• 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.

• Molecules and Cells
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• v.37 no.10
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• pp.759-765
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• 2014

N-myc downstream-regulated gene 2 (NDRG2), which is known to have tumor suppressor functions, is frequently down-regulated in breast cancers and potentially involved in preventing the migration and invasion of malignant tumor cells. In the present study, we examined the inhibitory effects of NDRG2 overexpression, specifically focusing on the role of cyclooxygenase-2 (COX-2) in the migration of breast cancer cells. NDRG2 overexpression in MDA-MB-231 cells inhibited the expression of the COX-2 mRNA and protein, the transcriptional activity of COX-2, and prostaglandin $E_2$ ($PGE_2$) production, which were induced by a treatment with phorbol-12-myristate-13-acetate (PMA). Nuclear transcription factor-${\kappa}B$ (NF-${\kappa}B$) signaling attenuated by NDRG2 expression resulted in a decrease in PMA-induced COX-2 expression. Interestingly, the inhibition of COX-2 strongly suppressed PMA-stimulated migration and invasion in MDA-MB-231-NDRG2 cells. Moreover, siRNA-mediated knockdown of NDRG2 in MCF7 cells increased the COX-2 mRNA and protein expression levels and the PMA-induced COX-2 expression levels. Consistent with these results, the migration and invasion of MCF7 cells treated with NDRG2 siRNA were significantly enhanced following treatment with PMA. Taken together, our data show that the inhibition of NF-${\kappa}B$ signaling by NDRG2 expression is able to suppress cell migration and invasion through the down-regulation of COX-2 expression.

• BMB Reports
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• v.52 no.12
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• pp.706-711
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• 2019

Cisplatin (Cis-DDP) is one of the most widely used anti-cancer drugs. It is applicable to many types of cancer, including lung, bladder, and breast cancer. However, its use is now limited because of drug resistance. p90 ribosomal S6 kinase (p90RSK) is one of the downstream effectors in the extracellular signal-regulated protein kinases 1 and 2 (ERK1/2) pathway and high expression of p90RSK is observed in human breast cancer tissues. Therefore, we investigated the role of p90RSK in the Cis-DDP resistance-related signaling pathway and epithelial-mesenchymal transition (EMT) in breast cancer cells. First, we discovered that MDA-MB-231 cells exhibited more Cis-DDP resistance than other breast cancer cells, including MCF-7 and BT549 cells. Cis-DDP increased p90RSK activation, whereas the inactivation of p90RSK using a small interfering RNA (siRNA) or dominant-negative kinase mutant plasmid overexpression significantly reduced Cis-DDP-induced cell proliferation and migration via the inhibition of matrix metallopeptidase (MMP)2 and MMP9 in MDA-MB-231 cells. In addition, p90RSK activation was involved in EMT via the upregulation of mRNA expression, including that of Snail, Twist, ZEB1, N-cadherin, and vimentin. We also investigated NF-κB, the upstream regulator of EMT markers, and discovered that Cis-DDP treatment led to NF-κB translocation in the nucleus as well as its promoter activity. Our results suggest that targeting p90RSK would be a good strategy to increase Cis-DDP sensitivity in triple-negative breast cancers.

• Korean Journal of Plant Resources
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• v.21 no.1
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• pp.96-102
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• 2008

Nelumbo nucifera Gaertn.(family Nymphaeaceae) has been used for summer heat syndrome as home remedy in Japan, China and Korea. Although whole plant parts are edible, root is commonly consumed. It has been reported that rhizome extract showed anti-diabetic and anti-inflammatory effects. However, in spite of usefulness for treatment of various diseases, the effect of Nelumbo nucifera rhizome(NNR) on proliferation, migration and matrix degrading enzymes-matrix metalloproteinsases(MMPs), the expression of which degrades extracellular matrix(ECM) leading to metastasis, has not been fully elucidated. We examined the effect of hot water extract of NNR on the proliferation, migration and secretion of MMP-2 and MMP-9 in rat smooth muscle cells(rSMC), epidermoid cancer cells(A431) and breast cancer cells(MDA-MB-231). The proliferation assay was carried out using MTT assay, the principle of which depends upon the conversion of MTT by mitochondrial dehydrogensases of viable cells to formazan crystals. The effect of NNR on migration of cells was examined using wound healing assay. Our results showed that there was inhibition in the proliferation, migration and expression of MMP-2 and MMP-9 in dose dependent fashion in all the cells used. Thus, we concluded that NNR could be used as traditional medicine in the treatment of various diseases where proliferation, migration and MMPs' expression plays a pathological role like in restenosis and metastasis.

