Detection kit for epithelial-mesenchymal transition in EB (Epstein-Barr) virus infected thymoma and application of detection kit

Abstract

The invention relates to a detection kit for epithelial-mesenchymal transition in EB virus infected thymoma and application, the detection kit comprises a quantum dot labeled antibody E-Cadherin and a quantum dot labeled antibody Vimentin, a quantum dot is coupled with a specific antibody, a thymoma paraffin section sample is dyed through the quantum dot and the specific antibody conjugate, and the EB virus infected thymoma is obtained. The conjugate can be specifically connected with an EMT related antigen expressed in the slice, so that the quantum dots can be used for qualitative or quantitative detection of the EMT-generated thymoma cells. The quantum dots are used for replacing fluorescent dye, direct marking of tissue slices can be achieved, local positioning of epithelial cells and mesenchymal tissues in the thymoma microenvironment is achieved, number detection and position detection can be achieved, and EMT condition evaluation is facilitated.

Description

Technical Field

[0001] The invention belongs to the technical field of biological detection, and in particular relates to a detection kit for epithelial-mesenchymal transition in thymoma infected by Epstein-Barr virus and its application. Background Art

[0002] Thymic epithelial tumor (TET) originates from thymic epithelial cells and is the most common tumor in the anterior mediastinum of adults, accounting for about 20% and with an incidence of about 3.2 cases per 1 million people. According to the latest World Health Organization classification guidelines for thoracic tumors, TET is divided into thymoma, thymic carcinoma, and the very rare thymic neuroendocrine tumors (NETs). The pathological morphology and structure of thymoma are complex, and it is divided into different types according to the ratio of epithelial cells and lymphocytes. Therefore, its pathological classification and biological characteristics are highly heterogeneous. The pathogenesis of thymoma is still unclear, including factors such as epigenetic changes and abnormal immune microenvironment.

[0003] At present, some studies have reported that viral infection exists in patients with thymoma, indicating that the thymus can be infected by the virus and that the virus may be involved in the malignant transformation of the normal thymus. Through the two-color immunofluorescence staining method, researchers identified functional EBV receptors in immature human thymocyte subsets, and found that stable viral infection could be established in thymocytes after 6 weeks of co-culture with EBV. In addition, some studies have reported that nearly half of the cases of lymphoepitheliomalike carcinoma (LELC) are EBV positive. Since the thymus is a very important central lymphoid organ in the human body and the thymic epithelium has certain lymphoepithelial characteristics, it is speculated that there is a certain connection between thymic epithelial tumors and EBV infection.

[0004] Epstein-Barr virus (EBV), also known as human herpesvirus 4 (HHV-4), is a member of the γ-herpesvirus family and a lymphotropic double-stranded DNA virus with an infection rate of about 95% of the global population. Due to its lymphotropic properties, early studies found that EBV mainly infects human B cells and replicates and lurks, and is highly associated with human lymphatic system malignancies. In recent years, more and more studies have shown that EBV can also infect a variety of epithelial cells and cause them to develop lesions.

[0005] Epithelial-mesenchymal transition (EMT) is a biological process in which epithelial cells change to mesenchymal cells in terms of morphology and function, characterized by reduced cell adhesion and enhanced cell migration and invasion abilities. The EMT process occurs during embryonic development under normal physiological conditions, specifically involved in the formation of gastrulation and the stratification of neural crest cells. However, during tumorigenesis, EMT is inappropriately reactivated by tumor cells. During the EMT process, epithelial cells transdifferentiate into a mesenchymal phenotype, accompanied by a reduction in intercellular adhesion connections, the removal of cell polarity, and the remodeling of the actin cytoskeleton. At the same time, through changes in the interaction between cells and the extracellular matrix (ECM), cells undergoing EMT show increased expression of mesenchymal markers and enhanced migration ability. A classic feature observed in cancer-associated EMT is a cadherin switch, specifically loss of expression of E-cadherin, a concomitant decrease in the expression of tight junctions, adherens junctions, and desmosomal proteins, and an aberrant increase in the expression of vimentin and other mesenchymal markers. Summary of the invention

[0006] In order to solve the above technical problems, the present invention provides a detection kit for epithelial-mesenchymal transition in thymoma infected with Epstein-Barr virus and its application.

[0007] The technical solution adopted by the present invention is: a detection kit, comprising quantum dot-labeled antibody E-Cadherin and quantum dot-labeled antibody Vimentin.

