Requirement of phosphatase of regenerating liver‐3 for the nucleolar localization of nucleolin during the progression of colorectal carcinoma

Phosphatase of regenerating liver‐3 (PRL‐3) is a protein tyrosine phosphatase (PTP) that is frequently overexpressed in liver metastases of colorectal carcinomas (CRCs). The PTP activity of the PRL‐3 protein is indispensable for the promotion of distant metastasis of CRC; however, little is known about the effect of PRL‐3 on cell growth. In this study, we investigated a novel protein that can connect to PRL‐3 to modulate the proliferation of CRC cells. In CRC‐derived SW480 cells, transduction of ectopic wild‐type PRL‐3, but not the C104S catalytic “dead” mutant, up‐regulated cell proliferation and increased the population of cells at the S and G₂/M phases. Also, inhibition of PTP activity of the PRL‐3 protein by treatment with the PRL‐3 inhibitor suppressed cell proliferation in a dose‐dependent manner as well as PRL‐3 knockdown by RNA interference. Using a comparative study of monodimensional gel electrophoresis of immunoprecipitates from PRL‐3‐transfected SW480 cells and subsequent mass spectrometry analysis, nucleolar‐specific protein nucleolin (NCL) was identified as a novel PRL‐3‐binding protein. We confirmed physiological interaction between PRL‐3 and NCL, and found that PRL‐3 phosphatase activity was associated with the suppression of the phospho‐NCL levels and nucleolar assembly of NCL protein. In CRC cases, nucleolar NCL expression was correlated not only with higher levels of PRL‐3 expression but also with frequent incidence of lymph node metastasis and a higher clinicopathologic stage. These findings suggest that NCL is involved in PRL‐3‐mediated cancer progression/metastasis signaling, which plays an important role in the acceleration of CRC growth. (Cancer Sci 2010)     

Astrocyte elevated gene‐1 interacts with β‐catenin and increases migration and invasion of colorectal carcinoma

To investigate the astrocyte elevated gene‐1 (AEG‐1) expression and its relationship with the clinicopathological features of colorectal carcinoma (CRC) and β‐catenin signaling pathway. Real‐time PCR, Western blot, immunohistochemistry, and immunofluorescence staining were performed to detect AEG‐1 expression in CRC cell lines, 8 pairs of fresh CRC and adjacent nontumor tissues (ANT), 120 pairs of paraffin‐embedded CRC specimens and ANT tissues, and 60 samples of lymph node metastatic CRC tissues. Scratch wound assay and transwell matrix penetration assay were performed to determine migration and invasion of SW480 cell lines with stable AEG‐1 overexpression or SW620 cell lines with AEG‐1 knockdown. AEG‐1 expression was upregulated in CRC cell lines and tissues compared with ANT. Furthermore, AEG‐1 expression level significantly correlated with UICC stage, and the N classification. AEG‐1 overexpression significantly enhanced migration and invasion of SW480 cell lines. However, AEG‐1 knockdown suppressed migration and invasion of SW620 cell lines. Meanwhile, there was a positive correlation between AEG‐1 high expression and β‐catenin nuclear expression in CRC. AEG‐1 overexpression increased nuclear β‐catenin accumulation in CRC cell lines. AEG‐1 knockdown decreased nuclear β‐catenin accumulation in CRC cell lines. Moreover, we firstly found that AEG‐1 interacted with β‐catenin in SW480 cell lines. Our results for the first time showed that AEG‐1 interacted with β‐catenin in CRC cells and AEG‐1 expression was closely associated with progression of CRC. AEG‐1 might be a potential therapeutic target in CRC. © 2012 Wiley Periodicals, Inc.     

