Folate receptor alpha targeting polypeptide and application thereof

Abstract

The invention discloses a polypeptide targeting a folate receptor alpha and application of the polypeptide, and belongs to the field of biological medicine. The amino acid sequence of the polypeptide is shown as any one of SEQ ID No.1 to SEQ ID No.4, the polypeptide is combined with a folate receptor alpha overexpressed in tumor cells in a targeted manner, and the polypeptide has important application value in tumor molecular diagnosis and / or targeted therapy.

Description

Technical Field

[0001] The present invention relates to the field of biomedicine, and in particular to a polypeptide targeting folate receptor α and an application thereof. Background Art

[0002] Folic acid is an essential vitamin required for DNA synthesis, repair and cell division. As a transmembrane single-chain glycoprotein linked to glycosylated phosphatidylinositol, the folate receptor has a high affinity for folate and can transport folate through endocytosis on the cell membrane, in which the folate receptor is internalized and then recycled back to the cell membrane. Four subtypes of folate receptors have been identified: FRα, FRβ, FRγ and FRδ, which are encoded by genes FOLR1, FOLR2, FOLR3 and FOLR4, respectively.

[0003] Folate receptor α (FRα), encoded by the FOLR1 gene, is a cell surface glycoprotein with a molecular weight of approximately 40KD. It was originally discovered as a folate binding protein, and later it was found that in addition to transporting folate, it is also involved in regulating the proliferation and metastasis of tumor cells. FRα is not expressed or expressed at a very low level in normal tissues, but is widely expressed in solid tumors, such as mesothelioma (72-100%), triple-negative breast cancer (35-68%), ovarian cancer (76-89%), and non-small cell lung cancer (14-74%); a certain proportion of FRα is expressed in non-malignant tissues such as the choroid plexus, and a certain proportion of FRα is also expressed in bronchial epithelial cells, thyroid, salivary glands, breast, colon, and bladder. Folate receptors are involved in tumor infiltration, metastasis, and progression, making them a very promising target for cancer treatment.

[0004] Currently, there are many types of FRα-targeted drugs for tumor treatment, including monoclonal antibodies, ADC drugs, CAR-T therapy, and bispecific antibodies. Among them, ADC drugs have made the fastest progress. The first FRa ADC product, Elahere, was approved for accelerated marketing by the FDA in 2022. ImmunoGen screened the monoclonal antibody Mirvetuximab targeting human FRα based on a hybridoma platform, and then connected a cytotoxic drug DM4 through a cleavable linker to develop Elahere. In addition, there are a number of ADC drugs under clinical development, including STRO-002 and CBP-1008, which have entered clinical phase II. Other drugs involving FRα-targeted drugs such as bispecific antibodies and CAR-T drugs are in clinical phase I, phase II, and preclinical stages. China Pharmaceutical University has disclosed a series of short peptides that specifically bind to folate receptor α and their applications in tumor diagnosis and targeted therapy (CN107353325A, CN107446020A, CN107674115A, CN107793471A, CN107446021A). The polypeptide specifically binds to folate receptor α overexpressed in tumor cells. The polypeptide can be effectively enriched in the tumor part and has tumor targeting in vivo, and has important application value in tumor molecular diagnosis and targeted therapy.

[0005] Folate receptors provide potential targets for the diagnosis and treatment of cancer. Although some anti-FRα antibodies have been developed, there is still a need for further development of targeted FRα drugs based on existing technologies, especially for the development of active molecules with high specificity, high biological activity, high endocytosis ability, and better in vivo safety. As one of the important biological substances, peptides are widely present in living organisms to regulate the functional activities of various system organs and cells in the body. In recent years, peptide drugs have attracted much attention in the development of anti-tumor drugs due to their advantages such as high targeting, low immunogenicity, high tissue permeability, and safety.

[0006] In view of this, the development of a peptide that can target and bind to FRα has potential application value and provides new ideas for the targeted treatment and diagnosis of tumors. Summary of the invention

[0007] The purpose of the present invention is to provide a polypeptide targeting folate receptor α and its application. The polypeptide targets and binds to folate receptor α overexpressed in tumor cells and has important application value in tumor molecular diagnosis and targeted therapy.

