Morphine Suppresses Liver Cancer Cell Tumor Properties In Vitro And In Vivo

Background and objective: Morphine is an analgesic widely adopted to relieve cancer pain.Besides,the perioperative management of pain in cancer surgical treatment patients most frequently involves opioids.A number of discrepancies,however,are presented by the published literature,with reports that suggest that opioids may either promote or inhibit the spread of cancer.So far,few studies have been reported in related to roles and molecular machnisms of morphine on liver cancer cells.Due to the high incidence and mortality of liver neoplasm in China,research on the effects of morphine on liver cancer is urgently required.In the present study,we investigated whether morphine may suppress liver cancer cell tumor properties in vitro and in vivo while utilized in liver cancer surgical treatment.Methods: Human Hep3B/HepG2 cells were cultured and treated with morphine with different concentrations(0,5?M and 10?M).Cell proliferation assay,wound healing assay,transwell migration and invasion assay,apoptosis assay and sphere formation assay were performed to evaluate the effects of morphine on the tumor properties of liver cancer cells in vitro.The xenograft experiments were conducted by intravenous injection of Hep3B/Hep G2 cells pretreated with 10?M morphine.Fluorescence imaging was tracked by Xenogen IVIS Imaging System to examined the tumorigenicity of Hep3B/Hep G2 cells in lung.After 5 weeks,the mice were sacrificed and lungs were dissected,fixed in formalin,embedded in paraffin,and sectioned for hematoxylin-eosin staining.Immunohistochemistry was performed to detect CD34+ microvessels in lung neoplasm.q RT-PCR and Western blot experiments were conducted to detect the m RNA and protein level of OGFR,MOR,u PA,MMP-9,PCNA,Ecadherin,Vimentin and Fibronectin in Hep3B/Hep G2 cells treated with morphine to explore the molecular mechanisms of morphine's effects on liver cancer cells.Results: Our results showed that morphine does not promote proliferative ability to cultured liver cancer cells.Morphine could induce the apoptosis of Hep3B/Hep G2 cells at the concentration of 5?M(Hep3B: P <0.05,Hep G2: P <0.01)and 10?M(Hep3B: P <0.001,Hep G2: P <0.001)respectively.Exposure to morphine resulted in decreased migratory ability of Hep3B/Hep G2 cells when compared with the control group,at the concentration of 5?M(Hep3B: P <0.001,Hep G2: P <0.001)and 10?M(Hep3B: P <0.001,Hep G2: P <0.001)respectively.Exposure to morphine resulted in decreased invasion capacity of Hep3B/Hep G2 cells when compared with the control group,at the concentration of 5?M(Hep3B: P <0.001,Hep G2: P <0.001)and 10?M(Hep3B: P <0.001,Hep G2: P <0.001).In addition,morphine exposure caused decreased the sphere size(control vs 5?M,Hep3B: P<0.001,Hep G2:P<0.001 and control vs 10?M,Hep3B: P<0.001,Hep G2: P<0.001,respectively)and number(control vs 5?M,Hep3B: P<0.001,Hep G2: P<0.001 and control vs 10?M,Hep3B: P<0.001,Hep G2: P<0.001,respectively).Exposure to morphine resulted in decreased expression of stemness makers such as Nanog,Oct4 and Sox2.More importantly,xenograft experiments indicated that morphine suppressed Hep3B/Hep G2 cells mobility in lung metastasis(control vs.morphine,Hep3B: P<0.001;Hep G2: P <0.001)and decrease the density(control vs.morphine,Hep3B: P<0.01;Hep G2: P <0.05)and perimeter(control vs.morphine,Hep3B: P <0.01;Hep G2: P <0.01)of CD34+ microvessels in lung neoplasm.Furthermore,q RT-PCR and Western blot results showed that morphine could suppress malignant behavior of liver cancer cells by up-regulation of the OGFR,Ecadherin and down-regulation of MOR,u PA,MMP-9,Vimentin,Fibronectin.Conclusions: Our results indicated that morphine could inhibit tumor properties in vitro and in vivo,which suggesting that morphine are appropriate for perioperative pain management related to HCC.