocarcinoma (CCA) cell lines. We found that concomitant activation of PI3K and Yap pathways triggered rapid liver tumor development in mice. Histologically, tumors were pure HCC, CCA, or mixed HCC/CCA. At the molecular level, PIK3CA/Yap tumors were characterized by activation of the mTORC1/2, ERK/MAPK, and Notch pathways. Simultaneous activation of PI3K and Yap pathways frequently occurred in human liver tumor specimens and their combined suppression was highly detrimental for the growth of HCC and CCA cell lines. In conclusion, our study demonstrates the oncogenic cooperation between PI3K and Yap pathways along liver carcinogenesis. The PIK3CA/Yap mouse represents an important preclinical liver tumor model for the development of novel therapeutics against this malignancy.     

Oncogenic PIK3CA mutations in colorectal cancers and polyps

Oncogenic PIK3CA mutations contribute to colorectal tumorigenesis by activating AKT signaling to decrease apoptosis and increase tumor invasion. A synergistic association of PIK3CA mutation with KRAS mutation has been suggested to increase AKT signaling and resistance to antiepidermal growth factor receptor inhibitor therapy for advanced colorectal cancer, although studies have been conflicting. We sought to clarify this by examining PIK3CA mutation frequency in relation to other key molecular features of defined pathways of tumorigenesis. PIK3CA mutation was assessed by high resolution melt analysis in 829 colorectal cancer samples and 426 colorectal polyps. Mutations were independently correlated with clinicopathological features including patient age, sex and tumor location as well as molecular features including microsatellite instability, KRAS and BRAF mutation, MGMT methylation and the CpG Island Methylator Phenotype (CIMP). Mutation of the helical (Exon 9) and catalytic (Exon 20) domain mutation hotspots were also examined independently. Overall, PIK3CA mutation was positively correlated with KRAS mutation (p < 0.001), MGMT methylation (p = 0.007) and CIMP (p < 0.001). Novel, exon-specific associations linked Exon 9 mutations to a subgroup of cancers characterized by KRAS mutation, MGMT methylation and CIMP-Low, whilst Exon 20 mutations were more closely linked to features of serrated pathway tumors including BRAF mutation, microsatellite instability and CIMP-High or Low. PIK3CA mutations were uncommonly, but exclusively, seen in tubulovillous adenomas (4/124, 3.2%) and 1/4 (25.0%) tubulovillous adenomas with a focus of cancer. These data provide insight into the molecular events driving traditional versus serrated pathway tumorigenesis.     

Integrative Bioinformatics Analysis Reveals Potential Target Genes and TNFα Signaling Inhibition by Brazilin in Metastatic Breast Cancer Cells

Objective: Metastasis is the most significant cause of morbidity and mortality in breast cancer patients. Previously, a combination of brazilin and doxorubicin has been shown to inhibit metastasis in HER2-positive breast cancer cells. This present study used an integrative bioinformatics approach to identify new targets and the molecular mechanism of brazilin in inhibiting metastasis in breast cancer. Methods: Cytotoxicity and mRNA arrays data were retreived from the DTP website, whereas genes that regulate metastatic breast cancer cells were retreived from PubMed with keywords “breast cancer metastasis”. Gene ontology (GO), Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment, and Drug association analysis were carried out by using WEB-based GEne SeT AnaLysis Toolkit (WebGestalt). Construction of protein-protein interaction (PPI) network analysis was performed by STRING-DB v11.0 and Cytoscape, respectively. The genetic alterations of the potential therapeutic target genes of brazilin (PB) were analyzed using cBioPortal. Results: Analysis of cytotoxicity with the public database of COMPARE showed that brazilin exerts almost the same cytotoxicity in the NCI-60 cells panel showing by similar GI50 value, in which the lowest GI50 value was observed in MDA-MB 231, a metastatic breast cancer cells. KEGG enrichment indicated several pathways regulated by brazilin such as TNF signaling pathway, cellular senescence, and pathways in cancer. We found ten drugs that are associated with PB, including protein kinase inhibitors, TNFα inhibitors, enzyme inhibitors, and anti-inflammatory agents. Conclusion: In conclusion, this study identified eight PB, including MMP14, PTGS2, ADAM17, PTEN, CCL2, PIK3CB, MAP3K8, and CXCL3. In addition, brazilin possibly inhibits metastatic breast cancer through inhibition of TNFα signaling. The study results study need to be validated with in vitro and in vivo studies to strengthen scientific evidence of the use of brazilin in breast cancer metastasis inhibition.     

