High Metastatic Potential Cells Research Articles

Ubiquitin-specific peptidase 15 regulates the TFAP4/PCGF1 axis facilitating liver metastasis of colorectal cancer and cell stemness

The tumor recurrence and metastasis of colorectal cancer (CRC) are responsible for most of CRC-linked mortalities. It is an urgent need to deeply investigate the pathogenesis of CRC metastasis and look for novel targets for its treatment. The current study aimed to investigate the effects of ubiquitin-specific peptidase 15 (USP-15) on the CRC progression. In vivo, a mouse model of liver metastasis of CRC tumor was established to investigate the role of USP-15. In vitro, the migrated and invasive abilities of CRC cells were assessed by transwell assay. Cell stemness was evaluated by using sphere formation assay. The underlying mechanism was further explored by employing the co-immunoprecipitation, dual luciferase reporter assay, oligonucleotide pull-down assay, and chromatin immunoprecipitation assay. The results showed that USP-15 was upregulated in CRC patients with liver metastasis and high metastatic potential cell lines of CRC. Loss of USP-15 repressed the epithelial-to-mesenchymal transition (EMT), migration, invasion, and stemness properties of CRC cells in vitro. Downregulation of USP-15 reduced the liver metastasis of mice in vivo. USP-15 upregulation obtained the contrary effects. Subsequently, USP-15 deubiquitinated transcription factor AP-4 (TFAP4) and enhanced its protein stability. TFAP4 could transcriptionally activated polycomb group ring finger 1 (PCGF1). The pro-cancer effects of USP-15 were rescue by the knockdown of TFAP4 or PCGF1. In conclusions: USP-15 facilitated the liver metastasis by the enhancement of cell stemness and EMT in CRC, which was at least partly mediated by the deubiquitination of TFAP4 upon the upregulation of PCGF1.

Defining the landscape of metabolic dysregulations in cancer metastasis

Metastasis is the primary cause of cancer related deaths due to the limited number of efficient druggable targets. Signatures of dysregulated cancer metabolism could serve as a roadmap for the determination of new treatment strategies. However, the metabolic signatures of metastatic cells remain vastly elusive. Our aim was to determine metabolic dysregulations associated with high metastatic potential in breast cancer cell lines. We have selected 5 triple negative breast cancer (TNBC) cell lines including three with high metastatic potential (HMP) (MDA-MB-231, MDA-MB-436, MDA-MB-468) and two with low metastatic potential (LMP) (BT549, HCC1143). The normal epithelial breast cell line (hTERT-HME1) was also investigated. The untargeted metabolic profiling of cells and growth media was conducted and total of 479 metabolites were quantified. First we characterized metabolic features differentiating TNBC cell lines from normal cells as well as identified cell line specific metabolic fingerprints. Next, we determined 92 metabolites in cells and 22 in growth medium that display significant differences between LMP and HMP. The HMP cell lines had elevated level of molecules involved in glycolysis, TCA cycle and lipid metabolism. We identified metabolic advantages of cell lines with HMP beyond enhanced glycolysis by pinpointing the role of branched chain amino acids (BCAA) catabolism as well as molecules supporting coagulation and platelet activation as important contributors to the metastatic cascade. The landscape of metabolic dysregulations, characterized in our study, could serve as a roadmap for the identification of treatment strategies targeting cancer cells with enhanced metastatic potential.

Hepatitis B Virus X Protein Induces SATB1 Expression Through Activation of ERK and p38MAPK Pathways to Suppress Anoikis.

