Knockdown of IGF2BP2 inhibits colorectal cancer cell proliferation, migration and promotes tumor immunity by down-regulating MYC expression / 细胞与分子免疫学杂志

Objective To investigate the effect of insulin-like growth factor 2 mRNA binding protein 2 (IGF2BP2) on the proliferation, migration and tumor immune microenvironment of colorectal cancer cells and its possible molecular mechanism. Methods The Cancer Genome Atlas (TCGA) database was used to analyze the expression levels of IGF2BP2 and MYC in colorectal cancer and adjacent tissues. The expression of IGF2BP2 in HCT-116 and SW480 human colorectal cancer cells was silenced by RNA interference (RNAi), and the silencing effect was detected by quantitative real-time PCR. After knocking down IGF2BP2, colony formation assay, CCK-8 assay and 5-ethynyl-2'-deoxyuridine (EdU) assay were employed to detect cell colony formation and proliferation ability. TranswellTM assay was used to detect cell migration ability. Quantitative real-time PCR was used to detect the mRNA expression of IGF2BP2, MYC, tumor necrosis factor-α (TNF-α), transforming growth factor-β (TGF-β) and interleukin-10 (IL-10). The protein expression of IGF2BP2 and MYC was detected by western blot. The binding ability of IGF2BP2 and MYC in HCT-116 cells was detected by quantitative real-time PCR after RNA immunoprecipitation. Results The results of TCGA database showed that the expression of IGF2BP2 and MYC in colorectal cancer tissues was significantly higher than that in adjacent tissues, and the survival time of colorectal cancer patients with high expression of IGF2BP2 was shorter. After silencing IGF2BP2, the viability, proliferation and migration of HCT-116 and SW480 cells were decreased. The mRNA expression of MYC, TGF-β and IL-10 in IGF2BP2 knockdown group was significantly decreased, while the expression of TNF-α mRNA was increased. The expression of MYC protein and the stability of MYC mRNA were significantly decreased. RIP-qPCR results showed that IGF2BP2 could bind to MYC mRNA. Conclusion Knockdown of IGF2BP2 inhibits colorectal cancer cell proliferation, migration and promotes tumor immunity by down-regulating MYC expression.

Correlation between expression of Lin28B and C-myc in patients with laryngeal squamous cell carcinoma and clinicopathological features and prognosis / 中南大学学报(医学版)

OBJECTIVES@#Laryngeal squamous cell carcinoma (LSCC) is a common malignant tumor of head and neck. Screening of target genes for malignant tumor therapy is one of the focuses of cancer research, with proto-oncogene and tumor suppressor gene as the breakthrough. It has become an urgent need to find the target gene related to the treatment and prognosis of LSCC.This study aims to explore the role of Lin28B and C-myc in LSCC by detecting the expressions of these two proteins and analyze the correlation between the expression of Lin28B and C-myc and clinicopathological features and prognosis of LSCC.@*METHODS@#We detected the expression of Lin28B and C-myc proteins in 102 specimens of LSCC and 90 specimens of adjacent tissues by immunochemistry, and analyzed the correlation between Lin28B and C-myc protein expressions in LSCC as well as the correlation between the expressions of the two proteins and the clinicopathological features of LSCC. At the same time, the Kaplan-Meier method was used to analyze the relation between Lin28B and C-myc protein levels with the postoperative survival rate of LSCC patients.@*RESULTS@#The protein levels of Lin28B and C-myc in the LSCC tissnes were significantly higher than those in the adjacent tissues (both P<0.05),and there was a positive correlation between the expression of Lin28B and C-myc in LSCC (r＝0.476, P<0.05). The expression of Lin28B protein was closely related to age, lymph node metastasis, clinical stage, tumor size, and pathological differentiation of LSCC patients (all P<0.05). while the expression of C-myc protein was closely related to lymph node metastasis, clinical stage, tumor size, and pathological differentiation of LSCC patients (all P<0.05). A relevant survival analysis showed that in patients with higher level of Lin28B (P＝0.001) or C-myc protein (P<0.001), the postoperative survival rate was relatively low.@*CONCLUSIONS@#Lin28B and C-myc proteins are highly expressed in LSCC with a positive correlation. Furthermore, they are closely related to lymph node metastasis, clinical stage, tumor size, pathological differentiation and prognosis, suggesting that both Lin28B and C-myc might be involved in the occurrence and development of LSCC.

