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author:("gossen, T")
1.  Splice variant PRKC-ζ-PrC is a novel biomarker of human prostate cancer 
British Journal of Cancer  2012;107(2):388-399.
Previously, using gene-knockdown techniques together with genome expression array analysis, we showed the gene protein Kinase C (PKC)-zeta (PRKCZ) to mediate the malignant phenotype of human prostate cancer. However, according to NCBI, the gene has undergone several major iterations. Therefore, to understand the relationship between its structure and biological activities, we have analysed its expressed sequence in prostate cancer cell lines and tissues.
Transcriptome-walking and targeted PCR were used to sequence the mRNA transcribed from PRKCZ. Hydropathy analysis was employed to analyse the hypothetical protein sequence subsequently translated and to identify an appropriate epitope to generate a specific monoclonal antibody.
A novel sequence was identified within the 3′-terminal domain of human PRKCZ that, in prostate cancer cell lines and tissues, is expressed during transcription and thereafter translated into protein (designated PKC-ζ-PrC) independent of conventional PKC-ζ-a. The monoclonal antibody detected expression of this 96 kD protein only within malignant prostatic epithelium.
Transcription and translation of this gene sequence, including previous intronic sequences, generates a novel specific biomarker of human prostate cancer. The presence of catalytic domains characteristic of classic PKC-β and atypical PKC-ι within PKC-ζ-PrC provides a potential mechanism for this PRKCZ variant to modulate the malignant prostatic phenotype out-with normal cell-regulatory control.
PMCID: PMC3394965  PMID: 22644296
prostate cancer; PRKCZ; structural variant; novel sequence
2.  Amphetamine, past and present – a pharmacological and clinical perspective 
Amphetamine was discovered over 100 years ago. Since then, it has transformed from a drug that was freely available without prescription as a panacea for a broad range of disorders into a highly restricted Controlled Drug with therapeutic applications restricted to attention deficit hyperactivity disorder (ADHD) and narcolepsy. This review describes the relationship between chemical structure and pharmacology of amphetamine and its congeners. Amphetamine’s diverse pharmacological actions translate not only into therapeutic efficacy, but also into the production of adverse events and liability for recreational abuse. Accordingly, the balance of benefit/risk is the key challenge for its clinical use. The review charts advances in pharmaceutical development from the introduction of once-daily formulations of amphetamine through to lisdexamfetamine, which is the first d-amphetamine prodrug approved for the management of ADHD in children, adolescents and adults. The unusual metabolic route for lisdexamfetamine to deliver d-amphetamine makes an important contribution to its pharmacology. How lisdexamfetamine’s distinctive pharmacokinetic/pharmacodynamic profile translates into sustained efficacy as a treatment for ADHD and its reduced potential for recreational abuse is also discussed.
PMCID: PMC3666194  PMID: 23539642
Abuse liability; amphetamine; attention deficit hyperactivity disorder (ADHD); drug formulations; lisdexamfetamine; microdialysis
3.  Regulation of Mouse Oocyte Microtubule and Organelle Dynamics by PADI6 and the Cytoplasmic Lattices 
Developmental biology  2010;350(2):311-322.
Organelle positioning and movement in oocytes is largely mediated by microtubules (MTs) and their associated motor proteins. While yet to be studied in germ cells, cargo trafficking in somatic cells is also facilitated by specific recognition of acetylated MTs by motor proteins. We have previously shown that oocyte-restricted PADI6 is essential for formation of a novel oocyte-restricted fibrous structure, the cytoplasmic lattices (CPLs). Here, we show that α-tubulin appears to be associated with the PADI6/CPL complex. Next, we demonstrate that organelle positioning and redistribution is defective in PADI6-null oocytes and that alteration of MT polymerization or MT motor activity does not induce organelle redistribution in these oocytes. Finally, we report that levels of acetylated microtubules are dramatically suppressed in the cytoplasm of PADI6-null oocytes, suggesting that the observed organelle redistribution failure is due to defects in stable cytoplasmic MTs. These results demonstrate that the PADI6/CPL superstructure plays a key role in regulating MT-mediated organelle positioning and movement.
