Disialoganglioside GD2 affinity peptide and its application

Abstract

The present invention discloses a disialoganglioside GD2 affinity peptide and its applications. The affinity peptide YQAF-X sequence is: COOH-Tyr-Gly-Tyr-His-X1-X2-Arg-NH2. Gangliosides are overexpressed in human tumors such as lung cancer, brain cancer, melanoma, etc., and have an impact on the EGFR signaling pathway. GANGLIOSIDE can be used as a carbohydrate antigen to treat cancer. The YQAF-X series of polypeptides can bind to tumor cells with high expression of GANGLIOSIDE, and in vivo optical imaging and results confirm excellent imaging results for various tumors. The tumor detection reagent and surgical navigation imaging agent prepared based on the YQAF-X series can be better applied to early tumor screening, early tumor diagnosis, and intraoperative navigation of tumor surgery.

Description

Technical Field

[0001] The present invention belongs to the field of biomedical engineering, and particularly relates to a disialoganglioside GD2 affinity peptide and its application. Background Art

[0002] Cancer is a global public health challenge that seriously endangers human health. Relevant data released by GLOBOCAN in December 2021 showed that there were 19 million new cancer cases globally in 2021, and 9.96 million cancer patients died. In recent years, malignant tumors have become the leading cause of death among urban residents in China. The fight against cancer by all mankind has entered a crucial stage. However, the current medical level is difficult to overcome advanced malignant tumors, and early detection and treatment remain the most effective means of treating malignant tumors at present. Therefore, early diagnosis of tumors is of great significance for improving the survival rate of patients. Currently, the conventional imaging techniques used for tumor diagnosis are mainly X-CT, magnetic resonance imaging, ultrasonic diagnosis, etc. Among them, molecular probes, as powerful tools for analytical sensing and optical imaging, can directly visualize biological analytes at the molecular level and provide useful information for complex biological structures and processes. The basic imaging principle of molecular probes is to inject the prepared fluorescent probes into living tissues in a way such as injection, so that the target interacts with the molecular probe, and then use a suitable imaging system to detect the information emitted by the molecular probe. With the help of molecular probes targeting tumors, early screening and early diagnosis of tumors can be achieved.

[0003] Surgical treatment is one of the means of tumor treatment. Patients can obtain a better prognosis after surgical resection. However, the accurate positioning of the tumor boundary has always been a scientific research problem to be overcome. Providing the surgical boundary for surgeons to completely remove the tumor can reduce the possibility of postoperative recurrence of patients. However, the surgical navigation imaging agents currently approved by the FDA for clinical use have low sensitivity and weak specificity. For example, indocyanine green, an imaging agent used for liver cancer surgical navigation, is difficult to meet clinical needs. Molecular probes targeting tumors have the advantages of strong specificity and high sensitivity, providing hope for the accurate positioning of tumor boundaries.

[0004] Sphingolipids are important components of cell membranes. Sphingolipids are divided into two categories: sphingomyelin and glycosphingolipids. Glycosphingolipids are composed of two parts: ceramide and sugar chains. According to the nature of the sugar chains, they can be divided into neutral glycosphingolipids and acidic glycosphingolipids. Acidic glycosphingolipids generally refer to glycosphingolipids in which the sugar group part contains sialic acid, also known as gangliosides.

[0005] Gangliosides are widely expressed in normal tissues, making most subtypes unsuitable as targets for cancer treatment. The GANGLIOSIDE subtype of gangliosides is expressed at low levels in normal tissues but overexpressed in a wide range of tumors. GANGLIOSIDE can be considered a tumor-associated antigen and is suitable as a target for cancer treatment. Depending on the type of tumor, GANGLIOSIDE is involved in tumor development and malignant phenotypes by enhancing cell proliferation, motility, migration, adhesion, and invasion. GANGLIOSIDE in the ganglioside family is a cell surface glycolipid composed of galactose, glucose, N-acetylgalactosamine, sialic acid, and ceramide, and is highly expressed on cancer cells of neuroectodermal origin, including neuroblastoma, retinoblastoma, melanoma, sarcoma, brain tumors, and small cell lung cancer. The GANGLIOSIDE affinity peptide in this patent can achieve early diagnosis of the above tumors. Summary of the Invention

[0006] The primary object of the present invention is to provide disialoganglioside GD2 affinity peptides, which can bind to tumor cells with high expression of gangliosides and achieve targeting of tumor lesions.