[0008] Furthermore, the present invention adopts the following technical solution:

[0009] In a first aspect, the present invention provides a polypeptide targeting folate receptor α, wherein the amino acid sequence of the polypeptide is shown in SEQ ID No. 1, SEQ ID No. 2, SEQ ID No. 3 or SEQ ID No. 4,

[0010] WCWMPHIAMHTQFGCGQ(SEQ ID No.1)、

[0011] GCYEWCLWHATYKECQSMCG(SEQ ID No.2)、

[0012] GEALLYVYKAQSMDWYYG(SEQ ID No.3)、

[0013] GCYGTCPERDHWFFEYCAKICAG (SEQ ID No. 4).

[0014] In a second aspect, the present invention provides a polypeptide derivative, which is a modified product of the polypeptide described in the first aspect or a variant obtained by adding and / or replacing one or more amino acids.

[0015] Preferably, the polypeptide derivative is a variant obtained by adding and / or replacing one, two or three amino acids of the polypeptide shown in SEQ ID No.1, SEQ ID No.2, SEQ ID No.3 or SEQ ID No.4.

[0016] Further preferably, the polypeptide derivative is a variant obtained by adding and / or replacing one amino acid to the polypeptide shown in SEQ ID No.1, SEQ ID No.2, SEQ ID No.3 or SEQ ID No.4.

[0017] Preferably, the polypeptide derivative is an N-terminal or C-terminal modification product of the polypeptide shown in SEQ ID No.1, SEQ ID No.2, SEQ ID No.3 or SEQ ID No.4, and the modification group is selected from one or more of an acetyl group, an amino group, an alkyl group, an aromatic group, a fatty acid group, a sugar group, a phosphate group, a sulfate group, a polyethylene glycol (PEG) group or a peptide linking group.

[0018] Further preferably, the modification is selected from: C-terminal amidation blocking and / or N-terminal modification of acetyl group.

[0019] In a third aspect, the present invention provides a polynucleotide encoding the above-mentioned polypeptide or polypeptide derivative.

[0020] In a fourth aspect, the present invention provides a vector containing the above-mentioned polynucleotide.

[0021] In a fifth aspect, the present invention provides a cell containing the above-mentioned vector.

[0022] In the sixth aspect, the present invention provides a composition comprising excipients and active ingredients, characterized in that the active ingredient comprises the polypeptide described in the first aspect or the polypeptide derivative described in the second aspect or the polynucleotide described in the third aspect or the vector described in the fourth aspect or the cell described in the fifth aspect; the excipients comprise at least one of a diluent, a filler, a binder, a wetting agent, an absorption enhancer, a surfactant, a lubricant and a stabilizer.

[0023] In the seventh aspect, the present invention provides the use of the polypeptide described in the first aspect or the polypeptide derivative described in the second aspect or the polynucleotide described in the third aspect or the vector described in the fourth aspect or the cell described in the fifth aspect or the pharmaceutical composition described in the sixth aspect in the preparation of a drug for preventing and / or treating a disease associated with folate receptor α, wherein the disease associated with folate receptor α is a cancer with high expression of folate receptor α.

[0024] Preferably, the cancer with high expression of folate receptor α is selected from at least one of ovarian cancer, non-small cell lung cancer, triple-negative breast cancer, mesothelioma, and lung cancer.

[0025] More preferably, the cancer with high expression of folate receptor α is ovarian cancer.

[0026] the term

[0027] As used herein, the term "amino acid" refers to a molecule containing an amino group and a carboxyl group. Suitable amino acids include, but are not limited to, the D- and L-isomers of naturally occurring amino acids, as well as non-naturally occurring amino acids prepared by organic synthesis or other metabolic pathways. The term amino acid includes, but is not limited to, α-amino acids, natural amino acids, non-natural amino acids, and amino acid analogs.

[0028] The term "naturally occurring amino acid" refers to any of the 20 L-amino acids commonly found in peptides synthesized in nature, i.e., the L-isomers of alanine (Ala or A), arginine (Arg or R), asparagine (Asn or N), aspartic acid (Asp or D), cysteine ​​(Cys or C), glutamic acid (Glu or E), glutamine (Glu or Q), glycine (Gly or G), histidine (His or H), isoleucine (Ile or I), leucine (Leu or L), lysine (Lys or K), methionine (Met or M), phenylalanine (Phe or F), proline (Pro or P), serine (Ser or S), threonine (Thr or T), tryptophan (Trp or W), tyrosine (Tyr or Y), and valine (Val or V).