PMCID: PMC3031771  PMID: 21147087
Cytoplasmic lattice; PADI6; Tubulin; Acetylated microtubule; Spindle; Organelle redistribution; Endoplasmic reticulum; Mitochondria; Oocyte maturation
4.  siRNA Knockdown of Ribosomal Protein Gene RPL19 Abrogates the Aggressive Phenotype of Human Prostate Cancer 
PLoS ONE  2011;6(7):e22672.
We provide novel functional data that posttranscriptional silencing of gene RPL19 using RNAi not only abrogates the malignant phenotype of PC-3M prostate cancer cells but is selective with respect to transcription and translation of other genes. Reducing RPL19 transcription modulates a subset of genes, evidenced by gene expression array analysis and Western blotting, but does not compromise cell proliferation or apoptosis in-vitro. However, growth of xenografted tumors containing the knocked-down RPL19 in-vivo is significantly reduced. Analysis of the modulated genes reveals induction of the non-malignant phenotype principally to involve perturbation of networks of transcription factors and cellular adhesion genes. The data provide evidence that extra-ribosomal regulatory functions of RPL19, beyond protein synthesis, are critical regulators of cellular phenotype. Targeting key members of affected networks identified by gene expression analysis raises the possibility of therapeutically stabilizing a benign phenotype generated by modulating the expression of an individual gene and thereafter constraining a malignant phenotype while leaving non-malignant tissues unaffected.
PMCID: PMC3142177  PMID: 21799931
5.  Portrait of an oocyte: our obscure origin 
Oocytes play a pivotal role in the cycle of human life. As we discuss here, after emerging from germline stem cells in the fetus, they grow in a follicular niche in which development is harmonized for timely ovulation and hormone secretion after puberty. Most human oocytes have poor developmental competence and are peculiarly vulnerable to chromosomal malsegregation, especially as women pass the optimal years of fertility and may begin to turn to assisted reproductive technologies (ARTs) and egg donation. Research needs to focus on the molecular factors involved and the environmental niche required for optimal development of oocytes, with the aim of increasing their numbers and quality for ARTs, since these are the factors that so often limit human fertility.
PMCID: PMC2846057  PMID: 20364095
6.  The Src Homology 2 Domain-Containing Adapter Protein B (SHB) Regulates Mouse Oocyte Maturation 
PLoS ONE  2010;5(6):e11155.
SHB (Src homology 2 domain-containing adapter protein B) is involved in receptor tyrosine kinase signaling. Mice deficient in the Shb gene have been found to exhibit a transmission ratio distortion with respect to inheritance of the Shb null allele among offspring and this phenomenon was linked to female gamete production. Consequently, we postulated that Shb plays a role for oocyte biology and thus decided to investigate oocyte formation, meiotic maturation, and early embryo development in relation to absence of the Shb gene. Oogenesis was apparently accelerated judging from the stages of oocyte development on fetal day 18.5 and one week postnatally in Shb −/− mice; but in adulthood ovarian follicle maturation was impaired in these mice. Completion of meiosis I (first polar body extrusion) was less synchronized, with a fraction of oocytes showing premature polar body extrusion in the absence of Shb. In vitro fertilization of mature oocytes isolated from Shb +/+, +/− and −/− mice revealed impaired early embryo development in the −/− embryos. Moreover, the absence of Shb enhanced ERK (extracellular-signal regulated kinase) and RSK (ribosomal S6 kinase) signaling in oocytes and these effects were paralleled by an increased ribosomal protein S6 phosphorylation and activation. It is concluded that SHB regulates normal oocyte and follicle development and that perturbation of SHB signaling causes defective meiosis I and early embryo development.
PMCID: PMC2886836  PMID: 20585392
7.  PRKC-ζ Expression Promotes the Aggressive Phenotype of Human Prostate Cancer Cells and Is a Novel Target for Therapeutic Intervention 
Genes & Cancer  2010;1(5):444-464.