We previously reported that there were potentially certain correlations between the high expression of SATB1 and the HBV infection in human hepatocellular carcinoma tissues, and SATB1 promoted tumor growth and metastasis in liver cancer. Hepatitis B virus (HBV) infection is internationally recognized as a contributing factor to metastasis in liver cancer. The anoikis prevention of detached malignant cancer cells is the precondition for metastasis. Our studies aimed to explore the relationship between HBV infection, SATB1 and liver cancer cell anoikis and their specific regulatory mechanisms in HBV-associated liver cancer. HepG2 cell was transiently transfected with pBlue-HBV and seven types of HBV-encoded protein plasmids. Anoikis assay and soft agarose colony formation experiment were analyzed in HepG2.2.15-SATB1 siRNA cells, HBx-overexpressing cells and HepG2-HBx-SATB1 siRNA cells. The inhibitors of signaling molecules were used to treat of HepG2-HBx cells, and then, the SATB1 expression and phosphorylation levels of signaling molecules were evaluated. Our data show that the high expression of SATB1 and enhanced anoikis resistance were observed in HBV stably expressing cell line HepG2.2.15 and high metastatic potential cell line SK-HEP-1. HBV can induce SATB1 expression and suppress anoikis of unattached liver cancer cells. Moreover, SATB1 expression and anoikis resistance were mainly regulated by HBV-encoded viral protein HBx through the activation of ERK and p38 MAPK signaling pathways to promote metastasis of liver cancer. These data suggest that the HBV-encoded HBx and SATB1 may play an important role in promoting anoikis resistance and metastasis in HBV-associated liver cancer.

Proximity of Metastatic Cells Enhances Their Mechanobiological Invasiveness.

A critical step in metastases formation is cancer-cell invasion through tissue. During invasion, cells change morphology and apply forces to their surroundings. We have previously shown that single, metastatic breast-cancer cells will mechanically indent a synthetic, impenetrable polyacrylamide gel with physiological-stiffness in attempted invasion; benign breast cells do not indent the gels. In solid tumors, e.g., breast cancers, metastases occur predominantly by collective cell-invasion. Thus, here we evaluate the effects of cell proximity on mechanical invasiveness, specifically throughchanges in gel indention. Gel indentation is induced by 56, 33 and 2% (in >1000 cells), respectively, of adjacent high metastatic potential (MP), low MP and benign breast cells, being double the amounts observed in single, well-separated cells. Single cells exhibited a distribution of indentationdepths below 10µm, while adjacent cells also showed a second peak of deeper indentations. The second peak included 65% of indenting high MP cells as compared to 15% in the low MP cells, illustrating the difference in theirinvasiveness. Thus, proximity of the metastatic cells enhances their mechanical ability to invade, demonstrating why collective cancer-cell migration is likely more efficient. This could potentially provide a rapid, quantitative approach to identify metastatic cells, and to determine their metastatic potential.

Loss of MicroRNA‐489‐3p promotes osteosarcoma metastasis by activating PAX3‐MET pathway

Osteosarcoma (OS) remains one deadly disease for many affected patients. MicroRNAs (miRNAs) are thought to have an important role in tumor metastasis by regulating diverse cellular pathways. Here, we describe the function and regulation network of miR-489-3p in osteosarcoma (OS) metastasis. MiR-489-3p expression was downregulated in OS cells especially in high metastatic potential cells and was also significantly decreased in metastatic lesions compared with their corresponding primary tumor samples. Both gain- and loss-of-function studies confirmed that miR-489-3p significantly suppressed OS cell invasion and metastasis both in vitro and in vivo. Mechanistically, paired box gene 3 (PAX3) was identified as a functional target of miR-489-3p in OS cells. MiR-489-3p inhibited OS metastasis by negatively regulating expression of PAX3. In addition, PAX3 expression was markedly higher in OS tissues than in adjacent non-cancerous tissues. Transwell assays and in vivo metastasis assays demonstrated that overexpression of PAX3 significantly promoted the invasiveness and pulmonary metastasis of OS cells. On the other hand, downregulation of PAX3 markedly reduced cell metastatic potential. Mechanistic investigations indicated that prometastasis function of PAX3 was mediated by upregulating downstream target MET tyrosine kinase receptor. In conclusion, our results reveal that miR-489-3p-PAX3-MET signaling is critical to OS metastasis. Targeting the pathway described here may open new therapeutic prospects to restrict the metastatic potential of OS. © 2016 Wiley Periodicals, Inc.

