Effect of lipid-lowering medications in patients with coronary artery bypass grafting surgery outcomes.

BACKGROUND: Increased life expectancy and improved medical technology allow increasing numbers of elderly patients to undergo cardiac surgery. Elderly patients may be at greater risk of postoperative morbidity and mortality. Complications can lead to worsened quality of life, shortened life expectancy and higher healthcare costs. Reducing perioperative complications, especially severe adverse events, is key to improving outcomes in patients undergoing cardiac surgery. The objective of this study is to determine whether perioperative lipid-lowering medication use is associated with a reduced risk of complications and mortality after coronary artery bypass grafting (CABG) with cardiopulmonary bypass (CPB). METHODS: After IRB approval, we reviewed charts of 9,518 patients who underwent cardiac surgery with CPB at three medical centers between July 2001 and June 2015. The relationship between perioperative lipid-lowering treatment and postoperative outcome was investigated. 3,988 patients who underwent CABG met inclusion criteria and were analyzed. Patients were divided into lipid-lowering or non-lipid-lowering treatment groups. RESULTS: A total of 3,988 patients were included in the final analysis. Compared to the patients without lipid-lowering medications, the patients with lipid-lowering medications had lower postoperative neurologic complications and overall mortality (P < 0.05). Propensity weighted risk-adjustment showed that lipid-lowering medication reduced in-hospital total complications (odds ratio (OR) = 0.856; 95% CI 0.781-0.938; P < 0.001); all neurologic complications (OR = 0.572; 95% CI 0.441-0.739; P < 0.001) including stroke (OR = 0.481; 95% CI 0.349-0.654; P < 0.001); in-hospital mortality (OR = 0.616; 95% CI 0.432-0.869; P = 0.006; P < 0.001); and overall mortality (OR = 0.723; 95% CI 0.634-0.824; P < 0.001). In addition, the results indicated postoperative lipid-lowering medication use was associated with improved long-term survival in this patient population. CONCLUSIONS: Perioperative lipid-lowering medication use was associated with significantly reduced postoperative adverse events and improved overall outcome in elderly patients undergoing CABG surgery with CPB.

Dosimetry of a novel converging X-ray source for kilovoltage radiotherapy.

PURPOSE: The objective of this work was to evaluate phantom dosimetry of a novel kilovoltage (kV) X-ray source, which employs a stationary tungsten anode and a linearly swept scanning electron beam. The source utilizes converging X-ray collimation along with orthogonal mechanical rotation to distribute surface flux over large area. In this study, this was investigated as a potential solution to fast-falloff limitations expected with kV radiotherapy. This was done with the aim of future clinical development of a lower cost radiotherapy alternative to megavoltage (MV) linac systems. METHODS: Radiochromic film was employed for dosimetry on the kV X-ray source of the linear-converging radiotherapy system (LCRS). The source utilizes charge particle optics to magnetically deflect and focus an electron beam along a stationary, reflection tungsten target in an ultra-high-vacuum stainless-steel chamber. Resulting X-rays were collimated into converging beamlets that span a large planar angle and converge at the system isocenter. In this study, radiochromic film dosimetry was done at 140 and 145 kVp for a designated planning treatment volume (PTV) of 4 cm diameter. An acrylic phantom was employed for dose distribution measurements of stationary and rotational delivery. Film dosimetry was evaluated in planes parallel to the source X-ray window at various depths, as well as in the plane of gantry rotation. RESULTS: At 140 and 145 kVp and using a collimated 4 cm square field at depth, lesion-to-skin dose ratio was shown to improve with additional beams from different relative source positions, where the different beams are focused at the same isocenter and do not overlap at the phantom surface. It was only possible to achieve a 1:1 Dmax -to-surface ratio with four delivery beams, but the ratio improved to 4:1 with 12 beams, focused at the same isocenter depth of 7.8 cm in an acrylic phantom. For the tests conducted, the following Dmax -to-surface ratios were obtained: 0.4:1 lesion-to-skin ratio for stationary delivery from one entry beam, 0.71:1 lesion-to-skin ratio was obtained for two beams, 1.07:1 ratio for four beams, and 4:1 for 12 beams. Dose-depth profiles were evaluated for stationary and rotational dosimetry. Additionally, rotational dosimetry was measured for a case more analogous to a clinical scenario, where the isocenter was located at an off-center simulated lesion. CONCLUSIONS: The results demonstrate potential dose-depth improvements with kV arc therapy by distributing the surface flux with a wide converging beam along with perpendicular mechanical source rotation of the LCRS. The system delivered tolerable dose to a large surface area when a threshold of multiple, separated beams was reached. The radiochromic film data support the feasibility of the construct of the LCRS kV radiotherapy system design.

