• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.29 no.4
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• pp.199-205
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• 2003

The p53 protein was discovered in 1979 as cellular 53-kD nuclear phosphoprotein bound to the large transforming antigen of SV40 virus. $P21^{WAF1/CIP1}$, which has been described as the critical downstream mediator of p53, is known to suppress DNA replication and arrest the G1 cell cycle by quaternary complex with cyclin D, cyclin-dependent kinase(CDK) and proliferating cell nuclear antigen(PCNA). In these days, some studies shows that the p21 can be induced by independent pathways. There are various reports about the expression of p21 (67%.82.4%) in oral squamous cell carcinoma. But these studies are mostly done in malignant tumor not in benign tumor. So we decided to study the expression of p21 in ameloblastoma and the relationship between p53 and p21 as a downstream mediator of p53 in ameloblastoma. We investigated the expression of p21 and p53 with the method of immunohistochemistry. We selected 30 cases of ameloblastoma tissue blocks (acanthomatous type: 5 cases, follicular type: 8 cases, plexiform type: 17 cases) imbedded in paraffin. We used 30 cases of normal gingival tissues and 30 cases of squamous cell carcinoma tissues (SCC) respectively and compared their results with those of ameloblastoma. We made slides with the streptavidin-biotin methods and used monoclonal antibody DO-7 (Novocastra, Newcastle, United Kingdom) as p53 antibody and monoclonal antibody M7202 (DAKO, California, U.S.A.) as p21 antibody. We used Pearson's correlation coefficient to analyse the relationship. The results were as follows: 1. p21 was expressed in ameloblastoma about 30% and this is lower than that of normal gingiva and SCC. 2. In normal gingiva and ameloblastoma, p21 expression was correlated with p53 expression. 3. In SCC, p21 were expressed about 83.3% and this is more than that of p53. But there was no correlation between p21 and p53 expression. We confirmed p21 expression and relation with p53 in ameloblastoma. But, to confirm the function of p21, more studies about p21 expression in malignant ameloblastoma and ameloblastic carcinoma are needed.

• Asian Pacific Journal of Cancer Prevention
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• v.13 no.8
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• pp.3757-3761
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• 2012

Objective: Crocin has been proposed as a promising candidate for cancer chemoprevention. The purpose of this investigation was to investigate the chemopreventive action and the possible mechanisms of crocin against human colon cancer cells in vitro. Methods: Cell proliferation was examined using MTT assay and the cell cycle distribution fractions were analyzed using fow cytometric analysis after propidium iodide staining. Apoptosis was detected using theTUNEL Apoptosis Detection Kit with laser scanning confocal microscope. DNA damage was assessed using the alkaline single-cell gel electrophoresis assay, while expression levels of p53, cdk2, cyclinA and P21 were examined by Western blot analysis. Results: Treatment of SW480 cells with crocetin (0.2, 0.4, 0.8 mmol/L) for 48 h signifcantly inhibited their proliferation in a concentration-dependent manner. Crocetin (0.8 mmol/L) signifcantly induced cell cycle arrest through p53-independent mechanisms accompanied by P21 induction. Crocetin (0.8 mmol/L) caused cytotoxicity in the SW480 cells by enhancing apoptosis and decreasing DNA repair capacity in a time-dependent manner. Conclusions: This report provides evidence that crocetin is a potential anticancer agent, which may be used as a chemotherapeutic drug.

