Geometric regulation of collective cell tangential ordering migration

Collective cell migration is a coordinated movement of multi-cell systems essential for various processes throughout life.The collective motions often occur under spatial restrictions,hallmarked by the collective rotation of epithelial cells confined in circular substrates.Here,we aim to explore how geometric shapes of confinement regulate this collective cell movement.We develop quantitative methods for cell velocity orientation analysis,and find that boundary cells exhibit stronger tangential ordering migration than inner cells in circular pattern.Furthermore,decreased tangential ordering movement capability of collective cells in triangular and square patterns are observed,due to the disturbance of cell motion at unsmooth corners of these patterns.On the other hand,the collective cell rotation is slightly affected by a convex defect of the circular pattern,while almost hindered with a concave defect,also resulting from different smoothness features of their boundaries.Numerical simulations employing cell Potts model well reproduce and extend experimental observations.Together,our results highlight the importance of boundary smoothness in the regulation of collective cell tangential ordering migration.

Runx2 regulates peripheral nerve regeneration to promote Schwann cell migration and re-myelination

Runx2 is a major regulator of osteoblast differentiation and function;however,the role of Runx2 in peripheral nerve repair is unclea r.Here,we analyzed Runx2expression following injury and found that it was specifically up-regulated in Schwann cells.Furthermore,using Schwann cell-specific Runx2 knocko ut mice,we studied peripheral nerve development and regeneration and found that multiple steps in the regeneration process following sciatic nerve injury were Runx2-dependent.Changes observed in Runx2 knoc kout mice include increased prolife ration of Schwann cells,impaired Schwann cell migration and axonal regrowth,reduced re-myelination of axo ns,and a block in macrophage clearance in the late stage of regeneration.Taken together,our findings indicate that Runx2 is a key regulator of Schwann cell plasticity,and therefore peripheral nerve repair.Thus,our study shows that Runx2 plays a major role in Schwann cell migration,re-myelination,and peripheral nerve functional recovery following injury.

Estimation of cancer cell migration in biomimetic random/oriented collagen fiber microenvironments

Increasing data indicate that cancer cell migration is regulated by extracellular matrixes and their surrounding biochemical microenvironment,playing a crucial role in pathological processes such as tumor invasion and metastasis.However,conventional two-dimensional cell culture and animal models have limitations in studying the influence of tumor microenvironment on cancer cell migration.Fortunately,the further development of microfluidic technology has provided solutions for the study of such questions.We utilize microfluidic chip to build a random collagen fiber microenvironment(RFM)model and an oriented collagen fiber microenvironment(OFM)model that resemble early stage and late stage breast cancer microenvironments,respectively.By combining cell culture,biochemical concentration gradient construction,and microscopic imaging techniques,we investigate the impact of different collagen fiber biochemical microenvironments on the migration of breast cancer MDA-MB-231-RFP cells.The results show that MDA-MB-231-RFP cells migrate further in the OFM model compared to the RFM model,with significant differences observed.Furthermore,we establish concentration gradients of the anticancer drug paclitaxel in both the RFM and OFM models and find that paclitaxel significantly inhibits the migration of MDA-MB-231-RFP cells in the RFM model,with stronger inhibition on the high concentration side compared to the low concentration side.However,the inhibitory effect of paclitaxel on the migration of MDA-MB-231-RFP cells in the OFM model is weak.These findings suggest that the oriented collagen fiber microenvironment resembling the late-stage tumor microenvironment is more favorable for cancer cell migration and that the effectiveness of anticancer drugs is diminished.The RFM and OFM models constructed in this study not only provide a platform for studying the mechanism of cancer development,but also serve as a tool for the initial measurement of drug screening.

