MicroRNA-92b augments sorafenib resistance in hepatocellular carcinoma via targeting PTEN to activate PI3K/AKT/mTOR signaling

Sorafenib (SOR) resistance is still a significant challenge for the effective treatment of hepatocellular carcinoma (HCC). The mechanism of sorafenib resistance remains unclear. Several microRNAs (miRNAs) have been identified as playing a role in impairing the sensitivity of tumor cells to treatment. We examined the mechanism behind the role of miR-92b in mediating sorafenib resistance in HCC cells. We detected that miR-92b expression was significantly upregulated in SOR-resistant HepG2/SOR cells compared to parental HepG2/WT cells. After transfection with miR-92b inhibitor, the proliferation of HepG2/SOR cells was remarkably weakened and rates of apoptosis significantly increased. PTEN was considered to be a functional target of miR-92b according to a luciferase reporter assay. Knockdown of PTEN significantly impaired the ability of miR-92b inhibitor on increasing sorafenib sensitivity of HepG2/SOR cells. Furthermore, we confirmed by western blotting and immunofluorescence that miR-92b can mediate sorafenib resistance by activating the PI3K/AKT/mTOR pathway in HCC cells by directly targeting PTEN. These findings further validate the mechanism of miR-92b in SOR resistance in HCC treatment.     

Suppression of hepatocellular carcinoma by baculovirus-mediated expression of long non-coding RNA PTENP1 and MicroRNA regulation

Long non-coding RNAs (lncRNAs) play regulatory roles in cancers. LncRNA PTENP1 is a pseudogene of the tumor suppressor gene PTEN but its roles in hepatocellular carcinoma (HCC) have yet to be explored. Here we confirmed that PTENP1 and PTEN were downregulated in several HCC cells, thus we constructed Sleeping Beauty (SB)-based hybrid baculovirus (BV) vectors for sustained PTENP1 lncRNA expression. Co-transduction of HCC cells with the SB-BV vector expressing PTENP1 elevated the levels of PTENP1 and PTEN, which suppressed the oncogenic PI3K/AKT pathway, inhibited cell proliferation, migration/invasion as well as induced autophagy and apoptosis. The overexpressed PTENP1 decoyed oncomirs miR-17, miR-19b and miR-20a, which would otherwise target PTEN, PHLPP (a negative AKT regulator) and such autophagy genes as ULK1, ATG7 and p62, indicating that PTENP1 modulated the HCC cell behavior and gene networks by miRNA regulation. Injection of the PTENP1-expressing SB-BV vector into mice bearing HCC tumors effectively mitigated the tumor growth, suppressed intratumoral cell proliferation, elicited apoptosis, autophagy and inhibited angiogenesis. These data collectively unveiled the molecular mechanisms of how PTENP1 repressed the tumorigenic properties of HCC cells and demonstrated the potential of the SB-BV hybrid vector for PTENP1 lncRNA modulation and HCC therapy.     

下调miR-21 抑制PI3K / AKT 信号通路对白血病细胞增殖凋亡的影响

目的:探讨miR-21 对白血病K562 细胞增殖凋亡的影响及对PI3K/ AKT 信号通路的调控作用。方法:将K562 细胞分为对照组、miR-21 NC 组和miR-21 干扰组,对照组不做处理,后两组采用阳离子脂质体LipofectamineTM2000 转染miR-21 inhibitor 和miR-21 negative control。转染48 h 后,利用实时荧光定量(qRT-PCR)检测各组细胞中miR-21 mRNA 的表达情况,采用MTT 比色法检测miR-21 对细胞增殖率的影响,流式细胞仪检测miR-21 对细胞周期和凋亡率的影响,蛋白质免疫印迹法(Western blot)检测miR-21 对各组细胞中PI3K/ AKT 信号通路相关蛋白PI3K、AKT 和p-AKT 表达的影响。结果:miR-21 干扰组中细胞的miR-21 mRNA 表达水平和细胞的存活率较对照组和miR-21 NC 组均明显降低;与对照组和miR-21 NC 组比较,流式细胞仪检测miR-3 干扰组中G0/ G1 期所占细胞比例明显升高,S 期细胞所占比例明显下降,细胞的凋亡率明显升高。Western blot 检测p-AKT 的表达水平较对照组和miR-21 NC 组明显下降,但PI3K 和AKT 蛋白的表达水平变化不大。结论:下调miR-21 能够抑制白血病K562 细胞的增殖,促进其凋亡,其作用机制可以与抑制PI3K/ AKT 信号通路有关。     