• Biomolecules & Therapeutics
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• v.28 no.4
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• pp.354-360
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• 2020

The hair cycle (anagen, catagen, and telogen) is regulated by the interaction between mesenchymal cells and epithelial cells in the hair follicles. The proliferation of dermal papilla cells (DPCs), mesenchymal-derived fibroblasts, has emerged as a target for the regulation of the hair cycle. Here, we show that vanillic acid, a phenolic acid from wheat bran, promotes the proliferation of DPCs via a PI3K/Akt/Wnt/β-catenin dependent mechanism. Vanillic acid promoted the proliferation of DPCs, accompanied by increased levels of cell-cycle proteins cyclin D1, CDK6, and Cdc2 p34. Vanillic acid also increased the levels of phospho(ser473)-Akt, phospho(ser780)-pRB, and phospho(thr37/46)-4EBP1 in a time-dependent manner. Wortmannin, an inhibitor of the PI3K/Akt pathway, attenuated the vanillic acid-mediated proliferation of DPCs. Vanillic acid-induced progression of the cell-cycle was also suppressed by wortmannin. Moreover, vanillic acid increased the levels of Wnt/β-catenin proteins, such as phospho(ser9)-glycogen synthase kinase-3β, phospho(ser552)-β-catenin, and phospho(ser675)-β-catenin. We found that vanillic acid increased the levels of cyclin D1 and Cox-2, which are target genes of β-catenin, and these changes were inhibited by wortmannin. To investigate whether vanillic acid affects the downregulation of β-catenin by dihydrotestosterone (DHT), implicated in the development of androgenetic alopecia, DPCs were stimulated with DHT in the presence and absence of vanillic acid for 24 h. Western blotting and confocal microscopy analyses showed that the decreased level of β-catenin after the incubation with DHT was reversed by vanillic acid. These results suggest that vanillic acid could stimulate anagen and alleviate hair loss by activating the PI3K/Akt and Wnt/β-catenin pathways in DPCs.

• The Korea Journal of Herbology
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• v.31 no.5
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• pp.71-78
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• 2016

Objectives : Diabetic nephropathy is one of the most common chronic complications of diabetes and a leading cause of end-stage renal failure in the world. Mesangial cell proliferation is known as the major pathologic features such as glomerulosclerosis and renal fibrosis. Wiryeongtang (WRT) is a well-known traditional herbal formula as therapeutic agents for chronic edema and dysuresia of renal homeostasis. In the present study, we investigated whether WRT inhibits high glucose (HG)-induced renal dysfunction by TGF-β/Smads signal regulation in cultured mesangial cells.Methods : Inhibitory effect of WRT (10-50 ㎍/ml) on HG-stimulated mesangial cells proliferation and dysfunction were evaluated by [³H]-thymidine incorporation, Western blot, and RT-qPCR.Results : WRT significantly decreased HG-accelerated thymidine incorporation in human renal mesangial cell in a dose-dependent levels. WRT induced down-regulation of cyclins/CDKs and up-regulation of CDK inhibitor, p21waf1/cip1 and p27kip1 expression. In addition, HG enhanced expression of dysfunction biomarker such as collagen IV and CTGF, which was markedly attenuated by WRT. WRT decreased TGF-β1 and Smad-2/Smad-4 expression, whereas increased Smad-7 expression under HG. Furthermore, WRT inhibited HG-induced inflammatory factors level such as ICAM-1 and MCP-1 as well as NF-κB p65 nuclear translocation and intracellular ROS production.Conclusions : These results suggested that WRT may alleviate mesangial proliferation and inflammation possibly involved in renal fibrotic process, further diabetic nephropathy through disturbing TGF-β1/Smad signaling and NF-κB/ROS pathway. Thus, WRT might prove to be effective in the treatment of renal dysfunction leading to diabetic nephropathy.

• Journal of Life Science
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• v.17 no.7 s.87
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• pp.976-982
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• 2007

The purpose of this study was to determine the modulating effects of histone deacetylase inhibitor, trichostatin A, on the differentiation of mouse C2C12 myoblasts. We demonstrated that trichostatin A induced morphological changes of C2C12 myoblasts into smooth muscles and significantly increased the gene expression of smooth muscle markers including smooth muscle ${\alpha}-actin$ and transgelin. These results were due to the change in the expression level of cell cycle regulators in trichostatin A-treated C2C12 cells. Real-time PCR data revealed that cyclin dependent kinase inhibitor, p21, mRNA expression was significantly increased in trichostatin A-treated C2C12 cells. However, trichostaDn A rapidly decreased cyclin Dl mRNA expression necessary for cell cycle progression in 24hr after treatment. In conclusion, the strong inhibitory effects of trichostatin A on histone deacetylation induced transdifferentiation of C2C12 myoblasts into smooth muscle cells and these results are partly due to the changes in the expression of cell cycle regulators such as p21 and cyclin D1.

