p66Shc protein, oxidative stress, and cardiovascular complications of diabetes: the missing link

Diabetes affects more than 150 million people worldwide, and it is estimated that this would increase to 299 million by the year 2025. The incidence of and mortality from cardiovascular disease are two- to eightfold higher in subjects with diabetes than in those without, coronary artery disease accounting for the large majority of deaths. Among the full spectrum of biochemical effects of high glucose, generation of oxygen-derived free radicals is one of the main pathophysiological mechanisms linking hyperglycemia to atherosclerosis, nephropathy, and cardiomyopathy. The adaptor protein p66^Shc is implicated in mitochondrial reactive oxygen species (ROS) generation and translation of oxidative signals into apoptosis. Indeed, p66^Shc−/− mice display prolonged lifespan, reduced production of intracellular oxidants, and increased resistance to oxidative stress-induced apoptosis. Accordingly, a series of studies defined the pathophysiological role of p66^Shc in cardiovascular disease where ROS represent a substantial triggering component. As p66^Shc modulates the production of cellular ROS, it represents a proximal node through which high glucose exerts its deleterious effects on different cell types; indeed, several studies tested the hypothesis that deletion of the p66^Shc gene may confer protection against diabetes-related cardiovascular complications. The present review focuses on the reported evidence linking p66^Shc signaling pathway to high glucose-associated endothelial dysfunction, atherogenesis, nephropathy, and cardiomyopathy.     

Detachment‐Based Equilibrium of Anoikic Cell Death and Autophagic Cell Survival Through Adaptor Protein p66Shc

Anoikis (detachment‐induced cell death) confers a tumor‐suppressive function in metastatic cancer cells. Autophagy, a conserved self‐degradative process, enhances the anoikis resistance of detached cancer cells by maintaining cellular homeostasis. However, the mechanism of regulating cell fate‐decision by balancing anoikis and autophagy has been poorly understood. Our previous studies have shown that the adaptor protein p66^Shc mediates anoikis through RhoA activation and inhibits tumor metastasis in vivo. We also found that p66^Shc depletion mitigates nutrient‐deprivation‐induced autophagy. These findings suggest p66^Shc may coordinately regulate these two processes. To verify this hypothesis, we investigated the effect of p66^Shc on the cell death of detached lung cancer cells, and measured autophagy markers and autophagic flux. Results showed that p66^Shc depletion significantly inhibited anoikis, and reduced the formation of LC3B‐II and the degradation of Sequestosome 1 (SQSTM1, p62) in detachment‐induced cells. Using monodansylcadaverine (MDC)‐LysoTracker double staining and monomeric Cherry (mCherry)‐GFP‐LC3 assay, we found that the autophagic flux was also mitigated by p66^Shc depletion. In addition, p66^Shc knockdown increased the formation of full‐length X‐linked inhibitor of apoptosis (XIAP)‐associated factor 1 (XAF1), which enhances anoikis sensitivity. In conclusion, p66^Shc plays an essential role in detachment‐based equilibrium of anoikic cell death and autophagic cell survival. Anat Rec, 299:325–333, 2016. © 2015 Wiley Periodicals, Inc.     

Role of DJ-1 siRNA in reverse sensitivity of breast cancer cells to chemotherapy and its possible mechanism

Breast cancer which has a high incidence rate is the 2^nd lethal diseases only followed by lung cancer in women. How to improve the recovery rate is the principal problem should be solved in clinical. Previous studies demonstrated the importance of DJ-1 in the existence of breast cancer for the secreted of protein into serum by breast cancer cells both in vitro and in vivo. So the DJ-1 probably could be selected as the target in breast cancer treatment. Adriamycin resistance breast cancer cells MCF-7 and DJ-1 siRNA plasmid were employed to explore the potential clinical application of DJ-1 in this study. Our results showed that the sensitivity of cancer cells to chemotherapeutics was significantly improved with the transfection of DJ-1 siRNA. Further mechanism studies indicated the role of PI3K/AKT/MTOR pathway in the improvement of apoptosis after treatment with adriamycin in DJ-1 silence group.     

