• Journal of Microbiology and Biotechnology
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• v.21 no.5
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• pp.477-482
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• 2011

There are accumulating evidences suggesting that connexin (Cx), a gap junction channel-forming protein, acts as a growth suppressor in various cancer cells, and this effect is attributeed to the gap junction-mediated intercellular communication (GJIC). In order to characterize the relationship between the growth-arresting activity of Cx26 and its cytoplasmic localizations after expression, we linked a nuclear export signal (NES) sequence to Cx26 cDNA before transfecting into a rat breast cancer cell line. A confocal fluorescent microscopic observation revealed that the insertion of NES minimized the nuclear expression of Cx26, and increased its cytoplasmic expression, including plasma membrane junctions. Total cell counting and BrdUrd-labeling experiments showed that the growth of the breast cancer cells was inhibited by 74% upon transfection of Cx26-NES, whereas only 9% inhibition was observed with only Cx26 cDNA.

• Asian Pacific Journal of Cancer Prevention
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• v.13 no.12
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• pp.6233-6237
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• 2012

Survivin, a new member of the inhibitor of apoptosis protein (IAP) family, both inhibits apoptosis and regulates the cell cycle. It is overexpressed in breast tumor tissues. In this study, we designed two survivin specific DNAzymes (DRz1 and DRz2) targeting survivin mRNA. The results showed that DRz1 could decrease the expression of survivin by nearly 60%. Furthermore, DRz1 significantly inhibited cell proliferation, induced apoptosis and inhibited migration in MCF-7 cells. In addition, down-regulation of survivin expression was associated with increased caspase-3 and -9 activities in MCF-7 cells after 24 h transfection. In our experiments, the efficacy of DRz1 to influence survivin levels and associated effects were better than DRz2. Survivin-DRz1 might have anti-tumorigenic activity and may potentially provide the basis for a novel therapeutic intervention in breast cancer treatment.

• Asian Pacific Journal of Cancer Prevention
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• v.14 no.12
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• pp.7601-7605
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• 2013

Background: Gambogenic acid is a major active compound of gamboge which exudes from the Garcinia hanburyi tree. Gambogenic acid anti-cancer activity in vitro has been reported in several studies, including an A549 nude mouse model. However, the mechanisms of action remain unclear. Methods: We used nude mouse models to detect the effect of gambogenic acid on breast tumors, analyzing expression of apoptosis-related proteins in vivo by Western blotting. Effects on cell proliferation, apoptosis and apoptosis-related proteins in MDA-MB-231 cells were detected by MTT, flow cytometry and Western blotting. Inhibitors of caspase-3,-8,-9 were also used to detect effects on caspase family members. Results: We found that gambogenic acid suppressed breast tumor growth in vivo, in association with increased expression of Fas and cleaved caspase-3,-8,-9 and bax, as well as decrease in the anti-apoptotic protein bcl-2. Gambogenic acid inhibited cell proliferation and induced cell apoptosis in a concentration-dependent manner. Conclusion: Our observations suggested that Gambogenic acid suppressed breast cancer MDA-MB-231 cell growth by mediating apoptosis through death receptor and mitochondrial pathways in vivo and in vitro.

• Asian Pacific Journal of Cancer Prevention
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• v.16 no.14
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• pp.6039-6046
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• 2015

