bluuebunny/crossref_metadata_2025 huggingface dataset:
Abstract B171: Involvement of Akt/NF-κ B pathway in antitumor effect of parthenolide on glioblastoma cells.
Authors: Nakabayashi Hiromichi , Shimizu Keiji
Published: June 2012

Background: Glioblastoma is the most common and aggressive form of malignant glioma and is very difficult to treat. Controlling glioblastoma cell invasion and angiogenesis is essential to improve the prognosis of glioblastoma patients. Constitutive activation of Nuclear factor-κB (NF-κB) is crucial for tumor progression. Inhibition of NF-κB may be an important pharmacological target for the control of tumor progression. Our study aimed to evaluate the antitumour effects of parthenolide, NF-κB inhibitor, on two human glioma cell lines (U87MG, U373) and the molecular mechanisms underlying these effects.

Methods: The anti-invasive effect of parthenolide was analysed by an in vitro invasion assay. An in vitro angiogenesis assay was also performed. In vitro growth inhibition of glioma cells by parthenolide was determined by the MTT assay. The effect of parthenolide on an orthotropic implantation model using athymic mice was also evaluated.

Results: Parthenolide suppressed the proliferation of glioblastoma cells. Parthenolide also suppressed both the invasion of glioblastoma cells and tumor-induced angiogenesis. Molecular-based studies demonstrated that parthenolide suppressed gene and protein expression of angiogenic factors. Furthermore, parthenolide reduced the phosphorylation of Akt and activated mitochondrial cascade, suggesting that the antitumor effect of parthenolide may be mediated by the inhibition of the Akt signal and the activation of apoptotic proteins. An in vivo intracerebral human glioblastoma xenograft mouse model demonstrated that parthenolide suppressed neovascularity and tumor growth.

Conclusions: The results of the present study suggest that parthenolide may be a new therapeutic agent for glioblastomas.

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 B171.
Abstract B172: Dietary administration of KIOM210091 attenuates xenograft tumor growth in H460 injected nude mice.
Authors: Kim Jinhee , Park Jong Shik , Oh Se Mi , Lee Jun , Kim No Soo , Bang Ok-Sun
Published: June 2012

KIOM210091 is an ethanol extract of seeds from one of Brassicaceae plant which has been widely used to relieve cough, prevent asthma, and reduce edema as traditional medicine in Korea and China. However, little is known about its chemical property, biological activity, and the molecular mechanism.

In our preliminary experiments, KIOM210091 showed potent cytotoxic effect on all of our 30 panels of different cancer cell lines originated from different tissue origins such as lung, kidney, intestine, prostate, uterine, and lymphocytes. It is previously unknown if KIOM210091 is effective against tumors when delivered as a dietary component, so we attempted to assess the anti-tumorigenic property of KIOM210091 in vivo xenograft tumor system.

Here our date showed that KIOM210091 attenuated tumor growth in H460-injected Balb/c athymic nude mice. A group of mice (n=6) was treated with 250mg/kg/d of KIOM210091 ad lib for 5 days/week for 3 week-period. This group of mice showed inhibited xenografted H460 cell tumor growth which was comparable to those groups treated with chemotherapeutic agents, rapamycin and 5-fluorouracil. However, low dose (50mg/kg/d) treatment had little or no effect on inhibition of tumor growth. Additionally, there was no adverse effect of KIOM210091 treatment during 3 week period administration.

Bioassy-guided fractionation revealed that the cytotoxic compound of KIOM210091 was found in ethyl acetate fraction and purification of single active compound is on the way. This fraction showed enhanced cytotoxic effects on tumor cells compared to the 80% ethanol extract. Our data also suggested that KIOM210091 as well as the active fraction had an effect on inhibiting the proliferative kinases and inducing apoptosis-related proteins.

Our data demonstrated the anti-tumorigenic effect of orally administrated KIOM210091, as well as the signaling pathway modulation. This study implicates this relatively safe, natural compound as a potential therapeutic and chemopreventive agent for lung cancer.

This research was supported by Korea Institute of Oriental Medicine Grant #K11062.

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 B172.
Abstract B174: KIOM 210102 inhibits proliferation of colon cancer cells by G2/M phase arrest.
Authors: Oh Se Mi , Yi Jin Mu , Kim Jinhee , Lee Jun , Bang Ok-Sun , Kim No Soo
Published: June 2012

KIOM210102 is ethanol extract, a medicinal plant belonging to the Aristolochiaceae that has been used to cure for pain and fever traditionally in Korea, Chinese and Japan. It has also been used for treatment of inflammation, allergy and histamine-related disease. Our preliminary study showed that KIOM210102 has a potent cytotoxic effects on several cancer cell lines including HCT116, a human colon carcinoma cell.

Here we attempted to assess the anti-carcinogenic mechanism of KIOM210102 in human colon carcinoma cell line. HCT116 cells were treated with different concentrations of KIOM210102 for 48 hrs for cell viability measured by MTS assay. At a concentration of 15.8×0.68 ug/ml, KIOM 210102 inhibited 50% of proliferation of HCT116. The cell cycle distribution and apoptosis were measured by flow cytometry using Propidium Iodide staining and immunoblotting method was used to study parameters associated with apoptosis and cell proliferation.

