LY3214996 relieves acquired resistance to sorafenib in hepatocellular carcinoma cells

Background: Sorafenib, an oral multi-kinase inhibitor of rapidly accelerated fibrosarcoma; vascular endothelial growth factor receptor-2/3, platelet-derived growth factor receptor, c-Kit, and Flt-3 signaling, is approved for treatment of advanced hepatocellular carcinoma (HCC). However, the benefit of sorafenib is often diminished because of acquired resistance through the reactivation of ERK signaling in sorafenib-resistant HCC cells. In this work, we investigated whether adding LY3214996, a selective ERK1/2 inhibitor, to sorafenib would increase the anti-tumor effectiveness of sorafenib to HCC cells.Methods: The Huh7 cell line was used as a cell model for treatment with sorafenib, LY3214996, and their combination. Phosphorylation of the key kinases in the Ras/Raf/MAPK and PI3K/Akt pathways, protein expression of the cell cycle, and apoptosis migration were assessed with western blot. MTT and colony-formation assays were used to evaluate cell proliferation. Wound-healing assay was used to assess cell migration. Cell cycle and apoptosis analyses were conducted with flow cytometry.Results: LY3214996 decreased phosphorylation of the Ras/Raf/MAPK and PI3K/Akt pathways, including p-c-Raf, p-P90RSK, p-S6K and p-eIF4EBP1 activated by sorafenib, despite increased p-ERK1/2 levels. LY3214996 increased the anti-proliferation, anti-migration, cell-cycle progression, and pro-apoptotic effects of sorafenib on Huh7^R cells.Conclusions: Reactivation of ERK1/2 appears to be a molecular mechanism of acquired resistance of HCC to sorafenib. LY3214996 combined with sorafenib enhanced the anti-tumor effects of sorafenib in HCC. These findings form a theoretical basis for trial of LY3214996 combined with sorafenib as second-line treatment of sorafenib-resistant in advanced HCC.     

p53和DNA损伤调节基因1在口腔癌组织中的表达及通过Wnt/β-catenin信号途径对口腔癌细胞自噬和凋亡的影响

目的：探讨p53 和DNA损伤调节基因1（PDRG1）在口腔癌组织中的表达及通过Wnt/β-catenin 信号途径对 口腔癌细胞自噬和凋亡的影响。方法：收集2017 年6 月至2019 年6 月在河南省第二人民医院60 例接受口腔癌切 除手术的患者的癌组织标本及配对的癌旁组织,qRT-PCR 和免疫印迹检测PDRG1 在口腔癌组织中的mRNA和蛋 白表达;同时体外培养正常人口腔角质形成细胞（NHOK）和口腔癌细胞系,qRT-PCR 和免疫印迹检测PDRG1 在口腔癌细胞系中的mRNA和蛋白表达;将口腔癌细胞系SCC-15 细胞分为shNC 组和shPDRG1 组,细胞集落形 成实验检测细胞增殖能力;免疫印迹检测细胞中LC3Ⅱ/LC3Ⅰ蛋白表达比例;透射电镜检测细胞中自噬体数量; 流式细胞术检测细胞凋亡率;免疫印迹检测Wnt/β-catenin 信号途径相关蛋白表达。结果：PDRG1 在口腔癌组织 和口腔癌细胞系中高表达;与shNC 组相比,shPDRG1 组SCC-15 细胞中PDRG1 mRNA 的表达显著下降, PDRG1 蛋白的表达水平明显下调。与shNC 组相比,shPDRG1 组SCC-15 细胞的集落数目明显减少,细胞中LC3Ⅱ/LC3Ⅰ 的比例减少;与shNC 组比较,shPDRG1 组细胞中自噬体数量减少,细胞的凋亡率明显提高,细胞中β-catenin、 c-Myc、cyclin D1 蛋白表达水平下调。结论：PDRG1 在口腔癌组织和口腔癌细胞系中高表达,沉默PDRG1 抑制 SCC-15 细胞增殖和自噬,增强SCC-15 细胞的凋亡率及抑制Wnt/β-catenin 信号途径。     

SH003 induces apoptosis of DU145 prostate cancer cells by inhibiting ERK-involved pathway

Background

Herbal medicines have been used in cancer treatment, with many exhibiting favorable side effect and toxicity profiles compared with conventional chemotherapeutic agents. SH003 is a novel extract from Astragalus membranaceus, Angelica gigas, and Trichosanthes Kirilowii Maximowicz combined at a 1:1:1 ratio that impairs the growth of breast cancer cells. This study investigates anti-cancer effects of SH003 in prostate cancer cells.