[0007] Another object of the present invention is to provide a fluorescent probe for ganglioside affinity peptides and a preparation method thereof;

[0008] Another object of the present invention is to provide a radionuclide probe for ganglioside E affinity peptides and a preparation method thereof.

[0009] Another object of the present invention is to provide the applications of several of the above-mentioned peptides, fluorescent, and radionuclide probes.

[0010] Sialic acid ganglioside affinity peptide YQAF-X, the affinity peptide sequence is: COOH-Tyr-Gly-Tyr-His-X 1 -X 2 -Arg-NH 2 ;

[0011] wherein, -X 1 -X 2 - is selected from -Gly-Gly-, -Gly-Met-, -Gly-Gln-, -Pro-Gly-, -Gly-Tyr-, or -Gly-Ala-.

[0012] The application of the sialic acid ganglioside affinity peptide described in the present invention in the preparation of reagents for tumor diagnosis or tracing; the tumor is preferably a tumor with high expression of sialic acid gangliosides; more preferably breast cancer, lung cancer, and liver cancer.

[0013] As a preference of the present invention, the application of ganglioside sialic acid in the preparation of tumor diagnostic imaging agents; preferably in the preparation of precise positioning of tumor boundaries and surgical navigation imaging reagents or in the preparation of radionuclide imaging reagents.

[0014] A modified polypeptide having the following general formula:

[0015] M-L-YQAF-X, or M-YQAF-X,

[0016] wherein M represents a photo label or a radionuclide label;

[0017] L is a linking group;

[0018] YQAF-X is the ganglioside sialic acid affinity peptide described in the present invention.

[0019] As a preference of the present invention, the photo label is selected from organic chromophores, organic fluorophores, light-absorbing compounds, light-reflecting compounds, light-scattering compounds or bioluminescent molecules.

[0020] When M is a near-infrared fluorescent dye, M-L-YQAF-X is a near-infrared fluorescence imaging probe. As a preference of the present invention, the photo label is selected from near-infrared fluorescent dyes MPA, IRDye800, Cy7.5, Cy5.5.

[0021] When M is a radionuclide label, M-L-YQAF-X is a radionuclide probe. As a preference of the present invention, the radionuclide is selected from 99m Tc, 68 Ga, 64 Cu, 67 Ga, 90 Y, 111 In or 177 Lu, 125 I. The radionuclide probe is the hydrogen at the ortho position of the phenolic hydroxyl group of tyrosine in the affinity peptide labeled by the radionuclide as claimed.

[0022] As a preference of the present invention, the radionuclide label is composed of a radionuclide ligand, a bifunctional chelating agent for radionuclide labeling and the radionuclide; the bifunctional chelating agent for radionuclide labeling is preferably HYNIC, DOTA, NOTA or DTPA.

[0023] As a preference of the present invention, the L is selected from azidovaleric acid, propiolic acid, polyethylene glycol, 1,4,7-triazacyclononane-1,4,7-triacetic acid, 7-[(4-hydroxypropyl)methylene]-1,4,7-triazacyclononane-1,4-diacetic acid, 1,4,7,10-tetraazacyclododecane-1,4,7,10-tetraacetic acid, mercaptoacetyltriglycine, MAF2, N3S, N2S2 ligands, diethylenetriaminepentaacetic acid, 1,4-succinic acid, 5-aminopentanoic acid, polyethyleneimine, 6-hydrazinylpyridine-3-carboxylic acid, benzyl bromoformate, N-(2-aminohexanoic acid)maleimide, or a combination thereof.

[0024] As a preference of the present invention, the L is selected from 6-aminohexanoic acid, PEG 4 , PEG 6 , any one or more of HYNIC-PEG4 or HYNIC.