Effect of Morus alba extract sanggenon C on growth and proliferation of glioblastoma cells / 中国中药杂志

Glioblastoma is the most common primary cranial malignancy, and chemotherapy remains an important tool for its treatment. Sanggenon C(San C), a class of natural flavonoids extracted from Morus plants, is a potential antitumor herbal monomer. In this study, the effect of San C on the growth and proliferation of glioblastoma cells was examined by methyl thiazolyl tetrazolium(MTT) assay and 5-bromodeoxyuridinc(BrdU) labeling assay. The effect of San C on the tumor cell cycle was examined by flow cytometry, and the effect of San C on clone formation and self-renewal ability of tumor cells was examined by soft agar assay. Western blot and bioinformatics analysis were used to investigate the mechanism of the antitumor activity of San C. In the presence of San C, the MTT assay showed that San C significantly inhibited the growth and proliferation of tumor cells in a dose and time-dependent manner. BrdU labeling assay showed that San C significantly attenuated the DNA replication activity in the nucleus of tumor cells. Flow cytometry confirmed that San C blocked the cell cycle of tumor cells in G_0/G_1 phase. The soft agar clone formation assay revealed that San C significantly attenuated the clone formation and self-renewal ability of tumor cells. The gene set enrichment analysis(GSEA) implied that San C inhibited the tumor cell division cycle by affecting the myelocytomatosis viral oncogene(MYC) signaling pathway. Western blot assay revealed that San C inhibited the expression of cyclin through the regulation of the MYC signaling pathway by lysine demethylase 4B(KDM4B), which ultimately inhibited the growth and proliferation of glioblastoma cells and self-renewal. In conclusion, San C exhibits the potential antitumor activity by targeting the KDM4B-MYC axis to inhibit glioblastoma cell growth, proliferation, and self-renewal.

Chidamide inhibits the NOTCH1-MYC signaling axis in T-cell acute lymphoblastic leukemia / 医学前沿

T-cell acute lymphoblastic leukemia (T-ALL) is one of the most dangerous hematological malignancies, with high tumor heterogeneity and poor prognosis. More than 60% of T-ALL patients carry NOTCH1 gene mutations, leading to abnormal expression of downstream target genes and aberrant activation of various signaling pathways. We found that chidamide, an HDAC inhibitor, exerts an antitumor effect on T-ALL cell lines and primary cells including an anti-NOTCH1 activity. In particular, chidamide inhibits the NOTCH1-MYC signaling axis by down-regulating the level of the intracellular form of NOTCH1 (NICD1) as well as MYC, partly through their ubiquitination and degradation by the proteasome pathway. We also report here the preliminary results of our clinical trial supporting that a treatment by chidamide reduces minimal residual disease (MRD) in patients and is well tolerated. Our results highlight the effectiveness and safety of chidamide in the treatment of T-ALL patients, including those with NOTCH1 mutations and open the way to a new therapeutic strategy for these patients.

Research progress on role of traditional Chinese medicine in hepatic fibrosis based on miRNA-mediated activation of NLRP3 inflammasome / 中国中药杂志

