Identification of Molecular Signatures in Mild Intrinsic Atopic Dermatitis by Bioinformatics Analysis

BACKGROUND: Atopic dermatitis (AD) is recognized as a common inflammatory skin disease and frequently occurred in Asian and Black individuals.OBJECTIVE: Since the limitation of dataset associated with human severe AD, this study aimed to screen potential novel biomarkers involved in mild AD.METHODS: Expression profile data (GSE75890) were obtained from the database of Gene Expression Omnibus. Using limma package, the differentially expressed genes (DEGs) between samples from AD and healthy control were selected. Furthermore, function analysis was conducted. Meanwhile, the protein-protein interaction (PPI) network and transcription factor (TF)-miRNA-target regulatory network were constructed. And quantitative real-time polymerase chain reaction (qRT-PCR) was used to validate the expressions patterns of key genes.RESULTS: In total, 285 DEGs including 214 upregulated and 71 downregulated genes were identified between samples from two groups. The upregulated DEGs were mainly involved in nine pathways, such as hematopoietic cell lineage, pertussis, p53 signaling pathway, staphylococcus aureus infection, and cell cycle, while tight junction was the only pathway enriched by the downregulated DEGs. Cyclin B (CCNB)1, CCNB2, cyclin A (CCNA)2, C-X-C motif chemokine ligand (CXCL)10, and CXCL9 were key nodes in PPI network. The TF-miRNA-target gene regulatory network focused on miRNAs such as miR-106b, miR-106a, and miR-17, TFs such as nuclear factor kappa B subunit 1, RELA proto-oncogene, Sp1 transcription factor, and genes such as matrix metallopeptidase 9, peroxisome proliferator activated receptor gamma , and serpin family E member 1. Moreover, the upregulation of these genes, including CCNB1, CCNB2, CCNA2, CXCL10, and CXCL9 were confirmed by qRT-PCR.CONCLUSION: CCNB1, CCNB2, CCNA2, and CXCL9 might be novel markers of mild AD. miR-106b and miR-17 may involve in regulation of immune response in AD patients.

Induction of Melanoma Cell-Selective Apoptosis Using Anti-HER2 Antibody-Conjugated Gold Nanoparticles

PURPOSE: This study was conducted to verify the induction and mechanism of selective apoptosis in G361 melanoma cells using anti-HER2 antibody-conjugated gold nanoparticles (GNP-HER2). MATERIALS AND METHODS: Following GNP-HER2 treatment of G361 cells, cell cycle arrest and apoptosis were measured by WST-1 assay, Hemacolor staining, Hoechst staining, immunofluorescence staining, fluorescence-activated cell sorting analysis, and Western blotting.

Anti-proliferative Effect of 15,16-Dihydrotanshinone I Through Cell Cycle Arrest and the Regulation of AMP-activated Protein Kinase/Akt/mTOR and Mitogen-activated Protein Kinase Signaling Pathway in Human Hepatocellular Carcinoma Cells

BACKGROUND: 15,16-dihydrotanshinone I (DHTS) is a natural abietane diterpenoid that is mainly found in the roots of Salvia miltiorrhiza Bunge (Labiatae). DHTS exhibits a potential anti-proliferative effect in various human cancer cells. However, the mechanisms of action of DHTS as an anti-cancer agent have not been fully elucidated. Therefore, the present study investigated the anti-cancer effect of DHTS in terms of cell cycle regulation and the regulation of the AMP-activated protein kinase (AMPK)/Akt/mTOR signaling pathway in SK-HEP-1 human hepatocellular carcinoma cells. METHODS: The anti-proliferative effects of DHTS were evaluated by the sulforhodamine B assay in SK-HEP-1 cells. Cell cycle distribution was analyzed by flow cytometry. The elucidation of mechanisms of action such as the AMPK/AKT/mTOR and mitogen-activated protein kinase (MAPK) pathway was assessed by Western blot analysis. RESULTS: DHTS showed a significant anti-proliferative activity against SK-HEP-1 cells. DHTS induced cell cycle arrest in the G0/G1 phase, which was mediated by downregulation of cyclin D1, cyclin A, cyclin E, CDK4, CDK2, c-Myc and p-Rb expression and with increased expression of the CDK inhibitor p21. DHTS also activated the AMPK signaling. In addition, DHTS downregulated the Akt/mTOR and MAPK signaling pathways. CONCLUSIONS: Our results suggest that the anti-proliferative activity of DHTS might be associated with the induction of G0/G1 phase cell cycle arrest and regulation of AMPK/Akt/mTOR and MAPK signaling pathways in SK-HEP-1 cells.