基因芯片筛选多形性胶质母细胞瘤差异表达基因和通路

目的 利用基因芯片技术和生物信息学分析方法,筛选出多形性胶质母细胞瘤相关的核心基因和信号通路,为寻找多形性胶质母细胞瘤早期诊断和靶向治疗潜在标志物提供依据。方法 从GEO数据库中获取多形性胶质母细胞瘤mRNA表达谱芯片原始数据,利用R软件分析得到明显差异表达基因（differentially expressed genes, DEGs）,对DEGs进行功能注释（GO ontology）和KEGG信号通路（KEGG signaling pathway）富集,进一步构建蛋白质相互作用网络（protein-protein interaction network, PPI）,筛选核心基因,最后利用TCGA肿瘤数据库进行验证。结果 通过Pearson聚类分析发现肿瘤和正常组织聚类区分明显,说明表达谱结果可靠;差异基因共2 142个,其中上调基因968个,下调基因1 174个;GO和KEGG富集结果显示,差异基因的功能主要涉及细胞周期、细胞分裂和增殖、突触传递等生物学功能和通路,通路网络分析表明MAPK信号通路起核心调控地位。通过构建PPI网络筛选出9个与GBM密切相关的核心基因,进一步利用TCGA肿瘤数据库验证,与芯片结果一致。结论 KEGG信号通路和核心基因可能揭示了多形性胶质母细胞瘤发生发展的分子机制,核心基因可能用作多形性胶质母细胞瘤的早期诊断的分子标志物和治疗靶点。     

基于网络药理学和动物实验探讨青蒿鳖甲汤抗血管新生的作用机制

目的:基于网络药理学预测青蒿鳖甲汤抗血管新生的潜在分子机制,并用Lewis肺癌小鼠移植瘤模型对STAT3/VEGF信号通路进行实验验证。方法:使用TCMSP、BATMAN-TCM数据库及文献筛选青蒿鳖甲汤的有效成分,利用Swiss Target Prediction平台预测成分靶点基因。GeneCards、OMIM、TTD等3个数据库检索血管新生靶点基因,与中药成分靶点基因匹配后,使用STRING数据库和Cytoscape 3.7.1软件进行蛋白质间相互作用（protein-protein interaction,PPI）分析,筛选关键靶点基因;Metascape平台对关键靶点基因进行基因本体（gene ontology,GO）功能富集分析及京都基因与基因组百科全书（Kyoto encyclopedia of genes and genomes,KEGG）通路富集分析。在动物实验中,C57BL/6J雄性小鼠接种Lewis肺癌细胞,建立皮下移植瘤模型,分为模型组,青蒿鳖甲汤高（16.0 g/kg）、中（8.0 g/kg）、低（4.0 g/kg）剂量组,贝伐株单抗组（15 mg/kg）,分别给予相应剂量青蒿鳖甲汤灌胃或贝伐株单抗腹腔注射。14天后处死,取皮下瘤组织,称量瘤重,计算瘤体积和抑瘤率。免疫组化法检测血管标志物CD31表达情况,计算微血管密度（microvascular density,MVD）;HE染色法观察瘤组织病理形态;Western blot法检测pSTAT3、STAT3及VEGF蛋白表达水平。结果:获取青蒿鳖甲汤有效成分61个及靶点基因523个,血管新生相关靶点基因1 229个,交集靶点基因176个,关键靶点基因22个,其中VEGF是青蒿鳖甲汤发挥抗血管新生作用的首位关键靶点基因,信号通路以癌症相关信号通路为主,如HIF-1、VEGF、JAK-STAT等。动物实验结果表明,与模型组相比,青蒿鳖甲汤中、高剂量组瘤重、瘤体积均显著降低（P＜0.05或P＜0.01）,高剂量组MVD降低（P＜0.01）;各给药组肿瘤细胞体积缩小,核固缩、碎裂现象多见,可见不同程度的坏死区及出血;高剂量组VEGF、pSTAT3蛋白表达水平及pSTAT3/STAT3水平均显著降低（P＜0.05）,中、低剂量组VEGF、pSTAT3蛋白水平虽有降低趋势,但差异无统计学意义。结论:青蒿鳖甲汤可以通过多成分-靶点-通路抑制血管新生,其作用机制可能与抑制STAT3/VEGF信号通路有关。     