Over‐expression of phosphatase of regenerating liver‐3 correlates with tumor progression and poor prognosis in nasopharyngeal carcinoma

This study aimed at clarifying the expression of phosphatase of regenerating liver‐3 (PRL‐3), one member of protein tyrosine phosphatase (PTP) superfamily, in nasopharyngeal carcinoma (NPC) and its correlation with clinicopathologic features, including the survival of patients with NPC. Real‐time PCR and Western blot showed that the expression level of PRL‐3 was markedly higher in NPC cell lines than that in the normal nasopharyngeal epithelial cell at both mRNA and protein levels. Immunohistochemical analysis revealed overexpression of PRL‐3 in 97 of 174 (55.7%) paraffin‐embedded archival NPC biopsies. Statistical analysis showed that PRL‐3 expression was positively correlated with N classification (p = 0.033), distant metastasis (M classification, p = 0.048) and clinical stage (p = 0.005) of patients. Patients with higher PRL‐3 expression had shorter overall survival time, whereas patients with lower level of PRL‐3 had better survival. Multivariate analysis suggested that PRL‐3 expression might be an independent prognostic indicator for the survival of patients with NPC. Disruption of endogenous PRL‐3 protein through a siRNA knockdown technique was shown to suppress the invasion ability and migration potency of 5‐8F and HONE1 cells, substantially. Interestingly, we also found that no significant effect on the proliferation of 5‐8F and HONE1 cells was observed after PRL‐3 was down‐regulated. Our results suggest that PRL‐3 protein is a valuable marker for progression of NPC patients. High PRL‐3 expression is associated with poor overall survival in patients with NPC. © 2008 Wiley‐Liss, Inc.     

转凝蛋白在结直肠癌组织中的表达及其对SW480细胞恶性生物学行为的影响

目的:探讨转凝蛋白(transgelin,TAGLN)在结直肠癌(colorectal cancer,CRC)组织中的表达及其对SW480细胞增殖、迁移及侵袭的影响.方法:选取郑州大学附属肿瘤医院2015年5月至2016年8月收治的97例CRC患者的癌及配对的癌旁组织标本,以及人CRC细胞系SW620、SW480、HC...     

Angiopoietin‐like protein 2 renders colorectal cancer cells resistant to chemotherapy by activating spleen tyrosine kinase–phosphoinositide 3‐kinase‐dependent anti‐apoptotic signaling

Angiopoietin‐like protein 2 (ANGPTL2) plays an important role in inflammatory carcinogenesis and tumor metastasis by activating tumor angiogenesis and tumor cell chemotaxis and invasiveness. However, it is unclear whether ANGPTL2 expression has an effect on tumor cell survival. Here, we explored that possibility by determining whether ANGPTL2 expression altered survival of human colorectal cancer cell lines treated with antineoplastic drugs. To do so, we generated SW480 cells expressing ANGPTL2 (SW480/ANGPTL2) and control (SW480/Ctrl) cells. Apoptosis induced by antineoplastic drug treatment was significantly decreased in SW480/ANGPTL2 compared to control cells. Expression of anti‐apoptotic BCL‐2 family genes was upregulated in SW480/ANGPTL2 compared to SW480/Ctrl cells. To assess signaling downstream of ANGPTL2 underlying this effect, we carried out RNA sequencing analysis of SW480/ANGPTL2 and SW480/Ctrl cells. That analysis, combined with in vitro experiments, indicated that Syk‐PI3K signaling induced expression of BCL‐2 family genes in SW480/ANGPTL2 cells. Furthermore, ANGPTL2 increased its own expression in a feedback loop by activating the spleen tyrosine kinase–nuclear factor of activated T cells (Syk–NFAT) pathway. Finally, we observed a correlation between higher ANGPTL2 expression in primary unresectable tumors from colorectal cancer patients who underwent chemotherapy with a lower objective response rate. These findings suggest that attenuating ANGPTL2 signaling in tumor cells may block tumor cell resistance to antineoplastic therapies.     

miR-107 Promotes Proliferation and Inhibits Apoptosis of Colon Cancer Cells by Targeting Prostate Apoptosis Response-4 (Par4)

