Rap2B promotes cell adhesion, proliferation, migration and invasion of human glioma.

PURPOSE: Rap2B, a member of the GTP-binding proteins, is generally up-regulated in numerous types of tumors. Nevertheless, the influence and regulatory mechanisms of Rap2B in gliomas are still not corroborated. Therefore, we analyzed the expression of Rap2B in glioma tissues and cells, and researched its significance in adhesion, proliferation, migration and invasion of the glioma cell line. METHODS: We analyzed the expression of Rap2B in different pathologic grades of glioma tissues by tissue microarray and immunohistochemistry. We assessed the expression of Rap2B in glioma tissue and non-tumor tissue by Western blot. And the expression of Rap2b protein in glioma cells and normal human astrocytes (NHA) was detected by Western blot. In addition, we disclosed the effect of Rap2B knockdown on cell adhesion, proliferation, migration and invasion by using cell attachment assay, CCK-8 assay, cell migration assay and Wound Healing assay, cell invasion assay, respectively. Western blot was used to detect the changes of expression level of NF-kB, MMP-2 and MMP-9 protein when downregulated the expression of Rap2B. RESULTS: The tissue microarray immunohistochemical results of glioma showed that the expression of Rap2B had no significant correlations between Rap2B expression and the clinicopathologic variables, including patient age (P = 0.352), gender (P = 0.858), WHO Grade (P = 0.693) and histology type (P = 0.877). Western blot analysis showed that the glioma tissue had a dramatically increase of Rap2B expression compared with the non-tumor tissues (P < 0.01). And the expression of Rap2B was markedly up-regulated in all 5 glioma cell lines compared with that in normal human astrocytes (NHA) (P < 0.01). We found that the ability of adhesion, proliferation, migration and invasion of glioma cells were significantly decreased after downregulated Rap2B expression compared with the control group (P < 0.05). In addition, Western blot results showed that the expression levels of NF-kB, MMP-2 and MMP-9 in the interference group were significantly lower than those in the negative control group (P < 0.05). CONCLUSIONS: Rap2B expression is up-regulated in glioma tissues and glioma cell lines. Knockdown of Rap2B inhibits glioma cells' adhesion and proliferation in vitro. Knockdown of Rap2B inhibits glioma cells' migration in vitro. Knockdown of Rap2B inhibits glioma cells' invasion and MMPs activity through NF-kB pathway.

Relationship between expression of XRCC1 and tumor proliferation, migration, invasion, and angiogenesis in glioma.

Recently, XRCC1 polymorphisms were reported to be associated with glioma in Chinese population. However, only a few studies reported on the XRCC1 expression, and cancer progression. In this study, we investigated whether XRCC1 plays a role in glioma pathogenesis. Using the tissue microarray technology, we found that XRCC1 expression is significantly decreased in glioma compared with tumor adjacent normal brain tissue (P < 0.01, χ2 test) and reduced XRCC1 staining was associated with WHO stages (P < 0.05, χ2 test). The mRNA and protein levels of XRCC1 were significantly downregulated in human primary glioma tissues (P < 0.001, χ2 test). We also found that XRCC1 was significantly decreased in glioma cell lines compared to normal human astrocytes (P < 0.01, χ2 test). Overexpression of XRCC1 dramatically reduced the proliferation and caused cessation of cell cycle. The reduced cell proliferation is due to G1 phase arrest as cyclin D1 is diminished whereas p16 is upregulated. We further demonstrated that XRCC1 overexpression suppressed the glioma cell migration and invasion abilities by targeting MMP-2. In addition, we also found that overexpression of XRCC1 sharply inhibited angiogenesis, which correlated with down-regulation of VEGF. The data indicate that XRCC1 may be a tumor suppressor involved in the progression of glioma.

H1/pHGFK1 nanoparticles exert anti-tumoural and radiosensitising effects by inhibition of MET in glioblastoma.

