Design, synthesis and biological evaluation of novel podophyllotoxin derivatives as tubulin-targeting anticancer agents

Abstract

Context

Podophyllotoxin (PPT) derivatives, used in cancer therapy, require development toward enhanced efficacy and reduced toxicity.

Objective

This study synthesizes PPT derivatives to assess their anticancer activities.

Materials and methods

Compounds E1-E16 antiproliferative activity was tested against four human cancer cell lines (H446, MCF-7, HeLa, A549) and two normal cell lines (L02, BEAS-2B) using the CCK-8 assay. The effects of compound E5 on A549 cell growth were evaluated through molecular docking, in vitro assays (flow cytometry, wound healing, Transwell, colony formation, Western blot), and in vivo tests in female BALB/c nude mice treated with E5 (2 and 4 mg/kg). E5 (4 mg/kg) significantly reduced xenograft tumor growth compared to the DMSO control group.

Results

Among the 16 PPT derivatives tested for cytotoxicity, E5 exhibited potent effects against A549 cells (IC₅₀: 0.35 ± 0.13 µM) and exceeded the reference drugs PPT and etoposide to inhibit the growth of xenograft tumours. E5-induced cell cycle arrest in the S and G2/M phases accelerated tubulin depolymerization and triggered apoptosis and mitochondrial depolarization while regulating the expression of apoptosis-related proteins and effectively inhibited cell migration and invasion, suggesting a potential to limit metastasis. Molecular docking showed binding of E5 to tubulin at the colchicine site and to Akt, with a consequent down-regulation of PI3K/Akt pathway proteins.

Discussion and conclusions

This research lays the groundwork for advancing cancer treatment through developing and using PPT derivatives. The encouraging results associated with E5 call for extended research and clinical validation, leading to novel and more effective cancer therapies.

Keywords:

• Tubulin
• apoptosis
• lung adenocarcinoma epithelial
• PI3K/akt signalling pathway
• compound synthesis

Disclosure statement

No potential conflict of interest was reported by the author(s).

Data availability statement

Data supporting the findings of this study are available from the corresponding author upon reasonable request.

Additional information

Funding

WS gratefully acknowledges financial support from various sources, including the Program for Taishan Scholar Project of Shandong Province (No. tsqn201812159), the Natural Science Foundation of Shandong Province (No. ZR2020MH375), the Scientific Research Foundation of Shandong Medical Association (No. YXH2021ZX001), Traditional Chinese Medicine Science and Technology Development Plan of Shandong Province (2019-0747), the Projects of medical and health technology development program in Shandong province (No. 202113050502), the Key R&D Program of Jining (No. 2022YXNS148, No. 2022YXNS118, No. 2023YXNS037), and the Doctoral Fund of Jining NO.1 People′s Hospital (NO. 2021-BS-008).