Cellular Effects of Troglitazone on YD15 Tongue Carcinoma Cells

An FDA approved drug for the treatment of type II diabetes, Troglitazone (TRO), a peroxisome proliferator–activated receptor gamma agonist, is withdrawn due to severe idiosyncratic hepatotoxicity. In the search for new applications of TRO, we investigated the cellular effects of TRO on YD15 tongue carcinoma cells. TRO suppressed the growth of YD15 cells in the MTT assay. The inhibition of cell growth was accompanied by the induction of cell cycle arrest at G₀/G₁ and apoptosis, which are confirmed by flow cytometry and western blotting. TRO also suppressed the expression of cell cycle proteins such as cyclin D1, cdk2, cdk4, cyclin B1, cdk1(or cdc2), cyclin E1 and cyclin A. The inhibition of cell cycle proteins was coincident with the up-regulation of p21(CIP1/WAF1) and p27(KIP1). In addition, TRO induces the activation of caspase-3 and caspase-7, as well as the cleavage of PARP. Further, TRO suppressed the expressions of Bcl-2 without affecting the expressions of Bad and Bax. Overall, our data supports that TRO induces cell cycle arrest and apoptosis on YD15 cells.

Anti-cancer Activity of Osmanthus matsumuranus Extract by Inducing G2/M Arrest and Apoptosis in Human Hepatocellular Carcinoma Hep G2 Cells

BACKGROUND: Osmanthus matsumuranus, a species of Oleaceae, is found in East Asia and Southeast Asia. The bioactivities of O. matsumuranus have not yet been fully understood. Here, we studied on the molecular mechanisms underlying anti-cancer effect of ethanol extract of O. matsumuranus (EEOM). METHODS: Inhibitory effect of EEOM on cell growth and proliferation was determined by WST assay in various cancer cells. To investigate the mechanisms of EEOM-mediated cytotoxicity, HepG2 cells were treated with various concentration of EEOM and analyzed the cell cycle arrest and apoptosis induction by flow cytometry, Western blot analysis, 4,6-diamidino-2-phenylindole (DAPI) staining and DNA fragmentation. RESULTS: EEOM showed the cytotoxic activities in a dose-dependent manner in various cancer cell lines but not in normal cells, and HepG2 cells were most susceptible to EEOM-induced cytotoxicity. EEOM induced G2/M arrest in HepG2 cells associated with decreased expression of cyclin-dependent kinase 1 (CDK1), cyclin A and cylcin B, and increased expression of phospho-checkpoint kinase 2, p53 and CDK inhibitor p21. Immunofluorescence staining showed that EEOM-treated HepG2 increased doublet nuclei and condensed actin, resulting in cell rounding. Furthermore, EEOM-mediated apoptosis was determined by Annexin V staining, chromatin condensation and DNA fragmentation. EEOM caused upregulation of FAS and Bax, activation of caspase-3, -8, -9, and fragmentation of poly ADP ribose polymerase. CONCLUSIONS: These results suggest that EEOM efficiently inhibits proliferation of HepG2 cells by inducing both G2/M arrest and apoptosis via intrinsic and extrinsic pathways, and EEOM may be used as a cancer chemopreventive agent in the food or nutraceutical industry.

