Nectin-4 targeted nucleic acid aptamer diagnosis and treatment integrated probe

Abstract

The invention discloses a Nectin-4 targeted nucleic acid aptamer diagnosis and treatment integrated probe, and relates to the field of biotechnology and diagnosis and treatment integration and treatment, and the Nectin-4 targeted nucleic acid aptamer diagnosis and treatment integrated probe comprises a Nectin-4 targeted nucleic acid aptamer and Vc-MMAE; the Nectin-4 targeting nucleic acid aptamer is connected with the Vc-MMAE through coupling, and the Nectin-4 targeting nucleic acid aptamer is connected with the Vc-MMAE through coupling; wherein the Nectin-4 targeting nucleic acid aptamer has a base sequence as shown in any one of SEQ ID NO.1-3, or has a base sequence of which the homology with the base sequence as shown in any one of SEQ ID NO.1-3 is more than 80%. The diagnosis and treatment integrated probe prepared by the invention realizes targeted diagnosis and treatment on Nectin-4 receptor protein overexpression tumors, and the probe is good in specific targeting effect and small in toxic and side effects.

Description

Technical Field

[0001] The present invention relates to the fields of biotechnology and integrated diagnosis and treatment, and particularly to a Nectin-4-targeted nucleic acid aptamer integrated diagnosis and treatment probe. Background Art

[0002] At present, the early clinical diagnosis of bladder cancer still has limitations. For example, traditional cystoscopy is invasive and may cause complications, and urine cytology detection has low sensitivity and is prone to false negatives or false positives, thus affecting clinical diagnosis and treatment decisions. There is an urgent need to develop new targeted diagnosis and treatment technologies.

[0003] In recent years, studies have found that Nectin-4 is overexpressed in a variety of malignant tumors, including bladder cancer, breast cancer, ovarian cancer, colorectal cancer, prostate cancer, and lung cancer, etc. Due to the high expression of Nectin-4 in a variety of tumors, it has become an important target for antibody-drug conjugates (ADCs). MMAE is a highly toxic microtubule inhibitor that cannot be used as a drug alone. Currently, it is mostly used to form antibody-drug conjugates with antibodies for targeted treatment of tumors. However, antibodies have many problems, such as high immunogenicity, high cost, large batch-to-batch differences, difficult modification, and the need for low temperature for storage and transportation. Nucleic acid aptamers (Apt) are known as the antibodies of chemists and have advantages over antibodies such as short screening time, easy chemical modification, low cost, high affinity, and good biocompatibility, showing great application potential in the field of tumor targeted diagnosis and treatment. In tumor detection, aptamers can target tumor-specific proteins, providing a new approach for non-invasive diagnosis and targeted treatment.

[0004] Therefore, those skilled in the art are committed to developing an integrated diagnosis and treatment probe with a nucleic acid aptamer as the targeting head, which has good specific targeting effect and low toxicity and side effects through reasonable design of molecular probes, and ultimately realizes the integrated diagnosis and treatment of tumors. Summary of the Invention

[0005] In view of the deficiencies of the prior art, the present invention provides a Nectin-4-targeted nucleic acid aptamer integrated diagnosis and treatment probe.

[0006] Diagnostic and therapeutic integrated probe In one aspect, the present invention provides a Nectin-4-targeted nucleic acid aptamer integrated diagnosis and treatment probe, including a Nectin-4-targeted nucleic acid aptamer and Vc-MMAE; the Nectin-4-targeted nucleic acid aptamer and Vc-MMAE are connected by coupling; Wherein, the Nectin-4-targeted nucleic acid aptamer has a base sequence shown in any one of SEQ ID NO.1-3, or a base sequence with a homology of more than 80% to the base sequence described in any one of SEQ ID NO.1-3.

[0007] In some embodiments, the Nectin-4 targeting nucleic acid aptamers of the present invention have a DNA or RNA base sequence as shown in SEQ ID No. 1, 2 or 3, and the specific nucleic acid aptamer names corresponding thereto in the present invention are NT1, NT2, and NT3.