[0008] Preferably, the quantum dot-antibody conjugates include QDs-585-Vimentin and QDs-525-E-Cadherin.

[0009] Preferably, antigen repair solution and nucleic acid staining solution are also included.

[0010] Preferably, quantum dots, EDC, and NHS are mixed at a molar ratio of 1:2500-3500:5000-6000 to activate the quantum dots, and antibodies are added to the activated quantum dot solution, with a molar ratio of quantum dots to antibodies of 1:20-80, to obtain QDs-Ab conjugates after the reaction; the supernatant is taken as a quantum dot-labeled antibody solution that can be used for staining.

[0011] Application of the detection kit in the detection of epithelial-mesenchymal transition in Epstein-Barr virus-infected thymoma.

[0012] Preferably, thymoma tissue sections are prepared, antigen repair is performed using an antigen repair solution, the tissue sections are stained using antibodies labeled with different quantum dots, the cells are then stained, the fluorescence information of the tissue sections is collected, and the expression level and spatial position of the epithelial cells and / or mesenchymal cells in the tissue sections are determined based on the fluorescence information.

[0013] Preferably, the tissue sections after antigen retrieval are stained with one or both of the quantum dot-antibody conjugates QDs-585-Vimentin and QDs-525-E-Cadherin.

[0014] Preferably, the quantum dot-labeled antibody E-Cadherin is used to detect the expression amount and spatial position of epithelial cells in thymoma tissue, and the degree of epithelial transformation in the thymoma microenvironment is reflected by calculating the average fluorescence intensity of the corresponding cells; And / or, the quantum dot-labeled antibody Vimentin is used to detect the expression amount and spatial location of the mesenchymal tissue in the thymoma tissue, and the degree of mesenchymal transformation in the thymoma microenvironment is reflected by calculating the average fluorescence intensity of the corresponding cells.

[0015] Preferably, in EBV-infected thymoma tissue, the average fluorescence intensity of the labeled antibody Vimentin is greater than the average fluorescence intensity of the labeled antibody E-Cadherin, indicating that epithelial-mesenchymal transition has occurred in the EBV-infected thymoma tissue; The average fluorescence intensity of the labeled antibody Vimentin was lower than that of the labeled antibody E-Cadherin, indicating that epithelial-mesenchymal transition did not occur in thymoma tissue infected with EB virus.

[0016] Preferably, the mean fluorescence intensity of E-Cadherin and Vimentin is statistically analyzed by ImageJ software, specifically using the following formula: Mean fluorescence intensity Mean = total fluorescence intensity of the region InDen / area of ​​the region Area; In EBV-infected thymoma tissues, the average fluorescence intensity of E-Cadherin was less than 128.655 and the average fluorescence intensity of Vimentin was greater than 501.987, indicating that epithelial-mesenchymal transition had occurred in EBV-infected thymoma tissues; In EBV-infected thymoma tissues, the average fluorescence intensity of E-Cadherin was greater than 543.956, and the average fluorescence intensity of Vimentin was less than 202.646, indicating that epithelial-mesenchymal transition did not occur in EBV-infected thymoma tissues.

[0017] The advantages and positive effects of the present invention are: using the method of using quantum dots to carry antibodies instead of multicolor immunofluorescence technology, eliminating the secondary antibody staining step, using direct labeling, and giving full play to the advantages of quantum dots themselves, the emission spectrum covers the entire visible light region, and it is not easy to have spectral overlap when multiple quantum dots are used at the same time, saving experimental time, improving efficiency and having good accuracy and sensitivity; By replacing fluorescent dyes with quantum dots, tissue sections can be directly labeled, and local positioning of epithelial cells and interstitial tissues in the thymoma microenvironment can be achieved. Both quantitative and positional detection can be achieved, facilitating the evaluation of epithelial-mesenchymal transition. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 The expression of Vimentin and E-Cadherin during epithelial-mesenchymal transition in thymoma tissue infected with Epstein-Barr virus; Figure 2 The expression of Vimentin and E-Cadherin in thymoma tissues infected with Epstein-Barr virus without epithelial-mesenchymal transition. DETAILED DESCRIPTION

[0019] The embodiments of the present invention are described below with reference to the accompanying drawings.

