Expression of E6AP and PML predicts for prostate cancer progression and cancer-specific death

BACKGROUND

The promyelocytic leukemia (PML) tumor suppressor plays an important role in the response to a variety of cellular stressors and its expression is downregulated or lost in a range of human tumors. We have previously shown that the E3 ligase E6-associated protein (E6AP) is an important regulator of PML protein stability but the relationship and clinical impact of PML and E6AP expression in prostatic carcinoma is unknown.

METHODS

E6AP and PML expression was assessed in tissue microarrays from a phase I discovery cohort of 170 patients treated by radical prostatectomy for localized prostate cancer (PC). Correlation analysis was carried out between PML and E6AP expression and clinicopathological variates including PSA as a surrogate of disease recurrence. The results were confirmed in a phase II validation cohort of 318 patients with associated clinical recurrence and survival data.

RESULTS

Survival analysis of the phase I cohort revealed that patients whose tumors showed reduced PML and high E6AP expression had reduced time to PSA relapse (P = 0.012). This was confirmed in the phase II validation cohort where the expression profile of high E6AP/low PML was significantly associated with reduced time to PSA relapse (P < 0.001), clinical relapse (P = 0.016) and PC-specific death (P = 0.014). In multivariate analysis, this expression profile was an independent prognostic indicator of PSA relapse and clinical relapse independent of clinicopathologic factors predicting recurrence.

CONCLUSION

This study identifies E6AP and PML as potential prognostic markers in localized prostate carcinoma and supports a role for E6AP in driving the downregulation or loss of PML expression in prostate carcinomas.

Survival gains needed to offset persistent adverse treatment effects in localised prostate cancer

Background:

Men diagnosed with localised prostate cancer (LPC) face difficult choices between treatment options that can cause persistent problems with sexual, urinary and bowel function. Controlled trial evidence about the survival benefits of the full range of treatment alternatives is limited, and patients' views on the survival gains that might justify these problems have not been quantified.

Methods:

A discrete choice experiment (DCE) was administered in a random subsample (n=357, stratified by treatment) of a population-based sample (n=1381) of men, recurrence-free 3 years after diagnosis of LPC, and 65 age-matched controls (without prostate cancer). Survival gains needed to justify persistent problems were estimated by substituting side effect and survival parameters from the DCE into an equation for compensating variation (adapted from welfare economics).

Results:

Median (2.5, 97.5 centiles) survival benefits needed to justify severe erectile dysfunction and severe loss of libido were 4.0 (3.4, 4.6) and 5.0 (4.9, 5.2) months. These problems were common, particularly after androgen deprivation therapy (ADT): 40 and 41% overall (n=1381) and 88 and 78% in the ADT group (n=33). Urinary leakage (most prevalent after radical prostatectomy (n=839, mild 41%, severe 18%)) needed 4.2 (4.1, 4.3) and 27.7 (26.9, 28.5) months survival benefit, respectively. Mild bowel problems (most prevalent (30%) after external beam radiotherapy (n=106)) needed 6.2 (6.1, 6.4) months survival benefit.

Conclusion:

Emerging evidence about survival benefits can be assessed against these patient-based benchmarks. Considerable variation in trade-offs among individuals underlines the need to inform patients of long-term consequences and incorporate patient preferences into treatment decisions.

Quantification of dissolved organic carbon at very low levels in natural ice samples by a UV-induced oxidation method

The study of chemical impurities trapped in solid precipitation and accumulated in polar ice sheets and high-elevation, midlatitude cold glaciers over the last several hundreds of years provides a unique way to reconstruct our changing atmosphere from the preindustrial era to the present day. Numerous ice core studies of inorganic species have already evaluated the effects of growing anthropogenic emissions of SO(2) or NO(x) on the chemical composition of the atmosphere in various regions of the world. While it was recently shown that organic species dominate the atmospheric aerosol mass, the contribution of anthropogenic emissions to their budget remains poorly understood. The study of organics in ice is at the infancy stage, and it still is difficult to draw a consistent picture of the organic content of polar ice from sparse available data. A UV oxidation method and IR quantification of CO(2) was optimized to obtain measurements of dissolved organic carbon content as low as a few ppbC. Stringent working conditions were defined to prevent contamination during the cleaning of ice. Measurements in various ice cores corresponding to preindustrial times revealed dissolved organic carbon content of less than 10 ppbC in Antarctica and up to 75 ppbC in alpine ice.