Cardiac surgeons' concerns, perceptions, and responses during the COVID-19 pandemic.

BACKGROUND: The coronavirus disease 2019 (COVID-19) pandemic has had an unprecedented impact on health care and cardiac surgery. We report cardiac surgeons' concerns, perceptions, and responses during the COVID-19 pandemic. METHODS: A detailed survey was sent to recruit participating adult cardiac surgery centers in North America. Data regarding cardiac surgeons' perceptions and changes in practice were analyzed. RESULTS: Our study comprises 67 institutions with diverse geographic distribution across North America. Nurses were most likely to be redeployed (88%), followed by advanced care practitioners (69%), trainees (28%), and surgeons (25%). Examining surgeon concerns in regard to COVID-19, they were most worried with exposing their family to COVID-19 (81%), followed by contracting COVID-19 (68%), running out of personal protective equipment (PPE) (28%), and hospital resources (28%). In terms of PPE conservation strategies among users of N95 respirators, nearly half were recycling via decontamination with ultraviolet light (49%), followed by sterilization with heat (13%) and at home or with other modalities (13%). Reuse of N95 respirators for 1 day (22%), 1 week (21%) or 1 month (6%) was reported. There were differences in adoption of methods to conserve N95 respirators based on institutional pandemic phase and COVID-19 burden, with higher COVID-19 burden institutions more likely to resort to PPE conservation strategies. CONCLUSIONS: The present study demonstrates the impact of COVID-19 on North American cardiac surgeons. Our study should stimulate further discussions to identify optimal solutions to improve workforce preparedness for subsequent surges, as well as facilitate the navigation of future healthcare crises.

Perioperative dexmedetomidine and 5-year survival in patients undergoing cardiac surgery.

BACKGROUND: Dexmedetomidine sedation has been associated with favourable outcomes after surgery. We aimed to assess whether perioperative dexmedetomidine use is associated with improved survival after cardiac surgery. METHODS: This retrospective cohort study included 2068 patients undergoing on-pump coronary artery bypass grafting and/or valve surgery. Among them, 1029 patients received dexmedetomidine, and 1039 patients did not. Intravenous dexmedetomidine infusion of 0.007 µg kg-1 min-1 was initiated before or immediately after cardiopulmonary bypass and lasted for < 24 h. The primary outcome was 5-year survival after cardiac surgery. The propensity scores matching (PSM), inverse probability of treatment weighting (IPTW), and overlap weighting approaches were used to minimise bias. Survival analyses were performed with Cox proportional-hazard models. RESULTS: The median age was 63 yr old and the male to female ratio was 71:29 in both groups. Baseline covariates were balanced between groups after adjustment using PSM, IPTW, or overlap weighting. Patients receiving dexmedetomidine in cardiac surgical procedures had higher survival during postoperative 5 yr in unadjusted analysis (hazard ratio [HR]=0.63; 95% confidence interval [CI], 0.51-0.78; P<0.001), and after adjustment with PSM (HR=0.63; 95% CI, 0.45-0.89; P=0.009), IPTW (HR=0.70; 95% CI, 0.51-0.95; P=0.023), or overlap weighting (HR=0.67; 95% CI, 0.51-0.89; P=0.006). The 5-yr mortality rate after cardiac surgery was 13% and 20% in the dexmedetomidine and non-dexmedetomidine groups, respectively (PSM adjusted odds ratio=0.61; 95% CI, 0.42-0.89; P=0.010). CONCLUSION: Perioperative dexmedetomidine infusion was associated with improved 5-yr survival in patients undergoing cardiac surgery.

