Effect of acetylalkannin from Arnebia euchroma on proliferation, migration, and invasion of human melanoma A375 cells / 中国中药杂志

This study aimed to explore the effect and mechanism of acetylalkannin from Arnebia euchroma on the proliferation, migration, and invasion of human melanoma A375 cells. A375 cells were divided into a blank group, and low-, medium-, and high-dose acetylalkannin groups(0.5, 1.0, and 2.0 μmol·L~(-1)). The MTT assay was used to detect cell proliferation. Cell scratch and transwell migration assays were used to detect cell migration ability, and the transwell invasion assay was used to detect cell invasion ability. Western blot was used to detect the protein expression of migration and invasion-related N-cadherin, vimentin, matrix metalloproteina-se-9(MMP-9), and Wnt/β-catenin pathway-related Wnt1, Axin2, glycogen synthase kinase-3β(GSK-3β), phosphorylated GSK-3β(p-GSK-3β), β-catenin, cell cycle protein D_1(cyclin D_1), and p21. Real-time fluorescence-based quantitative polymerase chain reaction(real-time PCR) was used to detect the mRNA expression of E-cadherin, matrix metalloproteinase-2(MMP-2), N-cadherin, vimentin, β-catenin, snail-1, and CD44. MTT results showed that the cell inhibition rates in the acetylalkannin groups significantly increased as compared with that in the blank group(P<0.01). The results of cell scratch and transwell assays showed that compared with the blank group, the acetylalkannin groups showed reduced cell migration and invasion, and migration and invasion rates(P<0.05, P<0.01) and weakened horizontal and vertical migration and invasion abilities. Western blot results showed that compared with the blank group, the high-dose acetylalkannin group showed increased expression of Axin2 protein(P<0.05), and decreased expression of N-cadherin, vimentin, MMP-9, Wnt1, p-GSK-3β, β-catenin, cyclin D_1, and p21 proteins(P<0.05, P<0.01). The expression of GSK-3β protein did not change significantly. PCR results showed that the overall trend of MMP-2, N-cadherin, vimentin, β-catenin, snail-1, and CD44 mRNA expression was down-regulated(P<0.01), and the expression of E-cadherin mRNA increased(P<0.01). Acetylalkannin can inhibit the proliferation, migration, and invasion of human melanoma A375 cells, and its mechanism of action may be related to the regulation of Wnt/β-catenin signaling pathway.

Mantle cell lymphoma presenting with lethal atraumatic splenic rupture

Mantle cell lymphoma is characterized by t(11;14) with CCND1-IGH fusion and manifests with a spectrum of disease ranging from relatively indolent to aggressive. Here, we present a case of pleomorphic mantle cell lymphoma with three fusion signals that presented with lethal atraumatic splenic rupture. We discuss on the implications of variant CCND1 signal patterns as well as the epidemiology and pathophysiology of atraumatic splenic rupture.

Various Wavelengths of Light-Emitting Diode Light Regulate the Proliferation of Human Dermal Papilla Cells and Hair Follicles via Wnt/β-Catenin and the Extracellular Signal-Regulated Kinase Pathways

BACKGROUND: The human dermal papilla cells (hDPCs) play an important role in regulation of hair cycling and growth. OBJECTIVE: The aim of this study was to investigate the effect of different wavelengths of light-emitting diode (LED) irradiation on the proliferation of cultured hDPCs and on the growth of human hair follicles (HFs) in vitro. METHODS: We examined the effect of LED irradiation on Wnt/β-catenin signaling and mitogen-activated protein kinase (MAPK) pathways in hDPCs. Anagen HFs were cultured with LED irradiation and elongation of each hair shaft was measured. RESULTS: The most potent wavelength in promoting the hDPC proliferation is 660 nm and 830 nm promoted hDPC proliferation to a lesser extent than 660 nm. Various wavelengths significantly increased β-catenin, Axin2, Wnt3a, Wnt5a and Wnt10b mRNA expression. LED irradiation significantly increased β-catenin and cyclin D expression, and the phosphorylation of MAPK and extracellular signal-regulated kinase (ERK). HFs irradiated with 415 nm and 660 nm grew longer than control. CONCLUSION: Our result suggests that LED has a potential to stimulate hDPC proliferation via the activation of Wnt/β-catenin signaling and ERK pathway. To our best knowledge, this is the first report which investigated that the effect of various wavelengths of LED on hDPC proliferation and the underlying mechanisms.