Our data revealed that there was an acute G2/M cell cycle arrest followed by massive cell death in the cells treated with KIOM210102. The effect of KIOM210102 was mediated by increased p53 and p21waf/cip expression and decreased cyclin B. These processes were accompanied by caspase-3 activation and PARP cleavage and down regulation of the anti-apoptotic protein Bcl-2.

These results suggest that KIOM210102 has a potential for a novel herbal anti-cancer therapeutics.

This research was supported by a grant from the Korea Institute of Oriental Medicine (KIOM, K11061).

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 B174.
Abstract B179: Mechanism of antitumor activity of BET inhibitors in models of lymphomas and leukemia.
Authors: Sandy Peter , Mertz Jennifer , Conery Andy , Bryant Barbara , Biagini Linda , Balasubramanian Srividya , Lora Jose , Sims Robert , Bergeron Louise
Published: June 2012

Proteins of the BET family bind to acetylated histones and promote gene expression by recruiting transcriptional activators. We developed BET inhibitors and demonstrated a strong association between biochemical inhibition of BET-chromatin binding, MYC suppression and reduced proliferation in hematopoietic cancer cells. We assessed the gene loci affected by BET inhibition by integrating ChipSeq and gene expression profiling, and identified genes that are directly regulated by BRD4 binding, most notably MYC, or genes that are targets of MYC. BET inhibition resulted in robust suppression of MYC expression in tumor xenograft models. Moreover, based on the PK/PD relationships established for these compounds we designed dosing regimens that resulted in significant anti-tumor efficacy in xenograft models of Burkitt's lymphoma and acute leukemia. Compound doses and schedules resulting in sustained MYC suppression were most effective in inhibiting tumor growth and were well tolerated.

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 B179.
Abstract B180: Novel candidate tumor markers identified by a high-throughput “immuno-reverse-proteomics” approach.
Authors: Pileri Piero , Pierleoni Andrea , Campagnoli Susanna , Grandi Alberto , Parri Matteo , Nogarotto Renzo , De Camilli Elisa , Abrignani Sergio , Viale Giuseppe , Sarmientos Paolo , Grandi Guido , Grifantini Renata Maria
Published: June 2012

Cancer biomarker discovery is an extremely active research field in both academia and pharmaceutical companies. Here we present a group of candidate tumor markers identified by a high-throughput immunohistochemistry approach based on the use of a library of 1600 mouse antibodies raised against marginally-characterized human proteins. Tissue microarray (TMA) representing breast, lung colon ovary and prostate cancers were used to identify novel tumor markers. Eighty-nine proteins were found over-expressed in one or more of the five tumors under analysis. The validation process is still in progress and so far has been undertaken on twenty-six of the eighty-nine hits. They are confirmed over-expressed in TMAs carrying 50 tumor samples for each tumor type and, in particular, nineteen proteins were found expressed in one or more tumors with frequencies ranging from 20% to 96%. Interestingly, some of the proteins are simultaneously over-expressed in specific patients' groups, thus opening the possibility of tissue diagnostic/prognostic/predictive applications based on combinatorial markers. Moreover, in vitro characterization studies indicated that some markers play a pivotal role in tumor-related cell processes like cell proliferation (EXN32; EXN36; EXN7), invasiveness (EXN32; EXN36; EXN7; EXN4), clonal growth (EXN1) and pro-angiogenesis (EXN11). A panel of monoclonal antibodies highly specific the biomarkers is already available and proved to specifically detect the markers in tumor cells derived from surgical resections. The newly identified candidate markers are new tools for the development of specific drug therapies and diagnostic products.

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 B180.
Abstract B183: Nkd2 expression and survival in lung adenocarcinoma.
Authors: Lui Natalie , Sheng Qing , Li Hui , Do Hanh , Jablons David , He Biao
Published: June 2012

Objectives: Lung cancer is the leading cause of cancer mortality in the United States and worldwide, and Wnt signaling pathway abnormalities have been implicated in its development. We planned to study the expression of Naked cuticle 2 (Nkd2), a Wnt signaling pathway antagonist, in lung adenocarcinoma tissue specimens.

Methods: Two hundred patients with lung adenocarcinoma underwent surgical resection. Tumor and adjacent normal specimens were collected at the time of the procedure and stored in liquid nitrogen until analysis. Clinical data, including patient age, sex, vital status, smoking status, as well as tumor histology and stage, were obtained by review of electronic medical records. RNA was extracted using the Qiagen RNeasy Mini Kit, and cDNA was synthesized using the Bio-Rad iScript Kit. Nkd2 expression was measured using a microarray in 110 patients and quantitative polymerase chain reaction (qPCR) in 90 patients. We looked for differences in Nkd2 expression between patients of different sex, histologic subtype, or vital status; and among patients with different smoking status or stage. We described the distribution of Nkd2 expression in both the microarray and qPCR cohorts. We analyzed the relation between Nkd2 expression and survival using the Kaplan-Meier method and a Cox proportional hazards model.

