The Associations Between Neuropsychiatric Symptoms and Cognition in People with Dementia: A Systematic Review and Meta-Analysis

Most people with dementia experience neuropsychiatric symptoms (NPS), including anxiety, depression or disinhibition. There is growing interest in the relationship between NPS and cognitive impairment, but data is still limited. This study aimed to investigate the specific associations between NPS and cognition in people with dementia. MEDLINE, EMBASE and PsycINFO were searched for published, peer-reviewed studies of associations between at least one NPS and one cognitive ability in people with dementia. The quality of the studies was assessed with the NIH National Heart, Lung and Blood Institute's quality assessment tools. A meta-analysis was conducted using Robumeta package for R. Ninety studies were included. We found significant associations between NPS, global cognition and cognitive domains, e.g. apathy was associated with global cognitive and memory impairment; dysphoria was associated with worse attention; delusions with executive dysfunction. Increased NPS in people with dementia are associated with worse cognitive performance. There were few studies looking at associations between some neuropsychiatric clusters and cognitive abilities, and there was little research on causal relationships. Our review was limited by the inclusion of studies that reported associations in specific formats, and most included people with a diagnosis of Alzheimer's disease (AD). However, given the large number of studies, this is unlikely to have biased results. More research is needed that includes diverse people with different dementia syndromes. Registration: PROSPERO 2020 CRD42020165565.

Evaluation of prognostic risk models for postoperative pulmonary complications in adult patients undergoing major abdominal surgery: a systematic review and international external validation cohort study

BACKGROUND

Stratifying risk of postoperative pulmonary complications after major abdominal surgery allows clinicians to modify risk through targeted interventions and enhanced monitoring. In this study, we aimed to identify and validate prognostic models against a new consensus definition of postoperative pulmonary complications.

METHODS

We did a systematic review and international external validation cohort study. The systematic review was done in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. We searched MEDLINE and Embase on March 1, 2020, for articles published in English that reported on risk prediction models for postoperative pulmonary complications following abdominal surgery. External validation of existing models was done within a prospective international cohort study of adult patients (≥18 years) undergoing major abdominal surgery. Data were collected between Jan 1, 2019, and April 30, 2019, in the UK, Ireland, and Australia. Discriminative ability and prognostic accuracy summary statistics were compared between models for the 30-day postoperative pulmonary complication rate as defined by the Standardised Endpoints in Perioperative Medicine Core Outcome Measures in Perioperative and Anaesthetic Care (StEP-COMPAC). Model performance was compared using the area under the receiver operating characteristic curve (AUROCC).

FINDINGS

In total, we identified 2903 records from our literature search; of which, 2514 (86·6%) unique records were screened, 121 (4·8%) of 2514 full texts were assessed for eligibility, and 29 unique prognostic models were identified. Nine (31·0%) of 29 models had score development reported only, 19 (65·5%) had undergone internal validation, and only four (13·8%) had been externally validated. Data to validate six eligible models were collected in the international external validation cohort study. Data from 11 591 patients were available, with an overall postoperative pulmonary complication rate of 7·8% (n=903). None of the six models showed good discrimination (defined as AUROCC ≥0·70) for identifying postoperative pulmonary complications, with the Assess Respiratory Risk in Surgical Patients in Catalonia score showing the best discrimination (AUROCC 0·700 [95% CI 0·683-0·717]).

INTERPRETATION

In the pre-COVID-19 pandemic data, variability in the risk of pulmonary complications (StEP-COMPAC definition) following major abdominal surgery was poorly described by existing prognostication tools. To improve surgical safety during the COVID-19 pandemic recovery and beyond, novel risk stratification tools are required.

FUNDING

British Journal of Surgery Society.

POS1120 ASSOCIATION OF ADIPOKINES WITH SEVERITY OF KNEE OSTEOARTHRITIS ASSESSED CLINICALLY AND ON MAGNETIC RESONANCE IMAGING

Background

Adipokines secreted by adipose tissue create a low grade systemic inflammatory state that could contribute to the pathogenesis of knee OA (KOA). Previous studies of association between adipokines and radiographic KOA represented late-stage disease shown as bony changes. Magnetic Resonance Imaging (MRI) has the advantage of showing early changes of KOA in all joint structures.

Objectives

We aimed to evaluate the association between the adipokines: Leptin, Adiponectin, Resistin, and hs-CRP with clinical, radiographical and MRI assessment of KOA severity.