Anti-obesity effect of EGCG and glucosamine-6-phosphate through decreased expression of genes related to adipogenesis and cell cycle arrest in 3T3-L1 adipocytes / 한국영양학회지

PURPOSE: Several studies have proven that EGCG, the primary green tea catechin, and glucosamine-6-phosphate (PGlc) reduce triglyceride contents in 3T3-L1 adipocytes. The objective of this study is to evaluate the combination effect of EGCG and PGlc on decline of accumulated fat in differentiated 3T3-L1 adipocytes. METHODS: EGCG and PGlc were administered for 6 day for differentiation of 3T3-L1 adipocytes. Cell viability was measured using the CCK assay kit. In addition, TG accumulation in culture 3T3-L1 adipocytes was investigated by Oil Red O staining. We examined the expression level of several genes and proteins associated with adipogenesis and lipolysis using real-time RT-PCR and Western blot analysis. A flow cytometer Calibar was used to assess the effect of EGCG and PGluco on cell-cycle progression of differentiating 3T3-L1 cells. RESULTS: Intracelluar lipid accumulation was significantly decreased by combination treatment with EGCG 60 microM and PGlc 200 microg/m compared with control and EGCG treatment alone. In addition, use of combination treatment resulted in directly decreased expression of PPARgamma, C/EBPalpha, and SREBP1. In addition, it inhibited adipocyte differentiation and adipogenesis through downstream regulation of adipogenic target genes such as FAS, ACSL1, and LPL, and the inhibitory action of EGCG and PGlc was found to inhibit the mitotic clonal expansion (MCE) process as evidenced by impaired cell cycle entry into S phase and the S to G2/M phase transition of confluent cells and levels of cell cycle regulating proteins such as cyclin A and CDK2. CONCLUSION: Combination treatment of EGCG and PGlc inhibit-ed adipocyte differentiation through decreased expression of genes related to adipogenesis and adipogenic and cell cycle arrest in early stage of adipocyte differentiation.

Protective effect and mechanism of astragaloside IV on oxidative stress injury of mesangial cells / 中国中药杂志

<p><b>OBJECTIVE</b>To study the protective effect of astragaloside IV (AS IV) on H2O2 induced human mesangial cells (HMC), and further explore its molecular mechanism.</p><p><b>METHOD</b>The cultured mesangial cells were divided into 5 groups: the normal control group, the H2O2 model group, the AS IV (12.5, 100 nmol x L(-1)) group and the Tempol (1 x 10(5) nmol x L(-1)) group. The MTT method was used to observe cell viability. Hoechst 33258 staining was used to observe the HMC apoptosis and DHE staining was used to detect the generation of reactive oxygen species (ROS). The flow cytometry was used to detect the changes in cell cycle. Western blot was used to detect the expression of Cyclin D1, CyclinA, p38, and T-p38.</p><p><b>RESULT</b>H2O2 (1 x 10(5), 2 x 10(5), 3 x 10(5), and 4 x 10(5) nmol x L(-1)) could induce HMC oxidative stress injury, with significant decrease in the cell survival rate. AS IV (100 nmol x L(-1)) could significantly inhibit HMC oxidative stress injury induced by H2O2 (3 x 10(5) nmol x L(-1)), increase the survival rate of HMC cells, inhibit cell apoptosis, and decrease intracellular ROS production. AS IV could also increase the expression of Cyclin D1, recover normal cell proliferation, and decrease the expression of p38.</p><p><b>CONCLUSION</b>AS IV can protect H2O2 induced oxidative stress injury in mesangial cells. Its mechanisms may be related to inhibiting the p38/MAPK signaling pathway, increasing the expression of Cyclin D1 and decreasing the intracellular ROS oxidative stress injury.</p>

Induction of Selective Cell Death of Oral Squamous Carcinoma Cells by Integrin alpha2 Antibody and EGFR Antibody

Expression Patterns of Ki-67, Cyclin A, and Cyclin D1 during Tooth Development / 체질인류학회지

Dental epithelial and mesenchymal cells that form the teeth undergo dynamic changes in cell cycle during tooth development and morphogenesis. Although proliferation has been known as a key event during odontogenesis, the cell cycle phases and their relations with the complicated molecular mechanisms of tooth development are not fully understood yet. This study comparatively examined the expression patterns of Ki-67, cyclin A, and cyclin D1 during tooth development in the mouse incisor and molar in order to identify the cell-cycle characteristics during odontogenesis. We found that Ki-67 and cyclin A were expressed in the proliferating cells in the dental epithelial and mesenchymal tissues at the bud, cap and bell stages. Cycln D1 showed distinct expression in the incisor odontoblast region and the enamel knot, in which Ki-67 nor cyclin A was expressed. Our results provide specific information on the cell cycle phases during tooth development that may provide clues to relate them with the complex odontogenic mechanisms. Furthermore, we suggest that our findings enlightened the previous studies on the incisor odontoblasts and the enamel knot during tooth development.

