Biological activity of SAD-2: a novel original STING pathway activator

Cover Page


Cite item

Full Text

Open Access Open Access
Restricted Access Access granted
Restricted Access Subscription or Fee Access

Abstract

BACKGROUND: STING pathway activators with targeted delivery to tumor nodules are a promising option in cancer immunotherapy, especially as immunoconjugates. Existing compounds, such as MSA-2, are insufficiently effective as active immunoconjugate components, necessitating the development of new, more active compounds.

AIM: The work aimed to examine the biological activity of the new compound SAD-2 and assess its potential as a new immunobiological drug for cancer therapy.

METHODS: The work used contemporary methods of fine organic synthesis and analysis of the resulting compounds. MSA-2 was obtained from veratrole by multistage synthesis. SAD-2 was synthesized from MSA-2 by esterification with isopropyl alcohol in the presence of thionyl chloride. The antiproliferative activity of the compounds was assessed by the MTT method using colorectal cancer cell lines and human peripheral blood mononuclear cells. The induction of the interferon beta gene was assessed by real-time polymerase chain reaction using the human monocytic cell line THP-1.

RESULTS: The new compound SAD-2 had 200–500 times higher antiproliferative activity according to IC50 than the existing compound MSA-2. Both MSA-2 and SAD-2 are active only in the presence of immune cells. SAD-2 showed 5–60 times higher relative induction of the IFNB1 gene than MSA-2, depending on the incubation time.

CONCLUSION: SAD-2 is a promising new compound for developing immunoconjugates for targeted STING pathway activation in tumor nodules.

Full Text

Restricted Access

About the authors

Yana O. Sadovskaya

Blokhin National Medical Research Center of Oncology

Author for correspondence.
Email: ja.sadovskaja@ronc.ru
ORCID iD: 0009-0009-7115-7797
SPIN-code: 8572-7717
Russian Federation, Moscow

Dmitriy V. Gusev

Blokhin National Medical Research Center of Oncology

Email: d.gusev@ronc.ru
ORCID iD: 0000-0003-0218-8265
SPIN-code: 4613-3230
Russian Federation, Moscow

Anastasia O. Karimova

Blokhin National Medical Research Center of Oncology; National Research University Higher School of Economics

Email: a.karimova@ronc.ru
ORCID iD: 0009-0000-0317-9948
SPIN-code: 8054-2753
Russian Federation, Moscow; Moscow

Mikhail A. Ryzhikov

Blokhin National Medical Research Center of Oncology; National Research University Higher School of Economics

Email: m.ryzhikov@ronc.ru
ORCID iD: 0009-0000-2292-8537
Russian Federation, Moscow; Moscow

Margarita G. Khotuleva

Blokhin National Medical Research Center of Oncology

Email: m.khotuleva@ronc.ru
ORCID iD: 0009-0008-6104-5233
Russian Federation, Moscow

Danila M. Zaichenko

Blokhin National Medical Research Center of Oncology

Email: danilamihailovich@mail.ru
ORCID iD: 0000-0003-0241-0065
SPIN-code: 3667-5888
Russian Federation, Moscow

Olga N. Solopova

Blokhin National Medical Research Center of Oncology

Email: o.solopova@ronc.ru
ORCID iD: 0000-0002-5465-6094
SPIN-code: 2807-7709

Cand. Sci. (Biology)

