bluuebunny/crossref_metadata_2025 huggingface dataset:
Abstract B37: Differential mRNA expression, microRNA regulation and gene networks are associated with the prostate cancer disparities in African American and Caucasian American populations
Authors: Wang Bi-Dar , Andrawis Ramez , Jarrett Thomas , Frazier Harold , Patierno Steven R. , Lee Norman H.
Published: June 2012

Prostate cancer (PCa) is a disease conferred by multiple gene mutations, numerous alternations in gene expression and aberrant changes in genome composition/architecture. An area of research that continues to garner attention is PCa health disparities, wherein the African American (AA) population exhibits higher incidence and mortality rates compared to Caucasian Americans (CA). Although accumulating evidences have suggested that the widespread microRNA deregulation may play crucial role in cancer development, the relationship between population-specific microRNAs and PCa disparities remains largely unknown. To identify the genetic predispositions and oncogenic networks associated with the observed PCa disparities, we applied a systems biology approach by combining mRNA expression profiling, microRNA profiling and microRNA target searches to characterize the genetic portraits of PCa in AA and CA populations. Affymetrix human exon 1.0ST arrays and Agilent human miRNA V2 arrays were used to analyze the global mRNA and microRNA expression profiles in AA and CA prostate tissue samples. From the mRNA profiling results, a 4-way statistical analysis (t-test with 10% FDR; AA normal vs. CA normal, AA cancer vs. CA cancer, AA cancer vs. AA normal, and CA cancer vs. CA normal) has identified 275 to 987 genes with differential expression in the 4-way comparisons. Furthermore, pathway analysis revealed that the mis-regulated testosterone metabolic pathway, activated inflammatory response and up-regulated oncogenic pathways (ERK, JNK and p38) are associated with the biological differences when comparing AA normal to CA normal, AA cancer to CA cancer and AA cancer to AA normal. In addition, a microRNA/mRNA-regulated network, generated by integrating microRAN-targeted mRNAs and mRNA profiling data, suggested that the population-specific microRNAs may contribute to differential cell-cycle control, protein synthesis and cell apoptosis in AA and CA prostate cancers. Our study has demonstrated that differential gene-network regulation, driven by the population-specific mRNA and microRNA expression, may explain in part the biological differences between AA and CA prostate cancers.

This work was supported by NCI grant 5U01-CA-116937 and ACS-IRG-08-091-01.

Citation Information: Cancer Epidemiol Biomarkers Prev 2011;20(10 Suppl):B37.
Abstract B46: Investigating the role of β-arrestin-2 in prostate cancer disparity using a β-arrestin-2 deficient mouse model of prostate cancer
Authors: Akins-Rivers E. Joy , Smith Nikia , Richardson Ricardo M.
Published: June 2012

African American men are more likely to develop and die from prostate cancer than Caucasian American men. While a complex interaction of social, environmental, and biological factors is likely to blame, molecular mechanisms of prostate cancer disparity remain poorly understood. Elucidation of these mechanisms is critical if we are to achieve better treatment options and ultimately, patient survival for African American men. β-arrestin-2 was initially recognized for its role in G-protein coupled receptor desensitization. More recent studies have demonstrated that several pathways critical to prostate cancer progression converge at β-arrestin-2 including androgen metabolism, angiogenesis, and metastasis. Preliminary data in our lab shows that prostate cell lines derived from Caucasian American men express less -arrestin-2 than those from African American men. This study aims to test the hypothesis that loss of β-arrestin-2 expression in prostate tumors attenuates tumor progression. In order to study this, we have established a β-arrestin-2 deficient TRAMP mouse model. TRAMP+/β-arrestin-2 KO mice develop tumors that are smaller than those in TRAMP+/β-arrestin-2 WT mice at 6 months of age. Similar results were observed when orthotopic TRAMP-C1 tumors were established in C57BL/6 mice. β-arrestin-2 knockdown in these cells resulted in delayed tumor growth. Taken together these data support the idea that increased β-arrestin-2 expression correlates with enhanced tumor progression providing a possible biological mechanism of prostate cancer disparity.

Citation Information: Cancer Epidemiol Biomarkers Prev 2011;20(10 Suppl):B46.
Abstract B60: Hsa-miR-27a drives an association of MBL2 3′UTR haplotype with colon cancer risk in African Americans
Authors: Haznadar Majda , Zanetti Krista , Robles Ana , Ryan Brid , McClary Andrew , Harris Curtis
Published: June 2012

