bluuebunny/crossref_metadata_2025_split huggingface dataset:
Abstract B21: CD1 d-expressing breast cancer cells promote iNKT-mediated antitumor immunity in a mouse model of breast cancer bone metastasis
Authors: Hix Laura M. , Shi Yihui H. , Stein Paul L. , Wang Chyung-Ru , Zhang Ming 
Published: June 2012

Abstract
Overcoming tumor tolerance and immune suppression remains a formidable obstacle to the development of immunotherapeutics that harness the immune system to eradicate breast cancer. We have developed a syngeneic mouse model to study mechanisms of tumor tolerance and immune suppression during breast cancer bone metastasis. Comparative analysis of low metastatic vs. highly bone metastatic tumor cells isolated from mice revealed several important genetic alterations related to immune control of tumor progression. Of these, a significant downregulation of cd1d1 was observed in the highly bone metastatic tumor cells. The cd1d1 gene in mice encodes the MHC class I-like molecule CD1d, which presents glycolipid antigens to a specialized subset of T cells that bridge the innate and adaptive immune response to cancer, known as invariant natural killer T (iNKT) cells. Activated iNKT cells mediate antitumor immunity in cell culture and in mouse models in vivo. Clinically, iNKT levels are significantly reduced in solid tumors, and this reduction is correlated with a poor prognosis in many types of cancers, including breast cancer. It is well known that the majority of advanced breast cancer patients present with bone metastases, and NKT cells have been shown to comprise a significant portion of the T cells found in healthy bone marrow. We hypothesize that downregulation of CD1d by breast cancer cells enables evasion of iNKT immune surveillance and inhibition of iNKT-mediated antitumor immunity, and may be an important prerequisite for the ability of breast cancer cells to colonize bone. In this study, we demonstrate in a mouse model of breast cancer bone metastasis that tumor cells expressing CD1d can induce direct iNKT-mediated cytolysis in a CD1d-dependent manner in vitro, and demonstrate increased CD1d-dependent iNKT-mediated antitumor immunity in vivo. Using transgenic knockout (KO) models, we show that the ability of CD1d-expressing tumor cells to metastasize to bone is dependent on the presence of CD1 d-restricted NKT cells. The results of this study further support research into therapeutic strategies that boost iNKT-mediated antitumor immunity for the treatment of advanced metastatic breast cancer. In addition, we propose the use of our novel mouse model of breast cancer bone metastasis as an ideal system for conducting further studies into mechanisms of immune regulation of breast cancer.
Citation Information: Clin Cancer Res 2010;16(14 Suppl):B21.
Abstract B22: Oncogenic MCT-1 upregulates EGFR expression through YY1 transcription factor that cooperatively prevents apoptosis
Authors: Lin Tai-Du 
Published: June 2012

Abstract
Multiple copies in T cell malignancy 1 (MCT-1) is an oncogene initially identified in a human lymphoid cell line. Constitutive expression of MCT-1 induces cell proliferation and activates survival pathways. We now demonstrate that MCT-1 upregulats epidermal growth factor receptor (EGFR) and Yin Yang 1 (YY1) proteins. EGFR modulates cell proliferation, differentiation, and survival. EGFR promoter function is modulated by YY1, a ubiquitously expressed, multifunctional zinc-finger transcription factor. By silencing of MCT-1, p53 is upregulated but EGFR and YY1 expressions are depressed. YY1 and EGFR levels are increased when the intrinsic p53 is abolished via shRNA interference, proving their counteraction relationship. Shedding YY1 levels in ectopic MCT-1 context, EGFR expression is repressed but p53 decline is attenuated. Intriguingly, upon NNK (tabacoo carcinogen) exposure advances ROS generation in ectopically expressed MCT-1 and EGFR conditions, but those cells still highly defy to apoptosis. Cooperative effect of MCT-1 and EGFR also more resist to apoptosis as counters with the oxidant in the gas phase of cigarette smoking, H2O2. Hence, MCT-1 inactivates p53 but stimulates YY1-mediated EGFR expression, subsequently prevents the oxidation-induced apoptosis. We prospect that the combination inactivation of MCT-1 and YY1 will undoubtedly develop new and improved targeted therapies for the cancers origin from EGFR deregulation.
Citation Information: Clin Cancer Res 2010;16(14 Suppl):B22.
Abstract B23: Dominant stablized ß-catenin induces adenomyosis formation and ablation of Mig-6 accelerates progress of adenomyosis formation
Authors: Shin Jung-Ho , Kim Tae Hoon , Large Michael J. , Cho Sung Nam , Oh Seo Jin , Lim Jeong Mook , Taketo Makoto M. , Broaddus Russell R. , Jeong Jae-Wook 
Published: June 2012