Methods

We performed a cross-sectional study in participants with early KOA. Demographics, clinical (WOMAC), and MRI (BLOKS scoring) KOA severity were assessed. Serum leptin, adipokines, resistin and hs-CRP were measured. Association of adipokines with clinical and MRI severity outcomes were evaluated using regression models with adjustment with age, sex, and body mass index (BMI).

Results

139 participants with early KOA (82% women, mean ± SD age: 55.5 ± 7.8 years) were included. Participants had moderate KOA symptoms, mean WOMAC pain and function were 31.1 ± 18.4, and 32.0 ± 19.9 respectively. Mean BMI was 26.0 ± 5.9 kg/m2. After adjustment with age, sex and BMI, Leptin (p=0.001) and hs-CRP (p=0.03) were positively associated, while adiponectin (p=0.02) and resistin (p=0.03) were negatively associated with osteophyte size (Table 1). In addition, leptin was statistically significantly associated with cartilage loss, synovitis, and effusion, while hs-CRP was associated with meniscus extrusion. As for WOMAC assessed severity, only adiponectin was statistical significantly associated with WOMAC function.

Table 1.

Association of adipokines with MRI features and clinical symptoms, adjusted with age, sex and BMI

KOA severityβ (95% confidence intervals)leptinAdiponectinResistinhs-CRPOST Size1.11 (0.5, 1.7)**-1.86 (-3.53, -0.18)*-2.12 (-3.95, -0.30)*0.17 (0.02, 0.31)*% Cart Loss0.37 (0.04, 0.71)*-0.45 (-1.32, 0.42)-0.72 (-1.67, 0.23)0.02 (-0.06, 0.10)BML Size0.24 (-0.02,0.50)-0.03 (-0.70,0.65)-0.15 (-0.92,0.56)0.02 (-0.04, 0.08)Synovitis0.24 (0.08, 0.40)**-0.21 (-0.63, 0.22)-0.33 (-0.79, 0.13)0.03 (-0.01, 0.07)Effusion0.21 (0.07, 0.35)**-0.25 (-0.62, 0.12)-0.09 (-0.49, 0.32)0.02 (-0.02, 0.05)Meniscus Extrusion0.09 (-0.06, 0.24)0.01 (-0.39, 0.40)-0.08 (-0.51, 0.35)0.04 (0.00, 0.07)*WOMAC pain1.72 (-1.45, 4.89)7.07 (-0.98, 15.1)-2.61 (-11.4, 6.14)0.04 (-0.68, 0.76)WOMAC function0.01 (-3.34,3.35)13.2 (5.0, 21.5)**-0.07 (-9.26, 9.12)-0.22 (-0.97, 0.54)

*p<0.05, **p<0.01, Bold: statistically significant.

Conclusion

Adipokines, particularly leptin was associated with severity of various structural defects of the knee joint beyond age, sex and BMI in early KOA.

MRI: Magnetic Resonance Imaging; %: percentage; BML: Bone Marrow Lesion; Cart: Cartilage; OST: Osteophyte; KL: Kellgren and Lawrence grading; WOMAC: Western Ontario and McMaster Universities Osteoarthritis Index.

Acknowledgements

This study is funded by the National Medical Research Council of Singapore (NMRC

Disclosure of Interests

Timothy Chong: None declared, Jin-Rong Tan: None declared, Cheryl Ma: None declared, Steven Bak-Siew Wong: None declared, Ying Ying Leung Speakers bureau: Honorarium from Abbvie, DKSH, Janssen, Novartis and Pfizer.

Alcohol Use, Mental Health, and Functional Capacity as Predictors of Workplace Disability in a Cohort With Manifest Huntington's Disease

OBJECTIVE

Huntington's disease (HD) is an inherited neurodegenerative disease involving motor, cognitive, psychiatric, and behavioral impairments that eventually affect work-role functioning. There is limited research regarding predictors of workplace disability in HD. The authors examined predictors of work impairment and disability in a cross-sectional cohort of employed persons with symptomatic HD participating in the worldwide Enroll-HD study.

METHODS

The study sample (N=316) comprised individuals with manifest HD and a CAG repeat length range between 39 and 60 and were currently engaged in paid full- or part-time employment. Univariate and multivariate logistic regression analyses identified predictors and the effect of all predictors in a fully adjusted model.

