OBJECTIVES: To evaluate the inhibitory effect of Macrothele raveni crude venom against proliferation of different cancer cells and identify the active components in the venom. METHODS: Different cancer cell lines were treated with different concentrations of Macrothele raveni venom for 48 h, and cell proliferation and the half-maximal inhibitory concentrations (IC₅₀) of the venom were assessed with CCK-8 assay. The apoptosis rate of breast cancer MCF7 cells following the treatment was analyzed with flow cytometry, and the changes in cellular caspase-8 and caspase-9 expressions were detected. The crude venom was separated into protein, peptide, and small-molecule compound fractions using gel filtration chromatography and high-performance liquid chromatography (HPLC). The protein and peptide components were identified using proteomics analysis, and small-molecule compounds were structurally characterized using nuclear magnetic resonance (NMR), mass spectrometry (MS), and HPLC. RESULTS The crude venom exhibited strong concentration-dependent inhibitory effects on proliferation of MCF7 cells and nasopharyngeal carcinoma SUNE1 and HONE1 cells (IC₅₀ of 2.14±0.29, 1.57±0.14, and 2.85±0.15 µg/mL, respectively), with less potent inhibitory effects in gastric cancer HGC27 cells and colorectal cancer SW620 cells (IC₅₀ of 3.02±0.27 and 3.02±0.28 µg/mL, respectively). The crude venom significantly promoted MCF7 cell apoptosis likely via the caspase 8 signaling pathway. The protein fraction from the crude venom showed a weak inhibitory effect in MCF7 cells, whereas the peptide fraction exhibited a much stronger inhibitory effect (IC₅₀ of 6.41±0.31 µg/mL). The peptides in the peptide fraction, with relative molecular mass around 10 000, were homologous to those found in Macrothele gigas venom. The small-molecule fraction consisted mainly of nucleotide metabolites without obvious inhibitory effects in MCF7 cells, but its combination with the peptide fraction showed significantly enhanced inhibitory activity. Conclusion The inhibitory effects of Macrothele raveni venom, which vary significantly across different cancer cell lines, are attributed primarily to its peptide components, which may act synergistically with the nucleotide metabolites.
Humans ; Cell Proliferation/drug effects* ; Apoptosis/drug effects* ; Animals ; Cell Line, Tumor ; MCF-7 Cells ; Caspase 8/metabolism* ; Peptides/pharmacology* ; Caspase 9/metabolism*

This study explored the effect and underlying mechanism of Stellera chamaejasme extract(SCE) on multidrug resistance of breast cancer. The chemotherapy-sensitive breast cancer cell line MCF-7 and adriamycin(ADR)-resistant cell line MCF-7/ADR were used as experimental subjects. MTT assay was used to detect cell proliferation activity. Pi staining was used to detect the cell cycle. 4',6-Diamidino-2-phenylindole, dihydrochloride(DAPI) staining and flow cytometry were used to detect apoptosis. Dansylcadaverine(MDC) staining and GFP-LC3B-Mcherry adenovirus transfection were used to detect autophagy. The protein expression of Bcl-2, Bax, caspase-9, caspase-3, LC3B, p62, and Beclin-1 was detected by Western blot. The results showed that SCE could significantly inhibit the proliferation of both sensitive and resistant breast cancer cell lines. The drug resistance factor was 0.53, which was significantly lower than 59 of ADR. Meanwhile, the proportion of sensitive/resistant cells in the G_0/G_1 phase increased significantly after SCE treatment. In addition, DAPI staining showed that a series of apoptosis phenomena such as nuclear pyknosis, staining deepening, and nuclear fragmentation appeared in sensitive/resistant cell lines after SCE administration. Moreover, the results of flow cytometry double staining showed that the proportion of apoptotic cells in sensitive/resistant cell lines increased significantly after SCE administration. Besides, Western blot showed that the protein expression levels of caspase-3, caspase-9, and Bcl-2 significantly decreased and the expression level of Bax protein significantly increased in both breast cancer cell lines after SCE administration. Furthermore, SCE could also increase the positive fluorescent spots after MDC staining and yellow fluorescent spots after GFP-LC3B-mcherry transfection, and up-regulate the expression levels of autophagy-related proteins LC3B-Ⅱ, p62, and Beclin-1 in breast cancer cells. In summary, SCE may play the role of anti-multidrug resistance by blocking the cell cycle of breast cancer multidrug-resistant cells, blocking autophagy flow, and ultimately interfering with the apoptosis resistance of drug-resistant cells.
Humans ; Female ; Breast Neoplasms/metabolism* ; MCF-7 Cells ; Caspase 3/metabolism* ; Caspase 9/metabolism* ; Beclin-1/pharmacology* ; Apoptosis ; Proto-Oncogene Proteins c-bcl-2/metabolism* ; Cell Line, Tumor ; Drug Resistance, Neoplasm ; Cell Proliferation