Abstract
Adenomyosis is a common gynecological disorder defined by the presence of endometrial glands and stroma within the myometrium. Despite its frequent occurrence, the precise etiology of adenomyosis is still unknown, although it has often been associated with endometrioid adenocarcinoma. β-catenin abnormalities are common in endometrioid type endometrial carcinomas. The expression of the dominant stabilized β-catenin in the murine uterus (PRcre/+ Ctnnb1f(ex3)/+) resulted in endometrial glandular hyperplasia. In addition to the glandular hyperplasia phenotype, uteri of PRcre/+ Ctnnb1f(ex3)/+ mice exhibited an abnormal myometrial structure and proceed to develop adenomyosis. Ablation of Mig-6 in the murine uterus (PRcre/+ Mig-6f/f) leads to the development of endometrial hyperplasia and estrogen-induced endometrial cancer. Concomitant stabilization of β -catenin and ablation of Mig-6 dramatically accelerated the development of adenomyosis and glandular hyperplasia compared to stablizing β-catenin alone. The adenomyosis phenotype of ovariectomized Pffre/+ Ctnnb1f&lt;ex3)/+ and PRcre/+ Ctnnb1f(ex3)/+Mig-6f/f mice manifests in the presence of E2 and P4, but not, however, in the absence of ovarian hormones. Importantly, increased nuclear β-catenin expression and decreased MIG-6 expression was observed in women with adenomyosis, providing compelling support for and implicating an important role of β-catenin and MIG-6 in the etiology of adenomyosis in both humans and mice. We have demonstrated that abnormal activation of β-catenin induces adenomyosis formation and ablation of Mig-6 accelerates the progress of adenomyosis formation in the murine uterus. These mouse models are useful and allow us to investigate in detail the initiation and progression of adenomyosis because they mimic several features of human adenomyosis.
Citation Information: Clin Cancer Res 2010;16(14 Suppl):B23.
Abstract B25: Effects of co-injection of somatic cells on stem cell allograft success and differentiation
Authors: Park Jong-Heum , Oh Seo-Jin , Gong Seung-Pyo , Kim Bo-Yun , Ahn Ji-Yeon , Lim Jeong-Mook 
Published: June 2012

Abstract
Two consecutive experiments were conducted for understanding immunity, stemness, and tumorigenesis of the embryonic stem cells (ESCs) in their allograft. In the first series of experiment, we evaluated whether co-injection of the stem cells with somatic cells could evade the immune response. Donor B6CBAF1 mouse ESCs were subcutaneously co-injected either alone or with ovarian stromal cells, fetal fibroblasts, or adult fibroblasts isolated from the recipient B6D2F1 mouse strain. ESCs by themselves induced teratomas (14%). However, when somatic cells were injected together, ESC-mediated teratoma formation significantly increased (33-75%). Especially, the highest rate of the teratoma formation was observed in ESCs and fetal fibroblasts co-injected recipient B6D2F1 mice (75%). Next, we derived ESC-like, cancer stem cells from the teratomas with enzymatic digestion and their differentiation potential was subsequently evaluated. Except for one cell line, other all cell lines showed a similar morphology to that of original ESCs and retained alkaline phosphatase activity, ESC-specific gene expression (Oct-4, Nanog, Cripto, and Rex-1), and Oct-4 protein expression regardless of their increased abnormality in chromosome number. Relative quantification of lineage-specific gene (Nestin, SMA, Desmin, and Krt8) expression of teratoma-derived cell lines showed the significant changes between the ESCs and the teratoma-derived, ESC-like cells derived from the cell co-injection. Variations in the type of co-injected cells led to lineage-specific changes, changes in gene expression in isolated colony-forming cells, and alterations in stem-cell-like cells derived from allografted tissues. In conclusion, our results suggest that cell-to-cell interaction regulates cellular immunity for implanted cells, which further affects tumorigenesis and stemness [Supported by a grant (SC-5160) from Stem Cell Research Center of the 21st Century Frontier Research Program awarded by Jeong-Mook Lim]. Jong-Heum Park and Seo-Jin Oh contributed equally to this work.
Citation Information: Clin Cancer Res 2010;16(14 Suppl):B25.
Abstract B26: A requirement for p63 function in squamous cell carcinoma in vivo: Can the pathway be targeted for therapy?
Authors: Ramsey Matthew R. , Wilson Catherine , Faquin William C. , Mills Alea A. , Ellisen Leif W. 
Published: June 2012