Russian Federation, Moscow

References

  1. Couillin I, Riteau N. STING Signaling and Sterile Inflammation. Frontiers in Immunology. 2021;12:753789. doi: 10.3389/fimmu.2021.753789 EDN: DYVWKT
  2. Zhang H, You QD, Xu XL. Targeting Stimulator of Interferon Genes (STING): A Medicinal Chemistry Perspective. Journal of Medicinal Chemistry. 2020;63(8):3785–3816. doi: 10.1021/acs.jmedchem.9b01705 EDN: DRPDFZ
  3. Zhao J, Tong A, Liu J, Xu M, Mi P. Tumor-targeting nanocarriers amplified immunotherapy of cold tumors by STING activation and inhibiting immune evasion. Science Advances. 2025;11(26):eadr1728. doi: 10.1126/sciadv.adr1728
  4. Yang J, Ding H, Shuai B, et al. Mechanism and effects of STING–IFN-I pathway on nociception: A narrative review. Frontiers in Molecular Neuroscience. 2022;15:1081288. doi: 10.3389/fnmol.2022.1081288
  5. Hussain B, Xie Y, Wang W, et al. Activation of STING Based on Its Structural Features. Frontiers in Immunology. 2022;13:859367. doi: 10.3389/fimmu.2022.859367 EDN: YOUTHJ
  6. Parker B, Rautela J, Hertzog P. Antitumour actions of interferons: implications for cancer therapy. Nature Reviews Cancer. 2016;16(3):131–144. doi: 10.1038/nrc.2016.14
  7. Yu X, Cai L, Yao J, Li C, Wang X. Agonists and Inhibitors of the cGAS-STING Pathway. Molecules. 2024;29(13):3121. doi: 10.3390/molecules29133121 EDN: FWOVPI
  8. Yang J, Luo Z, Ma J, et al. A next-generation STING agonist MSA-2: From mechanism to application. Journal of Controlled Release. 2024;371:273–287. doi: 10.1016/j.jconrel.2024.05.042 EDN: FQCKDU
  9. Yi M, Niu M, Wu Y, et al. Combination of oral STING agonist MSA-2 and anti-TGF-β/PD-L1 bispecific antibody YM101: a novel immune cocktail therapy for non-inflamed tumors. Journal of Hematology & Oncology. 2022;15(1):142. doi: 10.1186/s13045-022-01363-8 EDN: HKNHIB
  10. Liu Y, Uras G, Onuwaje I, et al. Novel inhibitors of AChE and Aβ aggregation with neuroprotective properties as lead compounds for the treatment of Alzheimer’s disease. European Journal of Medicinal Chemistry. 2022;235:114305. doi: 10.1016/j.ejmech.2022.114305 EDN: MVUOZK
  11. Sailer A, Ermer F, Kraus Y, et al. Hemithioindigos for Cellular Photopharmacology: Desymmetrised Molecular Switch Scaffolds Enabling Design Control over the Isomer‐Dependency of Potent Antimitotic Bioactivity. ChemBioChem. 2019;20(10):1305–1314. doi: 10.1002/cbic.201800752 EDN: DAGBRG
  12. Mukherjee C, Kamila S, De A. Application of Directed Metalation in Synthesis. Part 4: Expedient Synthesis of Substituted Benzo[b]thiophene and Naphthothiophene. Tetrahedron. 2003;59(26):4767–4774. doi: 10.1016/S0040-4020(03)00724-5 EDN: BJFOLJ
  13. Zhang A, Geng M, Ding C, et al. Fluorine-Containing Substituted Benzothiophene Compound, and Pharmaceutical Composition and Application Thereof. Canada patent CA3125505C. March 1, 2022. Available from: https://patents.google.com/patent/CA3125505C/en
  14. Patent RUS № 2811736/ 16.01.2024. Solopova ON, Gusev DV, Kosorukov VS, et al. A new chemical compound that stimulates the production of human interferon-beta by activating the STING signaling pathway, and a method for its production. Available from: https://patents.google.com/patent/RU2811736C1/ru (In Russ.) EDN: BBAVTF
  15. Patent RUS № 2739261/ 22.12.2020. Aliev TK, Panina AA, Sveshnikov PG, et al. Method for quantitative determination of anti-proliferative activity of human Interferon-beta. Available from: https://patents.google.com/patent/RU2739261C1/ru (In Russ.) EDN: PQZPDV
  16. Altman MD, Cash BD, Chang W, et al. Benzo[b]thiophene Compounds as STING Agonists. United States patent US10703738B2. July 7, 2020. Available from: patents.google.com›patent/US10703738B2/en
  17. Chen X, Meng F, Xu Y, et al. Chemically programmed STING-activating nano-liposomal vesicles improve anticancer immunity. Nature Communications. 2023:14(1):4584. doi: 10.1038/s41467-023-40312-y EDN: JXETMC
  18. Barber GN. STING: infection, inflammation and cancer. Nature Reviews Immunology. 2015;15(12):760–770. doi: 10.1038/nri3921
  19. De Rosa C, Iommelli F, De Rosa V, et al. PBMCs as Tool for Identification of Novel Immunotherapy Biomarkers in Lung Cancer. Biomedicines. 2024;12(4):809. doi: 10.3390/biomedicines12040809 EDN: XZIDKQ
  20. Sazonova EV, Chesnokov MS, Zhivotovsky B, et al. Drug toxicity assessment: cell proliferation versus cell death. Cell Death Discov. 2022:8:417. doi: 10.1038/s41420-022-01207-x
  21. Panina AA, Rybchenko VS, Solopova ON, et al. Recombinant bispecific antibodies to the human ErbB2 receptor and interferon-beta. Acta Naturae. 2020;12(2):95–104. doi: 10.32607/actanaturae.11156 EDN: OREPGE
  22. Thomsen EA, Andersen S, Marqvorsen MHS, et al. Single-Cell Monitoring of Activated Innate Immune Signaling by a d2eGFP-Based Reporter Mimicking Time-Restricted Activation of IFNB1 Expression. Frontiers in cellular and infection microbiology. 2022;11:784762. doi: 10.3389/fcimb.2021.784762
  23. Mikhalkevich N, Russ E, Iordanskiy S. Cellular RNA and DNA sensing pathways are essential for the dose-dependent response of human monocytes to ionizing radiation. Frontiers in Immunology. 2023;14:1235936. doi: 10.3389/fimmu.2023.1235936
  24. Lai Z, Zhang Y, Hu X, et al. Therapeutic Effect of Brucea Javanica Oil Emulsion in Mice with Irinotecan-Induced Delayed Diarrhea. Drug Des Devel Ther. 2025;19:5329–5347. doi: 10.2147/DDDT.S517973
  25. Pan BS, Perera SA, Piesvaux JA, et al. An orally available non-nucleotide STING agonist with antitumor activity. Science. 2020;369(6506):eaba6098. doi: 10.1126/science.aba6098 EDN: GBYZWZ
  26. Gehrcken L, Deben C, Smits E, et al. STING Agonists and How to Reach Their Full Potential in Cancer Immunotherapy. Adv Sci (Weinh). 2025;12(17):e2500296. doi: 10.1002/advs.202500296
  27. Nie J, Zhou L, Tian W, et al. Deep insight into cytokine storm: from pathogenesis to treatment. Sig Transduct Target Ther. 2025;10(1):112. doi: 10.1038/s41392-025-02178-y