IL-17 induces NSCLC cell migration and invasion by elevating MMP19 gene transcription and expression through the interaction of p300-dependent STAT3-K631 acetylation and its Y705-phosphorylation

The cancer cell metastasis is a major death reason for patients with non-small cell lung cancer(NSCLC).Although researchers have disclosed that interleukin 17(IL-17)can increase matrix metalloproteinases(MMPs)induction causing NSCLC cell metastasis,the underlying mechanism remains unclear.In the study,we found that IL-17 receptor A(IL-17RA),p300,p-STAT3,Ack-STAT3,and MMP19 were up-regulated both in NSCLC tissues and NSCLC cells stimulated with IL-17.p300,STAT3 and MMP19 overexpression or knockdown could raise or reduce IL-17-induced p-STAT3,Ack-STAT3 and MMP19 level as well as the cell migration and invasion.Mechanism investigation revealed that STAT3 and p300 bound to the same region(−544 to−389 nt)of MMP19 promoter,and p300 could acetylate STAT3-K631 elevating STAT3 transcriptional activity,p-STAT3 or MMP19 expression and the cell mobility exposed to IL-17.Meanwhile,p300-mediated STAT3-K631 acetylation and its Y705-phosphorylation could interact,synergistically facilitating MMP19 gene transcription and enhancing cell migration and invasion.Besides,the animal experiments exhibited that the nude mice inoculated with NSCLC cells by silencing p300,STAT3 or MMP19 gene plus IL-17 treatment,the nodule number,and MMP19,Ack-STAT3,or p-STAT3 production in the lung metastatic nodules were all alleviated.Collectively,these outcomes uncover that IL-17-triggered NSCLC metastasis involves up-regulating MMP19 expression via the interaction of STAT3-K631 acetylation by p300 and its Y705-phosphorylation,which provides a new mechanistic insight and potential strategy for NSCLC metastasis and therapy.

TATA-box-binding protein-associated factor 15 is a novel biomarker that promotes cell proliferation and migration in gastrointestinal stromal tumor

BACKGROUND Gastrointestinal stromal tumor(GIST)is a common neoplasm with high rates of recurrence and metastasis,and its therapeutic efficacy is still not ideal.There is an unmet need to find new molecular therapeutic targets for GIST.TATA-boxbinding protein-associated factor 15(TAF15)contributes to the progress of various tumors,while the role and molecular mechanism of TAF15 in GIST progression are still unknown.AIM To explore new molecular therapeutic targets for GIST and understand the biological role and underlying mechanisms of TAF15 in GIST progression.METHODS Proteomic analysis was performed to explore the differentially expressed proteins in GIST.Western blotting and immunohistochemical analysis were used to verify the expression level of TAF15 in GIST tissues and cell lines.Cell counting kit-8,colony formation,wound-healing and transwell assay were executed to detect the ability of TAF15 on cell proliferation,migration and invasion.A xenograft mouse model was applied to explore the role of TAF15 in the progression of GIST.Western blotting was used to detect the phosphorylation level and total level of RAF1,MEK and ERK1/2.RESULTS A total of 1669 proteins were identified as differentially expressed proteins with 762 upregulated and 907 downregulated in GIST.TAF15 was selected for the further study because of its important role in cell proliferation and migration.TAF15 was significantly over expressed in GIST tissues and cell lines.Overexpression of TAF15 was associated with larger tumor size and higher risk stage of GIST.TAF15 knockdown significantly inhibited the cell proliferation and migration of GIST in vitro and suppressed tumor growth in vivo.Moreover,the inhibition of TAF15 expression significantly decreased the phosphorylation level of RAF1,MEK and ERK1/2 in GIST cells and xenograft tissues,while the total RAF1,MEK and ERK1/2 had no significant change.CONCLUSION TAF15 is over expressed in GIST tissues and cell lines.Overexpression of TAF15 was associated with a poor prognosis of GIST patients.TAF15 promotes cell proliferation and migration in GIST via the activation of the RAF1/MEK/ERK signaling pathway.Thus,TAF15 is expected to be a novel latent molecular biomarker or therapeutic target of GIST.

