• Molecules and Cells
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• 제39권3호
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• pp.266-279
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• 2016

The mechanism by which 12-O-tetradecanoylphorbol-13-acetate (TPA) bypasses cellular senescence was investigated using human diploid fibroblast (HDF) cell replicative senescence as a model. Upon TPA treatment, protein kinase C (PKC) ${\alpha}$ and $PKC{\beta}1$ exerted differential effects on the nuclear translocation of cytoplasmic pErk1/2, a protein which maintains senescence. $PKC{\alpha}$ accompanied pErk1/2 to the nucleus after freeing it from $PEA-15pS^{104}$ via $PKC{\beta}1$ and then was rapidly ubiquitinated and degraded within the nucleus. Mitogen-activated protein kinase docking motif and kinase activity of $PKC{\alpha}$ were both required for pErk1/2 transport to the nucleus. Repetitive exposure of mouse skin to TPA downregulated $PKC{\alpha}$ expression and increased epidermal and hair follicle cell proliferation. Thus, $PKC{\alpha}$ downregulation is accompanied by in vivo cell proliferation, as evidenced in 7, 12-dimethylbenz(a)anthracene (DMBA)-TPA-mediated carcinogenesis. The ability of TPA to reverse senescence was further demonstrated in old HDF cells using RNA-sequencing analyses in which TPA-induced nuclear $PKC{\alpha}$ degradation freed nuclear pErk1/2 to induce cell proliferation and facilitated the recovery of mitochondrial energy metabolism. Our data indicate that TPA-induced senescence reversal and carcinogenesis promotion share the same molecular pathway. Loss of $PKC{\alpha}$ expression following TPA treatment reduces pErk1/2-activated SP1 biding to the $p21^{WAF1}$ gene promoter, thus preventing senescence onset and overcoming G1/S cell cycle arrest in senescent cells.

• 생명과학회지
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• 제27권1호
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• pp.1-7
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• 2017

비정상적 액틴의 재구성은 암세포의 대표적 특성이다. Thymosin ${\beta}_{10}$ (TB10)과 Profilin-1 (PFN-1)은 액틴중합조절에 필수적인 단백질이다. 이전의 연구에서 본 연구진은 TB10이 F-actin의 구조를 파괴하여 난소 암 세포의 사멸을 일으킨다는 사실을 보고하였으나 그 기전에 대하여 보고 된 바는 아직까지 없다. 본 연구에서는 TB10에 의하여 PFN-1의 발현이 조절되며, PFN-1의 난소 암 저해 유전자로서의 새로운 기능을 보고하였다. 우선 난소암세포주인 SKOV3 세포에서 TB10에 의하여 발현이 조절되는 단백질들을 전기영동법과 liquid chromatography-mass spectroscopy (LC-MS/MS) 방법을 통하여 분석하였다. 그 결과 PFN-1이 TB10에 의하여 발현이 급격히 증가되는 단백질로 동정되었으며, 이 PFN-1을 난소 암 세포주인 SKOV3에 과발현 시켰을 때 암세포의 증식과 이동을 저해하고 암세포 사멸을 유도하였다. 또한 이 결과는 PFN-1에 의하여 Erk 신호전달기전이 저해되고 부수적으로 Elk-1과 Egr-1의 발현이 저해 됨으로써 유도될 가능성을 보여준다. 결론적으로, PFN-1이 난소암세포의 성장과 이동을 저해함과 동시에 세포사멸을 일으키므로 난소 암 치료에 유용하게 이용될 가능성이 높다.

• 대한수의학회지
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• 제41권4호
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• pp.549-555
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• 2001

Indole-3-carbinol (I3C), one component of cruciferous vegetables (the Fammily of Cruciferae), has been shown to exert its chemopreventive effect in liver, colon and mammary tissue before or concurrent exposure of carcinogen, but there have been several evidences that consumption of I3C induced tumor promotion in some tissues. Our studies were investigated to examine the modifying effects of I3C in the 7,12-dimethylbenz[$\alpha$]anthracene (DMBA) induced rat mammary gland tumor model. Fifty-two female Sprague-Dawley rats were randomly divided into five groups. Animals of the group 1 were given the diet containing 100ppm I3C and animals of the groups 2 and 4 were given the diet containing 300ppm I3C from 6 weeks of age. At 7 weeks of age, the animals of the groups 1, 2 and 3 were intubated with DMBA. All amimals were killed at 20 weeks after carcinogen treatment. There were significant increases of food consumption in I3C feeding groups compared with those of basal diet feeding groups. The incidences of the mammary tumors in the group 1, 2 and 3 were 75.0% (9/12), 56.3% (9/16) and 93.8% (15/16), respectively and the average number of tumors of group 1 (DMBA+I3C 100ppm: $2.08{\pm}0.61$) and 2 (DMBA+I3C 300ppm: $1.19{\pm}0.32$) were significantly lower than that of group 3 (DMBA alone: $4.63{\pm}0.72$) at the value of P<0.05 and P<0.001, respectively. In the pathological examination of appearing tumors, most of them were adenocarcinoma. Many epithelial cells of tumors showed strong estrogen receptor (ER) $\alpha$ expression but there were slight difference of ER $\alpha$ expression among the type of tumors. We suggest that pre-initiation treatment of I3C has an inhibitory effects on mammary carcinogenesis induced by DMBA.

