Abstract 3522: Structural characterization of androgen receptor variant 7 in prostate cancer

Prostate cancer is an extremely common disease that affects one in every seven men in their lifetime. The standard care for late-stage cancer is designed to inhibit the activation of androgen receptor (AR). While this therapeutic approach is initially efficient, the cancer almost always develops resistance and gives rise to castration-resistant prostate cancer (CRPC). When therapy fails, the median survival of patients who suffer from CRPC is 12-16 months. It is critical to understand the mechanism of CRPC better to ameliorate the outcome of late-stage prostate cancer patients.

AR is a transcription factor that consists of an N-terminal domain (NTD), a DNA binding domain (DBD) and a ligand binding domain (LBD). Upon activation by androgen, an intramolecular interaction between NTD and LBD occurs. The AR translocates into the nucleus where it forms a homodimer. It binds to the promoter and enhancer elements of the AR target genes and triggers gene transcription. It has been demonstrated in many clinical studies that AR is important for the progression of prostate cancer including CRPC. In CRPC, although androgen production and binding is inhibited, how the AR can still be activated is a fundamental question to be answered. One of the several different mechanisms proposed is the alternative splicing of the AR generating truncated AR variants that lack LBD. These variants do not require androgens to be activated and they are intrinsically resistant to clinically approved therapeutics.

Despite the fact that the AR variants have been shown to be critical in late-stage prostate cancer, the mechanism of gene transcription initiation by the AR variants is not well-known. We propose to characterize the mechanism of the AR variant activation. Since ARV7 is the most commonly observed variant, we utilize ARV7. We develop a FRET based methodology to identify how ARV7 dimers form and to test if full-length AR is necessary for transcriptional activation mediated by ARV7. We are able to demonstrate possible intermolecular interaction between the full length AR and ARV7 measuring the FRET intensity between the fluorophores attached to the N and C terminus of two proteins. FRET measurements are analyzed by tracking single cells and recording the FRET intensities during the process. Our preliminary data suggest that the full-length AR and ARV7 may interact in the presence of androgen. ARV7 is always localized in the nucleus whereas the AR requires androgen to be activated and translocates into the nucleus. Being in close proximity, putative interaction between the AR and ARV7 occurs in the nucleus. Additionally, we use NTD and DBD point mutants to determine critical positions of intermolecular interaction between them.

Supporting the significance of ARV7 in prostate cancer, our results clarify the dimerization process. It gives an opportunity to test clinical drugs currently in development to effectively inhibit ARV7 activation.

Citation Format: Fatma Özgün, Zeynep Kaya, Halil Bayraktar, Selen Manioğlu, Doğancan Özturan, Nathan Lack. Structural characterization of androgen receptor variant 7 in prostate cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 3522. doi:10.1158/1538-7445.AM2017-3522

Aza-capped cyclodextrins for intra-cavity metal complexation

N,N-Chelators based on aza-capped cyclodextrins were designed to produce complexes with an encapsulated metal unit.

International Nosocomial Infection Control Consortium report, data summary of 50 countries for 2010-2015: Device-associated module

BACKGROUND

We report the results of International Nosocomial Infection Control Consortium (INICC) surveillance study from January 2010-December 2015 in 703 intensive care units (ICUs) in Latin America, Europe, Eastern Mediterranean, Southeast Asia, and Western Pacific.

METHODS

During the 6-year study period, using Centers for Disease Control and Prevention National Healthcare Safety Network (CDC-NHSN) definitions for device-associated health care-associated infection (DA-HAI), we collected prospective data from 861,284 patients hospitalized in INICC hospital ICUs for an aggregate of 3,506,562 days.