Systematic genetic dissection of p14ARF-mediated mitochondrial cell death signaling reveals a key role for p21CDKN1 and the BH3-only protein Puma/bbc3

Induction of cell death by p14^ARF is mediated through a Bax/Bak-dependent mitochondrial apoptosis pathway. To investigate the upstream signaling events required for the activation of Bax and/or Bak and to determine the functional impact of de-regulated cell cycle restriction point control in this context, we genetically dissected the impact of BH3-only proteins and the role of the cyclin-dependent kinase (cdk) inhibitor p21^CDKN1. Using isogenic HCT116 colorectal cancer cells, either wild-type or homozygously deleted for the BH3-only protein Puma/bbc3 and/or p21^CDKN1 or p53-reconstituted DU145 prostate cancer cells, we show that p14^ARF-induced apoptosis is attenuated in the absence of Puma. Upon expression of p14^ARF in HCT116 cells, Puma is rapidly induced at both the mRNA and protein level. Puma-proficient HCT116 cells undergo apoptotic (nuclear) DNA fragmentation, which is preceded by the N-terminal conformational change of Bax, the breakdown of the mitochondrial membrane potential, and induction of caspase-9 (LEHD)-like and caspase-3/7 (DEVD)-like activities. In contrast, p14^ARF-induced apoptosis is markedly attenuated in isogenic HCT116 cells bi-allelically deleted for puma. The sensitivity of Puma-deficient cells to p14^ARF-induced apoptosis is fully restored by functional reconstitution of Puma using a conditional adenoviral expression vector. Notably, the concomitant deletion of p21^CDKN1 strongly enhances p14^ARF-induced apoptosis in Puma-proficient cells, but not in isogenic Puma-deficient cells. These results indicate that p14^ARF-induced mitochondrial apoptosis critically depends on the BH3-only protein Puma. In the presence of a functional p53/Puma/Bax-signaling axis, p14^ARF-triggered apoptosis is enhanced by loss of p21^CDKN1-mediated cell cycle checkpoint control.     

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.     

Targeted RNA interference of phosphatidylinositol 3-kinase p110-beta induces apoptosis and proliferation arrest in endometrial carcinoma cells

Phosphatidylinositol 3-kinase (PI3K) signalling plays a pivotal role in intracellular signal transduction pathways involved in cell growth, cellular transformation, and tumourigenesis. PI3K is overexpressed in many human cancers, including endometrial carcinomas, one of the most common female genital tract malignancies. Here, we used small interfering RNA (siRNA) targeted to PI3K p110-beta to determine whether inhibition of the beta isoform could be a potential therapeutic target for endometrial carcinoma. In this study, treatment of HEC-1B endometrial cancer cells with PI3K p110-beta-specific siRNA resulted in increased apoptosis and decreased tumour cell proliferation. Depletion of PI3K p110-beta decreased the protein levels of AKT1, AKT2, pAKT, and mTOR-downstream targets of PI3K. Knock-down of PI3K p110-beta by siRNA also induced decreased expression of cyclin E and Bcl-2, suggesting that PI3K p110-beta stimulates tumour growth, at least in part by regulating cyclin E and Bcl-2. Thus, our results indicate that siRNA-mediated gene silencing of PI3K p110-beta may be a useful therapeutic strategy for endometrial cancers overexpressing PI3K p110-beta.     

慢病毒介导的RNA干扰沉默Slug基因对结肠癌HCT116细胞增殖和凋亡的影响

目的:探讨利用RNA干扰(RNA interference,RNAi)技术沉默Slug基因,观察对结肠癌HCT116细胞增殖和周期的影响。方法:构建Slug基因特异性siRNA慢病毒载体,感染结肠癌HCT116细胞,设立空白对照组、阴性对照组及SlugsiRNA三组,应用Real-time PCR和Western blot方法分别从基因和蛋白质水平检测各组干扰质粒对Slug基因的干扰效果,MTT法检测Slug基因在siRNA作用下的细胞增殖率,流式细胞仪检测细胞凋亡周期变化情况。结果:转染Slug siRNA后,结肠癌HCT116细胞中Slug基因mRNA和蛋白表达明显受到抑制(P<0.05);MTT检测,干扰组细胞增殖水平明显低于阴性对照组;流式细胞仪检测细胞G1期细胞百分比(52.3±0.6)高于阴性对照组(45.1±0.3,P<0.05)。结论:Slug siRNA能明显下调靶基因Slug的表达,在体外可抑制结肠癌HCT116细胞的生长并促进其凋亡。     

p21WAF1/CIP1 expression in colorectal carcinoma correlates with advanced disease stage and p53 mutations