[0020] The present invention relates to a detection kit for epithelial-mesenchymal transition in Epstein-Barr virus infected thymoma and its application. The kit includes quantum dot-labeled antibody E-Cadherin, quantum dot-labeled antibody Vimentin, antigen repair solution and nucleic acid staining solution. Quantum dots are coupled with specific antibodies, and paraffin section samples of thymoma are stained by the quantum dots and specific antibody conjugates. The conjugates can be specifically connected to EMT-related antigens expressed in the sections, thereby achieving the qualitative or quantitative analysis of thymoma cells undergoing EMT by quantum dots. E-Cadherin is a connecting molecule between epithelial cells, and the antibody E-Cadherin marks the connection state between epithelial cells; Vimentin is a cell matrix marker, and the antibody Vimentin marks the matrix expression state; by detecting the content and location of E-Cadherin and / or Vimentin, the epithelial-mesenchymal transition in Epstein-Barr virus infected thymoma can be evaluated.

[0021] In certain embodiments of the present invention, the quantum dots are selected from QDs-585 and QDs-525, which are coupled with E-Cadherin and Vimentin to obtain QDs-585-Vimentin and QDs-525-E-Cadherin, respectively. The coupling of quantum dots with specific antibodies includes the following steps: A1: Activation of quantum dots: QDs, EDC, and NHS were mixed at a molar ratio of 1: (2500-3500): (5000-6000), preferably 1: 3000: 5500, diluted with PBS, mixed on a shaker at room temperature, and then the pH was adjusted to 8-9 with PBS to obtain an activated quantum dot solution; A2: Preparation of QDs-Ab conjugate: adding specific antibody to activated quantum dot solution, the molar ratio of quantum dots to specific antibody is 1:20-80; reacting on a shaker at 4°C in the dark, and obtaining QDs-Ab conjugate after reaction; A3: After the reaction is completed, centrifuge at 8000 rpm to remove possible agglomerated precipitates, retain the supernatant, and purify the supernatant using a PD10 column to finally obtain specific antibodies coupled to quantum dots that can be used for staining.

[0022] The detection kit for epithelial-mesenchymal transition in Epstein-Barr virus infected thymoma includes QDs-585-Vimentin and QDs-525-E-Cadherin prepared by the above method, as well as antigen repair solution Tris-EDTA and nucleic acid staining solution DAPI stain. QDs-585-Vimentin and QDs-525-E-Cadherin can specifically connect with the junction molecules between epithelial cells and interstitial markers, respectively, wherein the E-Cadherin antibody is coupled with the quantum dot QDs-525, and the emission light is displayed as green; the Vimentin antibody is coupled with the quantum dot QDs-585, and the emission light is displayed as orange; after staining the same tissue section in sequence, the content and relative position of the junction molecules between epithelial cells and the interstitial markers can be observed by color contrast differences, so as to judge the situation of epithelial-mesenchymal transition in Epstein-Barr virus infected thymoma.

[0023] When the above detection kit is used for the detection of epithelial-mesenchymal transition in thymoma infected with Epstein-Barr virus, the following steps may be specifically included: 1. Take paraffin specimens from patients with AB-type thymoma infected with EB virus and make tissue sections (the tissues are from surgical puncture or excision samples and the EBER in situ hybridization test is positive for EBV infection), bake the tissue sections and dewax and dehydrate them; 2. Perform antigen retrieval on tissue sections using a microwave oven; 3. Staining tissue sections with quantum dots and antibody conjugates. When there are multiple quantum dots and antibody conjugates, staining is performed in order from strong to weak specific proteins in the tissue. 4 After the quantum dot staining is completed, the cell nucleus is stained, the slides are sealed and photographed, the quantity and location information of epithelial cells and interstitial tissues are detected and analyzed, and the degree of EMT is evaluated by the ratio of epithelial indicators and interstitial indicators in thymoma tissues.

[0024] The quantum dot-labeled antibody E-Cadherin is used to detect the expression level of epithelial cells in thymoma tissue, and the average fluorescence intensity of the corresponding cells is calculated to reflect the degree of epithelial transformation in the thymoma microenvironment; and / or, the quantum dot-labeled antibody Vimentin is used to detect the expression level of stromal tissue in thymoma tissue, and the average fluorescence intensity of the corresponding cells is calculated to reflect the degree of transformation of the stromal tissue in the thymoma microenvironment.

[0025] The detection images were analyzed using ImageJ under default conditions, and the average fluorescence intensity of E-Cadherin and Vimentin was statistically analyzed using ImageJ software, specifically using the following formula; Mean fluorescence intensity Mean = total fluorescence intensity of the region InDen / area of ​​the region Area; The expression level of E-Cadherin or Vimentin can be quantified by the average fluorescence intensity representing the E-Cadherin or Vimentin quantum dots.

