Expression Positively (expression + positively)

Distribution by Scientific Domains


Selected Abstracts


Proteome analysis of human androgen-independent prostate cancer cell lines: Variable metastatic potentials correlated with vimentin expression

PROTEINS: STRUCTURE, FUNCTION AND BIOINFORMATICS, Issue 12 2007
Mingfu Wu
Abstract To better understand the molecular mechanisms of prostate cancer (PCA) dissemination and to develop new anti-metastasis therapies, key regulatory molecules involved in PCA metastasis were identified in two human androgen-independent PCA cell lines, highly metastatic 1E8-H and lowly metastatic 2B4-L cells. Through 2-DE and MS analyses, 12 proteins with different expression levels in the two cell lines were identified. The following proteins were found to be significantly up-regulated in 1E8-H cells compared with 2B4-L cells: gp96 precursor, calreticulin precursor, vimentin (VIM), Hsp90,, peroxiredoxin 2, HNRPH1, ezrin, T-complex protein 1, alpha subunit, and hypothetical protein mln2339. In contrast, heart L -lactate dehydrogenase H chain, annexin I, and protein disulfide isomerase were notably down-regulated in 1E8-H cells compared with 2B4-L cells. To our knowledge, this study is the first to demonstrate that up-regulation of VIM expression positively correlates with the invasion and metastasis of androgen-independent PCA. [source]


ORIGINAL RESEARCH: Phosphodiesterase Type 5 Regulation in the Penile Corpora Cavernosa

THE JOURNAL OF SEXUAL MEDICINE, Issue S3 2009
Ching-Shwun Lin PhD
ABSTRACT Introduction., Penile detumescence depends on the hydrolysis of cyclic guanosine monophosphate (cGMP) by phosphodiesterase type 5 (PDE5). It is hoped that a review of publications relevant to the regulation of PDE5 in the penis will be helpful to both scientists and clinicians who are interested in the sciences of erectile function/dysfunction. Aims., The aim of this article is to comprehensively review the mechanisms by which PDE5 activity and expression in the penis are regulated. All published studies relevant to PDE5 regulation in the penis or penile cells will be reviewed. Methods., Entrez (PubMed) was used to search for publications relevant to the topics of this review. Keywords used in the searches included vascular, cavernous, penis, smooth muscle, signaling molecules, erection, priapism, and PDE5. Articles that are dedicated to the study of erectile function/dysfunction were prioritized for citation. Results., Regulation of PDE5 can occur at both protein and gene levels. At protein level, PDE5 is activated by phosphorylation and/or allosteric cGMP binding. Deactivation is carried out by protein phosphatase 1 and thus linked to the Rho-kinase signaling pathway. Cleavage of PDE5 into an inactive form has been shown as carried out by caspase-3. At the gene level, PDE5 expression is regulated at two alternative promoters, PDE5A and PDE5A2, both of which are positively regulated by cyclic adenosine monophosphate and cGMP. Downregulation of PDE5 has been observed in the penis of castrated animals; however, proof of androgen regulation of PDE5 gene requires examination of the smooth muscle content. Hyperoxia and hypoxia, respectively, regulate PDE5 expression positively and negatively. Hypoxic downregulation of PDE5 is a possible mechanism for the development of priapism. Conclusions., PDE5 can be regulated at protein and gene levels. In the penis, changes of PDE5 activity have been linked to its phosphorylation status, and downregulation of PDE5 expression has been associated with hypoxia. Lin CS. PDE5 regulation in the penile corpora nervosa. J Sex Med 2009;6(suppl 3):203,209. [source]


Partially circumventing peripheral tolerance for oncogene-specific prostate cancer immunotherapy

THE PROSTATE, Issue 7 2008
Yilin C. Neeley
Abstract BACKGROUND Failure of cancer immunotherapy is essentially due to immunological tolerance to tumor-associated antigens (TAAs), as these antigens are also expressed in healthy tissues. METHODS Here, we used transgenic adenocarcinoma of mouse prostate (TRAMP) mice, which develop lethal prostate cancer due to prostate-specific expression of SV40 T antigen (Tag), to evaluate effects of prostatic transformation on oncogene TAA-specific tolerance and to test the possibility of breaking such tolerance using a modified recombinant vaccinia virus. RESULTS We showed that Tag expression in TRAMP mice is uniquely extra-thymic, and levels of prostatic Tag expression positively correlate with malignant transformation of the prostate. Yet, young tumor-free TRAMP mice were tolerant to Tag antigen. We therefore attempted overcoming such peripheral oncogene-specific T cell tolerance through immunization with a vaccinia construct encoding Tag immunogenic epitopes. This vaccination modality showed that oncogene-specific tolerance was successfully overcome by effective in vivo priming of Tag-specific cytotoxic T cells (CTLs). However, this was restricted to young TRAMP mice. Tag-specific CTL from "tumor naïve" young TRAMP mice showed significant anti-tumor efficacy in vivo by eliminating established heterotopic prostate tumors and prolonging survival in SCID mice harboring Tag-expressing tumors. In contrast, older TRAMP mice with established prostate tumors exhibited oncogene-specific tolerance as evidenced by failure to generate Tag-specific CTL following Tag-specific immunization. CONCLUSIONS Peripheral tolerance can be overcome for effective anti-tumor therapy following oncogene-specific immunization. However, this ability to elicit oncogene-specific CTL is impeded in the tumor-bearing host, in the context of increased oncogene expression associated with tumor progression. Prostate 68: 715,727, 2008. © 2008 Wiley-Liss, Inc. [source]


Increasing transient expression of CAT gene in Porphyra haitanensis by Matrix attachment regions and 18S rDNA targeted homologous recombination

AQUACULTURE RESEARCH, Issue 7 2007
Zhenghong Zuo
Abstract To test whether matrix attachment regions (MARs) and 18S rDNA can influence CAT gene transient expression positively in the red algae Porphyra haitanensis, a targeting vector pHR-CAT containing a portion of the 18S rDNA from P. haitanensis, pMAR1-HR-CAT containing one MAR from silkworm and a portion of the 18S rDNA from P. haitanensis and pMAR2-HR-CAT containing two MARs from silkworm and a portion of the 18S rDNA from P. haitanensis were constructed. With the electroporation method, the vectors were transferred into the protoplasts from the thalli of P. haitanensis. The results showed that the expression of chloramphenicol acetyl transferase (CAT) protein in transformed cells reached a maximum at 96 h after transformation. It was increased markedly with the pMAR2-HR-CAT compared with the pHR-CAT or the pCAT@3-control vector (P<0.01), and it was increased inconspicuously with pHR-CAT compared with the pCAT@3-control vector (P>0.05). It is suggested that MAR from silkworm could enhance the transient expression of foreign genes in P. haitanensis. [source]