Network pharmacology and experimental validation to study the potential mechanism of Tongguanteng injection in regulating apoptosis in osteosarcoma

OBJECTIVE

The main objectives of this study were to identify the active components of Tongguanteng injection (TGT) and investigate the preclinical efficacy and mechanism of TGT on osteosarcoma using a combination of network pharmacology and experimental validation.

METHODS

To identify the active constituents and targets of TGT against osteosarcoma using network pharmacology, we constructed a network consisting of an 'active ingredient-disease-target-pathway' and a protein-protein interaction (PPI) network. The target organ network was utilized to investigate the distribution of core targets in tissues. Afterwards, the core targets underwent Gene ontology (GO) functional enrichment and Kyoto Encyclopedia of Genes and Genomes (KEGG) analyses. The binding energy between receptors and ligands was compared using molecular docking. In addition, SwissADME was employed to forecast the pharmacokinetic characteristics of the substances. Finally, real-time polymerase chain reaction (RT-PCR), cell proliferation assay, morphological analysis, apoptosis assay, mitochondrial membrane potential (MMP) detection, and Western blotting were utilized to confirm the potential mechanisms of TGT treatment in osteosarcoma cell lines 143B and SAOS2.

RESULTS

A total of 54 chemical constituents of TGT and 71 targets associated with osteosarcoma were acquired. Through the molecular docking technology, Tenacigenin B, Marsdekoiside, Taraxasterol, Tenacissoside G, Tenacissoside L, and Tenacissoside J were identified as the primary active components of TGT among the various compounds. Analysis of target organs suggests that TGT may play an anti-osteosarcoma role through immune regulation. The GO and KEGG enrichment analysis revealed that TGT could trigger osteosarcoma cell apoptosis by inhibiting the HIF-1 signalling pathway and modulating PD-1 expression and the PD-1 checkpoint pathway in cancer. SwissADME database predicted that Tenacigenin B and Taraxasterol had the best drug-likeness. In vitro studies also demonstrated that TGT suppressed the activity and induced alterations in the morphology of osteosarcoma cells. It decreased MMP levels, triggered apoptosis by increasing Bax expression and Caspase-3 activity, and decreased Bcl-2 expression, thereby exerting an anti-osteosarcoma effect. In the meantime, RT-PCR tests demonstrated that TGT could control immune response against tumors and hinder the proliferation and spread of cancerous cells by impacting the levels of critical factors, including JUN, HSP90AA1, HDAC1, and CDK1.

CONCLUSION

The study accurately anticipated the active components, targets, and pathways of TGT in the management of osteosarcoma. The molecular mechanism of TGT-induced apoptosis in osteosarcoma cells was demonstrated by in vitro experiments. These results provide theoretical and technical support for TGT as a clinical adjuvant drug for osteosarcoma.

Tongguanteng injection reverses paclitaxel resistance via upregulation of TAB1 expression in ovarian cancer in vitro and in vivo

ETHNOPHARMACOLOGICAL RELEVANCE

Tongguanteng injection (TGT), the water extract from the stem of the Traditional Chinese hebal medicine of Marsdenia tenacissima (Roxb.) Wight et Arn. has been used as anticancer remedy for decades. TGT was not only used in the treatment of many malignant cancers extensively, but also an adjuvant anticancer drug with chemotherapeutics clinically.

AIM OF THE STUDY

To evaluate the effects of TGT on reversing paclitaxel (PTX) resistance and investigate the potential mechanism related to TAB1 in ovarian cancer (OC) in vitro and in vivo.

MATERIALS AND METHODS

The synergistic effect and reversal ratio were determined by CCK8 assay and median-effect principle after the combination of TGT and PTX in OC A2780 and its PTX-resistant (A2780/T) cells. The biological functions in cell apoptosis, migration and invasion of A2780/T cells treated by PTX 4 μM with TGT 20, 40, 80 mg⋅mL^-1 for 24 h were evaluated by colony formation, flow cytometry, wound healing and transwell assays. Proteomics technique and bioinformatic analysis were used to indentify the change of TAB1 expression in A2780/T cells induced by TGT. The association between TAB1 expression and human OC was analyzed by gene expression databases. In A2780/T cells, western blotting and colony formation assays were used to investigate the relationship between TAB1 expression and PTX resistance after TAB1 overexpression by TAB1 plasmids. The mechanism of TGT and PTX regulating TAB1 and its related proteins were explored by western blotting and flow cytometry assays after TAB1 knock-down using siTAB1. Moreover, TUNEL staining, immunohistochemistry (IHC) and histopathology were used to observe the antitumor effects, TAB1 and p-p38 expression and the tissues impairments in nude mice xenograft model established by A2780/T cells after the co-treatment with TGT and PTX by in vivo.

RESULTS

TGT combined with PTX showed the synergistic effect (CI<1), which could reverse the IC₅₀ values of PTX in OC A2780 and A2780/T cells about 23.50 and 6.44 times, respectively. Besides, TGT combined with PTX could significantly inhibit the migration, invasion and promote apoptosis of A2780/T cells. We identified that TGT could induce TAB1 expression in A2780/T cells by proteomics analysis. TAB1 downregulation was significantly associated with tumorigenesis and poor prognosis in OC patients and PTX resistance in A2780/T cells. Furthermore, TGT could activate TAB1/TAK1/p38 MAPK signaling pathway targeting TAB1 and regulate the expression of Bax, Bcl-2 proteins to improve the sensitivity of A2780/T cells to PTX. TGT combined with PTX also showed a greater inhibition in tumor growth than PTX monotherapy in vivo. These promising results show the efficacy of TGT in reversing PTX resistance and provide a potential strategy that targeting TAB1/TAK1/p38 MAPK signaling pathway may improve the chemotherapy sensitivity in OC.

CONCLUSIONS

Our results revealed that Tongguanteng injection could reverse paclitaxel resistance and the potential mechanism might be associated with the activation of TAB1/TAK1/p38 MAPK signaling pathway in OC in vitro and in vivo. TAB1 might be a pivotal target for reversing PTX resistance. This study will provide a theoretical basis for the combination of Tongguanteng injection and paclitaxel in clinic.