Genetic deregulation of the PIK3CA oncogene in oral cancer

The phosphatidylinositol 3-kinase (PI3K)/Akt signaling pathway is one of the most commonly deregulated pathways in human cancers. PI3K comprises a catalytic (p110α) and regulatory subunit (p85), and p110α is encoded by the PIK3CA gene. Here, we summarize the known genetic alterations, including amplifications and mutations, of the PIK3CA oncogene in oral cancer. We discuss in detail PIK3CA mutations and their mutual exclusivity with pathway genes in addition to the incidence of PIK3CA mutations in relation to ethnicity. We describe the constitutive activation of PI3K signaling, oncogenicity, and the genetic deregulation of the PIK3CA gene and its association with oral cancer disease stage. We emphasize the importance of therapeutically targeting the genetically deregulated PIK3CA oncogene and its signaling. We also discuss the implications of targeting Akt and/or mTOR, which are the downstream effectors of PI3K that may possibly pave the way for molecular therapeutic targets for PIK3CA-driven oral carcinogenesis. Furthermore, this critical review provides a complete picture of the PIK3CA oncogene and its deregulation in oral cancer, which may facilitate early diagnosis and improve prognosis through personalized molecular targeted therapy in oral cancer.     

Hippo/YAP signaling pathway is involved inosteosarcoma chemoresistance

Background:Osteosarcoma is the most common bone malignancy in children and adolescents, and 20%–30% of the patients suffer from poor prognosis because of individual chemoresistance. The Hippo/yes?associated protein (YAP) signaling pathway has been shown to play a role in tumor chemoresistance, but no previous report has focused on its involvement in osteosarcoma chemoresistance. This study aimed to investigate the role of the Hippo/YAP sign?aling pathway in osteosarcoma chemoresistance and to determine potential treatment targets.
Methods:Using the Cell Titer?Glo Luminescent cell viability assay and lfow cytometry analysis, we determined the proliferation and chemosensitivity of YAP?overexpressing and YAP?knockdown osteosarcoma cells. In addition, using western blotting and the real?time polymerase chain reaction technique, we investigated the alteration of the Hippo/YAP signaling pathway in osteosarcoma cells treated with chemotherapeutic agents.
Results:Mammalian sterile 20?like kinase 1 (MST1) degradation was increased, and large tumor suppressor kinase 1/2 (LATS1/2) total protein levels were decreased by methotrexate and doxorubicin, which increased activation and nuclear translocation of YAP. Moreover, YAP increased the proliferation and chemoresistance of MG63 cells.
Conclusions:The Hippo/YAP signaling pathway plays a role in osteosarcoma chemoresistance, and YAP is a potential target for reducing chemoresistance.     

