bluuebunny/crossref_metadata_2025 huggingface dataset:
Abstract 4372: Chronic myeloid leukemia (CML) exosomes promote angiogenesis in a Src-dependent fashion in vitro and in vivo
Authors: Mineo Marco , Taverna Simona , Flugy Anna , Leo Giacomo De , Alessandro Riccardo , Kohn Elise C.
Published: August 2012

CML is an uncontrolled proliferation of bone marrow myeloid cells driven by the constitutively active fusion product tyrosine kinase BCR/ABL. Angiogenesis, the formation of new blood vessels from pre-existing vasculature, is newly recognized as a factor in CML progression. Exosomes, released by a broad spectrum of cells, are microvesicles that play an important role in cell-to-cell communication both in physiological and pathological conditions. The role of exosomes released by CML cells in angiogenesis is emerging; however, little is known about the mechanisms involved in this process. We first isolated and characterized exosomes released by K562 CML cells and we demonstrated their ability to stimulate human vascular endothelial cells (HUVECs) tube differentiation on Matrigel. K562 exosomes induced an increase of the cumulative tube length in a dose-dependent manner, with a maximum effect at 10ug/ml (p=0.003). Next, we evaluated the effect on exosome behavior of imatinib and dasatinib, two tyrosine kinase inhibitors in use in CML treatment. K562 CML cell treatment with either imatinib or dasatinib reduced exosome release by 58% and 56%, respectively (p<0.01). Equivalent exosome concentrations isolated from imatinib or dasatinib treated K562 cells maintained their ability to stimulate HUVEC tube formation, compared to those isolated from untreated cells. Dasatinib treatment of HUVECs strongly reduced exosome-induced vascular differentiation (p=0.0002). On the contrary, little effect was observed following treatment with imatinib. K562 exosomes stimulated vascularization when added to Matrigel plug in vivo; angiogenesis was markedly inhibited by oral administration of dasatinib (p<0.01), but not imatinib. Consistent with the differential effects of dasatinib and imatinib, exosome-induced HUVEC Src and FAK phosphorylation was only inhibited by dasatinib. Confocal images showed that both FAK and Src phosphorylation were increased at points of membrane-matrix contact. Immunoblot analysis confirmed that K562 exosomes induced a dasatinib-sensitive phosphorylation of Src and FAK and their downstream effectors, Erk and Akt. Again, imatinib was minimally active against exosome stimulation of HUVEC cell signaling. Thus, K562 CML exosomes stimulate angiogenesis in vitro and in vivo in a dasatinib-sensitive fashion. This credentials exosomes and angiogenesis as molecular targets in CML via activation of Src both in leukemia and its microenvironment.

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 4372. doi:1538-7445.AM2012-4372
Abstract 4378: Pericyte coverage of differentiated vessels inside tumor vasculature is an independent unfavorable prognostic factor for patients with clear cell renal cell carcinoma
Authors: Cao Yun , Zhang Zhi-Ling , Zhou Ming , Elson Paul , Rini Brian , Aydin Hakan , Feenstra Kristin , Tan Min-Han , Berghuis Bree , Tabbey Rebeka , Resau James , Zhou Fang-Jian , Teh Bin Tean , Qian Chao-Nan
Published: August 2012

Background: The clinical significance of pericyte coverage (PC) surrounding differentiated vessels in clear cell renal cell carcinoma (CCRCC) is unclear. Objective: To evaluate the effect of PC on the prognosis of patients with CCRCC. Methods: Samples from two cohorts of CCRCC patients (Asian, 101 cases; U.S., 542 cases) were immunohistochemically doubled-stained for a pericyte marker (α-SMA) and a differentiated vessel marker (CD34), followed by multispectral image capturing and computerized image analyses to quantify the microvessel density (MVD) and pericyte coverage of differentiated vessels. The correlations of PC or MVD with clinicopathological characteristics were analyzed. Univariate and multivariate survival analyses were performed. Results: Uneven distributions of differentiated MVD and PC were found, with higher MVD in the peripheral portion of the tumor and higher PC in the inner portion. There was an inverse correlation between differentiated MVD and PC. Higher PC correlated with more aggressive clinicopathological characteristics of CCRCC in both cohorts, including more advanced T-stage, higher pathological grades, and occurrence of tumor necrosis. The MVD:PC ratio was an independent favorable prognostic factor for overall survival in the Asian cohort and for recurrence-free survival in the U.S. cohort. PC and MVD were also independent prognostic factors, with higher PC or lower MVD predicting a poorer outcome. The combination of PC and MVD could better distinguish the outcome of CCRCC patients. PC combined with differentiated MVD, or MVD:PC ratio provided additional independent prognostic information to the Leibovich risk model, and using that information we generated improved risk models. Conclusions: The distributions of MVD and PC were uneven in CCRCC. Higher PC correlated with more aggressive clinicopathological characteristics. PC was an independent unfavorable prognostic factor. Targeting pericytes should be taken into consideration in anti-angiogenic therapy.

