Pharmacotranscriptomic profiling of resistant triple-negative breast cancer cells treated with lapatinib and berberine shows upregulation of PI3K/Akt signaling under cytotoxic stress.

Triple-negative breast cancer (TNBC) is the most incurable type of breast cancer, accounting for 15-20% of breast cancer cases. Lapatinib is a dual tyrosine kinase inhibitor targeting EGFR and Her2, and berberine (BBR) is a plant-based alkaloid suggested to inhibit several cancer signaling pathways. We previously reported that lapatinib activates the Akt oncoprotein in MDA-MB231 TNBC cells. The present study determined the mechanism(s) of Akt activation in response to lapatinib, BBR, and capivasertib (Akt inhibitor) as well as the role of Akt signaling in chemoresistance in TNBC cells. Genetic profiles of 10 TNBC cell lines and patients were analyzed using datasets obtained from Gene Expression Omnibus and The Cancer Genome Atlas Database. Then, the effects of lapatinib, BBR, and capivasertib on treated MDA-MB231 and MCF-7 cell lines were studied using cytotoxicity, immunoblot, and RNA-sequencing analyses. For further confirmation, we also performed real-time PCR for genes associated with PI3K signaling. MDA-MB231 and MCF-7 cell lines were both strongly resistant to capivasertib largely due to significant Akt activation in both breast cancer cell lines, while lapatinib and BBR only enhanced Akt signaling in MDA-MB231 cells. Next-generation sequencing, functional enrichment analysis, and immunoblot revealed downregulation of CDK6 and DNMT1 in response to lapatinib and BBR lead to a decrease in cell proliferation. Expression of placental, fibroblast growth factor, and angiogenic biomarker genes, which are significantly associated with Akt activation and/or dormancy in breast cancer cells, was significantly upregulated in TNBC cells treated with lapatinib and BBR. Lapatinib and BBR activate Akt through upregulation of alternative signaling, which lead to chemoresistance in TNBC cell. In addition, lapatinib overexpresses genes related to PI3K signaling in resistant TNBC cell model.

Jabbarzadeh Kaboli P ，Luo S ，Chen Y ，Jomhori M ，Imani S ，Xiang S ，Wu Z ，Li M ，Shen J ，Zhao Y ，Wu X ，Hin Cho C ，Xiao Z ... -  《-》

Antitumor effects of berberine against EGFR, ERK1/2, P38 and AKT in MDA-MB231 and MCF-7 breast cancer cells using molecular modelling and in vitro study.

Berberine is an alkaloid plant-based DNA intercalator that affects gene regulation, particularly expression of oncogenic and tumor suppressor proteins. The effects of berberine on different signaling proteins remains to be elucidated. The present study aimed to identify the effects of berberine against key oncogenic proteins in breast cancer cells. Molecular docking and molecular dynamics simulations were used for EGFR, p38, ERK1/2, and AKT. The effects of berberine and lapatinib on MAPK and PI3K pathways in MDA-MB231 and MCF-7 cells were evaluated using immunoflorescence assays, and the amounts of phosphorylated kinases were compared to total kinases after treating with different concentrations of berberine. Simulations showed berberine accurately interacted with EGFR, AKT, P38, and ERK1/2 active sites in silico (scores = -7.57 to -7.92 Kcal/mol) and decreased the levels of active forms of corresponding enzymes in both cell lines; however, berberine binding to p38 showed less stability. Cytotoxicity analysis indicated that MDA-MB231 cells were resistant to berberine compared to MCF-7 cells [72 h IC50 = 50 versus 15 μM, respectively). Also, lapatinib strongly activated AKT but suppressed EGFR in MDA-MB231 cells. The activity of EGFR, AKT, P38, and ERK1/2 were affected by berberine; however, berberine dramatically reduced EGFR and AKT phosphorylation. By way of its multikinase inhibitory effects, berberine might be a useful replacement for lapatinib, an EGFR inhibitor which can cause acquired drug resistance in patients.

Jabbarzadeh Kaboli P ，Leong MP ，Ismail P ，Ling KH ... -  《-》

Inhibition of PI3K/Akt/mTOR overcomes cisplatin resistance in the triple negative breast cancer cell line HCC38.

Gohr K ，Hamacher A ，Engelke LH ，Kassack MU ... -  《BMC CANCER》

Different mechanisms involved in the berberine-induced antiproliferation effects in triple-negative breast cancer cell lines.

Berberine (BBR) is known to be effective at inhibiting cell proliferation and promoting apoptosis in various cancer cells. However, the effects of BBR on triple-negative breast cancer (TNBC) cells remain unclear. The aim of this study was to investigate the cell inhibition effects of BBR on different subtypes of TNBC cells. Using human TNBC cell lines of different subtypes, namely, MDA-MB-231, MDA-MB-468, MDA-MB-453, and BT-549 as in vitro models, antiproliferative effects of BBR were investigated by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay, trypan blue exclusion assay, and clonogenic assay. Furthermore, cell apoptosis and autophagy were analyzed by flow cytometry, immunofluorescent staining, and LC3 I/II-targeted Western blotting. Various cell growth-related signaling pathways (AKT/ERK/p38) and the expression of proteins present in various cell cycle kinase complexes were analyzed by Western blotting. BBR concentration-dependently suppressed cell proliferation in MDA-MB-468 (0, 3, 6, and 12 μM) and MDA-MB-231 (0, 6.25, 12.5, and 25 μM). The inhibitory effect was not brought about by inducing cell apoptosis, necrosis, or autophagy. Cell cycle analysis disclosed an increased S+G2/M fraction among the BBR-treated MDA-MB-231 and MDA-MB-453 cells; while with the BBR-treated MDA-MB-468 and BT-549 lines, an increased G0/G1 fraction was found. In MDA-MB-231 and MDA-MB-453 cells, by Western blotting, BBR decreased the expression of Cyclin A and CDK1, On the other hand, in BBR-treated MDA-MB-468 and BT-549 cells, there was a decrease in Cyclin D and CDK4 expression. Our results demonstrate that the antiproliferation effects of BBR occur via different mechanisms in different subtypes of TNBC cells, which suggests that BBR has potential as a personalized treatment for TNBC patients.

Lin YS ，Chiu YC ，Tsai YH ，Tsai YF ，Wang JY ，Tseng LM ，Chiu JH ... -  《-》

Lapatinib inhibits CIP2A/PP2A/p-Akt signaling and induces apoptosis in triple negative breast cancer cells.

Liu CY ，Hu MH ，Hsu CJ ，Huang CT ，Wang DS ，Tsai WC ，Chen YT ，Lee CH ，Chu PY ，Hsu CC ，Chen MH ，Shiau CW ，Tseng LM ，Chen KF ... -  《Oncotarget》