Scaffold protein MAPK8IP2 expression is a robust prognostic factor in prostate cancer associated with AR signaling activity / 亚洲男科学杂志(英文版)

Mitogen-activated protein kinase-8-interacting protein 2 (MAPK8IP2) is a scaffold protein that modulates MAPK signal cascades. Although MAPK pathways were heavily implicated in prostate cancer progression, the regulation of MAPK8IP2 expression in prostate cancer is not yet reported. We assessed MAPK8IP2 gene expression in prostate cancer related to disease progression and patient survival outcomes. MAPK8IP2 expression was analyzed using multiple genome-wide gene expression datasets derived from The Cancer Genome Atlas (TCGA) RNA-sequence project and complementary DNA (cDNA) microarrays. Multivariable Cox regressions and log-rank tests were used to analyze the overall survival outcome and progression-free interval. MAPK8IP2 protein expression was evaluated using the immunohistochemistry approach. The quantitative PCR and Western blot methods analyzed androgen-stimulated MAPK8IP2 expression in LNCaP cells. In primary prostate cancer tissues, MAPK8IP2 mRNA expression levels were significantly higher than those in the case-matched benign prostatic tissues. Increased MAPK8IP2 expression was strongly correlated with late tumor stages, lymph node invasion, residual tumors after surgery, higher Gleason scores, and preoperational serum prostate-specific antigen (PSA) levels. MAPK8IP2 upregulation was significantly associated with worse overall survival outcomes and progression-free intervals. In castration-resistant prostate cancers, MAPK8IP2 expression strongly correlated with androgen receptor (AR) signaling activity. In cell culture-based experiments, MAPK8IP2 expression was stimulated by androgens in AR-positive prostate cancer cells. However, MAPK8IP2 expression was blocked by AR antagonists only in androgen-sensitive LNCaP but not castration-resistant C4-2B and 22RV1 cells. These results indicate that MAPK8IP2 is a robust prognostic factor and therapeutic biomarker for prostate cancer. The potential role of MAPK8IP2 in the castration-resistant progression is under further investigation.

Construction of the hit-deficient mutant strain of Streptococcus mutans ATCC25175 / 口腔疾病防治

Objective@#To construct a hit-deficient mutant strain of S. mutans ATCC25175 and verify its cell cycle regulatory function.@*Method @# Genomic DNA was extracted from S. mutans ATCC25175 strains, and then the upstream and downstream DNA fragments of the hit gene were cloned into the pFW5 vector (spectinomycin resistant) to construct recombinant plasmids using PCR amplification. Third, employed by natural genetic transformation in S. mutans ATCC25175 strains, the linearized recombinant plasmids were transformed into their genetic competence, induced by the synthesized competence-stimulating peptide (CSP), and then, homologous recombination was utilized to produce crossover and noncrossover products. Fourth, the hit-deficient mutant strains of S. mutans ATCC25175 were screened through the spectinomycin-resistance marker and identified by the electrophoresis of PCR products and PCR Sanger sequencing. Finally, its growth rate in vegetative BHI medium was also investigated.@* Results @# The upstream (856 bp) and downstream (519 bp) DNA fragments of the hit gene from the genomic DNA materials of S. mutans ATCC25175 were cloned into two multiple cloning sites (MCS-I and MCS-II) of the pFW5 vector, respectively, and the recombinant plasmid pFW5_hit_Up_Down was constructed and identified by double-emzyme digestion and PCR Sanger sequencing. The linearized recombinant plasmids were transformed into their genetic competence, induced by the synthetic CSP, and then, homologous recombination was utilized to produce various products. The hit-deficient mutant strains of S. mutans ATCC25175 were screened through the spectinomycin resistance marker and identified by the electrophoresis of PCR products and Sanger sequencing. The growth rate of the hit-deficient mutant strains versus their parental S. mutans ATCC25175 strains was increased greatly (P<0.001).@* Conclusion@# The hit-deficient mutant strains of S. mutans ATCC25175, having heritable traits, were successfully constructed, and the encoding Hit protein is growth-phase regulated in the cell cycle.

