阅读说明：本技术 一种抗肿瘤多肽及其制备方法和用途 (Anti-tumor polypeptide and preparation method and application thereof ) 是由 陈勇 赵宁 朱东烈 于 2019-10-14 设计创作，主要内容包括：本发明公开了一种抗肿瘤多肽及其制备方法和用途,筛选初始的多肽序列为：VLGLLAVVLVLVI。由于溶解性问题,进一步将初始13肽分成9肽(VL-9序列为：VLGLLAVVL)与4肽(序列为：VLVI)两部分,分别进行细胞功能学实验验证,结果发现9肽具有明显肿瘤抑制作用。本发明人发现将VL-9序列任意打乱之后得到的系列多肽,都保留较强的抑癌活性,且分别能够与人源性蛋白的片段相匹配,为了加强溶解性我们在9肽的两端各加上4个精氨酸而形成RR-17人源性抗肿瘤系列多肽,其中RR-171活性最为明显。本发明涉及的多肽是通过固相合成方法获得的。体内外药效学实验结果表明,本发明的多肽可显著抑制人肝癌细胞系Hep3B、MHCC97H的生长,具有潜在的抗肿瘤药物开发价值。(The invention discloses an anti-tumor polypeptide and a preparation method and application thereof, wherein the screening initial polypeptide sequence is as follows: VLGLLAVVLVLVI are provided. Due to the solubility problem, the initial 13 peptide is further divided into two parts, namely a 9 peptide (the VL-9 sequence is VLGLLAVVL) and a 4 peptide (the sequence is VLVI), and cell functional experiments are respectively carried out to verify that the 9 peptide has obvious tumor inhibition effect. The inventor finds that the series of polypeptides obtained by randomly scrambling a VL-9 sequence can retain stronger cancer inhibition activity, can be matched with fragments of human-derived proteins respectively, and adds 4 arginines at two ends of a 9 peptide to form RR-17 human-derived anti-tumor series polypeptides for enhancing solubility, wherein the RR-171 activity is most obvious. The polypeptide related to the invention is obtained by a solid phase synthesis method. In vivo and in vitro pharmacodynamic experiment results show that the polypeptide can obviously inhibit the growth of human liver cancer cell lines Hep3B and MHCC97H, and has potential antitumor drug development value.)

1. An anti-tumor polypeptide VL-9, characterized by an amino acid sequence as shown in SEQ ID: no. 1.

2. An antitumor polypeptide RR-171, characterized in that the amino acid sequence is as shown in SEQ ID: no. 2.

3. The anti-tumor polypeptide RR-171 of claim 2, wherein said polypeptide is a biologically effective polypeptide having substantial inhibitory activity against tumor cells.

4. The anti-tumor polypeptide RR-171 of claim 2, wherein said polypeptide RR-171 is useful for the preparation of an anti-tumor agent.

5. The anti-tumor polypeptide RR-171 of claim 2, comprising any one of said polypeptide or salt thereof, in admixture with pharmaceutically acceptable carriers, solvents, diluents, excipients, and other media.

Technical Field

The invention belongs to the technical field of biomedicine, and particularly relates to screening, synthesis and application of a polypeptide.

Background

Cancer remains an important factor threatening human health, China is a cancer kingdom, and both the number of morbidity and mortality are the first in the world. With the progress of modern medical technology, the treatment of cancer has been developed in a leap-up manner, and various treatment methods and treatment medicines are in a wide range, but the treatment effect is still not ideal. The situation of cancer treatment remains very complex, with cancer screening, precision treatment and aging being the main three aspects currently affecting tumor treatment. Therefore, the development of more effective tumor-targeted therapeutic drugs has become a hot spot of current research.

In recent years, many scientists have focused on the research of anticancer drugs on polypeptide drugs with less adverse reactions, high activity and less susceptibility to drug resistance. The polypeptide is a field crossed between chemistry and biology, is closely related to growth, metabolism, immunity, diseases and the like of organisms, and plays an important role in regulation and control. The polypeptide is easy to penetrate cell membranes, has small molecular weight and high activity, is not easy to generate drug resistance, is easy to modify, is more and more concerned by people, and is more and more widely applied to clinical trials. However, anti-tumor peptides (ACPs) have disadvantages, mainly including poor stability due to easy hydrolysis by some proteases in blood or absorption by the endothelial system. Secondly, the selectivity of the polypeptide is weak, and the polypeptide is easy to have some toxic and side effects on normal living cells of a human body. The design concept of the medicine has important influence on the antitumor activity, stability and selectivity of the ACPs. Through the design of amino acid sequence, the polypeptide with excellent antitumor activity can be screened out.