[0008] In other embodiments, the present invention also provides a variant of the Nectin-4 targeting nucleic acid aptamer, which is a DNA or RNA sequence having at least 80%, 81%, 82%, 83%, 84%, 85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99% or higher homology with the base sequence shown in SEQ ID No. 1, 2 or 3, and substantially retains the biological function of the nucleic acid aptamer from which it is derived (such as the biological activity of specifically binding to Nectin-4).

[0009] More specifically, the variant differs from the Nectin-4 targeting nucleic acid aptamer as described herein only by the deletion, substitution and / or insertion of one or more nucleic acid bases (for example, deletion, substitution and / or insertion of up to 20, up to 15, up to 10, up to 5 or up to 1 nucleic acid bases). The deletion of the nucleic acid base refers to knocking out one or more bases in the nucleic acid sequence. The substitution of the nucleic acid base refers to substituting one or more bases in the nucleic acid sequence with another or more bases, specifically changing adenine (A), guanine (G), cytosine (C), thymine (T), hydroxy purine or uracil (U) to another base, for example, substituting adenine with cytosine, thymine, uracil, hydroxy purine or guanine; substituting cytosine with adenine, thymine, uracil, hydroxy purine or guanine; substituting guanine with cytosine, thymine, uracil, hydroxy purine or adenine; substituting thymine with adenine, cytosine, uracil, hydroxy purine or guanine; substituting uracil with cytosine, thymine, adenine, hydroxy purine or guanine; substituting hydroxy purine with adenine, thymine, uracil or guanine. The insertion of the nucleic acid base refers to inserting one or more bases at one or more positions in the nucleic acid sequence.

[0010] As used herein, the sequence "homology" refers to the percentage of corresponding bases that are the same according to position, which can indicate the similarity level (also referred to as sequence identity, similarity or identity) between two or more nucleic acids.

[0011] As used herein, the Nectin-4 targeting nucleic acid aptamer can specifically bind to Nectin-4.

[0012] The term "specific binding" refers to a non-random binding reaction between two molecules, such as the reaction between an antibody and the antigen it targets. The strength or affinity of a specific binding interaction can be represented by the equilibrium dissociation constant (K D ). The smaller the equilibrium dissociation constant, the tighter the nucleic acid aptamer-antigen binding and the higher the affinity between the nucleic acid aptamer and the antigen.

[0013] The specific binding property between two molecules can be determined using methods well known in the art. One method involves measuring the rates of antigen binding site / antigen complex formation and dissociation. The "association rate constant" (k a or k on ) and the "dissociation rate constant" (k dis or k off ) can both be calculated from the concentrations and the actual rates of association and dissociation (see Malmqvist M, Nature, 1993, 361:186-187). The ratio of k dis / k on is equal to the dissociation constant K D (see Davies et al., Annual Rev Biochem, 1990; 59:439-473). Any effective method can be used to measure K D , k on and k dis values. In some embodiments, surface plasmon resonance (SPR) in a Biacore can be used to measure the dissociation constant. In addition, bioluminescence interferometry or Kinexa can also be used to measure the dissociation constant.

[0014] In the present invention, the Vc-MMAE, also known as mc-vc-PAB-MMAE, is a derivative of MMAE with a valine-citrulline (Vc) linker and is a drug-linker conjugate with antitumor activity, used for the synthesis of antibody-drug conjugates (ADCs).

[0015] In some embodiments, the Vc-MMAE is conjugated by reacting with the terminal thiol group of the nucleic acid aptamer.

[0016] In a specific embodiment, the present invention provides a Nectin-4-targeted nucleic acid aptamer theranostic probe Apt-MMAE, which enables non-invasive visualization detection of cells overexpressing the Nectin-4 receptor protein and further realizes the treatment of malignant bladder cancer.

