bluuebunny/crossref_metadata_2025 huggingface dataset:
Abstract A38: In vitro and in vivo characterization of a novel NEK2 inhibitor MBM5 for the treatment of gastrointestinal cancer
Authors: Fang Yanfen , Zhang Xiongwen , Hu Wenhao , Kong Yannan , Wang Hong , Zhu Mengli
Published: May 2016

NEK2 is a conserved mitotic regulator critical for centrosome splitting and correct chromosome segregation. Aberrant expression of NEK2 has been found in a variety of human cancers, making it an attractive molecular target for the design of novel anticancer therapeutics. Here we report the discovery of a novel small molecule NEK2 inhibitor, MBM5, for the treatment of gastrointestinal cancer cells. A series of compounds have been synthesized to determine their potency against NEK2. Through in vitro kinase assay, we found that compound MBM5 exhibited a significant inhibitory effect on the kinase activity of NEK2. MBM5 also demonstrated strong inhibition on proliferation of a broad spectrum of tumor cells, especially gastrointestinal cancer cells (IC50<1 μM). Treating cells with MBM5 triggered a significant accumulation of cells at G2/M phase and a modest accumulation of cells with >4N DNA content. By releasing cells from the G1/S boundary, we found that the progression from G2/M to G1 phases were completely abrogated in the presence of MBM5. In consistence, we further observed that MBM5 induced chromosomal misalignment in metaphase and slightly increased the level of multinucleated cells, confirming the perturbed mitotic progression. And these was correlated with MBM5-inhibited phosphorylation of Hec1 and Histone 3. Over time, the accumulation of chromosomal abnormalities led to apoptosis, as evidenced by the increased population of Annexin-V/PI positive cells, the up-regulated expression of cleaved-caspase 3 and the cleavage of PARP. In vivo daily treatment with MBM5 (ip, 20 mg/kg, 3 weeks) significantly inhibited the growth of MGC-803 gastric tumor and HCT-116 colonal tumor xenografts. Altogether, this study demonstrates that MBM5 interfered with NEK2 functions both in cells and tumor xenografts, thus showing its potential in anti-cancer treatment regimens.

Citation Format: Yanfen Fang, Xiongwen Zhang, Wenhao Hu, Yannan Kong, Hong Wang, Mengli Zhu. In vitro and in vivo characterization of a novel NEK2 inhibitor MBM5 for the treatment of gastrointestinal cancer. [abstract]. In: Proceedings of the AACR-NCI-EORTC International Conference: Molecular Targets and Cancer Therapeutics; 2015 Nov 5-9; Boston, MA. Philadelphia (PA): AACR; Mol Cancer Ther 2015;14(12 Suppl 2):Abstract nr A38.
Abstract A59: Exploration of Tid1 and mitochondrial EGFR in non-small cell lung carcinoma tumorgenesis
Authors: Chen Chi-Yuan , Lin Yu-Han , Pi Wen-Chieh
Published: May 2016

The epidermal growth factor receptor (EGFR) over activity has been associated with a number of cancers, including non-small cell lung carcinoma (NSCLC). Known the critical role of EGFR in NSCLC and the recent findings that mitochondrial accumulation of EGFR could contribute to tumorigenesis, several interesting oncology questions related with the intracellular trafficking of EGFR to mitochondria need to be addressed. Tid1 (also known a mitochondrial Hsp40) has 2 isoforms, Tid1-L and Tid1-S, which may function differently. Since we have recently shown that Tid1 can interact with EGFR and that Tid1 is a mitochondrial protein, we postulate that Tid1 may participate in the mitochondrial localization of EGFR and play a role in NSCLC tumorigenesis. Using immunofluorescence microscopy, we observed that EGFR and Tid1 co-located within mitochondria in NSCLC cells. Moreover, mitochondria EGFR (mtEGFR) interact with both Tid1 isoforms directly under EGF stimulation, although there is a stronger association with the Tid1-S. In NSCLC patient tumors have shown mtEGFR and Tid1-S to be an indicator for poor clinical outcomes in cancer patients. Moreover, EGFR mitochondrial translocation can be decreased by erlotinib treatment in H3255 cells and greatly decline of cell viability. From the above observations, we believe that an adequate quantity of mitochondrial EGFR is critical for survival in NSCLC. Additional experiments are needed to further explore if Tid1 plays a role in the mitochondrial accumulation of EGFR in NSCLC cells.

Citation Format: Chi-Yuan Chen, Yu-Han Lin, Wen-Chieh Pi. Exploration of Tid1 and mitochondrial EGFR in non-small cell lung carcinoma tumorgenesis. [abstract]. In: Proceedings of the AACR-NCI-EORTC International Conference: Molecular Targets and Cancer Therapeutics; 2015 Nov 5-9; Boston, MA. Philadelphia (PA): AACR; Mol Cancer Ther 2015;14(12 Suppl 2):Abstract nr A59.
Abstract A63: Role of the metastasis suppressor, NDRG1, in regulating the EGFR and ErbB family of receptors and its effects on key oncogenic signaling pathways in pancreatic cancer
Authors: Menezes Sharleen V. , Kovacevic Zaklina , Richardson Des R.
Published: May 2016

N-myc downstream regulated gene-1 (NDRG1) is a potent metastasis suppressor that has been shown to affect numerous signaling pathways that control oncogenesis. In this study, the role of NDRG1 was investigated on a key upstream effector, namely epidermal growth factor receptor (EGFR) and other members of the ErbB family, namely human epidermal growth factor 2 (HER2) and human epidermal growth factor receptor 3 (HER3). This is of interest, as the ErbB family of receptor tyrosine kinases are involved in regulating multiple cell responses, being key regulators of down-stream oncogenic-signaling.

