PTEN基因通过调控ROS抑制结肠癌细胞增殖

为了探讨PTEN基因在结肠癌中的作用以及其机制研究,MTT法检测结肠癌细胞细胞增殖;蛋白免疫印迹检测结肠癌细胞中Ki67蛋白的表达;DCFDA染色流式细胞仪检测结肠癌细胞中ROS水平。结果表明PTEN基因能明显抑制结肠癌细胞细胞增殖;PTEN基因能显著降低结肠癌细胞中Ki67蛋白的表达;细胞内ROS水平在PTEN基因处理组中明显高于空质粒结肠癌细胞组;NAC预处理可明显抑制PTEN基因抑制的细胞增殖;NAC预处理可显著抑制PTEN基因对结肠癌细胞Ki67蛋白的降低作用。PTEN基因能够抑制结肠癌细胞增殖并上调结肠癌细胞内ROS水平。     

Particulate matter 2.5 induced bronchial epithelial cell injury via activation of 5′-adenosine monophosphate-activated protein kinase-mediated autophagy

The impact of particulate matter 2.5 (PM2.5) on the respiratory system is a worldwide concern. However, the mechanisms by which PM2.5 causes disease are still unclear. In this study, we investigated the effect of PM2.5 on autophagy and studied the effect of PM2.5-induced autophagy and 5′-adenosine monophosphate-activated protein kinase (AMPK) on cell proliferation, cell cycle, apoptosis, reactive oxygen species (ROS), and airway inflammation using human bronchial epithelial cells 16HBE140 cells. Results showed that exposure of cells to PM2.5 at a concentration of 100 μg/mL for 24 hours was most effective for inhibiting cell viability. PM2.5 induced cell arrest in the G0/G1 phase and increased mitochondrial membrane potential, ROS, and cell apoptosis with increasing concentration. PM2.5 downregulated cyclin D and matrix metallopeptidase-9 (MMP-9) expression but upregulated tissue inhibitor of metalloproteinases-1 (TIMP-1) expression, significantly promoted interleukin-6 (IL-6), and tumor necrosis factor-α (TNF-α) production, and enhanced the level and activation of AMPK. The levels of autophagy-related protein 5 (ATG5), Beclin-1, and LC3II/I were significantly increased by PM2.5. The activation of Unc-51-like autophagy activating kinase 1 was significantly inhibited by PM2.5. Moreover, ATG5 knockdown inhibited PM2.5-induced autophagy, ROS, and cell apoptosis significantly. The expression of cyclin D, MMP-9, and TIMP-1 was reversed by ATG5 suppression. PM2.5-induction of IL-6 and TNF-α was significantly inhibited by knockdown of ATG5. Thus, inhibition of autophagy protected the cells from PM2.5-induced injury. PM2.5 induced injury in human bronchial epithelial cells via activation of AMPK-mediated autophagy, suggesting possible therapeutic targets for the treatment of respiratory diseases.     

IscU2对非小细胞肺癌增殖、迁移、侵袭能力的影响及其作用机制的研究

该文通过shRNA干扰技术敲低IscU2干扰细胞IscU2的表达,研究了干扰IscU2对非小细胞肺癌(NSCLC)细胞NCI-H520增殖、迁移及侵袭能力的影响。构建了稳定低表达IscU2的非小细胞肺癌细胞系NCI-H520;采用CCK-8和平板克隆实验检测细胞的增殖能力;流式细胞仪检测细胞周期、凋亡、ROS、线粒体膜电位变化情况;Transwell实验检测细胞迁移及侵袭能力;Western blot检测相关蛋白的表达。结果表明,干扰IscU2后,非小细胞肺癌细胞的增殖及克隆形成能力降低;细胞周期停滞在G1/G0期,同时伴随有p-AKT和Cyclin D1蛋白含量的下降;细胞晚期凋亡率明显增加,凋亡蛋白Cleaved-caspase3和Cleaved-PARP表达上调;细胞迁移和侵袭能力降低,上皮标志物E-Cadherin表达上调,间质标志物N-Cadherin和Snail表达下调;细胞ROS积累和线粒体膜电位下降。该研究结果表明,干扰IscU2显著抑制非小细胞肺癌的增殖、迁移、侵袭能力和上皮–间质转化,这为非小细胞肺癌的诊断和治疗提供了新的潜在靶点和视角。     

