bluuebunny/crossref_metadata_2025 huggingface dataset:
Abstract 3573: A small molecule PLK1 inhibitor, MLN0905, yields broad anti-tumor activity in human xenograft tumor models, and synergizes with taxane therapy
Authors: Lasky Kerri , Shi Judy , Shinde Vaishali , Stringer Bradley , Qian Mark G. , Liao Debra , Liu Ray , Duffey Matthew O. , Vos Tricia J. , D'Amore Natalie , Hyer Marc , Rao Youlan
Published: June 2012

PLK1 is a serine/threonine mitotic kinase that plays a key role in mitotic cell cycle progression, and its over-expression has been linked to poor patient prognosis. We have discovered a potent and selective small molecule inhibitor of PLK1, MLN0905, which reduces cell viability and inhibits cell proliferation in a broad range of human tumor cells. We explored the pharmacokinetic, pharmacodynamic, and anti-tumor properties on MLN0905 in human xenograft models grown in rodents. MLN0905 rapidly and extensively distributed to xenograft tumor with a high tumor-to-plasma exposure ratio. In human xenograft tumor tissue, MLN0905 modulates the pharmacodynamic biomarker phospho-Histone H3 (in a dose dependent fashion), enabling us to track pathway modulation in vivo. MLN0905 demonstrated robust anti-tumor activity (partial and complete responses) in a variety of solid and hematological human xenograft models, including cancers derived from colon (HCT-116, HT29), NSCLC (Calu-6), Ovarian (SKOV3), and Lymphoma (OCI-LY19, OCI-LY10, and the primary lymphoma PHTX-22L). Significant anti-tumor activity was observed when dosing on either a continuous (daily) or intermittent schedule, underscoring the dosing flexibility with this compound. In the SKOV3 and Calu-6 xenograft models, MLN0905 yielded a synergistic anti-tumor response when combined with the standard of care therapy Taxane. This is the first report of a PLK1 inhibitor synergizing with taxane therapy in vivo. In summary, our findings indicate MLN0905 has good drug-like pharmacokinetic properties, modulates the biomarker phospho-Histone H3, and yields significant anti-tumor activity in multiple xenograft models. These preclinical data support further evaluating MLN0905 as a novel anti-cancer agent.

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 3573. doi:10.1158/1538-7445.AM2011-3573
Abstract 3580: Discovery and SAR study of a novel and potent Itk inhibitor as a targeted therapeutic agent for T-cell lymphoma and leukemia
Authors: Liu Ruiwu , Guo Wenchang , Ma Aihong , Sanchez Eduardo , Wang Yan , Li Jixian , Xu Chunping , Ning Jinying , Huang Wenzhe , Mazloom Anisha , Song Aimin , Lam Kit S. , Xia Michelle , Chen Yiyou , Kung Hsing-Jien
Published: June 2012

Itk (IL2-inducible T-cell kinase) is a non-receptor protein tyrosine kinase. It is selectively expressed in T cells, Mast cells, and NK cells. It plays an important role in T-cell maturation, proliferation, and malignancies. Using Western blotting, Itk was only detected in three T-cell lymphoma and leukemia cell lines (Jurkat, Molt-4, and Hut78) out of 41 different cancer cell lines. A small molecule named CTA056 showed potent and selective inhibition of Itk kinase activity and growth in each of the three T-cell cancer cell lines. After treatment of Jurkat cells with CTA056, Itk phosphorylation was inhibited in a dose-dependent manner. In addition, apoptosis was induced in Jurkat cells following treatment with CTA056. In order to better understand structure-activity relationship (SAR) on CTA056, a series of analogs of CTA056 were designed, synthesized, and tested for their inhibition of both Itk phosphorylation and cancer cell growth. Several analogs showed better activity and selectivity. The results will be presented. Success in this endeavor could lead to the development of novel targeted therapy, rather than traditional chemotherapy, for T-cell lymphomas and leukemia.

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 3580. doi:10.1158/1538-7445.AM2011-3580
Abstract 359: Neuropeptides promote castration-resistant prostate cancer through intracrine androgen biosynthesis
Authors: Yang Joy C. , Kung Hsing-Jien , Gao Allen C. , Evans Christopher P.
Published: June 2012

Introduction and Objectives: Neuroendocrine differentiation is associated with castration resistant prostate cancer (CRPC) with detectable increased serum levels of chromogranin A in patients. Neuropeptides secreted from the neuroendocrine cells are believed to activate androgen receptor (AR) in low or no androgen environments. We hypothesize that neuropeptides sustain CRPC by promoting intracrine androgen synthesis.

Methods: We engineered LNCaP cells overexpressing gastrin-releasing peptide (GRP) and examined the level of androgen biosynthetic enzymes by RT-PCR and Western blots. Inhibition of androgen-free growth of LNCaP-GRP cells was performed with siRNA to AKR1C3 or CYP17A1 with or without Src inhibitor saracatinib. PSA and total testosterone levels were assessed in LNCaP-GRP cells, serum from tumor-bearing animals and xenografts.