Colon cancer (CC) is estimated to be the third most common cause of cancer deaths in the United States in 2010 and the incidence is higher among African Americans compared with Caucasians. Chronic intestinal inflammation is a risk factor for CC. Moreover, mediators of chronic inflammation have been implicated in CC development. MBL, a mannose-binding protein, is a critical component of the innate immune system, and it serves as a front-line protection against pathogens. MBL deficiency is common and present in approximately 5% of the population, predisposing individuals to bacterial and fungal infections. A previous resequencing analysis of the 10.0kbp region that includes the MBL2 gene showed a recombination hot-spot in the 3′ end of the gene, dividing MBL2 into two separate haplotype blocks: 5′UTR and 3′UTR haplotypes. In our previous work, we used a case-control study from the greater Baltimore, Maryland area (261 cases; 537 controls) and observed that haplotypes in both regions are associated with CC risk in African Americans, but not in Caucasians. Moreover, we showed that four single nucleotide polymorphisms (SNPs) comprising a 3′UTR region haplotype are individually associated with increased CC risk in African Americans: rs10082466, rs2120132, rs2099902, and rs10450310. In this study, we investigated whether the SNPs in this haplotype block fell within putative microRNA (miRNA) site due to the observed association of 3′UTR-region haplotypes and plasma MBL levels, using publicly available web-tools. We hypothesized that rs10082466 association with CC is driven by hsa-miR-27a binding to the C allele, resulting in decreased plasma MBL2 levels and activity. We tested the interaction of hsa-miR-27a with the 3′UTR region of MBL2 and its modulation by 3′UTR haplotypes in vitro using reporter constructs via luciferase activity. The increased binding affinity for the C allele of rs10082466 was reflected by a significant decrease in normalized luciferase activity, compared with the T allele. We also showed the C allele to be associated with lower plasma MBL2 levels and activity in cases and controls. Moreover, the fold increase of hsa-mir-27a precursor is significantly higher in African Americans compared to Caucasians in colon cancer. Therefore, 3′UTR haplotype association with CC may be driven by hsa-miR-27a binding to the C allele of rs10082466, which results in decreased plasma MBL2 levels and activity. In addition to the supporting evidence linking low levels of circulating MBL2 to increased susceptibility to infection, these results suggest that a genetic variant in MBL2 may increase colon cancer susceptibility in African Americans by creating a miRNA binding site.

Citation Information: Cancer Epidemiol Biomarkers Prev 2011;20(10 Suppl):B60.
Abstract B65: Coordinated care model to reduce rural disparities in breast cancer mortality
Authors: Gehlert Sarah J. , Beers Courtney , Colditz Graham A.
Published: June 2012

To identify underlying causes of excess breast cancer mortality in the Bootheel region of Missouri we conducted a needs assessment across 10 counties. An urban/rural disparity compounds the effects of racial disparity on breast cancer screening, incidence, and mortality rates in Missouri. The Bootheel region is the second most populous region ranked according to proportion of the population living below poverty level and has breast cancer mortality higher than other regions in the state.

We used GIS data to map county level data on breast cancer rates, poverty distribution, and geographic location of relevant specialty physicians/services such as mammography, surgeons, and medical oncologists. Overlay of poverty distribution and Show Me Healthy Women provider maps reflects accessibility of statewide assistance for breast cancer screening/diagnostic services in relation to areas of need. Provider-by-type maps represent the physical distance women would need to travel in order to receive breast health screening and/or services.

We conducted interviews with regional stakeholders including county health departments, hospitals, federallyqualified health centers & rural health clinics, private providers/offices, social service organizations, physicians, survivors, and age-eligible women. Needs assessment included on site interviews with over 50 individuals associated with breast cancer prevention and/or treatment in the region. Informants are diverse and representative of the region and their county.

Barriers to access to breast health services included financial constraints, geographic and cultural limitations, lack of funding for the breast and cervical cancer-screening program. This region exceeds state averages for the proportion of women over 40 who have never had a mammogram.

Breast health services along the continuum from early detection to access to treatment all need improvements. Research and service priorities include improved assistance for uninsured to access screening; improved understanding of physiologic social and environmental factors affecting breast health; implementation of sustainable programs to improve adherence to breast screening and risk factor reduction; improved patient navigation and communication between providers along the continuum of care; and increase awareness among community leaders of the magnitude of excess breast cancer burden in the Bootheel. The effectiveness of and strategies for effective navigation in a rural isolate population setting must be evaluated.

Citation Information: Cancer Epidemiol Biomarkers Prev 2011;20(10 Suppl):B65.
Abstract B85: WINCART Center: Technology and tobacco use assessment for young adult Pacific Islanders
Authors: Lee Cevadne , Sabado Melanie , Stifler Liliani , Pike James , Cen Steven , Xie Bin , Palmer Paula H. , Lepule Jonathan , Briand Greta , Guevara Linda , Pang Victor Kaiwi , Schmidt-Vaivao Dorothy , Semaia Aaron , Tuione Vanessa , Hui Brian
Published: June 2012

Introduction: This research study (WINCART – Weaving an Islander Network for Cancer Awareness, Research and Training) focuses on the development of a smoking cessation intervention for late adolescent and young adult PIs in Southern California.

Methods: The comprehensive tobacco use and quitting assessment is geared towards young adult Pacific Islanders between 18 and 29 years old. The assessment is comprised of four parts: 1) smoking history semistructured interview or “talk story” session with current and former tobacco users to understand the individual's tobacco use history; 2) Computerassisted Iowa Gambling Test (IGT), a neurocognitive decision-making test in the form of a card game, to assess affective decision making that may make an individual more susceptible to tobacco use, 3) Ecological momentary assessment (EMA) which will be used to track in real time, an individual's smoking behaviors and cues that are in response to stressors, moods, and other environmental influences, using an iPhone, and 4) online survey tool to collect relevant demographic information.

Results: Results of the assessment will be used to inform the development of an evidence-based online tobacco cessation program geared towards young adult Pacific Islanders. This study has been recently awarded and a work in progress. The WINCART community and academic research team have established a governance structure, developed measures, and is building the technological infrastructure.

Conclusion: When compared with all other major racial/ethnic groups in the U.S., young adult Pacific Islanders have a high prevalence rate of tobacco use. Evidence-based smoking cessation programs tailored to the culture and lifestyle of PIs in the U.S. do not exist. Findings from our assessment will fill many knowledge gaps and will lead in the development of a novel multicomponent cessation intervention for late adolescent and young adult PIs consisting of interactive technological components. The intervention will be highly engaging, interactive, and age- and culturally appropriate.

