Long Non-Coding RNA HULC Enhances Tumor Growth in Orthotopic Xenograft Model of Glioblastoma / 中山大学学报(医学科学版)

ABSTRACT

@#【Objective】To investigate the mechanism of action of long non-coding RNA highly up-regulated in liver cancer（LncRNA HULC）on the growth of glioblastoma U87 cells in vitro and in vivo.【Methods】The cultured glioblastoma U87 cells were divided into four groups：overexpression group（HULC-over）and its vector control group（VEC），silent expression group（HULC- siRNA）and its negative control group（NC）.Quantitative real- time polymerase chain reaction PCR（qRT-PCR）was used to verify the expression levels of HULC. CCK8 proliferation assay and colony formation assay were adopted to monitor the proliferation of glioblastoma U87 cells. Flow cytometry was utilized to detect the apoptosis of glioblastoma U87 cells. By injecting U87 cells，we divided the orthotopic xenograft mouse model into HULC- over group（n=10），VEC group（n=10），HULC-siRNA group（n=10）and NC group（n=10）accordingly. The survival of the mice in each group was observed. The expression of Ki67 was analyzed by immunohistochemistry. 【Results】 The expression level of HULC was significantly higher in HULC-over group than that in VEC group and significantly lower in HULC-siR NA group than that in NC group（P < 0.01）. The cell proliferation ability was significantly increased in HULC-over group compared with that in VEC group and significantly decreased in HULC- siRNA group compared with that in NC group（P < 0.01 on days2，3and4）. The colony formation rates in VEC group，HULC-over group，NC group and HULC-siRNA group were，respectively，（34.47 ± 1.56）% ，（95.4 ± 2.74）% ，（23.83 ± 0.92）% and （10.23 ± 0.61）% ，which revealed that overexpression of HULC elevated the colony formation rate and silencing expression of HULC reduced the colony formation rate（P < 0.01）. The early apoptosis rates in VEC group，HULC- over group，NC group and HULC- siRNA group were，respectively，（3.55±0.56）% ，（0.09±0.01）% ，（2.89±0.67）% ，and（7.13±0.14）% ，which showed that overexpression of HULC elevated the early apoptosis rate and silencing expression of HULC reduced the early apoptosis rate （P <0.01）. The survival curve of nude mouse indicated shorter survival time in HULC-over group than that in VEC group and longer survival time in HULC-siRNA group than that in NC group（P < 0.05）. Ki67 protein expression was up-regulated in the HULC-over group compared with that in VEC group and down-regulated in the HULC-siRNA group compared with that in NC group（P < 0.05）.【Conclusion】LncRNA HULC can enhance the growth of glioblastoma U87 cells in vitro and in vivo.