[0026] Through observation under a fluorescence microscope and statistics using ImageJ software, in EBV-infected thymoma tissues, the average fluorescence intensity of E-Cadherin was less than 128.655 and the average fluorescence intensity of Vimentin was greater than 501.987, indicating that epithelial-mesenchymal transition had occurred in EBV-infected thymoma tissues. The expression levels of related indicators when epithelial-mesenchymal transition occurred are shown in Table 1: Table 1

[0027] Through observation under a fluorescence microscope and statistics using ImageJ software, the average fluorescence intensity of E-Cadherin was greater than 543.956, and the average fluorescence intensity of Vimentin was less than 202.646, indicating that epithelial-mesenchymal transition did not occur in thymoma tissue infected with EB virus. The expression levels of related indicators when epithelial-mesenchymal transition did not occur are shown in Table 2: Table 2

[0028] By replacing fluorescent dyes with quantum dots, it is possible to detect the epithelial-mesenchymal transition of thymoma cells infected with Epstein-Barr virus. The detection method is simple and quick, which is convenient for clarifying the relationship between Epstein-Barr virus and thymoma. By replacing fluorescent dyes with quantum dots, it is possible to directly label tissue sections and localize epithelial cells and mesenchymal tissues in the thymoma microenvironment. It can detect both quantity and position, which is convenient for evaluating EMT.

[0029] The scheme of the present invention is described below in conjunction with the accompanying drawings, wherein the experimental methods without specific operating steps are all carried out in accordance with the corresponding product instructions, and the instruments, reagents, and consumables used in the examples can all be purchased from commercial companies unless otherwise specified.

[0030] Example 1: Preparation of QDs-Ab conjugates The quantum dots used in this embodiment are QDs-525 and QDs-585.

[0031] QDs, EDC, and NHS were mixed at a molar ratio of 1:3000:5500, diluted with PBS, and mixed on a shaker at room temperature for 30 minutes, and then the pH was adjusted to 8-9 with PBS (pH 9.18) to obtain quantum dot activation solution. 100ul of quantum dot activation solution was added to the reaction container. An appropriate amount of antibody stock solution was taken, diluted to 0.01mg / ml with PBS buffer, mixed thoroughly, and added to the above reaction container according to different ratios (reference quantum dots: antibody protein molar ratio of 1:20, 1:40, 1:80 for labeling), and reacted on a shaker at 4℃ in the dark for 4 hours.

[0032] After the reaction is completed, centrifuge at 8000 rpm for 3 minutes to remove possible agglomerated precipitates and keep the supernatant.

[0033] 1% agarose gel electrophoresis was used to detect and analyze, and the best conditions were screened. The supernatant obtained under the best coupling conditions was purified using a PD10 column, and the purified product was stored in a refrigerator at 4°C away from light for later use.

[0034] Example 2: Detection of E-Cadherin and Vimentin in thymoma tissue infected with EB virus Quantum dot-coupled antibodies QDs-585-Vimentin and QDs-525-E-Cadherin were prepared according to the preparation method of Example 1. The antibody E-Cadherin is available in abcam / ab40772, and the antibody Vimentin is available in abcam / ab92547.

[0035] Fifty AB-type thymoma tumor tissue specimens infected with EB virus were collected (positive EBER in situ hybridization test indicated EB virus infection, and the above samples were obtained from puncture or surgical specimens), and the specimens were soaked in 4% formalin for more than 48 hours; wax blocks were made from thymoma tissue specimens and placed on a microtome to make 3-4μm tissue sections. Information such as the source of the sections, staining index, date, and antibody ratio were recorded before staining began.

[0036] Place the tissue slices in a 60°C oven for 30 minutes for baking. Dewax and dehydrate, transfer the slices to No. 1 100% xylene for 15 minutes, No. 2 100% xylene for 15 minutes, No. 3 100% ethanol for 3 minutes, No. 4 100% ethanol for 3 minutes, No. 5 95% ethanol for 3 minutes, No. 6 75% ethanol for 3 minutes, No. 7 50% ethanol for 3 minutes, and rinse with PBS 3 times for 5 minutes each time.