Battle of the sexes: Contrasting roles of testis-specific protein Y-encoded (TSPY) and TSPX in human oncogenesis / 亚洲男科学杂志(英文版)

The Y-located testis-specific protein Y-encoded (TSPY) and its X-homologue TSPX originated from the same ancestral gene, but act as a proto-oncogene and a tumor suppressor gene, respectively. TSPY has specialized in male-specific functions, while TSPX has assumed the functions of the ancestral gene. Both TSPY and TSPX harbor a conserved SET/NAP domain, but are divergent at flanking structures. Specifically, TSPX contains a C-terminal acidic domain, absent in TSPY. They possess contrasting properties, in which TSPY and TSPX, respectively, accelerate and arrest cell proliferation, stimulate and inhibit cyclin B-CDK1 phosphorylation activities, have no effect and promote proteosomal degradation of the viral HBx oncoprotein, and exacerbate and repress androgen receptor (AR) and constitutively active AR variant, such as AR-V7, gene transactivation. The inhibitory domain has been mapped to the carboxyl acidic domain in TSPX, truncation of which results in an abbreviated TSPX exerting positive actions as TSPY. Transposition of the acidic domain to the C-terminus of TSPY results in an inhibitory protein as intact TSPX. Hence, genomic mutations/aberrant splicing events could generate TSPX proteins with truncated acidic domain and oncogenic properties as those for TSPY. Further, TSPY is upregulated by AR and AR-V7 in ligand-dependent and ligand-independent manners, respectively, suggesting the existence of a positive feedback loop between a Y-located proto-oncogene and male sex hormone/receptors, thereby amplifying the respective male oncogenic actions in human cancers and diseases. TSPX counteracts such positive feedback loop. Hence, TSPY and TSPX are homologues on the sex chromosomes that function at the two extremes of the human oncogenic spectrum.

RGC-32 involving in cell cycle regulation / 国际儿科学杂志

As one of the important response gene to complement,response gene to complement-32 (RGC-32) simultaneously involves in many other biological functions.Recent studies have shown that RGC-32 was one of the critical regulatory factors at the G2/M check point in the cell cycles and involved in the cell cycle regulation.The expression products of RGC-32 gene play the key roles in cell proliferation,differentiation,inflammation,tumor metastasis and other processes.However,it has not been clarified in its biological mechanisms of regulation in cell cycle.This article takes a brief review about RGC-32 on its gene structure,biological functions,regulation of cell cycle,and the relationship of cell cycle regulation which involves in RGC-32.

Expression and signification of cell cycle regulation protein Cyclin D1-CDK4-p21 in scar cancer / 医学研究生学报

Objective Dysfunction of cell cycle regulation is one of the key factors for cellular carcinogenesis .This paper aimed to study the expression and significance of cell cycle regulation protein Cyclin D 1-CDK4-p21 in scar cancer . Methods The expressions of Cyclin D1, CDK4 and p21 protains were detected in scar cancer group , pathological scar group and normal skin group respectively by using immunohistochemical staining (SP).The mRNA expression levels of Cyclin D1, CDK4 and p21 were detected by the use of nucleic acid-mediated in-situ hybridization .Correlation analysis was made on the indexes , and the average optical density and positive area were analyzed using image analysis . Results The expressions of Cyclin D1, CDK4 and p21 protains and the mRNA ex-pression levels of cyclin D1, CDK4 and p21 were high in scar cancer group, low in pathological scar group , and negative in normal skin group.The mean optical density and positive area in scar cancer group were significantly different from pathological scar group and normal skin group (P0.05).In terms of correlation analysis , the expressions of Cyclin D 1 and CDK4 as well as p21 and CDK4 in scar cancer tissue were both in posi-tive correlations. Conclusion The occurrence of scar cancer is related to the abnormal expression of Cyclin D 1 and CDK4.The complex formed by Cyclin D1 and CDK4 may promote the G1/S transition, proliferation and tumorigenesis of scar cancer .In scar canc-er, the inhibition of Cyclin D1-CDK4 complex might be caused by other members of CKI family or even inbibitors of other families apart from CDK family.

Regulation of cyclin E and cancers / 国际肿瘤学杂志

Cyclin E is expressed starting from the middle G1 phase of the cell cycle,and is accumulated in the G1/S boundry.Cyclin E binds to and activates the cyclin-dependent kinase CDK2.Cyclin E-CDK2 complex initiates a cascade of events that leads to DNA replication by phosphorylating its substrates,such as Rb,CDC6,NPAT and P107,etc.Additionally,cyclin E plays an important role in the regulation of genomic stability,spindle-organizing structure and centrosome cycle.Cyclin E expression is trans-activated by members of the transcription factor E2F family and degrades via the ubiquitin-proteasome pathway.At the same time,it is also negatively regulated by the CIP/KIP proteins.Cyclin E highly expressed in the initiation and progression of different human cancers,such as breast cancers,lung cancers,leukemia,lymphomas and others.

The Nucleolus and Viral Infection / 中国病毒学·英文版

The nucleolus is a subnuclear structure of eukaryocytes. It was thought that nucleolus only participates in the biogenesis and processing of rRNA. However, more and more evidence shows that it has many other functions, such as tRNA precursor processing, stress sensing and it is also involved in gene silencing, senescence and cell cycle regulation. Here, we summarize the recent understandings about the nucleolar functions, the regulation of nucleolar localization of proteins and the role that the nucleolus plays in virus infection, in which some related studies of Herpes simplex virus type 1 (HSV-1) US11, UL24 and bovine herpesvirus-1 infected cell protein 27 (BICP27) carried out in our lab will also be included.

