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Transcription factor (TF) DNA-binding dynamics govern cell fate and identity. However, our ability to pharmacologically control TF localization is limited. Here we leverage chemically driven binding site restriction leading to robust and DNA-sequence-specific redistribution of PU.1, a pioneer TF pertinent to many hematopoietic malignancies. Through an innovative technique, 'CLICK-on-CUT&Tag', we characterize the hierarchy of de novo PU.1 motifs, predicting occupancy in the PU.1 cistrome under binding site restriction. Temporal and single-molecule studies of binding site restriction uncover the pioneering dynamics of native PU.1 and identify the paradoxical activation of an alternate target gene set driven by PU.1 localization to second-tier binding sites. These transcriptional changes were corroborated by genetic blockade and site-specific reporter assays. Binding site restriction and subsequent PU.1 network rewiring causes primary human leukemia cells to differentiate. In summary, pharmacologically induced TF redistribution can be harnessed to govern TF localization, actuate alternate gene networks and direct cell fate., (© 2024. The Author(s).)

Nongenetic heterogeneity, or gene expression stochasticity, is an important source of variability in biological systems. With the advent and improvement of single molecule resolution technologies, it has been shown that transcription dynamics and resultant transcript number fluctuations generate significant cell-to-cell variability that has important biological effects and may contribute substantially to both tissue homeostasis and disease. In this respect, the pathophysiology of stem cell-derived malignancies such as acute myeloid leukemia and myelodysplastic syndromes, which has historically been studied at the ensemble level, may require reevaluation. To that end, it is our aim in this review to highlight the results of recent single-molecule, biophysical, and systems studies of gene expression dynamics, with the explicit purpose of demonstrating how the insights from these basic science studies may help inform and progress the field of leukemia biology and, ultimately, research into novel therapies., (© 2021 by The American Society of Hematology.)

MDMX is overexpressed in the vast majority of patients with acute myeloid leukemia (AML). We report that MDMX overexpression increases preleukemic stem cell (pre-LSC) number and competitive advantage. Utilizing five newly generated murine models, we found that MDMX overexpression triggers progression of multiple chronic/asymptomatic preleukemic conditions to overt AML. Transcriptomic and proteomic studies revealed that MDMX overexpression exerts this function, unexpectedly, through activation of Wnt/β-Catenin signaling in pre-LSCs. Mechanistically, MDMX binds CK1α and leads to accumulation of β-Catenin in a p53-independent manner. Wnt/β-Catenin inhibitors reverse MDMX-induced pre-LSC properties, and synergize with MDMX-p53 inhibitors. Wnt/β-Catenin signaling correlates with MDMX expression in patients with preleukemic myelodysplastic syndromes and is associated with increased risk of progression to AML. Our work identifies MDMX overexpression as a pervasive preleukemic-to-AML transition mechanism in different genetically driven disease subtypes, and reveals Wnt/β-Catenin as a non-canonical MDMX-driven pathway with therapeutic potential for progression prevention and cancer interception., Competing Interests: Declaration of interests L.A.C. is a past employee of Aileron Therapeutics. J.C. is currently an employee of Stelexis Therapeutics. ALRN-6924 was provided to U.S. from Aileron Therapeutics. U.S. has received research funding from GlaxoSmithKline, Bayer HealthCare, Aileron Therapeutics, and Novartis; has received compensation for consultancy services and for serving on scientific advisory boards from GlaxoSmithKline, Bayer Healthcare, Celgene, Aileron Therapeutics, Stelexis Therapeutics, and Pieris Pharmaceuticals; and has equity ownership in and is serving on the board of directors of Stelexis Therapeutics., (Copyright © 2021 Elsevier Inc. All rights reserved.)