Abstract
Squamous cell carcinoma (SCC) is a common form of human cancer that can arise in various epithelial tissues such as the lungs, skin, and head and neck region. Morbidity and mortality rates for SCC are high compared to many other cancers, and relatively little progress has been made in treatment due to a lack of molecular understanding of the disease. The p53-related protein p63 is essential for the formation of various epithelial tissues, such as the skin, and has many reported roles including suppression of apoptosis, maintenance of stem cell regenerative potential, regulation of differentiation, and maintenance of cellular adhesion. In SCC, p63 is overexpressed and has found to be the target of genomic amplification suggesting an important role in this disease. Previous in vitro studies have shown that p63 is required for survival of SCC cells in culture, however, cell lines lack the complex microenvironment found in human cancer, and thus the in vivo relevance of these results is unclear. To determine the role of p63 in vivo, we have generated a murine model of SCC, which faithfully recapitulates many of the molecular and pathological features of human SCC including invasion and metastasis. To test the role of p63 in tumor maintenance we crossed this model to a conditional p63-null allele (p63flox) and a tamoxifen-inducible Cre transgene, K14-CreER. We have found that genetic excision of both copies of p63 in established SCC tumors results in rapid and dramatic regression of tumors. In addition, even loss of a single copy of the p63 gene results in a reduced rate of growth, suggesting that SCC tumors are exquisitely sensitive to levels of p63 protein. These results support the idea that the p63 pathway is critical for the survival of SCC tumors in vivo, and targeting this pathway in SCC may result in more effective therapy for this highly refractory tumor type.
Citation Information: Clin Cancer Res 2010;16(14 Suppl):B26.
Abstract B28: Molecular basis of aberrant expression of alkaline phosphatase in renal brush border membrane from renal cell carcinoma patients
Authors: Sharma Ujjawal , Singh Sarwan Kumar , Prasad Rajendra 
Published: June 2012

Abstract
The incidence of renal cell carcinoma (RCC) has been increasing worldwide. It continues to present a diagnostic and therapeutic challenge. It accounts for approximately 3% of adult malignancies and 90% to 95% of neoplasm arising from kidney. RCC originates from proximal tubular epithelium of adult kidney. Alkaline phosphatase is abundantly expressed on the BBM and serves as an excellent marker for its integrity. Earlier reports have demonstrated that the activities of brush border membrane (BBM) enzymes are altered in cancer cells. The present study was conducted to find out the molecular basis of altered expression/activity of ALP in BBM from RCC in comparison to normal renal BBM. Total 30 histopathologically confirmed cases of RCC were included in the present study. The specific activity of ALP was drastically reduced in homogenate as well as in BBM from RCC as compared to BBM from adjacent normal kidney parenchyma. SDS-PAGE study showed that the BBM proteins of higher molecular weights were poorly expressed in BBM from RCC as compare to BBM from adjacent normal kidney parenchyma. Incubation of gel with BCIP/NBT dye showed that the expression of ALP in BBM from RCC was reduced as compared to adjacent normal kidney BBM. Western blot analysis using anti-ALP antibody also confirmed the reduced expression of ALP in RCC BBM. Further, to check whether this reduced expression of ALP occurs at mRNA level, a semiquantitative RT-PCR was done, which showed markedly reduced expression of ALP mRNA in RCC as compared to adjacent normal kidney.
Citation Information: Clin Cancer Res 2010;16(14 Suppl):B28.
Abstract B29: Genetic interactions between AKT/mTOR and Ras/MAPK pathways in liver cancer pathogenesis: from animal models to targeted therapy
Authors: Chen Xin , Ho Coral , Wang Chunmei , Lee Susie , Evert Matthias , Dombrowski Frank , Calvisi Diego 
Published: June 2012

