Journal of Natural Medicines

Digoxin targets BHLHE40 to inhibit epithelial-mesenchymal transition in cervical cancer cells via downregulation of ANGPTL3

This study aims to investigate the mechanism of action of BHLHE40 and its targeted drug, digoxin, in cervical cancer. The clinical significance of BHLHE40 was evaluated in cervical cancer samples using the UALCAN and Human Protein Atlas databases. The effects of BHLHE40 on proliferation, migration, invasion, and epithelial-mesenchymal transition (EMT) were then assessed through loss- and gain-of-function experiments coupled with CCK-8, wound healing, Transwell and Western blot analysis. A murine lung-metastasis model was further established to `validate the pro-metastatic role of BHLHE40 in vivo. JASPAR-based motif prediction, chromatin immunoprecipitation-qPCR (ChIP-qPCR), and luciferase reporter assays were employed to elucidate the transcriptional regulation of ANGPTL3 by BHLHE40. Molecular docking and cellular thermal shift assay (CETSA) were used to clarify the molecular interaction between digoxin and BHLHE40. BHLHE40 was markedly up-regulated in cervical cancer tissues and positively correlated with advanced tumor stage, lymph node metastasis, and poor prognosis. Knockdown of BHLHE40 suppressed proliferation, colony formation, migration, invasion, and attenuated EMT. Consistently, silencing BHLHE40 reduced the number of pulmonary metastatic nodules in nude mice. Mechanistically, BHLHE40 bound directly to the ANGPTL3 promoter and enhanced its transcriptional activity. Knock-down ANGPTL3 reversed BHLHE40-induced increases in migratory and invasive capacities as well as EMT-related phenotypic changes. Digoxin bound to the conserved domain of BHLHE40, down-regulated both BHLHE40 and ANGPTL3, and suppressed EMT and cell motility. Overexpression of BHLHE40 rescued these inhibitory effects of digoxin. Collectively, our findings demonstrate that BHLHE40 promotes EMT and metastasis in cervical cancer by transcriptionally activating ANGPTL3, whereas digoxin exerts anti-EMT effects by targeting this axis. These data highlight the critical role of the BHLHE40-ANGPTL3 axis in cervical cancer progression and suggest that repurposing digoxin offers a novel therapeutic strategy for suppressing EMT in this disease.

Cardamonin inhibits the expression of P-glycoprotein and enhances the anti-proliferation of paclitaxel on SKOV3-Taxol cells

Paclitaxel is widely used in the first-line treatment of ovarian cancer. Nevertheless, the development of acquired resistance to paclitaxel is a major obstacle for the therapy in clinic. Cardamonin is a novel anticancer chalcone which exhibits a wide range of pharmacological activities. However, the effect of cardamonin on paclitaxel-resistant ovarian cancer cells and its underlying molecular mechanisms are unknown. Here, we revealed whether cardamonin had a resensitivity for paclitaxel and furtherly explored the underlying mechanisms on SKOV3-Taxol cells. Our results showed that cardamonin combined with paclitaxel had a synergistic effect of anti-proliferation in SKOV3-Taxol cells, and CI was less than one. Cells apoptosis and G2/M phase arrest were enhanced by cardamonin with paclitaxel in a concentration-dependent way on SKOV3-Taxol cells (P < 0.05). Cardamonin significantly increased drug accumulation in SKOV3-Taxol cells (P < 0.05). Similar to verapamil, cardamonin decreased MDR1 mRNA and P-gp expression (P < 0.05). Cardamonin restrained NF-κB activation in SKOV3-Taxol cells (P < 0.05). Inhibitory effect of P-gp and NF-κB p65 (nuclear protein) expression was enhanced by cardamonin combined with PDTC, a NF-κB inhibitor. Cardamonin significantly inhibited the upregulation of NF-κB p65 (nuclear protein) and P-gp expression induced by TNF-α (P < 0.05). Taken together, cardamonin enhanced the effect of paclitaxel on inhibiting cell proliferation, inducing apoptosis and G2/M phase arrest, and then strengthened the cytotoxic effect of paclitaxel in SKOV3-Taxol cells. The mechanism might be involved in inhibition of P-gp efflux pump, reducing MDR1 mRNA and P-gp expression by cardamonin via suppression of NF-κB activation in SKOV3-Taxol cells.