[0025] The application of the modified polypeptide of the present invention in the preparation of a reagent for tumor diagnosis or tracing, preferably in the preparation of a fluorescence imaging or radioactive imaging reagent for tumors.

[0026] The ganglioside affinity peptide of the present invention has a good tumor targeting effect. After entering the body, it can efficiently bind to ganglioside GANGLIOSIDE on the cell membrane of tumor cells, has good aggregation and retention at the tumor site, has a high target-to-non-target ratio, is suitable for being prepared into a fluorescence imaging agent, and is used for an optical imaging agent for precise localization of tumor boundaries and an imaging agent for intraoperative navigation in tumor surgery.

[0027] The beneficial effects of the present invention are as follows:

[0028] 1. The present invention has developed a series of polypeptides with high affinity for ganglioside GANGLIOSIDE, which can be used to target ganglioside GANGLIOSIDE. Utilizing the high expression of GANGLIOSIDE on the cell membranes of various tumors such as neuroblastoma, retinoblastoma, melanoma, sarcoma, brain tumor, and small cell lung cancer, based on the principle of the binding of the YQAF-X (X = 1-6) polypeptide to GANGLIOSIDE, early diagnosis of various tumors such as neuroblastoma, retinoblastoma, melanoma, sarcoma, brain tumor, breast cancer, lung cancer, and liver cancer and intraoperative navigation are thus achieved.

[0029] 2. The polypeptides of the YQAF-X series are all low molecular weight polypeptides. The short peptides of this series are composed of natural amino acids, with easily available raw materials and low synthesis costs. By prolonging the half-life of the polypeptide to increase the circulation time of the polypeptide in the body, promoting the aggregation and retention of the imaging probe at the tumor site, and thus obtaining a better tumor imaging effect, which is conducive to the promotion of clinical applications.

[0030] 3. The polypeptide sequences provided in the present invention are all reported for the first time, and the synthesis method is simple and the acquisition channel is convenient.

[0031] 4. The polypeptides of the YQAF-X series have excellent imaging effects on various tumors, including neuroblastoma, retinoblastoma, melanoma, sarcoma, brain tumor, small cell lung cancer, etc.

[0032] 5. Taking advantage of the deeper penetration depth and weaker autofluorescence of background tissues of the near-infrared fluorescent dye MPA used in the present invention, it has good application prospects in fluorescence imaging and fluorescence-guided surgery.

[0033] 6. The YQAF-X series polypeptides prepared into radiopharmaceuticals can be used for tumor screening and early diagnosis, and can also non-invasively monitor early malignant tumors in real time in situ. Brief Description of the Drawings

[0034] Figure 1 It is for detecting the affinity of different near-infrared fluorescent probes in breast cancer MCF-7 by flow cytometry.

[0035] Figure 2 It is the optical imaging diagram of the near-infrared fluorescent probe MPA-YQAF-1 in nude mice bearing breast cancer MCF-7 tumors.

[0036] Figure 3 It is the optical imaging diagram of the near-infrared fluorescent probe MPA-YQAF-2 in nude mice bearing non-small cell lung cancer A549 tumors.

[0037] Figure 4 It is the optical imaging diagram of the near-infrared fluorescent probe MPA-YQAF-3 in nude mice bearing liver cancer HepG2 tumors.

[0038] Figure 5 It is the optical imaging diagram of the near-infrared fluorescent probe MPA-YQAF-4 in BalB / C white mice bearing breast cancer 4T1 tumors.

