阅读说明：本技术 Apobec3b抑制剂及其应用 (APOBEC3B inhibitor and application thereof ) 是由 高艳锋 吴亚红 陈春霞 宁浩明 翟文杰 祁元明 于 2021-10-20 设计创作，主要内容包括：本发明提供了一种式Ⅰ的APOBEC3B的小分子抑制剂,其可以通过抑制APOBEC3B的脱氨酶功能,降低突变负荷,能有效预防和治疗过度表达APOBEC3B的癌症。该化合物安全性高,价格低廉,具有良好的应用前景。(The invention provides a small-molecule inhibitor of APOBEC3B with a formula I, which can effectively prevent and treat cancer excessively expressing APOBEC3B by inhibiting the deaminase function of APOBEC3B and reducing mutation load. The compound has high safety, low price and good application prospect.)

1. The use of a compound of formula I or a pharmaceutically acceptable salt thereof, wherein R1 is selected from F, Cl or I, R2 is selected from I or H, R3 is selected from substituted or unsubstituted hydroxy or amino, and R4 is selected from H, halogen, mercapto, hydroxy or amino, for the preparation of an APOBEC3B inhibitor.

。

2. The use according to claim 1, wherein R1, R2 are selected from the following combinations:

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3. use according to claim 1 or 2, wherein R3 is selected from amino or R5-c (o) -substituted hydroxy or amino, preferably R5 is H or halogen, more preferably R3 is selected from amino or hc (o) -NH-.

4. Use according to claim 1 or 2, wherein R4 is selected from H or hydroxy.

5. Use according to claim 1, characterized in that the compound of formula i is selected from the following compounds:

6. use according to any one of the preceding claims, characterized in that the configuration of the C atom to which the compound of formula I R3 is attached is R or S, preferably S.

7. The use as claimed in claim 1, wherein the compound of the formula I is

8. Use according to claim 1, wherein the inhibitor is for the prevention and/or treatment of a cancer overexpressing APOBEC3B, preferably wherein the cancer is a solid tumor.

9. Use according to claim 1, characterized in that the inhibitor is for the prevention and/or treatment of colon cancer, head and neck squamous cell carcinoma, cervical cancer, ovarian cancer, endometrial cancer, lung cancer, gastric cancer, liver cancer, kidney cancer, bladder cancer, prostate cancer or esophageal squamous cell carcinoma.

The technical field is as follows:

the invention belongs to the technical field of medicines, and particularly relates to a small molecule inhibitor of apolipoprotein B mRNA catalytic polypeptide 3B (APOBEC3B) and application thereof in preparation of medicines for preventing and treating cancers.

Background art:

epidemiological studies show that exogenous factors such as drinking, smoking, exposure to carcinogens from the diet and deficiency of micronutrients can promote the occurrence and development of cancers. Although some chemopreventive drugs, such as dietary supplements, have been used to prevent the development of esophageal squamous carcinoma, the overall benefit remains controversial as the therapeutic targets and mechanisms are not yet clear. On the other hand, the results of extensive second-generation sequencing show that most human cancers are caused by accumulation of somatic mutations, and DNA damage and mutation will cause genomic instability, which is also the main single-base substitution characteristic in cancer. Therefore, the development of cancer prevention and treatment drugs aiming at DNA mutation driving targets has important clinical significance for preventing and treating the occurrence and development of cancers.

The apolipoprotein B mRNA catalytic polypeptide (APOBEC) family includes 11 members, of which APOBEC3B is highly expressed in a variety of tumors and is the second endogenous mutation driver, in addition to age factors. Overexpression of APOBEC3B causes carcinogenesis by acting on single stranded DNA (ssdna) produced by DNA damage or replication fork interruption, causing deamination of cytosine to uracil, resulting in C > T and C > G mutations, resulting in a number of somatic mutations.

