bluuebunny/crossref_metadata_2025 huggingface dataset:
Abstract 276: Recruitment of effector T cells into the tumor rim and center with neoadjuvant systemic GM-CSF in patients with localized prostate cancer
Authors: Wei Xiao X. , Chan Stephen , Lewis Jera , Kwek Serena , Dao Vinh , Fong Lawrence
Published: August 2015

Background: Granulocyte-macrophage colony-stimulating factor (GM-CSF, sargramostim) is a bone marrow growth factor that is often used as an adjuvant in cancer vaccine clinical trials and has the potential to enhance antitumor efficacy in combination with immune checkpoint blockade in preclinical studies and clinical trials. The effect of GM-CSF remains controversial, however. In this study, we sought to characterize the systemic and tissue-specific effects of GM-CSF in prostate cancer patients in the preoperative setting.

Methods: Patients with localized prostate cancer were treated on an open-label phase I/II study of neoadjuvant GM-CSF prior to planned radical prostatectomy (NCT00305669). Patients received GM-CSF 250mcg/m2 subcutaneously on days 1-14 (cohort 1), days1-21 (cohort 2), or days 1-28 (cohort 3), and underwent radical prostatectomy (RP) within 5 days after the last dose of GM-CSF. Blood collected at baseline, day 14, pre-RP, and 6 weeks post-RP were analyzed for immune cell subsets by flow cytometry. Immune infiltration in RP tissue were evaluated by immunohistochemistry and quantified by digital image analysis with comparison to RP tissue from untreated prostate cancer patients as controls.

Results: 18 patients were evaluated with 6 patients at each dose level. Treatment with GM-CSF was associated with an increase in the number of myeloid cells including myeloid dendritic cells. Treatment was also associated with increases in circulating conventional CD4 and CD8 T cells and NK cells. The number of FoxP3+ regulatory CD4+ T cells was also increased, but to a much lower magnitude. At the time of radical prostatectomy, treatment was associated with a recruitment of CD3+ T cells to the tumor rim, and with cohort 3, at the centers of tumor. These T cells were predominantly CD8+ T cells, although conventional CD4+ T cells were also increased. No increase in monocytes or dendritic cells was seen in the tissue.

Conclusion: Daily injection of systemic GM-CSF induces an increase in circulating antigen presenting cells as well as T and NK cells. While this treatment does not enhance the frequency of antigen presenting cells in the tumor microenvironment, this treatment recruits effector CD8+ T cells into the tumor rims.

Citation Format: Xiao X. Wei, Stephen Chan, Jera Lewis, Serena Kwek, Vinh Dao, Lawrence Fong. Recruitment of effector T cells into the tumor rim and center with neoadjuvant systemic GM-CSF in patients with localized prostate cancer. [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 276. doi:10.1158/1538-7445.AM2015-276
Abstract 2766: Advanced paternal age as a possible risk factor for retinoblastoma
Authors: Ayyasamy Vanniarajan , Gaikwad Namrata , Kannan Thirumalairaj , Abraham Aloysius A. , Muthukkaruppan Veerappan , Kim Usha
Published: August 2015

Retinoblastoma is a pediatric tumor arising in the retina with an incidence of 1 in 15000 to 18000 live births. Retinoblastoma is initiated by the inactivation of both the alleles of RB1 and it may be inherited or sporadic. There are several possible risk factors suggested for sporadic retinoblastoma including advanced paternal age.We evaluated the father's age in 42 children with retinoblastoma attending the Aravind Eye Hospital, Madurai, India from Mar 2013 to Feb 2014 retrospectively. Fathers with age 40 and above at the time of conception were included in the analysis. Patients with a positive family history were excluded from the analysis. Genetic analysis of RB1 was carried out in the tumor and blood samples of these patients of older father and their family.There were 5 patients (3 unilateral and 2 bilateral) having fathers with age 40 years and above. Genetic analysis identified RB1 mutations in the tumor samples of 4 patients and these mutations were not present in the blood samples of patient and family members. Since all these patients had somatic mutations, the involvement of paternal age impact was ruled out. In blood sample of one bilateral patient, we found de novo germline RB1 mutation possibly suggesting a role of advanced paternal age.In conclusion, the advanced paternal age seems to be a minor risk factor for retinoblastoma. Further study of large number of patients may provide a better understanding of the impact of advanced paternal age in retinoblastoma.

Citation Format: Vanniarajan Ayyasamy, Namrata Gaikwad, Thirumalairaj Kannan, Aloysius A. Abraham, Veerappan Muthukkaruppan, Usha Kim. Advanced paternal age as a possible risk factor for retinoblastoma. [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 2766. doi:10.1158/1538-7445.AM2015-2766
Abstract 2799: Goniothalamin, a natural product, modulates the inflammatory microenvironment on colitis and colitis-associated cancer
Authors: Vendramini Costa Débora Barbosa , Francescone Ralph A. , Dmitrieva Oxana , Hou Vivi , Posocco David , Pilli Ronaldo A. , Grivennikov Sergei
Published: August 2015

Despite anticancer drug discovery advances, the worldwide cancer incidence is remarkable. Thus, there is continuous necessity on new therapies development and tumor microenvironment offers multiple targets for cancer therapy, including inflammation. Nature has been a source of new therapeutic and preventive agents and the styryl-lactone goniothalamin (GTN) has shown to be a promising anti-proliferative and anti-inflammatory agent. In previous studies we showed that GTN has pro-apoptotic activity, gastroprotective effects and inhibits tumor development and acute inflammation in mice. Thus, the major goal of this study was to evaluate the therapeutic and preventive potentials of GTN on colitis and colitis-associate cancer (CAC) models, focusing on the elucidation of the relationship between the anti-proliferative and anti-inflammatory activities.