Perioperative use of renin-angiotensin system inhibitors and outcomes in patients undergoing cardiac surgery.

It remains disputable about perioperative use of renin-angiotensin system inhibitors (RASi) and their outcome effects. This multicenter retrospective cohort study examines association between use of perioperative RASi and outcomes in patients undergoing coronary artery bypass graft and/or valve surgery. After the exclusion, the patients are divided into 2 groups with or without preoperative RASi (PreRASi, n = 8581), or 2 groups with or without postoperative RASi (PostRASi, n = 8130). With using of propensity scores matching to reduce treatment selection bias, the study shows that PreRASi is associated with a significant reduction in postoperative 30-day mortality compared with without one (3.41% vs. 5.02%); PostRASi is associated with reduced long-term mortality rate compared with without one (6.62% vs. 7.70% at 2-year; 17.09% vs. 19.95% at 6-year). The results suggest that perioperative use of RASi has a significant benefit for the postoperative and long-term survival among patients undergoing cardiac surgery.

Monte Carlo calculated kilovoltage x-ray arc therapy plans for three lung cancer patients.

Purpose: The intent of this work was to evaluate the ability of our 200 kV kilovoltage arc therapy (KVAT) system to treat realistic lung tumors without exceeding dose constraints to organs-at-risk (OAR).Methods and Materials: Monte Carlo (MC) methods and the McO optimization framework generated and inversely optimized KVAT treatment plans for 3 SABR lung cancer patients. The KVAT system was designed to treat deep-seated lesions with kilovoltage photons. KVAT delivers dose to roughly spherical PTVs and therefore non-spherical PTVs were divided into spherical sub-volumes. A prescription dose of 12 Gy/fx × 4 fractions was planned to 90% of the PTV volume. KVAT plans were compared to VMC++ calculated, 6 MV stereotactic ablative radiotherapy (SABR) treatment plans. Dose distributions, dose volume histograms, gradient index (GI), planned mean doses and plan treatment times were calculated. Dose constraints for organs-at-risk (OAR) were taken from RTOG 101.Results: All plans, with the exception of the rib dose calculated in one of the KVAT plans for a peripheral lesion, were within dose-constraints. In general, KVAT plans had higher planned doses to OARs. KVAT GI values were 5.7, 7.2 and 8.9 and SABR values were 4.6, 4.1, and 4.7 for patient 1, 2 and 3, respectively. KVAT plan treatment times were 49, 65 and 17 min for patients 1, 2 and 3, respectively.Conclusions: Inverse optimization and MC methods demonstrated the ability of KVAT to produce treatment plans without exceeding TG 101 dose constraints to OARs for 2 out of 3 investigated lung cancer patients.

Perioperative aspirin and long-term survival in patients undergoing coronary artery bypass graft.

This study aimed to examine association between perioperative uses of aspirin and long-term survival in patients undergoing CABG. A retrospective cohort study was performed in 9,584 consecutive patients receiving cardiac surgery from three tertiary hospitals. Of all the patients, 4,132 patients undergoing CABG met inclusion criteria and were divided into four groups: with or without preoperative or postoperative aspirin respectively. 30-day postoperative and long-term mortality were compared with the use of propensity scores and inverse probability weighting adjustment to reduce the treatment-selection bias. The patients taking preoperative aspirin presented significantly more with comorbidities. However, the results of this study showed that preoperative aspirin (vs. no preoperative aspirin) was associated with significantly reduced the risk of 30-day mortality in the patients undergoing CABG. Further, the results of long-term mortality showed that the patients taking preoperative aspirin and postoperative aspirin (vs. not taking) were associated with significantly reduced the risk of 4-year mortality (14.8% vs. 18.1%, RR: 0.82, 95% CI: 0.75-0.89, P = 0.005; 10.7% vs. 16.2%, RR: 0.66, 95% CI: 0.50-0.82, P = 0.003). In conclusion, this cohort study showed that perioperative (before and after surgery) use of aspirin was associated with significant reduction in 30-day mortality without significant bleeding complications, also improved long-term survival in patients undergoing CABG.