Aims: To investigate effect of metallic nanoparticles, silver (AgNPs) and gold nanoparticles (AuNPs) as antitumor treatment in vitro against human breast cancer cells (MCF-7) and their associated mechanisms. This could provide new class of engineered nanoparticles with desired physicochemical properties and may present newer approaches for therapeutic modalities to breast cancer in women. Materials and Methods: A human breast cancer cell line (MCF-7) was used as a model of cells. Metallic nanoparticles were characterized using UV-visible spectra and transmission electron microscopy (TEM). Cytotoxic effects of metallic nanoparticles on MCF-7 cells were followed by colorimetric SRB cell viability assays, microscopy, and cellular uptake. Nature of cell death was further investigated by DNA analysis and flow cytometry. Results: Treatment of MCF-7 with different concentrations of 5-10nm diameter of AgNPs inhibited cell viability in a dose-dependent manner, with IC50 value of $6.28{\mu}M$, whereas treatment of MCF-7 with different concentrations of 13-15nm diameter of AuNPs inhibited cell viability in a dose-dependent manner, with IC50 value of $14.48{\mu}M$. Treatment of cells with a IC50 concentration of AgNPs generated progressive accumulation of cells in the S phase of the cell cycle and prevented entry into the M phase. The treatment of cells with IC50 concentrations of AuNPs similarly generated progressive accumulation of cells in sub-G1 and S phase, and inhibited the entrance of cells into the M phase of the cell cycle. DNA fragmentation, as demonstrated by electrophoresis, indicated induction of apoptosis. Conclusions: Our engineered silver nanoparticles effectively inhibit the proliferation of human breast carcinoma cell line MCF-7 in vitro at high concentration ($1000{\mu}M$) through apoptotic mechanisms, and may be a beneficial agent against human carcinoma but further detailed study is still needed.

• Asian Pacific Journal of Cancer Prevention
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• v.13 no.7
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• pp.3507-3511
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• 2012

Objective: The aim of this study was to investigate possible mechanisms of LOX gene effects on invasion and metastasis of breast cancer cells by RNA interference. Methods: LOX-RNAi-LV was designed, synthesized, and then transfected into a breast cancer cell line (MDA-MB-231). Expression of LOX, MMP-2 and MMP-9 was determined by real-time PCR, and protein expression of LOX by Western blotting. Cell migration and invasiveness were assessed with Transwell chambers. A total of 111 cases of breast cancer tissues, cancer-adjacent normal breast tissues, and 20 cases of benign lesion tissues were assessed by immunohistochemistry. Results: Expression of LOX mRNA and protein was suppressed, and the expression of MMP-2 and MMP-9 was significantly lower in the RNAi group than the control group (P<0.05), after LOX-RNAi-LV was transfection into MDA-MB-231 cells. Migration and invasion abilities were obviously inhibited. The expression of LOX protein in breast cancer, cancer-adjacent normal breast tissues and benign breast tumor were 48.6% (54/111), 26.1% (29/111), 20.0% (4/20), respectively, associations being noted with clinical stage, lymph node metastasis, tumor size and ER, PR, HER2, but not age. LOX protein was positively correlated with MMP-2 and MMP-9. Conclusion: LOX displayed an important role in invasion and metastasis of breast cancer by regulating MMP-2 and MMP-9 expression which probably exerted synergistic effects on the extracellular matrix (ECM).

• Archives of Pharmacal Research
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• v.27 no.6
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• pp.640-645
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• 2004

Histone deacetylase inhibitors are new class of chemotherapeutic drugs able to induce tumor cell apoptosis and／or cell cycle arrest. Trichostatin A, an antifungal antibiotic, and HC-toxin are potent and specific inhibitors of histone deacetylase activity. In this study, we have examined the antiproliferative activities of trichostatin A and HC-toxin in estrogen receptor positive human breast cancer, T47D cells. Both trichostatin A and HC-toxin showed potent antiprolifer-ative efficacy and cell cycle arrest at $G_2/M$ in T47D human breast cancer cells in a dose-dependent manner. Trichostatin A caused potent apoptosis of T47D human breast cancer cells and trichostatin A-induced apoptosis might be involved in an increase of caspase-3／7 activity. HC-toxin evoked apoptosis of T47D cells and HC-toxin induced apoptosis might not be medi-ated through direct increase in caspase-3/7 activity. We have identified potent activities of anti-proliferation, apoptosis, and cell cycle arrest of trichostatin A and HC-toxin in estrogen receptor positive human breast cancer cell line T47D.