The sources of the antitumor polypeptides are very wide, and the antitumor polypeptides mainly comprise the following components: 1. natural product peptide: it refers to bioactive polypeptide extracted from insect, animal, plant, marine organism and microbe or their metabolic products. For example, the anti-tumor polypeptide CS5931 obtained from ascidian sakazakii can induce the release of Cyc C of colon cancer cells, lead to the activation of caspase 3 and caspase 9, and kill the colon cancer cells. 2. Chemically synthesizing the peptide: the polypeptide is synthesized by using amino acid as a raw material by utilizing a chemical synthesis technology. The chemical synthesis method of the polypeptide is simple and has more yield. And the stability and the solubility of the compound can be improved by a chemical modification method, and the compound has great application value in the anti-tumor field. Solid-phase synthesis and liquid-phase synthesis are two methods commonly used for chemical synthesis of polypeptides. 3. Phage peptide library: the phage display technology is established by Smith in 1985, has wide application in screening functional polypeptides, and can screen related antigens, target peptides, research vaccines, immunodiagnosis and the like. One has screened phage heptapeptide library with KDR (vascular endothelial growth factor receptor) expressible on cell membrane and synthesized short peptide AATWLPPR by chemical method.

Disclosure of Invention

The invention aims to provide an anti-tumor polypeptide, a preparation method and application thereof, the polypeptide can obviously inhibit the growth of human liver cancer cell lines Hep3B and MHCC97H, and has potential anti-tumor drug development value.

The technical scheme of the invention is as follows:

an anti-tumor polypeptide VL-9, characterized by an amino acid sequence as shown in SEQ ID: no. 1.

An antitumor polypeptide RR-171, characterized in that the amino acid sequence is as shown in SEQ ID: no. 2.

An antitumor polypeptide RR-171, characterized in that the polypeptide is a biological effect polypeptide with significant inhibition of tumor cell activity.

An antitumor polypeptide RR-171, characterized by the application in preparing antitumor drugs.

An anti-tumor polypeptide RR-171, comprising any one of the polypeptides or a salt thereof, in admixture with pharmaceutically acceptable carriers, solvents, diluents, excipients, and other media.

The inventor obtains the 13 peptide with the sequence of VLGLLAVVLVLVI by high performance chromatography screening and MALDI-TOF MS mass spectrometry detection of umbilical cord serum. According to the sequence characteristics of the 13 peptide, the 13 peptide is divided into two parts of 9 peptide (the sequence of VL-9 is SEQ ID: No.1 VLGLLAVVL) and 4 peptide (the sequence is VLVI), and the results of cell functional experiments prove that VL-9 has obvious tumor inhibition effect. The inventor finds that the series of polypeptides obtained by randomly scrambling a VL-9 sequence can retain stronger cancer inhibition activity and can be matched with fragments of human proteins respectively, and adds 4 arginines at two ends of a 9 peptide to form RR-17 human anti-tumor series polypeptides in order to enhance the solubility, wherein the RR-171 tumor inhibition activity is most remarkable (the sequence of RR-171 is SEQ ID: No.2 RRRRLVAGVLVLLRRRR). The invention adopts a solid phase chemical synthesis method to obtain the target polypeptide with higher antitumor activity. Pharmacodynamic experiments show that the RR-171 human antitumor polypeptide can obviously inhibit the growth of human liver cancer cells in vitro and in vivo, and that the RR-171 human antitumor polypeptide can be used as an antitumor treatment drug.

The "RR-171 human antitumor polypeptide" of the present invention also includes polypeptides or proteins derived from the sequence of seq id No.2 by substituting or adding one or more amino acid residues and having the same activity, such as polypeptides or proteins with one or more amino acids added at the C-terminal and/or N-terminal, e.g., fusion of amino acids encoded by a vector, leader sequence, secretory sequence, or sequence or proprotein sequence for purifying the polypeptide; one or more conservative amino acid residues are substituted; or a polypeptide formed by fusing the mature polypeptide to another compound (e.g., a compound that increases the half-life of the polypeptide, such as polyethylene glycol); it may also be a polypeptide having a substituent group in one or several amino acid residues.

