Orientador: Jorg Kobarg / Tese (doutorado) - Universidade Estadual de Campinas, Instituto de Biologia / Made available in DSpace on 2018-08-11T07:55:23Z (GMT). No. of bitstreams: 1 Quaresma_AlexandreJoseChristino_D.pdf: 9068041 bytes, checksum: 9661a43a5c28440721d55ca90f6c94ac (MD5) Previous issue date: 2008 / Resumo: Os membros da família de proteínas chamada hnRNPs (heterogenous nuclear ribonuclein proteins) apresentam importantes papeis no controle da expressão gênica e no metabolismo dos mRNAs. Os membros hnRNPD (AUF1) e hnRNPQ (NSAP1) foram alvos deste estudo. AUF1 apresenta dois domínios de ligação à RNA do tipo RRM (RNA recognition motif) e participa ativamente no processo de desestabilização de uma classe de mRNAs que apresentam um motivo rico em AU na região 3' não traduzida. Demonstramos, através do sistema de duplo híbrido em levedura, que a isoforma p37 de AUF1 interagiu com as proteínas hnRNPQ, IMP-2, NSEP1 (YB-1) e UBC9. Além disso, a proteína hnRNPQ também foi pescada num outro ensaio de duplo híbrido em levedura, que utilizou como isca a proteína humana arginina metiltransferase (PRMT1). hnRNPQ apresenta, na sua região Cterminal, um ¿motivo rico em argininas e glicinas¿ (RGG box). Demonstramos que ela é alvo de metilação pela PRMT1 in vitro e in vivo. Funcionalmente, sua metilação é importante para sua localização nuclear. NSAP1 têm uma constituição modular com um domínio ácido (AcD) no seu Nterminal, seguido por três domínios de ligação à RNA do tipo RRM e o já mencionado RGG box no seu C-terminal. Funcionalmente hnRNPQ está envolvido em vários aspectos do etabolismo de RNA, incluindo a edição do mRNA da proteína humana ApoB. Para isso, ela interage não somente com o mRNA de ApoB, mas com a enzima efetora da edição Apobec1 e com a proteína que ativadora do Apobec1 (ACF1). Mostramos que o domínio ácido, de NSAP1 é capaz de interagir com Apobec1 e que sua fosforilação in vitro pela PKC inibe esta interação. Ainda identificamos que hnRNPQ interage com proteínas da família heat shock (incluindo HSP70 e BiP), e vimos que hnRNPQ é um alvo de fosforilação principalmente pela PKCd, in vitro. A localização sub-celular de hnRNPQ é modificada pela ativação in vivo das PKCs. Em conseqüência desta ativação ou da aplicação de estresse oxidativo, térmico ou indução de estresse do reticulo endoplasmático (tratamento com tapsigargina) hnRNPQ se desloca do núcleo para o citoplasma aonde se encontra em vesículas/corpúsculos definidas. Em resumo, nossos dados sugerem que as diversas funções da hnRNPQ relacionadas ao metabolismo de mRNAs, sofrem diferentes regulações, mediadas por modificações pós-traducionais (fosforilação e metilação), que interferem tanto na sua localização celular quanto na sua afinidade por determinados proteínas parceiras / Abstract: The members of the hnRNPs family (heterogenous nuclear ribonuclein proteins) play important roles in gene expression control and mRNAs metabolism. The proteins hnRNPD (AUF1) and hnRNPQ (NSAP1) were the main targets of this study. AUF1 has two RNA recognition motifs (RRM) and participates in the process of destabilization of a class of mRNAs that contain AU-rich sequences in their 3' untranslated regions (3'-UTR). We found, using the ¿yeast two-hybrid system¿ (Y2HS), that the isoform p37 of AUF1 (AUF1p37) interacts with the proteins: hnRNPQ, IMP-2, NSEP1 (YB-1) and UBC9. Moreover, the protein hnRNPQ was also identified as a prey protein in another Y2HS screen, which used as bait the human protein Arginine methyltransferase (PRMT1). HnRNPQ presents, in its C-terminal region, an "Arginine/Glicine-rich sequence" (RGG box). We are able to show that this RGG box is a target for methylation by PRMT1 in vitro and is methylated in vivo. Functionally, this methylation is important for its nuclear localization. hnRNPQ has a modular organization with an acid domain (AcD) in its N-terminal, followed by three RNA-binding domains (RRM) and the previously mentioned RGG box in its C-terminal. Functionally, hnRNPQ is involved in diverse aspects of RNA metabolism, including editing of the mRNA encoding the human protein ApoB. It has been shown previously to interact with the mRNA of ApoB, and also with the editing enzyme Apobec1 and the Apobec1 activation protein (ACF1). Here we show