Effect of Reducing Field of View on Multidetector Quantitative Computed Tomography Parameters of Airway Wall Thickness in Asthma.

OBJECTIVE: We reduced the computed tomography (CT)-reconstructed field of view (FOV), increasing pixel density across airway structures and reducing partial volume effects, to determine whether this would improve accuracy of airway wall thickness quantification. METHODS: We performed CT imaging on a lung phantom and 29 participants. Images were reconstructed at 30-, 15-, and 10-cm FOV using a medium-smooth kernel. Cross-sectional airway dimensions were compared at each FOV with repeated-measures analysis of variance. RESULTS: Phantom measurements were more accurate when FOV decreased from 30 to 15 cm (P < 0.05). Decreasing FOV further to 10 cm did not significantly improve accuracy. Human airway measurements similarly decreased by decreasing FOV (P < 0.001). Percent changes in all measurements when reducing FOV from 30 to 15 cm were less than 3%. CONCLUSIONS: Airway measurements at 30-cm FOV are near the limits of CT resolution using a medium-smooth kernel. Reducing reconstructed FOV would minimally increase sensitivity to detect differences in airway dimensions.

Vena cava thrombectomy and primary repair after radical nephrectomy for renal cell carcinoma: single-center experience.

BACKGROUND: Inferior vena cava (IVC) reconstruction for locally advanced renal cell carcinoma (RCC) includes resection with and without interposition grafting, patch graft, or primary repair. The proposed benefits of lateral venorrhaphy and primary repair are avoidance of foreign material, a more expeditious repair, and preservation of lower extremity venous outflow. METHODS: A single-center retrospective review of 22 patients with RCC and IVC tumor thrombus treated with radical nephrectomy, lateral venorrhaphy, thrombectomy, and primary vena cava repair between July 2002 and June 2009 was carried out. Demographic data, diagnostic information, radiographic cross-sectional imaging, and procedural outcomes were examined. RESULTS: Among the 13 men and nine women, the mean age was 62.1 years (42-83); mean tumor size was 9.8 cm (3-17 cm), and 90% (n = 18) of the cases with RCC were identified pathologically as clear cell adenocarcinoma; on the basis of the classification system adopted by Neves, level I was for 50% (n = 11), level II for 32% (n = 7), level III for 9% (n = 2), and level IV for 9% (n = 2) of the patients. All patients underwent en bloc radical nephrectomy with tumor thrombus removal and primary IVC repair. Mean total operative time was 547.9 ± 138.5 minutes, whereas mean IVC cross-clamp time was 10.8 minutes (6-29 minutes). There were no intraoperative deaths or pulmonary embolism and all IVC margins were found to be pathologically negative. Postoperative complications included one pulmonary embolism, one exacerbation of chronic lymphedema, and two cases of new onset erectile dysfunction. Mean follow-up was 36.4 ± 23.2 months (6-92 months). There were no radiographic or clinically significant changes in mean IVC diameter during follow-up. Five late deaths (23%) occurred as a result of metastatic RCC over a mean period of 24 months (range, 12-48), but without any local recurrences. CONCLUSION: For advanced RCC with tumor thrombus extension into the IVC, lateral venorrhaphy and primary IVC repair avoids complicated caval reconstructions and results in high patency rates with a low local tumor recurrence rate.

Suppressive roles of calreticulin in prostate cancer growth and metastasis.

Calreticulin is an essential, multifunctional Ca(2+)-binding protein that participates in the regulation of intracellular Ca(2+) homeostasis, cell adhesion, and chaperoning. Calreticulin is abundantly expressed and regulated by androgens in prostate epithelial cells. Given the importance of both calreticulin in multiple essential cellular activities and androgens in prostate cancer, we investigated the possibility of a role for calreticulin in prostate cancer progression. Immunohistochemistry revealed the down-regulation of calreticulin in a subset of human prostate cancer specimens. Prostate cancer cells overexpressing exogenous calreticulin produced fewer colonies in both monolayer culture and soft agar. Furthermore, calreticulin overexpression also inhibited tumor growth in the orthotopic PC3 xenograft tumor model and macroscopic lung metastasis in the rat Dunning AT3.1 prostate tumor model. To address the potential mechanism of calreticulin suppression of prostate cancer, we generated calreticulin mutants with different functional domains deleted. The calreticulin mutants containing the P-domain, which binds to other endoplasmic reticulum chaperone proteins, were sufficient for the suppression of PC3 growth in colony formation assays. Overall, our data support the hypothesis that calreticulin inhibits growth and/or metastasis of prostate cancer cells and that this suppression requires the P-domain.

