• Asian Pacific Journal of Cancer Prevention
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• 제16권8호
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• pp.3213-3222
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• 2015

Background: Cancer metastasis depends on cell motility which is driven by cycles of actin polymerization and depolymerization. Reactive oxygen species (ROS) and metabolic oxidative stress have long been associated with cancer. ROS play a vital role in regulating actin dynamics that are sensitive to oxidative modification. The current work aimed at studying the effects of sub-lethal metabolic oxidative stress on actin cytoskeleton, focal adhesion and cell migration. Materials and Methods: T47D human breast cancer cells were treated with 2-deoxy-D-glucose (2DG), L-buthionine sulfoximine (BSO), or doxorubicin (DOX), individually or in combination, and changes in intracellular total glutathione and malondialdehyde (MDA) levels were measured. The expression of three major antioxidant enzymes was studied by immunoblotting, and cells were stained with fluorescent-phalloidin to evaluate changes in F-actin organization. In addition, cell adhesion and degradation ability were measured. Cell migration was studied using wound healing and transwell migration assays. Results: Our results show that treating T47D human breast cancer cells with drug combinations (2DG/BSO, 2DG/DOX, or BSO/DOX) decreased intracellular total glutathione and increased oxidized glutathione, lipid peroxidation, and cytotoxicity. In addition, the drug combinations caused a reduction in cell area and mitotic index, prophase arrest and a decreased ability to form invadopodia. The formation of F-actin aggregates was increased in treated T47D cells. Moreover, combination therapy reduced cell adhesion and the rate of cell migration. Conclusions: Our results suggest that exposure of T47D breast cancer cells to combination therapy reduces cell migration via effects on metabolic oxidative stress.

• Asian Pacific Journal of Cancer Prevention
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• 제15권16호
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• pp.6627-6632
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• 2014

Purpose: The present study concerns molecular mechanisms involved in induction of apoptosis by a fungal taxol extracted from the fungus Cladosporium oxysporum in T47D human breast cancer cells. Materials and Methods: Apoptosis-induced by the fungal taxol was assessed by MTT assay, nuclear staining, DNA fragmentation, flow cytometry and pro- as well as anti-apoptotic protein expression by Western blotting. Results: Our results showed inhibition of T47D cell proliferation with an $IC_{50}$ value of $2.5{\mu}M/ml$ after 24 h incubation. It was suggested that the extract may exert its anti-proliferative effect on human breast cancer cell line by suppressing growth, arresting through the cell cycle, increase in DNA fragmentation as well as down-regulation of the expression of NF-${\kappa}B$, Bcl-2 and Bcl-XL and up-regulation of pro-apoptotic proteins like Bax, cyt-C and caspase-3. Conclusions: We propose that the fungal taxol contributes to growth inhibition in the human breast cancer cell through apoptosis induction via a mitochondrial mediated pathway, with possible potential as an anticancer therapeutic agent.

• Asian Pacific Journal of Cancer Prevention
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• 제17권5호
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• pp.2683-2688
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• 2016

A salt compound of a curcumin analogue, potassium pentagamavunon-0 (K PGV-0) has been synthesized to improve solubility of pentagamavunon-0 which has been proven to have anti-proliferative effects on several cancer cells. The purpose of this study was to investigate cytotoxic activity and metastasis inhibition by K PGV-0 alone and in combination with achemotherapeutic agent, doxorubicin (dox), in breast cancer cells. Based on MTT assay analysis, K PGV-0 showed cytotoxic activity in T47D and 4T1 cell lines with $IC_{50}$ values of $94.9{\mu}M$ and $49.0{\pm}0.2{\mu}M$, respectively. In general, K PGV-0+dox demonstrated synergistic effects and decreased cell viability up to 84.7% in T47D cells and 62.6% in 4T1 cells. Cell cycle modulation and apoptosis induction were examined by flow cytometry. K PGV-0 and K PGV-0+dox caused cell accumulation in G2/M phase and apoptosis induction. Regarding cancer metastasis, while K PGV-0 alone did not show any inhibition of 4T1 cell migration, K PGV-0+dox exerted inhibition. K PGV-0 and its combination with dox inhibited the activity of MMP-9 which has a pivotal role in extracellular matrix degradation. These results show that a combination of K PGV-0 and doxorubicin inhibits cancer cell growth through cell cycling, apoptosis induction, and inhibition of cell migration and MMP-9 activity. Therefore, K PGV-0 may have potential for development as a co-chemotherapeutic agent.

