Surface expression and functional characterization of alpha-granule factor V in human platelets: effects of ionophore A23187, thrombin, collagen, and convulxin

Factor V (FV) present in platelet alpha-granules has a significant but incompletely understood role in hemostasis. This report demonstrates that a fraction of platelets express very high levels of surface-bound, alpha-granule FV on simultaneous activation with 2 agonists, thrombin and convulxin, an activator of the collagen receptor glycoprotein VI. This subpopulation of activated platelets represents 30.7% +/- 4.7% of the total population and is referred to as convulxin and thrombin-induced-FV (COAT-FV) platelets. COAT-FV platelets are also observed on activation with thrombin plus collagen types I, V, or VI, but not with type III. No single agonist examined was able to produce COAT-FV platelets, although ionophore A23187 in conjunction with either thrombin or convulxin did generate this population. COAT-FV platelets bound annexin-V, indicating exposure of aminophospholipids and were enriched in young platelets as identified by the binding of thiazole orange. The functional significance of COAT-FV platelets was investigated by demonstrating that factor Xa preferentially bound to COAT-FV platelets, that COAT-FV platelets had more FV activity than either thrombin or A23187-activated platelets, and that COAT-FV platelets were capable of generating more prothrombinase activity than any other physiologic agonist examined. Microparticle production by dual stimulation with thrombin and convulxin was less than that observed with A23187, indicating that microparticles were not responsible for all the activities observed. These data demonstrate a new procoagulant component produced from dual stimulation of platelets with thrombin and collagen. COAT-FV platelets may explain the unique role of alpha-granule FV and the hemostatic effectiveness of young platelets. (Blood. 2000;95:1694-1702)

Quality of analgesic treatment in patients with advanced prostate cancer: do we do a better job now? The Swiss Group for Clinical Cancer Research (SAKK) experience

GOALS OF WORK: The aim of this study was to evaluate pain intensity and the application of the WHO guidelines for cancer pain treatment in patients with prostate cancer treated at Swiss cancer centers. MATERIALS AND METHODS: We analyzed a series of five multicenter phase II clinical trials which examined the palliative effect of different chemotherapies in patients with advanced hormone-refractory prostate carcinoma. Of 170 patients, 1,018 visits were evaluable for our purpose, including ratings of pain intensity by patients and prescribed analgesics. MAIN RESULTS: No or mild pain was indicated by patients in 36 to 55% of the visits, more than mild pain in 30 to 46%. In 21% of the visits, the WHO pain treatment criteria (treatment according to one of the three steps; oral, rectal or transdermal application of the main dose; administration on a regular schedule) were fulfilled, and the Cleeland index was positive according to all recommendations. In 6% of the visits, neither the WHO criteria were fulfilled nor was the Cleeland index positive. This indicates insufficient pain treatment not following the WHO guidelines and that the prescribed analgesics were not sufficiently potent for the rated pain intensity. CONCLUSIONS: In this selective Swiss sample, the standard of analgesic treatment is high. However, there is still scope for improvement. This cannot solely be solved by improving the knowledge of the physicians. Programs to change the patients' attitude towards cancer pain, training to improve the physicians' communication skills, and institutional changes may be promising strategies.

An open-label, noncomparative phase II trial to evaluate the efficacy and safety of docetaxel in combination with gefitinib in patients with hormone-refractory metastatic prostate cancer

BACKGROUND: Prostate cancer is the most common type of cancer in men, however, therapeutic options are limited. 50-90% of hormone-refractory prostate cancer cells show an overexpression of epidermal growth factor receptor (EGFR), which may contribute to uncontrolled proliferation and resistance to chemotherapy. In vitro, gefitinib, an orally administered tyrosine kinase inhibitor, has shown a significant increase in antitumor activity when combined with chemotherapy. PATIENTS AND METHODS: In this phase II study, the safety and efficacy of gefitinib in combination with docetaxel, a chemotherapeutic agent commonly used for prostate cancer, was investigated in patients with hormone-refractory prostate cancer (HRPC). 37 patients with HRPC were treated continuously with gefitinib 250 mg once daily and docetaxel 35 mg/m2 i.v. for up to 6 cycles. PSA response, defined as a =50% decrease in serum PSA compared with trial entry, was the primary efficacy parameter. PSA levels were measured at prescribed intervals. RESULTS: The response rate and duration of response were consistent with those seen with docetaxel monotherapy. The combination of docetaxel and gefitinib was reasonably well tolerated in this study. CONCLUSION: Future studies should investigate whether patients with specific tumor characteristics, e.g. EGFR protein overexpression, respond better to gefitinib than patients without, leading to a more customized therapy option.