Gene-based prediction of PSA recurrence for clinically localized prostate cancer patients

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Background: Accurate estimates of the risk of recurrence are needed for the optimal management of patients with clinically localized prostate cancer. We combined an established nomogram and novel molecular predictors into a new prognostic model of prostate specific antigen (PSA) recurrence. Methods: Gene expression profiles from formalin-fixed, paraffin-embedded (FFPE) localized prostate cancer tissues were analysed to identify genes associated with PSA recurrence. The profiles of the identified markers were reproduced by reverse-transcriptase-polymerase-chain-reaction (RTPCR). The RTPCR profiles from 3 of these genes, along with the output from the Kattan post-operative nomogram, were used to produce a predictive model of PSA recurrence. Results: After variable selection, a model of PSA recurrence was built that combined expression values of 3 genes and the postoperative nomogram. The 3-gene plus nomogram model predicted 5-year PSA recurrence with a concordance index (c-index) of 0.77 in a validation set compared to a c-index of 0.67 for the nomogram. This model identified a subgroup of patients that were at high risk for recurrence which were not identified by the nomogram. Conclusions: This new gene-based classifier has superior predictive power when compared against the 5-year nomogram to assess risk of PSA recurrence in patients with organ-confined prostate cancer. Our classifier should provide a more accurate stratification of patients into high and low risk groups for treatment decisions and adjuvant clinical trials.

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Role of granulocyte-macrophage colony-stimulating factor and its receptor in the genesis of acute respiratory distress syndrome through an effect on neutrophil apoptosis

HYPOTHESIS

That granulocyte-macrophage colony-stimulating factor (GM-CSF) and its receptor modulate the suppression of apoptosis (Ao) of normal neutrophils incubated in the plasma of patients with postraumatic acute respiratory distress syndrome (ARDS).

DESIGN

Experimental study using cultured human neutrophils.

SETTING

University hospital, level I trauma center.

PARTICIPANTS

Plasma was obtained from 14 patients with early, fulminant posttraumatic ARDS (mean Injury Severity Score, 22). All samples were drawn within 24 hours after injury. Plasma was also taken from up to 21 healthy control subjects. These volunteers were also used as sources of polymorphonuclear leukocytes (PMNs).

MAIN OUTCOME MEASURES

(1) Effect of early, fulminant ARDS and normal plasma on spontaneous Ao and GM-CSF receptor expression in PMNs in vitro. (2) Effect of ligation of either GM-CSF or its receptor with a neutralizing monoclonal antibody (mAb) on PMN Ao in ARDS and normal plasma. (3) Correlation of extracellular GM-CSF concentration with rate of PMN Ao. (4) Levels of GM-CSF in ARDS and normal plasma and in culture supernatant of normal PMNs incubated in early, fulminant ARDS and normal plasma.

RESULTS

Plasma from patients with ARDS enhanced PMN viability at 24 hours (data are given as mean +/- SEM) 52% +/- 3% control vs 60% +/- 3% ARDS, P<.05). Binding of the GM-CSF receptor with a neutralizing mAb significantly reduced PMN viability in ARDS plasma, but not in normal plasma (60% +/- 3% ARDS vs 53% +/- 3% ARDS + mAb, P<.05). Ligation of GM-CSF with mAb had no significant effect on PMN viability in either plasma. Only 1% of PMNs expressed detectable levels of the GM-CSF receptor when incubated for 24 hours in either ARDS or normal plasma. The GM-CSF levels were undetectable (>7 pg/mL) in both ARDS and normal plasma and in culture supernatants taken after 24 hours of incubation in both plasma types. Levels of GM-CSF ranging from 0 to 50000 pg/mL had no effect on PMN Ao in plasma-free medium.

CONCLUSIONS

The antiapoptotic effect of ARDS plasma appears to be mediated by the GM-CSF receptor. This effect occurs at both low levels of plasma GM-CSF and surface expression of its PMN receptor. Ligation of GM-CSF had no effect of PMN Ao, suggesting that Ao is triggered by Fc portion-mediated receptor cross-linking. These results provide the theoretical basis for alphaGM-CSF receptor mAb therapy as a novel modality of treatment for ARDS.

Growth factor involvement in progression of prostate cancer

Understanding how the regulation of growth factor pathways alters during prostate cancer (PC) progression may enable researchers to develop targeted therapeutic strategies for advanced disease. PC progression involves the shifting of cells from androgen-dependent growth to an androgen-independent state, sometimes with the loss or mutation of the androgen receptors in PC cells. Both autocrine and paracrine pathways are up-regulated in androgen-independent tumors and may replace androgens as primary growth stimulatory factors in cancer progression. Our discussion focuses on growth factor families that maintain homeostasis between epithelial and stromal cells in the normal prostate and that undergo changes as PC progresses, often making stromal cells redundant. These growth factors include fibroblast growth factor, insulin-like growth factors, epidermal growth factor, transforming growth factor alpha, retinoic acid, vitamin D3, and the transforming growth factor beta families. We review their role in normal prostate development and in cancer progression, using evidence from clinical specimens and models of PC cell growth.