[0029] The polypeptides of the present invention can be prepared using methods well known to those skilled in the art, including well-known chemical synthesis methods. Therefore, when a polypeptide or its derivatives contain one or more non-standard amino acids, it is very likely to be prepared by chemical synthesis. In addition to using chemical synthesis methods to prepare polypeptides or their derivatives, they can also be prepared by expressing encoding nucleic acids. This is particularly applicable to the preparation of polypeptides or their derivatives containing only natural amino acids, in which case well-known methods for preparing nucleic acid encoding polypeptide sequences can be used (see Sambrook et al., Molecular Cloning: A Labour Manua l, Third Ed., Cold Spring Harbor Laboratory, New York (2001); Ausubel et al., Current Protocols in Molecular Biology, John Wiley and Sons, Baltimore, MD (1999)). The polypeptide can be expressed in an organism and purified by well-known purification techniques.

[0030] Beneficial Effects

[0031] The FRα binding peptide provided by the present invention can specifically bind to the FRα recombinant protein. At the same time, through cell ELISA and flow cytometry experimental analysis, it is found that the screened phage-displayed short peptide can specifically bind to the natural FRα on the cell surface, and has potential medical and pharmaceutical value. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] Figure 1 The affinity between the polypeptide shown in SEQ ID No. 1 and FRα was detected by surface plasmon resonance method in Example 2;

[0033] Figure 2 The affinity between the polypeptide shown in SEQ ID No. 2 and FRα was detected by surface plasmon resonance method in Example 2;

[0034] Figure 3 This is a diagram of the cellular endocytosis of the polypeptide shown in SEQ ID No. 1 in Example 3;

[0035] Figure 4 This is a diagram of the cellular endocytosis of the polypeptide shown in SEQ ID No. 3 in Example 3;

[0036] Figure 5 This is a diagram of the cellular endocytosis of the polypeptide shown in SEQ ID No. 4 in Example 3. DETAILED DESCRIPTION

[0037] To make the purpose, technical scheme and advantages of the present invention clearer, the technical scheme of the present invention will be described in detail below. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments in the present invention, all other embodiments obtained by ordinary technicians in the field without making creative work belong to the scope of protection of the present invention. In the following examples, unless otherwise specified, the raw materials used are commercially available.

[0038] Example 1 Synthesis of polypeptide

[0039] The polypeptide provided by the present invention adopts a solid phase synthesis method to synthesize its linear precursor, and the crude target polypeptide is obtained after cutting. The solid phase carrier is 2-Chlotrityl Resin resin. In the synthesis process, the 2-Chlotrityl Resin resin is first fully swollen in N,N-dimethylformamide (DMF), and then the swollen solid phase carrier and the activated amino acid derivative are repeatedly condensed → washed → Fmoc protection → washed → the next round of amino acid condensation to achieve the desired length of the synthesized polypeptide chain, and finally a mixed solution of trifluoroacetic acid: water: triisopropylsilane: anisyl thioether (v:v:v:v=90:2.5:2.5:5) is reacted with the solid phase resin to cleave the polypeptide from the solid phase carrier, and then the crude target polypeptide is obtained after precipitation by frozen methyl tert-butyl ether. The crude target polypeptide is purified and separated by a C18 reverse phase preparative chromatography column in a 0.1% trifluoroacetic acid acetonitrile / water system to obtain a pure product of the polypeptide and its derivatives.

[0040] Table 1 Experimental raw materials and their sources

[0041]

[0042]

[0043] (1) Solid phase synthesis of the polypeptide represented by SEQ ID No. 1

[0044] SEQ ID No.1:WCWMPHIAMHTQFGCGQ

[0045] Step 1: Coupling of the first amino acid Fmoc-Gln-OH

[0046] 0.2mmol of 2-Chlorotrityl chloride resin was fully swollen in DCM for 1h. Fmoc-Gln-OH (0.16mmol) and diisopropylethylamine (DIEA, 0.64mmol) were weighed and dissolved in 8mL of DCM and added to the resin, and reacted at room temperature for 2h. After the reaction was completed, blocking solution (10mL) DCM: methanol: DIEA (85:10:5, v:v:v) was added at room temperature for 10min for blocking. The blocked resin was washed 5 times with DCM and 5 times with DMF.