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 4378. doi:1538-7445.AM2012-4378
Abstract 438: The importance of estrogen-ERβ axis in racial disparity of prostate cancer
Authors: Elmageed Zakaria Y. Abd , Moroz Krzysztof , Srivastav Sudesh K. , Crawford Byron E. , Moparty Krishnarao , Thomas Raju , Abdel-Mageed Asim B.
Published: August 2012

Purpose: The role of estrogens and estrogen receptors (ERs) in the disproportionate incidence and mortality of prostate cancer (PCa) has not been established. Although ERβ has been implicated in PCa progression, its ethnic-based expression and underlying mechanisms are not fully understood. The aim of this study is to establish correlation between estrogen-ERβ axis and clinical outcome in African American (AA) in comparison to Caucasian American (CA) men. Patients and Methods: 17β-Estradiol (E2) was determined in the blood procured from normal (n=30) and PCa patients (n=50) by ELISA. The expression of ERβ was assessed using an NCI-designed ethnicity-based tissue microarray (TMA) slide encompassing 150 each of AA and CA PCa tissue cores, 17 BPH, 13 normal biopsies, and 3 PCa cell lines (LNCaP, DU-145 and PC-3). Validation of ERβ in situ was validated by qRT-PCR in matched microdissected tumors and normal glands from both populations. Results: In comparison to normal subjects, circulating E2 levels were significantly (p=0.0160) elevated in AA-men than in CA-men with PCa. Additionally, a significant difference in E2 blood levels (p=0.0015) was observed between AA and AA PCa patients. Histoscore analysis demonstrate intense nuclear immunoreactivity (p=0.0018) against ERβ in tumors of AA than CA men. This notion was further validated by qRT-PCR on LCM-procured tumor cells (p=0.0315). In the adjusted multivariate analysis there was no correlation between ERβ expression and any clinical parameters in PCa tissues. In AA, there was a positive correlation between Gleason score (GS) and age but a negative correlation was found between GS, age and PSA-recurrence free. However, no correlation was found in CA. Conclusion: Together, high circulating levels of blood estrogens and mRNA levels coupled with a differential expression of ERβ in PCa tissues suggest a potential role for estrogen-ERβ axis in the development of castrate-resistant prostate cancer in AA men. Key words: E2, ER beta, mRNA, TMA, histoscore, African Americans, health disparities.

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 438. doi:1538-7445.AM2012-438
Abstract 4385: PD-1 blockade enhances T-cell migration to tumor through induction of IFN-γ inducible chemokines
Authors: Peng Weiyi , Liu Chenwen , Xu Chunyu , Chen Jieqin , Lou Yanyan , Overwijk Willem , Lizée Gregory , Yagita Hideo , Hwu Patrick
Published: August 2012

Adoptive cell transfer (ACT) is a promising therapeutic modality for cancer. Although tumor regression can be dramatic in some ACT-treated patients, other patients do not experience any clinical response, underscoring the need for further improvements. One limiting factor in ACT is immune suppression within the tumor microenvironment. In this study, we used a murine ACT model by treating gp100-expressing tumor-bearing mice with transgenic Pmel T-cells, which recognize gp100 in the context of H-2Db. We demonstrated that the expression of programmed death 1(PD-1) on transferred Pmel T-cells was upregulated at the tumor site, compared with transferred T cells in the spleen (48.07% vs 4.87% respectively). Given that PD-1 has been shown to attenuate T-cell mediated antitumor immune responses, we tested whether blockade of the PD-1 pathway by anti-PD-1 antibody could enhance the antitumor activity of adoptively transferred T-cells. We found that tumor-bearing mice treated with a combination of anti-PD-1 and ACT showed enhanced tumor regression compared to mice treated with ACT alone (median tumor size 11.30± 1.89 vs 43.85±7.28 mm2 on day 24 after tumor inoculation, respectively, p <0.001). We also observed increased accumulation of transferred Pmel T cells in the tumor sites of mice receiving combination therapy with ACT and anti-PD-1 using bioluminescence imaging compared to ACT alone (Median luciferase output of 6.5X106 vs 1.6X106 photons/s/cm2/sr, respectively on day 6 after T-cell transfer, p value =0.039). Although anti-PD-1 did not alter the number of immunosuppressive Treg cells and MDSCs, anti-PD-1 treatment did increase the expression of IFN-γ and the IFN-γ inducible chemokine, CXCL10, at the tumor site. Using flow cytometry to analyze the CXCL10 production in the tumor microenvironment, we found that most of the CXCL10-secreting cells were CD11b+ cells, indicating that myeloid cells are the major CXCL10-producing population. Furthermore, bone marrow chimera experiments with IFN-γR-/- mice implicated IFN-γ as a major nexus point for controlling PD-1 blockade-induced tumor infiltration by T cells. Taken together, our results imply that therapeutic blockade of the PD-1 pathway may trigger a positive feedback loop by increasing IFN-γ presence at the tumor site, which in turn induces chemokine-dependent trafficking of more immune cells to metastatic sites.

