Influence Of Circadian Genes HClock And HBmall On Chemosensitivity, Migration And Invasion Of Gastric Cancer

Objectives: To provide a theoretical basis for the best time to usechemotherapy drugs by detecting the expression level of circadian geneshClock and hBmal1in gastric cancer cell lines SGC-7901at different timepoints, and then observing the chemosensitivity of gastric cancer cell linesSGC-7901to docetaxel at the peak and nadir time point respectively. Toinvestigate the relationship between the circadian genes and the invasion andmigration by detecting the migration and invasion of SGC-7901cells at thepeak and nadir time point respectively.Methods:(1) The gastric cancer cell lines SGC-7901were culturedunder continuous darkness in vitro.(2) The expression level of the two maincircadian genes hClock and hBmal1at the different time were determined byReal Time Polymerase Chain Reaction.(3) Docetaxel was given at the peaktime point and nadir time point respectively. The inhibition of SGC-7901cellsproliferation was measured using a CCK-8kit.(4) The expression ofSGC-7901cells migration and invasion were detected by transwell chambers.Results:(1) It is shown that the expression of circadian genes hClockand hBmal1were different on different time by Real Time Polymerase ChainReaction. The expression of circadian genes hClock and hBmal1showedphase oseillation. The peak expression of hClock and hBmal1was at20:00and the nadir at08:00.(2) These results indicate that the peak phase, valleyvalue phase, amplitude, peak and valley value time of hBmal1and hClockgene expression are similar, with synchronized transcription feature.(3) Theinhibition rate of Docetaxel to SGC-7901cells at the maximum expression of hClock and hBmal1genes was significantly lower than that at the minimumexpression.(4) As compared with the nadir expression of hClock and hBmal1,the migration and invasion of SGC-7901cells were significantly higher at thepeak expression of hClock and hBmal1.Conclusion:(1) The circadian genes hClock and hBmal1in gastriccancer cell lines SGC-7901cultured in darkness in vitro showed phaseoscillation in their expressions featured with synchronized transcription.(2)SGC-7901cells are more sensitive to chemotherapy drugs at the nadirexpression of circadian genes hClock and hBmal1, during whichchemotherapy drugs can have better curative effects.(3) The migration andinvasion of SGC-7901cells were higher at the maximum expression ofcircadian genes hClock and hBmal1than those at the nadir expressionindicating that circadian genes hClock and hBmal1might play a role in themigration and invasion of gastric cancer of stomach cancer.