RESULTS

Although device use in INICC ICUs was similar to that reported from CDC-NHSN ICUs, DA-HAI rates were higher in the INICC ICUs: in the INICC medical-surgical ICUs, the pooled rate of central line-associated bloodstream infection, 4.1 per 1,000 central line-days, was nearly 5-fold higher than the 0.8 per 1,000 central line-days reported from comparable US ICUs, the overall rate of ventilator-associated pneumonia was also higher, 13.1 versus 0.9 per 1,000 ventilator-days, as was the rate of catheter-associated urinary tract infection, 5.07 versus 1.7 per 1,000 catheter-days. From blood cultures samples, frequencies of resistance of Pseudomonas isolates to amikacin (29.87% vs 10%) and to imipenem (44.3% vs 26.1%), and of Klebsiella pneumoniae isolates to ceftazidime (73.2% vs 28.8%) and to imipenem (43.27% vs 12.8%) were also higher in the INICC ICUs compared with CDC-NHSN ICUs.

CONCLUSIONS

Although DA-HAIs in INICC ICU patients continue to be higher than the rates reported in CDC-NSHN ICUs representing the developed world, we have observed a significant trend toward the reduction of DA-HAI rates in INICC ICUs as shown in each international report. It is INICC's main goal to continue facilitating education, training, and basic and cost-effective tools and resources, such as standardized forms and an online platform, to tackle this problem effectively and systematically.

Impact of glucocorticoid receptor gene (NR3C1) polymorphisms in Turkish patients with metabolic syndrome

BACKGROUND

The metabolic syndrome (MetS) is characterized by a cluster of metabolic factors, including insulin resistance and type-2 diabetes, abdominal obesity, dyslipidemia, hypertension and microalbuminuria. Impaired glucocorticoid receptor (GR) activity also plays an important role in the etiology of MetS. The objective of our study is to evaluate the effects of GR gene polymorphisms (BclI, N363S, TthIII1 and ER22/23EK) in Turkish patients with MetS.

MATERIALS AND METHODS

Seventy subjects with MetS and 185 healthy controls were enrolled in the study. PCR-RFLP analysis was used for genotyping. Results for each polymorphism have been verified by allele-specific oligonucleotide analysis.

RESULTS

BclI GG genotype was significantly associated with an increased risk of MetS (p = 0.02). Also, only in women, the G allele carriers were significantly associated with higher C-peptide. T allele carriers of TthIII1 polymorphism were significantly associated with higher C-peptide, triglyceride, insulin and C-reactive protein (CRP, p value 0.048, 0.022, 0.005 and 0.022, respectively), and lower fasting blood glucose (FBG, p = 0.02). The combined carriers of BclI polymorphism G allele and TthIII1 polymorphism T allele were significantly associated with higher diastolic blood pressure in all patients, and lower FBG and postprandial blood glucose in only men. All the ER22/23EK polymorphisms coexisted with polymorphic variant of TthIII1 (p = 0.0058).

CONCLUSION

The presence of homozygote polymorphic variant of BclI might be good predictive markers for the disease susceptibility. The BclI and the TthIII1 polymorphism are associated with sex-specific clinical parameters. Our findings also suggest that the combination of BclI and TthIII1 polymorphisms may play a protective role in blood glucose.

International Nosocomial Infection Control Consortium (INICC) report, data summary of 43 countries for 2007-2012. Device-associated module

We report the results of an International Nosocomial Infection Control Consortium (INICC) surveillance study from January 2007-December 2012 in 503 intensive care units (ICUs) in Latin America, Asia, Africa, and Europe. During the 6-year study using the Centers for Disease Control and Prevention's (CDC) U.S. National Healthcare Safety Network (NHSN) definitions for device-associated health care-associated infection (DA-HAI), we collected prospective data from 605,310 patients hospitalized in the INICC's ICUs for an aggregate of 3,338,396 days. Although device utilization in the INICC's ICUs was similar to that reported from ICUs in the U.S. in the CDC's NHSN, rates of device-associated nosocomial infection were higher in the ICUs of the INICC hospitals: the pooled rate of central line-associated bloodstream infection in the INICC's ICUs, 4.9 per 1,000 central line days, is nearly 5-fold higher than the 0.9 per 1,000 central line days reported from comparable U.S. ICUs. The overall rate of ventilator-associated pneumonia was also higher (16.8 vs 1.1 per 1,000 ventilator days) as was the rate of catheter-associated urinary tract infection (5.5 vs 1.3 per 1,000 catheter days). Frequencies of resistance of Pseudomonas isolates to amikacin (42.8% vs 10%) and imipenem (42.4% vs 26.1%) and Klebsiella pneumoniae isolates to ceftazidime (71.2% vs 28.8%) and imipenem (19.6% vs 12.8%) were also higher in the INICC's ICUs compared with the ICUs of the CDC's NHSN.