In recent years, liver fibrosis has become a hotspot in the field of liver diseases. MicroRNA(miRNA)-mediated Nod-like receptor pyrin domain containing 3(NLRP3) inflammasome activation is pivotal in the pathogenesis of liver fibrosis. The present study mainly discussed the role of miRNA-mediated NLRP3 inflammasome activation in the pathogenesis of liver fibrosis. Different miRNA molecules regulated liver fibrosis by mediating NLRP3 inflammasome activation, including miRNA-350-3 p(miR-350-3 p)/interleukin-6(IL-6)-mediated signal transducer and activator of transcription 3(STAT3)/c-myc signaling pathway, miR-148 a-induced autophagy and apoptosis of hepatic stellate cells via hedgehog signaling pathway, miR-155-mediated NLRP3 inflammasome by the negative feedback of the suppressor of cytokine signaling-1(SOCS-1), miR-181 a-mediated downstream NLRP3 inflammatory pathway activation through mitogen-activated protein kinase kinase(MEK)/extracellular signal-regulated kinase(ERK)/nuclear transcription factor κB(NF-κB) inflammatory pathway, miR-21-promoted expression of NF-κB and NLRP3 of RAW264.7 cells in mice by inhibiting tumor necrosis factor-α inducible protein 3(A20), and miR-20 b-promoted expression of IL-1β and IL-18 by activating NLRP3 signaling pathway. Additionally, the anti-liver fibrosis mechanism of different active components in Chinese medicines(such as Curcumae Rhizoma, Glycyrrhizae Radix et Rhizoma, Aurantii Fructus, Polygoni Cuspidati Rhizoma et Radix, Moutan Cortex, Paeoniae Radix Alba, Epimedii Folium, and Cinnamomi Cortex) was also explored based on the anti-liver fibrosis effect of miRNA-mediated NLRP3 inflammasome activation.

Are stem cell marker expression and cd133 analysis relevant to differentiate colorectal cancer? / A expressão de marcadores de células-tronco e a análise do cd133 são relevantes na diferenciação do câncer colorretal?

ABSTRACT Background: CD133 and AXL have been described as cancer stem cell markers, and c-MYC as a key regulatory cellular mechanism in colorectal cancer (CRC). Aim: Evaluate the prognostic role of the biomarkers CD133, AXL and c-MYC and their association with clinicopathologic characteristics in colorectal adenocarcinomas and adenomas. Methods: A total of 156 patients with UICC stage I-IV adenocarcinomas (n=122) and adenomas (n=34) were analyzed. Tissue microarrays (TMA) from primary tumors and polyps for CD133, c-MYC and AXL expression were performed and analyzed for their significance with clinicopathologic characteristics. Results: Poorly differentiated adenocarcinomas and disease progression were independent risk factors for poor overall survival. The median overall survival time was 30 months. Positive CD133 expression (35.9% of all cases), particularly of right-sided CRCs (44.8% of the CD133+ cases), was negatively correlated with death in the univariate analysis, which did not reach significance in the multivariate analysis. c-MYC (15.4% of all cases) was predominantly expressed in advanced-stage patients with distant (non-pulmonary/non-hepatic) metastasis. AXL expression was found only occasionally, and predominantly dominated in adenomas, with less penetrance in high-grade dysplasia. Conclusions: CD133 expression was not associated with inferior overall survival in CRC. While AXL showed inconclusive results, c-MYC expression in primary CRCs was associated with distant metastasis.

RESUMO Racional: CD133 e AXL são descritos na literatura como marcadores de células-tronco tumorais, e c-MYC cumpre papel chave como mecanismo de regulação celular no câncer colorretal (CCR). Objetivo: Avaliar o papel prognóstico dos biomarcadores CD133, AXL e c-MYC e sua associação com características clinicopatológicas de adenocarcinomas e adenomas colorretais. Métodos: Um total de 156 pacientes com adenocarcinomas de estádio UICC I-IV (n=122) e adenomas (n=34) colorretais foram avaliados. Microarranjos teciduais (TMA) dos tumores primários e adenomas foram realizados em busca de expressão de CD133, c-MYC e AXL, com posterior análise de relação significativa com características clinicopatológicas. Resultados: Adenocarcinomas pobremente diferenciados e progressão de doença foram fatores de risco independentes para má sobrevida global. A taxa mediana de sobrevida global foi de 30 meses. Expressão positiva de CD133 (35,9% dos casos), particularmente em cânceres de cólon direito (44,8% dos casos CD133+), correlacionou-se negativamente com óbito na análise univariada, sem significância estatística na análise multivariada. c-MYC (15,4% dos casos) teve predomínio de expressão em pacientes com estádio avançado com metástases distantes (não-pulmonares/não-hepáticas). Expressão de AXL foi pouco encontrada, com predomínio em adenomas, com menor penetrância em displasia de alto grau. Conclusão: Expressão de CD133 não se associou com sobrevida global inferior em CCR. Enquanto AXL demonstrou resultados inconclusivos, expressão de c-MYC em tumores primários se associou-se à metástases à distância.

