Citations

Abstract Purpose: Ovarian cancer has a high recurrence and mortality rate. A barrier to improved outcomes includes a lack of accurate models for preclinical testing of novel therapeutics. Experimental Design: Clinically relevant, patient-derived tumorgraft models were generated from sequential patients and the first 168 engrafted models are described. Fresh ovarian, primary peritoneal, and fallopian tube carcinomas were collected at the time of debulking surgery and injected intraperitoneally into severe combined immunodeficient mice. Results: Tumorgrafts demonstrated a 74% engraftment rate with microscopic fidelity of primary tumor characteristics. Low-passage tumorgrafts also showed comparable genomic aberrations with the corresponding primary tumor and exhibit gene set enrichment of multiple ovarian cancer molecular subtypes, similar to patient tumors. Importantly, each of these tumorgraft models is annotated with clinical data and for those that have been tested, response to platinum chemotherapy correlates with the source patient. Conclusions: Presented herein is the largest known living tumor bank of patient-derived, ovarian tumorgraft models that can be applied to the development of personalized cancer treatment. Clin Cancer Res; 20(5); 1288–97. ©2014 AACR.

IntroductionMuscle sympathetic nerve activity (MSNA) is an independent prognostic marker in patients with heart failure (HF). Therefore, its relevance to the treatment of HF patients is unquestionable.ObjectivesIn this study, we investigated the effects of cardiac resynchronization therapy (CRT) on MSNA response at rest and during exercise in patients with advanced HF.MethodsWe assessed 11 HF patients (51 ± 3.4 years; New York Heart Association class III–IV; left ventricular ejection fraction 27.8 ± 2.2%; optimal medical therapy) submitted to CRT. Evaluations were made prior to and 3 months after CRT. MSNA was performed at rest and during moderate static exercise (handgrip). Peak oxygen consumption (VO2) was evaluated by means of cardiopulmonary exercise test. HF patients with advanced NYHA class without CRT and healthy individuals were also studied.ResultsCRT reduced MSNA at rest (48.9 ± 11.1 bursts/min vs 33.7 ± 15.3 bursts/min, P < 0.05) and during handgrip exercise (MSNA 62.3 ± 13.1 bursts/min vs 46.9 ± 14.3 bursts/min, P < 0.05). Among HF patients submitted to CRT, the peak VO2 increased (12.9 ± 2.8 mL/kg/min vs 16.5 ± 3.9 mL/kg/min, P < 0.05) and an inverse correlation between peak VO2 and resting MSNA (r = –0.74, P = 0.01) was observed.ConclusionsIn patients with advanced HF and severe systolic dysfunction: (1) a significant reduction of MSNA (at rest and during handgrip) occurred after CRT, and this behavior was significantly superior to HF patients receiving only medical therapy; (2) MSNA reduction after CRT had an inverse correlation with O2 consumption outcomes.

AbstractBackgroundLiver biopsy has been the reference standard when evaluating fibrosis due to recurrent hepatitis after liver transplantation. Magnetic resonance elastography estimates liver stiffness, correlating to fibrosis.AimTo investigate the utility of elastography in staging liver fibrosis in transplant recipients with hepatitis C.MethodsFifty‐four patients, ≥12 months post‐transplant, underwent elastography within three months of biopsy. Discriminatory capability for METAVIR fibrosis stages F0–2 vs. F3–4 and receiver operating characteristic curve (ROC) analysis were determined.ResultsOn biopsy, 27 patients had METAVIR fibrosis score 0–1; 12 had a 3 or 4. There was significant correlation between histologic fibrosis and shear stiffness (R² = 0.588, p < 0.0001). Using a cutoff value of 3.5 kPa, elastography was 91% sensitive and 72% specific in differentiating fibrosis scores of ≥3 from 0 to 1. The AUC of elastography in predicting a fibrosis score of ≥3 was 0.92. Multivariate analysis revealed no correlation between the grade of histologic inflammation and liver stiffness measured by magnetic resonance elastography (R² = 0.265, p = 0.47).ConclusionMagnetic resonance elastography is an accurate non‐invasive technique for excluding stage ≥3 graft in recipients with hepatitis C.