Long noncoding RNA Pvt1 promotes the proliferation and migration of Schwann cells by sponging microRNA-214 and targeting c-Jun following peripheral nerve injury

Research has shown that long-chain noncoding RNAs(lncRNAs) are involved in the regulation of a variety of biological processes, including peripheral nerve regeneration, in part by acting as competing endogenous RNAs. c-Jun plays a key role in the repair of peripheral nerve injury. However, the precise underlying mechanism of c-Jun remains unclear. In this study, we performed microarray and bioinformatics analysis of mouse crush-injured sciatic nerves and found that the lncRNA Pvt1 was overexpressed in Schwann cells after peripheral nerve injury. Mechanistic studies revealed that Pvt1 increased c-Jun expression through sponging miRNA-214. We overexpressed Pvt1 in Schwann cells cultured in vitro and found that the proliferation and migration of Schwann cells were enhanced, and overexpression of miRNA-214 counteracted the effects of Pvt1 overexpression on Schwann cell proliferation and migration. We conducted in vivo analyses and injected Schwann cells overexpressing Pvt1 into injured sciatic nerves of mice. Schwann cells overexpressing Pvt1 enhanced the regeneration of injured sciatic nerves following peripheral nerve injury and the locomotor function of mice was improved. Our findings reveal the role of lncRNAs in the repair of peripheral nerve injury and highlight lncRNA Pvt1 as a novel potential treatment target for peripheral nerve injury.

How is the AKT/mTOR pathway involved in cell migration and invasion?

As a pathway that plays a role in nutrient absorption,anabolic response,cell growth and survival,the important role of AKT/mTOR in tumorigenesis has also come to light.For cancer patients,most deaths are caused by the growth of metastatic tumors outside the primary focus.Therefore,migration and invasion in the late stage of tumor progression are the main unresolved issues in the study of tumor pathogenesis,and AKT/mTOR has been found to participate in the migration and invasion of cancer cells,which means that the study of this pathway may contribute to a solution for the problem.Because of its extensive and complex functions in the organism,this pathway can be regulated by a variety of different signals in the body,and then realize its function through different downstream signal molecules.This article reviews the proteins that can indirectly affect this pathway by regulating the common upstream signaling molecules of this pathway,and the proteins that can directly affect the level of phosphorylation of AKT/mTOR in cancer cells.We also review the proteins that can co-regulate this pathway and its downstream pathways.Through this study,we hope to gain a deeper understanding of the regulatory mechanism of the AKT/mTOR pathway in cancer cells,in hopes of finding effective and harmless cancer treatment targets in the future.

Directional-to-random transition of cell cluster migration

Efficient cell migration is crucial for the functioning of biological processes, e.g., morphogenesis, wound healing, and cancer metastasis. In this study, we monitor the migratory behavior of the 3D fibroblast clusters using live cell microscopy,and find that crowded environment affects cell migration, i.e., crowding leads to directional migration at the cluster’s periphery. The number of cell layers being stacked during seeding determines the directional-to-random transition. Intriguingly,the migratory behavior of cell clusters resembles the dispersion dynamics of clouds of passive particles, indicating that the biological process is driven by physical effects(e.g., entropy) rather than cell communication. Our findings highlight the role of intrinsic physical characteristics, such as crowding, in regulating biological behavior, and suggest new therapeutic approaches targeting at cancer metastasis.

LIM1863 is useful to explore collective cancer cell migration,and the group of heterogeneous cells undergoing collective migration behaves like a supracellular unit

Collective cancer cell migration(CCCM)and epithelial-to-mesenchymal transition(EMT)play key roles in metastasis.This study reports that the colorectal carcinoma cell line LIM1863 is useful for the study of CCCM and EMT.Methods:Hematoxylin and eosin staining,scanning electron microscopy,transmission electron microscopy,and western blot analysis were performed.Results:LIM1863 automatically grew as spheroids in suspension and had important typical epithelial properties,including several layers of cells arranged around a central lumen,apical-basal polarity,and types of cell-cell junctions.Treatment with a combination of both TGF beta 1 and TNF alpha induced definite and distinct EMT,a spheroid changing phenotype to form a monolayer high-confluent patch without lumen,without polarity.Spontaneous CCCM occurred in spheroids.Flat EMT cells adhered to the base of a dish,exhibited persistent movement as a cluster of cells,and then shed,resulting in a cluster.All cells from one cluster undergoing CCCM died.Otherwise,all cells undergoing EMT disappeared and almost all cells located in the cell reservoir survived and proliferated.Conclusion:LIM1863 is an excellent cell line to study CCCM and EMT.The group of heterogeneous cells undergoing CCCM behaves like a supracellular unit.

