Application of CHAF1A inhibitor in preparation of medicine for treating esophageal cancer
By combining the CHAF1A inhibitor Baimaside with a PD-1 monoclonal antibody, the tumor microenvironment was remodeled by targeting the CHAF1A gene, which solved the problem of poor efficacy of immunotherapy in esophageal cancer and achieved significant anti-tumor effects and enhanced treatment sensitivity.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2026-02-05
- Publication Date
- 2026-04-03
AI Technical Summary
Current immune checkpoint inhibitors are not effective in treating esophageal cancer, exhibiting drug resistance, and tumor heterogeneity and immunosuppressive microenvironment prevent some patients from benefiting.
The combined use of the CHAF1A inhibitor Baimaside and PD-1 monoclonal antibody targets the CHAF1A gene, remodels the tumor immune microenvironment, promotes CD8+ T cell infiltration, and enhances the efficacy of immunotherapy.
It significantly inhibits esophageal cancer growth, enhances the immunotherapeutic activity of PD-1 monoclonal antibodies, increases the sensitivity of esophageal cancer to treatment, reverses immunotherapy resistance, and provides a novel combination immunotherapy strategy.
Smart Images
Figure CN121774993A_ABST
Abstract
Description
Technical Field
[0001] This invention belongs to the field of biomedical technology, and in particular relates to the application of CHAF1A inhibitors in the preparation of drugs for treating esophageal cancer. Background Technology
[0002] Esophageal cancer is one of the most aggressive malignant tumors worldwide. Difficult early diagnosis, rapid progression, and high susceptibility to lymph node metastasis are major factors contributing to its poor prognosis. Current comprehensive treatment regimens, primarily surgery, have limited effectiveness for advanced-stage patients, and the overall response to chemotherapy and radiotherapy remains unsatisfactory. In recent years, immunotherapy has brought new hope to the treatment of esophageal cancer, with programmed death receptor-1 (PD-1) inhibitors approved for second-line treatment of advanced esophageal squamous cell carcinoma. However, due to tumor heterogeneity and the presence of an immunosuppressive microenvironment, only a subset of patients benefit from immunotherapy, highlighting the urgent need to further explore the immune escape mechanisms of esophageal cancer, develop effective biomarkers, and formulate combination therapy strategies.
[0003] CHAF1A, the core subunit of chromatin assembly factor 1 (CAF-1), is a key factor in maintaining genome stability and chromatin assembly. It is a core regulatory protein in the DNA replication-coupled chromatin assembly process in eukaryotes, playing an irreplaceable role in DNA replication, repair, and the maintenance of higher-order chromatin structure. Existing research has confirmed that the functional regulation of CHAF1A is closely related to physiological processes such as cell cycle progression, stem cell stemness maintenance, and embryonic development. Abnormal expression of CHAF1A is widely involved in the development and progression of various malignant tumors. Studies have reported high expression of CHAF1A in solid tumors such as colorectal cancer and breast cancer, and its expression level is significantly correlated with cell proliferation, invasion and metastasis, clinical stage, and poor patient prognosis in these tumors. However, research on CHAF1A has not yet extended to esophageal cancer; its role and related regulatory mechanisms in the development and progression of esophageal cancer remain unclear. Summary of the Invention
[0004] To address the issues of poor efficacy and drug resistance in the treatment of esophageal cancer with existing immune checkpoint inhibitors, this invention provides the application of CHAF1A inhibitors in the preparation of drugs for treating esophageal cancer.
[0005] The technical solution of the present invention:
[0006] Application of CHAF1A inhibitors in the preparation of drugs for treating esophageal cancer.
[0007] Furthermore, the CHAF1A inhibitor is the compound Baimaside, whose chemical structural formula is shown in Formula I:
[0008] Formula I.
[0009] Furthermore, the mass content of Baimaside in the esophageal cancer treatment drug is 1-99%.
[0010] Furthermore, the esophageal cancer treatment drug is an oral dosage form.
