Human Colorectal Cancer Metastasis Research Articles

Evaluation of [18F]FDG/[18F]FLT/[18F]FMISO-based micro-positron emission tomography in detection of liver metastasis in human colorectal cancer

IntroductionPositron emission tomography (PET) is extensively used in clinical oncology for tumor detection. This study aimed to explore the application of the radiotracers [18F]fluorodeoxyglucose ([18F]FDG), 3′-deoxy-3′- [18F]fluorothymidine ([18F]FLT), and [18F]fluoromisonidazole ([18F]FMISO) in the diagnosis and monitoring of hepatic metastasis in human colorectal cancer (CRC). MethodsA mouse model of human CRC with hepatic metastasis was established by intrasplenic implantation of human CRC cell lines LoVo or HCT8. Metastatic potential of these two cell lines was evaluated by wound healing assay in vitro and survival analysis. Uptake of radiotracers between LoVo and HCT8 cells and uptake of radiotracers in the resulting mouse tumor models were examined by in vivo and in vitro experiments. Uptake of each radiotracer in hepatic metastatic lesions was quantified and expressed as standard uptake value (SUV). Protein expression of multiple tumor biomarkers was determined in metastatic lesions. The correlation between tracer uptake and tumor marker expression was evaluated using linear regression. ResultsLoVo cells exhibited a stronger metastatic potential and a higher radiotracer uptake ability than HCT8 cells, as evidenced by significantly greater wound closure percentage, shorter survival, higher incidence of liver metastases, and higher cellular radiotracer levels in LoVo cells or LoVo cell-xenografted mice. SUV values of [18F]FLT and [18F]FMISO, but not [18F]FDG, in LoVo cell-derived metastatic lesions were significantly greater than those in HCT8 lesions. Mechanistically, the expression of MACC1, HIF-1α, and GLUT-1(metastasis associated in colon cancer 1, MACC1; hypoxia-inducible factor 1-alpha, HIF-1α; and glucose transporter 1, GLUT-1, respectively) in LoVo cell-derived metastatic lesions was more effectively induced than in HCT8-derived ones. A linear regression analysis demonstrated significant positive correlations between [18F]FLT/[18F]FMISO uptake and tumor biomarker expression in metastatic tissues. Conclusions[18F]FLT and [18F]FMISO-based PET imaging may serve as a promising method for early detection and monitoring of hepatic metastasis in patients with CRC.

1076 – Forkhead Box K2 (FOXK2) Promotes Human Colorectal Cancer Metastasis by Upregulating Zeb1 and Egfr

1076 – Forkhead Box K2 (FOXK2) Promotes Human Colorectal Cancer Metastasis by Upregulating Zeb1 and Egfr

Human UTP14a promotes angiogenesis through upregulating PDGFA expression in colorectal cancer

The human UTP14a (hUTP14a) promotes degradation of p53 and RB. Moreover, hUTP14a stabilizes c-Myc and is associated with the metastasis of human colorectal cancer (CRC). Angiogenesis plays a key role in tumor growth and metastasis. However, how hUTP14a regulates angiogenesis is unknown. Here, we show that nucleolar expression of hUTP14a is positively associated with higher microvascular density (MVD) in the CRC tumor tissues. The conditioned medium (CM) from CRC cells HCT116 and LoVo with hUTP14a knockdown impairs tube formation and migration of human umbilical vein endothelial cells (HUVECs). RNA-seq analysis indicates that hUTP14a might regulate expression of angiogenic factors in tumor cells. We further demonstrate that hUTP14a upregulates transcription and secretion of platelet-derived growth factor subunit A (PDGFA) in CRC cells. The CRC-CM derived from hUTP14a-depleted cells inhibits the PDGFA-mediated signaling pathway and induces apoptosis in HUVECs. In contrast, the CRC-CM derived from cells expressing Flag-hUTP14a activates the PDGFA-mediated signaling pathway in HUVECs. Importantly, the CRC-CM derived from Flag-hUTP14a-expressing cells promotes angiogenesis in HUVECs, which is counteracted by PDGFR inhibitor imatinib. We thus demonstrate that hUTP14a promotes angiogenesis by upregulating expression and secretion of PDGFA. The in vivo Matrigel plug assay shows that depletion of hUTP14a dramatically decreased MVD in mice xenografts. Collectively, we demonstrate that hUTP14a promotes angiogenesis in CRC and indicate that targeting hUTP14a might improve the prognosis of the hUTP14a-expressing CRC patients.

