Effect Of Erythropoietin/Erythropoietin Receptor On The Proliferation Of Hepatoma Carcinoma Cells

Objective: Study on the roles of Erythropoietin(EPO) and Erythropoietin receptor(EPOR) in the proliferation of hepatocellular carcinoma cells(HCC), especially how hypoxia influence these effects.Methods: Tumor and adjacent non-tumor liver tissues were collected from 10 Chinese HCC patients who received curative surgery in tongji hospital. H22-bearing hepatocellular carcinoma mice model was established. The expression EPO, EPOR, Hypoxia inducible factor-1?(HIF-1?) and Ki67 in human and mouse hepatocellular carcinoma tissues were measured using immunohistochemistry, as well as in normal mice liver. Hep G2 cells were cultured with or without r Hu EPO, soluble-EPOR, LXA4 under normoxia and hypoxia condition. The proliferation rate of Hep G2 cells were analyzed by MTT and(Carboxyfluorescein diacetate, succinimidyl ester)-labeled/Flow cytometry-detected(CFSE-FCM) assays. The m RNA and protein level of EPO, EPOR and Proliferating Cell Nuclear Antigen(PCNA) in Hep G2 cells were analyzed by PCR and Western blot. Immunofluorescence analysis was applied to detect the cellular location of EPOR in Hep G2 cells.Results: 1. In vivo H22-bearing hepatocellular carcinoma was successfully established after H22 cells were injected and the tumor grew slower significantly of LXA4 group and the tumor size smaller than model group at the 14 th day. 2. The expression of EPO, EPOR, Hypoxia inducible factor-1?(HIF-1?) and Ki67 in hepatocellular carcinoma tissues both from HCC patients and transplanted tumor mice were higher than those in non-tumor liver tissues. LXA4 effectively inhibited above enhancement. 3. EPO and EPOR expression were up-regulated by hypoxia in the Hep G2 cells. And this proliferation rate was even significantly increased following r Hu EPO treatment, while it could be obviously reduced by the treatment of soluble-EPOR or LXA4. 4. Under hypoxia condition, EPOR protein trans-located from nuclear to cell membrance.Conclusion: The induction of EPO/EPOR by hypoxia may accelerate the proliferation of the HCC cells. The inhibitory effect of LXA4 on this process in hypoxia might be through decreasing the expression of EPO.