Results: The androgen biosynthetic enzymes were up-regulated in LNCaP-GRP cells, with AKR1C3, CYP17A1 and HSD17B2 displaying over 40 fold increase compared to the control line by real-time RT-PCR analysis. Transfection of siRNA against AKR1C3 and CYP17A1 inhibited LNCaP-GRP cell growth in androgen-free medium. Specific Src family kinase inhibitor saracatinib inhibits androgen-independent LNCaP-GRP cell growth in vitro and tumor metastasis in vivo. Saracatinib also reduced the expression of AKR1C3, AKR1C1/2 and HSD3B1/2 in GRP cells at both RNA and protein levels. When combined with siRNA for AKR1C3 and CYP17A1, saracatinib further inhibited androgen-independent LNCaP-GRP cell growth. Testosterone was detectable by EIA assay in LNCaP-GRP cell lysates (109.1 and 44.5 pg/mg protein vs. 18.3 in control), serum from castrated mice bearing GRP tumors (2235.5 pg/ml serum) and xenograft tissue (59.2 pg/mg tumor). These enhanced T levels were greatly reduced when treated with saracatinib, to 594 pg/ml serum and 12 pg/mg tumor, respectively.

Conclusions: Secretion of neuropeptides promotes CRPC through up-regulation of intracrine androgen biosynthesis. Saracatinib not only targets neuropeptide-mediated AR activation but also blocks steroidogenesis in CRPC.

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 359. doi:10.1158/1538-7445.AM2011-359
Abstract 3590: The Bruton tyrosine kinase inhibitor PCI-32765 prevents activation of pro-survival NF-kB pathways in OCI-Ly10 ABC DLBCL cells
Authors: Balasubramanian Sriram , Crowley Richard , Sirisawad Mint , Buggy Joseph J.
Published: June 2012

PCI-32765 is a potent and selective small molecule inhibitor of Bruton tyrosine kinase (BTK), a Tec family kinase that is essential to signaling via the B-cell Receptor (BCR) (Honigberg, Proc. Natl Acad. Sci. USA 107:13075, 2010). PCI-32765 is showing encouraging clinical activity in an ongoing Phase I trial (Advani et al., ASCO 2010 meeting, JCO 28: 8012, 2010) in patients with chronic lymphocytic leukemias (CLL), as well as in B-cell Non-Hodgkin's Lymphoma (NHL), including mantle cell, follicular, and diffuse large B-cell lymphomas. Nevertheless, in tissue culture, even at concentrations of PCI-32765 that lead to full occupancy of the active site of Btk, many of the cell lines derived from B cell malignancies do not undergo apoptosis or have significantly reduced growth. This is likely because most established B-cell lines no longer depend on antigen stimulation of the BCR for survival. Recently, Davis et al identified DLBCL cells of the ABC subtype such as OCI-Ly10 that have chronic active BCR signaling and are very sensitive to Btk inhibition by PCI-32765 (Davis et al, Nature 463: 88, 2010). Here we show that PCI-32765 potently and irreversibly inhibits the growth of OCI-Ly10 (EC50 continuous exposure = 10 nM, EC50 1 hour pulse = 50 nM) but not OCI-Ly3 cells, another ABC-DLBCL line in which NF-kB pathway is activated by a mutation in CARD11, which is downstream of BTK. In addition, induction of apoptosis, as shown by caspase activation, Annexin-V flow cytometry and increase in sub-G0 fraction is observed in OCI-Ly10 but not in OCI-Ly3 cells. Both sensitive and resistant cells express Btk at similar levels, and the active site of BTK is fully occupied by the inhibitor in both as shown using a fluorescently-labeled affinity probe. OCI-Ly10 cells are shown to have chronically active BCR signaling to NF-kB which is dose-dependently inhibited by PCI-32765. The activity of PCI-32765 in these lines are further characterized by comparing signal transduction profiles (Lyn, Syk, Btk, PLCγ, ERK, NF-kB), cytokine secretion profiles and mRNA expression profiles, both with and without BCR stimulation, and observed significant differences in these profiles that could lead to clinical biomarkers that identify the most sensitive patient populations to PCI-32765 treatment.

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 3590. doi:10.1158/1538-7445.AM2011-3590
Abstract 3594: Conformational control of FMS kinase for treatment of human malignancies
Authors: Wise Scott C. , Hood Molly M. , Smith Bryan D. , Lister Deanne , Lu Wei-Ping , Kaufman Michael D. , McConville Patrick , Flynn Daniel L.
Published: June 2012

FMS kinase is involved in the process of osteoclast maturation. Osteoclasts have been shown to play a role not only in arthritic diseases but also in a cancers ability to metastasize to the bone. This is especially true for breast, lung and prostate cancer. Taken together the ability to prevent osteoclast maturation and accumulation through FMS inhibition should be a good target for small molecule therapy of bone metastasis. Using Deciphera Pharmaceutical's approach to kinase inhibition, compounds have been designed that potently inhibit FMS kinase. These inhibitors can be highly selective with lead compounds inhibiting only a single kinase within 20 fold of FMS activity in a 300 kinase profile. A second class broadens the profile to include anti-angiogenic kinase targets in addition to potent FMS inhibition. This presentation will highlight the attributes and development status of these compounds for treatment of human malignancies.