Overexpression of Cell Cycle Proteins of Peripheral Lymphocytes in Patients with Alzheimer's Disease

OBJECTIVE: Biological markers for Alzheimer's disease (AD) will help clinicians make objective diagnoses early during the course of dementia. Previous studies have suggested that cell cycle dysregulation begins earlier than the onset of clinical manifestations in AD. METHODS: We examined the lymphocyte expression of cell cycle proteins in AD patients, dementia controls (DC), and normal controls (NC). One-hundred seventeen subjects (36 AD, 31 DC, and 50 NC) were recruited. The cell cycle proteins CDK2, CDK4, CDK6, cyclin B, and cyclin D were measured in peripheral lymphocytes. Cell cycle protein expression in the three groups was compared after adjusting for age and sex. RESULTS: The levels of cell cycle proteins CDK2, CDK4, CDK6, cyclin B, and cyclin D were significantly higher in AD patients than in the NC subjects. The DC group manifested intermediate levels of cell cycle proteins compared with the AD patients and the NC subjects. The present study indicates that cell cycle proteins are upregulated in the peripheral lymphocytes of AD patients. CONCLUSION: Cell cycle dysregulation in peripheral lymphocytes may present a promising starting point for identifying peripheral biomarkers of AD.

Novel prognostic biomarkers for HCC progression in Egyptian patients

Objectives: To evaluate values of Cyclin D and Cdk4 in HCC, chronic hepatitis C, HCV related liver cirrhosis and healthy controls, their clinico-radiological correlations and prognosis of HCC

Methods: Group 1: Fifty patients with HCC, Group 2.Fifty patients with chronic hepatitis C with or without cirrhosis and Group 3: Thirty healthy controls were enrolled. All patients were positive for hepatitis C virus [HCV] antibody and confirmed by HCV RNA. Calculation of Barcelona-Clinic Liver Cancer [BCLC] staging system, MELD and Child-Pugh scores. mRNA for cyclin Dl and Cdk4 were analyzed by quantitative RT-PCR

Results: The mean Cyclin Dl and Cdk4 values were higher in HCC group compared with the other two groups [p value= 0.001]. In HCC group, the mean Cdk4 and cyclin Dlvalues were significantly higher among HCC patients with multiple hepatic focal lesion [HFL] [p value= 0. 0001, and003 respectively] compared with those with single lesion. A significant correlation between size of [HFL], alpha-Fetoprotein[AFP] and mean Cdk4 value [p value= 0.028, 0.0001 respectively]

Conclusions: Significant values of cyclin Dl and Cdk4 were found in HCC, compared to normal and chronic hepatitis C and correlated to the number, size of HFL and AFP level. Thus, the assessment of cyclin Dl and Cdk4 may provide a novel strategy for prognostication and targeted therapy of HCC

Molecular markess of mucosa harboring gastric adenoass

Context Gastric adenoma is a precursor lesion of the adenocarcinoma. Objective To characterize gastric adenomas according to the mucin immunoexpression and to evaluate the immunoexpression of p53, p16ink4a, BCL-2, cyclin D, Ki-67, in the adenoma and in the gastric mucosa harboring adenoma. Methods Forty gastric specimens from 20 patients were classified as intestinal (MUC2 - goblet cell mucin) or foveolar (MUC5AC - gastric-foveolar mucin) adenomas. Immunohistochemistry was performed using streptavidin-biotin-complex method. Results Twelve (60%) patients were men. The mean age was 67.9 ± 12.9 years-old. Intestinal adenomas were detected in 13 (65%) patients and gastric type in 7 (35%). Low-grade dysplasia was present in 13 (65%) of the adenomas, high-grade in 3 (15%), and adenocarcinoma within the polyp in 4 (20%). Six (30%) patients had synchronous adenocarcinoma. p53 immunoexpression was observed in 6/20 (30%) of adenomas, and in 2/6 (33.3%) of synchronous tumors. There was an association between p53 immunoexpression and intestinal type of adenoma/tumor, P = 0.04. There was no association between p16ink4a, Bcl-2, cyclin D and Ki-67 and adenoma clinicopathological characteristics. Conclusion Immunohistochemistry may be useful to classify the adenomas subtypes and may define the pathway of adenoma to carcinoma sequence. .