LiCl suppresses tumor growth and inhibits DNA replication in prostate cancer / 中华病理学杂志

<p><b>OBJECTIVE</b>To assess the effects of LiCl on prostate cancer growth and to explore the underlying mechanisms.</p><p><b>METHODS</b>Effects of LiCl on cell growth in vitro and in vivo were determined by cell counting and xenografts of prostate cancer cells. Alterations in cell proliferation and the expression of DNA replication-related protein were determined by MTT assay, BrdU incorporation and Western blot.</p><p><b>RESULTS</b>Compared to PBS control group, the number of prostate cancer cells (PC-3) were lower treated with 10 mmol/L LiCl, the number was 1.9×10(5), 4.8×10(5) and the difference was significant (P < 0.05). The inhibition rate of cellular proliferation were 50%, 95% and 98%, respectively, in LiCl group, NaCl and KCl control group, the difference was significant (P < 0.05). The A-Value of BrdU incorporation was 1.5, 1.3 treated with 10 mmol/L, 30 mmol/L LiCl, while the A-value of BrdU incorporation was 4 in PBS control group, the difference was significant (P < 0.05). On the protein level, LiCl downregulates expression of cdc 6, cyclins A and cyclins E, and cdc 25C, and upregulates expression of the CDK inhibitor p21(CIP1). The mean volume and weight of xenograft tumor were 50 mm(3) and 296 mg after LiCl intraperitoneal injection, But PBS control group were 180 mm(3) and 957 mg, the difference was significant (P < 0.05).</p><p><b>CONCLUSION</b>LiCl disrupts DNA replication and suppresses tumor growth of prostate cancer cells in vitro and in vivo.</p>

Ethanol Elicits Inhibitory Effect on the Growth and Proliferation of Tongue Carcinoma Cells by Inducing Cell Cycle Arrest

Cellular effects of ethanol in YD-15 tongue carcinoma cells were assessed by MTT assay, caspase activity assay, Western blotting and flow cytometry. Ethanol inhibited the growth and proliferation of YD-15 cells in a dose- and time-dependent manner in an MTT assay. The effects of ethanol on cell cycle control at low percent range of ethanol concentration (0 to 1.5%), the condition not inducing YD-15 cell death, was investigated after exposing cells to alcohol for a certain period of time. Western blotting on the expression of cell cycle inhibitors showed that p21 and p27 was up-regulated as ethanol concentration increases from 0 to 1.5% whilst the cell cycle regulators, cdk1, cdk2, and cdk4 as well as Cyclin A, Cyclin B1 and Cyclin E1, were gradually down-regulated. Flow cytometric analysis of cell cycle distribution revealed that YD-15 cells exposed to 1.5% ethanol for 24 h was mainly arrested at G2/M phase. However, ethanol induced apoptosis in YD-15 cells exposed to 2.5% or higher percent of ethanol. The cleaved PARP, a marker of caspase-3 mediated apoptosis, and the activation of caspase-3 and -7 were detected by caspase activity assay or Western blotting. Our results suggest that ethanol elicits inhibitory effect on the growth and proliferation of YD-15 tongue carcinoma cells by mediating cell cycle arrest at G2/M at low concentration range and ultimately induces apoptosis under the condition of high concentration.