• Biomolecules & Therapeutics
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• 제26권3호
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• pp.322-327
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• 2018

A type of breast cancer with a defect in three molecular markers such as the estrogen receptor, progesterone receptor, and human epidermal growth factor receptor is called triple-negative breast cancer (TNBC). Many patients with TNBC have a lower survival rate than patients with other types due to a poor prognosis. In this study, we confirmed the anti-cancer effect of a natural compound, Gomisin G, in TNBC cancer cells. Treatment with Gomisin G suppressed the viability of two TNBC cell lines, MDA-MB-231 and MDA-MB-468 but not non-TNBC cell lines such as MCF-7, T47D, and ZR75-1. To investigate the molecular mechanism of this activity, we examined the signal transduction pathways after treatment with Gomisin G in MDA-MB-231 cells. Gomisin G did not induce apoptosis but drastically inhibited AKT phosphorylation and reduced the amount of retinoblastoma tumor suppressor protein (Rb) and phosphorylated Rb. Gomisin G induced in a proteasome-dependent manner a decrease in Cyclin D1. Consequently, Gomisin G causes cell cycle arrest in the G1 phase. In contrast, there was no significant change in T47D cells except for a mild decrease in AKT phosphorylation. These results show that Gomisin G has an anti-cancer activity by suppressing proliferation rather than inducing apoptosis in TNBC cells. Our study suggests that Gomisin G could be used as a therapeutic agent in the treatment of TNBC patients.

• Archives of Pharmacal Research
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• 제20권6호
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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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• 제37권8호
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• pp.605-612
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• 2014

The p73 gene contains an extrinsic P1 promoter and an intrinsic P2 promoter, controlling the transcription of the pro-apoptotic TAp73 isoform and the anti-apoptotic ${\Delta}Np73$ isoform, respectively. The DNA methylation status of both promoters act equally in the epigenetic transcriptional regulation of their relevant isoforms. The aim of this study was to analyze the different effects of these p73 isoforms in 5-aza-2'-deoxycytidine (5-aza-dC)-induced apoptosis in breast cancer cells. We investigated the effects of the DNA demethylation agent, 5-aza-dC, on the T-47D breast cancer cell line, and evaluated the methylation status of the p73 promoters and expression of TAp73 and ${\Delta}Np73$. Furthermore, we assessed the expression of p53 and p73 isoforms in 5-aza-dC-treated T-47D cells and p53 knockout cells. 5-aza-dC induced significant anti-tumor effects in T-47D cells, including inhibition of cell viability, G1 phase arrest and apoptosis. This was associated with p73 promoter demethylation and a concomitant increase in TAp73 mRNA and protein expression. In contrast, the methylation status of promoter P2 was not associated with ${\Delta}Np73$ mRNA or protein levels. Furthermore, demethylation of P2 failed to inhibit the expression of ${\Delta}Np73$ with 5-aza-dC in the p53 knockdown cell model. Our study suggests that demethylation of the P1 and P2 promoters has opposite effects on the expression of p73 isoforms, namely up-regulation of TAp73 and down-regulation of ${\Delta}Np73$. We also demonstrate that p53 likely contributes to 5-aza-dC-induced ${\Delta}Np73$ transcriptional inactivation in breast cancer cells.

• 한국환경성돌연변이발암원학회:학술대회논문집
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• 한국환경성돌연변이발암원학회 2004년도 춘계학술대회
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• pp.138-138
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• 2004

• 생명과학회지
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• 제17권4호
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• pp.522-528
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• 2007

본 연구에서 사용한 coffee에 다량 함유된 caffeic acid와 chlorogenic acid, 녹차에 함유된 EGCG 성분은 암세포의 증식을 억제하는데 중요한 기능을 담당하는 세포주기 조절인자인 p16 유전자의 DNA methylation 패턴을 유방암 T-47D 세포에서 유의하게 변화시켰다. MSP를 이용하여 p16 유전자의 promoter 지역에서의 methylation상태의 변화를 살펴본 결과 caffeic acid, chlorogenic acid, EGCG는 유전자의 hypermethylation을 감소시켰으며, 이로 인해 demethylation된 p16 유전자가 증가하는 경향을 보였다. 이러한 연구 결과는 coffee 폴리페놀인 caffeic acid, chlorogenic acid와 녹차 폴리페놀인 EGCG는 세포내의 DNA methylation을 억제하는 기능을 가지는데, 이는 coffee폴리페놀과 같이 COMT 효소에 의한 methylation 부산물인 SAH의 증가에 의한 DNMT의 억제이거나, EGCG와 같이 DNMT와 직접적으로 결합하여 methylation 반응을 억제하는 mechanism에 의한 것으로 사료된다. 따라서 앞으로 이미 개발된 항암제뿐만 아니라, 부작용과 독성이 적은 식이성분에 대한 연구가 좀 더 심도 있게 이루어 져야 할 것이며, 이러한 연구들은 암이 발생되고 난 후 치료 요법으로 사용됨은 물론, 암이 발생하기 전에 사전 예방법으로도 널리 적용하는데 있어 중요한 이론적 토대를 마련할 것으로 사료된다.