Deciphera's FMS program has afforded potent inhibitors that achieve single digit nanomolar inhibition in biochemical assays of FMS activity. The inhibitors retain this same level of potency in the presence of high (5mM) ATP concentrations. These same compounds are also selective with some inhibiting as few as three kinases within 50 fold of FMS potency. In addition, proliferation and FMS phosphoprotein assays performed with M-NFS-60 and THP-1 cells have demonstrated excellent inhibitory profiles with achieved potencies in the low nanomolar range. In functional osteoclast differentiation models, key compounds have demonstrated single digit nanomolar inhibition as assessed by TRAP assays. In vivo evaluation of the inhibitors produced excellent tolerance in two week MTD studies. Potent and durable efficacy in pharmacokinetic/pharmacodynamic xenograft models was also observed demonstrating on target effects. In vivo models of bone invasion coupled with non-invasive translational image-based biomarkers potentially provide a powerful method for visualization and quantification of osteoclast activity and FMS inhibition. Early results in imaging of bone invasion will be presented using micro CT and fluorescent activateable probes.

Deciphera's FMS inhibitors show acceptable ADME properties in cell permeability, cytochrome p450 inhibition, microsomal clearance and are orally bioavailable in rat and dog. Key prototype compounds have been evaluated in a two week rat tolerability study. These data demonstrate that Deciphera's technology has been used to identify potent and selective FMS inhibitors to be developed for treatment of cancers where metastasis to bone is an issue.

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 3594. doi:10.1158/1538-7445.AM2011-3594
Abstract 3602: Antitumor effects of epidermal growth factor (EGF) and insulin-like growth factor (IGF) inhibitors in the treatment of metastatic renal cell carcinoma
Authors: Elkahwaji Johny E. , Hauke Ralph J.
Published: June 2012

Background: Renal cell carcinoma (RCC) is associated with mutation or loss of function of the von Hippel-Lindau gene resulting in hypoxia-inducible factor 1-alpha accumulation and production of growth factors involved in proliferation and angiogenesis. Radical nephrectomy remains the primary treatment option for two thirds of RCC patients who present with tumors confined to the kidney. However, approximately one half of patients will develop metastatic RCC. Treatment of RCC has been hampered by its resistance to most chemotherapy and hormonal therapy, although selected patients have long term remission from high dose of interleukin-2. Despite the recent availability of several active targeted agents in this disease, therapy is not curative. As a result, there is continued demand for improving therapy for metastatic disease to enhance both clinical benefits and patients overall survival. The EGF and IGF-1 pathways have been implicated as potential therapeutic targets in RCC. The objective of this study was to investigate the antitumor response to EGF and IGF inhibitors as a novel combination therapy in metastatic RCC.

Methods: RCC cells lines (Caki-1 and Caki-2) were cultured in appropriate media supplemented with 10% FBS in a 5% CO2 incubator. Cells were treated for 24, 48, 72h, and 96h with different doses of EGFR (AG1478) and/or IGF-1R (AG1024) inhibitors (0-100 µM) given as single agent or in combination therapy. The epithelial cell proliferation was determined by AlamarBlue proliferation assay.

Results: Both AG1478 and AG1024, given as single agent, decreased the epithelial cell proliferation of RCC human malignant cell lines (Caki-1 and Caki-2) (p<0.05). The inhibition occurred in a dose-dependent manner and was more pronounced at higher doses of AG1478 or AG1024 (100 µM), and when both agents were given as combination therapy.

Conclusions: These data suggest that both inhibitors exhibit a synergistic antitumor effect when given as combination therapy. This synergistic benefit exhibits an anti-proliferative and pro-apoptotic effects on RCC cell lines in vitro and warrants further investigation as a potential therapeutic approach for metastatic RCC patients.

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 3602. doi:10.1158/1538-7445.AM2011-3602
Abstract 3614: In vivo efficacy of the carbonic anhydrase IX (CA9)-targeted antibody-drug conjugate BAY 79-4620 is superior to that of microtubule inhibitors in preclinical models of NSCLC, gastric and colorectal cancer
Authors: Petrul Heike , Kopitz Charlotte , Schatz Christoph , Beier Rudolf , Zatovicova Miriam , Pastorekova Silvia , Kreft Bertolt , Ziegelbauer Karl
Published: June 2012

BAY 79-4620 is a novel antibody drug conjugate (ADC) consisting of a fully human monoclonal antibody directed against carbonic anhydrase IX (CA9) conjugated to the auristatin derivative monomethyl auristatin E (MMAE) and is currently in Phase I clinical testing. CA9 is overexpressed in a range of tumor types, including gastric cancer, non-small cell lung cancer (NSCLC), pancreatic cancer and colorectal cancer. CA9 is a hypoxia-inducible protein regulated by HIF-1α, and its expression has been linked to higher aggressiveness of tumors and is predictive of poor prognosis in several cancers.

In this study, we first compared the internalization rates of the ADC BAY 79-4620 and of the naked antibody, which were found to be similar in several cell lines, indicating that CA9 internalization in vitro is not affected by the conjugated toxophore. It has previously been shown that the cytotoxicity of BAY 79-4620 depends on both CA9 expression and sensitivity of tumor cells to tubulin inhibitors. The anti-tumor efficacy of BAY 79-4620 was therefore compared to that of free toxophore MMAE as well as paclitaxel. At cumulative doses corresponding to a fraction of that of paclitaxel (calculated as toxophore equivalents), BAY 79-4620 showed equivalent or superior efficacy to paclitaxel and MMAE in xenograft models of human NSCLC and gastric carcinoma. Cumulative BAY 79-4620 doses corresponding to only 30% of the highest dose of free MMAE given showed equivalent or superior efficacy in xenograft models of non-small cell lung carcinoma. Moreover, BAY 79-4620 also showed efficacy in patient-derived NSCLC models that are resistant to paclitaxel and/or cisplatin.

