• Toxicological Research
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• v.27 no.4
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• pp.253-259
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• 2011

Transforming growth factor ${\beta}$ (TGF-${\beta}$) is involved in cellular processes including growth, differentiation, apoptosis, migration, and homeostasis. Generally, TGF-${\beta}$ is the inhibitor of cell cycle progression and plays a role in enhancing the antagonistic effects of many growth factors. Unlike the antiproliferative effect of TGF-${\beta}$, E2, an endogeneous estrogen, is stimulating cell proliferation in the estrogen-dependent organs, which are mediated via the estrogen receptors, $ER{\alpha}$ and $ER{\beta}$, and may be considered as a critical risk factor in tumorigenesis of hormone-responsive cancers. Previous researches reported the cross-talk between estrogen/$ER{\alpha}$ and TGF-${\beta}$ pathway. Especially, based on the E2-mediated inhibition of TGF-${\beta}$ signaling, we examined the inhibition effect of 4-tert-octylphenol (OP) and 4-nonylphenol (NP), which are well known xenoestrogens in endocrine disrupting chemicals (EDCs), on TGF-${\beta}$ signaling via semi-quantitative reverse-transcription PCR. The treatment of E2, OP, or NP resulted in the downregulation of TGF-${\beta}$ receptor2 (TGF-${\beta}$ R2) in TGF-${\beta}$ signaling pathway. However, the expression level of TGF-${\beta}1$ and TGF-${\beta}$ receptor1 (TGF-${\beta}$ R1) genes was not altered. On the other hand, E2, OP, or NP upregulated the expression of a cell-cycle regulating gene, c-myc, which is a oncogene and a downstream target gene of TGF-${\beta}$ signaling pathway. As a result of downregulation of TGF-${\beta}$ R2 and the upregulation of c-myc, E2, OP, or NP increased cell proliferation of BG-1 ovarian cancer cells. Taken together, these results suggest that E2 and these two EDCs may mediate cancer cell proliferation by inhibiting TGF-${\beta}$ signaling via the downregulation of TGF-${\beta}$ R2 and the upregulation of c-myc oncogene. In addition, it can be inferred that these EDCs have the possibility of tumorigenesis in estrogen-responsive organs by certainly representing estrogenic effect in inhibiting TGF-${\beta}$ signaling.

• Asian Pacific Journal of Cancer Prevention
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• v.13 no.5
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• pp.2087-2093
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• 2012

Previous evidence showed ${\beta}1$, 3-N-acetylglucosaminyltransferase 8 (${\beta}3GnT8$), which can extend polylactosamine on N-glycans, to be highly expressed in some cancer cell lines and tissues, indicating roles in tumorigenesis. However, so far, the function of ${\beta}3GnT8$ in laryngeal carcinoma has not been characterized. To test any contribution, Hep-2 cells were stably transfected with sense or interference vectors to establish cell lines that overexpressed or were deficient in ${\beta}3GnT8$. Here we showed that cell proliferation was increased in ${\beta}3GnT8$ overexpressed cells but decreased in ${\beta}3GnT8$ knockdown cells using MTT. Furthermore, we demonstrated that change in ${\beta}3GnT8$ expression had significant effects on tumor growth in nude mice.We further provided data suggesting that overexpression of ${\beta}3GnT8$ enhanced the expression of matrix metalloproteinase-2 (MMP-2) and matrix metalloproteinase-9 (MMP-9) at both the mRNA and protein levels, associated with shedding of tissue inhibitors of metalloproteinase TIMP-2. In addition, it caused increased production of transforming growth factor beta 1 (TGF-${\beta}1$), whereas ${\beta}3GnT8$ gene knockdown caused the reverse effect. The results may indicate a novel mechanism by which effects of ${\beta}3GnT8$ in regulating cellular proliferation are mediated, at least in partvia targeting MMPs/TIMPs and TGF-${\beta}1$ in laryngeal carcinoma Hep-2 cells. The finding may lay a foundation for further investigations into the ${\beta}3GnT8$ as a potential target for therapy of laryngeal carcinoma.

