Raju Chelluri

Asymmetric Hsp90 N Domain SUMOylation Recruits Aha1 and ATP-Competitive Inhibitors

The stability and activity of numerous signaling proteins in both normal and cancer cells depends on the dimeric molecular chaperone heat shock protein 90 (Hsp90). Hsp90s function is coupled to ATP binding and hydrolysis and requires a series of conformational changes that are regulated by cochaperones and numerous posttranslational modifications (PTMs). SUMOylation is one of the least-understood Hsp90 PTMs. Here, we show that asymmetric SUMOylation of a conserved lysine residue in the N domain of both yeast (K178) and human (K191) Hsp90 facilitates both recruitment of the adenosine triphosphatase (ATPase)-activating cochaperone Aha1 and, unexpectedly, the binding of Hsp90 inhibitors, suggesting that these drugs associate preferentially with Hsp90 proteins that are actively engaged in the chaperone cycle. Importantly, cellular transformation is accompanied by elevated steady-state N domain SUMOylation, and increased Hsp90 SUMOylation sensitizes yeast and mammalian cells to Hsp90 inhibitors, providing a mechanism to explain the sensitivity of cancer cells to these drugs.

Identification of Niclosamide as a Novel Anticancer Agent for Adrenocortical Carcinoma

Purpose: Adrenocortical carcinoma (ACC) is a rare and aggressive cancer, and no current effective therapy is available for locally advanced and metastatic ACC. Drug repurposing is an emerging approach for identifying new indications for existing drugs, especially for rare cancers such as ACC. The objective of this study was to use quantitative high-throughput screening to identify agents with antineoplastic activity against ACC. Experimental Design: A screening of 4,292 compounds was performed on three ACC cell lines: BD140A, SW-13, and NCI-H295R. Results: Twenty-one active compounds were identified, with an efficacy of >80% in all three cell lines. Of these, niclosamide showed higher efficacy and lower IC50 than established anti-ACC drugs. We then validated niclosamide-inhibited cellular proliferation in all three ACC cell lines. Next, we investigated the mechanism by which niclosamide inhibited ACC cell proliferation, and found that it induced caspase-dependent apoptosis and G1 cell-cycle arrest. Niclosamide also decreased cellular migration and reduced the level of mediators of epithelial-to-mesenchymal transition, such as N-cadherin and vimentin. Furthermore, niclosamide treatment resulted in decreased expression of β-catenin. We also evaluated the effect of niclosamide on energy metabolism in ACC cell lines and found it resulted in mitochondrial uncoupling. Niclosamide treatment inhibited ACC tumor growth with no observed toxicity in mice in vivo. Conclusions: Our findings suggest that niclosamide has anti-ACC activity through its inhibition of multiple altered cellular pathways and cellular metabolism in ACC. Our results provide a preclinical rationale for evaluating niclosamide therapy in a clinical trial for ACC. Clin Cancer Res; 22(14); 3458–66. ©2016 AACR.

Robotic conversion of cecostomy tube to catheterizable antegrade continence enema (ACE): Surgical technique

INTRODUCTION Antegrade continence enema (ACE) is a well described treatment for pediatric patients with neurogenic bowel refractory to medical and retrograde management. ACE can be carried out either by catheterizable channel with enteric conduit or a cecostomy tube appliance. For those patients who have issues with pain or leakage around the cecostomy appliance or wish to be appliance free, we present our initial results and description of a novel technique of laparoscopic conversion of cecostomy to catheterizable ACE which uses the existing tract and requires no enteric conduit. METHODS A single institution, retrospective chart review was carried out for 2014-2017 to identify patients undergoing ACE conversion. Preoperative parameters included age, sex, weight, neurogenic bowel etiology and time from initial cecostomy. Perioperative data included length of surgery, length of hospitalization and postoperative complications (via Clavien-Dindo scale). Postoperative follow up, ancillary procedures pertinent to the ACE and status at time of submission are also presented. RESULTS Six patients were identified (mean age 14.1 +/- 4.3 years) with median follow up of 36 months (range 18-65). Neurogenic bowel etiology was spina bifida in five and spinal cord injury in one; all patients had concurrent neurogenic bladder with preexisting appendicovesicostomy. Mean operative time was 168 +/- 37 min (range 122-228) and mean length of hospital stay was 2 days (range 1-4). Success rate is 83% (5/6 continue to catheterize ACE channel), with one patient opting back for appliance through same tract. One patient has required operative revision for stomal stenosis. CONCLUSION To our knowledge, this is the first report describing robotic-assisted laparoscopic conversion of cecostomy tube to a catheterizable ACE. The surgical technique we describe is simple and safe with minimal morbidity to the patient. It does not require an enteral conduit, and may represent a valid treatment in patients without the option of using the appendix.