Citation Information: Cancer Epidemiol Biomarkers Prev 2011;20(10 Suppl):B85.
Abstract ED01-01: Overview of biorepository best practices
Authors: Vaught Jimmie B.
Published: June 2012

There is considerable heterogeneity in the way that patients’ biospecimens (tissues, blood, urine for example) are collected, processed and stored in biorepositories. This unknown or uneven quality of biospecimens used for research can lead to unreliable and irreproducible results. In addition to technical and operational issues, many ethical, legal and policy guidelines and concerns must be addressed when conducting research involving the use of biospecimens from cancer patients and other research participants. After an extensive review of its own biorepostories, in 2007 the NCI Office of Biorepositories and Biospecimen Research (OBBR) published the NCI Best Practices for Biospecimen Resources (http://biospecimens.cancer.gov/practices/). The Best Practices do not comprise detailed procedures and are intended to be adapted, as appropriate, based on the mission and scientific needs of the individual biorepository. The technical best practices include recommendations for the collection, processing, storage and shipping of biospecimens, as well as quality control of processes and the proper collection of clinical data. The ethical, legal and policy practices provide guidance on informed consent, privacy and confidentiality, custodianship and intellectual property concerns. In response to questions and comments from the research community a new version of the Best Practices is being published in 2011. Major revisions include the addition of sections on biorepository management and operations and conflicts of interest, and expansion of recommendations related to custodianship and informed consent, harmonization with current Federal guidance documents and recommendations from international organizations. The revised Best Practices will be launched using an interactive web format, to provide a mechanism for more frequent updates and to encourage feedback from the community. The Best Practices will continue to evolve as the field of biospecimen biology advances; novel scientific, technological and clinical practices develop; and new ethical and legal policies and regulations emerge. The NCI is committed to maintaining current and scientifically accurate best practices for biorepositories and will continue to solicit input from stakeholders in the cancer research community.

Citation Information: Cancer Epidemiol Biomarkers Prev 2011;20(10 Suppl):ED01-01.
Abstract PL05-01: An overview of the global tobacco epidemic
Authors: Bloch Michele
Published: June 2012

Tobacco use is a leading cause of preventable death, including cancer death, worldwide. The World Health Organization has estimated that, globally, smoking is responsible for 12% of male deaths and 6% of female deaths and that the total number of tobacco-attributable deaths will rise from 5.4 million in 2005, to 8.3 million in 2030. Increasingly, the burden of tobacco mortality is shifting from high-income countries to low- and middle-income countries; between 2002 and 2030, tobacco-attributable deaths in low- and middle-income countries are projected to double from 3.4 million to 6.8 million, while deaths in high-income countries are projected to decline by 9%. In many countries, including the U.S., tobacco use is stratified by socioeconomic status and other demographic variables, and is an important contributor to disparities in health outcomes, including cancer health outcomes. The Framework Convention for Tobacco Control (FCTC), the first treaty ever negotiated under the auspices of the WHO, aims to “protect present and future generations from the devastating health, social and environmental and economic consequences of tobacco consumption and exposure to tobacco smoke by providing a framework for tobacco control measures.” As of January 2011, 172 countries are parties to the FCTC, which has become a crucial force spurring the development of evidence-based tobacco control policies around the world. This presentation will provide a broad overview of the global tobacco epidemic, and its impact on global cancer mortality. It will make use of the traditional epidemiologic model which posits that the agent (diverse tobacco products and secondhand smoke), host (individual user), and vector (tobacco manufacturers), interact in an environment that is shaped by familial, social, cultural, historical, legal, regulatory, economic, media, and other forces.

Citation Information: Cancer Epidemiol Biomarkers Prev 2011;20(10 Suppl):PL05-01.
Abstract A13: Reduction of tumor invasiveness and metastasis and prolongation of survival of RIP-Tag2 mice after inhibition of VEGFR plus c-Met by XL184
Authors: Sennino Barbara , Naylor Ryan M. , Tabruyn Sebastien P. , You Weon-Kyoo , Aftab Dana T. , McDonald Donald M.
Published: June 2012

Inhibition of vascular endothelial growth factor receptor (VEGFR) signaling can slow tumor growth and prolong host survival but can also promote invasiveness and metastasis in some preclinical models. Although the mechanisms involved are unclear, hypoxia-induced activation of pro-invasive pathways involving hepatocyte growth factor and its receptor c-Met may be a factor. We sought to address this mechanism by determining whether inhibition of VEGFR together with c-Met can reduce tumor invasiveness and improve host survival as well as reduce tumor growth. Our approach was to compare the effects of a tyrosine kinase inhibitor, XL184, that blocks VEGFR and c-Met with the effects of an antibody that selectively blocks mouse VEGF in 14-week-old RIP-Tag2 transgenic mice, a model of pancreatic neuroendocrine carcinoma. In this model, tumors arise from pancreatic islet beta cells in their natural microenvironment, and the effects of inhibitors can be tested at multiple stages of tumorigenesis. After treatment with anti-mouse VEGF antibody for 3 weeks, the tumors were smaller than vehicle-treated tumors (tumor area 4.3 ± 0.8 mm2 in antibody group versus 17.3 ± 6.5 mm2 in vehicle group; P < 0.05) but had greater expression of c-Met and had more irregular borders. After the anti-VEGF antibody, irregularity of the tumor perimeter indicative of invasion of the surrounding acinar pancreas was increased (invasion index 18.9 versus 12.7 in vehicle group; P < 0.05), and liver metastases were more numerous (metastases 2.73 ± 1.83 /mm2 versus 0.45 ± 0.12 /mm2 in vehicle group; P < 0.05). By comparison, tumors treated with XL184 not only were smaller (tumor area 0.7 ± 0.1 mm2; P < 0.05) than in the vehicle or anti-VEGF antibody group but also were less invasive (invasion index 4.5; P < 0.05) and had no liver metastases. All mice treated from 14 weeks of age with XL184 (n = 6) survived until 20 weeks, but none treated with vehicle (n = 14) or anti-VEGF antibody (n = 8) reached that end point. These results show that selective inactivation of VEGF reduces tumor growth but leads to greater invasiveness and metastasis in the RIP-Tag2 model. However, inhibition of VEGFR together with c-Met not only slows tumor growth but also decreases tumor invasiveness and liver metastases and prolongs host survival.