Drawings

FIG. 1 shows the biological activity of MTT assay polypeptides.

FIG. 2 is flow assay of tumor cell death.

FIG. 3 shows the in vivo verification of the anti-tumor properties of the polypeptides in nude mice tumor-bearing experiments.

FIG. 4 is a proportion of cells that cause apoptosis of MHCC97H compared to negative control polypeptide RR-170 and the PBS blank control group for polypeptide RR-171.

FIG. 5 is a graph showing the change in the volume of the polypeptide RR-171 in the tumors of nude mice in the polypeptide RR-171 injection group compared with the negative control polypeptide RR-170 and PBS blank control group.

Detailed Description

Polypeptide screening and restructuring

Preparation of serum samples: collecting about 5ml of fetal umbilical cord blood serum, standing at room temperature for 30min, storing at 4 deg.C for 4 hr, centrifuging (2000r/min, 10min), sucking supernatant, and storing at-80 deg.C.

Two-dimensional chromatography: size Exclusion Chromatography (SEC) serum samples were diluted 10-fold with PBS (pH7.4) and 100. mu.l each was injected. The mobile phase was 20 mmol.L-1 KH2PO4+ 100 mmol.L-1 NaCl, pH 7.0, flow rate 0.5 ml.min-1. Detection was carried out with an ultraviolet detector at 280 nm. The fraction is collected according to chromatographic elution curve, and the first fraction in serum is mainly high molecular weight protein in serum because SEC separation mainly depends on the size of the separated molecule. In the present study, two fractions were collected, 160min-180min and 200min-220min later, and the collected chromatographic fractions were concentrated and lyophilized, as shown in FIG. 1. Reverse Phase Liquid Chromatography (RPLC): the lyophilized chromatographic fractions were concentrated by thawing with 150. mu.l of ultrapure water. Separating 100 μ l with C18 macroporous reverse phase liquid chromatography column, and separating with CH₃OH-H₂O-1 ‰ trifluoroacetic acid (TFA) system as mobile phase, and liquid A is H₂O +1 ‰ TFA, and solution B is CH₃OH +1 ‰ TFA, linear gradient elution from 100% A to 100% B in 30min, and extension for 15 min. And (3) collecting related products of the reverse liquid chromatography by sections according to a chromatographic elution curve, performing mass spectrum identification, and detecting a specific peak at a cytoplasmic-nuclear ratio 2021. The sequence was determined to be VLGLLAVVLVLVI by sequencing and bioinformatic analysis. As shown in fig. 2.

Synthesis of di-and polypeptides

The polypeptide of the invention is obtained by a solid phase chemical synthesis method, and the specific steps are as follows:

the sequence of solid phase synthesis of polypeptides generally proceeds from the C-terminus (carboxy-terminus) to the N-terminus (amino-terminus). Taking Fmoc-Ile-wangcegin resin as a carrier, expanding the resin volume by DCM to ensure that the resin can be fully contacted with a reaction solvent in the subsequent reaction; removing the amino protecting group under the action of piperidine DMF solution to ensure that the first amino acid Fmoc-Ala-OH is connected to the solid phase carrier. Then the carboxyl group of the second amino acid with the blocked amino group is activated by N, N' -Dicyclohexylcarbodiimide (DCC), and the second amino acid after the activation of the carboxyl group is reacted with the amino group of the first amino acid which is grafted on the solid phase carrier to form a peptide bond, thereby forming a dipeptide with a protecting group on the solid phase carrier. And sequentially repeating the reaction steps to extend the peptide chain from the C end to the N end until the required length of the peptide chain is reached, and finally synthesizing Fmoc-Ala-OH at the N end. After the reaction is finished, under the action of a piperidine DMF solution, the protecting group of the amino group is removed, and finally, DCM is used again for swelling twice, and the peptide is obtained after contraction and drying by using ether or methanol.

