Citations

277 Background: SM88 is an oral tyrosine isomer ( TI) and repurposed drugs (CYP3a4 inducer, mTOR inhibitor, oxidative stress catalyst). This regimen has reported no drug related grade 3, 4 or 5 adverse events (JCO 2013 31: e22095) and potential clinical activity in PC (JCO 2018 36: TPS 4156). PC patients have risk factors for malabsorption and a cachexia syndrome rendering some oral therapies potential unreliable. We present PK data from the completely enrolled first stage of an ongoing dose finding phase II in PC. Methods: Open label randomized TI (control – 230 mg bid vs. experimental - 430 mg bid) along with the lowest approved doses of the other agents. Samples were drawn from four patients at pre-dose and up to six h post dosing on cycle day one for two cycles after a single dose of all four components. Results: Mean age: 71.3 (59 – 80), BMI = 25.3 (21.9 – 28.8) and median three prior chemo lines, two post-pancreas surgery and one s/p RT. There was no evidence that the combination altered the expected PKs at C2. There were no serious drug related adverse events. Favorable RECIST, PERCIST or biomarker activity was documented at both TI dose levels. The PK results of the repurposed drugs were consistent with the published data for these agents, despite the combination use and lower than typical label doses; data will be provided. These results were consistent with previous animal and healthier patient PK of SM88. Conclusions: Single dose C1 and C2 TI PKs are consistent with preclinical predictions (ESMO 2016. Ann Oncol (2016) 27 (supp_6): 1605P) and those previously reported in a healthier population of cancer patients (JCO 2018 36: TPS 4156). Based on these results and PK ones from the repurposed drugs, additional data is being collected in order to define the ongoing phase II expansion cohort dose. SM-88 appears to have predictable PK even in heavily pretreated PC patient with prior radiotherapy and surgery. Clinical trial information: NCT03512756. [Table: see text]

293 Background: Cholangiocarcinoma (CCA) is a deadly cancer with ~20% five year survival. Obtaining tissue to confirm diagnosis of CCA is often challenging. This also limits the use of tumor genotyping that could guide potential molecularly targeted treatment (such as FGFR inhibitors for a subset of cases). We investigated whether circulating tumor DNA (ctDNA) analysis in plasma is feasible for noninvasive tumor genotyping in patients with advanced CCA. Methods: We collected and processed plasma samples for ctDNA analysis from 17 patients with CCA at presentation and from 11 healthy volunteers. Following cell-free DNA extraction and quality assessment using digital PCR, we performed low-pass, shallow whole genome sequencing (sWGS). We analyzed sequencing data to identify copy number aberrations and quantify tumor fraction in plasma using recently published computational approaches. Results: Median total cfDNA concentration in patients with CCA was 7,003 genome equivalents (GEs)/mL plasma (range: 1,512- 107,707 GEs/mL) and significantly higher than healthy volunteers (two tailed t-test p < 0.04, median: 1,658 GEs/mL, range: 661-4,938 GEs/mL). We successfully sequenced all tumor libraries, generating a median of 173 million paired-end reads. ctDNA was detectable in 10/17 samples using sWGS. In these 10 samples, median tumor fraction in plasma DNA was 7.1% (range: 3.9%-44.6%). We found recurrent copy number aberrations expected in CCA including 1q gain in 80%, 7p gain in 50%, 1p loss in 70% and 3p loss in 50% of cases. Conclusions: ctDNA analysis for noninvasive tumor genotyping is feasible in patients with advanced cholangiocarcinoma. On-going work is focused on expanding these results using targeted and whole-exome sequencing.

Objective Despite advances in the identification of epigenetic alterations in pancreatic cancer, their biological roles in the pathobiology of this dismal neoplasm remain elusive. Here, we aimed to characterise the functional significance of histone lysine methyltransferases (KMTs) and demethylases (KDMs) in pancreatic tumourigenesis. Design DNA methylation sequencing and gene expression microarrays were employed to investigate CpG methylation and expression patterns of KMTs and KDMs in pancreatic cancer tissues versus normal tissues. Gene expression was assessed in five cohorts of patients by reverse transcription quantitative-PCR. Molecular analysis and functional assays were conducted in genetically modified cell lines. Cellular metabolic rates were measured using an XF24-3 Analyzer, while quantitative evaluation of lipids was performed by liquid chromatography-mass spectrometry (LC-MS) analysis. Subcutaneous xenograft mouse models were used to evaluate pancreatic tumour growth in vivo. Results We define a new antitumorous function of the histone lysine (K)-specific methyltransferase 2D (KMT2D) in pancreatic cancer. KMT2D is transcriptionally repressed in human pancreatic tumours through DNA methylation. Clinically, lower levels of this methyltransferase associate with poor prognosis and significant weight alterations. RNAi-based genetic inactivation of KMT2D promotes tumour growth and results in loss of H3K4me3 mark. In addition, KMT2D inhibition increases aerobic glycolysis and alters the lipidomic profiles of pancreatic cancer cells. Further analysis of this phenomenon identified the glucose transporter SLC2A3 as a mediator of KMT2D-induced changes in cellular, metabolic and proliferative rates. Conclusion Together our findings define a new tumour suppressor function of KMT2D through the regulation of glucose/fatty acid metabolism in pancreatic cancer.

