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Objective To determine characteristics of providers marketing vasectomy reversal (VR) online, degree of information available online, the ease with which patients can compare providers, and the differences in VR practice patterns between academic and private practices. Materials and Methods We identified VR practices operating within the top 50 most populous metropolitan areas in the US. Practice websites were reviewed to obtain information such as provider educational background, level of magnification, ability to perform vasoepididymostomy, surgical volume, and cost. Based on information available, providers were assigned a novel REVERSAL score created by the authors. Descriptive statistics were used to compare results. Results Of the 107 providers identified (29 academic, 78 private), the majority were male urologists with a Doctor of Medicine degree. Academic providers were more likely to have fellowship training than private practice providers, 96.6 vs 43.6%, respectively (P = 0.00001). Compared to non-urologists, urologists were less likely to purchase online ads or disclose cost. Non-urologists charged significantly less than urologists, $3,584 ± 1,554 and $6,591 ± 1,518, respectively (P = 0.00001). Only one provider provided complete information as defined by REVERSAL score of 12, with the majority (61.7%) of providers achieving score ≤6. Conclusion There is significant lack of transparency in publicly available information from VR practices. Practices should implement measures to improve dissemination of information to the public, so that patients can more easily compare providers and make informed decisions regarding VR.

Nitrous oxide (N2O) is underutilized in ambulatory urology. Here, we review available data regarding application, efficacy, and side effect profile of N2O in ambulatory urologic procedures. Data were available from 11 studies. N2O has been described in the setting of transrectal ultrasound-guided prostate biopsies, flexible cystoscopy, ureteral stent placement, and extracorporeal shockwave lithotripsy in adult patients and catheterization in children. Studies showed significant improvements in peri-procedural pain and anxiety relative to alternative (or none) forms of analgesia. Adverse effects were rare and self-limited. More widespread use of N2O may result in cost savings and better patient tolerance with outpatient procedures.

BACKGROUND We sought to assess the prognostic utility of 11C-choline positron emission tomography/computed tomography (PET/CT) in patients with metastatic castrate resistant prostate cancer (mCRPC) undergoing primary docetaxel chemotherapy. METHODS We performed a single institution retrospective analysis of 77 mCRPC patients who were treated with 6 cycles of docetaxel chemotherapy, and who also underwent 11C-choline PET/CT scans at baseline (before chemotherapy), mid-course (after 3 cycles), and posttherapy (after 6 cycles). We evaluated treatment response based on percent change in blood pool-corrected maximum standardized uptake value (SUVmax) of the target lesion on PET/CT, as well as percent change in serum prostate specific antigen (PSA). Logistic regression analysis was used to identify factors associated with complete treatment response. Progression free survival (PFS) analysis was performed using log-rank test and shown on Kaplan-Meier plot. RESULTS Percent change in blood pool-corrected SUVmax on mid-course scan was a significant predictor of complete response (odds ratio [OR]: 0.98, 95% confidence interval [CI]: 0.96-0.99, p = .0003), whereas percent change in PSA was not (OR: 0.99, 95% CI: 0.99-1.01, p = .6025). 57 of 77 patients (74%) achieved ≥20% reduction in blood pool-corrected SUVmax on mid-course; these patients were 3.6 times more likely to achieve complete response after full 6 cycles of docetaxel chemotherapy, compared to patients with

Objective To identify the incidence of venous thromboembolism (VTE) risk factors, postoperative VTE, and to assess the morbidity of perioperative pharmacologic VTE prophylaxis in men undergoing inflatable penile prosthesis (IPP) surgery. Methods We retrospectively reviewed 215 patients undergoing IPP surgery between July 2017 and June 2019. Univariate and multivariate statistical analyzes were performed to assess pre-operative Caprini risk score and compare post-operative day 0 scrotal drain output, scrotal hematoma formation, and VTE in men who received subcutaneous heparin (SqH) vs those who did not receive SqH. Results Of 215 IPP patients, 84% were classified as high or highest risk for VTE utilizing the Caprini risk score. A total of 119 (55%) received perioperative SqH with or without additional anti-thrombotics. Post-operative day 0 scrotal drain output was higher in those who received SqH compared to those who did not receive SqH, 99.9 mL vs 75.6 mL, respectively (P = .001). Minor scrotal hematomas occurred in similar rates in patients who received perioperative SqH vs those who did not, 3.8% vs 6.3%, respectively (P = .38). Similar results were found on subgroup analysis when eliminating patients who received SqH concurrently with other anti-thrombotics. The overall rate of postoperative VTE was 0.9%. No post-operative infections occurred. Conclusion Patients undergoing IPP surgery are at elevated risk for VTE. To our knowledge, this is the first study showing SqH use in the perioperative IPP surgery setting is safe when used in conjunction with a scrotal drain. Preoperative VTE risk stratification may be performed and can be used to guide clinical decision making regarding pharmacologic prophylaxis.

