Objective To investigate the regulating mechanism of Notch1 signaling pathway on the invasion and migration ofglioma initiating cells (GICs).Methods (1) Box-plotting was conducted to analyze the mRNA expression of Notch1 in normal brain tissue and glioblastoma tissue using Bredel Brain,Sun Brain and TCGA databases;Kaplan-Meier survival analysis was conducted to analyze the association between the prognosis of glioma patients with the expression of Hes1 in TCGA database;Heatmap was conducted to analyze the expression of Notch1 and CXCR4 in GICs and common cell line in GEO database.(2) Magnetic activated cell sorting was adopted to establish cell lines of U87 GICs and U251 GICs;immunofluorescence staining was used to detect expression of CXCR4 and Notch1.After the cell lines of U87 GICs and U251 GICs were divided into DMSO,shNC,MK0752 and shNotchl groups,the shNotch1 and shNC groups were transfected respectively with recombinant lentivirus of Notch1-shRNA and its control sequence while the MK0752 and DMSO groups were added respectively with MK-0752 of 80 nmol/mL and the same amount of DMSO.The protein expression of Notch1,CXCR4 and p-mTOR was detected by Westem blotting in the 4 groups.The capabilities of invasion and migration of the GICs were detected by Transwell assay in the shNotch1 and shNC groups.Results (1) The box-plotting showed the mRNA expression of Notch 1 in the glioblastoma tissue was significantly higher than in the normal brain tissue (P＜0.05).The Kaplan-Meier survival analysis showed that the life span ofglioma patients with high expression of Hes1 was significantly shorter than that of those with low expression of Hes1 (P＜0.05).Heatmaps showed that the expression levels of Notch1 and CXCR4 in GICs were higher than in the common cell line.(2) The immunofluorescence staining showed that Notch1 and CXCR4 were highly expressed and colocalized in cell lines of U87 GICs and U251 GICs.The Western blotting showed that the protein expression of Notch1,CXCR4 and p-mTOR in the cell lines of U87GICs and U251 GICs in the MK0752 and shNotch1 groups was lower than that in the DMSO and shNC groups.Transwell assay showed that the penetrating-membrane cells per visual field in the shNotch1group were significantly fewer than those in the shNC group (P＜0.05).Conclusion Notch1 signaling pathway can promote invasion and migration of GICs through regulating CXCR4 expression.

Objective To investigate the effect of acidic tumor microenvironment on invasion and migration and its mechanism in glioma cells. Methods (1) The pH value of the medium was adjusted by acid-base titration. Human glioma cells U87 and U251 were cultured in the acid group and the normal group with pH values of 6.4 and 7.4, respectively; and 3 d after cultivation, the expressions of hypoxia-inducible factor-2α (HIF-2α) and CD44 were detected by Western blotting; Transwell assay was used to examine the invasion and migration of U87 and U251 cells; immunofluorescence was employed to examine the CD44 expression. (2) The U87 and U251 cells were divided into small interfering RNA (siRNA) -nonsense sequence group and siRNA-CD44-1 group, and the siRNA nonsense sequences and siRNA-CD44-1 interfering fragments were transfected by lipofectin-3000, respectively; three d after transfection, the migration and invasion abilities of cells from the two groups were detected by Transwell assay. (3) U87 and U251 cells were divided into acid group (cultured with a pH value of 6.4), blank control group, siRNA nonsense sequence group, siRNA-CD44-1 group, and siRNA-CD44-2 group; and cells from the later four groups were cultured with a pH value of 7.4; after culture for 4 d, the siRNA-nonsense sequence group, siRNA-CD44-1 group and siRNA-CD44-2 group were transfected with siRNA-nonsense sequences, siRNA-cd44-1 interfering fragments and siRNA-CD44-2 interfering fragments, respectively; three d after transfection, the expressions of CD44, N-Ca, Vimentin, and matrix metalloproteinase (MMP)-2 proteins in these 5 groups were detected by Western blotting. Results (1) As compared with the normal group, the expression levels of HIF-2α and CD44 in U87 and U251 cells of the acid group were significantly increased; both Transwell and invasion experiments showed that the number of transmembrane cells in the acid group was significantly larger than that in the normal group (P<0.05); immunofluorescence staining showed that the CD44 expression in acid group was significantly higher than that in normal group (P<0.05). (2) Both Transwell and invasion experiments showed that the number of transmembrane cells in the siRNA-CD44-1 group was significantly smaller than that in the siRNA nonsense sequence group (P<0.05). (3) Western blotting showed that the expression levels of CD44, N-Ca, Vimentin and MMP-2 in U87 and U251 cells of the blank control group, siRNA nonsense sequence group, siRNA-CD44-1 group, and siRNA-CD44-2 group were obviously decreased as compared with those in the acid group; the expression levels of CD44, N-Ca, Vimentin and MMP-2 in U87 and U251 cells of the siRNA-CD44-1 group and siRNA-CD44-2 group were obviously lower than those in the siRNA nonsense sequence group. Conclusion Acidic tumor microenvironment enhances the capabilities of invasion and migration of glioma cells through increasing CD44 expression.