Bacillus Calmette-Guérin plus intravesical interferon alpha-2b in patients with superficial bladder cancer

OBJECTIVES

Bacillus Calmette-Guérin (BCG) and interferon alpha-2b (IFN alpha 2b) have been used individually for the treatment of bladder cancer. We used a low dose of BCG combined with IFN alpha 2b to determine the safety and to assess the efficacy of this combination therapy.

METHODS

A study of 12 patients with superficial bladder cancer evaluated the safety and efficacy of a combination of low-dose BCG and IFN alpha 2b, given weekly for 6 weeks. Three patients were assigned to each of four groups in which 60 mg of BCG was combined with 10, 30, 60, or 100 x 10(6) IU of IFN alpha 2b.

RESULTS

The combination BCG/IFN alpha 2b therapy was well tolerated, with adverse effects being mild to moderate and resolved at the end of treatment. At 12 months post-treatment there has been no tumor progression. Two patients with previous multifocal transitional cell carcinoma have had solitary recurrences. One patient has had recurrent carcinoma in situ.

CONCLUSIONS

This preliminary study found combination BCG/IFN alpha 2b induction therapy to be safe and well tolerated. These early results show a high response rate, but efficacy can only be determined with Phase II and III studies.

Antiproliferative effects of bacillus Calmette-Guerin and interferon alpha 2b on human bladder cancer cells in vitro

Direct inhibitory effects of bacillus Calmette-Guérin (BCG) and interferon alpha 2b (IFN alpha 2b) on six human bladder carcinoma cell lines, UCRU-BL-13, UCRU-BL-17, UCRU-BL-28, 5637, T24 and J82, were studied using an in vitro proliferation assay. Effects on proliferation following exposure to BCG or IFN alpha 2b were analysed by [3H]thymidine incorporation over 7 days. BCG had an antiproliferative effect on all bladder lines, while sensitivity to IFN alpha 2b varied greatly, being as remarkably low as 1 U/ml for some lines. The antiproliferative effect was greatest when cells were exposed continuously to either agent, but was still evident with a limited exposure. When clinical concentrations were simulated in vitro, BCG+IFN alpha 2b was more effective than BCG alone and as effective as a double BCG concentration. We conclude that, in addition to their immunomodulatory effects, BCG and IFN alpha 2b directly inhibit the proliferation of human bladder cancer cells, and often at extremely low concentrations.

Bacillus Calmette-Guerin (BCG) enhances monocyte- and lymphocyte-mediated bladder tumour cell killing

A cytotoxicity assay was used to study the action of bacillus Calmette-Guerin (BCG) and cytokines on four human bladder cancer cell lines. Monocytes and lymphocytes from peripheral blood were incubated with or without BCG or cytokines for 24 h, after which [3H]thymidine-labelled target cells were added and the 72 h percentage specific release determined. BCG had a direct cytotoxic effect against tumour cells and significantly enhanced monocyte/macrophage and enhanced lymphocyte cytotoxicity against one cell line (UCRU-BL-17). Supernatants (SNs) from BCG-activated monocytes/macrophages and lymphocytes increased the percentage specific release of [3H]thymidine from UCRU-BL-17 cells. Interferon alpha (IFN-alpha) and interleukin 2 (IL-2) were cytotoxic towards UCRU-BL-17. No synergy occurred between BCG and cytokines at the concentrations tested. The results suggest that BCG is superior to IFN-alpha, interferon gamma (IFN-gamma) and IL-2 in enhancing cell-mediated cytotoxicity.

Enhanced stability and potency of novel growth hormone-releasing factor (GRF) analogues derived from rodent and human GRF sequences