[0039] Figure 6 It is the optical imaging diagram of the radionuclide probe 99m Tc-HYNIC-Aca-YQAF-1 in nude mice bearing breast cancer 4T1 tumors. Detailed Embodiments

[0040] The sialic acid ganglioside affinity peptides involved in the following examples are shown as follows:

[0041] YQAF-1: COOH-Tyr-Gly-Tyr-His-Gly-Gly-Arg-NH 2 (SEQ ID NO.1),

[0042] YQAF-2: COOH-Tyr-Gly-Tyr-His-Gly-Met-Arg-NH 2 (SEQ ID NO.2),

[0043] YQAF-3: COOH-Tyr-Gly-Tyr-His-Gly-Gln-Arg-NH 2 (SEQ ID NO.3),

[0044] YQAF-4: COOH-Tyr-Gly-Tyr-His-Pro-Gly-Arg-NH 2 (SEQ ID NO.4),

[0045] YQAF-5: COOH-Tyr-Gly-Tyr-His-Gly-Tyr-Arg-NH 2 (SEQ ID NO.5),

[0046] YQAF-6: COOH-Tyr-Gly-Tyr-His-Gly-Ala-Arg-NH 2 (SEQ ID NO.6).

[0047] The present invention will be further illustrated by specific examples and application examples below: All the chemical substances used in the synthesis steps are existing substances or commercially available products. The polypeptides involved in each example were synthesized by Hangzhou Genscript Biotech Co., Ltd.

[0048] Example 1 takes the polypeptide YQAF-1 as an example and includes the following steps:

[0049] (1) Resin swelling

[0050] Add a certain amount of Rink Amide MBHA resin into the reaction column, then add an appropriate amount of dichloromethane (DCM), and gently blow nitrogen for 10 - 30 minutes to fully swell the resin. Drain the dichloromethane solution, and then wash it 3 times with dimethylformamide (DMF) and drain.

[0051] (2) Removal of Fmoc

[0052] Add a DMF solution of 20% piperidine into the reaction column, deprotect once for 5 minutes and once for 8 minutes. After the reaction, wash the resin 3 times with DMF, DCM, and DMF in sequence.

[0053] (3) Coupling

[0054] Accurately weigh 3 times the molar amount of Fmoc-Tyr-OH and O-benzotriazol-1-yl-N,N,N',N'-tetramethyluronium hexafluorophosphate (HCTU) based on the resin charged. Completely dissolve them in DMF. After adding N,N-diisopropylethylamine (DIPEA) to activate the carboxyl group, add the solution to the reaction column for reaction. After reacting for 30 minutes, wash it 3 times successively with DMF, DCM, and DMF, then drain the solvent. Take a small amount of resin and add one drop each of 6% ninhydrin / ethanol solution and 80% phenol / ethanol solution for detection. If the condensation is complete and there is no free amino group, the solution will be colorless or light yellow; otherwise, the resin or the solution will turn blue or reddish-brown, indicating incomplete reaction. After the reaction is completed, wash it 3 times successively with DCM, DCM, and DMF. Repeat the above operation and couple other amino acids in turn until the last amino acid Fmoc-Arg-OH is coupled. Wash the obtained peptidyl resin with methanol and dry it thoroughly in a vacuum drying oven.

[0055] (4) Cleavage A

[0056] Take 120 mL of cleavage solution (87.5% trifluoroacetic acid + 5% benzyl methyl sulfide + 2.5% ethanedithiol + 2.5% phenol + 2.5% water) and add it to the resin. Shake it at low temperature for 2 h, then separate the cleavage solution from the resin using a fritted funnel and retain the filtrate. Slowly drip the filtrate into ice-cold anhydrous ether. After dripping is complete, let it settle naturally for 30 min. Then centrifuge to obtain the solid, wash the solid three times with ether, and dry the obtained precipitate to get the dry powder crude product.

[0057] (5) Purification

[0058] Purification is carried out by high-performance liquid chromatography. The chromatographic packing material for purification is a 10-μm C18 preparative column. The mobile phase system is 0.1% TFA / aqueous solution - 0.1% TFA / acetonitrile solution. Gradient elution is used, and cyclic injection purification is carried out. Load the crude product solution onto the chromatographic column, start the mobile phase elution, collect the main peak, evaporate the acetonitrile, and obtain the target polypeptide concentrate. Then lyophilize it to obtain the target polypeptide YQAF-1: COOH-Tyr-Gly-Tyr-His-Gly-Gly-Arg-NH 2 , and finally measure the mass-to-charge ratio to determine the molecular weight [M-H] - = 809