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。     

参慈胶囊联合顺铂通过PI3K/AKT/mTOR信号通路逆转人肺腺癌顺铂耐药的机制研究

目的:探讨参慈胶囊联合顺铂是否通过PI3K/AKT/mTOR信号通路逆转接种人肺腺癌A549/DDP细胞的裸鼠体内的顺铂耐药。方法:建立裸鼠人肺腺癌移植瘤模型,随机分为对照组、参慈胶囊组、顺铂组和参慈胶囊+顺铂组。对照组予生理盐水,其余各组荷瘤裸鼠均用药21 d,断颈处死,取肿瘤组织,采用流式细胞术检测细胞周期与细胞凋亡;采用FQ-PCR技术检测A549/DDP肺癌组织PTEN、P-糖蛋白、PI3K、AKT和mTOR的mRNA表达情况。结果:参慈胶囊组、顺铂组和参慈胶囊+顺铂组与对照组比较,对人肺腺癌A549/DDP细胞的增殖均有抑制作用,其中参慈胶囊+顺铂组较其它治疗组能够进一步将人肺腺癌A549/DDP细胞阻滞于G_2/M期,促进细胞凋亡,增加PTEN的表达,抑制P-糖蛋白、PI3K、AKT和mTOR的表达。结论:参慈胶囊可能通过阻断PI3K/AKT/mTOR信号通路,促进PTEN的表达,或者抑制P-糖蛋白介导的耐药途径,增强裸鼠体内人肺腺癌A549/DDP耐药细胞对顺铂的敏感性。     

miR-200a通过调节PTEN影响小鼠肝细胞中AKT/GSK信号通路活性

目的 肝胰岛素抵抗能够导致严重的糖脂代谢紊乱,同2型糖尿病的发病密切相关.miR-200a属于miR-200家族,广泛表达于各个组织中,在许多癌症细胞中高表达.此研究探讨miR-200a通过下游靶基因PTEN调节AKT/GSK信号通路活性的机制,从microRNA角度阐明肝胰岛素抵抗的机制,为胰岛素抵抗的防治提供新的思路.方法 ① 脂质体在小鼠肝脏细胞株HEP1-6中转染miR-200a mimic和miR-200a inhibitor,用Real-time PCR检测细胞中miR-200a水平,并且检测AKT/GSK信号通路;② 用生物信息学方法预测miR-200a的下游靶基因;以双荧光素酶报告分析和Western印迹明确miR-200a的下游基因PTEN.③ 在HEP1-6细胞中共同转染miR-200a和si-PTEN,验证miR-200a通过PTEN调节AKT/GSK信号通路活性.结果 ① 用miR-200a mimic转染HEP1-6细胞,miR-200a水平升高,AKT/GSK信号通路活性增强;用miR-200a inhibitor转染HEP1-6细胞,miR-200a水平降低,AKT/GSK信号通路活性受到抑制;② 双荧光素酶报告分析和Western印迹结果表明,miR-200a能够直接同PTEN3′-UTR结合,抑制PTEN蛋白表达;③ 在HEP1-6细胞中沉默PTEN促进AKT/GSK信号通路活性;同时转染miR-200a和si-PTEN,能够逆转miR-200a inhibitor对AKT/GSK信号通路的抑制作用.结论 在HPE1-6细胞中miR-200a通过调节下游靶基因PTEN影响AKT/GSK信号通路活性.     