Novel 111In-labelled bombesin analogues for molecular imaging of prostate tumours

PURPOSE: It has been shown that some primary human tumours and their metastases, including prostate and breast tumours, overexpress gastrin-releasing peptide (GRP) receptors. Bombesin (BN) is a neuropeptide with a high affinity for these GRP receptors. We demonstrated successful scintigraphic visualisation of BN receptor-positive tumours in preclinical studies using the radiolabelled BN analogue [(111)In-DTPA-Pro(1),Tyr(4)]BN. However, the receptor affinity as well as the serum stability of this analogue leave room for improvement. Therefore new (111)In-labelled BN analogues were synthesised and evaluated in vitro and in vivo. METHODS AND RESULTS: The receptor affinity of the new BN analogues was tested on human GRP receptor-expressing prostate tumour xenografts and rat colon sections. Analogues with high receptor affinity (low nM range) were selected for further evaluation. Incubation in vitro of GRP receptor-expressing rat CA20948 and human PC3 tumour cells with the (111)In-labelled analogues resulted in rapid receptor-mediated uptake and internalisation. The BN analogue with the best receptor affinity and in vitro internalisation characteristics, Cmp 3 ([(111)In-DTPA-ACMpip(5),Tha(6),betaAla(11),Tha(13),Nle(14)]BN(5-14)), was tested in vivo in biodistribution studies using rats bearing GRP receptor-expressing CA20948 tumours, and nude mice bearing human PC3 xenografts. Injection of (111)In-labelled Cmp 3 in these animals showed high, receptor-mediated uptake in receptor-positive organs and tumours which could be visualised using planar gamma camera and microSPECT/CT imaging. CONCLUSION: With their enhanced receptor affinity and their rapid receptor-mediated internalisation in vitro and in vivo, the new BN analogues, and especially Cmp 3, are promising candidates for use in diagnostic molecular imaging and targeted radionuclide therapy of GRP receptor-expressing cancers.

Cerebellar cortical degeneration with selective granule cell loss in Bavarian mountain dogs

Three Bavarian mountain dogs aged between 18 and 20 months, not related to each other, were presented with chronic signs of cerebellar dysfunction. On sagittal T2-weighted magnetic resonance imaging brain images, the tentative diagnosis of cerebellar hypoplasia was established based on an enlarged cerebrospinal fluid space around the cerebellum and an increased cerebrospinal fluid signal between the folia. Post-mortem examination was performed in one dog and did show an overall reduction of cerebellar size. On histopathologic examination, a selective loss of cerebellar granule cells with sparing of Purkinje cells was evident. Therefore, the Bavarian mountain dog is a breed where cerebellar cortical degeneration caused by the rather exceptional selective granule cell loss can be seen as cause of chronic, slowly progressive cerebellar dysfunction starting at an age of several months.

FTY720 suppresses interleukin-1beta-induced secretory phospholipase A2 expression in renal mesangial cells by a transcriptional mechanism

BACKGROUND AND PURPOSE: FTY720 is a potent immunomodulatory prodrug that is converted to its active phosphorylated form by a sphingosine kinase. Here we have studied whether FTY720 mimicked the action of sphingosine-1-phosphate (S1P) and exerted an anti-inflammatory potential in renal mesangial cells. EXPERIMENTAL APPROACH: Prostaglandin E(2) (PGE(2)) was quantified by an enzyme-linked immunosorbent-assay. Secretory phospholipase A(2) (sPLA(2)) protein was detected by Western blot analyses. mRNA expression was determined by Northern blot analysis and sPLA(2)-promoter activity was measured by a luciferase-reporter-gene assay. KEY RESULTS: Stimulation of cells for 24 h with interleukin-1beta (IL-1beta) is known to trigger increased PGE(2) formation which coincides with an induction of the mRNA for group-IIA-sPLA(2) and protein expression. FTY720 dose-dependently suppressed IL-1beta-induced IIA-sPLA(2) protein secretion and activity in the supernatant. This effect is due to a suppression of cytokine-induced sPLA(2) mRNA expression which results from a reduced promoter activity. As a consequence of suppressed sPLA(2) activity, PGE(2) formation is also reduced by FTY720. Mechanistically, the FTY720-suppressed sPLA(2) expression results from an activation of the TGFbeta/Smad signalling cascade since inhibition of the TGFbeta receptor type I by a specific kinase inhibitor reverses the FTY720-mediated decrease of sPLA(2) protein expression and sPLA(2) promoter activity. CONCLUSIONS AND IMPLICATIONS: In summary, our data show that FTY720 was able to mimic the anti-inflammatory activity of TGFbeta and blocked cytokine-triggered sPLA(2) expression and subsequent PGE(2) formation. Thus, FTY720 may exert additional in vivo effects besides the well reported immunomodulation and its anti-inflammatory potential should be considered.

