• Biomolecules & Therapeutics
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• 제31권6호
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• pp.682-691
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• 2023

Cell transformation induced by epidermal growth factor (EGF) and 12-O-tetradecanoylphorbol-13-acetate (TPA) is a critical event in cancer initiation and progression, and understanding the underlying mechanisms is essential for the development of new therapeutic strategies. Licorice extract contains various bioactive compounds, which have been reported to have anticancer and anti-inflammatory effects. This study investigated the cancer preventive efficacy of licochalcone D (LicoD), a chalcone derivative in licorice extract, in EGF and TPA-induced transformed skin keratinocyte cells. LicoD effectively suppressed EGF-induced cell proliferation and anchorage-independent colony growth. EGF and TPA promoted the S phase of cell cycle, while LicoD treatment caused G1 phase arrest and down-regulated cyclin D1 and up-regulated p21 expression associated with the G1 phase. LicoD also induced apoptosis and increased apoptosis-related proteins such as cleaved-caspase-3, cleaved-caspase-7, and Bax (Bcl2-associated X protein). We further investigated the effect of LicoD on the AKT signaling pathway involved in various cellular processes and found decreased p-AKT, p-GSK3β, and p-NFκB expression. Treatment with MK-2206, an AKT pharmacological inhibitor, suppressed EGF-induced cell proliferation and transformed colony growth. In conclusion, this study demonstrated the potential of LicoD as a preventive agent for skin carcinogenesis.

• Biomolecules & Therapeutics
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• 제24권2호
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• pp.109-114
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• 2016

In Drosophila, rhomboid proteases are active cardinal regulators of epidermal growth factor receptor (EGFR) signaling pathway. iRhom1 and iRhom2, which are inactive homologs of rhomboid intramembrane serine proteases, are lacking essential catalytic residues. These are necessary for maturation and trafficking of tumor necrosis factor-alpha (TNF-${\alpha}$) converting enzyme (TACE) from endoplasmic reticulum (ER) to plasma membrane through Golgi, and associated with the fates of various ligands for EGFR. Recent studies have clarified that the activation or downregulation of EGFR signaling pathways by alteration of iRhoms are connected to several human diseases including tylosis with esophageal cancer (TOC) which is the autosomal dominant syndrom, breast cancer, and Alzheimer's disease. Thus, this review focuses on our understanding of iRhoms and the involved mechanisms in the cellular processes.

• 대한화장품학회지
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• 제42권2호
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• pp.111-118
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• 2016

여드름은 면포, 구진, 낭종, 결절, 색소 침착 등 다양한 피부병변으로 나타나는 모낭피지선의 만성 염증질환으로 사춘기부터 성인기까지 발생 연령대가 다양해지고 있다. 한편, 약물 부작용으로 여드름이 발생하기도 하는데, 표피성장인자(epidermal grouwth factor, EGF) 수용체 억제제 항암제를 사용할 경우 75 ~ 100%에서 여드름양 모낭염이 발생된다고 보고되고 있다. 여드름의 치료로 항생제, 레티노이드 경구 복용 및 외용 약제 도포 등 다양한 방법이 이용되고 있다. 그러나 최근 들어 레티노이드 기형 유발 가능성 및 Propionibacterium acne의 항생제 내성률 증가는 기존 치료의 한계로 여겨진다. 따라서 본 연구는 최근 여드름양 발진에 효과가 있다고 알려진 EGF를 함유한 외용제가 여드름 치료에 미치는 효과와 안정성을 평가하였다. 한국 성인 10 ~ 29세 23명을 대상으로 EGF 함유 제품(트러블컨트롤 EGF)과 3종 제품(트러블컨트롤 클래리파잉 클렌징폼, 트러블컨트롤 올-클리어 필링토너, 레드롤 카밍 모이스처)을 하루 두 번 사용하도록 하였다. 사용 후 영상 피지량, 경표피수분손실량, 피부 홍조 측정, 전문가 육안 평가, 사용 후 만족도 설문조사를 평가하였다. 최종 측정 시, 피부 피지량, 경피수분손실량, 피부 홍조가 통계학적으로 감소하였으며, 전문가 육안 평가에서 여드름 병변(면포, 구진)도 통계학적으로 감소하였다. 연구동안 심각한 부작용은 관찰되지 않았다. 표피성장인자 함유 외용제는 경도의 여드름에 안전하면서도 효과적으로 사용할 수 있을 것으로 생각된다.

