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。     

Therapeutic anti-tumor effect of exogenous apoptin driven by human survivin gene promoter in a lentiviral construct

Introduction

The aim of this study was to construct a lentivirus vector with survivin promoter (pSur)-driven apoptin and test its efficiency in suppressing the growth of tumor cells.

Material and methods

Expression cassettes with different fragments of survivin gene promoter (pSur, 161 bp, 272 bp, 990 bp) driving 6XHis-tagged apoptin were constructed to generate recombinant lentivirus, of which the inhibitory effect on tumor cells was compared. The activity of different pSur in 293FT, and 272 bp pSur in primary bone marrow mesenchymal stem cells (BMSCs), SW480, Hela and MCF-7 was examined by Western blot. Their ability to induce apoptosis in SW480 cells was determined by annexin-V staining. The inhibitory effect of letivirus containing different pSur-driven apoptin on nude mice-xenografted SW480 cells was assessed by tumor size and pathological observation.

Results

The 272 bp and 990 bp pSur displayed comparable effects in terms of promoter activity, cell apoptosis/necrosis and G1 phase arrest in vitro, and growth of xenograft tumor in vivo. When lentivirus containing 272 bp pSur was tested, it drove high apoptin expression in tumor cells (SW480, Hela and MCF-7) and weak expression in primary bone marrow mesenchymal stem cells. Xenograft to nude mice using infected Sw480 cells showed that lentiviruses possessing 272 bp and 990 bp pSur were able to significantly induce tumor cell death, focal necrosis, and tumor growth lag.

Conclusions

The data indicated that pSur-apoptin expression cassette in lentivirus vector ensures specific suppression of tumor cells, and may be applicable to monitor malignant transformation of transplanted cells.     

Cellular apoptosis susceptibility (chromosome segregation 1‐like,CSE1L) gene is a key regulator of apoptosis,migration and invasion in colorectal cancer

Cellular apoptosis susceptibility (chromosome segregation 1‐like, CSE1L) gene maps to chromosomal region 20q13.13, a region frequently amplified in solid tumours. In this study, we investigated the roles played by CSE1L in colorectal cancer by examining CSE1L expression and clinico‐pathological parameters in colorectal cancer and investigating the effect of CSE1L on the viability, adhesion and migration of colorectal cancer cells. RT‐PCR showed that CSE1L mRNA was over‐expressed in colorectal cancer. CSE1L depletion by knock‐down with CSE1L‐specific siRNA significantly reduced viability in HCT116 cells (p = 0.004) and SW480 cells (p = 0.003) whilst significantly increasing the proportion of apoptotic HCT116 cells (p < 0.001) and SW480 cells (p < 0.001). Furthermore, CSE1L depletion significantly reduced the adhesive capacity of HCT116 (p = 0.003) and SW480 cells (p = 0.004). Analysis by qRT‐PCR following CSE1L siRNA treatment of HCT116 and SW480 cells showed significant modulation of key apoptotic (p53, p73 and BAK) and adhesive (E‐cadherin, Ep‐CAM and ICAM‐1) molecules. Immunohistochemistry of a colorectal cancer tissue microarray showed that CSE1L had a significantly increased level in colorectal cancer compared to normal colorectal epithelium (p < 0.001). There were significant decreases in both nuclear (p = 0.006) and cytoplasmic (p = 0.003) staining of CSE1L in tumours with lymph node metastasis (stage 3 tumours) compared with lymph node‐negative tumours (stage 1 and 2 tumours). In lymph node‐negative patients, poor survival was associated with increased CSE1L cytoplasmic expression (p = 0.042). These results indicate that CSE1L is associated with viability and apoptosis, cellular adhesion and invasion, thus implicating CSE1L in the progression of colorectal cancer. Copyright © 2012 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.     

miR-126 对结肠癌细胞生物学行为的影响及其在调控结肠癌EMT 转化中的作用

目的:观察miR-126 在不同转移潜能的人结肠癌细胞系中的表达情况及其对结肠癌细胞增殖、侵袭转移能力的影响并探讨可能的作用机制。方法:采用实时荧光定量PCR 检测结肠癌细胞系(SW480、SW620 及HCT116)中miR-126 的表达量。通过脂质体瞬时转染法将miR-126 过表达(miR-126 mimics),并设置阴性对照组,然后采用CCK8 法检测细胞的增殖能力,细胞划痕实验检测细胞的迁移能力,Transwell 侵袭小室实验检测细胞的侵袭能力,Western blot 实验检测E-cadherin 和Vimentin 蛋白表达量的变化。结果:相对于低转移潜能的结肠癌细胞株SW480,miR-126 在高转移潜能的SW620 和HCT116细胞中的表达降低。过表达miR-126 可使SW620 细胞增殖、迁移和侵袭能力降低,E-cadherin 蛋白表达增加,Vimentin 蛋白表达降低,差异具有统计学意义(P<0.05)。结论:低表达的miR-126 与结肠癌的转移密切相关,miR-126 影响结肠癌细胞生物学行为的作用可能是通过调控EMT 进程实现的。     

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。     

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。     

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.     

