Effect of Notch1 gene overexpression on proliferation and cell cycle of human prostate cancer cell line PC-3

Abstract

Objective To study the effect of Notchl gene overexpression on proliferation and cell cycle of human prostate cancer cell line PC-3. Methods Notchl-ORF plasmid and its blank vector were transfected into PC-3 cells respectively. The expression of Notehl or Ki-67 was detected by real-time quantitative polymerase chain reaction （Real-time PCR） and Western blotting. The cell proliferation and cell cycle were analyzed by 3-（4,5-Dimethyhhiazol-2-yl）-5-（3-carboxymethoxyphenyl）-2-（4-sulfophenyl）-2H-tetrazolium （MTS） assay （20 μl/well） and flow cytometry respectively. Results Compared to negative control （3. 574 ± 0. 368 ） and untransfected group （ 3. 306 ± 0. 278）, Notehl expression in NotcH-ORF group （ 43. 740 ± 6. 438 ） was significantly increased （ P 〈 0. 01 ）. Meanwhile, proliferating cell nuclear antigen （Ki-67） level was decreased： 0. 576 ±0. 063, 1. 012 ±0. 011, and 1. 000 ±0. 007 in Notehl-ORF group, negative control group and untransfected group, respectively （P 〈0. 01 ）. MTS assay revealed that the absorbance value in Notchl-ORF group was significantly reduced at 24, 48 and 72 h （P 〈0. 01 ）. Flow cytometry analysis showed that the proportion of cells in G0/G1 phase in Notchl-ORF group was （64. 013 ± 1. 952） %, significantly higher than in negative control group [ （48. 917 ± 2. 771 ） % ] and blank control group [（51.317±1.907）%] （P〈0.01）. Conclusion Overexpression of Notchl gene in PC-3 cells promoted arrest of G0/G1 phase and suppressed cell proliferation probably by down-regulating Ki-67. Key words: Prostate cancer; Notchl gene; Proliferation; Cell cycle