Citations

Abstract Pancreatic cancer is the fourth leading cause of cancer deaths in the United States and continues to be a disease with few options for treatment. Current therapeutic regimens for pancreatic cancer often include the nucleoside analog gemcitabine (GEM), but while it has been in use for many years, the overall five year survival rate continues to be about 5%. New therapies are urgently needed to treat this disease. The nutritional supplement gamma-linolenic acid (GLA) is a poly-unsaturated fatty acid (PUFA) of the n-6 PUFA family, and has garnered attention for its cytotoxic effects against tumor cell lines while not affecting normal cells. In this study we look at the effect GLA has on Panc-1 cells and its ability to increase the sensitivity of these cells to treatment with GEM. Through the use of cell viability assays, immunofluorescence, 3-D growth assays, and western blotting, our results show that GLA alone will inhibit growth and induce apoptosis in Panc-1 cells. When GLA is combined with GEM, the results are synergistically enhanced. In addition, our results show that GLA may act through disruption of lipid rafts in the cellular membrane and may activate the extrinsic apoptotic pathway causing cell death. These results suggest that the nutritional supplement GLA could be used in combination with GEM to increase the therapeutic effectiveness of GEM while treating pancreatic cancer. 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 3854. doi:1538-7445.AM2012-3854

Abstract SGI-110 is a novel second generation HMA, formulated as a low volume SQ injection. It is designed as a dinucleotide incorporating decitabine and guanosine, to prolong in vivo exposure and potentially improve efficacy of its active component, decitabine by protecting decitabine from rapid deamination by cytidine deaminase. Preclinically, SGI-110 demonstrated potent activity in-vivo using different routes of administration. A randomized Phase 1-2 FIH PK/PD-guided, dose-escalation study is being conducted in subjects with relapsed/refractory intermediate or high-risk MDS or AML. The objective of the first stage of the study is to determine the safety and tolerability of SGI-110 and to establish the MTD and the biologically effective dose (BED). Subjects are randomized to one of two SQ regimens (daily x5 or once weekly x3, both given in 28-day courses). PD is evaluated by LINE-1 global DNA hypomethylation. The second stage of the study will be a randomized Phase 2 dose expansion, once the BED and MTD have been determined. Currently, 5 dose-cohorts have been fully enrolled, (n= 55) at doses ranging from 3mg/m2 to 60 mg/m2 daily x5, and 6mg/m2 to 90 mg/m2 weekly x3 but are not yet fully evaluable. PK guidance has allowed rapid dose escalation, and PD assessment of global hypomethylation has been correlated with increased dose and exposure levels. Apart from manageable local injection site pain, SGI-110 has been well tolerated. Other AE's were neutropenia, thrombocytopenia, or anemia. There have been 3 remissions in relapsed AML subjects: 1 CR with weekly (60mg/m2) and 1 PR and 1 CR with daily (36 and 60 mg/m2 respectively). The PK profile showed efficient conversion of SGI-110 to decitabine achieving exposures in the therapeutic range as predicted from the SGI-110 rational design, characterized by decitabine AUC in therapeutic range (cohorts 4-5), lower Cmax, and longer effective half life, as compared to historical data based on molar equivalent doses of IV decitabine. Dose-dependent hypomethylation induction in the first 5 cohorts was observed. The subject who achieved a CR had the highest degree of hypomethylation induction of all subjects tested to date, and also the highest decitabine AUC in the cohort. Updated efficacy, safety, PK, and PD data of both regimens will be presented. SGI-110 is safe and well tolerated to date; biologically effective and therapeutic dose levels have been achieved with little toxicity so far with both regimens. Preliminary efficacy (PR+CR) has been observed in relapsed AML subjects. The PK profile showed efficient conversion of SGI-110 to decitabine with achievable therapeutic exposures, longer apparent half life, and lower Cmax than predicted equivalent decitabine doses given IV. Global Hypomethylating effects were observed at all dose levels, evaluated to date with both regimens. The results justify the progress of the study to the second dose-expansion Phase 2 stage after establishing the BED and MTD. 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-214. doi:1538-7445.AM2012-LB-214