[0037] Antigen repair was performed on the dewaxed and dehydrated tissue sections. During antigen repair, acidic or alkaline antigen repair solution was selected according to the instructions of the corresponding antibody; the antigen repair solution was added to the container, placed in a microwave oven to heat and boil, and then the tissue sections were placed in the container, and heated on medium-low heat for 10 minutes before being taken out; after the tissue sections naturally cooled to room temperature, they were transferred to the immunohistochemistry washing box, washed with sterile water for 1 minute, and washed with 1×TBST for 2 minutes. The tissue was enclosed with an immunohistochemistry pen so that the entire tissue block on the section was located inside the seal.

[0038] First round of dyeing: Blocking: Remove 1× TBST solution, slowly add 10% BSA, and incubate at room temperature for 10 minutes.

[0039] Prepare antibodies: dilute the antibodies with 1×PBS to prepare QDs-525-E-Cadherin quantum dot labeled antibody solution.

[0040] Incubation with the first antibody: remove excess serum, add QDs-525-E-Cadherin quantum dot labeled antibody, place the tissue sections flat in an immunohistochemistry humidified box, and then place in a 4°C refrigerator overnight.

[0041] Rinse: Rinse three times with a wash bottle containing 1×TBST, 2 minutes each time, to remove unbound QDs-585-CD19 quantum dot-labeled antibodies.

[0042] After the first round of staining, the second round of staining was performed; Blocking: Remove 1× TBST solution, slowly add 10% BSA, and incubate at room temperature for 10 minutes.

[0043] Prepare antibodies: dilute the antibodies with 1×PBS to prepare QDs-585-Vimentin quantum dot-coupled antibody solution.

[0044] Secondary antibody incubation: remove excess serum, add QDs-585-Vimentin quantum dot-coupled antibody, place tissue sections flat in an immunohistochemistry humidified box, and then place in a 4°C refrigerator overnight.

[0045] Rinse: Rinse three times with a wash bottle containing 1×TBST, 2 minutes each time, to remove unbound QDs-625-CD1d quantum dot-coupled antibodies.

[0046] For the stained tissue sections, perform nuclear staining and use ddH20 1:100 to prepare 1×DAPI solution; add 1×DAPI solution to the sliced ​​tissue, incubate at room temperature in the dark for 5 minutes, rinse with 1×TBST for 2 minutes, and rinse with ddH2O for 1 minute. After removing the excess liquid on the slice, add 30μl of anti-fade mounting medium, then cover with a coverslip. After the tissue slice is stable, use a fluorescence microscope equipped with a 488nm laser to observe the results and take pictures. Among them, the green light signal represents E-Cadherin and the orange light signal represents Vimentin. The average fluorescence intensity of E-Cadherin and Vimentin was statistically analyzed by ImageJ software, and the specific formula is as follows; Mean fluorescence intensity Mean = total fluorescence intensity of the region InDen / area of ​​the region Area; The expression level of E-Cadherin or Vimentin can be quantified by the average fluorescence intensity representing the E-Cadherin or Vimentin quantum dots.

[0047] Through testing, it was found that among the 50 samples tested, there were 31 patients whose average fluorescence intensity of Vimentin was greater than that of E-Cadherin. In the data of these 31 samples, the maximum average fluorescence intensity of E-Cadherin was 128.655, and the minimum average fluorescence intensity of Vimentin was 501.987. It can be seen that in EBV-infected thymoma tissue, when the average fluorescence intensity of E-Cadherin was less than 128.655 and the average fluorescence intensity of Vimentin was greater than 501.987, it indicates that epithelial-mesenchymal transition has occurred in EBV-infected thymoma tissue.

[0048] Among the 50 samples tested, there were 19 patients whose average fluorescence intensity of E-Cadherin was greater than that of Vimentin. In the data of these 19 samples, the minimum average fluorescence intensity of E-Cadherin was 543.956, and the maximum average fluorescence intensity of Vimentin was 202.64. It can be seen that in EBV-infected thymoma tissue, when the average fluorescence intensity of E-Cadherin was greater than 543.956 and the average fluorescence intensity of Vimentin was less than 202.64, it indicates that epithelial-mesenchymal transition did not occur in EBV-infected thymoma tissue.

[0049] like Figure 1The following is the expression of quantum dot-labeled Vimentin and E-Cadherin in a thymoma tissue sample infected with EB virus. Figure 1 In the thymoma tissue infected with EB virus shown in the figure, the expression of mesenchymal marker Vimentin is higher than that of epithelial marker E-Cadherin, wherein the average fluorescence intensity of E-Cadherin is 125.609 and the average fluorescence intensity of Vimentin is 503.477, which indicates that epithelial-mesenchymal transition has occurred in this sample.