Molecular noise is a natural phenomenon that is inherent to all biological systems 1,2 . How stochastic processes give rise to the robust outcomes that support tissue homeostasis remains unclear. Here we use single-molecule RNA fluorescent in situ hybridization (smFISH) on mouse stem cells derived from haematopoietic tissue to measure the transcription dynamics of three key genes that encode transcription factors: PU.1 (also known as Spi1), Gata1 and Gata2. We find that infrequent, stochastic bursts of transcription result in the co-expression of these antagonistic transcription factors in the majority of haematopoietic stem and progenitor cells. Moreover, by pairing smFISH with time-lapse microscopy and the analysis of pedigrees, we find that although individual stem-cell clones produce descendants that are in transcriptionally related states-akin to a transcriptional priming phenomenon-the underlying transition dynamics between states are best captured by stochastic and reversible models. As such, a stochastic process can produce cellular behaviours that may be incorrectly inferred to have arisen from deterministic dynamics. We propose a model whereby the intrinsic stochasticity of gene expression facilitates, rather than impedes, the concomitant maintenance of transcriptional plasticity and stem cell robustness.

Nearly 50% of mouse and human genomes are composed of repetitive sequences. Transcription of these sequences is tightly controlled during development to prevent genomic instability, inappropriate gene activation and other maladaptive processes. Here, we demonstrate an integral role for H1 linker histones in silencing repetitive elements in mouse embryonic stem cells. Strong H1 depletion causes a profound de-repression of several classes of repetitive sequences, including major satellite, LINE-1, and ERV. Activation of repetitive sequence transcription is accompanied by decreased H3K9 trimethylation of repetitive sequence chromatin. H1 linker histones interact directly with Suv39h1, Suv39h2, and SETDB1, the histone methyltransferases responsible for H3K9 trimethylation of chromatin within these regions, and stimulate their activity toward chromatin in vitro. However, we also implicate chromatin compaction mediated by H1 as an additional, dominant repressive mechanism for silencing of repetitive major satellite sequences. Our findings elucidate two distinct, H1-mediated pathways for silencing heterochromatin., Competing Interests: The authors declare no competing interest.

Pu.1 is an ETS family transcription factor (TF) that plays critical roles in erythroid progenitors by promoting proliferation and blocking terminal differentiation. However, the mechanisms controlling expression and down-regulation of Pu.1 during early erythropoiesis have not been defined. In this study, we identify the actions of Runx1 and Pu.1 itself at the Pu.1 gene Upstream Regulatory Element (URE) as major regulators of Pu.1 expression in Burst-Forming Unit erythrocytes (BFUe). During early erythropoiesis, Runx1 and Pu.1 levels decline, and chromatin accessibility at the URE is lost. Ectopic expression of Runx1 or Pu.1, both of which bind the URE, prevents Pu.1 down-regulation and blocks terminal erythroid differentiation, resulting in extensive ex vivo proliferation and immortalization of erythroid progenitors. Ectopic expression of Runx1 in BFUe lacking a URE fails to block terminal erythroid differentiation. Thus, Runx1, acting at the URE, and Pu.1 itself directly regulate Pu.1 levels in erythroid cells, and loss of both factors is critical for Pu.1 down-regulation during terminal differentiation. The molecular mechanism of URE inactivation in erythroid cells through loss of TF binding represents a distinct pattern of Pu.1 regulation from those described in other hematopoietic cell types such as T cells which down-regulate Pu.1 through active repression. The importance of down-regulation of Runx1 and Pu.1 in erythropoiesis is further supported by genome-wide analyses showing that their DNA-binding motifs are highly overrepresented in regions that lose chromatin accessibility during early erythroid development., Competing Interests: The authors declare no conflict of interest.

Tle/Groucho proteins are transcriptional corepressors interacting with Tcf/Lef and Runx transcription factors, but their physiological roles in T cell development remain unknown. Conditional targeting of Tle1, Tle3 and Tle4 revealed gene dose-dependent requirements for Tle proteins in CD8 + lineage cells. Upon ablating all three Tle proteins, generation of CD8 + T cells was greatly diminished, largely owing to redirection of MHC-I-selected thymocytes to CD4 + lineage; the remaining CD8-positive T cells showed aberrant up-regulation of CD4 + lineage-associated genes including Cd4 , Thpok , St8sia6 , and Foxp3 Mechanistically, Tle3 bound to Runx-occupied Thpok silencer, in post-selection double-positive thymocytes to prevent excessive ThPOK induction and in mature CD8 + T cells to silence Thpok expression. Tle3 also bound to Tcf1-occupied sites in a few CD4 + lineage-associated genes, including Cd4 silencer and St8sia6 introns, to repress their expression in mature CD8 + T cells. These findings indicate that Tle corepressors are differentially partitioned to Runx and Tcf/Lef complexes to instruct CD8 + lineage choice and cooperatively establish CD8 + T cell identity, respectively., (© 2018 Xing et al.)