Serum ceruloplasmin levels in acute decompensated heart failure

BACKGROUND

Ceruloplasmin (Cp) is a serum protein that belongs to the family of α2-globulins and it is increased in patients with after acute myocardial infarction complicated with heart failure. Aim of the study was to investigate levels of serum Cp in patients with acute decompensated heart failure.

MATERIALS AND METHODS

The present cross-sectional observational study consists of three groups: Fifty patients with decompensated heart failure (Group 1) and same 50 patients after compensation (Group 2); 50 control patients group with comparable age and sex without heart failure (Group 3). Demographic, echocardiographic and biochemical data of patients were collected. Serum Cp level was determined spectrophotometrically.

RESULTS

Serum ceruloplasmin was significantly increased in Groups 1 (820.8 ± 78.5 IU/dL) and 2 (873.5 ± 121.0 IU/dL) compared, to Group 3 (640.6 ± 132.4 IU/dL) (p<0.001). In the sub-group analysis, this difference was due to the difference between Groups 3, Group 1 and 2 (both p=0.0001) whereas no significant difference was present between Group I and Group 2 (p>0.063). A positive correlation was found between Cp and female sex, heart rate, systolic and diastolic blood pressure, acetylsalisilic acid and diuretic use, left ventricular systolic and diastolic diameter, mitral regurgitation, and negative correlation was found between Cp and ejection fraction (p<0.05 for all) whereas none of the parameters were independently associated with serum Cp level (p>0.05).

CONCLUSIONS

Findings of the present study suggest that serum Cp level is increased in both decompensated and compensated HF compared to controls. Further large scale studies are needed to elucidate the pathophysiological mechanisms of increased Cp in HF.

Prevalence of sleep disturbance in chronic pain

OBJECTIVE

Sleep is a vital function for human beings, which can be affected by several factors. Chronic pain is one of these factors where it is the most frequent cause for seeking medical care in combination with insomnia. The aim of this study is to examine the prevalence and relationship between sleep disturbance and chronic pain.

PATIENTS AND METHODS

After approval, a total of 85 Family Medicine Units from over 170 in Tokat were randomly selected using a 50% sampling. A sample of 2635 subjects, over the age of 19 years, who were registered with the selected Family Medicine Units, were assessed due to gender, age group, and the urban/rural population size of Tokat using the stratified sampling method. The sample size distribution was calculated as 1515 urban subjects, 1120 rural subjects; 1345 female subjects, 1290 male subjects; 1123 subjects between 20-39 years of age, 1103 subjects between the ages of 40-64, and 409 subjects over 64 years of age. After sampling, subjects were invited to participate in the study via an invitation letter, and agreeing individuals were taken to the Family Medicine Unit for face-to-face meetings. Written, informed consent was obtained, along with demographic data. The presence of chronic pain was recorded. According to the presence of chronic pain, all subjects were separated into two groups as Group Chronic Pain and Group Non-Chronic Pain. The visual analog scale for pain intensity, and Pittsburgh Sleep Quality Index for sleep quality, were performed with all subjects. A multiple linear regression model was used to assess the predictors of sleep quality. Analyses were conducted using the Statistical Package for Social Sciences program (SPSS Inc., Chicago, IL, USA), version 20.0. The statistical significance for all analyses was set at p < 0.05.