Results: There was no difference in Nkd2 expression between patients of different sex, histologic subtype, or vital status; nor among patients with different smoking status or stage. Nkd2 expression in the tumor was upregulated in the microarray cohort, but downregulated in the qpCR cohort, compared to the adjacent normal. In the microarray cohort, Nkd2 expression was not significantly related to survival (p=0.71). In the qPCR cohort, after adjusting for age, sex, smoking status, bronchoalveolar carcinoma status, and stage, lower Nkd2 expression was significantly associated with longer survival (p=0.03). Stage was the only other significant predictor of survival (Wald test, p = 0.0002).

Conclusion: In one cohort in our study, lower Nkd2 expression was significantly associated with longer survival. It is unclear why lower expression of Wnt signaling pathway antagonist would be associated with longer survival, when higher Wnt signaling has been associated with carcinogenesis. One hypothesis is that there is a negative feedback mechanism, in which upregulation of Wnt signaling leads to upregulation of Nkd2. Molecular markers have a growing role in cancer research, and further studies on Nkd2 may lead to new diagnostic and therapeutic applications.

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 B183.
Abstract B196: Evaluation of the ubiquitin activating enzyme (UBA1) as a therapeutic target via inducible RNA interference in human tumor xenografts.
Authors: Li Zhi , Traore Tary , He Xingyue , Yang Yu , Li Ping , Bence Neil , Manfredi Mark , Smith Peter G. , Pulukuri Sai M.
Published: June 2012

The successful transition of the Nedd8-activating enzyme inhibitor, MLN4924, into clinical trials has greatly increased optimism for the application of other E1-activating enzyme inhibitor therapies in cancer. UBA1 is an essential E1 enzyme that controls the first step in the activation of ubiquitin. Ubiquitin is a 9 KDa protein that is involved in multiple cellular processes through conjugation to a large range of target proteins. Several of these processes are important in cancer including ubiquitin-dependent protein turnover, cell cycle progression, apoptosis and the DNA damage response. Thus, inhibiting UBA1 with small molecule inhibitors may prove to be a viable anticancer strategy. To validate UBA1 as an oncology target we utilized a lentiviral vector-mediated inducible knockdown of UBA1 by a microRNA-based shRNA (shRNAmir) in cells and xenografts derived from human cancer cells. Our data show that shRNAmir-mediated knockdown of UBA1 is tightly regulated by the inducer doxycycline in a concentration- and time-dependent manner in HCT-116 cells. Furthermore, UBA1 expression is restored upon withdrawal of the inducing agent, which coincides with decreased shRNAmir expression as marked by turboRFP. The shRNAmir-mediated depletion of UBA1 in cells resulted in reduced abundance of ubiquitin conjugates and decreased proliferation of HCT-116 cells, ultimately resulting in apoptosis. Next, we established inducible shRNAmir HCT-116 xenograft models in nude mice to examine the in vivo efficacy of inhibiting UBA1. Our results showed knockdown of UBA1 protein levels, decreased abundance of ubiquitin conjugates and apoptosis in vivo following doxycycline administration to mice. The effects of UBA1 knockdown and inhibition of ubiquitin conjugation resulted in tumor xenograft regressions in all mice. Withdrawal of doxycycline treatment resulted in regrowth of tumors with concomitant recovery of UBA1 levels and detectable ubiquitin conjugates in tumor xenografts. This study demonstrates that UBA1 knockdown effectively inhibits tumor growth and mediates tumor regression in a human xenograft model, implicating UBA1 as a novel therapeutic target for cancer.

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 B196.
Abstract B198: Integrated genomic analysis of breast cancer CNS metastasis to the CNS.
Authors: Salhia Bodour , Ross Juli , Paquette Kim , Fowler Aaron , Van Cott Courtney , Metpally Raghu , Baker Angela , Nasser Sara , Kiefer Jeff , Ramanathan Ramesh , Resau James , Berens Michael , Carpten John , Tran Nhan
Published: June 2012

With improvements in systemic therapies, the brain is becoming an increasingly common sanctuary site of metastatic disease in patients with breast cancer. There have been limited improvements in the treatment of brain metastases and current treatment paradigms focus on resection and radiation therapy. As cancer dissemination to the brain currently leads to fatal outcomes developing new therapeutic approaches is paramount. We performed a deep integrated genomic and epigenomic analysis to catalogue the compendium of common and rare events that underlie breast cancer CNS metastasis. Our samples represent breast cancer CNS metastasis, primary breast cancer, non-neoplastic brain and non-neoplastic breast tissue. We performed copy number analysis using array-based comparative genomic hybridization (aCGH, Agilent SurePrint G3 Human High-Resolution Discovery Microarray Kit 1×1M platform); gene expression profiling (GEP) (Agilent, Human GE 4×44 v2 Microarray platform); and DNA methylation analysis (Illumina, HumanMethylation 27 BeadChip). Here we report frequent large chromosomal gains in 1q, 8q, 10p, 21q, and 22q. Frequent large chromosomal deletions were also seen on 8p, and 17p. Focal gains and losses occurred frequently on chromosomes 14, 17 and 22. The PAM50 breast cancer intrinsic classifier was used to classify CNS metastasis tumors. The most common molecular subtypes identified were Luminal B, Her2+/ER negative and Basal-like tumors. Although breast CNS metastasis tumors retained features of their original intrinsic subtype, additional changes were acquired. In addition, DNA methylation analysis of the most variable methylated genes demonstrated epigenetic similarities among the individual molecular subtypes and that overall CNS metastasis is associated with hypermethylation. On average 108 genes had alterations by copy number, gene expression and DNA methylation. Among these are candidate tumor suppressor genes SERPINF1 and SFRP1. Pathway enrichment using Ingenuity Systems revealed a large number of enrichment maps concentrated around cell cycle and G2/M transition. This enrichment contained important cancer genes such AURKA, AURKB and FOXM1. Current studies are ongoing to validate novel candidates genes using cross platform and independent sample cohorts. Characterization of such candidates is expected to lead to novel therapeutic approaches and an enhanced understanding of the biology mediating breast CNS metastasis.

