bluuebunny/crossref_metadata_2025_split huggingface dataset:
Abstract 398: Molecular mechanisms of recurrence of PDGFB-dependent glioma in mice following inhibition of platelet-derived growth factor B expression
Authors: Liu Huan , Hitoshi Yasuyuki , Paolella Brenton , Israel Mark A. 
Published: February 2011

Abstract
Molecularly targeted therapies hold great promise for the treatment of cancer. Conditional transgenic mouse models offer unique opportunities for investigating whether the targeted inactivation of an oncogene is sufficient for tumor regression and for developing strategies to overcome the mechanisms by which tumors become resistant to targeted therapies. We developed transgenic mice (GFAP/tTA:TRE/PDGFB) in which human platelet-derived growth factor B (hPDGFB) is expressed in a doxycycline responsive manner. Without doxycycline these mice expressed PDGFB in the CNS and developed glioma. Doxycycline administration led to symptomatic recovery in the majority of tumor-bearing mice. However, sustained regression did not occur in 8 of 22 mice following 3 months of doxycycline treatment. In other experiments we implanted spheroid cells derived from other spontaneous mouse glioma arising in this model into the flanks of immuno-deficient mice. We initially observed a significant reduction in the size of established tumors with doxycycline administration, but residual cells from 5 out of 9 tumors began to grow rapidly following a prolonged period of the treatment. In vitro, spheroid cells derived from the relapsed tumors grew in a PDGFB-independent manner. Doxycycline addition to spheroid cultures effectively inhibited hPDGFB expression but did not inhibit proliferation or induce apoptosis. Examination of signaling pathways revealed that PDGFB receptor phopshorylation was significantly reduced by doxycycline but downstream AKT and Erk phosphorylation was sustained. Ongoing experiments are being conducted to identify upstream regulators of these signal transducers. (This work was supported in part by the Theodora B. Betz Foundation and the Andy Fund)
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 398.
Abstract 3983: Real-time imaging of human thyroid cancer progression in a fluorescent orthotopic nude mouse model
Authors: Cao Hop S. Tran , Kaushal Sharmeela , Snyder Cynthia S. , Ongkeko Weg M. , Hoffman Robert M. , Bouvet Michael 
Published: February 2011

Abstract
We report here a novel orthotopic mouse model of human thyroid cancer that can be imaged non-invasively with the use of red fluorescent protein (RFP).
Human thyroid cancer cell lines NPA (papillary) and KAK-1 (anaplastic) were stably transfected to express RFP or the green fluorescent protein (GFP). The cells were then injected into the thyroid glands of 8-week old athymic mice. The animals were noninvasively imaged weekly, and sacrificed when premorbid. Their tumor was subsequently resected en bloc with the respiratory system for further processing and analysis. H&E staining was performed to confirm the pathological diagnosis.
Both anaplastic and papillary thyroid cancer cell lines led to the robust development of orthotopic fluorescent tumors in nude mice. While RFP-expressing tumors were easily identified transcutaneously, autofluorescence of the skin prevented visualization of GFP-expressing tumors, making GFP a suboptimal model. Injection of 5 × 10^5 cells was as efficacious in allowing tumor development as 5 × 10^6 cells. Tumors were first visualized for both cell lines via whole-body noninvasive imaging as early as four weeks post-implantation and could be monitored over time. The time to premorbid conditions varied greatly between mice and seemed to be associated with the tumor growth pattern rather than tumor size. The earliest appearance of morbidity was five weeks post-implantation in an animal with cachexia due to local compression of the esophagus by the tumor. Other mice died at later stages from metastatic disease. The bright fluorescence of the tumors allowed identification of multiple micrometastases at necropsy in the lungs, lymph nodes, and the vascular system, lesions that were not visible under white light.
In summary, we have developed a novel orthotopic fluorescent mouse model of thyroid cancer that should serve a valuable role in the understanding of this disease and in the evaluation of new therapeutics, allowing assessment of the tumor response over time.
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 3983.
Abstract 3984: Effect of zeranol on beef skeletal muscle growth by differential image gel electrophoresis (DIGE)
Authors: Wick Macdonald , Reddish John M. , Ye Weiping , Lin Young C. 
Published: February 2011

