bluuebunny/crossref_metadata_2025 huggingface dataset:
Abstract 744: PEDF silencing a novel mechanism of antihormone resistance in breast cancer
Authors: Lewis-Wambi Joan S. , Huang Min
Published: June 2012

Despite the benefits of endocrine therapies in treating estrogen receptor alpha (ERα)-positive breast cancer, many tumors eventually become resistant. Identifying the underlying cellular and molecular mechanisms responsible for endocrine resistance remains a critical and immediate need. Pigment epithelium-derived factor (PEDF) is a multifunctional protein released by adipocytes and increased in metabolic syndrome and insulin-resistance. Moreover, PEDF belongs to the serine protease inhibitor family but does not inhibit proteases. It is a potent endogenous inhibitor of angiogenesis and a promising agent for diabetic retinopathy and potentially cancer. Previous studies have shown that PEDF expression is significantly reduced in breast cancer cells (compared to normal breast epithelium) and its reduction is associated with disease differentiation (lowest levels in poorly differentiated tumors), disease progression and poor patient outcome, however, it is not known whether PEDF plays a role in endocrine resistance. In the present study, we evaluated PEDF expression in endocrine-sensitive MCF-7, T47D, and ZR-75-1 breast cancer cells versus endocrine resistant MCF-7:5C, MCF-7:2A, and BT474 cells and found that PEDF mRNA and protein levels were dramatically reduced in the latter group of cells. In addition, tissue microarray analysis of primary tumors from patients (N=66) who subsequently developed invasive recurrence after adjuvant tamoxifen treatment revealed that expression of PEDF protein was reduced by 45% and loss of PEDF was associated with enhanced expression of phosphoSer167ERα and the receptor tyrosine kinase RET (Rearranged during Transfection). Importantly, we found that silencing endogenous PEDF in tamoxifen-sensitive MCF-7 and T47D breast cancer cells abolished their sensitivity to the inhibitory effects of tamoxifen whereas reexpression of PEDF in endocrine resistant MCF-7:5C and MCF-7:2A cells restored their sensitivity to tamoxifen and raloxifene. Furthermore, we found that reexpression of PEDF in endocrine-resistant cells significantly reduced the levels of RET, cyclin D1 and phospho-AKT, in these cells. Together, these findings suggest that PEDF silencing might be a novel mechanism for the development of endocrine resistance in breast cancer and that PEDF expression could be used as a predictive marker of endocrine sensitivity. Furthermore, these findings suggest that recombinant PEDF might be beneficial in treating patients with antihormone resistant disease with potential application in ER-negative disease.

This work was supported by the NIH Career Development Grant K01CA120051 01A2 and the Hollenbach Family Fund (JLW).

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 744. doi:10.1158/1538-7445.AM2011-744
Abstract 754: Heat shock protein vaccines for immunotherapy ofHer-2/neu positive breast cancers
Authors: Smith Annalise , Lopez Rodriguez Darlah M. , Podack Eckhard R. , Andreansky Samita S.
Published: June 2012

Over-expression of Her-2/neu protein, a member of the epidermal growth factor receptor (EGFR) involved in cell growth results in cancer development. 20-30% of breast cancers over-express Her-2/neu protein and this has been correlated with poor prognosis, leading to recurrence after their initial treatment. Thus new strategies are necessary to combat this devastating disease. The selective expression of HER-2/neu in epithelial carcinogenesis makes HER-2/neu antigen an ideal target for immunotherapy. The objective of our research is to explore vaccine strategies that impacts both B and T cell responses in HER-2/neu breast cancer models. We are exploring heat shock proteins (HSP) vaccines that will chaperone tumor-associated antigens including our antigen of interest Her-2/neu protein to elicit innate and adaptive responses. We are utilizing the rat Her-2/neu as our model antigen and are administering these vaccines in transplantable and transgenic her-2/neu murine models after tumor implantation. Our first approach was to generate a Her-2/neu derived HSP gp96 in a secretable form. It has been reported that gp96 can ubiquitously bind to cell associated peptides and cross present these antigens to CD8+ T-cells to generate an effective cytotoxic T cell (CTL) response. Cancer cells expressing rat Her-2/neu were stably transfected with a mouse gp96IgG eukaryotic expression vector, where the endoplasmic retention signal sequence KDEL of gp96 was replaced with the hinge and CH2 and CH3 domains of murine IgG1. 2×104 stably transfected cells secreted within 24h 100- 200ng gp96IgG. Our goal is to generate Her-2/neu specific CD8 T cell responses that would result in vivo tumor delay. Our second approach was to test the adjuvanticity of a mixture of HSPs in combination with irradiated tumor cells. Administration of the vaccine in a therapeutic setting not only delayed tumor growth, but also provided survival benefit. Additionally, vaccinated animals were superior in eliciting Her-2/neu specific antibody response when compared to the HSP vaccine or the irradiated tumor cells alone. Our long-term goal is to combine both approaches to enhance cytotoxic T cell (CTL) and B cell specific response against Her-2/neu specific cancers. Funded by: American Cancer Society MRSG# 08-064-01-LIB and Women's Cancer Association