Applicability and dosimetric impact of ultrasound-based preplanning in high-dose-rate brachytherapy of prostate cancer

BACKGROUND AND PURPOSE: Analyses of permanent brachytherapy seed implants of the prostate have demonstrated that the use of a preplan may lead to a considerable decrease of dosimetric implant quality. The authors aimed to determine whether the same drawbacks of preplanning also apply to high-dose-rate (HDR) brachytherapy. PATIENTS AND METHODS: 15 patients who underwent two separate HDR brachytherapy implants in addition to external-beam radiation therapy for advanced prostate cancer were analyzed. A pretherapeutic transrectal ultrasound was performed in all patients to generate a preplan for the first brachytherapy implant. For the second brachytherapy, a subset of patients were treated by preplans based on the ultrasound from the first brachytherapy implant. Preplans were compared with the respective postplans assessing the following parameters: coverage index, minimum target dose, homogeneity index, and dose exposure of organs at risk. The prostate geometries (volume, width, height, length) were compared as well. RESULTS: At the first brachytherapy, the matching between the preplan and actual implant geometry was sufficient in 47% of the patients, and the preplan could be applied. The dosimetric implant quality decreased considerably: the mean coverage differed by -0.11, the mean minimum target dose by -0.15, the mean homogeneity index by -0.09. The exposure of organs at risk was not substantially altered. At the second brachytherapy, all patients could be treated by the preplan; the differences between the implant quality parameters were less pronounced. The changes of prostate geometry between preplans and postplans were considerable, the differences in volume ranging from -8.0 to 13.8 cm(3) and in dimensions (width, height, length) from -1.1 to 1.0 cm. CONCLUSION: Preplanning in HDR brachytherapy of the prostate is associated with a substantial decrease of dosimetric implant quality, when the preplan is based on a pretherapeutic ultrasound. The implant quality is less impaired in subsequent implants of fractionated brachytherapy.

[Malignant lymphoma of the prostate--diagnosis on the second biopsy]

BACKGROUND: Malignant lymphoma of the prostate is rare. In the literature, about 165 cases with either a primary lymphoma of the prostate or secondary infiltration of the prostate by a lymphoma are described. CASE REPORT: The case of a 59-year-old patient with an irregular tumor in the prostatic region, but normal prostate-specific antigen (PSA), a fracture in the vertebral column and a bilateral enlargement of the suprarenal glands is presented. Repetitive prostate biopsy revealed the diagnosis of a diffuse large B cell lymphoma. Further staging examinations gave hints to an epidural infiltration. A polychemotherapy including intrathecal drug applications was initiated. Staging after four therapeutic cycles already showed good partial remission of all lymphoma manifestations. After two further therapeutic cycles, a CT scan showed a small rest of prostatic bulk, but PET-CT did not detect vital lymphatic tissue (complete remission). CONCLUSION: In cases of irregular prostatic enlargements, carcinoma has to be considered as the most frequent diagnosis. Nevertheless, also a solitary lymphoma or infiltration of the prostate by a systemic lymphoma has to be taken into account, especially if the PSA value is in the normal range.

Distinct subcellular expression patterns of neutral endopeptidase (CD10) in prostate cancer predict diverging clinical courses in surgically treated patients

PURPOSE: Neutral endopeptidase (CD10), an ectopeptidase bound to the cell surface, is thought to be a potential prognostic marker for prostate cancer. EXPERIMENTAL DESIGN: Prostate cancer patients (N = 3,261) treated by radical prostatectomy at a single institution were evaluated by using tissue microarray. Follow-up data were available for 2,385 patients. The cellular domain (membranous, membranous-cytoplasmatic, and cytoplasmatic only) of CD10 expression was analyzed immunohistochemically and correlated with various clinical and histopathologic features of the tumors. RESULTS: CD10 expression was detected in 62.2% of cancer samples and occurred preferentially in higher Gleason pattern (P < 0.0001). CD10 expression positively correlated with adverse tumor features such as elevated preoperative prostate-specific antigen (PSA), higher Gleason score, and advanced stage (P < 0.0001 each). Survival analyses showed that PSA recurrence was significantly associated with the staining pattern of CD10 expression. Outcome significantly declined from negative over membranous, membranous-cytoplasmatic, to exclusively cytoplasmatic CD10 expression (P < 0.0001). In multivariate analysis, CD10 expression was an independent predictor for PSA failure (P = 0.0343). CONCLUSIONS: CD10 expression is an unfavorable independent risk factor in prostate cancer. The subcellular location of CD10 protein is associated with specific clinical courses, suggesting an effect on different important biological properties of prostate cancer cells. The frequent expression of CD10 in prostate cancer and the strong association of CD10 with unfavorable tumor features may qualify this biomarker for targeted therapies.