Tannic acid (TA) is a water-soluble polyphenol compound found in various herbal plants. We investigated the chemopreventive effects of TA on FaDu hypopharyngeal squamous carcinoma cells. In an 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay, TA showed dose-dependent cytotoxicity with a half maximal inhibitory concentration (IC50) of 50 µM. Cell cycle analysis and immunofluorescence imaging demonstrated that under low-dose (25 µM) treatment, FaDu cells were arrested in G2/M phase, and as the dose of TA was increased, apoptosis was induced with the increase of cell population at sub-G1 phase. The expressions of various cyclins, including cyclin D1 and cyclin-dependent kinases (CDK-1 and CDK-2), were down-regulated at low doses of TA, whereas apoptotic effectors such as cleaved caspase 3, cleaved caspase 7, and poly (ADP-ribose) polymerase (PARP) were expressed in a dose-dependent manner in Western blotting. In addition, TA-induced apoptosis of FaDu cells might be mediated by the extracellular signal-regulated kinase (ERK)/mitogen-activated protein kinase pathway, with the upregulation of p-AKT/p-PKB (phosphorylated protein kinase B) and p-ERK. Overall, our data support the hypothesis that TA is a potential candidate agent for the treatment of hypopharyngeal cancer.
Apoptosis ; Blotting, Western ; Carcinoma, Squamous Cell ; Caspase 3 ; Caspase 7 ; Cell Cycle ; Cyclin D1 ; Cyclin-Dependent Kinases ; Cyclins ; Epithelial Cells ; Fluorescent Antibody Technique ; Hypopharyngeal Neoplasms ; Phosphotransferases ; Protein Kinases ; Tannins ; Up-Regulation

PURPOSE: Although the effect of lysosome-associated protein transmembrane 4 beta (LAPTM4B) on the proliferation, migration, and invasion of breast cancer (BC) cells has already been studied, its specific role in BC progression is still elusive. Here, we evaluated the effect of different levels of LAPTM4B expression on the proliferation, invasion, adhesion, and tumor formation abilities of BC cells in vitro, as well as on breast tumor progression in vivo. METHODS: We investigated the influence of LAPTM4B expression on MCF-7 cell proliferation, invasion, adhesion, and tube formation abilities in vitro through its overexpression or knockdown and on breast tumor progression in vivo. RESULTS: Cell growth curves and colony formation assays showed that LAPTM4B promoted the proliferation of breast tumor cells. Cell cycle analysis results revealed that LAPTM4B promoted the entry of cells from the G1 into the S phase. Transwell invasion and cell extracellular matrix adhesion assays showed that LAPTM4B overexpression increased the invasion and adhesion capabilities of MCF-7 cells. More branches were observed in MCF-7 cells overexpressing LAPTM4B under an electron microscope. In comparison with LAPTM4B overexpression, LAPTM4B knockdown decreased the expression of vascular endothelial growth factor-A and significantly inhibited the vasculogenic tube formation ability of tumors. These results were also verified with western blot analysis. CONCLUSION: LAPTM4B promoted the proliferation of MCF-7 cells through the downregulation of p21 (WAF1/CIP1) and caspase-3, and induced cell invasion, adhesion, and angiogenesis through the upregulation of hypoxia-inducible factor 1 alpha, matrix metalloproteinase 2 (MMP2), and MMP9 expression. This specific role deems LAPTM4B as a potential therapeutic target for BC treatment.
Blotting, Western ; Breast Neoplasms ; Breast ; Caspase 3 ; Cell Cycle ; Disease Progression ; Down-Regulation ; Extracellular Matrix ; Hypoxia-Inducible Factor 1 ; In Vitro Techniques ; Matrix Metalloproteinase 2 ; MCF-7 Cells ; S Phase ; Up-Regulation ; Vascular Endothelial Growth Factor A