TGR5, the G protein-coupled bile acid receptor that transmits bile acid signaling into a cell functional response via the intracellular cAMP signaling pathway, is expressed in human and rodent cholangiocytes. However, detailed information on the localization and function of cholangiocyte TGR5 is limited. We demonstrated that in human (H69 cells) and rat cholangiocytes, TGR5 is localized to multiple, diverse subcellular compartments, with its strongest expression on the apical plasma, ciliary, and nuclear membranes. To evaluate the relationship between ciliary TGR5 and the cholangiocyte functional response to bile acid signaling, we used a model of ciliated and nonciliated H69 cells and demonstrated that TGR5 agonists induce opposite changes in cAMP and ERK levels in cells with and without primary cilia. The cAMP level was increased in nonciliated cholangiocytes but decreased in ciliated cells. In contrast, ERK signaling was induced in ciliated cholangiocytes but suppressed in cells without cilia. TGR5 agonists inhibited proliferation of ciliated cholangiocytes but activated proliferation of nonciliated cells. The observed differential effects of TGR5 agonists were associated with the coupling of TGR5 to Gα i protein in ciliated cells and Gα s protein in nonciliated cholangiocytes. The functional responses of nonciliated and ciliated cholangiocytes to TGR5-mediated bile acid signaling may have important pathophysiological significance in cilia-related liver disorders (i.e., cholangiociliopathies), such as polycystic liver disease. In summary, TGR5 is expressed on diverse cholangiocyte compartments, including a primary cilium, and its ciliary localization determines the cholangiocyte functional response to bile acid signaling.

Abstract Primary cilia are multisensory organelles recently found to be absent in some tumor cells, but the mechanisms of deciliation and the role of cilia in tumor biology remain unclear. Cholangiocytes, the epithelial cells lining the biliary tree, normally express primary cilia and their interaction with bile components regulates multiple processes, including proliferation and transport. Using cholangiocarcinoma as a model, we found that primary cilia are reduced in cholangiocarcinoma by a mechanism involving histone deacetylase 6 (HDAC6). The experimental deciliation of normal cholangiocyte cells increased the proliferation rate and induced anchorage-independent growth. Furthermore, deciliation induced the activation of mitogen-activated protein kinase and Hedgehog signaling, two important pathways involved in cholangiocarcinoma development. We found that HDAC6 is overexpressed in cholangiocarcinoma and overexpression of HDAC6 in normal cholangiocytes induced deciliation and increased both proliferation and anchorage-independent growth. To evaluate the effect of cilia restoration on tumor cells, we targeted HDAC6 by short hairpin RNA (shRNA) or by the pharmacologic inhibitor, tubastatin-A. Both approaches restored the expression of primary cilia in cholangiocarcinoma cell lines and decreased cell proliferation and anchorage-independent growth. The effects of tubastatin-A were abolished when cholangiocarcinoma cells were rendered unable to regenerate cilia by stable transfection of IFT88-shRNA. Finally, inhibition of HDAC6 by tubastatin-A also induced a significant decrease in tumor growth in a cholangiocarcinoma animal model. Our data support a key role for primary cilia in malignant transformation, provide a plausible mechanism for their involvement, and suggest that restoration of primary cilia in tumor cells by HDAC6 targeting may be a potential therapeutic approach for cholangiocarcinoma. Cancer Res; 73(7); 2259–70. ©2013 AACR.

Abstract Learning Objectives Discuss methods for improving the efficiency of global clinical trials. Explain the need for national regulatory authorities and collaborative cancer groups to initiate efforts to quicken the activation process in their countries. Describe the activation process of phase III studies and its complex and heterogeneous regulation across different geographic and economic regions. Purpose. This study measured the time taken for setting up the different facets of Adjuvant Lapatinib and/or Trastuzumab Treatment Optimization (ALTTO), an international phase III study being conducted in 44 participating countries. Methods. Time to regulatory authority (RA) approval, time to ethics committee/institutional review board (EC/IRB) approval, time from study approval by EC/IRB to first randomized patient, and time from first to last randomized patient were prospectively collected in the ALTTO study. Analyses were conducted by grouping countries into either geographic regions or economic classes as per the World Bank's criteria. Results. South America had a significantly longer time to RA approval (median: 236 days, range: 21–257 days) than Europe (median: 52 days, range: 0–151 days), North America (median: 26 days, range: 22–30 days), and Asia-Pacific (median: 62 days, range: 37–75 days). Upper-middle economies had longer times to RA approval (median: 123 days, range: 21–257 days) than high-income (median: 47 days, range: 0–112 days) and lower-middle income economies (median: 57 days, range: 37–62 days). No significant difference was observed for time to EC/IRB approval across the studied regions (median: 59 days, range 0–174 days). Overall, the median time from EC/IRB approval to first recruited patient was 169 days (range: 26–412 days). Conclusion. This study highlights the long time intervals required to activate a global phase III trial. Collaborative research groups, pharmaceutical industry sponsors, and regulatory authorities should analyze the current system and enter into dialogue for optimizing local policies. This would enable faster access of patients to innovative therapies and enhance the efficiency of clinical research.

