• Asian Pacific Journal of Cancer Prevention
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• v.15 no.18
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• pp.7553-7558
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• 2014

The Piwi subfamily comprises two argonaute (Ago) family proteins, which are defined by the presence of PAZ and Piwi domains, with well known roles in RNA silencing. Hiwi, a human Piwi subfamily member, has been shown to play essential roles in stem cell self-renewal and gametogenesis. Recently, accumulating reports have indicated that abnormal hiwi expression is associated with poorer prognosis of multiple types of human cancers, including examples in the breast. However, little is known about details of the oncogenic role of hiwi in breast cancers. In present study, we confirmed overexpression of hiwi in breast cancer specimens and breast cancer cell lines at both mRNA and protein levels. Thus both RT-qPCR and Western blot data revealed significantly higher hiwi in intratumor than peritumor specimens, overexpression being associated with tumor size, lymph node metastasis and histological grade. Hiwi overexpression was also identified in breast cancer cell lines, MDA-MB-231 and MCF-7, and gain-of-function and loss-of-function strategies were adopted to identify the role of hiwi in the MCF-7 cell growth. Results demonstrated that hiwi expression in MCF-7 cells was significantly up- or down-regulated by the two strategies. We next evaluated the influence of hiwi overexpression or knockdown on the growth of breast cancer cells. Both cell count and colony formation assays confirmed promoting roles of hiwi in MCF-7 cells, which could be inhibited by hiwi specific blockage by siRNAs. In summary, the present study confirmed overexpression of hiwi in breast cancer specimens and breast cancer cell lines, and provided e vidence of promotion by hiwi of cell growth. The results imply an oncogenic role of hiwi in breast cancers.

• Asian Pacific Journal of Cancer Prevention
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• v.15 no.1
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• pp.273-276
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• 2014

Ellagic acid has been shown to inhibit tumor cell growth. However, the underlying molecular mechanisms remain elusive. In this study, our aim was to investigate whether ellagic acid inhibits the proliferation of MCF-7 human breast cancer cells via regulation of the TGF-${\beta}$/Smad3 signaling pathway. MCF-7 breast cancer cells were transfected with pEGFP-C3 or pEGFP-C3/Smad3 plasmids, and treated with ellagic acid alone or in combination with SIS3, a specific inhibitor of Smad3 phosphorylation. Cell proliferation was assessed by MTT assay and the cell cycle was detected by flow cytometry. Moreover, gene expression was detected by RT-PCR, real-time PCR and Western blot analysis. The MTT assay showed that SIS3 attenuated the inhibitory activity of ellagic acid on the proliferation of MCF-7 cells. Flow cytometry revealed that ellagic acid induced G0/G1 cell cycle arrest which was mitigated by SIS3. Moreover, SIS3 reversed the effects of ellagic acid on the expression of downstream targets of the TGF-${\beta}$/Smad3 pathway. In conclusion, ellagic acid leads to decreased phosphorylation of RB proteins mainly through modulation of the TGF-${\beta}$/Smad3 pathway, and thereby inhibits the proliferation of MCF-7 breast cancer cells.

• Journal of Food Hygiene and Safety
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• v.25 no.3
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• pp.209-214
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• 2010

Metastasis is the primary cause of from breast cancer mortality. Cell migration and invasion play important roles in neoplastic metastasis. Matrix metalloproteinase-9 (MMP-9), which degrades the extracellular matrix (ECM), plays an important role in cancer cell invasion. NF-${\kappa}B$ is transcription factor important in the regulation of MMP-9, as the promoter of MMP-9 gene contains binding sites for NF-${\kappa}B$. Brazilin, an active component of sappan wood (Caesalpinia sappan), decreases TPA-induced MMP-9 expression and invasion in MCF-7 cells. Also, brazilin suppressed NF-${\kappa}B$ activation in TPA-treated MCF-7 cells. Taken together, we demonstrated that the inhibition of TPA-induced MMP-9 expression and cell invasion by brazilin is mediated by the suppression of the NF-${\kappa}B$ pathway in MCF-7 cells. This result suggest brazilin provide a potential therapeutic app roach for the treatment of breast cancer.