Defects in the mechanisms controlling the cell cycle are crucial in cell transformation and/or tumour progression. p21^WAF1/CIP1 is an inhibitor of cyclin-dependent kinases, induced by p53-dependent and p53-independent pathways, which can block progression through the cell cycle. p21^WAF1/CIP1 expression has been investigated immunohistochemically in a series of 191 patients with colorectal cancer of known p53 status. The purpose of the study was two-fold: to assess the relationship between p21^WAF1/CIP1 immunoreactivity and p53 alterations, and to evaluate the prognostic significance of p21^WAF1/CIP1 expression. In 96 carcinomas (51 per cent), p21^WAF1/CIP1 was expressed in over 10 per cent of tumour cells, whereas in 26, p21^WAF1/CIP1 was detected in under 10 per cent of neoplastic cells; 69 tumours lacked p21^WAF1/CIP1 expression. Immunoreactivity was more frequent in tumours of the right colon (p < 0·003) and was inversely correlated with tumour stage (p < 0·03), p53 gene mutations (p < 0·0007), p53 protein accumulation (p < 0·019), and Bcl-2 expression (p < 0·0005). In univariate analysis, down-regulation of p21^WAF1/CIP1 expression was associated with poor overall (p = 0·0022) and disease-free survival (p = 0·0009). Multivariate analysis, however, did not confirm any independent prognostic significance of p21^WAF1/CIP1 expression. The results indicate that p21^WAF1/CIP1 is associated with abnormal accumulation of p53 protein and the occurrence of p53 gene mutations in colorectal cancer and that lack of p21^WAF1/CIP1 expression is correlated with reduced patient survival in univariate analysis. These data underline the crucial pathogenetic role of the p53–p21^WAF1/CIP1 pathway in carcinomas of the large bowel. Copyright © 1999 John Wiley & Sons, Ltd.     

小分子干扰RNA 沉默RhoGDI2 基因表达对结肠癌细胞增殖侵袭的影响及其机制

目的:应用小分子干扰RNA(siRNA)沉默RhoGDI2 基因的表达,初步探讨其对结肠癌细胞增殖、迁移能力的影响及可能的机制。方法:分别运用Western blot 和RT-qPCR 检测结肠癌细胞株RKO、HT29、SW620、SW480、HCT116 基因RhoGDI2 的表达情况。设计并合成RhoGDI2 siRNA 干扰序列,按照LipofectamineTM2000 转染方法将siRNA 干扰序列转染到目的细胞,设置实验干扰组、空白对照和阴性对照组;CCK-8 实验检测细胞增殖能力,细胞划痕试验和Transwell 实验检测细胞迁移、侵袭能力。结果:人结肠癌细胞株RhoGDI2 表达量由高到低依次是RKO、HT29、SW620、SW480、HCT116;RKO 细胞siRNA干扰后RhoGDI2 表达抑制率大于70%:实验干扰组、阴性对照组、空白对照组细胞增殖率分别是(0.683±0.013)、(0.866±0.088)、(0.905±0.008),P<0.05;实验干扰组细胞迁移、侵袭速率较对照组均减慢。沉默RhoGDI2 基因的表达,实验组细胞E-Cadherin 较对照组表达量高,Vimentin 蛋白表达下降。结论:结肠癌RhoGDI2 基因沉默可能通过抑制EMT 进程阻止肿瘤恶性生物学行为。     

Downregulation of Skp2 and p27/Kip1 synergistically induces apoptosis in T98G glioblastoma cells