Third, biological Effect

1. Effect of RR-171 polypeptide on the growth of liver cancer cell lines in vitro.

And (3) cell viability detection: hep3B cells were cultured in DMEM containing 10% fetal bovine serum and plated routinely in 96-well plates at approximately 5000 cells/200 ul per well. The polypeptide RR-171 and its control sequence RR-170 were added to each well at working concentrations of 0. mu.g/ml, 6.25. mu.g/ml, 12.5. mu.g/ml, 25. mu.g/ml, 50. mu.g/ml, 75. mu.g/ml, 100. mu.g/ml, 200ug/ml, respectively. After 24 hours of action of the polypeptide, the survival of the cells is detected by using an MTT method. Adding 20ul of MTT reagent into each well, continuously culturing for 4-6h at 37 ℃, discarding the culture solution, adding 150 ul of DMSO, shaking at room temperature in dark for 10min, and detecting the OD value by a multifunctional microplate reader with the wavelength of 490 nm.

The results show that: the polypeptide RR-171 can remarkably inhibit the activity of tumor cells (A is a liver cancer cell line, B is a pancreas cancer cell line, C is a colon cancer cell line, D is an ovary cancer cell line, E is a breast cancer cell line, F is a lung cancer cell line, and G is a stomach cancer cell line), and the biological effect of the polypeptide RR-171 shows a certain concentration gradient effect. The reference polypeptide RR-170 exhibited no biological activity, as shown in FIG. 3.

Flow cytometry detection: normally culturing MHCC97H cells until 70% fusion, adding the respective polypeptide RR-171 with the working concentration of 100 mug/ml, and continuously culturing for 24 h; collecting cells, centrifuging at 1000r/min for 5min, discarding culture solution, washing with incubation buffer (10mmol/L HEPES/NaOH, pH7.4, 140mmol/L NaCl, 5mmol/L CaCl2) for 1 time, and centrifuging at 1000r/min for 5 min; 100ul of labeling solution (FITC-Annexin V and PI are added into incubation buffer solution with the final concentration of 1ug/ml) is incubated for 15min at room temperature in a dark place, the incubation buffer solution is washed once, fluorescent solution (SA-FLOUS) is added, incubation is carried out for 20min at 4 ℃ in a dark place, and detection is carried out by a flow cytometer. The results show that: the polypeptide RR-171 can cause the proportion of MHCC97H apoptotic cells to be obviously increased. The control polypeptide RR-170 and blank did not have this effect, as shown in FIG. 4.

2. RR-17 human liver cancer MHCC97H nude mouse xenograft tumor mouse in vivo inhibitory activity research.

Constructing a nude mouse tumor-bearing model, and researching the in-vivo inhibitory activity of the polypeptide RR-17 on tumors. 6-7 weeks old female nude mice (purchased from Beijing) were injected subcutaneously into the back of each nude mouse at 3X 10⁶One MHCC97H cell, injection volume of 200 ul. One week later, the nude mice were randomly divided into three groups, and each of the nude mice was injected with 200ul PBS (blank control), RR-170 (negative control) (2mg/ml), and RR-171(2mg/ml) in tail vein once for 4 days, and after 20 consecutive days, the mice were sacrificed, and the tumor volume was measured, and the calculation formula of the Tumor Volume (TV) was: TV 1/2 × a × b²Wherein a and b represent length and width, respectively.

The results show that: RR-171 has obvious in-vivo tumor formation inhibition effect on human liver cancer cell MHCC 97H; compared with the negative control polypeptide RR-170 group and the PBS blank control group, the size of the tumor of the nude mice injected with the polypeptide RR-171 group is obviously reduced, as shown in FIG. 5.

It should be noted that: although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art will understand that various changes, modifications and substitutions can be made without departing from the spirit and scope of the invention as defined by the appended claims.

Any modification, equivalent replacement, or improvement made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Sequence listing

<110> courage

<120> an anti-tumor polypeptide, a preparing method thereof and applications of the polypeptide

<160>2

<170>SIPOSequenceListing 1.0

<210>1

<211>9

<212>PRT

<213> Artificial sequence (unknown)

<400>1

Val Leu Gly Leu Leu Ala Val Val Leu

1 5

<210>2

<211>17

<212>PRT

<213> Artificial sequence (unknown)

<400>2

Arg Arg Arg Arg Leu Val Ala Gly Val Leu Val Leu Leu Arg Arg Arg

1 5 10 15

Arg