We demonstrate that NDRG1 is able to significantly reduce the expression, localisation and activation of EGFR, HER2 and HER3, while also inhibiting the formation of EGFR/HER2 and HER2/HER3 heterodimers. This investigation also showed that a novel class of anti-cancer agents, namely di-2-pyridylketone 4,4-dimethyl-3-thiosemicarbazone (Dp44mT) and di-2-pyridylketone-4-cyclohexyl-4-methyl-3-thiosemicarbazone (DpC), were able to markedly up-regulate NDRG1. These agents were found to inhibit EGFR, HER2 and HER3 expression and phosphorylation in PANC-1 pancreatic cancer cells in vitro. Moreover, these compounds led to a significant reduction of the expression of these proteins in PANC-1 tumour xenografts in vivo.

Due to the limitations of current anti-cancer therapeutics, these agents were also compared to a clinically used EGFR inhibitor, Erlotinib. Our study showed that in comparison to Erlotinib, both Dp44mT and DpC displayed higher anti-proliferative activity in pancreatic cancer cells. This could be significant, as DpC is due to enter clinical trials this year for the treatment of aggressive solid tumours (http://www.colmeddev.com/oncochel/).

Together, these findings reveal the molecular mechanisms that underlie the anti-cancer effects of NDRG1, and in turn, demonstrate the potential origin of the extensive down-stream effects attributed to this molecule.

Citation Format: Sharleen V. Menezes, Zaklina Kovacevic, Des R. Richardson. Role of the metastasis suppressor, NDRG1, in regulating the EGFR and ErbB family of receptors and its effects on key oncogenic signaling pathways in pancreatic cancer. [abstract]. In: Proceedings of the AACR-NCI-EORTC International Conference: Molecular Targets and Cancer Therapeutics; 2015 Nov 5-9; Boston, MA. Philadelphia (PA): AACR; Mol Cancer Ther 2015;14(12 Suppl 2):Abstract nr A63.
Abstract A93: The Smac mimetic Debio 1143 synergizes with radiotherapy and immune checkpoint inhibitors to enhance antitumor immunity
Authors: BARKHOUSE Darryll , TAO Zhen , MYERS Carey , WIEDEMANN Norbert , GAVILLET Bruno , HARSHYNE Larry , DICKER Adam , HOOPER D.Craig , VUAGNIAUX Gregoire , Lu Bo
Published: May 2016

Introduction: Radiotherapy (RT) kills cancer cells, increases tumor antigenicity, and stimulates the immune response which can be further augmented by systemic immune-modulating agents. Debio 1143 is an oral antagonist of the inhibitors of apoptosis proteins (IAPs) currently in clinical development, which sensitizes tumor cells to RT- or chemotherapy-induced apoptosis, and modulates NFκ-B signalling. We hypothesized that, in addition to its activity on apoptosis, Debio 1143 could improve antitumor immunity by increasing the effects of RT and anti-PD1 treatment.

Experimental procedures: Using immunocompetent mouse models of lung cancer (Lewis lung cancer) and melanoma (B16F10), the anti-tumor activity of RT and anti-PD-1 was tested either alone or in combination with Debio 1143. The effects of the treatment on the immunological components were determined by FACS.

Results: Combining radiotherapy and Debio 1143 in vivo potently prevented tumor growth and increased the local accumulation of cytotoxic T cells. Activation of cytotoxic T cells proved to be mediated through the release of tumor necrosis factor alpha in the tumor microenvironment. In addition, Debio 1143 was able to potently stimulate the ability of an anti-PD1 antibody to kill tumor cells in vivo.

Conclusions: These data offer a new paradigm to improve the tumor immune response elicited by RT and immune checkpoint inhibitors and serve as the foundation for future clinical translation of combination therapy between Debio 1143, radiotherapy and immune-oncology agents.

Citation Format: Darryll BARKHOUSE, Zhen TAO, Carey MYERS, Norbert WIEDEMANN, Bruno GAVILLET, Larry HARSHYNE, Adam DICKER, D.Craig HOOPER, Gregoire VUAGNIAUX, Bo Lu. The Smac mimetic Debio 1143 synergizes with radiotherapy and immune checkpoint inhibitors to enhance antitumor immunity. [abstract]. In: Proceedings of the AACR-NCI-EORTC International Conference: Molecular Targets and Cancer Therapeutics; 2015 Nov 5-9; Boston, MA. Philadelphia (PA): AACR; Mol Cancer Ther 2015;14(12 Suppl 2):Abstract nr A93.
Abstract B114: Combination of BGJ398 with either a pan-PI3K inhibitor or a specific PIK3CA inhibitor shows synergy in FGFR2 mutant endometrial cancer cell lines
Authors: Pollock Pamela M. , Geng Xinyan , Bonazzi Vanessa F. , Mahon Clare , Stephenson Sally , Packer Leisl
Published: May 2016

Background: Our lab has identified FGFR2 mutations in 12% of over 1500 endometrioid endometrial cancers (ECs) analyzed. The majority of these tumors harbor genetic aberrations in the PI3K/AKT pathway resulting in constitutive activation. In other tissue types, PTEN loss has been shown to provide resistance to specific PIK3CA inhibition. We have previously reported that FGFR inhibition with PD173074 induced cell death despite loss of PTEN. We hypothesize that dual inhibition of FGFR2 and the PI3K pathway will lead to increased cell death and more effective tumor growth inhibition.

Materials and Methods: Two FGFR2 mutant EC cell lines were treated with BGJ398 (pan FGFR inhibitor) alone or in combination with either a pan-PI3K inhibitor (GDC0941) or a specific PI3KA inhibitor (BYL719). Synergy was assessed using the fixed ratio method proposed by Chou and Talalay. Cell death was determined by Annexin V staining and colony formation assays using low clinically relevant drug concentrations. Downstream signaling pathways were analyzed by Western blot analysis and BGJ398 in combination with either GDC0941 or BYL719 was assessed in vivo.

Results: Synergy was observed between BGJ398 and either the pan-PI3K inhibitor (GDC0941), or the specific PI3KA inhibitor (BYL719). Regression of tumor xenografts was observed in mice treated with BGJ398 and GDC0941 as well as BGJ398 and BYL719, despite PTEN inactivation.