Finally, regrowing CRC tumors after an initial response to BAY 79-4620 responded well to a second cycle of BAY 79-4620 treatment. This indicates that no resistance through clonal selection of CA9 negative tumor cells was induced and that repeated treatment cycles should be possible for cancer patients.

These results show the superiority of the CA9-targeted approach over the systemic administration of tubulin inhibitors, component of treatment regimens commonly used for the treatment of NSCLC and gastric cancer. Efficacy of BAY 79-4620 was particularly high in models expressing high levels of CA9, making BAY 79-4620 a promising agent for the treatment of CA9-positive NSCLC and 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 3614. doi:10.1158/1538-7445.AM2011-3614
Abstract 362: Comparison of Mig-6 and hormone receptor expression to BMI as predictors of responsiveness to progestin therapy for endometrial hyperplasia and cancer
Authors: Poisson Jessica , Rossi Emma , Young Steven , Gehrig Paola A. , Bae-Jump Victoria L.
Published: June 2012

Objectives: Mitogen-inducible gene 6 (Mig-6) is an immediate early response gene that can be induced by stressful stimuli and mitogens, including hormones and growth factors. Ablation of Mig-6 leads to epithelial hyperplasia and adenocarcinomas in a variety of organs, including the endometrium. Mig-6 has been identified as a downstream target of the progesterone receptor (PR) in the uterus. Thus, our goal was to compare Mig-6 and hormone receptor expression to BMI as predictors of responsiveness to progestin therapy for endometrial hyperplasia and cancer.

Methods: Women were identified who underwent progestin treatment (oral or IUD) for either endometrial hyperplasia or cancer. Expression of Mig-6 and the hormone receptors, G-protein coupled receptor 30 (GPR30), estrogen receptor (ER) and PR were evaluated by immunohistochemistry (IHC) in 58 paired formalin-fixed, paraffin-embedded endometrial biopsy specimens before and after progestin treatment. Tissue microarrays were constructed, and three cores were analyzed for each patient. IHC staining was scored according to the intensity (1+ to 3+) and qualitative percent cells staining per core. A “histoscore” was calculated, based on multiplying these two determinants ranging from 0 to 300 (i.e. intensity x % labeled). Results were analyzed using the Student t-test and ANOVA.

Results: There were 41 responders to progestin therapy and 17 non-responders. The majority had endometrial hyperplasia (56/58) but 2 women had grade I endometrial carcinomas. The BMI between the two groups was statistically different at 40.2 for the responders and 49.9 for the non-responders (p=0.0008). There was no difference in age or ER/PR status between the two groups. Mig-6 expression prior to treatment did not predict response to progestin therapy (183.5 = responders, 196.6 = non-responders, p=0.47). GPR30 expression prior to progestin treatment was 118.8 for the responders and 68.9 for the non-responders but was not statistically significant (p=0.06). Neither post-treatment Mig-6 (179.1 = responders, 204.0 = non-responders) or GPR30 (103.6 = non-responders, 108.6 = responders) histoscores or change in histoscores pre- and post-treatment predicted response to progestin therapy.

Conclusions: BMI but not Mig-6 expression or hormone receptor expression predicted response to progestin therapy in women with endometrial hyperplasia and cancer. GPR30 may have potential as a biomarker of progestin responsiveness but needs to be evaluated in a larger cohort of 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 362. doi:10.1158/1538-7445.AM2011-362
Abstract 3632: Nonclinical pharmacokinetics and safety of Angiocal, the first VEGF-A-specific alternative scaffold protein entering clinical development for cancer
Authors: Gille Hendrik , Christian Jürgen , Hülsmeyer Martin , Meyer Todd , Amirkhosravi Ali , Audoly Laurent P. , Stern Angelika C. , Jensen Kristian , Hohlbaum Andreas M.
Published: June 2012

Anticalins are high affinity scaffold proteins based on human lipocalins and represent a new class of biologics. Although lipocalins share limited sequence identity among each other they are all made up of a single conserved beta-barrel. The four loops protruding from the opening of the calyx contribute to the observed various binding functions of different lipocalins. The loop residues of human tear lipocalin were randomized to generate a combinatorial library and successive rounds of panning and screening were employed to generate an Anticalin with high affinity and specificity for VEGF-A, Angiocal. Angiocal was found to antagonize VEGF-A function by preventing its interaction with cognate membrane receptors. Following the initial characterization in cell-based and in vivo models as communicated previously (AACR 2008 #4077, AACR 2009 #2318) we sought to estimate the human pharmacokinetics of Angiocal by interspecies scaling. Therefore, PK profiles in mice, rats and cynomolgus monkeys were obtained and will be presented.