Soxllb regulates the migration and fate determination of Müller glia-derived progenitors during retina regeneration in zebrafish

The transcription factor Sox11 plays important roles in retinal neurogenesis during vertebrate eye development.However,its function in retina regeneration remains elusive.Here we report that Sox11 b,a zebrafish Sox11 homolog,regulates the migration and fate determination of Müller glia-derived progenitors(MGPCs)in an adult zebrafish model of mechanical retinal injury.Following a stab injury,the expression of Sox11 b was induced in proliferating MGPCs in the retina.Sox11 b knockdown did not affect MGPC formation at 4 days post-injury,although the nuclear morphology and subsequent radial migration of MGPCs were alte red.At 7 days post-injury,Sox11 b knockdown res ulted in an increased proportion of MGPCs in the inner retina and a decreased propo rtion of MGPCs in the outer nuclear layer,compared with controls.Furthermore,Sox11 b knockdown led to reduced photoreceptor regeneration,while it increased the numbe rs of newborn amacrines and retinal ganglion cells.Finally,quantitative polymerase chain reaction analysis revealed that Sox11 b regulated the expression of Notch signaling components in the retina,and Notch inhibition partially recapitulated the Sox11 b knockdown phenotype,indicating that Notch signaling functions downstream of Sox11 b.Our findings imply that Sox11 b plays key roles in MGPC migration and fate determination during retina regeneration in zebrafish,which may have critical im plications for future explorations of retinal repair in mammals.

Effects of ginsenoside Rh2 on growth and migration of pancreatic cancer cells

AIM:To investigate the effects of ginsenoside Rh2 on the human pancreatic cancer cell line Bxpc-3.METHODS:The human pancreatic cancer cell line Bxpc-3 was cultured in vitro and treated with or without ginsenoside Rh2.Growth rates for Bxpc-3 cells were assessed by methyl thiazolyl tetrazolium(MTT) and colony formation assays.Cell cycle changes were analyzed by flow cytometry.Apoptosis was measured by flow cytometry and Hoechst 33258 fluorescence staining.A scratch assay and a Matrigel invasion assay were used to detect cell migration and invasion.Expression of Bax,Bcl-2,survivin,cyclin D1,matrix metalloproteinase(MMP)-2,MMP-9,cleaved caspase-3,caspase-8,and caspase-9 mRNA were determined by reverse transcriptase-polymerase chain reaction(RT-PCR).Bax,Bcl-2,survivin,cyclin D1,cleaved caspase-3,caspase-8 and caspase-9 protein levels were examined by western blotting.Expression of MMP-2 and MMP-9 proteins in culture supernatants were determined by enzymelinked immunosorbent assay(ELISA).RESULTS:Rh2 significantly inhibited Bxpc-3 cell proliferation in a dose-and time-dependent manner,as evaluated by the MTT(P < 0.05) and colony formation assays(P < 0.05).Compared to the control group,Rh2 significantly increased the percentage of Bxpc-3 cells in the G 0 /G 1 phase from 43.32% ± 2.17% to 71.32% ± 1.16%,which was accompanied by a decrease in S phase(from 50.86% ± 1.29% to 28.48% ± 1.18%) and G 2 /M phase(from 5.81% ± 1.19% to 0.20% ± 0.05%) in a dose-dependent manner(P < 0.05),suggesting that Rh2 arrested cell cycle progression at the G 0 /G 1 phase,as measured by flow cytometry.Compared to the control group,cells treated with Rh2 showed significantly higher apoptosis ratios in a dosedependent manner(percentage of early apoptotic cells:from 5.29% ± 2.28% to 38.90% ± 3.42%(F = 56.20,P < 0.05);percentage of late apoptotic cells:from 4.58% ± 1.42% to 36.32% ± 2.73%(F = 86.70,P < 0.05).Rh2 inhibited Bxpc-3 cell migration and invasion,as detected by scratch wound healing assay and Matrigel invasion assay [percentages of scratch wound healing for 12 h,24 h and 48 h(control vs experimental group):37.3% ± 4.8%vs 18.30% ± 1.65%,58.7% ± 3.5% vs 38.00% ± 4.09% and 93.83% ± 4.65% vs 65.50% ± 4.09%,respectively;t = 6.489,t = 6.656 and t = 7.926,respectively,P < 0.05;the number of cells invading at various concentrations(0 μmol/L,35 μmol/L,45 μmol/L and 55 μmol/L):81.10 ± 9.55,46.40 ± 6.95,24.70 ± 6.88 and 8.70 ± 3.34,respectively(F = 502.713,P < 0.05)].RT-PCR,western blotting or ELISA showed that mRNA and protein expression of Bax,cleaved caspase-3 and caspase-9 were upregulated(P < 0.05),while mRNA and protein expression of Bcl-2,survivin,cyclin D1,MMP-2 and MMP-9 were downregulated(P < 0.05).CONCLUSION:Ginsenoside Rh2 inhibits proliferation,migration and invasion and induces apoptosis of the human pancreatic cancer cell line Bxpc-3.

