GPC3-targeted compound, radionuclide probe and application of GPC3-targeted compound and radionuclide probe

Abstract

The invention relates to the technical field of nuclear medicine imaging agents, in particular to a GPC3-targeted compound, a radionuclide probe and application of the GPC3-targeted compound and the radionuclide probe. The compounds targeting GPC3 comprise a GBP polypeptide, optionally a linking group, a radionuclide chelating group, and optionally an albumin binding group; the linking group is a group formed by a linker, and the linker is selected from at least one of a hydrocarbon chain linker, a polyethylene glycol linker and an amino acid linker. The radionuclide probe disclosed by the invention can be applied to diagnosis and treatment of GPC3 positive hepatocellular carcinoma, and has the advantages of high sensitivity, relatively low non-specific tissue uptake and high tumor and normal liver tissue uptake ratio.

Description

Technical Field

[0001] The present invention relates to the technical field of nuclear medicine imaging agents, and in particular to a compound and a radionuclide probe targeting GPC3 and applications thereof. Background Art

[0002] Liver cancer is one of the most common types of cancer in the world, with similar incidence and mortality, reflecting the very low survival rate of patients. Hepatocellular carcinoma (HCC) is the most common liver malignancy, accounting for about 75% of all types of liver cancer. Although a variety of therapies for HCC have been developed in recent years to effectively prolong the survival of patients, the overall treatment effect and treatment options are still limited for patients with advanced HCC. Therefore, methods for early diagnosis of HCC and monitoring of treatment efficacy are of great clinical significance. Screening and monitoring of liver cancer are generally performed through blood tests of alpha-fetoprotein (AFP) values ​​or ultrasound. If liver lesions are found, CT, MRI, and contrast-enhanced ultrasound are performed for further diagnosis and classification. However, AFP and ultrasound have low sensitivity and their diagnostic performance is not satisfactory. Moreover, although the sensitivity of first-line imaging diagnostic methods (CT, MRI, and ultrasound) is constantly improving, due to the lack of specificity, the uncertain lesions detected can only be further confirmed by repeated imaging or invasive biopsy to observe whether the lesions progress over time, which will delay the time for patients to receive treatment. PET can be used as a positron emission tomography (PET) to perform non-invasive real-time imaging of tiny lesions with high sensitivity by tracing specific physiological metabolic or pathological characteristics. However, the most commonly used drug, 2-deoxy-2-( 18 F) Fluoro-glucose ( 18 The detection sensitivity of F-FDG is only 50%-70%, and its ability to identify well-differentiated hepatocellular carcinoma is low. Although choline radionuclide probes have a high probe uptake value in hepatocellular carcinoma, they also have a high uptake in benign lesions such as nodular hyperplasia. Currently, the radionuclide probes used in clinical practice do not have the ability to target hepatocellular carcinoma with high sensitivity, high specificity and high image contrast. Therefore, it is necessary to develop highly sensitive and specific PET probes.

[0003] GPC3 is a glycoprotein anchored to the cell membrane surface by glycosylphosphatidylinositol (GPI). Most HCC patients have abnormally high serum GPC3 levels, and immunohistochemistry shows that GPC3 is highly expressed in cancerous areas, but not in normal liver tissue or hepatitis-affected areas. In addition, studies have found that the expression level of GPC3 is associated with the therapeutic effect after liver resection. Some clinical trials studying GPC3 targeted therapy have made encouraging progress. This makes GPC3 an effective biomarker for HCC diagnosis, efficacy evaluation, and optimization of patients with GPC3 treatment response. Designing radionuclide probes targeting GPC3 is expected to provide an important clinical imaging tool for early and accurate diagnosis and prognostic evaluation of hepatocellular carcinoma.

[0004] Existing reports of specific radionuclide probes targeting GPC3 include probes based on antibodies, single-domain antibodies, nanobodies, and peptides. Among them, peptide radionuclide probes are easy to clinically transform because they can be quickly cleared from non-target tissues in the body and have simple synthesis steps. However, the existing reported targeted GPC3 peptide probes have shortcomings such as low sensitivity, high nonspecific tissue uptake, and low ratio of tumor to normal liver tissue uptake. Therefore, it is of great significance to design a new type of radionuclide probe targeting GPC3 to improve the probe's target-to-target ratio, thereby improving the diagnostic sensitivity, image quality, and therapeutic efficacy of radiopharmaceuticals for hepatocellular carcinoma. Summary of the invention

[0005] The purpose of the present invention is to overcome the problems of low sensitivity, high nonspecific tissue uptake, low ratio of tumor to normal liver tissue uptake, etc. of existing probes, and to provide a compound and radionuclide probe targeting GPC3 and their application.

[0006] In order to achieve the above object, the present invention provides a compound targeting GPC3 on one hand, wherein the compound targeting GPC3 comprises a GBP polypeptide, optionally a linking group, a radionuclide chelating group and optionally an albumin binding group;

[0007] The linking group is a group formed by a linker, and the linker is selected from at least one of a hydrocarbon chain linker, a polyethylene glycol linker and an amino acid linker.

[0008] A second aspect of the present invention provides a radionuclide probe obtained by labeling the aforementioned compound targeting GPC3 with a radionuclide.

[0009] The third aspect of the present invention provides the use of the radionuclide probe described above in the preparation of an imaging agent for diagnosing liver cancer tumors or a drug for targeted treatment of liver cancer tumors.

[0010] A fourth aspect of the present invention provides an imaging agent for diagnosing liver cancer tumors, comprising the radionuclide probe described above.

[0011] The fifth aspect of the present invention provides a pharmaceutical composition comprising the radionuclide probe described above.

[0012] Compared with the prior art, the present invention has the following beneficial effects:

[0013] 1. The compound targeting GPC3 of the present invention can target and recognize GPC3 protein, and can be used as a precursor compound of a radionuclide probe targeting hepatocellular carcinoma.