S-Phase kinase associated protein (Skp) 2 is an F-box protein required for substrate recognition of the SCF^Skp2 ubiquitin ligase complex. Skp2 is often overexpressed in transformed cells and in various types of tumors. Downregulation or inhibition of Skp2 inhibits growth of breast cancer cells and small-cell lung carcinoma cells. We downregulated Skp2 in T98G glioblastoma cells using small interfering RNA (siRNA). Downregulation induced p27 and caused growth arrest and apoptosis. Downregulation of both Skp2 and p27 increased apoptosis synergistically. Cyclin E levels and cyclin E-CDK2 kinase activity increased dramatically when both Skp2 and p27 were downregulated. Coincidently, Bcl-2 but not Bcl-xL expression decreased, and caspase-3 was activated. Inhibition of cyclin E-CDK2 kinase activity by forced expression of p21 reversed these effects. Moreover, stable expression of Bcl-2 also abrogated apoptosis induced by downregulation of Skp2 and p27. We suggest that Skp2 in tumor cells suppresses apoptosis through Bcl-2 expression, potentially through regulation of cyclin E-CDK2 activity.     

TPX2通过p38 MAPK信号通路诱导直肠癌HR-8348细胞凋亡

目的:研究下调非洲爪蟾驱动蛋白样蛋白2靶蛋白(TPX2)对直肠癌细胞凋亡的影响及机制。方法:用TPX2小干扰RNA(si RNA)转染直肠癌HR-8348细胞,记为TPX2 si RNA组;以不做转染的细胞作为正常对照(control)组;以转染si RNA阴性对照(si RNA-NC)的细胞作为si RNA-NC组;用p38 MAPK抑制剂处理敲减TPX2表达后的直肠癌HR-8348细胞记为TPX2 si RNA+SB203580组。RT-qPCR和Western blot测定TPX2的表达水平,MTT法测定细胞存活率,流式细胞术测定细胞凋亡,Western blot测定细胞中p38 MAPK、p-p38 MAPK、cleaved caspase-3和Bcl-2的蛋白水平。结果:TPX2 si RNA转染后HR-8348细胞中TPX2的m RNA和蛋白表达水平显著下降(P 0. 05),而转染si RNA-NC对HR-8348细胞中TPX2的m RNA和蛋白水平没有影响。敲减TPX2表达后的直肠癌HR-8348细胞存活率降低,凋亡率升高,细胞中的cleaved caspase-3、p-p38 MAPK/p38 MAPK蛋白水平明显升高,Bcl-2水平水平降低,与control组比较,差异有统计学意义(P 0. 05)。与TPX2 si RNA组相比,TPX2 si RNA+SB203580组的HR-8348细胞凋亡率、cleaved caspase-3水平和p-p38 MAPK/p38 MAPK蛋白水平明显降低,存活率明显升高(P 0. 05)。结论:TPX2表达下调可以通过激活p38 MAPK促进直肠癌HR-8348细胞凋亡。     

MicroRNA-129-5p suppresses proliferation,migration and invasion of retinoblastoma cells through PI3K/AKT signaling pathway by targeting PAX6

BackgroundRetinoblastoma (RB) is the most common primary intraocular malignancy in children. Accumulating evidences have clarified that microRNAs (miRNAs) modulated signaling molecules by acting as oncogenes or tumor-suppressor genes in RB. Thus, in our study, we aimed to investigate the function of miR-129-5p in RB cells through PI3K/AKT signaling pathway by targeting PAX6. Two RB cell lines, Y79 and WERI-Rb-1, were selected in our study, followed by transfection of miR-129-5p inhibitor or si-PAX6 to explore the regulatory role of miR-129-5p in RB cell proliferation, invasion and migration.Material and methodsDual-luciferase assay was used for the detection of targeting relationship between miR-129-5p and PAX6. Besides, western blot analysis was applied to detect expression of cell cycle-related factors (CDK2 and Cyclin E) and PI3K/AKT signaling pathway-related factors (p-AKT and AKT). Nude mice tumorigenesis experiment was used to evaluate the effect of miR-129a-5p on RB growth in vivo.ResultsmiR-129-5p was down-regulated in RB cell lines. miR-129-5p directly targeted the 3′-untranslated region of PAX6. Artificial down-regulation of miR-129-5p promoted cell proliferation, migration and invasion in RB cell lines Y79 and WERI-Rb-1, and promoted RB growth in vivo via PI3K/AKT signaling pathway, which could be reversed by transfection with silencing PAX6.ConclusionThis study provides evidences that RB progression was suppressed by overexpressed miR-129-5p via direct targeting of PAX6 through PI3K/AKT signaling pathway, which may provide a molecular basis for better treatment for RB.     