Ultrasound imaging presents many positive attributes, including safety, real-time imaging, universal accessibility, and cost. However, inherent difficulties in discrimination between soft tissues and tumors prompted development of stabilized microbubble contrast agents. This presents the opportunity to develop agents in which drug is entrapped in the microbubble shell. We describe preparation and characterization of theranostic poly(lactide) (PLA) and pegylated PLA (PEG-PLA) shelled microbubbles that entrap gemcitabine, a commonly used drug for pancreatic cancer (PDAC). Entrapping 6 wt% gemcitabine did not significantly affect drug activity, microbubble morphology, or ultrasound contrast activity compared with unmodified microbubbles. In vitro microbubble concentrations yielding ≥ 500nM entrapped gemcitabine were needed for complete cell death in MIA PaCa-2 PDAC drug sensitivity assays, compared with 62.5 nM free gemcitabine. In vivo administration of gemcitabine-loaded microbubbles to xenograft MIA PaCa-2 PDAC tumors in athymic mice was well tolerated and provided substantial tumoral image enhancement before and after destructive ultrasound pulses. However, no significant differences in tumor growth were observed among treatment groups, in keeping with the in vitro observation that much higher doses of gemcitabine are required to mirror free gemcitabine activity. Statement of significance The preliminary results shown here are encouraging and support further investigation into increased gemcitabine loading. Encapsulation of gemcitabine within polylactic acid (PLA) microbubbles does not damage its activity towards pancreatic cancer (pancreatic ductal adenocarcinoma, PDAC) cells. Excellent imaging and evidence of penetration into the highly desmoplastic PDAC tumors is demonstrated. Microbubble destruction was confirmed in vivo, showing that elevated mechanical index shatters the microbubbles for enhanced delivery. The potential to slow PDAC growth in vivo is shown, but higher gemcitabine concentrations are required. Current efforts are directed at increasing drug loading by inclusion of drug-carrying nanoparticles for effective in vivo treatment.

Objective To evaluate clinical characteristics associated with patient attitudes toward surgical treatment of Peyronie's disease (PD) prior to consultation in a high-volume male sexual health clinic. Methods : From 2014-2018 a prospective database was created of patients presenting to the sexual health clinic at our institution. Multivariable regression analysis was conducted to determine factors associated with pre-visit consideration of surgery. Results : Of 1359 men presenting to clinic, 342 had a chief complaint of PD. Prior to consultation, 79% of patients (n = 270) stated they were willing to consider surgery to correct their PD symptoms. Factors associated with consideration of surgery included younger patient age (mean 55.8 vs 60.0 years; P = .008), history of depression/anxiety (21% vs 8%, P = .01), greater penile curvature (43.3 vs 34.6 degrees; P = .002), penile shortening (64% vs 44%; P = .003), pain with erections (46% vs 33%; P = .05) and decreased ability to have penetrative intercourse (51.9% vs 65.3%, P = .04). On multivariable analysis, age, history of depression, penile shortening, and mean curvature remained significantly associated. Symptom duration and relationship factors were not associated with a difference in the stated preference to consider surgery prior to consultation (P >.05 for all). Conclusion : Nearly 4 out of 5 patients reported willingness to consider surgical intervention for their PD-related symptoms prior to urologic consultation. On multivariable analysis, younger age, history of depression/anxiety, penile shortening, and curvature were associated with a greater likelihood of considering surgery. This information provides important insight into patient attitude toward undergoing surgery and will help drive patient counseling for men with PD.