Rab11a regulates MMP2 expression by activating the PI3K/AKT pathway in human hepatocellular carcinoma cells

As a member of the Rab GTPase family, Rab11a plays an important role in vesicle transport and tumor progression. However, it is not clear whether it can also be used as an oncoprotein in hepatocellular carcinoma (HCC). In this study, database and immunohistochemical analyses showed that Rab11a was highly expressed in HCC tissues, and associated with poor clinical prognosis. Rab11a overexpression promoted the proliferation, migration, invasion, and anti-apoptosis of human HCC cell lines, MHCC-97H and HCC-LM3, whereas the downregulation of Rab11a inhibited these biological tumor activities. Nude mice xenograft demonstrated that Rab11a had a positive effect on the growth of hepatocellular carcinoma cells in vivo. Further studies found that the PI3K/AKT pathway and matrix metalloproteinase 2 (MMP2) upregulation can be activated by over-expression of Rab11a. However, MMP2 upregulation induced by Rab11a can be inhibited by the PI3K/AKT pathway inhibitor, LY294002. Altogether, our study established for the first time that Rab11a can play a pro-cancer role in HCC, as a novel oncoprotein, by activating the PI3K/AKT pathway to regulate MMP2 expression.     

MicroRNA-145通过丝裂原活化蛋白激酶和磷脂酰肌醇3激酶/蛋白质丝氨酸苏氨酸激酶通路调控肺癌A549细胞系转移及侵袭

目的 探讨microRNA-145(miR-145)对非小细胞肺癌A549细胞转移、侵袭及对丝裂原活化蛋白激酶(MAPK)和磷脂酰肌醇3激酶/蛋白质丝氨酸苏氨酸激酶（PI3K/AKT）通路的作用。 方法 将非小细胞肺癌A549细胞分成miR-145模拟物（mimics）组和negative-mimics组（miR-NC）以及antago miR-145组（抑制剂组）和antago miR control 组（antago-NC）,采用Transwell迁移实验及基质胶侵袭实验等检测miR-145对人非小细胞肺癌A549迁移、侵袭能力的影响;Western blotting方法分析miR-145对MAPK和PI3K/AKT通路的影响。此外,采用细胞外调节蛋白激酶（ERK）及AKT的通路抑制剂分别作用于A549细胞系,检测A549细胞迁移、侵袭能力的改变。 结果 miR-145 mimics组穿过细胞数（90.67±10.33）明显少于miR-NC组（175.33±23.67）,miR-145 mimics组穿过基质胶的细胞数（153.33±22.33）少于miR-NC组 (77.33±13.67）,P<0.05;antago-NC组通过小室的细胞数量以及穿过基质胶的细胞数量明显少于antago miR-145组（P<0.05）,结果说明,miR-145具有抑制非小细胞肺癌A549细胞迁移、侵袭的能力;miR-145 mimics转染可分别抑制A549细胞中90%、78%以及73%的ERK1/2、AKT的ser-473位点和thr-308位点的磷酸化,antago miR-145转染可促进A549细胞中ERK1/2、AKT的ser-473位点和thr-308位点的磷酸化,增加115%、125%以及129%,而当抑制MAPK通路及PI3K/AKT通路的激活后,A549细胞的转移及侵袭能力下降。 结论 miR-145通过MAPK和PI3K/AKT通路调控肺癌A549细胞转移及侵袭。     

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。     

LncRNA DSCAM-AS1通过靶向miR-627-3p调控皮肤鳞状细胞癌增殖、侵袭和迁移

目的 探讨长链非编码RNA(LncRNA)唐氏综合征细胞粘附分子反义1(DSCAM-AS1)靶向miR-627-3p对人皮肤鳞状细胞癌增殖和侵袭能力的影响和分子机制.方法 采用实时荧光定量PCR(RT-qPCR)检测DSCAM-AS1和miR-627-3p在人永生化表皮细胞HaCaT和3种皮肤鳞状细胞癌细胞(SCC13...     