Disclosure of Invention

The invention identifies and obtains the small molecule inhibitor of the formula I of the targeted APOBEC3B through computer-assisted screening and in vivo and in vitro activity experiments

Wherein R1 is selected from F, Cl or I, R2 is selected from I or H, R3 is selected from substituted or unsubstituted hydroxyl or amino, and R4 is selected from H, halogen, mercapto, hydroxyl or amino. The inhibitor of the APOBEC3B can reduce a large number of somatic mutations caused by deamination of APOBEC 3B. The configuration of the C atom to which the compound of formula I R3 is attached is R or S, preferably S.

Furthermore, the compound shown in the formula I can obviously inhibit the growth of in vivo tumors, reduce the tumor volume and reduce the mutation number, and has no obvious toxic or side effect on in vivo organs.

Further, the cancer is a solid tumor, including but not limited to esophageal squamous carcinoma, breast cancer, colon cancer, head and neck squamous cell carcinoma, cervical cancer, ovarian cancer, endometrial cancer, lung cancer, gastric cancer, liver cancer, kidney cancer, bladder cancer, and prostate cancer.

Preferably, the compound of formula I is 3, 5-diiodotyrosine:

the invention discloses a formula I or a pharmaceutically acceptable salt thereof and an analogue thereof for preventing and/or treating cancers caused by high expression of APOBEC 3B.

The formula I of the present invention can be obtained by purchasing or conventional processes, such as extraction from kelp or artificial synthesis. In one embodiment, the invention discloses a medicament comprising formula I.

1. Further, the dosage form of the drug is any pharmaceutically therapeutically acceptable dosage form.

2. Further, the dosage of the drug is any therapeutically acceptable dosage of the drug.

3. Specifically, the dosage form of the medicine comprises but is not limited to tablets, granules, capsules, powder, pills, oral liquid, powder injection for injection, transdermal patches, gels and ointments.

Drawings

FIG. 1 is a graph of the statistical results of the inhibition of 4-NQO-induced established tumor growth in mice with idiopathic esophageal squamous carcinoma, including tumor nodule length and number of tumor nodules, by 3, 5-diiodotyrosine in a dose of 500 μ g/kg and 2mg/kg in normal saline;

FIG. 2 is a graph showing the statistical results of the number of mutations in the esophageal tissue exome of the normal saline group and the 500. mu.g/kg 3, 5-diiodotyrosine group esophageal squamous carcinoma mice.

Detailed Description

Example 1: screening and structure of APOBEC3B inhibitor

The Protein crystal structure "5 TD 5" of APOBEC3B was searched from a Protein Data Bank (PDB) database, and the enzyme activity site of APOBEC3B was determined from the ligand binding region and used as a docking pocket.

The APOBEC3B inhibitor with high affinity and binding stability with APOBEC3B is obtained by a molecular docking mode by using a computer-assisted drug screening method. Molecular Operation Environment (MOE) is utilized to carry out Molecular docking on 638 small Molecular compounds derived from a natural product database and APOBEC3B, and 30 candidate compounds with better affinity with APOBEC3B are finally obtained by screening according to a score (S < -7) and five major drug property principles for experimental verification.

Example 2: in vitro enzyme activity inhibition study of APOBEC3B small molecule inhibitor

The candidate compound obtained by the computer virtual screening is subjected to fluorescence labeling DNA cytosine deaminase method to obtain 3, 5-diiodotyrosine and analogues thereof which can have high affinity to APOBEC3B and show a dose gradient effect. The specific implementation method comprises the following steps:

1) diluting small molecular compounds to 10mM with DMSO respectively, diluting to obtain 6 concentration gradient samples (100. mu.M, 10. mu.M, 1. mu.M, 0.1. mu.M, 0.01. mu.M, 0.001. mu.M) with protein diluent containing 50mM Tris-Cl, 150mM NaCl and 1mM PMSF respectively in multiple ratio, taking 10. mu.L of each sample into a 384-well plate, and adding equal volume of diluent into a control well;

2) adding 0.04 μ M APOBEC3B protein 15 μ L into each well, mixing and shaking on an ELISA plate shaker for 1min, and incubating in an incubator at 37 deg.C for 15 min;

