Allyl Isothiocyanate Induces DNA Damage and Impairs DNA Repair in Human Breast Cancer MCF-7 Cells.

BACKGROUND/AIM: Ally lisothiocyanate (AITC), a constituent of naturally occurring isothiocyanates (ITCs) found in some Brassica vegetables, has been previously demonstrated to have anti-carcinogenic activity. However, there is no available information showing that AITC induces DNA damage and alters DNA damage repair proteins in human breast cancer MCF-7 cells. MATERIALS AND METHODS: In the present study, we investigated the effects of AITC on DNA damage and repair responses in human breast cancer MCF-7 cells in vitro. Cell viability was measured by flow cytometric assay. DNA condensation (apoptotic cell death) and DNA fragmentation (laddered DNA) were assayed by DAPI staining and DNA gel electrophoresis assays, respectively. Furthermore, DNA damage (comet tail) was measured by the comet assay. Western blotting was used to measure the expression of DNA damage- and repair-associated proteins. RESULTS: AITC decreased cell viability in a dose-dependent and induced apoptotic cell death (DNA condensation and fragmentation) and DNA damage in MCF-7 cells. AITC increased p-ATMSer1981, p-ATRSer428, p53, p-p53Ser15, p-H2A.XSer139, BRCA1, and PARP at 10-30 µM at 24 and 48 h treatments. However, AITC decreased DNA-PK at 24 and 48 h treatment, and decreased MGMT at 48 h in MCF-7 cells. CONCLUSION: AITC induced cytotoxic effects (decreased viable cell number) through induction of DNA damage and condensation and altered DNA damage and repair associated proteins in MCF-7 cells in vitro.

Effects and mechanism of bakuchiol-induced S-phase cell cycle arrest in human breast cancer MCF-7 cells / 中草药

Objective: To investigate the cell growth inhibitory effect and molecular mechanism of bakuchiol against human breast cancer MCF-7 cells. Methods: The growth inhibitory effect of bakuchiol on MCF-7 cells was tested by MTT assay. Flow cytometry was used to investigate the distribution of cell cycle and ROS generation. Fluorescence microscope was used to observe the change of cell nucleus. Western blotting was used to detect the expression of the protein related to cell cycle and MAPK family. The ROS scavenger and inhibitors of MAPK family were introduced to investigate the effect on the growth inhibitory rate and the levels of cell cycle related protein by bakuchiol. Results: Bakuchiol inhibited the cell growth on the MCF-7 cells in dose- and time-dependent manner, which showed stronger effect than that of 5-fluorouracil. Furthermore, bakuchiol induced S-phase arrest in MCF-7 cells via ROS generation. The production of ROS up-regulated p-p53 and p21 expression, and then decreased CDK2 and CyclinA2. The changes of bakuchiol on these proteins could be reversed by the ROS scavenger Trion, indicating that ROS was associated with bakuchiol-induced S-phase arrest. In addition, pretreatment with p38MAPK inhibitor SB203580 decreased bakuchiol-caused ROS generation, suggesting that the production of ROS was dependent on p38MAPK pathway. Conclusion: The proliferation inhibitory effect of bakuchiol on MCF-7 cells is related with S-phase cell cycle arrest, and ROS plays a role in the bakuchiol-induced S-phase arrest.

Baicalein, as a Prooxidant, Triggers Mitochondrial Apoptosis in MCF-7 Human Breast Cancer Cells Through Mobilization of Intracellular Copper and Reactive Oxygen Species Generation.

BACKGROUND: Baicalein, a natural flavonoid derived from traditional Chinese herb Scutellaria baicalensis Georg (known as Huang Qin in Chinese), has been reported to exhibit notable antitumor activity in various cancer cells, including breast cancer. However, the detailed mechanisms underlying its induced apoptosis as a prooxidant in breast cancer cells are still unknown. MATERIALS AND METHODS: In this study, we investigated the effect of endogenous copper on cytotoxic activity of baicalin against human breast cancer MCF-7 cells in vitro. RESULTS: Baicalein could remarkably reduce the cell viability in both dose- and time-dependent manners in MCF-7 cells but with lower cytotoxic effects on normal breast epithelial cells, MCF-10A. Such cell death could be prevented by pretreatment with Cu (I)-specific chelator neocuproine (Neo) and reactive oxygen species (ROS) scavengers. Meanwhile, baicalein could induce MCF-7 cell morphological changes, promote apoptotic cell death and increase the apoptotic cell number. Moreover, DCHF-DA staining, flow cytometry and Western blotting analyses proved that baicalein triggered the mitochondrial-dependent apoptotic pathway, as indicated by enhancement the level of intracellular ROS, disruption of mitochondrial membrane potential (ΔΨm), downregulation of anti-apoptotic protein Bcl-2, upregulation of pro-apoptotic protein Bax, release of cytochrome C and activation of caspase-9 and caspase-3 in MCF-7 cells. The pretreatment with Neo remarkably weakened these effects of baicalein. Furthermore, we confirmed that the prooxidant action of baicalein involved the direct production of hydroxyl radicals through redox recycling of copper ions. CONCLUSION: These findings suggested that baicalein, acting as a prooxidant, could trigger apoptosis in MCF-7 cells occurs via the ROS-mediated intrinsic mitochondria-dependent pathway.