Activation of PAX3-MET pathways due to miR-206 loss promotes gastric cancer metastasis.

MicroRNAs (miRNAs) are thought to have an important role in tumor metastasis by regulating diverse cellular pathways. Here, we describe the function and regulation network of miR-206 in gastric cancer (GC) metastasis. MiR-206 expression was downregulated in GC cells especially in high metastatic potential cells and was also significantly decreased in metastatic lesions compared with their corresponding primary tumor samples. Both gain- and loss-of-function studies confirmed that miR-206 significantly suppressed GC cell invasion and metastasis both in vitro and in vivo. Mechanistically, paired box gene 3 (PAX3) was identified as a functional target of miR-206 in GC cells. MiR-206 inhibited GC metastasis by negatively regulating expression of PAX3. In addition, PAX3 expression was markedly higher in GC tissues than in adjacent non-cancerous tissues. GC patients with positive PAX3 expression had shorter overall survival times. Transwell assays and in vivo metastasis assays demonstrated that overexpression of PAX3 significantly promoted the invasiveness and pulmonary metastasis of GC cells. On the other hand, downregulation of PAX3 markedly reduced cell metastatic potential. Mechanistic investigations indicated that prometastasis function of PAX3 was mediated by upregulating downstream target MET. Moreover, we found that levels of PAX3 and MET were positively correlated in matched human GC specimens, and their coexpression was associated with poor prognoses. In conclusion, our results reveal that miR-206-PAX3-MET signaling is critical to GC metastasis. Targeting the pathway described here may open new therapeutic prospects to restrict the metastatic potential of GC.

Membrane palmitoylated protein 3 promotes hepatocellular carcinoma cell migration and invasion via up-regulating matrix metalloproteinase 1

Membrane associated guanylate kinase (MAGUK) family, has been extensively studied in cellular adhesion and signal transduction at sites of cell–cell contact. Recently, growing attention has been paid to its role in the initiation and progression of various cancers. However, its role in hepatocellular carcinoma (HCC) has been rarely investigated. In this study, we found that membrane palmitoylated protein 3 (MPP3), a member of MAGUK family, was significantly up-regulated in both high metastatic potential cell lines and clinical tissue samples of HCC, and the most significant increase was observed in the tumors invading the portal veins. Higher level of MPP3 correlated with poorer survival of patients with HCC. Forced expression of MPP3 significantly enhanced HCC cell migration and invasion, whereas knockdown of this gene inhibited this oncogenic effect. Mechanismly, we found that MPP3 promoted HCC cell migration and invasion via up-regulating matrix metalloproteinase 1 (MMP1). These findings indicate that MPP3 play an important role in HCC metastasis by promoting cell migration and invasion, suggesting that it may serve as a novel prognostic marker and molecular target for therapy of HCC.

HSP27 Expression Levels are Associated with the Sensitivity of Hepatocellular Carcinoma Cells to 17-Allylamino-17-Demethoxygeldanamycin

AIMS, MATERIALS & METHODS: As heat-shock proteins are associated with tumor proliferation, differentiation, invasion and metastasis, we investigated whether targeting Hsp90 with the geldanamycin derivative 17-allylamino-17-demethoxygeldanamycin (17AAG) can inhibit the viability of hepatocellular carcinoma cell lines with various levels of metastatic potential. In addition, we investigated whether the use of Hsp27-siRNA can decrease resistance to 17AAG. Although 17AAG upregulated the expression of heat-shock proteins, it did not affect the expression of Hsp90 client proteins in normal hepatocytes. Hsp90 inhibition by 17AAG degraded its client proteins in both low- and high-metastatic potential cell lines. siRNA inhibited Hsp27 expression in cell lines and improved the sensitivity of 17AAG. 17AAG inhibited the viability of hepatocellular carcinoma cells by degrading Hsp90 client proteins. The sensitivity of cells to 17AAG is associated with the level of Hsp27 expression.