We show protein kinase C–zeta (PKC-ζ) to be a novel predictive biomarker for survival from prostate cancer (P < 0.001). We also confirm that transcription of the PRKC-ζ gene is crucial to the malignant phenotype of human prostate cancer. Following siRNA silencing of PRKC-ζ in PC3-M prostate cancer cells, stable transfectant cell line si-PRKC-ζ-PC3-MT1-6 is phenotypically nonmalignant in vitro and in vivo. Genome-wide expression analysis identified 373 genes to be differentially expressed in the knockdown cells and 4 key gene networks to be significantly perturbed during phenotype modulation. Functional interconnection between some of the modulated genes is revealed, although these may be within different regulatory pathways, emphasizing the complexity of their mutual interdependence. Genes with altered expression following PRKC-ζ knockdown include HSPB1, RAD51, and ID1 that we have previously described to be critical in prostatic malignancy. Because expression of PRKC-ζ is functionally involved in promoting the malignant phenotype, we propose PKC-ζ as a novel and biologically relevant target for therapeutic intervention in prostate cancer.
PMCID: PMC3092210  PMID: 21779455
prostate cancer; PRKC-ζ; siRNA
8.  The oocyte population is not renewed in transplanted or irradiated adult ovaries 
Human Reproduction (Oxford, England)  2008;23(10):2326-2330.
According to conventional theory, the oocyte population is not renewed in mammalian ovaries after birth. A new hypothesis proposes that oocytes are generated continuously from haematopoietic progenitor cells. There is, however, no evidence that they can ovulate, although they may partially restore fertility by organizing ‘helper follicles’. The hypothesis that follicles can form de novo in adult ovaries has been tested in a transplant model.
Ovaries from adult mice were transplanted under the kidney capsule or into the ovarian bursa of histocompatible, transgenic CAG::H2B-EGFP host animals. Some donors were sterilized before transplantation by X-irradiation to ensure ‘empty niches’ were available for repopulation. The phenotype of follicular oocytes at 2, 4 and 8 weeks post-transplantation was scored by epifluorescence.
A total of 819 oocytes were examined in 30 ovarian grafts. None expressed green fluorescence, as would be predicted if they had formed de novo from germ cell progenitors in the systemic circulation of the host. Furthermore, small follicles eliminated by irradiation were not replaced in transplanted ovaries, and the few growing follicles present were apparently survivors of the original population.
No evidence was found to support the hypothesis that progenitor cells from extra-ovarian sources can repopulate the adult ovary. The findings are consistent with the conventional view that a limited number of oocytes are formed before birth and declines with age. The study did not, however, rule out the possibility that germline stem cells may reside in the adult ovary.
PMCID: PMC2721721  PMID: 18596027
follicle; ovary; regeneration; transplantation; X-irradiation
9.  Social ontologies 
There is room for considerable cooperation between archaeology and neuroscience, but in order for this to happen we need to think about the interactions among brain–body–world, in which each of these three terms acts as cause and effect, without attributing a causally determinant position to any one. Consequently, I develop the term social ontology to look at how human capabilities of mind and body are brought about through an interaction with the material world. I look also at the key notion of plasticity to think about not only the malleable nature of human brains, but also the artefactual world. Using an example from the British Iron Age (approx. 750 BC–AD 43), I consider how new materials would put novel demands on the bodies and brains of people making, using and appreciating objects, focusing on an especially beautiful sword. In conclusion, I outline some possible areas of enquiry in which neuroscientists and archaeologists might collaborate.
PMCID: PMC2606704  PMID: 18292057
ontology; plasticity; brain–body–world; materials
10.  Female Sexual Polymorphism and Fecundity Consequences of Male Mating Harassment in the Wild 
PLoS ONE  2007;2(6):e580.