Effect of the Physiologically Active Compounds in Phlomidis Radix on Cell Cycle Regulation in Human Gingival Fibroblasts / 대한치주과학회지

The purpose of present study was to investigate the effects of physiologically active compound (SD62-122) from Phlomidis Radix on the cell cycle progression and its molecular mechanism in human gingival fibroblasts(HGFs). For this purpose, fibroblasts were isolated and cultured from excisioned gingiva during crown lengthening procedure in healthy adult. The following parameter were evaluated that there are cell number counting, MTT assay, cell cycle progression, western blot analysis. The cell number and MTT assay of primary cultured fibroblast was not increased at 2 days but significant increased compare to negative control at 3days(p<0.05). S phase was increased and G1 phase decreased in both 10(-8)M and 10(-9)M of SD62-122 in cell cycle analysis. The cell cycle regulation protein levels of Cyclin D1, Cyclin E, cdk 2, cdk 4 and cdk 6 were increased compare to control in both 10(-8)M and 10(-9)M of SD62-122. The protein levels of p21 and p53 were decreased compare to control, but the level of pRb was not changed compare to control in 10(-9)M of SD2-122. These results suggested that physiologically active compound (SD62-122) isolated from Phlomidis Radix increases the cell proliferation and cell cycle progression in HGFs, which is linked to increased cell cycle regulation protein levels of Cyclin D1, Cyclin E, cdk 2, cdk 4 and cdk 6, and decreased the levels of p21, p53.

The Cell Cycle Regulatory Effects of High Dose 5-fluorouracil on Breast Cancer Cell Line

BACKGROUND: Chemotherapy with 5-fluorouracil (5-FU) has been one of the mainstay in breast cancer treatment. The effects of high dose 5-FU on cell cycle regulation were studied in breast caner cells. METHODS: A breast cancer cell line MCF-7 was used. Protein expressions of G1/S cyclins, p21(Waf1/Cip1), cdk2, E2F1 and retinoblastoma were tested by western blot analysis. Immunoprecipitation and immune complex kinase assay were done for the assessment of E2F1/RB interacton and the activity of cdk2 respectively. RESULTS: p21(Waf1/Cip1) expression was barely detectable in control cells. With addition of 5-FU level of p21(Waf1/Cip1) were induced and cyclin D3 level was decreased as cell growth decreases. In accordance with increased expression of p21(Waf1/Cip1), cyclin E-associated cdk2 kinase activity was reduced. Retinoblastoma protein (RB) became dephosphorylated and E2F-1 binding activity with RB was increased. CONCLUSION: In this situation of high concentration of 5-FU breast cancer cells tend to be G1/S cell cycle arrested. Overexpression of p21(Waf1/Cip1) and dephosphorylation of RB may mediate the effectss of 5-FU by inhibiting E2F-1 activity, which contributes to G1/S cell cycle arrest. These results could be an indicating landmark for further study of high dose chemotherapy with 5-FU.

Alterations of Cell Cycle Regulation and Apoptosis Related Factors in Skin Tumors / 대한피부과학회지

BACKGROUND: Tumor growth and progression is dependent on a variety of factors including; increased cell survival, i. e. resistance to undergo apoptosis, increased proliferation, and the inability to undergo growth arrest or differentiation. The cyclins are a growing group of proteins that form the regulatory subunits in complexes with a specific catalytic protein kinase(cyclin-dependent kinase(CDK)) partner. Tumor suppressor gene such as Rb, p53 and cell cycle regulatory proteins such as p16, p27, WAF1(p21, or Cip 1) also act as a regulator of cyclin and CDK. Apoptosis regulatory proteins such as bcl-2, bcl-x act as a blocking protein of apoptosis and Ki-67 is frequently used as a marker for cell proliferation. OBJECTIVE: The purpose of this study was to investigate the alterations of cell cycle regulation and apoptosis in skin tumors. METHODS: We compared expressions for cyclin A, cyclin E, WAF1, Ki-67, p53, p27, Rb, bcl-2 and bcl-x in paraffin embedded samples from 5 normal adult skin tissues, 10 basal cell epithelioma, 10 squamous cell carcinoma, 10 Bowen's disease, 5 keratoacanthoma and 5 solar keratosis by immunohistochemical staining method. RESULTS: The stainings of the tumors showed some differences from normal tissues in expression of antigens according to the differentiation state and nature of tumors. CONCLUSION: These results support an important role for cell cycle and apoptosis regulatory proteins in the regulation of growth and differentiation of malignant keratinocyte in these cutaneous neoplasms. Aberrant expression of such proteins may participate in the multistep process of carcinogenesis.