Cardamonin induces G2/M arrest and apoptosis via activation of the JNK–FOXO3a pathway in breast cancer cells

Cardamonin (CD), a naturally occurring chalcone isolated from large black cardamom, was previously reported to suppress the proliferation of breast cancer cells. However, its precise molecular anti‐tumor mechanisms have not been well elucidated. In this study, we found that CD markedly inhibited the proliferation of MDA‐MB 231 and MCF‐7 breast cancer cells through the induction of G2/M arrest and apoptosis. Reactive oxygen species (ROS) plays a pivotal role in the inhibition of CD‐induced cell proliferation. Treatment with N‐acetyl‐cysteine (NAC), an ROS scavenger, blocked CD‐induced G2/M arrest and apoptosis in this study. Quenching of ROS by overexpression of catalase also blocked CD‐induced cell cycle arrest and apoptosis. We showed that CD enhanced the expression and nuclear translocation of Forkhead box O3 (FOXO3a) via upstream c‐Jun N‐terminal kinase, inducing the expression of FOXO3a and its target genes, including p21, p27, and Bim. This process led to the reduction of cyclin D1 and enhancement of activated caspase‐3 expression. The addition of NAC markedly reversed these effects, knockdown of FOXO3a using small interfering RNA also decreased CD‐induced G2/M arrest and apoptosis. In vivo, CD efficiently suppressed the growth of MDA‐MB 231 breast cancer xenograft tumors. Taken together, our data provide a molecular mechanistic rationale for CD‐induced cell cycle arrest and apoptosis in breast cancer cells.     

Knockdown of LncRNAZFAS1 suppresses cell proliferation and metastasis in non-small cell lung cancer

ABSTRACT

To evaluate the effects of LncRNAZFAS1 on cell proliferation and tumor metastasis in non-small cell lung cancer (NSCLC), we detected the expression level of LncRNAZFAS1 in NSCLC-related tissues and cells. qRT-PCR results revealed that LncRNAZFAS1 in tumor tissues was significantly higher than that in normal lung tissue, especially significantly up-regulated in stage III / IV and in metastatic NSCLC tissues. LncRNAZFAS1 expression was dramatically up-regulated in 4 NSCLC-related cells (A549, SPC-A1, SK-MES-1, and NCI-H1299), with having the highest expression level in A549 cells. Furthermore, we implemented a knockdown of LncRNAZFAS1 in A549 cells, and the results of CCK8 and Transwell assays suggested that knockdown of LncRNAZFAS1 significantly inhibited NSCLC cell proliferation and metastasis. Next, we constructed a tumor xenograft model to evaluate the effect of LncRNAZFAS1 on the NSCLC cell proliferation in vivo. The results indicated that knockdown of LncRNAZFAS1 dramatically inhibited A549 cells proliferation and repressed tumor growth. Additionally, knockdown of LncRNAZFAS1 drastically weakened the expressions of MMP2, MMP9 and Bcl-2 proteins, whereas noticeably strengthened the expression of BAX protein. Our results altogether suggest that knockdown of LncRNAZFAS1 has a negative effect on the proliferation and metastasis of NSCLC cell, which implying LncRNAZFAS1 is a potential unfavorable biomarker in patients with NSCLC.     

CRISPR/Cas9沉默PAK5抑制乳腺癌细胞增殖并促进细胞衰老

p21活化激酶5(p21-activated kinase 5,PAK5)是一种丝氨酸/苏氨酸激酶,调节多种细胞进程,包括细胞骨架重构、细胞增殖、迁移和侵袭.研究表明,PAK5是调控乳腺癌进程的关键因子,但与衰老关系的研究尚未见报道.本研究利用CRISPR/Cas9慢病毒感染方法,构建敲低PAK5的人乳腺癌MDA-MB...     