GTN was synthesized and evaluated in vitro in LPS-stimulated RAW 264.7 murine macrophages. Cells were pre-treated with GTN (20 μM) for 3 hours and then stimulated with LPS (1 μg/mL) for 4 hours. Gene expression was analyzed by real-time PCR and cytokines production by ELISA. Experimental colitis was induced by 3.5% dextran sulfate sodium (DSS) for 7 days and animals (mice, C57-BL/6) were treated with GTN daily by oral route (30 and 100 mg/kg). CAC was induced by Azoxymethane (AOM, 10 mg/kg) followed by 3 cycles of DSS (3.0%) and treatments with GTN (30 mg/kg) were conducted by oral route, twice week. Body weight was checked every week and in the end of experiments, colon tissues were collected and processed for microscopic, biochemical and gene expression evaluations.

GTN significantly reduced IL-1β, IL-6, TNF-α, IL-23, CXCL2 and iNOS expression on RAW cells, as well as levels of secreted IL-6 and TNF-α. Treatments with GTN also reduced inflammation severity on DSS-induced colitis model by reducing cytokines expression, thus suggesting a modulatory activity of the inflammatory environment. GTN treatment modulated tumor development in a mouse model of CAC. Together with previous data, these results highlight that goniothalamin can be used as a preventive and therapeutic agent to inhibit inflammation in colitis and cancer.

Citation Format: Débora Barbosa Vendramini Costa, Ralph A. Francescone, Oxana Dmitrieva, Vivi Hou, David Posocco, Ronaldo A. Pilli, Sergei Grivennikov. Goniothalamin, a natural product, modulates the inflammatory microenvironment on colitis and colitis-associated cancer. [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 2799. doi:10.1158/1538-7445.AM2015-2799
Abstract 280: Delta-24-RGDOX: making cancer more “visible” to the immune system
Authors: Jiang Hong , Fan Xuejun , Clise-Dwyer Karen , Bover Laura , Gumin Joy , Ruisaard Kathryn E. , Mukheef Farah J. , Lang Frederick F. , Gomez-Manzano Candelaria , Fueyo Juan
Published: August 2015

Emerging evidence indicates that host immunity is critical for successful cancer virotherapy. We found that oncolytic adenovirus Delta-24-RGD elicited antiglioma immunity in an immunocompetent murine model. Recent studies suggested that the therapeutic efficacy of immune checkpoint blockade in cancer patients could be enhanced by strategies inducing tumor inflammation. We hypothesized that highly immunogenic adenovirus combined with targeting immune co-stimulator would result in better anti-tumor efficiency. Thus, we used the backbone of Delta-24-RGD to express the mouse OX40 ligand to increase the recognition of tumor-associated antigens by immune cells. The resulting Delta-24-RGDOX adenovirus maintained the oncolytic potency of Delta-24-RGD and efficiently expressed OX40 ligand on infected cells. More importantly, compared to Delta-24-RGD, Delta-24-RGDOX induced higher antiglioma activity in immunocompetent glioma models but not in an immunodeficient model, and accordingly mediated greater lymphocyte infiltration at tumor sites and stronger lymphocyte antitumor activity. While blocking or stimulating immune checkpoints with antibodies currently dominates the clinical applications, our data demonstrate that intratumoral injection of oncolyticviruses carrying immune co-stimulatory ligands may constitute a powerful alternative to the use of antibodies and other strategies targeting immune checkpoints in cancer therapy.

Note: This abstract was not presented at the meeting.

Citation Format: Hong Jiang, Xuejun Fan, Karen Clise-Dwyer, Laura Bover, Joy Gumin, Kathryn E. Ruisaard, Farah J. Mukheef, Frederick F. Lang, Candelaria Gomez-Manzano, Juan Fueyo. Delta-24-RGDOX: making cancer more “visible” to the immune system. [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 280. doi:10.1158/1538-7445.AM2015-280
Abstract 2804: The thiazolidinedione pioglitazone enhances the cancer preventive activity of the rexinoid LG100268 in Her2/neu induced breast cancer
Authors: Uray Iván P. , Rodenberg Jennifer M. , Zhang Yun , Hill Jamal L. , Brown Powel H.
Published: August 2015

Two major unresolved issues for breast cancer prevention are the lack of effective preventive agents for estrogen receptor (ER)-negative disease and the potential toxicity of long-term pharmacologic treatment. The ability of retinoid X receptor (RXR)-selective retinoids (rexinoids) to inhibit breast cancer formation independently of ER-status was previously demonstrated in various preclinical models. The goal of our study was to identify ideal druggable targets for the synergistic amplification of the cancer preventive effect of synthetic rexinoids and test the efficacy of a low-dose combination treatment in vivo. We identified the nuclear hormone receptors essential for rexinoid-dependent growth suppression by a high throughput siRNA screen of mammary epithelial cells. Knock-down of ELP, COUP-TF II, GR, TR2, VDR and PPARgamma partially reversed the anti-proliferative effect of the rexinoid bexarotene. Conversely, expression profiling showed that the largest fraction of genes up-regulated by the synthetic rexinoid LG100268 represented regulators of lipid metabolism and putative target genes of the RXR partner receptor PPARgamma. Combination dose-response experiments showed that the PPARgamma agonist pioglitazone was synergistic with low doses (100-300 nM) of LG100268. Long-term daily treatment of MMTV-ErbB2 mice with LG100268 (25 mg/kg) or pioglitazone (20 mg/kg), or their combination resulted in a significant delay of tumor formation, while serum triglyceride levels were not significantly elevated by the combination. Suppression of cell proliferation measured by reduced Ki67 staining was enhanced by the addition of pioglitazone, in both lesions and intact mammary epithelium, while pioglitazone also increased the frequency of cells containing cleaved caspase 3. Furthermore, pioglitazone treatment was associated with a marked induction of microvesicle formation in the adipose issue. These data suggest that the combination of LG100268 and pioglitazone, while potentially targeting the same heterodimer, can invoke distinct biological processes resulting in more effective cancer prevention than achieved by either agent alone, and may be an effective strategy for the prevention of ER-negative breast cancer.

