β-elemene Inhibits The Growth Of Hepatocellular Carcinoma H22Cell Line Via Suppressing Stress-inducible Protein1Expression

Objective: To study the functional expression of STIP1in H22cells exposing toβ-elemene and its association with β-elemene and antitumor effect.Methods: Analysis of STIP1expression by RNA extraction and reversetranscriptase polymerase chain reaction (RT-PCR), western blotting andimmunofluorescence. Next, the expression of STIP1at different time points (0,4,24,48and72h) after exposing H22cells to β-elemene in vitro was detected in H22cells,which was analyzed using RT-PCR, western blotting and immunofluorescence. Thenthe expression levels of STIP1in various drug concentration groups and correspondingcontrol groups in vivo were detected in H22cells, which was analyzed using RT-PCR,western blotting and immunohistochemistry. HCC Xenograft Transplantation Modelwas constructed. BALB/c female mice were prepared. Each mouse was injected viaarmpit vein with4×10~7suspension of mice ascites, and the treatments were started after24hours. Mice were individually identified and randomly assigned to the control andtreated groups (N=4, n=7), according to the following regimens:1, Elemene-highergroup (100mg/Kg);2, Elemene-lower group (50mg/Kg);3,5-Fu group (20mg/Kg);4,physiological saline0.2ml each mouse.Results: RT-PCR, Western blotting analysis and Immunofluorescence assaydemonstrated that STIP1is expressed in hepatocellular carcinoma H22cell line, notonly in the cytoplasm and membrane, but also in cell nucleus. We measured theexpression level of STIP1was significantly decreased in H22cells in vitro, whichrevealed β-elemene inhibited expression of STIP1in a time-dependent way in H22cells.We also found that in vivo lower expressions of STIP1were observed in β-elemeneGroups, compared with the orthodox chemotherapeutic drug5-FU and physiological saline control. β-elemene blocks tumor growth in a Hepatocellular CarcinomaXenograft Transplantation Model. It was shown that β-elemene can suppress theexpression of STIP1.Conclusion: Base on our study, it is indicated that β-elemene inhibits the growthof hepatocellular carcinoma H22cell line via suppressing STIP1expression. It providesus a new mechanism of β-elemene on antitumor effect, suggesting STIP1has become apromising target of anti-tumor therapy.