Transparency of conflicts of interest is essential when assessing publications that address the benefits of robotic surgery over traditional laparoscopic and open operations. We assessed discrepancies between self-reported and actual conflicts of interest as well as whether conflicts of interest are associated with favorable endorsement of robotic surgery.We searched the Embase® and MEDLINE® databases for articles on robotic surgery within pediatric urology. We included English language articles published since 2013, when data in the Open Payments program (Centers for Medicare and Medicaid Services, Baltimore, Maryland) became available. For all United States based authors Open Payments was used to identify the total amount of financial payment received from Intuitive Surgical®. Chi-square test was used to assess the association between conflicts of interest and favorable endorsement of robotic surgery.A total of 191 articles were initially identified. After exclusion criteria were applied 107 articles remained (267 distinct authors). Of the articles 86 (80.4%) had at least 1 author with a history of payment from Intuitive Surgical, with 79 (91.9%) having at least 1 author who did not declare a conflict of interest despite history of payment. A total of 44 authors (16.5%) had a history of payment from Intuitive Surgical, with an average payment of $3,594.15. Articles with a first and/or last author with a history of payment were more likely to contain a favorable endorsement of robotic surgery compared to articles without a history of payment (85.1% vs 63.6%, p = 0.0124).Nondisclosure of conflict of interest with Intuitive Surgical is extremely common within pediatric urology. Steps to ensure accurate reporting of conflicts of interest are essential. There appears to be an association between a history of payment and favorable endorsement of robotic surgery.

INTRODUCTION AND OBJECTIVE:Rezūm is a minimally invasive technique to treat benign prostatic hyperplasia (BPH). Major advantages include no de novo erectile dysfunction and low rate of retrograde e...

INTRODUCTION AND OBJECTIVE:Patients with erectile dysfunction frequently have cardiovascular/cerebrovascular risk factors requiring antithrombotics (anticoagulation/antiplatelets). Limited data are...

INTRODUCTION AND OBJECTIVE:Climacturia is an underreported complication of definitive therapy for prostate cancer (PCa); i.e. radical prostatectomy (RP) or radiation therapy (RT). We sought to iden...

INTRODUCTION AND OBJECTIVE:Patients with erectile dysfunction frequently have concurrent risk factors for venous thromboembolism (VTE) including obesity, smoking history, hypertension, and advanced...

Testicular torsion remains the most frequent cause of testicular ischemia, especially in adolescents and young adults. Timely diagnosis and intervention are keys to saving the affected testicle. This review presents current trends in the diagnosis and treatment of torsion, potential pitfalls and consequent outcomes. Additionally, other salient issues surrounding testicular torsion are also discussed, including: pathogenesis of injury, legal ramifications, fertility outcomes, novel management techniques, and recent advances in diagnostic technology.

Background Climacturia is an under-reported complication of definitive therapy for prostate cancer (PCa) - that is, radical prostatectomy (RP) and/or radiation therapy (RT). Aim We sought to identify the prevalence and predictors of climacturia and associated patient/partner bother in patients with and without prior PCa treatment. Methods We analyzed a database of patients who presented to our Men's Health clinic and filled out a questionnaire related to sexual function and pertinent medical histories. The prevalence of climacturia and associated patient/partner bother in patients with/without prior RP/RT was calculated. Univariable and multivariable logistic regressions were performed to identify predictors associated with climacturia and patient/partner bother. Outcomes The primary outcomes were the prevalence and predictors of climacturia and associated patient/partner bother in patients with/without history of definitive PCa treatment. Results Among 1,117 patients able to achieve orgasm, 192 patients (17%) had prior history of definitive therapy for PCa (RP alone = 139 [72%]; RT alone = 22 [11%]; RP + RT = 31 [16%]). Climacturia was reported by 39%, 14%, 52%, and 2.4% of patients with history of RP alone, RT alone, RP + RT, and neither RP nor RT, respectively (P Among patients with prior RP/RT, stress urinary incontinence was associated with increased risk of climacturia, whereas diabetes was associated with decreased risk. No factors were associated with patient/partner bother. Among patients with prior RP, nerve-sparing technique did not predict presence of climacturia but was associated with reduced patient/partner bother. Clinical translation Given significant prevalence of climacturia and associated patient/partner bother, patients should be counseled on the risk of climacturia before undergoing RP/RT. Strengths and limitations Strengths include the large study population and the focus on both RP and RT. Limitations include the facts that this is a single-institution study that primarily relies on patients’ subjective reporting and that the study population may not represent the general population. Conclusions Climacturia affects a significant proportion of patients with history of RP/RT for PCa, and many patients and their partners find this bothersome.