Forkhead box K2 promotes human colorectal cancer metastasis by upregulating ZEB1 and EGFR.

Background: Metastasis is the major reason for high recurrence rates and poor survival among patients with colorectal cancer (CRC). However, the underlying molecular mechanism of CRC metastasis is unclear. This study aimed to investigate the role of forkhead box K2 (FOXK2), one of the most markedly increased FOX genes in CRC, and the mechanism by which it is deregulated in CRC metastasis.Methods: FOXK2 levels were analyzed in two independent human CRC cohorts (cohort I, n = 363; cohort II, n = 390). In vitro Transwell assays and in vivo lung and liver metastasis models were used to examine CRC cell migration, invasion and metastasis. Chromatin immunoprecipitation and luciferase reporter assays were used to measure the binding of transcription factors to the promoters of FOXK2, zinc finger E-box binding homeobox 1 (ZEB1) and epidermal growth factor receptor (EGFR). Cetuximab was utilized to treat FOXK2-mediated metastatic CRC.Results: FOXK2 was significantly upregulated in human CRC tissues, was correlated with more aggressive features and indicated a poor prognosis. FOXK2 overexpression promoted CRC migration, invasion and metastasis, while FOXK2 downregulation had the opposite effects. ZEB1 and EGFR were determined to be direct transcriptional targets of FOXK2 and were essential for FOXK2-mediated CRC metastasis. Moreover, activation of EGFR signaling by EGF enhanced FOXK2 expression via the extracellular regulated protein kinase (ERK) and nuclear factor (NF)-κB pathways. The EGFR monoclonal antibody cetuximab significantly inhibited FOXK2-promoted CRC metastasis. In clinical CRC tissues, FOXK2 expression was positively correlated with the expression of p65, ZEB1 and EGFR. CRC patients who coexpressed p65/FOXK2, FOXK2/ZEB1 and FOXK2/EGFR had poorer prognosis.Conclusions: FOXK2 serves as a prognostic biomarker in CRC. Cetuximab can block the EGF-NF-κB-FOXK2-EGFR feedback loop and suppress CRC metastasis.

Regulation between two alternative splicing isoforms ZNF148FL and ZNF148ΔN, and their roles in the apoptosis and invasion of colorectal cancer

ObjectiveTo investigate the effect of two alternative splicing isoforms of zinc finger protein (ZNF) 148 gene on the invasion and metastasis of human colorectal cancer (CRC) cells and their related mechanisms. MethodsQuantitative RT-PCR assays were used to detect the expression of twoZNF148 alternative splicing isoforms in SW480 cells. ZNF148FL-siRNA, ZNF148FL-over express vector, ZNF148ΔN-siRNA, and ZNF148ΔN-over express vector were introduced into SW480 cells. The transfection efficiency was confirmed by RT-PCR. The proliferation, invasion, and migration in vitro as well as the apoptosis of SW480 cells were detected by MTT, transwell, scratch assay and flow cytometry, respectively. ResultsBoth ZNF148FL and ZNF148ΔN were expressed in SW480 cells, and the level of ZNF148FL protein was higher than ZNF148ΔN. After ZNF148FL-siRNA and ZNF148ΔN-over express transfection, the expression level of ZNF148FL and ZNF148ΔN were significantly decreased and increased, respectively. In contrast, the expression of ZNF148FL and ZNF148ΔN were significantly increased and decreased, respectively, after ZNF148FL-over express and ZNF148ΔN-siRNA transfection (all P < 0.05). The proliferation of SW480 cells was increased in ZNF148FL-over express group and the ZNF148ΔN-siRNA group, while decreased in ZNF148FL-siRNA group and ZNF148ΔN-over express group. The invaded cell number and migrated distance in ZNF148FL-siRNA group and ZNF148ΔN-over express group were significantly decreased, but the apoptotic rate was significantly increased. In contrast, ZNF148FL-over express and ZNF148ΔN-siRNA group showed the significantly increased ability of invasion and migration but decreased apoptosis rate (all P < 0.05). ConclusionZNF148FL could increase proliferation, invasion, and migration of CRC cells, while ZNF148ΔN showed opposite effect; the two splicing isoforms of ZNF148 may exert a mutual antagonistic effect to each other on the malignant biological activities.