Citation Format: Iván P. Uray, Jennifer M. Rodenberg, Yun Zhang, Jamal L. Hill, Powel H. Brown. The thiazolidinedione pioglitazone enhances the cancer preventive activity of the rexinoid LG100268 in Her2/neu induced breast cancer. [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 2804. doi:10.1158/1538-7445.AM2015-2804
Abstract 2809: Chemopreventive studies of multiple agents in the methylnitrosourea-induced ER+ mammary cancer model in animals on standard and Western diets
Authors: Grubbs Clinton J. , Miller Mark S. , Steele Vernon E. , Moeinpour Fariba , Seifried Harold , Heckman-Stoddard Brandy M. , Lubet Ronald A.
Published: August 2015

Multiple positive and negative preventive agents [tamoxifen, vorozole (aromatase inhibitor), targretin (RXR agonist), gefitinib (EGFR inhibitor), metformin, and Lipitor] were examined for efficacy in rats given either standard Teklad (4% fat) diet or a modified Western diet [high fat (42%)]. Female Sprague Dawley rats were placed on the high fat or standard diet at 43 days of age, and administered methylnitrosourea (MNU) at 50 days of age. Rats on high fat diet vs standard diet gained approximately 40% more weight, exhibited a 50% increase in cancer multiplicity, and a decrease in cancer latency. The strong preventive agents (tamoxifen, vorozole, targretin, and gefitinib) were highly effective in animals on standard or high fat diets (reducing cancer multiplicity >75% in rats on either diet). It was unclear whether the altered physiology of animals on high fat diet or altered PK of agents in animals with higher fat content might alter activity of these agents. We had previously found that both metformin and Lipitor were ineffective in rats on a standard fat diet, but thought that they might be effective in rats on a high fat diet. Interestingly, neither compound decreased tumorigenesis; but, at least marginally, increased tumor incidence and final tumor weights in rats on both diets. The ability of the various agents to alter proliferation of normal mammary epithelium in MNU-treated rats exposed for 2 weeks to the various agents was determined. It was found that inhibition of proliferation in mammary epithelium corresponded well to the efficacy of these agents in long-term chemopreventive assays. These results demonstrated that: (1) a high fat diet can be employed in this rat model to increase tumor multiplicity; (2) tamoxifen, vorozole, targretin and gefitinib were highly effective in rats on standard or high fat diet; (3) metformin and Lipitor were ineffective with either diet; and (4) there is a correlation between inhibition of proliferation in normal mammary epithelium and long-term preventive efficacy of agents; but this may reflect the homogeneity of the rat mammary cancers. Supported by NCI contract HHSN261201200021I.

Citation Format: Clinton J. Grubbs, Mark S. Miller, Vernon E. Steele, Fariba Moeinpour, Harold Seifried, Brandy M. Heckman-Stoddard, Ronald A. Lubet. Chemopreventive studies of multiple agents in the methylnitrosourea-induced ER+ mammary cancer model in animals on standard and Western diets. [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 2809. doi:10.1158/1538-7445.AM2015-2809
Abstract 281: Virotherapy with a Semliki Forest virus-based vector encoding IL-12 synergizes with PD-1/PD-L1 blockade
Authors: Quetglas José I. , Labiano Sara , Aznar M. Ángela , Bolaños Elixabet , Azpilicueta Arantza , Rodríguez Inmaculada , Casales Erkuden , Rodríguez Alfonso , Smerdou Cristian , Melero Ignacio
Published: August 2015

Virotherapy and checkpoint inhibitors can be combined for the treatment of cancer with complementarity and potential for synergistic effects. We have developed a cytolytic but non-replicative viral vector system based on Semliki Forest virus that encodes IL-12 (SFV-IL-12). Following direct intratumoral injection, infected cells release transgenic IL-12, die and elicit an inflammatory response triggered by both abundantly copied viral RNA and IL-12. In difficult to treat mouse cancer models, such as those derived from MC38 and bilateral B16-OVA, SFV-IL-12 synergized with an anti-PD-1 monoclonal antibody (mAb) to induce tumor regression and prolong survival. Similar synergistic effects were attained upon PD-L1 blockade. Combined SFV-IL-12 + anti-PD-1 mAb treatment only marginally increased the elicited CTL response over SFV-IL-12 as a single agent, at least when measured by in vivo killing assays. In contrast, we observed that SFV-IL-12 treatment induced expression of PD-L1 on tumor cells in an IFNγ-dependent fashion. PD-L1-mediated adaptive resistance thereby provides a mechanistic explanation of the observed synergistic effects achieved by the SFV-IL-12 + anti-PD-1 mAb combination.