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 754. doi:10.1158/1538-7445.AM2011-754
Abstract 755: Dendritic-cell vaccine: Cross-presentation of carcinoembryonic antigen (CEA) by dendritic cells (DCs) through a fusion protein targeting CD74 on DCs
Authors: Chen Xiaochuan , Chang Chien-Hsing , Stein Rhona , Goldenberg David M.
Published: June 2012

Milatuzumab (hLL1, Immunomedics, Inc.) is a humanized anti-CD74 monoclonal IgG1 antibody (mAb) currently in phase I-II clinical trials as a therapeutic mAb for CD74-expressing non-Hodgkin lymphoma, chronic lymphocytic leukemia, and multiple myeloma. Since CD74 is also expressed by normal antigen-presenting cells (APCs), including DCs, we investigated the potential application of the Fab fragment of hLL1 as a novel targeting vector in a cancer vaccine.

Methods: A fusion protein, hLL1-Fab-A3B3, was constructed by fusing the Fab fragment of milatuzumab to the A3B3 domain of CEA. The binding profiles and cytotoxic potenial of hLL1-Fab-A3B3 on APC subsets in human peripheral blood mononuclear cells (PBMCs) were assessed by flow cytometry; the impact of hLL1-Fab-A3B3 on APC function was assessed by allogeneic mixed leukocyte reaction (MLR) through CFSE-based cell proliferation assay. The cross-presentation of CEA by DCs was evaluated by three rounds of weekly stimulation of autologous T cells with DCs loaded with hLL1-Fab-A3B3 or CEA protein, followed by measuring CEA-specific CD8+ T cells with HLA-A*0201-restricted CAP-1 pentamer (YLSGANLNL).

Results: Both bivalent milatuzumab and monvalent hLL1-Fab-A3B3 bound efficiently to human APC subsets, which include BDCA-1+ myeloid DCs type 1 (mDC1), BDCA-2+ plasmacytoid DCs (pDCs), BDCA-3+ myeloid DCs type 2 (mDC2), B lymphocytes, and monocytes, but neither of the two bound to T cells. While milatuzumab selectively reduced mDC1 (by 60.8%, P=0.003, n=6 donors) and mDC2 (by 53.8%, P=0.0026, n=7 donors) in PBMCs, presumably mediated by the presence of Fc, or a necessity for divalent milatuzumab binding, hLL1-Fab-A3B3 did not have this effect, nor did it affect the viability of T cells and other APC subsets (pDCs, monocytes, and B cells). The allogeneic MLR was significantly inhibited by milatuzumab (P<0.0001), but not by hLL1-Fab-A3B3 treatment (P=0.6644). After three rounds of weekly stimulation of autologous T cells, DCs loaded with hLL1-Fab-A3B3 were more efficient in inducing CEA-specific CD8+ T cells than DCs loaded with CEA, suggesting that the hLL1-Fab enhances the cross-presentation of CEA by DCs.

Conclusion: hLL1-Fab is a promising, novel targeting antibody for use as a cancer vaccine, because it enhances the cross-presentation of antigens without significant cytotoxicity and functional alteration on APCs.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 755. doi:10.1158/1538-7445.AM2011-755
Abstract 758: Cancer vaccine immunotherapy employing Saccharomyces cerevisiae (yeast) as a vector can modulate the balance between CD4+ T cells and regulatory T cells (Tregs) and enhance the specific antitumor immune response
Authors: Vergati Matteo , Cereda Vittore , Intrivici Chiara , Huen Ngar-Yee , Bari Maria Giovanna Di , Jochems Caroline , Gulley James L. , Apelian David , Schlom Jeffrey , Tsang Kwong Y.
Published: June 2012

Regulatory T cells (Tregs) have been broadly related to modulation of the antitumor immune response. We have previously shown that whole, heat-killed, recombinant Saccharomyces cerevisiae yeast genetically modified to express carcinoembryonic antigen (yeast-CEA) can efficiently activate human dendritic cells (DCs) and stimulate CEA-specific CD8+ T cells. In the present study, we further investigated how the balance between CD4+ T cells and Tregs induced by yeast-treated DCs might affect the generation of a CEA-specific immune response. Autologous CD4+ T cells were co-cultured with human DCs matured by yeast vs. CD40L. Activated CD4+CD25+ effector T cells (Teffs) and CD4+CD25+CD127- Tregs isolated from the two co-cultures were analyzed. A higher Teff/Treg ratio, greater levels of Th1-related cytokines, lower expression of FoxP3 in Tregs, decreased FoxP3 demethylation levels in the Treg-specific demethylated region, and decreased Treg suppressive function were found in the cells isolated from the yeast co-culture compared to those from the CD40L co-culture. DCs isolated from the yeast co-culture showed a significant decrease in surface expression of programmed death ligand 2 (PD-L2) vs. the CD40L co-culture (55.7% vs. 31.2%). No differences were observed in programmed death ligand 1 (PD-L1) levels. Teffs isolated from the yeast co-culture had higher levels of PD-L1 (22.9% vs. 13.7%), but significantly lower levels of programmed death 1 (PD-1, 2.4% vs. 11.6%), compared to the co-culture using CD40L-matured DCs. Tregs isolated from the yeast co-culture showed a significant increase in surface expression of PD-L1 (25.5% vs. 3.6%) and no difference in levels of PD-1 (0.7% vs. 1.4%) compared to the CD40L co-culture. These pro-inflammatory changes may partially explain both the increased CEA-specific CD4+ T-cell proliferation using yeast- vs. CD40L-treated DCs pulsed with CEA protein, and the higher percentage of CEA-specific CD4+ T cells generated when yeast-matured DCs vs. CD40L-treated DCs were used as antigen-presenting cells in the presence of CEA protein. This is the first study to report on the role of yeast-treated human DCs in modulating the balance between Teffs and Tregs and thus enhancing the antitumor immune response. Altogether, these preliminary findings provide a rationale for further evaluation of yeast constructs in cancer vaccine immunotherapy.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 758. doi:10.1158/1538-7445.AM2011-758
Abstract 772: Targeted cancer therapy with immunotoxins
Authors: Wiiger Merete T. , Fodstad Øystein , Andersson Yvonne
Published: June 2012

