Human and primate tumour viruses use PDZ binding as an evolutionarily conserved mechanism of targeting cell polarity regulators

A unique feature of the cancer-causing mucosotropic human papillomaviruses (HPVs) is the ability of their E6 proteins to interact with a number of PDZ domain-containing cellular substrates, including the cell polarity regulators hDlg and hScrib. These interactions are essential for the ability of these viruses to induce malignant progression. Rhesus papillomaviruses (RhPV) are similar to their human counterparts in that they also cause anogenital malignancy in their host, the Rhesus Macaque. However, unlike HPV E6, the RhPV E6 has no PDZ-binding motif. We now show that such a motif is present on the RhPV E7 oncoprotein. This motif specifically confers PDZ-binding activity and directs the interaction of RhPV E7 with the cell polarity regulator Par3, which it targets for proteasome-mediated degradation. These results demonstrate an amazing evolutionary conservation of function between the RhPV and the HPV oncoproteins, where both target proteins of the same cell polarity control network, although through different components and pathways.

Endometrial inhibin/activin beta-B subunit expression is related to decidualization and is reduced in tubal ectopic pregnancy

CONTEXT

Ectopic pregnancy is common but remains difficult to diagnose accurately. There is no serum test to differentiate ectopic from intrauterine gestation.

OBJECTIVE

Our objective was to investigate differential gene expression in decidualized endometrium of ectopic pregnancy.

DESIGN

Tissue and serum analysis informed by microarray study was performed.

SETTING

The study was performed at a large United Kingdom teaching hospital.

PATIENTS OR OTHER PARTICIPANTS

Women undergoing surgical termination of pregnancy (n = 8), evacuation of uterus for miscarriage (n = 6), and surgery for tubal ectopic pregnancy (n = 11) were included in the study. Endometrium was collected from normally cycling women undergoing hysterectomy.

INTERVENTIONS

Decidualized endometrium was subjected to microarray analysis, morphological assessment, and immunohistochemistry. Endometrial stromal fibroblasts were cultured in the presence of decidualizing stimuli.

MAIN OUTCOME MEASURES

Differential expression of potentially secreted molecules was calculated.

RESULTS

Inhibin/activin beta-B expression was lower in decidualized endometrium from ectopic pregnancies when compared with that of ongoing pregnancies (P < 0.01) or miscarriages (P < 0.01). The localization of the beta-B subunit was more marked in decidualized than nondecidualized stroma. Decidualization of stromal fibroblasts in vitro was associated with increased beta-B expression (P < 0.05). Endometrial stroma of ectopic pregnancies was less decidualized morphologically (P < 0.05), with lower prolactin (P < 0.01) and IGF binding protein-1 (P < 0.005) expression. Serum activin B was lower in ectopic pregnancies (P < 0.005) than in intrauterine pregnancies, whereas there was no difference in progesterone concentrations.

CONCLUSIONS

Despite similar concentrations of progesterone, the endometrium of ectopic pregnancies is less decidualized than intrauterine pregnancies. Expression of the beta-B subunit is related to decidualization and can be detected in the circulation as activin B. Serum activin B concentrations are lower in ectopic pregnancy.

The detection of urethritis pathogens among patients with the male urethritis syndrome, genital ulcer syndrome and HIV voluntary counselling and testing clients: should South Africa's syndromic management approach be revised?

OBJECTIVES

To determine the prevalence of urethritis pathogens amongst male symptomatic urethritis (MUS) patients, genital ulcer (GUS) patients without urethritis symptoms and men requesting HIV testing at a voluntary counselling and testing (VCT) clinic.

METHODS

A prospective study was conducted in Johannesburg, South Africa. Men from the three groups were screened for urethritis pathogens using molecular tests. Culture for Neisseria gonorrhoeae and, initially, trichomoniasis was performed. Antimicrobial susceptibility testing was undertaken for ciprofloxacin on all gonococcal isolates; ciprofloxacin resistant isolates were screened for ceftriaxone resistance.

RESULTS

664 participants were recruited (438 MUS, 76 GUS and 158 VCT) over 2 years. Gonorrhoea was detected in 62.3% MUS, 15.8% GUS and 3.2% VCT participants. Chlamydial infection was detected in 19.3% MUS, 13.2% GUS and 8.2% VCT participants. Trichomoniasis was detected in 4.9% MUS, 19.7% GUS and 3.8% VCT participants. Mycoplasma genitalium infection was detected in 14.4% MUS, 13.2% GUS and 7.0% VCT participants. Ciprofloxacin resistance increased from 13.0% in the first year to 26.3% in the second year; all resistant isolates were susceptible to ceftriaxone.

CONCLUSIONS

Urethritis pathogens, including Trichomonas vaginalis, should be covered in syndromic management treatment of genital ulcers in the absence of clinical urethritis. Consideration should be given to adding metronidazole to existing MUS treatment. Ciprofloxacin can no longer be relied upon to treat presumptive gonococcal infections in South Africa.