Conclusions: Dual targeting of the FGFR and PI3K pathways is more effective than targeting either of them alone. PTEN loss does not provide resistance to PIK3CA inhibition in our EC models suggesting context dependent differences in PI3K signaling.

Citation Format: Pamela M. Pollock, Xinyan Geng, Vanessa F. Bonazzi, Clare Mahon, Sally Stephenson, Leisl Packer. Combination of BGJ398 with either a pan-PI3K inhibitor or a specific PIK3CA inhibitor shows synergy in FGFR2 mutant endometrial cancer cell lines. [abstract]. In: Proceedings of the AACR-NCI-EORTC International Conference: Molecular Targets and Cancer Therapeutics; 2015 Nov 5-9; Boston, MA. Philadelphia (PA): AACR; Mol Cancer Ther 2015;14(12 Suppl 2):Abstract nr B114.
Abstract B115: Design and development of a novel series of PI3K-p110beta/delta-selective inhibitors with combined tumor immunotherapeutic, growth inhibition and anti-metastatic activity
Authors: Shuttleworth Stephen
Published: May 2016

The phosphatidylinositide 3-kinases (PI3Ks) have emerged as important therapeutic targets for the treatment of solid and hematological malignancies. In solid tumor therapy, the majority of clinical activity has centered on pan-class I (p110alpha, beta, delta and gamma) inhibitors of limited selectivity, or pan-class I/mTOR dual inhibitors, whereas targeting p110delta and p110gamma has been the main focus for hematological cancer treatment. Our research at Karus has focused on the emerging role of p110beta and p110delta in both cancer types, though increasingly in solid tumors, in which overexpression, mutation and PTEN-defectiveness have been shown to be key features in disease pathogenesis and progression. We have designed and developed a uniquely-selective series of orally-active molecules that inhibit the p110beta/delta isoforms, and which display extremely high specificity in the human kinome. The design of such molecules has enabled us to interrogate the function of p110delta in solid tumor immunotherapy and p110beta in primary tumor growth and metastasis, with our lead compounds showing promising oral activity in syngeneic models, in which they inhibit tumor growth and metastatic spread whilst also impacting on downstream biomarker levels. Additionally, through our ability to tune selectivity over p110alpha and p110gamma, elimination of the mechanism-related toxicities associated with those isoforms can be realized, making selective dual p110beta/delta inhibition, described herein for our lead compound, KA2237, potentially more conducive to combination therapy than for pan-inhibitors, including with signal transduction pathway inhibitors and other immunotherapeutics. KA2237, an orally-active, potent and selective small molecule p110beta/delta inhibitor, has completed GLP toxicology and will enter Phase I studies in 2015.

Citation Format: Stephen Shuttleworth. Design and development of a novel series of PI3K-p110beta/delta-selective inhibitors with combined tumor immunotherapeutic, growth inhibition and anti-metastatic activity. [abstract]. In: Proceedings of the AACR-NCI-EORTC International Conference: Molecular Targets and Cancer Therapeutics; 2015 Nov 5-9; Boston, MA. Philadelphia (PA): AACR; Mol Cancer Ther 2015;14(12 Suppl 2):Abstract nr B115.
Abstract B12: DNA methyltransferase 3A expression in cancer cells following treatment with DNMT inhibitors and in human solid tumors
Authors: Yang Sherry X. , Nguyen Dat , Rubinstein Larry , Chen Alice P. , Doroshow James H.
Published: May 2016

Background. The DNA methyltransferases (DNMTs) catalyze the addition of a methyl group to the 5-cytosine residue of CpG dinucleotides. This family of enzymes includes DNMT1 that functions as a DNA maintenance methyltransferase, and DNMT3A and DNMT3B that methylate previously unmethylated regions of DNA and are required for genome-wide de novo DNA methylation. However, there have been challenges to characterize DNMT3A protein expression in human tissue samples and it remains unclear its potential inhibition by classic and novel DNMT inhibitors. Materials and Methods. MCF-7 breast cancer and NCI-H23 non-small cell lung cancer cells were treated with DNMT inhibitors of 4'-thio-2'-deoxycytidine (T-dCyd), 4'-thio-5-aza-2'-deoxycytidine (aza-T-dCyd) and decitabine at 1 μM T-dCyd for 96h, and changes in DNMT3A expression were assessed by western blot and immunocytochemistry (ICC). DNMT3A expression was examined by immunohistochemistry in formalin-fixed and paraffin-embedded human breast, colorectal and lung cancers as well as lymphomas. Results. Expression of DNMT3A was decreased by all three DNMT inhibitors in MCF-7 and NCI-H23 cells detected by western blot and ICC. The mean staining index in NCI-H23 cells after T-dCyd treatment was 18.4, compared to 48.8 of vehicle control, by quantitative imaging and analysis (P <0.0001 by 2-sided t test). DNMT3A was primarily localized to the nucleus, and constitutively expressed in tumor cells at intermediate to high levels in 3.3% (2/60) of breast cancer, 0% (0/47) of colorectal cancer, 12% (9/75) of lung cancers, and 23% (34/148) of lymphomas across histology types including T-cell and diffuse B small cleaved/non-cleaved lymphomas as well as Hodgkin's disease. Additionally, DNMT3A expression was low in benign breast diseases (n = 16), normal colon tissues (n = 7) and normal lymph nodes (n = 11). Conclusions. The data demonstrate that DNMT3A is targeted for decrease by DNMT inhibitors and may serve as a pharmacodynamic and perhaps efficacy biomarker in early clinical trials. The intermediate to high levels of DNMT3A expression are rare in colorectal and breast cancers, and in 23% or fewer patients with either lymphomas or lung cancers.