Perception of the relationship between TMD and orthodontic treatment among orthodontists

INTRODUCTION: The consensus about the relationship between TMD and orthodontic treatment has gone from a cause and effect association between TMD and orthodontic treatment to the idea that there is no reliable evidence supporting this statement. OBJECTIVE: To assess the beliefs, despite scientific evidence, of Brazilian orthodontists about the relationship between TMD and orthodontic treatment with regards to treatment, prevention and etiology of TMD. METHODS: A survey about the relationship between TMD and orthodontic treatment was prepared and sent to Brazilian orthodontists by e-mail and social networks. Answers were treated by means of descriptive statistics and strong associations between variables were assessed by qui-square test. RESULTS: The majority of orthodontists believe that orthodontic treatment not only is not the best treatment option for TMD, but also is not able to prevent TMD. Nevertheless, the majority of orthodontists believe that orthodontic treatment can cause TMD symptoms. CONCLUSION: This study suggests that orthodontists' beliefs about the relationship between orthodontic treatment and TMD are in accordance with scientific evidence only when referring to treatment and prevention of TMD. The majority of orthodontists believe that, despite scientific evidence, orthodontic treatment can cause TMD. .

INTRODUÇÃO: o consenso sobre a relação entre DTM e tratamento ortodôntico foi de uma associação de causa e efeito à ideia de que não há evidências confiáveis que suportem essa afirmação. OBJETIVO: avaliar as crenças, sem considerar as evidências, de ortodontistas brasileiros sobre a relação entre DTM e tratamento ortodôntico com relação ao tratamento, prevenção e etiologia da DTM. MÉTODOS: um questionário sobre a relação entre DTM e tratamento ortodôntico foi preparado e enviado a ortodontistas brasileiros por meio de e-mail e mídias sociais. As respostas foram analisadas por estatística descritiva, e fortes associações entre as variáveis foram verificadas pelo teste χ2. RESULTADOS: a maioria dos ortodontistas acredita que o tratamento ortodôntico não é o melhor tratamento para DTM. Além disso, acreditam que não é a melhor forma para sua prevenção. Também, a maioria dos ortodontistas acredita que o tratamento ortodôntico pode causar sintomas de DTM. CONCLUSÃO: este estudo sugere que as crenças dos ortodontistas sobre a relação entre tratamento ortodôntico e DTM estão de acordo com as evidências científicas apenas quando se trata do tratamento e da prevenção de DTM. A maioria dos ortodontistas acredita que, apesar das evidências científicas, o tratamento ortodôntico pode causar DTM. .

Expression of ?-catenin and c-myc during human common bile duct development: a possible role in the morphogenesis of the common bile duct

β-catenin and c-myc play important roles in the development of tissues and organs. However, little is known about their expression patterns during the development of the human common bile duct. Immunohistochemistry was used to detect β-catenin and c-myc expression in common bile duct samples from postmortem tissues of 14 premature infants and 6 spontaneously aborted fetuses. The expression of β-catenin and c-myc was also analyzed by Western blot. The samples were divided into four groups based on the stage of human fetal development: 12, 13-27, 28-37, and >37 weeks. The Image-Pro Plus v. 6.0 image analysis software was used to calculate the mean qualifying score (MQS). At fetal stages 12, 13-27, 28-37, and >37 weeks, MQS of β-catenin were 612.52±262.13, 818.38±311.73, 706.33±157.19, and 350.69±110.19, respectively. There was a significant difference in MQS among the four groups (ANOVA, P=0.0155) and between the scores at >37 and 13-27 weeks (Student-Newman-Keuls, P<0.05). At fetal stages 12, 13-27, 28-37, and >37 weeks, the MQS of c-myc were 1376.64±330.04, 1224.18±171.66, 1270.24±320.75, and 741.04±219.19, respectively. There was a significant difference in MQS among the four groups (ANOVA, P=0.0087) and between the scores at >37 and 12 weeks, >37 and 13-27 weeks, and >37 and 28-37 weeks (all P<0.05, Student-Newman-Keuls). Western blots showed that β-catenin and c-myc expression were significantly higher in fetal than in postnatal control duct tissue (P<0.05). c-myc and β-catenin are involved in the normal development of the human common bile duct.