Quantification of healthy follicles in the neonatal and adult mouse ovary: evidence for maintenance of primordial follicle supply

Proliferation and partial meiotic maturation of germ cells in fetal ovaries is believed to establish a finite, non-renewable pool of primordial follicles at birth. The supply of primordial follicles in postnatal life should be depleted during folliculogenesis, either undergoing atresia or surviving to ovulation. Recent studies of mouse ovaries propose that intra- and extraovarian germline stem cells replenish oocytes and form new primordial follicles. We quantified all healthy follicles in C57BL/6 mouse ovaries from day 1 to 200 using unbiased stereological methods, immunolabelling of oocyte meiosis (germ cell nuclear antigen (GCNA)) and ovarian cell proliferation (proliferating cell nuclear antigen (PCNA)) and electronmicroscopy. Day 1 ovaries contained 7924+/-1564 (s.e.m.) oocytes or primordial follicles, declining on day 7 to 1987+/-203, with 200-800 oocytes ejected from individual ovaries on that day and day 12. Discarded oocytes and those subjacent to the surface epithelium were GCNA-positive indicating their incomplete meiotic maturation. From day 7 to 100 mean numbers of primordial follicles per ovary were not significantly depleted but declined at 200 days to 254+/-71. Mean numbers of all healthy follicles per ovary were not significantly different from day 7 to 100 (range 2332+/-349-3007+/-322). Primordial follicle oocytes were PCNA-negative. Occasional unidentified cells were PCNA-positive with mitotic figures observed in the cortex of day 1 and 12 ovaries. Although we found no evidence for ovarian germline stem cells, our data support the hypothesis of postnatal follicle renewal in postnatal and adult ovaries of C57BL/6 mice.

PML-RARα isoform at diagnosis is associated with disease-free survival (DFS) in patients enrolled in the intergroup trial (C-9710) for treatment of acute promyelocytic leukemia (APL)

6504

Background: Refinement of prognostic groups using molecular genetic features of the disease may facilitate the design of future risk-adapted trials for APL. Previous analyses of the prognostic value of PML-RARα transcript levels and isoform type have generated conflicting results. We sought to determine the clinical significance of measuring PML-RARα transcript level at the time of diagnosis using real-time quantitative RT-PCR (RQ-PCR) of the long (L) and short (S) isoforms of the fusion gene. Methods: PML-RARα transcript levels were measured in pretreatment bone marrow (BM) and/or paired blood (B) samples of 139 patients (pts) with newly diagnosed APL registered to C-9710, the intergroup phase III randomized study of concurrent tretinoin and chemotherapy with or without arsenic trioxide as initial consolidation therapy. Transcript levels were expressed as the normalized quotient (NQ) of PML-RARα/ABL or PML-RARα/GAPDH. Correlations between pre-treatment NQ values and other pre-treatment characteristics including age, presenting WBC and platelet count, and L or S isoform were explored. Results: Pre-treatment NQ values using ABL vs. GAPDH showed significant correlation (p < 0.0001). Pre-treatment transcript levels in B and BM for 57 pts with S-form were significantly higher than 82 L-form patients (p = 0.02) when NQ was determined using GAPDH as the control gene (but not with ABL). With a median follow-up of 24.3 months for all patients, there have been 19 events. Median DFS for either isoform has not been reached, however, DFS was significantly shorter for patients with S-isoform compared to those with L-isoform (p = 0.017) with an estimated hazard ratio of 3.28. Using a multivariate proportional hazard model, no other significant relationships were found between DFS and NQ level at diagnosis, age, presenting WBC or platelet count. Conclusions: The S-isoform of the PML-RARa fusion gene was associated with shorter DFS in a subset of patients entered onto C-9710. If confirmed in a larger cohort of C-9710 pts, presence of the S-isoform should be considered as a high-risk feature in the design of future risk-adapted treatment strategies for APL.

No significant financial relationships to disclose.

Prognostic significance of WT-1 levels in patients with myelodysplastic syndrome and leukemia after reduced-intensity allogeneic transplantation