Citation Information: Mol Cancer Ther 2009;8(12 Suppl):A13.
Abstract B120: Designing potent antibody-drug conjugates: The impact of lysosomal processing efficiency and conjugate linker selection on anticancer activity
Authors: Maloney Erin , Fishkin Nathan , Chari Ravi , Singh Rajeeva
Published: June 2012

Six different ADCs are in clinical testing that contain the maytansinoid agent DM1 or DM4. The two most advanced of these, trastuzumab-DM1 (T-DM1) and IMGN901, have demonstrated encouraging activity and tolerability. These conjugates differ in the linker used to keep the maytansinoid agent (DMx) attached to the antibody until target-cell entry and activation. T-DM1 employs a non-reducible thioether linker and IMGN901 employs a disulfide linker that is reducible intracellularly. Our findings support that the best linker choice can depend on the nature of the target cancer.

We tested conjugates consisting of an anti-EGF receptor antibody (anti-EGFR Ab) attached to DMx using either a reducible disulfide linker or a non-reducible thioether linker. In our initial cytotoxicity survey, we observed that anti-EGFR-DMx conjugates made with either type of linker were potent in vitro (IC50 = 0.07 nM) against MDA-MB-468 breast cancer cells, a cell line with high EGFR expression. In contrast, the reducible, disulfide-linked conjugate was 15-fold more potent (IC50 = 0.2 nM) than the non-reducible thioether-linked conjugate (IC50 = 3 nM) against the A431 epidermoid cell line, which also has high EGFR expression. The greater cytotoxicity of conjugate containing the disulfide linker over conjugate containing the non-cleavable linker against A431 cells was observed using two different disulfide linkers and two different anti-EGFR Abs. Use of fluorescently-labeled anti-EGFR Ab identified that trafficking to lysosomes was delayed in A431 cells, in contrast to the rapid lysosomal localization found in MDA-MB-468 cells. This observation of poor lysosomal processing in A431 cells was corroborated by a cellular metabolism study. Lower amounts of active metabolites were formed in A431 cells treated with the non-reducible linker conjugate than with the disulfide linker design. The disulfide linker conjugate also showed early DMx metabolite release (8 h) due to disulfide cleavage before any lysine-linker DMx metabolite (24 h) was produced by lysosomal degradation. The non-reducible linker conjugate showed only the lysine-linker DMx metabolite at 24 h. Making the disulfide linkage more prone to intracellular reduction (by chemical design) increased the amount of intracellular DMx thiol present and also improved the cytotoxicity of the conjugate. We previously have proposed a model for conjugate activation where lysosomal degradation precedes disulfide linker reduction. The data reported here support an additional pathway of conjugate activation for designs using disulfide linkers (intracellular disulfide cleavage prior to deficient lysosomal proteolysis), which can be beneficial for ADCs targeting cancer cells that have inefficient lysosomal processing or targeting tumor antigens that are, by their nature, inefficiently processed in lysosomes.

Citation Information: Mol Cancer Ther 2009;8(12 Suppl):B120.
Abstract B148: INK128 is a potent and selective TORC1/2 inhibitor with broad oral antitumor activity
Authors: Jessen Katayoun , Wang Shunyou , Kessler Linda , Guo Xin , Kucharski Jeff , Staunton Jocelyn , Lan Lucy , Elia Marikka , Stewart Josh , Brown Jolene , Li Liansheng , Chan Katrina , Martin Michael , Ren Pingda , Rommel Christian , Liu Yi
Published: June 2012

mTOR Ser/Thr protein kinase operates in two distinct multi-protein complexes, TORC1 and TORC2, which together regulate growth, metabolism, angiogenesis and survival by integrating nutrient and hormonal environmental signals. The activity of mTOR is frequently up-regulated in human cancer by constitutive mitogen stimuli or oncogenic mutations upstream of TORC1 and TORC2. Rapamycin provides mechanistic rationale and clinical proof of concept for the therapeutic value of targeting mTOR in human cancer, but it also provided insights into how ATP-competitive TORC1/2 inhibitors have the potential to demonstrate superior efficacy.

Through rational drug design we have discovered INK128, a potent, selective TORC1/2 inhibitor with excellent drug-like properties. INK128 inhibits mTOR kinase (sub-nanomolar) in an ATP-dependent fashion and demonstrates a high degree of selectivity against closely related kinases as well as against a panel of more than 400 kinases. INK128 inhibits both the phosphorylation of S6 and 4EBP1, the downstream substrates of TORC1, and selectively inhibits AKT phosphorylation at Ser473, the downstream substrate of TORC2, in vitro and in vivo. Interestingly, potent inhibition was also observed in cell lines resistant to rapamycin and pan-PI3K inhibitors. Daily, oral administration of INK128 (alone or in combination) inhibited angiogenesis and tumor growth in multiple xenograft models with predicted dose:exposure PK/PD relationship. We attribute the superior activity of INK128 to the fact that it is a more effective inhibitor of TORC1 relative to rapamycin.