The therapeutic options for patients with metastasis are generally limited and the need to develop better treatment modalities is obvious. Immunotoxins (ITs) represent a promising group of targeted therapeutics, consisingt of a cancer-specific antibody and a cell killing toxin. The number of IT protocols approved for treatment of cancer patients is expected to increase, as this type of treatment has several advantages compared to conventional strategies. Unfortunately, the clinical use of ITs has been hampered by liver toxicity and the induction of a strong anti-IT-antibody response. However, in an ongoing clinical phase I study with one of our ITs, targeting EpCAM, in combination with the immunosuppressor cyclosporin (CsA) we have demonstrated only transient liver toxicity and minimal/no anti-IT antibody response.

We are now investigating the potential use of our-clinical grade BM7PE for patients with triple-negative breast cancer (TNBC) and peritoneal carcinomatosis from ovarian cancer, for whom standard treatment is no longer an option. This IT targets Mucin-1 which is over-expressed and aberrantly glycosylated in these cancer types.

We have found that the combination of BM7PE and CsA caused a remarkable synergistic effect in killing the TNBC cell lines MDAMB468 and MDAMB231, as well as in the ovarian cell line B76, established from pleural effusion. The mechanisms underlying this synergism in vitro have been thoroughly studied in cell viability assays, western blot and PCR-arrays. Preliminary data show reduced Matrigel invasion, which was even more inhibited by the combination with CsA. This suggests that the IT treatment does regulate cellular migration and invasion. Further investigations are ongoing to identify molecular pathways involved in IT- (+/-CsA) induced cell death and invasion.

In conclusion, the combination of BM7PE and CsA might constitute an important improvement and increase the possible clinical potential of IT in these patient groups.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 772. doi:10.1158/1538-7445.AM2011-772
Abstract 775: Sequential common gamma-chain cytokines facilitate differentiation of tumor-reactive T cells that are resistant to MDSC and can induce rejection of breast tumors
Authors: Payne Kyle K. , Kmieciak Maciej , Basu Debasmita , Ramakrishnan Viswanathan , Bear Harry D. , Manjili Masoud H.
Published: June 2012

Adoptive T cell immunotherapy (AIT) utilizing ex vivo expanded HER-2/neu-specific T cells is a promising modality in the treatment of patients with breast carcinoma. Previously, our group has described the ability of tumor-sensitized T cells activated ex vivo with bryostatin 1 and ionomycin (B/I) and subsequently expanded with common γ-chain receptor family cytokines IL-2 and IL-7/IL-15 cultured in an alternating manner to induce primary breast tumor regression in FVBN202 transgenic mice. These results, however, required the combination of AIT with in vivo depletion of myeloid-derived suppressor cells (MDSCs) as the presence of these cells abrogated the anti-tumor efficacy of neu-specific lymphocytes. Presently, we report the implementation of a novel ex vivo expansion protocol, in which IL-2 and IL-7/IL-15 are cultured in a sequential manner post B/I with tumor-specific activated cells and support expansion of tumor reactive CD44+CD62L− effector T cells (TE) and CD44+CD62L+ central memory T cells (TCM). We show that tumor-specific cells activated in this manner induce rejection of primary breast tumor and provide long-term protection against the tumor, even in the presence of MDSC. Of particular interest, tumor-reactive CD4+ and CD8+ lymphocytes expanded with this method conferred resistance to the suppressive effects of MDSCs in vitro. Additionally, we demonstrate that innate immune cells are essential in eliciting tumor rejection. Flow cytometric analysis indicates Natural Killer (NK) and Natural Killer T-cell (NKT) as well as the Interferon-γ Producing Killer Dendritic Cell (IKDC) populations significantly increase following ex vivo expansion with sequential common γ-chain cytokines. Depletion of innate immune cells in adoptively transferred cells resulted in the failure of AIT to reject tumor. Together, our data suggest that sequential common γ-chain cytokines can support differentiation of tumor-reactive T cells which are resistant to MDSC, as well as innate immune cells which may be essential in supporting the anti-tumor efficacy of T cells. These results potentially provide a new paradigm in therapeutic AIT of breast carcinoma.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 775. doi:10.1158/1538-7445.AM2011-775
Abstract 785: The progesterone induced blocking factor, an immunomodulatory protein that may suppress natural killer cell activity in the tumor microenvironment, found to be a soluble protein possibly allowing the development of an enzyme-linked immunoabsorbent assay
Authors: Cohen Rachael , Srivastava Maya , Check Jerome H. , Dix Ebony
Published: June 2012