Nuclear factor-kappaB-mediated transforming growth factor-beta-induced expression of vimentin is an independent predictor of biochemical recurrence after radical prostatectomy.

PURPOSE: Transforming growth factor-beta (TGF-beta)-mediated epithelial-to-mesenchymal transition (EMT) has been shown to occur in some cancers; however, the pathway remains controversial and varies with different cancers. In addition, the mechanisms by which TGF-beta and the EMT contribute to prostate cancer recurrence are largely unknown. In this study, we elucidated TGF-beta-mediated EMT as a predictor of disease recurrence after therapy for prostate cancer, which has not been reported before. EXPERIMENTAL DESIGN: We analyzed TGF-beta-induced EMT using nuclear factor-kappaB (NF-kappaB) as an intermediate mediator in prostate cancer cell lines. A total of 287 radical prostatectomy specimens were evaluated using immunohistochemistry in a high-throughput tissue microarray analysis. Levels of TGF-beta signaling components and EMT-related factors were analyzed using specific antibodies. Results were expressed as the percentage of cancer cells that stained positive for a given antibody and were correlated with disease recurrence rates at a mean of 7 years following radical prostatectomy. RESULTS: In prostate cancer cell lines, TGF-beta-induced EMT was mediated by NF-kappaB signaling. Blockade of NF-kappaB or TGF-beta signaling resulted in abrogation of vimentin expression and inhibition of the invasive capability of these cells. There was high risk of biochemical recurrence associated with tumors that displayed high levels of expression of TGF-beta1, vimentin, and NF-kappaB and low level of cytokeratin 18. This was particularly true for vimentin, which is independent of patients' Gleason score. CONCLUSIONS: The detection of NF-kappaB-mediated TGF-beta-induced EMT in primary tumors predicts disease recurrence in prostate cancer patients following radical prostatectomy. The changes in TGF-beta signaling and EMT-related factors provide novel molecular markers that may predict prostate cancer outcomes following treatment.

[18F]fluorodeoxyglucose positron emission tomography for lung antiinflammatory response evaluation.

RATIONALE: Few noninvasive biomarkers for pulmonary inflammation are currently available that can assess the lung-specific response to antiinflammatory treatments. Positron emission tomography with [(18)F]fluorodeoxyglucose (FDG-PET) is a promising new method that can be used to quantify pulmonary neutrophilic inflammation. OBJECTIVES: To evaluate the ability of FDG-PET to measure the pulmonary antiinflammatory effects of hydroxymethylglutaryl-coenzyme A reductase inhibitors (statins) and recombinant human activated protein C (rhAPC) in a human model of experimentally-induced lung inflammation. METHODS: Eighteen healthy volunteers were randomized to receive placebo, lovastatin, or rhAPC before intrabronchial segmental endotoxin challenge. FDG-PET imaging was performed before and after endotoxin instillation. The rate of [(18)F]FDG uptake was calculated as the influx constant K(i) by Patlak graphical analysis. Bronchoalveolar lavage (BAL) was performed to determine leukocyte concentrations for correlation with the PET imaging results. MEASUREMENTS AND MAIN RESULTS: There was a statistically significant decrease in K(i) in the lovastatin-treated group that was not seen in the placebo-treated group, suggesting attenuation of inflammation by lovastatin treatment despite a small decrease in BAL total leukocyte and neutrophil counts that was not statistically significant. No significant decrease in K(i) was observed in the rhAPC-treated group, correlating with a lack of change in BAL parameters and indicating no significant antiinflammatory effect with rhAPC. CONCLUSIONS: FDG-PET imaging is a sensitive method for quantifying the lung-specific response to antiinflammatory therapies and may serve as an attractive platform for assessing the efficacy of novel antiinflammatory therapies at early phases in the drug development process. Clinical trial registered with www.clinicaltrials.gov (NCT00741013).

