P12-of Lox Inhibitors On Human Gastric Cancer Cell And Its Mechanism Discussed

Background: Gastric carcinoma, one of the most common humanmalignant tumors, ranks as the first leading cause of cancer-relatedmortality in our country in spite of the second incidence. As reported, theoccurrence of gastric cancer is related to the metabolism of AA. 12-LOX,one of the family of lipoxygenases, is the key enzyme during theconversion from AA to 12-HETE. The relationship between 12-LOX(especially p12-LOX) 12-HETE and malignant tumor is a hotspot.BAI, a chemical flavonoid compound extracted from ChineseMedicine baicalein with the activity of anti-inflammation, anti-oxidization and anti-cancer, is the selective inhibitor of p12-LOX. BAIreveals function of the inhibition of proliferation and the induction ofapoptosis. Presently the effect of BAI on gastric carcinoma is lessreported.1. The expression of p12-LOX in human SGC-7901 cellObjectives To investigate the expression of the p12-LOX in humanSGC-7901 cell.Methods The expression of p12-LOX rnRNA and protein in SGC-7901cell were analyzed by RT-PCR and Western Blot respectively.Results The outcome of RT-PCR of SGC-7901 cell showed a band ofgene expansion of p12-LOX with the length of 337 bp and gene expansion ofβ-actin with the length of 651 bp. Western Blot suggestedhuman SGC-7901 cell expressed p12-LOX protein.Conclusion p12-LOX mRNA and protein are expressed in SGC-7901cell.2. The effect of BAI on the proliferation and cell cycle ofSGC-7901 cellObjectives To explore the effect of BAI on proliferation and cell cycleof SGC-7901 cell.Methods MTT assay and FCM was used respectively to detect theeffect of BAI on the proliferation and cell cycle of SGC-7901 cell.Results The rate of cell survival descended obviously with the increaseof the concentration of BAI from 0 to 80μmol/L and with the extensionof time from 24 h to 72 h. Cell cycle analysis revealed a marked decreasefrom 62.27±3.20% to 29.36±1.37% in the G₀/G₁-phase and a strikingincrease from 23.18±1.39 % to 68.21±1.64% in the S-phase cellpopulation following 24 h exposure to BAI from 0 to 80μmol/L.Conclusion BAI can inhibit the proliferation of SGC-7901 cell in atime-dependent and concentration-dependent manner. BAI may change tothe distribution of cell cycle in concentration-dependent manner.3. The effect of BAI on expression and significance of VEGF inSGC-7901 cellObjectives To explore the effect of BAI on expression of VEGF in human SGC-7901 cellMethods RT-PCR was used to detect the effect of BAI on expressionof VEGF mRNA, ELISA showed the influence of BAI on expression ofVEGF protein.Results RT-PCR revealed 6 bands ofgene expansion of VEGF with thelength of 333bp and GAPDH with the length of 371bp. The analysiswith GEL-Pro image software showed a striking decrease of theexpression of VEGF mRNA with comparison to control group (p＜0.05, except 5μmol/L group)after exposure to BAI 6 h. Furthermore, withthe increase of concentration, the expression of VEGF mRNA reducedgradually. ELISA showed the expression of experimental group of VEGFprotein descended remarkably with comparison to control group (p＜0.05, except 5μmol/L group) in SGC-7901 cell after exposure to BAIfrom 0 to 80μmol/L 24 h. The above-mentioned result suggested BAIcan inhibit the expression of VEGF protein in concentration-dependentmanner.Conclusion BAI can inhibit the expression of VEGF mRNA andprotein in SGC-7901 cell in concentration-dependent manner. The effectof inhibition of BAI on SGC-7901 cell may be related to decrease ofexpression of VEGF.