Tenacissoside G reverses paclitaxel resistance by inhibiting Src/PTN/P-gp signaling axis activation in ovarian cancer cells

Ovarian cancer (OC) is the most common malignant gynecologic tumor, with the highest mortality rate among female reproductive system cancers. Resistance to chemotherapy drugs, which often develops after long-term use, is a major cause of treatment failure. In recent years, traditional Chinese medicine has been widely used in the treatment of tumor for their advantages in improving the efficacy of chemotherapy and alleviating the toxic side effects. Tenacissoside G (Tsd-G), as one of the main active ingredients of Marsdenia tenacissima, exhibits anti-tumor effects. However, its impact on ovarian cancer is not well understood. To assess the role and mechanism of Tsd-G in reversing paclitaxel (PTX) resistance, the reversal fold of Tsd-G in combination with PTX on OC PTX-resistant (A2780/T) cells was determined using CCK-8 assay. The apoptosis level and migration ability of A2780/T cells after 24 h treatment with Tsd-G and PTX were assessed by Hoechst 33,342, flow cytometry, and wound healing assay. Western Blot and Src overexpression plasmid were used to explore the relationship between Src and PTX resistance. The relationship between Src expression and human OC was analyzed by gene expression database. The effect of Tsd-G on P-gp activity was detected by flow cytometry. Western blot and RT-PCR experiments were performed to detect the differences in mRNA and protein expression of Src/PTN/P-gp signaling axis to validate the mechanism of Tsd-G in reversing the resistance to PTX in ovarian cancer. The results showed that Tsd-G reverses PTX resistance in ovarian cancer cells by regulating cell proliferation, cell cycle, inducing apoptosis, and inhibiting migration. The mechanism might associate with the inhibition of Src expression and phosphorylation activation, which in turn inhibits the expression and activity of downstream PTN and P-gp. This study provides a new idea for the treatment of PTX-resistant OC patients and provides theoretical support for revealing the anti-ovarian cancer active ingredients in Marsdenia tenacissima.

Red ginseng prevents niraparib-induced myelosuppression in C57BL/6 mice via inhibiting p53-mediated upregulation of p21 and p27

Abstract Myelosuppression is a serious and common complication of targeted therapy for cancer patients, and there are few studies exploring the efficacy of natural drugs in this condition. Niraparib is a widely used targeted therapy for the treatment of advanced ovarian cancer. As a poly (ADP-ribose) polymerase (PARP) inhibitor, niraparib significantly improves progression-free and overall survival in patients. We aimed to explore the potential effect of red ginseng (RG) on niraparib-induced myelosuppression and to further reveal its possible molecular mechanism. Female C57BL/6 mice were divided into control, tumor, model, and RG groups (n = 6). After receiving ID8 ovarian cancer cell inoculation, the mice received niraparib treatment (80 mg/kg) for 3 days. Meanwhile, RG groups (100 and 200 mg/kg) were intragastrically treated with RG extract for 7 days. Compared with the model group, RG extract increased the counts of peripheral blood cells and enhanced the hematopoietic function of bone marrow. Furthermore, RG extract increased the colony yield of hematopoietic progenitor cells (HPCs), facilitated DNA damage repair, alleviated the G0/G1 phase cell cycle arrest, and significantly reversed the increased expression levels of p53, p21, and p27, while stimulating cyclinE1 expression levels. These findings indicate that RG might have therapeutic potential on niraparib-induced myelosuppression, which encourages further clinical trials. This study is the first to explore the efficacy and mechanism of RG in preventing myelosuppression induced by niraparib. Graphical abstract

Betulinic acid induces apoptosis of HeLa cells via ROS-dependent ER stress and autophagy in vitro and in vivo

Betulinic acid (BA), a naturally occurring lupane-type triterpenoid, possesses a wide range of potential activities against different types of cancer. However, the molecular mechanisms involved in anti-cervical cancer about BA were rarely investigated. Herein, the role of BA in cervical cancer suppression by ROS-mediated endoplasmic reticulum stress (ERS) and autophagy was deeply discussed. The findings revealed that BA activated Keap1/Nrf2 pathway and triggered mitochondria-dependent apoptosis due to ROS production. Furthermore, BA increased the intracellular Ca