We further demonstrated that TORC1/2 inhibitors cause death of murine and human leukemia cells in models of pre-B acute lymphoblastic leukemia. In vivo, oral daily treatment with TORC1/2 inhibitors delayed leukemia onset and augmented the effects of ABL kinase inhibitors. Unexpectedly, these novel TORC1/2 inhibitors had much weaker effects than rapamycin on proliferation and function of normal lymphocytes. These findings establish that transformed lymphocytes are selectively sensitive to active-site TORC1/2 inhibitors and further support the development of such compounds for leukemia therapy in addition to solid tumors.

In summary, INK128 is a potent, selective, and orally active TORC1/2 dual inhibitor positioned to enter clinical development. TORC1/2 inhibitors are mechanistically distinct from rapamycin and offer a compelling approach to the treatment of cancer by targeting translational control, cell metabolism, growth and angiogenesis.

Citation Information: Mol Cancer Ther 2009;8(12 Suppl):B148.
Abstract B154: Thymoquinone causes mitochondrial membrane disruption and potentiates chemotherapeutic drug- and radiation-induced cytotoxicity in breast cancer cells
Authors: Sutton Kimberly M. , Hoskin David W.
Published: June 2012

Thymoquinone, which is the active constituent of the volatile oil extracted from black caraway seeds (Nigella sativa), has been reported to have antiinflammatory, antioxidant, and antineoplastic activities in vitro and in vivo. In this study we explored the mechanism by which thymoquinone inhibits breast cancer cell growth, as well as the potential of using thymoquinone in combination with conventional chemotherapeutic drugs or radiation therapy. Cytofluorimetric analysis of Oregon Green 488-stained MDA-MB-231 and MDA-MB-468 breast cancer cells following thymoquinone treatment demonstrated inhibition of cell proliferation. Colorimetric 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assays performed on MDA-MB-231, MDA-MB-468, and T-47D breast cancer cells after 24, 48, and 72 h treatment with thymoquinone (0.5–10 µM) showed a time- and dose-dependent cytotoxic effect, while untransformed human mammary epithelial cells were not adversely affected by thymoquinone. Longer exposure (144 h) to lower doses of thymoquinone (0.25–1 µM) was also cytotoxic for breast carcinoma cells. Importantly, staining of thymoquinone-treated breast cancer cells with annexin-V-FLUOS/propidium iodide indicated that cell death was by apoptosis. Western blot analysis of thymoquinone-treated breast cancer cells revealed increased cytosolic cytochrome c and PARP cleavage, which suggested induction of the mitochondrial pathway of apoptosis. However, broad spectrum caspase inhibitors (Bod-D and z-VAD-fmk) did not prevent thymoquinone-induced cytotoxicity, implying caspase-independent cell death. Thymoquinone treatment also sensitized breast cancer cells to γ-radiation and the conventional chemotherapeutic agents docetaxel and cisplatin. We conclude that thymoquinone caused caspase-independent apoptosis in breast cancer cells that involved the loss of mitochondrial membrane integrity. Furthermore, the ability of thymoquinone to potentiate the cytotoxic effects of chemotherapeutic drugs and -radiation may have application in a clinical setting.

Citation Information: Mol Cancer Ther 2009;8(12 Suppl):B154.
Abstract B204: Development of ALN-VSP: An RNAi therapeutic for liver malignancies
Authors: Toudjarska Iva , Judge Adam , Buck Tim , McClintock Kevin , de Jong Susan , Ambegia Ellen , Brodsky Joshua , Akinc Akin , Racie Timothy , Jeffs Lloyd , Yaworski Ed , MacLachlan Ian , Sah Dinah W. , Gollob Jared , Bumcrot David A.
Published: June 2012

Malignancies of the liver, including primary (hepatocellular carcinoma) and secondary (metastatic) tumors, represent a significant unmet medical need. We are developing a therapeutic for solid tumors involving the liver that is comprised of lipid particle-formulated small interfering RNAs (siRNAs) targeting VEGF and the mitotic kinesin, KSP (Eg5). For each target, potent siRNA duplexes were selected following extensive screening in tissue culture cells. To assess efficacy in vivo, a stable nucleic acid lipid particle (SNALP) formulation was developed based on similar formulations previously shown to silence liver-expressed genes via systemic administration in multiple species. A SNALP-formulated combination of the KSP and VEGF siRNAs (referred to as ALN-VSP) was tested in orthotopic liver tumor models in which human tumor cells are implanted directly into the livers of immunocompromised mice. We show that intravenous administration of ALN-VSP leads to silencing of both KSP and VEGF expression in established liver tumors. This is accompanied by the formation of numerous aberrant mitotic figures (“monoasters”) in tumor cells indicative of the pharmacologic inhibition of KSP. In addition, we demonstrate that ALN-VSP treatment provides a clear survival benefit even when treatment is initiated in animals with a significant tumor burden. A Phase 1 clinical trial of ALN-VSP has recently been initiated.

