Expression of KITENIN in human colorectal cancer and its relation to tumor behavior and progression

KAI1 COOH-terminal interacting tetraspanin (KITENIN) contributes to tumor invasion and metastasis in various cancers. The aim of current study was to evaluate whether KITENIN affects tumor cell invasion and prognosis in human colorectal cancers. We investigated the biologic role of KITENIN on tumor cell invasion by using small interfering RNA in Caco2, DLD1, and SW480. We evaluated the expression of KITENIN and activator protein-1 (AP-1) target genes in human colorectal cancer tissues. The tumor cell invasion was decreased by knockdown of KITENIN in three tested cell lines. The mRNA expression of cyclin D1 and COX-2 was decreased in KITENIN knockdown Caco2 and the mRNA expression of MMP-3 and COX-2 was decreased in KITENIN knockdown DLD1 and SW480. The extracellular-signal protein kinase 1/2 (ERK1/2) phosphorylation was decreased in KITENIN knockdown in three tested cell lines. Expression of KITENIN and AP-1 target genes was significantly increased in human colorectal cancer tissues. The ERK1/2, c-Jun N-terminal kinase (JNK) and p38 phosphorylations were increased in human colorectal cancer tissues. Expression of KITENIN was significantly associated with lymphovascular invasion, depth of invasion, lymph node metastasis, tumor stage and poor survival. These results indicate that KITENIN is associated with human colorectal cancer progression including invasion and metastasis.     

蜂胶黄酮PB3A作用下结肠癌细胞株中miRNA-198和miRNA-296-5p的表达及功能预测

目的:探讨蜂胶黄酮短叶松素-3-乙酸酯(pinobanksin-3-acetate,PB3A)对结肠癌SW480细胞微小RNA(microRNA,miRNA)表达谱的影响,为结肠癌的治疗及靶向药物研发提供理论依据。方法:使用miRNA芯片技术分析检测蜂胶黄酮PB3A处理人类结肠癌SW480细胞后miRNA表达谱的变化。通过实时荧光定量PCR方法检测miRNA-198和miRNA-296-5p的表达水平,以此来验证miRNA芯片结果的准确性和可靠性。利用miRWalk、Micro T、miRanda等12个网上数据库预测这2条miRNAs的靶基因并进行靶基因功能富集分析。结果:miRNA芯片分析结果显示,蜂胶黄酮PB3A干预24 h后结肠癌SW480细胞中差异表达倍数在2倍及以上的miRNA有267条,其中差异表达倍数达10倍及以上的miRNA有30条,28条为上调表达,2条下调表达;RT-qPCR实验结果显示miRNA-198和miRNA-296-5p的表达量趋势跟miRNA芯片结果一致,表达差异有统计学意义(P0.05)。miRNA靶基因预测发现miRNA-198有859个靶基因,miRNA-296-5p有906个靶基因;对这些可能被调控的靶基因进行Gene Class分析,结果显示miRNA-198和miRNA-296-5p的靶基因功能主要为转录因子、拷贝数变异、细胞分化、癌基因、蛋白激酶、组蛋白、转移癌基因、肿瘤抑制基因等(P0.05)。信号通路富集分析结果显示,miRNA-198靶基因显著富集于肿瘤通路、Wnt信号通路、胞吞通路、Erb B信号通路、黏着斑通路、黑素生成通路等信号通路,而miRNA-296-5p靶基因在MAPK信号通路、胞吞通路、轴突导向通路、Wnt信号通路、胰岛素信号通路、钙离子信号通路等信号通路中出现聚集(P0.05)。结论:蜂胶黄酮PB3A影响结肠癌SW480细胞的miRNA表达谱。PB3A作用下miRNA-198和miRNA-296-5p的异常表达可能参与PB3A抗结肠癌的过程。     

成纤维细胞与结肠癌细胞相互作用促进细胞外基质金属蛋白酶诱导因子的表达

目的研究成纤维细胞与结肠癌细胞相互作用对二者表达细胞外基质金属蛋白酶诱导因子（EMMPRIN）的影响,初步探讨肿瘤-基质相互作用在结肠癌侵袭转移中的作用。方法结肠癌SW480细胞与HELF成纤维细胞以RPMI1640培养液分别共培养0、12、24、48h,通过RT-PCR和免疫细胞化学方法检测SW480和HELF细胞中EMMPRIN的表达。结果共培养组SW480细胞EMMPRINmRNA和蛋白的表达均明显升高,HELF细胞本来不表达EMMPRIN,与SW480细胞共培养12、24、48h后检测到EMMPRIN表达,且随时间延长而表达增加。结论成纤维细胞与结肠癌细胞相互作用上调SW480细胞EMMPRIN的表达,并诱导HELF细胞表达EMMPRIN,有可能在结肠癌侵袭转移中发挥重要作用。     