BACKGROUND: The therapeutic resistance to ionising radiation (IR) and anti-angiogenesis mainly impair the prognosis of patients with glioblastoma. The primary and secondary MET aberrant activation is one crucial factor for these resistances. The kringle 1 domain of hepatocyte growth factor (HGFK1), an angiogenic inhibitor, contains a high-affinity binding domain of MET; however, its effects on glioblastoma remain elusive. METHODS: We formed the nanoparticles consisting of a folate receptor-targeted nanoparticle-mediated HGFK1 gene (H1/pHGFK1) and studied its anti-tumoural and radiosensitive activities in both subcutaneous and orthotopic human glioma cell-xenografted mouse models. We then elucidated its molecular mechanisms in human glioblastoma cell lines in vitro. RESULTS: We demonstrated for the first time that peritumoural injection of H1/pHGFK1 nanoparticles significantly inhibited tumour growth and prolonged survival in tumour-bearing mice, as well as enhanced the anti-tumoural efficacies of IR in vivo by reducing Ki-67 expression, enhancing TUNEL staining-indicated apoptotic indexes, reducing microvascular intensity and reversing IR-induced MET overexpression in tumour tissues. Furthermore, we showed that HGFK1 suppressed the proliferation and induced cell apoptosis and enhanced sensitivity to IR in glioblastoma cell lines, mainly by suppressing the activities of MET receptor, down-regulating ATM-Chk2 axis but up-regulating Chk1. CONCLUSIONS: H1/pHGFK1 exerts anti-tumoural and radiosensitive activities mainly through the inhibition and reversal of IR-induced MET and ATM-Chk2 axis activities in glioblastoma. H1/pHGFK1 nanoparticles are a potential radiosensitiser and angiogenic inhibitor for glioblastoma treatment.

CTHRC1 mediates multiple pathways regulating cell invasion, migration and adhesion in glioma.

Recently, collagen triple helix repeat containing-1 (CTHRC1) has been reported to be increased in several types of human solid cancers and to be associated with tumor invasion and metastasis. However, the expression and function of CTHRC1 in glioma have not yet been reported. In the present study, we investigated whether CTHRC1 plays a role in glioma pathogenesis. Using the tissue microarray technology, we found that CTHRC1 expression is significantly increased in glioma compared with tumor adjacent normal brain tissue (P<0.01, χ2 test) and increased CTHRC1 staining was associated with WHO stages (P<0.05, χ2 test). The mRNA and protein levels of CTHRC1 were significantly upregulated in human primary glioma tissues (P<0.001, χ2 test). We also found that CTHRC1 was significantly increased in glioma cell lines compared to normal human astrocytes (P<0.01, χ2 test). Furthermore, Knockdown of CTHRC1 suppressed glioma cell invasion and inhibited enzyme activity of MMP-2. Moreover, our data showed that knockdown of CTHRC1 inhibited glioma cell migration and adhesion capacity when compared with the control cells, and CTHRC1-siRNA reduced the levels of phosphorylated Src and FAK protein expression. Taken together, this study suggests that CTHRC1 plays a role in glioma development and progression by regulating invasion, migration and adhesion capabilities of cancer cells.

PinX1 is up-regulated and associated with poor patients' survival in gliomas.

PinX1, a conserved nuclear protein, could maintain telomere integrity and plays an important role in regulating telomerase activity. It has been reported that the expression of PinX1 is down-regulated in some cancer and associated with cancer prognosis. However, the value of PinX1 in gliomas has not been studied. In this study, two independent retrospective gliomas cohorts with the corresponding gliomas tissue microarrays (TMAs) were established to detect the expression level of PinX1 and the correlation of PinX1 expression with the clinicopathological features and the patients' survival. Compared with non-cancerous brain tissues, PinX1 protein levels were remarkably up-regulated in gliomas (P = 0.001), and further increased from benign gliomas tissues to malignant gliomas tissues (P = 0.090). Moreover, high PinX1 expression was significantly positively associated with gliomas WHO grade in the training set (P = 0.019) and the validation set (P = 0.037). High PinX1 expression significantly correlated with a worse 5-year overall (P = 0.016) and disease-specific survival (P = 0.026). Simultaneously, the multivariate COX regression analysis showed that PinX1 was an independent unfavorable prognostic factor for 5-year overall survival (hazard ratio (HR) = 2.078, P = 0.015) and disease-specific survival (HR = 2.429, P = 0.012) after adjusting with age, sex and WHO grade in gliomas. In conclusion, PinX1 expression may serve as a prognostic and predictive biomarker for gliomas.

PinX1 inhibits cell proliferation, migration and invasion in glioma cells.

PinX1 induces apoptosis and suppresses cell proliferation in some cancer cells, and the expression of PinX1 is frequently decreased in some cancer and negatively associated with metastasis and prognosis. However, the precise roles of PinX1 in gliomas have not been studied. In this study, we found that PinX1 obviously reduced the gliomas cell proliferation through regulating the expressions of cell cycle-relative molecules to arrest cell at G1 phase and down-regulating the expression of component telomerase reverse transcriptase (hTERT in human), which is the hardcore of telomerase. Moreover, PinX1 could suppress the abilities of gliomas cell wound healing, migration and invasion via suppressing MMP-2 expression and increasing TIMP-2 expression. In conclusion, our results suggested that PinX1 may be a potential suppressive gene in the progression of gliomas.

Cullin1 regulates proliferation, migration and invasion of glioma cells.