Contexto Adenoma gástrico é uma lesão precursora do adenocarcinoma. Objetivo Melhor caracterizar os adenomas de acordo com a imunoexpressão de mucinas e avaliar a imunoexpressão de p53, p16ink4a, BCL-2, cyclin D, Ki-67, nos adenomas e na mucosa gástrica adjacente. Métodos Quarenta espécimes gástricos provenientes de 20 pacientes portadores de adenomas foram classificados como do tipo intestinal (MUC2 – mucina presente nas células caliciformes) ou gástrico (MUC5AC – mucinas de padrão foveolar). Realizou-se imunoistoquímica para p53, p16ink4a, BCL-2, cyclin D e Ki-67 pelo método do complexo da estreptavidina-biotina. Resultados Doze (60%) pacientes eram homens e a média de idade foi de 67,9 ± 12,9 anos. Os adenomas foram classificados como do tipo intestinal em 13 (65%) pacientes e do tipo gástrico em 7 (35%). Displasia (neoplasia intraepitelial) de baixo grau estava presente em 13 (65%), displasia de alto grau em 3 (15%), e adenocarcinoma no pólipo adenomatoso em 4 (20%) pacientes. Observou-se immunoexpressão do p53 em 6/20 (30%) adenomas, e em 2/6 (33,3%) dos tumores sincrônicos. Houve associação entre imunoexpressão do p53 e adenoma/tumor tipo intestinal, P = 0.04. Não houve associação entre imunoexpressão do p16ink4a, Bcl-2, ciclina D e Ki-67 e as características clinicopatológicas dos adenomas. Conclusão Imunoistoquímica pode ser utilizada para caracterizar os subtipos de adenoma e talvez indicar o caminho de carcinogênese. .

Retinoic Acid Increases the Cell Cycle Progression of Human Gingival Fibroblasts by Increasing Cyclin E and CDK 2 Expression and Decreasing p21WAF1/CIP1 and p16INK4A Expression

Retinoic acid plays an important role in the regulation of cell growth and differentiation. In our present study, we evaluated the effects of all-trans retinoic acid (RA) on cell proliferation and on the cell cycle regulation of human gingival fibroblasts (HGFs). Cell proliferation was assessed using the MTT assay. Cell cycle analysis was performed by flow cytometry, and cell cycle regulatory proteins were determined by western blot. Cell proliferation was increased in the presence of a 0.1 nM to 1 microM RA dose range, and maximal growth stimulation was observed in cells exposed to 1 nM of RA. Exposure of HGFs to 1 nM of RA resulted in an augmented cell cycle progression. To elucidate the molecular mechanisms underlying cell cycle regulation by RA, we measured the intracellular levels of major cell cycle regulatory proteins. The levels of cyclin E and cyclin-dependent kinase (CDK) 2 were found to be increased in HGFs following 1 nM of RA treatment. However, the levels of cyclin D, CDK 4, and CDK 6 were unchanged under these conditions. Also after exposure to 1 nM of RA, the protein levels of p21WAF1/CIP1 and p16INK4A were decreased in HGFs compared with the control group, but the levels of p53 and pRb were similar between treated and untreated cells. These results suggest that RA increases cell proliferation and cell cycle progression in HGFs via increased cellular levels of cyclin E and CDK 2, and decreased cellular levels of p21WAF1/CIP1 and p16INK4A.

Sunitinib Malate Synergistically Potentiates Anti-Tumor Effect of Gemcitabine in Human Bladder Cancer Cells