Experimental Study of Cell Migration and Functional Differentiation of Transplanted Neural Stem Cells Co-labeled with Superparamagnetic Iron Oxide and Brdu in an Ischemic Rat Model

Objective To explore the migration of transplanted neural stem cells co-labeled with superparamagnetic iron oxide （SPIO） and bromodeoxyuridine （Brdu） using the 4.7T MR system and to study the cell differentiation with immuno-histochemical method in ischemic rats. Methods Rat neural stem cells （NSCs） co-labelled with SPIO mediated by poly-L-lysine and bromodeoxyuridine （BrdU） were transplanted into the unaffected side of rat brain with middle cerebral artery occlusion （MCAO）. At weeks 1, 2, 3, 4, 5, and 6 after MCAO, migration of the labelled cells was monitored by MRI. At week 6 the rats were killed and their brain tissue was cut according to the migration site of transplanted ceils indicated by MRI and subjected to Prussian blue staining and immunohistochemical staining to observe the migration and differentiation of the transplanted NSCs. Results Three weeks after transplantation, the linear hypointensity area derived from the migration of labelled NSCs was observed by MRI in the corpus callosum adjacent to the injection site. Six weeks after the transplantation, the linear hypointensity area was moved toward the midline along the corpus callosum. MRI findings were confirmed by Prussian blue staining and immunohistochemical staining of the specimen at week 6 after the transplantation. Flourescence co-labelled immunohistochemical methods demonstrated that the transplanted NSCs could differentiate into astrocytes and neurons. Conclusion MRI can monitor the migration of SPIO-labelled NSCs after transplantation in a dynamical and non-invasive manner. NSCs transplanted into ischemic rats can differentiate into astrocytes and neurons during the process of migration.

Effects of rAAV-CD151 and rAAV-antiCD151 on the Migration of Human Tongue Squamous Carcinoma Cell Line Tca8113