• Molecules and Cells
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• 제28권6호
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• pp.537-543
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• 2009

Keratinocyte overgrowth after UVB exposure is believed to contribute to skin photoageing and cancer development. However, little is known about the transcription factors that epigenetically regulate keratinocyte response to UVB. Recently, $HIF-1{\alpha}$ was found to play a role in epidermal homeostasis by controlling the keratinocyte cell cycle, and thus, we hypothesized that $HIF-1{\alpha}$ is involved in UVB-induced keratinocyte growth. In cultured keratinocytes, $HIF-1{\alpha}$ was found to be down-regulated shortly after UVB exposure and to be involved in UVB-induced proliferation. In mice repeatedly treated with UVB, the epidermis became hyperplasic and keratinocytes lacked $HIF-1{\alpha}$ in nuclei. Based on these results, we suggest that the deregulation of $HIF-1{\alpha}$ is associated with UVB-induced hyperplasia of the epidermis. This work provides insight of the molecular mechanism underlying UV-induced photoageing and skin cancer development.

• 생약학회지
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• 제50권1호
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• pp.18-24
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• 2019

Andrographolide, the main compound of Andrographis paniculata (A. paniculata), shows various biological properties including anti-viral, anti-inflammatory, anti-diabetic, and hepatoprotective effects. Our previous study has shown that A. paniculata extract exerts antiaging effects by activation of stemness in epidermal stem cells (EpSCs). In this study, we investigated the effect of andrographolide as a main compound of A. paniculata on EpSCs and its mechnism of action using several in vitro assays. Andrographolide increased the proliferation of EpSCs and induced cell cycle progression. Additionally, andrographolide increased VEGF production and the expression of stem cell markers integrin ${\beta}1$ and p63. Furthermore, phosphorylation levels of extracellular signal-regulated kinase 1/2 (ERK1/2), S6 ribosomal protein (S6RP) and Akt were increased by andrographolide. Taken together, these results indicate that andrographolide-induced proliferation of EpSCs is mediated by the ERK1/2, Akt-dependent pathway with increased production of VEGF and upregulated stemness through integrin ${\beta}1$ and p63.

• Archives of Pharmacal Research
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• 제21권2호
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• pp.120-127
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• 1998

Peroxisome proliferators induce hepatic peroxisome proliferation and hepatic tumors in rodents. These chemicals increase the expression of the peroxisomal $\beta$-oxidation pathway and the cytochrome P-450 4A family, which metabolizes lipids, including eicosanoids. Peroxisome proliferators transiently induce increased cell proliferation in vivo. However, peroxisome proliferators are weakly mitogenic and are not co-mitogenic with epidermal growth factor (EGF) in cultured hepatocytes. Earlier study found that the peroxisome proliferator ciprofibrate is cornitogenic with eicosanoids. In order to study possible mechanisms of the comitogenicity of peroxisome proliferator ciprofibrate and eicosanoids' we hypothesized that the co-mitogenicity may result from synergistic or additive increases of second messengers in mitogenic signal pathways. We therefore examined the effect of the peroxisome proliferator ciprofibrate, prostaglandin $F_2_{\alpha}$($PGF_2{\alpha}$) and the combination of ciprofibrate and $PGF_2{\alpha}$ with or without growth factors on the protein kinase C (PKC) activity, and inositol-1, 4, 5-triphosphate ($IP_{3-}$) and intracellular calcium ($[Ca^{2+}]_i$) concentrations in cultured rat hepatocytes. The combination of ciprofibrate and $PGF_2{\alpha}$ significantly increased particulate PKC activity. The combination of ciprofibrate and $PGF_2{\alpha}$ also significantly increased EGF, transforming growth factor-$\alpha$ ($TGF_2{\alpha}$) and hepatic growth factor (HGF)-induced particulate PKC activity. The combination of ciprofibrate and $PGF_2_\alpha$greatly increased $[Ca^{2+}]_i$. However, the increases of PKC activity and $[Ca^{2+}]_i$ by ciprofibrate and $PGF_2{\alpha}$ alone were much smaller. Neither ciprofibrate or $PGF_2{\alpha}$ alone nor the combination of ciprofibrate and $PGF_2{\alpha}$ significantly increased the formation of $IP_3$. The combination of ciprofibrate and $PGF_2{\alpha}$, however, blocked the inhibitory effect of $TGF-{\beta}$ on particulate PKC activity and formation of $IP_3$ induced by EGF. These results show that co-mitogenicity of the peroxisome proliferator ciprofibrate and eicosanoids may result from the increase in particulate PKC activity and intracellular calcium concentration but not from the formation of $IP_3$.