A unique 34 kDa protein expressed by gamma delta thymic (T) cells during pregnancy suppresses natural killer (NK) cell activity and helps to shift the balance of thymic helper (TH) 1 to TH2 cytokine dominance. The mechanism involved in making this immunomodulaotry protein involves de novo induction of progesterone (P) receptors on gamma delta T cells by the allogeneic stimulus of the fetal semi-allograft and the interaction of the P receptors with a high concentration of P generated at the maternal fetal interface. There is evidence that certain cancer cells may use a similar mechanism to escape NK cell surveillance as evidenced by all 27 different human leukemia cells tested showing a very high level of messenger RNA for this immunomodulatory protein known as the progesterone induced blocking factor (PIBF). Furthermore adding the P receptor antagonist mifepristone down-regulated PIBF expression. PIBF may be synthesized by gamma delta T cells in the tumor microenvironment of solid tumors thus inhibiting NK cell immunosurveillance. Previous studies were performed using an immunocytochemistry technique using a polyclonal antibody because the PIBF protein was not purified. Recombinant DNA technology has allowed the production of a pure protein and thus the development of a monoclonal antibody. The present study was aimed at determining if PIBF is a soluble protein, which if it is could lead to the development of a much more practical and sensitive enzyme linked immunoabsorbent assay (ELISA). Serum samples were blindly assessed for the presence of PIBF using a novel sandwich ELISA we developed with full length (amino acid 1 to 757) recombinant human PIBF, rabbit polyclonal antibody to amino acid 1-300, and affinity purified goat polyclonal antibody to the internal region of PIBF conjugated to horseradish peroxidase. Color was developed using tetramethylbenzidine substrate stopped by 2N H2SO4 and read at 450 lambda. Bovine serum albumin served as negative control. Soluble PIBF was detected in several samples, with highest levels in pregnant patients at over 10 microgram/ml concentration. There were significant inter-individual differences. PIBF, does indeed also exist in a soluble form and can be detected in serum. With further refinement of our ELISA we aim to improve sensitivity and specificity, allowing for the simple measurement of PIBF on a rapid, high throughput basis, making it a more practical test to predict cancers that would benefit from progesterone receptor antagonist therapy.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 785. doi:10.1158/1538-7445.AM2011-785
Abstract 791: T cells in visceral adipose tissue: A potential source of inflammation to drive tumorigenesis
Authors: Lysaght Joanne , Allott Emma H. , Donohoe Claire L. , Howard Julia M. , Pidgeon Graham P. , Reynolds John V.
Published: June 2012

Introduction: Visceral adipose tissue is believed to be fuelling a state of chronic inflammation in obese patients, establishing an environment favourable for tumor growth. However, the exact immunological mechanisms remain unclear. Recent animal studies have pointed to an important role for visceral adipose tissue CD8+ T cells in both the establishment of and maintenance of adipose tissue inflammation in obese models. This novel study aimed to phenotypically characterize both CD4+ and CD8+ T cells in the omentum of esophageal adenocarcinoma (EAC) patients, as EAC has one of the strongest association with obesity and arises in a background of inflammation.

Methods: Peripheral blood and visceral adipose tissue from the greater omentum were taken from 30 EAC patients at the commencement of resectional surgery. Peripheral blood mononuclear cells were isolated using density centrifugation and the stromal vascular fraction of the adipose tissue was obtained following collagenase digestion. T cell activation status and cytokine production were assessed by both surface and intracellular flow cytometry and serum cytokines were determined by ELISA.

Results: The omentum was found to be a rich source of both CD4+ and CD8+ T cells, which display an activated inflammatory phenotype, expressing significantly higher (p<0.0001) CD69, CD107a, CD45RO and IFN-γ than T cells in the blood. Omental CD8+ T cells also expressed significantly higher (p<0.0001) IFN-γ than CD4+ T cells, suggesting that CD8+ T cells are an important source of this inflammatory cytokine within visceral fat. The highest circulating levels of the IFN-γ were detected in the serum of viscerally obese cancer patients.

Conclusions: This novel study demonstrates that omental T cells may be key players in driving adipose tissue inflammation, potentially mediated by IFN-γ. The highest serum levels of IFN-γ were detected in viscerally obese cancer patients, suggesting that visceral adipose tissue may be the source of this inflammatory cytokine, thus providing an immunotherapeutic target to attenuate chronic inflammation associated with visceral obesity.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 791. doi:10.1158/1538-7445.AM2011-791
Abstract 793: Direct inhibitory effects of gastric cancer against dendritic cells
Authors: Iwauchi Takehiko , Tanaka Hiroaki , Yoshii Mami , Ito Gentaro , Kimura Kenjiro , Nagahara Hisashi , Noda Eiji , Amano Ryosuke , Kubo Naoshi , Muguruma Kazuya , Yamada Nobuya , Yashiro Masakazu , Maeda Kiyoshi , Ohira Masaichi , Hirakawa Kosei
Published: June 2012

