Experimental study of YKL-40 regulating cisplatin resistance in endometrial cancer

CHENG Chunlai; DING Wen; CHE Yuan

doi:10.3969/j.issn.1009-0460.2019.02.004

Abstract：Objective To investigate the effect of silenced chitinase 40 (YKL-40) expression on cisplatin-resistant endometrial cancer cell line Ishikawa/DDP. Methods Ishikawa/DDP drug-resistant cell lines were established by DDP long-term concentration gradient method in vitro, and the expression of MDR1, Bcl-2, Bax and caspase-3 were detected. The proliferation activity of Ishikawa cells and Ishikawa/DDP cells was detected by MTT method, and the half inhibitory concentration (IC50) was calculated. Ishikawa/DDP was transfected with NC negative sequence (NC group) and siRNA YKL-40 (si-YKL-40 group), respectively. The untransfected cells were set as blank control group. The effects of DDP on proliferation, migration and apoptosis of Ishikawa/DDP cells in siYKL-40 group were detected by MTT, scratch test and Annexin V/PE double staining. Results Ishikawa/DDP resistant cell lines were successfully established in vitro. The inhibitory rates of 3. 125, 6. 25, 12. 5, 25, 50 and 100 μmol/L DDP on proliferation of Ishikawa/DDP cells were (6. 93 ± 2. 45) ％, (8. 14 ± 4. 50) ％, (11. 37 ± 4. 62) ％, (15. 18 ± 3. 97) ％, (26. 29 ± 5. 08) ％, (41. 32 ±7. 64) ％, which were significantly lower than those of Ishikawa cells (P＜0. 05). The IC50 were 14. 58 μmol/L and 116. 70 μmol/L, respectively. The resistance index of Ishikawa/DDP was 8. 004. The expression of YKL-40, MDR1 and Bcl-2 in Ishikawa/DDP cells were 1. 87±0. 40, 2. 34±0. 46 and 1. 52±0. 28, which were higher than those in Ishikawa cells (P＜0. 05). The expression of Bax and caspase-3 in Ishikawa/DDP cells were 0. 72±0. 21 and 0. 49±0. 17, which were lower than those in Ishikawa cells (P＜0. 05). The inhibitory rates of 3. 125, 6. 25, 12. 5, 25, 50 and 100 μmol/L DDP on the proliferation of si-YKL-40 cells were (10. 95± 2. 74) ％, (18. 73± 5. 30) ％, (32. 79 ± 5. 47) ％, (52. 28 ± 6. 58) ％, (61. 73 ± 5. 26) ％, (65. 45 ± 7. 33) ％, respectively, which were significantly higher than those of blank control group and NC group (P＜0. 05). The IC50 of DDP on si-YKL-40 cells was 22. 19 μmol/L. Compared with the blank control group and NC group, the apoptotic rate increased and the healing rate decreased in the si-YKL-40 group, while the expression of YKL-40, MDR1 and Bcl-2 decreased, while the expression of Bax and caspase-3 increased (P＜0. 05).Conclusion Silencing YKL-40 can significantly increase the sensitivity of Ishikawa/DDP cell lines to cisplatin and promote cell apoptosis, which may be related to down-regulation of MDR1, Bcl-2 expression and up-regulation of Bax and caspase-3 expression.