that the acid domain of hnRNPQ mediates the interaction with Apobec1 and that its in vitro phosphorylation (by PKC) inhibits this interaction. Furthermore, we found that hnRNPQ interacts with members the heat shock family of proteins (including HSP70 and BiP), and demonstrated that hnRNPQ can be in vitro phosphorylated by PKCd. Finally, we discovered that the sub-cellular localization of hnRNPQ undergoes modification after activation of PKC pathways. This also occurs after application of endoplasmic reticulum stress (using tarpsigargin), oxidative or heat stress. Under all of these conditions hnRNPQ translocated from the nucleus to the cytoplasm, where it is found at defined vesicles or granules. In summary, our data suggest that the diverse functions of hnRNPQ in the context of mRNA metabolism, may suffer specific regulations, by post-translational modifications, including phosphorylation and methylation, which modify both the proteins sub-cellular localizations as well as its affinity to interacting protein partners / Doutorado / Bioquimica / Doutor em Biologia Funcional e Molecular

Orientador: Célia Marisa Rizzatti Barbosa / Tese (Doutorado) - Universidade Estadual de Campinas, Faculdade de Odontologia de Piracicaba / Made available in DSpace on 2018-08-21T22:52:21Z (GMT). No. of bitstreams: 1 Meloto_CarolinaBeraldo_D.pdf: 1035478 bytes, checksum: c619d52bbc7d2858940483c9c5fc660e (MD5) Previous issue date: 2013 / Resumo: Catecolamina-O-metiltransferase (COMT) é uma enzima com amplas funções biológicas, inclusive a modulação da dor, exercidas através da metabolização de substratos como a dopamina, adrenalina, e noradrenalina. Já é sabido que a atividade da COMT é geneticamente polimórfica em humanos, e se correlaciona com a percepção individual da dor e eficiência na sua remissão entre pacientes com disfunção temporomandibular (DTM) tratados com propranolol. Por isso, nosso primeiro objetivo foi investigar novos polimorfismos de nucleotídeo único (SNP) que pudessem marcar para este benefício. De fato, encontramos um novo SNP, rs165774 (G>A), que se mostrou associado à DTM ou fenótipos intermediários em duas coortes diferentes. Este polimorfismo, por sua vez, se localiza em proximidade a um segundo SNP, rs165895 (T>C), ambos na região 3' não traduzida (3'UTR) de um mRNA alternativo da COMT ainda não caracterizado. Assim, também foi nossos objetivos (i) verificar a expressão deste transcrito em diferentes tecidos humanos e linhas de células, rastreando-o por RT-PCR (Reverse Transcriptase - Polymerase Chain Reaction); (ii) predizer a estrutura cristalina da enzima codificada por ele, através de modelagem pelo método dinâmico molecular discreto; (iii) expressá-lo em um sistema celular e comparar sua expressão relativa e atividade enzimática às da isoforma convencional, determinando-as por RT-PCR e HPLC (High Performance Liquid Chromatography), respectivamente; e (iv) verificar os efeitos dos SNPs rs165774 e rs165895 sobre este transcrito, criando-se diferentes mutantes por mutação sítio-dirigida e observando seus efeitos sobre a expressão relativa e atividade enzimática. Nossos resultados mostraram que (i) o transcrito alternativo da COMT é expresso em diferentes tecidos humanos e sistemas celulares; (ii) a estrutura cristalina de sua enzima exibe uma região C-terminal único que é distinta da isoforma convencional; e que este transcrito é (iii) menos relativamente expresso e sua enzima menos ativa que o transcrito e a enzima convencionais, respectivamente, e (iv) sofre regulação em nível transcricional pelos SNPs rs165774 e rs165895. Com este estudo, pudemos concluir que o SNP rs165774 é um forte marcador genético para DTM; que juntamente com o SNP rs165895, localizam-se na região 3'UTR de uma forma alternativa de mRNA da COMT que, pela primeira vez, provou ser capaz de codificar para uma isoforma alternativa da enzima que exibe atividade enzimática; e que esta isoforma alternativa de mRNA da COMT sofre efeitos regulatórios, em nível transcricional, causados por ambos os SNPs / Abstract: Catecolamine-O-methyltransferase (COMT) is an enzyme with broad biological functions, including pain modulation, exerted through metabolization of substrates such as dopamine, epinephrine, and norepinephrine. It is well known that