MiR-138 targeting human telomerase reverse transcriptase enhanced the sensitization of colon cancer cell SW480 to 5-fluorouracil

Abstract

Objective To observe the effect of miR-138 on the expression of human telomerase reverse transcriptase (hTERT) in human colon cancer cell SW480 and to evaluate influence of miR-138 mimic on the sensitization of SW480 to 5-fluorouracil (5-Fu).Methods Flow cytometry was used to detect the expression of hTERT in SW48 cells transfected with 50 and 10 nmol/L miR-138 mimic.Both SW480 cells transfected and un-transfected with 50 nmol/L miR-138 mimic were stained by FITC-labeled Ki-67 antibody and assayed by using flow cytometry.The apoptosis of both SW480 cells transfected and untransfected with 50 nmol/L miR-138 mimic was tested by using PI single dye method and Annexin Ⅴ-PI apoptosis assay.Results miR-138 mimic at 50 and 10 nmol/L down-regulated the expression of hTERT at (30.25 ± 1.34)％ and (60.03 ±2.78)％ respectively,and the expression rate of hTERT in the control group was (87.50 ± 1.63)％.In SW480 cells transfected or un-transfected with 50 nmol/L of miR-138 mimic,the Ki-67 positive rate was (58.18 ± 2.90)％ was (83.45 ± 2.41)％,sub-G0 rate was (27.33 ±1.70)％ and (1.05 ±0.19)％,and apoptosis rate was (29.50 ±2.27)％ and (5.30 ±1.74)％,respectively.In miR-138 mimic-transfected group,5-Fu-treated group,and combined treatment group,proliferation rate was (61.00 ± 1.73)％,(57.00 ±2.03)％ and (23.00 ± 1.24)％,sub-G0 rate was (28.12±1.47)％,(34.87 ±2.01)％ and (70.94 ±3.04)％,and apoptosis rate was (32.15 ±2.76) ％,(40.07 ± 2.58) ％ and (80.84 ± 3.06) ％ in SW480 cells,respectively.All differences were statistically significant (P ＜ 0.05).Conclusion miR-138 mimic inhibited the expression of hTERT in SW480 cells,and enhanced sensitization of SW480 cells to 5-Fu. Key words: Colon carcinoma; Telomerase; 5-fluorouracil; miR-138