The role of micro RNAs let7c, 100 and 218 expression and their target RAS, C-MYC, BUB1, RB, SMARCA5, LAMB3 and Ki-67 in prostate cancer

OBJECTIVE: The aim of this study is to verify the expression of proteins that are controlled by miR-let7c, 100 and 218 using immunohistochemistry in tissue microarray representative of localized and metastasized the lymph nodes and bone prostate cancer. METHODS: To verify the expression of proteins that are controlled by miR-let7c (C-MYC, BUB1, RAS) 100 (SMARCA5, RB) and 218 (LAMB3) and cell proliferation (Ki-67) we used immunohistochemistry and computerized image system ImageJ MacBiophotonics in three tissue microarrays representative of localized prostate cancer and lymph node and bone metastases. miRNA expression was evaluated by qRT-PCR using 60 paraffin blocks to construct the tissue microarray representative of localized disease. RESULTS: RAS expression was increased in localized prostate cancer and bone metastases compared to the lymph nodes (p=0.017). RB showed an increase in expression from localized prostate cancer to lymph node and bone metastasis (p=0.036). LAMB3 was highly expressed in localized and lymph node metastases (p<0.001). Cell proliferation evaluated by Ki-67 showed an increase from localized prostate cancer to metastases (p<0.001). We did not found any relationship between C-MYC (p=0.253), BUB1 (p=0.649) and SMARCA5 (p=0.315) protein expression with prognosis or tumor behavior. CONCLUSION: We found that the expression of RAS, RB, LAMB3 and Ki-67 changed in the different stages of prostate cancer. Furthermore, we confirmed the overexpression of the miRNAs let7c, 100 and 218 in localized prostate cancer but failed to show the control of protein expression by the putative controller miRNAs using immunohistochemistry. .

Prevalence of c-myc expression in breast lesions associated with microcalcifications detected by routine mammography / Expressão de c-myc em lesões mamárias associadas a microcalcificações detectadas por mamografia de rotina

CONTEXT AND OBJECTIVE: Genetic abnormalities in cell proliferation-regulating genes have been described in premalignant lesions. The aims here were to evaluate c-myc protein expression in non-palpable breast lesions associated with microcalcifications, detected by screening mammography, and to compare these results with histopathological, clinical and epidemiological variables. DESIGN AND SETTING: Analytical cross-sectional study, with retrospective data collection, in a university hospital in São Paulo. METHODS: Seventy-nine female patients who underwent routine mammography between 1998 and 2004 were studied. Lesions classified by the Breast Imaging Reporting and Data System (BI-RADS) as 4 or 5 underwent percutaneous biopsy using a large-core needle. Ninety-eight lesions were studied anatomopathologically. Paraffin blocks properly representing the lesions were selected for immunohistochemical analyses using the streptavidin-biotin-peroxidase technique with monoclonal mouse c-myc antibodies. RESULTS: Among the 98 lesions, 29 (29.6 percent) contained malignant neoplasia; 40 (40.8 percent) had a positive immunohistochemical reaction for c-myc. When the groups were divided between lesions without atypias versus atypical lesions plus malignant lesions, 31.03 percent of the 58 lesions without atypias were positive for c-myc and 55 percent of the 40 malignant and atypical lesions (P = 0.018). Comparing the atypical lesions with ductal carcinoma in situ versus the benign lesions without atypias, c-myc was present in 51.61 percent of the 31 atypical lesions and 31.03 percent of the benign lesions without atypias (P = 0.057). CONCLUSION: C-myc protein was more frequently expressed in atypical and malignant lesions than in benign lesions without atypias. C-myc expression correlated with the presence of atypias (P = 0.018).