The tumor suppressor p53 is often inactivated via its interaction with endogenous inhibitors mouse double minute 4 homolog (MDM4 or MDMX) or mouse double minute 2 homolog (MDM2), which are frequently overexpressed in patients with acute myeloid leukemia (AML) and other cancers. Pharmacological disruption of both of these interactions has long been sought after as an attractive strategy to fully restore p53-dependent tumor suppressor activity in cancers with wild-type p53. Selective targeting of this pathway has thus far been limited to MDM2-only small-molecule inhibitors, which lack affinity for MDMX. We demonstrate that dual MDMX/MDM2 inhibition with a stapled α-helical peptide (ALRN-6924), which has recently entered phase I clinical testing, produces marked antileukemic effects. ALRN-6924 robustly activates p53-dependent transcription at the single-cell and single-molecule levels and exhibits biochemical and molecular biological on-target activity in leukemia cells in vitro and in vivo. Dual MDMX/MDM2 inhibition by ALRN-6924 inhibits cellular proliferation by inducing cell cycle arrest and apoptosis in cell lines and primary AML patient cells, including leukemic stem cell-enriched populations, and disrupts functional clonogenic and serial replating capacity. Furthermore, ALRN-6924 markedly improves survival in AML xenograft models. Our study provides mechanistic insight to support further testing of ALRN-6924 as a therapeutic approach in AML and other cancers with wild-type p53., (Copyright © 2018 The Authors, some rights reserved; exclusive licensee American Association for the Advancement of Science. No claim to original U.S. Government Works.)

Acute megakaryoblastic leukemia (AMKL) is a heterogeneous disease with a relatively poorly understood pathogenesis. In this issue of Cancer Cell, Thirant and colleagues systematically examine unique transcriptional and functional effects of ETO2-GLIS2, an oncogenic fusion protein frequently encountered in AMKL, and elucidate a therapeutic vulnerability in this poor-prognosis leukemia., (Copyright © 2017 Elsevier Inc. All rights reserved.)

In recent years, advances in next-generation sequencing (NGS) technology have provided the opportunity to detect putative genetic drivers of disease, particularly cancers, with very high sensitivity. This knowledge has substantially improved our understanding of tumor pathogenesis. In hematological malignancies such as acute myeloid leukemia and myelodysplastic syndromes, pioneering work combining multi-parameter flow cytometry and targeted resequencing in leukemia have clearly shown that different classes of mutations appear to be acquired in particular sequences along the hematopoietic differentiation hierarchy. Moreover, as these mutations can be found in "normal" cells recovered during remission and can be detected at relapse, there is strong evidence for the existence of "pre-leukemic" stem cells (pre-LSC). These cells, while phenotypically normal by flow cytometry, morphology, and functional studies, are speculated to be molecularly poised to transform owing to a limited number of predisposing mutations. Identifying these "pre-leukemic" mutations and how they propagate a pre-malignant state has important implications for understanding the etiology of these disorders and for the development of novel therapeutics. NGS studies have found a substantial enrichment for mutations in epigenetic/chromatin remodeling regulators in pre-LSC, and elegant genetic models have confirmed that these mutations can predispose to a variety of hematological malignancies. In this review, we will discuss the current understanding of pre-leukemic biology in myeloid malignancies, and how mutations in two key epigenetic regulators, DNMT3A and TET2, may contribute to disease pathogenesis.

