bluuebunny/crossref_metadata_2025_split huggingface dataset:
Abstract 2200: A rational approach for discovery of inhibitors of YAP-TEAD interaction
Authors: Fromond Claudia , Chene Laurent , Soude Anne , Barth Martine , Montalbetti Christian , Broqua Pierre 
Published: August 2015

Abstract
The Hippo signalling pathway plays a major role in organ growth regulation and tumorigenesis. By sensing contact inhibition, the central kinase network of the hippo pathway controls nuclear translocation and activity of the YAP transcription factor. Once translocated in the nucleus, YAP interacts with the TEAD family of transcription factors and drives expression of gene involved in cell survival and proliferation. Deregulation of the hippo pathway frequently occurs in cancers and high nuclear expression of YAP has been documented in many tumors including lung, colorectal, ovarian and skin cancers. These data suggest that targeting the hippo pathway is a new therapeutic option for the treatment of a large number of cancers. Several approaches are currently proposed to target the hippo pathway such as inhibition of kinases and GPCRs that are upstream regulators of YAP nuclear translocation. However, because YAP and TEAD are the downstream effectors of the Hippo pathway, we believe that targeting YAP-TEAD interaction is the most promising approach to selectively counteract abnormal activity of the Hippo pathway. We have started a drug discovery program aimed at identifying potent inhibitors of YAP-TEAD interaction, based on a combined FBLD/HTS strategy. Druggability of the TEAD protein was assessed by a fragment screen using NMR and SPR technologies. This approach, conforted by assigned HSQC protein NMR information, provided fragment hits which are used as starting points for the identification of more potent binders. We have also designed a dedicated AlphaScreen assay to validate the ability of our compounds to disrupt the YAP-TEAD interaction. Fifty thousand compounds of the Inventiva's library were screened using the AlphaScreen. Several hits in the micromolar range were identified and further confirmed using SPR. Hits are currently tested for their ability to disrupt YAP-TEAD interaction in a cellular context with a transactivation assay and for their ability to block tumoral cell proliferation.
Citation Format: Claudia Fromond, Laurent Chene, Anne Soude, Martine Barth, Christian Montalbetti, Pierre Broqua. A rational approach for discovery of inhibitors of YAP-TEAD interaction. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 2200. doi:10.1158/1538-7445.AM2015-2200
Abstract 2205: Identification of transcript abundance difference at lung cancer and COPD risk genes in normal bronchial epithelial cells
Authors: Yeo Jiyoun , Zhang Xiaolu , Crawford Erin , Willey James 
Published: August 2015

Abstract
Background: Lung cancer and chronic obstructive pulmonary disease (COPD) and are leading causes of morbidity and mortality both in the United States and worldwide. Inhalation of cigarette smoke is the primary known and preventable cause but only 10-15% of heavy smokers develop these diseases. This suggests that cigarette smoke exposure interacts with inherited susceptibility factors to determine risk. There is urgent need to identify heritable susceptibility factors that explain the majority of lung cancer and COPD risk. In prior studies, we and/or others have observed large inter-individual variation in normal bronchial epithelial cell (NBEC) expression of antioxidant, DNA repair, and cell regeneration control genes and altered regulation in NBEC of subjects with lung cancer or COPD. We collected normal bronchial epithelial cell (NBEC) samples from over 500 subjects with or demographically at risk for lung cancer. In this pilot study, we assessed total expression of multiple putative risk genes in NBEC samples from 78 subjects.
Methods: A targeted competitive multiplex next generation sequencing (NGS) method (Blomquist et al, PLOS one 2013) was used to quantify transcript abundance at 70 marker sites among 33 target genes in NBEC total RNA from 78 subjects (18 cancer cases and 60 non-cancer controls). Approximately half of the cancer group (N = 10) and non-cancer group (N = 30) had COPD (FEV1/FVC&lt;0.7).
Results: TP73 was expressed higher and XRCC1 and MUC5B lower in cancer. GSTP1, MUC5B, OGG1, and TP73 were expressed at significantly higher level in COPD vs control by t-test in non-cancer group.
Conclusions: This study of 78 subjects provides evidence for transcript abundance difference in selected genes with high prior likelihood for contributing to lung cancer and COPD risk. Those genes will be the focus of additional studies in BEC samples from over 500 subjects with or at risk for lung cancer and/or COPD in effort to further optimize current tests for lung cancer and COPD risk.
Note: This abstract was not presented at the meeting.
Citation Format: Jiyoun Yeo, Xiaolu Zhang, Erin Crawford, James Willey. Identification of transcript abundance difference at lung cancer and COPD risk genes in normal bronchial epithelial cells. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 2205. doi:10.1158/1538-7445.AM2015-2205
Abstract 2218: Qualitative and quantitative analysis of IDH1 mutation in progressive gliomas by allele-specific quantitative RT-PCR and Western blot analysis
Authors: Timmer Marco , Perrech Moritz , Röhn Gabriele , Dreher Lena , Goldbrunner Roland 
Published: August 2015