Dendritic cells (DC) are professional antigen-presenting cells which englobe tumor-associated antigens and activated cytotoxic T lymphocytes. Otherwise, in recent studies, it has been demonstrated that immature DC such as tolerogenic DC were associated with suppression of anti-tumor immune response. The immature DC infiltrating tumor microenvironment promote tumor growth and angiogenesis in lung cancer, ovarian cancer and breast cancer. Various cytokines secreted by pancreatic cancer suppress the maturation of DC. CD4+CD25+ regulatory T cells inhibit the anti-tumor response against colon cancer. Although it has been suggested that regulatory T cells and tolerogenic DC might be associated with the immunosuppressive mechanism in cancer patients, it has not been revealed yet. In this study, we examined direct inhibitory effects of gastric cancer against DC. We designed to assess the effects of tumor-associated cytokines secreted by gastric cancer cells on DC maturation and function. Next, after culturing DC in the medium with supernatant of gastric cancer and protein-bound polysaccharide K (PSK), we examined cytokines of interleukin-10 (IL-10) of DC, which considered immunosuppressive cytokine. Various gastric cancer cell lines, included scirrhous gastric cancer secreted immunosuppressive cytokines, such as TGF-β, IL-10 and VEGF. The expression of HLA-DR as positive costimulatory molecule of DC was decreased, and that of programmed death-ligand 2 (PD-L2), as negative costimulatory molecule was increased in the medium included supernatant of gastric cancer cells. IL-10 secreted in the supernatant of DC cultured with supernatant of gastric cancer cells was increased, and inhibited by co-culturing with PSK. In conclusion, the maturation of DC was inhibited by various immunosuppressive cytokines secreted by gastric cancer cells and tolerogenic DC were induced. These results suggest that tolerogenic DC infiltrates around tumors, inhibits immune response against tumors and promote growth of tumor in gastric cancer patients. In addition, PSK might suppress the effects of tolerogenic DC.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 793. doi:10.1158/1538-7445.AM2011-793
Abstract 796: Impact of histological types on infiltration of regulatory T cells in gastric cancer
Authors: Yoshii Mami , Tanaka Hiroaki , Sakurai Katsunobu , Nagahara Hisashi , Kimura Kenjirou , Amano Ryousuke , Noda Eiji , Kubo Naoshi , Muguruma Kazuya , Yamada Nobuya , Yashiro Masakazu , Maeda Kiyoshi , Sawada Tetsuji , Ohira Masaichi , Ishikawa Tetsurou , Hirakawa Kosei
Published: June 2012

Introduction: It is recently known that regulatory T cells (Tregs) are naturally present in the immune system and play important roles of suppression in host's antitumoural immune response. The transcription factor forkhead box P3 (FoxP3) is the most reliable marker for Tregs, and involved in the development and function of Tregs. Previous studies have pointed out that increasing of Tregs were associated with progression of many solid cancers such as breast cancer, melanoma, head and neck cancer, esophageal cancer. However, few reports were found about gastric cancer. Signet ring cell carcinoma with more advanced stage increase the risk of metastasis, like scirrhous carcinoma. It is uuclear whether the number of Tregs is correlated with the progression of signet ring cell carcinoma. The aim of this study is to investigate the population of tumor infiltrating Tregs and the impact of histological types on that in gastric cancer.

Materials and methods: A total of 100 patients with gastric cancer who underwent gastrectomy between 2003 and 2008 at our institute were enrolled. FoxP3 expression in primary gastric cancer was analyzed by immunohistochemistry. T cells expressed FoxP3 were defined as Tregs.

Results: Our cohort of 100 patitents included almost all histological types of gastric cancer, including tubular adenocarcinoma, poorly differentiated adenocarcinoma, mucinous adenocarcinoma, papillary adenocarcinoma, squamous cell carcinoma, and signet ring cell carcinoma. We detected FoxP3 expression in more than 90% of primary tumors. FoxP3 positive cells infiltrating into tumor were considered as Tregs. The localization of observed infiltrating Tregs expanded to not only tumor but also regional lymph node. The number of Tregs in tumor increased according to the differentiation of the cancer cells. Importantly, we detected significant few tumor infiltrating Tregs in signet ring cell carcinoma compared with the other histological types. On the other hand, signet ring cells themselves expressed FoxP3, indicating that signet ring cells might play a role of suppression of immune response to cancer.

Conclusion: We have observed that there were differences between signet ring cell carcinoma and other histological types with regard to the distribution of FoxP3 expression cells. Although the detail clinical investigation is needed, our result suggested that taylor made arrangement associated with histological types should be required for immunotherapy against gastric cancer.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 796. doi:10.1158/1538-7445.AM2011-796
Abstract 801: Uptake of exogenous neutrophil elastase by breast cancer cells: A novel link between innate immunity, inflammation and breast cancer immunity
Authors: Mittendorf Elizabeth A. , Alatrash Gheath , Qiao Na , Xiao Haile , Sukhumalchandra Pariya , Quintanilla Kathryn , Clise-Dwyer Karen , Molldrem Jeffrey
Published: June 2012

Introduction: High level of neutrophil elastase (NE) in tumor tissue from breast cancer (BrCa) patients is associated with poor metastasis-free survival. Modest endogenous expression of NE in some BrCa cell lines has also been observed. However, because the major source of NE is from azurophil granules of activated neutrophils, we hypothesized that breast cancer cells may take up soluble NE released by abundant inflammatory cells in the tumor microenvironment.