Introduction: We evaluated renal function following partial nephrectomy with cold ischemia (CI) versus warm ischemia (WI)., Methods: Data were collected from 1,396 patients at six institutions who underwent partial nephrectomy for a renal mass with normal contralateral kidney to evaluate percent change in glomerular filtration rate (GFR) at 3-18 months. A multivariate linear regression model tested the association of percent change GFR with clinical, operative, and pathologic factors., Results: A total of 874 patients (63 %) underwent PN with CI and 522 (37 %) with WI. All patients undergoing laparoscopic and robotic-assisted partial nephrectomy (n = 443) had WI, whereas 92 % of open partial nephrectomy patients (n = 953) had CI. The CI group had a lower mean baseline GFR (72 vs. 80 ml/min/1.73 m(2)), longer median ischemia time (33 vs. 29 min), and larger mean tumor size (3.2 vs. 2.9 cm) with more advanced pathologic stage (T1b-T3: 25 vs. 16 %) (all p values <0.001). Patients with CI and WI demonstrated 12.3 and 10.1 % reductions in renal function from baseline, respectively (p = 0.067). Increasing age, female gender, and increasing tumor size were associated with reduction in renal function (all p values <0.001). Neither renal hypothermia nor operative technique independently predicted reduced renal function. Sensitivity analyses limited to ischemia time >30 min, baseline estimated glomerular filtration rate <60 ml/min/1.73 m(2), or tumors >4 cm did not significantly alter the findings., Conclusions: Increasing age, female gender, and larger tumor size independently predict a decrease in renal function following partial nephrectomy with a normal contralateral kidney. Within the limitations of a non-randomized comparison, including lack of parenchymal preservation percentage, neither surgical approach (open or laparoscopic) nor presence of hypothermia appears to be associated with long-term renal function.

Hematopoiesis is a complex process that relies on various cell types, signaling pathways, transcription factors and a specific niche. The integration of these various components is of critical importance to normal blood development, as deregulation of these may lead to bone marrow failure or malignancy. Tle4, a transcriptional corepressor, acts as a tumor suppressor gene in a subset of acute myeloid leukemia, yet little is known about its function in normal and malignant hematopoiesis or in mammalian development. We report here that Tle4 knockout mice are runted and die at around four weeks with defects in bone development and BM aplasia. By two weeks of age, Tle4 knockout mice exhibit leukocytopenia, B cell lymphopenia, and significant reductions in hematopoietic stem and progenitor cells. Tle4 deficient hematopoietic stem cells are intrinsically defective in B lymphopoiesis and exhaust upon stress, such as serial transplantation. In the absence of Tle4 there is a profound decrease in bone mineralization. In addition, Tle4 knockout stromal cells are defective at maintaining wild-type hematopoietic stem cell function in vitro. In summary, we illustrate a novel and essential role for Tle4 in the extrinsic and intrinsic regulation of hematopoiesis and in bone development.

Objectives: We report our experience with laparoscopic partial nephrectomy (LPN) to identify preoperative factors associated with an increased risk of postoperative complications., Materials and Methods: Among patients undergoing LPN, we analyzed demographic and preoperative tumor characteristics as the exposure variables and postoperative complications as the outcomes. Multivariable logistic regression modeling identified variables associated with increased risk of complications., Results: Of 336 consecutive patients undergoing LPN, 120 (35.7%) had a complication, including 22 (6.6%) with major complications, 12 (3.6%) developing urine leak, 29 (8.6%) requiring blood transfusion, and 11 (3.3%) undergoing nephrectomy. There were no perioperative deaths. On univariable analysis, larger tumor diameter increased the odds of any complication (odds ratio [OR] 2.3, P = 0.007), hemorrhage (OR 1.4, P = 0.007), and urine leak (OR 1.7, P = 0.001). Each 1 cm increase in tumor diameter was associated with a 33% increased odds of a major complication (P = 0.04). In a multivariable model, changes in tumor diameter increased the odds of any complication (OR 2.4, P = 0.006) and hemorrhage (OR 1.5, P = 0.01); tumor depth was a better predictor of a major complication (OR 1.1, P = 0.004). In the multivariable model, advanced age also was associated with hemorrhage (OR 2.6, P = 0.05)., Conclusions: Tumor diameter, depth of tumor penetration, and advanced patient age are associated with increased odds of complications in patients undergoing LPN. This information is important for counseling patients preoperatively regarding their risk of complications following LPN and in selecting the appropriate intervention for a particular tumor., (Copyright © 2013 Elsevier Inc. All rights reserved.)