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Background: Expression of WT-1, a zinc-finger transcription factor, is elevated at diagnosis in many kinds of leukemia. The prognostic significance of the WT-1 transcript level before and after stem cell transplant is controversial. We performed real-time quantitative PCR (RQ-PCR) on samples from pts with leukemia and MDS undergoing allo stem-cell transplant (SCT) to determine if WT-1 expression correlates with survival (OS) and/or disease-free survival (DFS). Methods: Pts were conditioned with fludarabine, melphalan and alemtuzumab. cDNA was synthesized for RQ-PCR, which was performed on bone marrow (BM) and peripheral blood (PB) samples drawn prior to transplant admission and at day 28 (D28) post transplantation. All samples were analyzed using LightCycler technology and reported as a normalized ratio of WT-1 copy number to ABL copy number. Results: Data on 48 patients who underwent allo SCT are reported here. During a median follow up of 17 months, 24 patients died and the OS rate at one year was 52%. The DFS rate at one year was 34%. There was a statistically significant association between pretransplant WT-1 levels measured in PB and OS, with increase in risk of death by 36% for every 10 fold increase in WT-1 levels (p=0.048). Pretransplant WT-1 levels in both PB and BM also predicted DFS: the risk of relapse or death was increased by 44% (PB) and 71% (BM) for every 10 fold increase in WT-1 levels (p=0.012; p=0.048). However, after controlling for disease status at transplantation using a Cox model, pretransplant WT-1 levels were no longer a significant predictor because these levels were highly correlated with disease status at transplantation. We did not find any significant correlation between WT-1 levels 28 days post-transplantation and outcome. Conclusions: Our preliminary results differ from several published studies demonstrating prognostic significance of WT-1 RQ-PCR after allo SCT. Although elevated WT-1 levels prior to transplantation correlate with higher risk of post-transplant relapse and death from any cause, these preliminary data fail to establish an independent prognostic role for WT-1 RQ-PCR in the setting of reduced intensity allo SCT. Analysis of additional post-transplant time points is proceeding.

No significant financial relationships to disclose.

Atypical development of Sertoli cells and impairment of spermatogenesis in the hypogonadal (hpg) mouse

Testes of hypogonadal (hpg) mice show arrested postnatal development due to congenital deficiencies of gonadotrophin-releasing hormone (GnRH) and gonadotrophin synthesis and secretion. Follicle-stimulating hormone (FSH), androgen or oestrogen treatment restore qualitatively normal spermatogenesis in hpg testes. Understanding the cellular and molecular changes accompanying hormone-induced spermatogenesis in hpg mice requires detailed morphological analyses of the germ cells and Sertoli cells in the untreated hpg testis. We compared seminiferous epithelial cytology in adult hpg, immature and adult wild-type mice using unbiased optical disector-based stereology, immunolocalization of Sertoli cell microtubules (MT), espin (a component of the blood-testis barrier), markers of Sertoli cell maturity (p27(kip1) and WT-1), and electron microscopy. Hpg testes had marked reductions in weight, seminiferous cord volume and length, and severe spermatogenic impairment with germ cells per testis < 1% of adult wild-type testes. Sertoli cell nuclei expressed WT-1 in hpg testes, but often were centrally located, similar to 9-14-day-old wild-type testes, and they expressed p27(kip1), indicating that hpg Sertoli cells were post-mitotic. Hpg testes had significantly (P < 0.05) reduced Sertoli cells per testis (0.56 million) compared with 10-day wild-type (1.15 million) and adult wild-type testes (2.06 million). Immunofluorescence labelling of normal adult Sertoli cells showed supranuclear MT columns and basally located espin, but these features were absent in 10-day-old and hpg Sertoli cells. Hpg Sertoli cells showed pleomorphic nuclear ultrastructure with mature-type nucleoli, similar to normal adult-type Sertoli cells, but hpg Sertoli cells exhibited incomplete tight junctions that lacked ectoplasmic specializations. We conclude that in hpg mice, chronic gonadotrophin insufficiency restrains Sertoli cell proliferation and maturation, forming pseudo-adult-type Sertoli cells that are incapable of supporting germ cell proliferation and maturation.

Impact of hormone therapy on acute radiotherapy toxicity in the treatment of prostate cancer

PURPOSE

To analyze the impact of neoadjuvant hormone therapy (HT) on acute gastrointestinal (GI) and genitourinary (GU) toxicity from radiotherapy (RT).

SCOPE

The toxicity rates of 480 consecutive prostate cancer patients were reviewed and compared using the chi2 test. Ordered logit regression analyses were performed including the major demographic, disease, and treatment factors. Although no reduction in acute GI toxicity from HT use was observed (P=0.067), a lower rate of acute GU toxicity was observed (P=0.002). No factor reached statistical significance on regression analysis.

CONCLUSIONS

Observed toxicity rates were similar or lower in patients receiving HT. Thus, increased RT toxicity should not be a concern when deciding to add neoadjuvant HT to RT for prostate cancer.

Phase II study of prolonged ambulatory infusion carboplatin and oral etoposide for patients progressing through hormonal therapy for prostate cancer

AIM

To develop a well-tolerated outpatient chemotherapy regimen for hormone-insensitive prostate cancer.

METHOD

Forty patients received carboplatin 20 mg/m2 by continuous ambulatory infusion with oral etoposide 50 mg/day for 21 days repeated every 6 weeks.