Methods

SH003 extract in 30% ethanol was used to treat the prostate cancer cell lines DU145, LNCaP, and PC-3. Cell viability was determined by MTT and BrdU incorporation assays. Next, apoptotic cell death was determined by Annexin V and 7-AAD double staining methods. Western blotting was conducted to measure protein expression levels of components of cell death and signaling pathways. Intracellular reactive oxygen species (ROS) levels were measured using H₂DCF-DA. Plasmid-mediated ERK2 overexpression in DU145 cells was used to examine the effect of rescuing ERK2 function. Results were analyzed using the Student’s t-test and P-values?<?0.05 were considered to indicate statistically-significant differences.

Results

Our data demonstrate that SH003 induced apoptosis in DU145 prostate cancer cells by inhibiting ERK signaling. SH003 induced apoptosis of prostate cancer cells in dose-dependent manner, which was independent of androgen dependency. SH003 also increased intracellular ROS levels but this is not associated with its pro-apoptotic effects. SH003 inhibited phosphorylation of Ras/Raf1/MEK/ERK/p90RSK in androgen-independent DU145 cells, but not androgen-dependent LNCaP and PC-3 cells. Moreover, ERK2 overexpression rescued SH003-induced apoptosis in DU145 cells.

Conclusions

SH003 induces apoptotic cell death of DU145 prostate cancer cells by inhibiting ERK2-mediated signaling.

     

干扰素诱导蛋白p204对大鼠血管平滑肌细胞增殖的影响及其机制

目的: 研究干扰素诱导蛋白p204对大鼠血管平滑肌细胞(VSMCs)增殖的影响并探讨其可能的机制。方法: 应用干扰素α(IFN-α)和p204基因(Ifi204)的小干扰RNA(siRNA)瞬时干预体外培养的VSMCs,用MTT法测定细胞活力反映细胞增殖,流式细胞术分析细胞周期,用实时 qRT-PCR法和Western blotting 分别检测mRNA和蛋白表达。结果: IFN-α可诱导大鼠VSMCs p204 mRNA和蛋白表达上调,抑制VSMCs细胞活力和细胞周期G₁/S转换,伴Ras蛋白表达减少,Raf和ERK磷酸化水平下降。转染Ifi204 siRNA可抑制p204表达,提高VSMCs细胞活力和促进细胞周期G₁/S转换,伴Ras蛋白表达增多,Raf和ERK磷酸化水平升高。结论: p204表达可抑制鼠VSMCs的增殖,该效应可能与p204抑制Ras/Raf/MEK/ERK信号通路的激活有关。     

Silibinin inhibited autophagy and mitochondrial apoptosis in pancreatic carcinoma by activating JNK/SAPK signaling

BackgroundPrevious investigation have indicated Silibinin induces apoptosis and JNK/SAPK in human pancreatic cancer cells. This study aims to evaluate the further mechanism of Silibinin in pancreatic cancer treatment.Materials and methodsHuman pancreatic cancer cell lines SW1990 was treated with Silibinin and/or JNK/SAPK inhibitor SP600125 followed by measurement of cell viability, apoptosis, autophagy, ROS and ATP, and western blotting.ResultsSilibinin promoted cell viability and promoted cell apoptosis. The expression of ROS and ATP associated with mitochondrial function was also promoted by the treatment of silibinin. Silibinin also promoted autophagy in pancreatic cancer cells. All these biological effects of Silibinin can be reversed by JNK/SAPK inhibitor.ConclusionsThe biological effects regulated by Silibinin can be mediated by JNK/SAPK signaling. This provides a solid theoretical basis for the role of Silibinin in the treatment of pancreatic cancer.     