[0017] Preparation method In one aspect, the present invention provides a method for preparing a Nectin-4-targeted nucleic acid aptamer theranostic probe, specifically including the following steps: S1. Prepare the Nectin-4-targeted nucleic acid aptamer after stability modification; S2. Conduct a coupling reaction between the Nectin-4-targeted nucleic acid aptamer after stability modification and Vc-MMAE to obtain the theranostic probe.

[0018] Composition In another aspect, the present invention provides a composition comprising the Nectin-4-targeted nucleic acid aptamer theranostic probe as described herein. The composition can be used for visualizing the expression of Nectin-4, diagnosing Nectin-4-related tumors, predicting the progression and prognosis of Nectin-4-related tumors, predicting the therapeutic effect of Nectin-4-related tumors, and / or treating Nectin-4-related tumors.

[0019] In some embodiments, the composition can be a pharmaceutical composition.

[0020] In some embodiments, the pharmaceutical composition may further comprise a pharmaceutically acceptable carrier and / or excipient.

[0021] In some embodiments, the pharmaceutical composition may further comprise an additional pharmaceutically active agent.

[0022] In some embodiments, the additional pharmaceutically active agent is an anti-inflammatory drug or an immunosuppressant.

[0023] In some embodiments, in the pharmaceutical composition, the Nectin-4-targeted nucleic acid aptamer theranostic probe as described herein and the additional pharmaceutically active agent can be provided as separate components or as mixed components. Therefore, the Nectin-4-targeted nucleic acid aptamer theranostic probe as described herein and the additional pharmaceutically active agent can be administered simultaneously, separately, or sequentially.

[0024] In some embodiments, the pharmaceutically acceptable carrier and / or excipient may comprise a sterile injectable liquid (such as an aqueous or non-aqueous suspension or solution). In certain exemplary embodiments, such sterile injectable liquids are selected from water for injection (WFI), bacteriostatic water for injection (BWFI), sodium chloride solution (e.g., 0.9% (w / v) NaCl), glucose solution (e.g., 5% glucose), solution containing a surfactant (e.g., 0.01% polysorbate 20), pH buffer solution (e.g., phosphate buffer solution), Ringer's solution, and any combination thereof.

[0025] The pharmaceutical composition of the present invention may include a "therapeutically effective amount" of the Nectin-4-targeted nucleic acid aptamer theranostic probe as described herein. A "therapeutically effective amount" refers to an amount sufficient to cure or at least partially arrest the disease and its complications in a patient suffering from the disease. The therapeutically effective amount may vary depending on factors such as the severity of the disease to be treated, the overall status of the patient's own immune system, the general condition of the patient such as age, weight and gender, the mode of administration of the drug, and other treatments administered simultaneously, etc.

[0026] Kit The present invention also provides a kit comprising the Nectin-4-targeted nucleic acid aptamer theranostic probe as described herein.

[0027] The kit can be used for visualizing the expression of Nectin-4, diagnosing Nectin-4-related tumors, predicting the progression and prognosis of Nectin-4-related tumors, predicting the therapeutic effect of Nectin-4-related tumors and / or treating Nectin-4-related tumors.

[0028] The kit may further comprise a container, instructions for use, and other reagents and buffers required for practical applications, such as a lysis medium for dissolving samples, various buffers, detection labels, detection substrates, etc.

[0029] Diagnostic and therapeutic applications In the Nectin-4-targeted nucleic acid aptamer theranostic probe of the present invention, the Nectin-4-targeted nucleic acid aptamer used has extremely high affinity for Nectin-4, and thus can be used for visualizing the expression of Nectin-4, diagnosing Nectin-4-related tumors, predicting the progression and prognosis of Nectin-4-related tumors, predicting the therapeutic effect of Nectin-4-related tumors and / or treating Nectin-4-related tumors.

[0030] As used herein, Nectin-4-related tumors may include various tumors or cancers well known in the art. For example, Nectin-4-related tumors are tumors with abnormally high expression of Nectin-4, which may include bladder tumors with abnormally high expression of Nectin-4. The present invention uses a tumor-bearing mouse model of advanced bladder cancer to verify the molecular radioimaging and therapeutic efficacy of the targeted nucleic acid aptamer theranostic probe.