Citation Information: Mol Cancer Ther 2009;8(12 Suppl):B204.
Abstract B92: P38 MAPK activation is critical for FGFR3-induced cell transformation in human bladder carcinoma
Authors: Bernard-Pierrot Isabelle , Dunois-Larde Claire , Stransky Nicolas , Herault Aurelie , Lepage May-Linda , Ouerhani Slah , Abbou Claude , Laplanche Agnes , Benhamou Simone , Lebret Thierry , Allory Yves , Radvanyi François
Published: June 2012

Bladder cancer is estimated to be the fifth most prevalent type of cancer in industrialized countries. In most of the cases (more than 90 %), tumors are urothelial cell carcinoma (UCC). Activating mutations of the fibroblast growth factor receptor 3 (FGFR3) are the most frequent genetic alteration in UCC (up to 80% in low grade Ta tumors). We have previously described that the mutated receptor displays oncogenic properties (Bernard-Pierrot et al., 2006). In this study, we aimed to better understand the signaling properties of the oncogenic mutated FGFR3. We performed a systematic analysis of phosphoproteins involved in classical signaling pathways activated by FGFRs coupled to a pharmacological study in NIH-3T3 cells expressing the mutated receptor or not. We identified p38 MAPK as a key down-stream signaling molecule of FGFR3-induced NIH-3T3 cell transformation. We further showed that activation of p38 is also critical for FGFR3-induced tumorigenesis of epithelial cells. Indeed, in vitro, p38- siRNAs and SB203580, a specific p38 MAPK inhibitor, inhibited the transforming properties of MGH-U3 cells derived from a human bladder tumor and expressing mutated FGFR3. Moreover, in vivo, treatment with SB203580, inhibited mutated FGFR3-induced proliferation both in MGH-U3 xenografted tumors and in transgenic mice expressing mutated FGFR3 in the skin (Logié et al.,2005). Finally, we identified p38 activation in all FGFR3 mutated human bladder tumors studied and more generally in all human bladder tumors presenting identified FGFR3 signaling pathway alterations. Taken together, those results suggest that p38 is a key signaling molecule in a high proportion of human bladder tumors and could represent an interesting therapeutic target both in muscle non-invasive and invasive tumors mutated for FGFR3 or more generally in tumors with FGFR3 pathway activation.

Citation Information: Mol Cancer Ther 2009;8(12 Suppl):B92.
Abstract C208: CCT129254 (AT11854) is a well tolerated, orally bioavailable inhibitor of AKT/PKB with pharmacodynamic and antitumor activity in a range of xenograft models
Authors: Davies Barry R. , Dudley Philippa , Cosulich Sabina , Luke Richard , Thompson Neil , Collins Ian , McHardy Tatiana , Garrett Michelle , Ogilvie Donald
Published: June 2012

The PI3K/AKT/mTOR pathway is the most frequently deregulated pathway in human cancer. The serine/threonine kinase AKT (PKB), a member of the AGC family of protein kinases, is central to this pathway and is considered an important target for cancer therapy. However, the development of well tolerated, orally bioavailable inhibitors of catalysis targeting this enzyme has proved challenging and there are currently no such agents that have progressed to phase II clinical studies. We have characterised the pharmacodynamic and anti-tumor activity of CCT129254, a small molecule inhibitor of AKT. CCT129254 was well tolerated when dosed chronically at up to 200 mg/kg qd in nude mice. Acute doses of 100–200 mg/kg CCT129254 caused dose-dependent transient elevations of blood glucose concentration and inhibition of AKT substrate phosphorylation in xenografts. An acute dose of 200 mg/kg qd CCT129254 significantly reduced pGSK3 for >6h in U87-MG xenografts, and this pharmacodynamic activity correlated with plasma drug concentration. Moreover, chronic dosing of CCT129254 caused a dose-dependent inhibition of tumor growth in this model. Chronic once daily dosing of CCT129254 significantly inhibited tumor growth in 14 of 16 other xenograft models, including breast, prostate, lung, ovarian, kidney and colon. The highest single agent activity was seen in two breast cancer xenografts (BT474c and HCC-1954). Significant activity was also seen in the gefitinib-resistant NCI-H1975 NSCLC model with respectively activating and resistance L858R and T790M mutations in EGFR. Increased efficacy is also seen when CCT129254 is combined with the cytotoxic agents cisplatin, doxorubicin and taxotere in xenograft models. CCT129254 exemplifies an oral, well tolerated inhibitor of AKT catalysis with the potential to inhibit the growth of a wide range of solid tumors both as monotherapy and in combination with cytotoxic agents.

Citation Information: Mol Cancer Ther 2009;8(12 Suppl):C208.
Abstract B111: Targeting of calreticulin exposure for optical imaging of etoposide-induced immunogenic tumor cell death.
Authors: Jung Kyung-Ho , Paik Jin-Young , Park Jinwon , Quach Cung , Lee Eun Jeong , Choe Yearn Seong , Lee Kyung-Han
Published: June 2012

Objective: There is growing interest in reinforcing response to anticancer therapies by promoting immunogenic cell death. This mode of cell death induces surface exposure of calreticulin (CRT) in a manner that precedes apoptosis. In this study, we explored whether CRT-targeted optical imaging may have potential as a biomarker of immunogenic cell death.

Methods: We used a monoclonal antibody against human CRT (FMC 75) conjugated with a phycoerythrin label as a fluorescent imaging probe for CRT. Human CT-26 colon cancer cells were used for in vitro studies, and immunogenic cell death was induced by treatment with 25 M etoposide. Targeting of the probe to CRT exposed on the surface of etoposide-treated cells was verified by confocal microscopy and fluorescence-activated cell sorting (FACS) analysis. In vivo imaging was performed in tumor bearing Balb/C nude mice xenografted by subcutaneous injection of MDA-MB-468 human breast cancer cells. Tumors approximately 1 cm in diameter were treated with 100 μM etoposide intra-tumorally injected in 100 μl PBS. Phycoerythrin labeled anti-CRT antibody was injected into the tail vein 3 hr later. Optical imaging of fluorescent signals was performed on an IVIS® Spectrum system (Xenogen) at 4 and 21 hr post-injection using an excitation filter of 570 nm and emission filter of 620 nm.