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 B198.
Abstract B21: The difference in the role of PI3K/Akt/mTOR pathway between oropharyngeal squamous cell carcinoma and oral cavity squamous cell carcinoma.
Authors: Won Hye Sung , Hong Ji Hyung , Jeon Eun Kyoung , Ko Yoon Ho , Chun Sang Hoon , Jung Chan-Kwon , Kang Jin-Hyoung
Published: June 2012

Recently, there is growing evidence to support that oral cavity and oropharyngeal squamous cell carcinoma are two distinct diseases with different etiology. The aim of this study was to evaluate the expression of EGFR, PI3K/Akt/mTOR pathway, and PTEN in oral cavity and oropharyngeal cancers, and to investigate their clinical significance as prognostic markers.

One hundred twenty-one patients who underwent curative surgery for oral cavity or oropharyngeal squamous cell carcinoma in Seoul St. Mary's Hospital between January 1995 and September 2009 were evaluated. The level of protein expression of EGFR, PIK3CA, pAkt, mTOR, and PTEN was assessed by immunohistochemistry. In situ hybridization was used for assessment of human papillomaviruses (HPV).

Nineteen of 61 patients with oropharyngeal cancer showed HPV-positive tumors, and 2 of 60 patients with oral cavity cancer showed HPV-positive tumors. EGFR and pAkt expression were significantly higher in oray cavity cancer than in oropharyngeal cancer. Loss of PTEN was significantly higher in oral cavity cancer than in oropharyngeal cancer. There were no significant differences in PIK3CA, mTOR, and p53 expressions. HPV-negative tumors overexpressed more EGFR and pAkt than HPV-positive tumors. Loss of PTEN expression was more frequent in HPV-negative tumors than in HPV-positive tumors. In multivariate cox regression analysis, pAkt expression showed a significant impact on relapse-free survival. There was a significantly negative correlation between PTEN and pAkt expression, and positive correlation between pAkt and mTOR expression.

We concluded that there were differences in expression of EGFR, pAkt, and PTEN between oropharyngeal and oral cavity cancer. It was attributed to etiologic role of human papillomaviruses in oropharyngeal cancer. The expression of pAkt may be a prognostic marker for relapse-free survival in oropharyngeal cancer.

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 B21.
Abstract B220: Artificially inducing protein-membrane anchorage: Introducing a new therapeutic modality.
Authors: Avadisian Miriam , Fletcher Steven , Liu Baoxu , Zhao Wei , Yue Peibin , Turkson James , Gradinaru Claudiu , Gunning Patrick
Published: June 2012

We aim to develop an innovative therapeutic modality of inhibiting aberrant protein function through suppression of activation and/or nuclear translocation. Nature has developed prenylation, a post-translational modification that covalently attaches a hydrophobic prenyl group to a protein to facilitate protein-membrane association to the plasma membrane. We hypothesize that mimicking Nature by artificially inducing protein-membrane anchorage through the use of a rationally designed protein-membrane anchor (PMA), we can simultaneously inhibit the activation and nuclear translocation of oncogenic proteins. Our aim is to explore the therapeutic potential of the protein-membrane anchor and potentially develop a novel drug modality that can be utilized by cancer patients.

Our proof-of-concept PMA was design to target signal transducer and activator of transcription 3 (Stat3) protein.

Constitutively-active Stat3 directly contributes to the progression of cancer and is present in numerous human cancers. A number of studies have shown that down-regulation of this oncogene via iRNA knockdown induces cellular apoptosis. Thus, Stat3 is an attractive target for the development of potent anti-cancer therapeutics for cancer.

Our proto-type PMA 1 was composed of two binding modules: a recognition motif to bind the protein and an anchor to sequester the protein complex to the membrane. The PMA was comprised of a potent Stat3 recognition sequence GpYLPQTV-NH2 covalently attached to a cholesterol membrane anchor.