Suppression of prostate tumor growth by U19, a novel testosterone-regulated apoptosis inducer.

Androgens control prostate homeostasis and regulate androgen response genes. Here, we report the identification and characterization of U19, a novel testosterone-regulated apoptosis inducer with tumor suppressive activity. U19 is an evolutionarily conserved protein expressed in many human tissues, with the most abundant expression in the prostate, bone marrow, kidney, and lymph nodes. Overexpression of U19 in 12 surveyed cell lines induced apoptosis, and new protein synthesis is required for apoptosis induction. Expression of U19 in xenograft prostate tumors markedly induced apoptosis and inhibited tumor growth in vivo. Consistent with its tumor-suppressive role, U19 down-regulation was observed in all of the surveyed prostate cancer cell lines and in 19 of 23 clinical human prostate tumor specimens. Loss of heterozygosity analysis revealed U19 allelic loss in 19 of the 23 specimens. Furthermore, two of the specimens had homozygous U19 deletions, and one specimen had hypermethylated U19 promoter, indicating that U19 can be inactivated genetically or epigenetically. These observations suggest that U19 is growth inhibitory and tumor suppressive and that the disruption of androgen-dependent growth inhibition via U19 down-regulation is commonly associated with prostate cancer progression.

Fifteen-year experience with renal cell carcinoma with associated venous tumor thrombus.

BACKGROUND: For patients with renal cell carcinoma with venous tumor thrombus (VTT), the importance of the extent of the VTT on survival has inconsistent published results. The aim of the study was to evaluate the prognostic value of the VTT on morbidity and mortality of our patients with renal cell carcinoma. METHODS: This was a single institution review of all patients who underwent resection of renal cell carcinoma with VTT over a 15-year period. RESULTS: Thirty-seven patients (26 men, 11 women) with a mean age of 61 years were analyzed. The majority of the cohort were of Neves level II (n = 19), while 8 were of Neves 0 (only renal vein) or I, and 10 were of Neves III (extending into retrohepatic cava) or IV (extending supradiaphragmatically). When compared with Neves 0-II patients, there were more Neves III-IV patients with operative time >3 hours (70% vs 30%), blood loss >2,000 mL (70% vs 33%), and intensive care unit stay longer than one day (60% vs 30%) (P ≤ .05 each). Mean follow-up was 58 months. The overall 5-year survival was 71%, and all 10 patients with Neves III-IV had survived since the operation. CONCLUSION: We found advanced tumor thrombus involvement did not impact long-term survival; however, cases with suprahepatic VTT had increased operative time, blood loss, and duration of hospital stay.

Implications of therapy choice on overall survival in metastatic renal cell carcinoma: a single institution experience.

PURPOSE: To compare the effect of high-dose interleukin-2 (HD IL-2) vs other cytokine therapies on 1-, 2, and 5-yr overall survival in patients with metastatic renal cell cancer (RCC). PATIENTS AND METHODS: We conducted a retrospective chart review of patients with untreated metastatic RCC treated by a single investigator. The different treatment groups included HD IL-2, low-dose IL-2 alone or in combination, interferon alpha alone and other therapies. The primary end point was survival from time of treatment. RESULTS: A total of 85 patients were studies with a median follow up of 13 mo (0.6-112.9). Median age at treatment was 59 yr with predominantly male patients and histology of clear cell type. Thirty-four percent received HD IL-2 and treatment was initiated less than 6 mo from the time of diagnosis in 66%. For all patients, median survival was 16 mo with a 5-yr survival of 12%. Two factors were good predictors of overall survival: Karnofsky performance status (KPS) of 100 (p < 0.0001) and soft tissue metastasis (p = 0.01). When comparing HD IL-2 to all other groups, median survival was 18 vs 14 mo and 1-yr survival was 74% vs 51%, respectively. CONCLUSION: HD IL-2 is associated with clinically meaningful improvement in median and 1-yr survival.