Up-regulation of Ras/Raf/ERK1/2 signaling impairs cultured neuronal cell migration, neurogenesis, synapse formation, and dendritic spine development

The Ras/Raf/ERK1/2 signaling pathway controls many cellular responses such as cell proliferation, migration, differentiation, and death. In the nervous system, emerging evidence also points to a death-promoting role for ERK1/2 in both in vitro and in vivo models of neuronal death. Recent studies have suggested that abnormal apoptosis in the central nervous system may be involved in the pathogenesis of autism. Two studies reported that both a microdeletion and microduplication on chromosome 16, which includes the MAPK3 gene that encodes ERK1, are associated with autism. In addition, our recent work showed that Ras/Raf/ERK1/2 signaling activities were significantly up-regulated in the frontal cortex of autistic individuals and in the BTBR murine model of autism. To further investigate how Ras/Raf/ERK1/2 up-regulation may lead to the development of autism, we developed a cellular model of Raf/ERK up-regulation by over-expressing c-Raf in cultured cortical neurons (CNs) and cerebellar granule cells (CGCs). We found that Raf/ERK up-regulation stimulates the migration of both CNs and CGCs, and impairs the formation of excitatory synapses in CNs. In addition, we found that Raf/ERK up-regulation inhibits the development of mature dendritic spines in CNs. Investigating the possible mechanisms through which Raf/ERK up-regulation affects excitatory synapse formation and dendritic spine development, we discovered that Raf/ERK up-regulation suppresses the development and maturation of CNs. Together, these results suggest that the up-regulation of the Raf/ERK signaling pathway may contribute to the pathogenesis of autism through both its impairment of cortical neuron development and causing neural circuit imbalances.     

重组IL-12对人乳腺癌细胞自噬的研究

目的 探讨重组人IL-12（rIL-12）对乳腺癌细胞自噬的影响。方法 两株乳腺癌细胞（MDA-MB-231和MCF7）分别用rIL-12处理,经免疫蛋白印迹技术和细胞免疫荧光技术检测其自噬微管相关蛋白轻链3（LC3）的变化,以观察自噬情况;另外,用透射电镜观察rIL-12处理乳腺癌细胞前后自噬小体的变化。分别用胰岛素样生长因子1（IGF-1）激活磷脂酰肌醇-3激酶/蛋白激酶B（PI3K/Akt）通路,再加入rIL-12处理后,蛋白免疫印迹法检测相关通路蛋白PI3K/Akt, 哺乳动物雷帕霉素靶点（TOR）磷酸化变化及LC3的表达。结果 与空白组相比,rIL-12组细胞的自噬标志蛋白LC3表达增高,差异有统计学意义（P＜0.05）,且增加程度呈时间和浓度依赖性;荧光显微镜观察自噬体形成的结果显示,与空白组相比,rIL-12处理组的细胞核周点状聚集的绿色荧光增多;使用电镜观察到rIL-12处理组明显有自噬小体形成。与rIL-12组相比,IGF-1+rIL-12组的LC3Ⅱ表达减少,差异有统计学意义（P＜0.05）。结论 rIL-12可以激活乳腺癌细胞自噬,并通过抑制PI3K/Akt信号通路的机制,促进自噬标志蛋白LC3,特别是LC3Ⅱ的表达。     

顺铂对膀胱癌细胞自噬和凋亡的作用及其相关性

目的研究顺铂(DDP)能否激活人膀胱癌T24细胞自噬以及其中可能的机制,并且探索自噬和凋亡之间相关性。方法用MTT法检测不同浓度的顺铂(0、10、20和40μg/m L)对T24细胞的增殖作用。透射电镜观察细胞内自噬小体;用Western blot技术检测细胞内LC3-Ⅱ、P62蛋白和细胞外信号调节蛋白激酶1/2(ERK1/2)和磷酸化ERK1/2蛋白的表达量。研究自噬对于DDP处理后T24细胞增殖和凋亡的影响。结果 DDP可显著抑制T24细胞的增殖(P0.05),并呈浓度依赖性,半数抑制浓度(IC50)为(30.3±2.4)μg/m L。DDP可以诱导T24细胞发生自噬,细胞自噬体数目明显增加;明显上调LC3-Ⅱ蛋白的表达(P0.05),下调P62蛋白的表达(P0.05)。DDP能上调ERK1/2的磷酸化(P0.05);ERK1/2通路抑制剂U0126可以抑制DDP诱导的自噬,表现为LC3-Ⅱ蛋白表达明显下降(P0.05)。自噬抑制剂渥曼青霉素(WTM)抑制自噬后明显加强DDP对T24细胞的增殖抑制和凋亡促进作用(P0.05);在DDP和WTM联合处理组,细胞凋亡相关蛋白多聚ADP-核糖聚合酶1(PARP 1)裂解增强,cleaved-caspase-3增多(P0.05)。结论自噬对T24细胞具有保护作用,可抑制DDP诱导的细胞凋亡,自噬活化的机制可能与ERK信号通路的激活有关。     