Citation Format: José I. Quetglas, Sara Labiano, M. Ángela Aznar, Elixabet Bolaños, Arantza Azpilicueta, Inmaculada Rodríguez, Erkuden Casales, Alfonso Rodríguez, Cristian Smerdou, Ignacio Melero. Virotherapy with a Semliki Forest virus-based vector encoding IL-12 synergizes with PD-1/PD-L1 blockade. [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 281. doi:10.1158/1538-7445.AM2015-281
Abstract 2822: Aspirin and other non-steroidal anti-inflammatory drug prescriptions after diagnosis and upper aerodigestive tract cancer survival
Authors: Macfarlane Tatiana V.
Published: August 2015

Aspirin and other NSAIDs are widely used as analgesics and preventative agents for vascular events. Research evidence supports an effect of aspirin in reducing overall cancer incidence and mortality in the general population. Data on the chemo preventative role of these drugs on the mortality in patients with upper aerodigestive tract cancer (UADT) are insufficient.

The aim of this study was to investigate the effect of aspirin and other NSAIDs prescriptions after cancer diagnosis on the survival in UADT cancer patients.

Patients with UADT cancer (oral cavity, oropharynx, hypopharynx, larynx or esophagus) were identified from the Primary Care Clinical Informatics Unit (PCCIU) database which contains information from a sample of general medical practices in Scotland, United Kingdom. Cox regression was used for statistical data analysis.

There were 2,392 cases of UADT cancer diagnosed between 1996 and 2010 from 131 general medical practices. The mean age of patients was 66 years (SD 12), and most were male (63%). Median survival in head and neck cancer (HNC) patients was 94 months, while median survival in oesophageal cancer patients was 10 months.

For HNC, improved survival was observed with aspirin prescription (ever vs never Hazard Ration (HR) = 0.5 95% Confidence Interval (CI) 0.4, 0.7) and other NSAIDs prescription (ever vs never HR = 0.7 95% CI 0.6, 0.9), however there was no association with COX-2 prescriptions. For oesophageal cancer patients, improved survival was observed with aspirin prescriptions (ever vs never HR = 0.5 95% CI 0.5, 0.6), Cox-2 prescriptions (HR = 0.8 95% CI 0.6, 0.9) and other NSAIDs (HR = 0.7 95% CI 0.6, 0.8).

Conclusion: Aspirin and other NSAIDs prescriptions after diagnosis may reduce all-cause mortality in UADT cancer patients.

Citation Format: Tatiana V. Macfarlane. Aspirin and other non-steroidal anti-inflammatory drug prescriptions after diagnosis and upper aerodigestive tract cancer survival. [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 2822. doi:10.1158/1538-7445.AM2015-2822
Abstract 2824: Evaluation of Ibuprofen loaded solid lipid nanoparticles and its combination regimens for pancreatic cancer chemoprevention
Authors: Thakkar Arvind , Chenreddy Sushma , Wang Jeffrey , Prabhu Sunil
Published: August 2015

The objective of the present study was to establish the individual and combined chemopreventive potential of a widely used non-steroidal anti-inflammatory drug, ibuprofen (IBU), encapsulated in solid lipid nanoparticles (SLNs) for the chemoprevention of pancreatic cancer. The synergistic effect of combination of IBU with sulforaphane (SFN) was also evaluated. Cell viability studies were conducted followed by colony formation and NF-κB DNA binding assays. The IC50 concentration of free IBU in human pancreatic cancer cells Panc-1 and MIA PaCa-2 were 1.25mM and 1.26 mM, respectively. SLN optimization study of IBU revealed stearic acid (1:2 drug to lipid ratio) formulated with Poloxamer 188 to be the most efficacious in cell viability study. Upon encapsulation in SLNs, IC50 concentration of IBU-SLN was 113.8 μM and 122.6 μM for Panc-1 and MIA PACa-2 cells respectively, reflecting a 10-fold reduction compared to free IBU. Combinations of low doses of free IBU (250 μM) and SFN (5 μM) reduced cell viability by ∼55% (P<0.01), whereas a lower dose of encapsulated IBU-SLN (62.5 μM) and free SFN (5 μM) reduced cell viability by ∼80% (P<0.001) for both Panc-1 and MIA PaCa-2 cells. These results reflect 4-fold reduction in IBU-SLN dose in combination compared to free IBU. Moreover, IBU-SLN and free SFN combination reduced number of colonies by ∼50% (P<0.01). Further, IBU-SLN and SFN combinations showed down-regulation of DNA binding activity of the p50 subunit of NF-κB. In conclusion, these preliminary results demonstrate the potential of IBU as a chemopreventive agent against pancreatic cancer. Furthermore, when encapsulated in nanotechnology-based SLN delivery systems and delivered in combination with SFN provide evidence of a promising approach for pancreatic cancer prevention and therapy.

Citation Format: Arvind Thakkar, Sushma Chenreddy, Jeffrey Wang, Sunil Prabhu. Evaluation of Ibuprofen loaded solid lipid nanoparticles and its combination regimens for pancreatic cancer chemoprevention. [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 2824. doi:10.1158/1538-7445.AM2015-2824
Abstract 283: Smac mimetic and radiotherapy synergize to enhance antitumor immunity in lung cancer by targeting immunosuppressive cells
Authors: Tao Zhen , Myers Carey , Wiedemann Norbert , Vuagniaux Gregoire , Harshyne Larry , Dicker Adam , Hooper D. Craig , Lu Bo
Published: August 2015

Purpose

Hypofractionated radiotherapy (RT) directly kills lung cancer cells and stimulates tumor antigen release, the immune response to which can be augmented further by systemic immune-modulating agents. However, local relapses often occur after RT alone, indicating that inhibitory mechanisms may limit the anti-tumor immune responses elicited by apopotic tumor cells. We hypothesized that delivery of Smac mimetic, which sensitizes cells to apoptosis by counteracting the activity of inhibitor of apoptosis (IAP) proteins, following RT might lead to prolonged antitumor immunity by promoting the destruction of immunosuppressive myeloid cells.

