ABSTRACT
Objective To investigate the expression of BRAF-activated long non-coding RNA (BANCR) in colorectal cancer,and the influence of BANCR on the biological function of HCT116 cells.Methods Fifty-six samples of colorectal cancer specimen (including the cancer tissues and precancerous tissues) were obtained at the First Affiliated Hospital of Nanjing Medical University from March 2012 to June 2013.The expressions of BANCR in all the specimens were detected by qRT-PCR (28 cases in the BANCR-high expression group and 28 cases in the BANCR-low expression group).The relationship between the expressions of BANCR and the clinicopathological factors of colorectal cancer was analyzed.The HCT116 cells were divided into 4 groups after interfering BANCR with lentiviral-mediated shRNA-1 and shRNA-2:interference group 1 (HCT116 cells transfected with LV-shRNA-1),interference group 2 (HCT116 cells transfected with LV-shRNA-2),negative control group (HCT116 cells transfected with lentivirus vector with nonsense sequence) and blank control group (HCT116 cells cultured in RPMI 1640 medium).The proliferation,apoptosis and migration of HCT116 cells in the 4 groups were detected by CCK-8 assay,flow cytometry and Transwell assay,respectively.The comparison between the 2 groups was analyzed by u test,and multiple groups were compared by one-way analysis of variance,repeated measurement analysis of variance and LSD-t test.Multivariate analysis was done by Logistic regression model.The difference between categorical data was compared by chi-square test.Results The relative expression of BANCR in the cancer tissues was 1.6 ± 0.4,which was significantly higher than 0.9 ± 0.7 of the precancerous tissues (u =1 020.000,P ＜ 0.05).The result of univariate analysis showed that the high expression of BANCR was correlated with the lymph node metastasis and tumor stage (x2 =4.595,7.487,P ＜ 0.05).The result of multivariate analysis showed that lymph node metastasis and tumor stage (stage Ⅲ-Ⅳ) were the independent risk factors influencing the high expression of BANCR(OR =4.000,5.914,95％ CI:1.230-12.900,1.685-20.760,P ＜ 0.05).The relative expressions of BANCR of the interference group 1,interference group 2,negative control group and the blank control group were 0.25 ±0.04,0.20±0.06,0.96 ±0.04,0.98 ±0.03,with significant difference among the 4 groups (F =271.610,P ＜ 0.05).The cell proliferation rates at day 6 of the interference group 1,interference group 2 and the negative control group were 80.6％ ± 7.6％,81.2％ ± 5.1％ and 87.9％ ± 13.6％,with no significant difference among the 3 groups (F =0.559,P ＞ 0.05).The apoptotic rates of the interference group 1,interference group 2,negative control group and the blank control group were 4.7％ ± 1.7％,5.1％ ± 1.1％,3.1％ ± 0.6％ and 2.8％ ± 0.9％,with no significant difference among the 4 groups (F =2.881,P ＞ 0.05).The numbers of transmembrane cells of the interference group 1,interference group 2,negative control group and the blank control group were 135 ± 29,107 ± 18,240 ± 24 and 245 ± 22,with significant difference among the 4 groups (F =45.194,P ＜ 0.05).Conclusions BANCR was overexpressed in the HCT116 cells,and the BANCR overexpression was correlated with lymph node metastasis and tumor stage.BANCR can promote the migration of HCT116 cells.BANCR could be an important biomarker for the diagnosis and prognosis of colorectal cancer.