Dual regulation of proliferation and growth arrest in prostatic stromal cells by transforming growth factor-beta1.

In a preliminary study, we observed that TGF-beta1 induced both proliferation and growth arrest in prostatic stromal cells, depending on the concentration of TGF-beta1 used in the culture medium. In this study, we explored possible mechanisms of this dual effect of TGF-beta. Primary cultures of prostatic stromal cells, established from clinical surgical specimens and treated with low doses of TGF-beta1 (0.001-0.01 ng/ml), resulted in an increase in cell proliferation. The addition of neutralizing antibody against platelet-derived growth factor (PDGF)-BB, but not anti-PDGF-AA, abrogated this stimulatory effect of TGF-beta1. TGF-beta1 treatment resulted in a dose-related increase in PDGF-BB production as measured by ELISA. Cells underwent growth arrest at high concentrations of TGF-beta1 (1.0 and 10 ng/ml). An inhibitor of cyclin-dependent kinase (cdk), p15INK4b, was up-regulated at both transcript and protein levels in these cultures by TGF-beta1 in a dose-related manner as determined by RT-PCR and Western blot analysis. The transcript, but not the protein, for another cdk inhibitor, p21Cip1, was up-regulated with treatment of TGF-beta1 to these cells. Levels of other cdk inhibitors, such as p16INK4a and p27Kip1, were constitutively expressed in prostatic stromal cells and were not significantly affected by TGF-beta1 treatment. Finally, the growth arrest effect of TGF-beta1 was abrogated when antisense oligonucleotides to p15INH4b, but not p21Cip1, were added to the culture medium. These data indicate that the dual effect of TGF-beta1 is mediated, at least, by up-regulation of PDGF-BB and p15INK4b, respectively.

Regional pulmonary perfusion in patients with acute pulmonary edema.

UNLABELLED: Redistribution of pulmonary blood flow (PBF) away from edematous regions of the lung is characteristic of experimental acute lung injury (ALI), helping to preserve ventilation-perfusion matching and gas exchange. The purpose of this study was to determine if such perfusion redistribution occurs in acute pulmonary edema in humans. METHODS: We measured the regional distribution of lung water concentration (LWC) and PBF with PET in 9 patients with ALI, 7 patients with non-ALI pulmonary edema, and 7 healthy subjects. RESULTS: The average patient chest radiographic score was 7.5 +/- 2.2 (scale: 0-12, where > or =4 met our criterion for pulmonary edema). The mean partial pressure of oxygen, arterial/fraction of inspired oxygen ratio (PaO(2)/FIO(2)) was 192 +/- 78. LWC was 35 +/- 4 mL H(2)O/100 mL lung versus 20 +/- 5 mL H(2)O/100 mL lung in the healthy subjects (P < 0.05). On average, the ventral-to-dorsal regional distribution of PBF was similar in patients with pulmonary edema and healthy subjects, regardless of the etiology of the pulmonary edema. However, LWC and an index of perfusion redistribution away from edematous lung regions, when combined, were a significant determinant of the PaO(2)/FIO(2) (coefficient of determination [R2] = 0.53; P = 0.03). CONCLUSION: These results suggest that hypoxic vasoconstriction is severely blunted in ALI. The perfusion redistribution that does exist contributes slightly to improved oxygenation during early pulmonary edema in humans.

Overexpression of adrenomedullin gene markedly inhibits proliferation of PC3 prostate cancer cells in vitro and in vivo.