Experimental Design

Using a murine model of lung cancer, we tested whether combination treatment with radiotherapy and the Smac mimetic Debio1143 would target immunosuppresive myeloid-derived suppressor cells (MDSCs) in the tumor microenvironment and enhance the efficacy of cytotoxic T cells.

Results

We demonstrate that administration of Debio1143 enhances the efficacy of RT by inducing LLC and LLC-OVA cells apoptosis in vitro. In addition, we show that combining radiotherapy and Debio1143 in vivo synergistically reduces the local accumulation of tumor-infiltrating MDSCs through a cytotoxic T cell-dependent mechanism. Activation of cytotoxic T cells by combination therapy proved to be mediated through the enhanced release of tumor necrosis factor alpha (TNF-α) in the tumor microenvironment.

Conclusions

These data offer a new paradigm to limit immunosuppresion by targeting MDSC and serve as the foundation for future clinical translation of combination therapy with Smac mimetics and radiotherapy.

Citation Format: Zhen Tao, Carey Myers, Norbert Wiedemann, Gregoire Vuagniaux, Larry Harshyne, Adam Dicker, D. Craig Hooper, Bo Lu. Smac mimetic and radiotherapy synergize to enhance antitumor immunity in lung cancer by targeting immunosuppressive cells. [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 283. doi:10.1158/1538-7445.AM2015-283
Abstract 2839: Specific mutant tumor DNA can be detected in ovarian cystic fluid of an unknown ovarian tumor cyst
Authors: Sundfeldt Karin , Kristjansdottir Björg , Vogelstein Bert
Published: August 2015

Can we detect rare mutations in ovarian cystic fluid of unknown severity in order to develop a molecular genetic test for epithelial ovarian cancer?

Background: Benign and malignant ovarian cysts are difficult to distinguish. Early diagnose is life saving, however 75% of ovarian adenocarcinomas is found in late stage. Approx. one operated ovarian cyst in 7-10 are found to be cancer and potentially life-threatening, subjecting the woman to unnecessary oophorectomy and morbidity. A genetic test of fine needle aspirated cystic fluid has to be very accurate to be able to substitute the histopathologic examination following surgery.

Methods: DNA was purified from 78 ovarian cystic fluids (collected at the time of operation) from serous adenomas/adenocarcinomas and corresponding tumor tissues and subjected to state-of-the-art genetic analysis. We evaluated ∼10,000 bp for subtle mutations (single base substitutions, small insertions, small deletions). Under the conditions used, mutations present in >0.1% of template molecules could be detected. The analyses were carried out in a completely blind fashion. We then evaluated the DNA of the primary tumor.

Results: We detected zero, one, or two mutations per cyst. The same mutations were identified in the corresponding tumor tissue, and no others. This dramatically confirms the specificity of the approach. 91% of the malignant cysts (n = 32) had at least one mutation and 62% of these were in TP53; 17% in low (n = 12) and 90% in high (n = 20) grade serous adenocarcinoma regardless of stage. In low-grade tumors mutations in KRAS dominated over PIK3C and PTEN. 65% of the borderline type (LMP n = 20) tumors had a BRAF V600E mutation. The mutant allelic fraction was much higher in malignant than benign tumors; the DNA concentration was relatively low in 20 benign cysts and no mutations were identified in this group consisting of 10 serous adenoma and 10 simple cysts (healthy controls). Results will be correlated to survival.

Conclusion: Data proofs that we can detect mutant tumor DNA corresponding to the primary ovarian tumor in the ovarian cystic fluid. Data suggest that gene-testing of ovarian cystic fluid could aid in diagnostics and further guide its management.

Citation Format: Karin Sundfeldt, Björg Kristjansdottir, Bert Vogelstein. Specific mutant tumor DNA can be detected in ovarian cystic fluid of an unknown ovarian tumor cyst. [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 2839. doi:10.1158/1538-7445.AM2015-2839
Abstract 2845: Co-acquisition of T790M and EMT in resistant EGFR mutant non-small cell lung cancer can be overcome by combined irreversible EGFR and BCL-XL inhibition
Authors: Hata Aaron N. , Niederst Matthew J. , Archibald Hannah L. , Mulvey Hillary , Ham Jungoh , Gomez-Caraballo Maria , Kalsy Anuj , Faber Anthony C. , Engelman Jeffrey
Published: August 2015

The development of acquired drug resistance limits the effectiveness of targeted therapies for lung cancer. In 50% of patients with EGFR mutant non-small cell lung cancer (NSCLC), acquired resistance to EGFR inhibitors can be attributed to the development of a secondary T790M mutation that prevents drug binding. Third generation irreversible EGFR inhibitors that effectively inhibit EGFR with T790M are currently under clinical development. Using patient-derived EGFR mutant NSCLC models of T790M+ acquired resistance, we observed that the presence of a mesenchymal phenotype was associated with a decreased response to subsequent irreversible EGFR inhibitor therapy. Epithelial-to-mesenchymal transformation (EMT) led to suppression of pro-apoptotic signaling and a blunted apoptotic response to EGFR inhibition. Combination BCL-XL and irreversible EGFR inhibitor therapy restored the apoptotic response and resulted in regressions of T790M+ resistant tumors that exhibited poor response to single agent irreversible EGFR inhibitors. This suggests that combining BCL-XL and irreversible EGFR inhibitors may be an effective treatment strategy for T790M+ resistant EGFR mutant lung cancers with suppressed apoptotic signaling due co-acquisition of a mesenchymal phenotype.

