Detection Of Novel Multi-target Microsatellite Instability In Gastric Cancer Tissues And Its Relationship With The Expression Of HER2 P53

Objective: By studying the expression of HER2 、 P53 protein and microsatellite instability(MSI)in gastric cancer tissues,evaluating the relationship between HER2 and P53 protein,the microsatellite instability was prelarily investigated.Methods: Collecting the medical record of 103 gastric cancer cases of yueyang city second people’s hospital from January 2018 to January2021,analysing their wax block specimens samples from radical operation、gastroscope biopsy samples to return wax block specimen and pathological biopsy,then detecting tumor tissue of patients with gastric cancer and the expression of HER2 、mismatch repair protein(MLH1PMS2 MSH2 MSH6)and P53 protein from the same patients,then comparing with the normal tissue adjacent to carcinoma;At the same time,seven microsatellite sites(ACVR2,BTBD7,Did O1,MRE11,RYR3,SEC31 A Sulf2)were selected by Idylla MSI method to conduct automatic dewaxing DNA extraction,automatic PCR amplification and fluorescent staining of the selected microsatellite sites in the wax specimens of gastric cancer tissue in the special kit and the equipment matching the kit Finally after MSI testing special software to identify biomarkers specificity fluorspar spectra after software to calculate the probability of specific biomarkers of score(MSI)in the evaluation of specific microsatellite instability of biomarkers and further obtain microsatellite instability(MSI)expression rate of missing The adoption SPSSP 25.0software for data analysis,counting data by chi-square Fisher’s exact probability method.When the P ≤0.05 indicates that the difference is statistically significant.Results:In this study,among 103 gastric cancer patients,77(74.8%)showed microsatellite stability(MSS)by IHC,26(MSI)by IHC;77(74.8%)by Idylla MSI,and 26(MSI)by Idylla MSI.Conclusion:(1)IHC and PCR were used to detect the microsatellite instability of tumor tissue,and the consistency between the two was 100%.(2)There was no significant correlation between the expression of HER2 and the state of MSI in gastric cancer tissues,while the expression of P53 was negatively correlated with the state of MSI.