[0047] Step 2: Linear peptide chain synthesis

[0048] The resin obtained in step 1 was fully swollen in DMF for 1 hour. Then, the linear precursor sequence was synthesized in the order from the second amino acid at the carboxyl end to the amino end. Each coupling cycle was performed as follows:

[0049] · Fmoc-deprotection was performed twice with 20% piperidine / DMF (20% v / v, 10 mL), each time for 8 min.

[0050] • Rinse the resin 6-8 times with DMF until neutral pH.

[0051] Dissolve 0.5 mmol of Fmoc-AA, 0.5 mmol of 6-chlorobenzotriazole-1,1,3,3-tetramethyluronium hexafluorophosphate (HCTU) and 1 mmol of 4-methylmorpholine (NMM) in DMF, add the resin and react at room temperature for 1 h.

[0052] • Rinse the resin 4-6 times with DMF before coupling the next amino acid.

[0053] After the linear peptide synthesis, the resin was washed 5 times with DMF and 5 times with DCM. The resin was dried in vacuo.

[0054] Step 3: Cleavage of the linear precursor peptide chain

[0055] Freshly prepared cutting cocktail (10 mL) trifluoroacetic acid: water: triisopropylsilane: thioanisole (90: 2.5: 2.5: 5:, v: v: v: v) was added to the resin obtained in step 1 and shaken for 2 hours at room temperature. After the reaction, the reaction solution was filtered, and the resin was washed with trifluoroacetic acid, combined with the reaction solution, and precipitated with 4 volumes of cold MTBE to obtain a crude product. The crude product was washed with MTBE 3 times and dried in a vacuum.

[0056] Step 4: Peptide purification

[0057] After filtering through a 0.45um membrane, the mixture was separated using a reverse phase high performance liquid chromatography system, with buffers A (0.1wt% trifluoroacetic acid, aqueous solution) and B (0.1wt% trifluoroacetic acid, acetonitrile). The product-related fractions were collected, and after HPLC identification of the purity, the fractions with a purity of >95% were combined and freeze-dried to obtain the pure polypeptide.

[0058] Step 5: Detection and characterization methods

[0059] The purified peptide from step 4 was subjected to analytical HPLC and LC / MS to confirm purity and compound.

[0060] (2) Solid Phase Synthesis of the Peptide Represented by SEQ ID No. 3

[0061] SEQ ID No.3: GEALLYVYKAQSMDWYYG

[0062] Step 1: Coupling of the first amino acid Fmoc-Gly-OH

[0063] 0.2mmol of 2-Chlorotrityl chloride resin was fully swollen in DCM for 1h. Fmoc-Gly-OH (0.16mmol) and diisopropylethylamine (DIEA, 0.64mmol) were weighed and dissolved in 8mL of DCM and added to the resin, and reacted at room temperature for 2h. After the reaction was completed, blocking solution (10mL) DCM: methanol: DIEA (85:10:5, v:v:v) was added at room temperature for 10min for blocking. The blocked resin was washed 5 times with DCM and 5 times with DMF.

[0064] Step 2: Linear peptide chain synthesis

[0065] The resin obtained in step 1 was fully swollen in DMF for 1 hour. Then, the linear precursor sequence was synthesized in the order from the second amino acid at the carboxyl end to the amino end. Each coupling cycle was performed as follows:

[0066] · Fmoc-deprotection was performed twice with 20% piperidine / DMF (20% v / v, 10 mL), each time for 8 min.

[0067] • Rinse the resin 6-8 times with DMF until neutral pH.

[0068] Dissolve 0.5 mmol Fmoc-AA, 0.5 mmol 6-chlorobenzotriazole-1,1,3,3-tetramethyluronium hexafluorophosphate (HCTU) and 1 mmol 4-methylmorpholine (NMM) in DMF, add to the resin and react at room temperature for 1 h.

[0069] • Rinse the resin 4-6 times with DMF before coupling the next amino acid.

[0070] After the linear peptide synthesis, the resin was washed 5 times with DMF and 5 times with DCM. The resin was dried in vacuo.