RESULTS

Of the sample, 20.3% reported missing work due to HD, 60.1% reported experiencing impairment while working due to HD, 79.1% reported having work-related activity impairment due to HD, and 60.8% reported impairment in overall work productivity due to HD. Individuals had 25% higher odds of missing work time if they had a higher level of functional impairment (odds ratio=0.76, 95% CI=0.64, 0.91) and had three times greater odds of missing work if they were current alcohol drinkers, compared with nondrinkers (odds ratio=2.86, 95% CI=1.62, 5.03). Individuals with lower self-perceived mental health were also 5% more likely to experience impairment at work due to HD. Motor impairment was not a strong predictor of workplace disability.

CONCLUSIONS

These findings provide important new knowledge that can inform the development of strategies or targeted intervention trials to support persons with symptomatic HD to maintain their work roles.

Behavioural activation in nursing homes to treat depression (BAN-Dep): study protocol for a pragmatic randomised controlled trial

INTRODUCTION

Depression is a common disorder among older people living in residential aged care facilities. Several trials have demonstrated the effectiveness of behavioural therapies in treating depressive symptoms in older adults living in the community and in residential aged care. Behavioural Activation is demonstrably effective even when delivered by non-specialists (staff without formal psychological training), although strategies for adapting its use in residential aged care facilities are yet to be explored. This study will determine whether training residential care staff in the use of a structured Behavioural Activation programme is more effective at decreasing depressive symptoms among older residents than internet-based training about depression recognition and management alone.

METHOD AND ANALYSIS

The behavioural activation in nursing homes to treat depression (BAN-Dep) trial is a pragmatic two-arm parallel clustered randomised controlled trial. It will recruit 666 residents aged 60 or older from 100 residential aged care facilities, which will be randomly assigned to the Behavioural Activation or control intervention. Staff in both treatment groups will be encouraged to complete the Beyondblue Professional Education to Aged Care e-learning programme to improve their recognition of and ability to respond to depression in older adults. Selected staff from intervention facilities will undergo additional training to deliver an 8-module Behavioural Activation programme to residents with subthreshold symptoms of depression-they will receive ongoing Mental support from trained Behavioural Activation therapists. Outcome measures will be collected by blind research officer at baseline and after 3, 6 and 12 months. The Patient Health Questionnaire-9 is the primary outcome measure of the study.

ETHICS AND DISSEMINATION

The trial will comply with the principles of the Declaration of Helsinki for Human Rights and is overseen by the University of Western Australia (reference RA/4/20/4234) and Melbourne Health (reference number HREC/18/MH/47) Ethics Committees. The results of this research project will be disseminated through publications and/or presentations in a variety of media to health professionals, academics, clinicians and the public. Only de-identified group data will be presented.

TRIAL REGISTRATION

ACTRN12618000634279.

Predictors of Workplace Disability in a Premanifest Huntington's Disease Cohort

Huntington's disease (HD) is an inherited neurodegenerative disease involving motor, cognitive, and psychiatric/behavioral impairments that will eventually affect work role functioning. Few objective data exist regarding predictors of workplace disability in HD. The authors explored the predictors of work impairment and disability in a cross-sectional cohort of 656 employed, premanifest HD (preHD) individuals. In this cohort-the majority of whom were female, urban-dwelling, married/partnered, and working full-time, with minimal cognitive impairment, good function, minimal motor abnormality, and no indication of significant mental health issues-the number of participants who reported that they had missed work due to HD was low (2.4%). However, 12% of the study sample reported experiencing impairment while working due to preHD, 12.2% reported work-related activity impairment due to preHD, and 12.7% reported impairment in their overall work ability. Higher numbers of CAG repeats on the mutant allele and having more motor symptoms were associated with significantly higher odds of experiencing workplace impairment. Importantly, several modifiable factors were also found to predict workplace disability. Specifically, higher levels of anxiety symptoms were associated with significantly higher odds of experiencing workplace impairment. Good mental and physical health served as protective factors, where good physical health was associated with 6% lower odds of experiencing impairment or missing work time and good mental health was associated with of 10%-12% lower. The results provide important new knowledge for the development of future targeted intervention trials to support preHD individuals in maintaining their work roles as long as possible.

Autophagy suppresses the proliferation of renal carcinoma cell

OBJECTIVE

To investigate the effetcs of autophagy on the proliferation of renal carcinoma (RCCs).

MATERIALS AND METHODS

Authophagy related protein 7 (Atg7)-overexpressing and knockdown RCC cell lines were established using lentiviral transfection and shRNA interference, respectively. (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide) (MTT) was used to determine the Cell growth rate, and western blot was used to determine the expression of protein. In order to establish xenograft animal models, stable transfected cells were injected into nude mice. After that those mice were used to detect the effect of autophagy on the growth of RCC in vivo.