• 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.

• Journal of Microbiology and Biotechnology
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• v.26 no.2
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• pp.287-294
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• 2016

The effect of kaempferol (3,5,7,4-tetrahydroxyflavone), a flavonoid compound that was identified in barnyard millet (Echinochloa crus-galli var. frumentacea) grains, on G₂-checkpoint and apoptotic pathways was investigated in human acute leukemia Jurkat T cell clones stably transfected with an empty vector (J/Neo) or a Bcl-xL expression vector (J/Bcl-xL). Exposure of J/Neo cells to kaempeferol caused cytotoxicity and activation of the ATM/ATR-Chk1/Chk2 pathway, activating the phosphorylation of p53 (Ser-15), inhibitory phosphorylation of Cdc25C (Ser-216), and inactivation of cyclin-dependent kinase 1 (Cdk1), with resultant G₂-arrest of the cell cycle. Under these conditions, apoptotic events, including upregulation of Bak and PUMA levels, Bak activation, mitochondrial membrane potential (Δψm) loss, activation of caspase-9, -8, and -3, anti-poly (ADP-ribose) polymerase (PARP) cleavage, and accumulation of apoptotic sub-G₁ cells, were induced without accompanying necrosis. However, these apoptotic events, except for upregulation of Bak and PUMA levels, were completely abrogated in J/Bcl-xL cells overexpressing Bcl-xL, suggesting that the G₂-arrest and the Bcl-xL-sensitive mitochondrial apoptotic events were induced, in parallel, as downstream events of the DNA-damage-mediated G₂-checkpoint activation. Together these results demonstrate that kaempferol-mediated antitumor activity toward Jurkat T cells was attributable to G₂-checkpoint activation, which caused not only G₂-arrest of the cell cycle but also activating phosphorylation of p53 (Ser-15) and subsequent induction of mitochondria-dependent apoptotic events, including Bak and PUMA upregulation, Bak activation, Δψm loss, and caspase cascade activation.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.21 no.2
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• pp.139-148
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• 1999

Oral cancer is a common neoplasm in humans and etiologic mechanism is not well known, so treatment and evaluation of oral cancer is difficult problem. Traditional TNM classification between prognosis of tumors and classification of histopathologic differentiation has problem like lack of objectivity through operators. In molecular biology, cancer is developed by alteration of activation of oncogene and/or inactivation of tumor suppressor gene. The p53 gene, one of the tumor suppresor genes, is believed to play an important role through mutation and overexpression in the progression of human cancers. The p53 mutation is most frequent genetic disorder in humans. The Cyclin D1 has tumor suppresion activity by regulation of cell cycle. The Cyclin D1 regulate activity of Rb tumor suppresor gene by stimulation of CDK4 The purpose of this study was to observe the expression of p53 protein and Cyclin D1 in oral squamous cell carcinoma, and to get expectation of the malignancy and prognosis of oral squamous cell carcinoma. Using the 15 cases of squamous cell carcinoma and the microscopic H&E and immunohistochemical stain. We divided it into 3 groups according to the stain extent, clinical stage and histologic differentiation. The results were as follows1.In the features of immunohistochemical stain of 15 cases of squamous cell carcinoma, positive reaction of p53 was identified in 8 cases (53.3%) and positive reaction of cyclin D1 was identified in 3 cases (20%). Both positive reaction of p53 protein and Cyclin D1 was show in only one case. 2.8 of p53 positive cases were linked in 87.5% of the end stage tumor, 62.5% of neck node involvement, 87.5% of poorly and moderately histopathplogic differentiation. 3. All 3 of Cyclin D1 positive cases were linked in the end stage tumor, neck node involvement, poorly and moderately histopathologic differentiation. From above results, expression of p53 protein was identified in 53.3% of 15 cases and these results mean oral squamous cell carcinoma was drived by mutation of p53 protein. Especially, highly positive reaction of p53 protein and Cyclin D1 was identified in cases that involvement of neck lymph node and the end stage tumors and it means that the evaluation of p53 protein and Cyclin D1 was useful for evaluation of malignant tumor as specific tumor marker.