Therapeutic antibodies such as bevacizumab are usually well tolerated while significant toxicities occur in a subset of patients, for example leading to an enhanced risk for thromboembolic events. It has been demonstrated that bevacizumab forms multimeric immune complexes in vivo which may be a cause for these effects. Furthermore, immune complex deposition in glomeruli of the kidney may cause glomerulosclerosis. With respect to thromboembolic complications of bevacizumab use, these were mirrored in human FcgammaIIa receptor transgenic mice where administration of complexes between heparin, Bevacizumab and heparin-binding isoforms of its VEGF-A target lead to platelet aggregation and thrombosis (Meyer, T. et al. J. Thromb. Haemost. 2009, 7: 171-181). Angiocal was tested in the same model and does not cause any of these adverse effects on platelets in vivo.

GLP toxicology studies with Angiocal were performed in two relevant species to determine the NOAEL. In addition, we did not observe effects on inflammatory cytokines or complement factors in these studies while exaggerated pharmacodynamic effects consistent with potent VEGF neutralization were seen. Angiocal is currently undergoing phase Ib clinical testing in cancer patients to establish Anticalins as novel and safe class of therapeutic molecules.

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 3632. doi:10.1158/1538-7445.AM2011-3632
Abstract 364: Impact of glucocorticoid in patients with locally advanced esophageal cancer treated with concurrent chemoradiotherapy
Authors: Lu Yen-Shen , Lin Chia-Chi , Hsu Chih-Hung , Lien Huang-Chun , Yeh Pei-Yen , Yeh Ling-Chiun , Cheng Ann-Lii
Published: June 2012

Background: Concerns about the effect of glucocorticoids (GC) on tumor growth and chemosensitivity have been raised recently. Our pervious study shows that GC receptor is highly expressed in esophageal squamous cell carcinoma (ESCC) tumor tissues (Histopathology 2008;52:314-324). This study sought to further characterize the GC effect on the efficacy of conventional anti-cancer therapy to ESCC.

Materials and Methods:The in vitro study was performed in 2 esophagus cell lines: KYSE-70 and KYSE-410. The cell viability is determined by MTT assay and clonogenic assay. The effect of GC on cytotoxic treatment -induced apoptotic cell death was determined by flow cytometric and Western blot analysis. Further, we retrospectively analyzed impact of GC usage on the outcomes of 92 patients with locally advanced ESCC who received preoperative concurrent chemoradiotherapy in a prospective clinical trial. Among 92 locally advanced ESCC patients, 39 patients who received GC twice weekly for four to six weeks (a total of eight doses or more) and 53 patients who received GC only two doses in the first week at discretion of individual physicians.

Results: In vitro study showed pretreatment of GC confer resistance to cytotoxic agents including paclitaxel, gemcitabine and 5-FU, and resistance to irradiation. The effect of increase chemo-resistance by GC may be through decrease of the apoptosis according to PI/annexin V staining flow cytometric study and Western blot study. In the retrospective clinical study, the two groups were well balanced with respect to disease stage and other prognostic factors. Multivariate analysis showed that corticosteroid usage and performance status were independently prognostic of survivals. The median overall survivals of the two-dose group the eight-dose-or-more group were 38.4 and 15.1 months, (p = 0.089), respectively. The median progression-free survivals were 27.5 and 9.4 months (p = 0.024), respectively.

Conclusion: This data suggest that GC decrease chemo-sensitivity and radio-sensitivity of ESCC cells. Frequent usage of GC during concurrent chemoradiotherapy may have a detrimental effect on patients with locally advanced ESCC.

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 364. doi:10.1158/1538-7445.AM2011-364
Abstract 3647: Characterization of the relationship between mature neutrophils and tumor associated granulocytic myeloid-derived suppressor cells
Authors: Youn Je-In , Collazo Michelle M. , Gabrilovich Dmitry
Published: June 2012

Myeloid-derived suppressor cells (MDSC) is a group of cells with potent immune suppressive activity that accumulate in many pathologic conditions. In cancer, most of MDSC are represented by cells with granulocytic phenotype, CD11b+Ly6ClowLy6G+, and morphology and are thus called granulocytic MDSC (G-MDSC). This phenotype and morphology are also shared by mature neutrophils (Neu) in naive mice. The relationship, if any, between G-MDSC and Neu remains unclear. In this study, we compared tumor associated G-MDSC and mature Neu. G-MDSC were freshly isolated from spleen of tumor-bearing mice. Because there are no known specific markers that differentiate between Neu and G-MDSC in tumor being mice or Neu and immature myeloid cells in naïve mice; Neu were isolated from naive mice by mobilizing them to the peritoneum (pNeu). We found that in contrast to pNeu, a substantial proportion of G-MDSC express the M-CSF receptor, CD115, CXCR4 and the CD244 molecule, also known as 2B4. pNeu have high amounts of lysosomes, endosomes and proteasomes, which was validated using immunofluorescence microscopy to measure the expression of associated proteins, LAMP2, EEA1, PSMA5, respectively. G-MDSC had significantly lower expression of LAMP2, EEA1, PSMA5. Also, G-MDSC, compared to pNeu, had significantly lower phagocytic activity, as measured by the uptake of latex beads in vitro. On the other hand, G-MDSC, but not pNeu, suppressed T-cell IFN-γ production upon antigen-specific stimulation. Interestingly, pNeu had higher arginase activity and nitric oxide production than G-MDSC, while G-MDSC had a significantly higher increase in reactive oxygen species levels upon PMA stimulation in vitro. This may explain the differences in suppressive activity. G-MDSC survived 3 days in culture, in the presence of GM-CSF. Within 24 hours in culture with GM-CSF, they became phenotypically and functionally similar to pNeu, with increased phagocytic capacity and LAMP2 expression and decreased expression of CD115, CXCR4, and CD244. These data suggest that, in cancer, G-MDSC may represent pathologically activated precursors of neutrophils.