Citation Format: Sherry X. Yang, Dat Nguyen, Larry Rubinstein, Alice P. Chen, James H. Doroshow. DNA methyltransferase 3A expression in cancer cells following treatment with DNMT inhibitors and in human solid tumors. [abstract]. In: Proceedings of the AACR-NCI-EORTC International Conference: Molecular Targets and Cancer Therapeutics; 2015 Nov 5-9; Boston, MA. Philadelphia (PA): AACR; Mol Cancer Ther 2015;14(12 Suppl 2):Abstract nr B12.
Abstract B120: Maternal embryonic leucine zipper kinase(MELK) induces invasion and migration of glioblastoma
Authors: Choi Sang-Un , Kim KwangRok , Cheon Hyo Zin , Shon Yoo Hwa
Published: May 2016

Maternal Embryonic Leucine Zipper Kinase(MELK) induces invasion and migration of glioblastoma

Glioblastoma multiforme (GBM) is the most common cancer of the primary malignant brain tumors and one of the most difficult tumors to treat effectively. This tumor arises from star-shaped glial cells called “astrocytes.”

Maternal embryonic leucine zipper kinase (MELK) is a member of the snf1/AMPK family of serin-threonine kinase which is cell cycle-dependent protein kinase. Although several members of the family are known to play roles in cell survival under metabolically challenging condition, the exact function of MELK has not previously been identified. MELK has recently emerged as an important gene in the field of cancer research. Several studies have reported that MELK level is dramatically increased in cancer tissues and it possibly contributes to cancer development. The several proteins such as ZPR9, NIPP1, and Cdc25B are reported the substrates of MELK, so far, but the significance of their phosphorylation is not clear.

To identify the role of MELK in malignancy of GBM, we introduced the drug-induced transgene expression system to U87MG cell line by using the tetracycline(Tet)-inducible gene expression systems. To elucidate the MELK signaling pathway in brain cancer cells, we conducted human phospho-kinase array, 2D-PAGE and mass spectrometric analysis. We identified the vimentin as a downstream factor of MELK, and confirmed the expression of this target by artificial increased MELK.

Vimentin, the intermediate filament protein, is reported as an important marker of Epithelial-to-mesenchymal transition (EMT) and a requisite regulator of mesenchymal cell migration. EMT is a critical event in the induction of cell motility and increased survival both under physiological situations like wound healing and during development as well as in malignant cells undergoing invasion and metastasis. Vimentin is characteristically upregulated in tumor cells undergoing EMT.

Here, we show that MELK is necessary for the vimentin function in vitro, influencing their ability to cell migration. The data strongly support the hypothesis that MELK, unlike other family members, functions by regulating migration and invasion for tumor cell EMT induction rather than the cell cycle through regulation of vimentin.

Citation Format: Sang-Un Choi, KwangRok Kim, Hyo Zin Cheon, Yoo Hwa Shon. Maternal embryonic leucine zipper kinase(MELK) induces invasion and migration of glioblastoma. [abstract]. In: Proceedings of the AACR-NCI-EORTC International Conference: Molecular Targets and Cancer Therapeutics; 2015 Nov 5-9; Boston, MA. Philadelphia (PA): AACR; Mol Cancer Ther 2015;14(12 Suppl 2):Abstract nr B120.
Abstract B127: An innovative, ultra-accurate method for cancer mutation detection in cell-free DNA from plasma
Authors: Zhao Grace , Tang Paul , Sun Johnny , Lin Shengrong
Published: May 2016

The application of cell-free DNA (cfDNA) as a biomarker holds great potential in advancing personalized cancer treatments. However, two major limitations need to be addressed for the development of a practical cfDNA-based cancer diagnostic assay: 1) the low concentration of cfDNA in blood, which presents challenges for detecting mutations at low allele frequency, and 2) the relatively high background noise caused by next generation sequencing (NGS) error, which can mask bona fide cancer mutation signals. Here we introduce an innovative, ultra-accurate, and scalable NGS-based cancer mutation detection system that overcomes these limitations. Our system amplifies nanogram quantities of highly fragmented cfDNA from the whole genome to >1000-fold, and no significant biases were observed. By combining molecular biology techniques with bioinformatics, we reduced the random background error from sequencing to achieve high accuracy (calculated error rate of 10-6), with a detection of 1:10,000 in a cell line gDNA model system, and 1:1000 in cfDNA. We implemented a 127-gene panel with 1 Mb target region, and 2000x-3000x deep sequencing to detect mutations from stage II hepatocellular carcinoma (HCC) cfDNA samples, and 75% of the HCC signature mutations (including those mutations with <1% allele frequencies) were confirmed by tumor gDNA exome sequencing. Furthermore, we developed an algorithm for basic cancer type classification, which in a preliminary study, this algorithm classified our breast and pancreatic cancer cfDNA samples with a sensitivity of 85%, and a specificity of 100%. In summary, this unbiased cfDNA amplification and highly accurate mutation detection system serves as a first step toward developing a reliable, non-invasive cancer genome analysis, which will dramatically enhance options for personalizing cancer treatments and ultimately screening high risk populations.

Citation Format: Grace Zhao, Paul Tang, Johnny Sun, Shengrong Lin. An innovative, ultra-accurate method for cancer mutation detection in cell-free DNA from plasma. [abstract]. In: Proceedings of the AACR-NCI-EORTC International Conference: Molecular Targets and Cancer Therapeutics; 2015 Nov 5-9; Boston, MA. Philadelphia (PA): AACR; Mol Cancer Ther 2015;14(12 Suppl 2):Abstract nr B127.
Abstract B15: Androgen receptor recruitment to c-Jun promoter region regulates chemosensitivity of prostate cancer cells to taxane therapy
Authors: Dizeyi Nishtman , Tinzl Martina V. , van der Molen Marieke , Semenas Julius , Abrahamsson Per-Anders
Published: May 2016

Introduction & Objectives. We have previously reported that response of prostate cancer (PC) to taxane therapy is based on the interplay between androgen receptor (AR) and c-jun However, the cellular mechanisms of taxane treatment in prostate cancer cells are not fully elucidated. The aim of this study was to investigate the effect of sustained down-regulation of c-jun on the outcome of taxane therapy using LNCaP cells transfected with c-jun shRNA, and to characterize the nature of the c-jun and AR interaction in regard to their corresponding promoter regions.