Purpose: We performed a multi-institutional retrospective cohort study to evaluate baseline renal function of patients who underwent partial nephrectomy for renal tumors, and determined rates of progression to higher stages of chronic kidney disease., Materials and Methods: The Modification of Diet in Renal Disease study equation was used to estimate glomerular filtration rate. Preoperative and postoperative serum creatinine values were obtained from patients who underwent partial nephrectomy at 6 institutions with a normal contralateral kidney, and had baseline chronic kidney disease stage I (estimated glomerular filtration rate greater than 90 ml/minute/1.73 m(2)), II (estimated glomerular filtration rate 60 to 89 ml/minute/1.73 m(2)) or III (estimated glomerular filtration rate 30 to 59 ml/minute/1.73 m(2)). The end point was change in chronic kidney disease stage at long-term followup (3 to 18 months). Multivariate logistic and Cox regression models tested the association of newly acquired chronic kidney disease stage III or greater with pertinent demographic, tumor and surgical factors., Results: For 1,228 patients with followup creatinine data at least 3 months after partial nephrectomy median baseline glomerular filtration rate was 74 ml/minute/1.73 m(2). At baseline 19%, 59% and 22% of patients had chronic kidney disease stage I, II and III, respectively. At long-term followup for patients with baseline chronic kidney disease stage I or II median postoperative glomerular filtration rate was 67 ml/minute/1.73 m(2) with 29% having progression to chronic kidney disease stage III or greater. Increasing age, female gender, increasing tumor size, clamping of the renal artery and vein, and lower preoperative estimated glomerular filtration rate were independently associated with newly acquired chronic kidney disease stage III or greater. The presence of comorbid conditions such as coronary artery disease, diabetes mellitus or hypertension did not independently predict an increased risk of higher chronic kidney disease stage., Conclusions: Chronic kidney disease stage III or greater will develop postoperatively in approximately a third of patients with an estimated glomerular filtration rate greater than 60 ml/minute/1.73 m(2), and this progression is associated with definable demographic, tumor and surgical factors., (Copyright © 2011 American Urological Association Education and Research, Inc. Published by Elsevier Inc. All rights reserved.)

Purpose: A novel equation, the Chronic Kidney Disease Epidemiology Collaboration, has been proposed to replace the Modification of Diet in Renal Disease for estimated glomerular filtration rate due to higher accuracy, particularly in the setting of normal renal function. We compared these equations in patients with 2 functioning kidneys undergoing partial nephrectomy., Materials and Methods: We assembled a cohort of 1,158 patients from 5 institutions who underwent partial nephrectomy between 1991 and 2009. Only subjects with 2 functioning kidneys were included in the study. The end points were baseline estimated glomerular filtration rate, last followup estimated glomerular filtration rate (3 to 18 months), absolute and percent change estimated glomerular filtration rate ([absolute change/baseline] × 100%), and proportion of newly developed chronic kidney disease stage III. The agreement between the equations was evaluated using Bland-Altman plots and the McNemar test for paired observations., Results: Mean baseline estimated glomerular filtration rate derived from the Modification of Diet in Renal Disease and Chronic Kidney Disease Epidemiology Collaboration equations were 73 and 77 ml/minute/1.73 m(2), respectively, and following surgery were 63 and 67 ml/minute/1.73 m(2), respectively. Mean percent change estimated glomerular filtration rate was -12% for both equations (p = 0.2). The proportion of patients with newly developed chronic kidney disease stage III following surgery was 32% and 25%, according to the Modification of Diet in Renal Disease and Chronic Kidney Disease Epidemiology Collaboration equations, respectively (p = 0.001)., Conclusions: For patients with 2 functioning kidneys undergoing partial nephrectomy the Chronic Kidney Disease Epidemiology Collaboration equation provides slightly higher glomerular filtration rate estimates compared to the Modification of Diet in Renal Disease equation, with 7% fewer patients categorized as having chronic kidney disease stage III or worse., (Copyright © 2010 American Urological Association Education and Research, Inc. Published by Elsevier Inc. All rights reserved.)