Colorectal cancer (CRC) is one of the most common malignancies in the world, with a high incidence and a high mortality. However, the pathogenesis of CRC carcinogenesis is still unexplored. In this study, we investigated the role of miR-107 in the regulation of CRC cell proliferation and apoptosis. First, the expression of miR-107 was observed to be aberrantly increased in human CRC tumor tissues and cell lines when compared to the colonic control tissues and colon epithelial cells. Further study showed that the proliferative and apoptotic capacities of human CRC SW480 and LoVo cells were aberrantly regulated by miR-107. The proliferation of SW480 and LoVo cells was remarkably enhanced by the miR-107 mimic but suppressed by the miR-107 inhibitor when compared to the negative control. On the contrary, the apoptotic rate of both SW480 and LoVo cells was significantly inhibited by miR-107 overexpression but increased by miR-107 inhibition. In addition, we identified prostate apoptosis response-4 (Par4) as a direct target of miR-107 with a potential binding site on the 3 -UTR of mRNA, as evaluated by bioinformatics prediction and luciferase reporter assay. Par4 expression levels were significantly inhibited by the miR-107 mimic but upregulated by the miR-107 inhibitor in both SW480 and LoVo cells. Compared to the control, the increase in Par4 expression significantly inhibited the induction role of miR-107 in the proliferation of SW480 and LoVo cells, and the apoptotic rate of cells repressed by the miR-107 mimic was also reversed by Par4 overexpression. In summary, our results demonstrated that miR-107 exerts a positive role in the survival of CRC cells by directly targeting Par4. This might reveal a novel understanding about human CRC pathogenesis.     

MicroRNA‐143‐3p inhibits colorectal cancer metastases by targeting ITGA6 and ASAP3

MicroRNAs, which regulate mRNAs, operate through a variety of signaling pathways to participate in the development of colorectal cancer (CRC). In this study, we found that microRNA (miR)‐143‐3p expression was significantly lower in both CRC and liver metastatic CRC tissues from liver compared with normal colonic tissues. Functional assays showed that miR‐143‐3p inhibited CRC cell invasion and migration in vitro. Using a bioinformatics approach, we identified miR‐143‐3p target mRNAs. Among the candidate targets, only the expression of integrin alpha 6 (ITGA6) and ArfGAP with the SH3 domain and ankyrin repeat and PH domain 3 (ASAP3) were significantly reduced by miR‐143‐3p mimics as examined by western blot, and the metastasis potential of CRC cells was attenuated by endogenous ITGA6 and ASAP3 knockdown, determined by migration and invasion assays. Both ITGA6 and ASAP3 were upregulated in CRC tissues compared to normal tissues. Analysis of the relationship between clinicopathological features and ITGA6/ASAP3 protein expression in 200 patients with CRC showed a significant difference in positive ITGA6 expression between the early stage (I + II) and the advanced stage (III + IV), and ASAP3 expression levels positively correlated with metastasis in the lymph nodes. These results indicate that miR‐143‐3p acts as an anti‐oncogene by downregulating ITGA6/ASAP3 protein expression and could offer new insight into potential therapeutic targets for CRC.     

Oncogenic microRNA‐27a is a target for anticancer agent methyl 2‐cyano‐3,11‐dioxo‐18β‐olean‐1,12‐dien‐30‐oate in colon cancer cells

Methyl 2‐cyano‐3,11‐dioxo‐18β‐olean‐1,12‐dien‐30‐oate (CDODA‐Me) is a synthetic derivative of glycyrrhetinic acid, a triterpenoid phytochemical found in licorice extracts. CDODA‐Me inhibited growth of RKO and SW480 colon cancer cells and this was accompanied by decreased expression of Sp1, Sp3 and Sp4 protein and mRNA and several Sp‐dependent genes including survivin, vascular endothelial growth factor (VEGF), and VEGF receptor 1 (VEGFR1 or Flt‐1). CDODA‐Me also induced apoptosis, arrested RKO and SW480 cells at G₂/M, and inhibited tumor growth in athymic nude mice bearing RKO cells as xenografts. CDODA‐Me decreased expression of microRNA‐27a (miR‐27a), and this was accompanied by increased expression of 2 miR‐27a‐regulated mRNAs, namely ZBTB10 (an Sp repressor) and Myt‐1 which catalyzes phosphorylation of cdc2 to inhibit progression of cells through G₂/M. Both CDODA‐Me and antisense miR‐27a induced comparable responses in RKO and SW480 cells, suggesting that the potent anticarcinogenic activity of CDODA‐Me is due to repression of oncogenic miR‐27a. © 2009 UICC     