Robotic-assisted coronary artery bypass surgery: an 18-year single-centre experience.

BACKGROUND: Minimally invasive robot-assisted direct coronary artery bypass (RADCAB) has emerged as a feasible minimally invasive surgical technique for revascularization that might offer several potential advantages over conventional approaches. We present our 18-year experience in RADCAB. METHODS: Between February 1998 and February 2016, 605 patients underwent RADCAB. Patients underwent post-procedural selective graft patency assessment using cardiac catheterization. RESULTS: The mortality rate was 0.3%. The rate of conversion to sternotomy for any cause was reduced from 16.0% of the first 200 cases to 6.9% of the last 405 patients. The patency rate of the LITA-to-LAD anastomosis was 97.4%. Surgical re-exploration for bleeding occurred in 1.8% of patients, and the transfusion rate was 9.2%. Average ICU stay was 1.2 ± 1.4 days, and average hospital stay was 4.8 ± 2.9 days. CONCLUSIONS: Robot-assisted coronary artery bypass grafting is safe, feasible and it seems to represent an effective alternative to traditional coronary artery bypass grafting in selected patients.

The Effect of Dexmedetomidine on Outcomes of Cardiac Surgery in Elderly Patients.

OBJECTIVE: The goal of this retrospective study was to investigate the effects of perioperative use of dexmedetomidine (Dex) on outcomes for older patients undergoing cardiac surgery. DESIGN: Retrospective investigation. SETTING: Patients from a single tertiary medical center. PARTICIPANTS: A total of 505 patients (≥65 years old) who underwent coronary artery bypass graft (CABG) or valve surgery. CABG and/or valve surgery plus other procedures were divided into 2 groups: 283 received intravenous Dex infusion (Dex group) and 222 did not (Non-Dex group). INTERVENTIONS: Perioperative Dex intravenous infusion (0.24 to 0.6 µg/kg/h) initiated after cardiopulmonary bypass and continued for<24 hours postoperatively in the ICU. MEASUREMENTS AND MAIN RESULTS: Data were risk adjusted, propensity score weighted, and multivariate logistic regression was used. The primary outcome was mortality. Secondary outcomes included postoperative stroke, coma, myocardial infarction, heart block, cardiac arrest, delirium, renal failure, and sepsis. Perioperative Dex infusion significantly decreased in-hospital mortality (0.90% v 2.83%; adjusted odds ratio (OR), 0.099; 95% confidence interval (CI), 0.030-0.324; p = 0.004) and operative mortality (1.35% v 3.18%; adjusted OR, 0.251; 95% CI, 0.077-0.813; p = 0.021). Perioperative Dex treatment also reduced the risk of stroke (0.90% v 1.77%; adjusted OR, 0.15; 95% CI, 0.038-0.590; p = 0.007), and delirium (7.21% v 10.95%; adjusted OR, 0.35; 95% CI, 0.212-0.578; p < 0.0001). CONCLUSIONS: Results from this study (ClinicalTrials.gov identifier: NCT01683448) suggested perioperative use of dexmedetomidine was associated with decreases in in-hospital and operative mortality in elderly patients following cardiac surgery. It also reduced incidences of postoperative stroke and delirium in elderly patients.

Impact of Body Mass Index on Outcomes in Cardiac Surgery.