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 3647. doi:10.1158/1538-7445.AM2011-3647
Abstract 3686: Activation of signal transducer and activator of transcription 3 fails to confer resistance against withaferin A-induced apoptosis in human breast cancer cells
Authors: Lee Joomin , Hahm Eun-Ryeong , Singh Shivendra V.
Published: June 2012

We have shown previously that withaferin A (WA), a constituent of Indian Ayurvedic medicine plant Withania somnifera that has been used safely for thousands of years for treatment of different ailments, inhibits growth of cultured MDA-MB-231 (an estrogen receptor negative cell line with mutant p53) and MCF-7 (an estrogen-responsive cell line with wild-type p53) human breast cancer cells. Moreover, the WA administration significantly inhibits growth of MDA-MB-231 xenografts in female athymic mice without causing any side effects. The WA-mediated inhibition of breast cancer cell growth in culture and xenografts correlates with apoptosis induction. However, the mechanism underlying proapoptotic effect of WA is not fully understood. The present study was designed to study the role of signal transducer and activator of transcription 3 (STAT3), an oncogenic transcription factor activated in many human malignancies including breast cancer, in proapoptotic response to WA using MDA-MB-231 and MCF-7 cells. Growth suppressive and proapoptotic concentrations of WA (2 and 4 μM) decreased constitutive (MDA-MB-231) or interleukin-6 (IL-6)-inducible (MDA-MB-231 and MCF-7) phosphorylation of STAT3 (Tyr705) and its upstream regulator Janus-activated kinase 2 (JAK2; Tyr1007/1008) in MDA-MB-231, which was accompanied by suppression of their protein levels especially at the higher concentration. Exposure of MDA-MB-231 or MCF-7 cells to WA also resulted in suppression of (a) transcriptional activity of STAT3 with or without IL-6 stimulation in both cells; (b) dimerization of STAT3 (MDA-MB-231); and (c) nuclear translocation of Tyr705 phosphorylated STAT3 in both cells. To our surprise, the IL-6-stimulation, either before or after WA treatment, did not have an appreciable effect on WA-mediated apoptosis in MDA-MB-231 or MCF-7 cell line. The IL-6-stimulated activation of STAT3 conferred only a modest protection against WA-mediated suppression of MDA-MB-231 cell invasion. General implication of these findings is that WA can trigger apoptosis and largely inhibit cell migration/invasion of breast cancer cells even after IL-6-induced activation of STAT3, which should be viewed as a therapeutic advantage for this agent. This investigation was supported by the USPHS grant CA142604-01, 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 3686. doi:10.1158/1538-7445.AM2011-3686
Abstract 3691: Selective depletion of mutant p53 by isothiocyanates and its structure-activity relationships
Authors: Chung Fung-Lung , Pasqua Anthony Di , Wang Xiantao , Govind Suhda , Hong Charles , Mi Lixin , York Tomita , Woodrick Rebbecca Covington
Published: June 2012

It has been shown that isothiocyanates (ITCs), derived from hydrolysis of glucosinolates in cruciferous vegetables via Lossen rearrangement by myrosinase, induce apoptosis in cancer cells. We here demonstrate that certain naturally-occurring ITCs selectively deplete mutant p53, but not the wild type, and do so via a post-transcriptional mechanism. Direct p53 binding and the sequential conformational changes appears to be one of the mechanisms by which mutant p53 is depleted. Structure-activity relationship studies (SARs) using naturally-occurring and synthetic ITCs show that depletion is influenced by the structure of the ITC side chain moiety. Consistent with the gain of function by mutant p53, we show that cells with p53 mutations are more sensitive to the cytotoxicity of phenethylisothiocyanate (PEITC) than are those with the wild type. Furthermore, 2,2-diphenylethyl ITC, a synthetic ITC and one of the most potent depletors of mutant p53 studied, induces apoptosis to the greatest extent in breast cancer cells with mutant p53 status. Collectively, this study shows that mutant p53 depletion may be an important novel target for cancer chemoprevention and therapy by natural and synthetic ITCs.

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 3691. doi:10.1158/1538-7445.AM2011-3691
Abstract 3696: Effect of dietary omega-3/omega-6 ratio on mammary carcinogenesis, circulating biomarkers and molecular regulators in rats
Authors: Zhu Zongjian , Jiang Weiqin , McGinley John N. , Manni Andrea , El-Bayoumy Karam , Thompson Henry J.
Published: June 2012

