bluuebunny/crossref_metadata_2025_split huggingface dataset:
Abstract 3590: Resistance mechanisms to ALK inhibitors
Authors: Katayama Ryohei , Yanagitani Noriko , Koike Sumie , Sakashita Takuya , Kitazono Satoru , Nishio Makoto , Okuno Yasushi , Engelman Jeffrey A. , Shaw Alice T. , Fujita Naoya 
Published: August 2015

Abstract
Purpose: ALK-rearranged non-small cell lung cancer (NSCLC) was first reported in 2007. Approximately 3-5% of NSCLCs harbor an ALK gene rearrangement. The first-generation ALK tyrosine kinase inhibitor (TKI) crizotinib is a standard therapy for patients with advanced ALK-rearranged NSCLC. Several next-generation ALK-TKIs have entered the clinic and have shown promising antitumor activity in crizotinib-resistant patients. As patients still relapse even on these next-generation ALK-TKIs, we examined mechanisms of resistance to one next-generation ALK-TKI - alectinib - and potential strategies to overcome this resistance.
Experimental Procedure: We established a cell line model of alectinib resistance, and analyzed resistant tumor specimens from patients who had relapsed on alectinib. Cell lines were also established under an IRB-approved protocol when there was sufficient fresh tumor tissue. We established Ba/F3 cells expressing EML4-ALK and performed ENU mutagenesis to compare potential crizotinib or alectinib-resistance mutations. In addition, we developed Ba/F3 models harboring ALK resistance mutations and evaluated the potency of multiple next-generation ALK-TKIs including 3rd generation ALK inhibitor in these models and in vivo. To elucidate structure-activity-relationships of ALK resistance mutations, we performed computational thermodynamic simulation with MP-CAFEE.
Results: We identified multiple resistance mutations, including ALK I1171N, I1171S, and V1180L, from the ENU mutagenesis screen and the cell line model. In addition we found secondary mutations at the I1171 residue from the Japanese patients who developed resistance to alectinib or crizotinib. Both ALK mutations (V1180L and I1171 mutations) conferred resistance to alectinib as well as to crizotinib, but were sensitive to ceritinib and other next-generation ALK-TKIs. Based on thermodynamics simulation, each resistance mutation is predicted to lead to distinct structural alterations that decrease the binding affinity of ALK-TKIs for ALK.
Conclusions: We have identified multiple alectinib-resistance mutations from the cell line model, patient derived cell lines, and tumor tissues, and ENU mutagenesis. ALK secondary mutations arising after alectinib exposure are sensitive to other next generation ALK-TKIs. These findings suggest a potential role for sequential therapy with multiple next-generation ALK-TKIs in patients with advanced, ALK-rearranged cancers.
Citation Format: Ryohei Katayama, Noriko Yanagitani, Sumie Koike, Takuya Sakashita, Satoru Kitazono, Makoto Nishio, Yasushi Okuno, Jeffrey A. Engelman, Alice T. Shaw, Naoya Fujita. Resistance mechanisms to ALK inhibitors. [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 3590. doi:10.1158/1538-7445.AM2015-3590
Abstract 3604: Targeting the PIM kinases in combination with BTK inhibition is synergistic in preclinical models of B-cell malignancies
Authors: Bearss Jeremiah J. , Bahr Brigham L. , Soh Katie K. , Peterson Peter W. , Whatcott Clifford J. , Siddiqui-Jain Adam , Bearss David J. , Warner Steven L. 
Published: August 2015

Abstract
BTK inhibitors (e.g. ibrutinib) have significantly impacted the treatment of B-cell malignancies in a positive way. Single agent response rates with ibrutinib are 65% or higher in B-cell lymphomas and chronic lymphocytic leukaemia with the majority of patients enjoying a prolonged duration of response. Continued clinical development is needed, however, as most patients achieve only a partial response from their treatment and ultimately patients become refractory to ibrutinib leading to relapse and disease progression. Targeted combinations with ibrutinib could potentially increase the number of patients undergoing complete remission and combat emergent resistant mechanisms. The PIM family (1, 2, and 3) are serine/threonine kinases that have proven to be oncogenic in-part due to their ability to suppress c-Myc induced apoptosis. The PIM kinases have emerged as important regulators of drug resistance in multiple cancer types. Tolero Pharmaceutical's second generation PIM Kinase inhibitor, TP-3654 has exhibited favorable activity in preclinical models of prostate cancer, AML, and lymphoma. Due to the signaling crosstalk between BTK and PIM through the STAT transcription factors, we hypothesized that synergies may arise through the simultaneous targeting of both kinases. Here, we report a significant increase in drug activity when a BTK inhibitor (ibrutinib) was combined with TP-3654 in various lymphoma cell lines. In Granta-519 cells, the IC50 of ibrutinib decreased 3.5-fold, from 0.7 μM to 0.2 μM, when cultured in combination with a subtoxic concentration of TP-3654 (300 nM). Similarly, the IC50 of TP-3654 decreased 6-fold, from 2.4 μM to 0.4 μM, when cells were cultured in combination with a subtoxic concentration of ibrutinib (100 nM). BTK is known to attenuate the activity of the transcription factor STAT3, a major regulator of PIM kinase levels in cells. Due to this, mechanistic studies focused on analyzing the STAT3 pathway are ongoing to determine the downstream effects of using ibrutinib and TP-3654 in combination. Several lymphoma xenograft studies are also ongoing to further explore this combination in vivo. These results provide a strong rationale that inhibitors of PIM and BTK could be used in combination for the treatment of B-cell malignancies and other B-cell mediated diseases.
Citation Format: Jeremiah J. Bearss, Brigham L. Bahr, Katie K. Soh, Peter W. Peterson, Clifford J. Whatcott, Adam Siddiqui-Jain, David J. Bearss, Steven L. Warner. Targeting the PIM kinases in combination with BTK inhibition is synergistic in preclinical models of B-cell malignancies. [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 3604. doi:10.1158/1538-7445.AM2015-3604
Abstract 361: Opposite regulation of stromelysin expression in prostate tumor and its microenvironment
Authors: Sung Shian-Ying , Hsieh Chia-Ling 
Published: August 2015