• Archives of Pharmacal Research
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• v.20 no.6
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• pp.572-578
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• 1997

To gain further insight into how antiestrogens modulate cell function, the effects of antiestrogen on cell proliferation were studied in human breast cancer cells. We examined the effects of trans-tamoxifen on the proliferation of three human breast cancer cell lines that differed in their estrogen receptor contents. Trans-tamoxifen $(1{\mu}M)$ markedly inhibited the estrogen stimulated proliferation of MCF-7 human breast cancer cells that contained high levels of estrogen receptor $(1.15{\pm}0.03 pmole/mg protein)$ over that of control. In T47D cells that contained low levels of estrogen receptor $(0.23{\pm}0.05 pmole/mg protein)$, trans-tamoxifen $(1{\mu}M)$ showed minimal inhibition of estrogen stimulated cell proliferation over that of control. MDA-MB-231 cells, that contained no detectable levels of estrogen receptors, had their growth unaffected by trans-tamoxifen treatment. These results showed their sensitivity to growth inhibition by antiestrogen conrrelated well with their estrogen receptor content. Also we examined the effect of antiestrogen on cellular progestrone receptor level as well as plasminogen activator activity in MCF-7 cells. Trans-tamoxifen $(1{\mu}M)$ showed maximal inhibition of estrogen stimulated progestrone receptor level as well as plasminogen activator activity in MCF-7 cells that were stimulated by estrogen. It is not clear whether these inhibitions of progestrone receptor and plasminogen activator activity by estrogen are related to the antiestrogen inhibition of cell proliferation of MCF-7 cells. From the results of this study, it is clearly demonstrated that trans-tamoxifen is an antiestrogen in MCF-7 human breast cancer cells. Our data suggest that the biological effectiveness of trans-tamoxifen appear to result from its affinity of interaction with the estrogen receptor.

• BMB Reports
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• v.51 no.9
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• pp.450-455
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• 2018

Tamoxifen (TAM) is commonly used to treat estrogen receptor (ER)-positive breast cancer. Despite the remarkable benefits, resistance to TAM presents a serious therapeutic challenge. Since several HOX transcription factors have been proposed as strong candidates in the development of resistance to TAM therapy in breast cancer, we generated an in vitro model of acquired TAM resistance using ER-positive MCF7 breast cancer cells (MCF7-TAMR), and analyzed the expression pattern and epigenetic states of HOX genes. HOXB cluster genes were uniquely up-regulated in MCF7-TAMR cells. Survival analysis of in slico data showed the correlation of high expression of HOXB genes with poor response to TAM in ER-positive breast cancer patients treated with TAM. Gain- and loss-of-function experiments showed that the overexpression of multi HOXB genes in MCF7 renders cancer cells more resistant to TAM, whereas the knockdown restores TAM sensitivity. Furthermore, activation of HOXB genes in MCF7-TAMR was associated with histone modifications, particularly the gain of H3K9ac. These findings imply that the activation of HOXB genes mediate the development of TAM resistance, and represent a target for development of new strategies to prevent or reverse TAM resistance.

• Asian Pacific Journal of Cancer Prevention
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• v.16 no.18
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• pp.8445-8450
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• 2016

Background: Breast cancer is the most common neoplasm in women and the most frequent cause of death in those between 35 and 55 years of age. All multicellular organisms have an innate immune system, whereas the adaptive or 'acquired' immune system is restricted to vertebrates. This study focused on the effect of conditioned medium isolated from cultured breast cancer cells on NB4 neutrophil-like cells. Materials and Methods: In the current study neutrophil-like NB4 cells were incubated with MCF-7 cell-conditioned medium. After 6 h incubation the intracellular receptor TLR2, was analyzed. Results: The results revealed that MCF-7 cell-conditioned medium elicited expression of TLR2 in NB4 cells. Conclusions: This treatment would result in the production of particular stimulants (i.e. soluble cytokines), eliciting the expression of immune system receptors. Furthermore, the flow cytometry results demonstrated that MCF-7 cell-conditioned medium elicited an effect on TLR2 intracellular receptors.

• YAKHAK HOEJI
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• v.54 no.3
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• pp.168-173
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• 2010

We investigated whether three flavonoids including daidzein, baicalein, hesperidin and ursolic acid, a triterpene acid, affect proliferation of MCF-7 human breast cancer cells stimulated by estrogenic compounds. Ursolic acid and baicalein inhibited proliferation of MCF-7 cells induced by PhIP, a food-derived carcinogen with estrogenic activity. Daidzein and hesperidin inhibited estradiol-induced proliferation of MCF-7 cells. These compounds should be further investigated for the possible involvement in signaling pathway after estrogen receptor binding in breast cancer cells.