PURPOSE: Sunitinib malate (Sutent; Pfizer, New York, NY, USA) is a highly selective multi-targeted agent and has been reported to have potent anti-tumor effects against various tumors, including renal cell carcinoma and gastrointestinal stromal tumors. In this study, we explored in vitro the anti-tumor effect and related molecular mechanisms of sunitinib malate against human bladder cancer cell lines. We also determined the synergistic anti-tumor effect between sunitinib and conventional cytotoxic drugs, cisplatin and gemcitabine, in bladder cancer cells. MATERIALS AND METHODS: Six human cancer cell lines (HTB5, HTB9, T24, UMUC14, SW1710, and J82) were exposed to an escalating dose of sunitinib alone or in combination with cisplatin/gemcitabine, and the cytotoxic effect of the drugs was examined by CCK-8 assay. The synergistic effect between sunitinib and cisplatin/gemcitabine was determined by the combination index (CI) and clonogenic assay. Alterations in cell cycle (cyclin D, B1), survival (p-Akt, t-Akt), and apoptosis (Bax, Bad) regulator expression were analyzed by Western blotting. RESULTS: Like cisplatin and gemcitabine, sunitinib exerted a dose- and time-dependent anti-tumor effect in bladder cancer cells. However, sunitinib exhibited entirely different sensitivity profiles from cisplatin and gemcitabine. Sunitinib suppressed the expression of cyclin B1, p-Akt, and t-Akt while augmenting the expression of cyclin D and pro-apoptotic Bax and Bad in HTB5 cells. Analysis of the drug combination by the isobolic method and clonogenic assay revealed that sunitinib acts in synergy with gemcitabine in HTB5 cells. CONCLUSIONS: These results indicate that sunitinib malate has a potent anti-tumor effect and may synergistically enhance the anti-tumor effect of gemcitabine in human bladder cancer cells.

Losartan Inhibits Vascular Smooth Muscle Cell Proliferation through Activation of AMP-Activated Protein Kinase

Losartan is a selective angiotensin II (Ang II) type 1 (AT1) receptor antagonist which inhibits vascular smooth muscle cells (VSMCs) contraction and proliferation. We hypothesized that losartan may prevent cell proliferation by activating AMP-activated protein kinase (AMPK) in VSMCs. VSMCs were treated with various concentrations of losartan. AMPK activation was measured by Western blot analysis and cell proliferation was measured by MTT assay and flowcytometry. Losartan dose- and time-dependently increased the phosphorylation of AMPK and its downstream target, acetyl-CoA carboxylase (ACC) in VSMCs. Losartan also significantly decreased the Ang II- or 15% FBS-induced VSMC proliferation by inhibiting the expression of cell cycle associated proteins, such as p-Rb, cyclin D, and cyclin E. Compound C, a specific inhibitor of AMPK, or AMPK siRNA blocked the losartan-induced inhibition of cell proliferation and the G0/G1 cell cycle arrest. These data suggest that losartan-induced AMPK activation might attenuate Ang II-induced VSMC proliferation through the inhibition of cell cycle progression.

A Case of Mantle Cell Lymphoma with Skin Metastasis / 대한피부과학회지

Mantle cell lymphoma is a malignant lymphoma derived from a subset of B-cells that are localized in the mantle area of the lymphoid follicle. Extranodal involvement is frequent, and especially in the bone marrow, spleen, gastrointestinal tract and Waldeyer's ring, but skin is rarely affected. A 47-year-old male presented with a 40 day history a nodule on the abdomen on the abdomen. The histopathologic examination showed numerous atypical, small to medium sized lymphoid cells in the entire dermis. Immunohistochemically, the tumor cells were positive for CD20, CD5, CD79a and cyclin D. Our patient showed complete disappearance of his skin lesions and lymphadenopathy after combination chemotherapy.

Heme Oxygenase-1 Induced by Aprotinin Inhibits Vascular Smooth Muscle Cell Proliferation Through Cell Cycle Arrest in Hypertensive Rats

Spontaneous hypertensive rats (SHR) are an established model of genetic hypertension. Vascular smooth muscle cells (VSMC) from SHR proliferate faster than those of control rats (Wistar-Kyoto rats; WKY). We tested the hypothesis that induction of heme oxygenase (HO)-1 induced by aprotinin inhibits VSMC proliferation through cell cycle arrest in hypertensive rats. Aprotinin treatment inhibited VSMC proliferation in SHR more than in normotensive rats. These inhibitory effects were associated with cell cycle arrest in the G1 phase. Tin protoporphyrin IX (SnPPIX) reversed the anti-proliferative effect of aprotinin in VSMC from SHR. The level of cyclin D was higher in VSMC of SHR than those of WKY. Aprotinin treatment downregulated the cell cycle regulator, cyclin D, but upregulated the cyclin-dependent kinase inhibitor, p21, in VSMC of SHR. Aprotinin induced HO-1 in VSMC of SHR, but not in those of control rats. Furthermore, aprotinin-induced HO-1 inhibited VSMC proliferation of SHR. Consistently, VSMC proliferation in SHR was significantly inhibited by transfection with the HO-1 gene. These results indicate that induction of HO-1 by aprotinin inhibits VSMC proliferation through cell cycle arrest in hypertensive rats.