错配修复基因hMLH1在雌激素诱导结肠癌细胞凋亡中的作用

 摘 要 目的：探讨错配修复基因hMLH1在雌激素诱导结肠癌细胞凋亡中的作用。方法：将含野生型hMLH1-cDNA的质粒转入hMLH1缺陷的人结肠癌细胞株HCT116,在不同浓度的雌激素干预下,分别以流式细胞仪和活细胞计数试剂盒（cell counting kit-8）法检测转染后细胞的凋亡率和活性。结果：与空载组相比,转染hMLH1后雌激素能明显诱导HCT116细胞活性降低,且凋亡率增加。结论:hMLH1参与雌激素诱导的结肠癌细胞株HCT116凋亡。     

JK1 (FAM134B) represses cell migration in colon cancer: a functional study of a novel gene

Background

JK1 is a novel cancer-related gene with unknown functional role in carcinogenesis. The aim of this study is to investigate the role of JK1 gene in carcinogenesis in an in vitro cell proliferation and migration analysis model.

Methods

Small hairpin RNAs (shRNA) were designed to knock-down JK1 expression in colon cancer cell line (SW480) using transduction ready lentiviral particles. Cell proliferation and cell migration assays were performed on multiple extracellular matrices to investigate the cellular effects of JK1 in colon cancer cells. A non-cancer colonic epithelial cell line (FHC) was used to compare the expression of JK1 in cancer cell line.

Results

JK1 knock-down did not affect cellular proliferation or survival in colon cancer. However, the manipulation increased cancer cell migration rates on collagen and fibronectin substrates.

Conclusions

JK1 was shown for the first time to have a functional role in the pathogenesis of colon cancer. The results imply that JK1 represses the capacity of cancer cells to migrate within their tissue. They also concurred with the previous findings of JK1 activity correlations with clinical and pathological features in colon cancer. The capacity may have utility as a means to prevent cancer cells forming metastases.     

LncRNA OGFRP1 promotes angiogenesis and epithelial-mesenchymal transition in colorectal cancer cells through miR-423-5p/CTCF axis

ObjectiveTo investigate the mechanism of lncRNA OGFRP1 affecting angiogenesis and epithelial-mesenchymal transition (EMT) in colorectal cancer (CRC) and provide a new target for the treatment of CRC.MethodsThe expressions of OGFRP1, miR-423-5p, and CTCF were measured in CRC cell lines (HT29, LoVo, HCT116, SW620, and SW480) and normal colonic epithelial cells NCM460. Gain and loss of function experiments were performed on HCT116 and SW620 cells, after which the proliferation, apoptosis, EMT, invasion, and migration of the cells were measured using CCK-8 and colony formation assays, flow cytometry, Western blotting, Transwell, and scratch assay. The transfected cells were incubated with human umbilical vein endothelial cells (HUVECs) to assess angiogenesis using tube formation assay. ELISA was performed to detect VEGF in the conditioned medium of HCT116 and SW620 cells. The interactions among OGFRP1, CTCF and miR-423-5p were validated by dual-luciferase reporter assay.ResultsCRC cell lines had increased expression levels of OGFRP1 and CTCF and a suppressed expression level of miR-423-5p when compared with NCM460 cells. Suppression on OGFRP1 or CTCF and overexpression of miR-423-5p led to inhibited proliferation, EMT, invasion and migration and increased apoptosis of HCT116 and SW620 cells. HUVECs incubated with cells transfected with si-OGFRP1, si-CTCF or miR-423-5p mimic had suppressed angiogenesis ability. The effect of OGFRP1 suppression in CRC cells could be counteracted by miR-423-5p inhibition. Both CTCF and OGFRP1 could bind to miR-423-5p.ConclusionOGFRP1 promotes proliferation, EMT, and angiogenesis in CRC through miR-423-5p/CTCF axis.     