Background: Acinar cell carcinoma is a rare form of pancreatic cancer, accounting for 1–2% of all cases of exocrine pancreatic neoplasms in adults. Due to its rarity, no randomized controlled trials have been performed to determine the optimal treatment options. As such, high-quality case reports and case series are needed to help guide clinicians in the management of this deadly disease. Case Presentation: A 56-year-old Caucasian male presenting with abdominal pain and weight loss was diagnosed with stage III acinar cell carcinoma of the pancreatic body with celiac axis involvement. Although initially deemed unresectable, the patient responded favorably to nine cycles of 5-fluorouracil-based neoadjuvant chemotherapy. The tumor was successfully resected through distal pancreatectomy with en bloc splenectomy and en bloc celiac artery resection (Appleby procedure). Final pathology analysis showed negative resection margins and complete chemotherapeutic response within the pancreas, with residual tumor cells detected in only a single peripancreatic lymph node. Conclusion: 5-fluorouracil-based chemotherapy may be a promising option for the neoadjuvant treatment of locally unresectable acinar cell carcinoma. With sufficient expertise, negative surgical resection margins are possible even with vascular involvement. Due to the generally poor prognosis associated with acinar cell carcinoma, such aggressive treatment measures are warranted.

Growing evidence shows that cancer cells use mRNA-binding proteins and miRNAs to posttranscriptionally regulate signaling pathways to adapt to harsh tumor microenvironments. In ovarian cancer, cytoplasmic accumulation of mRNA-binding protein HuR (ELAVL1) is associated with poor prognosis. In this study, we observed high HuR expression in ovarian cancer cells compared with ovarian primary cells, providing a rationale for targeting HuR. RNAi-mediated silencing of HuR in ovarian cancer cells significantly decreased cell proliferation and anchorage-independent growth, and impaired migration and invasion. In addition, HuR-depleted human ovarian xenografts were smaller than control tumors. A biodistribution study showed effective tumor-targeting by a novel Cy3-labeled folic acid (FA)-derivatized DNA dendrimer nanocarrier (3DNA). We combined siRNAs against HuR with FA-3DNA and found that systemic administration of the resultant FA-3DNA-siHuR conjugates to ovarian tumor–bearing mice suppressed tumor growth and ascites development, significantly prolonging lifespan. NanoString gene expression analysis identified multiple HuR-regulated genes that function in many essential cellular and molecular pathways, an attractive feature of candidate therapeutic targets. Taken together, these results are the first to demonstrate the versatility of the 3DNA nanocarrier for in vivo–targeted delivery of a cancer therapeutic and support further preclinical investigation of this system adapted to siHuR-targeted therapy for ovarian cancer. Cancer Res; 76(6); 1549–59. ©2016 AACR.

This retrospective study aimed to investigate the role that an RNA-binding protein, HuR, plays in the response of high-grade serous ovarian tumors to chemotherapeutics. We immunohistochemically stained sections of 31 surgically-debulked chemo-naive ovarian tumors for HuR and scored the degree of HuR cytoplasmic staining. We found no correlation between HuR intracellular localization in tumor sections and progression free survival (PFS) of these patients, 29 of whom underwent second-line gemcitabine/platin combination therapy for recurrent disease. Ribonucleoprotein immunoprecipitation (RNP-IP) analysis of ovarian cancer cells in culture showed that cytoplasmic HuR increases deoxycytidine kinase (dCK), a metabolic enzyme that activates gemcitabine. The effects of carboplatin treatment on HuR and WEE1 (a mitotic inhibitor) expression, and on cell cycle kinetics, were also examined. Treatment of ovarian cancer cells with carboplatin results in increased HuR cytoplasmic expression and elevated WEE1 expression, arresting cell cycle G2/M transition. This may explain why HuR cytoplasmic localization in chemo-naive tumors is not predictive of therapeutic response and PFS following second-line gemcitabine/platin combination therapy. These results suggest treatment of recurrent ovarian tumors with a combination of gemcitabine, carboplatin, and a WEE1 inhibitor may be potentially advantageous as compared to current clinical practices.