RESULTS

The mean global Pittsburgh Sleep Quality Index score of Group Chronic Pain (5.30 ± 4.29) was significantly higher than in Group Non-Chronic Pain (3.22 ± 3.30; p < 0.01). The mean Pittsburgh Sleep Quality Index scores of females (5.69 ± 4.40) were significantly higher than males (4.54 ± 3.96) in Group Chronic Pain (p = 0.000045). A total of 40.7% of patients in Group Chronic Pain, and 21.9% in Group Non-Chronic Pain demonstrated poorer sleep quality according to the Pittsburgh Sleep Quality Index scores, with a cut-off level > 5. A moderate positive correlation was found between the global Pittsburgh Sleep Quality Index and Visual Analog Scale scores (r = 0.310, p < 0.01). A multiple linear regression analysis showed that age, gender, income, Visual Analog Scale, and presence of depression were the significant predictors for Pittsburgh Sleep Quality Index score.

CONCLUSIONS

The current study revealed that chronic pain and pain intensity are important predictors of sleep quality.

Delayed right atrial lateral electromechanical coupling relative to the septal one can be associated with paroxysmal atrial fibrillation

BACKGROUND

Non-invasive prediction of paroxysmal atrial fibrillation (PAF) is one of the most recent interests of cardiology.

AIM

The current study investigates the relationship between the atrial electromechanical coupling time (EMCT) and PAF.

PATIENTS AND METHODS

A group of 35 patients with PAF was compared with a group of 37 subjects without PAF. Pulsed wave tissue Doppler evaluations of atrial walls were performed from apical four chambers view under ECG monitoring. The time intervals from the onset of P wave to the onset of late diastolic wave (A') at right atrial wall (P-RA), interatrial septum (P-IAS), and left atrial wall (P-LA, maximum EMCT) were measured. The right atrial EMCT (P-RA minus P-IAS), left atrial EMCT (P-LA minus P-IAS) and interatrial EMCT (P-LA minus P-RA) were computed. A' wave velocities were measured from each atrial wall.

RESULTS

RA (16.0±13.1 vs. -8.7±18.6 ms, p < 0.001) and maximum (91.5±32.6 vs. 72.0±23.1 ms, p = 0.001) EMCT were longer, RA A' velocity was higher in the patient group. There were no differences between the groups in LA and interatrial EMCT, and septal and LA A' velocities. Regression analysis revealed that only RA [OR: 1.148 (1.041-1.267), p = 0.006] and maximum [OR: 1.099 (1.009-1.197), p = 0.031] EMCT were independent variables for PAF. In order to predict patients with PAF, we have chosen +7.5 msn for the RA EMCT which yielded 69% sensitivity and 71.4% specificity to predict patients.

CONCLUSIONS

Delayed RA lateral EMCT relative to septal one and delayed maximum EMCT detected by tissue Doppler could be a valuable method for identifying patients with PAF.

Effects of isoflurane in an intoxication model: experimental study

BACKGROUND

Isoflurane is a volatile anaesthetic that has been commonly used since 1980. The major metabolites of isoflurane are fluoride ion and trifluoroacetate, both excreted in the urine.

AIM

This study manage to show the histopathological findings of ingested isoflurane on liver, kidney and lugs in an animal model. Twenty-one rabbits were selected and divided into three groups: Group Isoflurane-5 (I-5); Group Isoflurane-10 (I-10); and Group Control (C). Each group consisted of seven rabbits. I-5 and I-10 received 5 ml/kg and 10 ml/kg of liquid isoflurane, respectively, via nasogastric tube, while C received 5 ml/kg saline (0.9% NaCI). All animals in I-5 and I-10 were sacrificed without anesthetic drug administration. Tissue samples from livers, kidneys and lungs were collected, preserving tissue unity and avoiding infliction of any trauma. Samples were fixed in 10% formalin solution, embedded in paraffin blocks and sliced into 5 μm sections. To investigate the effects of isoflurane, sections were examined under light microscope and histopathological changes were scored.