Citation Format: Aaron N. Hata, Matthew J. Niederst, Hannah L. Archibald, Hillary Mulvey, Jungoh Ham, Maria Gomez-Caraballo, Anuj Kalsy, Anthony C. Faber, Jeffrey Engelman. Co-acquisition of T790M and EMT in resistant EGFR mutant non-small cell lung cancer can be overcome by combined irreversible EGFR and BCL-XL inhibition. [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 2845. doi:10.1158/1538-7445.AM2015-2845
Abstract 2862: MBD3 regulates chromatin accessibility at active promoters
Authors: Shimbo Takashi , Lavender Christopher , Grimm Sara A. , Doi Makiko I. , Henriques Telmo , Cannady Kimberly R. , Murphy Kevin J. , Gilchrist Daniel A. , Burkholder Adam , Hayes Jeffrey J. , Adelman Karen , Archer Trevor K. , Zaret Kenneth S. , Wade Paul A.
Published: August 2015

Chromatin structure is tightly regulated in cells and its dysregulation is associated with diseases such as cancer. The Mi-2/NuRD (Nucleosome Remodeling Deacetylase) complex is postulated to organize chromatin structure using its nucleosome remodeling and histone deacetylase activities. MBD3 is an integral component of NuRD, which potentially targets the complex to the specific sites of the genome. Recently, we have demonstrated that MBD3/NuRD targets regulatory elements of active genes, a finding diametrically opposed to historical models depicting NuRD as a co-repressor localized to transcriptionally non-permissive chromatin. Moreover, MBD3 co-localized with RNA polymerase II (pol II) at loci where promoter-enhancer loops are formed. Although our previous findings shed light on the role of NuRD in the regulation of active genes, the detailed mechanism of how NuRD is involved in transcriptional regulation is yet not fully understood. To investigate this question, we have developed a next generation, tagmentation based chromatin immunoprecipitation method followed by massively parallel sequencing (ChIP-nexo), which substantially increased the resolution of the MBD3/NuRD mapping. ChIP-nexo defined MBD3/NuRD localization at high resolution, showing accumulation of MBD3 at active promoters with a dip at transcription start site, suggesting an active role of NuRD in modulation of the cell-type specific transcriptional network. To interrogate the detailed functions of NuRD at active promoters, we conducted MNase-seq using conditions which measures both nucleosome positioning and sensitivity, in MBD3 depleted cells. Depletion of MBD3 changed the accessibility of nucleosomes at promoters, while maintaining overall nucleosome positioning. These data indicate an active regulatory function of NuRD in fine tuning the transcriptional network by modulating transcription rates of pol II. We propose that NuRD may be involved in establishing cell type specific gene expression patterns in diverse cell types by organizing promoter nucleoprotein architecture.

Citation Format: Takashi Shimbo, Christopher Lavender, Sara A. Grimm, Makiko I. Doi, Telmo Henriques, Kimberly R. Cannady, Kevin J. Murphy, Daniel A. Gilchrist, Adam Burkholder, Jeffrey J. Hayes, Karen Adelman, Trevor K. Archer, Kenneth S. Zaret, Paul A. Wade. MBD3 regulates chromatin accessibility at active promoters. [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 2862. doi:10.1158/1538-7445.AM2015-2862
Abstract 2866: Defining epigenetic vulnerabilities in synovial sarcoma
Authors: Banito Ana , Tasdemir Nilgun , Ladanyi Marc , Lowe Scott W.
Published: August 2015

Synovial sarcoma constitutes 10% of all soft-tissue sarcomas and arises most frequently in adolescents and young adults. The defining genetic event of synovial sarcoma and main driver of the disease is the translocation of the SS18 gene on chromosome 18q11 to either the SSX1 and SSX2 genes located on chromosome Xp11. The resulting SS18-SSX fusion oncogene lacks a DNA binding domain, but is thought to exert its function via interaction with transcription factors and chromatin remodelers such as polycomb-group chromatin remodeling factors, and components of the SWI/SNF complex. The fact that the fusion oncogene is the defining event in this disease suggests that, on its own, it is able to generate an epigenetic profile that drives tumorigenesis.

In this study we expressed SS18-SSX2 in C2C12 myoblasts to recreate the epigenetic events driving synovial sarcoma. C2C12 myoblasts expressing SS18-SSX1/2 did not show significant differences in cell growth however became completely refractory to differentiation to myotubes. In addition, knockdown of SS18-SSX2 in a mouse synovial sarcoma cell line (derived from a mouse model in which the human SS18-SSX2 fusion oncogene is expressed in the myogenic progenitor compartment) led to strong growth arrest and induction of induction of p16 and p21 cell cycle regulators. This results support the notion that the SS18-SSX oncogene drives tumorigenesis by blocking differentiation programs and by repressing tumor suppressor genes to maintain self-renewal of synovial sarcoma cells. To identify epigenetic vulnerabilities that are specifically generated by the SS18-SSX fusion protein we screened two cell lines using an shRNA library targeting epigenetic modulators: the synovial sarcoma cell line mentioned above and C2C12 myoblasts. Three control shRNAs targeting the SS18-SSX2 oncogene were within the top depletion hits in the synovial sarcoma cell line but were neutral in the C2C12 myoblasts, validating the screen performance. To uncover SS18-SSX specific hits we concentrated in genes within this list that specifically depleted in the synovial sarcoma cell line but not in myoblasts. Genes within this list and to which at least two independent shRNAs scored were subjected to extensive one-by one validation. Our results may uncover epigenetic mechanisms required to maintain self-renewal in synovial sarcoma.