[0071] Step 3: Cleavage of the linear precursor peptide chain

[0072] Freshly prepared cutting cocktail (10 mL) trifluoroacetic acid: water: triisopropylsilane: thioanisole (90: 2.5: 2.5: 5:, v: v: v: v) was added to the resin obtained in step 1 and shaken for 2 hours at room temperature. After the reaction, the reaction solution was filtered, and the resin was washed with trifluoroacetic acid, combined with the reaction solution, and precipitated with 4 volumes of cold MTBE to obtain a crude product. The crude product was washed with MTBE 3 times and dried in a vacuum.

[0073] Step 4: Peptide purification

[0074] After filtering through a 0.45um membrane, the mixture was separated using a reverse phase high performance liquid chromatography system, with buffers A (0.1wt% trifluoroacetic acid, aqueous solution) and B (0.1wt% trifluoroacetic acid, acetonitrile). The product-related fractions were collected, and after HPLC identification of the purity, the fractions with a purity of >95% were combined and freeze-dried to obtain the pure polypeptide.

[0075] Step 5: Detection and characterization methods

[0076] The purified peptide from step 4 was subjected to analytical HPLC and LC / MS to confirm purity and compound.

[0077] The remaining polypeptides of the present invention can be prepared by referring to the above-mentioned Fmoc solid phase synthesis method. The purity (>90%) and identity of the polypeptides were determined by HPLC and mass spectrometry, respectively.

[0078] Example 2 Surface Plasmon Resonance (SPR) Detection of Peptide Binding Affinity

[0079] Experimental Materials:

[0080] (1) Main reagents

[0081]

[0082] (2) Main consumables

[0083] name Production brand Part Number Storage environment SA sensor chip Cytiva BR100531 4℃ 1.5ml centrifuge tube without cap Cytiva BR100287 RT 0.8ml centrifuge tube without cap Cytiva BR100212 RT

[0084] Experimental steps:

[0085] The FOLR1-Biotin protein was captured onto the SA chip, and the sample was diluted into a concentration gradient (3000, 1000, 333.3, 111.1, 37.04 nM). The chip was regenerated using Glycine 1.5 solution, the flow rate was set to 30 μL / min, the injection time for each cycle was set to 120 s, the dissociation time was set to 600 s, and a single cycle kinetic test was performed according to the Biacore instrument program flow. Finally, the binding-dissociation curve was analyzed and fitted using the Biacore T200 Evaluation Software to calculate the affinity-related parameters.

[0086] In the single concentration test, the peptide was used at a concentration of 500 nM and 100 nM.

[0087] Single-cycle kinetics: Set program parameters, place samples according to plate layout, and perform single-cycle kinetics to determine KD.

[0088] Detection conditions (parameters): flow rate 30 μL / min, association time 120 s, dissociation time 600 s.

[0089] Buffer: 1×HBS-EP+.

[0090] Regeneration conditions: 10 mM Glycine-HCl, 30 s.

[0091] Blocking solution: 10 μg / mL biocytin.

[0092] Experimental Results

[0093] The binding constants KD of SEQ ID No.1 and SEQ ID No.2 to FRα were 1.366 μM and 415.4 nM, respectively. Figure 1 , Figure 2 As shown, Figure 1 is the detection result of the polypeptide shown in SEQ ID No.1, Figure 2 This is the detection result of the polypeptide shown in SEQ ID No.2.

[0094] The experimental results show that the polypeptides of the present invention have a strong affinity for FRα. In summary, the polypeptides of the present invention can effectively target cells with high expression of FRα, and thus have the potential to be used as a drug component or drug carrier for the prevention, diagnosis or treatment of cancers with high expression of FRα, and can meet subsequent in vivo applications.

[0095] Example 3 Endocytosis Experiment

[0096] Experimental Materials:

[0097] Cells: Positive cells: FOLR1 (CHO-K1); Negative cells: CHO-K1.

[0098] (1) Main reagents

[0099] Reagent name factory Part Number FBS Excell FSP500 Puromycin Invivogen ant-pr-1 4% paraformaldehyde fixative Beyotime P0099 DAPI solution (10ug / ml, ready to use) Solarbio C0065 Streptavidin-Cy5(SA-Cy5) ApexBio K1080 Streptomycin sulfate Aladdin S105491 Penicillin G Sodium Aladdin P105489)

[0100] (2) Main consumables

[0101] name Production brand Part Number Storage environment 96WellTC-TreatedBlackMicroplates Agilent 204626-100 RT

[0102] (3) Cell lines

[0103] Cell lines Culture medium CHO-K1 F12K+10%FBS FOLR1(CHO-K1) F12K+10%FBS+1%P / S+4μg / mlpuromycin

[0104] Experimental steps:

[0105] Prepare SA-Cy5 dilution: dilution ratio 1:50, diluent: cell growth medium.