增殖抑制基因抑制乳腺癌细胞生长和侵袭及其相关机制研究

目的 研究增殖抑制基因(HSG)对乳腺癌MDA-MB-231细胞(简称231细胞)生物学行为的影响并对其作用机制进行探讨.方法 构建HSG全长真核表达载体,通过脂质体瞬时转染法使其在231细胞中高表达,通过MTT比色实验检查肿瘤细胞的体外增殖能力、Matrigel穿膜实验检测肿瘤细胞体外侵袭能力和应用流式细胞术检测肿瘤细胞的细胞周期及凋亡情况;并应用GST-pulldown法检测HSG高表达对乳腺癌细胞Ras蛋白活性的影响.结果 将构建好的重组人HSG真核表达质粒pcDNA3-MYC-HSG转染至231细胞中,MTT比色实验结果显示HSG的过表达可以抑制肿瘤细胞的增殖;Matrigel侵袭实验显示转染HSG的肿瘤细胞的穿膜细胞数(HSG/231组,78.5个±5.8个)与转染空载体组(vector/231组,131.1个±14.5个)相比明显减少.流式细胞分析结果显示转染HSG/231组细胞出现了G_0/G_1期阻滞(56.3%±2.3%),且凋亡细胞的百分比与对照组(vector/231组为50.4%±1.9%)相比有所增加.Ras蛋白活性检测发现转染HSG/231组的乳腺癌细胞Ras蛋白活性明显下降.结论 HSG表达上调可抑制高侵袭性231细胞的体外增殖和侵袭能力,使其出现G_0/G_1期细胞周期阻滞,并可促进细胞凋亡.HSG对乳腺癌细胞的抑制作用可能与其抑制细胞Ras活性有关.     

A MEK inhibitor abrogates myeloproliferative disease in Kras mutant mice

Chronic and juvenile myelomonocytic leukemias (CMML and JMML) are aggressive myeloproliferative neoplasms that are incurable with conventional chemotherapy. Mutations that deregulate Ras signaling play a central pathogenic role in both disorders, and Mx1-Cre, Kras(LSL-G12D) mice that express the Kras oncogene develop a fatal disease that closely mimics these two leukemias in humans. Activated Ras controls multiple downstream effectors, but the specific pathways that mediate the leukemogenic effects of hyperactive Ras are unknown. We used PD0325901, a highly selective pharmacological inhibitor of mitogen-activated or extracellular signal-regulated protein kinase kinase (MEK), a downstream component of the Ras signaling network, to address how deregulated Raf/MEK/ERK (extracellular signal-regulated kinase) signaling drives neoplasia in Mx1-Cre, Kras(LSL-G12D) mice. PD0325901 treatment induced a rapid and sustained reduction in leukocyte counts, enhanced erythropoiesis, prolonged mouse survival, and corrected the aberrant proliferation and differentiation of bone marrow progenitor cells. These responses were due to direct effects of PD0325901 on Kras mutant cells rather than to stimulation of normal hematopoietic cell proliferation. Consistent with the in vivo response, inhibition of MEK reversed the cytokine hypersensitivity characteristic of Kras(G12D) hematopoietic progenitor cells in vitro. Our data demonstrate that deregulated Raf/MEK/ERK signaling is integral to the growth of Kras-mediated myeloproliferative neoplasms and further suggest that MEK inhibition could be a useful way to ameliorate functional hematologic abnormalities in patients with CMML and JMML.     