We tested the ability of our PMA to anchor Stat3 to the cell membrane in MDA-MB-231 breast cancer cells which are known to have constitutively-active Stat3. We immunostained these cells with membrane stain FM-4–64 (red), anti-Stat3 antibody (green) and DAPI (nucleus, blue). In the absence of PMA 1, there was strong Stat3 nuclear presence. Most excitingly, in the presence of 25 μM concentration PMA 1, we observed complete sequestration of Stat3 to the cell membrane through PMA-Stat3 association. Currently, we are designing and synthesizing more drug-like, nonphosphorylated PMAs that are less prone to metabolic degradation. We will conduct further studies to determine the biochemical and biological utility of these PMAs.

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 B220.
Abstract B238: Novel imidazo[1,2-a]pyridines as inhibitors of the IGF-1R tyrosine kinase.
Authors: Ducray Richard , Simpson Iain , Jones Clifford D. , Curwen Jon , Trigwell Catherine B. , Veldman-Jones Margaret H. , Fitzek Martina , Walker Graeme E. , Ward Lara T. , Hudson Kevin , Pass Martin
Published: June 2012

The Insulin-like Growth Factor-1 Receptor (IGF-1R) is a receptor tyrosine kinase which plays an important role in cancer by promoting proliferation and survival through activation of the Ras/Raf/MAPK and PI3K/Akt signaling pathways. Deregulation of the IGF-1R axis has been reported in a variety of solid cancers and occurs by overexpression of either the receptor or its ligands (IGF-1 and IGF-2) or by down-regulation of IGF binding proteins (in particular IGFBP3). Therapeutic approaches to inhibit IGF-1R signaling include antibodies targeting the receptor and small molecule inhibitors of the tyrosine kinase. The latter strategy offers a potential advantage by simultaneously inhibiting the closely related Insulin Receptor A (IR-A) tyrosine kinase. Indeed, IR-A can drive tumor growth in some cancer cell lines and has been suggested has a potential escape mechanism for IGF-1R inhibition.

Following a cell based high throughput screening, we have identified a series of imidazo[1,2-a]pyridines inhibiting the IGF-1R kinase. Although hit compounds carried a significant activity against CDK2, modifications of the aniline part has led to more potent and selective inhibitors. We selected 1-[4-[4-[(5-chloro-4-imidazo[1,2-a]pyridin-3-yl-pyrimidin-2-yl)amino]-3-methoxy-phenyl]piperazin-1-yl]ethanone (5) as a lead compound having good pharmacokinetics in pre-clinical species. Compound (5) displays a dual inhibition of IGF-1R and the insulin receptor tyrosine kinase as measured in biochemical assays as well as in cellular auto-phosphorylation assays. Structure-activity relationship around (5) is described for IGF-1R inhibition as well as for the hERG ion channel.

Compound (5) has been assessed in an in vivo efficacy model based on the NIH 3T3 fibroblast cell line transfected to express human IGF-1R and IGF1 ligand. In contrast to the non-transfected parent line, this cell line rapidly grows as a sub-cutaneous xenograft in nude mouse, thus providing a suitable model to measure anti-IGF-1R pharmacology by tumor growth inhibition. The high expression of IGF-1R also enables the generation of good quality PD data using receptor phosphorylation as an endpoint.

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 B238.
Abstract B239: Inhibition of myeloproliferative neoplasms by combinations of JAK2 and PI3K inhibitors.
Authors: Choong Meng Ling , Pecquet Christian , Tai Shi Jing , Yong Jacklyn Wei Yan , Pendharkar Vishal , Wang SiFang , Defour Jean-Philippe , Diaconu Carmen C. , Sangthongpitag Kanda , Constantinescu Stefan N. , Lee May Ann
Published: June 2012

This study focuses on three main myeloproliferative neoplasms, namely, polycythaemia vera, essential thrombocytosis, and primary myelofibrosis. The main pathological causes of these three diseases are a mutation in the JAK2 protein or a mutation in the thrombopoietin receptor that arises in the hematopoietic stem/progenitor cells. Both type of mutations lead to constitutive activation of the JAK2 signaling pathways. Current JAK2 inhibitors in clinical trials are not expected to be selective and specific enough to suppress the multiple signaling pathways activated by the aberrant JAK2 signaling. Hence, we are seeking a combination treatment using a specific JAK2 inhibitor with another specific kinase inhibitor to inhibit the multiple signaling pathways activated by the constitutively active JAK2. Mouse Ba/F3 cells were engineered to express either JAK2 WT, or JAK2 V617F, or TpoR W515L, or TpoR JAK2 WT, or TpoR JAK2 V617F, or Bcr-abl. The effect of JAK2 inhibitors in combination with a panel of kinase inhibitors in an 8×8 constant ratio drug combination design were used to test for the inhibition of cell viability in the cell models. Calculation of drug synergism was carried out using the Chou-Talalay method. We found that JAK2 inhibitors synergized with PI3K inhibitors. The JAK2-PI3K inhibitors combination was specific for JAK2 signaling as survival of Ba/F3 cells expressing Bcr-abl was unaffected by this combination treatment. Balb/c mice inoculated with Ba/F3 cells expressing TpoR JAK2 V617F were found to have increased spleen weight. Our combination treatment could drastically reduce spleen weight compared to treatment with individual compound alone. The combination treatment also resulted in significant survival benefit in Balb/c mice inoculated with Ba/F3 cells expressing TpoR JAK2 V617F compared to untreated mice or mice given either compound alone.