Expression of IARS2 gene in colon cancer and effect of its knockdown on biological behavior of RKO cells

Objective: To investigate the expression level of IARS2 gene in colon cancer tissues and various cell strains of the cancer; to explore cytologically the effect of IARS2 gene knockdown on proliferation, apoptosis and cell cycle of RKO cells in the cancer. Methods: Real-time, fluorescence-based quantitative PCR (qPCR) was used to detect the expression of IARS2 gene in human colon cancer and surrounding tissues and in various cell strains of the cancer; the RNA interference target of IARS2 gene was designed and the target was detected by Western blot; the IARS2-siRNA lentiviral vector was established and used to infect the RKO cells of colon cancer; qPCR was employed to determine the effect of gene knockdown; changes of the RKO cells in growth, apoptosis, cell cycle and clone formation were observed after IARS2 gene knockdown. Results: The expression of IARS2 gene was higher in human colon cancer tissues than in surrounding tissues; there was expression of IARS2 gene in colon cancer cells, and the expression level of IARS2 gene mRNA was higher in the RKO cells than in the SW480, HCT116, DLD1, HT-29 and SW620 cells. After infection of the RKO cells with IARS2-siRNA lentivirus, the expression of IARS2 gene was inhibited in the level of mRNA; proliferation rate of the RKO cells was significantly inhibited; the G1 phase arrest of the RKO cells was increased with less RKO cells in S phase; the apoptotic RKO cells increased significantly; and the number of colonies of the RKO cells reduced. Conclusion: The expression of IARS2 gene is different in human colon cancer and surrounding tissues; after knockdown of IARS2 gene, proliferation of the RKO cells is inhibited; there are more cells in G phase and fewer cells in S phase; apoptosis of cells is increased; and formation of colonies is reduced. IARS2 gene is probably a cancer-promoting gene.     

Response gene to complement 32 is required for C5b-9 induced cell cycle activation in endothelial cells

Proliferation of vascular endothelial cells (EC) and smooth muscle cells (SMC) is a critical event in angiogenesis and atherosclerosis. We previously showed that the C5b-9 assembly during complement activation induces cell cycle in human aortic EC (AEC) and SMC. C5b-9 can induce the expression of Response Gene to Complement (RGC)-32 and over expression of this gene leads to cell cycle activation. Therefore, the present study was carried out to test the requirement of endogenous RGC-32 for the cell cycle activation induced by C5b-9 by knocking-down its expression using siRNA. We identified two RGC-32 siRNAs that can markedly reduce the expression of RGC-32 mRNA in AEC. RGC-32 silencing in these cells abolished DNA synthesis induced by C5b-9 and serum growth factors, indicating the requirement of RGC-32 activity for S-phase entry. RGC-32 siRNA knockdown also significantly reduced the C5b-9 induced CDC2 activation and Akt phosphorylation. CDC2 does not play a role in G1/S transition in HeLa cells stably overexpressing RGC-32. RGC-32 was found to physically associate with Akt and was phosphorylated by Akt in vitro. Mutation of RGC-32 protein at Ser 45 and Ser 47 prevented Akt mediated phosphorylation. In addition, RGC-32 was found to regulate the release of growth factors from AEC. All these data together suggest that cell cycle induction by C5b-9 in AEC is RGC-32 dependent and this is in part through regulation of Akt and growth factor release.     

TIPE3 干扰质粒对SW480 结肠癌细胞生长的作用及相关机制探讨

目的:通过TIPE3 干扰质粒转染SW480 结肠癌细胞,验证干扰TIPE3 表达对SW480 结肠癌细胞生长的影响并探讨相关机制。方法:构建TIPE3-shRNA-pSIREN-RetroQ 干扰质粒,通过脂质体转染法成功将干扰质粒导入SW480 细胞,通过RT-PCR、Western blot 检测重组质粒的干扰效率。应用CCK-8 方法检测SW480 细胞生存率。AnnexinV-FITC/ PI 流式细胞法检测细胞凋亡。使用Western blot 检测细胞增殖、凋亡相关分子的表达情况。结果:成功设计、构建和筛选具有生物活性且干扰效率最佳的TIPE3-shRNA-pSIREN-RetroQ 干扰质粒。CCK-8 检测证实干扰SW480 结肠癌细胞TIPE3 表达可以抑制细胞生长。流式结果显示,TIPE3-shRNA3 干扰组的凋亡率为(27.99±1.087)%,显著高于正常细胞组(12.10±2.213)% 及转染空载质粒组(11.44±0.277 0)%。证实了降低TIPE3 表达可以增加SW480 对aDR5ScFv 所诱导的细胞凋亡敏感性。Western blot结果显示干扰TIPE3 表达可以活化caspase3 蛋白,降低p-AKT、p-PDK1、PCNA 等分子的表达。结论:干扰TIPE3 的表达对 SW480 结肠癌细胞具有促进凋亡,抑制增殖的作用。     