Expression of Cyclin A, B1, D1, D3, and E in Non-Small Lung Cancers

PURPOSE: Cyclins, and their associated cyclin dependent kinases, regulate progression of the cell cycle through the G1 phase and into the S-phase during the DNA replication process. Cyclin E regulation is an important event in cell proliferation. Despite its importance, abnormalities of these genes and their protein products have yet to be found in lits asoociation with lung cancer. MATERIALS AND METHODS: The relationships between expression of cyclin A, cyclin B1, cyclin D1, cyclin D3, and cyclin E and clinicopathologic factors were investigated in 103 cases with non-small cell carcinomas, using immunohistochemical analysis. RESULTS: The positive immunoreactivity was observed in 51 cases (50%) for cyclin A, 33 cases (32%) for cyclin B1, 83 cases (81%) for cyclin D1, 19 cases (18%) for cyclin D3, and 11 cases (11%) for cyclin E. Expression of cyclin E was significant for lymph node metastasis (p=0.004, Chi-square test). There was no relationship between cyclin A, B1, D1, and E and histological typing, tumor size, lymph node metastasis, or pathological tumor, node and metastasis staging. CONCLUSION: These findings suggest that the expression of cyclin E played a role, to some degree, in the lymph node metastasis.

Immunohistochemical Expressions of Ki-67, Cyclin A, p53, and p16 in Actinic Keratosis, Bowen's Disease and Squamous Cell Carcinoma / 대한피부과학회지

BACKGROUND: Actinic keratosis (AK) and bowen's disease (BD) are pre-cancerous diseases, and are regarded as an early squamous cell carcinoma (SCC). AK and BD can be progressed into SCC. In this process, tumor suppressor and cell proliferative proteins may play important roles. OBJECTIVE: To investigate the differences of expression patterns of the immunohistochemical (IHC) staining and useful markers for differential diagnosis in AK, BD and SCC. METHODS: Biopsy had proven 17 cases of AK, 20 cases of BD and 17 cases of SCC, which were all selected. IHC staining for Ki-67 and cyclin-A, as cell proliferative markers, p53 and p16 as tumor suppressor markers, were performed. Labeling index (LI) and distribution pattern of IHC expressions were measured. RESULTS: LI of Ki-67 in AK, BD and SCC were 30.6%, 60.2% and 54.8%, respectively. LI of cyclin-A in AK, BD and SCC were 9.2%, 24.4% and 24.1%, respectively. LI of p53 in AK, BD and SCC were 20.7%, 37.9%, and 39.9%, respectively. LI of p16 in AK, BD and SCC were 10.6%, 38.3% and 39.9%, respectively. Lower 1/3 was the most frequent distribution pattern in AK in all IHC stains, full thickness lower 2/3 were the most frequent distribution pattern in BD and SCC in all IHC stains. CONCLUSION: LI and distribution pattern of Ki-67, cyclin-A, and p16, as well as the distribution pattern of p53 may be useful markers to differentiate AK from BD and SCC. Higher degree and full-thickness distribution pattern of IHC expressions in all stains may be helpful in the diagnosis of BD, rather than AK.

Mismatch repair, minichromosome maintenance complex component 2, cyclin A, and transforming growth factor β receptor type II as prognostic factors for colorectal cancer: results of a 10-year prospective study using tissue microarray analysis / 中华医学杂志(英文版)

<p><b>BACKGROUND</b>The expression of genes encoding a number of pathogenetic pathways involved in colorectal cancer could potentially act as prognostic markers. Large prospective studies are required to establish their relevance to disease prognosis.</p><p><b>METHODS</b>We investigated the relevance of 19 markers in 790 patients enrolled in a large randomised trial of 5-fluorouracil using immunohistochemistry and chromogenic in situ hybridisation. The relationship between overall 10-year survival and marker status was assessed.</p><p><b>RESULTS</b>Minichromosome maintenance complex component 2 (MCM2) and cyclin A were significantly associated with overall survival. Elevated MCM2 expression was associated with a better prognosis (HR = 0.63, 95%CI: 0.46 - 0.86). Cyclin A expression above the median predicted an improved patient prognosis (HR = 0.71, 95%CI: 0.53 - 0.95). For mismatch repair deficiency and transforming growth factor β receptor type II (TGFBRII) overexpression there was a borderline association with a poorer prognosis (HR = 0.69, 95%CI: 0.46 - 1.04 and HR = 2.11, 95%CI: 1.02 - 4.40, respectively). No apparent associations were found for other markers.</p><p><b>CONCLUSION</b>This study identified cell proliferation and cyclin A expression as prognostic indicators of patient outcome in colorectal cancer.</p>