miR-302a对结直肠癌细胞奥沙利铂化疗敏感性的影响及机制

目的:探究miR-302a对结直肠癌细胞奥沙利铂化疗敏感性的影响及机制。方法:在四株结直肠癌细胞系HT29、HCT8、SW480、SW1463中,通过转染miR-302a mimic构建miR-302a过表达模型,RT-PCR检测过表达效果;CCK-8法检测转染48 h后高表达miR-302a细胞的增殖能力及对奥沙利铂的敏感性;蛋白质印迹法检测转染后P-gp蛋白及Wnt/β-catenin通路相关蛋白MMP-7、c-Jun、c-myc、β-catenin、LEF1的变化。结果:相比正常小肠上皮细胞HIEC,miR-302a在结直肠癌细胞系HT29、HCT8、SW480、SW1463中的表达较低。转染mimic后,miR-302a的表达明显上调（P<0.001）。增殖实验发现miR-302a的上调并不影响结直肠癌细胞的增殖,而在转染miR-302a的细胞中加入奥沙利铂,miR-302a组HT29、HCT8、SW480和SW1463细胞存活率相比miR-NC组分别降低2.46、1.89、2.39、2.86倍。进一步探究miR-302a增加奥沙利铂敏感性的机制,发现miR-302a可抑制P-gp蛋白的表达,并且抑制Wnt/β-catenin通路相关蛋白MMP-7、c-Jun、c-myc、β-catenin、LEF1的表达。结论:miR-302a可增加结直肠癌细胞奥沙利铂化疗敏感性,其机制可能是通过抑制P-gp的蛋白表达,并抑制Wnt/β-catenin信号通路相关蛋白表达而实现。     

Inflammation‐induced S100A8 activates Id3 and promotes colorectal tumorigenesis

The aberrant expression of S100A8 and S100A9 is linked to nonresolving inflammation and ultimately to carcinogenesis, whereas the underlying mechanism that allows inflammation to progress to specific cancer types remains unknown. Here, we report that S100A8 was induced by inflammation and then promoted colorectal tumorigenesis downstream by activating Id3 (inhibitor of differentiation 3). Using gene expression profiling and immunohistochemistry, we found that both S100A8 and S100A9 were upregulated in the chemically‐induced colitis‐associated cancer mouse model and in human colorectal cancer specimens. Furthermore, we showed that S100A8 and S100A9 acted as chemoattractant proteins by recruiting macrophages, promoting the proliferation and invasion of colon cancer cell, as well as spurring the cycle that culminates in the acceleration of cancer metastasis in a nude mouse model. S100A8 regulated colon cancer cell cycle and proliferation by inducing Id3 expression while inhibiting p21. Id3 expression was regulated by Smad5, which was directly phosphorylated by Akt1. Our study revealed a novel mechanism in which inflammation‐induced S100A8 promoted colorectal tumorigenesis by acting upstream to activate the Akt1‐Smad5‐Id3 axis.     

Significant antitumor effect of an antibody against TMEM180, a new colorectal cancer‐specific molecule

The present state of therapy for colorectal cancer (CRC) is far from satisfactory, highlighting the need for new targets for this disease. We identified a new CRC‐specific molecule, TMEM180, a predicted 11‐pass transmembrane protein that apparently functions as a cation symporter. We developed an anti‐TMEM180 mAb and then succeeded in humanizing the mAb. Immunohistochemistry (IHC) in CRC with the mAb showed a similar positivity rate as compared with anti‐epidermal growth factor receptor mAb, and IHC with anti‐TMEM180 mAb did not show staining in major organs used in this study. Immune electron microscopy clearly indicated that TMEM180 was present on the tumor exosome. The TMEM180 promoter region contains 10 hypoxia‐responsive element consensus sequences; accordingly, SW480 cells upregulated TMEM180 under low‐oxygen conditions. Anti‐TMEM180 mAb has in vitro antibody‐dependent cell‐mediated cytotoxicity and complement‐dependent cytotoxicity activity, and SW480 CRC xenografts were eradicated by the mAb. These data indicate that TMEM180 may be a new CRC marker and that a mAb against this protein could be used as antibody‐based therapy against CRC.     