Summary: This study was designed to determine the effects of the recombinant adeno-associated virus vector containing sense CD151 gene (rAAV-CD151) and antisense CD151 gene (rAAV-antiCD151) on the migration of Tca8113 cell. Functional fragment of CD151 gene was amplified by RT-PCR, and inserted into the vector pAAV in the sense direction and antisense direction, respectively. The rAAV-CD151 and rAAV-antiCD151 were produced and the titers were determined by dot blot. The CD151, at protein level, was detected by Western blot. The Transwell chamber was used to detect the effects of the rAAV-CD151 and rAAV-antiCD151 on the tumor cell migration. The titers of the rAAV-CD151 and rAAV-antiCD151 were 2×10~11 pfu/ml and 1.0×10~11 pfu/ml, respectively. The expression of CD151 was increased by 108 % in the cells transfected with rAAV-CD151 and decreased by 79 % in the cells transfected with rAAV-antiCD151, as compared with non-transfected cells, respectively. The number of the migrating cells was significantly increased in the cells transfected with rAAV-CD151 (93.56±11.59) and decreased in the cells transfected with rAAV-antiCD151 (24.00±4.36) as compared with non-transfected and rAAV-GFP transfected cells (53.00±6.56 and 46.00±7.00, P<0.05). It is an important molecular mechanism of the tumor metastasis that the overexpression of CD151 promotes the migration of the tumor cells. The rAAV-antiCD151 is a novel tool, which can reduce the expression of CD151 and inhibit the migration of the tumor cells, and brings us a new approach of anti-sene gene therapy targeted at CD151 in human carcinoma.

Novel miRNA, miR-sc14, promotes Schwann cell proliferation and migration

MicroRNAs refer to a class of endogenous,short non-coding RNAs that mediate numerous biological functions.MicroRNAs regulate various physiological and pathological activities of peripheral nerves,including peripheral nerve repair and regeneration.Previously,using a rat sciatic nerve injury model,we identified many functionally annotated novel microRNAs,including miR-sc14.Here,we used real-time reverse transcription-polymerase chain reaction to examine miR-sc14 expression in rat sciatic nerve stumps.Our results show that miRsc14 is noticeably altered following sciatic nerve injury,being up-regulated at 1 day and diminished at 7 days.EdU and transwell chamber assay results showed that miR-sc14 mimic promoted proliferation and migration of Schwann cells,while miR-sc14 inhiThe study was approved by the Jiangsu Provincial Laboratory Animal Management Committee,China on March 4,2015(approval No.20150304-004).bitor suppressed their proliferation and migration.Additionally,bioinformatic analysis examined potential target genes of miR-sc14,and found that fibroblast growth factor receptor 2 might be a potential target gene.Specifically,our results show changes of miR-sc14 expression in the sciatic nerve of rats at different time points after nerve injury.Appropriately,up-regulation of miR-sc14 promoted proliferation and migration of Schwann cells.Consequently,miR-sc14 may be an intervention target to promote repair of peripheral nerve injury.The study was approved by the Jiangsu Provincial Laboratory Animal Management Committee,China on March 4,2015(approval No.20150304-004).

Vascular endothelial growth factor A, secreted in response to transforming growth factor-β1 under hypoxic conditions, induces autocrine effects on migration of prostate cancer cells

Hypoxia and transforming growth factor-β1 （TGF-β1） increase vascular endothelial growth factor A （VEGFA） expression in a number of malignancies. This effect of hypoxia and TGF-β1 might be responsible for tumor progression and metastasis of advanced prostate cancer. In the present study, TGF-β1 was shown to induce VEGFA165 secretion from both normal cell lines （HPV7 and RWPE1） and prostate cancer cell lines （DU 145 and PC3）. Conversely, hypoxia-stimulated VEGFA165 secretion was observed only in prostate cancer cell lines. Hypoxia induced TGF-β1 expression in PC3 prostate cancer cells, and the TGF-β1 type I receptor （ALK5） kinase inhibitor partially blocked hypoxia-mediated VEGFA16s secretion. This effect of hypoxia provides a novel mechanism to increase VEGFA expression in prostate cancer cells. Although autocrine signaling of VEGFA has been implicated in prostate cancer progression and metastasis, the associated mechanism is poorly characterized. VEGFA activity is mediated via VEGF receptor （VEGFR） 1 （Fit-l） and 2 （FIk-I/KDR）. Whereas VEGFR-1 mRNA was detected in normal prostate epithelial cells, VEGFR-2 mRNA and VEGFR protein were expressed only in PC3 cells. VEGFA165 treatment induced phosphorylation of extracellular signal-regulated kinase 1/2 （ERKI/2） in PC3 cells but not in HPV7 cells, suggesting that the autocrine function of VEGFA may be uniquely associated with prostate cancer. Activation of VEGFR-2 by VEGFA165 was shown to enhance migration of PC3 cells. A similar effect was also observed with endogenous VEGFA induced by TGF-β1 and hypoxia. These findings illustrate that an autocrine loop of VEGFA via VEGFR-2 is critical for the tumorigenic effects of TGF-β1 and hypoxia on metastatic prostate cancers.