[0050] like Figure 2 The following is the expression of Vimentin and E-Cadherin labeled by quantum dots in another thymoma tissue sample infected with EB virus. Figure 2 As shown, in the thymoma tissue infected with EB virus, the expression of the mesenchymal marker Vimentin is low, while the expression of the epithelial marker E-Cadherin is high. The average fluorescence intensity of E-Cadherin is 546.218, and the average fluorescence intensity of Vimentin is 200.833. It can be seen that the sample did not undergo epithelial-mesenchymal transition.

[0051] From the experimental results, we can know that in thymoma tissue infected with EB virus, by comparing the contents of Vimentin and E-Cadherin in the same tissue section, the epithelial-mesenchymal transition of the section can be clearly judged according to its average fluorescence intensity.

[0052] The embodiments of the present invention are described in detail above, but the contents described are only preferred embodiments of the present invention and cannot be considered to limit the scope of implementation of the present invention. All equivalent changes and improvements made within the scope of the present invention should still fall within the scope of the patent coverage of the present invention.

Claims

1. A detection kit, characterized in that: Including quantum dot-labeled antibody E-Cadherin and quantum dot-labeled antibody Vimentin.

2. The detection kit according to claim 1, characterized in that: It includes quantum dot-antibody conjugates QDs-585-Vimentin, QDs-525-E-Cadherin, antigen repair solution and nucleic acid staining solution.

3. The detection kit according to claim 1 or 2, characterized in that: The quantum dots, EDC and NHS are mixed at a molar ratio of 1:2500-3500:5000-6000 to activate the quantum dots, and the antibody is added to the activated quantum dot solution, the molar ratio of quantum dots to antibodies is 1:20-80, and QDs-Ab conjugates are obtained after the reaction; the supernatant is taken as a quantum dot-labeled antibody solution that can be used for staining.

4. Use of the detection kit according to any one of claims 1 to 3 in the detection of epithelial-mesenchymal transition in Epstein-Barr virus-infected thymoma for non-disease diagnosis and treatment purposes.

5. The use according to claim 4, characterized in that: Prepare thymoma tissue sections, use antigen retrieval solution to perform antigen retrieval, then use different quantum dot-labeled antibodies to stain the tissue sections, then stain the cells, collect fluorescence information of the tissue sections, and determine the expression level and spatial position of epithelial cells and / or mesenchymal cells in the tissue sections based on the fluorescence information.

6. The use according to claim 5, characterized in that: The tissue sections after antigen retrieval were stained with one or both of the quantum dot-antibody conjugates QDs-585-Vimentin and QDs-525-E-Cadherin.

7. The use according to claim 5, characterized in that: The quantum dot-labeled antibody E-Cadherin was used to detect the expression and spatial location of epithelial cells in thymoma tissues, and the average fluorescence intensity of the corresponding cells was calculated to reflect the degree of epithelial transformation in the thymoma microenvironment. And / or, the quantum dot-labeled antibody Vimentin is used to detect the expression amount and spatial location of the mesenchymal tissue in the thymoma tissue, and the degree of mesenchymal transformation in the thymoma microenvironment is reflected by calculating the average fluorescence intensity of the corresponding cells.

8. The use according to claim 7, characterized in that: In EBV-infected thymoma tissues, the average fluorescence intensity of the labeled antibody Vimentin was greater than that of the labeled antibody E-Cadherin, indicating that epithelial-mesenchymal transition had occurred in EBV-infected thymoma tissues; The average fluorescence intensity of the labeled antibody Vimentin was lower than that of the labeled antibody E-Cadherin, indicating that epithelial-mesenchymal transition did not occur in thymoma tissue infected with EB virus.

9. The use according to claim 8, characterized in that: In EBV-infected thymoma tissues, the average fluorescence intensity of E-Cadherin was less than 128.655 and the average fluorescence intensity of Vimentin was greater than 501.987, indicating that epithelial-mesenchymal transition had occurred in EBV-infected thymoma tissues; In EBV-infected thymoma tissues, the average fluorescence intensity of E-Cadherin was greater than 543.956, and the average fluorescence intensity of Vimentin was less than 202.646, indicating that epithelial-mesenchymal transition did not occur in EBV-infected thymoma tissues.

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