Methods: Endogenous NE expression was evaluated in MCF7, HER18, MDA-MB-231 (231) and MDA-MB-453 BrCa cell lines by western blot analysis and RT-PCR. Uptake of soluble NE was quantified by flow cytometry by intracellular staining of NE-pulsed BrCa and compared to non-specific uptake of OVA. Dose and time course experiments were performed. Confocal immunoflourescence microscopy was used to confirm uptake and demonstrate subcellular localization of NE. BrCa cells were also co-incubated with activated neutrophils to determine if they were able to take up cell-associated NE.

Results: Western blot analysis of BrCa cell lysates showed no NE protein expression in all 4 cell lines. Furthermore, RT-PCR with NE-specific primers demonstrated no NE mRNA expression in the 4 BrCa cell lines. However, BrCa cells pulsed with 5 to 25 μg/ml of soluble NE took up NE in a time and dose dependent manner, consistent with a receptor-mediated mechanism. Maximal intracellular uptake of NE by 231 cells occurred by 24 hours when NE accumulated at comparable levels to that of HL60 leukemia cells that express high levels of NE (987 vs 1300 MFI, p=ns). Uptake was enzyme-independent because it was not affected by alpha-1-antitrypsin, a protease inhibitor. Confocal microscopy demonstrated that NE accumulates in membrane bound compartments by 20 minutes after uptake, whereas there was no significant uptake of OVA by BrCa cells. Similarly, after co-incubation of 231 cells with activated neutrophils, significant uptake of NE was detected (p<.001).

Conclusions: These data show that BrCa cells do not express NE but the cells take up extracellular NE by a receptor-mediated enzyme-independent mechanism. This establishes a novel link between NE, a naturally secreted mediator of inflammation and cell growth, and BrCa. Because neutrophils are the major source of NE and chronic inflammation by tumor-infiltrating neutrophils is associated with positive tumor growth, this suggests NE could mediate growth control of BrCa.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 801. doi:10.1158/1538-7445.AM2011-801
Abstract 830: Angiotensin converting enzyme inhibitor and angiotensin receptor blocker suppress obesity-related colonic preneoplastic lesions in male C57BL/KsJ-db/db obese mice
Authors: Kubota Masaya , Shimizu Masahito , Yasuda Yoichi , Sakai Hiroyasu , Tanaka Takuji , Moriwaki Hisataka
Published: June 2012

Obesity and related metabolic abnormalities, including a state of chronic inflammation and oxidative stress, are risk factors for colon cancer. Dysregulation the renin-angiotensin system (RAS) also plays a critical role in obesity-related metabolic disorders and certain types of carcinogenesis. In the present study, we examined the effects of angiotensin converting enzyme (ACE) inhibitor and angiotensin receptor blocker (ARB), both of which target RAS, on the development of azoxymethane (AOM)-initiated colonic premalignant lesions in C57BL/KsJ-db/db (db/db) obese mice. Male db/db mice were given 4 weekly subcutaneous injections of AOM (15 mg/kg body weight) and then they received drinking water containing captopril (ACE inhibitor, 5 mg/kg/day) or telmisartan (ARB, 5 mg/kg/day) for 7 weeks. At sacrifice, administration of captopril and telmisartan significantly reduced the total number of colonic premalignant lesions, aberrant crypt foci and β-catenin accumulated crypts, compared with the control untreated-group. Both agents decreased the expression levels of TNF-α mRNA on the colonic mucosa of experimental mice. The expression levels of TNF-α, COX-2, IL-1β, IL-6, and PAI-1 mRNAs on the visceral fat were also decreased by administration of these agents. In addition, captopril and telmisartan significantly decreased the levels of urinary 8-OHdG, a surrogate marker of oxidative damage to DNA, in the experimental mice. These findings suggest that both ACE inhibitor and ARB suppress obesity-related colon carcinogenesis by attenuating chronic inflammation and reducing oxidative stress. Targeting the dysregulation of RAS might be, therefore, one of the effective strategies for the chemoprevention of obesity-related colon cancer.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 830. doi:10.1158/1538-7445.AM2011-830
Abstract 838: Suppression of constitutive and interleukin-6-inducible activation of signal transducer and activator of transcription 3 in human prostate cancer cells by diallyl trisulfide, a cancer chemopreventive constituent of garlic
Authors: Chandra-Kuntal Kumar , Singh Shivendra V.
Published: June 2012