OBJECTIVES: Body mass index (BMI) commonly is used in obesity classification as a surrogate measure, and obesity is associated with a cluster of risk factors for cardiovascular disease. The aim of this study was to investigate the impact of BMI on short-term outcomes after cardiac surgery. DESIGN: A retrospective cohort study. SETTING: University teaching hospital, 2 centers. PARTICIPANTS: The study comprised 4,740 patients who underwent cardiac surgery at 2 hospitals-from July 1, 2001, to June 30, 2013, in 1 hospital and from September 1, 2003, to August 31, 2014, in a second hospital. INTERVENTIONS: No changes to standard practice were required. MEASUREMENTS AND MAIN RESULTS: Patients were assigned into 6 BMI groups as follows: underweight (BMI<18.5 kg/m(2)), normal weight (≥18.5 to<25 kg/m(2)), overweight (≥25 to<30 kg/m(2)), class I obese (≥30 to<35 kg/m(2)), class II obese (≥35 to<40 kg/m(2)), and class III obese (BMI≥40 kg/m(2)). Short-term major postoperative complications (postoperative stroke, cardiac arrest, new atrial fibrillation/flutter, permanent rhythm device insertion, deep sternal infection, sepsis, prolonged ventilation, pneumonia, renal dialysis, renal failure, intensive care unit readmission, total intensive care unit hours, and readmission in 30 days, and mortalities (in-hospital mortality, 30-day mortality, surgical mortality) were compared among various BMI groups after cardiac surgery. Age, sex, surgery type, family history of coronary artery disease, diabetes, hypertension, heart failure, and lipid-lowering medication were the risk factors for early outcomes. Multiple logistic regression analysis indicated that the underweight and class III obese BMI groups demonstrated significant, adverse differences in some short-term outcomes, including deep sternal infection, prolonged ventilation, new atrial fibrillation/flutter, and renal failure. However, being in the overweight or class I obese group demonstrated a positive effect on discharge and surgical mortality. CONCLUSIONS: The results of this study demonstrated that extreme obesity and underweight were significantly associated with early major adverse clinical outcomes. However, there was an "obese paradox" in short-term mortality after cardiac surgery.

Many young men with prostate-specific antigen (PSA) screen-detected prostate cancers may be candidates for active surveillance.

UNLABELLED: WHAT'S KNOWN ON THE SUBJECT? AND WHAT DOES THE STUDY ADD?: Little is known as to the potential for over-treatment of young men diagnosed with prostate cancer. We show that for men aged ≤55 years with PSA screen-detected disease, 45% of the tumours are classified as very low risk and 85% of these have favourable pathology, yet most are actively treated. These findings raise the spectre of over-treatment for a group of men likely to be affected by treatment side-effects. OBJECTIVE: To identify a population of young men (aged <55 years at diagnosis) with very-low-risk prostate cancer (stage cT1c, with prostate-specific antigen [PSA] density of <0.15 ng/mL/g, Gleason score ≤6, and ≤2 positive biopsy cores with <50% tumour involvement) that may be candidates for active surveillance (AS). PATIENTS AND METHODS: We queried a Department of Defense tumour registry and hard-copy records for servicemen diagnosed with prostate cancer from 1987 to 2010. Statistical analyses were undertaken using Fisher's exact and chi-square testing. RESULTS: From 1987-1991 and 2007-2010, PSA screen-detected tumours diagnosed in men aged ≤55 years rose >30-fold. Data for a subset of men (174) with PSA screen-detected cancer were evaluable for disease risk assessment. Of the 174 men with screen-detected disease, 81 (47%) had very-low-risk disease. Of that group, 96% (78/81) selected treatment and, of 57 men undergoing radical prostatectomy (RP), the tumours of 49 (86%) carried favourable pathology (organ confined, <10% gland involvement, Gleason ≤6). CONCLUSIONS: Nearly half of young men with PSA screen-detected prostate cancer are AS candidates but the overwhelming majority seek treatment. Considering that many tumours show favourable pathology at RP, there is a possibility that these patients may benefit from AS management.

Regulation of u-PAR gene expression by H2A.Z is modulated by the MEK-ERK/AP-1 pathway.

The urokinase receptor (u-PAR) which is largely regulated at the transcriptional level has been implicated in tumor progression. In this study, we explored the epigenetic regulation of u-PAR and showed that the histone variant H2A.Z negatively regulates its expression in multiple cell lines. Chromatin immunoprecipitation assays revealed that H2A.Z was enriched at previously characterized u-PAR-regulatory regions (promoter and a downstream enhancer) and dissociates upon activation of gene expression by phorbol ester (PMA). Using specific chemical and dominant negative expression constructs, we show that the MEK-ERK signaling pathway terminating at AP-1 transcription factors intersects with the epigenetic control of u-PAR expression by H2A.Z. Furthermore, we demonstrate that two other AP-1 targets (MMP9 gene and miR-21 microRNA) are also H2A.Z regulated. In conclusion, our work demonstrates that (i) the expression of two genes and a microRNA all implicated in tumor progression are directly regulated by H2A.Z and (ii) MEK-ERK signaling terminating at AP-1 intersects with the epigenetic control of target gene expression by H2A.Z.