Material & Methods. Chromatin immunoprecipitation (CHIP) assay was performed to examine gene recruitment. LNCaP cells were treated with Docetaxel (Doc) or Paclitaxel (Pac) and resulting chromatin preparations were analyzed by PCR. To analyse the impact of c-jun downregulation on AR and prostate cancer response to therapy we used LNCaP cells harboring stable knocked down c-jun (LNsiJun). Cells were exposed to Doc, Pac DHT for different time-points and the medium were subjected for PSA analysis using DELFIA 1234 fluorometer and cell response to drugs assessed by MTT assay.

Results. Taxane treatment of LNsiJun cells led to a statistically significant decrease of cell viability compared to parental LNCaP cells (p<0,05) independent on the substance used. Interestingly, exposure of LNsiJun cells to DHT resulted in increased cell death. LNsiJun cells treated with docetaxel (Doc) showed an up-regulation of AR and PSA protein levels after 24 hours, whereas Paclitaxel (Pac) treatment resulted in a down-regulation of both proteins which matched our observations in parental LNCaP cells. To further investigate this taxane specific effect on AR, ChIP assay revealed that AR binds to the c-jun promoter region upon Doc exposure. However, Pac treatment failed to do so. Both taxanes resulted in an enhanced binding of c-jun to the corresponding promoter region.

Conclusions. In conclusion, down-regulation of endogenous c-jun enhances sensitivity of LNCaP cells to taxane treatment. Binding of AR to the c-jun promoter is taxane specific and results in different expression levels of AR and PSA.

Citation Format: Nishtman Dizeyi, Martina V. Tinzl, Marieke van der Molen, Julius Semenas, Per-Anders Abrahamsson. Androgen receptor recruitment to c-Jun promoter region regulates chemosensitivity of prostate cancer cells to taxane therapy. [abstract]. In: Proceedings of the AACR-NCI-EORTC International Conference: Molecular Targets and Cancer Therapeutics; 2015 Nov 5-9; Boston, MA. Philadelphia (PA): AACR; Mol Cancer Ther 2015;14(12 Suppl 2):Abstract nr B15.
Abstract B164: Identification and validation of PRMT1 as a therapeutic target in breast cancer
Authors: Silvestre David C. , Brisson Amelie , Marty-Prouvost Bérengère , Gentien David , Loew Damarys , Dingli Florent , Maire Virginie , Némati Fariba , Ye Mengliang , Meseure Didier , Nicolas André , Roman-Roman Sergio , Dubois Thierry
Published: May 2016

Triple-negative breast cancer (TNBC) represents a subgroup of breast cancers (BC) associated with the most aggressive clinical behavior. No targeted therapy is currently available for the treatment of patients with TNBC. In the present study, we found that Protein Arginine Methyltransferase 1 (PRMT1) is overexpressed in TNBC at the mRNA level. At the protein level, PRMT1 was overexpressed in all breast cancer subtypes compared to normal breast tissue. The depletion of PRMT1 using siRNA in BC cell lines triggered apoptosis, reduced cell viability and the ability to form colonies in an anchorage-independent manner. Treatment with Furamidine, a new PRMT1-specific inhibitor, blocked proliferation specifically in BC cells, with no measurable effect in normal breast cells. Furamidine treatment of a TNBC patient-derived xenograft (PDX) model significantly slowed tumor growth. To address the cellular pathways regulated by PRMT1, we identified its protein partners by mass spectrometry and the transcriptomic changes following its depletion in TNBC cell lines. Interestingly, we found that PRMT1 directly activates key oncogenic pathways. Furthermore, we found a synergistic interaction between PRMT1 inhibitors and inhibitors for some of those pathways. Our results show that PRMT1 activity is necessary for breast cancer cell survival and oncogenic pathway activation. Our results point out PRMT1 as an emerging target for the treatment of BC.

Citation Format: David C. Silvestre, Amelie Brisson, Bérengère Marty-Prouvost, David Gentien, Damarys Loew, Florent Dingli, Virginie Maire, Fariba Némati, Mengliang Ye, Didier Meseure, André Nicolas, Sergio Roman-Roman, Thierry Dubois. Identification and validation of PRMT1 as a therapeutic target in breast cancer. [abstract]. In: Proceedings of the AACR-NCI-EORTC International Conference: Molecular Targets and Cancer Therapeutics; 2015 Nov 5-9; Boston, MA. Philadelphia (PA): AACR; Mol Cancer Ther 2015;14(12 Suppl 2):Abstract nr B164.
Abstract B198: Pharmacological profile of the PGE2 EP4 receptor antagonist E7046
Authors: Albu Diana I. , Wu Jiayi , Huang Kuan-chung , Wright-Michaud Renee , Xu Shanqin , Kuznetsov Galina , Bao Xingfeng , Woodall-Jappe Mary
Published: May 2016

E7046 is a potent and selective small molecule antagonist of the type 4 prostaglandin E2 (PGE2) receptor EP4. The discovery and evaluation of this novel EP4 antagonist for cancer treatment was recently presented at the AACR 2015 annual conference (abstract # 275). Here we show new evidence of E7046 in vivo activity against a series of syngeneic tumor models as well as its pharmacological effect on APCMin/+ mice, which possess a mutation in the adenomatous polyposis coli (APC) tumor suppressor gene. We found that daily oral administration of E7046 was able to both slow down the growth of established subcutaneous tumors and significantly delay the recurrence of tumors after surgical resection. These activities of E7046 correlated with differences in the immune cell composition of the microenvironments of each type of tumor. In this context, cyclooxygenase 2 - positive (COX-2+) tumors that were rich in myeloid cells showed an enhanced response to E7046 regardless of their T lymphocyte infiltration status. In addition, E7046 was superior to the COX-2 inhibitor celecoxib against mutant APC-driven neoplastic polyp formation in the intestines of APCMin/+ mice exposed to dextran sodium sulfate. Using the APCMin/+ mouse model, we found that E7046 significantly reduced the combined colon polyp area and the size of individual polyps without influencing the total polyp number. For each of these parameters, E7046 activity against colon and small intestine tumors was greater than that of a comparable dose of celecoxib. Quantification of cyclin D1 staining in colon and small intestine polyps further indicated that both compounds led to a significant reduction in the proliferation of tumor cells, with a greater effect for E7046 compared to celecoxib. Overall, these preclinical results suggest that this agent should be further investigated in patients with COX-2+ tumors infiltrated with myeloid cells, including patients with APC-mutated colon cancer. First-In-Human study of E7046 is currently enrolling patients (IND 125272).