MicroRNA-196a overexpression promotes cell proliferation and inhibits cell apoptosis through PTEN/Akt/FOXO1 pathway

MicroRNAs (miRNAs) are endogenous, non-coding, small RNAs, which play a critical role in regulating varieties of the biological and pathologic processes. MiR-196a has been reported to take part in tumorigenic progression of osteosarcoma (OS). However, the effects of miR-196a on OS are still unclear. The objective of this study is to investigate the molecular mechanism of miR-196a in osteosarcoma cells. In the present study, the expression of miR-196a in OS cell lines was detected by real-time PCR. We found that the expression level of miR-196a was markedly up-regulated in osteosarcoma cell lines compared with normal osteoblastic cells. Then, the miR-196a mimic was transiently transfected into MG63 and U2OS cells using Lipofectamine™ 2000 reagent. Subsequently, the MTT and Brdu-ELISA results showed that up-regulation of miR-196a promoted the cell viability and proliferation. Our results also showed that miR-196a mimic accelerated cell cycle progression of MG63 and U2OS cells by down regulation of p21 and p27, and upregulation of cyclin D1. In addition, overexpression of miR-196a suppressed apoptosis of MG63 and U2OS cells due to increasing BCL2L2 and MCL-1 expressions, and then inactivating caspase-3. Eventually, the effect of miR-196a mimic on the PTEN/phosphoinositide 3-kinase (PI3K)/Akt signaling pathway was explored by Western blot. From our results, transfection of miR-196a decreased the expression of PTEN and increased the phosphorylation of PI3K and Akt. Taken together, miR-196a should be an oncogene in osteosarcoma. The possible mechanism was that overexpression of miR-196a promoted proliferation of MG63 and U2OS cells by modulating the PTEN/PI3K/Akt signaling pathway.     

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.     

MicroRNA-101 inhibits growth and metastasis of human ovarian cancer cells by targeting PI3K/AKT

IntroductionOvarian cancer is the most frequent cause of gynecological cancer related mortality in woman. This study was designed to investigate the role and therapeutic potential of miRNA-101 in ovarian cancer.Material and methodsExpression analysis was carried out by real-time quantitative polymerase chain reaction. Transfections were performed with the help of Lipofectamine 2000 reagent. AO/EB and annexin V/PI staining was used to detect apoptosis and flow cytometry was used for cell cycle analysis. Western blotting was employed for cell cycle analysis.ResultsIt was found that miRNA-101 was significantly down-regulated in ovarian cancer cells. The over-expression of miRNA-101 causes a significant decrease in the viability of ovarian cancer cells via the initiation of apoptosis and sub-G1 arrest of OVACAR-3 cells. It was indicated that PTEN was the potential target of miRNA-101 in OVACAR-3 cells. There was 4.5-fold up-regulation of PTEN expression in ovarian cancer cell lines and the over-expression of miRNA-101 in OVACAR-3 cells resulted in the down-regulation of PTEN expression. The inhibition of PTEN in the OVACAR-3 cells arrested the proliferation of these cells. The over-expression of miRNA-101 causes significant down-regulation in PI3K and AKT expression of OVACAR-3 cells.ConclusionsIt can be concluded that miRNA-101 acts as a tumor suppressor which may be beneficial in the treatment of ovarian cancer.     

CircCBFB is a mediator of hepatocellular carcinoma cell autophagy and proliferation through miR-424-5p/ATG14 axis

This study aims to investigate the role of circCBFB in hepatocellular carcinoma (HCC) cell proliferation and autophagy. qRT-PCR and Western blotting analyses quantified the expression levels of circCBFB, miR-424-5p, and ATG14 in HCC tissues and/or HCC cell lines. After transfection with pcDNA3.1-CircCBFB, sh-CircCBFB, miR-424-5p mimic, miR-424-5p inhibitor, pcDNA3.1-ATG14, sh-ATG14, sh-CircCBFB?+?miR-424-5p inhibitor, pcDNA3.1-CircCBFB?+?miR-424-5p mimic, sh-CircCBFB?+?pcDNA3.1-ATG14, or pcDNA3.1-CircCBFB?+?sh-ATG14, the proliferation, cell cycle, and apoptosis of Huh-7 and HCCLM3 cells were detected, respectively, through MTT assay and flow cytometry. Western blotting measured the expression levels of ATG14 and autophagy-related proteins (LC3-ΙΙ/LC3-Ι, Beclin1, and p62). The interactions among circCBFB, miR-424-5p, and ATG14 were identified through RNA fluorescence in situ hybridization and RNA immunoprecipitation. In HCC tissues, circCBFB and ATG14 were highly expressed, and miR-424-5p expression was downregulated. Transfection of pcDNA3.1-CircCBFB, miR-424-5p inhibitor, or pcDNA3.1-ATG14 into HCC cells facilitated HCC cell proliferation and autophagy, while suppressing cell apoptosis, evidenced by elevated cell viability, increased protein levels of autophagosome markers (LC3-ΙΙ/LC3-Ι and Beclin1), repressed apoptosis rate, and suppressed protein level of autophagy receptor p62. miR-424-5p was a target gene of circCBFB, and miR-424-5p negatively mediated ATG14. CircCBFB inhibits miR-424-5p and upregulates ATG14, thus promoting HCC cell proliferation and autophagy.