COMT activity is genetically polymorphic in humans, and correlates to individual pain perception and efficiency in its remission among temporomandibular disorder (TMD) patients treated with propranolol. Thus, our first aim was to investigate new single nucleotide polymorphism (SNP) that might mark for this benefit. Indeed, we have found a new SNP, rs165774 (G>A), that was associated with TMD or intermediate phenotypes in two different cohorts. This polymorphism, in turn, is in close proximity to a second SNP, rs165895 (T>C), both in the 3' untranslated region (3'UTR) of an alternative COMT mRNA that has not yet been characterized. Therefore, we also aimed to (i) verify the expression of this transcript in different human tissues and cell systems, tracking it through RT-PCR (Reverse Transcriptase - Polymerase Chain Reaction); (ii) predict the crystalline structure of the enzyme encoded by it, modeling it with discrete molecular dynamics; (iii) express it in a cell system and compare its relative expression and enzymatic activity to the conventional isoform, using RT-PCR and HPLC (High Performance Liquid Chromatography), respectively; and (iv) verify the effects of SNPs rs165774 and rs165895 on the transcript, creating different mutants by site-directed mutagenesis and observing their effects on the relative expression and enzymatic activity. Our findings show that (i) the alternative COMT transcript is expressed in different human tissues and cell systems; (ii) the crystalline structure of its enzyme exhibits a unique C-terminus that is distinct from the conventional isoform; and that this transcript is (iii) less relatively expressed and its enzyme is less active than the conventional transcript and enzyme, respectively, and (iv) is regulated, at transcriptional level, by the SNPs rs165774 e rs165895. With this study, we conclude that SNP SNPs rs165774 is a strong genetic marker for TMD; that along with SNPs rs165895, they are located in the 3'UTR of an alternative COMT mRNA which proved, for the first time, to be able of encoding an alternative isoform of the enzyme that exhibits enzymatic activity; and that this alternative COMT mRNA is regulated, at transcriptional level, by both SNPs / Doutorado / Protese Dental / Doutora em Clínica Odontológica

mRNA decay is an important cellular process that regulates gene expression and is tightly linked to the process of translation. Many studies have illustrated the link between mRNA turnover and translation, indicating that mRNA decay is a cytoplasmic event. In order to investigate further the link between translation and turnover, seven mutants in translation initiation factors were analyzed for their effect on mRNA decay, including: i) three mutant alleles of the PRT1 gene (prt1-1, prt1-26 and prt1-63), which encodes a subunit of elF3; ii) sui1-1, which encodes the smallest subunit of elF3; iii) sui2-1, which encodes elF2; iv) GCN2c, which encodes the elF2 kinase, and v) cdc33-42, a mutant in the cap binding protein elF4E. The results demonstrate that the prt1-1 mutation results in stabilization of nonsense containing mRNAs without affecting the half-lives of most other mRNAs, a phenotype similar to a upf1Δ strain. To identify substrates for the nonsense-mediated mRNA decay pathway, mRNA differential display analysis was performed using RNA prepared from prt1-1, PRT1, upf1Δ and UPF1 strains. Although the abundance of the HHF2 mRNA is increased in the mutant strains the half-life is unaffected. However, the mRNA half-life of the transcriptional regulator SPT10 was increased in the mutant strains indicating the SPT10 transcript is a substrate for the nonsense-mediated mRNA decay pathway. Further characterization of the SPT10 transcript showed that it is a substrate for this pathway because the initiator AUG is present in a poor translation initiation context which results in aberrant translation initiation. Finally, several other mRNAs, predicted to be substrates for the pathway based on the leaky scanning model, were subsequently shown to decay through this pathway. These transcripts included the REV7, STE50, and UBP7 mRNAs. The results from these experiments lay the groundwork for addressing the potential regulatory role of the nonsense-mediated mRNA decay pathway.