RESULTS

Atg7 overexpression could up-regulate the level of LC3II in RCC cell lines, while Atg7-knockdown suppressed the expression of light chain 3 II (LC3II) in RCC cell lines. Atg7-overexpression cells exhibited a decreased growth profile, while suppressing the expression of Atg7 could accelerate the growth of RCC formed tumors.

CONCLUSIONS

Our data indicated that autophagy could suppress the growth of RCC cells in vivo and in vitro, and autophagy appeared to be a new therapeutic target for treating advanced renal cell carcinoma.

Abstract P4-07-06: MicroRNAs associated with acquired taxane resistance in a breast cancer cell line model

Background: Acquired chemoresistance remains the major cause of therapeutic failure in the treatment of breast cancer. Improved knowledge of the transition from drug sensitive to resistant breast cancer will pave the way for novel preventative and therapeutic strategies. MicroRNAs (miRNA) are endogenous, small non-coding RNAs that regulate gene expression by targeting the 3'UTR region of messenger RNAs. There is a growing body of evidence to suggest miRNAs may be involved in the development of chemoresistance and may play a role in the regulation of drug resistance pathways.

Methods: An in vitro model of paclitaxel resistance was developed through the generation of resistant MDA-MB-231 cell lines by serial culture in escalating doses of taxane until resistance was achieved. The chemoresistant model was used to compare differential miRNA expression with the sensitive, parental line using the Nanostring® platform, analysing 800 human miRNAs. Confirmation of differential expression was performed by QRT-PCR.

Results: This analysis resulted in 30 significantly altered miRNA (1.5 fold, p value &lt; 0.05) at 25nM paclitaxel and 48 significantly altered miRNA at 50nM paclitaxel. The top up-regulated miRNA cluster in MDA-MB-231 25PACR is hsa-miR-548l (fold change: 2.89, p value: 0.016) and top down-regulated was hsa-miR-449a (fold change: -4.1. p value: 0.001). In MDA-MB-231 50PACR the top up-regulated miRNA cluster is hsa-miR-193a-5p (fold change: 3.746, p value: 0.008) and the top down-regulated miRNA cluster is hsa-miR-135a (fold change: -4.085, p value: 0.001). To explore the molecular mechanisms of the differentially expressed miRNAs in paclitaxel resistance, targets were predicted by in silico analysis. Pathways and networks designated by miRNA targets included the cell cycle, PI3K/Akt pathways and focal adhesion.

Conclusion: In this study we identified candidate resistance-associated miRNAs which were differentially expressed between in vitro derived paclitaxel resistant MDA-MB-231 and the sensitive parental line. Further validation to ascertain their role in the transition to a chemoresistant phenotype is currently ongoing.

Citation Format: Taylor KJ, Chong T, D'Costa A, Yao C, Gourley C, Cameron DA, Bartlett JMS, Spears M. MicroRNAs associated with acquired taxane resistance in a breast cancer cell line model [abstract]. In: Proceedings of the 2016 San Antonio Breast Cancer Symposium; 2016 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2017;77(4 Suppl):Abstract nr P4-07-06.

The effect of rapamycin on TGFβ1 and MMP1 expression in a rabbit model of urethral stricture

PURPOSE

To investigate the effect of rapamycin on TGFβ1 and MMP1 expression in a rabbit model of urethral stricture.

METHODS

Twenty-four adult New Zealand male rabbits underwent an electrocoagulation of the bulbar urethra with a 13Fr pediatric resectoscope. Then rabbits were randomly divided into three groups: (1) normal control group: normal saline (NS), (2) the vehicle control group: dimethyl sulfoxide (DMSO), and (3) the treatment group: effective-dose rapamycin in DMSO (Ra), with 12, 6, and 6 rabbits in each group, respectively. Drugs were given by urethral irrigation daily for 4 weeks. Urethral tissue was harvested for histological and molecular analyses. TGFβ1 and MMP1 expression levels were evaluated by real-time quantitative PCR and immunohistochemistry.

