Study On The Relationship Between Farnesol X Receptor And Survival Time In Patients With Pancreatic Cancer Based On Tissue Chip And RNAScope Technique

Background Farnesol X receptor(FXR),also known as bile acid receptor,belongs to(nuclear receptor subfamily 1 group H member 4 NR1H4,a member of the nuclear receptor superfamily.Farnesol X receptor is a ligand activated transcription factor.FXR can play a potential anti-tumor effect by promoting apoptosis and inhibiting cell proliferation.At present,some small sample studies have been carried out on esophageal cancer,breast cancer,hepatocellular carcinoma,pancreatic cancer and colon cancer,most of which do not involve the potential relationship between FXR expression and clinicopathological parameters and prognosis of patients.The study of FXR in pancreatic cancer has the results of carcinogenesis and inhibition of cancer.According to the previous research data,the mechanism of action of FXR is tissue-specific.The particularity of pancreatic cancer tissue is more obvious,and the research data of different scholars show different results.Obviously,very different results have prompted us to re-explore the role of FXR in pancreatic cancer,that is a fatal disease.Objective The expression of NR1H4 m RNA and protein in pancreatic ductal carcinoma was detected by RNAsope and Immunohistochemistry,and its correlation with clinicpathological data,prognosis and clinical significance were studied.the characteristics of RNAscope technique were also discussed to ensure the reliability of Immunohisto chemical results.Methods The expression of NR1H4(FXR)m RNA and protein in 176 human pancreatic cancer tissue microarray was detected by RNAscope in situ hybridization and IHC.RNAscope technique and NR1H4 probe were used.IHC used polymer two-step method to purchase FXR antibodies of four different companys and different clone numbers.Before the experiment,small human pancreatic cancer tissue microarray(20cases of cancer tissue,4 cases of normal liver tissue)were used to optimize the experimental conditions of NR1H4 probe and 4 kinds of FXR antibody,and strict quality control was carried out.Results The positive rates of NR1H4(FXR)m RNA and protein were 68.75%(121/176)and 77.27%(136/176),respectively,and the positive rates of ab187735,ab235094,25055-1-ap and sc-25309 were 68.75%(121/176),75.57%(133/176),73.30%(129 /176)and 77.02%(125/176),respectively.The expression of m RNA and protein wassignificantly correlated(r=0.307,p<0.001).The expression of NR1H4(FXR)m RNA and protein was associated with the clinical stages of the patient(?~2=5.391,P< 0.05 and?~2=4.108,P<0.05)and the degree of differentiation(?~2= 6.56,P< 0.01and?~2=4.969,P< 0.05).Protein expression was significantly correlated with tumor size(?~2 = 4.957,p<0.05),whereas there was no significant correlation with sex,age,nerve invasion,and lymph node metastasis(p>0.05).The results of multivariate analysis showed that the total expression of IHC-FXR was significantly correlated with the total survival of pancreatic ductal adenocarcinoma(HR= 0.338,95% CI= 0.244,0.468,p< 0.001)and progression-free survival(HR= 0.309,95% CI= 0.195–0.490,p<0.001).The RNAscope in situ hybridization for NR1H4(FXR)m RNA expression was significantly correlated with the total survival of pancreatic ductal adenocarcinoma(HR= 0.550,95% CI =0.390–0.775,p<0.001)and progression-free survival(HR= 0.5223,95% CI: 0.3281-0.8315,p=0.01).Conclusion 1.The application of RNAsope in situ hybridization technique can effectively ensure the reliability and accuracy of immunohistochemical results and ensure the authenticity and reliability of the research results.2.In this experiment,RNAsope in situ hybridization technique was applied to confirm the immunohistochemical results obtained from the NR1H4(FXR)antibody,which made the results more credible and accurate and improved the evidence grade of the data.It is confirmed that this technique can be widely used in the detection and experimental study of clinicopathological related gene targets in the future.