Correlation between Akt phosphorylation and loss of PTEN protein expression in non-small-cell lung cancer / 中国癌症杂志

Purpose:To clarify roles of overexpression of phosphorylated Akt(p-Akt) and loss of phosphatase and tensin homologue deleted on chromosome 10(PTEN) expression in biological behavior of non-small-cell lung cancer(NSCLC). Methods:Immunohistochemical staining was used to determine the expression of p-Akt and PTEN in 20 cases of normal lung tissues and 102 patients with NSCLC.Results:Negative p-Akt expression and positive PTEN expression were found in normal lung tissues, while the positive incidences of p-Akt expresssion and loss of incidences of PTEN expresssion in NSCLC were 41.2% (42/102) and 46.1% (47/102)respectivtly.The overexpression of p-Akt and loss of PTEN expression were correlated to degree of differention of cancer, metastasis(including lymph node), and clinical stages. A significant negative correlation was observed between expression of p-Akt and PTEN(Phi r=-0.425,P

Cell Cylce Regulatory Effects of Cyclic AMP in Cancer Cells Which Lack Wild-type p53 / 대한암학회지

PURPOSE: The activator of protein kinase A, cyclic AMP, has been a recognized growth inhibitor of certain cell types. The present study aimed to investigate the effects of dibutyryl cAMP on the growth of cancer cells which lack wild-type p53 and to determine the mechanism of growth inhibition. MATERIALS AND METHODS: Prostate and breast cancer cells were treated with dibutyryl cAMP and compared with untreated cells. Growth patterns of cells were assessed by trypan blue-excluding method and western blot was done to determine protein levels of cell cycle regulatory proteins which govern G1 and G1/S phase. Northern blot and immunoprecipitation were done to determine the level of mRNA of p21 and the association between cell cycle regulatory proteins. In vitro immune complex kinase assay was done to assess the activity of cdk2. RESULTS: cAMP reduced cell growth by 48 h. Cyclin D3 level was downregulated and RB protein level was decreased and mostly unphosphorylated forms remained. The association of RB with E2F1 was increased. While cdk2 levels remained constant throughout cAMP treatment, the activity of cdk2/cyclin E complex, which is responsible for entry into S phase, was downregulated. Cdk inhibitors, p27 and p21 were induced with cAMP treatment. CONCLUSION: These observation suggest that the growth inhibitory effects of dibutyryl cAMP on prostate and breast cancer cells were mediated by induction of cdk inhibitors such as p21 and p27 and RB activation in accordance with downregulation of cdk2.

Association of HSP90 with the heme-regulated eukaryotic initiation factor 2α kinase—A collaboration for regulating protein synthesis.

Among the various heat shock proteins (HSPs), members of the HSP70 and HSP90 families have drawn particular attention due to their heat shock-unrelated functions. HSP90, an ubiquitous and abundant member of the HSP90 family has been shown to be associated with a large array of protein factors. These proteins reside in the nucleus as well as in the cytoplasm and are involved in various physiological processes, such as, regulation of chromatin structure, cell cycle, cytoskelelal architecture, protein trafficking and protein synthesis. In this article, we focus our interest on the role of HSP90 in protein synthesis. Recent data obtained from a few laboratories strongly suggest that HSP90 interacts with the heme-regulated eukaryotic initiation factor 2α (elF-2α) kinase, also called the heme-regulated inhibitor, and causes its activation which leads to inhibition of protein synthesis. On the basis of data reported from various laboratories, including our own, we propose a possible model on the mechanism of HSP90- mediated activation of heme-regulated inhibitor and regulation of protein synthesis.

EXPRESSION OF Polo-LIKE KINASE 1 DURING THE DIFFERENTIATION OF CARDIOMYOCYTES IN RATS / 解剖学报

Objective To understand the mechanism of how cardiomyocytes exit from the cell cycle,we examined the expression of polo-like kinase 1(plk1) in the postnatal developmental process of cardiac myocytes. Methods Mitotic Index(MI) of cardiomyocytes was examined in the neonatal,2-week-old,4-week-old,and adult rat hearts(five cases per groups) by double immunofluorescence stained with H3P and ?-sarcomeric actin antibodies.plk1 mRNA and protein expression during the postnatal developmental process of cardiac myocytes were detected by RT-PCR and Western blot analysis in rat hearts. Results The MI of cardiomyocytes in 0-day-old hearts(0.905?0.087%) was approximately 2.4 times over that in 2-week-old hearts(0.372?0.094%)(P