[0014] 2. The radionuclide probe of the present invention can be applied to the diagnosis and treatment of GPC3-positive hepatocellular carcinoma, and has the advantages of high sensitivity, low nonspecific tissue uptake, and high ratio of tumor to normal liver tissue uptake. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 is a synthetic route diagram of the compound represented by formula (1) of the present invention;

[0016] Figure 2 is a synthetic route diagram of the compound represented by formula (2) of the present invention;

[0017] Figure 3 is a synthetic route diagram of the compound represented by formula (3) of the present invention;

[0018] Figure 4 is a synthetic route diagram of the compound represented by formula (4) of the present invention;

[0019] Figure 5 is the mass spectrum of the product prepared in Example 1;

[0020] Figure 6 is the mass spectrum of the product prepared in Example 2;

[0021] Figure 7 is the mass spectrum of the product prepared in Example 3;

[0022] Figure 8 is the mass spectrum of the product prepared in Example 4;

[0023] Fig. 9 is the mass spectrum of the product prepared in Example 5;

[0024] Fig.10 The radioactive high performance liquid chromatography in Example 6 68 Ga-compound 1 and 68 Radiochemical purity results of Ga-compound 2;

[0025] Fig.11 The radioactive high performance liquid chromatography in Example 6 18The radiochemical purity result diagram of F-labeled compound 3;

[0026] Fig.12 The radioactive high performance liquid chromatography in Example 6 18 The radiochemical purity result diagram of F-labeled compound 4;

[0027] Fig.13 The radioactive high performance liquid chromatography in Example 6 18 The radiochemical purity result diagram of F-labeled compound 5;

[0028] Fig.14 is a test result diagram of immunohistochemical analysis of the expression level of GPC3 in (a) HepG2 hepatocellular carcinoma in situ tumor, (b) Huh7 subcutaneous tumor and (c) PC3 subcutaneous tumor in the test case;

[0029] Fig.15 This is the probe in test case 1 68 PET / CT imaging results of Ga-compound 1 on Huh7 subcutaneous tumor Balb / c model mice;

[0030] Fig.16 This is the probe in test case 1 68 Time activity curve of the region of interest in the PET / CT imaging results of Ga-compound 1 on Huh7 subcutaneous tumor Balb / c model mice;

[0031] Fig.17 This is the probe in test case 1 68 PET / CT imaging results of Ga-compound 2 on Huh7 subcutaneous tumor Balb / c model mice;

[0032] Fig.18 This is the probe in test case 1 68 Time activity curve of the region of interest in the PET / CT imaging results of Ga-compound 2 on Huh7 subcutaneous tumor Balb / c model mice;

[0033] Fig.19 This is the probe in test case 1 68 PET / CT imaging results of Ga-compound 2 on HepG2 liver tumor in situ C-NKG model for 14 hours;

[0034] Fig. 20 This is the probe in test case 1 18 F- PET / CT imaging results of compound 3 on Huh7 subcutaneous tumor Balb / c model mice;

[0035] Fig.21 This is the probe in test case 1 18F- PET / CT imaging results of compound 4 on Huh7 subcutaneous tumor Balb / c model mice;

[0036] Fig. 22 In test case 1, it is the probe 18 F- PET / CT imaging results of compound 5 on Huh7 subcutaneous tumor Balb / c model mice;

[0037] Fig.23 This is the probe in test case 1 68 Ga-compound 2 and probe 18 Comparative analysis results of MicroPET / CT imaging of F-FDG;

[0038] Fig.24 In test case 3 68 Ga-compound 1 and 68 Results of Ga-compound 2 uptake in cells. DETAILED DESCRIPTION

[0039] The specific embodiments of the present invention are described in detail below. It should be understood that the specific embodiments described herein are only used to illustrate and explain the present invention, and are not used to limit the present invention.

[0040] The endpoints and any values ​​of the ranges disclosed in this article are not limited to the precise ranges or values, and these ranges or values ​​should be understood to include values ​​close to these ranges or values. For numerical ranges, the endpoint values ​​of each range, the endpoint values ​​of each range and the individual point values, and the individual point values ​​can be combined with each other to obtain one or more new numerical ranges, which should be considered as specifically disclosed in this article.

[0041] In one aspect, the present invention provides a compound targeting GPC3, wherein the compound targeting GPC3 comprises a GBP polypeptide, optionally a linking group, a radionuclide chelating group, and optionally an albumin binding group;

[0042] The linking group is a group formed by a linker, and the linker is selected from at least one of a hydrocarbon chain linker, a polyethylene glycol linker and an amino acid linker.

[0043] According to some specific embodiments of the present invention, the compound targeting GPC3 includes a GBP polypeptide, a linking group and a radionuclide chelating group connected in sequence.

[0044] In the present invention, the GBP polypeptide is a targeting polypeptide with high nucleophilicity to the GPC3 protein, and the amino acid sequence of the GBP polypeptide is shown in SEQ.ID.NO: 1. Preferably, in the compound targeting GPC3, the GBP polypeptide is linked to other parts through a covalent bond.

[0045] SEQ.ID.NO:1:

[0046] SPLQNPSVHT

[0047] In the present invention, the linker is preferably at least one of a hydrocarbon chain linker, an amino acid linker and a polyethylene glycol linker, which can play a role in increasing tumor uptake, prolonging tumor retention time and improving the ratio of tumor to non-target uptake. Among them, the hydrocarbon chain linker can be selected from compounds containing amino and carboxyl groups at both ends (NH2-hydrocarbon-COOH), for example, it can be selected from at least one of β-Ala, Gaba, Ava, Ahx, Aoc, Aun, D-1-Nal-OH and 4-Amc-OH, which can increase the lipophilicity of the probe. The amino acid linker refers to a linker formed by a single amino acid or a combination of multiple amino acids, which can be selected from one or a combination of Ser, Lys, Glu, Gln, Cys, Asn and Gly, which can improve the hydrophilicity of the probe and reduce the uptake of non-targeted liver tissues. The polyethylene glycol linker can be NH2-(PEG)n-COOH, n is an integer; it can improve the hydrophilicity of the probe and the linker is not easily degraded by endogenous enzymes, thereby improving the stability of the probe; preferably, n=1-12, and n is an integer.

[0048] The compound targeting GPC3 of the present invention can be used as a precursor compound of a nuclear probe targeting hepatocellular carcinoma, and by combining it with a radioactive nuclide, a nuclear probe for diagnosis and treatment of liver cancer tumors can be obtained.

[0049] According to some preferred embodiments of the present invention, the structural formula of the compound targeting GPC3 is shown in any one of formula (1) to formula (4);

[0050]

[0051]

[0052] Among them, M 1 、M 2 、M 3 and M 4 Each is independently selected from a radionuclide chelating group, R 1 and R 2 Each is independently selected from an albumin binding group, n=1-12, and n is an integer.

[0053] According to some specific embodiments of the present invention, the value of n can be 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11 or 12.