Splicing of mRNA precursors (pre-mRNA) comprises a series of ATP-dependent steps, the first of which is the stable binding of U2 snRNP at the pre-mRNA branchpoint. The basis of ATP use in splicing is not well understood. Several yeast splicing factors belong to DEAD/H box family of RNA-dependent ATPase, and are implicated in dynamic RNA structure rearrangement during spliceosome assembly. In mammals, however, such information is conspicuously lacking. In fact, none of the known mammalian splicing factors has characteristics for ATP hydrolysis. In an attempt to identify mammalian splicing factors involved in ATP usage, we have developed a novel approach to identify and purify spliceosomal ATP binding proteins. Six spliceosomal ATP binding proteins were found, one of them, SAFp56, was purified and microsequenced, and found to be a DEAD box protein containing unique DECD motif instead of the canonical DEAD motif. During the course of this work, a new functional region in U2AF65, an essential splicing factor required for U2 snRNP entry into the spliceosome, was defined. This information was used to clone a human U2AF65 associated protein (UAP). UAP and SAFp56 are identical. We refer to this protein as hUAP56 (human 56 kDa U2AF65 associated protein). We present evidence that hUAP56 is an essential splicing factor required for the U2 snRNP binding to pre-mRNA. Interestingly, UAP56 is recruited to pre-mRNA in a polypyrimidine tract bound U2AF65-dependent fashion. This result underscores a new function of U2AF65, and provides the first description of how a specific DEAD box protein is directed to a pre-mRNA splicing signal, and/or, to the proximity of its substrate at a particular stage. Like an authentic DEAD box protein. hUAP56 has ATP binding, RNA-stimulated ATPase, as well as RNA binding activity. A particularly novel result is that the ATPase activity of UAP56 is stimulated by U2AF65. This observation strongly suggests the role of UAP56 in ATP dependent mechanism during U2 snRNP binding to the pre-mRNA branchpoint, and implies that UAP56 may function through a distinct mechanism. We identify yeast UAP (yUAP), a highly conserved S. cerevisiae homologue of hUAP56. yUAP is essential for viability, can be functionally substituted for by hUAP56, and like its human counterpart, is an essential pre-mRNA splicing factor required for spliceosome assembly. Furthermore, we show that yUAP is required for formation of the branchpoint dependent commitment complex, the precursor for U2 snRNP addition. Site-directed mutagenesis revealed that all DEAD box protein consensus motifs are required for yUAP function. Interestingly, a strain harboring a yUAP mutant in which the DECD sequence, characteristic of UAP members, was changed to canonical sequence, is inviable. Our results demonstrate that UAP is structurally and functionally conserved from yeast to man. In conjunction with previous studies, we conclude that at least two DEAD box proteins, Prp5p and yUAP, are required for the U2 snRNP-branchpoint interaction.