PP2A Inhibits Cervical Cancer Cell Migration by Dephosphorylation of p-JNK,p-p38 and the p-ERK/MAPK Signaling Pathway

Protein phosphatase 2 A（PP2 A） was reported to play an important role in cancer development;however,the relationship between PP2 A and cervical cancer development has yet to be fully understood.The present study aimed to explore the role of PP2 A in the development of cervical cancer.Serum levels of PP2 A were detected by ELISA in 23 patients with cervical cancer and 30 patients with benign cervical lesions.Furthermore,the PP2 A activities and the m RNA and protein levels of PP2 A were measured in cervical cancer（n=8） and chronic cervicitis（n=10） tissues.The results showed that the serum levels of PP2 A were significantly reduced in patients with cervical cancer.Further studies showed that not only the activities of PP2 A but also the m RNA and protein levels of PP2 A were significantly decreased in cervical cancer tissues.Wound healing and Transwell assays demonstrated that pharmacological and genetic upregulation of PP2 A could inhibit the migration of He La cells,but the downregulation of PP2 A promoted cellular migration.The activation of PP2 A also inhibited the remodeling of actin and the activity of mitogen-activated protein kinases（MAPKs） including p-JNK,p-p38 and p-ERK.Meanwhile,the activation of PP2 A was found to downregulate MMP-9 levels,which further inhibited the migration and invasion of He La cells.In conclusion,our data suggest that the activity and expression of PP2 A are significantly reduced in cervical cancer tissues,and the activation of PP2 A may inhibit the migration of cervical cancer cells by inhibiting the phosphorylation of p-JNK,p-p38 and the p-ERK/MAPK signaling pathway as well as by downregulating MMP-9,implying that PP2 A plays an important role in cervical cancer development.

Inhibitory Effects of Rap1GAP Overexpression on Proliferation and Migration of Endothelial Cells via ERK and Akt Pathways

Rapl is expressed in human umbilical vein endothelial cells （HUVECs）. Rapl-GTPase activating protein （RaplGAP）, with its specific target, Rapl, has been shown to be important in the regulation of many physiological and certain pathological processes. In this study, we investigated the effect of RaplGAP expression on endothelial cell function, or, more specifically, proliferation and migration of endothelial cells. HUVECs were transfected with pcDNA3.1 （empty vector）, pcDNA3.1 containing Flag-tagged-RaplGAP or Myc-tagged-RaplN17. The proliferation, migration and tube formation were examined and compared among the 3 groups. Expression of Rapl, RaplGAP, extracellular signal-regulated kinase （ERK）, phospho-ERK, Akt, phosphor-Akt was detected by Western blotting. The results showed that the proliferation, migration and tube formation were significantly reduced in RaplGAP- and RaplN17-transfected HUVECs as compared with empty vector-transfected control. These changes were coincident with increased expression of Rap 1GAP and decreased expression of activated Rap l, phospho-ERK and -Akt. After treatment of Rap l GAP-transfected HUVECs with a stimulator of Rapl guanine-nucleotide-exchange factor （RaplGEF） 8CPT-2＇OMe-cAMP, it was found that Rapl activity was decreased as compared with empty vector-transfected control. Pretreatment of HU- VECs with an ERK inhibitor PD98059 or a PI3K inhibitor LY294002 prior to stimulation not only blocked 8CPT-2＇OMe-cAMP-induced phosphorylation of ERK and Akt, but also significantly reduced cell proliferation and migration. Finally, we examined the effect of vascular endothelial growth factor （VEGF） on HUVECs overexpressing RaplGAP. VEGF-stimulated Rapl activity, phosphorylation of ERK and Akt, cyclin D1 expression and cell proliferation were repressed in HUVECs overexpressing RaplGAP as compared to empty vector-transfected Control. Taken together, our findings demonstrate that RaplGAP/Rapl and their downstream effectors regulate proliferation and migration of HUVECs via ERK and Akt pathways.