A tipping-point for apoptosis following dual inhibition of HER2 signaling network by T-DM1 plus GDC-0980 maximizes anti-tumor efficacy

HER2 signaling network and its complex relationship with the PI3K-AKT-mTOR pathway explain the acquired resistance to anti-HER2 therapy observed in clinics. Such complexity has been clinically evident from the limited efficacy of data in the BOLERO-1 and BOLERO-3 trials, which tested combinations of trastuzumab (T), everolimus, and chemotherapy in women with HER2+ advanced BC. In the following MARIANNE trial also, a combination of T-DM1 plus pertuzumab delivered a non-inferior but yet not superior PFS compared to trastuzumab plus a taxane. Algorithmic inhibition of PI3K/mTOR along with T or T-DM1 is, therefore, an attractive drug combination, and we tested the combination(s) in HER2+ BC, especially in T-resistant and PIK3CA mutated conditions. GDC-0980, a dual pan-PI3K/mTOR inhibitor alone or in combination with T or T-DM1, was examined in a panel of HER2+ T-sensitive (BT474, SKBR3), HER2+ T-resistant (BT474HerR), HER2+/PIK3CA mutant (HCC1954, MDA-MB453), and HER2+/PTEN mutant (HCC1569) BC cell lines. GDC-0980 re-sensitized trastuzumab-resistant, PIK3CA mutant, or PTEN mutant cells to T and acted additively with T. Importantly, this activity was more when GDC-0980 is combined with T-DM1. The combination (with T or with T-DM1) was then tested in the HER2+/T-sensitive, HER2+/T-resistant, and HER2+/PIK3CA mutated BC xenograft models for the anti-tumor effect. Along with its anti-tumor effect, GDC-0980 effectively decreased tumor angiogenesis (CD31 staining). Maximum anti-tumor (from tumor growth inhibition to tumor regression) efficiency was observed in all three xenograft models when T-DM1 was combined with GDC-0980. The anti-proliferative effects of GDC-0980 as evidenced by a decreased p-AKT (Ser473, The308), p-P70S6K, p-S6RP, and p-4EBP1, along with blockade of clonogenic 3D growth was accompanied by the initiation of apoptotic activity (annexin V, CASPASE3, cleaved PARP1 and mitochondrial depolarization); and was significantly superior when GDC-0980 combined with T-DM1. Interestingly, both trastuzumab and T-DM1 induce PD-L1 expression in HER2 amplified BC cells. Our data provide evidence that an oncogenic mutation of PIK3CA and HER2-amplification may represent biomarkers to identify patients who may benefit most from the use of GDC-0980 and an opportunity to include immunotherapy in the combination of anti-HER2 therapy.     

Novel mutant-enriched sequencing identified high frequency of PIK3CA mutations in pharyngeal cancer

We previously reported 4 PIK3CA mutations in 38 head and neck cancer samples, 3 of which were identified in 6 pharyngeal cancer samples. To determine the mutation frequency of PIK3CA in pharyngeal cancer, we studied 24 additional cases of pharyngeal squamous cell carcinoma in this study. Using both direct genomic DNA sequencing and novel mutant-enriched sequencing methods developed specifically for the 3 hot-spot mutations (H1047R, E545K and E452K) of PIK3CA, we detected 5 mutations of PIK3CA in the 24 pharyngeal cancers (20.8%). Three of the 5 mutations had been missed by the conventional sequencing method and were subsequently detected by novel mutant-enriched sequencing methods. We showed that the mutant-enriched sequencing method for the H1047R hot-spot mutation can identify the mutation in a mixed population of mutant and wild-type DNA sequences at 1:360 ratios. These novel mutant-enriched sequencing methods allow the detection of the PIK3CA hot-spot mutations in clinical specimens which often contain limited tumor tissues (i.e., biopsy specimens). The data further support that oncogenic PIK3CA may play a critical role in pharyngeal carcinogenesis, and the mutant-enriched sequencing methods for PIK3CA are sensitive and reliable ways to detect PIK3CA mutations in clinical samples. Because PIK3CA and its pathway are potential targets for chemotherapy and radiation therapy, and frequent somatic mutation of PIK3CA has been identified in many human cancer types (e.g., breast cancer, colorectal cancer), the abilities to detect PIK3CA mutations with enhanced sensitivities have great potential impacts on target therapies for many cancer types.