Effects of LncRNA HULC on radiosensitivity of osteosarcoma cells / 中华放射医学与防护杂志

ABSTRACT

Objective To investigate the effect of LncRNA HULC on radiosensitivity of osteosarcoma cells. Methods Osteosarcoma cells OS732 was infected by shRNA HULC lentivirus, and the interference effect was determined by qRT-PCR. Osteosarcoma cells infected with shRNA HULC lentivirus were irradiated with 8 Gy X-rays. MTT, PI monochrome staining and Annexin V-FITC/PI double staining were used to detect cell proliferation, cell cycle and apoptosis, respectively. Western blot was used to detect the protein levels of p21, Cyclin D1, C-Caspase-3 and Cyt-C in cytoplasm and mitochondria. Plate cloning assay was used to evaluate cell radiosensitivity. Results The expression of HULC in osteosarcoma cells was significantly down-regulated by shRNA HULC lentivirus infection. Down-regulation of HULC or irradiation inhibited osteosarcoma cell proliferation [(100. 00±9. 65)％ vs. (71. 36±5. 27)％, (63. 48± 5. 93)％, t=4. 512, 5. 585, P<0. 05 ] , blocked cell cycle [ ( 50. 15 ± 5. 14 )％ vs. ( 62. 35 ± 4. 22 )％, (66. 05±5. 23)％,t=3. 177,3. 756,P<0. 05], induced cell apoptosis [(2. 98±0. 23)％ vs. (22. 61± 3. 26)％, (26. 14±2. 81)％,t=8. 898,10. 498,P<0. 05], promoted the expressions of p21 and Cyclin D1 in cells, down-regulated the level of C-Caspase-3 protein, increased the level of Cyt-C protein in cytoplasm, and down-regulated the level of Cyt-C protein in mitochondria. Downregulation of HULC combined with irradiation yield much more effects on cell proliferation inhibition [ ( 71. 36 ± 5. 27 )％, (63.48±5.93)％ vs. (49.32±5.76)％, t=4.890, 2.967, P<0.05], cell cycle arrest [(62.35± 4. 22)％, (66. 05±5. 23)％ vs. (77. 17±7. 54)％, t=2. 983, 2. 106, P<0. 05], apoptosis induction [(22. 61±3. 26)％, (26. 14±2. 81)％ vs. (36. 21±3. 26) ％,t=6. 164, 4. 564, P<0. 05] and the expressions of p21, Cyclin D1, C-Caspase-3 and Cyt-C in osteosarcoma cells. The radiosensitization ratio of down-regulation of HULC was 1. 432. Conclusions Down-regulation of HULC enhances radiosensitivity of osteosarcoma cells, which may be related to cell cycle arrest and apoptosis induction.