Objective To investigate the effects of orlistat on the viability of human gall-bladder cancer (GBC) cells.

Methods The experimental study was conducted. The human GBC NOZ cells with high expression of FSAN was screened out through in vitro cultivating human GBC-SD, SGC-996 and NOZ cells. The cell proliferation assay, clone formation assay and protein detection experiment were used to analysis of the effects of orlistat on the viability of human GBC cells. Cell grouping: NOZ cells cultured with medium were set as the control group, cultured with medium + 10 μmol/L orlistat were set as the low-dose orlistat group, cultured with medium + 100 μmol/L orlistat were set as the high-dose orlistat group, respectively. Observation indicators: (1) expression of FASN protein in human GBC cells; (2) effects of orlistat on the proliferation of human GBC NOZ cells; (3) effects of orlistat on apoptosis of human GBC NOZ cells. Measurement data with normal distribution were represented as Mean±SD, the ANOVA test was used for comparison between groups and the least significant difference method was used for pairwise comparison.

Results (1) Expression of FASN protein in human GBC cells. Results of western blot showed that the relative expression of FASN protein in human GBC NOZ, GBC-SD and SGC-996 cells was 0.57±0.06, 0.12±0.04 and 0.10±0.02, respectively, showing a significant difference among them (F=115.67, P<0.05). There were significant differences between the NOZ cells and the GBC-SD or the SGC-996 cells (P<0.05), and there was no significant difference between the GBC-SD cells and the SGC-996 cells (P>0.05). (2) Effects of orlistat on the proliferation of human GBC NOZ cells. ① Results of cell proliferation assay showed that the absorbance value of NOZ cells was 2.34±0.12, 1.57±0.08 and 1.07±0.13 in the control group, low-dose orlistat group and high-dose orlistat group, respectively, showing a significant difference among them (F=205.88, P<0.05). ② Results of clone formation assay showed that the number of NOZ cells clones was 257±23, 153±11 and 83±11 in the control group, low-dose orlistat group and high-dose orlistat group, respectively, showing a significant difference among them (F=92.64, P<0.05). ③Results of western blot showed that the relative expression of Cyclin-D1 protein of NOZ cells was 2.31±0.10, 1.52±0.05 and 1.23±0.11 in the control group, low-dose orlistat group and high-dose orlistat group, respectively, showing a significant difference among them (F=120.73, P<0.05). The relative expression of CDK-4 protein of NOZ cells was 1.58±0.04, 1.21±0.02 and 1.19±0.04 in the control group, low-dose orlistat group and high-dose orlistat group, respectively, showing a signifi-cant difference among them (F=110.45, P<0.05). (3) Effects of orlistat on apoptosis of human GBC NOZ cells. Results of western blot showed that the relative expression of Bcl-2 protein of NOZ cells was 1.07±0.03, 0.36±0.03 and 0.15±0.02 in the control group, low-dose orlistat group and high-dose orlistat group, respectively, showing a significant difference among them (F=1 242.93, P<0.05). The relative expression of Bax protein of NOZ cells was 0.51±0.03, 0.38±0.05 and 1.38±0.04 in the control group, low-dose orlistat group and high-dose orlistat group, respectively, showing a signifi-cant difference among them (F=583.51, P<0.05).

Conclusion Orlistat can inhibit the growth of human GBC NOZ cells and promote their apoptosis.