Solasodine reverses stemness and epithelial-mesenchymal transition in human colorectal cancer

Adverse side effects of conventional chemotherapy, acquired resistance and fatal tumor metastasis of human colorectal cancer (CRC) are propelling the exploration for novel selective anticarcinogens. Solasodine is a main active component isolated from Solanum incanum L that exhibited a potent stemness and invasion inhibitory effect on human colorectal cancer HCT116 cells. Colony Spheroid formation assay showed that solasodine dose-dependently prohibited HCT116 cell stemness. CD133, CD44, Nanog, Oct-4 and Sox-2 were inhibited by solasodine to reverse stemness and similar mechanism was stimulated in vivo. Transwell and scratch wound assays revealed that solasodine impeded HCT116 cell invasion and migration potential strengthened by TGF-β1. Moreover, solasodine attenuated TGF-β1-induced EMT and decreased MMPs while in vivo study showed the same trend. The results of this study implied that solasodine may be a novel therapeutic drug for CRC treatment.

MLLT10 promotes tumor migration, invasion, and metastasis in human colorectal cancer

Objectives: Colorectal cancer (CRC), one of the most aggressive gastrointestinal malignancies, is a frequently diagnosed life-threatening cancer worldwide. Most CRC patients have poor prognosis mainly because of frequent metastasis and recurrence. Thus, it is crucial to find out some new biomarkers and to show deeper insights into the mechanisms of CRC. MLLT10, Myeloid/lymphoid or mixed-lineage leukemia translocated to 10, also known as AF10, a recurrent MLL partner. In this study, we found that MLLT10 promotes CRC tumor invasion and metastasis both in vitro and in vivo.Methods: Here, the expression of MLLT10 was evaluated by immunohistochemistry. Then, the plasmid and lentivirus particles for MLLT10 overexpression or knockdown were designed and constructed into SW620 and HT29 cells. Finally, cell proliferation assay, cell adhesion assay, transwell migration, and invasion assay were used to detect the migration and invasion ability of MLLT10 in CRC cells. A tail vein injection assay was employed to evaluate the role of MLLT10 in tumor metastases.Results: MLLT10 expression was significantly higher in CRC tissues than in noncancerous tissues and was associated with some clinicopathological factors. In vitro, the overexpression of MLLT10 promoted CRC cell migration and invasion, while after MLLT10 was knocked down, the opposite results were observed. Furthermore, we used animal metastasis models to detect the function of MLLT10 in vivo, the results are same with the outcomes in vitro. In lung metastasis sites, the knockdown of MLLT10 in SW620 cells significantly inhibited Vimentin expression, whereas the E-Cadherin was increased.Conclusions: These results indicate that MLLT10 regulates the metastasis of CRC cells via EMT.

Capping Actin Protein Overexpression in Human Colorectal Carcinoma and Its Contributed Tumor Migration.

Objective Human colorectal cancer (CRC) is the third most common cancer; patients with metastatic colorectal cancer (mCRC) show poor prognosis than those with CRC cases. There are no reliable molecular biomarkers for the diagnosis of CRC prognosis except with pathological features. Therefore, it is urgent to develop a biomarker for diagnosis and/or prediction of human CRC. In addition, capping actin protein (CapG) belongs to the gelsolin family and has been reported to contribute on tumor invasion/metastasis in multiple human cancers. Here, we are the first to evaluate the expression of CapG in human CRCs. Study Design To investigate the expression levels of CapG in human tissue array by immunohistochemistry (IHC) staining. Moreover, the mRNA and protein levels were also confirmed in four CRC cell lines and determined using real-time RT-PCR and Western blotting. Finally, a Matrigel transwell invasion assay was used to evaluate the invasion ability in CapG high or low expression cells. Results We demonstrated that CapG could be determined in the normal colon tissue and human CRC specimens. However, CapG was significantly overexpressed in the mCRC specimens compared with that in CRC specimens and normal cases. It was also detectable in the four CRC cell lines including mRNA and protein levels. We also found that knockdown of the expression of CapG reduced tumor migration. Conclusions In this study, we suggested that CapG could be used as a biomarker for metastatic CRC in the clinical specimens. Moreover, our in vitro study demonstrated that CapG might contribute on tumor metastasis in human CRCs.