Prostate cancer incidence in U.S. Air Force aviators compared with non-aviators.

INTRODUCTION: Several studies investigating whether prostate cancer incidence is elevated in aviators both in the civilian and military sectors have yielded inconsistent findings. Most investigations have compared aviators to the general population. Instead, our study compared prostate cancer incidence rates among officer aviators and non-aviators in the U.S. Air Force (USAF) to reduce confounding by socioeconomic status and frequency of medical exams. METHODS: This retrospective analysis ascertained prostate cancer cases using the Automated Cancer Tumor Registry of the Department of Defense linked to personnel records from the USAF Personnel Center to identify aviators and non-aviators. Survival analysis using the Cox Proportional Hazards model allowed comparison of prostate cancer incidence rates in USAF aviators and non-aviators. RESULTS: After adjustment for age and race, the hazards ratio for prostate cancer incidence comparing aviators with non-aviators was 1.15 (95% confidence interval, 0.85-1.44). Neither prostate cancer incidence nor time to diagnosis differed significantly between the two groups. CONCLUSION: Our study compared prostate cancer rates in aviators with a reference group of non-aviators similar in socio-economic level and frequency of exams. When compared to this internal reference group the risk of prostate cancer in USAF officer aviators appeared similar with no significant excess.

Increasing low risk prostate cancer incidence in United States Air Force servicemen and selection of treatments.

PURPOSE: Periodic Health Assessments have been mandated for United States Air Force servicemen since the mid 1990s. Thus, we determined whether United States Air Force prostate cancer incidence rates increased thereafter and how these tumors segregate into low and intermediate/high risk categories. We also identified treatment choices. MATERIALS AND METHODS: We queried the Department of Defense Automated Central Tumor Registry for prostate cancer diagnosed in United States Air Force servicemen between 1991 and 2008 to determine incidence rates, disease risk category and treatments. RESULTS: Age adjusted rates in white active duty servicemen diagnosed for the most recent period of 2005 to 2008 increased 3-fold relative to the rate in the earliest period of 1991 to 1994. A similar trend was evident in black servicemen. Relative to the Surveillance, Epidemiology and End Results population prostate cancer rates in active duty United States Air Force men between 1995 and 2008 were significantly increased for the 2 racial groups. A significantly greater proportion of active duty servicemen than retirees (62% vs 40%) presented with low risk disease, defined as prostate specific antigen less than 10 ng/ml, Gleason sum less than 7 and clinical stage T1a-T2a. Of those with low risk disease significantly more active duty servicemen elected curative surgery than retirees (93% vs 53%). CONCLUSIONS: Prostate cancer incidence rates in United States Air Force servicemen have increased with time, exceeding rates in the Surveillance, Epidemiology and End Results population. While most cases are characterized as low risk, aggressive management is elected.

Accelerated urokinase-receptor protein turnover triggered by interference with the addition of the glycolipid anchor.

u-PAR (urokinase-type plasminogen activator receptor), anchored to the cell surface via a glycolipid moiety, drives tumour progression. We previously reported that colon cancer cells (RKO clone 2 FS2), attenuated for in vivo tumorigenicity, are diminished >15-fold for u-PAR display when compared with their tumorigenic isogenic counterparts (RKO clone 2), this disparity not reflecting altered transcription/mRNA stability. FACS, confocal microscopy and Western blotting using a fused u-PAR-EGFP (enhanced green fluorescent protein) cDNA revealed a >14-fold differential in the u-PAR-EGFP signal between the isogenic cells, ruling out alternate splicing as a mechanism. Although metabolic labelling indicated similar synthesis rates, pulse-chase revealed accelerated u-PAR-EGFP turnover in the RKO clone 2 FS2 cells. Expression in RKO clone 2 cells of a u-PAR-EGFP protein unable to accept the glycolipid moiety yielded diminished protein amounts, thus mirroring the low endogenous protein levels evident with RKO clone 2 FS2 cells. Transcript levels for the phosphatidylglycan anchor biosynthesis class B gene required for glycolipid synthesis were reduced by 65% in RKO clone 2 FS2 cells, and forced overexpression in these cells partially restored endogenous u-PAR. Thus attenuated u-PAR levels probably reflects accelerated turnover triggered by inefficient addition of the glycolipid moiety.