Exopolysaccharide from Marine Bacillus velezensis MHM3 Induces Apoptosis of Human Breast Cancer MCF-7 Cells through a Mitochondrial Pathway

Objective: The production of new natural pharmaceutical agents that increase the efficiency of chemotherapy without affecting the normal cells is the goal of all researchers. Therefore, the present study expects to evaluate the antioxidant and anticancer studies against MCF-7 cell lines of EPS produced by novel Egyptian marine bacterial strain. Methods: Marine bacterium was isolated, purified and identified by 16S rRNA gene amplification and sequence analyses. MHMEPS (the produced EPS) was analyzed by Fourier Transform Infra-red (FTIR), monosugars identification by HPLC, molecular weight estimation and sulfur content were determined. While, in-vitro antioxidants characters was determined using various methods and anticancer studies against MCF-7 cell lines. Results: Bacillus velezensis MHM3 produced 5.8 g/L of MHMEPS. The chemical analysis of MHMEPS showed 24% uronic acid and 18.19% sulfate and monosugars glucuronic acid, glucose, fructose and rhamnose with molar ratio of 4.00: 2.00: 1.00: 0.13, correspondingly, with an overall weight average molecular weight Mw of 1.145×104 g/mol and the number average of molecular weights Mn of 5.155 ×103 g/mol. The FTIR analysis and periodate oxidation indicate the existence of ß-(1­4) linkage acidic polysaccharide. MHMEPS showed antioxidant scavenging activity against DPPH•, H2O2 and Metal chelating activity, respectively. So, reducing power method give high activity at 500 µg/ml. MHMEPS hinder the proliferation of MCF-7 cells at 5-80 µg/ml compared to the control group. Moreover, induced apoptosis was associated with activation of caspase-3. Also increased cytochrome C levels significantly in a dose-dependent manner compared with the control. The Caspase-3 activity was raised in MHMEPS treated MCF-7 cells compared with the control (p<0.05) in a dose-dependent manner. Therefore, the result of DNA fragmentation was confirmed by DNA ladder assay. We presume that MHMEPS has high potential at its low concentration, as a novel restorative agent for the treatment of MCF-7 cells, with no cytotoxicity against normal cells.

Development of fisetin-loaded folate functionalized pluronic micelles for breast cancer targeting.

The natural flavonoid fisetin (FS) has shown anticancer properties but its in-vivo administration remains challenging due to its poor aqueous solubility. The aim of the study was to develop FS loaded pluronic127 (PF)-folic acid (FA) conjugated micelles (FS-PF-FA) by the way of increasing solubility, bioavailability and active targetability of FS shall increase its therapeutic efficacy. FA-conjugated PF was prepared by carbodiimide crosslinker chemistry. FS-PF-FA micelles were prepared by thin-film hydration method and evaluated in comparison with free FS and FS loaded PF micelles (FS-PF). The smooth surfaces with spherical in shape of FS-PF-PF micelles displayed smaller in size (103.2 ± 6.1 nm), good encapsulation efficiency (82.50 ± 1.78%), zeta potential (-26.7 ± 0.44 mV) and sustained FS release. Bioavailability of FS from FS-PF-PF micelles was increased by 6-fold with long circulation time, slower plasma elimination and no sign of tissue toxicity as compared to free FS. Further, the FS-PF-FA micelles demonstrated active targeting effect on folate overexpressed human breast cancer MCF-7 cells. The concentration of the drug needed for growth inhibition of 50% of cells in a designed time period (GI50) was 14.3 ± 1.2 µg/ml for FS while it was greatly decreased to 9.8 ± 0.78 µg/ml, i.e. a 31.46% decrease for the FS-PF. Furthermore, the GI50 value for FS-PF-FA was 4.9 ± 0.4 µg/ml, i.e. a 65.737% decrease compared to FS and 50% decrease compare to FS-PF. The results indicate that the FS-PF-FA micelles have the potential to be applied for targeting anticancer drug delivery.