Role of response gene to complement 32 in diseases

The role of response gene to complement (RGC)-32 as a cell cycle regulator has been attributed to its ability to activate cdc2 kinases and to induce S-phase entry and mitosis. However, recent studies revealed novel functions for RGC-32 in diverse processes such as cellular differentiation, inflammation, and fibrosis. Besides responding to C5b-9 stimulation, RGC-32 expression is also induced by growth factors, hormones, and cytokines. Transforming growth factor β activates RGC-32 through Smad and RhoA signaling, thus initiating smooth muscle cell differentiation. Accumulating evidence has drawn attention to the deregulated expression of RGC-32 in human malignancies, hyper-immunoglobulin E syndrome, and fibrosis. RCG-32 expression is up-regulated in cutaneous T cell lymphoma and colon, ovarian, and breast cancer, but down-regulated in invasive prostate cancer, multiple myeloma, and drug-resistant glioblastoma. A better understanding of the mechanism by which RGC-32 contributes to the pathogenesis of these diseases will provide new insights into its therapeutic potential. In this review we provide an overview of this field and discuss the most recent research on RGC-32.     

慢病毒介导的GHSR1a shRNA对结直肠癌细胞生长的影响

目的:构建生长激素促泌素受体1a(growth hormone secretagogue receptor 1a,GHSR1a)基因短发夹干扰RNA(short hairpin RNA,shRNA)慢病毒载体,感染人结直肠癌细胞系SW480,观察沉默GHSR1a基因对SW480细胞生长的影响,并探讨其作用机制。方法:构建特异性靶向GHSR1a基因的shRNA慢病毒表达载体和阴性对照序列慢病毒载体;建立稳定表达GHSR1a shRNA的SW480细胞、阴性对照细胞(NC)及空白对照细胞(BC),RTPCR检测GHSR1a的mRNA在细胞中的表达;通过Western blot技术检测细胞中GHSR1a、ghrelin、PTEN、p-AKT及p53蛋白的水平;CCK-8法测定GHSR1a shRNA对SW480细胞活力的影响;建立裸鼠结直肠癌皮下移植瘤模型,实验结束后处死裸鼠并测量各组裸鼠肿瘤重量;免疫组织化学法检测肿瘤组织中Ki-67和PTEN的阳性表达。结果:在体外实验中,GHSR1a在人结直肠癌细胞株Caco-2及SW480中的表达明显高于人正常结肠上皮细胞株NCM460的表达;成功建立了稳定表达GHSR1a shRNA的SW480细胞;GHSR1a shRNA能明显抑制SW480细胞GHSR1a mRNA及蛋白的表达;沉默GHSR1a基因后SW480细胞活力明显减弱;与NC组相比较,GHSR1a shRNA组细胞中PTEN mRNA及蛋白水平上调,AKT磷酸化被抑制,p53的表达明显增加;在体内实验中,与NC组相比较,GHSR1a shRNA组裸鼠结直肠癌皮下移植瘤重量明显减轻,同时Ki-67表达下调,PTEN表达上调。结论:慢病毒介导的GHSR1a shRNA对体内、外人结肠癌细胞的生长有明显抑制作用,该作用可能通过上调PTEN及其下游PI3K/AKT通路实现。     

骨桥蛋白基因真核表达载体构建及对结肠癌细胞的作用

目的：构建骨桥蛋白（Osteopontin,OPN）基因真核表达载体,转染人结肠癌细胞SW480,分析其对SW480细胞株增殖及生存能力的作用。方法：构建重组表达载体pEGFP-N1/OPN,经测序鉴定无误后,转染人结肠癌SW480细胞。RT-PCR检测SW480细胞转染后OPN mRNA表达;Western blot检测SW480细胞转染后OPN蛋白表达量;Cell Counting Kit-8（CCK-8）测定细胞增殖;软琼脂克隆形成实验观察细胞的锚定非依赖性生长能力。结果：pEGFP-N1/OPN转染SW480后,OPN基因获得很好转录,OPN蛋白表达增高,转染OPN后SW480细胞增殖率（光吸收值）显著高于转染阴性组（P〈0.05）,软琼脂克隆形成速度增快,数量明显多于对照组和空载体组（P〈0.05）。结论：OPN基因真核表达载体pEGFP-N1/OPN构建成功,OPN具有促进SW480细胞增殖、存活的作用,为进一步研究OPN作用机制奠定了重要基础。     