RESULTS

Ten, six, and six rabbits were evaluated finally in Ra, DMSO, and NS group, respectively. Histological examination revealed the distribution of fibrosis and the degree of collagen deposition in the Ra group were smaller and slighter than the two control groups. Collagen content was significantly less in the Ra group than in the DMSO group (P < 0.001) and the NS group (P < 0.001). qRT-PCR analysis showed a higher expression of MMP1 mRNA in the Ra group than in the DMSO group (P < 0.001) and the NS group (P < 0.001). Immunohistochemistry showed the protein levels of MMP1 in the Ra group were significantly increased when compared with the DMSO group (P < 0.01) and the NS group (P < 0.01). On the other hand, no statistical difference could be found between every two groups in both mRNA and protein levels of TGFβ1.

CONCLUSIONS

Rapamycin enhances the expression of MMP1 in a rabbit model of urethral stricture, but has no direct effect on the expression of TGFβ1.

Management of steroid-resistant late acute cellular rejection following face transplantation: a case report

Face transplants have been clinically established, and early acute rejections have been reported. Late acute rejections have been less common. Immediate and accurate diagnosis along with successful treatment is critical to prevent graft damage. This case report describes the successful treatment of a severe, steroid-resistant rejection 2 years after a full face transplant.

Molecular events are associated with resistance to vinblastine in bladder cancer

Bladder cancer occurs in the majority of cases in males, which represents the fourth highest incident cancer in men and tenth in women. It is associated with a high rate of recurrence, and prognosis is poor once the cancer metastasizes to distant sites. Transitional cell cancer (TCC) is the most predominant histological type. Bladder cancer is highly chemosensitive. However, the presence of acquired drug resistance is one of the primary impediments to the success of chemotherapy. To differentiate and delineate the molecular events, we developed drug resistant human transitional bladder cancer T24 cells (DRC) by treating cells with the increasing concentration of vinblastine. We found that DRC was resistant to vinblastine in comparison to parental T24 cells. We analyzed the contributory factors that may be involved in the development of resistance. As expected, expression of permeability glycoprotein (P&mdash;gp) was up&mdash;regulated in DRC. In addition, levels of Caveolin&mdash;1 (Cav&mdash;1), Fatty acid synthase (FASN) and Cytochrome P450 (CYP450) were elevated in DRC. Downregulation of these proteins by respective specific pharmacological inhibitors and/or by siRNAs resensitized cells to vinblastine. These results suggested that differential levels of P&mdash;gp, Cav&mdash;1 and FASN except CYP450 play a major role in acquired resistant phenotype in bladder cancer.

The value of superstitions

This paper estimates the value of superstitions by studying the auctions of vehicle license plates. We show that the value of superstitions is economically significant, which justifies their persistence in human civilization. We also document the changes of the value of superstitions across different types of plates, across different policy regimes, and across different macroeconomic environments. Interestingly, some of the changes are rather consistent with economic intuition.

Reflections on facilitated discharge from a mental health service

OBJECTIVE

The aim of this paper is to review research evidence and describe our experience of facilitated discharge from mental health services to primary care.

METHOD

A literature review of facilitated discharge was conducted. In addition, the clinical characteristics of 21 discharged and 21 non-discharged patients from one shared care service were compared in a retrospective file review. Thirty-one patients in another facilitated discharge program were surveyed.

RESULTS

Discharged patients had a higher level of function. There was a trend towards discharged patients being female and employed with less chronic illness, involuntary treatment, behavioural symptoms, depot medication, triage contact, service contact with family, and more mood disorder. Of the 10 survey respondents, 60% reported feeling better compared with their last service contact, 70% felt not having contact was a good thing and most saw their doctors regularly and reported a good relationship.

CONCLUSIONS

There was a trend towards more stable patients being discharged and it appeared that they responded positively to this, without a clear indication of which factors best determine suitability for discharge. Consequently, we elected to incorporate discharge planning processes as a core function of case management and increase shared care with the primary care sector.

Germ cell specification and regeneration in planarians

In metazoans, two apparently distinct mechanisms specify germ cell fate: Determinate specification (observed in animals including Drosophila, Caenorhabditis elegans, zebra fish, and Xenopus) uses cytoplasmic factors localized to specific regions of the egg, whereas epigenetic specification (observed in many basal metazoans, urodeles, and mammals) involves inductive interactions between cells. Much of our understanding of germ cell specification has emerged from studies of model organisms displaying determinate specification. In contrast, our understanding of epigenetic/inductive specification is less advanced and would benefit from studies of additional organisms. Freshwater planarians--widely known for their remarkable powers of regeneration--are well suited for studying the mechanisms by which germ cells can be induced. Classic experiments showed that planarians can regenerate germ cells from body fragments entirely lacking reproductive structures, suggesting that planarian germ cells could be specified by inductive signals. Furthermore, the availability of the genome sequence of the planarian Schmidtea mediterranea, coupled with the animal's susceptibility to systemic RNA interference (RNAi), facilitates functional genomic analyses of germ cell development and regeneration. Here, we describe recent progress in studies of planarian germ cells and frame some of the critical unresolved questions for future work.