Abstract Recently, the use of oncolytic viruses encoding the sodium-iodide symporter (NIS) has become an attractive approach to achieve radionuclide imaging of cancer. However, the potential of virus-induced NIS expression to facilitate therapy with radioactive 131I has not been fully explored. We designed a tumor-selective, infectivity-improved oncolytic adenovirus (Ad5/3-Cox2-NIS-ADP) modified to express high quantities of NIS. This virus induced radioisotope uptake in prostate and lung cancer cells and facilitated SPECT/CT imaging, but more importantly, supported the effective therapy with 131I. In our original vector, enhanced oncolysis was mediated by overexpression of adenoviral death protein (ADP). Although this structure was operative in detection and therapeutic regimens, we were concerned that the cytolytic effect of ADP may affect NIS membrane localization, and diminish its effectiveness as a theranostic tool. We therefore designed an identical Ad5/3-Cox2-NIS-ADP-deleted virus {ADP(-)} and assessed the impact of ADP on NIS expression and radioisotope uptake. Western blot and immunocytochemical analyses of pancreatic cancer cells infected with ADP(-) demonstrated higher NIS levels when compared to the ADP(+) counterpart. This correlated with an improved 125I uptake in vitro. SPECT/CT imaging studies assessing 99mTcO4- accumulation in mice to visualize pancreatic adenocarcinoma (PDAC) using patient-derived xenografts (PDX) showed that a single dose of ADP(-) accumulated far greater levels of 99mTcO4- when compared to ADP(+). Remarkably, ADP(-) produced stronger signal that was maintained up until day 32, and this outlasted ADP(+) and the control vector, replication-deficient AdCMV-NIS, currently employed in a clinical trial. Notably, within the PDAC, ADP(-) showed a distinct NIS cell membrane distribution pattern as it co-localized with cell membrane bound-cytokeratin-4. Unlike ADP(-), ADP(+) produced a punctate NIS staining pattern, with little to no cell membrane localization. These results support our hypothesis that ADP-cytolytic effect reduces NIS membrane localization, subsequently affecting radionuclide uptake. To evaluate the therapeutic potential of NIS-based radiotherapy, we treated mice bearing PDAC tumors with virotherapy alone or in combination with 131I. NIS-expressing OAds in combination with 131I significantly reduced tumor growth when compared to viro- or radiotherapy alone. The therapeutic effect in mice treated with ADP(-) combined with 131I outperformed that with ADP(+) or AdCMV-NIS vectors. Quantitative analyses of 131I uptake in tumor tissues with a gamma counter showed a clear trend where ADP(-) retained higher 131I uptake than ADP(+). These findings support the clinical applicability of the ADP-deleted OAd as the more sensitive tool for NIS-based cancer diagnosis and therapy. We are currently investigating the biodistributon and toxicity of our vectors in a pig model. Citation Format: Lisa Koodie, Eriko Iguchi Kawakami, Kari Jacobsen, Zuzan Cayci, Andrew Taylor, Edward W. Greeno, Robert J. Schumacher, John C. Morris, Martin E. Fernandez-Zapico, Julia Davydova. A novel oncolytic adenovirus for radioiodine therapy and imaging [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 5925.

AbstractBackground: Pathogenic germline mutations in the CDKN2A tumor suppressor gene are rare and associated with highly penetrant familial melanoma and pancreatic cancer in non-Hispanic whites (NHW). To date, the prevalence and impact of CDKN2A rare coding variants (RCV) in racial minority groups remain poorly characterized. We examined the role of CDKN2A RCVs on the risk of pancreatic cancer among minority subjects.Methods: We sequenced CDKN2A in 220 African American (AA) pancreatic cancer cases, 900 noncancer AA controls, and 183 Nigerian controls. RCV frequencies were determined for each group and compared with that of 1,537 NHW patients with pancreatic cancer. Odds ratios (OR) and 95% confidence intervals (CI) were calculated for both a case–case comparison of RCV frequencies in AAs versus NHWs, and case–control comparison between AA cases versus noncancer AA controls plus Nigerian controls. Smaller sets of Hispanic and Native American cases and controls also were sequenced.Results: One novel missense RCV and one novel frameshift RCV were found among AA patients: 400G&gt;A and 258_278del. RCV carrier status was associated with increased risk of pancreatic cancer among AA cases (11/220; OR, 3.3; 95% CI, 1.5–7.1; P = 0.004) compared with AA and Nigerian controls (17/1,083). Further, AA cases had higher frequency of RCVs: 5.0% (OR, 13.4; 95% CI, 4.9–36.7; P &lt; 0.001) compared with NHW cases (0.4%).Conclusions: CDKN2A RCVs are more common in AA than in NHW patients with pancreatic cancer and associated with moderately increased pancreatic cancer risk among AAs.Impact: RCVs in CDKN2A are frequent in AAs and are associated with risk for pancreatic cancer. Cancer Epidemiol Biomarkers Prev; 27(11); 1364–70. ©2018 AACR.