Imbalanced LIMK1 and LIMK2 expression leads to human colorectal cancer progression and metastasis via promoting \u03b2-catenin nuclear translocation

Epithelial–mesenchymal transition (EMT)-induced metastasis contributes to human colorectal cancer (CRC) progression, especially in advanced CRC. However, the underlying mechanism of β-catenin in this process is elusive. We identified that LIM domain kinase (LIMK)2 was progressively downregulated with tumor progression from precancerous lesions to advanced cancer. Gain- and loss-of-function assays revealed that LIMK2 inhibits cell proliferation via cell cycle arrest at the G1–S transition and suppresses the ability of cell metastasis by restricting the EMT process. Reduced LIMK2 expression enhanced the nuclear accumulation of β-catenin and activated the Wnt signaling pathway, thus contributing to tumor progression. A homolog of the LIMK family, LIMK1, which was overexpressed throughout tumor progression, served as a competitive inhibitor of LIMK2 via β-catenin nuclear translocation. The imbalanced expression of LIMK1 and LIMK2 is important in CRC progression, and the combined effects provide a new insight into the mechanism of CRC progression. These findings provide a new understanding for LIMK-based anticancer therapy.

PO-148 Suppression of carnosine on adhesion and extravasation in human colorectal cells

Introduction Colorectal cancer is the third most commonly diagnosed cancer in the word. Carnosine is an endogenous dipeptide found in muscle and brain tissues. The aims of this study are to investigate the regulation of carnosine on adhesion and extravasation of metastasis in human colorectal cancer. Material and methods The human colorectal cancer cells (HCT-116) and human umbilical vein cell line (EA. hy926) cultured were as experimental models. Those adhesive and extravasate abilities and regulate molecular expression were analysed in this study. Results and discussions In adhesion ability assay results shown carnosine were significantly decreased HCT-116 cells adhesion to endothelial cells (EA. hy926 cells). From adhesion-regulating proteins expression analysis result show that carnosine was decreased the levels of integrin in HCT-116 cells and ICAM-1 and E-selectin in EA hy926 cells after 24 hour incubation (p Conclusion The results indicate that carnosine can inhibit the adhesion and extravasation through suppressing of carnosine on NF-κB transcript activation and its regulator adhesion and extravasation related molecular expression in HCT-116 cells and EA hy926 cells.

Peroxisome proliferator-activated receptor γ coactivator-1α is a predictor of lymph node metastasis and poor prognosis in human colorectal cancer.

Peroxisome proliferator-activated receptor γ (PPARγ) and PPARγ coactivator-1α (PGC-1α) expression levels are correlated with clinical outcome in breast cancer. However, the potential biological and clinical significance of PPARγ and PGC-1α in colorectal cancer remains unknown. Here we investigated PPARγ and PGC-1α expression in colorectal cancer, and the associations of these expression levels with clinicopathological features. We also evaluated the roles of PPARγ and PGC-1α as prognostic factors in colorectal cancer. We performed immunohistochemical analysis to investigate PPARγ and PGC-1α expression in human colorectal cancer tissues and adjacent normal tissues from 108 primary colorectal cancer patients. We then examined how these expression levels correlated with clinicopathological features. Using the Kaplan-Meier method, we evaluated 3-year disease-free survival (DFS) and overall survival (OS) in patients with tumors expressing different levels of PPARγ and PGC-1α. Our results revealed that PPARγ expression was not significantly correlated with age at surgery, gender, differentiation, depth of infiltration, relapse, or TNM stage. Additionally, PGC-1α expression was not significantly correlated with age at surgery, differentiation, depth of infiltration, relapse, or TNM stage. However, PGC-1α expression was significantly correlated with nodal metastasis (p=0.020). Survival analysis demonstrated reduced OS in the PGC-1α-positive group compared to the PGC-1α-negative group (p=0.03). Our present findings suggest that PGC-1α may be useful for predicting nodal metastasis, and may represent a biomarker for poor prognosis in colorectal cancer.

α7 nicotinic acetylcholine receptor in tumor-associated macrophages inhibits colorectal cancer metastasis through the JAK2/STAT3 signaling pathway.