[0054] In the present invention, the radionuclide chelating group is a group formed by a bifunctional chelating agent. The bifunctional chelating agent can be selected from bifunctional chelating agents commonly used in the art. In a preferred embodiment, the bifunctional chelating agent is selected from one or more of DOTA, NOTA, NODA, NODAGA, DOTAGA, DBCO, DOTP, TETA, TRAP, ATSM, PTSM, EDTA, EC, HBEDCC, DTPA, SBAD, BAPEN, Df, DFO, DFO*, TACN, NO2A / NOTAM, CB-DO2A, Cyclen, NOTA-AA, DO3A, DO3AP, MAG3, MAS3, HYNIC and isonitrile; more preferably, one or more of DOTA, NOTA and NODAGA.

[0055] In the present invention, DOTA refers to 1,4,7,10-tetraazacyclododecane-N',N",N"'-tetraacetic acid; the structural formula of the radionuclide chelating group formed by DOTA is:

[0056]

[0057] In the present invention, the NOTA refers to 1,4,7,10-tetraazanonane-1,4,7-triacetic acid (1,4,7-triazacylononane-1,4,7-triacetic acid); the structural formula of the radionuclide chelating group formed by NOTA is:

[0058]

[0059] In the present invention, NODAGA refers to 1,4,7,10-tetraazanonane-1,4,7-triacetic acid (2,2'-{7-[4-amino-1-carboxyl-4-oxobutyl]-1,4,7-triazacyclononane-1,4-diyl}diacetic acid), and the structural formula of the radionuclide chelating group formed by NODAGA is:

[0060]

[0061] According to some preferred embodiments of the present invention, the structural formula of the albumin binding group is:

[0062]

[0063] Wherein, X is methyl, Cl or I.

[0064] In the present invention, the compound targeting GPC3 shown in formula (1) comprises a GBP polypeptide and a radionuclide chelating group, and can be obtained by coupling a GBP polypeptide and a bifunctional chelating agent. The compound shown in formula (1) can be prepared by conventional organic synthesis methods in the art. For example, it can be prepared by Figure 1 The raw materials involved in the route can be obtained commercially, and the process conditions of each step can refer to the reaction conditions known in the field of organic synthesis.

[0065] In the present invention, the compound targeting GPC3 shown in formula (2) comprises a GBP polypeptide, a group formed by a polyethylene glycol linker and a radionuclide chelating group connected in sequence. The introduction of a polyethylene glycol (PEG) chain can reduce the lipophilicity of the probe to a suitable range, so that its main metabolic pathway is urine metabolism through the kidneys, rather than metabolism through the liver, ensuring lower uptake by normal liver tissue and a higher image-target ratio.

[0066] In the present invention, the compound represented by formula (2) can be prepared by conventional organic synthesis methods in the art. Figure 2 The raw materials involved in the route can be obtained commercially, and the process conditions of each step can refer to the reaction conditions known in the field of organic synthesis.

[0067] In the present invention, the compound targeting GPC3 shown in formula (3) is a compound targeting GBP polypeptide as a targeting group, and is modified with a radionuclide chelating group, a linking group (formed by lysine) and an albumin binding group. The blood half-life of the probe targeting GPC3 obtained by the compound targeting GPC3 modified with the above groups is increased, and its pharmacokinetics are greatly improved, which can solve the problem of low tumor uptake caused by too fast clearance rate of the probe in the body, so as to obtain high contrast PET or SPECT imaging with a high tumor to liver uptake ratio.

[0068] In the present invention, the compound represented by formula (3) can be prepared by conventional organic synthesis methods in the art. Figure 3 The raw materials involved in the route can be obtained commercially, and the process conditions of each step can refer to the reaction conditions known in the field of organic synthesis.

[0069] In the present invention, the compound targeting GPC3 shown in formula (4) uses GBP polypeptide as a targeting group, and is modified with a radionuclide chelating group, a linking group (composed of a group formed by (R)-2-amino-3-(1-naphthyl)propionic acid, a group formed by 4-aminomethyl-cyclohexanecarboxylic acid and a group formed by lysine) and an albumin binding group. The blood half-life of the probe targeting GPC3 obtained by the compound targeting GPC3 modified with the above groups is increased, so that the stability and pharmacokinetics of the probe are greatly improved.

[0070] In the present invention, the compound represented by formula (4) can be prepared by conventional organic synthesis methods in the art. Figure 4 The raw materials involved in the route can be obtained commercially, and the process conditions of each step can refer to the reaction conditions known in the field of organic synthesis.

[0071] In a preferred embodiment, the compound targeting GPC3 is selected from the group consisting of the following compounds:

[0072] Compound 1: a compound represented by formula (2), wherein M 2 For the group formed by DOTA, n = 2:

[0073] Compound 2: a compound represented by formula (3), wherein M 3 is a group formed by DOTA, X is a methyl group;

[0074] Compound 3: A compound represented by formula (1), wherein M 1 The group formed for NOTA:

[0075] Compound 4; A compound represented by formula (3), wherein M 3 is a group formed by NODAGA, X is a methyl group;

[0076] Compound 5: A compound represented by formula (4), wherein M 4 It is a group formed by NODAGA, and X is a methyl group.

[0077] The second aspect of the present invention provides a radionuclide probe obtained by labeling the compound targeting GPC3 as described above with a radionuclide. The radionuclide probe has the potential to be used as an integrated diagnosis and treatment probe and is applied to the diagnosis and treatment of liver cancer tumors.

[0078] In the present invention, the radionuclide is a diagnostic or therapeutic radionuclide. Preferably, the radionuclide is selected from 18 F. 68 Ga, 11 C. 125 I. 123I. 124 I. 94 Tc, 99m Tc, 90 In, 111 In, 67 Ga, 68 Ga, 89 Zr, 89 Sr. 86 Y. 90 Y. 177 Lu, 151 Tb, 186 Re, 188 Re, 64 Cu, 67 Cu, 55 Co. 57 Co. 43 Sc, 44 Sc, 47 Sc, 225 Ac, 211 At 223 Ra, 213 Bi, 212 Bi, 212 Pb, 227 Th, 153 Sm, 166 Ho, 152 Gd, 153 Gd, 157 Gd and 166 One or more of Dy.

[0079] In the present invention, the method for radionuclide labeling of the compound targeting GPC3 may be a conventional method in the art. For example, a method for labeling the compound with a bifunctional chelating group chelating a radionuclide may be used. 18 F aluminum fluoride chelate labeling method, 18 F or 211 At nucleophilic substitution labeling method, etc.