• Archives of Plastic Surgery
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• v.34 no.1
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• pp.8-12
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• 2007

Purpose: Protein tyrosine kinase(PTK), protein kinase C(PKC), oxidase, as a mediator, have been known to take a role in signal transduction pathway of angiogenesis. The authors confirmed that PKC is the most noticeable mediator for abnormal proliferation of vascular endothelial cells through in vitro study model using the inhibitors, targeting the formation of three co-enzymes. In this study, we would investigate which isoform of PKC play an important role in abnormal angiogenesis of vascular endothelial cell. Methods: In 96 well plates, $10^4$ HUVECs(human umbilical vein endothelial cells) were evenly distributed. Two groups were established; the control group without administration of DMH(1,2-dimethylhydrazine) and the DMH group with administration of $7.5{\times}10^{-9}M$ DMH. RNA was extracted from vascular endothelial cell of each group and expression of the PKC isoform was analyzed by RT-PCR(reverse transcriptase-polymerase chain reaction) method. Results: RT-PCR analysis showed that $PKC{\alpha}$, $-{\beta}I$, $-{\beta}II$, $-{\eta}$, $-{\mu}$ and $-{\iota}$ were expressed in vascular endothelial cells of each group. DMH incresed the expression of $PKC{\alpha}$ and $PKC{\mu}$, and decreased $PKC{\beta}I$, $PKC{\beta}II$ expression dominantly. Conclusion: Based on the result of this study, it was suggested that $PKC{\alpha}$ and $PKC{\mu}$ may have significant role in abnormal proliferation of vascular endothelial cell.

• Journal of the Korean Society of Food Science and Nutrition
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• v.36 no.2
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• pp.186-193
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• 2007

The prevalence of diabetes has increased to 8% of population. Unlike type 2 diabetes in the western countries, Korean diabetic patients are nonobese and have low serum insulin levels. As the increased prevalence of diabetes and the peculiar characteristics may be related to dietary fat contents, we determined their effects on insulin resistance, insulin secretion and pancreatic $\beta-cell$ mass in 90% pancreatectomized (Px) diabetic rats in the present study. The rats were provided with low fat diet (LF, 10 energy% fat), moderate fat diet (MF, 25 energy% fat) and high fat diet (HF, 40 energy% fat) for 6 months. HF increased body weight and epidydimal fat pads parallel with increased food intake compared to LF and MF. Fasting serum glucose and insulin levels and homeostasis model assessment of insulin resistance were higher in HF, compared to LF and MF, indicating that HF increased insulin resistance. Rats fed LF and MF diets reduced insulin resistance, but only rats fed MF improved pancreatic $\beta-cell$ mass and insulin secretion capacity, measured by hyperglycemic clamp and in situ pancreatic perfusion. LF had low insulin secretion capacity and pancreatic $\beta-cell$ mass, indicating the increased possibility of diabetic prevalence and progression. MF increased $\beta-cell$ mass by stimulating $\beta-cell$ proliferation and neogenesis and reducing $\beta-cell$ apoptosis. In conclusion, MF is effective for the prevention of prevalence and progression of diabetes.

• The Korean Journal of Food And Nutrition
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• v.19 no.2
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• pp.176-182
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• 2006

Sorghum bicolor L. Moench(Sorghum, Su-Su) is a major cereal food crop used in many parts of the world. It is used as a human food resource and folk medicines in Asia and Africa. The stem of sorghum has been used as a digestive aid and an anti-diarrheal agent. Sorghum hybrids contain high levels of diverse phenolic compounds that may provide health benefits. High levels of polyflavanols, anthocyanins, phenolic acids, and other antioxidant compounds have been reported in sorghums, which have also been shown to possess various biological activities such as anti-mutagenic, anti-carcinogenic, and HMG-CoA reductase inhibitory activities. In an in vitro experiment, we examined mice splenocyte proliferation and production of three types of cytokine($IL-1{\beta},\;IL-6,\;TNF-{\alpha}$) by peritoneal macrophages cultured with ethanol and water extracts of Sorghum bicolor L. Moench. A single cell suspension of splenocytes was prepared and the cell proliferation of the splenocytes was examined by MTT assay. The splenocyte proliferation was increased when water extracts of Sorghum bicolor L. Moench were used as supplements in all concentrations investigated. The production of cytokine($IL-1{\beta},\;IL-6,\;TNF-{\alpha}$) by activated peritoneal macrophage was detected by ELISA using the cytokine kit. $IL-1{\beta},\;IL-6,\;and\;TNF-{\alpha}$ production by activated macrophages were increased by supplementation with Sorghum bicolor L. Moench water extracts. This study suggests that supplementation of with Sorghum bicolor L. Moench water extracts may enhance immune function by regulating the splenocyte proliferation and enhancing the cytokine production by activated macrophages in vitro.

