Degradation of MCL-1 by bufalin reverses acquired resistance to osimertinib in EGFR-mutant lung cancer.

Although osimertinib, an EGFR tyrosine kinase inhibitor, has become the standard therapy for treating non-small cell lung cancer (NSCLC) patients with EGFR-activating mutation, upregulation of MCL-1 induces acquired resistance to osimertinib. Bufalin, a natural digoxin-like ingredient isolated from a traditional Chinese medicine Chan Su, has been shown to downregulate MCL-1 in NSCLC cells. However, whether bufalin reverses this acquired resistance to osimertinib in NSCLC cells remains unclear. In this study, bufalin reduced cell viability and promoted apoptosis in osimertinib-resistant cells. Moreover, co-treatment with bufalin and osimertinib restored the sensitivity of osimertinib-resistant cells to osimertinib-induced growth regression and apoptosis in vitro and in vivo. Mechanistically, MEK/ERK-dependent MCL-1 phosphorylation and Ku70-mediated MCL-1 overexpression confer osimertinib resistance in EGFR-mutant NSCLC cells. In osimertinib-resistant cells, bufalin modulates Ku70-mediated MCL-1 degradation, but not MEK/ERK/MCL-1 signaling. In conclusion, our study suggests that bufalin eliminates resistance to osimertinib by inhibiting Ku70-mediated MCL-1 overexpression, indicating that a combination of osimertinib and bufalin could be an effective additional treatment to overcome acquired resistance to osimertinib in NSCLC cells.

Efficacy of a Chinese Herbal Medicine Compound Zhangpi Ointment against Hydroxyurea-Induced Leg Ulcers: A Prospective, Randomized, Open-Label, Controlled Clinical Trial.

Objective. The randomized controlled trial was to evaluate the efficacy of topical Chinese herbal Zhangpi Ointment for hydroxyurea-induced leg ulcers in patients with myeloproliferative neoplasms. Patients and Methods. This single-center, prospective, randomized, open-label, controlled clinical trial conducted at Shanghai Ninth People's Hospital enrolled 54 patients with hydroxyurea-induced leg ulcers. Patients were randomly assigned to the control group (n = 27) treated with chlorhexidine dressing or the intervention group (n = 27) treated with the Zhangpi Ointment. Finally, 26 patients in the control group and 23 patients in the intervention group completed 8 weeks of observation. Results. The rate of complete healing was 100% for the intervention group, which was significantly higher than that of the control group (96.15%) (P<0.05). Furthermore, the intervention group achieved a significantly higher rate of wound healing (95.56%) than the control group (69.02%) at week 4 (P<0.01). The intervention group took 34 ± 5 days to achieve complete healing while the control group took 41 ± 7 days (P < 0.01). Moreover, grade 3/4 side effects were observed in neither group. Conclusion. The Zhangpi Ointment is effective in promoting the healing of hydroxyurea-induced leg ulcers in patients with myeloproliferative neoplasms, providing a therapeutic option for a condition that is recalcitrant to conventional therapy.

Yiqi formula enhances the antitumor effects of erlotinib for treatment of triple-negative breast cancer xenografts.

Yiqi formula (YF), a traditional herbal prescription, has long been used to treat triple-negative breast cancer (TNBC) patients. The present study aims to investigate the effects and the related mechanism of YF for treatment of TNBC xenografts. MDA-MB-231 (human TNBC) cells were subcutaneously injected into the second mammary fat pad of 40 female nude mice, which were divided into four groups: control, erlotinib (an epidermal growth factor receptor (EGFR) tyrosine kinase inhibitor), YF, and combination (YF plus erlotinib). All treatments were administered orally for 30 days. Inhibition rate of tumor weight by erlotinib, YF, and the combination was 26.47%, 17.24%, and 39.15%, respectively. Western blotting showed that YF, erlotinib, and the combination downregulated p-EGFR (P < 0.01) and p-Akt1 (pT308) (P < 0.05) and upregulated PTEN compared with control, and the combination was more efficacious than erlotinib alone (P < 0.05). Similar results were detected by immunohistochemistry. Real-time quantitative PCR showed that YF, erlotinib, and the combination increased PTEN mRNA (P < 0.05, P < 0.01) compared with control, and the combination was more efficacious than erlotinib alone (P < 0.05). In conclusion, YF can regulate the main components of the PI3K/Akt pathway in TNBC xenografts. When YF was used in combination with erlotinib, it enhanced the antitumor effects of erlotinib on TNBC xenografts. These findings suggest that YF is suitable to use for the treatment of TNBC patients.

Bufalin Reverses HGF-Induced Resistance to EGFR-TKIs in EGFR Mutant Lung Cancer Cells via Blockage of Met/PI3k/Akt Pathway and Induction of Apoptosis.