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 4385. doi:1538-7445.AM2012-4385
Abstract 4386: Effects of interferon-α-transduced tumor cell vaccines and blockade of programmed cell death 1 on the growth of established tumors
Authors: Omori Risa , Eguchi Junichi , Hiroishi Kazumasa , Ishii Shigeaki , Sasagawa Ayako , Sakaki Masashi , Doi Hiroyoshi , Kajiwara Atsushi , Imawari Michio
Published: August 2012

Progress in treatments for cancer has improved the prognosis of patients with colorectal cancer. However, there is a strong need for the development of a new intervention therapy that suppresses the occurrence or recurrence effectively with fewer side effects. Immunotherapy may be such a treatment and gene therapy using tumor cells that are genetically modified to produce cytokines has been studied in several therapeutic models. We have previously reported that the interferon (IFN)-α gene-transduced tumor-based vaccination therapy suppresses the outgrowth of established tumors. Although the suppressive effects on established tumors were observed, we did not see reductions in the size of all of the parental tumors. Therefore, further improvements in the treatment are needed before clinical application, we focused on programmed cell death 1 (PD-1), which has been identified as a marker of exhausted T cells. In this study, we evaluated the efficacy of the combination of IFN-γ-transduced tumor cell vaccines and PD-1 blockade, and investigated the mechanisms of the antitumor effects of the combined therapy. A poorly immunogenic murine colorectal cancer cell line, MC38, was transduced to overexpress IFN-γ (MC38-IFNα). In a therapeutic model, parental tumor-bearing mice were inoculated with MC38-IFNα cells and an anti-PD-1 antagonistic antibody. Significant suppression of outgrowth of the established tumors was observed in the IFN-γ and anti-PD-1 combination treatment group (IFN+ anti-PD-1, 174.17 ± 35.54 mm2 vs control, 328.67 ± 26.36 mm2 on day 28, P = 0.0114 vs controls). Immunohistochemical analyses showed marked infiltration of CD4+ cells as well as CD8+ cells in the established tumors of mice treated with both IFN-γ and anti-PD-1. To investigate induction of tumor-specific immune responses, we stimulated splenocytes of IFN-γ or/and anti-PD-1 treated mice twice weekly by DCs in vitro. Significant tumor-specific cytolysis was detected when splenocytes of mice treated with both IFN-γ and anti-PD-1 were used as effector cells (58.1% ± 6.7% for MC38 and 14.1% ± 1.7% for YAC-1, effector:target = 20, P < 0.001). Our findings suggest that blockade of the PD-1 PD-ligand enhanced the Th1-type antitumor immune responses induced by IFN-γ. The combination of IFN-γ gene-transduced tumor cell vaccines and PD-1 blockade may be a possible candidate for a cancer vaccine for clinical trials.

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 4386. doi:1538-7445.AM2012-4386
Abstract 4391: CD20 as a target for therapy in solid tumors
Authors: Affara Nesrine I. , Ruffell Brian , Johansson Magnus , Fujikawa Kerri , Bergsland Emily , DeNardo David G. , Chen Heather I. , Wadhwani Nikhil , Steinhoff Martin , Truitt Morgan , Olson Peter , Hanahan Douglas , Li Yijin , Gong Qian , Ma Yan , Wiesen Jane F. , Kim Grace , Tempero Margaret , Balkwill Frances , Irving Bryan , Coussens Lisa M.
Published: August 2012

Using the K14-HPV16 mouse model of squamous carcinogenesis (SCC), we previously reported that B cells foster neoplastic progression through deposition of immunoglobulin complexes in premalignant tissue via Fcα receptor-dependent activation of recruited myeloid cells. Here we evaluated therapeutic interventions targeting these pathways in preclinical trials through administration of depleting αCD20 antibody and small molecule inhibitor of Syk kinase. Both approaches harbored efficacy in preventing premalignant progression to the dysplastic/carcinoma in situ state. Screening a diverse spectrum of human solid tumors revealed SCCs of the vulva, head and neck, as well as pancreatic ductal adenocarcinomas (PDAC) as scoring positively for “signatures” of B cell or plasma cell infiltration, i.e. Ig or CD20 mRNA expression, thereby identifying carcinomas potentially amenable to anti-B cell therapies. Accordingly, B cell-deficient mice failed to support growth of either transplantable orthotopic SCC or PDAC. While administration of αCD20 mAB as a single agent was inefficient in impeding growth of preexisting SCCs, when delivered in combination with cytotoxic chemotherapy, e.g., paclitaxel, carboplatin or cisplatin, αCD20 mAb significantly improved chemotherapeutic response and improved survival by a mechanism dependent on CD8+ T cells. These data reveal that blocking protumorigenic programs regulating by humoral immunity, in combination with chemotherapy, effectively reprograms the tumor immune microenvironment and improves outcome. The authors acknowledge generous support from the NIH/NCI (R01CA130980, R01CA13256, R01CA140943, R01CA15531), the Department of Defense (W81XWH-09-1-0342, W81XWH-10-BCRP-EOHS-EXP) and the Susan G Komen Foundation (KG111084)

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 4391. doi:1538-7445.AM2012-4391
Abstract 4393: Optimizing DC vaccination by combination with oncolytic adenovirus coexpressing IL-12 and GM-CSF
Authors: Zhang Song-Nan , Choi Il-Kyu , Huang Jing-Hua , Yoo Ji-Young , Choi Kyung-Ju , Yun Chae-Ok
Published: August 2012

Dendritic cell (DC)-based vaccination is a promising strategy for cancer immunotherapy. However, clinical trials have indicated that immunosuppressive microenvironments induced by tumors profoundly suppress antitumor immunity and inhibit vaccine efficacy, resulting in insufficient reduction of tumor burdens. To overcome these obstacles and enhance the efficiency of DC vaccination, we generated IL-12- and GM-CSF-coexpressing oncolytic adenovirus (Ad-αB7/IL12/GMCSF) as suitable therapeutic adjuvant to eliminate immune suppression and promote DC function. By treating tumors with Ad-αB7/IL12/GMCSF prior to DC vaccination, DCs elicited greater antitumor effects than in response to either treatment alone. DC migration to draining lymph nodes (DLNs) dramatically increased in mice treated with the combination therapy. This result was associated with upregulation of CCL21+ lymphatics in tumors treated with Ad-αB7/IL12/GMCSF. Moreover, the proportion of CD4+CD25+ T cells and VEGF expression was decreased in mice treated with the combination therapy. Furthermore, combination therapy using immature DCs also showed effective antitumor effects when combined with Ad-αB7/IL12/GMCSF. The combination therapy had a remarkable therapeutic efficacy on large tumors. Taken together, oncolytic adenovirus coexpressing IL-12 and GM-CSF in combination with DC vaccination has synergistic antitumor effects and can act as a potent adjuvant for promoting and optimizing DC vaccination.