[0059] Example 2 Preparation of polypeptide YQAF-X (X = 2 - 6)

[0060] Prepare sialic acid ganglioside affinity peptide YQAF-2 according to the method of Example 1. The sequence is COOH-Tyr-Gly-Tyr-His-Gly-Met-Arg-NH 2 , and confirm it by mass spectrometry [M-H] -= 883. Sialic acid ganglioside affinity peptide YQAF-3, with the sequence COOH-Tyr-Gly-Tyr-His-Gly-Gln-Arg-NH 2 , confirmed by mass spectrometry as [M-H] - = 880. Sialic acid ganglioside affinity peptide YQAF-4, with the sequence COOH-Tyr-Gly-Tyr-His-Pro-Gly-Arg-NH 2 , confirmed by mass spectrometry as [M-H] - = 849. Sialic acid ganglioside affinity peptide YQAF-5, with the sequence COOH-Tyr-Gly-Tyr-His-Gly-Tyr-Arg-NH 2 , confirmed by mass spectrometry as [M-H] - = 915. Sialic acid ganglioside affinity peptide YQAF-6, with the sequence COOH-Tyr-Gly-Tyr-His-Gly-Ala-Arg-NH 2 , confirmed by mass spectrometry as [M-H] - = 823.

[0061] Example 3 Preparation of Fluorescent Targeting Compound MPA-YQAF-1

[0062] (1) MPA is from a previously filed invention patent by our research group, with the authorized patent number: CN101440282. Take 0.02 mmol of MPA and dissolve it in 200 μL of ultra-dry DMSO. Add 3.7 mg of 1-ethyl-(3-dimethylaminopropyl)carbodiimide hydrochloride and 2.2 mg of N-hydroxysuccinimide (EDCI / NHS) (molar ratio of MPA:EDCI:NHS = 1:1.5:1.5), and react in the dark for 4 h for carboxyl activation reaction.

[0063] (2) Take 0.02 mmol of the solid-phase synthesized polypeptide YQAF-1, 0.1 mmol of triethylamine and 200 μL of ultra-dry DMSO and add them to a 5 mL reaction flask. React for 10 min under nitrogen protection; add the solution in the above reaction (1) to the reaction solution in (2), and stir at room temperature for 12 h.

[0064] (3) After the reaction was completed, the reaction solution was concentrated by freeze-drying, then diluted with distilled water, and separated and purified by preparative liquid chromatography. The preparative liquid chromatography conditions were as follows: An Agilent 1220 Infinity Ⅱ series HPLC system equipped with an Agilent ZORBAX SB-C18 semi-preparative column (9.4×250 mm, 5 μm) was used, with gradient elution for 60 minutes at a flow rate of 2 mL / min. Mobile phase A was ultrapure water (0.01% TFA), and B was acetonitrile (0.01% TFA). The elution gradient was set as follows: from 0 to 5 minutes, 95% A and 5% B; at 15 minutes, 85% A and 15% B; at 30 minutes, 70% A and 30% B; at 45 minutes, 50% A and 50% B. The finally obtained green product was confirmed to be the expected product MPA-YQAF-1 by analytical HPLC and ESI-MS mass spectrometry. In the above preparation process, by replacing the YQAF-1 polypeptide used in the step with the solid-phase synthesized YQAF-X (X = 2 - 6) polypeptide, other various polypeptide compounds with tumor-targeted optical imaging functions, namely MPA-YQAF-1, MPA-YQAF-2, MPA-YQAF-3, MPA-YQAF-4, MPA-YQAF-5, and MPA-YQAF-6, can be obtained.

[0065] Example 4 Preparation of a radionuclide probe, taking 99m Tc-HYNIC-Aca-YQAF-1 as an example

[0066] Dissolve 5 mg of the synthesized and purified intermediate (PEG 4 ) 2 E-HYNIC in 0.3 mL of DMSO, then add 2.1 mg of EDCI and 1.25 mg of NHS, react at room temperature for 5 hours, detect the reaction progress by analytical high-performance liquid chromatography. After the reaction is completed, add 7.8 mg of the mimic peptide YQAF-1, then add 5.6 mg of DIPEA, react at room temperature for 3 hours. After the reaction is completed, separate and purify by preparative liquid chromatography, and finally obtain 6.5 mg of a yellow solid, which is confirmed to be the target product by mass spectrometry.