The expression of the gene encoding adrenomedullin (AM), a multifunctional peptide hormone, in the prostate is localized to the epithelial cells. Prostate cancer cells are derived from prostatic epithelial cells. To elucidate the potential role of the AM gene in prostate cancer progression, we have stably-transfected the PC3 human prostate cancer cell line with an AM gene expression vector. The AM-transfected PC3 sublines were studied along with parental and empty vector transfected PC3 cells as controls. The average level of AM in the conditioned media of AM-transfected cells was 0.959+/-0.113 nM, a physiologically relevant concentration. The ectopic expression of AM gene inhibited the proliferation of PC3 cells in culture dishes. In addition, anchorage-independent growth of the transfected sublines was virtually abolished in soft agar assays. Flow cytometry studies showed that overexpression of AM gene caused a very significant G(1)/G(0) cell cycle arrest. In vivo experiments demonstrated that AM gene expression markedly inhibited the growth of xenograft tumors in nude mice. Our in vivo and in vitro studies suggest that AM could strongly suppress the malignancy of prostate cancer cells, via autocrine and/or paracrine mechanisms.

Vitamin D deficiency predicts prostate biopsy outcomes.

PURPOSE: The association between vitamin D and prostate biopsy outcomes has not been evaluated. We examine serum vitamin D levels with prostate biopsy results in men with an abnormal prostate-specific antigen and/or digital rectal examination. EXPERIMENTAL DESIGN: Serum 25-hydroxyvitamin D (25-OH D) was obtained from 667 men, ages 40 to 79 years, prospectively enrolled from Chicago urology clinics undergoing first prostate biopsy. Logistic regression was used to evaluate the associations between 25-OH D status and incident prostate cancer, Gleason score, and tumor stage. RESULTS: Among European American (EA) men, there was an association of 25-OH D <12 ng/mL with higher Gleason score ≥ 4+4 [OR, 3.66; 95% confidence interval (CI), 1.41-9.50; P = 0.008] and tumor stage [stage ≥ cT2b vs. ≤ cT2a, OR, 2.42 (1.14-5.10); P = 0.008]. In African American (AA) men, we find increased odds of prostate cancer diagnosis on biopsy with 25-OH D < 20 ng/mL [OR, 2.43 (1.20-4.94); P = 0.01]. AA men demonstrated an association between 25-OH D < 12 ng/mL and Gleason ≥ 4+4 [OR, 4.89 (1.59-15.07); P = 0.006]. There was an association with tumor stage ≥ cT2b vs. ≤ cT2a [OR, 4.22 (1.52-11.74); P = 0.003]. CONCLUSIONS: In AA men, vitamin D deficiency was associated with increased odds of prostate cancer diagnosis on biopsy. In both EA and AA men, severe deficiency was positively associated with higher Gleason grade and tumor stage.

Longitudinal changes in airway remodeling and air trapping in severe asthma.

RATIONALE AND OBJECTIVES: Previous cross-sectional studies have demonstrated that airway wall thickness and air trapping are greater in subjects with severe asthma than in those with mild-to-moderate asthma. However, a better understanding of how airway remodeling and lung density change over time is needed. This study aimed to evaluate predictors of airway wall remodeling and change in lung function and lung density over time in severe asthma. MATERIALS AND METHODS: Phenotypic characterization and quantitative multidetector-row computed tomography (MDCT) of the chest were performed at baseline and ∼2.6 years later in 38 participants with asthma (severe n = 24 and mild-to-moderate n = 14) and nine normal controls from the Severe Asthma Research Program. RESULTS: Subjects with severe asthma had a significant decline in postbronchodilator forced expiratory volume in 1 second percent (FEV1%) predicted over time (P < .001). Airway wall thickness measured by MDCT was increased at multiple airway generations in severe asthma compared to mild-to-moderate asthma (wall area percent [WA%]: P < .05) and normals (P < .05) at baseline and year 2. Over time, there was an increase in WA% and wall thickness percent (WT%) in all subjects (P = .030 and .009, respectively) with no change in emphysema-like lung or air trapping. Baseline prebronchodilator FEV1% inversely correlated with WA% and WT% (both P < .05). In a multivariable regression model, baseline WA%, race, and health care utilization were predictors of subsequent airway remodeling. CONCLUSIONS: Severe asthma subjects have a greater decline in lung function over time than normal subjects or those with mild-to-moderate asthma. MDCT provides a noninvasive measure of airway wall thickness that may predict subsequent airway remodeling.

Natural products and transforming growth factor-beta (TGF-ß) signaling in cancer development and progression.