Inhibitory effect of β-elemene on human breast cancer cells

It has been approved for the clinical application of β-elemene to treat various cancers mainly brain tumors in China. In the present study, we found that β-elemene significantly inhibited the in vitro growth of human breast cancer cells by inducing apoptosis. In addition, β-elemene also induced the conversion of LC3-I into LC3-II as well as the formation of autolysosomes, indicating the activation of autophagy. Interestingly, inhibition of autophagy significantly potentiated the growth-inhibitory effect of β-elemene on breast cancer cells. In summary, β-elemene induced cytoprotective autophagy in human breast cancer cells in addition to apoptosis. Inhibition of autophagy significantly enhanced the cytotoxicity of β-elemene to human breast cancer cells. Therefore, combination of β-elemene with autophagy inhibitors could be a promising strategy for the treatment of breast cancer.     

Influence of copper (I) nicotinate complex and autophagy modulation on doxorubicin-induced cytotoxicity in HCC1806 breast cancer cells

PurposeDoxorubicin is regarded as the most therapeutic active agent available for triple-negative breast cancer (TNBC) treatment. However, the development of drug resistance and toxicity limits its effectiveness. Thus, developing novel strategies for TNBC treatment remains a significant challenge and doxorubicin-based combinations either by metal complexes (Copper I nicotinate complex) or with autophagy modulators could provide novel strategies and alternative strategies contributed to cancer cell death pathways, autophagy and apoptosis.Materials and methodsThe viability of HCC1806 TNBC cells and IC₅₀ values of Doxorubicin (DOX), Torin-1 (TOR), Chloroquine (CQ) and Copper (I) nicotinate complex (CNC) were assessed by MTT assay. ELISA was used for detecting microtubule-associated protein 1 light chain 3 (LC3) level. Real time PCR was used to determine (NBR1) gene expression. Cell cycle analysis and quantitative detection of acid vesicular organelles (AVOs) was performed by flow cytometry. TOR and CQ were used as autophagy modulators for induction and suppression of autophagy, respectively.ResultsThe half-maximal inhibition effect of TOR combination with DOX was revealed to the induction of autophagic cell death and apoptotic cell death. On the other hand, combination of CQ with DOX increased the growth inhibitory effect, induced accumulation of AVOs and suppressed apoptotic cell death. However, combination of CNC with DOX inhibited autophagy and induced cell cycle arrest.ConclusionDoxorubicin drug based combinations either with TOR, CQ or CNC could positively affect DOX effectiveness and reduce DOX doses applied on HCC1806 cells through modulation of autophagy.     

虫草素通过ERK1/2、Ezrin和Akt信号通路抑制胆囊癌细胞SNU-308的增殖和迁移

目的:探讨虫草素对胆囊癌细胞SNU-308增殖和迁移的影响及其分子机制。方法:MTT法和平板集落形成实验检测不同浓度虫草素对胆囊癌SNU-308细胞活力和集落形成能力的影响;Annexin V/PI双染法检测细胞凋亡率;Western blot法检测细胞凋亡和自噬相关蛋白以及Akt、ERK1/2和Ezrin蛋白的磷酸化水平;免疫荧光染色法检测细胞内LC3的表达水平;划痕愈合实验和Transwell实验检测虫草素对胆囊癌细胞迁移能力的影响;划痕实验检测Akt抑制剂和ERK1/2抑制剂及Ezrin基因沉默对细胞迁移能力的影响。结果:虫草素可显著抑制胆囊癌细胞的活力和集落形成能力(P0.05)。流式细胞术结果显示,虫草素可诱导胆囊癌细胞凋亡(P0.05)。Western blot结果显示,虫草素处理后Bcl-2表达降低,Bax、细胞色素C(Cyto C)、Fas、Fas L和cleaved caspase-3蛋白水平升高,自噬标识蛋白LC3-II/I比例和beclin 1表达上调(P0.05)。免疫荧光染色结果显示,虫草素处理后SNU-308细胞胞浆中LC3荧光颗粒的数量明显增多。划痕实验和Transwell实验结果显示虫草素可抑制细胞迁移(P0.05)。虫草素明显抑制Akt、ERK1/2和Ezrin蛋白的磷酸化水平(P0.05)。Ezrin基因沉默及Akti-1/2和GDC-0994均可抑制胆囊癌细胞的迁移作用(P0.05)。结论:虫草素通过诱导凋亡和自噬抑制胆囊癌细胞的增殖和迁移,其机制可能与调控ERK1/2,Ezrin和Akt信号通路有关。     