[0080] The third aspect of the present invention provides the use of the radionuclide probe described above in the preparation of an imaging agent for diagnosing liver cancer tumors or a drug for targeted treatment of liver cancer tumors. The imaging agent can be used for positron emission tomography or single photon emission computed tomography.

[0081] A fourth aspect of the present invention provides an imaging agent for diagnosing liver cancer tumors, comprising the radionuclide probe described above.

[0082] The fifth aspect of the present invention provides a pharmaceutical composition comprising the radionuclide probe described above.

[0083] In a preferred embodiment, the pharmaceutical composition further comprises a carrier, and the carrier is an aqueous carrier, a water-miscible carrier or a non-aqueous carrier.

[0084] Terminology Note:

[0085] β-Ala represents 3-aminopropionic acid;

[0086] Gaba indicates gamma-aminobutyric acid;

[0087] Ava stands for 5-aminovaleric acid;

[0088] Ahx represents 6-aminohexanoic acid;

[0089] Aoc stands for 8-aminooctanoic acid;

[0090] Aun represents 11-aminoundecanoic acid;

[0091] D-1-Nal-OH represents (R)-2-amino-3-(1-naphthyl)propionic acid, and its structural formula is:

[0092]

[0093] 4-Amc-OH represents 4-aminomethyl-cyclohexanecarboxylic acid, and its structural formula is:

[0094]

[0095] Ser indicates serine;

[0096] Lys indicates lysine;

[0097] Glu represents glutamate;

[0098] Gln indicates glutamate;

[0099] Cys indicates cysteine;

[0100] Asn indicates aspartic acid;

[0101] Gly represents glycine;

[0102] Fmoc represents fluorenylmethoxycarbonyl;

[0103] Fmoc-Thr(tBu) represents fluorenylmethoxycarbonyl-OH-O-tert-butyl-L-threonine;

[0104] Fmoc-Val-OH represents fluorenylmethoxycarbonyl-L-valine;

[0105] Fmoc-Ser(tBu)-OH represents fluorenylmethoxycarbonyl-O-tert-butyl-L-serine;

[0106] Fmoc-Pro-OH represents fluorenylmethoxycarbonyl-L-proline;

[0107] Fmoc-Asn(Trt)-OH represents fluorenylmethoxycarbonyl-N-trityl-L-asparagine;

[0108] Fmoc-Gln(Trt)-OH represents fluorenylmethoxycarbonyl-N-trityl-L-glutamine;

[0109] Fmoc-Gly-OH represents fluorenylmethoxycarbonyl-glycine;

[0110] Fmoc-Leu-OH represents fluorenylmethoxycarbonyl-L-leucine;

[0111] Fmoc-D-2-Na1-OH represents fluorenylmethoxycarbonyl-3-(2-naphthyl)-D-alanine;

[0112] Fmoc-trans-4-Amc-OH represents trans-4-(N-fluorenylmethoxycarbonylaminomethyl)cyclohexanecarboxylic acid;

[0113] Fmoc-Lys(Dde)-OH represents N-fluorenylmethoxycarbonyl-N'-[1-(4,4-dimethyl-2,6-dioxocyclohexylidene)ethyl]-D-lysine;

[0114] DCM means dichloromethane;

[0115] DMAP indicates 4-dimethylaminopyridine;

[0116] DIC stands for N,N'-diisopropylcarbodiimide;

[0117] HOBt represents 1-hydroxybenzotriazole;

[0118] DMF stands for N,N-dimethylformamide;

[0119] TFA denotes trifluoroacetic acid;

[0120] TIPS stands for triisopropylsilane;

[0121] ACN means acetonitrile;

[0122] 18 F-FDG stands for fluorine[ 18 F]-deoxyglucose.

[0123] In the present invention, 18 O(p,n) 18 F represents cyclotron proton bombardment [ 18 O]H2O generation 18 Nuclear reaction of F nuclide; QMA column means solid phase extraction column; "68 Ga represents gallium-68; 18 F stands for fluorine-18; PBS stands for phosphate buffered saline; %ID / g stands for the percentage of the injected dose per gram of tissue; %ID / 1mio cells stands for the percentage of the injected dose per million cells; M stands for mole per liter; nM stands for nanomole per liter; nmol / ml stands for nanomole per liter; mmol stands for millimole; MBg stands for the unit of radioactivity, megabecquerel (10 6 Becquerel); GBg / umo1 means 10 becquerel per micromole; μCi means the unit of radioactivity, microcurie.

[0124] In the present invention, Huh7 cells are a type of human hepatocellular carcinoma cell with high expression of GPC3; HepG2 cells are another type of human hepatocellular carcinoma cell with high expression of GPC3; PC3 cells are a type of human prostate cancer cell with low expression of GPC3; Bone means bone; Muscle means muscle; Lung means lung; Brain means brain; Heart means heart; Liver means liver; Kindey means kidney; gall bladder means gall bladder; Stomach means stomach; Intestine means intestine; Blood means blood; Tumor means tumor.

[0125] In the present invention, IC50 means the half-maximal inhibitory concentration of the drug being measured; PET means positron emission tomography; CT means electronic computed tomography; and micro-PET / CT means small animal positron emission computed tomography.

[0126] The present invention will be described in detail below through examples, but the protection scope of the present invention is not limited thereto.

[0127] Example 1

[0128] Compound 1: a compound represented by formula (2), wherein M 2 It is a group formed by DOTA, n=2; the structural formula is:

[0129]

[0130] The preparation process is as follows:

[0131] 1) Wang resin beads 1 (0.5 mmol, degree of substitution = 1.06) were swollen in 20 mL of DCM overnight; 3 equivalents of Fmoc-Thr(tBu)-OH, DMAP and DIC were added and stirred at room temperature for 3 h to complete the condensation reaction; 20 mL of 20% by volume piperidine in DMF solution was used to selectively remove the Fmoc protecting group to obtain resin beads 2;

[0132] 2) DMF, Fmoc-His(Trt)-OH, HOBt and DIC were mixed, then added to the resin beads 2, and shaken at room temperature for 1.5 hours; Fmoc was removed with a DMF solution of 20% by volume of piperidine, and the resin beads were washed to obtain 3;

[0133] 3) Fmoc-Val-OH, HOBt and DIC were added to DMF, and then a DMF solution of 20% by volume of piperidine was added to obtain resin beads 4;