Abstract
Diagnostic of the IDH1 mutation (IDH1mut) is so far based on DNA sequencing and immunohistochemistry (IHC), methods limited in terms of sensitivity and ease of use. Recently, measuring the IDH1mut level by real time PCR was introduced as alternative method. Therefore, we aimed to (i) validate this new technique in a larger patient cohort, compare it to control tissue, and (ii) investigate if the expression of both, IDH1mut and IDH1 wildtype (IDH1wt) correlates with the course of disease and different treatment regimens.
A total of 113 tumor samples were obtained intraoperatively from 84 glioma patients with diagnosis of diffuse glioma (WHO°II), anaplastic glioma (WHO°III), secondary glioblastoma +/- chemotherapy (CTx), primary glioblastoma +/- CTx (WHO°IV). Tumor samples were snap frozen and processed for sectioning, RNA and protein isolation. The quantitative expression of IDH1 mRNA was assessed using real-time PCR with specific primers for IDH1mut and -wt; protein expression was verified by Western Blot analysis and IHC. Additionally, 19 samples of LGG and their consecutive HGG were analyzed at different time points of disease.
Allele-specific quantitative RT-PCR does work in larger patient cohorts and seems to be an easy and ∼10 times more sensitive method for quantitative IDH1mut evaluation compared to the ones used so far. Our results with this new method confirmed previous data showing that most astrocytomas and secondary GBM bear the mutation (conc. 0.13 to 0.2) whereas most primary GBM do not (conc. ∼0.025). Quantitative analysis revealed that IDH1mut expression is upregulated in sGBM (mean±SEM: 3.52±0.55) compared to lower grade glioma (II° = 1.54±0.22; III° = 1.67±0.23). By contrast, IDH1wt expression is upregulated in all glioma grades (con. &gt;0.1) compared to control brain tissue (0.007± 0.0016). Western Blot analysis showed a high concordance to both, sequencing and RT-PCR results in qualitative analysis of IDH1mut status (specificity 100% and sensitivity 100%). Moreover, semiquantitative protein expression analysis also showed higher expression levels of mutated IDH1 in sGBM.
Taken together, recurrent disease and radiochemotherapy do not alter the general IDH1 status. Moreover, we found an increase of IDH1mut gene expression in sec. GBM compared to lower grade glioma indicating a pivotal role of IDH1mut not only in gliomagenesis but also in glioma progression.
Citation Format: Marco Timmer, Moritz Perrech, Gabriele Röhn, Lena Dreher, Roland Goldbrunner. Qualitative and quantitative analysis of IDH1 mutation in progressive gliomas by allele-specific quantitative RT-PCR and Western blot analysis. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 2218. doi:10.1158/1538-7445.AM2015-2218
Abstract 2219: Development of an assay to detect transcription misincorporation errors in Escherichia coli
Authors: Irizarry-Caro Jorge A. , Ernst Mary , Court Carolyn , Rattray Alison , Bubunenko Mikhail , Jin Ding , Court Donald , Strathern Jeffrey 
Published: August 2015