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 4393. doi:1538-7445.AM2012-4393
Abstract 4394: Combination therapy of dendritic cells and cytokine-induced killer cells prolong survival after the removal of tumor in gastrointestinal cancer
Authors: Gao Diaqing , Yang Yizeng
Published: August 2012

Heterogeneity of cancer cells with expression of MHC-I is a major concern for insufficiency of immunotherapy. Targeting either cancer cells with MHC-I, such as cytotoxic T cells (CTL) initiated by dendritic cells (DCs) stimulated with tumor antigens, or cells without MHC-I, such as cytokine-induced killer cells (CIK), have been believed to kill all type of cancer cells. In present study, we recruited 26 cases of gastrointestinal tract cancers registered in our center during 2005-2010 including 12 gastric cancer, 13 colorectal cancers and 1 esophagus cancer. Subjects were administrated with 1X105 unites of IL-2 for 5 days before mononuclear cells and CIKs were isolated from peripheral blood. After original tumor were removed by surgery, 1-3 dose of DCs and CIKs were perfused via peripheral veins. Our results show that 84% patient's symptoms were improved, 8 cases got relapse in 5 year after surgery, 3 were died. Total survival rates in 1, 3 years are 98%, 93.5%, while control group are only 35%, 33%. Location of tumor in gastrointestinal tract did not show significant difference in 1,3,5 years survival rate, gastric cancer (96%, 95%, 95%) and colorectal cancers (100%, 100%, 100%), but tumor free survival rate in gastric cancer (92%, 88%,88%) was lower than colorectal cancer (100%, 91%, 91%). Our results suggested that the combination of multiple approaches, particularly DC-CIK, significantly improve the efficacy of immunotherapy in gastrointestinal tract cancers.

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 4394. doi:1538-7445.AM2012-4394
Abstract 4395: Cure of castration-resistant prostate cancer in TRAMP mice by reactivating tumor immunity with a phosphatidylserine-targeting antibody
Authors: Yin Yi , Huang Xianming , Barbero Gustavo , Ye Dan , Thorpe Philip E.
Published: August 2012

Androgen deprivation therapy (ADT) is initially effective against prostate cancer, but many patients eventually relapse and die from the outgrowth of castration-resistant disease. Here, we tested the hypothesis that tumor immunity against castration-resistant prostate cancer can be elicited by combining ADT with treatment with a monoclonal antibody that binds exposed phosphatidylserine (PS). The rationale was that PS is an immunosuppressive lipid that becomes exposed on tumor blood vessels and malignant cells in prostate tumors responding to ADT, and inhibits immune responses to prostate tumor antigens. To validate this hypothesis, we castrated TRAMP mice after they had developed prostatic adenocarcinomas and treated them with the PS-targeting antibody, mch1N11. We first demonstrated that PS exposure was induced on tumor vascular endothelium and tumor cells by castration. PS exposure on vessels coincided with regions of hypoxia generated in the tumor microenvironment. Next, we demonstrated that castration combined with treatment with mch1N11 inhibited tumor growth and progression. About half of the treated TRAMP mice did not develop castration-resistant tumors, and eventually died of old age. Immunohistochemical studies revealed that the mch1N11 treatment combined with castration generated T-cell immune responses against TRAMP tumor antigens that kept the tumor in check. Extensive disruption of tumor vasculature and abundant infiltration of immune cells, including CD8 positive T lymphocytes, Natural killer (NK) cells and dendritic cells were observed. Splenocytes from mice treated with mch1N11 plus castration were able to kill TRAMP-C2 specifically in vitro, whereas splenocytes from mice in the other groups could not. These results demonstrate that PS, which becomes exposed on prostate cancer cells and tumor vasculature after ADT, inhibits immunity to TRAMP tumor antigens. Treatment with the PS-targeting antibody mch1N11 reactivates tumor immunity, which can permanently hold new tumor development in check.

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 4395. doi:1538-7445.AM2012-4395
Abstract 4398: Liver is a major primary target for the Toll-like receptor-5 agonist CBLB502 providing radioprotective, antimicrobial and antitumor responses
Authors: Burdelya Lyudmila , Leonova Katerina , Gitlin Ilya , Kojouharov Bojidar , Aygun-Sunar Semra , Veith Jean , Johnson Christopher , Gleiberman Anatoli , Haderski Gary , Allamaneni Shyam , Skitzki Joseph , Stanhope-Baker Patricia , Scheblyakov Dmitry , Logunov Denis , Narodisky Boris , Gudkov Andrei
Published: August 2012

