The effect of eleven-nineteen lysine-rich leukemia gene 2 on proliferation of prostate cancer cell C4-2

Abstract

Objective To observe the level of eleven-nineteen lysine-rich leukemia gene 2 (ELL2) in human prostate cancer tissues and its effect on proliferation of prostate cancer cell C4-2. Methods The expression of ELL2 in human prostate cancer tissues was analyzed by immunohistochemical method, and the relationship between ELL2 and malignancy degree of prostate cancer was evaluated. The human prostate cancer cell line C4-2 was stimulated with synthetic androgen R1881 to detect its response to androgen at different time points. ELL2-small interfering RNA (siRNA) and overexpression of ELL2-bearing plasmid were transfected into C4-2 cells respectively, then cell proliferation was evaluated by methyl thiazol tetrazolium (MTT) assay. The DNA synthesis ability of cells was assessed by 5-Bromo-2’-deoxy-uridine (BrdU) incorporation assay. Results The expression of ELL2 was significantly lower in human prostate cancer than that of benign specimen, and decreased with the increase of malignancy of prostate cancer. The correlation analysis between ELL2 and prostate cancer Gleason score reveal a negative correlation result (r=0.836, P=0.000). The protein expression of ELL2 was significantly increased in 48 h and increased by (38.27±10.11)% (t=7.573, P=0.005) and (58.34±13.70)% (t=8.519, P=0.003) at 24 h and 48 h, respectively. The expression of ELL2 protein in the two RNA interference groups were significantly decreased, and the decreased rate were (56.38±11.26)% (t=10.010, P=0.002) and (65.27±12.10)% (t=10.790, P=0.002), respectively. While the ELL2 protein expression in the overexpression group was significantly increased at (80.23±20.94)% (t=7.662, P=0.005). The proliferation ability of C4-2 cells was significantly increased (39.28±8.52)% (t=11.300, P=0.000) and (48.2±7.87)% (t=15.000, P=0.000) in the two RNA interference groups, respectively, compared with the control group. While its proliferation ability decreased (42.74±10.38)% (t=10.090, P=0.000) in ELL2-bearing plasmid. Transfection of ELL2-specific interfering RNA increased the ability of DNA synthesis, while the transfection of ELL2-bearing plasmid cells had lower DNA synthesis ability. Conclusion ELL2 is lowly expressed in human prostate cancer tissues and negatively correlated with the malignant degree. ELL2 can inhibit the proliferation of prostate cancer cells to a certain extent. Key words: Prostate cancer; Eleven-nineteen lysine-rich leukemia gene 2; Proliferation