Objective To study the influence of micro (miR)-325 in progression of glioma and its molecular mechanism by regulating transferrin receptor (TFRC) gene expression in glioma cells. Methods (1) Thirty-five glioma tissues and paired adjacent normal tissues were collected during surgical excision performed in our hospital from January 2015 to January 2018. The miR-325 and TFRC mRNA expression levels in the glioma tissues and paired adjacent normal tissues were detected by inverse transcription-quantitative PCR (RT-qPCR); the expression of miR-325 in glioma tissues of patients with different clinical characteristics and the survival curves of patients with low or high miR-325 expressions were compared. (2) RT-qPCR was used to examine the miR-325 expression in HA, U251, and U87 cell lines in vitro; the regulatory relations between miR-325 and its potential target gene TFRC in U251, and U87 cell lines were measured by luciferase report assay; miR-325 mimic and its negative control were transfected into U251 and U87 cell lines for 48 h, and then, the mRNA and protein expressions of TFRC were detected by RT-qPCR and Western blotting, respectively; control small interfering RNA (siRNA)+nonsense inhibitor, TFRC siRNA+nonsense inhibitor, and siTFRC+miR-325 inhibitor were transfected into U251 and U87 cell lines for 48 h, respectively, Western blotting was employed to detect the TFRC protein expression, cell proliferation was detected by CCK-8 assay, and cell invasion was detected by Transwell assay; pcDNA3.1 empty vector+nonsense sequence, TFRC pcDNA3. 1+nonsense sequence, TFRC pcDNA3.1+miR-325 mimic were transfected into U251 and U87 cell lines for 48 h, respectively, TFRC protein expression was detected by Western blotting, cell proliferation was detected by CCK-8 assay, and cell invasion was detected by Transwell assay. Results (1) As compared with those in the adjacent tissues, the miR-325 expression was significantly decreased and the TFRC mRNA expression was statistically increased in glioma tissues (P<0.05); the TFRC mRNA expression and miR-325 expression were negatively correlated in glioma tissues (P<0.05); as compared with patients with Karnofsky functional status scores≥80, patients with scores<80 had significantly decreased miR-325 expression; as compared with glioma tissues of WHO grading I-II, glioma tissues of grading III-IV had significantly decreased miR-325 expression (P<0.05); the survival rate of patients with low miR-325 expression was statistically lower than that of patients with high miR-325 expression (P< 0.05). (2) As compared with that in HA cells, the miR-325 expression was statistically down-regulated in U87 and U251 cells (P<0.05); in TFRC wild-type (TFRC WT) transfected cells, the miR-325 mimic group had significantly lower luciferase activity than the nonsense sequence group, while the miR-325 inhibitor group had significantly higher luciferase activity than the nonsense inhibitor group (P<0.05); as compared with those in the nonsense sequence group, the TFRC mRNA and protein expressions were statistically decreased in U87 and U251 cells of miR-325 mimic group; as compared with those in the control siRNA+nonsense inhibitor group, the TFRC protein expression and absorbance value were significantly decreased, and number of invasive cells was significantly smaller in the siTFRC+nonsense inhibitor group; and as compared with those in the siTFRC+nonsense inhibitor group, the TFRC protein expression and absorbance value were significantly increased, and number of invasive cells was significantly larger in the siTFRC+miR-325 inhibitor group (P<0.05); as compared with the pcDNA3.1 empty vector+nonsense sequence group, the TFRC protein expression and absorbance value were significantly increased, and number of invasive cells was significantly larger in the TFRC pcDNA3.1 +nonsense sequence group, and as compared with the TFRC pcDNA3.1+nonsense sequence group, the TFRC protein expression and absorbance value were significantly decreased, and number of invasive cells was significantly smaller in the TFRC pcDNA3.1+miR-325 mimic group (P<0.05). Conclusion The miR-325 expression is decreased in glioma cells and has a tumor suppressor effect; patients with low miR-325 expression have poor prognosis; miR-325 inhibits cancer cell progression by inhibiting the expression of the target gene TFRC.

Objective To observe the changes of invasion and migration patterns and integrin expression of malignant glioma cells when Rac and Rho pathways are suppressed,respectively,in 3D hydrogel.Methods Liposome mediated pCMVLifeAct-TagGFP2 plasmids were transfected into glioma U87 cells,and then,these cells were divided into NSC23766 treatment group,Y-27632 treatment group,NSC23766 and Y-27632 combined treatment group,and control group.The three treatment groups were added NSC23766 (100 nmol/mL),Y-27632 (10 nmol/mL),100 nmol/mL NSC23766 and 10 nmol/mL Y-27632,respectively;the cells in the control group were added the same amount of medium.Cells were cultured in hydrogel;the composition of round cells,spindle cells and the mesenchymal and amoeboid cell movement transition were observed under confocal microscopy.The hydrogels of each group were infused into the microslide,and the cell chemotaxis effect were recorded and the cell movement velocities and distances were calculated in the living cell workstation.Immunofluorescence was used to observe the alternation ofintegrin expression.Results U87 cells cultured in 3D hydrogel exhibited spindle-like and round-like shapes,corresponding to mesenchymal and amoeboid cell movement.As compared with that in the control group,the proportion of round cells in the NSC23766 treatment group was significantly higher,and that of spindle cells in the Y-27632 treatment group was significantly higher (P＜0.05).The conversion rate ofmesenchymal-amoeboid transition was 50.0％ in NSC23766 treatment group and amoeboid mesenchymal transition was 42.8％ in Y-27632 treatment group as compared with that in the control group,with significant differences (P＜0.05).The velocity and distance of cells cultured in 3D hydrogel decreased orderly in NSC23766 treatment group,control group,Y-27632 treatment group and combined treatment group in chemotaxis test.The immunofluorescence test showed that integrin expression in the Y-27632 treatment group was significantly higher than that in the other three groups,and that in the control group was statistically higher than that in the NSC23766 treatment group and combined treatment group (P＜0.05).Conclusions 3D hydrogel can be used as a favorable substrate for cell culture.The combination targeted inhabitation of Rac 1 and RohA pathways provides theoretical basis for anti-invasion treatment against glioma.