This study was designed to explore the role of Cullin1 (Cul1) in the pathogenesis of human glioma and to investigate the role of Cul1 in the growth, migration and invasion of glioma cells. Expression of Cul1 in 191 glioma tissues, 8 normal brain tissues and 8 tumor adjacent normal brain tissues was analyzed by tissue microarray and immunohistochemistry. Cul1 expression in human glioblastoma cells was knocked down by specific siRNA to study the effect of down-regulation of Cul1 on proliferation, invasion and migration of glioma cells. Our results showed that Cul1 expression increased significantly in tissues from the benign tumor and malignant tumor in comparison with those from the tumor-adjacent normal brain (P<0.05 for both). We did not find any correlation between Cul1 expression and clinicopathological parameters. In addition, we found that knockdown of Cul1 by RNA interference markedly inhibited cell proliferation and caused cessation of cell cycle. This reduced cell proliferation was due to G1 phase arrest as cyclinA, cyclinD1 and cyclinE were diminished, whereas p21 and p27 were up-regulated. We further demonstrated that silencing of Cul1 in glioma cells inhibited the cell migration and invasion abilities, and down-regulation of MMP-2 and MMP-9 expression greatly contributed to the reduced cell invasion and migration abilities. Our data indicated that Cul1 expression significantly increased in human glioma, and it may be involved in proliferation, migration and invasion of glioma cells.

BRMS1 suppresses glioma progression by regulating invasion, migration and adhesion of glioma cells.

Breast cancer metastasis suppressor 1 (BRMS1) is a metastasis suppressor gene in several solid tumors. However, the expression and function of BRMS1 in glioma have not been reported. In this study, we investigated whether BRMS1 play a role in glioma pathogenesis. Using the tissue microarray technology, we found that BRMS1 expression is significantly decreased in glioma compared with tumor adjacent normal brain tissue (P<0.01, χ(2) test) and reduced BRMS1 staining is associated with WHO stages (P<0.05, χ(2) test). We also found that BRMS1 was significantly downregulated in glioma cell lines compared to normal human astrocytes (P<0.01, χ(2) test). Furthermore, we demonstrated that BRMS1 overexpression inhibited glioma cell invasion by suppressing uPA, NF-κB, MMP-2 expression and MMP-2 enzyme activity. Moreover, our data showed that overexpression of BRMS1 inhibited glioma cell migration and adhesion capacity compared with the control group through the Src-FAK pathway. Taken together, this study suggested that BRMS1 has a role in glioma development and progression by regulating invasion, migration and adhesion activities of cancer cells.

MiR-29c inhibits glioma cell proliferation, migration, invasion and angiogenesis.

Previous studies reported that miR-29c is significantly downregulated in several tumors. However, little is known about the effect and molecular mechanisms of action of miR-29c in human glioma. Using quantitative RT-PCR, we demonstrated that miR-29c was significantly downregulated in glioma cell lines and human primary glioma tissues, compared to normal human astrocytes and matched non-tumor associated tissues (P < 0.05, χ(2) test). Overexpression of miR-29c dramatically reduced the proliferation and caused cessation of cell cycle. The reduced cell proliferation is due to G1 phase arrest as cyclin D1 and cyclin E are diminished whereas p27 and p21 are upregulated. We further demonstrated that miR-29c overexpression suppressed the glioma cell migration and invasion abilities by targeting MMP-2. In addition, we also found that overexpression of miR-29c sharply inhibited angiogenesis, which correlated with down-regulation of VEGF. The data indicate that miR-29c may be a tumor suppressor involved in the progression of glioma.

RUNX3 suppresses migration, invasion and angiogenesis of human renal cell carcinoma.

RUNX3 (runt-related transcription factor-3) is a known tumor suppressor gene which exhibits potent antitumor activity in several carcinomas. However, little is known about the role of RUNX3 in human renal cell carcinoma (RCC). To investigate the clinical relevance of RUNX3 in RCC patients, immunohistochemistry was performed to detect the clinical relevance of RUNX3 in 75 RCC tissues and paired non-cancerous tissues by using tissue microarray (TMA). We also investigated the role of RUNX3 in RCC cell migration, invasion and angiogenesis. The RUNX3 expression was decreased dramatically in human RCC tissue. The RUNX3 expression was significantly correlated with tumor size (P<0.001), depth of invasion (P<0.001), and of TNM stage (P<0.001). Restoration of RUNX3 significantly decreased renal carcinoma cell migration and invasion capacity compared with controls. In addition, we found that overexpression of RUNX3 reduced the proliferation and tube formation of human umbilical vascular endothelial cells (HUVECs). Gelatin zymography and Western blot showed that RUNX3 expression suppressed matrix metalloproteinase-9 (MMP-9) protein level and enzyme activity. Western blot and ELISA showed that RUNX3 restoration inhibited the expression and secretion of vascular endothelial growth factor (VEGF). Taken together, our studies indicate that decreased expression of RUNX3 in human RCC tissue is significantly correlated with RCC progression. Restoration of RUNX3 expression significantly inhibits RCC cells migration, invasion and angiogenesis. These findings provide new insights into the significance of RUNX3 in migration, invasion and angiogenesis of RCC.