[0031] Advantages of the present invention: The sequence of the nucleic acid aptamer used in the present invention can be solid-phase synthesized using a DNA synthesizer; the sequence can be customized; and the difference between batches is small. The nucleic acid aptamer itself has targeting and tumor specificity, and can achieve tumor-specific drug enrichment and tumor killing. At the same time, the diagnostic and therapeutic probe Apt-MMAE formed by conjugating the Vc-MMAE drug with the nucleic acid aptamer can be used for non-invasive visual molecular imaging and treatment of malignant bladder cancer, achieving targeted treatment of tumors and reducing the toxic side effects of drugs. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] Figure 1 It is a schematic diagram of the result of examining the targeting binding ability of the nucleic acid aptamer by flow cytometry in Example 1 of the present invention; Figure 2 It is a schematic diagram of the result of examining the remaining toxicity of Apt-MMAE to T24 cells by CCK8 experiment in Example 1 of the present invention; Figure 3 It is a schematic diagram of the result of examining the remaining toxicity of Apt-MMAE to BFTC905 cells by CCK8 experiment in Example 1 of the present invention; Figure 4 It is a fluorescence imaging diagram of animals in the experimental group (NT1-MMAE, NT3-MMAE), blank group (Saline), control group (Vc-MMEA), and control group (lib-MMAE) at different times during in-situ administration treatment in Example 3 of the present invention; Figure 5 It is a schematic diagram of the result of examining the targeted treatment effect of the experimental group (NT1-MMAE, NT3-MMAE), blank group (Saline), control group (Vc-MMEA), and control group (lib-MMAE) through in-vivo experiments on mice in Example 3 of the present invention; among them, Figure 5 A is the change curve of the in-situ tumor fluorescence intensity in fluorescence imaging; Figure 5 B is the result of the tumor weight and the tumor photo. DETAILED DESCRIPTION OF THE INVENTION

[0033] The following introduces multiple preferred embodiments of the present invention with reference to the accompanying drawings of the specification, making its technical content clearer and easier to understand. The present invention can be embodied in many different forms of embodiments, and the protection scope of the present invention is not limited to the embodiments mentioned in the text.

[0034] The nucleic acid aptamer involved in the embodiments of the present invention is a synthetic single-stranded DNA or RNA, which is usually obtained by in-vitro screening using the systematic evolution of ligands by exponential enrichment (SELEX) method, and has high affinity and specificity with the target ligand.

[0035] In an embodiment of the present invention, a Nectin-4 targeted aptamer-based theranostic probe Apt-MMAE- is disclosed, which is composed of a Nectin-4 targeted aptamer (Apt) and a drug. Among them, Apt (Aptmer) is any one of NT1, NT2, and NT3, and the drug is Vc-MMAE; the chemical formula of the aptamer-based theranostic probe is: ; Among them, Aptamer represents a Nectin-4 targeted aptamer.

[0036] In the aptamer-based theranostic probe, the Nectin-4 targeted aptamer NT1 is obtained by screening through the exponential enrichment ligand evolution technology of Nectin-4 protein. Specifically, it is from a large number (10 12 ~10 15 ) of random nucleic acid sequences (that is, when synthesizing DNA, after selecting a specific number of bases, the base types are not specified, and during the synthesis process, randomly combined to obtain a library with the same length but random sequences), by screening sequences that specifically bind to Nectin-4 protein and do not bind to human serum albumin, and after multiple rounds of screening, a specific Nectin-4 targeted nucleic acid sequence is obtained. The Nectin-4 targeted aptamers NT2 and NT3 are obtained by simulating the other two specific Nectin-4 targeted nucleic acid sequences obtained by the same method as described above to obtain their conformational information, and then truncating the full-length sequences step by step while ensuring that the specific conformation of each sequence remains unchanged and the change in Gibbs free energy △G is not significant.