CONTEXTO E OBJETIVO: Alterações nos genes reguladores da proliferação celular foram descritas em lesões pré-malignas. Os objetivos foram avaliar a expressão da proteína c-myc em biópsias de lesões mamárias não-palpáveis associadas a microcalcificações detectadas em mamografias de rastreamento e comparar estes resultados com as variáveis histopatológicas, clínicas e epidemiológicas. DESENHO E LOCAL: Estudo retrospectivo, em um hospital universitário em São Paulo. MÉTODOS: Setenta e nove pacientes do sexo feminino submetidas a mamografia de rotina de 1998 a 2004 foram estudadas. As lesões classificadas pelo sistema BI-RADS (Breast Imaging Reporting and Data) como 4 e 5 sofreram biópsias percutâneas com agulha grossa. Do ponto de vista anatomopatológico, foram estudadas 98 lesões. Os blocos com representação adequada para estudo imunoistoquímico com a técnica da estreptoavidina-biotina-peroxidase com o anticorpo monoclonal de camundongo c-myc foram incluídos. RESULTADOS: Das 98 lesões, 29 (29,6 por cento), continham neoplasia maligna; 40 (40,8 por cento) tiveram reação de imunoistoquímica positiva para o c-myc. Quando divididos os grupos em lesões sem atipia versus lesões atípicas mais lesões malignas, encontramos o c-myc positivo em 31,03 por cento das 58 lesões sem atipias e 55 por cento das 40 lesões atípicas e malignas (P = 0,018). Quando agrupamos as lesões atípicas com o carcinoma ductal in situ (CDIS) versus as lesões benignas sem atipias, observamos a presença do c-myc em 51,61 por cento das 31 lesões atípicas e 31,03 por cento das lesões benignas sem atipias (P = 0,057). CONCLUSÃO: A proteína c-myc está mais frequentemente expressa em lesões atípicas e malignas do que em lesões benignas sem atipia. A expressão do c-myc está correlacionada com a presença de atipia (P = 0,018).

Repeated electroconvulsive seizure induces c-Myc down-regulation and Bad inactivation in the rat frontal cortex

Repeated electroconvulsive seizure (ECS), a model for electroconvulsive therapy (ECT), exerts neuroprotective and proliferative effects in the brain. This trophic action of ECS requires inhibition of apoptotic activity, in addition to activation of survival signals. c-Myc plays an important role in apoptosis of neurons, in cooperation with the Bcl-2 family proteins, and its activity and stability are regulated by phosphorylation and ubiquitination. We examined c-Myc and related proteins responsible for apoptosis after repeated ECS. In the rat frontal cortex, repeated ECS for 10 days reduced the total amount of c-Myc, while increasing phosphorylation of c-Myc at Thr58, which reportedly induces degradation of c-Myc. As expected, ubiquitination of both phosphorylated and total c-Myc increased after 10 days ECS, suggesting that ECS may reduce c-Myc protein level via ubiquitination-proteasomal degradation. Bcl-2 family proteins, caspase, and poly(ADP-ribose) polymerase (PARP) were investigated to determine the consequence of down-regulating c-Myc. Protein levels of Bcl-2, Bcl-X(L), Bax, and Bad showed no change, and cleavage of caspase-3 and PARP were not induced. However, phosphorylation of Bad at Ser-155 and binding of Bad to 14-3-3 increased without binding to Bcl-X(L) after repeated ECS, implying that repeated ECS sequesters apoptotic Bad and frees pro-survival Bcl-X(L). Taken together, c-Myc down-regulation via ubiquitination-proteasomal degradation and Bad inactivation by binding to 14-3-3 may be anti-apoptotic mechanisms elicited by repeated ECS in the rat frontal cortex. This finding further supports the trophic effect of ECS blocking apoptosis as a possible therapeutic effect of ECT.