Damnacanthal inhibits the NF-κB/RIP-2/caspase-1 signal pathway by inhibiting p56lck tyrosine kinase

Damnacanthal is a major constituent of Morinda citrifolia L. (noni) and exhibits anti-cancer and anti-inflammatory activities. However, the effects of damnacanthal on allergic diseases have not been determined. In this study, we investigated the effect of damnacanthal on mast cell-mediated allergic inflammatory responses. Damnacanthal significantly and dose-dependently inhibited compound 48/80-induced systemic anaphylactic shock, histamine release and intracellular calcium levels. In particular, IgE-mediated passive cutaneous anaphylaxis was significantly inhibited by the oral administration of damnacanthal. In addition, we report for the first time that p56^lck tyrosine kinase was expressed in phorbol 12-myristate 13-acetate and calcium ionophore A23187 (PMACI)-stimulated mast cells. Furthermore, damnacanthal inhibited the up-regulation of p56^lck tyrosine kinase activity by PMACI and repressed PMACI-induced histidine decarboxylase expression and activity. Damnacanthal also inhibited PMACI-induced interleukin (IL)-1β, IL-6 and tumor necrosis factor-α expressions by suppressing nuclear factor-kappa B (NF-κB) activation and suppressed the activation of caspase-1 and the expression of receptor interacting protein-2. This study shows damnacanthal inhibits the NF-κB/receptor-interacting protein-2/caspase-1 signal pathway by inhibiting p56^lck tyrosine kinase and suggests that damnacanthal has potential for the treatment of mast cell-mediated allergic disorders.     

Aberrant integrin activation induces p38 MAPK phosphorylation resulting in suppressed Fas-mediated apoptosis in T cells: Implications for rheumatoid arthritis

Delayed Fas-mediated apoptosis in T cells is associated with inflammatory diseases including rheumatoid arthritis (RA). CD3⁺ T cells in RA synovia expressed high amounts of phospho-p38 MAPK. Exposure to RA synovial fluid or soluble collagen, a degradation product of extracellular matrix abundant in RA synovium, induced the phosphorylation of p38 MAPK in Jurkat T cells accompanied by resistance against Fas-mediated apoptosis. Blocking β1 integrin by antibody diminished this effect. In addition, ectopic expression of auto-activated β1 integrin variant in T cells profoundly induced the phosphorylation of p38 MAPK. Suppression of p38 MAPK sensitized T cells to Fas-mediated apoptosis and increased caspase-8 and caspase-3 cleavage. A physical interaction of p38 MAPK and caspase-8 was demonstrated by using confocal microscopic imaging and co-immunoprecipitation assay. RA synovial fluid markedly increased the formation of phospho-p38 MAPK/caspase-8 complex in Jurkat T cells. In conclusion, abnormal activation of p38 MAPK to prevent Fas-mediated apoptosis may represent a common survival mechanism of RA synovial T cells contributing to the persistent inflammation of affected synovium.     

PI3K/AKT inhibition induces caspase-dependent apoptosis in HTLV-1-transformed cells