OBJECTIVES: We tested cytoplasmic HuR (cHuR) as a predictive marker for response to chemotherapy by examining tumor samples from the international European Study Group of Pancreatic Cancer-3 trial, in which patients with resected pancreatic ductal adenocarcinoma (PDA) received either gemcitabine (GEM) or 5-fluorouracil (5-FU) adjuvant monotherapy. BACKGROUND: Previous studies have implicated the mRNA-binding protein, HuR (ELAVL1), as a predictive marker for PDA treatment response in the adjuvant setting. These studies were, however, based on small cohorts of patients outside of a clinical trial, or a clinical trial in which patients received multimodality therapy with concomitant radiation. METHODS: Tissue samples from 379 patients with PDA enrolled in the European Study Group of Pancreatic Cancer-3 trial were immunolabeled with an anti-HuR antibody and scored for cHuR expression. Patients were dichotomized into groups of high versus low cHuR expression. RESULTS: There was no association between cHuR expression and prognosis in the overall cohort [disease-free survival (DFS), P = 0.44; overall survival, P = 0.41). Median DFS for patients with high cHuR was significantly greater for patients treated with 5-FU compared to GEM [20.1 months, confidence interval (CI): 8.3–36.4 vs 10.9 months, CI: 7.5–14.2; P = 0.04]. Median DFS was similar between the treatment arms in patients with low cHuR (5-FU, 12.8 months, CI: 10.6–14.6 vs GEM, 12.9 months, CI: 11.2–15.4). CONCLUSIONS: Patients with high cHuR-expressing tumors may benefit from 5-FU-based adjuvant therapy as compared to GEM, whereas those patients with low cHuR appear to have no survival advantage with GEM compared with 5-FU. Further studies are needed to validate HuR as a biomarker in both future monotherapy and multiagent regimens.

144 Background: Despite having well-recognized limitations, urologists often rely on serial PSA testing as a marker for treatment response or disease progression. To determine if PSA was indeed a reliable marker for treatment response or disease progression, we compared PSA levels against C-11 choline PET/CT in the evaluation of patients with advanced prostate cancer treated with second generation hormonal therapy (2nd-HT). Methods: We retrospectively identified 239 patients who were undergoing treatment with 2nd-HT (enzalutamide or abiraterone) for advanced prostate cancer. While on treatment, patients underwent serial PSA testing and C-11 choline PET/ CTs every 3 – 6 months. Paradoxical response was defined as increasing blood pool-corrected SUVmax of known choline-avid lesions and/or identification of new choline-avid lesions, despite stable or down-trending PSA. Results: Median (IQR) age was 70.4(64.3 – 75.7) years and median (IQR) primary Gleason Score was 8 (7 – 9). In our study, 19% of patients (n = 46/239) who were receiving 2nd-HT exhibited paradoxical response. Median (IQR) PSA and corrected SUVmax at baseline evaluation were 1.3 ng/mL (0.3 – 12.8 ng/mL) and 3.5 (1.8 – 5.8), respectively. Median (IQR) PSA and corrected SUVmax at the time of paradoxical response were 0.4 ng/mL (0.1 – 5.4 ng/mL) and 4.5 (2.8 – 6.8), respectively. The median duration of 2nd-HT treatment prior to detection of paradoxical response was 4.8 months (2.9 – 10.1 months). No significant difference was noted between patients receiving enzalutamide versus abiraterone (p = 0.35). Independent predictors of paradoxical response were prior primary systemic treatment (i.e. hormonal/chemo-hormonal therapy versus local therapy) and patient’s age at time of 2nd-HT initiation on univariate and multivariate analysis. Conclusions: Our retrospective review demonstrated prostate cancer disease progression discordant with PSA down-trending in 19% of patients receiving 2nd-HT. We conclude that in this subset of patients with advanced prostate cancer, PSA may not be a reliable marker of treatment response of disease progression, and routine radiographic evaluation in these patients is warranted.