Abstract Background. Autophagy maintains energy metabolism and enables tumor cell survival during cellular stress. Beclin 1 is involved in autophagosome formation during which membrane-bound LC3 binds to p62/sequestosome 1. We reported that ectopic p62 can promote 5-fluorouracil-induced cell death (JBC 286:40002-12, 2011). It is unknown whether these autophagy markers can predict clinical outcome. Materials & Methods. Beclin 1, LC3B, and p62 proteins were analyzed by immunohistochemistry in tissue microarrays containing stage II and III colon carcinomas (N=151) from patients receiving 5-FU or surgery alone. The mean weighted score (intensity x extent) was dichotomized for survival analysis using Cox models. Results. Increased levels of cytoplasmic LC3, Beclin 1, and p62 expression were detected in 21%, 14%, and 68% of cancers, respectively, and were not associated with tumor site, stage or grade. By multivariable analysis, increased LC3 was significantly associated with worse disease-free survival (DFS) (p=0.022), but not overall survival (OS) [p=0.069](Table). Beclin 1 was not prognostic, but increased p62 was significantly associated with improved DFS (p=0.038), but not OS (p= 0.176)[Table]. When restricted to 5-FU-treated patients, increased LC3 was associated with worse DFS [HR= 2.38 (1.19, 4.75, p=0.020), elevated Beclin 1 predicted worse OS [HR=2.83 (1.27, 6.34), p = 0.019], and p62 was not prognostic. Conclusion. LC3 and Beclin 1 overexpression were independently associated with adverse outcome. Increased p62 was associated with better outcome consistent with its ability to promote cell death. These data support strategies to inhibit autophagy for therapeutic advantage. 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 4112. doi:1538-7445.AM2012-4112

Abstract Background: Cyr61, also known as CCN1, is a survival and pro-angiogenic factor overexpressed in invasive breast tumors that promotes tumorigenicity. We investigated whether Cyr61 plays important roles in breast cancer and evaluated its potential role as a chemotherapeutical target. Methods: We analyzed Cyr61 expression in a tissue microarray from breast cancer patients consisting of primary breast carcinomas and recurrences. Cyr61 was silenced in the metastatic MDA-MB-231 cells using a Cyr61-specific short hairpin RNA (Cyr61-shRNA). The effect of Cyr61 silencing on anchorage dependent- and independent growth, migration and invasiveness was characterized in vitro. The mechanism by which Cyr61 mediates the proliferation effects was investigated. The effect of Cyr61 in tumor growth was investigated in a subcutaneous orthotopic tumor xenograft model and the histological and immunohistochemical analysis ware performed. All statistical tests were two-sided. Results: Cyr61 is highly expressed in about 47% of the metastatic breast cancer patients analyzed. The expression is higher in the recurrences than in the primary tumors. Silencing Cyr61 inhibits cell proliferation, prevents anchorage-dependent and -independent growth, and suppresses the invasive potential of the cells by inhibiting migration in vitro. We also found that silencing Cyr61 decreases the expression of its own receptor αvβ3, and decreases its signaling activities. Remarkably, the in vivo studies showed that after silencing Cyr61 the tumor burden is significantly decreased and there is poor vascularized compared to control tumors. Conclusions: Our findings provide the proof of concept that Cyr61 is a key promoter of breast cancer tumorigenicity. It should be considered as a potential target for developing therapies to breast cancers patients that overexpress Cyr61. 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 1846. doi:1538-7445.AM2012-1846

Abstract Lung cancer is the most common cause of smoking-related mortality in worldwide. However, approximately 10 to 25 % cases are not attributable to smoking. Cumulative evidence suggests that lung cancer from never smokers (<100 cigarettes lifetime) may develop via molecular mechanisms that are different from lung cancers in smokers. Recently, miRNAs have been identified as a new class of regulatory molecules that participate in a variety of biological processes. Because each miRNAs can potentially target a large set of mRNA making and therefore may play a critical role in lung tumorigenesis and patient outcome, we sought to examine the role of miRNA in lung adenocarcinoma among never smokers. A total of 298 samples were analyzed in this study including 168 fresh frozen (FF) tissues from 88 lung adenocarcinomas and 80 adjacent non-involved lung tissues; and 132 formalin-fixed paraffin embedded (FFPE) tissues from 68 tumors and 64 normal lung samples. Gene expression profiling was performed for miRNA and mRNA using Illumina Whole Genome DASL platform. We identified 20 miRNAs with the most significant expression changes between the tumor and normal in both FF and FFPE samples (Fold change > 1.5, p <0.01, FDR <0.05). We also examined mRNA expression signature using 56 matched FF tumors and normal lung tissues. Cox proportional hazard analysis was performed independently for both FF and FFPE cohorts and showed that increased expression of mir-708 was strongly associated with an increased risk of patient death after adjusting for age, sex and tumor stage (FF cohort, HR =1.92; 95% CI =1.02–3.63; p < 0.05 and FFPE cohort, HR=1.90; 95% CI=1.08–3.34; P < 0.05). Candidate biological targets of mir-708 were identified using TargetScan and MicroCosm Targets databases. A total of 13 candidate genes were found and one of these genes, CMT11 (Candidate Mir-708 Target), was down-regulated 1.6 fold on average in tumors that were high in mir-708 expression. Based on the sequence, CMT11 is a novel transmembrane protein. In Cox analysis, reduced CMT11 expression was strongly correlated with an increased risk of death in patients (HR = 2.43, 95% CI = 1.17 − 5.26; P <0.01). Functionally, overexpression of mir-708 in A549 and HEK293T cells significantly increased the rate of cellular proliferation and migration. Over expression of mir-708 in HEK293T cells also repressed ∼70% of the luciferase activity when the reporter RNA contained the 3′ UTR of CMT11. Recently, several studies have showed mir-708 is a potential squamous cell lung cancer marker and one of miRNAs that may predict the recurrence of Stage I lung cancer after surgical resection. Additional evidence also suggests that CMT11 is a negative regulator of Wnt-signaling pathway. Our data provides clinical and functional evidence supporting an important role of mir-708 in lung cancer progression and identifies CMT11 as a down stream target gene mediating this process. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr LB-346. doi:10.1158/1538-7445.AM2011-LB-346