Actions of many herbal medicine products for cancer treatment are linked to an altered production of TGF-ß in the target cells. An altered TGF-ß production in the target cells will have profound effects on the patients. Therefore, it is important that we review the pros and cons of these products on cancer development and progression in terms of TGF-ß signaling. It has been well established that TGF-ß is growth inhibitory to benign cells or early stages of cancer cells but it is tumor promoting and metastatic for advanced malignancies. Further, many dietary components can alter gene-specific DNA methylation levels in systemic and in target tissues. Since TGF-ß signaling in cancer is closely linked to the DNA methylation profiles, we also review the effect of dietary components on DNA methylation. In light of this knowledge, it is important to note that many natural products that can induce TGF-ß production in the target cells may be beneficial in preventing cancer development but may be harmful for cancer patients, especially when they harbor advanced stage cancer. A discussion of the effect of herbal natural products on cancer can be divided into three categories. The first category of herbal medicine products will be those related to the induction of cancer as far as TGF-ß is concerned. Since TGF-ß is growth inhibitory and pro-apoptosis to benign cells, any herbal medication that can induce the production of TGF-ß in the target cells will be beneficial to the patients. However, such herbal medicine may not necessarily be beneficial for patients with established and advanced cancer. The second category of herbal products will inhibit TGF-ß signaling and will reduce TGF-ß mediated growth promotion and metastasis in advanced cancers. For patients with established and advanced cancer, agents that can inhibit the production of TGF-ß may also inhibit cancer growth and metastasis. Finally, the third category of herbal products has no impact on TGF-ß signaling, such as lycopene.

TGF-ß regulates DNA methyltransferase expression in prostate cancer, correlates with aggressive capabilities, and predicts disease recurrence.

BACKGROUND: DNA methyltransferase (DNMT) is one of the major factors mediating the methylation of cancer related genes such as TGF-ß receptors (TßRs). This in turn may result in a loss of sensitivity to physiologic levels of TGF-ß in aggressive prostate cancer (CaP). The specific mechanisms of DNMT's role in CaP remain undetermined. In this study, we describe the mechanism of TGF-ß-mediated DNMT in CaP and its association with clinical outcomes following radical prostatectomy. METHODOLOGY/PRINCIPAL FINDINGS: We used human CaP cell lines with varying degrees of invasive capability to describe how TGF-ß mediates the expression of DNMT in CaP, and its effects on methylation status of TGF-ß receptors and the invasive capability of CaP in vitro and in vivo. Furthermore, we determined the association between DNMT expression and clinical outcome after radical prostatectomy. We found that more aggressive CaP cells had significantly higher TGF-ß levels, increased expression of DNMT, but reduced TßRs when compared to benign prostate cells and less aggressive prostate cancer cells. Blockade of TGF-ß signaling or ERK activation (p-ERK) was associated with a dramatic decrease in the expression of DNMT, which results in a coincident increase in the expression of TßRs. Blockade of either TGF-ß signaling or DNMT dramatically decreased the invasive capabilities of CaP. Inhibition of TGF-ß in an TRAMP-C2 CaP model in C57BL/6 mice using 1D11 was associated with downregulation of DNMTs and p-ERK and impairment in tumor growth. Finally, independent of Gleason grade, increased DNMT1 expression was associated with biochemical recurrence following surgical treatment for prostate cancer. CONCLUSIONS AND SIGNIFICANCE: Our findings demonstrate that CaP derived TGF-ß may induce the expression of DNMTs in CaP which is associated with methylation of its receptors and the aggressive potential of CaP. In addition, DNMTs is an independent predictor for disease recurrence after prostatectomy, and may have clinical implications for CaP prognostication and therapy.

A pilot study of denileukin diftitox (DD) in combination with high-dose interleukin-2 (IL-2) for patients with metastatic renal cell carcinoma (RCC).