Cross talk in photochemical three-dimensional optical recording

It is shown that the cross talk in three-dimensional optical photochemical recording results in ineffectiveness of single-photon recording. For two-photon recording for a given allowed cross-talk level there are optimal distances between spots that provide the maximum memory density. Estimations show that real restrictions here are connected with the reading of information.

Visual acuity, lens flexure, and residual astigmatism of keratoconic eyes as a function of back optic zone radius of rigid lenses

The purpose of this study was to determine whether the visual acuity of keratoconic eyes was affected by alteration of back optic zone radii (BOZRs) of rigid gas permeable lenses (RGP) contact lenses. Visual acuity, spherical and sphero-cylindrical over-refraction and keratometry of the front surface of the RGP lenses of nine keratoconic eyes were measured. The BOZR of the five lenses varied from steeper to flatter than that habitually worn by the subjects. The steepest lenses produced significantly greater lens flexure and residual astigmatism (P < 0.002) and worse high and low contrast visual acuity with the spherical over-refraction (P < 0.05). There was no statistical difference in visual acuity across the range of BOZR when a sphero-cylindrical over-refraction was applied. Thus reduced visual acuity in keratoconus with steep lenses is likely due to uncorrected residual astigmatism from a combination of several possible sources.

Apopain/CPP32 cleaves proteins that are essential for cellular repair: a fundamental principle of apoptotic death

Proteolysis mediated by the interleukin 1 beta-converting enzyme (ICE) homologues is an important mechanism of the apoptotic process. The ICE homologue apopain/CPP-32/Yama (subsequently referred to as apopain) cleaves poly(ADP-ribose)polymerase (PARP) early during apoptosis. Additional apoptosis-specific protein cleavages have been observed in which the direct involvement of ICE-like proteases has been postulated. These substrates include the 70-kD protein component of the U1-ribonucleoprotein (U1-70kD), and the catalytic subunit of the DNA-dependent protein kinase (DNA-PKcs). The present studies demonstrate that U1-70kD and DNA-PKcs are excellent substrates for apopain, with cleavage occurring at sites that are highly similar to the cleavage site within PARP. The fragments generated from isolated protein substrates by apopain are identical to those observed in intact apoptotic cells, in apoptotic cell extracts, and in normal cell extracts to which apopain has been added. Like PARP, cleavage of these substrates in apoptotic cell extracts is abolished by nanomolar concentrations of Ac-DEVD-CHO and micromolar amounts of Ac-YVAD-CHO, confirming the involvement of apopain or an apopain-like activity. We propose that a central function of apopain or similar homologues in apoptosis is the cleavage of nuclear repair proteins, thereby abolishing their critical homeostatic functions.

Suppression of the yeast mutation rft1-1 by human p53

Mutations in the gene encoding p53 have been found to be the most common genetic alterations in human cancer, p53 is thought to exert its function of tumor suppression through inhibition of cell proliferation or induction of apoptosis in response to DNA damage. Although there have been no proteins homologous to p53 identified in lower eucaryotic organisms, it is known that overexpression of wild-type human p53 can inhibit cell growth of Schizosaccharomyces pombe and Saccharomyces cerevisiae (Bischoff et al., 1992; Nigro et al., 1992), suggesting that certain aspects of p53 function may manifest or exist in yeast. In an attempt to identify the p53-like proteins in the yeast S. cerevisiae, we isolated a mutant that requires wild-type p53 for its viability. The mutant, rft1-1, is defective in cell cycle progression and arrests before mitosis when p53 protein is depleted. Genetic and biochemical studies show that p53 suppresses the rft1-1 mutation by forming a protein-protein complex with the Rft1 protein.