[0011] Furthermore, the esophageal cancer treatment drug is a combination of Baimaside and PD-1 monoclonal antibody.
[0012] Furthermore, the PD-1 monoclonal antibody is CD279.
[0013] The beneficial effects of this invention are:
[0014] This invention provides the application of the CHAF1A gene target in the preparation of drugs for the treatment of esophageal cancer and proposes a dual therapy regimen of the CHAF1A inhibitor Baimaside combined with a PD-1 monoclonal antibody. In preclinical animal models, the CHAF1A inhibitor alone significantly inhibited the growth of subcutaneous esophageal cancer xenografts. Furthermore, the combination regimen of the CHAF1A inhibitor and the PD-1 monoclonal antibody showed a significant synergistic therapeutic effect, significantly enhancing the immunotherapeutic activity of the PD-1 monoclonal antibody, effectively inhibiting tumor proliferation, increasing the sensitivity of esophageal cancer to PD-1 monoclonal antibody therapy, and reversing its immunotherapy resistance.
[0015] This invention is the first to demonstrate that CHAF1A is a potential molecular marker and important therapeutic target for esophageal cancer immunotherapy failure, and that CHAF1A inhibitors can reshape the tumor immune microenvironment and promote CD8 activation. + T-cell infiltration to sensitize immunotherapy provides a novel strategy and theoretical basis for combined immunotherapy of esophageal cancer. Attached Figure Description
[0016] Figure 1 A comparison of the mRNA expression levels of chemokines Cxcl9, Cxcl10, and Cxcl11 in esophageal cancer cells before and after treatment with different compounds;
[0017] Figure 2 The diagrams show the two-dimensional and three-dimensional molecular docking between Baimaside and Human CHAF1A protein. A is the two-dimensional molecular docking diagram, and B is the three-dimensional molecular docking diagram.
[0018] Figure 3 This is a comparison graph of the tumor volume changes over time in the two groups of mice in Example 2;
[0019] Figure 4 This is a comparison image of the transplanted tumors in the two groups of mice at the end of the experiment in Example 2;
[0020] Figure 5This is a comparison chart of the average weight of the xenografts in the two groups of mice at the end of the experiment in Example 2;
[0021] Figure 6 This is a comparison of the tumor volume changes over time in the four groups of mice in Example 3;
[0022] Figure 7 This is a comparison image of the four groups of mouse xenografts at the end of the experiment in Example 3;
[0023] Figure 8 This is a comparison chart of the average weight of the xenografts in the four groups of mice at the end of the experiment in Example 3;
[0024] Figure 9 CD8+ in the four groups of mouse xenograft tissues in Example 3 + Immunohistochemical staining of cells. Detailed Implementation
[0025] The technical solution of the present invention will be further described below with reference to embodiments, but it is not limited thereto. Any modifications or equivalent substitutions to the technical solution of the present invention without departing from the spirit and scope of the technical solution of the present invention should be covered within the protection scope of the present invention. In the following embodiments, the process equipment or apparatus not specifically specified are all conventional equipment or apparatus in the art. Unless otherwise specified, the raw materials used in the embodiments of the present invention are all commercially available; unless otherwise specified, the technical means used in the embodiments of the present invention are all conventional means well known to those skilled in the art.
[0026] Example 1
[0027] This embodiment provides a virtual screening method for CHAF1A inhibitors and molecular docking verification results.
[0028] I. Virtual Screening Method for CHAF1A Inhibitors
[0029] 1. Preparation of the initial compound library
[0030] The initial compound library used in this embodiment contains 99,000 compounds derived from commercially available diverse small molecule libraries, specifically the MCE compound libraries (HY-L001 and HY-L901P). These small molecule compound libraries cover drug-like small molecules with drug-making potential, natural product derivatives, and targeted anti-tumor compounds, possessing characteristics such as structural diversity, drug-likeness, and syntheticability, providing a rich pool of candidate molecules for subsequent screening.