Abstract
In contrast to errors in DNA replication which can product heritable mutations, errors in transcription cause only transient alterations. The temporary nature of these transcription mistakes has made them difficult to detect and genetic screens to identify mutations that lower the fidelity of transcription have been problematic. We addressed this problem by developing methods to turn transient transcription errors into permanent genetic changes. The principle is based on suppression of a mutation in the active site of the cre recombinase. This assay is based on two parts: a source of Cre, which is actually the transcription misincorporation substrate, and a genetic reporter with a phenotypic change created by Cre-mediated recombination between lox sites. To develop a substrate for E. coli we chose the galactokinase gene (galK) as our reporter. From an alignment of the galK protein from E.coli, H. sapiens and L. lactis we identified sites that might be able to accept a 12aa insertion encoded by the LoxP sequence without disrupting its function. We selected four different sites that were away from the GalK active site and on the surface of the protein. We started our project using the strain MG1655, which is galK (+), able to grow in galactose as a carbon source and red on a MacConkey galactose plate (MAcGal). Using oligo recombineering, we first inserted a 7 base sequence, which caused a frame-shift mutation, the cells became galK (-) and, therefore white on MacGal. To put it back in frame, we next replaced the 7 bases with a 36 base loxP site, which, if it does not disrupt the function of galK will make the cells galK (+) again. To our surprise, the insertion of this LoxP site was completely successful, putting the gene back in frame and making the cells galK (+) and, therefore, red at each of the four sites we chose. A derivative of this reporter was made with the a portion of the galK gene inverted at one of the loxP sites. Active Cre recombinase can be detected by flipping the inversion to restore galK function. The active site mutant cre-Y324C exhibits a very low inversion rate. Mutations that reduce the accuracy of transcription, such as cells defective in greA, exhibit an elevated frequency of galK (+) inversions. This system will be used to identify additional mutations that reduce the fidelity of transcription in E. coli.
Citation Format: Jorge A. Irizarry-Caro, Mary Ernst, Carolyn Court, Alison Rattray, Mikhail Bubunenko, Ding Jin, Donald Court, Jeffrey Strathern. Development of an assay to detect transcription misincorporation errors in Escherichia coli. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 2219. doi:10.1158/1538-7445.AM2015-2219
Abstract 2227: Effects of cathepsin S in differentiated and stem-like glioblastoma cells
Authors: Foster Robyn A. , Al Rashid Shahnaz T. , Burden Roberta E. , Scott Christopher J. , Prise Kevin M. , Flannery Thomas J. 
Published: August 2015

Abstract
Background:
Glioblastoma (GBM) is the most common and aggressive brain tumour subtype with a poor prognosis of ∼15 months. A GBM stem-like population within the tumour is hypothesised to promote resistance to current treatment and invasion through normal tissue. Cathepsin S (Cat S) is a lysosomal cysteine protease that remains catalytically active at neutral pH and has been shown to play a role in radiation resistance and invasion of cancer cells. It is also an independent predictor of GBM patient survival.
Materials and methods:
GBM cell lines (U87MG and LN229) with lentiviral shRNA knockdown of Cat S are grown in serum-free medium with growth factors that allow de-differentiation of the cells into a stem-like state. A transwell system is used for quantifying monolayer invasion. Under stem conditions, spheroid structures are formed and their invasion in 3D is analysed with GFP expression.
Protein expression determined via Western blot. Radiation response determined via clonogenic survival assay. Proliferation measured using MTT assay. Cat S-like activity measured using fluorogenic peptide substrate cleavage.
Results:
Radiation induces Cat S protein expression and protease activity in both GBM cell lines at 24 hours. Knockdown of Cat S induces radiation sensitivity in both cell lines when differentiated. In stem-like conditions, this is observed for U87MG but not for LN229 cells.
Similarly, Cat S knockdown has no effect on proliferation of cell lines, except LN229 stem-like cells where it is increased.
Finally, Cat S knockdown reduces the invasive capacity of both differentiated cell lines and U87MG stem-like cells 3D invasion through both collagen and matrigel, but has no effect on LN229 stem-like cells. Cat S-like activity is reduced in all but stem LN229, despite complete knockdown.
Further investigation into differential effects in stem-like cells will examine possible role of autophagy, which is linked to radiation resistance and Cat S inhibition.
Conclusion
Cat S is a potential drug target in GBM as it reduces invasion and radio-resistance of glioma cell lines. The differential effect seen in stem-like cells suggests that the genetic background of tumours may be an important factor in determining utility of Cat S therapy in targeting the stem-like GBM population thought to be responsible for recurrence.
Citation Format: Robyn A. Foster, Shahnaz T. Al Rashid, Roberta E. Burden, Christopher J. Scott, Kevin M. Prise, Thomas J. Flannery. Effects of cathepsin S in differentiated and stem-like glioblastoma cells. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 2227. doi:10.1158/1538-7445.AM2015-2227
Abstract 2237: Involvement of Retinoic Acid Receptors RARβ and RARγ in growth, self-renewal and differentiation on mammary cancer stem cells
Authors: Berardi Damian E. , Flumian Carolina , Diaz Bessone Maria I. , Cirigliano Stefano M. , Bal de Kier Joffe Elisa D. , Urtreger Alejandro J. , Todaro Laura B. 
Published: August 2015

