Effects of pseudogene POU5F1B on proliferation, invasion and migration of cervical cancer cell line SiHa

YU Jingwen; ZHU Ping; ZHOU Liulin.

doi:10.3969/j.issn.1009-0460.2019.07.001

Abstract：Objective To explore the expression level of POU domain class 5 transcription factor 1B genes ( POU5F1B) in cervical cancer cells, and its effect on the proliferation, migration and invasion of cervical cancer cells lines and the possible mechanism. Methods The relative expression of POU5F1B in SiHa,HeLa and C33A cervical cancer cell lines, and normal cer?vical epithelial cells ( End1／e6e7 ) was detected by QPCR. The specific small interfering RNA for POU5F1B ( si?POU5F1B group) or negative control sequences ( si?NC group) were transfected into the cell lines with highest expression of POU5F1B. The CCK?8 assay, clone formation experiment and EdU assay were respectively employed to detect cell proliferation of the two groups. Cell scratch assay were employed to detect cell migration of the two groups. Matrigel invasion assay was used to observe cell inva?sion of the two groups. Western blotting analysis was performed to detect the effect of down?regulated pseudogene POU5F1B on the expression of functional gene OCT4 protein. The effect of down?regulated pseudogene POU5F1B on the xenograft weight in nude mice was observed by animal experiments. Results In comparison with End1／e6e7 cells, the relative expression of POU5F1B in SiHa, C33A and HeLa cell lines was 3. 34±0. 23, 2. 03±0. 15 and 1. 13±0. 06. SiHa cell line was chosen for the following experiments. The relative expression of POU5F1B in si?POU5F1B group was 0. 2 ± 0. 012, lower than that in si?NC group( P＜0. 01). CCK?8 assay showed that the absorption value was lower in si?POU5F1B group compared with si?NC group ( P＜0. 05). EdU experiment showed that compared with si?NC group, the ratio of positive cells in si?POU5F1B group was(18± 1. 36)%, lower than (34±2. 63)% of si?NC group ( P＜0. 01). The colony formation experiment showed that the number of col?onies in si?POU5F1B group was 173±15. 27, lower than 318±8. 41 in si?NC group (P＜0. 01). Cell scratch experiment showed that the healing rate of si?POU5F1B group after 48 h was ( 45. 60±2. 27)%, lower than (87. 15±3. 32)% of si?NC group ( P＜0. 01). Matrigel invasion assay showed that the number of cells in the invasion chamber of si?POU5F1B group was 303±10. 29, lower than 933±11. 88 in si?NC group (P＜0. 01). Western blotting analysis showed that the expression level of OCT4 decreased after the down?regulation of POU5F1B ( P＜0. 05 ). In animal experiments, the xenograft weight of si?POU5F1B group was (203. 50±54. 83) mg, lower than (578. 06±84. 66) mg of si?NC group ( P＜0. 01). Conclusion The down?regulated pseud?ogene POU5F1B can inhibit the proliferation, migration and invasion of cervical cancer cells and inhibit the growth of cervical cancer cells, which may be related to the down?regulation of its functional gene OCT4.