Aberrant expression of LncRNA CASC2 mediated the cell viability,apoptosis and autophagy of colon cancer cells by sponging miR19a via NFB signaling pathway

Abnormal and rapid proliferation of colon cancer cells is a severe problem that can be regulated by noncoding RNAs. Thus, our study focused on effects of lncRNA CASC2 and miR19a on colon cancer cells. Expressions of lncRNA CASC2, miR19a, Bcl2, Bax and NFB/p65 were examined by RTqPCR. Cell viabilities were detected by CCK8. A luciferase report assay was used for measuring binding conditions between lncRNA CASC2 and miR19a. Western blotting was used to evaluate expression of LC3I, LC3II and p62 related to autophagy. Expression of lncRNA CASC2 lower in cancer cell lines and the overexpression reduced the cell viability of HT29 and SW480. Furthermore, Bcl2 was suppressed by overexpressed lncRNA CASC2, while Bax was upregulated. LC3 and p62 were both inhibited, but LC3 was promoted. MiR19a was predicted to bind lncRNA CASC2 and expressed higher in cancer cell lines. Overexpressed miR19a reduced expression of lncRNA CASC2 and increased cell viability. This was repressed by upregulated lncRNA CASC2. Bcl2 and Bax expression and proteins implicated in autophagy that are regulated by lncRNA CASC2 upregulation were reversed by miR19a overexpression. NFB was upregulated in colon cancer cell lines, while inhibition of NFB reversed functions of lncRNA CASC2 and magnified roles of miR19a. Our findings showed that lncRNA CASC2 inhibited cell viability in colon cancer cell lines and miR19a reversed its functions through the NFB signalling pathway, suggesting that these could be factors in treating colon cancer in the future.     

Overexpression of RGC-32 in colon cancer and other tumors

Tumors often exhibit deregulation of the cell cycle and overexpression of cyclins and cyclin-dependent kinases (CDKs). Response gene to complement (RGC)-32 is a substrate and regulator of CDC2 and its overexpression induces cell cycle activation. We investigated RGC-32 mRNA and protein expression in tumors with special emphasis in colon carcinoma. By using an expression array technique we found that 19% of tumor tissues showed increased RGC-32 mRNA expression over the levels of corresponding normal tissues. On the other hand, an increased RGC-32 protein was found in 70% of colon adenocarcinoma samples tested. In colon carcinomas, two major patterns of RGC-32 immunoreactivity were seen: staining of malignant epithelial cells only in some tumors and RGC-32 reactivity of both malignant epithelia as well as cells in the interstitium in others. Colonic epithelium obtained from normal individuals was consistently negative for RGC-32 protein. Overexpression of RGC-32 protein was found in other tumors including prostate, bladder, breast, lung, and other digestive tract tumors. RGC-32 expression was present in the same malignant epithelial cells that also expressed the proliferation marker Ki-67. Our data suggest that RGC-32 overexpression might be part of the deregulation of the cell cycle that is required for the growth of tumor cells.     

MicroRNA-98通过下调EZH2表达抑制结直肠癌细胞的活力与侵袭能力

目的:探讨微小RNA-98(mi R-98)与Zeste基因增强子同源物2(EZH2)之间的靶向关系,及其对结直肠癌细胞活力和侵袭能力的影响。方法:Target Scan软件预测EZH2和mi R-98之间的靶向结合,双萤光素酶报告基因实验验证mi R-98与EZH2之间的靶向关系。用mi R-98 mimic和mi R-98 inhibitor分别转染人结直肠癌SW480细胞和SW620细胞,Western blot检测EZH2的蛋白表达; MMT法检测细胞活力; Transwell法检测细胞的侵袭能力。转染EZH2过表达质粒检测其对细胞活力和侵袭的影响。结果:mi R-98能够靶向调节EZH2并负向调节SW480细胞和SW620细胞中EZH2的蛋白表达。在SW480细胞和SW620细胞中,过表达mi R-98显著下调细胞活力和侵袭能力,而抑制mi R-98表达显著促进细胞生长和侵袭。过表达EZH2也可促进SW480细胞和SW620细胞的生长和侵袭。结论:mi R-98通过下调EZH2表达抑制SW480细胞和SW620细胞的活力和侵袭。本研究为结直肠癌的治疗提供了新的靶点和方向。     