Nuclear factor I and epithelial cell-specific transcription of human papillomavirus type 16

The transcription of human papillomavirus type 16 (HPV-16) is mediated by the viral enhancer. Epithelial cell-specific activation is achieved by the cooperative interaction of apparently ubiquitous transcriptional factors. One of them, nuclear factor I (NFI), binds seven sites within the HPV-16 enhancer. Point mutations on enhancer fragments, which retain epithelial cell specificity, verify the functional contribution of NFI. In band shift experiments, the epithelial cell-derived NFI proteins CTF-1, CTF-2, and CTF-3 form a characteristic pattern of heterodimeric complexes which are observed in all epithelial cells tested. Divergence from this pattern in fibroblasts, liver cells, and lymphoid cells correlates with the lack of HPV-16 enhancer activation. The HPV-16 enhancer can be activated by CTF-1 in SL-2 cells, which lack NFI-like proteins. However, exogenous CTF-1 fails to overcome the inactivity of the viral enhancer in fibroblasts. Western immunoblot and supershift analysis shows that exogenously introduced CTF-1 proteins form different heterodimer complexes with the given subset of endogenous NFI proteins in epithelial or fibroblast cells. Polymerase chain reaction analysis and cDNA library screens identified the endogenous fibroblast type NFI as NFI-X, an NFI family member originally cloned from hamster liver cells. The strict correlation between the activation or lack of activation of the HPV-16 enhancer and cell-specific subsets of NFI proteins argues for the pivotal role of NFI binding sites in the epithelial cell-specific function of the viral enhancer.

The enhancer of human papillomavirus type 16: binding sites for the ubiquitous transcription factors oct-1, NFA, TEF-2, NF1, and AP-1 participate in epithelial cell-specific transcription

The enhancer of human papillomavirus type 16 (HPV-16) is considered to be specific for epithelial cells, in particular for cervical carcinoma-derived cell lines. We reexamined this hypothesis with the complete enhancer as well as nonoverlapping subclones and found all clones to be active in epithelial cell lines derived from the epidermis and from carcinomas of the cervix, mammary gland, and colon, but inactive in fibroblast, lymphoma, and embryonal carcinoma cells. Although the virus infects only human mucosal epithelia, enhancer activity was independent of the exact type or of the species of origin of the transfected epithelial cell. In spite of epithelial cell specificity, we found that the activity of the HPV-16 enhancer varied strongly from a cytomegalovirus enhancer and the simian virus 40 enhancer in a cell line-dependent manner. This suggests varying quantitative contributions of enhancer elements rather than regulation by an all-or-none switch. Cell type specificity was maintained by a 91-bp subclone of the 400-bp enhancer. Most of the enhancer activity of this fragment was eliminated by alternative mutations in binding sites for the ubiquitous factors AP-1, nuclear factor 1 (NF1), or TEF-2. These three types of factors bind this 91-bp enhancer without cooperation, although activation appears to be synergistic. Outside the 91-bp fragment, a motif typical for papillomavirus enhancers, namely an octamerlike sequence flanked by an NF1-binding site, contributes to enhancer function, as the activity was strongly reduced upon its deletion. In HPV-16, this motif is bound by the oct-1 factor as well as by a probably novel factor, NFA, whereas a related motif of HPV-11 is recognized only by NFA. On examination, none of the five types of transcription factors involved in HPV enhancer activation was restricted to epithelial cells, but NF1, AP-1, and oct-1 were present in higher concentration in HeLa cells than in fibroblasts. Only NF1 showed some qualitative cell type-specific differences. We propose that the epithelial specificity of the HPV-16 enhancer is brought about via binding sites for supposed ubiquitous transcription factors. The mechanism of this activation apparently involves synergism between factors that vary in concentration and may include cell-specific functional differences residing outside the DNA-binding domain of these factors.

Sequence variants of human papillomavirus type 16 in clinical samples permit verification and extension of epidemiological studies and construction of a phylogenetic tree

Genomic variability between different viral isolates provides a powerful epidemiological tool for verifying ultrasensitive diagnostic procedures, understanding infectious pathways in individuals and human populations, and studying viral evolution. The potential of this approach has not yet been exploited for the diagnosis of human papillomaviruses (HPVs) like HPV type 16 (HPV-16), which are involved in genital cancer. Toward this end, we amplified by polymerase chain reaction, cloned, and sequenced a 364-bp noncoding segment of the HPV-16 genome from cell lines, cervical biopsy specimens, and cervical smears. The HPV-16 genomes in the cell lines SiHa and CaSki showed an identical point mutation, and in the SiHa cell line it had an additional 38-bp deletion. Only 4 of 22 cervical lesions biopsied from patients at several hospitals in Singapore contained HPV-16 DNA with the prototype sequence, while the DNAs of the other 18 cervical lesions differed by 1 to 10 mutations. This excludes contaminations with cloned HPV-16 DNA as the source of this DNA. To test whether this diversity was a geographic idiosyncrasy, we analyzed 25 cervical biopsy specimens from Brazil. Eight of these contained the prototype sequence, while 17 were mutated. Altogether, 11 genomic variants were found in the Singaporean samples and 12 genomic variants were found in the Brazilian samples, and only 5 of these occurred identically in both cohorts. All variants could be connected to form a phylogenetic tree, with some branches being specific for each cohort. This suggests that the variants did not originate over a short period in the individual patient but, rather, evolved consecutively while spreading throughout humankind.(ABSTRACT TRUNCATED AT 250 WORDS)