Abstract
Introduction: Hepatocellular carcinoma (HCC) and cholangiocellular carcinoma (CCC) are deadly malignant liver tumors lacking of efficient treatment options. Akt/mTOR and Ras/MAPK pathways have been implicated in hepatic carcinogenesis. Our study is to define the genetic interactions between Akt/mTOR and Ras/MAPK pathways in liver carcinogenesis.
Methods: Activation of Akt/mTOR and Ras/MAPK signaling was assayed in 62 human HCC and 25 CCC samples. An activated Akt (myr-Akt) was stably transfected into the mouse liver alone or together with activated N-Ras (RasV12) via hydrodynamic gene delivery. Molecular and biochemical features of liver lesions were analyzed. A primary cell line (Akt/Ras) was isolated from a tumor co-injected with Akt and Ras protooncogenes. Akt/Ras cells and human HCC cell lines were treated with different mTOR inhibitors, including NVP-BEZ235, PP242 and Rapamcyin, as well as the MEK inhibitor AZD6244.
Results: Using human HCC samples, we demonstrated the coordinated activation of Akt/mTOR and Ras/MAPK pathways in subsets of HCC and CCC characterized by poor prognosis. We found that coexpression of myr-Akt with RasV12 synergizes to promote liver tumor development in mice, leading to HCC and CCC formation within 4 to 6 weeks post injection. At cellular level, tumors from Akt/N-Ras co-injection cells are characterized by high proliferation and low apoptotic index, and disrupted expression of genes involved in cell cycle regulation. At the molecular level, liver tumors show high levels of activated Akt/mTOR and Erk cascades. A primary cell line (Akt/Ras) was isolated from a tumor and used to test the response to different mTOR and MEK inhibitors. We found that dual PI3K/mTOR inhibitor NVP-BEZ235 has superior activity inhibiting Akt/Ras cell proliferation with IC50 around 2nM. It also efficiently inhibits phospho-S6, phospho-4EBP1 and cyclin D1 expression in Akt/Ras cells. Furthermore, NVP-BEZ235 synergizes with the MEK inhibitor AZD6244 to dramatically reduce the growth of the Akt/Ras cell line. Equivalent results were obtained in human HCC cell lines with the same inhibitors.
Conclusion: Coordinated activation of Akt/mTOR and Ras/MAPK signaling is the hallmark of aggressive subtypes of human HCC and CCC. Activated Akt cooperates with activated Ras/MAPK to rapidly promote liver tumor formation in mice. The Akt/Ras mouse model is a useful pre-clinical system to test anti-neoplastic therapeutic approaches against HCC and CCC in vivo. In addition, our preliminary studies suggest that the combination of a dual PI3K/mTOR inhibitor with a MEK inhibitor may represent a promising novel targeted therapy for treating human HCC harboring activated Akt/mTOR and Ras/MAPK pathways.
Citation Information: Clin Cancer Res 2010;16(14 Suppl):B29.
Abstract B30: Altered response to the prodrug of gemcitabine LY2334737 by overexpression or knockdown of carboxylesterase 2 (CES2)
Authors: Durland-Busbice Sara , Pratt Susan E. , Shepard Robert L. , Iversen Philip W. , Kays Lisa , Ballard Darryl , Heinz-Taheny Kathleen , Dantzig Anne H. 
Published: June 2012

Abstract
Gemcitabine (gem) is a nucleoside anticancer agent that inhibits cell cycle in S-phase and is registered clinically for the treatment of a number of solid tumors. A prodrug of gemcitabine, LY2334737, was developed for oral administration for metronomic dosing with the aim of growth inhibition of more tumor cells as they go through the cell cycle. LY is well absorbed and systemically cleaved in humans. The rate of hydrolysis is slow resulting in circulating levels of LY that are 10-fold higher than gemcitabine in plasma. Studies with cell lines and recombinant protein indicate that LY is cleaved to gemcitabine by carboxylesterase 2 (CES2). Because LY circulates in the plasma for an extended period of time, we wondered if expression of CES2 by the tumor could alter its response to the prodrug. The present study was undertaken to determine if the expression of CES2 alters cellular response to LY in vitro and in vivo. The constitutive expression of CES2 in SKOV-3 was knocked down by shRNA. A stable subclone was obtained that had CES2 expression reduced by 80%.
Stable HCT-116 transfectants were prepared that overexpressed CES2. Cell lines, transfectants and knock down cells were evaluated for drug sensitivity in a cytotoxicity assay. They were also evaluated for CES2 expression by biochemical cellular assay, Western analysis, and qRT-PCR. A xenograft study was conducted employing transfected HCT-116 cells. Immunohistochemical (IHC) staining was used to evaluate cell lines and tumors for CES2 expression. LY was less cytotoxic to SKOV-3 cells when CES2 was knocked down while sensitivity to gem was unaltered. Transfection of CES2 into low CES2 endogenously expressing HCT-116 cells enhanced LY drug sensitivity with no change in gemcitabine sensitivity. Stably transfected CES2 and mock HCT-116 transfectants were grown as a xenograft. The transfectants had identical growth rates in vivo and were equally sensitive to gem treatment. IHC staining of the tumors indicated that CES2 expression was maintained throughout the growth period. CES2 expressing tumors demonstrated a statistically significant greater response to LY than mock transfectant tumors. Taken together, these studies indicate that CES2 cleaves the prodrug and tumor expression of CES2 can enhance response to treatment with LY2334737.
Citation Information: Clin Cancer Res 2010;16(14 Suppl):B30.
Abstract B31: Potential for patient tailoring for prodrug of gemcitabine (LY2334737) by assessment carboxylesterase II expression in solid tumor biopsies
Authors: Holzer Timothy R. , Heinz-Taheny Kathleen , Ballard Darryl W. , Powell Eric L. , Dolled-Filhart Marisa P. , Christiansen Jason , Gustavson Mark , Biryukov Jennifer , Virayah Jagatheswari , Pratt Susan E. , Shepard Robert L. , Busbice Sara C. Durland- , Dantzig Anne H. 
Published: June 2012