敲减NOB1基因表达对人结肠癌SW480细胞药物敏感性及侵袭和迁移能力的影响

目的:探讨通过小干扰RNA(small interfering RNA, siRNA)技术敲减NOB1基因表达对人结肠癌SW480细胞活力、药物敏感性、凋亡、细胞周期及侵袭和迁移能力的影响。方法:利用脂质体Lipofectamine 3000将NOB1 siRNA转染至SW480细胞,采用real-time PCR和Western blot检测转染后SW480细胞中NOB1 mRNA和蛋白表达的变化;采用MTT法检测敲减NOB1基因表达后SW480细胞活力及其对不同化疗药物(顺铂、5-氟尿嘧啶、奥沙利铂和卡培他滨)敏感性的变化;流式细胞术检测敲减NOB1基因表达对SW480细胞凋亡和周期的影响;Transwell方法检测敲减NOB1基因表达对结肠癌SW480细胞侵袭和迁移能力的影响。结果:转染NOB1 siRNA后,SW480细胞中NOB1的mRNA和蛋白表达水平明显降低(P0.05);与对照组和阴性对照siRNA组相比,NOB1 siRNA转染组的SW480细胞在24～72 h的细胞活力显著降低,顺铂、5-氟尿嘧啶、奥沙利铂和卡培他滨对该细胞的半数抑制浓度均显著降低,细胞凋亡率显著增加,细胞周期受到阻滞,细胞侵袭和迁移能力显著降低(P0.05)。结论:NOB1 siRNA转染能够抑制结肠癌SW480细胞活力及侵袭和转移能力,并增强细胞对药物的敏感性,促进细胞凋亡。NOB1能够成为结肠癌诊断和治疗的新靶点。     

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。     

miR-496过表达抑制结肠癌细胞生长和转移

目的:研究miR-496过表达对结肠癌细胞生长和转移的影响及其分子机制。方法:运用生物信息学软件筛选miR-496靶向相互作用蛋白;real-time PCR和Western blot法测定结肠癌细胞系HT29、HCT116、SW480以及正常结肠上皮细胞NCM460中miR-496、CTNNB1 mRNA和β-catenin蛋白的表达;运用Lipofectamine 2000将miR-496 mimics转染HT29、HCT116和SW480细胞,分别命名为HT29-miR-496 mimics、HCT116-miR-496 mimics和SW480-miR-496 mimics细胞,转染scramble为阴性对照;运用MTT法、乳酸脱氢酶(LDH)试剂盒法、克隆形成实验和Transwell分别测定细胞活力、LDH漏出率、克隆形成能力和转移能力;萤光素酶报告基因实验测定miR-496启动子活性;Western blot法测定β-catenin、真核细胞翻译起始因子4E结合蛋白1(4E-BP1)、p-4E-BP1、低密度脂蛋白受体相关蛋白6(LRP6)、p-LRP6、MMP-7、MMP-9、MMP-13以及TIMP-2的蛋白水平。结果:miR-496与β-catenin内源性相互作用;miR-496在HT29、HCT116和SW480细胞中低表达,而在NCM460高表达;β-catenin在HT29、HCT116和SW480细胞中高表达,而在NCM460低表达;培养24 h、48 h、72 h、96 h的HT29-miR-496 mimics、HCT116-miR-496 mimics和SW480-miR-496 mimics细胞活力、LDH漏出率、克隆形成率和转移的细胞数均显著低于对照组(P0.05);萤光素酶报告基因实验结果显示转染miR-496 mimics细胞中的miR-496启动子活性明显增加(P0.05),分别是对照组的1.75倍、2.04倍和1.61倍。Western blot实验结果显示miR-496过表达抑制β-catenin蛋白表达,p-4E-BP1和p-LRP6的蛋白水平降低;siRNA或miR-496过表达介导的β-catenin表达下调能显著抑制MMP-7和MMP-9的表达,促进TIMP-2的表达。结论:miR-496在结肠癌细胞中低表达,在正常结肠上皮细胞中高表达;miR-496过表达抑制结肠癌细胞的生长和转移,其机制是通过抑制Wnt/β-catenin通路进一步抑制MMP-7和MMP-9表达,促进TIMP-2表达,从而抑制结肠癌细胞的恶性表型。