Abstract
Zeranol is a resorcylic acid lactone produced by fungi of the genus Fusarium that grows on corn, wheat, barley, oats and sorghum. As such Zeranol is a virtually unavoidable contaminant of crops used to feed animals that are consumed by humans.
Zeranol has been shown to have a positive impact on muscle growth during the finishing phase of beef cattle production, was first approved and licensed for use as a growth promotant in cattle and sheep in the USA by FDA in 1969. However, the mechanism of this interaction is unknown but is likely related to changes in muscle specific proteins observable during the increased growth phase during finishing.
To determine the affect of Zeranol on beef cattle muscle growth, we performed four DIGE experiments. We compared protein expression level changes between beef cattle treated with Zeranol and untreated beef cattle. On day zero, 10 cattle were implanted with 72 mg of Zeranol pellets, the other half (n = 10) were implanted with vehicle. The beef cattle were raised at the Ohio State University Department of Animal Sciences Beef Barn in accordance with industry standards for 120 days. At 60 days, half the implanted beef cattle and half of the control beef cattle were harvested and the remaining beef cattle were harvested at day 120. Muscle samples were analyzed by DIGE and bioinformatics
Seven proteins associated with energy metabolism (creatine kinase, glycogen phosphorylase, glyceraldehyde-3-phosphate dehydrogenase, phosphoglucomutase I, aconitase 2, enolase I, and triosephophate isomerase), 5 proteins with regulation of muscle contraction (slow skeletal muscle troponin T, calsequestrin I, myosin light chains 2 and 3, tropomyosin 3), 3 structural proteins (alpha actin, myosin binding protein C and kelch repeat and BTB domain), a protein associated with myotube formation, dihydrolipoamide dehydrogenase, and HSP70, a protein associated with meat quality, and albumin were identified. The differential regulation of these proteins indicates that muscle growth in cattle implanted with Z is due to fast skeletal muscle. (Supported by NIH grant R01 ES 015212).
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 3984.
Abstract 3986: Effects of immunohistochemistry on biomolecules in tissue specimens: Importance for expression-based microdissection technologies
Authors: Tangrea Michael A. , Kreitman Matthew S. , Rosenberg Alex M. , Ory Eleanor C. , Mukherjee Sumana , Eberle Franziska C. , Wallis Benjamin S. , Hanson Jeffrey C. , Rodriguez-Canales Jaime , Emmert-Buck Michael R. 
Published: February 2011

Abstract
Immuno-Laser Capture Microdissection (LCM) and Expression Microdissection (xMD) are techniques that rely on immunohistochemistry (IHC) to specifically define target cells for microdissection. While these techniques have been successfully applied to LCM and xMD, the full effects of IHC on the biomolecules extracted from stained samples are not well characterized. The goal of our study was to evaluate the integrity of DNA, RNA and protein biomolecules obtained from tissue sections after standard IHC or immunofluorescence (IF) techniques. Utilizing snap frozen human prostate and ovarian carcinoma specimens, as well as mouse liver samples, we evaluated biomolecule recovery from immunostained samples, including histone and pan-cytokeratins AE1/AE3 targeted antibodies. Standard horseradish peroxidase and diaminobenzidine (DAB) based IHC was used as well as Alexa Fluor 488 for indirect-IF. In general, biomolecule recovery was diminished in IHC stained tissues compared to standard hematoxylin and eosin (H&E) staining. RNA was affected the most and showed significantly reduced quantity and quality after staining. DNA was recoverable, but quantities were reduced when compared to the standard H&E. However, PCR amplification was possible with all stained samples studied. Protein analysis also demonstrated a reduction of quantity of the proteins recovered from IHC stained samples, with a variable effect depending on the protein analysis methodology. The results demonstrated that IHC techniques using DAB labeling significantly affect the extracted biomolecules. Improved staining protocols are required to address these concerns and to further the capabilities of these potentially powerful microdissection techniques.
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 3986.
Abstract 3994: Expression levels of EGFR-ligands are up-regulated in EGFR tyrosine kinase inhibitor-resistant cell line
Authors: Sakai Kazuko , Arao Tokuzo , Furuta Kazuyuki , Nagai Tomoyuki , Kudo Kanae , Kaneda Hiroyasu , Tamura Daisuke , Aomatsu Keiichi , Fujita Yoshihiko , Matsumoto Kazuko , Koizumi Fumiaki , Nishio Kazuto 
Published: February 2011