[0037] In a specific embodiment, the preparation process of the Nectin-4 targeted aptamer-based theranostic probe is described in detail, and its retained toxicity is verified.

[0038] In another specific embodiment, the process of constructing a Nectin-4 expressing positive bladder cancer-bearing mouse model is described in detail. The tumor-bearing mice with the constructed malignant bladder cancer tumor model are used to verify the molecular imaging and therapeutic efficacy of the Nectin-4 targeted aptamer-based theranostic probe on bladder cancer.

[0039] In the following examples, the T24 cells used were purchased from the Cell Bank of the Chinese Academy of Sciences, the BFTC905 cells were purchased from the Cell Bank of the Chinese Academy of Sciences, and the Scaber-luc cells were purchased from the Cell Bank of the Chinese Academy of Sciences; all the reagents used were commercially available or prepared by existing methods.

[0040] In the following examples, all the nucleic acid sequences were synthesized by solid-phase synthesis.

[0041] Example 1 A preparation method of a Nectin-4-targeted aptamer-based theranostic probe (Apt-MMAE) specifically includes the following steps: (1) Preparation of aptamer with a thiol group modified at the end: Prepared by a conventional commercial modification method, a thiol group is respectively modified at the end (5') of the sequences of aptamers NT1, NT2, and NT3 to obtain aptamers with a thiol group modification at the end; The sequence (SEQ ID NO.1) of the aptamer NT1 is: 5'-CGTACGGTCGACGCTAGCCGAGGTGCTCGTTGGAGTGGATTGCAAAGGACTGCTGTTCCACGTGGAGCTCGGATCC-3'; The sequence (SEQ ID NO.2) of the aptamer NT2 is: 5'-AGCAGTCAAAGGGCCTGGCGTCCCGATTGGGGAAGTTGATTGCCAC-3'; The sequence (SEQ ID NO.3) of the aptamer NT3 is: 5'-ACGCTAGCAGTCAAAGGGCCTGGCGTCCCGATTGGGGAAGTTGATTGCCACGTGGA-3'.

[0042] (2) Conjugation of Vc-MMAE with the aptamer with a thiol group modification at the end: This step is entrusted to Bioengineering (Shanghai) Co., Ltd. for preparation.

[0043] (3) Verification of the targeting binding ability: The targeting binding ability of the prepared aptamer-based theranostic probe is investigated by flow cytometry. The specific steps are as follows: 250 nM of the aptamer-based theranostic probes (NT1-MMAE, NT2-MMAE, NT3-MMAE), the pure aptamers (NT1, NT2, NT3), and the control probe (Control) are conjugated with the fluorescent group Cy5 and then incubated with bladder cancer cells T24 in a 200 μl buffer system for 30 minutes respectively. After washing, the fluorescence on the cell surface is detected.

[0044] The control probe is a conjugate of a fluorescently labeled random sequence and Vc-MMAE. The random sequence is a library obtained by randomly combining bases during DNA synthesis without specifying the base type after selecting a specific number of 76 bases.

[0045] The results are as Figure 1 shown. Figure 1The results show that compared with simple nucleic acid aptamers, the prepared nucleic acid aptamer theranostic probes all retain the specific targeting of nucleic acid aptamers.

[0046] (4)Test for the retained toxicity to T24 cells: Different concentrations of nucleic acid aptamer theranostic probes (NT1-MMAE, NT2-MMAE, NT3-MMAE) and Vc-MMAE were incubated with bladder cancer cells T24 in a 200 μl buffer system respectively. After 24 hours, CCK-8 was added, the absorbance value was detected, and the cell survival rate was calculated. The results are as Figure 2 shown. As can be seen from Figure 2 the results, compared with simple Vc-MMAE (IC50 value is 1247 nM), the three nucleic acid aptamer theranostic probes prepared in the examples of the present invention all retain their toxicity, and due to the improved binding ability to target cells, the drug efficacy is improved (compared with simple Vc-MMAE, the IC50 values of the three nucleic acid aptamer theranostic probes decreased to 103.4 - 327.1 nM).

