ABSTRACT
ObjectiveTo investigate the inhibitory effects and mechanism of the compound Phyllanthus urinaria Ⅱ （CPU Ⅱ）on the growth of transplanted hepatocellular carcinoma Hep3B2.1-7 （Short for Hep3R） cells in nude mice. MethodAfter the establishment of a xenograft model of hepatocellular carcinoma Hep3B cells in mice， the model mice were randomly divided into a model group， a high-dose CPU Ⅱ group （57.5 g·kg-1）， a low-dose CPU Ⅱ group （28.75 g·kg-1）， and a 5-fluorouracil （5-FU） group （0.025 g·kg-1）， with eight mice in each group. The mice in the high- and low-dose CPU Ⅱ groups were treated with drugs by gavage， once per day， and those in the model group were treated with the same volume of normal saline. The mice in the 5-FU group were treated by 5-FU by intraperitoneal injection， once every other day. After 28 days of administration， mice were sacrificed， and transplanted tumors were collected. Immunohistochemistry （IHC） was used to detect the expression of proliferating cell nuclear antigen （PCNA） of tumor tissues. Terminal-deoxynucleotidyl transferase-mediated nick end labeling （TUNEL） was used to detect cell apoptosis of tumor tissues. The mRNA expression of miR-122 and insulin-like growth factor 1 receptor （IGF-1R） in tumor tissues was detected by Real-time quantitative PCR （Real-time PCR）. The protein expression of CCAAT/enhancer-binding protein α （C/EBPα）， hepatocyte nuclear factor-4α （HNF-4α）， and IGF-1R in tumor tissues was detected by Western blot. ResultThe tumor suppression rates of the high- and low-dose CPU Ⅱ groups and the 5-FU group were 74.90%， 63.62%， and 64.15%， respectively. Compared with the model group， the CPU Ⅱ groups and the 5-FU group showed reduced weight （P<0.01） and volume of tumors （P<0.01）， decreased PCNA positive cells， shallow staining， increased apoptosis cells of transplanted tumor tissues （P<0.05， P<0.01）， increased expression of mRNA expression of miR-122 （P<0.01）， down-regulated mRNA expression of IGF-1R （P<0.01）， and up-regulated protein expression of C/EBPα and HNF-4α in nude mouse transplanted tumor tissues （P<0.01）. The expression of IGF-1R protein in the high-dose CPU Ⅱ group was down-regulated （P<0.05）. Compared with the low-dose CPU Ⅱ group， the high-dose CPU Ⅱ group showed increased apoptotic cells （P<0.01）， up-regulated mRNA expression of miR-122 （P<0.01）， and increased expression of C/EBPα and HNF-4α proteins （P<0.01）. ConclusionCPU Ⅱ has an obvious inhibitory effect on the growth of transplanted hepatocellular carcinoma Hep3B cells in nude mice. The mechanism of action is related to enhancing the expression of transcription factors HNF-4α and C/EBPα， thereby promoting the expression of miR-122 and inhibiting the expression of its target gene IGF-1R.