Abstract
Epidermal growth factor receptor (EGFR) is often highly expressed in many solid tumors and EGFR tyrosine kinase inhibitor (EGFR-TKI) demonstrated the therapeutic benefit for non small cell lung cancer in clinical setting. We previously established the EGFR-TKI resistant cell lines derived from highly parental sensitive cell line with constitutively active EGFR mutation, PC-9. EGFR-TKI-resistant cell line shows about 1000 fold resistant for EGFR-TKI compared with parental PC-9 cells. We performed the microarray and exon array analysis for these cell lines and identified that 30 genes were altered the gene expressions over 5 fold between two cell lines. There were no gene expression changes in EGFR, HER4, AKT and adaptor molecules, whereas HER2 and HER3 were down-regulated and MET were up-regulated in resistant cells. Interestingly, several ligands of EGFR such as TGF alpha, epiregulin, amphiregulin and HB-EGF were up-regulated in EGFR-TKI resistant cell lines, suggesting that the ligand expression change are associated with the phenotype of drug resistant and may be useful molecular biomarkers for EGFR-TKI treatment. We are now investigating the functional analysis for these identified genes and analysing the result of exon array.
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 3994.
Abstract 4005: JAK/STAT activation following Src inhibition is mediated by the loss of SOCS2 expression
Authors: Sen Banibrata , Peng Shaohua , Johnson Faye M. 
Published: February 2011

Abstract
Systemic therapy that results in both decreased invasion and significant cytotoxicity would be ideal to treat head and neck squamous cell carcinoma (HNSCC). One promising therapeutic target is Src due to its well-defined roles in both invasion and survival. STAT3 is a key mediator of the oncogenic effects of Src. However we previously found that sustained Src inhibition resulted in only transient inhibition of STAT3. Likewise, Src inhibition resulted in a universal reduction in invasion, but a more variable effect on apoptosis. Restoring STAT3 inhibition enhanced apoptosis. Previously we showed that STAT3 reactivation was mediated by JAK2 kinase activation and altered JAK2-STAT3 binding. Reactivation of JAK2/STAT3 suggests a feedback loop, possibly via the loss of a negative regulator. Of the three known feedback loops that regulate JAK/STAT function, we considered the most likely candidate to be the suppressors of cytokine signaling (SOCS) proteins, which can compete for STAT binding and inhibit JAK kinase activity. To determine if SOCS proteins are involved in JAK/STAT3 reactivation, we measured RNA levels of all 8 SOCS family members in 5 HNSCC cell lines using quantitative PCR. The expression of most of the SOCS decrease after initial Src inhibition, but recover, consistent with their regulation by STAT3. However, the expression of SOCS2 decreased in all 5 lines. Likewise, we found that the addition of a molar stoichiometric amount of recombinant SOCS2 inhibits Jak2 kinase activity in vitro. To confirm that SOCS2 regulates STAT3 activity, we knocked-down SOCS2 by siRNA which resulted in the activation of STAT3. Similarly, transient overexpression of SOCS2 resulted in significant downregulation of activated STAT3. Others have reported that STAT5 can regulate SOCS2 expression. Consistent with this, we found that Src inhibition led to durable STAT5 inhibition. Moreover, the depletion of both isoforms of STAT5 (a and b) with siRNA resulted in a dramatic downregulation of the SOCS2 expression. To determine the biological significance of SOCS2 expression, we discovered that specific SOCS2 depletion reduced HNSCC cytotoxicity following Src inhibition. Our results demonstrate that sustained Src inhibition leads to the loss of SOCS2 expression via STAT5 inhibition. The loss of SOCS2 allows the recovery of JAK2 kinase activity, JAK2/STAT3 binding, STAT3 activation, and cell survival despite durable Src inhibition. To our knowledge, this feedback pathway has never been described previously. Given that pharmacologic Src and JAK inhibitors are currently being evaluated in clinical trials, these results have significant implications for cancer therapy.
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 4005.
Abstract 4010: Adaptor protein Lnk binds to JAK3 and negatively regulates a mutant activating allele associated with megakaryocytic leukemia
Authors: Koren-Michowitz Maya , Gery Sigal , Nowak Daniel , Koeffler H. Phillip 
Published: February 2011