A key process underlying synapse development and plasticity is stimulus-dependent translation of localized mRNAs. This process entails RNA packaging into translationally silent granules and exporting them over long distances from the nucleus to the synapse. Little is know about (a) where ribonucleoprotein (RNP) complexes are assembled, and if in the nucleus, how do they exit the nucleus; (b) how RNPs are transported to specific synaptic sites. At the Drosophila neuromuscular junction (NMJ), we uncovered a novel RNA export pathway for large RNP (megaRNP) granules assembled in the nucleus, which exit the nucleus by budding through the nuclear envelope. In this process, megaRNPs are enveloped by the inner nuclear membrane (INM), travel through the perinuclear space as membrane-bound granules, and are deenveloped at the outer nuclear membrane. We identified Torsin (an AAA-ATPase that in humans is linked to dystonia), as mediator of INM scission. In torsin mutants, megaRNPs accumulate within the perinuclear space, and the mRNAs fail to localize to postsynaptic sites leading to abnormal NMJ development. We also found that nuclear envelope budding is additionally used for RNP export during Drosophila oogenesis. Our studies also suggested that the nuclear envelope-associated protein, Nesprin1, forms striated F-actin-based filaments or ‘‘railroad tracks,’’ that span from muscle nuclei to postsynaptic sites at the NMJ. Nesprin1 railroad tracks wrap aoround the postsynaptic regions of immature synaptic boutons, and serve to direct RNPs to sites of new synaptic bouton formation. These studies elucidate novel cell biological mechanisms for nuclear RNP export and trafficking during synapse development.

Maternally inherited poly(A)+ RNAs are important for directing early development in many animal species. This thesis investigates the regulation of maternal mRNA in the South African clawed frog, Xenopus laevis. The first portion of this thesis examines an unusual class of maternal RNA, interspersed poly(A)+ RNA, which is composed of co-linear repeat and single copy sequences. A cDNA clone, called pXR, contains the repeat portion of an interspersed RNA that hybridizes to several different oocyte transcripts of diverse size that persist until the neurula stage. DNA sequence analysis of the cDNA and hybrid selection of the oocyte transcripts followed by in vitro translation show that molecules of this repeat family are not translatable. This data, combined with the developmental profile of XR containing RNAs, indicate that members of this repeat family are not likely to be maternal messenger RNAs. The second part of this thesis investigates the expression of a class of maternal mRNAs that are regulated by cytoplasmic polyadenylation during progesterone induced oocyte maturation. One particular mRNA G10, is stored as a polyadenylated RNA in the cytoplasm of stage VI oocytes until maturation when the process of poly(A) elongation stimulates its translation. Injection of mutant and wild-type mRNAs, synthesized in vitro, revealed that two sequence elements, UUUUUUAUAAAG and AAUAAA, were both necessary and sufficient for polyadenylation and polysomal recruitment of G10. Maturation promoting factor and cyclin as well as progesterone can induce polyadenylation but in each case protein synthesis is required. Extracts from oocytes and unfertilized eggs were employed to identify factors that may be responsible for maturation-specific polyadenylation. An 82 kd protein that binds to the UUUUUUAUAAAG in egg, but not oocyte extracts, was identified by UV crosslinking. This data suggests that p82 is a good candidate for a developmentally regulated protein that controls the expression of maternal messenger RNAs in early Xenopus development.