We have previously shown that activation of Toll-like receptor 5 (TLR5) by bacterial flagellin and by pharmacologically optimized flagellin derivative CBLB502 protects mice and monkeys from lethal radiation injury to the hematopoietic and gastrointestinal systems. Here, we report that the liver is a major primary CBLB502 target organ in mice, with hepatocytes specifically showing rapid and strong NF-kB and STAT3 activation. Livers from CBLB502-treated mice showed up-regulation of numerous downstream genes encoding intracellular and secreted proteins with anti-apoptotic, anti-microbial and immunomodulatory activities. Unlike the TLR4 agonist LPS, the liver response to TLR5 agonists appears to be direct and does not involve high levels of proinflammatory cytokines. Thus, while LPS is toxic, TLR5 agonists have strong clinical potential. The importance of liver for CBLB502 radioprotective activity was confirmed by temporary occlusion of liver blood circulation which completely abrogated the protective effect of CBLB502 on hematopoietic precursor cells in irradiated mice. CBLB502 also protected liver tissue itself, increasing mouse resistance to lethal Salmonella tiphymurium liver infection and to hepatotoxic Fas agonistic antibodies. By testing CBLB502 in combination with radiation treatment of experimental mouse tumors in vivo, we demonstrated that its tissue protection properties are limited to normal tissues with no tumor protection detected in any of numerous mouse tumor models. Moreover, direct antitumor effects of CBLB502 treatment was observed in several tumor models. Comparison of the effect of CBLB502 on in vivo growth of isogenic pairs of tumor cell lines differing in their TLR5 status showed that the antitumor effect of the TLR5 agonist is TLR5 dependent and is associated with tumor infiltration by immunocytes, presumably attracted following activation of TLR5 signaling in the tumor cells. Remarkably, CBLB502 caused an immunotherapeutic effect in TLR5-negative tumors (CT26 colon adenocarcinoma and A20 lymphoma) growing as experimental liver metastases. Based on these results, we project clinical applications of CBLB502 as an anticancer immunotherapeutic drug against liver metastases independently on TLR5 status and TLR5-expressing tumors in other locations as well as supporting care drug to reduce adverse hepatotoxicity from radiation and chemotherapy.

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 4398. doi:1538-7445.AM2012-4398
Abstract 440: Wnt signaling regulates neuropilin-2 (NRP2) expression and contributes to cancer cell invasiveness in castration-resistant prostate cancer (CRPC)
Authors: Liu Shuman , Jia Zhengyu , Sun Zheng , Li Xuesen , Guo Yi , Lilly Micheal , Mercola Dan , Hoang Bang H. , Zi Xiaolin
Published: August 2012

Progression to CRPC represents a major challenge for treatment of advanced PCa. However, underlying mechanisms of this process remain largely unknown. We found that androgen deprivation in mice bearing PCa patient-derived tumors and in PCa LNCaP cells resulted in increased expression of wnt transcriptional factors: TCF4 and LEF1, as well as c-myc and NRP2. Using GenBank and MatInspector software, we identified five potential binding sites for TCF4 in the 5′ flanking promoter region spanning from –3891 to +108 base pairs of the NRP2 gene. Treatment of LNCaP cells with Wnt3a and Wnt 5a conditioned medium increased NRP2 mRNA expression; and inhibition of Wnt signaling by overexpression of secreted Wnt antagonists (WIF1 and Frzb/sFRP3) in two CRPC cell lines: C4-2B and PC3 down-regulated the expression of NRP2 in both in vitro cell cultures and in in vivo xenograft tumors. Chromatin immunoprecipitation/real-time PCR a! nalysis revealed that both WIF1 and Frzb/sFRP3 expression decreased the in vivo binding of TCF4 and beta-catenin to the NRP2 promoter at five predicted sites. Knock-down of NRP2 by short-hairpin RNA in CRPC cell lines markedly reduced cellular invasiveness and migration capacity. Furthermore, we analyzed gene microarray data sets from the UCI SPECS project. The total of 204 samples from 82 patients include 66 tumors, 65 tumor-adjacent stromas, 28 far stromas and 45 normal prostate samples. The mRNA expression levels of the genes of interest were normalized to the average expression levels of these genes from the normal prostate samples. We showed that the percentage of samples with WIF1 down-regulation progressively increased from far stroma to adjacent stroma and tumors. Strikingly, the levels of NRP2 mRNA are up-regulated in all tested adjacent stroma and most of tumor samples. Furthermore, the expression levels of NRP2 in far and adjacent stroma and tumors are inversely related to WIF1 mRNA levels (correlation coefficients are –0.6918, –0. 2349 and –0.5931; Ps<0.01). For a large series of clinical samples, NRP2 expression appears to be associated with WIF1 down-regulation. These results suggest that NRP2 may be a novel Wnt target gene and contribute to progression of CRPC.