MDM2 mediates ubiquitination and degradation of activating transcription factor 3.

Activating transcription factor 3 (ATF3) is a common stress sensor, and its rapid induction by cellular stresses (e.g. DNA damage) is crucial for cells to mount appropriate responses (e.g. activating the tumor suppressor p53) and maintain homeostasis. Although emerging evidence suggests that dysregulation of ATF3 contributes to occurrences of human diseases including cancer, the mechanism(s) by which ATF3 expression is regulated is largely unknown. Here, we demonstrate that mouse double minute 2 (MDM2) is a bona fide E3 ubiquitin ligase for ATF3 and regulates ATF3 expression by promoting its degradation. MDM2 via its C-terminal RING finger can bind to the Basic region of ATF3 and mediate the addition of ubiquitin moieties to the ATF3 leucine zipper domain. As a consequence, ATF3, but not a mutant deficient in MDM2 binding (Delta80-100), is degraded by MDM2-mediated proteolysis. Consistent with these results, ablation of MDM2 in cells not only increases basal ATF3 levels, but results in stabilization of ATF3 in late stages of DNA damage responses. Because ATF3 was recently identified as a p53 activator, these results suggest that MDM2 could inactivate p53 through an additional feedback mechanism involving ATF3. Therefore, we provide the first evidence demonstrating that ATF3 is regulated by a posttranslational mechanism.

Direct intracranial extension of malignant eccrine spiradenoma of the face.

UNLABELLED: Malignant eccrine spiradenomas are exceedingly rare tumours. They are aggressive tumours normally arising in long-standing benign eccrine spiradenomas. We present a case of malignant eccrine spiradenoma of the right side of the face with direct intracranial extension without distant metastasis. A 48 years old woman presented with a large exophytic tumour on the right side of her face. Radiological imaging of the head and neck region revealed extensive invasion of the facial tissues around right orbit, maxilla and extension into the middle cranial fossa involving the right temporal lobe. She underwent craniotomy and debulking of the right temporal lobe and biopsy of the facial tumour. Histopathological findings were consistent with malignant eccrine spiradenoma. This is a rare case of facial malignant eccrine spiradenoma with direct intracranial extension with no distant metastasis. A literature search revealed that it is first case to be reported of this kind. KEYWORDS: Eccrine carcinoma; Spiradenoma; Adnexal carcinoma; Malignant eccrine spiradenoma.

Unbiased screening for transcriptional targets of ZKSCAN3 identifies integrin beta 4 and vascular endothelial growth factor as downstream targets.

We previously described the novel zinc finger protein ZKSCAN3 as a new "driver" of colon cancer progression. To investigate the underlying mechanism and because the predicted structural features (tandem zinc fingers) are often present in transcription factors, we hypothesized that ZKSCAN3 regulates the expression of a gene(s) favoring tumor progression. We employed unbiased screening to identify a DNA binding motif and candidate downstream genes. Cyclic amplification and selection of targets using a random oligonucleotide library and ZKSCAN3 protein identified KRDGGG as the DNA recognition motif. In expression profiling, 204 genes were induced 2-29-fold, and 76 genes reduced 2-5-fold by ZKSCAN3. To enrich for direct targets, we eliminated genes under-represented (<3) for the ZKSCAN3 binding motif (identified by CAST-ing) in 2 kilobases of regulatory sequence. Up-regulated putative downstream targets included genes contributing to growth (c-Met-related tyrosine kinase (MST1R), MEK2; the guanine nucleotide exchanger RasGRP2, insulin-like growth factor-2, integrin beta 4), cell migration (MST1R), angiogenesis (vascular endothelial growth factor), and proteolysis (MMP26; cathepsin D; PRSS3 (protease serine 3)). We pursued integrin beta 4 (induced up to 6-fold) as a candidate target because it promotes breast cancer tumorigenicity and stimulates phosphatidyl 3-kinase implicated in colorectal cancer progression. ZKSCAN3 overexpression/silencing modulated integrin beta 4 expression, confirming the array analysis. Moreover, ZKSCAN3 bound to the integrin beta 4 promoter in vitro and in vivo, and the integrin beta 4-derived ZKSCAN3 motif fused upstream of a tk-Luc reporter conferred ZKSCAN3 sensitivity. Integrin beta 4 knockdown by short hairpin RNA countered ZKSCAN3-augmented anchorage-independent colony formation. We also demonstrate vascular endothelial growth factor as a direct ZKSCAN3 target. Thus, ZKSCAN3 regulates the expression of several genes favoring tumor progression including integrin beta 4.