• 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.

• Asian Pacific Journal of Cancer Prevention
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• v.16 no.6
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• pp.2351-2354
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• 2015

In this study, the antiproliferative effects of the metformin was evaluated on MCF-7 Cells (human breast adenocarcinoma cell line). For this purpose cell kinetic parameters including cell proliferation assay, mitotic index and labelling index analysis were used. $30{\mu}M$, $65{\mu}M$ and $130{\mu}M$ Metformin doses were applied to cells for 24, 48 and 72 hours. The results showed that there was a significant decrease in cell proliferation, mitotic index and labelling index for all experimental groups (p<0.05) for all applications.

• Asian Pacific Journal of Cancer Prevention
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• v.14 no.4
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• pp.2599-2605
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• 2013

The study aimed to evaluate immune-stimulating effects of a well-known Thai folkloric remedy when used for adjuvant therapy with conventional chemotherapeutics for treatment of breast cancer. Immunostimulating influence of the remedy (215 mg/kg body weight per day) on NK cell activity and TNF-${\alpha}$ release from the monocytes/macrophages were investigated in a total of 15 healthy women and 13 female patients with breast cancer (Group 1). The effect of breast tumor surgery on NK cell activity was further investigated in 18 female patients with breast cancer (Group 2). NK cell cytotoxic activity was determined by chromium release cytotoxic assay using K562, an erythroleukemic cell line. TNF-${\alpha}$ release from monocytes/macrophages separated from blood samples was determined through a biological assay using actinomycin D-treated L929 mouse fibroblast cells in the presence and absence of LPS. Baseline NK cell activity of the monocytes/macrophages separated from Group 2 patients expressed as %cytotoxicity was significantly lower than in the healthy subjects at E:T ratios of 100:1 and 25:1. In healthy subjects, there was no change in NK cell cytotoxic activity (%cytotoxicity or LU) following 1 and 2 weeks of treatment with the remedy compared with the baseline at various E:T ratios but the binding activity (%binding) was significantly increased after 2 weeks of treatment. The addition of one or two conventional chemotherapeutic regimens did not significantly reduce the NK cytotoxic activity but did affect release of TNF-${\alpha}$ in both unstimulated and LPS-stimulated samples. Surgery produced a significant suppressive effect on NK cell activity. The use of the remedy as an adjunct therapy may improve therapeutic efficacy and safety profiles of conventional chemotherapeutic regimens through stimulation of the immune system in cancer patients.

• Asian Pacific Journal of Cancer Prevention
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• v.15 no.10
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• pp.4311-4317
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• 2014

Background: Nano-biotechnology is recognized as offering revolutionary changes in the field of cancer therapy and biologically synthesized gold nanoparticles are known to have a wide range of medical applications. Materials and Methods: Gold nanoparticles (GNPs) were biosynthesized with an aqueous extract of the red alga Corallina officinalis, used as a reducing and stabilizing agent. GNPs were characterized using UV-Vis spectroscopy, transmission electron microscopy (TEM), energy dispersive analysis (EDX) and Fourier transform infra-red (FT-IR) spectroscopy and tested for cytotoxic activity against human breast cancer (MCF-7) cells cultured in Dulbecco's modified Eagle medium supplemented with 10% fetal bovine serum, considering their cytotoxicty and effects on cellular DNA. Results: The biosynthesized GNPs were $14.6{\pm}1nm$ in diameter. FT-IR analysis showed that the hydroxyl functional group from polyphenols and carbonyl group from proteins could assist in formation and stabilization. The GNPs showed potent cytotoxic activity against MCF-7 cells, causing necrosis at high concentrations while lower concentrations were without effect as indicated by DNA fragmentation assay. Conclusions: The antitumor activity of the biosynthesized GNPs from the red alga Corallina officinalis against human breast cancer cells may be due to the cytotoxic effects of the gold nanoparticles and the polyphenolcontent of the algal extract.