     

miR-634 在肝癌中的表达及对肝癌细胞生物学行为的影响

目的:检测microRNA-634(miR-634)在肝癌中的表达水平及其对肝癌细胞常见生物学行为的调控作用。方法:采用实时荧光定量PCR(RT鄄qPCR)法检测肝癌细胞系(HepG2、SMMC7721、Bel7402、Bel7404、SNU739)、69 例肝癌组织及匹配癌旁组织中miR-634 的相对定量,分析miR-634 表达与肝癌患者性别、年龄、肿瘤直径、分化程度、Child-Pugh 分级、BCLC 分期、门静脉癌栓及肝外转移的关系,同时构建miR-634 的真核表达载体并转染肝癌细胞系,采用活细胞计数试剂盒CCK-8、流式细胞仪Annexin V/ PI 双染法和Transwell 侵袭实验检测转染miR鄄634 对细胞增殖、凋亡和侵袭能力的影响。结果:与正常人肝细胞系L-02 相比,肝癌细胞的miR-634 水平均降低(P <0.05),表达量依次为HepG2 >SNU739 >Bel7402 > Bel7404 >SMMC7721;69 例肝癌组织的miR鄄634 水平为(0.253±0.019),低于匹配癌旁组织(P<0.05),且与肿瘤直径、分化程度、BCLC分期、门静脉癌栓及肝外转移均有关(P<0.05)。过表达组转染24 ~96 h 后的miR鄄634 水平持续升高,与对照组和空转染组的差异有统计学意义(P<0.05);与对照组和空转染组相比,转染组的增殖抑制率、凋亡率均升高,但穿膜细胞数降低,差异有统计学意义(P<0.05)。结论:miR-634 在肝癌组织和细胞中均为低表达,且与临床病理参数有关,上调其水平可抑制肝癌细胞增殖及侵袭并诱导凋亡,对于肝癌防治有重要借鉴价值。     

GKN2在胃癌细胞增殖、转移中的作用及机制

目的 探讨胃动蛋白2(gastrokine 2,GKN2)对胃癌细胞的生长增殖、侵袭、转移的影响及分子机制.方法 利用qRT-pCR和Western blot法检测GKN2在胃癌组织中的表达;构建对照细胞株AGS-CON、SGC-7901-CON与GKN2过表达细胞株AGS-GKN2、SGC-7901-GKN2,应用q...     

SIRT1 promotes proliferation and inhibits apoptosis of human malignant glioma cell lines

In mammalian cells, SIRT1 decreases PTEN acetylation and inactivates the AKT pathway in a SIRT1 deacetylase-dependent manner. However, the function of SIRT1 in glioma was unknown. SIRT1 reexpression or knockdown was induced in human glioma cell lines. The cell synchronization, BrdU labeling and mitotic index were detected. Subsequently, cell cycle, cell viability, apoptosis, cell growth and proliferation were analyzed. Our work identified that SIRT1-knockdown significantly delayed mitotic entry of glioma cells, inhibited its growth and proliferation, and promoted its apoptosis. The apoptosis was related to PTEN/PI3K/AKT signaling pathway. The results showed that SIRT1 might be a promoter factor on tumorigenesis of glioma through PTEN/PI3K/AKT signaling pathway.     