3) adding 15 mu L of 0.5 mu M ssDNA substrate and 0.03unit uracil glycosylase (UDG) into the mixed solution, shaking the enzyme label plate for 1min, and incubating in an incubator at 37 ℃ for 2h for reaction;

4) adding 5 mu L of 4M NaOH into the reaction system, shaking the enzyme label plate for 1min, and incubating in an incubator at 37 ℃ for 30 min;

5) adding 40 μ L stop solution (35 μ L2M Tris-Cl (PH7.9) +5 μ L4M HCl) into the reaction system to stop reaction, placing the reaction system on a room temperature microplate and shaking for 3 min;

6) the 384 well plate was placed in a microplate reader and the fluorescence intensity was measured under excitation light at 490nm and emission light at 520 nm. The statistical method comprises the following steps: the results are expressed as mean ± standard deviation (means ± SD).

The experimental results are as follows:

example 3: in order to further verify that the compound can inhibit the activity of APOBEC3B in exerting cytosine deaminase, bacterial recombination sequencing is carried out, and the specific implementation method is as follows:

1) constructing a prokaryotic expression vector: inserting the full-length sequence of APOBEC3B into a prokaryotic vector pET-28a sequence;

2) transferring the prokaryotic expression vector into escherichia coli BL 21;

3) selecting a monoclonal, performing amplification culture in an LB (LB) culture medium, treating with Vehicle and 3, 5-diiodotyrosine, culturing a bacterial solution for 3 days, and adding zinc ions;

4) extracting bacterial genome DNA for bacterial group re-sequencing analysis.

The experimental results are as follows: the bacterial re-sequencing result shows that the number of C > T single base variation which is specific to the APOBEC3B is obviously reduced after the 3, 5-diiodotyrosine is used for treating the bacteria.

Example 4: in vivo study of antitumor Activity

1) Experimental Material

Reagent:

4-nitroquinoline-1-oxide (4-NQO), physiological saline, 3, 5-diiodotyrosine

2) Laboratory animal

6 week old C57BL/6J female mice, SPF grade, purchased from Beijing Wintonli Hua Biotech, Inc. The experimental animals are fed aseptically in the whole process and are free to eat drinking water. The cage, the feed, the padding and the drinking water are sterilized and disinfected at high pressure, and the feeding environment meets the requirements of environmental facilities of medical experimental animals.

Mouse model of esophageal squamous carcinoma: after the purchased mice are adaptively raised for one week in an experimental animal center, the mice are fed with prepared drinking water (placed in a light-shielding drinking bottle) containing 100 mu g/mL 4-NQO, and after the mice are continuously fed for 16 weeks, the mice are changed into normal sterile drinking water to continue to form the esophageal squamous cell carcinoma mice by spontaneous induction. At 28 weeks of induction, mice were randomly divided into two groups, and normal saline, 500. mu.g/kg and 2mg/kg of 3, 5-diiodotyrosine were administered intraperitoneally, the body weight of the mice was measured every other day using an electronic balance, once every two days, and the mice were sacrificed after 14 days for subsequent experiments. The statistical method comprises the following steps: the comparisons between groups were performed using a t-test (p <0.05, p <0.01, p < 0.001).

The tumor inhibition experiment of 4-NQO induced esophageal squamous cell carcinoma mice shows that 3, 5-diiodotyrosine can effectively inhibit the growth of esophageal squamous cell carcinoma tumors, and the mutation load in an exome is reduced and the progression of esophageal squamous cell carcinoma is inhibited by targeting APOBEC3, so that the effective prevention effect is achieved, and the results are shown in fig. 1 and fig. 2.

Finally, it should be noted that the above embodiments are only used for illustrating the technical solutions of the present invention and not for limiting the protection scope of the present invention, and although the present invention is described in detail with reference to the preferred embodiments, it should be understood by those skilled in the art that modifications or equivalent substitutions can be made on the technical solutions of the present invention without departing from the spirit and scope of the technical solutions of the present invention.