• Asian Pacific Journal of Cancer Prevention
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• v.14 no.5
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• pp.3093-3099
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• 2013

Background: Phytic acid (PA) is a polyphosphorylated carbohydrate that can be found in high amounts in most cereals, legumes, nut oil, seeds and soy beans. It has been suggested to play a significant role in inhibition of colorectal cancer. This study was conducted to investigate expression changes of ${\beta}$-catenin and cyclooxygenase-2 (COX-2) and cell proliferation in the adenoma-carcinoma sequence after treatment with rice bran PA by immunocytochemistry. Materials and Methods: Seventy-two male Sprague-Dawley rats were divided into 6 equal groups with 12 rats in each group. For cancer induction two intraperitoneal injections of azoxymethane (AOM) were given at 15 mg/kg bodyweight over a 2-weeks period. During the post initiation phase, two different concentrations of PA, 0.2% (w/v) and 0.5% (w/v) were administered in the diet. Results: Results of ${\beta}$-catenin, COX-2 expressions and cell proliferation of Ki-67 showed a significant contribution in colonic cancer progression. For ${\beta}$-catenin and COX-2 expression, there was a significant difference between groups at p<0.05. With Ki-67, there was a statistically significant lowering the proliferating index as compared to AOM alone (p<0.05). A significant positive correlation (p=0.01) was noted between COX-2 expression and proliferation. Total ${\beta}$-catenin also demonstrated a significant positive linear relationship with total COX-2 (p=0.044). Conclusions: This study indicated potential value of PA extracted from rice bran in reducing colonic cancer risk in rats.

• Archives of Pharmacal Research
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• v.26 no.8
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• pp.620-630
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• 2003

The proliferative effects of thirty Oriental medicinal herbs on MCF-7 (estrogen-sensitive breast cancer cell line) and ROS 17/2.8 osteoblast-like cells were determined using the MTT assay. Methanol extracts from several herbs was found to show proliferative activity on the above two cell lines in the range of 5 to 100 $\mu$g/mL. Among these active herbs, the methanol extract from the rhizomes of Drynaria fortunei showed the most potent proliferative activity, and the cell proliferations were significantly increase by 136 and 158% in the MCF-7 and ROS 17/2.8 cells, respectively, when treated with 100 $\mu$ g/mL. Through a bioassay-guided separation, eight flavonoids, including four new flavan-3-ols and two propelargonidins, together with the known (-)-epiafzelechin and naringin, were isolated. Their chemical structures were characterized as (-)-epiafzelechin (1), (-)-epiafzelechin-3-O-$\beta$-D-allopyranoside (2), (-)-epiafzelechin-3-O-(6"-O-acetyl)-$\beta$-D-allopyranoside (3), 4$\beta$-carboxymethyl-(-)-epiafzelechin methyl ester (4), 4$\beta$-car-boxymethyl-(-)-epiafzelechin sodium salt (5), naringin (6), (-)-epiafzelechin-(4$\beta$\rightarrow8)-4$\beta$-car-boxymethylepiafzelechin methyl ester (7) and (-)-epiafzelechin-($4\beta\rightarrow8, 2\beta\rightarrowΟ\rightarrow7)-epiafzelechin-(4\beta\righarrow8)-epiafzelechin (8) by extensive 1D and 2D NMR spectroscopy. Most of these flavonoids, in the range of $10^{-15}∼10^{-6}$ M, accelerated the proliferation of MCF-7 cell, with compounds 7 and 8, in the range of $10^{-15}∼10^{-12}$ M, showing especially potent proliferation effects. Meanwhile, seven flavonoids, with the exception of compound 4, stimulated the proliferation of ROS 17/2.8 cells in the range of $10^{-15}∼10^{-6}$ M, with compounds 5-8 especially accelerating the proliferation, in dose-dependent manners ($10^{-15}∼10^{-9}$ M), and their proliferative effect was much stronger than that of $E_2$ and genistein. These results suggest that propelargonidin dimers and trimers isolated from the rhizomes of Drynaria fortunei may be useful as potential phytoestrogens, which play important physiological roles in the prevention of postmenopausal osteoporosis.