Effect of Selective Cyclooxygenase 2 Inhibitor in TCDD Pre-exposed Thyroid Papillary Carcinoma Cell Line

BACKGROUND: Cyclooxygenase 2 (COX-2) is related to carcinogenesis and progression of cancer. COX-2 has been detected in thyroid cancer. This suggests that COX-2 inhibitor may be useful to control the growth of thyroid cancer cells as well as the progression of thyroid cancer. Tetrachlorodibenzodioxin (TCDD), acting as an inflammatory cytokine, directly induces the expression of COX-2. We examine whether TCDD controls the effect of COX-2 inhibitor on thyroid cancer cells. METHODS: The effects of TCDD and celecoxib on thyroid papillary carcinoma cell line (SNU790) were examined using cell proliferation and fluorescence-activated cell sorting analysis. Western blot analysis was performed to determine the expressed COX-2 levels and the cell cycle-related proteins. The matrix metalloproteinase-2 (MMP-2) expression and gelatinolytic activity were examined using real time-polymerase chain reaction and zymography. RESULTS: TCDD directly induced the growth of SNU790 and the expression of cyclin D1, cyclin A, cyclin E, p21 and COX-2. Celecoxib suppressed the growth of SNU790 and the expression of cyclin D1 and cyclin E. Celecoxib reduced the MMP-2 expression and the gelatinolytic activity, but those effects were decreased in the SNU790 by either pre-treatment with TCDD or co-treatment with TCDD and celecoxib. CONCLUSIONS: Celocoxib effect is directly reduced depending on the exposure to TCDD. TCDD exposure should be considered in the treatment with Celecoxib.

S Phase Cell Cycle Arrest and Apoptosis is Induced by Eugenol in G361 Human Melanoma Cells

Eugenol is an essential oil found in cloves and cinnamon that is used widely in perfumes. However, the significant anesthetic and sedative effects of this compound have led to its use also in dental procedures. Recently, it was reported that eugenol induces apoptosis in several cancer cell types but the mechanism underlying this effect has remained unknown. In our current study, we examined whether the cytotoxic effects of eugenol upon human melanoma G361 cells are associated with cell cycle arrest and apoptosis using a range of methods including an XTT assay, Hoechst staining, immunocytochemistry, western blotting and flow cytometry. Eugenol treatment was found to decrease the viability of the G361 cells in both a time- and dose-dependent manner. The induction of apoptosis in eugenol-treated G361 cells was confirmed by the appearance of nuclear condensation, the release of both cytochrome c and AIF into the cytosol, the cleavage of PARP and DFF45, and the downregulation of procaspase-3 and -9. With regard to cell cycle arrest, a time-dependent decrease in cyclin A, cyclin D3, cyclin E, cdk2, cdk4, and cdc2 expression was observed in the cells after eugenol treatment. Flow cytometry using a FACScan further demonstrated that eugenol induces a cell cycle arrest at S phase. Our results thus suggest that the inhibition of G361 cell proliferation by eugenol is the result of an apoptotic response and an S phase arrest that is linked to the decreased expression of key cell cycle-related molecules.

The expression of Cyclin A and p21cip1 in fibroblast of hypertrophic scar / 中华整形外科杂志