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 B239.
Abstract B241: Targeting the mitotic checkpoint with NMS-P153, a novel MPS1 kinase inhibitor.
Authors: Colombo Riccardo , Caldarelli Marina , Giorgini Maria Laura , Sola Francesco , Cappella Paolo , Perrera Claudia , Avanzi Nilla , Berthrand Jay A. , Pesenti Enrico , Isacchi Antonella , Donati Daniele , Moll Jurgen , Galvani Arturo
Published: June 2012

Aneuploidy is one of the major hallmarks of cancer and is a unique property of tumoral cells. Thus, targeting the molecular mechanisms required for the growth of aneuploid cells might be expected to yield more cancer cell specific therapeutic approaches. The Spindle Assembly Checkpoint (SAC) is a mitotic mechanism required for proper chromosomal segregation, ensuring that cells do not divide until all sister chromatids correctly align to the metaphase plate. It is a complex machinery tightly regulated by a number of members which are rarely mutated in tumors. Rather, checkpoint components have been found to be upregulated in aneuploid tumor cells, suggesting a potential tumor “addiction” to SAC functions. MPS1 kinase, (also known as TTK) is an essential SAC enzyme aberrantly overexpressed in a wide range of tumors and necessary for tumor cell proliferation. We previously reported the identification of NMS-P715 as a selective and orally bioavailable MPS1 inhibitor capable of promoting mitotic acceleration, thereby causing aneuploidy and cancer cell death both in vitro and in vivo. Supported by the proof that MPS1 small-molecule inhibitors display the expected mechanism of action and promote tumor growth inhibition in preclinical cancer models, further medicinal chemistry efforts were undertaken and led to the discovery of NMS-P153 as an early candidate product.

NMS-P153 is highly selective, and compared to NMS-P715, shows improved in vitro enzymatic potency on MPS1 (IC50 of 3 nM), 10-fold increased mitotic override activity, longer dissociation half-life and better mouse and rat PK parameters, leading to impressive tumor growth inhibition associated with tumor regression in efficacy studies.

Proliferation data performed on a large panel of cell lines (>100) have been obtained and will be essential to decipher the most sensitive genetic backgrounds to chemical abrogation of MPS1 function. In addition, single and repeated toxicology studies in rat are being carried out to establish therapeutic safety margins. Inhibiting the spindle assembly checkpoint by targeting MPS1 kinase could represent a promising new approach to cancer 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 B241.
Abstract B28: Organic anion transporting polypeptide 1B3 as a novel biomarker for hypoxia in prostate cancer.
Authors: Pressler Heather M. , Pisle Stephen , Sissung Tristan M. , Cropp Cheryl D. , Price Douglas K. , Figg William D.
Published: June 2012

The organic anion transporting polypeptide 1B3 (OATP1B3) is aberrantly expressed in prostate cancer. We showed that OATP1B3 expression correlated to Gleason score in primary prostate cancer samples. As a transporter, OATP1B3 functions to influx both endogenous small molecules and xenobiotics. We also demonstrated that decreased survival and decreased progression in patients with prostate cancer was associated with a polymorphism in SLCO1B3, the gene encoding OATP1B3. However, OATP1B3 has not been validated as a clinical biomarker and the cause of expression in cancer is unknown. The purpose of this study was to identify a molecular regulation that explains OATP1B3 expression in cancer. In this study, we show that hypoxia increases the transcriptional and translational expression of OATP1B3 in cancer, that hypoxia-inducible factor 1-alpha (HIF1-alpha) binds putative hypoxia response elements in the SLCO1B3 promoter region by chromatin immunoprecipitation, and show co-localization of hypoxia and OATP1B3 by immunohistochemistry in clinical tissue samples. Additionally, cooperation between androgen- and hypoxia-signaling pathways explains the increased expression of OATP1B3 in prostate cancer xenografts under castration conditions. These data provide a foundation for the use of OATP1B3 as a biomarker of cancerous disease.

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 B28.
Abstract B3: Allosteric MEK inhibitor BAY 86-9766 acts synergistically with sorafenib to inhibit tumor growth, angiogenesis, and tumor cell survival in ectopic patient-derived xenograft models of human hepatocellular carcinoma.
Authors: Ong Richard , Puehler Florian , Scholz Arne , Chung Alex , Soo Khee Chee , Hung Huynh T.
Published: June 2012

Background: Hepatocellular carcinoma (HCC) is a particularly vascularized solid tumor and the Raf/MEK/ERK pathway is activated in HCC. Sorafenib has been shown to prolong survival of patients with advanced HCC. BAY 86-9766 (RDEA119) is an orally available, potent, allosteric MEK inhibitor currently in Phase I/II trials. A combination therapy of MEK inhibitor BAY 86-9766 with sorafenib might enhance the therapeutic efficacy of sorafenib in HCC. This study aims to investigate the potential of such a combined therapeutic approach in preclinical models of HCC.