[0134] 4) coupling Fmoc-Ser(tBu)-OH, Fmoc-Pro-OH, Fmoc-Asn(Trt)-OH, Fmoc-Gln(Trt)-OH, Fmoc-Gly-OH, Fmoc-Leu-OH, Fmoc-Pro-OH and Fmoc-Ser(tBu)-OH to the amino side chain of resin bead 4 to obtain resin bead 5;

[0135] 5) Resin beads 5, DMF, Fmoc-NH-PEG2-COOH, HOBt and DIC were mixed, and then the protecting group of Fmoc was removed with a DMF solution of 20% by volume of piperidine to obtain resin beads 6;

[0136] 6) 3 equivalents of DOTA, HOBt, DIC and resin beads 6 were reacted in DMF solvent for 1.5 h to couple the chelating agent to modify the N-terminus of resin beads 6, and then washed with DMF (3 times), DCM (2 times) and methanol (2 times), and dried;

[0137] 7) TFA, TIPS and ultrapure water were mixed in a volume ratio of 95:2.5:2.5 to obtain a cleavage solution, and then the intermediate product obtained in step 6) was cleaved in 10 mL of the cleavage solution for 2 h. After filtering, the filtrate was poured into 100 mL of ice ether to form a large amount of solid, and the mixture was sent to a centrifuge; the solid was dissolved in a mixture of ACN and ultrapure water (ACN and ultrapure water were mixed in a volume ratio of 1:1), purified by a reverse phase C18 column, and identified by mass spectrometry to obtain compound 1 (mass spectrum as shown in FIG. Figure 5 shown).

[0138] Example 2

[0139] Compound 2: a compound represented by formula (3), wherein M 3 It is a group formed by DOTA, X is a methyl group; its structural formula is:

[0140]

[0141] The preparation process is as follows:

[0142] 1) preparing resin beads 5 according to the method described in Example 1;

[0143] 2) dissolving resin beads 5 in a mixed solution of DMF, Fmoc-Lys(Dde)-OH, HOBt and DIC, and then removing the protecting group of Fmoc with a DMF solution of 20% by volume of piperidine to obtain resin beads 7;

[0144] 3) 3 times the equivalent of DOTA, HOBt, DIC and resin beads 7 were reacted in DMF solvent for 1.5 h to couple the chelating agent to modify the N-terminus of resin beads 7; the Dde protecting group was removed with N2H4·H2O to generate resin beads 8;

[0145] 4) The resin beads 8 were dissolved in 20 mL of DMF, and then 4-(p-methylphenyl)butyric acid, HOBt and DIC were added. The mixture was stirred at room temperature, and then washed with DMF (3 times), DCM (2 times), and MeOH (2 times), and dried;

[0146] 5) TFA, TIPS and ultrapure water were mixed at a volume ratio of 95:2.5:2.5 to obtain a cleavage solution, and then the intermediate product obtained in step 4) was cleaved in 10 mL of the cleavage solution for 2 h. After filtering, the filtrate was poured into 100 mL of ice ether to form a large amount of solid, and the mixture was sent to a centrifuge; the solid was dissolved in a mixture of ACN and ultrapure water (ACN and ultrapure water were mixed at a volume ratio of 1:1), purified by a reverse phase C18 column, and identified by mass spectrometry to obtain compound 2 (mass spectrum as shown in FIG. Figure 6 shown).

[0147] Example 3

[0148] Compound 3: A compound represented by formula (1), wherein M 1 It is a group formed by NOTA; its structural formula is:

[0149]

[0150] The preparation process is as follows:

[0151] 1) Resin beads 5 were obtained by referring to the preparation method described in Example 1;

[0152] 2) 3 equivalents of NODAGA, HOBt, DIC and resin beads 5 were reacted in DMF for 1.5 h, then washed with DMF (3 times), DCM (2 times) and methanol (2 times), and dried;

[0153] 3) TFA, TIPS and ultrapure water were mixed in a volume ratio of 95:2.5:2.5 to obtain a cleavage solution, and then the intermediate product obtained in step 2) was cleaved in 10 mL of the cleavage solution for 2 h. After filtering, the filtrate was poured into 100 mL of ice ether to form a large amount of solid, and the mixture was sent to a centrifuge; the solid was dissolved in a mixture of ACN and ultrapure water (ACN and ultrapure water were mixed in a volume ratio of 1:1), purified by a reverse phase C18 column, and identified by mass spectrometry to obtain compound 3 (mass spectrum as shown in FIG. Figure 7 shown).

[0154] Example 4

[0155] Compound 4: a compound represented by formula (3), wherein M 3 It is a group formed by NODAGA, X is a methyl group; its structural formula is:

[0156]

[0157] Compound 4 was prepared by referring to the preparation method of compound 2. The mass spectrum is shown in Figure 8 shown.

[0158] Example 5

[0159] Compound 5: A compound represented by formula (4), wherein M 4 It is a group formed by NODAGA, X is a methyl group; its structural formula is:

[0160]

[0161] The preparation process is as follows:

[0162] 1) Prepare resin beads 5 according to the method described in Example 1;

[0163] 2) dissolving resin beads 5 in a mixed solution of Fmco-D-1-Nal-OH, HOBt, DIC and DMF, stirring at room temperature for 1.5 hours, removing DMF, washing with DMF three times, adding a 20% by volume piperidine DMF solution, stirring at room temperature for 30 minutes, removing the solvent, and washing with DMF five times to obtain resin beads 9;

[0164] 3) Take resin beads 9, add Fmoc-trans-4-Amc-OH, HOBt, DIC and DMF, stir at room temperature for 1.5 hours, remove DMF, wash with DMF three times, add 20% by volume piperidine DMF solution (20 ml), stir at room temperature for 30 minutes, remove the solvent, and wash with DMF five times to obtain resin beads 10;

[0165] 4) dissolving the resin beads 10 in a DMF solution containing Fmoc-Lys(Dde)-OH, HOBt and DIC, and then removing the protecting group of Fmoc with a DMF solution containing 20% ​​by volume of piperidine to obtain resin beads 11;

[0166] 5) 3 times the equivalent of NODAGA, HOBt and DIC were reacted in DMF solvent for 1.5 h to couple the chelating agent to modify the N-terminus of the resin bead 11; the Dde protecting group was removed with N2H4·H2O to generate the resin bead 12;

[0167] 6) The resin beads 12 were dissolved in 20 mL of DMF, and then 4-(p-methylphenyl)butyric acid, HOBt and DIC were added. The mixture was stirred at room temperature, and then washed with DMF (3 times), DCM (2 times) and MeOH (2 times), and dried;

[0168] 7) TFA, TIPS and ultrapure water were mixed at a volume ratio of 95:2.5:2.5 to obtain a cleavage solution, and then the intermediate product obtained in step 6) was cleaved in 10 mL of the cleavage solution for 2 h. After filtering, the filtrate was poured into 100 mL of ice ether to form a large amount of solid, and the mixture was sent to a centrifuge; the solid was dissolved in a mixture of ACN and ultrapure water (ACN and ultrapure water were mixed at a volume ratio of 1:1), purified by a reverse phase C18 column, and identified by mass spectrometry to obtain compound 5 ( Fig. 9 ).

