BACKGROUND: Recent study showed that osteocalcin may elevate Insulin secretion and sensitivity, prevent the fat accumulation, play a role in the metablism of glucose and lipid. Undercarboxylated osteocalcin works as the main role. OBJECTIVE: To investigate the effect of different concentrations of glucose on osteoblast undercarboxylated osteocalcin. METHODS: The rib trabeculae were resected and broken, trypsinizated and washed completely by PBS. Bone surface and non-adhesive floating cells in cleaning fluid were observed with inverted microscope. Rib trabeculae was washed by DMEM culture medium once, and cultured in culture bottle. The culture liquid was replaced by new one once a week. The osteoblast was moved from the scledte a week later. The cells were fused monolayer and could be subcultured 4 to 6 weeks later. The active second or third generation cells were inoculated to 6-pore plate forming 5 groups. Osteoblast were stimulated by 5.6 mmol/L., 7.6 mmol/L, 9.6 mmol/L, 12.6 mmol/L, 20.6 mmol/L glucose medium respectively after the 80% cells were fused, the vitamin K_2 was added into the culture liquid until the concentration of it to be 10~(-5) mol/L. Supernatant was collected after half hour culturing, the undercarboxylated osteocalcin level were detected with RIA test kit, and corrected it as the total the undercarboxylated osteccalcin, calculated the carboxylated incomplete osteocalcin rate. RESULTS AND CONCLUSION: The rate of ostecblast carboxylated incomplete osteocalcin was different under different concentration glucose. The rate of 7.6 mmol/L, 9.6 mmol/L, 20.6 mmol/L concentration glucose groups were higher than that of 5.6 mmol/L glucose group [(0.27±0.02)%, (0.29±0.04)%, (0.12±0.02)%, P < 0.05]. It is indicated that osteoblast could sense the change of glucose concentration by regulating the secretion of the undercarboxylated osteocalcin between the concentration of 5.6mmol/L to 9.6mmol/L, while the carboxylated incomplete osteocalcin decreased as the concentration of glucose increased.

ObjectiveTo measure the expression of divalent metal transporter 1 (DMT1) in hepatocellular carcinoma (HCC) and to explore its clinical and pathological significance. MethodsFifty-seven liver cancer specimens collected from patients with HCC and preserved in paraffin in Second Affiliated Hospital of Shantou University Medical College from July 1999 to July 2011 were established as HCC tissue group, and 7 specimens of normal liver tissues from autopsy and 8 specimens of liver tissues from patients with intrahepatic bile duct stones and preserved in paraffin were established as normal control group. SP immunohistochemistry was applied to measure the expression of DMT1 in 15 specimens of normal liver tissues and 57 specimens of HCC tissues. One-way analysis of variance was applied to analyze the difference in expression of DMT1 in HCC tissues with varying degrees of differentiation, and χ2 test was applied for the comparison of rates; the correlation between expression of DMT1 and tumor size was analyzed by Pearson correlation analysis. ResultsDMT1 in the liver tissues in normal control group was negative or weakly positive, with a positive rate of 20% (3/5); in HCC tissue group, the positive rate was 789% (45/57), with a strong positive rate of 15.8% (9/57); the two groups showed a significant difference in positive rate (P＜0.05). The expression of DMT1 varied significantly between patients with varying degrees of differentiation in HCC tissues (F=4.011, P＜0.05), while the positive rate of DMT1 showed no significant differences between patients with different clinical stages and with or without blood vessel infiltration (all P＞0.05). Correlation analysis did not find the correlation between expression of DMT1 and tumor size (r=-0.047, P＞005). ConclusionThe positive expression rate of DMT1 increases significantly in HCC tissues and is closely related to the degree of tumor differentiation, which is potentially valuable for clinical and pathological grading of liver cancer.