143 Background: Systemic treatment in the management of metastatic prostate cancer is inevitable. However, there is a growing interest in metastases-directed therapy (MDT). We sought to investigate the efficacy of MDT in treating patients with solitary metastatic prostate cancer and hence, delaying initiation of systemic treatment (i.e., Androgen deprivation therapy or chemotherapy). Methods: We retrospectively identified 61 patients treated with targeted therapy in the form of surgery (n = 30), stereotactic body radiation therapy (SBRT) (n = 25), or cryotherapy (n = 7) for their solitary metastases prostate cancer. Complete response was defined by achieving a PSA value of ≤0.2 ng/ml plus resolution of the solitary metastatic lesion on C-11 choline PET choline scan, while incomplete response was defined by a residual PSA of > 0.2 ng/ml and/or radiographic evidence of disease following metastases-targeted therapy. Results: Mean (±SD) age was 68.4 (±7.8) yrs., median (IQR) primary Gleason Score was 7 (7-9) and median (IQR) pre-MDT PSA was 2 (1.3-3.8) ng/ml. Median (IQR) time from primary treatment of the prostate to MDT was 5.1 (2.7-10.1) years. None of the patients were on hormone therapy at the time of presentation with solitary metastases prostate cancer. 30 patients had bone metastases, 29 patients had lymph node metastases, 1 patient had soft tissue metastasis (pelvic metastatic mass), and another patient had visceral metastasis (to the lung). 42% of the patients (n = 26) achieved complete response to targeted therapy. Median time to initiation of 2nd line systemic treatment following MDT was 17.8 months for the complete responders versus 9.3 months for incomplete responders. 11% of the patients (n = 7) did not require 2nd line therapy after their MDT for a mean (±SD) time of 56.9 (±22.5) months. Conclusions: The use of targeted therapy in the management of patients with solitary metastatic disease or low-volume metastatic disease can provide comparable outcomes to those of systemic treatment. Further studies are warranted.

Deoxycytidine kinase (dCK) and human antigen R (HuR) have been associated with response to gemcitabine in small studies. The present study investigates the prognostic and predictive value of dCK and HuR expression levels for sensitivity to gemcitabine and 5-fluorouracil (5-FU) in a large phase III adjuvant trial with chemoradiation backbone in pancreatic ductal adenocarcinoma (PDA). The dCK and HuR expression levels were determined by immunohistochemistry on a tissue microarray of 165 resected PDAs from the Radiation Therapy Oncology Group (RTOG) 9704 trial. Association with overall survival (OS) and disease-free survival (DFS) status were analyzed using the log-rank test and the Cox proportional hazards model. Experiments with cultured PDA cells were performed to explore mechanisms linking dCK and HuR expression to drug sensitivity. dCK expression levels were associated with improved OS for all patients analyzed from RTOG 9704 (HR: 0.66, 95% CI [0.47-0.93], P = 0.015). In a subset analysis based on treatment arm, the effect was restricted to patients receiving 5-FU (HR: 0.53, 95% CI [0.33-0.85], P = 0.0078). Studies in cultured cells confirmed that dCK expression rendered cells more sensitive to 5-FU. HuR cytoplasmic expression was neither prognostic nor predictive of treatment response. Previous studies along with drug sensitivity and biochemical studies demonstrate that radiation interferes with HuR's regulatory effects on dCK, and could account for the negative findings herein based on the clinical study design (i.e., inclusion of radiation). Finally, we demonstrate that 5-FU can increase HuR function by enhancing HuR translocation from the nucleus to the cytoplasm, similar to the effect of gemcitabine in PDA cells. For the first time, in the pre-treatment tumor samples, dCK and HuR cytoplasmic expression were strongly correlated (chi-square P = 0.015). This dual-institutional follow up study, in a multi-institutional PDA randomized clinical trial, observed that dCK expression levels were prognostic and had predictive value for sensitivity to 5-FU.