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 440. doi:1538-7445.AM2012-440
Abstract 4414: Distinct taxonomic, metagenomic and metabolomic profiles from a comprehensive gut flora analysis in healthy and colon adenoma African Americans
Authors: Brim Hassan , Sumner Susan , Lee Edward , Namin Hassan Hassanzadeh , Smoot Duane T. , Nelson Karen , Yooseph Shibu , Sears Cynthia , Pathmasiri Wimal , Ashktorab Hassan
Published: August 2012

Background: Gut flora has long been suspected to play a role in colorectal cancer (CRC) pathogenesis. Elegant experiments have substantiated such claims with the use of single pathogenic bacteria in germ free colon cancer mouse models. Here we run a comprehensive taxonomic, metagenomic and metabolomics analysis of stool samples from healthy and colon adenoma African American (AA) patients to define further this role. Patients & Methods: DNA extracts from stool samples of 6 healthy and 6 colon adenoma patients were used for the taxonomic and metagenomic analysis. The sequencing was done using a 454 pyrosequencer and the generated data was processed using informatics pipeline for phylogenetic bacterial affiliation and for bacterial functions assignment. For the metabolomics analysis, 10 fecal water extracts from healthy individuals and 10 from colon adenoma patients were analysed for their metabolites’ contents using NMR spectrometry. Results: The analysis of 16S-rDNA sequences revealed the existence of 22 groups of bacteria. A phylogenetic clustering revealed colon adenoma cases clustering together. Most predominant groups in both sets of samples were Clostridia and Bacteroides. No Lactobacilli or Bifidobacteria (good bacteria) were detected. The synergistetes_Dynergistia group -involved in gastrointestinal infections and Firmicutes phylum: Firmicutes group - involved in energy resorption and obesity were 20 and 10 folds more prevalent in adenoma patients, respectively. Bacteria TM7 group that contain active agents in IBD was 5 folds more represented in the control compared to the adenoma group. The metagenomic experiment have led to the generation of about 100,000 reads per sample, 80% of which were successfully annotated. Among the annotated functions, many were differentially present in the colon adenoma compared to healthy individuals. The metabolomics analysis led to a strong clustering of the adenoma samples metabolomes further consolidating the role of bacteria and their metabolites in colon cancer pathology. Conclusion: Our taxonomic, metagenomic and metabolomics analysis have led the presence of clear differential profiles in colon adenoma patients vs. healthy persons. Lack of detection of “good bacteria” (Lactobacilli and Bifidobacteria) in this study defines already a first level of intervention in this high risk CRC population. A comprehensive analysis of all the results is underway to bridge the Taxo, Meta and metabolomics data.

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 4414. doi:1538-7445.AM2012-4414
Abstract 4418: The histopathological characteristics of mucin-depleted foci in patients with sporadic colorectal cancer
Authors: Sakai Eiji , Takahashi Hirokazu , Yamada Eiji , Higurashi Takuma , Ohkubo Hidenori , Hosono Kunihiro , Endo Hiroki , Kato Shingo , Nakajima Atsushi , Cui Changxu , Takamatsu Reika , Yoshimi Naoki
Published: August 2012

Introduction: In experimental models, Mucin-depleted foci (MDF), formed by dysplastic crypts devoid of mucin production have been recognized to be correlated with colorectal carcinogenesis and to serve as preneoplastic lesions of colorectal cancer (CRC). In humans, there is only one report of identification of MDF mainly in patients with familial adenomatous polyposis, however the histological characteristics of human MDF was not discussed sufficiently in this report. Therefore, we conducted this study to identify MDF in sporadic CRC patients and to evaluate the histological characteristics of human MDF. Materials and Methods: Colonic samples from 53 patients of sporadic CRC were stained with Alcian blue and examined for the presence of MDF. Subsequently, the samples were also examined for the presence of aberrant crypt foci (ACF) by methylene blue staining. We classified MDF into two categories, namely, flat-MDF and protruded-MDF (having the characteristics of both ACF and MDF), and analyzed their histological characteristics. Results: We found a total of 354, 41 and 19 colonic mucosal lesions with a mean multiplicity of 44, 38.9 and 66.9 crypts (ACF, flat-MDF and protruded-MDF, respectively). The density of MDF was 0.0082 lesions/cm2. ACF identified in sporadic CRC patients corresponded to hyperplastic or non-dysplasic lesions. On the other hand, MDF (both of flat-MDF and protruded-MDF) identified in these patients corresponded to low-grade dysplasia. In addition, we found that Paneth cell metaplasia and inflammatory cell infiltration were specific histological features of MDF. These histopathological characteristics have been reported to be associated with the development of CRC. Conclusions: This is the first report of a study conducted to investigate the density and histopathological characteristics of MDF in a large sample of sporadic CRC patients. Our results indicate that MDF might represent preneoplastic lesions in human colorectal carcinogenesis.

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 4418. doi:1538-7445.AM2012-4418
Abstract 4420: Serum regulates reovirus-mediated cytopathy in K-Ras activated colorectal cancer and intestinal epithelial cell lines
Authors: Maitra Radhashree , Augustine Titto , Seetharam Raviraja N. , Coffey Matthew C. , Klampfer Lidija , John.Mariadason John , Goel Sanjay
Published: August 2012