Acrylamide induces HepG2 cell proliferation through upregulation of miR-21 expression

Acrylamide, a potential carcinogen, exists in carbohydrate-rich foods cooked at a high temperature. It has been reported that acrylamide can cause DNA damage and cytotoxicity. The present study aimed to investigate the potential mechanism of human hepatocarcinoma HepG2 cell proliferation induced by acrylamide and to explore the antagonistic effects of a natural polyphenol curcumin against acrylamide via miR-21. The results indicated that acrylamide (≤100 μmol/L) significantly increased HepG2 cell proliferation and miR-21 expression. In addition, acrylamide reduced the PTEN expression in protein level, while induced the expressions of p-AKT, EGFR and cyclin D1. The PI3K/AKT inhibitor decreased p-AKT protein expression and inhibited the proliferation of HepG2 cells. In addition, curcumin effectively reduced acrylamide-induced HepG2 cell proliferation and induced apoptosis through the expression of miR-21. In conclusion, the results showed that acrylamide increased HepG2 cell proliferation via upregulating miR-21 expression, which may be a new target for the treatment and prevention of cancer.     

上调GDF-15 表达对H2O2 诱导的H9C2 心肌细胞生物学特性及PI3K/ AKT 信号通路的影响

目的：探讨上调生长分化因子-15（GDF-15）的表达对H₂O₂诱导的H9C2心肌细胞增殖、凋亡及PI3K/AKT信号通路的影响。方法：CCK8法检测不同浓度的H₂O₂处理H9C2心肌细胞后的细胞增殖情况;H9C2心肌细胞分为Control组、NC组、H₂O₂组、GDF-15+H₂O₂组,各组细胞处理24 h后收集细胞,RT-PCR及Western blot分别检测各组细胞中GDF-15的mRNA及蛋白表达;CCK8法及流式细胞术分别检测细胞的增殖和凋亡情况;2′,7′-二氯二氢荧光素黄二乙酸酯（DCFH-DA）探针检测细胞活性氧簇（ROS）水平;Western blot检测Ki67、B细胞淋巴瘤/白血病-2（Bcl-2）、Bcl-2相关X蛋白(Bax)、PI3K、p-AKT蛋白表达。10 μmol/L的PI3K/AKT信号通路抑制剂LY294002处理H9C2心肌细胞,通过CCK8法及流式细胞术分别检测GDF-15+H₂O₂组及PI3K/AKT信号通路抑制剂组细胞活力及凋亡率,Western blot检测Ki67、Bcl-2、Bax、PI3K、p-AKT蛋白表达。结果：不同浓度H₂O₂处理H9C2心肌细胞后,细胞活力均受到抑制,且有浓度依赖性（P<0.05）,由于200 μmol/L的H₂O₂处理H9C2心肌细胞后可抑制将近一半的细胞增殖,选择200 μmol/L的H₂O2作为研究对象;与Control组比较,H2O2组GDF-15的mRNA及蛋白表达均显著升高,细胞增殖显著降低,凋亡率增加,ROS水平升高,Ki67、Bcl-2、PI3K、p-AKT蛋白表达降低,Bax蛋白表达升高（P<0.05）;与H₂O₂组比较,GDF-15+H₂O₂组细胞GDF-15的mRNA及蛋白表达均显著升高,细胞增殖显著增加,凋亡率降低,ROS水平降低,Ki67、Bcl-2、PI3K、p-AKT蛋白表达升高,Bax蛋白表达降低（P<0.05）。PI3K/AKT信号抑制剂组细胞活力及Bcl-2、PI3K和p-AKT的蛋白表达均显著低于GDF-15+H₂O₂组,细胞凋亡率及Bax蛋白表达显著高于GDF-15+H₂O₂组（P<0.05）。结论：上调GDF-15表达可促进H₂O₂诱导的H9C2心肌细胞增殖,降低细胞凋亡,其机制可能与调节细胞中ROS水平,Ki67、Bcl-2、Bax表达及PI3K/AKT信号通路有关。