Phosphatase of regenerating liver-3 promotes migration and invasion by upregulating matrix metalloproteinases-7 in human colorectal cancer cells

Phosphatase of regenerating liver (PRL)-3, a member of a subgroup of protein tyrosine phosphatases that can stimulate the degradation of the extracellular matrix, is over-expressed in metastatic colorectal cancer (CRC) relative to primary tumors. To determine whether PRL-3-induced enhancement of migration and invasion is dependent on the expression of matrix metalloproteinases (MMPs), PRL-3 was expressed in DLD-1 human CRC cells. The motility, migration and invasion characteristics of the cells were examined, and metastasis to the lung was confirmed in a nude mouse using PRL-3-overexpressing DLD-1 cells [DLD-1 (PRL-3)]. Migration and invasion of the cells were inhibited by phosphatase and farnesyltransferase inhibitors. Expression of MMPs was enhanced 3- to 10-fold in comparison to control cells, and migration and invasion were partially inhibited by small interfering RNA (siRNA) knockdown of MMP-2, -13 or -14. Importantly, siRNA knockdown of MMP-7 completely inhibited the migration and invasion of DLD-1 (PRL-3) cells, whereas overexpression of MMP-7 increased migration. The expression of MMP-7 was also downregulated by phosphatase and farnesyltransferase inhibitors. It was found that PRL-3 induced MMP-7 through oncogenic pathways including PI3K/AKT and ERK and that there is a relationship between the expression of PRL-3 and MMP-7 in human tumor cell lines. The expression of MMP-13 and -14 was very sensitive to the inhibition of farnesyltransferase; however, the migration and invasion of DLD-1 (PRL-3) cells did not strongly depend on the expression of MMP-13 or -14. These results suggest that the migration and invasion of PRL-3-expressing CRC cells depends primarily on the expression of MMP-7.     

Oxidative stress‐dependent increase in ICAM‐1 expression promotes adhesion of colorectal and pancreatic cancers to the senescent peritoneal mesothelium

Intercellular adhesion molecule‐1 (ICAM‐1) has been implicated in adhesion of colorectal and pancreatic cancer cells (of the SW480 and PSN‐1 line, respectively) to the peritoneal mesothelium. It has been demonstrated that ICAM‐1 expression increases with senescence in some cell types, however, the significance of this phenomenon in the context of malignant dissemination remains elusive. In this report we show that the adherence of SW480 and PSN‐1 cells to senescent human omentum‐derived mesothelial cells (HOMCs) in vitro is greater than to early‐passage cells and that the effect is mediated by ICAM‐1. Senescent HOMCs display increased expression of ICAM‐1 mRNA and cell surface protein. The development of this phenotype is related to increased oxidative stress in senescent cells. The augmented ICAM‐1 expression in HOMCs can be reduced by culturing cells with antioxidants; in contrast, exposure of HOMCs to an oxidant, t‐BHP, leads to cellular senescence and increased ICAM‐1 expression. The effect is partly mediated by activation of p38 MAPK and AP‐1 signaling pathways. Finally, culture of HOMCs in the presence of a strong antioxidant, PBN, significantly reduces the senescence‐associated increase in SW480 and PSN‐1 cancer cell binding. These results indicate that increased oxidative stress and increased expression of ICAM‐1 in senescent HOMCs may facilitate peritoneal adhesion of selected colorectal and pancreatic cancers.     

CCL20 通过AKT/MMP3 轴而非EMT途径诱导结肠癌SW480 细胞的侵袭和转移

[摘要] 目的：探讨趋化因子CCL20/CCR6促进结肠癌SW480细胞侵袭和迁移的分子机制。方法：筛选高表达CCR6 的结肠癌SW480细胞,加入外源性重组人CCL20后,采用Transwell、划痕愈合实验检测其侵袭和迁移能力,以免疫荧光、WB实验检测SW480细胞EMT标志蛋白、AKT信号蛋白以及靶标蛋白MMP3 的表达;通过MK2206 阻断实验验证AKT信号是其作用机制,通过TCGA数据库资源（https://portal.gdc.cancer.gov/）分析CCL20和MMP3在结直肠癌组织中的表达水平及其相关性。结果：趋化因子CCL20能够明显促进结肠癌SW480细胞侵袭和迁移（均P<0.01）,其间并不伴随细胞的EMT变化,而是通过AKT信号的激活及下游靶标蛋白MMP3 表达上调是其诱因之一;阻断AKT信号能够明显抑制SW480细胞侵袭和迁移能力,且下调MMP3 的表达水平（P<0.05 或P<0.01）。TCGA 平台数据提示,结肠癌组织中CCL20 和MMP3 的表达明显高于正常肠黏膜组织,且两者呈明显正相关（r=0.051,P<0.01）。结论：趋化因子CCL20 通过AKT/MMP3 信号轴而非EMT机制促进结肠癌SW480 细胞的侵袭和迁移。     