Citation Format: Ana Banito, Nilgun Tasdemir, Marc Ladanyi, Scott W. Lowe. Defining epigenetic vulnerabilities in synovial sarcoma. [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 2866. doi:10.1158/1538-7445.AM2015-2866
Abstract 2879: Profiling of lung microbial communities in lung cancer and chronic obstructive pulmonary disease patients
Authors: Liu Yanhong , Ajami Nadim J , Wong Matthew C , Scheurer Michael , Amirian E. Susan , Petrosino Joseph F , Spitz Margaret R , Bondy Melissa L , Kheradmand Farrah
Published: August 2015

Background: The composition and structure of site-specific microbiota have recently been described as a biomarker associated with a variety of high impact diseases including cancer. This study sought to identify lung microbial signatures in smokers with lung cancer (LC) and/or chronic obstructive pulmonary disease (COPD).

Material and Methods: We employed 16S rRNA gene compositional analysis to compare the microbiota in Optimal Cutting Temperature (OCT) embedded biopsies of lung-tissue from 30 smokers, including 10 patients with LC only, 10 patients with COPD only, and 10 patients with both LC and COPD, selected from a longitudinal study of COPD exacerbation conducted in Houston, Texas, during 2005 to 2012.

Results: Microbial signatures calculated based on the 16S rRNA gene data showed that patients with COPD only presented a very distinct microbial structure defined by a significantly lower Shannon Diversity Index compared to patients with LC only (P = 0.04), and patients with both LC and COPD (P = 0.003), suggesting lower bacterial richness and evenness. Furthermore, biopsies from patients with COPD only were characterized by an increased prevalence of Acinetobacter (P < 0.0001) and Acidovorax (P < 0.0001), and a lower prevalence of Bifidobacterium, Streptococcus, and Ruminococcus species compared to patients with LC only and those with both LC and COPD. However, patients with both COPD and LC were indistinguishable from those with LC only.

Conclusions: This study is the first and largest to examine the composition of the lung microbiome in smokers with LC and/or COPD. Specific bacterial signatures were identified in patients with LC only and those with both COPD and LC demonstrating that the lung microbiome can be used as a biomarker for the two diseases. Altogether, we observed altered lung microbiota of COPD and LC, but whether this is involved in disease causation or is a consequence of host selection remains unclear.

Citation Format: Yanhong Liu, Nadim J Ajami, Matthew C Wong, Michael Scheurer, E. Susan Amirian, Joseph F Petrosino, Margaret R Spitz, Melissa L Bondy, Farrah Kheradmand. Profiling of lung microbial communities in lung cancer and chronic obstructive pulmonary disease patients. [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 2879. doi:10.1158/1538-7445.AM2015-2879
Abstract 288: TG3003, an immunomodulatory anti-CD115 mAb targeting M2-macrophage polarization in the tumor microenvironment
Authors: Haegel Hélène , Ziller-Remy Christelle , Barraud Luc , Bonnefoy Jean-Yves , Cochin Sandrine , Duong Vanessa , Geist Michel , Grellier Benoit , Hallet Rémy , Marchand Jean-Baptiste , Menguy Thierry , Rooke Ronald , Thioudellet Christine , Reymann Carine , Préville Xavier
Published: August 2015

Cancer progression has been associated with the presence of tumor-associated M2-type macrophages (M2-TAMs) able to inhibit anti-tumor immune responses, stimulate neo-angiogenesis and facilitate metastasis. Colony-stimulating factor-1 (CSF-1, M-CSF) is a cytokine required for the survival and differentiation of myeloid cell lineages, and CSF-1 signaling is known to polarize macrophages towards the M2-type. M2-TAMs can represent the most abundant immunosuppressive cell population in the tumor microenvironment, notably recruited by CSF-1 and MCP-1/CCL2.

Transgene has developed a monoclonal antibody (mAb), TG3003, directed against the CSF-1 cell-surface receptor, CD115 (CSF-1R, M-CSFR). This mAb does not block the binding of CSF-1 to its receptor, but down-modulates CD115 signaling. In contrast to other anti-CD115 mAbs currently in development, whose modes of action rely on the blockade of ligand binding, TG3003 is not cytotoxic to normal myeloid cells that require CD115-mediated signaling for their survival. In vitro, TG3003 skews monocyte differentiation from M2-type macrophages towards dendritic cells, most potent antigen-presenting cells capable of stimulating efficacious T cell responses. It inhibits the secretion of MCP-1/CCL2 by differentiating macrophages and decreases their IL-6 production. Through this inhibition of M2-TAMs, TG3003 may potentiate immune responses in patients and impact on tumor progression. Moreover, due to its unique non-competitive mode of action, TG3003 does not block the physiological pathway for CSF-1 clearing from the circulation, thus avoiding the issue of toxic or rebound effects in treated patients.

To investigate the properties of TG3003 in vivo, we have generated a transgenic mouse strain where the mAb epitope has been inserted into murine CD115 without affecting murine CSF-1 binding nor signaling. We will present the results of preclinical proof-of-concept experiments validating the mechanism of action and the immunomodulatory properties of mAb TG3003.