The initial mechanism's investigation of pilose antler polypeptides resisting replicative senescence of rat chondrocyte / 中国骨伤

<p><b>OBJECTIVE</b>To investigate the mechanism of pilose antler polypeptides (PAP) resisting replicative senescence of rat chondrocyte serially subcultivated in vitro by means of PAP interfering and controlled experiment.</p><p><b>METHODS</b>The successive tert-generation (2nd passage, 3rd passage, 4th passage) chondrocytes and the 4th passage cells intervented by PAP were studied for senenscence mechanism. In this course, immunocytochemistry was applied for pl6, pRb, E2F, CyclinD, CDK4 and TRAP-ELISA (telomerase repeat amplification protocol assay-enzyme linked immunosorbent assay) was applied for telomerase activation to observe targets' changing regarding to senescence and the function of PAP.</p><p><b>RESULTS</b>Along with cell's replicative senescence, pl6, pRb and Cyclin D express significantly rised (P < 0.01), while E2F, CDK4 and telomerase express significantly lowerd (P < 0.01). Meanwhile, in PAP interfered group compared with which in 4th passage group, pl6, pRb and Cyclin D express significantly lowerd (P < 0.01l), while E2F, CDK4 and telomerase express significantly rised (P < 0.01).</p><p><b>CONCLUSION</b>PAP has function that it reversingly affect the express of factors which controlling cell life cycle and cell growth to postpone chondrocyte senenscence.</p>

Methylation Patterns of Cancer-Associated Genes in Breast Cancer / 한국유방암학회지

PURPOSE: To investigate the methylation status of cancerassociated genes in breast cancer to assess its use in the diagnosis of breast cancer and the relationship with distinctive clinical and pathological features. METHODS: A total of 29 benign tumors and their adjacent normal tissues as well as 67 malignant tumors and adjacent normal samples, from women undergoing surgery for primary invasive breast carcinoma at Uijongbu St. Mary's Hospital, between March 2003 and March 2005, were used. Eleven candidate genes were chosen; P14, P16, DAPK, MGMT, h-MLH, E-cadherin, RASSF1 , Twist, RAR , HIN-1, and Cyclin D. DNA was extracted from fresh tissues, and methylation specific PCR performed. RESULT: The number of methylated genes was increased in the malignant tissues compared to the benign tumors and adjacent normal tissues. 7 genes; P14, P16, MGMT, RASSF1, Twist, RAR beta and Cyclin D, were more frequently methylated in malignant than benign tumors, with the differences in the p14, p16, and RAR beta genes were statistically significant (p<0.05). In benign tumors, the p16 and HIN-1 genes were the most infrequently (6.9%) and frequently methylated (82.8 %), respectively. In malignant tumors, the h-MLH and RASSF1 genes were most infrequently and frequently methylated genes, respectively. The ubgroup showing methylation of the DAPK gene had a higher nuclear grade and greater progesterone receptor negativity. The group in which the RASSF1 gene was methylated, had greater estrogen receptor (ER) and progesterone receptor (PgR) positivities. The Twist gene was frequently methylated in the subgroup showing higher nuclear and histologic grades. The group with HIN- 1 and cyclin D methylation had a tendency to show greater ER positivity. CONCLUSION: The subgroups showing methylated DAPK and Twist should be more intensely treated and followed up more carefully than those with RASSF1 , HIN-1 and Cyclin D methylation. Gene methylation may be linked to various pathological features of breast cancer; however, this will require confirmation from larger studies.

Effect of sodium butyrate in combination with ATRA on the proliferation/differentiation of MDS cell line SKM-1 / 中国实验血液学杂志

The study was purposed to explore the molecular mechanisms of sodium butyrate (NaB) action on SKM-1 cell proliferation/differentiation and to study its synergistic effect with all-trans retinoic acid (ATRA). SKM-1 cells were grown in the absence or presence of NaB and/or ATRA; the percentage of viable cells was determined by trypan blue exclusion; differentiation was investigated by nitro-blue tetrazolium (NBT) reduction; adhesion molecules of cell surface were analysed by FACS; cell cycle distribution was studied after DNA staining by propidium iodide; D-type cyclins, CDK and P21 mRNA were detected by reverse transcription-polymerase chain reaction (RT-PCR). The results showed that NaB and/or ATRA blocked cells mainly in the G0/G1 phase of the cell cycle; ATRA inhibited the mRNA expression of CDK6, CDK4, cyclin D3 and cyclin D1; NaB inhibited the mRNA expression of CDK2, cyclin D2 and cyclin D1; ATRA and NaB inhibited the mRNA expression of CDK6, CDK4, CDK2, cyclin D1, cyclin D2 and cyclin D3; ATRA and/or NaB both stimulated p21 expression at the mRNA levels. It is concluded that the NaB effect on cell proliferation/differentiation may be linked to its ability to induce expression of p21 mRNA and inhibit the cyclin D-CDK complexes. These observations support the claim that NaB has the synergistic effect with ATRA.

