Effect Of SiRNA Silenced COX-2Gene Synergy Shikonin On Cells Metastasis In Gastric Cancer

AIM: To observe and explore the effect of Shikonin on the expression of COX-2andVEGF-C gene and gastric cancer cell and metastasis of cancer cell by study the effects ofshikonin collaborated with siRNA interfered COX-2gene in gastric cancer cell. Researchon the possible anticancer mechansim of Shikonin synergy COX-2siRNA. Provite a new ideafor anticancer application of Lithospermum erythrorhizon.METHODS: BGC-823and SGC-7901cells in good conditions were divided into:control group, negative control group, Shikonin synergy siRNA group, siRNA interferedgroup, and Shikon group. RT-PCR were performed to detect the expression of COX-2andVEGF-C gene in mRNA levels in different groups of BGC-823and SGC-7901;the fluorescence immunoassay method were performed to detect the expression of COX-2andVEGF-C in protein level in different groups; the cell scratch tests were performed toinvestigate cell migration changes of gastric cancer cells after siRNA interference andShikonin treatment; Tanswell assay was used to evaluated the invasion changes of gastriccancer cell after siRNA interference and Shikonin synergistic.Results: There’s no obvious change in the cell morphology of BGC-823andSGC-7901after siRNA interference.(1).RT-PCR shown that: There’s no obvious difference between the blank group and thenegative control group in the two factor expressions (P>0.05). After treatmen with siRNAinterference and Shikon synergy siRNA, the mRNA expressions of COX-2and VEGF-Cdecreased significantly (P<0.05); the mRNA level of VEGF-C gene have no obvious decreaseafter Shikonin treatment (P>0.05); no distinctive differences were found between the siRNAinterference group and the Shikonin synergy siRNA group (P>0.05); the difference betweenthe Shikon synergy siRNA group and the other two groups was statistically significant (P <0.05).(2). Immunofluorescence test shown that：There’s no significant difference between theblank group and the negative group (P>0.05). Comparing with the blank group and thenegative control group，the protein expressions of COX-2and VEGF-C in the siRNA interfered group and Shikon synergy siRNA group decreased significantly (P <0.05); nosignificant difference between the two groups in the expression of VEGF-C (P>0.05);statistically significant differences were found in the COX-2expression (P <0.05). Theexpression of COX-2in Shikonin group decreased obviously (P <0.05), while the expressionof VEGF–C has no significant difference (P>0.05).(3). Cell scratch experiment shown：Comparing to the blank group，the migration abilityof gastric cancer cells declined after siRNA interfered and Shikon synergy siRNA treatment.Transwell experimental shown that there’s no significant difference between the blank groupand the negative group in migration quantity (P>0.05). Comparing to the blank group, thecells migration obviously decreased in siRNA interfered group and the Shikonin synergysiRNA group (P <0.05); no significant difference was found in Shikonin group (P>0.05).Conclusion: siRNA of COX-2gene could successfully silence the expression of COX-2gene in gastric cancer cells BGC-823and SGC-7901. Shikonin could inhibit the expressionof COX-2gene in BGC-823and SGC-7901in a certain extent, but the effect on VEGF-Cgene was not obvious; when interfered by Shikonin synergy siRNA, the inhibition on theexpression of the two factors were obvious, suggesting that Shikonin could affect theexpression of COX-2gene and inhibit the invasion of gastric cancer cell to inhibit themigration of tumor cells in the blood and lymph vessels.