[0067] Prepare solutions of TPPTS (triphenylphosphine trisulfonate) at a concentration of 100 mg / mL, Tricine (trimethylglycine) at a concentration of 130.0 mg / mL, and succinic acid-sodium succinate buffer at a concentration of 102.4 mg / mL (where succinic acid is 77.0 mg and sodium succinate is 25.4 mg). Take 10.0 μL of the TPPTS solution, 10.0 μL of the Tricine solution, 10.0 μL of the succinic acid-sodium succinate buffer, and 10.0 μL (1.0 g / mL) of the said (YQAF-1) 2 -(PEG 4 )2 E-HYNIC was mixed in a vial, and then 10 mCi of Na 99m TcO4 was heated in a metal bath at 100 °C for 20 minutes. After the reaction ended, it was cooled to room temperature to obtain the radionuclide probe (YQAF-1). 2 -(PEG 4 ) 2 E-HYNIC-99mTc. The product was analyzed and identified by an Agilent ZORBAX SB-Aq analytical column. The HPLC method used was an Agilent 1220 Infinity II series HPLC system equipped with a radioactive on-line detector (Flow-RAM) and an Agilent ZORBAX SB-Aq analytical column (4.6×250 mm, 5 μm). Gradient elution was performed for 45 minutes at a flow rate of 1 mL / min. The mobile phase A was ultrapure water (0.01% TFA), and B was acetonitrile (0.01% TFA). The elution gradient was set as follows: at 0 - 5 minutes, 95% A and 5% B; at 15 minutes, 70% A and 30% B; at 20 minutes, 65% A and 35% B; at 25 minutes, 45% A and 55% B; at 45 minutes, 5% A and 95% B.

[0068] Affinity of the compound MPA-YQAF-X (X = 1 - 6) prepared in Example 5 for breast cancer MCF-7.

[0069] The cultured breast cancer MCF-7 cells were eluted from the 12-well plate and resuspended in PBS solution. They were co-incubated with MPA-YQAF-X (X = 1 - 6) (10 μmol / L) prepared in the example for 2 hours, and the average fluorescence intensity was detected by flow cytometry. The stronger the fluorescence intensity, the stronger the affinity for the cells. When the probe has a strong affinity for the receptor on the cells, the average fluorescence intensity value of the cells detected by the flow cytometer is high. See Figure 1 . The results of the in vitro affinity experiment showed that after the probes of MPA-YQAF-X (X = 1 - 6) with the same concentration were incubated with breast cancer MCF-7 with high expression of GANGLIOSIDE respectively, YQAF-1 of the present invention had the strongest affinity for MCF-7 cells and the greatest affinity intensity.

[0070] Optical imaging map of the compound MPA-YQAF-1 prepared in Example 6 in breast cancer MCF-7 tumor-bearing mice.

[0071] The compound MPA-YQAF-1 prepared in Example 3 was formulated into a physiological saline solution (1 mg / mL). 15 μL of the drug MPA-YQAF-1 solution was injected into 3 nude mice bearing breast cancer MCF-7 tumors (weighing about 20 grams) via the tail vein, and optical signal acquisition was performed at 1 h, 2 h, 4 h, 6 h, 12 h, and 24 h after administration. The distribution of the probe in the mice and its enrichment in the tumor region were observed. The imaging results of the compound MPA-YQAF-1 in the 3 tumor-bearing nude mice were basically the same. It could be seen from the imaging map at 1 h that the probe had significantly aggregated in the tumor, and the tumor edge contour was relatively clear. The probe still remained in the tumor until 24 h. The imaging results are as Figure 2 shown. Among them, the probe was most enriched in the tumor at 2 h, while the uptake and clearance in other background organs were relatively fast. It could be inferred from the information of the bladder that this probe was mainly metabolized through the kidneys.