MP57-04 NOVEL THERAPIES TARGETING ANDROGEN RECEPTOR VARIANTS IN AN IN VITRO MODEL OF CASTRATE RESISTANT PROSTATE CANCER

INTRODUCTION AND OBJECTIVES: Prostate cancer (PCa) is the second leading cause of cancer deaths in men. AR signaling is known to play a critical role in androgen responsive prostate cancer cells. Androgen deprivation therapy (ADT) is a standard of care for patients when prostate cancer has spread beyond the prostate. Almost all the prostate cancer (PCa) deaths result from castration resistant prostate cancer (CRPC). With the development of newer anti-androgen Enzalutamide (ENZ) there has been a marked improvement in CRPC. However, almost all patients develop resistance to ENZ in part due to expression of ARv7. Thus, to date, no acceptable treatment options are available for ENZ resistant CRPC. In the present study we evaluated the effects of TET, a derivative of bis-benzyly isoquinoline, Tetrandrine on two enzalutamide resistant prostate cancer cell lines on sensitizing these cells to Enzalutamide. We also evaluated the effects of TET on AR and ARv7 levels. METHODS: Enz resistant Prostate cancer cell lines (22rv1 and LNCaP-abl) were used in the present study. Cells were grown in supplemented media and maintained at 370C in a 5%CO2 incubator (as described elsewhere). Where indicated cells were treated with Enzalutamide or TET alone or in combination. Cell viability was measured by crystal violet and MTT assays. Protein levels were measured by Western Blot assays. mRNA expression measured in RTPCR assays. RESULTS: Treatment with Enz had only a marginal effect on growth and viability of 22rv1 cells. TET inhibited growth and proliferation of enzalutamide resistant prostate cancer cells in both dose and time dependent manner with an IC50 in the range of 5-10uM at 72 hr. However TET treatment did not result in death of RWPE cells, a line of normal prostate cells. Moreover, combination of TET and Enz was more effective than either treatment alone. Treatment with TET resulted in decreased levels of full length AR as well as ARv7 within 24-48h. We also observed that TET treatment was associated with decreased cyclin D1 and increased CDK inhibitors p21 and p27. Over all Tet alone and in combination with Enz promoted cell growth arrest and cell death in ENZ resistant CRPC cells and sensitized these cells to Enz. CONCLUSIONS: This study shows that TET sensitizes CRPC cells to Enz in part by decreasing protein levels of AR and ARv7.

Expanded criteria in men on active surveillance monitored by MRI-TRUS fusion biopsy.

115 Background: Active surveillance (AS) is an established option for men with prostate cancer. Studies have shown that multiparametric-MRI along with MRI-TRUS fusion-guided biopsy (FB) may better assess risk in patients eligible for AS, compared to 12-core biopsy, due to improved detection of clinically significant cancers. The objective is to evaluate the performance of expanded criteria eligibility in men on AS being monitored with MRI-TRUS guided biopsy. Methods: Men on AS were included if they had mp-MRI and pathology data for 2 or more FB sessions. FB procedures consisted of targeted biopsies and random 12 core biopsies. Men participated in AS with low and intermediate risk prostate cancer, Gleason score ≤ 3+4=7 with no restriction on percent core involvement or number of cores positive. Progression was defined by patients with initial Gleason 3+3=6 to any Gleason 4, and Gleason 3+4=7 disease progressing to a primary Gleason 4 or higher. Results: 124 men on AS met study criteria. Low risk men had a ...

MP82-20 PREOPERATIVE MULTIPARAMETRIC PROSTATE MRI IDENTIFIES PATIENTS AT RISK FOR LYMPH NODE INVOLVEMENT AT RADICAL PROSTATECTOMY

Scholars Program, a public-private partnership supported jointly by the NIH and generous contributions to the Foundation for the NIH from Pfizer Inc., The Doris Duke Charitable Foundation, The Alexandria Real Estate Equities, Inc. and Mr. and Mrs. Joel S. Marcus, and the Howard Hughes Medical Institute, as well as other private donors. For a complete list, please visit the Foundation website at: http://fnih.org/work/education-training-0/ medical-research-scholars-program

MRI/US fusion-guided biopsy to detect clinically significant prostate cancer in the central gland correlating with index lesion.

44 Background: Central gland (CG) prostate cancers (CaP) are reported with lesser incidence and smaller tumor volume compared to the peripheral zone (PZ). Index tumor lesions defined by highest grade may be missed when in the CG. MRI/US fusion-guided biopsy allows targeting of lesions, potentially identifying cancer outside the traditional TRUS biopsy template. Methods: Retrospective review of 1,003 patients who underwent multiparametric MRI (mpMRI) found 2,119 suspicious lesions. Targets were biopsied and stratified by zonal distribution, CG or PZ. Cancer detection rates (CDR) were tabulated by location and correlated with PSA, Gleason score, prostate volume and MRI suspicion. Results: Fusion-guided biopsy targeted lesions in the central (711, 34%) or peripheral (1408, 66%) prostatic zones. CDR was similar between zones: 35.2% CG compared to 33.6% PZ (Table). CDR of clinically significant disease (Gleason >4+3) was similar in the CG and PZ despite higher prostate volume in those with CG lesions. In contr...