[0169] Example 6

[0170] Preparation of radionuclide probes:

[0171] 1. 68 Ga-labeled compounds 1 and 2

[0172] The marking method is as follows:

[0173] Elute with 5 mL 0.6 M HCl 68 Ge / 68 Ga generator to obtain gallium-68, 1 mL of 1 M sodium acetate buffer solution was mixed with 50 μL of aqueous solution of the compound to be labeled, and then added to 4 mL of 68 Ga hydrochloric acid solution; incubate at 100°C for 10 minutes to complete the radiolabeling reaction; add 5 mL of water to the reaction mixture to quench the reaction; separate and purify through a C18 column, dissolve with 0.9% NaCl injection, adjust the pH value to 6-8, and pass through a 0.22 μm filter into a sterile bottle.

[0174] The above method was used to label compound 1 and compound 2 to obtain 68 Ga-compound 1 and 68Ga-compound 2. After decay correction, 68 The radiochemical yields of Ga-labeled compounds 1 and 2 were 77±4% and 76±5%, respectively.

[0175] Radiochemical purity (RCP%) was determined by HPLC, with the mobile phases being 0.1% TFA-H2O (phase A) and 0.1% TFA-acetonitrile (phase B). The HPLC elution was performed using a gradient solvent system consisting of A and B: 0-2 min, 90% A; 2-15 min, 90-20% A; 15-20 min, 20% A, total time 20 min, flow rate 3.0 mL / min -1 The test results are as follows: Fig.10 As shown, Fig. 9 a is 68 Ga-compound 1, Fig. 9 b is 68 Ga-compound 2. The radiochemical purity of the labeled product is >98%, and the HPLC retention time is consistent with that of the labeled precursor. 68 Compounds 1 and 2 were successfully labeled with Ga.

[0176] 2. 18 F-labeled compounds 3, 4 and 5

[0177] The marking method is as follows:

[0178] Cyclotron 18 O(p,n) 18 F nuclear reaction produces 18 F-ion, 18 F- ions were enriched by QMA column. The QMA column was eluted with sodium acetate solution (pH=3.9, 0.3 mL). 18 F- ions were dripped into the reaction bottle.

[0179] Dissolve 50 μg of the compound to be labeled in 50 μL of pure water in a 2 mL centrifuge tube, add 10 μL of 2 mM A1C13 (1.6 μg), 300 μL of dimethyl sulfoxide, mix well, and add 18 The reaction bottle of F- ion was heated at 100°C for 10 minutes; 5 mL of water was added to the reaction mixture to quench the reaction; it was separated and purified by C18 column, dissolved with 0.9% NaCl injection, the pH value was adjusted to 6-8, and passed through a 0.22 μm filter into a sterile bottle.

[0180] Compound 3, compound 4 and compound 5 were labeled by the above method to obtain 18 F-compound 3, 18 F-compound 4 and 18 F-compound 5. After decay correction,18 The radiochemical yields of F-labeled compound 3, compound 4, and compound 5 were 29±5%, 7.4±0.6%, and 6.7±0.3%, respectively.

[0181] Radiochemical purity (RCP%) was determined by HPLC, with the mobile phases being 0.1% TFA-H2O (phase A) and 0.1% TFA-acetonitrile (phase B). HPLC elution was performed using a gradient solvent system consisting of A and B: 0-2 min, 90% A; 2-15 min, 90-20% A; 15-20 min, 20% A; total time 20 min, flow rate 3.0 mL / min -1 . 18 The test results of F-compound 3 are as follows Fig.11 As shown, 18 The test results of F-compound 4 are as follows Fig.12 As shown, 18 The test results of F-compound 5 are as follows Fig.13 The radiochemical purity of the labeled product is >98%, and the HPLC retention time is consistent with that of the labeled precursor. 18 F can successfully and efficiently label compounds 3-5.

[0182] Test Example 1

[0183] 1. Construction and verification of a GPC3-positive hepatocellular carcinoma mouse model

[0184] HepG2 and Huh7 are two human hepatoma cell lines, and PC3 is a prostate cancer cell line. 7 Huh7 or PC3 cells were suspended in 0.1 mL of sterile PBS and injected subcutaneously into the right axilla of male BALB / c nude mice. The tumors took about 4 weeks to reach the appropriate size. 6 The orthotopic liver cancer model was obtained by implanting 10 cells under the liver capsule of male C-NKG mice. Approximately 3 weeks after inoculation, the cells were used for micro PET / CT and biodistribution studies.

[0185] Subcutaneous tumors and in situ liver cancer tumors were surgically removed, paraffin-embedded and sliced ​​(5-10 μm) with 4% paraformaldehyde, and then the tumor tissues were subjected to immunohistochemical staining. They were incubated with GPC3-alpha primary antibody (dilution 1:2000, Affinity) and goat anti-mouse secondary antibody (dilution 1:2000, Servicebio), respectively. The secondary antibody is a molecule formed by the combination of horseradish peroxidase (HRP) and goat anti-mouse IgG. After the primary and secondary antibodies are combined, the sections are reacted with DAB staining solution. DAB produces a brown precipitate under the catalysis of HRP, which amplifies the signal and forms color. After a series of routine treatments, the immunohistochemical image ( Fig.14). The results showed that HepG2 and Huh7 cell lines overexpressed GPC3, while the expression level of GPC3 in PC3 cell line was relatively low.

