Expression And Significance Of LncRNA XIST,miR-204 And FN1 In Papillary Thyroid Carcinoma

Objective:According to pathological classification,thyroid cancer can be divided into papillary thyroid carcinoma(PTC),undifferentiated carcinoma(ATC),medullary carcinoma(MTC)and follicular carcinoma(FTC).Among them,PTC is the most common type of thyroid cancer,accounting for 75% to 85% of all thyroid cancer cases.Compared with other pathological types,PTC has good differentiation,slow growth,and low malignancy,so the overall prognosis is relatively good,5 years the survival rate can reach more than90%.However,PTC may have cervical lymph node metastasis earlier.Therefore,it is very important to diagnose PTC as soon as possible and actively treat it.Clinically,the diagnosis of PTC is generally confirmed by pathological slices.However,pathological diagnosis alone may confuse PTC with other benign thyroid diseases,such as nodular goiter,papillary thyroid adenoma,or Hashimoto’s thyroiditis,leading to misdiagnosis and overtreatment.Therefore,in recent years,some markers for the differential diagnosis of PTC and benign thyroid tumors with papillary hyperplasia have gradually developed,such as CK19,Galectin-3 and HBME1.However,due to their relatively low sensitivity and specificity,their clinical application is limited.Therefore,looking for new potential diagnostic markers of PTC is conducive to the early diagnosis of PTC and has important clinical significance.The purpose of this study is to verify the expression,interaction and cellular localization of LncRNAXIST,miR-204 and FN1 in PTC,to find potential diagnostic markers of thyroid papillary carcinoma,and to provide new data and methods for clinical targeted treatment of PTC.Methods:This experiment is an experimental study,with 20 subjects in total.Surgical specimens of patients undergoing thyroidectomy in the Affiliated Hospital of Qingdao University from July 2019 to August 2020 were collected.(1)All patients have complete clinical data.All patients were divided into 2 groups of thyroid cancer and paracarcinoma,20 cases of papillary thyroid carcinoma(thyroid carcinoma group),paired with paracancerous normal tissues(paracancerous group)(paracancerous tissues were taken from a position> 0.8 cm from the edge of the cancerous focus))In 20 cases,all of the above thyroid specimens were diagnosed by the pathology department of our hospital,and the patients all signed the experimental informed consent.(2)3 strains of papillary thyroid carcinoma cell lines(BCPAP,TPC-1,KTC-1).(3)human 293 T cells.Fluorescence quantitative PCR was used to detect the expression of LncRNA XIST,miR-204 and FN1 in 20 PTC samples,fluorescence quantitative PCR was used to detect the expression of LncRNA XIST and miR-204 in BCPAP,TPC-1,KTC--1 cell lines,fluorescence in situ hybridization((FISH))was used to detect the expression and location of lncRNA XIST in BCPAP cells,and double luciferase reporter gene was used to detect the interaction of LncRNA XIST,miR-204 and FN1 in human 293 T cells.The mapping software was Graphpad prism 5(Graphpad Software,San Diego,CA);fluorescence quantitative software Image J,and the data analysis software Graphpad prism 5(Graphpad Software,San Diego,CA);T-test was used to analyze the expression of LncRNA XIST,miR-204 and FN1 in PTC carcinoma and paracancerous tissues;One-way analysis of variance and TUKEY method were used to carry out post-hoc tests to study the expression differences of LncRNA XIST and miR-204 in the three cell lines of BCPAP,TPC-1 and KTC-1.Two-way analysis of variance and TUKEY method were used for post-hoc tests to study the relationship between LncRNA XIST and miR-204,FN1 and miR-204 in human293 T cells.P <0.05 and P <0.01 were used as the screening criteria for significant and extremely significant differences.Results:(1)Comparison of the expression of LncRNAXIST and miR-204 in papillary thyroid carcinoma and adjacent tissues: The fluorescence quantitative PCR results showed that the expression level of lncRNAXIST in the cancerous tissue group was significantly up-regulated compared with the adjacent group(P<0.05);Compared with the adjacent group,the expression level of miR-204 in the cancer tissue group was extremely significantly down-regulated(P <0.01);compared with the adjacent group,the expression level of FN1 in the cancer tissue group was extremely significantly upregulated(P <0.01).The differences are statistically significant.(2)Fluorescence quantitative PCR results showed that in the three groups of cell lines(BCPAP,TPC-1 and KTC-1),the expression of LncRNA XIST and the expression level of BCPAP cells were higher than those of TPC-1 cells(P <0.05)and KTC-1 cells(P < 0.01)was significantly up-regulated,and the expression of miR-204 and BCPAP cells were significantly downregulated compared with TPC-1 cells(P <0.05)and KTC-1 cells(P <0.01).The differences were statistically significant.The expression level of LncRNA XIST in BCPAP cells was the highest,and the expression level of miR-204 was the lowest,so this cell was selected for subsequent experiments.(3)Fluorescence in situ hybridization(FISH)showed that lncRNA XIST was mainly expressed in the cytoplasm.(4)Double luciferase reporter gene assay showed that: LncRNA XIST interacted with miR-204(P<0.05),and FN1 interacted with miR-204(P<0.05),the differences are statistically significant.Conclusion:(1)LncRNA XIST may be a new target for the diagnosis and treatment of thyroid papillary carcinoma.(2)The interaction between LncRNA XIST,miR-204 and FN1 is involved in the occurrence and development of thyroid papillary carcinoma,and can provide a theoretical basis for the search of potential diagnostic markers and therapeutic targets for thyroid papillary carcinoma.