The Inhibitory Effect Of Hyperthermia Combined With Cisplatin On The Proliferation Of Human Gastric Cancer Drug- Cells SGC-7901/DDP And Its Molecular Mechanism

Objective:To research the effects of hyperthermia（HT）combined with cisplatin（DDP）on the inhibition of human gastric cancer drug-resistant cell SGC-7901/DDP in vitro and explore its possible molecular mechanism.To provide an evidence for the research and treatment of cisplatin combined with hyperthermia in patients with gastric cancer resistance.Methods:Routine culture tumor resistant cell SGC-7901/DDP in vitro.Divide cells into control group,cisplatin group,hyperthermia group and hyperthermia combined with cisplatin group.Observe cell morphology with inverted phase contrast microscope after being cultured at 41℃,44℃,47℃ and 50℃ for 12 h,24 h,36 h;MTT assay detected the proliferation of SGC-7901/DDP at different time and temperature,and the proliferation of SGC-7901/DDP at 41℃,44℃ and 47℃ combined with 1 μg/ml,2 μg/ml and 3 μg/ml cisplatin concentrations,to clarify the interaction between hyperthermia and cisplatin;Using Annexin V-FITC/PI double staining assay apoptotic rate of SGC-7901/DDP cells in control group,cisplatin group（2 μg/ml）,hyperthermia group（47℃）,and cisplatin combined hyperthermia group（47℃ and 2 μg/ml）.High-throughput chip technique was applied to test lncRNAs expression in SGC-7901/DDP cells from the control group,cisplatin group and hyperthermia combined with cisplatin groups.Then,to verify the expression of lncRNA TCONS₀0018082,TCONS₀0015171,ENST00000584911.1,ENST00000412526.1,and ENST00000592460.1 in cisplatin combined hyperthermia group versus control group by real-time fluorescence quantitative polymerase chain reaction（RT-PCR）.Results:（1）MTT results showed that the inhibition of SGC-7901/DDP cell proliferation was dramatically enhanced after 47℃ hyperthermia combined with 2 μg/ml cisplatin compared with the single factor intervention（P<0.05）and the control group（P<0.05）,and the combination had a synergistic effect;（2）Under the same conditions,Annexin V-FITC/PI double staining experiment result expressed that hyperthermia combined with cisplatin increased the rate of early apoptosis of SGC-7901/DDP cells compared with using the hyperthermia or cisplatin alone;（3）LncRNA high-throughput chip expression profile showed that a large number of lncRNAs and mRNAs opposite to the control group appeared in the cells of the hyperthermia combined cisplatin group;（4）RT-PCR test results confirmed that lncRNA TCONS₀0018082 and ENST00000412526.1 were significantly up-regulated（P<0.01）,while the relative expression levels of lncRNA TCONS₀0015171 and ENST00000584911.1 were significantly down-regulated（P<0.01）.Conclusions:（1）After being cultured for 24 hours,the hyperthermia at 47℃ combined with 2 μg/ml cisplatin can synergistically inhibit human gastric cancer drug-resistant cells SGC-7901/DDP proliferation and promote early apoptosis;（2）Hyperthermia at 47℃ combined with 2 μg/ml cisplatin reversed the expression of a large number of mRNA and lncRNA in human gastric cancer drug-resistant cells SGC-7901/DDP.（3）The molecular mechanism of inhibiting proliferation of human gastric cancer drug-resistant cells SGC-7901/DDP by combining hyperthermia at 47℃ with 2 μg/ml cisplatin may be closely related to up-regulation of TCONS₀0018082 and ENST00000412526.1,and down-regulation of TCONS₀0015171 and ENST00000584911.1.