Protein regulation and Apoptotic induction in human breast carcinoma cells (MCF-7) through lectin from G. beauts.

Lectins are proteins that show a variety of biological activities. Nevertheless, information on lectin from Gluttonous beauts and their anticancer activities are very limited. In this study, we purified a lectin from hemolymph of G. beauts and identified its molecular weight to be 66kDa. The effect of lectin at different concentrations (µg/mL) on the cell growth and apoptosis were evaluated against MCF-7 and MCF-10A cells, whereas cytotoxicity to the MCF-7 cells mediated by lectin was observed and the mechanism of action of the lectin in including apoptosis in cancer cells via the intrinsic pathway was also proposed. The MCF-7 cells were employed for in vitro studies on cytotoxicity, induction of apoptosis and apoptotic DNA fragmentation. In MCF-10A cells lectin did not show any adverse effect even at higher concentration. Cell cycle analysis also showed a significant cell cycle arrest on selected cells after lectin treatment. Western blotting suggested that lectin up regulates the apoptotic protein expression in MCF-7 cells while it down regulates the level of Bcl-2 expression.

Effects of Active Constituents of Sinopodophylli Fructus on Cell Proliferation,Cell Cycle and Mitochon-drial Membrane Potential of Human Breast Cancer Cell / 中国药房

OBJECTIVE:To explore the effects and mechanism of extracts,active constituents and constituent combination of Sinopodophylli Fructus on cell proliferation of human breast cancer. METHODS:Acid phosphatase method was conducted to deter-mine the effects of 4 extracts [ethanol extract (Xc),petroleum ether extract from ethanol extract (Xp),ethyl acetate extract from ethanol extract (Xe),n-butanol extract from ethanol extract (Xz)],5 active constituents [podophyllotoxin (S1),deoxypodophyllo-toxin (S2),4-desmethyl deoxypodophyllotoxin (S3),8-isopentenyl kaempferol (S4),8,2′-diisoprenyl quercetin-3-methyl ether (S5)] and 3 active constituent combination [combination 1,S1-S2-S3-S4-S5 (2:4:1:4:32),Z1;combination 2,S2-S4 (1:1),Z2;combination 3,S3-S4(1:4),Z3] on the MDA-MB-231,MCF-7 cell proliferation;flow cytometry was adopted to detect the effects of above-mentioned samples on MDA-MB-231,MCF-7(T47D)cell cycle and mitochondrial membrane potential. RESULTS:The active constituent combination Z1 showed significant inhibitory effects on MDA-MB-231,MCF-7 cells,the half inhibitory concen-trations(IC50)were(0.27±0.2),(0.11±0.1)μg/mL;extracts Xc,Xp,Xe,active constituents S2,S4 and active constituent combi-nation Z2,Z3 showed relatively strong inhibitory effects on MDA-MB-231,MCF-7 (T47D) cell proliferation (IC50<15 μg/mL). Both extracts and active constituents can block MDA-MB-231,MCF-7 cell cycle in G2/M phase;all active constituents can block MDA-MB-231,T47D cell cycle in G0/G1 phase,and can reduce MDA-MB-231,T47D cell mitochondrial membrane potential. CONCLUSIONS:The active constituents and constituent combination of Sinopodophylli Fructus can inhibit cell proliferation of breast cancer by affecting cell cycle and mitochondrial mem-brane potential.

Exogenous and Endogeneous Disialosyl Ganglioside GD1b Induces Apoptosis of MCF-7 Human Breast Cancer Cells.

Gangliosides have been known to play a role in the regulation of apoptosis in cancer cells. This study has employed disialyl-ganglioside GD1b to apoptosis in human breast cancer MCF-7 cells using exogenous treatment of the cells with GD1b and endogenous expression of GD1b in MCF-7 cells. First, apoptosis in MCF-7 cells was observed after treatment of GD1b. Treatment of MCF-7 cells with GD1b reduced cell growth rates in a dose and time dependent manner during GD1b treatment, as determined by XTT assay. Among the various gangliosides, GD1b specifically induced apoptosis of the MCF-7 cells. Flow cytometry and immunofluorescence assays showed that GD1b specifically induces apoptosis in the MCF-7 cells with Annexin V binding for apoptotic actions in early stage and propidium iodide (PI) staining the nucleus of the MCF-7 cells. Treatment of MCF-7 cells with GD1b activated apoptotic molecules such as processed forms of caspase-8, -7 and PARP (Poly(ADP-ribose) polymerase), without any change in the expression of mitochondria-mediated apoptosis molecules such as Bax and Bcl-2. Second, to investigate the effect of endogenously produced GD1b on the regulation of cell function, UDP-gal: ß1,3-galactosyltransferase-2 (GD1b synthase, Gal-T2) gene has been transfected into the MCF-7 cells. Using the GD1b synthase-transfectants, apoptosis-related signal proteins linked to phenotype changes were examined. Similar to the exogenous GD1b treatment, the cell growth of the GD1b synthase gene-transfectants was significantly suppressed compared with the vector-transfectant cell lines and transfection activated the apoptotic molecules such as processed forms of caspase-8, -7 and PARP, but not the levels of expression of Bax and Bcl-2. GD1b-induced apoptosis was blocked by caspase inhibitor, Z-VAD. Therefore, taken together, it was concluded that GD1b could play an important role in the regulation of breast cancer apoptosis.