The silence of p66Shc in HCT8 cells inhibits the viability via PI3K/AKT/Mdm-2/p53 signaling pathway

Colon cancer is the second most common cause of cancer-related death, indicating that some of its cancer cells are not eradicated by current therapies. The previous studies demonstrated that p66^Shc protein, a member of Shc family, is highly expressed in colon cancer cells, but the role of p66^Shc in the progress of colon cancer still unknown. In this study, we found that p66^Shc highly expressed in colon cancer tissue and colon cancer cell line SW620 cells, HCT8 cells, HCT116 cells and CaCO₂ cells. The silence of p66^Shc in HCT8 cells reduced the proliferation and accelerated the apoptosis, in addition, the expression of pro-apoptotic proteins caspase-3, caspase-9, Bax was enhanced and the expression of anti-apoptotic protein Bcl-2 was declined. Moreover, the cell cycle arrest in G0/G1 phase after HCT8 cells treated with p66^Shc siRNA. Furthermore, after HCT8 cells treated with p66^Shc siRNA, the phosphorylation of PI3K and AKT was significantly suppressed, and the expression of Mdm-2, a downstream of AKT, was obviously prohibited, while the expression of p53 was enhanced. These results indicate that the silence of p66^Shc in HCT8 cells inhibits the viability via PI3K/AKT/Mdm-2/p53 signaling pathway, it may provide a promising approach to prevent the progress of colon cancer cell.     

艰难梭菌毒素B诱导结肠癌细胞凋亡及相关机制研究

目的检测艰难梭菌毒素B(TcdB)对结肠癌SW480细胞增殖与凋亡的影响,研究其引起细胞凋亡的相关机制。方法采用不同浓度的TcdB处理SW480细胞,采用MTT法检测细胞增殖情况;用流式细胞术检测细胞的凋亡及线粒体膜电位变化情况。结果TcdB显著抑制了结肠癌SW480细胞的增殖,作用48 h后的抑制率为46.36%,呈一定的时间-浓度相关性;流式细胞仪检测结果表明,浓度为800 ng/ml的TcdB作用48 h,SW480细胞凋亡率为20.83%,呈一定的时间-浓度相关性。结论艰难梭菌毒素B能够抑制结肠癌SW480细胞增殖、诱导细胞凋亡,其机制可能与启动线粒体凋亡途径有关。     

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。     

CD40配体对结肠癌细胞株的体外抑制作用

研究免疫共刺激分子CD40在结肠癌细胞株的表达及重组可溶性人CD40配体(rshCD40L)对结肠癌细胞株的体外抑制作用。采用流式细胞仪分别检测4株结肠癌细胞(HCT116、Caco-2、SW48和COLO-320)CD40分子的表达,同时利用流式细胞仪检测γ干扰素(IFN-γ)对结肠癌细胞株CD40表达的影响。MTT法检测rshCD40L对结肠癌细胞的抑制作用,TUNEL法检测rshCD40L对结肠细胞的促凋亡作用,同时检测联合rshCD40L和IFN-γ抗结肠癌作用。结果流式细胞仪检测有3株结肠癌细胞(HCT116、Caco-2和SW48)表达CD40分子,IFN-γ能增强CD40+结肠癌细胞CD40分子的表达。rshCD40L能明显抑制CD40+结肠癌细胞的增殖作用(抑制率分别为HCT116:33.5%±5.5%;Caco-2:21.5%±3.6%;SW48:30.1%±4.2%),而对CD40-结肠癌细胞株(COLO-320)无明显抑制作用(P<0.05)。rshCD40L能诱导CD40+结肠癌细胞的凋亡作用(凋亡细胞百分比为HCT116:25.6%±4.52%;Caco-2:15.71%±2.27%;SW48:18.0%±3.7%),而对CD40-结肠癌细胞株(COLO-320)无诱导凋亡作用(P<0.05)。另外,IFN-γ能明显增强rshCD40L对结肠癌细胞的抑制增殖和促凋亡作用。重组人CD40配体与IFN-γ联合可显著诱导CD40阳性的结肠癌细胞凋亡,抑制其增殖,具有潜在的抗肿瘤作用。     

Dendritic cell-based immunotherapy for colon cancer using an HLA-A*0201-restricted cytotoxic T-lymphocyte epitope from tumor-associated antigen 90K

Tumor-associated antigen 90K is implicated in cell–cell and cell-extracellular matrix adhesion through its interaction with galectin-3 and integrin-β1 and is highly expressed in malignant tissues, making it a novel target for the development of new immunotherapies. We investigated a potential immunotherapy treatment for colon cancer using 90K-specific cytotoxic T lymphocytes induced by autologous dendritic cells and pulsed with 90K peptides. We selected three peptides (90K₃₅₁, 90K₅ and 90K₅₂₃) that bind to HLA-A*0201 molecules on the basis of their binding affinity, as determined by a peptide-T2 binding assay. Dendritic cells pulsed with 90K peptides resulted in the efficient generation of mature dendritic cells and exhibited enhanced T-cell stimulation and polarization of naive T cells toward Th1. Dendritic cells pulsed with 90K peptides generated potent cytotoxic T-lymphocytes that lysed T2 cells loaded with each 90K peptide, and 90K⁺/HLA-A2⁺ colon cancer cell lines, including HCT116 and SW480, in a dose-dependent and HLA-A*0201-restricted manner. No killing was observed in 90K⁺/HLA-A2⁻ DLD1 or 90K⁻/HLA-A2⁻ K562 cells. Therefore, we believe that cytotoxic T-lymphocytes stimulated by 90K peptide-pulsed dendritic cells naturally recognize the 90K peptide presented by colon cancer cells in the context of HLA-A2, and kill 90K-positive tumor cells. Dendritic cells pulsed with 90K peptides led to the induction of granzyme B and perforin positive CD8⁺ T cells against HCT116 and SW480 cells, but not DLD1 cells. In conclusion, 90K-specific cytotoxic T lymphocytes, generated by stimulating T cells with 90K peptide-pulsed dendritic cells, could be useful effector cells for the immunotherapy treatment of colon cancer.     