Abstract Despite advances in chemotherapeutic options over the last four decades, ovarian cancer remains the most lethal gynecologic malignancy with a cure rate that is essentially unchanged. A major barrier is lack of treatment-naïve, clinically- relevant in vivo models of epithelial ovarian cancer (EOC). To target this problem, we have developed low-passage in vivo models of EOC derived from patient primary debulking procedures at Mayo Clinic (Rochester, MN). Tumors were obtained from consented patients with suspected ovarian cancer, minced and injected into severe combined immunodeficiency (SCID) mice intraperitoneally for model establishment. To the date, we have heterotransplanted 129 EOC or ovarian malignant mixed mullerian (MMMT) tumors. The most common histologic subtype is serous (70.5%), followed by endometrioid (12.4%), clear cell (6.9%), and others (9.9%). The tumors were injected intraperitoneally into severe combined immunodeficiency (SCID) mice and the average time to moribund (TTM) was 174 +/− 83 days. In general, tumors grew faster with serial passages, TTM for epithelial tumors was 87 +/− 15 days and 19.5 +/− 3 days for MMMT. De novo ascites developed in 17 models and 24 models developed bowel metastasis, two clinically-relevant complications in late-stage ovarian cancer patients. Tumorgrafts were histologically similar to their source patient tumors and were positive for expression epithelial markers (pan-cytokeratin). The engraftment rate was 72.4% (n=87) after ≤ 6 months of lead-time, which is the average time to tumorgraft harvest. Passage of well-established tumorgrafts in SCID mice was successful in 88.6 % (n= 70) of all mice but only 56% (n=16) of athymic nude mice, consistent with prior studies demonstrating improved engraftment rates in more immunodeficient mice. Molecular characterization of tumorgrafts by array comparative genomic hybridization revealed similar gains and losses between the patient, early-passage, and later-passage tumorgraft tissues, indicating the tumorgrafts were genetically similar to their primary tumor. Analysis of tumorgrafts using the Affymetrix Human Plus 2.0 arrays revealed a predominance of previously described molecular subtypes C3, C4, and C5. Current investigations with both standard chemotherapy and novel targeted therapies are ongoing. Taken together, these models are as diverse as the patient population from which they are derived, produce clinically-relevant complications of EOC, maintain genetic fidelity in SCID mice, and are useful preclinical models for testing and development of novel therapeutics for ovarian cancer. High rates of engraftment are feasible. These tumorgrafts may help define predictors of response and eventually, lead to better treatments for patients. This work is funded by the Mayo Ovarian SPORE (CA136393) and the Minnesota Ovarian Cancer Alliance. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 3274. doi:1538-7445.AM2012-3274