Background: GPRC5A is an orphan G-protein coupled receptor acting as an oncogene in some cancers and as a tumor suppressor in other. Its role in pancreatic cancer has not been studied systematically. ELAV-like protein 1, also known as “HuR,” is an RNA binding protein that is encoded by the ELAVL1 gene. HuR post-transcriptionally regulates multiple genes, plays key roles in human malignancies, and is known to mediate the efficacy of gemcitabine. Our preliminary data indicated that, in pancreatic cells, GPRC5A transcription responded to gemcitabine treatment and that its mRNA likely interacted with HuR. Methods: We immunohistochemically analyzed GPRC5A protein expression in primary and metastatic pancreatic cancer samples. We examined the effects of GPRC5A on pancreatic cells’ ability to proliferate, migrate, and invade, and how gemcitabine modulates this ability. We also studied the interaction between GPRC5A and HuR and examined how it is affected by gemcitabine. Lastly, we used microarray expression analyses to identify the genes and pathways linked to GPRC5A in pancreatic cancer cells. Results: We analyzed public mRNA expression data from 675 human cancer cell lines and 10,609 samples from The Cancer Genome Atlas (TCGA): GPRC5A mRNA abundance in pancreatic cancer was the highest (cell lines) or second highest (TCGA) among all tissues and cancer types. We analyzed an independent set of 252 pancreatic normal and cancer samples: we found GPRC5A mRNA to be up-regulated in primary tumor samples compared to normal pancreas, and even further up-regulated in metastatic pancreatic cancer. We immunostained 208 cores (103 primary and metastatic pancreatic cancer samples): we found GPRC5A protein to be barely expressed in normal pancreatic ductal cells and highly expressed in both primary and metastatic pancreatic ductal cancer cells. We carried out in vitro studies of multiple pancreatic cancer cell lines: we found that increasing GPRC5A protein levels promoted pancreatic cancer cell growth and migration whereas siRNA-mediated knockdown of GPRC5A impaired proliferation and invasion. We found that gemcitabine treatment enhanced GPRC5A expression in pancreatic cancer cells. Conversely, siRNA-mediated knockdown of GPRC5A sensitized the cells to gemcitabine. We showed that HuR/ELAVL1 up-regulated GPRC5A protein in the first 18 hours following gemcitabine treatment by stabilizing GPRC5A’s mRNA through binding to at least on site in GPRC5A’s 3´UTR. Microarray analysis showed that GPRC5A overexpression impacts several signaling networks. Conclusions: Our results indicate that GPRC5A acts as an oncogene in pancreatic cancer. Unexpectedly, gemcitabine was found to increase GPRC5A's mRNA and protein levels. We showed that this increase is mediated by HuR, a known enabler of gemcitabine efficacy, through a direct interaction between HuR and GPRC5A’s mRNA. It appears that the sensitivity of pancreatic cancer cells to gemcitabine can be augmented through down-regulation of GPRC5A. Citation Format: Honglei Zhou, Aristeidis Telonis, Yi Jing, Masaya Jimbo, Fernando Blanco, Eric Londin, Jonathan Brody, Isidore Rigoutsos.{Authors}. GPRC5A acts as a potent oncogene in pancreatic cancer. [abstract]. In: Proceedings of the AACR Special Conference on Pancreatic Cancer: Advances in Science and Clinical Care; 2016 May 12-15; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2016;76(24 Suppl):Abstract nr A41.

We read with great optimism To and colleagues' ([1][1]) article about PARP inhibitors as effective chemopreventive strategy for treating homologous repair (HR)–deficient tumors. Their overarching conclusion stated in the discussion is that “…synthetic lethality (i.e., PARP inhibitor therapy