Abstract
The adaptor protein Lnk is known to associate with hematopoietic cytokine receptors such as cKIT, MPL and PDGFR, as well as, non-receptor tyrosine kinases such as JAK2, and is considered to have an inhibitory effect on these signaling pathways. JAK3 is expressed mainly in the hematopoietic system and its absence is associated with autosomal recessive severe combined immunodeficiency (SCID). Recently, activating mutations of JAK3 were described in transient myeloproliferative disorder (TMD) and acute megakaryocytic leukemia (AMKL) in Down syndrome (DS) patients as well as adult non-DS AMKL. JAK3 mutations were also rarely described in solid tumors and B-ALL. The 50% homology between JAK3 and JAK2 has led us to study the association between Lnk and JAK3.
293T cells were co-transfected with cDNAs encoding either wild-type (WT) JAK3 or JAK3 harboring an activating A572V mutation (JAK3 A572V), as well as the WT V5-tagged Lnk. Whole cell lysates were used for immunoprecipitation with either V5-tag or JAK3 antibodies. Binding of Lnk and JAK3 was detected by Western blot probed with JAK3 or V5-tag antibodies. To determine which domain of Lnk is responsible for the binding, we constructed a series of V5-tagged Lnk mutants including a mutation in the SH2 domain (R392E), deletion of the SH2 domain (del SH2) and deletion of the PH and SH2 (del SH2/PH) domains. Our results show that WT Lnk binds to WT JAK3, as well as JAK3 A572V. The R392E and del SH2 Lnk mutants retained JAK3 binding capacity while deletion of both SH2 and PH domains of Lnk abolished JAK3 binding. In order to study the biological effect of Lnk binding to JAK3, we infected CMK cells, a megakaryocytic leukemia cell line harboring JAK3 A572V, with a bicistronic retroviral MSCV-IRES-GFP (MIG) WT Lnk vector. Effect on growth was assessed in GFP positive sorted cells by cell count and colony formation in methylcellulose. CMK cells infected with MIG WT Lnk grew slower in liquid culture and had decreased clonogenic growth in soft agar culture compared to cells infected with MIG vector alone.
In summary, we show for the first time that Lnk can bind to WT and mutant JAK3 and slow the growth of leukemic cells harboring an activating JAK3 mutation. Developing a small molecule mimetic of Lnk may have a therapeutic role in the treatment of hematopoietic malignancies associated with a variety of activated tyrosine kinase receptors and non-receptor tyrosine kinases including JAK3, as well as secondary signaling proteins.
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 4010.
Abstract 4013: Functional analysis of Bcr-Abl-dependent phosphorylation of SOCSs
Authors: Chen Jilong , Guo Guijie 
Published: February 2011