Results: Confocal microscopy displayed specific binding of phycoerythrin anti-CRT antibodies to the surface of etoposide-treated CT-26 cancer cells. FACS analysis with the probe showed a right-shift of fluorescent signals in cells treated with etoposide. Hence, signal-positive cells were increased from 1.83 ± 0.1% to 5.81 ± 0.5% by 4 and 24 hr of treatment, respectively. In vivo optical imaging following intra-tumoral etoposide injection demonstrated clear tumor uptake of phycoerythrin anti-CRT antibody from 4 hr post-injection. Tumor contrast was substantially enhanced at 21 hr post-injection owing to reduction of background activity, which resulted in high tumor-to-muscle signal ratios.

Conclusion: This study provides the first evidence that targeted imaging of cell surface-exposed CRT may be useful for noninvasive monitoring of immunogenic cell death during anticancer therapy.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the AACR-NCI-EORTC International Conference: Molecular Targets and Cancer Therapeutics; 2011 Nov 12-16; San Francisco, CA. Philadelphia (PA): AACR; Mol Cancer Ther 2011;10(11 Suppl):Abstract nr B111.
Abstract B221: Clopidogrel augments cisplatin cytotoxicity by enhancing delivery and direct receptor mediated effects.
Authors: Pandey Ambarish , Sarangi Sasmit , Roy Bhaskar , Sengupta Poulomi , Basu Sudipta , Kopparam Jawahar , Dadwal Ushashi Chand , Sengupta Shiladitya
Published: June 2012

Clopidogrel, a well known P2Y12 (purinergic receptor) inhibitor is widely used for its role in preventing thrombosis by platelet aggregation inhibition. Tumor vasculature is critically dependent on platelet mediated hemostasis and disruption of the same can promote its leakiness. This can increase the intra-tumoral delivery of chemotherapeutic nanoformulations, which depend on the Endothelial permeability and retention (EPR) effect. Also, Expression of P2Y12 receptors has been documented in some cancer cell lines like C6 glioma, kidney carcinoma and colon carcinoma. However, its direct role in altering response to chemotherapeutics has not been studied. In this project we evaluated the role of P2Y12 receptor inhibitors (Clopidogrel and 2-Methylthioadenosine 5-Monophosphate) in potentiating the tumor cytotoxicity of cisplatin based chemotherapeutics in vitro and in vivo.

Western blot studies in 4T1 breast cancer cell lines showed a low basal expression of P2Y12 receptors with significant up regulation by cisplatin treatment in a time and dose dependent fashion. Co-administration of P2Y12 inhibitor (MeSAMP) with cisplatin resulted in significantly increased upregulation of caspase dependent apoptotic pathway when compared to cisplatin alone. This was mediated by downstream inhibition of PI3K-pAKT-mTOR pathway by the P2Y12 inhibitor. In-vitro cell proliferation assay showed that co-administration of 2-MeSAMP significantly reduced the IC-50 of cisplatin from 3.9 μM to 1.8μM.

In-vivo studies in murine syngenic 4T1 breast cancer model showed significantly decreased tumour growth and increased survival in treatment groups using combination of clopidogrel and cisplatin (free and nanoformulation forms). This was more pronounced with cisplatin nano-formulation combination therapy. Further analysis of tumour tissue using Inductive Coupled Plasma-spectrophotometry confirmed that co-treatment with clopidogrel increased the delivery of free and nanoformulation form of cisplatin to tumor tissue by 1.8 and 4 folds respectively.

Taken together our study findings suggest that clopidogrel can enhance therapeutic efficiency of cytotoxic agents by increasing delivery and by direct receptor level effects.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the AACR-NCI-EORTC International Conference: Molecular Targets and Cancer Therapeutics; 2011 Nov 12-16; San Francisco, CA. Philadelphia (PA): AACR; Mol Cancer Ther 2011;10(11 Suppl):Abstract nr B221.
Abstract B233: Identification and characterization of LY2835219: A potent oral inhibitor of the cyclin-dependent kinases 4 and 6 (CDK4/6) with broad in vivo antitumor activity.
Authors: Gelbert Lawrence M. , Cai Shufen , Lin Xi , Sanchez-Martinez Concepcion , del Prado Miriam , Lallena Maria Jose , Torres Raquel , Ajamie Rose T. , Kreklau Emiko , Wishart Graham N. , Flack Robert Steven , Neubauer Blake , Young Jamie , Chan Edward M. , Iversen Phillip , Cronier Damien , De Dios Alfonso
Published: June 2012