[0186] 2. Example 6 Preparation of Radionuclide Probe 68 Ga-compound 1, 68 Ga-compound 2, 18 F-compound 3, 18 F-compound 4 and 18 PET imaging of F-compound 3 in different hepatocellular carcinoma animal models

[0187] The imaging method is as follows: the model mice were scanned with MicroPET / CT by Madiclab PSA146 PET / CT / FMT instrument (Linyi, China); each model mouse was intravenously injected with about 10MBq (0.1mL) of the probe to be tested under isoflurane (1%) anesthesia; the animals were subjected to 60-minute dynamic scanning and static scanning at multiple time points; the blocking experiment used 100μg of the probe precursor compound to be tested and 10MBq of the probe to be tested co-injected; the images were reconstructed using the three-dimensional ordered subset expected maximum (OSEM) algorithm and converted into the percentage of injected dose per gram of tissue (%ID / g) images; the data were analyzed using PMOD software (version 4.3, PMOD Technologies Ltd., Zurich, Switzerland), and the regions of interest (ROI) of tumors and major organs were manually drawn on the attenuation-corrected whole-body coronal images. The model mice can be Huh7 subcutaneous tumor Balb / c model mice, PC3 subcutaneous tumor Balb / c model mice, or HepG2 liver orthotopic tumor C-NKG model mice.

[0188] Fig.15 For probe 68 PET / CT imaging results of Ga-compound 1 on Huh7 subcutaneous tumor Balb / c model mice, Fig.16 For probe 68 The time activity curve of the region of interest (ROI) in the PET / CT imaging results of Ga-compound 1 in Huh7 subcutaneous tumor Balb / c model mice, Fig.17 For probe 68 The PET / CT imaging results of Ga-compound 2 on Huh7 subcutaneous tumor Balb / c model mice. Fig.18 For probe 68 Time activity curve of the region of interest in the PET / CT imaging results of Ga-compound 2 on Huh7 subcutaneous tumor Balb / c model mice, Fig.19 It is a probe 68The PET / CT imaging results of Ga-compound 2 on HepG2 liver tumor in situ C-NKG model for 1 hour. Fig. 20 It is a probe 18 F- PET / CT imaging results of compound 3 on Huh7 subcutaneous tumor Balb / c model mice, Fig.21 It is a probe 18 F- PET / CT imaging results of compound 4 on Huh7 subcutaneous tumor Balb / c model mice, Fig. 22 It is a probe 18 F-PET / CT imaging results of compound 5 on Huh7 subcutaneous tumor Balb / c model mice. Fig.23 It is a probe 68 Ga-compound 2 and probe 18 Comparative analysis of F-FDG MicroPET / CT imaging results, where (a) tail vein injection 68 MicroPET / CT imaging of subcutaneous Huh7 xenografts 3 hours after Ga-compound 2, uptake group and inhibition group. (b) Tail vein injection 68 3 h after Ga-compound 2 and tail vein injection 18 MicroPET / CT imaging of subcutaneous PC3 xenografts 1 hour after F-FDG. (c) 68 Tumor uptake values ​​of Ga-Compound 2. ***P≤0.001.

[0189] Combination Figure 15-22 By comparing PET images at different times, we can get 68 Ga-compound 1, 68 Ga-compound 2, 18 F-compound 3, 18 F-compound 4 and 18 F-Compound 3, the optimal imaging time of each probe in Huh7 subcutaneous tumor Balb / c model mice is: 0.5h, 3h, 0.5h, 2h and 4h. The tumor uptake value at the optimal imaging time can reach: 2.17±0.13%ID / g, 3.17±0.16%ID / g, 2.32±0.27%ID / g, 2.62±0.25%ID / g and 6.02±0.38%ID / g. The tumor and liver probe uptake ratio can reach: 1.61±0.16, 1.96±0.11, 4.56±0.10, 2.46±0.20, and 2.26±0.08. The tumor-to-muscle probe uptake ratios can reach: 2.91±0.11, 5.17±1.09, 9.43±0.62, 9.45±0.02, and 11.83±2.74.

[0190] 18 F-FDG, fluorine[ 18F]-deoxyglucose is a glucose analogue that is widely used in clinical practice at home and abroad for tumor diagnosis, staging and treatment monitoring. It is the most commonly used positron-emitting drug. However, it is based on glucose metabolism imaging and cannot specifically distinguish tumor phenotypes. In addition, the uptake value is low for highly differentiated tumors and high in inflammatory tissues. Fig.23 It was found that in the Huh7 subcutaneous tumor Balb / c model mice, 18 One hour after intravenous injection of F-FDG, the tumor-to-liver probe uptake ratio and the tumor-to-muscle probe uptake ratio were only 1.44±0.17 and 3.00±0.11, respectively, indicating that the GBP polypeptide-based radioactive probe of the present invention has a high image contrast. 18 F-FDG is the most widely used positron-emitting radiopharmaceutical in clinical practice. Fig.23 Available, 18 Although F-FDG has certain uptake values ​​in GPC3-positive tumors (Huh7) and GPC3-negative tumors (PC3), it cannot identify the expression level of GPC3. 68 There is a significant difference in the uptake of Ga-compound 2 in these two groups of tumors, and the uptake value of GPC3-positive tumors (Huh7) can be significantly inhibited by injecting excessive amounts of compound 2. All of these indicate that the GBP polypeptide-based radionuclide probe provided by the present invention has high specificity and can identify tumor GPC3 expression through non-invasive in vivo imaging.

[0191] Combination Fig.19 Available, 68 The maximum tumor uptake value of Ga-compound 2 in HepG2 liver tumor in situ C-NKG model mice can reach: 2.82±0.15%ID / g (3h). The tumor to liver probe uptake ratio can reach: 2.29±0.13. The tumor to muscle probe uptake ratio can reach: 13.03±1.63. It shows that the radionuclide probe based on GBP polypeptide provided by the present invention has high sensitivity and can accurately locate the tumor in situ.

[0192] Test Example 2

[0193] Determination of probe hydrophilicity

[0194] The hydrophilicity test method is as follows: in a centrifuge tube, add about 100 μCi of the probe to be tested to a mixed solution of PBS (pH 7.4, 600 μL) and n-octanol (600 μL). After the PBS and n-octanol are completely separated by a centrifuge, take an equal amount of the two-phase liquid (100 μL) and measure the radioactivity with a γ counter. Repeat three times. log P is calculated as the logarithm of the ratio of the radioactivity in the n-octanol and PBS phases.