• Asian Pacific Journal of Cancer Prevention
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• v.15 no.20
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• pp.8829-8836
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• 2014

Background: Cyclooxygenase-2 (COX-2), considered to have tumor-promoting potential, is highly expressed in a variety of tumors, including breast cancer. Since the functions and action mechanisms of COX-2 in breast cancer have not been fully elucidated, in the present study, the effects of target inhibiting COX-2 with recombinant adenovirus Ad-COX-2-shRNA on malignant biological behavior were investigated in representative cell lines. Materials and Methods: Breast cancer MDA-MB-231 and MCF-7 cells were transfected with Ad-COX-2-shRNA and COX-2 expression was tested by RT-PCR and Western blotting. Changes in proliferation, apoptosis and invasion of breast cancer cells were detected with various assays including MTT, colony forming, flowcytometry and Transwell invasion tests. The expression of related proteins involved in the cell cycle, apoptosis, invasion and signaling pathways was assessed by Western blotting. Results: COX-2 expression was significantly reduced in both breast cancer cell lines infected with Ad-COX-2-shRNA, with obvious inhibition of proliferation, colony forming rate, G2/M phase passage and invasion, as well as induction of apoptosis, in MDA-MB-231 and MCF-7 cells, respectively. At the same time, proteins related to the cell cycle, anti-apoptosis and invasion were significantly downregulated. In addition, c-myc expression and phosphorylation activation of Wnt/${\beta}$-catenin and p38MAPK pathways were reduced by the Ad-COX-2-shRNA. Conclusions: COX-2 expression is associated with proliferation, apoptosis and invasion of breast cancer cells, and its mechanisms of action involve regulating expression of c-myc through the p38MAPK and Wnt/${\beta}$-catenin pathways.

• Asian Pacific Journal of Cancer Prevention
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• v.17 no.4
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• pp.1967-1971
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• 2016

Background: In tumor cells, aberrant differentiation programs have been described. Several neuronal proteins have been found associated with morphological neuronal-glial changes in breast cancer (BCa). These neuronal proteins have been related to mechanisms that are involved in carcinogenesis; however, this regulation is not well understood. Microtubule-associated protein-tau (MAP-Tau) has been describing in BCa but not its variants. This finding could partly explain the neuronal-glial morphology of BCa cells. Our aim was to determine mRNA expression of MAP-tau variants 2, 4 and 6 in breast cancer cell lines. Materials and Methods: Cultured cell lines MCF-10A, MDA-MB-231, SKBR3 and T47D were observed under phase-contrast microscopy for neural morphology and analyzed for gene expression of MAP-Tau transcript variants 2, 4 and 6 by real-time PCR. Results: Regarding morphology like neural/glial cells, T47D line shown more cells with these features than MDA-MB-231 and SKBR. In another hand, we found much greater mRNA expression of MAP-Tau transcript variants 2, and to a lesser extent 4 and 6, in T47D cells than the other lines. In conclusion, regulation of MAP-Tau could bring about changes in cytoskeleton, cell morphology and motility; these findings cast further light on neuronal transdifferentiation in BCa.