The phosphatidylinositol-3-kinase (PI3K) and AKT (protein kinase B) signaling pathways play an important role in regulating cell cycle progression and cell survival. In previous studies, we demonstrated that AKT is activated in HTLV-1-transformed cells and that Tax activation of AKT is linked to p53 inhibition and cell survival. In the present study, we extend these observations to identify regulatory pathways affected by AKT in HTLV-1-transformed cells. We demonstrate that inhibition of AKT reduces the level of phosphorylated Bad, an important member of the pro-apoptotic family of proteins. Consistent with the decrease of phosphorylated Bad, cytochrome c is released from the mitochondria and caspase-9 is activated. Pretreatment of the cells with caspase-9 specific inhibitor z-LEHD-FMK or pan caspase inhibitor Ac-DEVD-CHO prevented LY294002-induced apoptosis. Of interest, p53 siRNA prevents LY294002-induced apoptosis in HTLV-1-transformed cells, suggesting that p53 reactivation is linked to apoptosis. In conclusion, the AKT pathway is involved in targeting multiple proteins which regulate caspase- and p53-dependent apoptosis in HTLV-1-transformed cells. Since AKT inhibitors simultaneously inhibit NF-kappaB and activate p53, these drugs should be promising candidates for HTLV-1-associated cancer therapy.     

miR-296-5p 靶向 PLK1 调控 PI3K/ AKT 通路诱导骨肉瘤细胞中的自噬并抑制上皮-间质转化

目的 探讨 miR-296-5p 靶向 PLK1 对骨肉瘤 (osteosarcoma, OS) 细胞自噬及抑制上皮-间质转化 (EMT) 的作用机制。 方法 qRT-PCR 检测 miR-296-5p 在 OS 细胞中的表达。 采用生物信息学分析预测 miR-296-5p 的靶基因, 验证 miR-296-5p 对靶基因 PLK1 的直接靶向调控; 细胞转染构建 miR-296-5p 过表达 和干扰细胞, CCK-8、 克隆形成、 Transwell 小室、 流式、 蛋白免疫印迹实验检测 miR-296-5p 的不同表达对 U2OS 细胞中 PTBP1 表达水平及细胞增殖、 侵袭、 凋亡、 自噬及 EMT 的影响。 结果 与对照组比较, miR-296-5p 在 OS 中表达降低, 而 PLK1 则升高 (P< 0. 05); 与 miR-NC 组比较, mimic 组的克隆形成率、 侵袭 细胞数目及 PTBP1、 p62、 N-cadherin、 Vimentin、 p-PI3K/ PI3K、 p-AKT/ AKT 水平降低, 细胞凋亡率、 Beclin-1、 LC3-Ⅱ/ Ⅰ、 E-cadherin 水平升高 (P< 0. 05); 与 PLK1 组比较, PLK1 + mimic 组的克隆形成率、 侵袭 细胞数目及 PTBP1、 p62、 N-cadherin、 Vimentin、 p-PI3K/ PI3K、 p-AKT/ AKT 水平降低, 细胞凋亡率、 Beclin-1、 LC3-Ⅱ/ Ⅰ、 E-cadherin 水平升高 (P< 0. 05)。 结论 miR-296-5p 可能能够靶向 PLK1 调控 PI3K/ AKT 通路诱导 OS 细胞中的自噬并抑制 EMT。     

miR-130b-3p有望作为人膀胱癌的标志物

目的进一步了解miRNA在膀胱癌中的潜在机制。方法芯片分析4对人膀胱癌组织和相邻正常组织中的miRNA的表达。并用RT-q PCR来验证两个最上调的miRNA及其靶基因的表达是否符合miRNA/mRNA芯片结果。通过相关性分析和双荧光素酶报告实验推断并验证miR-130b-3p可以靶向PTEN。应用CCK8、EDU、流式细胞术、划痕、Transwell和细胞骨架等实验证明miR-130b可以影响膀胱癌细胞的增殖、凋亡、迁移和侵袭。用Western blot检测PI3K/AKT和整合素β1/FAK信号通路的关键靶蛋白。结果人膀胱癌中miR-130b-3p表达高于癌旁且与PTEN表达呈负相关。miR-130b-3p可下调PTEN表达,导致PI3K/AKT和整合素β1/FAK信号通路的激活,且与膀胱癌EJ细胞的增殖、迁移和侵袭相关。细胞转染miR-130b-3p抑制剂时,可以重排细胞骨架。结论本结果揭示miR-130b/PTEN有望用于人膀胱癌诊断和治疗的标志物。     

Suppressive effect of platycodin D on bladder cancer through microRNA-129-5p-mediated PABPC1/PI3K/AKT axis inactivation