Migration of hepatic stellate cells in fibrotic microenvironment of diseased liver model

BACKGROUND: In liver fibrosis, alterations within the space of Disse microenvironment facilitate the progression of chronic liver disease. The normal basement membranelike matrix in the space of Disse converts to a matrix rich in fibril-forming collagens during the fibrosis. This study aimed to investigate the impact of alterations in the space of Disse microenvironment on the migration of hepatic stellate cells (HSCs) in the process of liver fibrosis, and to explore the novel mechanism ofliver fibrosis from the viewpoint of cell migration. METHODS: A modified in vitro Boyden chamber system was employed to partially mimic the in vitro microenvironment of the Disse space in normal liver and in fibrosis. The effects of fibrogenetic growth factors on the migration of HSCs in simulated liver fibrosis were assessed by cell migration and cell proliferation experiments. RESULTS: Enhanced platelet-derived growth factor (PDGF)-BB, transforming growth factor-beta 1 (TGF-beta 1) and/or epithelial growth factor (EGF) in liver fibrosis resulted in an increase in migratory capacity of activated HSCs. The enhanced migration of HSCs, induced by PDGF-BB was proliferation -independent. The elevation of basic fibroblast growth factor (bFGF) or vascular endothelial growth factor (VEGF) during liver fibrosis had no effect on the migration of HSCs. CONCLUSIONS: The study provides valuable insights into the role of the space of Disse microenvironment in regulating the migratory behavior of HSCs. TGF-beta 1, PDGF-BB and EGF, which increase in liver fibrosis, induce the migration of activated HSCs. However, bFGF and VEGF have no effect although they also increase during liver fibrosis.

Migration capacity of human umbilical cord mesenchymal stem cells towards glioma in vivo

High-grade glioma is the most common malignant primary brain tumor in adults. The poor prognosis of glioma, combined with a resistance tQ currently available treatments, necessitates the develop- ment of more effective tumor-selective therapies. Stem cell-based therapies are emerging as novel cell-based delivery vehicle for therapeutic agents. In the present study, we successfully isolated human umbilical cord mesenchymal stem cells by expiant culture. The human umbilical cord mes- enchymal stem cells were adherent to plastic surfaces, expressed specific surface phenotypes of mesenchymal stem cells as demonstrated by flow cytometry, and possessed multi-differentiation potentials in permissive induction media in vitro. Furthermore, human umbilical cord mesenchymal stem cells demonstrated excellent glioma-specific targeting capacity in established rat glioma models after intratumoral injection or contralateral ventricular administration in vivo. The excellent glioma-specific targeting ability and extensive intratumoral distribution of human umbilical cord mesenchymal stem cells indicate that they may serve as a novel cellular vehicle for delivering therapeutic molecules in glioma therapy.

Effects of microtubule-associated protein tau expression on neural stem cell migration after spinal cord injury

Our preliminary proteomics analysis suggested that expression of microtubule-associated protein tau is elevated in the spinal cord after injury. Therefore, the first aim of the present study was to examine tau expression in the injured spinal cord. The second aim was to determine whether tau can regulate neural stem cell migration, a critical factor in the successful treatment of spinal cord injury. We established rat models of spinal cord injury and injected them with mouse hippocampal neural stem cells through the tail vein. We used immunohistochemistry to show that the expression of tau protein and the number of migrated neural stem cells were markedly increased in the injured spinal cord. Furthermore, using a Transwell assay, we showed that neural stem cell migration was not affected by an elevated tau concentration in the outer chamber, but it was decreased by changes in intracellular tau phosphorylation state. These results demonstrate that neural stem cells have targeted migration capability at the site of injury, and that although tau is not a chemokine for targeted migration of neural stem cells, intracellular tau phosphorylation/dephosphorylation can inhibit cell migration.