• The Korean Journal of Physiology and Pharmacology
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• v.17 no.3
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• pp.203-208
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• 2013

As the abnormal proliferation of vascular smooth muscle cells (VSMCs) plays a critical role in the development of atherosclerosis and vascular restenosis, a candidate drug with antiproliferative properties is needed. We investigated the antiproliferative action and underlying mechanism of a newly synthesized naphthoquinone derivative, 5,8-dimethoxy-2-nonylamino-naphthalene-1,4-dione (2-nonylamino-DMNQ), using VSMCs treated with platelet-derived growth factor (PDGF). 2-Nonylamino-DMNQ inhibited proliferation and cell number of VSMCs induced by PDGF, but not epidermal growth factor (EGF), in a concentration-dependent manner without any cytotoxicity. This derivative suppressed PDGF-induced $[^3H]$-thymidine incorporation, cell cycle progression from $G_0/G_1$ to S phase, and the phosphorylation of phosphor-retinoblastoma protein (pRb) as well as the expression of cyclin E/D, cyclin-dependent kinase (CDK) 2/4, and proliferating cell nuclear antigen (PCNA). Importantly, 2-nonylamino-DMNQ inhibited the phosphorylation of PDGF receptor${\beta}$(PDGF-$R{\beta}$) enhanced by PDGF at $Tyr^{579}$, $Tyr^{716}$, $Tyr^{751}$, and $Tyr^{1021}$ residues. Subsequently, 2-nonylamino-DMNQ inhibited PDGF-induced phosphorylation of STAT3, ERK1/2, Akt, and $PLC{\gamma}1$. Therefore, our results indicate that 2-nonylamino-DMNQ inhibits PDGF-induced VSMC proliferation by blocking PDGF-$R{\beta}$ autophosphorylation, and subsequently PDGF-$R{\beta}$-mediated downstream signaling pathways.

• The Korean Journal of Food And Nutrition
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• v.21 no.3
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• pp.263-268
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• 2008

Codonopsis lanceolata has long been used as a seasonal food and as a traditional tonic medicine with anti-inflammatory and anti-oxidation properties. The present study investigated the in vitro effect of Codonopsis lanceolata extracts on immune function in mice. After preparing a single cell suspension splenocyte proliferation was determined by the MTT(3-[4,5-dimethylthiazol-2-y]-2,5-diphenyl terazolium bromide) assay. The cytokines IL-1${\beta}$, IL-6, and TNF-$\alpha$ were not secreted by macrophages stimulated with or without LPS as determined by an ELISA cytokine kit assay. After a 48-hr incubation with the mitogens ConA or LPS there was an increase in splenocytes proliferation and in the production of IL-1${\beta}$, IL-6, and TNF-$\alpha$ in the suspensions supplemented with 50, 100, 250, 500 ${\mu}g/m{\ell}$ Codonopsis lanceolata water extract. The results suggest Codonopsis lanceolata water extract may enhance immune function by regulating splenocyte proliferation and stimulating cytokine production.

• The Korean Journal of Physiology and Pharmacology
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• v.16 no.4
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• pp.225-230
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• 2012

We investigated the effects of ${\beta}$-glucan purified from Paenibacillus polymyxa JB115 on the viability and proliferation of splenocytes. Splenocytes play a critical role in host immunity. MTT assays and trypan blue exclusion tests revealed that ${\beta}$-glucan significantly promoted the viability and proliferation of splenocytes over a range of concentrations. However, there was no specific subset change. ${\beta}$-glucan protected splenocytes from cytokine withdrawal-induced spontaneous cell death. For further mechanistic studies, ELISA assay revealed that ${\beta}$-glucan enhanced the expression of anti-apoptotic molecules and interleukin 7 (IL-7), a cytokine critical for lymphocyte survival. We also investigated the IL-2 dependency of ${\beta}$-glucan-treated splenocytes to determine if treated cells could still undergo clonal expansion. In flow cytometric analysis, ${\beta}$-glucan induced increased levels of the activation marker CD25 on the surface of splenocytes and ${\beta}$-glucan-treated splenocytes showed higher proliferation rates in response to IL-2 treatment. This study demonstrates that ${\beta}$-glucan can enhance the survival of splenocytes and provides valuable information to broaden the use of ${\beta}$-glucan in research fields.