[0047] (5)Test for the retained toxicity to BFTC905 cells: Different concentrations of nucleic acid aptamer theranostic probe (NT1-MMAE) and Vc-MMAE were incubated with BFTC905 cells in a 200 μl buffer system respectively. After 24 hours, CCK-8 was added, the absorbance value was detected, and the cell survival rate was calculated. The results are as Figure 3 shown. As can be seen from Figure 3 the results, compared with simple Vc-MMAE (IC50 value is 93.32 nM), the drug efficacy of the nucleic acid aptamer theranostic probe NT1-MMAE is improved (the IC50 value of NT1-MMAE decreased to 1.418 nM).

[0048] Example 2 Construct a Nectin-4 expression positive bladder cancer xenograft mouse model. Specifically, it includes the following steps: (1)Use the bladder cancer tumor cell Scaber-luc cell line with positive Nectin-4 determined by Western blot for subculture in advance; (2)Digest the cultured Scaber-luc tumor cells with 0.25% trypsin digestion solution, resuspend them in cell culture medium with DPBS, and then mix them with Matrigel (Corning 354234), and the volume ratio of the two is 1:1. Place the mixed cell suspension on ice and perform tumor implantation as soon as possible; (3)Take 20 μl of the cell suspension prepared in step (2) (which contains 4×10 5Cells), were injected into the bladders of 4- to 5-week-old Balb / c nude mice (purchased from Hangzhou Ziyuan Laboratory Animal Technology Co., Ltd.) to establish an orthotopic transplantation tumor model.

[0049] Example 3 A Nectin-4-targeted nucleic acid aptamer theranostic probe (Apt-MMAE) was used for intravesical perfusion treatment of bladder tumors. The specific steps are as follows: (1) 50 μl of 0.2 μM Apt-MMAE was intravesically perfused into each orthotopic tumor-bearing mouse (8 mice per group, once a week for 4 weeks) as the experimental group, the blank group (Saline) was perfused with an equal volume of normal saline, the control group 1 (Vc-MMAE) was perfused with an equal volume of Vc-MMAE at a concentration of 10 μM, and the control group 2 (Lib-MMAE) was perfused with an equal volume of a control probe at a concentration of 0.2 μM. This control probe was formed by conjugating Vc-MMAE with a random sequence lib of the nucleic acid aptamer Nectin-4 replacing the nucleic acid aptamer Nectin-4 of the present invention; the random sequence Lib of Nectin-4 was obtained by randomly combining a library with a specific base number of 76 during DNA synthesis without specifying the base type, resulting in a library with the same length but random sequences.

[0050] (2) In this example, the tumors of the tumor-bearing mice were constructed using Scaber-luc cells. Therefore, by intraperitoneally injecting the luciferase substrate, the tumors could autofluoresce. The size of the tumors in the mice could be observed by observing the fluorescence at the tumor sites of the mice using a small animal imager. The fluorescence at the tumor sites of the mice was observed every 7 days after administration, and the experiment was terminated after 4 weeks of continuous observation, and all the mice were euthanized. As Figure 4 shown, the experimental results showed that the nucleic acid aptamer-drug conjugates (i.e., NT1-MMAE, NT3-MMAE) prepared in this Example 1 had the ability to inhibit the growth of orthotopic tumors compared with the control random sequence drug conjugates (Lib-MMAE).