Acute and late toxicity in prostate cancer patients treated by dose escalated intensity modulated radiation therapy and organ tracking

BACKGROUND: To report acute and late toxicity in prostate cancer patients treated by dose escalated intensity-modulated radiation therapy (IMRT) and organ tracking. METHODS: From 06/2004 to 12/2005 39 men were treated by 80 Gy IMRT along with organ tracking. Median age was 69 years, risk of recurrence was low 18%, intermediate 21% and high in 61% patients. Hormone therapy (HT) was received by 74% of patients. Toxicity was scored according to the CTC scale version 3.0. Median follow-up (FU) was 29 months. RESULTS: Acute and maximal late grade 2 gastrointestinal (GI) toxicity was 3% and 8%, late grade 2 GI toxicity dropped to 0% at the end of FU. No acute or late grade 3 GI toxicity was observed. Grade 2 and 3 pre-treatment genitourinary (GU) morbidity (PGUM) was 20% and 5%. Acute and maximal late grade 2 GU toxicity was 56% and 28% and late grade 2 GU toxicity decreased to 15% of patients at the end of FU. Acute and maximal late grade 3 GU toxicity was 8% and 3%, respectively. Decreased late > or = grade 2 GU toxicity free survival was associated with higher age (P = .025), absence of HT (P = .016) and higher PGUM (P < .001). DISCUSSION: GI toxicity rates after IMRT and organ tracking are excellent, GU toxicity rates are strongly related to PGUM.

Post-translational tyrosine nitration of eosinophil granule toxins mediated by eosinophil peroxidase

Nitration of tyrosine residues has been observed during various acute and chronic inflammatory diseases. However, the mechanism of tyrosine nitration and the nature of the proteins that become tyrosine nitrated during inflammation remain unclear. Here we show that eosinophils but not other cell types including neutrophils contain nitrotyrosine-positive proteins in specific granules. Furthermore, we demonstrate that the human eosinophil toxins, eosinophil peroxidase (EPO), major basic protein, eosinophil-derived neurotoxin (EDN) and eosinophil cationic protein (ECP), and the respective murine toxins, are post-translationally modified by nitration at tyrosine residues during cell maturation. High resolution affinity-mass spectrometry identified specific single nitration sites at Tyr349 in EPO and Tyr33 in both ECP and EDN. ECP and EDN crystal structures revealed and EPO structure modeling suggested that the nitrated tyrosine residues in the toxins are surface exposed. Studies in EPO(-/-), gp91phox(-/-), and NOS(-/-) mice revealed that tyrosine nitration of these toxins is mediated by EPO in the presence of hydrogen peroxide and minute amounts of NOx. Tyrosine nitration of eosinophil granule toxins occurs during maturation of eosinophils, independent of inflammation. These results provide evidence that post-translational tyrosine nitration is unique to eosinophils.

Androgen deprivation therapy for the treatment of prostate cancer: consider both benefits and risks

CONTEXT: Androgen deprivation therapy (ADT) is increasingly used for the treatment of prostate cancer (PCa), even in clinical settings in which there is no evidence-based proof of prolonged overall survival (OS). ADT, however, may be associated with numerous side effects, including an increased therapy-related cardiovascular mortality. OBJECTIVE: To discuss different clinical settings in which ADT is currently used and to critically weigh the benefits of ADT against its possible side effects. EVIDENCE ACQUISITION: A MEDLINE search was conducted to identify original articles and review articles addressing the efficacy and side effects of ADT for the treatment of PCa. Keywords consisted of prostate cancer, hormonal therapy, adverse effects, radical prostatectomy, and radiotherapy. The articles with the highest level of evidence for the various examined end points were identified with the consensus of all authors and were reviewed. EVIDENCE SYNTHESIS: Even short-term use of ADT may lead to numerous side effects, such as osteoporosis, obesity, sarcopenia, lipid alterations, insulin resistance, and increased risk for diabetes and cardiovascular morbidity. Despite these side effects, ADT is commonly used in various clinical settings in which a clear effect on improved OS has not been shown. CONCLUSIONS: ADT is associated with an increased risk of multiple side effects that may reduce quality of life and/or OS. Consequently, these issues should be discussed in detail with patients and their families before initiation of ADT. ADT should be used with knowledge of its potential long-term side effects and with possible lifestyle interventions, especially in settings with the highest risk-benefit ratio, to alleviate comorbidities.