Leukocytes express a family of high molecular weight glycoproteins called leukocyte common antigens (CD45) which have tyrosine phosphatase activity and are involved in phosphotyrosine signal transduction. Antibodies to different CD45 isoforms distinguish functionally different CD4+ T cell subsets in humans, rats, and mice. Selected protein isoforms are expressed through a process of exon splicing which is cell-type and differentiation-state specific. Splicing of the three variable exons, A, B, and C, which encode amino acids located near the extracellular amino terminus of the protein, potentially results in generation of eight different mRNA transcripts. The purpose of this study was to determine the relative levels of all eight different CD45 transcripts present in a panel of murine CD4+ T cell lines and normal murine and human CD4+ T cell subsets separated with antibodies to CD45 variable exons. I show, as expected, that the broad features of CD45 surface isoform expression in these cells can be accounted for by the relative amounts of the eight differentially spliced transcripts. Unexpectedly, all the differences in CD45 isoform expression among the CD4+ T cell subpopulations that I measured could be accounted for by differences in the overall level of variable exon expression. I did not see differences among T cell populations in the relative expression of particular variable exons. Exon B was always found in greater abundance than exons C or A. Of the dual exon species, only AB and BC were found in CD4+ T cells. The AC species was undetectable. Human CD4+ T cells, especially those in the naive subset, express higher levels of CD45 variable exons than murine CD4+ T cells. In unrelated studies, I have generated a rat-mouse hybridoma which secretes a rat IgG antibody reactive with mouse CD45. I show that the monoclonal antibody, 25D10, defines a novel epitope consistent with a post-translational modification of CD45, similar but distinct from the epitope recognized by monoclonal antibody RA3.6B2 (anti-B220). This conclusion is based on evidence that it precipitates similar molecular weight bands from cells as does a framework monoclonal antibody to CD45, yet has a distinct cell surface expression as determined by flow cytometric analysis. It stains activated Th cell lines at a higher intensity than resting Th cells, stains 60-70% of splenocytes, and 25-30% of lymph node cells. It stains all class II positive cells but not freshly isolated CD4+, CD8+ T cells or CD45 transfected fibroblasts.

No description available.

by Lau Hoi Lun. / Thesis (M.Phil.)--Chinese University of Hong Kong, 1998. / Includes bibliographical references (leaves 83-96). / Abstract also in Chinese. / Abstract --- p.i / Acknowledgements --- p.iv / Abbreviations --- p.v / Table of contents --- p.vi / Chapter Chapter 1 --- Introduction / Chapter 1.1 --- Endocrine control of normal and abnormal growth of prostate --- p.1 / Chapter 1.1.1 --- Androgen regulation of prostate gland --- p.1 / Chapter 1.1.2 --- Estrogen regulation of prostate gland --- p.4 / Chapter 1.2 --- Gonadotropin-releasing hormone plays a central role in reproduction --- p.6 / Chapter 1.2.1 --- GnRH gene --- p.7 / Chapter 1.2.2 --- GnRH receptor --- p.9 / Chapter 1.3 --- Therapeutic strategies using GnRH analogs to treat prostate cancer --- p.12 / Chapter 1.4 --- Expression of GnRH or its receptor in reproductive tissues --- p.12 / Chapter 1.4.1 --- Expression of GnRH in reproductive --- p.13 / Chapter 1.4.2 --- Expression of GnRH and its receptor in pituitary and reproductive tissues --- p.13 / Chapter 1.5 --- Animal models for the study of prostate cancer --- p.15 / Chapter 1.5.1 --- Nobel rat inducible model --- p.15 / Chapter 1.5.2 --- Androgen dependent rat Dunning prostatic tumor --- p.16 / Chapter 1.5.3 --- Androgen-independent prostatic carcinoma line of Noble rat --- p.18 / Chapter 1.6 --- Aim of study --- p.18 / Chapter Chapter 2 --- Materials and Methods / Chapter 2.1 --- Origin and supply of Nobel rat --- p.20 / Chapter 2.2 --- Induction of dysplasia in Nobel rat prostate gland by long-term treatment with steroids --- p.20 / Chapter 2.2.1 --- Chemicals --- p.20 / Chapter 2.2.2 --- Preparation of steroid hormone-filled Silastic tubings --- p.20 / Chapter 2.2.3 --- Surgical implantation of Silastic® tubings --- p.21 / Chapter 2.2.4 --- Protocols of hormonal treatments --- p.21 / Chapter 2.3 --- Androgen- dependent Dunning rat prostatic adenocarcinoma --- p.22 / Chapter 2.4 --- Androgen- independent prostatic carcinoma line (ALT) of Noble rat --- p.22 / Chapter 2.5 --- Detection of mRNA expression of gonadotropin- releasing hormone (GnRH) in normal and neoplastic rat prostates --- p.23 / Chapter 2.5.1 --- Preparation of tissue for total RNA extraction --- p.23 / Chapter 2.5.2 --- Total RNA extraction --- p.24 / Chapter 2.5.3 --- Reverse-transcription Polymerase Chain Reaction (RT-PCR) --- p.25 / Chapter 2.5.4 --- Purification of DNA fragments from agarose gels --- p.27 / Chapter 2.5.5 --- Subcloning of DNA into vector --- p.27 / Chapter 2.5.6 --- Nucleotide sequencing --- p.30 / Chapter 2.5.7 --- Southern blot analysis --- p.32 / Chapter 2.5.7.1 --- Southern blotting --- p.32 / Chapter 2.5.7.2 --- Preparation of α-32P-dCTP labelled GnRH probe --- p.32 / Chapter 2.5.7.3 --- Hybridization --- p.33 / Chapter 2.6 --- Detection of mRNA expression of gonadotropin-releasing hormone receptor (GnRH-R) in normal and neoplastic rat prostates --- p.34 / Chapter 2.6.1 --- Cloning of GnRH-R cDNA and synthesis of its probe --- p.34 / Chapter 2.6.2 --- Detection of GnRH receptor mRNA expression in normal and dysplastic Nobel rat prostates by Southern blot --- p.36 / Chapter 2.6.3 --- Detection of GnRH receptor mRNA expression in Dunning tumor --- p.37 / Chapter 2.6.4 --- Detection of the GnRH receptor mRNA expression in AIT tumor by RT-PCR --- p.37 / Chapter Chapter 3 --- Results / Chapter 3.1 --- Detection of mRNA expression of gonadotropin-releasing hormone (GnRH) in normal and neoplastic rat prostates --- p.38 / Chapter 3.1.1 --- Reverse -transcription Polymerase Chain Reaction (RT-PCR) --- p.38 / Chapter 3.1.2 --- Purification of DNA fragments amplified by PCR from the agarose gel --- p.38 / Chapter 3.1.3 --- Subcloning of DNA into vector --- p.39 / Chapter 3.1.4 --- Nucleotide sequencing --- p.39 / Chapter 3.1.5 --- Southern-blot analysis --- p.39 / Chapter 3.2 --- Detection of gonadotropin-releasing hormone receptor mRNA expression in normal and neoplastic rat prostates --- p.40 / Chapter 3.2.1 --- Cloning of gonadotropin-releasing hormone receptor (GnRH) cDNA and synthesis of probe from the normal Noble rat pituitary gland --- p.40 / Chapter 3.2.2 --- Detection of GnRH receptor mRNA expression in normal and dysplastic Nobel rat prostates --- p.42 / Chapter 3.2.3 --- Detection of GnRH receptor mRNA expression in rat Dunning tumor by PCR --- p.43 / Chapter 3.2.4 --- Detection of GnRH receptor mRNA expression in AIT tumor --- p.43 / Chapter Chapter 4 --- Discussion / Chapter 4.1 --- Detection of mRNA expression of gonadotropin-releasing releasing hormone(GnRH) in normal and neoplastic rat prostates --- p.69 / Chapter 4.1.1 --- Expression of GnRH mRNA in normal Nobel rat prostate gland --- p.69 / Chapter 4.1.2 --- Expression of GnRH mRNA in dysplastic Nobel rat prostate --- p.71 / Chapter 4.1.3 --- Expression of GnRH mRNA in androgen-dependent rat Dunning prostatic tumor --- p.72 / Chapter 4.1.4 --- Expression of GnRH mRNA in AIT tumor --- p.74 / Chapter 4.2 --- Detection of GnRH receptor in normal and dysplastic rat prostates --- p.75 / Chapter 4.2.1 --- Negative expression of GnRH receptor in normal and dysplastic Nobel in rat prostates --- p.75 / Chapter 4.2.2 --- Positive expression of GnRH receptor mRNA in rat Dunning tumor --- p.77 / Chapter 4.2.3 --- Negative expression of GnRH receptor mRNA in ALT tumor --- p.78 / Chapter Chapter 5 --- Summary and Conclusions --- p.80 / References --- p.83

