Research On Multidrug Resistance Of The Liver Tumor And Its Reversion

Heme oxygenase-1 is a key enzyme effecting metabolism of heme. Heme oxygenase-1 has various biological activities, such as anti-inflammatory, anti-oxidation, anti-apoptosis, adjustment of microcirculation and so on. According recent reports, it has been found that high expression of heme oxygenase-1 is in the tumor cell of drug-resistance. At the same time, multidrug-resistance is the important reason of the failure of chemotherapy. Therefore, the research of relations between high expressions of heme oxygenase-1and multidrug-resistance of liver tumor is very important to kwon the mechanism multidrug-resistance of liver tumor and to raise the effect of chemotherapy.Objective: After increasing and reducing the expression of heme oxygenase-1, we examine the expression of P-GP and GST-Ï€, two multidrug-resistance marker, and examine the function of P-GP that can excrete various drugs in the cell.Finally; we demonstrate whether high expression of heme oxygenase-1 is one of the reasons of multidrug resistance of liver tumor.Methods: First, liver multidrug-resistance tumor cell (Bel/Fu) were dealt by hemin and Zinc (â…¡) protorphyrin IX for 24 hours repectively.Second, we examine the survival rate of Bel/Fu by MTT after the cells were dealt by 5-Flauouracil, Adriamycin and Mitomycin for 24 hours respectively. Third, we examine the mRNA expression of heme oxygenase-1 , P-GP and GST-Ï€by RT-PCR; we examine the protein expression of P-GP by western blotting; we exame the protein expression of GST-Ï€by immunocytochemistry. Finally, we examine the excretion function of P-GP by flow cytometry.Result:1. MTT result:(1) After the cells were treated with 5-Flauouracil for 24 hours, the survival rate of Bel/Fu in the hemin group is much higher than in the control group (P<0.05). However, the survival rate of Bel/Fu in the znpp group is much lower than in the control group (P<0.05).(2) After the cells were treated with Adriamycin for 24 hours, the survival rate of Bel/Fu in the hemin group is much higher than in the control group (P<0.05). However, the survival rate of Bel/Fu in the znpp group is much lower than in the control group (P<0.05).(3) After the cells were treated with Mitomycin for 24 hours, the survival rate of Bel/Fu in the hemin group is much higher than in the control group (P<0.05). However, the survival rate of Bel/Fu in the znpp group is much lower than in the control group (P<0.05).2. RT-PCR result:(1) As the concentration of hemin became higher, the expression of heme oxygenase-1 became higher gradually; as the concentration of Zinc (â…¡) protorphyrin IX became higher, the expression of heme oxygenase-1 became lower gradually.(2) As the concentration of hemin became higher, the expression of P-GP became higher gradually; as the concentration of Zinc (â…¡) protorphyrin IX became higher, the expression of P-GP became lower gradually.(3) As the concentration of hemin became higher, the expression of GST-Ï€became higher gradually; as the concentration of Zinc (â…¡) protorphyrin IX became higher, the expression of GST-Ï€became lower gradually.3. Western blotting result:As the concentration of hemin became higher, the expression of P-GP became higher in the protein level gradually; as the concentration of Zinc (â…¡) protorphyrin IX became higher, the expression of P-GP became lower in the protein level gradually.4. Immunocytochemistry result: The expression of GST-Ï€protein in the hemin group is much higher than in the control group.however, the expression of GST-Ï€protein in the znpp group is much lower than in the control group.5. Flow cytometry result:As the concentration of hemin became higher, the excretion functions of P-GP beame stronger gradually; as the concentration of Zinc (â…¡) protorphyrin IX became higher, the excretion function of P-GP became weaker gradually.Conclusion:1. It is proved that hemin can induce the high expression of heme oxygenase-1 in the liver tumor cell of multidrug-resistance; Zinc (â…¡) protorphyrin IX can supress the expression of heme oxygenase-1 in the liver tumor cell of multidrug-resistance.2. There is the positive relation between the expression of heme oxygenase-1 and the expressions of P-GP and GST-Ï€. At the same time, the expression of heme oxygenase-1 can impact the excretion function of P-GP.3. The high expression of heme oxygenase-1 is the one of mechanism that leads to the multidrug-resistance of the liver tumor.