Overexpression of phosphatidylethanolamine-binding protein 4 (PEBP4) associates with recurrence of meningiomas.

BACKGROUND AND PURPOSE: Abnormal expression of phosphatidylethanolamine-binding protein 4 (PEBP4) has been identified in various types of malignant tumors. In the present study, we investigated the expression of PEBP4 in meningioma cases and examined whether PEBP4 expression was correlated with outcomes among these patients. MATERIALS AND METHODS: The expression levels of PEBP4 and Ki-67 in human meningioma tissues from 65 patients were evaluated by immunohistochemical staining. The correlation between PEBP4 immunoreactivity in meningioma samples and patients' clinical outcomes was examined using the Kruskal-Wallis correlation test. The prognostic value of PEBP4 expression in meningiomas patients also was investigated. RESULTS: Immunohistochemical analysis revealed up-regulated PEBP4 expression in both atypical and anaplastic meningiomas compared with classical meningiomas (13.38 ± 4.19% vs. 3.64 ± 2.04%, P < 0.001). PEBP4 immunoreactivity in meningioma samples was closely correlated with that for Ki-67 (Spearman r = 0.7922, P < 0.0001). PEBP4 expression was also associated with tumor differentiation grade and clinical recurrence (P < 0.05). Multivariate regression analysis showed with high PEBP4 expression was associated with a longer recurrence-free survival (hazard ratio=0.252, 95% confidence interval: 0.067-0.940, P = 0.040). CONCLUSION: PEBP4 may play an important role in the progression of meningioma, as high PEBP4 expression was associated with a higher pathological grade of meningioma. Moreover, PEBP4 expression may be a meaningful prognostic biomarker in meningioma.

[Induced RAS association domain family gene 1A gene expression by arsenic trioxide in nasopharyngeal carcinoma cell].

OBJECTIVE: To investigate the effect of arsenic trioxide (As2O3) on expression of anti-oncogene RAS association domain family gene 1A(RASSF1A) in nasopharyngeal carcinoma cell line CNE-2Z. METHODS: CNE-2Z cells were treated with various concentrations of As2O3 for different times. The IC(50) values were detected by trypan blue stain assay. Cell cycle redistribution was analyzed by flow cytometry. The final concentration 2 micromol/L, 1 micromol/L, 0.5 micromol/L of As2O3 was added to CNE-2Z cell for succedent experiments. The controls and no drugs of CNE-2Z cells were cultivated for 48 h. Methylation specific PCR was used to detect the change of methylation status of RASSF1A gene. The expression of RASSF1A gene was detected by reverse transcription PCR and Western blot at mRNA and protein level. RESULTS: The suppression of cell proliferation by As2O3 was time and dose-dependent. After being treated with As2O3, the IC(50) values of As2O3 were (1.50 +/- 0.05), (1.09 +/- 0.13), (0.65 +/- 0.04) micromol/L at 24, 48, and 72 h, respectively. As2O3 also arrested CNE-2Z cells in G2/M phase of cell cycle. After the effect of As2O3, the methylation of RASSF1A gene became weaker by increasing the concentration of As2O3; and the expression of RASSF1A gene became stronger at mRNA and protein level. Between different concentration of As2O3 group and no drugs group, the differences had statistical significance (P < 0.05). Along with increasing the concentration of As2O3, the expression of RASSF1A gene became stronger at mRNA and protein level, the methylation of RASSF1A gene became weaker and weaker. CONCLUSIONS: As2O3 can activate the expression of RASSF1A gene to inhibit the cell cycle progress of nasopharyngeal carcinoma cell line.