Circulating RNA was previously demonstrated through the identification of tumour-derived transcripts in the plasma and serum of cancer patients. This finding inspired the detection of cell-free fetal mRNA in maternal plasma which in turn facilitated the development of promising non-invasive prenatal assessment strategies applicable to pregnancies regardless of fetal sex. / Finally, in the last study, I implemented what I have learnt from the analysis of circulating fetal RNA into the development of brain-derived RNA transcripts for detection in the plasma of patients who had sustained brain injuries. A systematic approach based on gene expression microarray analysis was adopted to search for circulating brain-specific mRNA markers. Transcripts showing high expression levels in brain tissues but low expression levels in peripheral blood were identified. However, the detectability of these brain-derived mRNA markers in both peripheral and jugular plasma was found to be low. Instead, concentrations of these mRNA markers were found to be higher in cerebral spinal fluid (CSF) from brain-injured than non-brain-injured patients. / In section IV of this thesis, I reviewed and modified the blood sample processing and plasma RNA extraction protocols that were previously practised, in an attempt to enrich circulating fetal RNA in maternal plasma. Besides mRNA, extraction protocols for microRNAs (miRNAs), a new class of circulating nucleic acid markers, were also evaluated. The modifications in the protocols that I introduced led to significant improvements in RNA yield and enhanced the accuracy and reliability of circulating RNA detection in plasma, especially for those marginally detectable transcripts. / Recently, in addition to maternal plasma, there have been studies by other research groups reporting the presence of placental/fetal mRNA in maternal whole blood. In the first part of this thesis, I studied a list of previously identified placental mRNA transcripts, including chorionic somatomammotropin hormone 1 (CSH1), KiSS-1 metastasis-suppressor (KISS1), placenta-specific 4 (PLAC4) and placenta-specific 1 (PLAC1) in maternal whole blood and determined if this whole blood-based approach offered advantages over maternal plasma analysis. The presence of KISS1, PLAC4 and PLAC1 in non-pregnant and post-partum blood samples as well as the confirmed maternal contribution of PLAC4 mRNA in maternal blood proved that most of the detected 'placental' mRNA molecules in maternal whole blood were of maternal origin. To explore if more pregnancy-associated circulating mRNA markers could be developed for maternal whole blood analysis, candidates were mined after performing gene expression microarray comparison of whole blood samples from pregnant and non-pregnant individuals. The pregnancy-specificity of the identified gene candidates was further investigated. However, their presence in non-pregnant whole blood and lack of clearance after pregnancy indicated that they were not "pregnancy-specific" markers. These data suggested that pregnancy specific transcripts could be more readily identified from maternal plasma than whole blood. / The results presented in this thesis have not only provided a foundation facilitating the precise and accurate detection of fetal-specific RNA markers but have also improved the current understanding of the biology of circulating RNA. / Heung, May Sze. / Advisers: Dennis Lo; Rossa Wk Chiu. / Source: Dissertation Abstracts International, Volume: 72-11, Section: B, page: . / Thesis (Ph.D.)--Chinese University of Hong Kong, 2009. / Includes bibliographical references (leaves 212-239). / Electronic reproduction. Hong Kong : Chinese University of Hong Kong, [2012] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Electronic reproduction. [Ann Arbor, MI] : ProQuest Information and Learning, [201-] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Abstract also in Chinese.