<p><b>OBJECTIVE</b>To study the relation of the mRNA and protein expression of Cyclin A and p21cip1 in different stages hypertrophic scar fibroblast (FB) with its cell cycle, so as to provide theoretical evidence for intervention therapy of cell cycle gene being used in hypertrophic scar.</p><p><b>METHODS</b>The hypertrophic scar samples at different stages (the third month, the sixth month, the twelfth month, the twenty-fourth month) in 32 cases and the normal skin samples in 8 cases were used in this study. The expression of Cyclin A, p21cip1 mRNA and protein was detected by quantitative real-time PCR and Western Blot. And at the same time, the flow cytometer was used to detect the fibroblastic cell life cycle.</p><p><b>RESULTS</b>1) The expression of Cyclin A mRNA and protein in the third month group, the sixth month group, the twelfth month group, the twenty-fourth month group were 19.34 +/- 2.41, 0.99 +/- 0.11; 19.30 +/- 1.42, 0.96 +/- 0.09; 10.73 +/- 2.93, 0.66 +/- 0.58; 9.29 +/- 0.97, 0.65 +/- 0.14, respectively. And in corresponding stages, the expression of p21cip1 mRNA and protein were 2.80 +/- 0.69, 0.35 +/- 0.07; 4.95 +/- 1.82, 0.44 +/- 0.07; 9.98 +/- 1.19, 0.56 +/- 0.06; 10.25 +/- 1.46, 0.59 +/- 0.06, respectively. The expression intensity of Cyclin A mRNA and protein was no significantly different between the third month group and the sixth month group (P > 0. 05), but it was higher respectively than that in the twelfth month group, the twenty-fourth month group and normal group (P < 0.05). And the expression intensity was no different between the above three groups (P > 0.05). The expression intensity of P21cip1 mRNA and protein in the third month group was lower than that in the sixth month group, but that in the above two groups was lower respectively than that in the twelfth month group, the twenty-fourth month group and normal group (P < 0.05). And the expression intensity had no difference between the three later stage groups (P > 0.05). 2) Most FB were in S and G2/M stage (cycle) in 3rd month, 6th month group. And most FB were in G0/G1 stage (cycle) in 12th month, 24th month group and normal group.</p><p><b>CONCLUSIONS</b>The expression of mRNA and protein of Cyclin A in hypertrophic scar changes from high level to low level as the hypertrophic scar develops, while the expression of P21cip1 changes from low level to high level. The mRNA and protein expression of Cyclin A and p21cip1 respectively are basically corresponded to different stages of hypertrophic scar. The distribution of cell life cycle of fibroblastic are also corresponded to the expression intensity of Cyclin A and p21cip1 in different stages hypertrophic scar. An early stage intervention to the two gene can be effective to prevent from the genesis and development of hypertrophic scar.</p>

Curcumin Induces Downregulation of E2F4 Expression and Apoptotic Cell Death in HCT116 Human Colon Cancer Cells; Involvement of Reactive Oxygen Species

E2F transcription factors and their target genes have been known to play an important role in cell growth control. We found that curcumin, a polyphenolic phytochemical isolated from the plant Curcuma longa, markedly suppressed E2F4 expression in HCT116 colon cancer cells. Hydrogen peroxide was also found to decrease E2F4 protein level, indicating the involvement of reactive oxygen species (ROS) in curucmin-induced downregulation of E2F4 expression. Involvement of ROS in E2F4 downregulation in response to curcumin was confirmed by the result that pretreatment of cells with N-acetylcystein (NAC) before exposure of curcumin almost completely blocked the reduction of E2F4 expression at the protein as well as mRNA level. Anti-proliferative effect of curcumin was also suppressed by NAC which is consistent to previous reports showing curcumin-superoxide production and induction of poly (ADP-ribose) polymerase (PARP) cleavage as well as apoptosis. Expression of several genes, cyclin A, p21, and p27, which has been shown to be regulated in E2F4-dependent manner and involved in the cell cycle progression was also affected by curcumin. Moreover, decreased (cyclin A) and increased (p21 and p27) expression of these E2F4 downstream genes by curcumin was restored by pretreatment of cells with NAC and E2F4 overexpression which is induced by doxycycline. In addition, E2F4 overexpression was observed to partially ameliorate curcumin-induced growth inhibition by cell viability assay. Taken together, we found curcumin-induced ROS down-regulation of E2F4 expression and modulation of E2F4 target genes which finally lead to the apoptotic cell death in HCT116 colon cancer cells, suggesting that E2F4 appears to be a novel determinant of curcumin-induced cytotoxicity.