Regulation of Inhibitors of Differentiation Family Proteins by Thyroid-Stimulating Hormone in FRTL-5 Thyroid Cells

Members of the inhibitors of differentiation (Id) family of helix-loop-helix (HLH) proteins are known to play important roles in the proliferation and differentiation of many cell types. Thyroid-stimulating hormone (TSH) regulates proliferation and differentiation by activating TSH receptor (TSHR) in thyrocytes. In this study, we found that Id2, one of the Id family proteins, is a major target for regulation by TSH in FRTL-5 thyroid cells. TSH rapidly increases the Id2 mRNA level in FRTL-5 thyroid cells but the Id2 protein showed biphasic regulatory patterns, being transiently reduced and subsequently induced by TSH treatment. Transient reduction of Id2 protein was noted within 2 hr of TSH treatment and was mediated by proteasomal degradation. Moreover, reduced Id2 expression correlated with the activity of the phosphatidylinositol 3 kinase pathway, which is activated by TSH. Although TSH increases the activity of the Id2 promoter, TSH-induced activation of this promoter was independent of c-Myc. Id2 did not alter TTF-1- and Pax-8-mediated effects on the regulation of the Tg promoter. Thus, in summary, we found that TSH regulates Id2 expression, but that Id2 does not alter the expression of thyroid-specific genes, such as Tg, in FRTL-5 thyroid cells.

Overexpression of c-Myc in primary central nervous system lymphoma of Thais.

BACKGROUND: c-Myc protooncogenes have been implicated in the tumourigenesis of extracerebral lymphomas, however only afew studies on this oncogenic molecule have been available for primary central nervous system lymphoma (PCNSL). OBJECTIVE: To determine the prevalence ofprotein overexpression and gene amplification of c-Myc in PCNSL and to correlate with histological and immunophenotypic subtypes of malignant lymphoma according to WHO classification of tumors of haematopoietic and lymphoid tissue 2001. SETTING: King Chulalongkorn Memorial Hospital, Thailand. DESIGN: Descriptive study. MATERIAL: 25 Thai patients presented between 2001 and 2005. METHOD: The overexpression and amplification of c-Myc in malignant lymphoma were studied by means of immunohistochemistry and chromogenic in situ hybridization (CISH), respectively, in formalin-fixed, paraffin-embedded specimens. The histomorphology and immunohistochemistry were used to subclassify PCNSLs according to WHO classification 2001. RESULTS: Fourteen males and eleven females were recruited. They were between the ages of 21 and 86 years with the mean of 53 years. Eight had documented human immune deficiency virus (HIV) infection. Four of 17 immunocompetent cases overexpressed c-Myc protein without c-Myc gene amplification. No immunocompromised cases showed overexpression of c-Myc protein. All PCNSLs were classified as diffuse large B-cell lymphoma. CONCLUSION: In PCNSL, c-Myc overexpression is notfound immunocompromised (HIV-infected) patients and is found in 23.5% of the immunocompetent individuals without c-Myc gene amplification. All PCNSLs are diffuse large B-cell lymphoma according to WHO classification 2001.

Expression of c-myc protein on rats' brains after brain concussion / 法医学杂志

OBJECTIVE@#To study the changes of expression of c-myc protein on rats' brains after brain concussion.@*METHODS@#sixty rats were randomly divided into brain concussion groups and control group. The expression of c-myc protein was microscopically observed by immunohistochemical method.@*RESULTS@#No expression of c-myc protein in control group were observed. However, positive expression of c-myc protein in some neurons was seen at 20 min after brain concussion, and reach to the peak at 8h after brain concussion and then decreased gradually.@*CONCLUSION@#These findings suggest that the detection of c-myc protein could be an index of diagnosis of brain concussion.

Changes in the expression of c-myc, RB and tyrosine-phosphorylated proteins during proliferation of NIH 3T3 cells induced by hyaluronic acid

We have shown that hyaluronic acid stimulates the proliferation of quiescent NIH 3T3 cells. We have shown that treatment of 1 mg/ml hyaluronic acid results in increase of tyrosine phosphorylation of two proteins, MW 124 kDa and 60 kDa as detected by anti-tyrosine antibodies by Western blot analysis. Maximum phosphorylation occurred within 2 h after addition of 1 mg/ml hyaluronic acid. Stimulation of proliferation was also accompanied by increase in c-Myc protein, which was inhibited by amlloride, an inhibitor of Na+/H+ antiporter and EGTA and increase in the steady state level of pRb, the RB gene product. These results suggest that the intracellular signal transduction pathways that mediate the stimulatory effects of hyaluronic acid on cellular proliferation are similar to those of growth factors.