Considerable evidence has implied that α7 nicotinic receptor subtypes play an important role in chronic inflammatory and neuropathic pain signaling. The aim of the present study was to determine the role of endogenous α7nAChR signaling in tumor-associated macrophages (TAMs) in human colorectal cancer (CRC) metastasis and prognosis. α7nAChR expression in primary tumor cells and adjacent stroma cells especially in TAMs in 51 CRC patients was observed. Using a human monocyte THP-derived macrophages (TMs) with α7nAChR-siRNA knockdown (TMα7−/−) and a CRC cell Transwell co-culture model, the migration and invasion of two CRC cells, LoVo and SW620, were determined. Western blotting was carried out to investigate the expression of multiple molecules involved in the NF-κB, STAT3, PI3K signaling pathways in mimic TAMs, i.e., TMs exposed to in-direct LoVo cell stimulation. A nicotinic α7 receptor antagonist [α-bungarotoxin (α-Btx)] and three pharmaceutical inhibitors: AG490 (JAK2/STAT3 inhibitor), LY294002 (PI3K inhibitor) and Bay 11–7082 (NF-κB inhibitor) were applied to evaluate whether these signaling pathways were associated with the enhanced migration of CRC cells when co-cultured with α7nAChR knockdown TMs. The results revealed that the expression of α7nAChR in TAMs differed in patients. However, CRC patients who had a high incidence of hepatic metastasis showed no or low expression of α7nAChR in TAMs. TMs with α7nAChR-siRNA knockdown (TMα7−/−) significantly enhanced the migration and invasion of the two CRC cell lines LoVo and SW620. α7nAChR knockdown in TMs significantly downregulated phosphorylation of STAT3, PI3K p85 and NF-κB p65 after co-culturing with LoVo cells. Inhibition of JAK2/STAT3 prevented the TMα7−/−-enhanced migration of LoVo cells. α7nAChR expressed in TAMs in human CRC patients plays an important role in preventing metastasis and could be a prognostic marker in CRCs, which may be regulated by the JAK2/STAT3 signaling pathway.

Tumour evolution: Metastasis takes a different route.

A new study has looked at the evolutionary origins of lymphatic and distant metastases in human colorectal cancer and found that, in most cases, cancer spread to lymph nodes is not a precursor for seeding of cancer cells to other organs.

Origins of lymphatic and distant metastases in human colorectal cancer.

The spread of cancer cells from primary tumors to regional lymph nodes is often associated with reduced survival. One prevailing model to explain this association posits that fatal, distant metastases are seeded by lymph node metastases. This view provides a mechanistic basis for the TNM staging system and is the rationale for surgical resection of tumor-draining lymph nodes. Here we examine the evolutionary relationship between primary tumor, lymph node, and distant metastases in human colorectal cancer. Studying 213 archival biopsy samples from 17 patients, we used somatic variants in hypermutable DNA regions to reconstruct high-confidence phylogenetic trees. We found that in 65% of cases, lymphatic and distant metastases arose from independent subclones in the primary tumor, whereas in 35% of cases they shared common subclonal origin. Therefore, two different lineage relationships between lymphatic and distant metastases exist in colorectal cancer.

MicroRNA-184 inhibits cell proliferation and metastasis in human colorectal cancer by directly targeting IGF-1R.

Colorectal cancer is currently the third most common cancer in males and the second in females worldwide. In spite of marked progress having been achieved in surgical resection, radiotherapy and chemotherapy, the prognosis for patients with colorectal cancer remains poor. Previous studies have demonstrated that the abnormal expression of microRNAs contributed to human cancer carcinogenesis and progression, suggesting miRNAs as novel therapeutic targets in colorectal cancer. The aim of the present study was to investigate the expression, functions and underlying molecular mechanisms of microRNA-184 (miR-184) in colorectal cancer. The results identified that miR-184 was significantly downregulated in colorectal cancer tissues and cell lines. In vitro functional studies demonstrated that miR-184 significantly inhibited colorectal cancer cell proliferation, migration and invasion. Notably, insulin-like growth factor 1 receptor (IGF-1R) was identified as a direct target of miR-184 in colorectal cancer. Furthermore, the functions of IGF-1R small interfering RNA were similar to those induced by miR-184 in colorectal cancer, suggesting IGF-1R as a functional target of miR-184 in colorectal cancer. The results of the present study indicated that miR-184 may be a novel therapeutic strategy regimen of targeted therapy for colorectal cancer.