Transcription of the transforming genes of the oncogenic human papillomavirus-16 is stimulated by tumor promotors through AP1 binding sites

The promoter P97 of human papillomavirus-16 (HPV-16) gives rise to transcripts that encode the principal transforming genes of the virus, E6 and E7. The activity of P97 is regulated by a cell-type-specific enhancer, as well as by glucocorticoids and progesterone. We show here, that in CaSki cells, which contain HPV-16 genomes, P97 is also inducible by phorbol esters. Functional analysis of restriction fragments and oligonucleotides of the viral enhancer localizes two phorbol ester response elements on two transcription factor binding sites termed fp4e and fp9e. Sequence comparison, footprint analysis and bandshift competition of the cloned motifs suggest that both fp4e and fp9e are bound by the transcription factor AP1. These AP1 binding sites in HPV-16 and other papillomaviruses may provide a link between cellular oncogenes like jun, fos and possibly ras, whose transcription stimulating activity may lead to an elevated expression of the viral transforming genes E6 and E7.

Transcriptional activation of human papillomavirus 16 by nuclear factor I, AP1, steroid receptors and a possibly novel transcription factor, PVF: a model for the composition of genital papillomavirus enhancers

Human papillomavirus 16 (HPV-16), which is involved in genital carcinogenesis, contains an enhancer of transcription that is activated by cellular factors rather than by the viral E2 proteins. The activity resides on a 232 bp segment with 5 binding sites for nuclear factor 1 (NF1), 2 for AP1, and 1 for steroid receptors. Deletions and point mutations show that the constitutive enhancer and the steroid response depend on NF1 sites located 5' or 3' of a 65 bp fragment with AP1 sites that by itself shows little activity. Enhancement through a fragment with AP1 and NF1 sites is strongly reduced by mutation of the AP1 sites, or by mutation of the sequence AGGCACATAT. Sequence comparison and footprint analysis make it likely that this sequence binds a novel transcription factor which we call PVF. Fragments with one or several binding sites only for NF1, or AP1, or PVF exhibit little enhancement by themselves, suggesting the functional dependence of the HPV-16 enhancer on the cooperation of these factors. A comparison of our findings with the genomes and transcription factor binding sites of HPV-6, 11, 18, 31 and 33 lead us to propose a model of the composition of enhancers of genital papillomaviruses.

Numerous nuclear proteins bind the long control region of human papillomavirus type 16: a subset of 6 of 23 DNase I-protected segments coincides with the location of the cell-type-specific enhancer

The long control region of the human papillomavirus type 16 genome is 856 base pairs (bp) long. It contains a cell-type-specific enhancer, a glucocorticoid response element, and sequences mediating the response to the viral gene products of open reading frame E2; all three regulate the promoter P97. We mapped binding sites of trans-acting proteins relevant for the cell-type-specific enhancer and other cis-acting elements by DNase I footprint experiments with nuclear extracts from HeLa cells. Throughout the human papillomavirus type 16 long control region 23 footprints protect 557 of 900 bp. Nine footprints fall into a 400-bp segment that was previously identified to contain the cell-type-specific enhancer. Variations of the protein concentration in the footprint reaction do not affect six of these nine footprints. At high protein concentrations, three footprints fuse to a 106-bp protected region, suggesting that this segment specifically binds several proteins of lower affinity or abundance. Unexpectedly, extracts from human MCF7 and mouse 3T3 cells, in which the enhancer is inactive, give footprints identical to those obtained with HeLa extracts. Seven footprints contain the sequence 5'-TTGGC-3'. Footprint competition experiments suggest that factor NFI binds to these seven motifs. Competition with cloned oligonucleotides in transfections suggests that these elements contribute to the enhancer function. Subcloning identifies a 232-bp fragment between positions 7524 and 7755 as sufficient for full enhancer activity. Several of the six footprinted elements on this segment may cooperate functionally, since subclones of this region show decreased or no cell-type-specific enhancer function.