[0072] Optical imaging map of the compound MPA-YQAF-2 prepared in Example 7 in nude mice bearing non-small cell lung cancer A549 tumors.

[0073] The compound MPA-YQAF-2 prepared in Example 3 was formulated into a physiological saline solution (1 mg / mL). 15 μL of the drug MPA-YQAF-2 solution was injected into 3 nude mice bearing non-small cell lung cancer A549 tumors (weighing about 20 grams) via the tail vein, and optical signal acquisition was performed at 1 h, 2 h, 4 h, 6 h, 12 h, and 24 h after administration. The distribution of the probe in the mice and its enrichment in the tumor region were observed. The imaging results of the compound MPA-YQAF-2 in the 3 tumor-bearing nude mice were basically the same. It could be seen from the imaging map at 1 h that the probe had significantly aggregated in the tumor, and the tumor edge contour was relatively clear. The probe still remained in the tumor until 24 h. The imaging results are as Figure 3 shown. Among them, the probe was most enriched in the tumor at 2 h, while the uptake and clearance in other background organs were relatively fast. It could be inferred from the information of the bladder that this probe was mainly metabolized through the kidneys.

[0074] Optical imaging map of the compound MPA-YQAF-3 prepared in Example 8 in nude mice bearing liver cancer HepG2 tumors.

[0075] The compound MPA-YQAF-3 prepared in Example 3 was formulated into a physiological saline solution (1 mg / mL). 15 μL of the drug MPA-YQAF-3 solution was injected into 3 nude mice bearing hepatocellular carcinoma HepG2 tumors (weighing about 20 grams) via the tail vein, and optical signal acquisition was performed at 1 h, 2 h, 4 h, 6 h, 12 h, and 24 h after administration. The distribution of the probe in the mice and its enrichment in the tumor region were observed. The imaging results of the compound MPA-YQAF-3 in the 3 tumor-bearing nude mice were basically the same. It can be seen from the imaging map at 1 h that the probe had obvious aggregation in the tumor, and the outline of the tumor edge was relatively clear. The probe still remained in the tumor until 12 h. The imaging results are as Figure 4 shown. Among them, the probe had the most enrichment in the tumor at 2 h, while the uptake and clearance in other background organs were relatively fast. It can be inferred from the information of the bladder that this probe was mainly metabolized through the kidneys.

[0076] Optical imaging map of the compound MPA-YQAF-4 prepared in Example 9 in a mouse bearing a 4T1 breast cancer tumor.

[0077] The compound MPA-YQAF-4 prepared in Example 3 was formulated into a physiological saline solution (1 mg / mL). 15 μL of the drug MPA-YQAF-4 solution was injected into 3 mice bearing 4T1 breast cancer tumors (weighing about 20 grams) via the tail vein, and optical signal acquisition was performed at 1 h, 2 h, 4 h, 6 h, 12 h, and 24 h after administration. The distribution of the probe in the mice and its enrichment in the tumor region were observed. The imaging results of the compound MPA-YQAF-4 in the 3 tumor-bearing mice were basically the same. It can be seen from the imaging map at 1 h that the probe had obvious aggregation in the tumor, and the outline of the tumor edge was relatively clear. The probe still remained in the tumor until 12 h. The imaging results are as Figure 5 shown. Among them, the probe had the most enrichment in the tumor at 2 h, and the uptake and clearance in other background organs were relatively fast. It can be inferred from the information of the bladder that this probe was mainly metabolized through the kidneys.

[0078] SPECT-CT imaging map of the radionuclide probe 99mTc-HYNIC-Aca-YQAF-1 prepared in Example 10 in a mouse bearing a 4T1 breast cancer tumor.