Effects of DCA on Cell Cycle Proteins in Colonocytes

PURPOSE: Evidence that indicates bile acid is a promoter of colon cancer exists. Deoxycholic acid (DCA) modifies apoptosis or proliferation by affecting intracellular signaling and gene expression. However, because previous studies have been based on studies on colon cancer cell lines, the effect of DCA on normal colonocytes is unknown. METHODS: Normal colonocytes and Caco-2 and HCT116 cells were treated with 20 micrometer and 250 micrometer of DCA, and the effect of different concentrations of DCA was measured based on the expression of cell-cycle-related proteins by using Western blots. RESULTS: The expressions of CDK2 and cyclin D1 for different concentrations of DCA in normal colonocytes and colon cancer cells were similar, but the expressions of cyclin E and A were significantly different. In HCT116 colon cancer cells, the expression of cyclin E increased regardless of the DCA concentration, but in normal colonocytes and Caco-2 cells, the expression of cyclin E was not changed or decreased. In HCT116 colon cancer cells, the expression of cyclin A was not changed or decreased regardless of the DCA concentration, but in normal colonocytes and Caco-2 cells, the expression of cyclin A was increased at a DCA concentration of 20 micrometer. CONCLUSION: The effect of DCA on stimulating cell proliferation suggests that DNA synthesis is stimulated by an increased expression of cyclin E in colon cancer cells. Our results suggest that a low dose of DCA induces cellular proliferation through increased expression of cyclin A and that a high dose of DCA induces decreased expression of cyclin E and CDK2 in normal colonocytes.

Azidothymidine inhibition of telomerase activity and proliferation of TJ905 human glioblastoma cells / 中华病理学杂志

<p><b>OBJECTIVE</b>To investigate the pharmacological effects and underlying mechanism of azidothymidine (AZT) on human glioblastoma cells in vitro.</p><p><b>METHODS</b>The telomerase activity of human glioblastoma TJ905 cells was determined by TRAP assay after 24 hrs' incubation with 50, 100, 200 micromol/L AZT and control vehicle solution. Colony formation efficiencies of the cells were recorded. Cells of the 1st, 3rd and 6th generations were harvested, followed by evaluations of cyclin A protein expression by Western blot, cell cycle distribution by flow cytometry, apoptotic level by single cell gel electrophoresis and proliferation index by Ki-67 immunocytochemical staining.</p><p><b>RESULTS</b>AZT inhibited telomerase activity of TJ905 cells. Cyclin A expression levels in the cells treated with 50 and 100 micromol/L AZT were significantly lower than controls (P < 0.01), and down-regulation of the expression was in a dose- and time-dependent manner. Compared with controls, G(0)/G(1) phase cells were obviously decreased (P < 0.05 approximately 0.01) and S phase cells significantly increased (P < 0.05 approximately 0.01) after treatment with 50, 100 and 200 micromol/L AZT. The cell numbers of G(0)/G(1) and S phases at the 1st generation of above three treated groups changed in a dose-dependent manner, whereas S phase cells increases in all AZT treatment groups and G(0)/G(1) phase cell decrease in group treated with 50 micromol/L AZT were also in a time-dependent manner. Both the apoptotic cells of the 1st and 6th generations of all AZT treatment groups were significantly more than controls (P < 0.05 approximately 0.01), their numbers of the 6th generations of the three groups increased with AZT concentration (P < 0.05 approximately 0.01), and all of them were more than the 1st and 3rd generations of the same dosage group (P < 0.05 approximately 0.01). Colony formation efficiencies and Ki-67 labeling indexes of the three AZT treatment groups were distinctly lower than controls (P < 0.01), and they were also decreased with the elevation of AZT concentration and/or the elongation of the incubating time. The difference of any above parameter had no significance among the 1st, 3rd and 6th generations of control group (P > 0.05).</p><p><b>CONCLUSION</b>AZT blocks S/G(2) conversion of TJ905 cells by inhibition of telomerase activity and cyclin A expression, leading to an enhancement of apoptosis and suppression of cell proliferation.</p>