Signal transducer and activator of transcription 3 (STAT3) is an oncogenic transcription factor implicated in prostate cancer development. The STAT3 is constitutively active in a large fraction of human prostate cancer cells and clinical prostate cancer specimens. Hyperactivity of STAT3 is associated with advanced prostate cancer. Furthermore, STAT3 activation promotes survival and inhibits apoptosis in prostate cancer cells. Agents that are safe but can either suppress activation of STAT3 or overcome STAT3 activation for their anticancer effects are attractive for prevention and treatment of prostate cancer. Natural products have attracted tremendous attention for the discovery of novel agents potentially useful for prevention and treatment of human cancers. The present study demonstrates that diallyl trisulfide (DATS), a promising cancer chemopreventive constituent of processed garlic, inhibits phosphorylation (activation) of STAT3 in prostate cancer cells in culture and in vivo. Exposure of DU145 and LNCaP human prostate cancer cells to growth suppressive and pharmacologically-relevant concentrations of DATS (20 and 40 μmol/L) resulted in suppression of constitutive (DU145) as well as interleukin-6 (IL-6)-induced (LNCaP) phosphorylation of STAT3 (Tyr705). The DATS-mediated suppression of STAT3 activation correlated with inhibition of Janus-activated kinase 2 phosphorylation. Constitutive and/or IL-6-induced nuclear translocation of pSTAT3 as well as STAT3 dimerization was also inhibited markedly on treatment with DATS in both cell lines. Inhibition of prostate cancer development in Transgenic Adenocarcinoma of Mouse Prostate (TRAMP) mice by gavage with DATS correlated with a visible decrease in the levels of pSTAT3. Interestingly, the IL-6-mediated activation of STAT3 failed to confer protection against proapoptotic response to DATS in either cell line. Likewise, the DATS-mediated inhibition of cell migration was either not affected or minimally reversed by the IL-6 treatment or ectopic expression of constitutively active STAT3. In conclusion, the present study indicates that DATS treatment suppresses STAT3 phosphorylation in prostate cancer cells in culture and in vivo, but activation of this oncogenic transcription factor is largely dispensable for cellular responses to DATS. Ability of DATS to overcome STAT3 activation is a therapeutic advantage for this chemopreventive agent. This study was supported by the USPHS grant 2 RO1 CA113363-06, awarded by the National Cancer Institute.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 838. doi:10.1158/1538-7445.AM2011-838
Abstract 848: Prevention of colitis-associated colorectal cancer with 8-hydroxydeoxyguanosine
Authors: Ock Chan Young , Kim Eun-Hee , Hong Kyung Sook , Hahm Ki-Baik , Chung Myung-Hee
Published: June 2012

Colitis-associated colorectal cancer (CAC) is one of clear examples of inflammation-carcinogenesis sequence, based on which strict control of colitis provides the right rationale of the intervention of anti-inflammatory drug on the chemoprevention. We have shown that 8-OHdG, which traditionally has been acknowledged as a marker of oxidative stress-related mutagenesis, could paradoxically exerted potent anti-inflammatory and anti-oxidant action in various inflammation models (Ock CY et al, Biochem Pharmacol, 2010). Based on the fact that Rac1 binds and activates STAT3 which is significantly up-regulated in inflammatory bowel disease (IBD) as well as CAC, we hypothesized that attenuation of Rac1-STAT pathway by exogenous 8-OHdG treatment may block inflammatory bouts in dextran sodium sulfate (DSS) induced colitis and can reduce carcinogenesis promoted by azoxymethane (AOM) followed by DSS ingestion. First we have checked whether exogenous 8-OHdG can ameliorate IBD, for which IL10 knock-out mice, IBD prone mice, are designed to ingest 5% DSS in tap water ad libitum for a week, and 8-OHdG (50, 100, or 150 mg/kg) is given intraperitoneal route daily. Treatment with 8-OHdG significantly reduced complication rates, pathologic grade of inflammation and edema compared with DSS only group. On pathogenic basis, the expressions of various inflammatory mediators such as TNF-α, IL-6, COX-2 and iNOS were decreased, as well as Rac1 activity and phosphorylation of STAT3 in 8-OHdG treated group in a dose-dependent manner. Next, in order to document the chemoprevention effects of 8-OHdG, mice were injected AOM (10 mg/kg) intraperitoneally followed by drinking 2.5% DSS for a week, after which AIN76 diet that contains 0.03 % and 0.06 % 8-OHdG was given for 20 weeks. As results, mice which consumed 8-OHdG-contained diet were significantly reduced tumor incidence and tumor multiplicity. Increased activity of Rac1 and phosphorylation of STAT3 with AOM plus DSS administration were significantly attenuated in 8-OHdG treatment group. These results were further validated with human colorectal adenocarcinoma cell line Caco-2 in vitro model. Conclusively, for the very first time, we clearly showed chemopreventive effect of exogenous 8-OHdG against CAC. Since 8-OHdG, one of well-known by-products generated by oxidative stress, paradoxically blocks inflammation-carcinogenesis sequence in colitis-associated cancer model, 8-OHdG could be a promising chemopreventive drug for the patient suffering from longstanding and extensive IBD, high risk group for CAC.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 848. doi:10.1158/1538-7445.AM2011-848
Abstract 850: Selenium compounds activate ATM-dependent DNA damage response via the mismatch repair protein hMLH1 in colorectal cancer cells
Authors: Qi Yongmei , Schoene Norberta W. , Lartey Frederick M. , Cheng Wen-Hsing
Published: June 2012