A loop involving NRF2, miR-29b-1-5p and AKT,regulates cell fate of MDA-MB-231 triple-negative breast cancer cells

The present study shows that nuclear factor erythroid 2-related factor 2 (NRF2) and miR-29b-1-5p are two opposite forces which could regulate the fate of MDA-MB-231 cells, the most studied triple-negative breast cancer (TNBC) cell line. We show that NRF2 activation stimulates cell growth and markedly reduces reactive oxygen species (ROS) generation, whereas miR-29b-1-5p overexpression increases ROS generation and reduces cell proliferation. Moreover, NRF2 downregulates miR-29b-1-5p expression, whereas miR-29b-1-5p overexpression decreases p-AKT and p-NRF2. Furthermore, miR-29b-1-5p overexpression induces both inhibition of DNA N-methyltransferases (DNMT1, DNMT3A, and DNMT3B) expression and re-expression of HIN1, RASSF1A and CCND2. Conversely, NRF2 activation induces opposite effects. We also show that parthenolide, a naturally occurring small molecule, induces the expression of miR-29b-1-5p which could suppress NRF2 activation via AKT inhibition. Overall, this study uncovers a novel NRF2/miR-29b-1-5p/AKT regulatory loop that can regulate the fate (life/death) of MDA-MB-231 cells and suggests this loop as therapeutic target for TNBC.     

肿瘤微环境中ROS介导IgG表达对膀胱癌细胞增殖和侵袭能力的影响

摘要 目的：探讨肿瘤微环境（TME）中活性氧（ROS）介导免疫球蛋白G（IgG）表达对膀胱癌EJ细胞增殖、迁移和侵袭能力的影响。方法：临床收集的18例膀胱癌患者样本,通过Western blot法检测膀胱癌和癌旁正常组织样本中IgG表达量。利用免疫荧光染色（IF）技术分别对膀胱癌组织和癌旁正常组织中ROS和IgG分子进行共定位和相对定量分析。将活性氧清除剂N-乙酰基-L-半胱氨酸（NAC）加入膀胱癌细胞EJ中,实验分为3组：空白组（EJ细胞）、阴性对照组（EJ+PBS）、实验组（EJ+PBS+NAC）,10 mM NAC药物处理48小时后,运用DHE-ROS荧光探针技术和Western blot实验检测药物NAC对ROS和IgG相对表达水平的影响;通过克隆集落形成实验、划痕实验、Transwell实验检测去除ROS后对膀胱癌细胞增殖、迁移和侵袭的影响。结果：人体膀胱癌组织中ROS和IgG分子表达水平显著高于癌旁正常组织（P<0.001）;荧光显微镜显示膀胱肿瘤组织中正常膀胱尿路上皮细胞组织被肿瘤细胞严重破坏,结构紊乱不规则,IgG和ROS表达水平均升高,而癌旁组织膀胱尿路上皮组织的结构均匀规则;NAC药物处理EJ细胞后,与空白组和阴性对照组相比ROS和IgG表达显著降低,同时实验组细胞的增殖、迁移和侵袭能力明显下降（P<0.01）。结论：ROS和IgG在临床膀胱癌组织和体外膀胱癌细胞株EJ中均显著高表达,在肿瘤微环境中ROS通过调控IgG表达,从而促进膀胱癌细胞的增殖、迁移、侵袭。ROS和IgG可能成为膀胱癌早期诊断和生物治疗的临床新靶点。     

Differentiation agents increase the potential AraC therapy of AML by reactivating cell death pathways without enhancing ROS generation

Acute myeloid leukemia (AML) has a poor prognosis and requires new approaches for treatment. We have reported that a combination of vitamin D-based cell differentiation agents (doxercalciferol/carnosic acid [D2/CA]) added following the cytotoxic drug arabinocytosine (AraC) increases AML cell death (CD), a model for improved therapy of this disease. Because AraC-induced CD is known to involve reactive oxygen species (ROS) generation, here we investigated if the modulation of cellular REDOX status plays a role in the enhancement of cell death (ECD) by D2/CA. Using thiol antioxidants, such as N-acetyl cysteine (NAC), we found a significant inhibition of ECD, yet this occurred in the absence of any detectable change in cellular ROS levels. In contrast, NAC reduced the vitamin D receptor (VDR) abundance and its signaling of ECD. Importantly, VDR knockdown and NAC similarly inhibited ECD without producing an additive effect. Thus, the proposed post-AraC therapy may be compromised by agents that reduce VDR levels in AML blasts.     