Abstract Some studies show that childbearing at older age is associated with lower risk of endometrial cancer, but whether the association is independent of number of children or other factors still requires clarification. We pooled individual-level data from epidemiologic studies in the Epidemiology of Endometrial Cancer Consortium (E2C2). Data on age at last birth and/or last pregnancy were available from 14 studies: 11 case-control studies and 3 cohort studies; the latter were analyzed using a nested case-control design. A total of 9,613 endometrial cancer cases and 17,112 controls were included in the analysis. The majority of women were White (82%) and older than 55 years (69%). We estimated the effects of age at last birth using data from 12 studies and age at last pregnancy using data from 10 studies on the risk of endometrial cancer by calculating odds ratios (OR) and 95% confidence intervals (95% CI) using logistic regression models. Potential confounders included in the analysis were race, body mass index, parity, age at menarche, age at first birth, oral contraceptive use, postmenopausal hormone use, smoking status, and report of diabetes. After adjusting for potential confounders, a reduction in endometrial cancer risk was observed in women with increasing age at last birth (P trend <0.0001) and age at last pregnancy (P trend <0.0001). The OR per five-year increase in age at last birth and age at last pregnancy was 0.90 (95%CI: 0.86, 0.94) and 0.91 (95% CI: 0.87, 0.95), respectively. Women who had their last child at an age >40 years were at a 34% decreased risk compared with women who had their last child at an age <25 years (95% CI: 0.52, 0.82). Compared to women with age at last pregnancy <25 years, those with age at last pregnancy >40 years had a 30% decreased risk of endometrial cancer (95%CI: 0.57, 0.86). Inverse associations were observed for Whites and Asians in race-specific analysis and also in analysis restricted to women with at least 2 births. In this large pooled analysis, we show that late age at last birth or last pregnancy is a strong and independent protective factor for endometrial cancer. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 1900. doi:10.1158/1538-7445.AM2011-1900

Abstract Background. Several recent studies have reported an inverse relationship between sun exposure and non-Hodgkin (NHL) risk. One hypothesis is that vitamin D mediates this effect. We evaluated the association of sun exposure at various ages and common variants in vitamin D related genes with risk of NHL and its major subtypes. Methods. Newly diagnosed NHL cases (N=1023) and frequency matched controls (N=1254) were enrolled in a clinic-based case-control study conducted at the Mayo Clinic. Thirty-eight single nucleotide polymorphisms (SNPs) from 5 candidate genes relevant to vitamin D metabolism and sun sensitivity (IRF4, RXR, VDR, CYP24A1, CYP27B1) were genotyped. Participants also completed a detailed questionnaire, including self-reported sun exposure at ages 13-21, 22-40, and 41+ years. Odds ratios (OR), 95% confidence intervals (CI), and tests for trend and effect modification were estimated using unconditional logistic regression adjusted for age and gender. ORs are reported for the highest vs. lowest exposure category or as the ordinal OR for SNPs. Results. The mean age of diagnosis/enrollment was 61 years for cases and 60 years for controls. The most common subtypes were chronic lymphocytic leukemia/small lymphocytic lymphoma (CLL/SLL; 34%), follicular (FL; 24%), and diffuse large B-cell (DLBCL; 18%) lymphomas. There was a significant decrease in NHL risk with increased sun exposure at ages 13-21 years (OR=0.66, 95% CI 0.44-1.00; ptrend=0.04), which attenuated with increasing age at exposure. Exploratory analysis by NHL subtype indicated a trend toward a protective effect of sun exposure at ages 13-21 years for each of the major subtypes, though these estimates did not reach statistical significance. Of the 38 SNPs evaluated, there was a significant association for 3 SNPs in VDR and 1 SNP in CYP24A1: rs3819545 (OR=1.24, 95% CI 1.10-1.40, p=0.0004), rs2239186 (OR=1.22, 95% CI 1.05-1.41, p=0.009), and rs886441 (OR=0.82, 95% CI 0.70-0.96, p=0.02) for VDR and rs2762939 (OR=0.85, 95% CI 0.75-0.98, p=0.02) for CYP24A1. Both the VDR and CYP24A1 associations were observed for CLL/SLL, FL, but were attenuated for DLBCL. There was no evidence of any significant effect modification of sun exposure at ages 13-21 years by genotype in these four SNPs for NHL overall, or for NHL subtypes. Conclusions. We observed an inverse association between the frequency of sun exposure at ages 13-21 years and NHL risk, which attenuated for sun exposure at older ages, suggesting that early life exposure may be more relevant. While genetic variation in VDR and CYP24A1 were associated with NHL risk, there was no evidence for an interaction of sun exposure with these genes, suggesting that a sun association may not act through the vitamin D metabolism pathway. This would be consistent with a lack of association of circulating vitamin D with NHL risk recently published from the Cohort Consortium pooling project. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 1894. doi:10.1158/1538-7445.AM2011-1894