Amygdalin, D-mandelonitrile-beta-D-glucoside-6-beta-glucoside, belongs to aromatic cyanogenic glycoside group derived from rosaceous plant seed. Mounting evidence has supported the anti-cancer effects of amygdalin. However, whether amygdalin indeed acts as an anti-tumor agent against breast cancer cells is not clear. The present study aimed to investigate the effect of amygdalin on the proliferation of human breast cancer cells. Here, we show that amygdalin exerted cytotoxic activities on estrogen receptors (ER)-positive MCF7 cells, and MDA-MB-231 and Hs578T triple-negative breast cancer (TNBC) cells. Amygdalin induced apoptosis of Hs578T TNBC cells. Amygdalin downregulated B-cell lymphoma 2 (Bcl-2), upregulated Bcl-2-associated X protein (Bax), activated of caspase-3 and cleaved poly ADP-ribose polymerase (PARP). Amygdalin activated a pro-apoptotic signaling molecule p38 mitogen-activated protein kinases (p38 MAPK) in Hs578T cells. Treatment of amygdalin significantly inhibited the adhesion of Hs578T cells, in which integrin alpha5 may be involved. Taken together, this study demonstrates that amygdalin induces apoptosis and inhibits adhesion of breast cancer cells. The results suggest a potential application of amygdalin as a chemopreventive agent to prevent or alleviate progression of breast cancer, especially TNBC.
Adenosine Diphosphate Ribose ; Amygdalin* ; Apoptosis* ; bcl-2-Associated X Protein ; Breast Neoplasms ; Caspase 3 ; Humans ; Integrin alpha5 ; Lymphoma, B-Cell ; MCF-7 Cells ; p38 Mitogen-Activated Protein Kinases ; Plants ; Receptors, Estrogen ; Triple Negative Breast Neoplasms*

PURPOSE: MicroRNAs (miRNAs) have received much attention owing to their aberrant expression in various stages of cancer. In many biological processes, miRNAs negatively regulate gene expression, and may be useful in therapeutic strategies. The present study evaluated the effects of silibinin (silybin), a natural flavonoid, on miRNA expression and attempted to elucidate therapeutic targets in MCF-7 breast cancer cells. METHODS: The rates of cell proliferation and apoptosis were determined in silibinin-treated and untreated MCF-7 cells. Furthermore, the expression levels of miR-21 and miR-155 were measured in MCF-7 cells after incubation with silibinin (100 µg/mL), and the putative targets of the miRNAs within the apoptotic pathways were predicted using bioinformatic approaches. The expression levels of some of these targets were evaluated by quantitative reverse transcription polymerase chain reaction (qRT-PCR). RESULTS: Silibinin induced apoptosis in MCF-7 cells in a dose- and time-dependent manner. qRT-PCR analysis revealed a decrease in miR-21 and miR-155 expression levels in silibinin-treated cells relative to the levels in the untreated cells. Potential miR-21 and miR-155 targets within the apoptotic pathways, such as CASP-9, BID, APAF-1, CASP-3, CASP-8, and PDCD4, were predicted by in silico analysis. qRT-PCR analysis showed upregulation of some of these potential targets including caspase-9 (CASP-9) and BID after silibinin treatment for 48 hours. CONCLUSION: Our results suggest a correlation between the expression of miR-21 and miR-155, and MCF-7 cell proliferation. The antiproliferative activity of silibinin may partly be attributable to the downregulation of miR-21 and miR-155, and the upregulation of their apoptotic targets. Furthermore, the upregulation of CASP-9 and BID indicates that silibinin induces apoptosis through both the extrinsic and intrinsic pathways.
Apoptosis* ; Biological Processes ; Breast Neoplasms* ; Breast* ; Caspase 9 ; Cell Proliferation ; Computer Simulation ; Down-Regulation* ; Gene Expression ; Humans* ; MCF-7 Cells ; MicroRNAs ; Polymerase Chain Reaction ; Reverse Transcription ; Up-Regulation

PURPOSE: Cell-in-cell structures are created by one living cell entering another homotypic or heterotypic living cell, which usually leads to the death of the internalized cell, specifically through caspase-dependent cell death (emperitosis) or lysosome-dependent cell death (entosis). Although entosis has attracted great attention, its occurrence is controversial, because one cell line used in its study (MCF-7) is deficient in caspase-3. METHODS: We investigated this issue using MCF-7 and A431 cell lines, which often display cell-in-cell invasion, and have different levels of caspase-3 expression. Cell-in-cell death morphology, microstructures, and signaling pathways were compared in the two cell lines. RESULTS: Our results confirmed that MCF-7 cells are caspase-3 deficient with a partial deletion in the CASP-3 gene. These cells underwent cell death that lacked typical apoptotic properties after staurosporine treatment, whereas caspase-3-sufficient A431 cells displayed typical apoptosis. The presence of caspase-3 was related neither to the lysosome-dependent nor to the caspase-dependent cell-in-cell death pathway. However, the existence of caspase-3 was associated with a switch from lysosome-dependent cell-in-cell death to the apoptotic cell-in-cell death pathway during entosis. Moreover, cellular hypoxia, mitochondrial swelling, release of cytochrome C, and autophagy were observed in internalized cells during entosis. CONCLUSION: The occurrence of caspase-independent entosis is not a cell-specific process. In addition, entosis actually represents a cellular self-repair system, functioning through autophagy, to degrade damaged mitochondria resulting from cellular hypoxia in cell-in-cell structures. However, sustained autophagy-associated signal activation, without reduction in cellular hypoxia, eventually leads to lysosome-dependent intracellular cell death.
Apoptosis ; Autophagy ; Caspase 3* ; Cell Death ; Cell Hypoxia ; Cell Line ; Cytochromes c ; Entosis ; MCF-7 Cells* ; Mitochondria ; Mitochondrial Swelling ; Staurosporine