The epidermal growth factor receptor tyrosine kinase inhibitors (EGFR-TKIs), such as gefitinib and erlotinib, have shown promising therapeutic efficacy in nonsmall cell lung cancer (NSCLC) patients harboring epidermal growth factor receptor- (EGFR-) activating mutation. However, the inevitable recurrence resulting from acquired resistance has limited the clinical improvement in therapy outcomes. Many studies demonstrate that hepatocyte growth factor- (HGF-) Met axis plays an important role in tumor progression and drug sensitivity. HGF may induce resistance to EGFR-TKIs in EGFR mutant lung cancer cells by Met/PI3K/Akt signaling. The purpose of this study was to determine whether bufalin, a major bioactive component of Venenum Bufonis, could reverse HGF-induced resistance to reversible and irreversible EGFR-TKIs in mutant lung cancer cells PC-9, HCC827, and H1975. Our studies showed that bufalin could reverse resistance to reversible and irreversible EGFR-TKIs induced by exogenous HGF in EGFR mutant lung cancer cells by inhibiting the Met/PI3K/Akt pathway and inducing death signaling. These results suggested that bufalin might have a potential to overcome HGF-induced resistance to molecular-targeted drugs for lung cancer.

[Effects of Astragalus polysaccharide on proliferation and Akt phosphorylation of the basal-like breast cancer cell line].

OBJECTIVE: To investigate the effects of Astragalus polysaccharide (APS) on proliferation of basal-like breast cancer cell line MDA-MB-468 cells and Akt phosphorylation in MDA-MB-468 cells. METHODS: APS at different concentrations was used to culture MDA-MB-468 cells for different time periods, and then proliferation of MDA-MB-468 cells was assayed using methyl thiazolyl tetrazolium (MTT) assay to determine the time- and dose-dependent effects of APS. For observing the effects of APS on phosphor-Akt (p-Akt), in-cell Western blot method was used after 1, 2, 4 and 7 d of culture in APS to detect protein expressions of p-Akt (Thr308) and p-Akt (Ser473). Protein levels of the key targets in p53/murine double minute 2 (MDM2) signaling pathway, such as p53, MDM2 and phosphatase and tensin homolog deleted on chromosome ten (PTEN) were also detected. After PTEN gene was silenced by small interfering RNA (siRNA) in MDA-MB-468 cells, expressions of p-Akt (Thr308 and Ser473) were assayed by the in-cell Western blot method after 2 d of APS treatment. RESULTS: APS at 1 and 0.5 mg/mL concentrations effectively inhibited the proliferation of MDA-MB-468 cells and was used in subsequent tests. Compared with the control group, APS decreased the protein expression of p-Akt (Thr308) in MDA-MB-468 cells after 1-, 2-, 4- and 7-day culture, and also decreased the protein expression of p-Akt (Ser473) and up-regulated the protein expression of MDM2 in MDA-MB-468 cells after 1- and 2-day culture. Expressions of p53 and PTEN were up-regulated after 7 d of APS culture. After silencing PTEN gene by siRNA, APS could not mediate Akt phosphorylation. CONCLUSION: APS can inhibit proliferation of basal-like breast cancer cell line MDA-MB-468, and down-regulate the expression of Akt phosphorylation. The antiproliferation mechanisms may be related to its effects of up-regulating the expressions of p53 and PTEN by regulating p53/MDM2 positive and negative feedback loops.

[Differentially expressed genes in adrenal gland of H22 liver cancer mice with different syndromes and in different stages].

OBJECTIVE: To reveal the characteristics of gene expression in adrenal gland of H22 tumor mice with typical syndromes and in different liver cancer stages. METHODS: By the quantitative four diagnosis and syndrome differentiation methods and GeneChip Mouse Exon 1.0 ST Array, we observed adrenal gland gene expression in H22 tumor mice with pathogenic factor-toxin predominance syndrome and qi deficiency syndrome in the earlier stage, yang-qi deficiency syndrome in the intermediate stage, and qi-yin-yang deficiency syndrome in the advanced stage. Genes highly expressed and remarkably different were analyzed in this study. RESULTS: A total of seventy-three up-regulated coincident genes and twenty-six down-regulated coincident genes in different stages were investigated in the study. Up-regulated coincident genes included Hp, C3, Anxa1, Procr, C2, Il4ra, Cd14, Ptprc, Cd52, C4b, Eno3, Xdh, Gpx3, and so on. Down-regulated coincident genes included nervous system function-related genes such as Plp1, Mbp, Aldh1a1, Cck, Atn1, genes associated with electrolyte metabolism such as Aldh1a1 and Slc22a17, genes related to signal transduction such as Cxcr4, Spag5 and Stmn3, etc, and genes related to transcriptional control and protein biosynthesis such as Hspa1a, Dnajb1, Thra, Hhex and so on. CONCLUSION: With the development of the tumorigenesis, the symptoms and signs and differentially expressed genes in adrenal gland of H22 tumor mice can be measured. Up-regulated and down-regulated coincident genes may be the features of H22 tumor mice different from those of normal mice.