<italic>In vitro</italic> effects of phenytoin and DAPT on MDA-MB-231 breast cancer cells

Abstract

Voltage-gated sodium channel (VGSC) activity enhances cell behaviors related to metastasis, such as motility, invasion, and oncogene expression. Neonatal alternative splice form of Nav1.5 isoform is expressed in metastatic breast cancers. Furthermore, aberrant Notch signaling pathway can induce oncogenesis and may promote the progression of breast cancers. In this study, we aimed to analyze the effect of the nNav1.5 inhibitor phenytoin and Notch signal inhibitor N-[N-(3,5-difluorophenacetyl)-L-alanyl]-S-phenylglycine-t-butyl ester (DAPT) on triple negative breast cancer cell line (MDA-MB-231) via inhibition of nNav1.5 VGSC activity and Notch signaling, respectively. In order to determine the individual and combined effects of these inhibitors, the 4-[3-(4-iyodophenyl)-2-(4-nitrophenyl)-2H-5-tetrazolio]-1,3-benzene disulfonate (WST-1) test, wound healing assay, and zymography were performed to detect the proliferation, lateral motility, and matrix metalloproteinase-9 (MMP9) activity, respectively. The expressions of nNav1.5, Notch4, MMP9, and tissue inhibitor of metalloproteinases-1 (TIMP1) were also detected by quantitative real-time reverse transcriptase-polymerase chain reaction. DAPT caused an antiproliferative effect when the doses were higher than 10 µM, whereas phenytoin showed no inhibitory action either alone or in combination with DAPT on the MDA-MB-231 cells. Furthermore, it was found that the lateral motility was inhibited by both inhibitors; however, this inhibitory effect was partially rescued when they were used in combination. Meanwhile, the results showed that the MMP9 activity and the ratio of MMP9 mRNA to TIMP1 mRNA were only decreased by DAPT. Thus, we conclude that the combined effect of DAPT and phenytoin is not as beneficial as using DAPT alone on MDA-MB-231 breast cancer cells.

Signaling pathway inhibitors target breast cancer stem cells in triple-negative breast cancer

“…Although a number of previous studies demonstrated that these five signaling inhibitors exert inhibitory effects on TNBC in animal models and in clinical trials (49)(50)(51)(52)(53), in the present study, it was demonstrated that all five signaling inhibitors suppressed stemness of BCSCs in extensive aspects, including proliferation, invasion, apoptosis, self-renewal, mammosphere formation and tumorigenesis. In addition, the inhibition efficacy of these five inhibitors against TNBC was compared.…”

Expression and influence of Notch signaling in oral squamous cell carcinoma

“…Notch signaling inhibition resulted in the attenuation of cancer cell invasion and migration (55,56,59). In this regard, DAPT significantly inhibited breast cancer cell migration in an in vitro wound healing assay.…”

Preparation of Nanoparticle-Loaded Extracellular Vesicles Using Direct Flow Filtration

“…This cell line is the most studied triple-negative breast cancer cell line, which has a significant practical value. For example, MDA-MB-231 cells have been extensively used for cancer metastasis [ 42 , 43 ] and drug resistance studies [ 44 , 45 ]. During this process, QFeNPs were used as the loading NPs for several reasons.…”