Available evidence indicates that diets enriched in the ratio of n-3 to n-6 fatty acids have a broad range of health-related benefit; however, the epidemiological and preclinical data for breast cancer risk are mixed. The majority of animal carcinogenesis experiments have been done using diets that were high in the percent of dietary calories provided from fat (40 to 50%) and few studies have investigated the impact of the n-3/n-6 ratio despite the fact that considerable emphasis has been placed on this ratio in hypothesized mechanisms of action. The objective of this investigation was to determine the effect of a wide range of dietary n-3/n-6 ratios on mammary carcinogenesis, on plasma levels of cancer associated growth factors and cytokines and on molecular regulators in mammary carcinomas using a pre-clinical rat model for breast cancer. Female Sprague Dawley rats were injected with 1-methyl-1-nitrosourea (50 mg/kg) and 7 days thereafter randomized to groups (n=30/group) in which the n-3/n-6 ratio varied widely and diets were fed in the presence or absence of tamoxifen treatment. Rats were fed a modification of the AIN-93G diet formulation that contained 30% of dietary calories from fat (currently recommended in the US Dietary guidelines). It was observed that mammary cancer incidence, cancer multiplicity and tumor burden were reduced when the dietary ratio of n-3/n-6 was > 5:1. Cancer inhibition was observed in both the presence and absence of tamoxifen. The protective dietary n-3/n-6 ratio was associated with significant reductions in plasma IGF-1, insulin, and leptin and increased adiponectin compared to rats fed the control diet (n-3/n-6=1:1, p<0.05), effects that were not modified by tamoxifen treatment. Carcinomas induced in the protected animals were smaller in mass with altered levels of proteins in the PPAR-NFkB pathway. This work was supported by grant KG081632 from the Susan G. Komen Foundation.

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 3696. doi:10.1158/1538-7445.AM2011-3696
Abstract 3702: 2-Hydroxyflavanone inhibits renal cancer growth by inhibiting tumor cell proliferation and angiogenesis
Authors: Nagaprashantha Lokesh Dalasanur , Vatsyayan Rit , Singhal Jyotsana , Lelsani Poorna , Awasthi Yogesh , Awasthi Sanjay , Singhal Sharad S.
Published: June 2012

Renal cell carcinoma (RCC) is one of the top ten cancers prevalent in USA. Loss-of-function mutation in the VHL is an established risk factor for RCC contributing to 75% of total reported cases of RCC. Loss of VHL leads to highly vascularized phenotype of renal tumors. Intake of oranges has been proven to reduce the risk of RCC in multi-center international clinical trials. Hence, we studied effects of 2HF, an active anti-cancer compound of oranges, in VHL- mutant RCC. Our in vitro investigations revealed that 2HF selectively inhibits VHL-mutant RCC by inhibiting EGFR signaling which is increased due to VHL mutations in RCC. Our results also revealed for the first time, that 2HF inhibits GSTπ activity. 2HF inhibited cyclin B1 and CDK4, and induced G2/M phase arrest in VHL-mutant RCC. Importantly, 2HF inhibited the angiogenesis in VHL-mutant RCC by decreasing VEGF expression. Our in vivo studies in mice xenografts confirmed our in vitro results as evident by decreased levels of proliferation marker, Ki67 and angiogenic marker CD31, in 2HF treated (0.01%, w/w) mice xenografts of VHL-mutant RCC. 2HF also increased the expression of E-cadherin in VHL-mutant RCC which would be of significance in restoring the normal epithelial phenotype. Collectively, our in vitro and in vivo results revealed the potent anti-proliferative and anti-angiogenic effects of 2HF in VHL-mutant RCC, sparing normal cells, which could have significant implications not only in the specific management of VHL-mutant RCC but also in treating other VHL syndromes with highly vascularized phenotype.

(Supported in part by NIH grant CA 77495 (SA), CA 155350, Cancer Research Foundation of North Texas, and Institute for Cancer Research & the Joe & Jessie Crump Fund for Medical Education (SSS))

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 3702. doi:10.1158/1538-7445.AM2011-3702
Abstract 3705: Deguelin suppresses epithelial to mesenchymal transition (EMT) in pancreatic cancer cells by Snail repression and RKIP induction: Pivotal role of NF-kB
Authors: Boreddy Srinivas Reddy , Srivastava Sanjay K.
Published: June 2012

Metastatic disease is a primary cause of death for most cancer patients and is associated with the loss of epithelial features and the acquisition of mesenchymal characteristics, a process known as epithelial to mesenchymal transition (EMT). Hence, targeting EMT would be a novel therapeutic modality in cancer prevention. Previous reports have shown that deguelin, a derivative of rotenone induces apoptosis in cancer cells by inhibiting AKT but its potential as anti-metastatic agent remained elusive. In the present study we investigated the anti-metastatic (EMT) properties of deguelin in PanC-1 and MIA PaCa-2 pancreatic cancer cells. Our results show that deguelin significantly (P<0.0001) suppressed the migration of PanC-1 and MIA PaCa-2 cells in a wound healing assay. Further, deguelin treated PanC-1 and MIA PaCa-2 cells show reduced expression of E-cadherin and cytokeratin 18, the markers of epithelial cell phenotype. On the other hand, the expression of mesenchymal markers N-cadherin and vimentin were up regulated by degulin treatment in both the cell lines. Furthermore, deguelin significantly reduced the expression of Snail, a known EMT inducer, and increased the expression of RKIP, a tumor suppressor gene in both the cell lines. Since NF-kB hyperactivation is associated with tumor metastasis via regulation of EMT, we evaluated whether deguelin inhibit the phosphorylation of NF-kB in PanC-1 and MIA PaCa-2 cells. Our results show that deguelin significantly suppressed the constitutive phosphorylation of NF-kB at Ser-536. Inhibition of NF-kB activation by deguelin was further confirmed by DNA binding activity and EMSA. IL-1β has been shown to activate NF-κB and its transcriptional target Snail leading to increase in the expression of E-cadherin. Treatment of PanC-1 cells with IL-1β significantly attenuated deguelin induced E-cadherin repression and N-cadherin induction, indicating the involvement of NF-kB in deguelin mediated anti-metastatic activity. Ectopic expression of either Snail or NF-kB completely abolished EMT protection offered by deguelin in PanC-1 cells confirming the role of NF-kB and Snail in deguelin induced EMT inhibition. Taken together our results provide convincing evidence on the anti-metastsis properties of deguelin in pancreatic cancer. [Supported in part by R01 grants CA106953 and CA129038 (to S.K.S) 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 3705. doi:10.1158/1538-7445.AM2011-3705
Abstract 3706: Novel analogs of dietary thymoquinone with superior bioavailability and anti-tumor activity against GI cancers
Authors: Azmi Asfar S. , Padhye Subhash , Banerjee Sanjeev , Aboukameel Amro , Sarkar Fazlul H. , Mohammad Ramzi M.
Published: June 2012