High-dose (HD) IL-2 is approved to treat renal cell carcinoma (RCC) with modest response rates and significant toxicity. Enhancement of cytotoxic T-cell activity by IL-2 is 1 mechanism of action. IL-2 also stimulates regulatory T lymphocytes (Tregs), which are associated with poor prognosis. Favorable outcomes are associated with greater rebound absolute lymphocyte count (Fumagalli 2003). DD depletes IL-2 receptor (CD25 component) expressing cells. We hypothesized that sequential therapy could complement each other; DD would deplete Tregs so IL-2 could more effectively stimulate proliferation and activity of cytotoxic T lymphocytes. Patients (n=18) received standard HD IL-2 and 1 dose of DD daily for 3 days; periodic flow cytometry and complete blood counts were performed. Group A included 3 patients to assess safety only with DD 6 µg/kg between the IL-2 courses. Group B included 9 patients at 9 µg/kg DD before the IL-2 courses. Group C included 6 patients at 9 µg/kg DD between the IL-2 courses. Efficacy using the RECIST criteria was assessed after the treatment. Fifteen patients from a study of IL-2 without DD served as controls for toxicity comparison and 13 of these for flow cytometry comparisons. No unusual toxicity was noted. For group B/C patients receiving DD, the median decline in Tregs was 56.3% from pre-DD to post-DD (P=0.013). Peak absolute lymphocyte count change from baseline was +9980/µL for group B, +4470/µL for group C, and +4720/µL for the controls (P=0.005 B vs. C). The overall response rate was 5 of 15 (33%); 3 of 9 (33%) and 2 of 6 (33%) for groups B and C, respectively, including 2 patients with sarcomatoid RCC and 1 with earlier sunitinib therapy.

Overexpression of transforming growth factor ß1 in malignant prostate cells is partly caused by a runaway of TGF-ß1 auto-induction mediated through a defective recruitment of protein phosphatase 2A by TGF-ß type I receptor.

OBJECTIVES: To elucidate the mechanism of transforming growth factor (TGF)-ß1 overexpression in prostate cancer cells. METHODS: Malignant (PC3, DU145) and benign (RWPE1, BPH1) prostate epithelial cells were used. Phosphatase activity was measured using a commercial kit. Recruitment of the regulatory subunit, Bα, of protein phosphatase 2A (PP2A-Bα) by TGF-ß type I receptor (TßRI) was monitored by coimmunoprecipitation. Blockade of TGF-ß1 signaling in cells was accomplished either by using TGF-ß-neutralizing monoclonal antibody or by transduction of a dominant negative TGF-ß type II receptor retroviral vector. RESULTS: Basal levels of TGF-ß1 in malignant cells were significantly higher than those in benign cells. Blockade of TGF-ß signaling resulted in a significant decrease in TGF-ß1 expression in malignant cells, but not in benign cells. Upon TGF-ß1 treatment (10 ng/mL), TGF-ß1 expression was increased in malignant cells, but not in benign cells. This differential TGF-ß1 auto-induction between benign and malignant cells correlated with differential activation of extracellular signal-regulated kinase (ERK). Following TGF-ß1 treatment, the activity of serine/threonine phosphatase and recruitment of PP2A-Bα by TßRI increased in benign cells, but not in malignant cells. Inhibition of PP2A in benign cells resulted in an increase in ERK activation and in TGF-ß1 auto-induction after TGF-ß1 (10 ng/mL) treatment. CONCLUSIONS: These results suggest that TGF-ß1 overexpression in malignant cells is caused, at least in part, by a runaway of TGF-ß1 auto-induction through ERK activation because of a defective recruitment of PP2A-Bα by TßRI.

17Beta-estradiol at low concentrations acts through distinct pathways in normal versus benign prostatic hyperplasia-derived prostate stromal cells.