Background: Pancreatic ductal adenocarcinoma (PDA) is the fourth most common cause of cancer-related death in the Unites States, with an overall 5-year survival rate of Methods: Stable MiaPaCa2 cell lines were generated that produce two different shRNAs against the HuR coding sequence (labeled Mia.sh290 and Mia.sh700) in response to doxycycline (DOX) induction. HuR silencing was validated by RT-qPCR and Western blotting. Similarly, a DOX-inducible MiaPaCa2 cell line that overexpresses HuR cDNA (Mia.HuR) was generated and validated. Sustained ∼50% knockdown and 1.5-2-fold overexpression were achieved, respectively. Following characterization of HuR expression in these cell lines under ±DOX conditions, we performed a 7-day cell proliferation (PicoGreen) assay and assessed anchorage-independence over a 4-week period by soft agar colony formation assay. Metastatic potential was measured by Matrigel invasion and in vitro scratch test assays. Results: Upon DOX induction, Mia.sh290 and Mia.sh700 cell lines showed significantly reduced cell proliferation over 7 days (22% and 15% reduction compared to non-induced in sh290 and sh700 respectively, p Conclusion: Taken together with our previous findings, our work demonstrates that manipulation of HuR expression affects key characteristics of tumorigenesis (i.e. proliferation, invasion, and migration). These findings, along with ongoing in vivo work, continue to support the notion that targeting HuR in PDA cells may be a promising therapeutic strategy. Citation Format: Masaya Jimbo, Fernando F. Blanco, Brad Screnci, Gabriela Cosma, Vitali Alexeev, Yu-Hung Huang, Jordan M. Winter, Charles J. Yeo, Janet A. Sawicki, Jonathan R. Brody. The RNA-binding protein HuR facilitates proliferation and metastasis in human pancreatic ductal adenocarcinoma. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 5133. doi:10.1158/1538-7445.AM2015-5133

Background: PDA will become the 2nd leading cause of cancer-related mortality in the US by 2020. A recent Phase III randomized controlled trial revealed a 4 month overall survival benefit in metastatic PDA with FOLFIRINOX (Folinic acid, 5-Fluorouracil (5FU), Irinotecan, and Oxaliplatin) compared to gemcitabine, the standard of care. However, the long-term clinical efficacy of FOLFIRINOX and other chemotherapy regimens are limited by tumor-associated drug resistance driven by factors in the tumor microenvironment (e.g., hypoxia). We identified a novel drug resistance mechanism driven by the hypoxia-inducible pro-oncogenic kinase PIM1 and regulated by the RNA binding protein HuR. Herein, we launched into developing a strategy to target this tractable mechanism in an effort to optimize current therapeutic treatments for PDA. Methods: To model hypoxia, PDA cells were incubated in 1% O2 and responses to 5FU or oxaliplatin assessed to obtain IC50 doses. Stabilizing interactions between the RNA-binding protein HuR and PIM1 mRNA were quantified in vitro through binding assays, and confirmed in patients by immunohistochemistry in resected PDAs (n = 44). The contribution of HuR-mediated regulation of PIM1 to resistance to 5FU or oxaliplatin in hypoxia was examined using MS-444 (Novartis), a low-molecular-weight HuR inhibitor. Results: In response to hypoxia, HuR translocates from the nucleus to the cytoplasm where it binds and stabilizes the PIM1 mRNA transcript, thus amplifying PIM1 translation and protein expression. Clinically, we identified a positive correlation (p = 0.011) between cytoplasmic HuR and PIM1 protein expression in a cohort of PDA patients from our institution. In vitro mechanistic studies demonstrated that hypoxia-mediated induction of PIM1 overexpression enhanced DNA repair and evaded the apoptotic response elicited by hypoxic stress. Targeted inhibition of HuR by the HuR inhibitor MS-444 abrogated hypoxia-induced PIM1 overexpression, enhancing PDA cell sensitivity to oxaliplatin and 5FU (P Conclusion: The mRNA-stability factor HuR post-transcriptionally induces PIM1 expression under hypoxic conditions, and thereby promotes hypoxia-induced chemoresistance. Ongoing pre-clinical studies will evaluate pharmacologic inhibition of HuR's regulation of PIM1 (e.g., MS-444) as a novel modality to enhance the therapeutic value of FOLFIRINOX for the treatment of metastatic PDA. Citation Format: Fernando F. Blanco, Masaya Jimbo, Liz Enyenihi, Nicole Meisner-Kober, Eric Londin, Isidore Rigoutsos, Makarand Risbud, Peter McCue, Charles Yeo, Jordan Winter, Jonathan R. Brody. Targeting tumor-associated hypoxia to overcome chemoresistance in pancreatic ductal adenocarcinoma (PDA). [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 2113. doi:10.1158/1538-7445.AM2015-2113