Abstract
Carboxylesterase II (CES2), a serine ester hydrolase, is the major carboxylesterase responsible for the conversion of the prodrug of gemcitabine into its active form, gemcitabine (LY2334737), an anticancer chemotherapeutic. In humans, the ratio of plasma levels of prodrug to active form is 10:1. Therefore, increased availability of LY2334737 can result in cleavage of the prodrug into its active form at the tumor site and has potential for greater tumor cytotoxicity. Relatively high levels of expression of CES2 within non-neoplastic human tissue occur in the liver, kidney and gastrointestinal tract as visualized by immunohistochemistry (IHC). CES2 is also reported to be expressed in human cancers such as non-small cell lung carcinoma and colon adenocarcinomas. In this study, we analyzed CES2- transfected in vitro cell lines by real-time PCR, chromogenic IHC, and automated quantitative analysis (AQUA) of immunofluorescent in situ protein expression and showed that high levels of CES2 correlate with higher cytotoxicity. qRT-PCR analysis revealed that the mRNA levels of CES2 measured in formalin-fixed paraffin-embedded tumors correlate with protein levels. CES2 transcriptional profiling was performed to identify additional tumor types with high levels of expression of CES2. CES2 overexpression was detectable by IHC and/or AQUA analysis in human colon carcinoma, mesothelioma, non-small cell lung cancer, and tumors of the breast and ovary. CES2 IHC labeling in colonic adenocarcinomas was diffuse. However, labeling in non-neoplastic mucosa showed low levels in proliferating cells at the crypt base and increasingly higher expression toward the terminally differentiated cells at the tips—cells that would not progress through the cell cycle and should not be affected by antiproliferative agents. In conclusion, we have developed robust IHC and AQUA-based assays for differential expression of CES protein levels in a variety of archival human tumor types and have shown high correlation with CES2 transcript levels by qRT-PCR. These methodologies can identify tumors with high levels of CES2, a biomarker that may further be investigated in biomarker-driven clinical trials to identify patients who will more likely respond to LY2334737.
Citation Information: Clin Cancer Res 2010;16(14 Suppl):B31.
Abstract B32: TGF-β blockade improves the distribution and efficacy of chemotherapeutic agent in breast carcinoma
Authors: Liu Jieqiong , Liao Shan , Huang Yuhui , Jain Rakesh K. , Xu Lei 
Published: June 2012

Abstract
In its journey from blood vessels to cancer cells, a therapeutic agent must overcome the transport barrier posed by the interstitial matrix. In contrast to our understanding of blood vessels, our understanding of the formation and function of the tumor interstitial matrix is still in its infancy. A primary component of the interstitial matrix, collagen type I, has been shown to inversely correlate with diffusive transport in solid tumors. TGF-β can stimulate production of collagen by stromal cells in tumors. Thus, we studied the effect of blocking TGF-β pathway in breast carcinoma progression and response to chemotherapy. To this end, we used a soluble Fc:TGF-β type II receptor fusion protein (sTβRII) to block TGF-β pathway in two breast cancer models (human MDA-MB-231 cells and mouse 4T1 cells). TGF-β blockade significantly impaired the growth and metastasis of orthotopic tumors in both tumor models. The recruitment of myofibroblasts and interstitial matrix content was determined by immunohistochemistry, TGF-β blockade significantly decreased the recruitment of myofibroblast and the level of collagen I. Next, to determine the effect of TGF-β blockade on interstitial transport, we injected fluorescent doxorubicin into the tail vein of mice and observed the intratumoral distribution of doxorubicin autofluorescence by confocal microscopy. We found that TGF-β blockade increased the transvascular flux of fluorescent doxorubicin. As a result, doxorubicin liposome (DOXIL) treatment was significantly more effective in inhibiting tumor progression in TGF-β blocked tumors compared to parental tumors. In summary, our study characterized the functional role of TGF-β in modulating tumor interstitial matrix in breast cancer xenografts and suggested that blocking TGF-β signaling pathway may represent a testable therapeutic approach to be combined with conventional chemotherapy in breast cancer treatment.
Citation Information: Clin Cancer Res 2010;16(14 Suppl):B32.