[0079] The 99m Tc-HYNIC-Aca-YQAF-1 prepared in Example 4 was formulated into a physiological saline solution (1 mg / mL). 15 μL of the drug 99m Tc-HYNIC-Aca-YQAF-1 was injected into 3 nude mice bearing 4T1 breast cancer tumors (weighing about 20 grams) via the tail vein, and SPECT signal acquisition was performed after administration. The distribution of the probe in the mice and its enrichment in the tumor region were observed. The imaging effect is as Figure 6As shown, the distribution of the radionuclide probe in the mouse body and its enrichment in the tumor area were observed. 99m Tc-HYNIC-Aca-YQAF-1 showed obvious uptake in the tumor part and was mainly metabolized through the kidneys.

Claims

1. Sialic acid ganglioside affinity peptide, characterized in that , the sequence of the affinity peptide is: YQAF-X: COOH-Tyr-Gly-Tyr-His-X 1 -X 2 -Arg-NH 2 ; wherein, -X 1 -X 2 -selected from -Gly-Gly-, -Gly-Met-, -Gly-Gln-, -Pro-Gly-, -Gly-Tyr- or -Gly-Ala-.

2. Use of the sialic acid ganglioside affinity peptide according to claim 1 in the preparation of a tracer reagent for breast cancer, lung cancer or liver cancer.

3. According to the use described in claim 2, characterized in that the sialic acid ganglioside affinity peptide described in claim 1 is used in the preparation of a precise positioning and surgical navigation imaging reagent for the boundary of breast cancer, lung cancer or liver cancer or in the preparation of a radionuclide imaging reagent.

4. A modified polypeptide, characterized in that it has the following general formula: M-L-YQAF-X, or M- YQAF-X, wherein, M represents a photo label or a radionuclide label; L is a linking group; YQAF-X is the sialic acid ganglioside affinity peptide described in claim 1.

5. According to the modified polypeptide described in claim 4, characterized in that the photo label is selected from photoabsorbing compounds, photoreflective compounds, light-scattering compounds or bioluminescent molecules.

6. According to the modified polypeptide described in claim 5, characterized in that the photoabsorbing compound is an organic chromophore or an organic fluorophore.

7. According to the modified polypeptide described in claim 5, characterized in that the photo label is selected from near-infrared fluorescent dyes MPA, IRDye800, Cy7.5, Cy5.

5.

8. According to the modified polypeptide described in claim 4, characterized in that The radioactive nuclide is selected from 99m Tc, 68 Ga, 64 Cu, 67 Ga, 90 Y, 111 In, 177 Lu or 125 I.

9. According to the modified polypeptide described in claim 8, characterized in that the radionuclide label consists of a radionuclide ligand, a bifunctional chelating agent for radionuclide labeling and a radionuclide.

10. According to the modified polypeptide described in claim 9, characterized in that the bifunctional chelating agent for radionuclide labeling is selected from HYNIC, DOTA, NOTA or DTPA.

11. According to the modified polypeptide described in claim 4, characterized in that the L is selected from azidovaleric acid, propargylic acid, polyethylene glycol, 1,4,7-triazacyclononane-1,4,7-triacetic acid, 7-[(4-hydroxypropyl)methylene]-1,4,7-triazacyclononane-1,4-diacetic acid, 1,4,7,10-tetraazacyclododecane-1,4,7,10-tetraacetic acid, mercaptoacetyltriglycine, MAF2, N3S, N2S2 type ligands, diethylenetriaminepentaacetic acid, 1,4-succinic acid, 5-aminopentanoic acid, polyethyleneimine, 6-hydrazinylpyridine-3-carboxylic acid, benzyl bromoformate, N-(2-aminohexanoic acid) maleimide or a combination thereof.

12. According to the modified polypeptide described in claim 4, characterized in that The L described above is selected from any one or more of 6-aminocaproic acid, PEG 4 , PEG 6 , HYNIC-PEG4 or HYNIC.

13. Use of the modified polypeptide according to any one of claims 4 to 12 in the preparation of a tracer reagent for breast cancer, lung cancer or liver cancer.

14. According to the use described in claim 13, characterized in that the modified polypeptide is used in the preparation of a fluorescence imaging or radionuclide imaging reagent for breast cancer, lung cancer or liver cancer.

Images