Introduction: Histotripsy is an extracorporeal focused ultrasound (US) technology that uses controlled cavitation to induce nonthermal mechanical tissue fractionation. Feasibility of histotripsy ablation of normal renal tissue in an in vivo rabbit model has previously been demonstrated. Our specific objective in this study was to characterize the histologic effects of histotripsy on VX-2 tumor implanted in the kidneys of an in vivo rabbit model., Methods: VX-2 tumor was implanted below the renal capsule in 15 New Zealand white rabbits. Two weeks after implantation, tumors were localized with diagnostic US imaging. Targeted volumes within the observed tumor were treated with short (3 micros) pulses of 1 MHz acoustic energy at a repetition frequency of 300 Hz. Twenty tumors were treated with histotripsy and 7 served as tumor controls. Three normal kidneys were also treated with histotripsy. Kidneys and lungs were harvested, grossly inspected, and processed for histopathologic analysis., Results: Real-time US imaging confirmed presence of cavitation during all histotripsy treatments. Examination of tumor and kidney specimens revealed 100% tumor growth with an average tumor diameter of 7 mm (range 2-12). In 16 of 20 tumors treated with histotripsy, acellular zones of debris and finely disrupted cellular architecture were present on histology. Kidneys harvested 24 hours after treatment revealed an extensive inflammatory reaction., Conclusions: Transcutaneous application of histotripsy to implanted VX-2 tumor in rabbit kidney produced fractionation of malignant tissue. These findings support the further study and development of histotripsy for potential oncologic application.

Objective: To assess the impact of patient age on outcomes after radical nephroureterectomy (RNU) for upper tract urothelial carcinoma (UTUC)., Patients and Methods: Data were collected on 1453 patients treated with RNU at 13 centres. Pathological slides were reviewed by dedicated genitourinary pathologists according to standardized criteria. Age at RNU was analysed both as a continuous and categorical variable (<50, n = 85; 50-59.9, n = 229; 60-69.9, n = 416; 70-79.9, n = 523; > or =80 years, n = 200). RESULTS Patients aged <50 years were less likely to have undergone previous ureteroscopy and to have a history of bladder cancer (P < or = 0.026). Advanced age was associated with infiltrative architecture and female gender (P < or = 0.003). Patients aged >70 years were less likely to undergo lymphadenectomy and to receive adjuvant chemotherapy (P < or = 0.026). In multivariable analyses, being older was associated with decreased all-cause (AC) survival (>60 years) and cancer-specific survival (CSS; >80 years) after controlling for the effects of standard pathological features (P < or = 0.006). However, addition of age did not improve the predictive accuracy of a base model that included standard pathological features for prediction of either disease recurrence, AC survival or CSS., Conclusions: Being older at the time of RNU was associated with decreased survival. This finding could be due to a change in the biological potential of the tumour cell, a decrease in the host's defence mechanisms, or differences in care patterns. Further work is needed to improve our understanding of UTUC outcomes in this growing segment of the population and to develop strategies to improve cancer control in the elderly.

Purpose: We assessed the influence of renal ischemia on long-term global renal function after laparoscopic partial nephrectomy in patients with 2 functioning kidneys in a large, multicenter cohort., Materials and Methods: Collected data included demographic, clinical and surgical characteristics, tumor parameters and renal function outcomes at 4 institutions in a total of 401 patients with 2 functioning kidneys who underwent laparoscopic partial nephrectomy. Renal function was assessed in the immediate postoperative period (days 1 to 3) and at last followup (greater than 1 month) using the estimated glomerular filtration rate calculated by the 4-variable Modification of Diet in Renal Disease equation. Ischemia time and covariates were modeled on the percent change in the estimated glomerular filtration rate using linear regression., Results: Median ischemia time was 29 minutes (IQR 22, 34). The postoperative change and the last (long-term) change in the estimated glomerular filtration rate were -16% and -11%, respectively. Median time to the last estimated glomerular filtration rate measurement was 13 months (IQR 6, 24). On multivariate analysis shorter ischemia and operative times, external or ureteral irrigation with cold saline and female gender were associated with less postoperative percent change in the estimated glomerular filtration rate. Smaller tumor size and absent diabetes were associated with less of a final percent change in the estimated glomerular filtration rate. Ischemia time was not associated with a percent change in the estimated glomerular filtration rate at last followup., Conclusions: Within the range of times in these series renal ischemia did not have a clinically significant impact on global renal function in patients with 2 functioning kidneys who underwent laparoscopic partial nephrectomy, as measured by the estimated glomerular filtration rate., (2010 American Urological Association Education and Research, Inc. Published by Elsevier Inc. All rights reserved.)