[0106] Sample preparation: dilute directly from the stock solution to the required concentration (0.1-1 μM), diluent: the SA-Cy5 diluent prepared in 1. Premix at room temperature in the dark for 1 hour.

[0107] Sample addition: Aspirate the culture medium in the well and replace it with samples of corresponding concentration (0.1-1 μM), incubate at 37°C for 2 h.

[0108] Fixation: Wash cells 3 times with DPBS, add 60 μL / well fixative, incubate at 4°C in dark for 30 min.

[0109] Nuclear staining: Wash cells 3 times with DPBS, add 40-50 μL / well DAPI nuclear staining solution, incubate at 37°C in dark for 20 min.

[0110] Experimental Results

[0111] The experimental results are as follows Figure 3 to Figure 5 As shown, the polypeptide of the present invention can enter the cell through cellular endocytosis in FOLR1 (CHO-K1) cells that highly express FRα, especially the polypeptide shown in SEQ ID No. 3 has cellular endocytosis at 0.1 μM.

[0112] In summary, the above results prove that the polypeptide of the present invention has FRα targeting, and at the same time has good penetration ability of highly expressed FRα cells, and can achieve high-sensitivity in vivo imaging of tiny tumors. Therefore, in practical applications, the polypeptide of the present invention can be used as a homing peptide, combined with anticancer drugs or imaging agents, for targeted treatment and imaging of tumors.

[0113] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A polypeptide targeting folate receptor α, characterized in that: The polypeptide specifically binds to folate receptor α, and the amino acid sequence of the polypeptide is shown in SEQ ID No.1, SEQ ID No.2, SEQ ID No.3 or SEQ ID No.4, WCWMPHIAMHTQFGCGQ(SEQ ID No.1)、 GCYEWCLWHATYKECQSMCG(SEQ ID No.2)、 GEALLYVYKAQSMDWYYG(SEQ ID No.3)、 GCYGTCPERDHWFFEYCAKICAG (SEQ ID No. 4).

2. A polypeptide derivative, characterized in that: The polypeptide derivative is a modified product of the polypeptide according to claim 1 or a variant obtained by adding and / or replacing one or more amino acids of the polypeptide according to claim 1.

3. The polypeptide derivative according to claim 2, characterized in that: The polypeptide derivative is a modified product of the N-terminus or C-terminus of the polypeptide according to claim 1, and the modified group is selected from one or more of an acetyl group, an amino group, an alkyl group, an aromatic group, a fatty acid group, a sugar group, a phosphate group, a sulfate group, a PEG group or a peptide linking group; preferably, the modification is selected from: C-terminal amidation blocking and / or N-terminal modification of an acetyl group.

4. The polypeptide derivative according to claim 2, characterized in that: The polypeptide derivative is a variant obtained by adding and / or replacing one, two or three amino acids of the polypeptide according to claim 1.

5. A polynucleotide encoding the polypeptide according to claim 1 or the polypeptide derivative according to any one of claims 2 to 4. A vector comprising the polynucleotide according to claim 5.

7. A cell containing the vector according to claim 6.

8. A composition comprising an auxiliary material and an active ingredient, characterized in that: The active ingredient includes the polypeptide according to claim 1, or the polypeptide derivative according to any one of claims 2 to 4, or the polynucleotide according to claim 5, or the vector according to claim 6, or the cell according to claim 7; the excipients include at least one of a diluent, a filler, a binder, a wetting agent, an absorption enhancer, a surfactant, a lubricant and a stabilizer.

9. Use of the polypeptide according to claim 1, the polypeptide derivative according to any one of claims 2 to 4, the polynucleotide according to claim 5, the vector according to claim 6, the cell according to claim 7, or the pharmaceutical composition according to claim 8 in the preparation of a drug for preventing and / or treating a disease associated with folate receptor α, wherein the disease associated with folate receptor α is a cancer in which folate receptor α is highly expressed. 10 . The use according to claim 9 , wherein the cancer with high expression of folate receptor α is selected from at least one of ovarian cancer, non-small cell lung cancer, triple-negative breast cancer, mesothelioma, and lung cancer.

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