Genetic and phenotypic variation in female response towards male mating attempts has been found in several laboratory studies, demonstrating sexually antagonistic co-evolution driven by mating costs on female fitness. Theoretical models suggest that the type and degree of genetic variation in female resistance could affect the evolutionary outcome of sexually antagonistic mating interactions, resulting in either rapid development of reproductive isolation and speciation or genetic clustering and female sexual polymorphisms. However, evidence for genetic variation of this kind in natural populations of non-model organisms is very limited. Likewise, we lack knowledge on female fecundity-consequences of matings and the degree of male mating harassment in natural settings. Here we present such data from natural populations of a colour polymorphic damselfly. Using a novel experimental technique of colour dusting males in the field, we show that heritable female colour morphs differ in their propensity to accept male mating attempts. These morphs also differ in their degree of resistance towards male mating attempts, the number of realized matings and in their fecundity-tolerance to matings and mating attempts. These results show that there may be genetic variation in both resistance and tolerance to male mating attempts (fitness consequences of matings) in natural populations, similar to the situation in plant-pathogen resistance systems. Male mating harassment could promote the maintenance of a sexual mating polymorphism in females, one of few empirical examples of sympatric genetic clusters maintained by sexual conflict.
PMCID: PMC1892802  PMID: 17593979
11.  Human LINE-1 retrotransposon induces DNA damage and apoptosis in cancer cells 
Long interspersed nuclear elements (LINEs), Alu and endogenous retroviruses (ERVs) make up some 45% of human DNA. LINE-1 also called L1, is the most common family of non-LTR retrotransposons in the human genome and comprises about 17% of the genome. L1 elements require the integration into chromosomal target sites using L1-encoded endonuclease which creates staggering DNA breaks allowing the newly transposed L1 copies to integrate into the genome. L1 expression and retrotransposition in cancer cells might cause transcriptional deregulation, insertional mutations, DNA breaks, and an increased frequency of recombinations, contributing to genome instability. There is however little evidence on the mechanism of L1-induced genetic instability and its impact on cancer cell growth and proliferation.
We report that L1 has genome-destabilizing effects indicated by an accumulation of γ-H2AX foci, an early response to DNA strand breaks, in association with an abnormal cell cycle progression through a G2/M accumulation and an induction of apoptosis in breast cancer cells. In addition, we found that adjuvant L1 activation may lead to supra-additive killing when combined with radiation by enhancing the radiation lethality through induction of apoptosis that we have detected through Bax activation.
L1 retrotransposition is sensed as a DNA damaging event through the creation DNA breaks involving L1-encoded endonuclease. The apparent synergistic interaction between L1 activation and radiation can further be utilized for targeted induction of cancer cell death. Thus, the role of retrotransoposons in general, and of L1 in particular, in DNA damage and repair assumes larger significance both for the understanding of mutagenicity and, potentially, for the control of cell proliferation and apoptosis.
PMCID: PMC1464142  PMID: 16670018
12.  Comparative maturation of cynomolgus monkey oocytes in vivo and in vitro 
In vitro maturation (IVM) of oocytes followed by fertilization in vitro (IVF) and embryo transfer offers an alternative to conventional IVF treatment that minimises drug administration and avoids ovarian hyperstimulation. However, the technique is less efficient than maturation in vivo. In the present study, a non-human primate model was used to address the hypothesis that the number of oocytes is increased and their nuclear and cytoplasmic maturity after IVM are improved when maturation is initiated in vivo by priming with hCG.
Young, adult cynomolgus monkeys were given recombinant human (rh) gonadotropins to stimulate the development of multiple follicles, and oocytes were aspirated 0, 12, 24, or 36 h after injection of an ovulatory dose of rhCG. The nuclear status of oocytes was determined at the time of recovery and after culture for a total elapsed time of 40–44 hours after hCG.
Priming with hCG significantly increased the number of oocytes harvested, especially after delaying aspiration for 24 h or longer. Nuclear maturation after the full period in culture was also enhanced by priming: 71.5, 83.6, and 94.6% of oocytes collected at 0, 12, and 24 h hCG had progressed to MII by the end of the culture period, compared to 87.8% of oocytes that were retrieved at 36 h. A large proportion of oocytes reaching the MII stage had either or both abnormal spindles (>40%) and misaligned chromosomes (>60%), judging by immunofluorescence microscopy, but these abnormalities were independent of culture time. The mitochondria were evenly distributed throughout the cytoplasm at all stages of maturation. Importantly, there was no microscopic evidence that the duration of culture had any injurious effects on the cells.