Citation Format: Hélène Haegel, Christelle Ziller-Remy, Luc Barraud, Jean-Yves Bonnefoy, Sandrine Cochin, Vanessa Duong, Michel Geist, Benoit Grellier, Rémy Hallet, Jean-Baptiste Marchand, Thierry Menguy, Ronald Rooke, Christine Thioudellet, Carine Reymann, Xavier Préville. TG3003, an immunomodulatory anti-CD115 mAb targeting M2-macrophage polarization in the tumor microenvironment. [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 288. doi:10.1158/1538-7445.AM2015-288
Abstract 2887: Epigenetic silencing of the DNA repair genes, BRCA1 and MLH1, induced by hypoxic stress in a pathway dependent on the histone demethylase, LSD1
Authors: Lu Yuhong , Chu Adrian , Wajapeyee Narendra , Turker Mitchell S. , Glazer Peter M.
Published: August 2015

Hypoxia is a key microenviromental stress in solid tumors that is associated with poor prognosis. It has been indicated that hypoxia induces genetic instability through multiple mechanisms. Previously, we have shown that BRCA1 and RAD51, in the homology dependent repair (HDR) pathway, and MLH1 and MSH2, key components of MMR, are down-regulated at the transcriptional level in response to hypoxia. Here we show that hypoxia also drives epigenetic modification of the BRCA1 and MLH1 promoters, with decreased H3K4 methylation as a key repressive modification produced by the lysine specific histone demethylase, LSD1. In cells containing the BRCA1 promoter driving a selectable HPRT gene, long-term silencing of the promoter was observed following exposure to hypoxic stress. The silenced clones showed decreased H3K4 methylation and decreased H3K9 acetylation in the BRCA1 promoters, consistent with the acute effects of hypoxic stress. Similarly, we also found that hypoxia causes durable long-term silencing of the MLH1 promoter in a pathway that requires LSD1. Knockdown of LSD1 or its co-repressor, CoREST, also prevents the re-silencing (and associated cytosine DNA methylation) of the endogenous MLH1 promoter in RKO colon cancer cells following transient reactivation by treatment with the DNA methyltransferase inhibitor 5-aza-2′-deoxycytidine (5-aza-dC). These results suggest that hypoxia is a driving force for long-term silencing of DNA repair genes, including BRCA1 and MLH1, thereby promoting genome instability and tumor progression.

Citation Format: Yuhong Lu, Adrian Chu, Narendra Wajapeyee, Mitchell S. Turker, Peter M. Glazer. Epigenetic silencing of the DNA repair genes, BRCA1 and MLH1, induced by hypoxic stress in a pathway dependent on the histone demethylase, LSD1. [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 2887. doi:10.1158/1538-7445.AM2015-2887
Abstract 2895: Phosphorylation of EZH2 at T416 by CDK2 promotes development of mammary tumors with basal-like phenotype
Authors: Nie Lei , Wei Yongkun , LaBaff Adam , Yang Cheng-Chieh , Xia Weiya , Huo Longfei , Liu Dongping , Hsu Yi-Hsin , Hortobagyi Gabriel N. , Yao Jun , Kleer Celina G. , Hung Mien-Chie
Published: August 2015

Basal-like breast cancer, also referred to as triple negative breast cancer (TNBC) due to the lack of expression of ErbB2, PR, and ER alpha receptors, is considered to be one of the most aggressive breast cancers, which display high rates of tumor cell proliferation, metastasis, and post-surgical re-occurrence. This subtype of breast cancer presents a major challenge for breast cancer oncologists as currently there is no effective therapy available. Here, we show that Cyclin E and EZH2, the methyltransferase component of the polycomb repressive complex 2 (PRC2) are exclusively co-expressed in TNBC tumor tissues. We further show that CDK2, the only known enzymatic partner of Cyclin E, can phosphorylate EZH2 at T416 in vivo. CDK2-mediated modification of EZH2 at T416 leads to gain-of-function, enhancing its ability to promote breast cancer cell migration/invasion, expansion and self-renewal of tumor sphere in vitro, and tumor growth in vivo. In addition, our immunohistochemistry-staining of 247 primary breast tumor tissues validates that high EZH2/T416 phosphorylation correlates with poor survival in TNBC but not in non-TNBC patients. To further attest the oncogenic role of EZH2/T416 phosphorylation by CDK2 in vivo, we generated transgenic mice expressing EZH2T416D mutant, a mimicking phosphorylated form of EZH2, in mammary glands. In contrast to previously reported EZH2WT transgenic mice, which did not develop mammary tumors, our EZH2T416D-expressing mice developed malignant mammary tumor with basal-like and highly metastatic potential phenotypes. These genetic evidence revealed that CDK2/Cyclin E mediated site-specific phosphorylation of EZH2 is capable of inducing the basal-like/TNBC phenotype and maintaining cancer stem cell population of breast cancers so that the T416 phosphorylation of EZH2 might serve as a biomarker for TNBC prognosis and effective therapy.

Citation Format: Lei Nie, Yongkun Wei, Adam LaBaff, Cheng-Chieh Yang, Weiya Xia, Longfei Huo, Dongping Liu, Yi-Hsin Hsu, Gabriel N. Hortobagyi, Jun Yao, Celina G. Kleer, Mien-Chie Hung. Phosphorylation of EZH2 at T416 by CDK2 promotes development of mammary tumors with basal-like phenotype. [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 2895. doi:10.1158/1538-7445.AM2015-2895