Abstract
Retinoids exert different effects on cell differentiation and malignant phenotype reversion through the modulation of Retinoid Acid Receptors (RAR).
In this work we have analyzed the involvement of retinoid system induction on proliferation, self-renewal and differentiation of cancer stem cells (CSC) using the triple negative mammary cell line LM38-LP.
In order to obtain a CSC enriched culture, cells where cultured under mammosphere conditions. We performed mammosphere cultures in order to enrich in CSC.
The treatment with All-trans retinoid acid (ATRA1μM for 96 h) reduced CSC growth rate evaluated as mammosphere diameter (Control: 176±8 μm vs. ATRA: 129±10 μm; p≤0.05). Surprisingly, ATRA pre-treatment for 96 h increased CSC self-renewal evaluated as the number of secondary mammospheres (Control: 313±19; ATRA: 495±21; p≤0.05) and as the clonogenic capacity of LM38-LP CSC (Control: 6±0.5; ATRA: 11±1.2; p≤0.05). Concomitant with these biological effects, the same treatment showed, by RT-PCR, an increase in RARβ and RARγ levels in LM38-LP- CSC.
Through the use of specific RAR antagonists, we found that RARγ inhibition impaired ATRA effects on self-renewal but RARβ inhibition increased the number of secondary mammospheres (Control: 382±27; ATRA: 735±11; ATRA/RARγ antagonist: 352±17; ATRA/RARβ Antagonist: 1260±177; p≤0.05). A similar result was observed when clonogenic capacity in RARγ blocked CSC was analyzed.
Finally, we performed a matrigel 3D culture using cells from LM38-LP mammospheres. Under these conditions, colonies presented large irregular structures while ATRA treatment led to the formation of differentiated colonies with evidence of lumen.
Our findings suggest that RARγ down modulation and RARβ induction could lead to CSC self-renewal inhibition and differentiation in triple negative mammary cancers.
Citation Format: Damian E. Berardi, Carolina Flumian, Maria I. Diaz Bessone, Stefano M. Cirigliano, Elisa D. Bal de Kier Joffe, Alejandro J. Urtreger, Laura B. Todaro. Involvement of Retinoic Acid Receptors RARβ and RARγ in growth, self-renewal and differentiation on mammary cancer stem cells. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 2237. doi:10.1158/1538-7445.AM2015-2237
Abstract 2241: MDM2 silencing promotes tumor-initiating cells in osteosarcoma and breast cancer
Authors: Olivos David J. , Mayo Lindsey D. 
Published: August 2015

Abstract
Chemotherapy has made remarkable strides in the past century to alleviate tumor burden across most cancer types, yet it remains ineffective at achieving complete tumor remission. To improve chemotherapy efficacy and patient survival, novel drugs will require a greater mechanistic understanding of tumor initiating cell (TIC) regulatory pathways. Intratumoral heterogeneity is a major obstacle for conventional targeted treatment modalities, which select for aggressive phenotypes with acquired drug resistance and TIC enrichment. Here we focus on elucidating the role of Mdm2 in mediating TIC levels in osteosarcoma (MG-63, Saos2) and breast cancer (MDA 231, MDA 468, and BT474) cell lines. We demonstrate Mdm2 silencing by ShRNA results in increased levels of Nanog, Oct4a, and Sox2, and diminished expression of ERα and ERβ by western blot. We observed an increase in the immunophenotypic expression of CD133 in ShMdm2 osteosarcoma and breast cancer cell lines by flow cytometry. Our data provides the first evidence that loss of Mdm2 results in increased TIC population. Further analysis will examine the affects of TIC using small molecular inhibitors to Mdm2. This insight will contribute to the molecular foundations defining the role of Mdm2 in TIC and will determine if targeting Mdm2 therapeutically is a prognostic indicator for recurrence.
Citation Format: David J. Olivos, Lindsey D. Mayo. MDM2 silencing promotes tumor-initiating cells in osteosarcoma and breast cancer. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 2241. doi:10.1158/1538-7445.AM2015-2241
Abstract 2247: SHP2 expression and function in different subtypes of glioblastoma
Authors: Roccograndi Laura , Bi Yingtao , Davuluri Ramana , Dahmane Nadia , O'Rourke Donald M. 
Published: August 2015