Methods: We treated 15 patient-derived HCC xenograft models (Asian origin) with i) sorafenib, ii) BAY 86-9766, and iii) sorafenib plus BAY 86-9766. Western blotting was employed to determine pharmacodynamic changes in biomarkers relevant to both angiogenesis and MEK signaling. Apoptosis, microvessel density, and cell proliferation were analyzed by immunohistochemistry.

Results: We report here that sorafenib significantly suppressed tumor growth with the T/C ratios ranging from 0.25 to 0.6, angiogenesis and cell proliferation with modest elevation of pERK Thr202/Tyr204. BAY 86-9766 treatment caused a modest tumor growth inhibition (ranging from 30 to 60%) and dephosphorylation of ERK, Bim and p90RSK. The addition of BAY 86-9766 to sorafenib significantly augmented the antitumor activity of sorafenib in 15 models of HCC. The T/C ratios for the sorafenib/BAY 86-9766 ranged from 0.03 to 0.2. Such inhibition led to further increase in Bad, Bim and apoptosis. Profound inhibition of cell proliferation, angiogenesis and inactivation of p90RSK and mTOR targets were also observed in the combined therapy.

Conclusion: We show that sorafenib/BAY 86-9766 treatment is considerably more effective than either single agents in suppressing tumor growth, angiogenesis, cell proliferation and cell survival. Our findings underscore the potential of sorafenib/BAY 86-9766 combination in the treatment of HCC.

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 B3.
Abstract B41: Overcoming chemo/radioresistance of castration-resistant prostate cancer via modulating autophagy.
Authors: Xu Liang
Published: June 2012

Chemo/radioresistance markedly impair the efficacy of prostate cancer therapy. Anti-apoptotic Bcl-2 family proteins such as Bcl-xL, Bcl-2 and Mcl-1 are overexpressed in castration-resistant prostate cancer (CRPC) and contribute to prostate tumor initiation, progression and resistance to radiotherapy. A natural BH3-mimetic, small molecule inhibitor of Bcl-2/Bcl-xL/Mcl-1, (−)-gossypol, shows promise in multiple Phase I-II clinical trials for human prostate cancer. We have recently shown that (−)-gossypol preferentially induces autophagy in CRPC cells that have high levels of Bcl-2/Bcl-xL/Mcl-1 and are resistant to apoptosis, both in vitro and in vivo, but not in androgen-dependent cells with low Bcl-2 and sensitive to apoptosis (Cell Death Diff 2011, 18(1):60–71). Our results demonstrate for the first time that (−)-gossypol can interrupt the interaction between Beclin1 and Bcl-2/Bcl-xL at the endoplasmic reticulum, thus releasing the BH3-only pro-autophagic protein Beclin1, which in turn triggers the autophagic cascade. (−)-Gossypol-induced autophagy is Beclin1- and Atg5-dependent, together with Bcl-2 downregulation and Beclin1 upregulation. (−)-Gossypol increased autophagic cell death induced by either X-ray radiation or chemotherapeutics in the CRPC cells. Orally administered (−)-gossypol achieved a much greater efficacy with long-term tumor regression when used in combination with ionizing radiation or first-line chemotherapy. We have also explored a series of gossypol derivatives and identified two novel BH3-mimetic lead compounds that are more potent than the parental compound in inducing autophagic cell death in CRPC. Taken together, (−)-gossypol significantly enhances the anti-tumor activity of chemo/radiotherapy in vitro and in vivo, and represents a promising new regime for treatment of castration-resistant human prostate cancer with overexpression of Bcl-2. Our data provide new insights into the mode of cell death induced by Bcl-2 inhibitors, which would facilitate the rational design of clinical trials by selecting patients who are most likely to benefit from the Bcl-2-targeted molecular 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 B41.
Abstract B59: Polycomb group ring finger protein plays a role in gamma ionizing radiation-induced DNA damage response in MCF7 cell line.
Authors: Lee Chang Se , Kim Karam , Yoon Young A , Hwang Chang Sun , Jang Sungjae , Park In-chul , An Sungkwan , Jin Young Woo , Kim Tae Jin , Lee Jae Ho
Published: June 2012

Polycomb group (PcG) gene product is a family of proteins that were accumulated with complexes in nuclear and plays an important role in development and maintaining stem cell population of hematopoietic and neuronal cell lineages. PcG complexes can regulate the transcriptional activity of many genes by epigenetic silencing involved in embryogenesis. Recent reports showed the overexpressions of PcG proteins were correlated with the severity of many cancers. To investigate the underlying mechanisms of PcG ubiquitin ligase (PCGF1-6) on DNA damage response after exposure to gamma ionizing radiation, we generated the stable knockdown MCF7 breast cancer cell lines capable of silencing each of PcG ubiquitin ligase genes. Cell survival and proliferation analysis in stable PcG ubiquitin ligase knockdown MCF7 cell lines was compared to the analysis in control MCF7 cell lines after treatment of gamma ionizing radiation using MTT and colony forming assay. Furthermore, we found that loss of several PcG ubiquitin ligases sensitizes MCF7 cell lines to gamma ionizing radiation-mediated growth inhibition. We further demonstrate that several PCGF PcG ubiquitin ligases are localized at γ-H2AX foci after treatment of gamma ionizing radiation. These results demonstrate that PCGF family can coordinately regulate the cell resistance mechanism in DNA damage response.