Origin of active transport in breast-cancer cells

Living cells are active systems, continuously adapting to respond to their environment. The dynamic cytoskeleton and especially the molecular motors acting on it provide the cell with its remodeling capabilities and allow active transport within the cell. While active transport in living cells has been well-documented, the underlying mechanisms have not been determined. Hence, we systematically target the cytoskeleton, molecular motors, and ATP energy related processes to determine their roles in particle transport. We perform intracellular particle tracking in low and high metastatic potential (MP) breast-cancer cells and analyze particle motion through the mean square displacement and other powers of the displacement. From those experiments, we show that the motion in both cell types is actively driven by fluctuating microtubules and their associated molecular motors. In the two cells, however, the relative importance of the mechanisms varies. In the low MP cells, particles are mostly transported by motors and likely remain on a single microtubule. In those cells, microtubule fluctuations cause intermittent jumps and actin typically hinders motion in the dense intracellular microenvironment. In contrast, particle motion in the high MP cells is driven by indirect motor-transport or by jumping between microtubules and is highly impacted by fluctuations of the microtubules. Thus, we are able to provide insight into mechanisms driving active transport in living cells, using intracellular particle tracking.

Tamoxifen-resistant, ER-positive MAC 51 cell line with a high metastatic potential developed from a spontaneous breast cancer mouse model

We developed and characterized an estrogen-responsive and ER-positive murine breast cancer cell line (MAC51) from a spontaneous breast cancer animal model. These cells are overexpressed with K8, K18 and K19 proteins in an immunofluoresence assay. Upregulation of ER alpha was observed in the immunofluoresence assay, real-time PCR analysis and western blot assay. A colocalization experiment in MAC 51 showed cytoplasmic colocalization of K18 and K19 proteins with ER α. Real-time analysis of tumor samples from engrafted animals, MAC 51, metastatic liver and metastatic ovary revealed overexpression of K8 and K18 compared to the respective controls. A hormone responsive experiment in immunodeficient mice showed highly significant decreases in estrogen and tumor volume after 14 days ovariectomization. The tumorogenicity assay showed higher (3 × 10 (5)) and lower (3 × 10(4)) concentrations of MAC 51 cells that developed tumors within 2weeks post-transplantation. Tumor morphology and histology resembled a sarcoma pattern but our spontaneous model appeared in an adenocarcinoma pattern. Metastasis to different organs occurred through hematogenous and lymphatic routes. We assessed the potency of the anticancer effect in MAC 51 cells by treating various anticancer drugs with E2, followed by studying apoptotic gene expression profiles. E2 and E2+ tamoxifen-treated cells showed upregulation of apoptotic genes caspase 1, 3, 9, P53 and Bcl-xl but the tamoxifen- and paclitaxel-treated cells did not upregulate the apoptotic genes. Tamoxifen-resistant, ER-positive and high metastatic potential cell lines from murine origin are very rare. Also, estrogen greatly induced apoptosis in this cell line, hence MAC 51 has a greater application potential to evaluate low doses of estrogen with other targeted therapeutic drugs to treat breast cancer.

Expression of osteopontin in different metastatic potential uveal melanoma and its significance