• 생명과학회지
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• 제25권6호
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• pp.686-692
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• 2015

암조직에 대한 면역반응은 종양의 성장을 억제하거나 유도한다. Foxp3 양성 T 림프구는 종양에 대한 면역억제 반응을 유도하여 종양의 성장을 유도하는 반면 CD8 양성 T 림프구는 종양의 성장을 억제한다. 본 연구에서는 피부에서 발생한 편평세포암종, 편평세포 암종의 전암병변인 광선각화증과 보웬병 그리고 기저세포암종 조직에 면역조직화학염색을 시행하여 CD8 양성 T 림프구 및 Foxp3 양성 T 림프구의 분포 그리고 두 종류의 림프구의 비(CD8/Foxp3)를 조사하여 다음과 같은 결과를 얻었다. CD8 양성 T 림프구와 Foxp3 양성 T 림프구는 보웬병과 평평세포암종의 침습부위에서 광선각화증과 기저세포암종의 침습부위에 비하여 더 많이 침윤하였으며 CD8/Foxp3는 보웬병에서 광선각화증과 기저세포암종의 침습부위에 비하여 낮았다. CD8 양성 T 림프구와 Foxp3 양성 T 림프구의 침윤 정도 및 CD8/Foxp3는 보웬병과 편평세포암종의 침습부위에서 유의한 차이가 없었다. 기저세포암종과 편평세포암종에서 CD8 양성 T 림프구와 Foxp3 양성 T 림프구는 침습부위에서 종양의 중심부위에 비하여 더 많이 침윤하였다. 이러한 결과로 보아 편평세포종양과 기저세포암종은 서로 다른 면역반응을 보이며 종양내에서도 부위에 따라 상이한 면역반응을 보인다고 생각된다.

• Asian Pacific Journal of Cancer Prevention
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• 제14권4호
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• pp.2201-2205
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• 2013

Colorectal cancer (CRC) is one of the most common cancers in many parts of the world. Its development is a multi-step process involving three distinct stages, initiation that alters the molecular message of a normal cell, followed by promotion and progression that ultimately generates a phenotypically altered transformed malignant cell. Reports have suggested an association of the phosphoinositide-3-kinase (PI3K)/Akt pathway with colon tumorigenesis. Activation of Akt signaling and impaired expression of phosphatase and tensin homolog (PTEN) (a negative regulator of Akt) has been reported in 60-70% of human colon cancers and inhibitors of PI3K/Akt signaling have been suggested as potential therapeutic agents. Around 80% of human colon tumors possess mutations in the APC gene and half of the remainder feature ${\beta}$-catenin gene mutations which affect downstream signaling of the PI3K/Akt pathway. In recent years, there has been a great focus in targeting these signaling pathways, with natural and synthetic drugs reducing the tumor burden in different experiment models. In this review we survey the role of PI3K/Akt/mTOR and Wnt signaling in CRC.

• Asian Pacific Journal of Cancer Prevention
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• 제13권9호
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• pp.4815-4822
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• 2012

Invasion and metastasis are the major causes of cancer-related death. Pharmacological or therapeutic interventions such as chemoprevention of the progression stages of neoplastic development could result in substantial reduction in the incidence of cancer mortality. (-)-Epigallocatechin-3-gallate (EGCG), a promising chemopreventive agent, has attracted extensive interest for cancer therapy utilizing its antioxidant, anti-proliferative and inhibitory effects on angiogenesis and tumor cell invasion. In this study, we assessed the influence of EGCG on the proliferative potential of HeLa cells by cell viability assay and authenticated the results by nuclear morphological examination, DNA laddering assay and cell cycle analysis. Further we analyzed the anti-invasive properties of EGCG by wound migration assay and gene expression of MMP-9 and TIMP-1 in HeLa cells. Our results indicated that EGCG induced growth inhibition of HeLa cells in a dose- and time-dependent manner. It was observed that cell death mediated by EGCG was through apoptosis. Interestingly, EGCG effectively inhibited invasion and migration of HeLa cells and modulated the expression of related genes (MMP-9 and TIMP-1). These results indicate that EGCG may effectively suppress promotion and progression stages of cervical cancer development.