Alterations in multiple signaling pathways are a hallmark of most epithelial cancers, including pancreatic (PC) and colon cancers (CC). In principle, agents such as dietary bioactive compounds that affect multiple pathways should exhibit superior effectiveness due to their pleiotrophic actions compared to single pathway targeted therapies. Earlier we had shown that thymoquinone (TQ), a bioactive agent derived from edible black seed plant Nigella Sativa exerts anticancer activity against PC and CC alone or can enhance the effects of chemotherapeutics through mechanisms involving down-regulation of multiple pathways [such as NF-kB, cell cycle, inflammation, anti-apoptosis and angiogenic signaling (Cancer Research 69(13) 2009)]. However, due to poor bioavailability the anti-tumor effects of TQ that are observed at pharmacological high doses (>25 µM in vitro that translates to ∼7.4 g/kg in humans) cannot be considered clinically relevant. To address this problem we have developed a series of potent TQ analogs and among them two (TQ-THB and TQ-TFB patent pending) were found to have greater potency (growth inhibition and apoptosis) than parent TQ (IC50s 5 and 7µM respectively). TQ-THB and TQ-TFB not only show superior in vitro activity against PC, they also demonstrate greater anti-tumor activity in a highly metastatic BxPC-3 pancreatic xenograft model. The analogs are well tolerated and can be given i.v. Most interestingly, these analogs synergize with gemcitabine and FOLFOX that are the standard care for pancreatic and colon cancer respectively. The synergy was found both in cell culture and animal tumor models. Molecular Docking studies revealed that both TQ-THB and TQ-TFB binds very strongly to Cox-2 and NF-kB. This suggests that the analogs work by inhibiting the tumor survival and angiogenic pathways. Based on our novel findings we believe that these dietary analogs hold promise as anticancer agents that warrant further clinical development.

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 3706. doi:10.1158/1538-7445.AM2011-3706
Abstract 3720: Obesity and mortality among black women and white women with invasive breast cancer
Authors: Lu Yani , Ma Huiyan , Malone Kathleen E. , Norman Sandra A. , Sullivan-Halley Jane , Strom Brian L. , Marchbanks Polly A. , Spirtas Robert , Burkman Ronald T. , Deapen Dennis , Folger Suzanne G. , Simon Michael S. , Press Michael F. , McDonald Jill A. , Bernstein Leslie
Published: June 2012

PURPOSE To evaluate the effect of obesity on survival among black and white women with invasive breast cancer; and determine whether different distribution of obesity accounts for the poorer survival of black women.

METHODS 4538 (1604 black, 2934 white) women ages 35 to 64 years when diagnosed with first incident invasive breast cancer between 1994 and 1998, who participated in the Women's Contraceptive and Reproductive Experiences Study, were followed up for a median of 8.6 years. Multivariate Cox regression models were used to examine height, body mass index (BMI, kg/m2) at different ages on the risk of all-cause mortality and breast cancer-specific mortality.

RESULTS During follow-up, 1053 (519 black, 534 white) women died, 828 (412 black, 416 white) from breast cancer. Compared to women with a recent (5 years before diagnosis) BMI of 20-24.9 kg/m2, those who were obese (BMI≥30 kg/m2) had a greater risk of all-cause mortality (relative risk [RR], 1.23; 95% confidence interval [CI], 1.04-1.47) and breast cancer-specific mortality (RR, 1.20; 95% CI, 0.99-1.46). However, these risk patterns were only observed among white women (all-cause RR, 1.54; 95% CI, 1.21- 1.96; breast cancer RR, 1.46; 95% CI, 1.11-1.92), but not among black women (all-cause RR, 1.03; 95% CI, 0.81-1.29; breast cancer RR, 1.02; 95% CI, 0.79-1.33).Similar risk patterns were observed in different strata of estrogen receptor(ER) status, tumor stage, menopausal status, and education level.

CONCLUSION Obesity may play an important role in mortality among white but not black breast cancer patients. It is unlikely that differences in obesity distributions between black and white women account for the poorer survival of black 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 3720. doi:10.1158/1538-7445.AM2011-3720