Background Osteopontin is highly expressed in many metastatic tumors,but its expression in uveal melanoma and the relationship of osteopontin with metastasis is still under investigation. Objective This study was to investigate the relationship between osteopontin expression and uveal melanoma metastatic potential.Methods Fifty samples of uveal melanoma were collected in Beijing Tongren Hospital.The expressions of osteopontin in the samples were detected using immunohistochemistry,and expressions of osteopontin mRNA in different metastatic potential uveal melanoma cell lines (MU M-2B,C918,OCM-1A) were analyzed using quantitative polymerase chain reaction (Q-PCR). Results Osteopontin was positively expressed in 10 samples of 13 patients with metastasis and 14 samples of 37 patients without metastasis,showing a significant difference between them (x2=5.888,P=0.000).There were 11 samples and 13 samples exhibiting the positive expression of osteopontin in 15 epithelial type and 35 non-epithelial type of uveal melanoma respectively with the significant difference (x2=5.510,P =0.000).The positive expressing numbers of osteopontin were 20 tumors of 30 affected tumors and 4 tumors of 20unaffected ciliary tumors with the significant difference (x2 =10.470,P =0.000 ).No significant differences in the expression of osteopontige were found between different gender,age,eyes,largest basal diameters and invasion of scleral canal( P =0.536,0.256,0.802,0.848,0.555 ).The relative expression value of osteopontin mRNA was in turn 1.00±0.04,0.91 ±0.03,0.08±0.01 in MUM-2B,C918,OCM-1A with the significant difference among three cell lines( F=33.135,P＜0.05).The osteopontige mRNA expression was significant enhanced in high metastatic potentialcell lines( MUM-2B,C918 ) compared with low metastatic potential cell lines( OCM-1 A) (P＜0.05 ),but no significant difference was seen between two high metastatic potential cell lines(MUM-2B,C918) (P=0.804). Conclusions Osteopontige expression is associated with the uveal melanoma cell line invasion and metastasis potential.These results imply that osteopontige expression maybe an indicator of uveal melanoma invasion and metastasis ability. Key words: Uveal melanoma; Osteopontin; Invasion and metastasis

Biomarkers of metastatic potential in cultured adenocarcinoma clones

Two-dimensional isoelectric focusing and gel electrophoresis followed by mass spectrometry were used to detect, measure, and identify changes in protein expression correlated with differences in the metastatic potential of cultured rat mammary adenocarcinoma cells. MTC is a non-metastatic cell clone derived from a primary tumor. MTLn2 and MTLn3 are low and high metastatic potential cell clones derived from lung metastases of the primary tumor. A total of 1,500 proteins was detected. The patterns of protein expression of MTLn2 and MTLn3 cells were similar. Only five spots had a threefold or greater statistically significant difference in staining intensity between MTLn2 and MTLn3 cells, whereas 70 spots differed between MTC and MTLn3 cells. Twenty spots were selected for further study, ten that had a positive correlation of staining intensity with metastatic potential and ten that had a negative (inverse) correlation. Of the 17 unique proteins that were identified, five have often been cited as tumor biomarkers. These included the positive biomarkers nucleophosmin (NPM) and 14-3-3 protein sigma and the negative biomarkers raf kinase inhibitor protein (RKIP), peroxiredoxin-2, and galectin-1. The only identified protein that was markedly higher in MTLn3 cells than in the less-metastatic MTLn2 cells was 14-3-3 protein sigma. The results indicate that increased metastatic potential is associated with positive and negative changes in expression of particular proteins. Proteins that are positively correlated with metastatic potential may prove more useful as clinical biomarkers, but those with negative correlations may still provide useful information about underlying mechanisms of metastatic spread.

Abstract 3301: Tumor biomarkers in mammary adenocarcinoma cell clones of different metastatic potential