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 B59.
Abstract B61: Targeting the ATM pathway through histone deacetylase inhibition.
Authors: Thurn K. Ted E. , Thomas Scott , Raha Paromita , Munster Pamela N.
Published: June 2012

Ataxia telangiectasia mutated (ATM) is a major regulator of DNA double strand break repair. It is a member of the phosphatidyl inositol 3' kinase-related (PIKK) family of serine/threonine kinases, whose activation is promoted by the MRN complex (MRE11, Rad50, NBS1) in the presence of DNA damage. Mutations in ATM lead to increased susceptibility to developing lymphoid and breast cancers. Cells with mutated ATM often demonstrate enhanced chromatin decondensation, increased genomic instability, and greater sensitivity to DNA damaging agents. Interestingly, pharmacological inhibition of histone deacetylases (HDACs) often results in many of these same traits. Inhibitors of histone deacetylases (HDACs) have been demonstrated to potentiate the effects of various DNA damaging therapies through regulation of chromatin structure and down-regulating DNA repair. The contribution of HDAC proteins to DNA repair have yet to be fully understood. Therefore, we examined the effect of HDACs on DNA damage signaling and repair.

Treatment of cancer cells with HDAC inhibitors led to a significant decrease in ATM mRNA and protein levels. This caused attenuated induction of the DNA damage response signaling downstream of ATM in the presence of DNA damage. HDAC inhibition led ultimately to reduced DNA repair after therapeutic induction of DNA damage, and decreased overall cell survival. Select depletion of HDAC1 and HDAC2 was sufficient to reduce ATM expression, and potentiate the effects of DNA damaging agents. These results were recapitulated in vivo and demonstrated that pharmacological inhibition of HDACs significantly reduced the activation of the ATM pathway in response to chemotherapeutic induction of DNA damage. Specifically, HDAC inhibition significantly reduced the levels of ATM and down-stream stabilized p53 after treatment of tumors with therapeutic DNA damaging agents. Taken together, these results suggest a contribution of histone deacetylase enzymes in regulating the ATM pathway in response to DNA damage.

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 B61.
Abstract B7: Activation of PPARα suppresses HIF-1α signaling in human cancer cells.
Authors: Zhou Jundong , Zhang Shuyu , Avery Jori E. , Wu Jinchang , Ding Wei-Qun
Published: June 2012

Background: Hypoxia inducible factor-1α (HIF-1α) is a therapeutic target in solid tumors because it activates transcription of the genes associated with tumor growth, angiogenesis and chemo/radio-resistance. Activation of PPARα has been demonstrated to inhibit tumor growth and angiogenesis, yet the mechanisms behind these actions remain obscure. The present study examined the effects of PPARα activation on HIF-1α mediated signaling in human cancer cells.

Methods: The human cancer lines MCF-7 (breast) and A2780 (ovarian), and human endothelial line, EA.hy926 were used as model systems for this study. Hypoxia was achieved via a hypoxia chamber. The HRE-luciferase reporter gene and Western blot were applied to analyze HIF-1α expression and activity. RT-PCR and co-immunoprecipitation were performed to understand the molecular mechanisms of PPARα-mediated suppression of HIF-1α signaling. The level of vascular endothelial growth factor (VEGF) in cultured medium was determined using an ELISA, and in vitro angiogenesis was evaluated using the tube formation assay.

Results: Incubation of cancer cells with 1 % oxygen for 16 hours significantly induced HIF-1α expression and activity. Treatment of the cells with PPARα agonists, but not a PPARγ agonist, prior to hypoxia diminished hypoxia-induced HIF-1α expression and activity. Consistently, a PPARα antagonist attenuated PPARα agonist-induced suppression of HIF-1α signaling. Over-expression of an HA-tagged HIF-1α and HIF-1α-P402/P564A mutant protein demonstrated that activation of PPARα promotes HIF-1 α degradation in our model system. This was further confirmed by the use of MG-132, a proteasome inhibitor, which reversed PPARα-mediated suppression of the HIF-1α signaling, and by RT-PCR analysis of HIF-1α mRNA, which was unchanged by PPARα activation. Using the co-immunoprecipitation technique, we found that activation of PPARα enhances the binding of hydroxylated HIF-1α to the Von Hippel-Lindau tumor suppressor, a protein known to mediate HIF-1α degradation through the ubiquitin-proteasome pathway. Consequential to the PPARα-mediated suppression of HIF-1α signaling, vascular endothelial growth factor secretion from cancer cells was found to be significantly reduced, and the tube formation by EA.hy926 cells was dramatically impaired.

Summary: Activation of PPARα suppresses HIF-1α expression and activity by promoting HIF-1α degradation in cancer cells. PPARα agonists are potential anticancer agents that inhibit tumor angiogenesis via the suppression of HIF-1α signaling.

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 B7.