Anti-carcinogenic actions of glycoprotein conjugated with isoflavones from submerged-liquid culture of Agaricus blazei mycelia through reciprocal expression of Bcl-2 and Bax proteins / 동물의과학연구지

Glycoproteins isolated from fruit bodies and mycelial cultures of mushrooms exhibit anti-carcinogenic actions in human cancer cells and animal tumor cells by induction of apoptosis. Here, we report that isoflavone-conjugated glycoproteins (designate Gluvone), exhibit strong anti-carcinogenic effects on human breast cancer MCF-7 cells by induction of apoptosis. Gluvone with 9.4 kDa of molecular weight was isolated from submerged-liquid culture of Agaricus blazei mycelia (ABM) in soy flake-containing liquid medium. MCF-7 cells were incubated with various amounts of Gluvone (0~250 microM) for a period of 6 days. Gluvone exhibited anti-proliferative actions in a dose-dependent manner and 62% growth inhibition at 200 microM for 4 days relative to control. Hoechst 33258 staining analysis revealed that Gluvone induced formation of apoptotic bodies. Gluvone was associated with down-regulation of anti-apoptotic Bcl-2 protein expression as well as up-regulation of pro-apoptotic Bax protein expression. Gluvone treatment induced proteolytic activation of caspase-9 and caspase-3 through cytochrome c release from mitochondria to cytosol as well as concomitant degradation of poly (ADP-ribose) polymerase (PARP). In addition, Gluvone induced activation of caspase-8. Taken all together, these results indicate that the anti-proliferative effect of Gluvone is associated with induction of apoptotic cell death through the mitochondrial dysfunction pathway mediated by enhancement of Bax protein expression and suppression of Bcl-2 protein expression.

Inhibition of vinorelbine on invasion and metastasis of breast cancer cell and its mechanism / 中草药

The MCF-7 and MDA-MB-435 cells were treated with 1 and 10 μmol/L VRB. The cell adhesion was tested by MTS, the invasion was detected by Transwell, secretion of TGF-β was detected using ELISA, the activities of MMP-2 and MMP-9 were detected by zymography, the expression of proteins, including E-cadherin (E-CAD), N-cadherin (N-CAD), MMP-2, and MMP-9, p-JNK and, p-Akt was evaluated by Western blotting, RT-PCR was used to detect E-CAD, N-CAD, MMP-2, and MMP-9 genes, and dual-luciferase reporter assay was used to validate the activities of AP-1 and NF-κB. Results After being treated with 1 and 10 μmol/L VRB, for MCF-7 and MDA-MB-435, the adhesion ability was decreased by 34.8% and 66.8%, 42.6% and 72.3%; The metastatic ability was decreased by 44.4% and 72.2%, 47.7% and 86.4%; The secretion of TGF-β was reduced by 28.2% and 52.1%, 39.0% and 55.1%, significantly; The mRNA expression levels of E-CAD were increased by 86.5% and 181.6%, 116.6% and 160.7%; while the levels of N-CAD were decreased by 33.7% and 74.1%, 57.6% and 76.9%; The gene expression of MMP-2 was decreased by 71.6% and 88.4%, 57.4% and 69.4%; The gene expression of MMP-9 was decreased by 15.0% and 84.0%, 22.1% and 73.0%, respectively. The protein expression of E-CAD was up-regulated while the protein expression of N-CAD, MMP-2, MMP-9, p-JNK, and p-Akt were down-regulated significantly; And dual-luciferase reporter assay validated VRB could inhibit the transcriptional activity of AP-1 and NF-κB by 27.7% and 68.2%, 34.8% and 71.4%, 18.4% and 44.8%, 24.4% and 51.9%, respectively. Conclusion VRB could inhibit the metastasis of breast cancer MCF-7 and MDA-MB-435 cells via down-regulation of inhibition and blocking of signaling pathway correlated with metastasis and epithelial-mesenchymal transition.