Native human GRF(1-44)-NH2(hGRF44) is subject to biological inactivation by both enzymatic and chemical routes. In plasma, hGRF44 is rapidly degraded via dipeptidylpeptidase IV (DPP-IV) cleavage between residues Ala2 and Asp3. The hGRF44 is also subject to chemical rearrangement (Asn8-->Asp8, beta-Asp8 via aminosuccinimide formation) and oxidation [Met27-->Met(O)27] in aqueous environments, greatly reducing its bioactivity. It is therefore advantageous to develop long-acting GRF analogues using specific amino acid replacements at the amino-terminus (to prevent enzymatic degradation): residue 8 (to reduce isomerization) and residue 27 (to prevent oxidation). Inclusion of Ala15 substitution (for Gly15), previously demonstrated to enhance receptor binding affinity, would be predicted to improve GRF analogue potency. Substitution of [His1,Val2]-(from the mouse GRF sequence) for [Tyr1,Ala2]-(human sequence) in [Ala15,Leu27]hGRF(1-32)-OH analogues completely inhibited (24-h incubation) DPP-IV cleavage and greatly increased plasma stability in vitro. Additional substitution of Thr8 (mouse GRF sequence), Ser8 (rat GRF sequence), or Gln8 (not naturally occurring) for Asn8 (human GRF sequence) resulted in analogues with enhanced aqueous stability in vitro (i.e., decreased rate of isomerization). These three highly stable and enzymatically resistant hGRF(1-32)-OH analogues, containing His1, Val2, Thr/Gln8, Ala15, and Leu27 replacements, were then bioassayed for growth hormone (GH)-releasing activity in vitro (rat pituitary cell culture) and in vivo (SC injection into pigs). Enhanced bioactivity was observed with all three hGRF(1-32)-OH analogues. In vitro, these analogues were approximately threefold more potent than hGRF44, whereas in vivo they were eleven- to thirteenfold more potent.(ABSTRACT TRUNCATED AT 250 WORDS)

Injectable collagen for type 3 female stress incontinence: the first 50 Australian patients

OBJECTIVE

To assess the safety, efficacy and durability of injectable glutaraldehyde cross-linked (GAX) collagen in the treatment of type 3 female stress incontinence.

DESIGN AND SETTING

A prospective study of incontinent women attending a private practice for clinical and urodynamic assessment.

PATIENTS

Fifty women who had had an average of 1.8 previous operations for stress urinary incontinence took part in the study. Each had been diagnosed as having type 3 genuine stress incontinence (poor or nonfunctioning urethral sphincter mechanism in the presence of a bladder neck which is well supported, usually by scar tissue from previous surgery). Subject to a negative skin test for allergy, each patient underwent the implantation of GAX collagen (Contigen), a biocompatible product causing no foreign body reaction.

INTERVENTIONS

The implant was performed by a short day-only procedure involving cystoscopically controlled periurethral (71%) or transurethral (29%) injection of Contigen. The aim was to achieve closure of the urethra at the bladder neck and increase resistance to urine loss. Top-up injections were used as required. The follow-up period ranged from one to 21 months (mean, 11 months).

RESULTS

Of these first 50 female patients, 41 (82%) were successfully treated. Twenty-one (42%) were no longer incontinent; 20 (40%) desired no further treatment because their condition was improved; seven (14%) did not respond to treatment and two patients were awaiting top-up injections. The average number of injections given was 1.9 and the average volume injected was 14.4 mL. There were no allergic reactions or infections. Side effects were temporary and of a minor nature.

CONCLUSIONS

Injectable GAX collagen appears to be a safe and effective treatment for type 3 stress urinary incontinence. Its durability awaits further follow-up.

Effect of human growth hormone-releasing factor and a potent analog on antibody formation in African green monkeys

African Green monkeys were injected (2 x daily subcutaneously for six months) with human GRF(1-44)-NH2 (10 micrograms/kg BW) or a more potent analog, [desNH2Tyr1,Ala15]-hGRF(1-29)-NH2 (2 micrograms/kg BW) to determine the potential of each peptide to induce antibody formation. Blood samples were taken every two weeks, diluted 1:100 and tested for ability to bind radioiodinated hGRF. One animal in the hGRF(1-44)-NH2 group [N = 6] produced low-titer GRF antibodies by 6 weeks (19% binding) and continued throughout the 24 weeks of treatment (average = 50-60% binding). Similarly, one animal in the hGRF analog group [N = 6] displayed low-titer GRF antibodies by 18 weeks (14% binding), with the highest binding observed at 24 weeks (51% binding). Subsequent dilutions (1:1,000 and 1:3,000) of these bleedings confirmed that higher GRF antibody titers were not masked by antibody excess. Dialyzed sera from these two animals did not affect the abilities of hGRF(1-44)-NH2 or [desNH2Tyr1,Ala15]-hGRF(1-29)-NH2 to stimulate GH secretion by rat pituitary cells in vitro. After 20 weeks of treatment, significant GH responses (increased mean GH area under the curve 2.3-2.5 fold and GH peak 3.5-3.7 fold, that of control) were observed following hGRF or hGRF analog injection. Therefore, the low titer GRF antibodies detected in monkey sera during six months of treatment with hGRF or a potent analog were biologically non-neutralizing.