RESULTS

Mean injury scores and the appearance of portal lymphocyte infiltration in liver samples showed significant increases in I-5 and I-10 compared to C (p = 0.005, p = 0.001 and p = 0.001, respectively). Mean lung injury scores revealed significant increases after isoflurane treatment in I-5 and I-10 compared to C (p = 0.026 and p = 0.017, respectively).

CONCLUSIONS

Ingested isoflurane led to mild liver and lung injuries in rabbits.

Association of serum paraoxonase activity and coronary artery calcification

AIM

It has been known that there was a relation between the activities of serum paraoxonase (PON) and the severity of the coronary artery disease. However, little is known about association of coronary artery calcification (CAC) and serum PON activities. The aim of this study is to evaluate the relationship between CAC and serum PON activities.

PATIENTS AND METHODS

We measure serum PON activities from 122 patients (42 female, mean age = 62±10 years) with angiographically documented CAC (Group I), and 138 patients (54 female, mean age = 60±10 years) without CAC (Group II). Coronary calcification was detected with fluoroscopy before coronary angiography. Serum PON activities were measured by spectrophotometrically method. Patient characteristics and baseline data were recorded from patient's files.

RESULTS

The triglyceride levels is lower in group I than group II (p = 0.040). Diastolic blood pressure and frequency of diabetes mellitus was higher in the group I than group II (respectively p = 0.012 and p = 0.022). The other clinic and laboratory parameters were similar in two groups (all p > 0.05). The only statistically significant differences between with CAC and without CAC groups in respect to serum PON activities were present (170.6 ± 59.6 vs. 209.6 ± 69.8 U/ml; respectively, p < 0.001). There was a negative correlation between serum PON activities and presence of CAC (p < 0.001).

CONCLUSIONS

These data indicate that the serum PON activities are decreased in patients with CAC. The serum PON activities may play a role in development of the CAC and reduced serum PON activity might represent a biochemical marker of CAC.

Prospective, randomized, double-blinded comparison of the effects of caudally administered levobupivacaine 0.25% and bupivacaine 0.25% on pain and motor block in children undergoing circumcision surgery

BACKGROUND

Caudal anesthesia is widely used as intraoperative and postoperative analgesia in children's subumbilical surgeries such as on the urogenital system, lower extremities and lower abdomen to reduce the stress response to surgery and to facilitate the general anesthesia.

AIM

The purpose of this study was to compare the effects of caudally administered bupivacaine and levobupivacaine of equal volume and concentration on motor block and postoperative pain in children undergoing circumcision surgery.

PATIENTS AND METHODS

The prospective, randomized, double-blind study included 60 patients with ages ranging from 1-10 years and ASA (American Society of Anesthesiologists) physical status of I-II who underwent elective circumcision surgery. The patients were divided into two groups: group B received 0.5 ml/kg of bupivacaine 0.25% caudally and group L received 0.5 ml/kg of levobupivacaine 0.25% caudally. Postoperative pain was assessed by children's and infant's postoperative pain scale and motor block was assessed by the Bromage scale.

RESULTS

The mean children's and infant's postoperative pain scale of group B was significantly lower than that of group L (p < 0.001). Three patients in group B and seven patients in group L needed additional analgesia after the incision. There was no significant difference between groups in terms of Bromage scores and in both groups the residual motor block was found to be zero at the 150th minutes.

CONCLUSION

According to these findings, bupivacaine has an adequate quality of analgesia than levobupivacaine. We suggest that bupivacaine for caudal block at the concentration of 0.25% (0.5 ml/kg) provides an adequate level of analgesia for outpatient circumcision surgery.