The effects of interferon-gamma on the expression of the cyclin D isoforms in cord blood hematopoietic stem/progenitor cells / 中国实验血液学杂志

To explore the hematopoiesis inhibition mechanisms of interferon-gamma (IFN-gamma), the effects of IFN-gamma on the expression of the cyclin D in the umbilical cord blood hematopoietic stem/progenitor cells were observed. In the experiments the CD34(+) cells were isolated from the cord blood with MIDI-MACS system; semi-solid methylcellulose culture technique was used to measure the formation of CFU-GM; the expression levels of cyclin D isoforms were assayed by semi-quantitative RT-PCR, after the hematopoietic stem/progenitor cells were incubated with IFN-gamma. The results indicated that IFN-gamma could inhibit the formation of CFU-GM and down-regulate the expression of cyclin D2 and cyclin D3 at the mRNA level. It is concluded that the IFN-gamma could inhibit the proliferation of hematopoietic stem cells and down-regulate the expression of cyclin D, that may be one mechanism underlying the hematopoietic inhibition of IFN-gamma.

Immunohistochemical study of p21 and p53 expression in ameloblastoma

The p53 protein was discovered in 1979 as cellular 53-kD nuclear phosphoprotein bound to the large transforming antigen of SV40 virus. P21WAF1/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.

Effect of irradiation on cell cycle, cell death and expression of its related proteins in normal human oral keratinocytes / 대한구강악안면방사선학회지

PURPOSE: To investigate the radiosensitivity of the normal human oral keratinocytes (NHOK), and the effect of irradiation on cell cycle and protein expression. MATERIALS AND METHODS: To evaluate the radiosensitivity of NHOK, the number of colonies and cells were counted after irradiation and the SF2 (survival fraction at 2 Gy) value, and the cell survival curve fitted on a linear-quadratic model were obtained. LDH analysis was carried out to evaluate the necrosis of NHOK at 1, 2, 3, and 4 days after 2, 10, and 20 Gy irradiation. Cell cycle arrest and the induction of apoptosis were analyzed using flow cytometry at 1, 2, 3, and 4 days after 2, 10, and 20 Gy irradiation. Finally, proteins related cell cycle arrest and apoptosis were analysed by Western blot. RESULTS: The number of survived cell was significantly decreased in a dose-dependent manner. The cell survival curve showed SF2, alpha, and beta values to be 0.568, 0.209, and 0.020 respectively. At 20 Gy irradiated cells showed higher optical density than the control group. After irradiation, apoptosis was not observed but G2 arrest was observed in the NHOK cells. 1 day after 10 Gy irradiation, the expression of p53 remained unchanged, the p21 (WAF1/Cip1) increased and the mdm2 decreased. The expression of bax, bcl-2, cyclin B1, and cyclin D remained unchanged. CONCLUSION: These results indicate that NHOK responds to irradiation by G2 arrest, which is possibly mediated by the expression of p21 WAF1/Cip1, and that cell necrosis occurs by high dose irradiation.

Influence of glucagon-like peptide-2 on the proliferation of the intestinal mucosal cells in scalded rats / 中华烧伤杂志

