Inhibition On The Producte Of Protein Of Hepatocellular Carcinoma Cells Leaded By Nano-Hydroxyapatite

Previous studies show that nano-hydroxyapatite (nHAP) significantly inhibits the proliferation of hepatocellular carcinoma cells, but not that of hepatocytes in vitro. The inhibition of nHAP on carcinoma cells may provide a new way for medical research. The known main mechanism is that nHAP inhibits carcinoma cell proliferation by regulating the mRNA expression of c-myc and p53, arresting the hepatocellular carcinoma cells at G1 phase, and activating caspase-9 which ultimately leads to paraptosis. In order to further explore the mechanisms, this paper studied the influnence of nHAP on cell protein synthesis.The inhibition rate of cells was measured using MTT method. After treating human hepatocellular carcinoma Bel-7402 cells and human liver L02 cells with nHAP of different concentrations for different time periods, the cell activity was measusred. It was found that, in a certain rang of concentration and time, nHAP inhibited the growth of Bel-7402 cells while had little effect on L02 cells.The location of nHAP in cells is observed with confocal laser scanning microscopy. After treating Bel-7402 cells and L02 cells with Eu-nHAP, the nucleus and endoplasmic reticulum were stained with DAPI and DiOC6(3) separately. Eu-nHAP was found locating in the endoplasmic reticulum. The results showed that nHAP may effect the protein synthesis, secreting, space folding and glycosylation of cells.The protein synthesis of nHAP was measured by H3-Leucine incorporation. It was found that the total protein synthesis rate of Bel-7402 cells slowed in varying degrees after treated with nHAP of less than 0.7mg/ml for 3days. In contrast, nHAP had less effect on L02 cells. It showed that nHAP inhibited hepatocellular carcinoma cells growth and proliferation by disrupting protein synthesis.The expression of transferrin receptor in cells was measured by fluorescence intensity using FITC-labelled transrerrin. It was found that nHAP significantly decreased the expression of transferrin receptor in Bel-7402 cells, in contrast, nHAP had little effect on the expression of transferrin receptor in L02 cells. It showed that nHAP inhibited hepatocellular carcinoma cells growth and proliferation by decreasing the expression of transferrin receptor and arresting human hepatocellular carcinoma at G1 phase.In summary, nHAP enters hepatocellular carcinoma cells, locates in endoplasmic reticulum, and inhibits human hepatocellular carcinoma growth and proliferation by disrupting protein synthesis, decreaseing the expression of transferrin receptor and arresting human hepatocellular carcinoma at G1 phase.