Background— Use of the left internal mammary artery (LIMA) in multivessel coronary artery disease improves survival after coronary artery bypass graft surgery; however, the survival benefit of multiple arterial (MultArt) grafts is debated. Methods and Results— We reviewed 8622 Mayo Clinic patients who had isolated primary coronary artery bypass graft surgery for multivessel coronary artery disease from 1993 to 2009. Patients were stratified by number of arterial grafts into the LIMA plus saphenous veins (LIMA/SV) group (n=7435) or the MultArt group (n=1187). Propensity score analysis matched 1153 patients. Operative mortality was 0.8% (n=10) in the MultArt and 2.1% (n=154) in the LIMA/SV ( P =0.005) group, which was not statistically different ( P =0.996) in multivariate analysis or the propensity-matched analysis ( P =0.818). Late survival was greater for MultArt versus LIMA/SV (10- and 15-year survival rates were 84% and 71% versus 61% and 36%, respectively [ P <0.001], in unmatched groups and 83% and 70% versus 80% and 60%, respectively [ P =0.0025], in matched groups). MultArt subgroups with bilateral internal mammary artery/SV (n=589) and bilateral internal mammary artery only (n=271) had improved 15-year survival (86% and 76%; 82% and 75% at 10 and 15 years [ P <0.001]), and patients with bilateral internal mammary artery/radial artery (n=147) and LIMA/radial artery (n=169) had greater 10-year survival (84% and 78%; P <0.001) versus LIMA/SV. In multivariate analysis, MultArt grafts remained a strong independent predictor of survival (hazard ratio, 0.79; 95% confidence interval, 0.66–0.94; P =0.007). Conclusions— In patients undergoing isolated coronary artery bypass graft surgery with LIMA to left anterior descending artery, arterial grafting of the non–left anterior descending vessels conferred a survival advantage at 15 years compared with SV grafting. It is still unproven whether these results apply to higher-risk subgroups of patients.

Abstract Purpose: Aflibercept is a novel decoy receptor that efficiently neutralizes circulating VEGF. A pediatric phase I trial was conducted to define the dose-limiting toxicities (DLT), maximum tolerated dose (MTD), and pharmacokinetics (PK) of aflibercept. Experimental Design: Cohorts of three to six children with refractory solid tumors received aflibercept intravenously over 60 minutes every 14 days, at 2.0, 2.5, or 3.0 mg/kg/dose. PK sampling and analysis of peripheral blood biomarkers were conducted with the initial dose. Results: Twenty-one eligible patients were enrolled; 18 were fully evaluable for toxicity. One of six patients receiving 2.0 mg/kg/dose developed dose-limiting intratumoral hemorrhage and two of six receiving 3.0 mg/kg/dose developed either dose-limiting tumor pain or tissue necrosis. None of the six patients receiving 2.5 mg/kg/dose developed DLTs, defining this as the MTD. The most common non-DLTs were hypertension and fatigue. Three patients with hepatocellular carcinoma, hepatoblastoma and clear cell sarcoma had stable disease for &gt;13 weeks. At the MTD, the ratio of free-to-bound aflibercept serum concentration was 2.10 on day 8 but only 0.44 by day 15. A rapid decrease in VEGF (P &lt; 0.05) and increase in placental growth factor (PlGF; P &lt; 0.05) from baseline was observed in response to aflibercept by day 2. Conclusions: The aflibercept MTD in children of 2.5 mg/kg/dose every 14 days is lower than the adult recommended dose of 4.0 mg/kg. This dose achieves, but does not sustain, free aflibercept concentrations in excess of bound. Tumor pain and hemorrhage may be evidence of antitumor activity but were dose-limiting. Clin Cancer Res; 18(18); 5081–9. ©2012 AACR.