Background: Prognostic factors after radical nephroureterectomy (RNU) for upper tract urothelial carcinoma (UTUC) are inconclusive, because most data in the literature have been obtained from small series., Objective: To assess the association of tumour necrosis with cancer recurrence and survival in a large international series of patients treated with RNU., Design, Setting, and Participants: Data were collected from 1425 patients treated with RNU at 13 centres and combined into a relational database. Pathologic slides were re-reviewed by genitourinary pathologists according to strict criteria. Extensive tumour necrosis was scored as >10% of the tumour area., Intervention: Patients underwent either open or laparoscopic RNU. Lymph node dissection was performed in the presence of enlarged nodes., Measurements: Recurrence was defined as tumour relapse in the operative field, lymph node (LN) metastasis, and/or distant metastases. Bladder recurrences were not considered. Associations of extensive tumour necrosis with recurrence-free survival and cancer-specific survival were evaluated by univariate and multivariate analyses., Results and Limitations: Extensive tumour necrosis was observed in 364 patients (25.5%) and was associated with advanced tumour stage, high tumour grade, sessile architecture, lymphovascular invasion (LVI), concomitant carcinoma in situ, and LN metastasis (p<0.0001 each). Extensive tumour necrosis was independently associated with disease recurrence and survival (p=0.037 and p=0.046, respectively) after adjusting for the effects of pathologic stage, grade, LVI, and LN status. The addition of extensive tumour necrosis to a base model comprising standard pathologic predictors marginally improved its predictive accuracy for both cancer-specific recurrence (1.5%) and survival (1.4%)., Conclusions: Extensive tumour necrosis is an independent predictor of clinical outcomes in patients who undergo RNU for UTUC. Assessment of tumour necrosis may help to identify patients who could benefit from multimodal therapy after RNU in the future. Evaluation of extensive tumour necrosis should be part of standard pathologic reporting., (Copyright © 2009 European Association of Urology. Published by Elsevier B.V. All rights reserved.)

Objectives: To further explore the phenomenon of minimal bleeding after histotripsy by performing extensive prostate histotripsy treatments in anticoagulated canines. Histotripsy is a noninvasive ultrasound technology which induces microbubble formation (cavitation) within tissues producing mechanical tissue fractionation. During initial in vivo feasibility canine studies of prostate ablation, minimal hematuria was observed., Methods: Histotripsy was performed on 9 canine subjects pretreated with 6 mg of oral warfarin for 3-5 days using an extracorporeal 750 kHz therapeutic ultrasound transducer delivering acoustic pulses to the prostatic urethra and periurethral parenchyma. After 7-28 days, the subjects were euthanized, transrectal prostate ultrasound was performed, and the prostate was harvested. Serum hemoglobin and International Normalization Ratio were measured immediately before histotripsy treatment and at euthanasia., Results: Mean treatment International Normalization Ratio was 4.6 (median, 2.4; range, 1.2-11.3). There was no clinically significant change in hemoglobin concentration at euthanasia compared with baseline. At harvest, histologic sections of the prostate revealed a large cavity corresponding to the planned treatment volume incorporating the prostatic urethra and parenchyma in all subjects. Urine was clear within 2 days of treatment, and no blood clots were seen., Conclusions: Despite therapeutic and supratherapeutic anticoagulation, histotripsy resulted in minimal bleeding despite significant fractionation and tissue debulking of the prostate. These results have prompted further studies to understand the mechanism of nonthermal hemostasis underlying histotripsy., (2010 Elsevier Inc. All rights reserved.)