miR-92a 在结直肠癌中的表达及其对肿瘤血管生成的作用*

目的:探讨miR-92a 在结直肠癌中的表达及其对肿瘤血管新生功能的影响和作用机制。方法:采用qRT-PCR方法检测广东医学院附属深圳南山医院2014年6 月至2015年12月经手术切除的25例结直肠癌组织和对应癌旁组织及4 种结直肠癌细胞（HCT 116、SW620、SW480、HT29）中miR-92a 的表达;免疫组织化学法检测结直肠癌和癌旁组织中CD31阳性表达的微血管密度（microvesseldensity,MVD）,Pearson相关性分析探讨miR-92a 表达与肿瘤血管新生MVD的相关性。通过转染miR-92a-mimic、inhibitor 上调或抑制结直肠癌细胞HCT 116、SW620 中miR-92a 的表达水平,采用小管形成实验检测miR-92a 不同表达对HUVEC小管形成的影响,免疫印迹法检测对其下游潜在靶点PTEN的蛋白表达的影响。结果:结直肠癌组织miR-92a 的表达水平显著高于对应癌旁组织（P < 0.01）;4 种人结肠癌细胞系miR-92a 的表达水平均显著高于正常肠上皮组织（P < 0.05）;结直肠癌组织CD31阳性微血管密度显著高于癌旁组织（P < 0.01）,miR-92a 表达水平与结直肠癌血管新生MVD呈显著正相关（r = 0.580,P = 0.01）;上调miR-92a 表达的HCT 116 细胞培养上清液可以显著促进HUVEC小管形成（P < 0.05）;上调miR-92a 表达可以显著抑制HCT116 细胞中PTEN蛋白表达水平（P < 0.01）。 结论:miR-92a 在结直肠癌细胞和组织中高表达,与肿瘤血管新生增加密切相关;miR-92a 可能通过抑制PTEN的表达发挥促进结直肠癌血管新生的生物学功能。      

Activation of the human immune system by chemotherapeutic or targeted agents combined with the oncolytic parvovirus H-1

Background

Inactivating mutations of SMAD4 are frequent in metastatic colorectal carcinomas. In previous analyses, we were able to show that restoration of Smad4 expression in Smad4-deficient SW480 human colon carcinoma cells was adequate to suppress tumorigenicity and invasive potential, whereas in vitro cell growth was not affected. Using this cellular model system, we searched for new Smad4 targets comparing nuclear subproteomes derived from Smad4 re-expressing and Smad4 negative SW480 cells.

Methods

High resolution two-dimensional (2D) gel electrophoresis was applied to identify novel Smad4 targets in the nuclear subproteome of Smad4 re-expressing SW480 cells. The identified candidate protein Keratin 23 was further characterized by tandem affinity purification. Immunoprecipitation, subfractionation and immunolocalization studies in combination with RNAi were used to validate the Keratin 23-14-3-3ε interaction.

Results

We identified keratins 8 and 18, heat shock proteins 60 and 70, plectin 1, as well as 14-3-3ε and γ as novel proteins present in the KRT23-interacting complex. Co-immunoprecipitation and subfractionation analyses as well as immunolocalization studies in our Smad4-SW480 model cells provided further evidence that KRT23 associates with 14-3-3ε and that Smad4 dependent KRT23 up-regulation induces a shift of the 14-3-3ε protein from a nuclear to a cytoplasmic localization.

Conclusion

Based on our findings we propose a new regulatory circuitry involving Smad4 dependent up-regulation of KRT23 (directly or indirectly) which in turn modulates the interaction between KRT23 and 14-3-3ε leading to a cytoplasmic sequestration of 14-3-3ε. This cytoplasmic KRT23-14-3-3 interaction may alter the functional status of the well described 14-3-3 scaffold protein, known to regulate key cellular processes, such as signal transduction, cell cycle control, and apoptosis and may thus be a previously unappreciated facet of the Smad4 tumor suppressive circuitry.