• 대한한의학회지
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• 제30권3호
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• pp.61-69
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• 2009

Objectives : This experiment was conducted to evaluate the inhibitory effects against lung metastasis and promotion of splenocytes by water-soluble components from five mushrooms extracts (WEFM): Garnoderma frondosa, Corious versicolor, Codyceps militaris, Hericium erinaceus and Lentinula edodes. Methods : Colon 26-L5 carcinoma cells were injected through the tail vein to induce lung metastatic cancer. Changes in weight of lung were observed and cytokine level was analyzed to evaluate immunological changes. Results : Oral administration of WEFM resulted in a significant inhibition of lung metastasis after intravenous injection of colon 26-L5 cells in a dose-dependent manner. There was also a significant increase in T cell and B cell mitogenic stimuli and production of IFN-g by splenocytes stimulated with Con A compared to untreated controls. Conclusion : WEFM may have anti-tumor activities via Th1-type dominant immune responses.

• 한국환경성돌연변이발암원학회지
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• 제19권1호
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• pp.56-62
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• 1999

Resveratrol (3,5,4'-trihydroxy-trans-stilbene) has been considered to be as one of major antioxidants present in grapes responsible for beneficial effects of red wine consumption on coronary heart disease. This triphenolic stilbene has been suggested as a potential cancer chemopreventive agent based on its striking inhiitory effects on diverse cellular events associated with tumor initiation, promotion, and progression. The compound has strong antioxidative and anti-inflammatory activities which amy contribute to its chemopreventive/chemoprotective properties. In the present work, we have found that resveratrol reduces viability and DNA synthesis capability of cultured human promyelocytic leukemia (HL-60) cells. Likewise, the viability of human breast cancer cell line, MCF-7 was reduced by resveratrol treatment. The growth inhibitory and antiproliferative properties of resveratrol appear to be associated with its induction of apoptotic cell death as determined by morphological and ultrastructural changes, agarose gel electrphoretic analysis of internucleosomal DNA fragmentation, and in situ terminal end-labeling of fragmented DNA (TUNEL). This compound also inhibited the phorbol ester-induced expression of cyclooxygenase-2 (COX-2) protein in immortalized human mammary epithelial MCF-10A cells. These results suggest that resveratrol has the promising cancer therapeutic/chemopreventive potential.

• Asian Pacific Journal of Cancer Prevention
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• 제16권14호
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• pp.5823-5828
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• 2015

Micronutrients in food have been found to have chemopreventive effects, supporting the conclusions from epidemiologie studies that consumption of fresh fruits and vegetables reduces cancer risk. The present study was carried out to evaluate the role of querctin (Q) and sodium gluconate (GNA) supplementation separately or in combination in ameliorating promotion of colon tumor development by dimethyl-hydrazine (DMH) in mice. Histopathological observation of colons in mice treated with DMH showed goblet cell dysplasia with inflammatory cell infiltration. This pathological finding was associated with significant alteration in oxidative stress markers in colon tissues and carcinoembryonic antigen (CEA) levels in plasma. Mice co-treated with GNA and Q showed mild changes of absorptive and goblet cells and inflammatory cell infiltration in lamina properia, with improvement in oxidative stress markers. In conclusion, findings of the present study indicate significant roles for reactive oxygen species (ROS) in pathogenesis of DMH-induced colon toxicity and initiation of colon cancer. Also, they suggest that Q, GNA or the combination of both have a positive beneficial effect against DMH induced colonic cancer induction in mice.

• Asian Pacific Journal of Cancer Prevention
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• 제15권24호
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• pp.10557-10563
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• 2015

It is well known that conventional chemotherapy and radiation therapy can result in toxicity to both normal cells and tumor cells, which causes limitations in the application of these therapeutic strategies for cancer control. Novel and effective therapeutic strategies for cancers with no or low toxicity for normal cells are a high priority. Therefore, natural products with anticancer activity have gained more and more attention due to their favorable safety and efficacy profiles. Pre-clinical and clinical studies have demonstrated that several representative natural compounds such as resveratrol, epigallocatechin-3-gallate, curcumin, allicin and ginsenosides have obvious anticancer potential. In this article, we summarize autophagy-associated targeting pathways of such natural products for inducing the death of cancer cells, and discuss the core autophagic pathways involved in cancer treatments. Recent advances in the discovery, evaluation and exploitation of natural compounds as therapeutic agents for cancers will provide references and support in pre-clinical and clinical application of novel natural drugs for the treatment of primary and metastatic tumors in the future.