• Journal of Acupuncture Research
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• v.17 no.2
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• pp.169-186
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• 2000

To study anti-cancer effect and molecular biological mechanism of bee venom for aqua-acupuncture, the effects of bee venom on cell viability, apoptosis, and cell cycle were analyzed using MTT assay, tryphan blue assay, [3H]thymidine release assay, flow cytometric analysis, activity of caspase-3 protease activity assay, and immunocytometric analysis of PCNA. To explore whether anti-cancer effects of bee venom are associated with the transcriptional control of gene expression, quantitative RT-PCR analysis of apoptosis- and cell cycle-related genes was performed. The obtained results are summarized as follows: 1. The MTT assay demonstrated that cell viability was decreased by bee venom in a dose-dependant manner. 2. Significant induction of apoptosis was identified using tryphan blue assay, [$^3H$]thymidine release assay, and flow cytometric analysis of sub $G_1$ fraction. 3. In analysis of caspase-3 protease activity, the activity had increased significantly, in a dose-dependant manner. 4. Quantitative RT-PCR analysis of the apoptosis-related genes showed that Bcl-2 and $Bcl-X_L$ were down-regulated whereas Bax was up-regulated by bee venom treatment. 5. In flow cytometric analysis of cell cycle and immunocytometric analysis of PCNA expression, cell numbers of $G_1$ phase was increased by a dose-dependant manner. 6. In quantitative RT-PCR analysis of the cell cycle-related genes, p21, p27, and p57 were increased, while Cyclin D1, CDK4, c-Myc, c-Fos, and Histone H3 were decreased. In contrast, there were no remarkable changes in expression levels of CDC2 and c-Jun.

• Molecules and Cells
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• v.41 no.5
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• pp.390-400
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• 2018

Studies have revealed that miR-103a-3p contributes to tumor growth in several human cancers, and high miR-103a-3p expression is associated with poor prognosis in advanced gastric cancer (GC) patients. Moreover, bioinformatics analysis has shown that miR-103a-3p is upregulated in The Cancer Genome Atlas (TCGA) stomach cancer cohort. These results suggest that miR-103a-3p may function as an oncogene in GC. The present study aimed to investigate the role of miR-103a-3p in human GC. miR-103a-3p expression levels were increased in 33 clinical GC specimens compared with adjacent nontumor stomach tissues. Gain- and loss-of-function studies were performed to identify the correlation between miR-103a-3p and tumorigenesis in human GC. Inhibiting miR-103a-3p suppressed GC cell proliferation and blocked the S-G2/M transition in MKN-45/SGC-7901 cells, whereas miR-103a-3p overexpression improved GC cell proliferation and promoted the S-G2/M transition in vitro. Bioinformatics and dual-luciferase reporter assays confirmed that ATF7 is a direct target of miR-103a-3p. Analysis of the TCGA stomach cancer cohort further revealed that miR-103a-3p expression was inversely correlated with ATF7 expression. Notably, silencing ATF7 showed similar cellular and molecular effects as miR-103a-3p overexpression, namely, increased GC cell proliferation, improved CDK2 expression and decreased P27 expression. ATF7 overexpression eliminated the effects of miR-103a-3p expression. These findings indicate that miR-103a-3p promotes the proliferation of GC cell by targeting and suppressing ATF7 in vitro.