The aim of this study was to identify differential responses to low concentrations of 17beta-estradiol (E2) in primary stromal cell cultures derived from either normal organ donors or benign prostatic hyperplasia or hypertrophy (BPH) specimens. Furthermore, we sought to identify the potential mechanism of E2 action in these cell types, through either a genomic or nongenomic mechanism. We initially treated stromal cells derived from five normal prostates or five BPH specimens with low concentrations of E2 (0.001-1.0 nM) and analyzed their growth response. To determine whether genomic or nongenomic pathways were involved, we performed studies using specific estrogen receptor antagonists to confirm transcriptional activity or MAPK inhibitors to confirm the involvement of rapid signaling. Results of these studies revealed a fundamental difference in the mechanism of the response to E2. In normal cells, we found that a nongenomic, rapid E2 signaling pathway is predominantly involved, mediated by G protein-coupled receptor-30 and the subsequent activation of ERK1/2. In BPH-derived prostate stromal cells, a genomic pathway is predominantly involved because the addition of ICI 182780 was sufficient to abrogate any estrogenic effects. In conclusion, prostate stromal cells respond to far lower concentrations of E2 than previously recognized or examined, and this response is mediated through two distinct mechanisms, depending on its origin. This may provide the basis for new insights into the causes of, and possible treatments for, BPH.

Intra-operative pubic arch interference during prostate seed brachytherapy in patients with CT-based pubic arch interference of < or =1cm.

PURPOSE: There are only a few reports on the frequency of intra-operative pubic arch interference (I-PAI) during prostate seed brachytherapy (PB). MATERIALS AND METHODS: Two hundred and forty-three patients with a CT-based pubic arch interference (PAI) of < or =1 cm and a prostate volume of < or =50-60 cc underwent PB. Those patients requiring needle repositioning by > or =0.5 cm on the template were scored as having I-PAI. The incidence of I-PAI and its impact on biochemical control were analyzed. RESULTS: Intra-operative PAI was encountered in 47 (19.3%) patients. Forty two patients (17.3%) had I-PAI in 1-2 needles, two (0.8%) had I-PAI in four needles and three patients (1.2%) had I-PAI in six needles. Overall, 1.4% of needles required repositioning due to I-PAI. BMI>27 kg/m(2) and wider (>75 mm) pubic bone separation at mid ramus (PS-ML) were associated with a lower incidence of I-PAI. At a median follow-up of 50.1 months, the 3- and 5-year bPFS was 97.3% and 95.2%, respectively. The 5-year bPFS rates for patients with and without I-PAI were 95.6% and 95%, respectively (p=0.28). CONCLUSIONS: The use of CT-based PAI of < or =1cm as a selection criterion for PB is a simple and reliable method for minimizing the incidence of I-PAI and maintaining excellent biochemical control rates.

Topoisomerase II alpha expression in testicular germ cell tumors.

OBJECTIVES: Inhibitors of topoisomerase II alpha (TopoIIalpha), an enzyme with a crucial role in DNA maintenance, are included in the chemotherapy protocols for testicular germ cell tumors (GCTs). Despite the success of current chemotherapy regimens, a significant number of patients experience relapse. We analyzed TopoIIalpha expression in primary and metastatic testicular GCTs because this enzyme is a target for some antineoplastic agents. METHODS: Primary GCT specimens from 109 patients, including 57 seminomas and 52 mixed GCTs (41 embryonal carcinomas, 23 yolk sac tumors, 19 seminomas, 8 choriocarcinomas, 17 teratomas with immature elements, and 16 teratomas with mature elements), were obtained from our archives. The metastatic lesions from 11 of the patients with mixed GCTs included seven teratomas with mature components, five embryonal carcinomas, one yolk sac tumor, one choriocarcinoma, and one teratoma with immature components. Representative sections were subjected to immunohistochemistry with monoclonal antibody against TopoIIalpha, and the nuclear staining findings were evaluated. RESULTS: Most embryonal carcinoma (100%), yolk sac tumor (95%), seminoma (88%), and choriocarcinoma (62%) components of the GCTs were TopoIIalpha immunoreactive. None of the teratoma specimens with mature elements expressed TopoIIalpha. CONCLUSIONS: The results of our study have shown that TopoIIalpha is expressed in most seminomas, embryonal carcinomas, yolk sac tumors, and choriocarcinomas, suggesting a possible mechanism of sensitivity of these components to TopoIIalpha inhibitors. Teratomas with mature and immature elements expressed low levels of TopoIIalpha, which might contribute to their chemoresistance. These findings imply that the variable chemoresponsiveness of testicular GCTs could have an underlying molecular basis.