Abstract
SHP2, a Src-homology 2 domain (SH2)-containing tyrosine phosphatase encoded by PTPN11, is a ubiquitously expressed cytoplasmic enzyme that regulates events downstream of several growth factor and cytokine receptors involved in survival, pro-migratory and differentiation signaling. In the normal developing nervous system, SHP2 is involved in neural stem cell self renewal. Dysregulation of SHP2 function has been implicated in tumorigenesis and characterized as an activated downstream regulator of oncogenes in gastric carcinoma, anaplastic large-cell lymphoma, breast cancer and glioblastoma. In the context of glioblastoma, we have shown that SHP2, and specifically its phosphatase activity, is directly involved in EGFRvIII-induced oncogenesis. Our present research aims at understanding the function of SHP2 within different glioma cell types as well as the four characterized subtypes of glioblastoma (GBM). Genomic analysis of SHP2 expression using the TCGA GBM cohort shows differential expression among the recently characterized subtypes of GBMs, with higher SHP2 mRNA expression in the classical subtype. Additionally, SHP2 is preferentially expressed in glioma stem cells versus differentiated cells isolated from the same patients. Furthermore, our current analysis shows that reduction of SHP2 expression in glioma stem cells affects the expression of genes linked to stemness. SHP2 PTPase function may therefore be a link between normal stem cell proliferation and gliomagenesis induced by EGFR/RTK activated signaling.
Citation Format: Laura Roccograndi, Yingtao Bi, Ramana Davuluri, Nadia Dahmane, Donald M. O'Rourke. SHP2 expression and function in different subtypes of glioblastoma. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 2247. doi:10.1158/1538-7445.AM2015-2247
Abstract 2256: GLI2 inhibition suppresses metastasis of HER2+ breast cancer
Authors: Gupta Parul , Ranjan Alok , Fofaria Neel M. , Srivastava Sanjay K. 
Published: August 2015

Abstract
Metastasis of breast cancer is a significant problem majorly in HER2 positive cancer, as there are no therapeutic targets known. Due to inherent complexity of the process, underlying mechanisms of metastasis are largely unknown. We have shown previously that HER2 overexpression enhances the metastatic potential of breast cancer cells. The results from our previous studies showed that a 22 fold increase in HER2 expression in MDA-MB-231 cells lead to several orders of magnitude increase in the metastasis of the MDA-MB-231 cells. However, HER2 inhibition alone did not significantly suppress metastasis. Hence we investigated the molecular changes induced by HER2 expression that may promote metastasis of breast cancer cells. Interestingly, we observed an increased expression of GLI2 in the metastatic tumors formed by HER2+ cells in the mice lungs. GLI2 is a transcription factor of sonic hedgehog pathway and aberrant signaling of this pathway has been implicated in several cancers. In addition, GLI2 is overexpressed in breast tumors and associated with poor prognosis in breast cancer patients. GLI2 was therefore silenced using shRNA to study its role in metastasis of MDA-MB-231 high HER2 (HH) breast cancer cells. We achieved about 66% knock down of GLI2 expression using GLI2 shRNA. Our results showed that silencing of GLI2 inhibited the migration of HH cells by more than 60%. Our results also demonstrated over 80% inhibition of the invasion of (HH) cells with silenced GLI2. Furthermore, HH luciferase expressing cells were transfected with GLI2 shRNA or scrambled shRNA and equal numbers of live cells were injected intravenously in athymic nude mice. The trajectory and growth of control and GLI2 silenced MDA-MB-231 HH cells were monitored by non-invasive IVIS imaging system. A drastic reduction of luminescence was observed in the lungs of mice injected with GLI2 silenced HH cells as compared to mice injected with control HH cells, indicating inhibition of metastasis. Taken together our results establish GLI2 as an important target for therapy in HER2+ metastatic breast cancer. Further mechanistic studies are in progress. [Supported in part by R01 grant CA129038 awarded to S.K.S. by the National Cancer Institute]
Citation Format: Parul Gupta, Alok Ranjan, Neel M. Fofaria, Sanjay K. Srivastava. GLI2 inhibition suppresses metastasis of HER2+ breast cancer. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 2256. doi:10.1158/1538-7445.AM2015-2256