Abstract Changes in the pattern of protein expression by tumor cells reflect the stage of tumor progression, the potential for invasion and metastasis, and drug resistance. Objectives: To use proteomic analysis to detect differences in protein expression that serve as biomarkers of tumor cell properties and to translate the results into diagnostic and prognostic tools based on immuno-cytological staining and immunoassay. Methods: Two-dimensional isoelectric focusing and gel electrophoresis (2-DG) followed by mass spectrometry were used to detect, measure, and identify changes in protein expression. MTC is a non-metastatic cell clone derived from a primary rat mammary adenocarcinoma. MTLn2 and MTLn3 are low and high metastatic potential cell clones derived from lung metastases of the primary tumor. 2-DG was performed simultaneously on samples of 3 extracts from cultured cells of each of the 3 clones. The 9 gels were stained with SYPRO Ruby. Matching of protein spots, densitometric analysis, and statistical analysis were performed using PDQuest 7.1 software. Excised proteins were identified by comparing the mass and sequence of tryptic peptides with those of all known rat proteins using liquid chromatography electrospray-ionization quadrupole ion trap mass spectrometry, SEQUEST software, and the NCBI protein database. Results: A total of 1500 proteins were detected. The patterns of protein expression of MTLn2 and MTLn3 cells were similar. Only 5 spots had a greater than 3-fold difference in staining intensity that was statistically significant (p<0.05), whereas 48 spots differed between MTC and MTLn3 cells. Twenty spots were selected for further study, 10 that had a positive correlation of staining intensity with metastatic potential and 10 that had a negative correlation. Of the 17 unique proteins that were identified, five were of special interest because they are often cited as potential tumor biomarkers. These included the positive biomarkers nucleophosmin (NPM) and protein 14-3-3 sigma and the negative biomarkers raf kinase inhibitor protein (RKIP), peroxiredoxin-2, and galectin-1. Immuno-cytological staining and ELISA confirmed increased NPM and protein 14-3-3 sigma expression and decreased galectin-1 expression. The results suggest a role for stromal elements in biomarker expression. Conclusions: Increased metastatic potential is associated with positive and negative changes in protein expression. Proteins that are positively correlated with metastatic potential may be more useful as clinical biomarkers, whereas those with negative correlations may provide information about underlying mechanisms of metastatic spread and possible stromal influences. Changes in protein expression with differences in tumor properties will provide a consensus panel of biomarkers for diagnostic and prognostic tests. Supported in part by the Sam Mount, Jr. Endowment for Oral Cancer Research. Note: This abstract was not presented at the AACR 101st Annual Meeting 2010 because the presenter was unable to attend. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 101st Annual Meeting of the American Association for Cancer Research; 2010 Apr 17-21; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2010;70(8 Suppl):Abstract nr 3301.

A decade's studies on metastasis of hepatocellular carcinoma.

Metastasis remains one of the major challenges before hepatocellular carcinoma (HCC) is finally conquered. This paper summarized a decade's studies on HCC metastasis at the Liver Cancer Institute of Fudan University. We have established a stepwise metastatic human HCC model system, which included a metastatic HCC model in nude mice (LCI-D20), a HCC cell line with high metastatic potential (MHCC97), a relatively low metastatic potential cell clone (MHCC97L) and several stepwise high metastatic potential cell clones (MHCC97H, HCCLM3, and HCCLM6) from their parent MHCC97 cell. Endeavors have been made for searching human HCC metastasis-related chromosomes/proteins/genes. Monogene-based studies revealed that HCC invasion/metastasis was similar to that of other solid tumors, and the biological characteristics of small HCC were only slightly better than that of large HCC. Using comparative genomic hybridization (CGH), fluorescence in situ hybridization (FISH), genotyping, cDNA microarray, and 2-dimensional gel electrophoresis, we obtained some interesting results. In particular, in collaboration with the National Institute of Health (NIH) in the United States, we generated a molecular signature that can classify metastatic HCC patients, identified osteopontin as a lead gene in the signature, and found that genes favoring metastasis progression were initiated in the primary tumors. We also found that chromosome 8p deletion, particularly in the region of 8p23, was associated with HCC metastasis. Cytokeratin 19 was identified as one of the proteins, which was found in MHCC97H, but not in MHCC97L cells. Experimental interventions using the high metastatic nude mice model have provided clues for the prevention of HCC metastasis. Translation from workbench to bedside demonstrated that serum VEGF, microvessel density, and p53 scoring may be of value for the prediction of postoperative metastatic recurrence. Interferon alpha proved effective for the prevention of recurrence both experimentally and clinically. In conclusion, HCC metastasis that probably initiated in the primary tumor is a multigene-involved, multistep, and changing process. The further elucidation of the mechanism underlying HCC metastasis will provide a more solid basis for the prediction and prevention of the metastatic recurrence of HCC.