• BMB Reports
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• 제54권9호
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• pp.470-475
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• 2021

Low-dose metronomic chemotherapy has been introduced as a less toxic and effective strategy to inhibit tumor angiogenesis, but its anti-angiogenic mechanism on endothelial progenitor cells (EPCs) has not been fully elucidated. Here, we investigated the functional role of regulated in development and DNA damage response 1 (REDD1), an endogenous inhibitor of mTORC1, in low-dose doxorubicin (DOX)-mediated dysregulation of EPC functions. DOX treatment induced REDD1 expression in bone marrow mononuclear cells (BMMNCs) and subsequently reduced mTORC1-dependent translation of endothelial growth factor (VEGF) receptor (Vegfr)-2 mRNA, but not that of the mRNA transcripts for Vegfr-1, epidermal growth factor receptor, and insulin-like growth factor-1 receptor. This selective event was a risk factor for the inhibition of BMMNC differentiation into EPCs and their angiogenic responses to VEGF-A, but was not observed in Redd1-deficient BMMNCs. Low-dose metronomic DOX treatment reduced the mobilization of circulating EPCs in B16 melanoma-bearing wild-type but not Redd1-deficient mice. However, REDD1 overexpression inhibited the differentiation and mobilization of EPCs in both wild-type and Redd1-deficient mice. These data suggest that REDD1 is crucial for metronomic DOX-mediated EPC dysfunction through the translational repression of Vegfr-2 transcript, providing REDD1 as a potential therapeutic target for the inhibition of tumor angiogenesis and tumor progression.

• BMB Reports
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• 제28권2호
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• pp.87-93
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• 1995

To investigate the biological functions of the EGF-like domain of mouse betacellulin (BTC), mouse BTC(33-80), a 48-residue peptide corresponding to the EGF-like domain, was synthesized by stepwise solidphase methods using a 9-fluorenylmethoxycarbonyl (Fmoc) strategy. The homogeneity of synthetic mouse BTC(33-80) was confirmed by analytical reversed phase (RP)-HPLC, amimo acid analysis, and fast atom bombardment mass spectrometer (FAB-MS). Three disulfide bond pairings of synthetic mouse BTC(33-80) were established by amino acid analysis of cysteine-containing fragments derived from thermolytic digestion. These were consistent with the pairings of EGF and transforming growth factor ($TGF-{\alpha}$). The EGF-Iike domain of mouse BTC showed equipotent activity in both EGF-receptor binding on A-431 epidermoid carcinoma cells, and mitogenesis on NIH-3T3 fibroblast cells, as compared with authentic h-EGF. Results suggest that the EGF-Iike domain of BTC plays a significant role in mitogenic activity with an EGF-receptor mediated system.

• BMB Reports
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• 제31권5호
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• pp.468-474
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• 1998

Membrane depolarization in PC12 cells induces calcium influx via an L-type voltage-sensitive calcium channel (L-VSCC) and increases intracellular free calcium, which leads to tyrosine phosphorylation of epidermal growth factor (EGF) receptor and the associated adaptor protein, She. This activated EGF receptor complex then can activate mitogen-activated protein (MAP) kinase, as in nerve growth factor (NGF) receptor activation. In the present study, we investigated the role of EGF receptor in the signaling pathway initiated by membrane depolarization of PC12 cells. Prolonged membrane depolarization induced phosphorylation of extracellular signal-regulated kinase (ERK) within 1 min in undifferentiated PC12 cells. Pretreatment of PC12 cells with the calcium chelator EGTA abolished depolarization-stimulated ERK phosphorylation, but NGF-induced phosphorylation of ERK was not affected. The chronic treatment of phorbol ester, which down-regulated the activity of protein kinase C (PKC), did not affect the phosphorylation of ERK upon depolarization. In the presence of an inhibitor of EGF receptor, neither depolarization nor calcium ionophore increased the level of ERK phosphorylation. These data imply that the EGF receptor is functionally necessary to activate ERK and neurite outgrowth in response to the prolonged depolarization in PC12 cells, and also that PKC is apparently not involved in this signaling pathway.

• Natural Product Sciences
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• 제25권3호
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• pp.248-254
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• 2019

In the present study, we investigated whether quercitrin, quercetin and afzelin derived from Houttuynia cordata affect the production and gene expression of MUC5AC mucin from airway epithelial cells. Confluent NCI-H292 cells were pretreated with quercitrin, quercetin or afzelin for 30 min and then stimulated with epidermal growth factor (EGF) or phorbol 12-myristate 13-acetate (PMA) for 24 h. The MUC5AC mucin gene expression and production were measured by RT-PCR and ELISA, respectively. The results were as follows: (1) Quercitrin, quercetin and afzelin inhibited EGF- and PMA-induced MUC5AC mucin production from NCI-H292 cells; (2) The three natural products also decreased EGF- and PMA-induced MUC5AC mucin gene expression in NCI-H292 cells. These results suggest that quercitrin, quercetin and afzelin showed the regulatory effect on the steps of gene expression and production of mucin, by directly acting on airway epithelial cells.