Citation Format: Diana I. Albu, Jiayi Wu, Kuan-chung Huang, Renee Wright-Michaud, Shanqin Xu, Galina Kuznetsov, Xingfeng Bao, Mary Woodall-Jappe. Pharmacological profile of the PGE2 EP4 receptor antagonist E7046. [abstract]. In: Proceedings of the AACR-NCI-EORTC International Conference: Molecular Targets and Cancer Therapeutics; 2015 Nov 5-9; Boston, MA. Philadelphia (PA): AACR; Mol Cancer Ther 2015;14(12 Suppl 2):Abstract nr B198.
Abstract B202: Combined therapy of temozolomide and PF-562271, a PYK2 inhibitor, reduces glioma tumor growth and dispersal compare to temozolomide monotherapy
Authors: Rolon-Reyes Kimberleve , Cubano Luis A. , Quiñones-Hinojosa Alfredo , Kucheryavykh Lilia
Published: May 2016

Microglia infiltrate majority of gliomas and release factors, which favor tumor growth and dispersal. Previously we demonstrated that microglia residing within the tumor stimulate glioma cell dispersal through the proline rich tyrosine kinase 2 (Pyk2) signaling cascade (Rolon-Reyes et al. 2015). We hypothesize that the use of pharmacological inhibitors of Pyk2 in applied therapy can significantly reduce the dispersal of tumor cells and improve the outcome of treatment.

In the present study, we investigated both in vitro and in vivo, the effect of the combined treatment of glioblastoma with temozolomide (TMZ) together with PF-562271 (a Pyk2 and FAK inhibitor), vs. TMZ monotherapy. Proliferation and migration assays were performed for a number of primary human glioma cell lines, as well as U87 and HS683cell lines in the presence and absence of microglia. Tumor size and invasion area were evaluated in brains of GL261 tumor bearing C57BL/6 mice for the assessment of the effectiveness of treatment.

Our data demonstrate that PF-562271 (16nM) and TMZ (100μM) given alone reduced in vitro migration and proliferation of glioma cells in the presence of microglia. PF-562271 (16nM) given in combination with TMZ at a concentration of just 10μM provided the same effect as TMZ 100 μM along, without reduction of efficacy. In vivo experiments demonstrated that oral administration of PF-562271 (twice/daily, 25 mg/kg, orally) reduced invasion of glioma cells at the tumor edge, while TMZ (50 mg/kg, once/day, orally) reduced the tumor growth. Combined treatment revealed significantly more prominent effect on both tumor growth and invasion compare to monotherapy.

These data indicate that the combination of TMZ and PF-562271 reduces both tumor growth and dispersal of tumor cells to surrounding areas. Moreover, in vitro experiments revealed a complex effect of these drugs on glioma cell proliferation and migration, allowing the reduction of the applied concentration of TMZ without the loss of its therapeutic effect.

This research was made possible by NIH grant numbers: 1SC2GM102040-01A1, 8G12MD007583-27, Title V PPOHA grant number P031M105050, NIH NIMH R25 MH055929 and RO1-CA18382701A1.

Citation Format: Kimberleve Rolon-Reyes, Luis A. Cubano, Alfredo Quiñones-Hinojosa, Lilia Kucheryavykh. Combined therapy of temozolomide and PF-562271, a PYK2 inhibitor, reduces glioma tumor growth and dispersal compare to temozolomide monotherapy. [abstract]. In: Proceedings of the AACR-NCI-EORTC International Conference: Molecular Targets and Cancer Therapeutics; 2015 Nov 5-9; Boston, MA. Philadelphia (PA): AACR; Mol Cancer Ther 2015;14(12 Suppl 2):Abstract nr B202.
Abstract B45: Molecular modeling approach for exploring the MDM2 active site for the discovery of new P53-MDM2 inhibitors
Authors: Atatreh Noor , Mansour Ramez A. , Ghattas Mohammad A.
Published: May 2016

MDM2 is a protein that regulates the action of tumor suppressor protein P53. Inhibiting the interaction between the two proteins is widely considered in anti-cancer drug discovery approach. Targeting p53-bindig site on the MDM2 protein can be useful for the development of new anticancer agents. Several drugs with selective activity have been introduced to the market and are used for treatment of several types of cancers.

In this study we explored the inhibition of MDM2 activity through studying 32 crystal structures of MDM2-ligand complexes downloaded from protein data bank (PDB). MDM2 protein structures were analyzed using protein-ligand interaction fingerprint to determine key residues for ligand binding. A 3D pharmacophore set was created and validated with a set of features that include aromatic and hydrophobic properties. Furthermore libraries of potential small lead-like ligands were screened on the pharmacophore. Ligands which pose three pharmacophoric features were carried to the next step where receptor-based virtual screening was performed using GLIDE docking software.

The top 10% obtained from this screening were then redocked into the MDM2 binding site using more extensive search and scoring technique (GLIDE_XP) in order to enhance screening accuracy. The resultant top list was visually examined and compounds with best binding mode were selected for experimental testing. This virtual technique for discovering new lead-like MDM2 inhibitors will take into consideration several features that current inhibitors may lack such as solubility and bioavailability.