<p><b>OBJECTIVE</b>To explore the influence of glucagon-like peptide-2 (GLP-2) on the proliferation of the intestinal mucosal cells in scalded rats.</p><p><b>METHODS</b>Fifty-five Wistar rats were employed in the study and were randomly divided into normal control (C), simple scald (S) and scald with GLP-2 treatment (G) groups. The rats in G group received GLP-2 introperitoneally in a dose of 200 micro g/kg two times a day. The rats in S and G groups were sacrificed at 6 postburn hours (PBHs), 12 PBHs, 1 postburn day (PBD1), PBD3 and PBD5 and the rats in C group were also sacrificed. Plasma diamine oxidase (DAO) activity, cell cycle protein cyclin D expression and the proliferating cell nuclear antigen (PCNA) in all groups were determined. And the histological change in the intestinal mucosal tissue was observed simultaneously. with all the above determinations.</p><p><b>RESULTS</b>Compared with those in C group, the PCNA expression at 6 and 12 PBHs in S group was enhanced slightly and weakened at PBD1, reaching the lowest level at PBD3 and it was still lower than that in C group at PBD5. Changes in PCNA in G group were similar to that in S group, except that the expression at PBD3 and PBD5 was stronger than that in S group. The intestinal mucosal cyclin D protein expression was increased at 6 and 12 PBHs in S group, but decreased by 40% before injury at PBD1. Nevertheless, the cyclin D protein expression in G group was much higher than that in S group at PBD1, PBD3 and PBD5. The plasma DAO activity increased significantly in rats after burn injury. But the activity decreased obviously after GLP-2 treatment for 5 days (P < 0.01). It was observed histologically in G group that the lining of Exogenous intestinal villi was regular and well arranged without evident epithelial exfoliation.</p><p><b>CONCLUSION</b>Exogenous GLP-2 might ameliorate intestinal mucosal injury in scalded rats, and promotion of the expression of PCNA and cyclin D, resulting in proliferation of injured intestinal mucosal cells, might be the underlying mechanisms.</p>

Effects of hexamethylene bisacetamide on cell cycle and expression of its regulatory proteins in HL-60 cells / 中国实验血液学杂志

Hexamethylene bisacetamide (HMBA) is referred as a differentiation-inducer for the clinical treatment of acute myeloid leukemia and myelodysplastic syndrome. However, the molecular mechanism of the effects of HMBA on myeloid leukemic cells remains unknown. In this study, the effects of HMBA on cell cycle and expression of cell cycle regulatory proteins in HL-60 cell were investigated in order to explore its pharmacological mechanism. The altered distribution of cell cycle and expression of its regulatory proteins (cyclin D, cyclin E and p27) in HL-6 0 cell induced by HMBA were analyzed by flow cytometry. The effects on transcription for mRNA of CKI p15, p16 and p27 in HL-60 cell were further studied by RT-PCR. The results showed that HMBA could mainly commit HL-60 cell to G0/G1 arrest and the significantly decreased endocytic cyclin E protein and increased cyclin D/p27 protein after HMBA treatment were found. There was no expression of p15, p16 mRNA in untreated HL-60 cell and 3 mmol/L of HMBA could make them expressed after exposed for 24 h or 48 h respectively. The expression of p27 mRNA was positive and no obviously different in untreated HL-60 cells exposed for 24 h, 48 h and 72 h. These results suggested that one of the pharmacological mechanisms of HMBA was to elevate the expression of p27 and reduce the cyclin E expression as well as to activate the expression of p15, p16 gene mRNA, that arrested cell at G0/G1 and exerted its effects of anti-proliferation.

Effect and comparison of sodium butyrate and trichostatin A on the proliferation/differentiation of K562 / 华中科技大学学报（医学）（英德文版）

In order to explore the molecular mechanisms of sodium butyrate and trichostatin A on K562 cell proliferation/differentiation, K562 cells were grown in the absence or presence of sodium butyrate or trichostatin A. The percentage of viable cells was determined by trypan blue exclusion. Differentiation was determined by nitro-blue tetrazolium (NBT) reduction and cell surface adhesion molecules analyzed by FACS. Cell cycle distribution was studied after DNA staining by propidium iodide. Cell cycle regulatory proteins were detected by Western blot and reverse transcription-polymerase chain reaction. The results showed that sodium butyrate blocked cells mainly at the G0/G1 phase of the cell cycle, whereas trichostatin A arrested the cells at G2 phase. Sodium butyrate could down-regulate the mRNA expression of cyclin D1, but not affect its protein expression; down-regulate the protein expression of cyclin D3, but not affect its mRNA expression. Trichostatin A showed similar effects on cyclin D1 and D3 as sodium butyrate. Both sodium butyrate and trichostatin A could stimulate p21 expression of K562 cells at mRNA and protein levels. It may be concluded that sodium butyrate and trichostatin A could promote the proliferation/differentiation of the K562 cells, which might be contributed to the induced expression of cyclin D3 and p21 proteins.