• 한국환경독성학회:학술대회논문집
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• 한국환경독성학회 2003년도 추계국제학술대회
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• pp.181-181
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• 2003

We have studied the mechanism of action of TCDD on CYP1A1 promoter activity in both Hepa Ⅰ and MCF-7 cells using transient transfection system with p1A1-Luc reporter gene. When HDAC inhibitors, such as trichostatin A, HC toxin and a novel HDAC inhibitor, IN2001 were cotreated with TCDD to the cells transfected with plAt-Luc reporter gene, the basal promoter activity of CYP1A1 was increased by HBAC inhibitors. Also, in MCF-7 human breast cancer cells, HDAC inhibitors, such as IN2001 and trichostatin A increased the basal activity of CYP1A1 promoter but TCDD stimulated CYP1A1 promoter activity was not changed by HDAC inhibitors. And, in stably-transfected Hepa Ⅰ cells with p1A1-Luc, HDAC inhibitors increased the basal promoter activity only Also, we have investigated the effects of HDAC inhibitors on the human breast and prostate cancer cells in terms of cell proliferation and apoptosis based on SRB assay. IN2001 as well as trichostatin A inhibited the MCF-7, MDA-MB-231, MDA-MB-468, T47D, ZR75-1, PC3 cell growth dose-dependently. The growth inhibition of these cells with HDAC inhibitors was associated with profound morphological change, which suggests the HDAC inhibitors induced apoptosis of cells. The result of cell cycle analysis after 24h exposure of IN2001 showed G2/M cell cycle arrest in MCF-7 cells and apoptosis in T47D and MDA-MB-231 cells.

• Asian Pacific Journal of Cancer Prevention
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• 제16권3호
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• pp.1241-1245
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• 2015

Background: Thyroid carcinoma is the most common malignancy of the endocrine organs. Although the majority of thyroid cancer patients experience positive outcomes, anaplastic thyroid carcinoma is considered one of the most aggressive malignancies. Current therapeutic regimens do not confer a significant survival benefit, and new therapies are urgently needed. Oncolytic herpes simplex virus (oHSV) may represent a promising therapy for cancer. In the present study, we investigated the therapeutic effects of a third-generation HSV vector, $G47{\Delta}$, on various human thyroid carcinoma cell lines in vitro. Two subcutaneous (s.c.) models of anaplastic thyroid carcinoma were also established to evaluate the in vivo anti-tumor efficacy of $G47{\Delta}$. Materials and Methods: The human thyroid carcinoma cell line ARO, FRO, WRO, and KAT-5, were infected with $G47{\Delta}$ at different multiplicities of infection (MOIs) in vitro. The survival rates of infected cells were calculated each day. Two s.c. tumor models were established using ARO and FRO cells in Balb/c nude mice, which were intratumorally (i.t.) treated with either $G47{\Delta}$ or mock. Tumor volumes and mouse survival times were documented. Results: $G47{\Delta}$ was highly cytotoxic to different types of thyroid carcinomas. For ARO, FRO, and KAT-5, greater than 30% and 80% of cells were killed at MOI=0.01 and MOI=0.1, respectively on day 5. WRO cells displayed modest sensitivity to $G47{\Delta}$, with only 21% and 38% of cells killed. In the s.c. tumor model, both of the anaplastic thyroid carcinoma cell lines (ARO and FRO) were highly sensitive to $G47{\Delta}$; $G47{\Delta}$ significantly inhibited tumor growth and prolonged the survival of mice bearing s.c. ARO and FRO tumors. Conclusions: The oHSV $G47{\Delta}$ can effectively kill different types of human thyroid carcinomas in vitro. $G47{\Delta}$ significantly inhibited growth of anaplastic thyroid carcinoma in vivo and prolonged animal survival. Therefore, $G47{\Delta}$ may hold great promise for thyroid cancer patients.