Platycodin D (PD) is a major constituent of Platycodon grandiflorum and has multiple functions in disease control. This study focused on the function of PD in bladder cancer cell behaviors and the molecules involved. First, we administered PD to the bladder cancer cell lines T24 and 5637 and the human uroepithelial cell line SV-HUC-1. Cell viability and growth were evaluated using MTT, EdU, and colony formation assays, and cell apoptosis was determined using Hoechst 33342 staining and flow cytometry. The microRNAs (miRNAs) showing differential expression in cells before and after PD treatment were screened. Moreover, we altered the expression of miR-129-5p and PABPC1 to identify their functions in bladder cancer progression. We found that PD specifically inhibited the proliferation and promoted the apoptosis of bladder cancer cells; miR-129-5p was found to be partially responsible for the cancer-inhibiting properties of PD. PABPC1, a direct target of miR-129-5p, was abundantly expressed in T24 and 5637 cell lines and promoted cell proliferation and suppressed cell apoptosis. In addition, PABPC1 promoted the phosphorylation of PI3K and AKT in bladder cancer cells. Altogether, PD had a concentration-dependent suppressive effect on bladder cancer cell growth and was involved in the upregulation of miR-129-5p and the subsequent inhibition of PABPC1 and inactivation of PI3K/AKT signaling.     

Inhibition of hsa_circ_0001313 (circCCDC66) induction enhances the radio-sensitivity of colon cancer cells via tumor suppressor miR-338-3p: Effects of cicr_0001313 on colon cancer radio-sensitivity

Circular RNA_0001313 (circ_0001313), also known as circCCDC66, is a novel circRNA that recently found to be upregulated in colon cancer tissues and promote colon cancer progression. However, the role of circ_0001313 in regulating radio-sensitivity of colon cancer and its molecular mechanism remain undetermined. Here we found circ_0001313 was significantly upregulated and miR-338-3p was downregulated in radio-resistant colon cancer tissues compared to radio-sensitive tissues. Radiation treatment in colon cells triggered a remarkable upregulation of circ_0001313 and a downregulation of miR-338-3p. Knockdown of circ_0001313 reduced cell viability, colony formation rate and increased caspase-3 activity in colon cancer cells under irradiation. Moreover, circ_0001313 act as a sponge for miR-338-3p in colon cancer cells. Furthermore, miR-338-3p could reverse the effects of circ_0001313 knockdown on cell viability, colony formation, and caspase-3 activity. These findings revealed that knockdown of circ_0001313 could induce radio-sensitivity of colon cancer cells by negatively regulating miR-338-3p.     

Roles of Foxp3 in the occurrence and development of cervical cancer

Objective: This study aimed to evaluate the relationship between forkhead box P3 (Foxp3) expression and clinicopathological characteristics of cervical cancer and to explore the influence of Foxp3 on the biological behaviors of cervical cancer cells. Methods: In this study, immunohistochemistry, lentivirus mediated transfection, Transwell assay; CCK-8 assay, real-time PCR and flow cytometry were employed to confirm the roles of Foxp3 in the occurrence and development of cervical cancer. Results: Foxp3 and p16^INK4a were highly expressed in the cervical cancer and their expressions were related to the FIGO stage, tumor size, lymph node metastasis and serum SCC. Foxp3 had a high expression in the cervical cancer cells, tumor interstitium and metastatic lymph nodes. Foxp3 expression was positively related to p16^INK4a expression in the cervical cancer. Foxp3 expression in the cervical cancer was negatively related to the prognosis: high Foxp3 expression predicted a poor prognosis. Silencing of Foxp3 was able to inhibit the proliferation and invasiveness of cervical cancer cells, promote their apoptosis, and induce the change in cell cycle. Silencing of Foxp3 also reduced the mRNA and protein expressions of p16^INK4a in cervical cancer cells. Conclusion: Foxp3 is highly expressed in the cervical cancer, and able to facilitate the proliferation and invasiveness of cervical cancer, change cell cycle and inhibit their apoptosis, resulting in the occurrence, development and metastasis of cervical cancer.