[0195] The hydrophilicity of the probe prepared in Example 6 was tested according to the above method.68 Ga-compound 1 and 68 The log P values ​​of Ga-compound 2 were -3.00±0.10 and -2.63±0.13, respectively. 18 F-compound 3, 18 F-compound 4 and 18 The logP values ​​of F-compound 5 are -1.40±0.03, -1.54±0.09 and -1.11±0.01, respectively, indicating that the radionuclide probe based on GBP polypeptide coupling of the present invention has excellent hydrophilicity.

[0196] Test Example 3

[0197] Probe cellular uptake, inhibition and endogenization validation

[0198] Uptake test: In the cell uptake blocking experiment, 74 kBq / well of the probe to be tested and 33 μg of excess precursor compound were added to each well and incubated for 60 minutes; after removing the culture medium, the cells were washed twice with 1.0 mL PBS; finally, the cells were lysed with 1.0 mL NaOH (1.0 M). The radioactivity count of the cell lysate was measured by a γ-counter. Huh7 and HepG2 are GPC3 high-expressing cell lines, and PC3 is a GPC3 low-expressing cell line.

[0199] The probe was 68 Ga-compound 1 and 68 Ga-compound 2 was detected, 68 Ga-compound 1 and 68 The uptake of Ga-compound 2 in cells is as follows Fig.24 As shown. Among them, Fig.24 a is 68 Test results of Ga-compound 1, Fig.24 b is 68 Test results of Ga-compound 2; **P≤0.01; ***P≤0.001; ****P≤0.0001.

[0200] Combination Fig.24 It can be seen that the probe 68 Ga-compound 1 and 68 Ga-compound 2 showed strong binding to GPC3 high-expressing cell lines, and the uptake values ​​were significantly different from those of low-expressing cell lines, indicating that the probe was specifically taken up by tumors.

[0201] Test Example 4

[0202] Probe cell competition binding assay to measure probe affinity

[0203] Test method: Huh7 cells were incubated in a culture medium containing a precursor compound (10-11M to 10-5M) and a probe to be tested (74kBq / well) for 60min; the culture medium was removed, washed twice with 1ml PBS (pH 7.4), and then 1.0ml of NaOH (1.0M) was added to lyse the cells. Each independent experiment was repeated 3 times. After counting the radioactivity on a γ-counter, nonlinear regression fitting was performed to calculate the 50% inhibition concentration (IC50).

[0204] The above method was used for detection and experimental determination 68 The IC50 values ​​of Ga-compound 1 for HepG2 and Huh7 cells were 790 nM and 140 nM, 68 The Ga-compound 2 was 236 nM and 71.5 nM. The results showed that the radionuclide probe obtained by modifying the GBP polypeptide in the present invention still had good affinity to the GBP polypeptide.

[0205] The preferred embodiments of the present invention are described in detail above, but the present invention is not limited thereto. Within the technical concept of the present invention, the technical solution of the present invention can be subjected to a variety of simple modifications, including the combination of various technical features in any other suitable manner, and these simple modifications and combinations should also be regarded as the contents disclosed by the present invention and belong to the protection scope of the present invention.

Claims

1. A compound targeting GPC3, characterized in that: The compound targeting GPC3 comprises a GBP polypeptide, optionally a linking group, a radionuclide chelating group and optionally an albumin binding group; The linking group is a group formed by a linker, and the linker is selected from at least one of a hydrocarbon chain linker, a polyethylene glycol linker and an amino acid linker.

2. The compound targeting GPC3 according to claim 1, characterized in that The structural formula of the compound targeting GPC3 is shown in any one of formula (1) to formula (4); Among them, M 1 、M 2 、M 3 and M 4 Each is independently selected from a radionuclide chelating group, R 1 and R 2 Each is independently selected from an albumin binding group, n=1-12.

3. The compound according to claim 2, characterized in that The radionuclide chelating group is a group formed by a bifunctional chelating agent; Preferably, the bifunctional chelating agent is selected from one or more of DOTA, NOTA, NODA, NODAGA, DOTAGA, DBCO, DOTP, TETA, TRAP, ATSM, PTSM, EDTA, EC, HBEDCC, DTPA, SBAD, BAPEN, Df, DFO, DFO*, TACN, NO2A / NOTAM, CB-DO2A, Cyclen, NOTA-AA, DO3A, DO3AP, MAG3, MAS3, HYNIC and isonitrile.

4. The compound according to claim 2 or 3, characterized in that The structural formula of the albumin binding group is: Wherein, X is methyl, Cl or I.

5. The compound according to claim 2, characterized in that The compound targeting GPC3 is selected from the group consisting of the following compounds: Compound 1: a compound represented by formula (2), wherein M 2 is the group formed by DOTA, n=2; Compound 2: a compound represented by formula (3), wherein M 3 is a group formed by DOTA, X is a methyl group; Compound 3: A compound represented by formula (1), wherein M 1 The group formed by NOTA; Compound 4; A compound represented by formula (3), wherein M 3 is a group formed by NODAGA, X is a methyl group; Compound 5: A compound represented by formula (4), wherein M 4 It is a group formed by NODAGA, and X is a methyl group.

6. A radionuclide probe, characterized in that: The compound targeting GPC3 according to any one of claims 1 to 5 is obtained by labeling with a radionuclide.

7. The radionuclide probe according to claim 6, characterized in that: The radionuclide is a diagnostic or therapeutic radionuclide; Preferably, the radionuclide is selected from 18 F. 68 Ga, 11 C. 125 I. 123 I. 124 I. 94 Tc, 99m Tc, 90 In, 111 In, 67 Ga, 68 Ga, 89 Zr, 89 Sr. 86 Y. 90 Y. 177 Lu, 151 Tb, 186 Re, 188 Re, 64 Cu, 67 Cu, 55 Co. 57 Co. 43 Sc, 44 Sc, 47 Sc, 225 Ac, 211 At 223 Ra, 213 Bi, 212 Bi, 212 Pb, 227 Th, 153 Sm, 166 Ho, 152 Gd, 153 Gd, 157 Gd and 166 One or more than one of Dy.

8. Use of the radionuclide probe according to claim 6 or 7 in the preparation of an imaging agent for diagnosing liver cancer tumors or a drug for targeted treatment of liver cancer tumors.

9. An imaging agent for diagnosing liver cancer tumors, characterized in that: Comprising the radionuclide probe according to claim 6 or 7.

10. A pharmaceutical composition, characterized in that Comprising the radionuclide probe according to claim 6 or 7.

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