[0031] 2. Glide HTVS (High-Throughput Virtual Screening)
[0032] Glide HTVS, developed by Schrödinger, is a high-throughput virtual screening module suitable for rapid initial screening of large-scale compound libraries. This mode efficiently predicts the initial binding potential of compounds to the active pocket of the CHAF1A protein core domain by reducing the conformational search space and employing a fast scoring function. This study used the Glide docking score (GlideScore) as the core evaluation indicator, retaining the top 30% (HY-L001) and top 15% (HY-L901P) compounds based on their scores.
[0033] 3. Glide SP (Standard Precision Interlock)
[0034] Glide SP is the standard precision docking mode in the Glide software, used for secondary precision screening of HTVS initial screening results. This mode performs more thorough conformational sampling and incorporates solvation effects and refined scoring, more accurately predicting the binding mode of compounds to the active pocket of the CHAF1A protein. This study used a combination of Glide precision docking scores, the number of hydrogen bonds and hydrophobic interactions, and the rationality of the binding conformation as evaluation indicators, retaining the top 30% (HY-L001) and top 15% (HY-L901P) candidate compounds.
[0035] 4. Glide XP (High-precision docking)
[0036] Glide XP is a high-precision docking mode in the Glide software for the final, refined evaluation of candidate compounds. This mode achieves conformational optimization at the entire atom level and employs a rigorous protein-ligand interaction scoring function for comprehensive evaluation. Accumulation, cations Key interactions, such as interaction and polar complementarity, were theoretically used to accurately predict the binding mode of compounds to the CHAF1A protein. This study, by comprehensively considering high-precision docking scoring, the strength of interactions with key amino acid residues, and the stability of the binding mode, ranked the top 10 high-quality candidate compounds using multiple indicators, and selected them accordingly.
[0037] 5. In vitro screening:
[0038] The transcriptional levels of chemokines Cxcl9, Cxcl10, and Cxcl11 in esophageal cancer cells were quantitatively detected by qPCR after treatment with different compounds, thereby assessing the regulatory effects of the compounds. Results are as follows: Figure 1As shown, Baimaside treatment significantly upregulated the mRNA expression levels of Cxcl9, Cxcl10, and Cxcl11 in esophageal cancer cells. Based on these results, Baimaside, a candidate CHAF1A inhibitor, was screened and its chemical structure is shown in Formula I.
[0039] Formula I.
[0040] II. Molecular docking verification results
[0041] To verify the binding ability of Baimaside to the CHAF1A protein, molecular docking experiments were performed. Figure 2 Two-dimensional and three-dimensional molecular docking diagrams of Baimaside with the Human CHAF1A protein are shown. The results show that Baimaside can stably bind to the active pocket of the CHAF1A protein, forming several key hydrogen bonds and hydrophobic interactions.
[0042] In summary, Baimaside can upregulate the mRNA expression levels of key anti-tumor immune regulatory molecules Cxcl9, Cxcl10, and Cxcl11 in esophageal cancer cells and can stably bind in the active pocket of CHAF1A protein. This theoretically predicts its feasibility as a CHAF1A inhibitor and provides important experimental evidence for further investigation into the mechanism by which Baimaside regulates the immune microenvironment of esophageal cancer by targeting CHAF1A.
[0043] Example 2
[0044] In vivo evaluation of the efficacy of the CHAF1A inhibitor Baimaside monotherapy against AKR cell homologous mouse subcutaneous xenografts.
[0045] I. Construction of a mouse model of subcutaneous esophageal cancer tumor
[0046] 1. Five- to six-week-old female AKR cell line mice were selected to construct a homologous subcutaneous xenograft model;
[0047] 2. Esophageal cancer cell line AKR derived from AKR / J inbred mice was cultured in vitro, counted, and then resuspended in PBS;
[0048] 3. Set the cell concentration to 5 × 10⁻⁶. 5 100 μL of cell suspension was inoculated subcutaneously on the right side of mice;
[0049] 4. Observe the mice daily until the transplanted tumor grows to approximately 100 mm. 3 At that time, the administration of drugs to groups began.