Epidemiological and animal studies indicate that selenium supplementation suppresses risk of colorectal and other cancers. The majority of colorectal cancers are characterized by a defective DNA mismatch repair (MMR). Here, we have employed the MMR-deficient HCT 116 colorectal cancer cells and the MMR-proficient HCT 116 cells with hMLH1 complementation to investigate the role of hMLH1 in selenium-induced DNA damage response, a tumorigenesis barrier. The ATM (ataxia telangiectasia mutated) protein responds to clastogens and initiates DNA damage response. We show that hMLH1 complementation sensitizes HCT 116 cells to methylseleninic acid, methylselenocysteine, and sodium selenite via reactive oxygen species and facilitates the selenium-induced oxidative 8-oxoguanine damage, DNA breaks, G2/M checkpoint response, and ATM pathway activation. Pretreatment of the hMLH1-complemented HCT 116 cells with the antioxidant N-acetylcysteine or 2,2,6,6-tetramethylpiperidine-1-oxyl or the ATM kinase inhibitor KU55933 suppresses hMLH1-dependent DNA damage response to selenium exposure. Selenium treatment stimulates the association between hMLH1 and hPMS2 proteins, a heterodimer critical for functional MMR, in a manner dependent on ATM and reactive oxygen species. Taken together, the results suggest a new role of selenium in mitigating tumorigenesis by targeting the MMR pathway, whereby the lack of hMLH1 renders the HCT 116 colorectal cancer cells resistant to selenium-induced DNA damage response.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 850. doi:10.1158/1538-7445.AM2011-850
Abstract 900: Tissue CA125 expression levels as a biomarker of endometrial cancer
Authors: Zhou Shu-Feng , He Shu-Ming
Published: June 2012

Serum CA125 has been recognized as a biomarker of gynecological tumors. However, serum CA125 detection is not very sensitive and specific in the diagnosis of cervical and endometrial carcinoma. This study has investigated the endometrial CA125 expression in patients with endometrial polyps, hyperplasia and carcinoma in comparison with normal endometrium. A total of 242 subjects were recruited into this study and they were classified into six groups, namely proliferative phase endometrium (n = 24), secretory phase endometrium (n = 21), non-functional endometrial polyps (n = 24), simple hyperplasia (n = 24), complex hyperplasia (n = 26), and endometrial carcinoma (n = 126). An immunohistochemistry method was used to detect endometrial CA125 expression. The results showed that there were significant differences in CA125 levels between normal and diseased endometrium, with significantly increased CA125 expression in patients with endometrial polyps, complex hyperplasia, and carcinoma compared to those with normal endometrium. There was only a weak CA125 expression in normal endometrium and simple endometrium hyperplasia. There were significant differences in CA125 expression levels between patients with non-functional endometrial polyps, simple hyperplasia, and complex hyperplasia (χ2 = 9.652, p < 0.005). In endometrial carcinoma group, there was a significant difference in CA125 expression among patients with pathological grade I, II and III of endometrial carcinoma (χ2=11.975, p < 0.01), while there was no significant difference in CA125 expression between grade I and grade II carcinoma (χ2=3.698, p > 0.05). These findings indicate that endometrial CA125 expression can be used as a reliable biomarker in the diagnosis and clinical staging of endometrial carcinoma in Chinese women.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 900. doi:10.1158/1538-7445.AM2011-900
Abstract 903: Expression of estrogen receptor beta together with aromatase predicts survival in non-small cell lung cancer
Authors: Mah Vei , Marquez Diana , Alavi Mohammad , Maresh Erin L. , Yoon Nam , Horvath Steve , Bagryanova Lora , Fishbein Michael , Chia David , Pietras Richard , Goodglick Lee
Published: June 2012

Lung cancer continues to be the leading cause of cancer mortality. There is increasing evidence suggesting estrogens and estrogen signaling play a significant role in lung cancer pathophysiology. Estrogen receptors (ER) alpha and beta are expressed in normal lung and many non-small cell lung cancers. Previously we found that in women 65 years and older with non-small cell lung cancer (NSCLC), higher aromatase levels in tumor cells conferred a worse prognosis for survival. Here we examine whether ER alpha and ER beta levels in conjunction with aromatase can further define different patient groups with respect to survival outcomes and possible treatment regimens. Methods: Immunohistochemistry was performed on a high-density tissue microarray with marker data and clinical information available for 378 patients. Patients were subcategorized by gender, age, smoking status and tumor histology. Survival data was determined using the Cox proportional hazards model and Kaplan-Meier curves. Results: Unlike aromatase, neither ER alpha nor ER beta alone were predictors of survival in NSCLC patients or any subset of these patients examined. However, when coupled with aromatase expression, higher ER beta levels predicted poorer survival in those patients whose tumors expressed higher levels of aromatase. Although this survival difference was present in patients of both genders, it was more pronounced in women > 65 years old, where higher expression of both ER beta and aromatase showed a markedly worse survival rate than that determined by aromatase alone. Conclusion: Combined expression of ER beta with aromatase has predictive value for survival in different gender and age subgroups of NSCLC patients. This predictive value is stronger than each individual marker alone. These results suggest that possibly treatment with aromatase inhibitors alone or combined with estrogen receptor modulators may have benefit in some subpopulations of NSCLC patients.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 101st Annual Meeting of the American Association for Cancer Research; 2010 Apr 17-21; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2010;70(8 Suppl):Abstract nr 903. doi:10.1158/1538-7445.AM2011-903