The previously undescribed ZKSCAN3 (ZNF306) is a novel "driver" of colorectal cancer progression.

A relatively new view of colorectal cancer is that its development/progression reflects the contribution of a large set of altered gene products in varying combinations, each providing a "fitness advantage." In searching for novel contributing gene products using Unigene cluster data mining, we found overrepresentation of expressed sequence tags corresponding to a previously uncharacterized gene (ZKSCAN3) in colorectal tumors. ZKSCAN3 was pursued for several reasons: (a) its sequence similarity with bowl required for Drosophila hindgut development; (b) it lies in a chromosomal region (6p22.1) amplified in colorectal cancer; and (c) its coding sequence predicts tandem C(2)H(2) zinc finger domains present in a class of proteins gaining attention for their role in oncogenesis/tumor progression. Reverse transcription-PCR confirmed overexpression in colorectal tumor tissue compared with adjacent nonmalignant mucosa due in part to gene amplification determined by Southern blotting. Further, immunohistochemistry with an antibody generated to the predicted protein sequence revealed higher ZKSCAN3 expression in invasive compared with noninvasive tumors. Intriguingly, the ZKSCAN3 protein was also expressed in tumors wild-type for genes (APC, p53, K-Ras) commonly targeted in colorectal cancer. ZKSCAN3 knockdown in two independent colon cancer cell lines impaired anchorage-independent growth and orthotopic tumor growth, whereas overexpression in a third cell line had the opposite effect and increased 5-fluorouracil resistance. Liposomal delivery of a ZKSCAN3-targeting small interfering RNA reduced tumorigenicity of orthotopic colon cancer. Thus, the hitherto uncharacterized ZKSCAN3 adds to an expanding set of encoded products contributing to the progression of colorectal cancer.

A novel high-throughput screening system identifies a small molecule repressive for matrix metalloproteinase-9 expression.

Aberrant gene expression is one of the driving forces for cancer progression and is considered an ideal target for chemical intervention. Although emerging bioluminescence reporter systems allow high-throughput searches for small molecules regulatory for gene expression, frequent silencing of reporter genes by epigenetic mechanisms hinders wide application of this drug discovery strategy. Here we report a novel system that directs the integration of a promoter-reporter construct to an open chromosomal location by Flp-mediated homologous recombination, thereby overcoming reporter-gene silencing. Using this system, we have screened more than 8000 compounds in the DIVERSet chemical library for repressors of a matrix metalloproteinase-9 (MMP-9) promoter and identified 5-methyl-2-(4-methylphenyl)-1H-benzimidazole (MPBD) inhibitory for MMP-9 gene expression. Consistent with this effect, MPBD inhibits MMP-9-dependent invasion of UMSCC-1 oral cancer cells, preosteoclast migration, and receptor activator of nuclear factor-kappaB ligand-induced osteoclast activity over concentration ranges that repressed MMP-9 expression. Mechanistic studies indicated that MPBD antagonizes AP-1 function by inhibiting its transactivation activity. We conclude that the Flp-mediated homologous recombination system to direct reporter integration into open chromatin regions represents a novel strategy allowing for the development of high-throughput systems screening for lead compounds targeting aberrant gene expression in cancer.