Supplementary files

Supplementary Files
Action
1. JATS XML
Download
2. Fig. 1. Synthesis scheme of 5,6-dimethoxy-γ-oxobenzo[b]thiophene-2-butanoic acid isopropyl ether from 4-(5,6-dimethoxy-1-benzothiophene-2-yl)-4-oxobutanoic acid.

Download (73KB)
Indexing metadata
3. Fig. 2. Inhibition curves of DLD-1 cell proliferation by STING activators SAD-2 and MSA-2 in the presence and absence of peripheral blood mononuclears. МПК — peripheral blood mononuclears.

Download (168KB)
Indexing metadata
4. Fig. 3. Antiproliferative activity of the STING activator MSA-2 on the DLD-1 cell line in co-culture with PBMCs compared to the control. * p=0.0286, ns — difference is statistically insignificant relative to the control (N=4, Mann-Whitney test), PBMCs — peripheral blood mononuclears, +PBMCs are samples containing PBMCs, -PBMCs are control samples without PBMCs.

Download (106KB)
Indexing metadata
5. Fig. 4. Antiproliferative activity of the STING activator SAD-2 on the DLD-1 cell line in co-culture with peripheral blood mononuclears compared to the control. * p=0.0286, ns — difference is statistically insignificant relative to the control (N=4, Mann-Whitney test), PBMCs — peripheral blood mononuclears, +PBMCs — samples containing PBMCs, -PBMCsare — control samples without PBMCs.

Download (116KB)
Indexing metadata
6. Fig. 5. Comparative antiproliferative activity of STING activators MSA-2 and SAD-2 on the DLD-1 cell line in the presence of peripheral blood mononuclears. * p=0.0286, ns — the difference is statistically insignificant (N=4, Mann-Whitney criterion), MSA-2 — samples containing MSA-2, SAD-2 — samples containing SAD-2.

Download (128KB)
Indexing metadata
7. Fig. 6. Inhibition of HT-29 cell line proliferationby STING activators SAD-2 and MSA-2 in the presence and absence of peripheral blood mononuclears. PBMCs — peripheral blood mononuclears.

Download (162KB)
Indexing metadata
8. Fig. 7. Antiproliferative activity of the STING activator MSA-2 on the HT-29 cell line in co-culture with peripheral blood mononuclears in compared to the control. * p=0.0286, ns — the difference is statistically insignificant relative to the control (N=4, Mann-Whitney test), PBMCs — peripheral blood mononuclears, +PBMCs — samples containing PBMCs, -PBMCs — control samples without PBMCs.

Download (162KB)
Indexing metadata
9. Fig. 8. Antiproliferative activity of the STING activator SAD-2 on the HT-29 cell line in co-culture with PBMCsin compared to the control. * p=0.0286, ns — the difference is statistically insignificant relative to the control (N=4, Mann-Whitney test), PBMCs — peripheral blood mononuclears, +PBMCs — samples containing PBMCs, -PBMCs — control samples without PBMCs.

Download (111KB)
Indexing metadata
10. Fig. 9. Comparative antiproliferative activity of STING activators MSA-2 and SAD-2 on the HT-29 cell line in the presence of peripheral blood mononuclears. * p=0.0286, ns — the difference is statistically insignificant (N=4, Mann-Whitney criterion), MSA-2 are samples containing MSA-2, SAD-2 are samples containing SAD-2.

Download (122KB)
Indexing metadata
11. Fig. 10. Relative expression of the IFNB1 gene (normalized to GAPDH) in THP-1 cell line assessed by real-time polymerase chain reaction after 3-, 6-, and 24-hour induction with STING activators SAD-2 and MSA-2.

Download (129KB)
Indexing metadata

Copyright (c) 2025 Eco-Vector

License URL: https://eco-vector.com/for_authors.php#07
СМИ зарегистрировано Федеральной службой по надзору в сфере связи, информационных технологий и массовых коммуникаций (Роскомнадзор).
Регистрационный номер и дата принятия решения о регистрации СМИ: ПИ № ФС 77 - 86496 от 11.12.2023 г. 
СМИ зарегистрировано Федеральной службой по надзору в сфере связи, информационных технологий и массовых коммуникаций (Роскомнадзор).
Регистрационный номер и дата принятия решения о регистрации СМИ: ЭЛ № ФС 77 - 80673 от 23.03.2021 г.