RESULTS

Four patients had a partial response and 16 patients had stable disease. Two of the partial responders and three additional patients recorded falls in prostate specific antigen of 50% or more. The median freedom from progression was 24 weeks and median survival 32 weeks. Twenty-four of 31 patients had decreasing pain scores and 20 of 34 patients recorded improved quality of life with at least one cycle of treatment. The main toxicity occurred in seven patients with World Health Organization (WHO) grade 4 neutropenia and in four patients with WHO grade 3 neutropenia. Only one patient developed febrile neutropenia. Six patients had grade 3 anaemia and three patients had grade 3 thrombocytopenia. Two patients reported grade 3 lethargy whereas 11 patients had grade 2 lethargy.

CONCLUSION

This was a well-tolerated regimen that improved symptomatic control of hormone-insensitive prostate cancer.

Beware the rooster: smokeless tobacco companies who claim they want to help

It should not be assumed that smokeless tobacco manufacturers share our public health goals

Methods for quantifying follicular numbers within the mouse ovary

Accurate estimation of the number of ovarian follicles at various stages of development is an important indicator of the process of folliculogenesis in relation to the endocrine signals and paracrine/autocrine mechanisms that control the growth and maturation of the oocytes and their supporting follicular cells. There are 10-fold or greater differences in follicular numbers per ovary at similar ages and/or strains reported in earlier studies using various methods, leading to difficulties with interpretation of ovarian function in control vs experimental conditions. This study describes unbiased, assumption-free stereological methods for quantification of early and growing follicular numbers in the mouse ovary. A fractionator approach was used to sample a defined fraction of histological sections of adult wild-type ovaries. Primordial and primary follicles were counted independently with the optical and physical disector methods. The fractionator/disector methods, which are independent of follicular size or shape, gave estimations of 1930 ± 286 (S.E.M.) and 2227 ± 101 primordial follicles, and 137 ± 25 and 265 ± 32 primary follicles per ovary at 70 and 100 days of age respectively. From exact counts on serial sections, secondary and later follicular numbers at 100 days of age were estimated at 135 per ovary. Remnants of zona pellucidae (a marker of previous follicular atresia) were estimated using a fractionator/physical disector approach and were approximately 500 per ovary. The application of the quantitative methods described will facilitate an improved understanding of follicular dynamics and the factors that mediate their growth and maturation and allow for a better comparison between different studies.

Antiviral beta-L-nucleosides specific for hepatitis B virus infection

Three simple, related nucleosides, beta-L-2'-deoxycytidine (LdC), beta-Lthymidine (LdT), and beta-L-2'-deoxyadenosine (LdA), have been discovered to be potent, specific and selective inhibitors of the replication hepatitis B virus (HBV), as well as the closely related duck and woodchuck hepatitis viruses (WHV). Structure-activity relationship analysis indicates that the 3'-OH group of the beta-L-2'-deoxyribose of the beta-L-2'-deoxynucleoside confers specific anti-hepadnavirus activity. The simple nucleosides had no effect on the replication of 15 other RNA and DNA viruses, and did not inhibit human DNA polymerases (alpha, beta and gamma) or compromise mitochondrial function. The nucleosides are efficiently converted intracellularly into active triphosphate metabolites that have a long half-life. Once-daily oral administration of these compounds in the woodchuck efficacy model of chronic HBV infection reduced viral load by as much as 10(8) genome equivalents/ml serum and there was no drug-related toxicity. In addition, a decline in WHV surface antigen (WHsAg) paralleled the decrease in viral load. This class of nucleosides displays an excellent overall safety profile. The first compound, LdT, has already entered clinical trials and LdC, currently being developed as a prodrug, is expected to enter the clinic in the near future. These compounds have the potential for use in combination therapy with the goal of achieving superior viral suppression and diminishing the onset of resistance.

Task Force I: methodological aspects of blood pressure measurement

OBJECTIVE

To reach a consensus on important methodological aspects of blood pressure measurement.

METHODS

A Task Force on the methodological aspects of blood pressure measurement wrote this review after the Eighth International Consensus Conference on Blood Pressure Monitoring, in Sendai, Japan (28-31 October 2001). This consensus paper is based on the papers presented by Task Force I and on the discussion sessions, and is therefore representative of a broad spectrum of expert opinion.

POINTS OF CONSENSUS

Consensus was reached on the following five issues: (1) there is an urgent need for a simplified protocol for the validation of blood pressure measuring devices; (2) there is a need for a means of updating the "state of the market" for validated devices so that users can have easy access to this information; (3) new devices must be validated independently, and existing devices that have not been validated must be reappraised; (4) manufacturers should confirm when new models use algorithms which have been validated previously; (5) the Food and Drug Administration now accepts that when ambulatory blood pressure measurement is used in clinical short-term trials in which side-effects are not being assessed, a placebo arm is not required.