• 한국약용작물학회:학술대회논문집
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• 2010.10a
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• pp.495-496
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• 2010

• Asian Pacific Journal of Cancer Prevention
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• v.13 no.11
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• pp.5865-5869
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• 2012

RHOXF1 has been shown to be expressed in embryonic stem cells, adult germline stem cells and some cancer lines. It has been proposed as a candidate gene to encode transcription factors regulating downstream genes in the human testis with antiapoptotic effects. Its expression in cancer cell lines has implied a similar role in the process of tumorigenesis. The human breast cancer cell lines MDA-MB-231 and MCF-7 were cultured in DMEM medium and transfected with a pGFP-V-RS plasmid bearing an RHOXF1 specific shRNA. Quantitative real-time RT-PCR was performed for RHOXF1, CASP8, BCL2 and HPRT genes. Decreased RHOXF1 expression was confirmed in cells after transfection. shRNA knock down of RHOXF1 resulted in significantly decreased BCL2 expression in both cell lines but no change in CASP8 expression. shRNA targeting RHOXF1 was shown to specifically mediate RHOXF1 gene silencing, so RHOXF1 can mediate transcriptional activation of the BCL2 in cancers and may render tumor cells resistant to apoptotic cell death induced by anticancer therapy. shRNA mediated knock down of RHOXF1 can be effective in induction of apoptotic pathway in cancer cells via BCL2 downregulation, so it can have potential therapeutic utility for human breast cancer.

• Asian Pacific Journal of Cancer Prevention
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• v.13 no.6
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• pp.2813-2818
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• 2012

Background: Considerable evidence suggests that metadherin (MTDH) is a potentially crucial mediator of tumor malignancy and an important therapeutic target for simultaneously enhancing chemotherapy efficacy and reducing metastasis risk. Inhibition of MTDH expression by RNA interference has been shown in several previous research, but silencing MTDH expression by microRNA (miRNA) interference in breast cancer has not been established. In the present study, we investigated the role of MTDH-miRNA in down-regulation of proliferation, motility and migration of breast carcinoma cells. Methods: Expression vectors of recombinant plasmids expressing artificial MTDH miRNA were constructed and transfected to knockdown MTDH expression in MDA-MB-231 breast cancer cells. Expression of MTDH mRNA and protein was detected by RT-PCR and Western blot, respectively. MTT assays were conducted to determine proliferation, and wound healing assays and transwell migration experiments for cell motility and migration. Results: Transfection of recombinant a plasmid of pcDNA-MTDH-miR-4 significantly suppressed the MTDH mRNA and protein levels more than 69% in MDA-MB-231 breast cancer cells. This knockdown significantly inhibited proliferation, motility and migration as compared with controls. Conclusions: MTDH-miRNA may play an important role in down-regulating proliferation, motility and migration in breast cancer cells, and should be considered as a potential small molecule inhibitor therapeutic targeting strategy for the future.

• Biomolecules & Therapeutics
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• v.25 no.4
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• pp.404-410
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• 2017

Benzylideneacetophenone derivative (1E)-1-(4-hydroxy-3-methoxyphenyl) hept-1-en-3-one (JC3) elicited cytotoxic effects on MDA-MB 231 human breast cancer cells-radiation resistant cells (MDA-MB 231-RR), in a dose-dependent manner, with an $IC_{50}$ value of $6{\mu}M$ JC3. JC3-mediated apoptosis was confirmed by increase in sub-G1 cell population. JC3 disrupted the mitochondrial membrane potential, and reduced expression of anti-apoptotic B cell lymphoma-2 protein, whereas it increased expression of pro-apoptotic Bcl-2-associated X protein, leading to the cleavage of caspase-9, caspase-3 and poly (ADP-ribose) polymerase. In addition, JC3 activated mitogen-activated protein kinases, and specific inhibitors of these kinases abrogated the JC3-induced increase in apoptotic bodies. JC3 increased the level of intracellular reactive oxygen species and enhanced oxidative macromolecular damage via lipid peroxidation, protein carbonylation, and DNA strand breakage. Considering these findings, JC3 is an effective therapy against radiation-resistant human breast cancer cells.