Abstract
Previous studies have demonstrated that constitutive activation of JAK/STAT (Janus tyrosine kinase/signal transducers and activators of transcription) signaling is required for efficient transformation by the Abelson murine leukemia virus (A-MuLV), which results from the expression of the v-Abl oncogene. Although the activation of JAK/STAT signaling pathway in cells expressing BCR-ABL still remains controversial, there is increasing evidence that deregulation of the JAK or STAT activity plays an important role in BCR-ABL malignant transformation. The suppressors of cytokine signaling (SOCS) are inhibitors of Jak kinases and as such are critically involved in a negative feedback loop of Jak/STAT signal transduction pathway. The mechanism by which Abl oncogene bypasses SOCS negative regulation remains poorly defined. Here, we found that co-expression of BCR-ABL with some SOCS proteins resulted in phosphorylation of SOCSs. Moreover, we observed that BCR-ABL-dependent phosphorylation of SOCSs altered SOCS function at least at two levels. One involves alteration of direct interaction of SOCSs with JAKs, which maintains JAK kinase activity. The other level involves inhibition of interaction of SOCS box with the Elongin BC complex, which disrupted the formation of E3 ubiquitin ligase complex that mediates proteosomal degradation of JAK kinases. Together, these results suggest that the BCR-ABL may regulate the inhibitory function of SOCSs through mediating phosphorylation of SOCS proteins.
Note: This abstract was not presented at the AACR 101st Annual Meeting 2010 because the presenter was unable to attend.
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 4013.
Abstract 4014: Differential expression and activation of IRS1 and IRS2 in breast cancer cell lines
Authors: Porter Holly A. , Keegan Achsah D. 
Published: February 2011

Abstract
Numerous studies have shown that IL-4 can protect various types of tumor cells from chemotherapeutic agents including breast cancer cells. There are two main signaling pathways activated by IL-4; the STAT6, signal transducers and activators of transcription pathway, that results in expression of IL-4-responsive genes and the IRS1/2 signaling pathway that influences cellular proliferation and survival. IL-4 can act directly on many tumor cell types to prevent apoptosis. The IL-4-induced activation of STAT6 has been shown to up-regulate anti-apoptotic proteins, cFlip and BcLxL, in cancer. IRS1/2 molecules link the IL-4R and IGF-1R to signaling pathways that regulate cellular proliferation and survival, and are therefore implicated in cancer progression. Recent studies showed that IRS2 regulates mammary tumor metastasis in a mouse model of breast cancer and that knocking out IRS2 rendered the tumor cells less invasive and more susceptible to apoptosis in response to growth factor withdrawal. IRS1 was not required for metastasis and was actually suggested to be a suppressor of metastasis in breast cancer and an enhancer of proliferation. IRS2 suppressed the function of IRS1 by strongly activating the Akt/mTOR signaling pathway and inducing the serine phosphorylation of IRS1. We have found that expression of IRS1, in contrast to IRS2, leads to enhanced sensitivity to chemotherapy-induced cell death in 32D cells. Furthermore, it has been shown that MCF7 cells are more sensitive to docetaxel-induced death as compared to MDA-MB-231 cells. We propose that sensitivity of breast cancer cells to chemotherapy is in part regulated by the relative abundance of IRS1 and IRS2 and their phosphorylation status. To begin to test this hypothesis, we cultured breast cancer cells lines in the presence or absence of IL-4 and evaluated the IRS pathways. We found that MCF7 cells highly expressed IRS1 with little IRS2 while MDA-MB-231 cells expressed relatively equal amounts of IRS1 and IRS2. In MCF7 cells IL-4 induced the potent tyrosine phosphorylation of IRS1 with very little tyrosine phosphorylation of IRS2. However, in MDA-MB-231 cells, IL-4 induced the tyrosine phosphorylation of both IRS1 and IRS2 equally. However, the level of IRS1 phosphorylation in MDA-MD-231 cells was less than that observed in MCF7 cells. Taken together with previous publications, these results suggest that the differential activation status of IRS1 and IRS2 in breast cancer can lead to differential metastatic and chemosensitivity phenotypes.
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 4014.