In conclusion, the evidence supports this non-human primate as a model for human IVM and the practice of priming with hCG to promote developmental potential.
PMCID: PMC1482709  PMID: 16595009
18.  Specialist outreach clinics in general practice: what do they offer? 
BACKGROUND: Specialist outreach clinics in general practice, in which hospital-based specialists hold outpatient clinics in general practitioners' (GPs) surgeries, are one example of a shift in services from secondary to primary care. AIM: To describe specialist outreach clinics held in fundholding general practices in two specialties from the perspective of patients, GPs, and consultants, and to estimate the comparative costs of these outreach clinics and equivalent hospital outpatient clinics. METHOD: Data were collected from single outreach sessions in fundholding practices and single outpatient clinics held by three dermatologists and three orthopaedic surgeons. Patients attending the outreach and outpatient clinics, GPs from practices in which the outreach clinics were held, and the consultants all completed questionnaires. Managers in general practice and hospital finance departments supplied data for the estimation of costs. RESULTS: Initial patient questionnaires were completed by 83 (86%) outreach patients and 81 (75%) outpatients. The specialist outreach clinics sampled provided few opportunities for increased interaction between specialists and GPs. Specialists were concerned about the travelling time resulting from their involvement in outreach clinics. Waiting times for first appointments were shorter in some outreach clinics than in outpatient clinics. However, patients were less concerned about the location of their consultation with the specialist than they were about the interpersonal aspects of the consultation. There was some evidence of a difference in casemix between the dermatology patients seen at outreach and those seen at outpatient clinics, which confounded the comparison of total costs associated with the two types of clinic. However, when treatment and overhead costs were excluded, the marginal cost per patient was greater in outreach clinics than in hospital clinics for both specialties studied. CONCLUSION: The study suggests that a cautious approach should be taken to further development of outreach clinics in the two specialties studied because the benefits of outreach clinics to patients, GPs and consultants may be modest, and their higher cost means that they are unlikely to be cost-effective.
PMCID: PMC1313104  PMID: 9406489
21.  What is to be done about fundholding? 
BMJ : British Medical Journal  1997;315(7101):170-171.
PMCID: PMC2127133  PMID: 9251549
22.  Delayed childbearing. 
BMJ : British Medical Journal  1995;311(7020):1585-1586.
PMCID: PMC2551491  PMID: 8555792
24.  Parental origin of transcription from the human GNAS1 gene. 
Journal of Medical Genetics  1994;31(8):607-614.
Variation in the phenotypic expression of Albright's hereditary osteodystrophy (AHO) determined by the parent of transmission, suggests that the human Gs alpha gene (GNAS1), in which mutations occur in AHO, may be under imprinted control. GNAS1 is also known to map to a chromosomal region (20q13.11) showing syntenic homology with the imprinted mouse region 2E1-2H3. To establish if GNAS1 is indeed imprinted, we have examined the parental origin of GNAS1 transcription in human fetal tissues. Of 75 fetuses genotyped, at gestational ages ranging from 6 to 13 weeks, 13 heterozygous for a FokI polymorphism in exon 5 of GNAS1 were identified whose mothers were homozygous for one or other allele. RNA from up to 10 different tissues from each fetus was analysed by RT-PCR. In all cases expression from both parental alleles was shown by FokI digestion of RT-PCR products and quantification of the resulting fragments. No tissue specific pattern of expression was discerned in these experiments. If genomic imprinting regulates the expression of the human GNAS1 gene, our data suggest that the effect must either be subtle and quantitative, or be confined to a small subset of specialised hormone responsive cells within the target tissues.
PMCID: PMC1050021  PMID: 7815417

Results 1-25 (46)