Citation Format: Noor Atatreh, Ramez A. Mansour, Mohammad A. Ghattas. Molecular modeling approach for exploring the MDM2 active site for the discovery of new P53-MDM2 inhibitors. [abstract]. In: Proceedings of the AACR-NCI-EORTC International Conference: Molecular Targets and Cancer Therapeutics; 2015 Nov 5-9; Boston, MA. Philadelphia (PA): AACR; Mol Cancer Ther 2015;14(12 Suppl 2):Abstract nr B45.
Abstract B51: Tumor genetic shift post standard of care therapy
Authors: Jonathan Dry R. , Greenawalt Danielle , Lai Zhongwu , Barrett Carl
Published: May 2016

Our current understanding of the mutation spectrum of relapse/refractory patients is limited. Public sequencing efforts have focused, by design, on diagnostic (pre-treatment) biopsies, while re-biopsy of patients who are refractory to first line therapy or who relapse on treatment is not standard protocol. Many gold standard algorithms used to call mutations perform poorly in ultra-deep sequencing data necessary for sensitive detection of resistance mutations emerging in circulating tumor DNA. They can also miss a wide range of complex genetic aberrations prevalent in cancer genomes. We have performed whole exome sequencing on post treatment core needle biopsies from 47 DLBCL patients post-relapse following anthracycline-based therapy such as R-CHOP, 8 with matched diagnostic biopsies. Similarly we have profiled 88 post-treatment solid tumor biopsies from triple negative breast and lung adenocarcinoma patients recurrent following platinum or multi-agent chemotherapy, 12 with matched diagnostic biopsies. We compared the somatic variant frequencies and copy number variation between matched pre- and post-treatment samples, and with published data for cohorts of primary (diagnostic) samples matched by patient and tumor characteristics. NGS data from all samples were processed using the same mutation caller, VarDict http://github.com/AstraZeneca-NGS/VarDict, optimized to call large InDels and complex variants in ultra-deep sequencing. For DLBCL, the average mutation rate and founding driver mutation profile were similar, however a number of oncogenic driver mutations were found to have emerged in the post-treatment biopsies. Collectively these data further highlight the value of re-assessing the tumor genetic landscape at the time therapeutic choices are made.

Citation Format: Dry R. Jonathan, Danielle Greenawalt, Zhongwu Lai, Carl Barrett. Tumor genetic shift post standard of care therapy. [abstract]. In: Proceedings of the AACR-NCI-EORTC International Conference: Molecular Targets and Cancer Therapeutics; 2015 Nov 5-9; Boston, MA. Philadelphia (PA): AACR; Mol Cancer Ther 2015;14(12 Suppl 2):Abstract nr B51.
Abstract B54: Type II interleukin 1 receptor-modulated SET/PP2A/p-ERK signaling is associated with regorafenib resistance in human colorectal cancer cells
Authors: Mar Ai-Chung , Chu Chun-Ho , Yang Shung-Haur , Jiang Jeng-Kai , Shiau Chung-Wai , Lee Te-Chang
Published: May 2016

Regorafenib, a newly approved multi-kinase inhibitor by US FDA, has recently demonstrated overall survival benefits in late-stage colorectal cancer (CRC) patients. We have observed that the expression type II interleukin 1 receptor (IL1R2), an IL-1 decoy receptor, were closely associated with regorafenib resistance in human CRC cells. In addition, IL1R2 expression was associated with poor prognosis of patients with CRC cancer. In this study, we conducted experiments to elucidate the roles of IL1R2 in regorafenib resistance. We first demonstrated that silencing of IL1R2 in HT29 cells by shRNA overcame their resistance to regorafenib, whereas ectopic expression of IL1R2 in HCT116 cells increased their resistance to regorafenib in either in vitro or in vivo systems. We further established regorafenib-resistant DLD-1 cells (DLD-1-R) by long-term culturing DLD-1 cells in the presence of regorafenib. Our results demonstrated increased expression of IL1R2 in DLD-1-R cells compared to parental DLD-1 cells. We observed that IL1R2 expression is associated with p-ERK level, which is crucial for survival of cancer cells. Pretreatment of HT29, IL1R2-overexpressing HCT116, and DLD-1-R cells with MEK/ERK inhibitor U0126 significantly reversed their resistance to regorafenib. Mechanistically, we revealed that SET/PP2A signaling plays crucial role on increasing p-ERK levels in IL1R2-overexpressing cells. Taken together, our present study suggested that enhanced IL1R2 mediates through SET/PP2A/p-ERK signaling to induce regorafenib resistance and, therefore, IL1R2 associated regorafenib resistance is overcome by combination treatment of CRC patients with regorafenib and MEK/ERK inhibitor.

Citation Format: Ai-Chung Mar, Chun-Ho Chu, Shung-Haur Yang, Jeng-Kai Jiang, Chung-Wai Shiau, Te-Chang Lee. Type II interleukin 1 receptor-modulated SET/PP2A/p-ERK signaling is associated with regorafenib resistance in human colorectal cancer cells. [abstract]. In: Proceedings of the AACR-NCI-EORTC International Conference: Molecular Targets and Cancer Therapeutics; 2015 Nov 5-9; Boston, MA. Philadelphia (PA): AACR; Mol Cancer Ther 2015;14(12 Suppl 2):Abstract nr B54.
Abstract B67: Sarcoma cell line screen of oncology drugs and investigational agents identifies patterns associated with gene and microRNA expression
Authors: Teicher Beverly A. , Polley Eric , Kunkel Mark , Evans David , Silvers Thomas , Delosh Rene , Laudeman Julie , Ogle Chad , Reinhart Russell , Selby Michael , Connelly John , Harris Erik , Monks Anne , Morris Joel
Published: May 2016

The diversity in sarcoma phenotype and genotype make treatment of this family of diseases exceptionally challenging. Sixty-three human adult and pediatric sarcoma lines were screened with 100 FDA approved oncology agents and 345 investigational agents. The investigational agents library enabled comparison of several compounds targeting the same molecular entity allowing comparison of target specificity and heterogeneity of cell line response. Gene expression was derived from exon array data and microRNA expression was derived from direct digital detection assays. The compounds were screened against each cell line at 9 concentrations in triplicate with an exposure time of 96 hrs using Alamar blue as the endpoint. Results are presented for inhibitors of the following targets: aurora kinase, IGF-1R, MEK, BET bromodomain, and PARP1. Chemical structures, IC50 heat maps, concentration response curves, gene expression and miR expression heat maps are presented for selected examples. In addition, two cases of exceptional responders are presented. The drug and compound response, gene expression and microRNA expression data are publicly available at http://sarcoma.cancer.gov. These data provide a unique resource to the cancer research community.