Dysregulation of the cell cycle, which normally regulates cell proliferation in response to mitogenic signaling and other extracellular stimuli, is a hallmark of cancer. The G1 restriction point is a primary mechanism controlling cell cycle progression and is controlled by the CDK4/6 pathway (CDK4/6-cyclin D1-Rb-CDKN2). The importance of this pathway is highlighted by inactivation of restriction point control in a majority of human tumors. Transition through the restriction point requires phosphorylation of Rb by CDK4/6, and these kinases are considered highly validated cancer drug targets. We have identified and characterized a potent and selective dual CDK4/6 inhibitor, LY2835219. Preclinical characterization was performed with the monomesylate salt (LY2835219-MsOH), which inhibits these kinases with a IC50 of 2 and 10 nM for CDK4 and CDK6, respectively. In vitro, LY2835219-MsOH is a potent inhibitor of Rb phosphorylation resulting in a G1 arrest, and its activity is specific for tumors that have functional Rb protein. In a multiplexed in vivo target inhibition assay (IVTI), LY2835219-MsOH is a potent inhibitor of Rb phosphorylation and induces complete cell cycle arrest 24 hrs after a single dose. In tumor-bearing mice, oral administration of LY2835219-MsOH inhibits tumor growth in a dose-dependent manner in colon (colo-205), glioblastoma (U87MG), acute myeloid leukemia (MV4–11), mantle cell lymphoma (Jeko-1), and lung (H460) xenografts. LY2835219-MsOH may be administered up to 56 days without adverse events or tumor outgrowth. LY2835219-MsOH enhances the in vivo activity of cytotoxic drugs, suggesting that this novel CDK4/6 inhibitor can be used in combination with these anti-neoplastic agents. In summary, we have identified an oral small molecule inhibitor of CDK4/6 that may provide therapeutic benefit to cancer patients with tumors that have functional Rb protein.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the AACR-NCI-EORTC International Conference: Molecular Targets and Cancer Therapeutics; 2011 Nov 12-16; San Francisco, CA. Philadelphia (PA): AACR; Mol Cancer Ther 2011;10(11 Suppl):Abstract nr B233.
Abstract C117: Preclinical pharmacokinetics of an antibody-drug conjugate targeting 5T4.
Authors: Leal Mauricio , Wentland Joann , Clark Tracey , Zhang Jenny , Marcek John , Khandke Kiran , DiJoseph John , Lucas Judy , Groeber Elizabeth , Han Xiaognag , Hu George , Gerber Hans-Peter , Sapra Puja
Published: June 2012

The pharmacokinetics of a novel antibody (huA1)-drug (auristatin tubulin inhibitor MMAF) conjugate, targeting 5T4-expressing cells, were obtained in female nu/nu mice after a single IV dose of 1, 3 or 10 mg/kg and in male cynomolgus monkeys from a 2-cycle exploratory toxicity study at doses of 1, 3 or 10 mg/kg/cycle. Plasma/serum samples, collected over a 336 hr period after dosing, were analyzed using an ELISA-based method for antibody and conjugate (ADC) as well as for the Auristatin payload using an LC/MS/MS method. A comparison across doses (1 − 10 mg/kg) suggests lower CL values at the higher doses (3 and 10 mg/kg) in mice. Exposure in the mouse at anti-tumor doses was within the exposure observed at nontoxic doses with the monkeys. The huA1 and conjugate toxicokinetic data in monkeys dosed with A1mcMMAF indicates that exposure (AUC) increases with increasing dose although it appears to increase in a greater than proportional manner at the higher doses. In both mice and monkeys, the elimination half-life was longer as the dose increased from 1 to 10 mg/kg (from 4.2 to 8.7 days in monkeys, respectively). Systemic exposure (as assessed by Cmax and AUC) of the released payload increased with increasing dose although exposure was very low and its pharmacokinetics appeared to be formation rate limited. The analytical data from these studies are being used to inform PKPD models, to both quantitatively characterize the system and ultimately provide dose projections for this ADC construct

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the AACR-NCI-EORTC International Conference: Molecular Targets and Cancer Therapeutics; 2011 Nov 12-16; San Francisco, CA. Philadelphia (PA): AACR; Mol Cancer Ther 2011;10(11 Suppl):Abstract nr C117.
Abstract C166: Preclinical studies of Ureidomustin, a potent water-soluble anticancer agent.
Authors: Su Tsann-Long , Chen Yi-Ren , Kakadiya Rajesh , Hsiao Pei-Wen , Lee Te-Chang , Chou Ting-Chao
Published: June 2012

Most anticancer agents have poor water-solubility and thus, have a higher risk of failure during the period of new drug discovery and development. Our previous exploration of water-soluble N-mustard-benzene conjugates has led to an anticancer drug candidate, Ureidomustin (1-[3-((2-(dimethylamino)ethyl) carbamoyl)phenyl]-3-[4- (bis(2-chloroethyl)amino)phenyl]urea hydrochloride. This agent exhibits a broad spectrum of antitumor activity. Ureidomustin shows potent therapeutic efficacy against various human solid tumor xenografts. Complete tumor remission was observed in nude mice bearing human breast carcinoma MX-1 xenograft treated with Ureidomustin. This was observed continuously for 75 days; no tumor relapse was detected and the average body-weight was recovered after ceasing of drug treatment. In addition, this water-soluble derivative exhibits potent antitumor activity against other tumor xenografts. This agent induced >95% suppression of human colon cancer HCT-116 and >99% suppression of prostate adenocarcinoma PC3 xenografts (subcutaneous implantation) in nude mice. We also found that this agent is as potent as Docetaxel (>93% suppression), but more potent than carboplatin (65% suppression) in nude mice bearing colon tumor 22Rv/HL2 (orthotropic implantation). Examination of the pathology changes of different organs removed from Ureidomustin treated mice showed that there are no apparently pathological changes between the control group and the drug treated groups. Moreover, the average body-weight of the drug treated mice recovered after stopping of drug treatment. These results indicate that Ureidomustin has very little toxicity to the host. Studies on the mechanism of action of this agent revealed that this compound is able to induce DNA interstrand cross-linking. Furthermore, the pharmacokinetic (PK) study revealed that Ureidomustin has an acceptable PK profile in rats with a half-life of 0.77 h. Rapid distribution and slow elimination were found after administrating this agent in rats. In summary, Ureidomustin is a promising candidate for clinical application and is currently undergoing further preclinical studies.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the AACR-NCI-EORTC International Conference: Molecular Targets and Cancer Therapeutics; 2011 Nov 12-16; San Francisco, CA. Philadelphia (PA): AACR; Mol Cancer Ther 2011;10(11 Suppl):Abstract nr C166.