Background: The oncolytic potency of replication competent REOvirus has been demonstrated in various cancers. The activity is most pronounced in Kras mutant cancer cells, which account for 30-40 % of all cancers. Herein we simultaneously utilized isogenic human derived colorectal cancer cell lines that differ only by the presence of mutant Kras and normal rat intestinal epithelial cells with inducible Kras to evaluate whether the presence of oncogenic Kras alters the sensitivity of colon cancer cells to reovirus. Methods: Reovirus was obtained from Oncolytics Biotech Inc. Rat IEC's harboring IPTG inducible mutant Ras oncogene (IEC-iKras) were treated with reovirus ± IPTG. The infectivity was maintained at a multiplicity of infection (MOI) of 2. MTT assay was performed at 72 hours to determine cell vability (CV). Similar experiments were also performed with HCT116 (Kras mut) and its isogenic derivative Hke3 [(Kras wild type (WT)]. Cells were cultured and treated in both serum rich (SR) and serum free (SF) media to determine the effect of growth factors on sensitivity to reovirus. Alterations in gene expression were determined by real time PCR and protein expression by western blot. Results: The activity of reovirus was observed in all cell lines studied. Reduction in CV was greater in Kras mutant HCT116 compared to WT Hke3 cells. Consistently, induction of Kras in IEC cells increased the potency of reovirus. Furthermore, this effect was more prominent in cells cultured in SF suggesting that growth factors in the serum may attenuate the effect of mutant Kras on reovirus sensitivity. Expression of the cell cycle regulator, p21 was preferentially increased upon reovirus infection in Kras mutant compared to WT cells, and in cells cultured in SF compared to SR conditions. Conclusion: Oncogenic Kras mutations increase the sensitivity of colon cancer cells to Reovirus. Clinical trials are underway testing reovirus in patients with Kras mutant metastatic colorectal 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 4420. doi:1538-7445.AM2012-4420
Abstract 4479: Polymorphisms in the nucleotide excision repair genes, ERCC1 and ERCC2/XPD and carcinogen DNA adducts in human lung
Authors: Lee Mi-Sun , Liu Chen-yu , Su Li , Wain John C. , Mark Eugene J. , Christiani David C.
Published: August 2012

Objectives Excision repair cross-complementing group 1 (ERCC1) and excision repair cross-complementing group 2/xeroderma pigmentosum group D (ERCC2/XPD) in the nucleotide excision repair (NER) pathways that removes DNA damage caused by tobacco smoking carcinogen such as polycyclic aromatic hydrocarbons (PAHs). However, no studies have examined their role in DNA adducts in target human lung tissue, a dosimeter for lung cancer risk. Therefore, we investigated whether the polymorphisms in SNPs in NER pathways associated with the DNA adduct formation in human lung tissue. We further analyzed these relationship divided by adenocarcinoma and squamous cell carcinoma, main type of non-small cell lung cancer (NSCLC). Methods The study population consisted of 135 lung cancer patients from the Massachusetts General Hospital (MGH). Genotyping was completed for SNPs in ERCC1 [C8092A (rs3212986) and C118T (rs11615)] and ERCC2/XPD [Asp312Asn (rs1799793) and Lys751Gln (rs1052559)] using PCR-RFLP method and the PCR with fluorescent allele-specific oligonucleotide probes (TaqMan method). DNA adduct levels were measured as relative adduct levels per 1010 nucleotides by 32P-postlabeling in the lung. Multiple regression models were used to estimate adjusted percent change in DNA adduct levels associated with genotypes of the NER genes ERCC1 and ERCC2/XPD. Results After adjusting for potential confounders, DNA adduct levels in lung increased by 73.5% [95% confidence interval (CI), –22.6 to 288.9] for the ERCC2/XPD rs1799793AA genotype and by 43.7% (95% CI, –30.0 to 194.6) for ERCC2/XPD rs1052559GG genotype compared with their corresponding wild type homozygous genotypes in overall lung cancer patients, but it did not reach statistical significance. We found that DNA adducts levels in lung increased by 166.6% (95% CI, –5.0 to 648.3, P = 0.07) for ERCC2/XPD rs1799793AA genotype in patients with squamous cell carcinoma and the trend was borderline significant (P for trend = 0.06). Conclusions Polymorphisms of DNA repair genes, ERCC2/XPD Asp312Asn, may affect increased level of DNA adducts in the lung. Further large scale studies are needed to confirm our findings. Supported by NIH grants CA074386, CA092824, and CA90578.

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 4479. doi:1538-7445.AM2012-4479
Abstract 4481: Vitamin D pathway gene variants associated with vitamin D deficiency in African Americans
Authors: Batai Ken , Shah Ebony , Ruden Maria , Newsome Jennifer , Murphy Adam , Kittles Rick A.
Published: August 2012

Background: Cancer incidence and mortality rate is disproportionate among the racial/ethnic groups in the U.S. and higher in African Americans (AAs) due to a combination of genes and environmental factors. The difference in serum vitamin D3, 25(OH)D, concentration among racial groups is suspected to be one of the sources of cancer health disparities. Vitamin D has protective effects against several types of cancer, and vitamin D deficiency is more common among AAs than the European Americans (EAs). Genome-Wide Association Studies (GWAS) among EAs found vitamin D pathway gene (VDPG) variants associated with serum 25(OH)D level, but association between VDPG variants and serum 25(OH)D level has not examined in AAs. Here, we tested if thirty-nine VDPG variants are associated with serum 25(OH)D concentration. Samples and Methods: Nineteen variants in GC, VDR, CYP3A4, CYP2R1, and CYP24A1 were genotyped in a total of 462 AAs from Washington, D.C. and Chicago area. Twenty GWAS identified VDPG variants were genotyped in a subset of subjects (n=332). West Africa Ancestry (WAA) was estimated using STRUCTRE from 105 ancestry informative markers typed. Then, we tested for association adjusting for WAA, age, and skin color. Results: Eight GWAS identified SNPs (five in GC, one in CYP2R1, and two in DHCR7/NADSYN1) were associated with serum 25(OH)D levels and/or vitamin D deficiency. Among darker-skinned AAs, the VDR SNP rs11568820 (Cdx2), was significantly associated (P<0.05) with the risk of vitamin D deficiency (<20 ng/ml) (OR=1.94; CI 1.11-3.38). Conclusion: We found VDPG variants associated with serum 25(OH)D level and/or vitamin D deficiency in AAs. We also replicated the findings from a previous GWAS in EAs and found that the same variants were associated with serum 25(OH)D in AAs. Additional studies are necessary to assess whether these variants are associated with cancer risk. Impact: Increased attention is focused on the role of vitamin D in cancer risk. Our findings provide insights on the biological and environmental modifiers of serum vitamin D3 and will help guide future studies on the role of vitamin D in cancer in high risk populations such as AAs.