IGFBP7对人乳腺癌MCF-7细胞增殖的影响及其机制

目的: 探究胰岛素样生长因子结合蛋白7(IGFBP7)对人乳腺癌MCF-7细胞增殖的影响及其分子生物学机制。方法: 将质粒pCMV6-IGFBP7转染MCF-7细胞,构建稳定表达IGFBP7的MCF-7细胞系;采用Western blotting检测IGFBP7在MCF-7细胞稳定转染子的表达;采用软琼脂培养克隆形成实验检测IGFBP7对MCF-7细胞克隆形成能力的影响;采用流式细胞术检测IGFBP7对MCF-7细胞周期的影响;采用Western blotting检测IGFBP7对MCF-7细胞细胞外信号调节激酶1/2(ERK1/2)、p-ERK1/2、细胞周期素D1(cyclin D1)、细胞周期素依赖性激酶4(CDK4)、cyclin E、CDK2、p21^CIP1/WAF1、p27^KIP1、p53、视网膜母细胞瘤蛋白(Rb)和p-Rb蛋白含量的影响。结果: (1)只有稳定转染质粒pCMV6-IGFBP7的MCF-7细胞表达IGFBP7。(2)IGFBP7能够显著降低MCF-7细胞的克隆形成率(P<0.01),阻止细胞从G₁期进入S 期,使其停滞于G₁期(P<0.01)。(3)IGFBP7能够显著抑制ERK1/2的磷酸化(P<0.01)。(4)IGFBP7能够下调cyclin D1和cyclin E蛋白表达(P<0.01),上调p27^KIP1、p21^CIP1/WAF1和p53蛋白表达(P<0.01),抑制Rb的磷酸化(P<0.01)。(5)MEK1/2阻断剂PD98059可部分模拟IGFBP7的肿瘤抑制效应。结论: (1) IGFBP7可通过下调cyclin D1和cyclin E蛋白表达,上调p27^KIP1、p21^CIP1/WAF1和p53蛋白表达,以及抑制Rb磷酸化发挥抗肿瘤作用;(2) IGFBP7对cyclin D1和p27^KIP1的调节可能与其抑制ERK1/2信号通路有关。     

Cancer-associated fibroblasts promote cell growth by activating ERK5/PD-L1 signaling axis in colorectal cancer

BackgroundColorectal cancer (CRC) is one of the most common diseases, accounting for about 10 % cancer-related deaths. Previous studies have found that caner-associated fibroblasts (CAFs) are closely related to the occurrence and metastasis of CRC, but the detailed mechanism is not precise.MethodsTumor cells and fibroblasts were co-cultured with a transwell system. Cell Counting Kit-8 and colony formation assays were performed to test the ability of cell proliferation. The flow cytometry was used to detect cell apoptosis. Western Blot was performed to assess protein expression levels. Quantitative real-time PCR was performed to detect mRNA expression levels. ERK5-IN-1 was used to inhibit the autophosphorylation of ERK5.ResultsCAFs promoted cell proliferation and inhibited cell apoptosis in CRC cells. CAFs promoted the phosphorylation of ERK5 and the expression of programmed death-ligand 1 (PD-L1). Activated ERK5 promotes cell proliferation and inhibited cell apoptosis in CRC cells. The expression levels of ERK5 correlated with the expression of PD-L1 in CRC cells. CAFs promote cell growth by activating the ERK5/PD-L1 signaling axis in colorectal cancer.ConclusionsCAFs significantly promoted cell proliferation and inhibited cell apoptosis in CRC cells, which features are dependent on regulating the ERK5/PD-L1 signaling axis.     

The leucine-rich repeat protein SUR-8 enhances MAP kinase activation and forms a complex with Ras and Raf

Caenorhabditis elegans sur-8 encodes a positive regulator of Ras signaling. We investigated the mechanism by which the human Sur-8 homolog can positively regulate Ras-MAP kinase signaling in mammalian cells. Sur-8 expression enhances Ras- or EGF-induced Raf and ERK activation but has no effect on ERK activation induced by active Raf or MEK. Furthermore, Sur-8 expression does not increase AKT or JNK activation. Sur-8 interacts with Ras and Raf and is able to form a ternary complex with the two proteins. Thus, Sur-8 may function as a scaffold that enhances Ras-MAP kinase signal transduction by facilitating the interaction between Ras and Raf.     