An FDA approved drug for the treatment of type II diabetes, Troglitazone (TRO), a peroxisome proliferator–activated receptor gamma agonist, is withdrawn due to severe idiosyncratic hepatotoxicity. In the search for new applications of TRO, we investigated the cellular effects of TRO on YD15 tongue carcinoma cells. TRO suppressed the growth of YD15 cells in the MTT assay. The inhibition of cell growth was accompanied by the induction of cell cycle arrest at G₀/G₁ and apoptosis, which are confirmed by flow cytometry and western blotting. TRO also suppressed the expression of cell cycle proteins such as cyclin D1, cdk2, cdk4, cyclin B1, cdk1(or cdc2), cyclin E1 and cyclin A. The inhibition of cell cycle proteins was coincident with the up-regulation of p21(CIP1/WAF1) and p27(KIP1). In addition, TRO induces the activation of caspase-3 and caspase-7, as well as the cleavage of PARP. Further, TRO suppressed the expressions of Bcl-2 without affecting the expressions of Bad and Bax. Overall, our data supports that TRO induces cell cycle arrest and apoptosis on YD15 cells.
Apoptosis ; Blotting, Western ; Caspase 3 ; Caspase 7 ; Cell Cycle Checkpoints ; Cell Cycle Proteins ; Cyclin A ; Cyclin B1 ; Cyclin D1 ; Cyclins ; Flow Cytometry ; Peroxisomes ; Tongue* ; Up-Regulation

Plant-derived triterpenoids commonly possesses biological properties such as anti-inflammatory, anti-microbial, anti-viral and anti-cancer. Luvunga scandens is one of the plant that produced triterpenoids. The aims of the study was to analyze cell cycle profile and to determine the expression of p53 unregulated modulator of apoptosis (PUMA), caspase-8 and caspase-9 genes at mRNA level in MCF-7 cell line treated with two triterpenoids, flindissol (1) and 3-oxotirucalla-7,24-dien-21-oic-acid (2) isolated from L. scandens. The compounds were tested for cell cycle analysis using flow cytometer and mRNA expression level using quantitative RT-PCR. The number of MCF-7 cells population which distributed in Sub G1 phase after treated with compound 1 and 2 were 7.7 and 9.3% respectively. The evaluation of the expression of genes showed that both compounds exhibited high level of expression of PUMA, caspase-8 and caspase-9 as normalized to β-actin via activation of those genes. In summary, the isolated compounds of L. scandens plant showed promising anticancer properties in MCF-7 cell lines.
Apoptosis ; Caspase 8 ; Caspase 9 ; Cell Cycle Checkpoints* ; Cell Cycle* ; Flow Cytometry ; G1 Phase ; Gene Expression* ; MCF-7 Cells* ; Plants ; Puma ; RNA, Messenger

6-Gingerol exerts anti-tumor effects in various cancer cell models. We evaluated the effect of 6-gingerol on the growth of MCF-7 breast cancer cells and MCF-10A breast epithelial cells to determine whether any growth-inhibitory effects found were attributable to apoptosis, and to elucidate the underlying mechanism of action. 6-Gingerol inhibited the viability of both cell lines in a dose- and time-dependent manner; however, the degree of inhibition was greater in MCF-7 than MCF-10A cells. By flow cytometry, induction of dose- and time-dependent apoptosis was found, and the magnitude of apoptosis was also markedly greater in MCF-7 than MCF-10A cells. Expression of caspase-3 and poly (ADP-ribose) polymerase (PARP) was observed in MCF-7 cells treated with 6-gingerol, and further cleavage of PARP occurred in these cells. We suggest that 6-gingerol induces apoptosis in human breast cancer cells mainly by promoting caspase-3 expression and subsequent degradation of PARP.
Apoptosis ; Breast Neoplasms* ; Breast* ; Caspase 3 ; Cell Line ; Epithelial Cells ; Flow Cytometry ; Humans* ; MCF-7 Cells