Abstract Cholangiocarcinoma (CCA) is a malignancy arising from cholangiocytes, the epithelial cells lining the biliary tree. Cholangiocytes normally express primary cilia extending from their apical plasma membrane into the ductal lumen. Our data show that CCA cells are devoid of primary cilia both in vivo and in vitro; therefore, ciliary loss may be associated with cancer development. Histone deacetylase 6 (HDAC6) is localized to the cell cytoplasm and functions as a tubulin deacetylase, and the activation of HDAC6 promotes ciliary disassembly. Therefore, we hypothesized that in CCA, overexpression of HDAC6 induces the resorption of primary cilia leading to derepression of tumorigenic signaling pathways and development of a malignant phenotype. To test this hypothesis, we analyzed the effect of pharmacologic and molecular deciliation on the phenotype of two normal human cholangiocyte cell lines (H69, NHC) using chloral hydrate treatment or shRNA silencing of IFT88, respectively. We found that deciliation increased the proliferation rate of cholangiocytes and induced anchorage independent growth and invasion. Furthermore, deciliation induced the activation of MAPK and Hh signaling pathways by 6- and 3-fold, respectively. To begin to understand why CCA cells lack cilia, we assessed expression of HDAC6 by western blot analysis on two different CCA cell lines (Hucct-1 and KMCH); we found increased expression (by 100%) of HDAC6 compared to normal cultured cholangiocytes (H69). Interestingly, overexpression of HDAC6 correlated with the decreased amount of its target, acetylated α-tubulin. Using confocal immunofluorescence microscopy, we also observed that HDAC6 was overexpressed in liver specimens from patients with CCA compared to normals. Furthermore, the in vitro overexpression of HDAC6 in normal cells induced deciliation, increased proliferation, anchorage independent growth, and invasion. Finally, to evaluate the effect of cilia restoration on tumor cells, we targeted HDAC6 by shRNA silencing or by the inhibitor tubastatin-A, and found that HDAC6 downregulation restored the expression of primary cilia in a cancer cell line, decreased cell proliferation (by 30%), and anchorage-independent growth (by 50%). When tumor cells unable to regenerate cilia by the stably transfection of IFT88 shRNA were used, the effects of tubastatin-A were abolished. In summary, expression of primary cilia is decreased in CCA by a mechanism involving the overexpression of HDAC6. Experimental deciliation of normal cholangiocytes induces a malignant phenotype as shown by increased cell proliferation, anchorage independent growth, invasion, and activation of Hh and MAPK signaling pathways. We speculate that the restoration of primary cilia in tumor cells by HDAC6 targeting may be a potential therapeutic approach for cholangiocarcinoma. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr LB-505. doi:1538-7445.AM2012-LB-505

Abstract Objective The prevalence and mortality for head and neck cancer (HNC) has not improved significantly in the last several decades. It is the sixth most common cancer with an estimated 600,000 new cases diagnosed worldwide every year and has ∼50% 5-year survival rate. Of these, 47000 new cases are diagnosed in the US annually. The most common risk factors for HNC are tobacco and alcohol use but a growing subset is also attributed to human papillomavirus (HPV) infection. Late stage HNCs are treated with a combination of surgery, radiation, and chemotherapy (often platinum-based), but the cancers treated with platinum-based chemotherapy often develop drug resistance. Identification of target genes using high-throughput RNAi (HT-RNAi) gene-silencing technology has become an increasingly popular method in the field of cancer research. The objective of our study is to use this functional genomics based approach to identify genes that, when silenced, increase the sensitivity of the platinum drugs. This would possibly help us in identifying potentiators of platinum-based drugs to more effectively treat HNC patients. Methods We performed drug dose response (DDR) experiments on nine HNC cell lines; including two are HPV-positive lines, to identify cisplatin-resistant and -sensitive cancer cell lines. To identify sensitizers of cisplatin response, we used a siRNA library targeting 572 kinases. Each kinase is represented by two different siRNA sequences in the library. Based on the data mined from published literature on head and neck cancer as well as genes thought to confer a functional relationship between HPV infection and HNC, a more focused siRNA library was also designed and included in the screening. Cell lines were reverse transfected with the siRNAs in a 384 well format, dosed with cisplatin after 24 hours and the plates were read 72 hours later. Results We calculated the inhibitory concentrations using DDR experiments for all the nine HNC cell lines and identified cisplatin-resistant (UMSCC47 and SCC9) and -sensitive (Cal27, UMSCC14C, and SCC090) HNC cell lines. HT-RNAi experiments have been performed on the cisplatin-resistant cell lines, one of which is HPV-positive. After data analysis, confirmation of silencing and validation of drug modulation will be done on a subset of candidate genes. Conclusions HNC patients with surgically non-resectable tumors could have improved treatment with chemotherapeutic drugs; however, acquired drug resistance often inhibits a successful treatment. Identification of sensitizing targets may provide hope for a better outcome, but may also allow for use of smaller doses of more toxic drugs, such as cisplatin. In addition, this study may also identify alternate genes that can be targeted in the subset of HPV-positive HNC. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 5136. doi:1538-7445.AM2012-5136