[0051] After the treatment was completed, the mice in each group were euthanized to end the experiment. After dissection, the weights of the bladder tumors were measured and photographed. As Figure 5 shown in A, by measuring the autofluorescence of the tumors to evaluate the tumor treatment effect, the nucleic acid aptamer-drug conjugate had a similar efficacy to Vc-MMAE and could effectively inhibit tumors. At the same time, as Figure 5As shown in B, the tumor weight of the experimental group was significantly smaller than that of the above-mentioned normal saline blank group and the control group 2 of the random sequence drug conjugate; compared with the control group 1 of the pure drug, the treatment effect of the experimental group was comparable. In particular, the treatment effect of the experimental group using NT3-MMAE was closest to that of the control group 1 of the pure drug, but the drug concentration used in the experimental group of NT3-MMAE was only one-fiftieth (0.02 times) of the drug concentration used in the control group 1 of the pure drug. This shows that due to the drug aggregation caused by targeting, its treatment effect is better than that of the pure drug. Therefore, the nucleic acid aptamer diagnosis and treatment integrated probe constructed by the present invention can show an effective treatment effect on bladder cancer at a low dose. In addition, the body weights of all mice in this experiment fluctuated within a small range, and no serious toxic and side effects occurred. This experiment verified the ability of the Nectin-4-targeted nucleic acid aptamer diagnosis and treatment integrated probe to inhibit tumor growth, and no obvious physiological toxicity was found.

[0052] The preferred specific embodiments of the present invention have been described in detail above. It should be understood that those of ordinary skill in the art can make many modifications and variations according to the concept of the present invention without creative work. Therefore, all technical solutions that can be obtained by those skilled in the art in the technical field based on the concept of the present invention through logical analysis, reasoning or limited experiments on the basis of the prior art should be within the protection scope determined by the claims.

Claims

1. A Nectin-4-targeted aptamer-based theranostic probe, characterized in that, The diagnosis and treatment integrated probe comprises a Nectin-4 targeting nucleic acid aptamer and Vc-MMAE; the Nectin-4 targeting nucleic acid aptamer and Vc-MMAE are connected by coupling; Among them, the Nectin-4 targeting nucleic acid aptamer has a base sequence shown in any one of SEQ ID NO.1 to 3.

2. The Nectin-4 targeted nucleic acid aptamer-based theranostic probe according to claim 1, wherein The Nectin-4 targeting nucleic acid aptamer has a base sequence shown in SEQ ID NO.

1.

3. The Nectin-4-targeted nucleic acid aptamer-based theranostic probe according to claim 1, wherein The Nectin-4 targeting nucleic acid aptamer has a base sequence shown in SEQ ID NO.

2.

4. The Nectin-4-targeted aptamer-based theranostic probe according to claim 1, wherein The Nectin-4 targeting nucleic acid aptamer has a base sequence shown in SEQ ID NO.

3.

5. The Nectin-4-targeting aptamer-based theranostic probe according to any one of claims 1 to 4, characterized in that, The Nectin-4 targeting nucleic acid aptamer needs to be subjected to stability modification before being coupled with Vc-MMAE.

6. The Nectin-4-targeted nucleic acid aptamer-based theranostic probe according to claim 5, wherein, The stability modification is carried out by thiol modification and / or C6 modification at the end of the Nectin-4 targeting nucleic acid aptamer.

7. The Nectin-4-targeted nucleic acid aptamer-based theranostic probe according to claim 1, wherein The diagnosis and treatment integrated probe has a chemical structural formula shown in the following formula I: ； Among them, Aptamer represents the Nectin-4 targeting nucleic acid aptamer.

8. A method for preparing the Nectin-4-targeting nucleic acid aptamer-based theranostic probe according to any one of claims 1 to 7, characterized in that, Comprising the following steps: S1. Prepare the Nectin-4 targeting nucleic acid aptamer after stability modification; S2. Carry out a coupling reaction on the Nectin-4 targeting nucleic acid aptamer after stability modification and Vc-MMAE to obtain the diagnosis and treatment integrated probe.

9. Use of the Nectin-4 targeting nucleic acid aptamer diagnosis and treatment integrated probe according to any one of claims 1 to 7 in the preparation of a kit or composition for visualizing the expression of Nectin-4, diagnosing Nectin-4-related tumors, predicting the progression and prognosis of Nectin-4-related tumors, predicting the therapeutic effect of Nectin-4-related tumors and / or treating Nectin-4-related tumors; The Nectin-4-related tumor is a bladder tumor with abnormally high expression of Nectin-4 protein.

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