白细胞介素-6信号通路在银屑病发病机制中的研究进展

银屑病是一种病因不明的自身免疫性炎症性多基因遗传的皮肤疾病,其病理变化的形成需要多种信号通路和细胞因子的共同参与.近年来关于银屑病相关细胞因子信号转导通路及细胞调控信号的研究受到广泛关注,其中IL-6触发的三条途径,包括Ras/Raf/MEK/ERK途径、PI3K/AKt途径和JAK/STAT途径,共同促进银屑病角质形成细胞增殖、炎症反应及血管生成等病理变化;下面针对IL-6信号通路在银屑病发病机制中的研究进展做一综述.     

DICER activates autophagy and promotes cisplatin resistance in non-small cell lung cancer by binding with let-7i-5p

ObjectiveDrug resistance is the main obstacle in the treatment of non-small cell lung cancer (NSCLC). This study aimed to explore the mechanism of DICER in NSCLC resistance and its downstream signaling pathways.MethodsThe A549 cisplatin (DDP)-resistant strain A549/DDP was established. A549/DDP cells were transfected with DICER- and let-7i-5p-related vectors, and treated with autophagy activator rapamycin. The cell viability and apoptosis were tested by CCK-8 assay and flow cytometry, respectively. The formation of autophagosomes was observed with a transmission electron microscopy. RT-qPCR and Western blot assay were conducted to detect expression levels of DICER, let-7i-5p, autophagy-related proteins, and the PI3K/AKT/mTOR pathway-related proteins. The dual luciferase reporter gene assay was implemented to confirm the targeted binding of DICER and let-7i-5p.ResultsDICER was highly expressed in DDP-resistant NSCLC tissues and cells, and DICER could target and negatively regulate the expression of let-7i-5p. DDP treatment could inhibit the viability and promote cell apoptosis of A549/DDP cells. Downregulation of DICER in A549/DDP cells exhibited a decrease of cell viability, a decreased ratio of LC3-II/LC3-I and autophagosomes, together with an elevation of cell apoptosis rate and the phosphorylation levels of PI3K/AKT/mTOR. Treatment of rapamycin and let-7i-5p inhibitor reversed the effects of downregulated DICER in cell viability, ratio of LC3-II/LC3-I, autophagosomes, cell apoptosis rate and the phosphorylation levels of PI3K/AKT/mTOR in A549/DDP cells.ConclusionOur research suggests that DICER promotes autophagy and DDP resistance in NSCLC through downregulating let-7i-5p, and inhibits the activation of PI3K/AKT/mTOR pathway.     

Raf-induced MMP9 disrupts tissue architecture of human breast cells in three-dimensional culture and is necessary for tumor growth in vivo

Organization into polarized three-dimensional structures defines whether epithelial cells are normal or malignant. In a model of morphogenesis, we show that inhibiting key signaling pathways in human breast cancer cells leads to "phenotypic reversion" of the malignant cells. Using architecture as an endpoint, we report that, in all cases, signaling through Raf/MEK/ERK disrupted tissue polarity via matrix metalloproteinase9 (MMP9) activity. Induction of Raf or activation of an engineered, functionally inducible MMP9 in nonmalignant cells led to loss of tissue polarity, and reinitiated proliferation. Conversely, inhibition of Raf or MMP9 with small molecule inhibitors or shRNAs restored the ability of cancer cells to form polarized quiescent structures. Silencing MMP9 expression also reduced tumor growth dramatically in a murine xenograft model. LC-MS/MS analysis comparing conditioned medium from nonmalignant cells with or without active MMP9 revealed laminin 111 (LM1) as an important target of MMP9. LM1 has been implicated in acinar morphogenesis; thus, its degradation by MMP9 provides a mechanism for loss of tissue polarity and reinitiation of growth associated with MMP9 activity. These findings underscore the importance of the dynamic reciprocity between the extracellular matrix integrity, tissue polarity, and Raf/MEK/ERK and MMP9 activities, providing an axis for either tissue homeostasis or malignant progression.