Citation Format: Beverly A. Teicher, Eric Polley, Mark Kunkel, David Evans, Thomas Silvers, Rene Delosh, Julie Laudeman, Chad Ogle, Russell Reinhart, Michael Selby, John Connelly, Erik Harris, Anne Monks, Joel Morris. Sarcoma cell line screen of oncology drugs and investigational agents identifies patterns associated with gene and microRNA expression. [abstract]. In: Proceedings of the AACR-NCI-EORTC International Conference: Molecular Targets and Cancer Therapeutics; 2015 Nov 5-9; Boston, MA. Philadelphia (PA): AACR; Mol Cancer Ther 2015;14(12 Suppl 2):Abstract nr B67.
Abstract B68: Screening for the compound that induces cell death selectively in β-catenin mutant tumor cells
Authors: Shikata Yuki , Kiga Masaki , Tashiro Etsu , Imoto Masaya
Published: May 2016

The Wnt signal transduction pathway plays a central role for the cell proliferation, differentiation and apoptosis. β-catenin, a component of Wnt pathway, translocates to nucleus and forms an active complex with TCF4, leading to activate cell growth signaling, and this activity is tightly regulated by the “destruction complex” consisting of Axin, APC, GSK3β and CK1α. However, when β-catenin is actively mutated, this cell growth signaling would be hyperactive and drive oncogenesis. As β-catenin is mutated in up to 10% of all sporadic colon carcinomas resulting from point mutations or in-frame deletions of serine and threonine residues phosphorylated by GSK3β, mutated β-catenin has been considered as promising targets for therapeutic intervention.

Therefore, we screened the compound that induced cell death selectively in tumor cell lines harboring β-catenin mutation from an in-house natural product library, and finally we isolated and found that nonactin, a well-known antibiotics, exhibited this activity. To confirm its apoptosis-inducing ability selectivity in β-catenin mutated cell lines, we examined the effect of nonactin on cell viability in 15 human tumor cell lines. Nonactin potently induced PARP-cleavage in 5 cell lines harboring β-catenin mutation (A427, HCT116, LS-174T, SK-MEL-1, SW48 cells), whereas the others, which do not harbor a mutation of β-catenin activation, were resistant to nonactin. In addition, overexpression of actively mutated β-catenin accelerated apoptosis induced by nonactin in the nonactin-resistant A375 cells, and β-catenin knockdown by siRNA reduced nonactin-induced apoptosis in HCT116 cells. Furthermore, nonactin induced tumor regression only in β-catenin mutated HCT116 xenograft mice.

Taken together, these findings suggested that the β-catenin mutated tumor cell lines are highly sensitive to nonactin, and it would be potential drug-seed for tumor cells harboring β-catenin mutation.

Citation Format: Yuki Shikata, Masaki Kiga, Etsu Tashiro, Masaya Imoto. Screening for the compound that induces cell death selectively in β-catenin mutant tumor cells. [abstract]. In: Proceedings of the AACR-NCI-EORTC International Conference: Molecular Targets and Cancer Therapeutics; 2015 Nov 5-9; Boston, MA. Philadelphia (PA): AACR; Mol Cancer Ther 2015;14(12 Suppl 2):Abstract nr B68.
Abstract C181: RRx-001 combined with anti-PD-L1 antibody increases the complete response rate in a preclinical myeloma model
Authors: Knox Susan J. , Ning Shoucheng , Peehl Donna , Oronsky Bryan , Scicinski Jan
Published: May 2016

BACKGROUND: RRx-001, a novel oxidizing and epigenetic agent, has shown promise as a single agent in a Phase I trial and is currently in Phase II trials, both alone and in combination with immunotherapy (Nivolumab), chemotherapy and radiation therapy.

OBJECTIVE: The primary objective of the experiments described here was to test the hypothesis that RRx-001 combined with the checkpoint inhibitor, anti-PD-L1 would increase the complete response (CR) rate in a preclinical model of myeloma.

METHODS and RESULTS: BALB/c mice with well established J558L myeloma tumors (100-150 mm3 in volume) were treated with anti-PD-L1 antibody alone (10 mg/kg, i.p., twice a week for two weeks), RRx-001 alone (10 mg/kg, i.p., two doses on Day 0 and day 4) or the combination of anti-PD-L1 + RRx-001. Tumors were measured every other day and tumor response as well as the tumor volume quadrupling time (4X TGT) were calculated. In an initial pilot experiment with 4 mice/group, the combined therapy group had the best response compared to either treatment alone or the untreated control group. In a larger duplicate experiment with 8-10 mice/group, the CR rate was 0%, 37.5%, 22.2% and 75% for the untreated control, anti-PD-L1, RRx-001, and combined group, respectively. In terms of a comparison of the 4X TGT, RRX-001 + anti-PD-L1 was more efficacious than the untreated control (P < 0.01), RRx-001 alone (P = 0.01) and anti-PD-L1 alone (P = 0.1).

CONCLUSIONS: These results demonstrate that inhibition of the PD-1/PD-L1 axis in combination with RRx-001 can significantly increase the CR rate in a preclinical model of myeloma. Experiments are ongoing to optimize this treatment regimen, study the effects of the combined treatment on the tumor immune microenvironment, and the study the efficacy of this combined therapy in other tumor types. Results from this ongoing work will be presented, and have near term translational potential.

Citation Format: Susan J. Knox, Shoucheng Ning, Donna Peehl, Bryan Oronsky, Jan Scicinski. RRx-001 combined with anti-PD-L1 antibody increases the complete response rate in a preclinical myeloma model. [abstract]. In: Proceedings of the AACR-NCI-EORTC International Conference: Molecular Targets and Cancer Therapeutics; 2015 Nov 5-9; Boston, MA. Philadelphia (PA): AACR; Mol Cancer Ther 2015;14(12 Suppl 2):Abstract nr C181.