[0050] II. Grouping and Administration Methods
[0051] Reagent preparation: Baimaside (purchased from MCE, catalog number HY-N2183) was prepared into a stock solution with dimethyl sulfoxide (DMSO). It was prepared fresh each time it was used. The stock solution was taken and mixed with DMSO and 20% sulfobutyl ether-β-cyclodextrin saline solution at a volume ratio of 1:9 to obtain the Baimaside working solution.
[0052] The constructed AKR esophageal cancer subcutaneous tumor mouse model was divided into two groups, and the specific administration methods are as follows:
[0053] (1) Control group: One volume of blank working solution without Baimaside (prepared by gavage according to the volume ratio of DMSO and 20% sulfobutyl ether-β-cyclodextrin saline solution of 1:9) was administered once daily for a total of 10 days.
[0054] (2) Baimaside treatment group: Baimaside was administered by gavage, 50 mg / kg, once a day for a total of 10 days.
[0055] III. Measurement of tumor volume and weight
[0056] 1. Tumor volume monitoring:
[0057] Starting from the start of drug administration, the volume of the transplanted tumor was non-invasively measured every 3 days using vernier calipers to obtain the major diameter (a) and minor diameter (b) of the transplanted tumor, calculated using the formula V = 1 / 2 × a × b. 2 Calculate the tumor volume and monitor the results as follows: Figure 3 As shown, compared with the control group, the growth rate of the transplanted tumor in mice treated with Baimaside was significantly slowed down, indicating that Baimaside effectively delayed the growth of the transplanted tumor by inhibiting CHAF1A activity.
[0058] Mice were sacrificed on day 13 after drug administration, and the transplanted tumors were removed. The actual tumor samples from both groups of mice are shown below. Figure 4 As shown, the tumors in the control group were generally larger and fuller in appearance, indicating that the tumors grew vigorously without drug intervention; while the tumors in the Baimaside treatment group were significantly smaller, and some tumors appeared shrunken, directly proving the inhibitory effect of the drug on the growth of the tumors.
[0059] 2. Measurement of tumor weight:
[0060] The transplanted tumor obtained after dissection was weighed, and the results are as follows: Figure 5 As shown, the average tumor weight in the Baimaside treatment group was significantly lower than that in the control group, further confirming the tumor-suppressing effect of Baimaside.
[0061] This embodiment demonstrates that the CHAF1A inhibitor Baimaside can significantly inhibit the growth of subcutaneous esophageal cancer xenografts in AKR mice, exhibiting good in vivo antitumor activity and providing a new potential strategy for the treatment of esophageal cancer.
[0062] Example 3
[0063] In vivo evaluation of the efficacy of the CHAF1A inhibitor Baimaside in combination with PD-1 monoclonal antibody against AKR cell homologous mouse subcutaneous xenografts.
[0064] I. Construction of a mouse model of subcutaneous esophageal cancer tumor
[0065] 1. Five- to six-week-old female AKR cell line mice were selected to construct a homologous subcutaneous xenograft model;
[0066] 2. Esophageal cancer cell line AKR derived from AKR / J inbred mice was cultured in vitro, counted, and then resuspended in PBS or serum-free medium;
[0067] 3. Set the cell concentration to 5 × 10⁻⁶. 5 100 μL of cell suspension was inoculated subcutaneously on the right side of mice;
[0068] 4. Observe the mice daily until the transplanted tumor grows to approximately 100 mm. 3 At that time, the administration of drugs to groups began.
[0069] II. Grouping and Administration Methods
[0070] Reagent preparation: Baimaside (purchased from MCE, catalog number HY-N2183) was prepared into a stock solution with dimethyl sulfoxide (DMSO). It was prepared fresh for each use. The stock solution was taken and mixed with DMSO and 20% sulfobutyl ether-β-cyclodextrin (SBE-β-CD) saline solution at a volume ratio of 1:9 to obtain the Baimaside working solution.