Tumor-derived CXCL5 promotes human colorectal cancer metastasis through activation of the ERK/Elk-1/Snail and AKT/GSK3\u03b2/\u03b2-catenin pathways

BackgroundMetastasis is a major cause of death in human colorectal cancer patients. However, the contribution of chemokines in the tumor microenvironment to tumor metastasis is not fully understood.MethodsHerein, we examinined several chemokines in colorectal cancer patients using chemokine ELISA array. Immunohistochemistry was used to detect expression of CXCL5 in colorectal cancer patients tissues. Human HCT116 and SW480 cell lines stably transfected with CXCL5, shCXCL5 and shCXCR2 lentivirus plasmids were used in our in vitro study. Immunoblot, immunofluorescence and transwell assay were used to examine the molecular biology and morphological changes in these cells. In addition, we used nude mice to detect the influence of CXCL5 on tumor metastasis in vivo.ResultsWe found that CXCL5 was overexpressed in tumor tissues and associated with advanced tumor stage as well as poor prognosis in colorectal cancer patients. We also demonstrated that CXCL5 was primarily expressed in the tumor cell cytoplasm and cell membranes, which may indicate that the CXCL5 was predominantly produced by cancer epithelial cells instead of fibroblasts in the tumor mesenchyme. Additionally, overexpression of CXCL5 enhanced the migration and invasion of colorectal cancer cells by inducing the epithelial-mesenchymal transition (EMT) through activation of the ERK/Elk-1/Snail pathway and the AKT/GSK3β/β-catenin pathway in a CXCR2-dependent manner. The silencing of Snail and β-catenin attenuated CXCL5/CXCR2-enhanced cell migration and invasion in vitro. The elevated expression of CXCL5 can also potentiate the metastasis of colorectal cancer cells to the liver in vivo in nude mice intrasplenic injection model.ConclusionIn conclusion, our findings support CXCL5 as a promoter of colorectal cancer metastasis and a predictor of poor clinical outcomes in colorectal cancer patients.

Annexin A13 promotes tumor cell invasion in vitro and is associated with metastasis in human colorectal cancer.

PurposeAberrantly upregulated expression of selected members of annexin, a group of calcium- and membrane-binding proteins, have been found to be associated with metastasis, poor prognosis, and other clinical characteristics in colorectal cancer (CRC), the third most diagnosed cancer. However, ANXA13 (encoding protein annexin A13), the original founder gene of the annexin A family, has not been studied carefully as a potential prognostic biomarker in CRC.MethodsThe protein level of annexin A13 was determined by western blot in a panel of CRC cell lines. Tumor cell invasion was determined by a Matrigel in vitro invasion assay in selected CRC cells with either upregulated (via plasmid transfection) or downregulated (via siRNA treatment) expression of ANXA13. The clinicopathological features and prognostic values associated with ANXA13 expression were also evaluated in a group of 125 CRC patients.ResultsANXA13 was expressed at a high level in HCT116 and HT29 cells but undetected or at a lower level in SW620, SW48, and Rko cells. CRC cell invasion was promoted by ANXA13 overexpression in SW620 or Rko cells and was reduced by ANXA13 downregulation in HCT116 or HT29 cells. In CRC patients, ANXA13 expression levels correlated with lymph node metastasis and were associated with poor overall survival.ConclusionsANXA13 is associated with CRC cell invasion in vitro, and with lymph node metastasis and poor survival in CRC patients. Our results indicate that ANXA13 can be exploited as a biomarker for its diagnostic and prognostic values.

Inhibition of human colorectal cancer metastasis by notoginsenoside R1, an important compound from Panax notoginseng.