• Korean Journal of Oriental Medicine
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• v.18 no.1
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• pp.75-84
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• 2012

Objective : The purpose of this study was to investigate the anti-cancer effects of Sophorae Radix and the effects of Doxorubicin (DOX) in human breast adenocarcinoma cells (MCF-7). Method : We used human breast adenocarcinoma cell line, MCF-7 cells. We examined cell death by MTT assay and caspase 3 assay with Sophorae Radix. To examine the inhibitory effects of Sophorae Radix, cell cycle analysis was done the MCF-7 cells after three days with Sophorae Radix. The reversibility of Sophorae Radix was examined on one day to five days treatment with 100 ${\mu}g/ml$ Sophorae Radix. Result : Sophorae Radix inhibited the growth of MCF-7 cells in a dose-dependent fashion. Also we showed that Sophorae Radix induced apoptosis in MCF-7 cells by MTT assay, caspase 3 assay and sub-G1 analysis. Sophorae Radix combined with DOX markedly inhibited the growth of MCF-7 cells compared to Sophorae Radix or DOX alone. After 3 days treatment of MCF-7 cells with Sophorae Radix, the fraction of cells in sub-G1 phase was much higher than that of the control group. Conclusion : Our findings provide insight into unraveling the effects of Sophorae Radix in human breast adenocarcinoma cells and developing therapeutic agents against breast cancer.

• Asian Pacific Journal of Cancer Prevention
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• v.15 no.2
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• pp.643-646
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• 2014

Objective: This study aimed to explore the expression of tissue factor (TF), protease activated receptor-2 (PAR-2), and matrix metalloproteinase-9 (MMP-9) in the MCF-7 breast cancer cell line and influence on invasiveness. Methods: Stable MCF-7 cells transfected with TF cDNA and with TF ShRNA were established. TF, PAR-2, and MMP-9 protein expression was analyzed using indirect immunofluorescence and invasiveness was evaluated using a cell invasion test. Effects of an exogenous PAR-2 agonist were also examined. Results: TF protein expression significantly differed between the TF cDNA and TF ShRNA groups. MMP-9 protein expression was significantly correlated with TF protein expression, but PAR-2 protein expression was unaffected. The PAR-2 agonist significantly enhanced MMP-9 expression and slightly increased TF and PAR-2 expression in the TF ShRNA group, but did not significantly affect protein expression in MCF-7 cells transfected with TF cDNA. TF and MMP-9 expression was positively correlated with the invasiveness of tumor cells. Conclusion: TF, PAR-2, and MMP-9 affect invasiveness of MCF-7 cells. TF may increase MMP-9 expression by activating PAR-2.

• Biomolecules & Therapeutics
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• v.26 no.3
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• pp.328-334
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• 2018

Because of the unsatisfactory treatment options for breast cancer (BC), there is a need to develop novel therapeutic approaches for this malignancy. One such strategy is chemotherapy using non-toxic dietary substances and botanical products. Studies have shown that Panduratin A (PA) possesses many health benefits, including anti-inflammatory, anti-bacterial, anti-oxidant and anticancer activities. In the present study, we provide evidence that PA treatment of MCF-7 BC cells resulted in a time- and dose-dependent inhibition of cell growth with an $IC_{50}$ of $15{\mu}M$ and no to little effect on normal human MCF-10A breast cells. To define the mechanism of these anti-proliferative effects of PA, we determined its effect critical molecular events known to regulate the cell cycle and apoptotic machinery. Immunofluorescence and flow cytometric analysis of Annexin V-FITC staining provided evidence for the induction of apoptosis. PA treatment of BC cells resulted in increased activity/expression of mitochondrial cytochrome C, caspases 7, 8 and 9 with a significant increase in the Bax:Bcl-2 ratio, suggesting the involvement of a mitochondrial-dependent apoptotic pathway. Furthermore, cell cycle analysis using flow cytometry showed that PA treatment of cells resulted in G0/G1 arrest in a dose-dependent manner. Immunoblot analysis data revealed that, in MCF-7 cell lines, PA treatment resulted in the dose-dependent (i) induction of $p21^{WAF1/Cip1}$ and p27Kip1, (ii) downregulation of Cyclin dependent kinase (CDK) 4 and (iii) decrease in cyclin D1. These findings suggest that PA may be an effective therapeutic agent against BC.