[0071] The constructed AKR esophageal cancer subcutaneous tumor mouse model was divided into 4 groups, and the specific drug administration methods are as follows:
[0072] (1) Control group: One volume of blank working solution without Baimaside (prepared by gavage according to the volume ratio of DMSO and 20% sulfobutyl ether-β-cyclodextrin saline solution of 1:9) was administered once daily for a total of 10 days.
[0073] (2) Baimaside treatment group: Baimaside was administered by gavage, 50 mg / kg, once daily for a total of 10 days;
[0074] (3) PD-1 group: CD279 was injected intraperitoneally, 200 μg / animal, once every three days, for a total of four times;
[0075] (4) Baimaside combined with PD-1 group: Baimaside was administered by gavage, 50 mg / kg, once a day for a total of 10 days; CD279 was injected intraperitoneally, 200 μg / animal, once every three days for a total of four times; the two drugs were administered at the same time.
[0076] III. Efficacy Evaluation:
[0077] 1. Tumor volume and weight:
[0078] Monitoring changes in xenograft volume over time, results are as follows Figure 6 As shown, mice were sacrificed on day 13 after the start of drug administration, and the transplanted tumors were removed. The actual tumor tissue and average tumor weight of the four groups of mice were compared as follows: Figure 7 and Figure 8 As shown, in the control group without drug intervention, the tumor volume of the transplanted tumors showed a rapid growth trend, with the largest and most abundant tumors and the heaviest average tumor weight. Treatment with PD-1 monoclonal antibody alone slowed the growth of the transplanted tumors compared to the control group, and both the tumor volume and weight decreased, indicating that PD-1 monoclonal antibody has some tumor-suppressing activity, but the effect is limited. Treatment with Baimaside alone further slowed the growth of the transplanted tumors, and the tumor volume and weight were significantly smaller than those in the control group. However, the combination therapy of Baimaside and PD-1 monoclonal antibody significantly inhibited the growth of the transplanted tumors, resulting in the smallest tumor volume, with some tumors even shrinking, and the average tumor weight was lower than that of the control group and the monotherapy group. This demonstrates that the combination therapy had a significantly better tumor-suppressing effect than the monotherapy group, indicating that the two have a synergistic anti-tumor effect and can more significantly inhibit the growth of esophageal cancer transplanted tumors.
[0079] 2. Analysis of immune cell infiltration in xenografts
[0080] At the end of the experiment, a portion of the transplanted tumor tissue was taken for formalin fixation and paraffin embedding, and sections were prepared. CD8 levels were detected by immunohistochemical staining. + T cell infiltration status. Results as follows: Figure 9 As shown, compared with the control group or the monotherapy group, the combination therapy of Baimaside and PD-1 monoclonal antibody significantly increased the number of CD8+ T cells in the xenograft tissue, indicating that the combination therapy effectively improved the immune microenvironment of the xenograft and enhanced the anti-tumor immune response.
Claims
1. Application of CHAF1A inhibitors in the preparation of drugs for the treatment of esophageal cancer.
2. The use of the CHAF1A inhibitor according to claim 1 in the preparation of a drug for treating esophageal cancer, characterized in that, The CHAF1A inhibitor is the compound Baimaside, whose chemical structural formula is shown in Formula I: Formula I.
3. The use of the CHAF1A inhibitor according to claim 2 in the preparation of drugs for treating esophageal cancer, characterized in that, The mass content of Baimaside in the esophageal cancer treatment drug is 1-99%.
4. The use of the CHAF1A inhibitor according to claim 3 in the preparation of a drug for treating esophageal cancer, characterized in that, The drug for treating esophageal cancer is an oral dosage form.
5. The use of the CHAF1A inhibitor according to claim 4 in the preparation of a drug for treating esophageal cancer, characterized in that, The drug used to treat esophageal cancer is a combination of Baimaside and PD-1 monoclonal antibody.
6. The use of the CHAF1A inhibitor according to claim 5 in the preparation of a drug for treating esophageal cancer, characterized in that, The PD-1 monoclonal antibody is CD279.