Apoptosis signal-regulating kinase 1 mediates denbinobin-induced apoptosis in human lung adenocarcinoma cells

In the present study, we explore the role of apoptosis signal-regulating kinase 1 (ASK1) in denbinobin-induced apoptosis in human lung adenocarcinoma (A549) cells. Denbinobin-induced cell apoptosis was attenuated by an ASK1 dominant-negative mutant (ASK1DN), two antioxidants (N-acetyl-L-cysteine (NAC) and glutathione (GSH)), a c-Jun N-terminal kinase (JNK) inhibitor (SP600125), and an activator protein-1 (AP-1) inhibitor (curcumin). Treatment of A549 cells with denbinobin caused increases in ASK1 activity and reactive oxygen species (ROS) production, and these effects were inhibited by NAC and GSH. Stimulation of A549 cells with denbinobin caused JNK activation; this effect was markedly inhibited by NAC, GSH, and ASK1DN. Denbinobin induced c-Jun phosphorylation, the formation of an AP-1-specific DNA-protein complex, and Bim expression. Bim knockdown using a bim short interfering RNA strategy also reduced denbinobin-induced A549 cell apoptosis. The denbinobin-mediated increases in c-Jun phosphorylation and Bim expression were inhibited by NAC, GSH, SP600125, ASK1DN, JNK1DN, and JNK2DN. These results suggest that denbinobin might activate ASK1 through ROS production to cause JNK/AP-1 activation, which in turn induces Bim expression, and ultimately results in A549 cell apoptosis.     

Knockdown of thioredoxin-interacting protein ameliorates high glucose-induced epithelial to mesenchymal transition in renal tubular epithelial cells

Epithelial to mesenchymal transition (EMT) of tubular cells contributes to the renal accumulation of matrix protein that is associated with diabetic nephropathy. Both high glucose and transforming growth factor-β (TGF-β) are able to induce EMT in cell culture. In this study, we examined the role of the thioredoxin-interacting protein (TXNIP) on EMT induced by high glucose or TGF-β1 in HK-2 cells. EMT was assessed by the expression of α-smooth muscle actin (α-SMA) and E-cadherin and the induction of a myofibroblastic phenotype. High glucose (30 mM) was shown to induce EMT at 72 h. This was blocked by knockdown of TXNIP or antioxidant NAC. Meanwhile, we also found that knockdown of TXNIP or antioxidant NAC inhibited high glucose-induced generation of reactive oxygen species (ROS), phosphorylation of p38 MAPK and ERK1/2 and expression of TGF-β1. HK-2 cells that were exposed to TGF-β1 (4 ng/ml) also underwent EMT. The expression of TXNIP gene and protein was increased in HK-2 cells treated with TGF-β1. Transfection with TXNIP shRNA was able to attenuate TGF-β1 induced-EMT. These results suggested that knockdown of TXNIP antagonized high glucose-induced EMT by inhibiting ROS production, activation of p38 MAPK and ERK1/2, and expression of TGF-β1, highlighting TXNIP as a potential therapy target for diabetic nephropathy.     

Protease Activity of Procaspase-8 Is Essential for Cell Survival by Inhibiting Both Apoptotic and Nonapoptotic Cell Death Dependent on Receptor-interacting Protein Kinase 1 (RIP1) and RIP3

Caspase-8 has an important role as an initiator caspase during death receptor-mediated apoptosis. Moreover, it has been reported to contribute to the regulation of cell fate in various types of cells including T-cells. In this report, we show that caspase-8 has an essential role in cell survival in mouse T-lymphoma-derived L5178Y cells. The knockdown of caspase-8 expression decreased the growth rate and increased cell death, both of which were induced by the absence of protease activity of procaspase-8. The cell death was associated with reactive oxygen species (ROS) accumulation, caspase activation, and autophagosome formation. The cell death was inhibited completely by treatment with ROS scavengers, but only partly by treatment with caspase inhibitors, expression of Bcl-xL, and knockdown of caspase-3 or Atg-7 which completely inhibits apoptosis or autophagosome formation, respectively, indicating that apoptosis and autophagy-associated cell death are induced simultaneously by the knockdown of caspase-8 expression. Further analysis indicated that RIP1 and RIP3 regulate this multiple cell death, because the cell death as well as ROS production was completely inhibited by not only treatment with the RIP1 inhibitor necrostatin-1, but also by knockdown of RIP3. Thus, in the absence of protease activity of procaspase-8, RIP1 and RIP3 simultaneously induce not only nonapoptotic cell death conceivably including autophagic cell death and necroptosis but also apoptosis through ROS production in mouse T-lymphoma cells.