Pancreatic cancer has one of the highest mortality rates among all types of cancers. The disease is highly aggressive and typically diagnosed in late stage making it difficult to treat. Currently, the vast majority of therapeutic regimens have only modest curative effects, and most of them are in the surgical/neo-adjuvant setting. There is a great need for new and more effective treatment strategies in common clinical practice. Previously, pathogenesis of pancreatic cancer was attributed solely to genetic mutations; however, recent advancements in the field have demonstrated that aberrant activation of epigenetic pathways contributes significantly to the pathogenesis of the disease. The identification of these aberrant activated epigenetic pathways has revealed enticing targets for the use of epigenetic inhibitors to mitigate the phenotypic changes driven by these cascades. These pathways have been found to be responsible for overactivation of growth signaling pathways and silencing of tumor suppressors and other cell cycle checkpoints. Furthermore, new miRNA signatures have been uncovered in pancreatic ductal adenocarcinoma (PDAC) patients, further widening the window for therapeutic opportunity. There has been success in preclinical settings using both epigenetic inhibitors as well as miRNAs to slow disease progression and eliminate diseased tissues. In addition to their utility as anti-proliferative agents, the pharmacological inhibitors that target epigenetic regulators (referred to here as readers, writers, and erasers for their ability to recognize, deposit, and remove post-translational modifications) have the potential to reconfigure the epigenetic landscape of diseased cells and disrupt the cancerous phenotype. The potential to “reprogram” cancer cells to revert them to a healthy state presents great promise and merits further investigation.

Significance Pancreatic ductal adenocarcinoma (PDA) is the third leading of cause of cancer death in the United States and is predicted to be the second one by 2030. The tumor microenvironment is a major source of soluble mediators that influence tumor progression and hinder the success of therapeutic strategies. Using a genetically engineered mouse model and human cell-based systems, we identify galectin-1 (Gal1) as a critical soluble factor capable of regulating tumor–stroma crosstalk promoting proliferation, angiogenesis, and modulation of inflammatory responses, resulting in enhanced tumor development and metastasis. Our data provide an integrated view of the role of Gal1 in the PDA microenvironment and reinforce the high therapeutic value of Gal1 inhibition in PDA treatment.

Abstract Purpose: ZIP4 is overexpressed in human pancreatic cancer and promotes tumor growth. However, little is known about the role of ZIP4 in advanced stages of this dismal neoplasm. Our goal is to study the underlying mechanism and define a novel signaling pathway controlled by ZIP4-modulating pancreatic tumor metastasis. Experimental Design: The expression of ZIP4, ZO-1, claudin-1, and ZEB1 in human pancreatic cancer tissues, genetically engineered mouse model, xenograft tumor model, and pancreatic cancer cell lines were examined, and the correlations between ZIP4 and those markers were also analyzed. Functional analysis of ZO-1, claudin-1, and ZEB1 was investigated in pancreatic cancer cell lines and orthotopic xenografts. Results: Genetic inactivation of ZIP4 inhibited migration and invasion in pancreatic cancer and increased the expression of ZO-1 and claudin-1. Conversely, overexpression of ZIP4 promoted migration and invasion and increased the expression of ZEB1 and downregulation of the aforementioned epithelial genes. ZIP4 downregulation of ZO-1 and claudin-1 requires the transcriptional repressor ZEB1. Further analysis demonstrated that ZIP4-mediated repression of ZO-1 and claudin-1 leads to upregulation of their targets FAK and Paxillin. Silencing of ZIP4 caused reduced phosphorylation of FAK and Paxillin, which was rescued by simultaneous blocking of ZO-1 or claudin-1. Clinically, we demonstrated that ZIP4 positively correlates with the levels of ZEB1 and inversely associates with the expression of ZO-1 and claudin-1. Conclusions: These findings suggest a novel pathway activated by ZIP4-controlling pancreatic cancer invasiveness and metastasis, which could serve as a new therapeutic target for this devastating disease. Clin Cancer Res; 24(13); 3186–96. ©2018 AACR.