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 4481. doi:1538-7445.AM2012-4481
Abstract 4485: Prediction of esophageal cancer risk through quantification of gamma-H2AX levels in peripheral blood lymphocytes
Authors: Zhang Fanmao , Gu Jian , Gong YiLei , Hawk Ernest , Ajani Jaffer A. , Wu Xifeng
Published: August 2012

Increased susceptibility to DNA damage has been shown to be associated with increased risk of many cancers. Accumulation of gamma-H2AX (γ-H2AX) in cultured cells after stimulation by ionizing radiation or other genotoxic agents is a sensitive indicator of DNA double-strand breaks (DSBs) induction. We hypothesize that higher level of DSBs, as measured by γ-H2AX levels in peripheral blood lymphocytes (PBLs), may be able to predict higher cancer risk. We first developed an objective, high-throughput, and image-based method to quantify immunofluorescence intensities of γ-H2AX in cultured PBLs. To test this hypothesis, using an ongoing esophageal cancer case control study, we measured the γ-H2AX levels at baseline and after gamma-radiation in the PBLs from 245 newly diagnosed, previously untreated esophageal cancer patients and 400 healthy control subjects, and calculated the ratio of radiation-induced to the baseline γ-H2AX levels as a parameter of DSBs. The mean γ-H2AX ratio was significantly higher in cases (1.48±0.14) than controls (1.39±0.11) (P =1.47×10-14). When dichotomized at the median level of the γ-H2AX ratio in control subjects, individuals in the high γ-H2AX ratio group exhibited a significantly increased risk of esophageal cancer (odds ratio [OR]=2.83, 95% confidence intervals [CI]: 2.00-4.00). When subjects were categorized into tertiles defined by the distribution of the relative γ-H2AX ratio in control subjects, a significant dose-response relationship was observed between γ-H2AX ratio and risk of esophageal cancer. Compared to subjects in the lowest tertile of γ-H2AX ratio, those in the middle and the highest tertiles exhibited increased risks of esophageal cancer with ORs of 1.60 (95% CI: 1.00-2.55) and 3.72 (95% CI: 2.43-5.70), respectively (P for trend =2.24×10-10). Quartile analysis also showed similar dose-response relationship. Our data suggest that higher ratio of gamma-radiation-induced to baseline γ-H2AX is significantly associated with an increased risk of esophageal cancer. This study supports that measurement of this ratio may be used as a novel phenotypic assay to identify individuals at high risk for esophageal 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 4485. doi:1538-7445.AM2012-4485
Abstract 4487: Inverse associations between soluble cytokine receptors and colorectal cancer risk
Authors: Ho Gloria YF , Xue Xiaonan , Zheng Lilly S. , Cushman Mary , Xu Jianfeng , Tinker Lesley , Wang Tao , Wassertheil-Smoller Sylvia , Strickler Howard D. , Gunter Marc J. , Rohan Thomas E.
Published: August 2012

Laboratory studies have suggested that soluble receptors of proinflammatory cytokines could be anti-inflammatory by acting as decoy receptors, blocking binding of the cytokines to their membrane receptors, and hence inhibiting cytokine signaling. Thus, relatively high levels of soluble cytokine receptors and receptor antagonists may be protective factors against colorectal cancer, which is an inflammation-associated disease. This case-cohort study nested within the Women's Health Initiative Observational Study of postmenopausal women 50-79 years of age at baseline (1993-1998) examined whether baseline plasma levels of IL-1 receptor antagonist (IL-1Ra) and the soluble receptors of IL-6 (sIL-6R and sgp130), TNF (sTNF-R1 and sTNF-R2), and IL-1 (sIL-1R2) were inversely associated with colorectal cancer risk. Analytes were measured in 433 incident colorectal cancer cases and 823 subcohort members using multiplex assays (Millipore, Billerica, MA). Circulating levels of IL-6, TNF-α, insulin, and estradiol measured previously were also available for data analyses. IL-1Ra and the 5 soluble receptors did not correlate with each other or with their ligands (all correlations r < 0.3), with the exception of sTNFR2, which was moderately correlated with sTNFR1 (r=0.51) and TNF-α (r=0.43). The table below shows the hazard ratios for colorectal cancer risk, when each analyte was entered separately into a Cox regression model adjusting for other colorectal cancer risk factors. Colorectal cancer risk decreased significantly with increasing levels of sIL-6R and sIL-1R2. The ratios of IL-6 or TNF-α to their soluble receptors were not associated with colorectal cancer risk. There were also no significant interactions between pairs of soluble receptors or between soluble receptors and their ligands. Increased circulating levels of sIL-6R and sIL-1R2 may confer protection against colorectal cancer. If our results are confirmed, these soluble receptors can be considered for chemoprevention.

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 4487. doi:1538-7445.AM2012-4487