Tropical Journal of Pharmaceutical Research

Original Research Article | OPEN ACCESS

Bryostatin inhibits proliferation of ependymoma cells by suppressing expressions of cyclooxygenase-2 and interleukin-8

Weiyuan Xu¹, Chengren Xie² , Yuchen Feng³

¹Department of Orthopedics, Lanzhou University Second Hospital, Lanzhou 730030; ²Department of Neurosurgery, Wuwei People's Hospital, Wuwei 733000; ³Second Clinical Medical College, Lanzhou University, Lanzhou 730030, China.

For correspondence:- Chengren Xie Email: Clementinavacri@yahoo.com Tel:+869355820285

Accepted: 16 January 2019 Published: 28 February 2019

Citation: Xu W, Xie C, Feng Y. Bryostatin inhibits proliferation of ependymoma cells by suppressing expressions of cyclooxygenase-2 and interleukin-8. Trop J Pharm Res 2019; 18(2):251-256 doi: 10.4314/tjpr.v18i2.5

© 2019 The authors.
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Abstract

Purpose: To investigate the effect of bryostatin on the proliferation of ependymoma cells, and the underlying mechanism(s).

Methods: Ependymoma cell lines (SC-EPN1 and SC-EPN2) were cultured in Dulbecco's modified Eagle's medium (DMEM) supplemented with 10 % fetal bovine serum (FBS) and streptomycin (10 mg/ml) in a humidified incubator at 37 °C and 5 % CO₂ atmosphere. Rhe cells were randomly assigned to six groups: control group and five bryostatin groups treated with increasing concentrations of bryostatin (10 - 50 µM). Cell proliferation was determined by MTT assay, while real-time quantitative polymerase chain reaction (qRT-PCR) was used to determine the levels of expressions of apoptosis-related genes. expressions of cyclooxygenase-2 (COX-2), interleukin-8 (IL-8), Bcl-2, Bax and P-glycoprotein were determined using Western blotting.

Results: Treatment with bryostatin significantly and concentration-dependently down-regulated COX-2 and IL-8 mRNAs expressions (p < 0.05). On the other hand, proliferation of SC-EPN1 and SC-EPN2 cells were significantly and concentration-dependently inhibited by bryostatin, relative to control group (p < 0.05). After 72 h of treatment with bryostatin (50 µM), the extent of apoptosis was significantly higher in SC-EPN1 (57.43 %) and SC-EPN2 cells (52.29 %) than in control group (2.37 %, p < 0.05). The results of Western blotting showed that treatment with bryostatin significantly reduced the expressions of Bcl-2 in ependymoma cells, relative to the control group (p < 0.05). However, there were no significant differences in the expression of Bax among the groups (p > 0.05). P-glycoprotein expression was significantly higher in bryostatin groups than in control group (p < 0.05). The results of flow cytometric analysis of rhodamine-123 (rh123) fluorescence showed that after 72 h of treatment with bryostatin (50 µM), rhl23 fluorescence significantly decreased in SC-EPN1 (8.10 %) and SC-EPN2 cells (10.11 %), relative to control group (20.83 %, p < 0.05).

Conclusion: Bryostatin exerts anti-proliferative and apoptotic effects on ependymoma cells by suppressing COX-2 and IL-8 expressions. Thus, the inhibition of COX-2 expression may constitute an effective chemotherapeutic strategy for ependymoma treatment.

Keywords: Bryostatin, Ependymoma cells, Proliferation, Apoptosis, expression