Panax notoginseng (P.notoginseng) and its components are used as traditional Chinese medicine for cardiovascular disease, although studies concerning the anti-metastatic properties of these compounds are limited. The goal of this study was to investigate the effects of notoginsenosideR1(NGR1), an important compound derived from P.notoginseng, on the metastasis of human colorectal cancer(CRC). The migratory, invasive, and adhesive abilities of cultured human CRC cells (HCT-116) treated with NGR1 and expression of metastasis‑associated regulatory molecules were assessed. The migratory and invasive abilities of the HCT-116 cells were reduced after treatment with 75, 150 or 300µM NGR1 for 24h. When HCT-116 cells were incubated with 150 or 300µM NGR1 for 24h, matrix metalloproteinase(MMP)-9 expression was reduced compared with that of the control group. In the adhesion reaction assays, treatment with 150 or 300µM NGR1 led to significantly decreased adhesion of the HCT-116 cells to endothelial cells (EA.hy926 cells). Levels of integrin-1 protein were significantly decreased in the HCT-116 cells following treatment with 75, 150 or 300µM NGR1, and levels of E-selectin and intercellular adhesion molecule1(ICAM-1) proteins were significantly decreased in the EA.hy926 cells treated with 75, 150 or 300µM NGR1. Scanning electron microscopy examination indicated that HCT-116 cells treated with lipopolysaccharide(LPS) combined with 300µM NGR1 exhibited a less flattened and retracted shape compared with cells treated with LPS alone, and this change in shape is characteristic of extravasation. Additionally, the transepithelial electrical resistance of the EA.hy926 endothelial cell monolayer increased after incubation with 150 or 300µM NGR1 for 24h. Overall, these results demonstrated the anti-metastatic properties of 150 or 300µM NGR1, a compound that affects CRC metastasis by inhibiting cell migration, invasion, and adhesion and by regulating expression of metastasis-associated signalling molecules.

The FOXD3/miR-214/MED19 axis suppresses tumour growth and metastasis in human colorectal cancer.

Background:MiR-214 is aberrantly regulated in several tumours, but its underlying mechanisms in colorectal cancer (CRC) metastasis remain largely unknown. This study aimed to demonstrate the function and potential mechanism of miR-214 in regulating invasion and metastasis of CRC.Methods:The transcription factor and targets of miR-214 were predicted by bioinformatics and validated using ChIP and dual-luciferase reporter assay. DNA methylation status was explored using bisulphite sequencing PCR. The in vitro and in vivo function of miR-214 in CRC was evaluated using MTT, plate colony formation, Matrigel invasion and animal models. Real-time PCR or western blotting was performed to detect FOXD3, miR-214 and MED19 expressions in CRC cells and clinical specimens.Results:MiR-214 was downregulated in CRC and was significantly correlated with lymphatic metastasis. Downregulation of miR-214 might due to promoter hypermethylation in CRC. FOXD3 was validated as a transcription factor of miR-214 by ChIP assay. Dual-luciferase assay identified MED19 as a target of miR-214 in CRC. In vitro and in vivo experiments showed that miR-214 mediated the inhibiting effect of FOXD3 on proliferation, invasion and metastasis by targeting MED19. Spearman's correlation analysis showed a positive correlation between FOXD3 and miR-214, and negative correlations between FOXD3 and MED19, miR-214 and MED19 in CRC cells and clinical specimens.Conclusions:FOXD3/miR-214/MED19 axis is important for the regulation of growth, invasion and metastasis of CRC. Targeting the miR-214-mediated axis might be helpful for the treatment of CRC.

MiR-384 inhibits human colorectal cancer metastasis by targeting KRAS and CDC42

Colorectal cancer (CRC) is the third most common cancer worldwide. Metastatic progression is a primary factor contributing to lethality of CRC patients. However, the molecular mechanisms forming early local invasion and distant metastatic colonies are still unclear and the present therapeutic approaches for CRC are unsatisfactory. Therefore, novel therapies targeting metastatic invasion that could prevent tumor spreading and recurrence are urgently needed. Our study showed that the decrease of miR-384 was found in 83.0% (83/100) CRC patients. And low-leveled expression of miR-384 was closely correlated with the invasive depth, lymph node and distant metastasis of CRC. Overexpression of miR-384 could inhibit the invasive and migrating abilities of CRC cells in vitro and the metastatic potential in vivo. Luciferase assays showed that miR-384 repressed the expression of Kirsten Ras (KRAS) and Cell division cycle 42 (CDC42) by directly targeting their 3’-untranslated regions. There is functional and mechanistic relationship between miRNA-384 and KRAS, CDC42 in the invasion and metastasis of CRC. And our findings suggest that miR-384could be a potent therapeutic target for CRC. Restoration of miR-384 expression might provide novel therapeutic approach to the reduction of CRC metastasis.