BRG1 is a prognostic marker and potential therapeutic target in human breast cancer.

BRG1, a core component of the SWI/SNF chromatin-remodeling complex, has been implicated in cancer development; however, the biological significance of BRG1 in breast cancer remains unknown. We explored the role of BRG1 in human breast cancer pathogenesis. Using tissue microarray and immunohistochemistry, we evaluated BRG1 staining in 437 breast cancer specimens and investigated its role in breast cancer cell proliferation, migration and invasion. Our Kaplan-Meier survival curves showed that high BRG1 expression is inversely correlated with both overall (P = 0.000) and disease-specific (P = 0.000) 5-year patient survival. Furthermore, we found that knockdown of BRG1 by RNA interference markedly inhibits cell proliferation and causes cessation of cell cycle. This reduced cell proliferation is due to G1 phase arrest as cyclin D1 and cyclin E are diminished whereas p27 is upregulated. Moreover, BRG1 depletion induces the expression of TIMP-2 but reduces MMP-2, thereby inhibiting the ability of cells to migrate and to invade. These results highlight the importance of BRG1 in breast cancer pathogenesis and BRG1 may serve as a prognostic marker as well as a potentially selective therapeutic target.

BRG1 expression is increased in human glioma and controls glioma cell proliferation, migration and invasion in vitro.

PURPOSE: The purposes of our study were to elucidate the role of BRG1 in the development of human glioma and to determine the effect of BRG1 on glioma cell growth, migration and invasion. METHODS: Using tissue microarray and immunohistochemistry, we evaluated BRG1 staining in 190 glioma tissues, 8 normal brain tissues and 8 tumor adjacent normal brain tissues. We studied glioma cell proliferative ability with reduced BRG1 expression by siRNA using CCK-8 cell proliferation assay and cell cycle analysis. We studied the role of BRG1 in glioma cell migration and invasion by cell migration assay and matrigel invasion assay. We performed western blot to detect cyclin D1, cyclin B1 and MMP-2 protein expression. We also detected MMP-2 enzyme activity by gelatin zymography. RESULTS: Our results showed that BRG1 expression was increased in benign tumor and malignant tumor compared with tumor adjacent normal brain tissue (P < 0.01 for both). We did not find any correlation between BRG1 expression and clinicopathological parameters. In addition, we found that knockdown of BRG1 in glioma cell lines inhibits cell growth due to the G1 phase arrest by downregulating cyclin D1. We further demonstrated that silencing of BRG1 in glioma cells inhibited the cell migration and invasion abilities, and downregulation of MMP-2 expression greatly contributed to the reduced cell invasion and migration abilities. CONCLUSIONS: Our data indicated that BRG1 expression is significantly increased in human glioma and it may be involved in the process of glioma cell proliferation, migration and invasion.

RUNX3 expression is lost in glioma and its restoration causes drastic suppression of tumor invasion and migration.

PURPOSE: The aim of this study is to investigate whether the expression of RUNX3 is related to the development of glioma, and the role of RUNX3 in glioma cells growth, invasion and migration. METHODS: We analyzed the protein expression of RUNX3 by immunohistochemistry in 188 glioma tissues, 8 normal brain tissues and 8 tumor adjacent normal brain tissues using tissue microarray technique. We studied whether RUNX3 restoration can suppress glioma cells growth, invasion and migration by performing MTT cell proliferation assay, matrigel cell invasion assay, wound-healing assay and migration assay. We also detected MMP-2 protein expression and enzyme activity by western blot analysis and gelatin zymography. RESULTS: We found that RUNX3 expression was decreased in benign tumor and malignant tumor compared with tumor adjacent normal brain tissue (P < 0.01 and P < 0.05, respectively). We did not find any correlation between RUNX3 expression and clinicopathological parameters. In addition, we demonstrated that re-expression of RUNX3 in glioma cells resulted in significantly inhibited cell invasion and migration abilities. This reduced cell invasion and migration abilities were due to MMP-2 protein expression and enzyme activity suppression after RUNX3 restoration. CONCLUSIONS: Our data indicated that RUNX3 expression is significantly decreased in human glioma, and targeting of the RUNX3 pathway may constitute a potential treatment modality for glioma.