转化生长因子β受体Ⅱ对微立星不稳定结肠癌细胞凋亡和迁移的影响

目的 研究转化生长因子β受体Ⅱ（TGFBRⅡ）表达对微卫星不稳定（MSI）结肠癌细胞凋亡和迁移的影响。方法 选择野生型PIK3CAHCT116细胞（HCT116wt）作为MSI结肠癌细胞模型。将TGFDRⅡ转染HCTll6wt细胞获得HCTll6wt—RⅡ细胞,并以HCT116wt空质粒细胞作为对照。通过生长因子缺失应激（GFDS）诱导细胞凋亡。采用Western印迹检测磷酸化Smad2（TGFD信号通路关键因子）、磷酸化AKT（P13K／AKT信号通路关键因子）、Bim（TGFB信号通路下游因子）和E-cadherin（诱导上皮向间质转化的标志物）表达。采用DNA碎片ELISA分析检测HCTll6wt—RⅡ细胞凋亡情况。通过Transwell实验检测HCT116wt—RⅡ细胞迁移活力。结果加入TGFB后,HCTll6wt—RlI细胞的TGFB信号通路得以启动,GFDS诱导的HCT116wt-RⅡ细胞凋亡受到显著抑制（DNA碎片值：0．69＋0．02比0．41±0．04,P〈0．01）;细胞迁移活力明显增强（2．10±0．15比4．03±0．48,P〈0．01）。P13K抑制剂（LY294002）可以逆转TGF[3对HCTll6wt—RⅡ细胞的凋亡抑制和迁移活力增强作用。TGFβ作用于HCT116wt．RⅡ细胞后,Bim和E—cadherin表达明显减少。结论TGFβRⅡ在MSI结肠癌细胞中的再表达可以增加MSI结肠癌细胞的存活能力和迁移活力,该作用依赖P13K／AKT途径,从而为MSI结肠癌患者的良好预后提供了一个分子水平的解释。     

KLF4对结直肠癌细胞生长抑制及化疗敏感性的影响

目的:探讨Krüppel样因子4(KLF4)对结直肠癌细胞活力、凋亡及顺铂化疗敏感性的影响。方法:Western blot法检测KLF4在结直肠癌Caco2、SW480和HCT116细胞中的表达。将SW480细胞分为pc DNA3. 1组(转染pc DNA3. 1空质粒)、pc DNA3. 1-KLF4组(转染构建的pc DNA3. 1-KLF4过表达质粒)和pc DNA3. 1-KLF4+顺铂组(转染pc DNA3. 1-KLF4 48 h后用1 mg/L顺铂处理细胞48 h),Western blot检测KLF4、p-IκBα、细胞周期素D1(cyclin D1)和生存素(survivin)的蛋白水平; CCK-8法检测各组细胞活力;流式细胞术检测细胞凋亡率; DCFH-DA探针检测活性氧簇(ROS)含量。结果:KLF4在结直肠癌细胞中的表达均显著低于在人结肠黏膜上皮NCM460细胞的表达(P 0. 05)。与pc DNA3. 1组相比,pc DNA3. 1-KLF4组的KLF4蛋白表达显著增高(P 0. 05),细胞活力及cyclin D1和survivin的蛋白表达均显著降低,细胞凋亡率、ROS含量及p-IκBα的蛋白表达均显著增高;而pc DNA3. 1-KLF4+顺铂组细胞活力及cyclin D1和survivin的蛋白表达均显著低于pc DNA3. 1-KLF4组,细胞凋亡率、ROS含量及p-IκBα的蛋白表达均显著高于pc DNA3. 1-KLF4组(P 0. 05)。结论:上调结直肠癌细胞KLF4基因表达可降低肿瘤细胞活力,诱导细胞凋亡,增强顺铂化疗敏感性,其机制可能与提高细胞内ROS含量及下调NF-κB信号关键分子IκBα的磷酸化水平有关。