Purpose: The Expanded Prostate Cancer Index Composite is a validated health related quality of life instrument that is commonly administered after prostate cancer treatment. We classified Expanded Prostate Cancer Index Composite-Short Form sexual summary scores into clinically meaningful groups., Materials and Methods: A development cohort of 561 patients undergoing radical prostatectomy was used to define sexual summary groups by correlation with their responses on the Sexual Health Inventory for Men. A separate validation cohort of 430 patients was used to compare Expanded Prostate Cancer Index Composite-Long Form sexual bother scores among these sexual summary groups., Results: A sexual summary group score of 0 to 33, 34 to 45, 46 to 60, 61 to 75 and greater than 75 correlated with Sexual Health Inventory for Men groups of severe--1 to 7, moderate--8 to 11, mild/moderate--12 to 16, mild--17 to 21 and no erectile dysfunction--22 to 25, respectively. In the validation group mean sexual bother scores in each of the 5 sexual summary groups were significantly different from each other after controlling for patient age, stage, hormone treatment, marital status and nerve sparing (p <0.0001)., Conclusions: Expanded Prostate Cancer Index Composite-Short Form sexual summary scores can be categorized into 5 groups for which excellent correlation is found with similar validated groups based on the Sexual Health Inventory for Men. Also, sexual bother scores are significantly different among the groups, showing that they represent discrete, clinically relevant cutoffs. This will help patients and physicians interpret Expanded Prostate Cancer Index Composite scores and help define potency for comparison among various prostate cancer treatments.

Objectives: To establish the safety and efficacy of planned multi-session retrograde endoscopic lithotripsy (REL) for the treatment of large renal calculi in the morbidly obese., Methods: We retrospectively reviewed charts of patients who underwent multi-session REL procedures from 2003 to 2008. Inclusion criteria included body mass index > 35, total linear stone diameter > 2.0 cm, and patients with a preoperative plan to perform multi-session ureteroscopy. A total of nine patients (six with staghorn calculi) underwent 21 separate procedures. Stone size was measured on preoperative imaging and was defined as length in greatest diameter. Stone free was defined as the complete absence of residual stone on postoperative imaging., Results: Mean body mass index of the patients was 47.8 kg/m2. Mean total linear stone diameter was 3.8 cm. Three of nine patients (33%) were stone free after their final treatment. Mean decrease in stone size from preoperative imaging was 3.3 cm (83%). There were no intraoperative complications. Mean length of follow up was 0.88 years., Conclusions: Multi-session REL is a safe alternative to percutaneous nephrolithotomy (PCNL) in obese patients with very large stones, including staghorn calculi. We recognize that the stone free rate in this series is lower than would be expected with REL for smaller stone burdens or with PCNL. Due to the limitations imposed by both the patient's general medical conditions as well as technical considerations, these patients are left with few options for treatment. Our experience is that management with staged ureteroscopy offers a reduction in stone burden and in some patients a stone free status that provides an acceptable patient outcome.

The use of bioadhesives, tissue sealants, and hemostatic agents has allowed for increased use of minimally invasive techniques for complex reconstructive urologic procedures. Hemostatic agents can facilitate clot formation through enzymatic reactions with host factors, mechanical compression, or a combination of the two. Tissue sealants and bioadhesives act through polymerization between themselves and adjacent tissues. This article reviews the unique features, mechanism of action, safety profile, and prototypical applications of the agents most commonly used in urologic surgery.

Dendritic cells hold promise as adjuvant for immunotherapy for cancer and infectious diseases. We demonstrate that a significant number of cryopreserved peripheral blood CD34(+) cells from HIV-infected subjects can be transduced with a replication-incompetent lentiviral vector expressing HIV antigens. In addition, untransduced and transduced CD34(+) cells from HIV-infected individuals were able to differentiate into dendritic cells with strong T-cell stimulatory capacity. Thus, cryopreserved CD34(+) cells from HIV-infected subjects may prove useful for immunotherapy for HIV/AIDS., (Copyright 2003 Wiley-Liss, Inc.)

Recent findings show that human immunodeficiency virus (HIV)-1 protease inhibitors designed to specifically inhibit the aspartic protease of HIV-1 nonetheless exert various effects on immune cell function in vitro and in vivo. Dendritic cells (DC), central players of the immune system, express several aspartic proteases that are important for DC function. In the present study, we demonstrate that all of the HIV-1 protease inhibitors tested affect DC maturation. In addition, saquinavir had a strong inhibitory effect on the T-cell stimulatory capacity of mature DC. In contrast, indinavir had only a slight effect on DC induced T-cell proliferation and allowed efficient transduction of DC with a replication-incompetent HIV-1 vector designed for DC-based immunotherapy. HIV-1 protease inhibitors that have little or no effect on DC function may be preferable for combination with immunotherapy for HIV/AIDS.