Abstract
Crosstalk between cancer and milieu cells plays a central role during cancer progression, which includes determine the faith of increasing metalloproteinase secretion by cancer epithelial cells. Here, we showed prostate tumor and stromal fibroblasts expressed opposite levels of Stromelysin-1 and -2 in both 3D co-culture and paired patient samples. Macroarray and quantitative RT-PCR studies demonstrated significantly decreased of Stromelysin-1 expression in co-cultured HS27AC4-2 and 4 paired tumor associated fibroblasts that were collected in previous report. We noticed the Stromelysin-1 expression level was decreased in stromal region of prostate cancer. By contrast, Stromelysin-1 level was increased in malignant cancer epithelial cells in both cells and tissue staining. Canonical pathway study revealed of differentially gene expression between HS27AC4-2 and HS27ARWV including the majority of pathway enrichment in TGF-β and hydrogen peroxide as central mediators. Induction of Stromelysin-1 and -2 by TGF-β and/or hydrogen peroxide were preliminary validated in the conditioned medium of prostate cancer cells, PC3 and DU145, and paired patient stromal fibroblasts that confirmed the opposite regulation of Stromelysin-1 and -2 expression by hydrogen peroxide but not TGF-β. Our results demonstrate the differential regulation of Stromelysin-1 and -2 expression in prostate cancer cells and stromal fibroblasts through ROS, such as hydrogen peroxide, as mediator and shed the light on the potentially useful as indication for the differential regulation between cancer and stromal cells.
Citation Format: Shian-Ying Sung, Chia-Ling Hsieh. Opposite regulation of stromelysin expression in prostate tumor and its microenvironment. [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 361. doi:10.1158/1538-7445.AM2015-361
Abstract 3613: P300 inhibition enhances cytotoxic effect of Gemcitabine through E2F1 activation in pancreatic cancer
Authors: Ono Hiroaki , Basson Marc D. , Ito Hiromichi 
Published: August 2015

Abstract
Background:
Transcriptional cofactor, P300 has been reported to regulate cell cycle on G1/S transition. Previously, we shown that prolonged S-phase is associated with increased apoptosis induced by Gemcitabine (GEM) in pancreatic cancer cells. Thus, we hypothesized that targeting P300 enhances the cytotoxic effect of GEM on pancreatic cancer.
Methods:
We studied 2 human pancreatic cancer cell lines, Panc1 and MIAPaCa2. P300 was gene-silenced using siRNA, and P300 histone acetyltransferase (HAT) activity was inhibited by specific inhibitor C646. Cell viability was measured by WST-8 assay and GEM-induced apoptosis was measured using Caspase3 and PARP by Western blotting, Tunel assay by immunofluorescence staining, and Annexin V-PI staining by flow cytometry. CDK4/6 inhibitor Palbociclib was used to block S-phase entry.
Results:
Robust P300 expression was observed in pancreatic cancer cell lines and human pancreatic adenocarcinoma tissues. When P300 expression was depleted by specific P300 siRNA, cell viability after GEM treatment was decreased significantly compared with the control pancreatic cancer cells (43% decrease in MIAPaCa2 and 39% decrease in Panc1, respectively, p&lt;0.05). Increased GEM-induced apoptosis was confirmed by increased cleaved forms of Caspase3 and PARP, increased tunel positive cells, and increased Annexin positive cells in P300-depleted cells compared to the control cells. When S phase entry was blocked by Palbociclib, the effect of gene silencing of P300 on GEM-induced apoptosis was abolished. As Rb-E2F1 complex is known as the key regulator of the S phase specific gene transcriptions, we evaluated the effect of P300 gene silencing on Rb and E2F1. While P300 gene-silencing did not affect Rb phosphorylation after GEM treatment, it increased E2F1 expression significantly (56% increase in MIAPaCa2 and 119% increase in Panc1, respectively, p&lt;0.05). When pancreatic cancer cells were treated with combination of GEM and C646, P300 specific HAT inhibitor, the cell viability was reduced significantly compared with when treated with GEM alone (48% decrease for Panc1, and 58% for MIAPaCa2, respectively, p&lt;0.05).
Conclusion:
Targeting P300 by siRNA or HAT inhibitor enhances the efficacy of GEM on pancreatic cancer cells. Our observation suggests the presence of Rb-independent E2F1 regulatory mechanism in pancreatic cancer cells. This pathway may be an important therapeutic target to potentiate GEM chemotherapy in the treatment of pancreatic cancer.
Citation Format: Hiroaki Ono, Marc D. Basson, Hiromichi Ito. P300 inhibition enhances cytotoxic effect of Gemcitabine through E2F1 activation in pancreatic 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 3613. doi:10.1158/1538-7445.AM2015-3613
Abstract 3616: Development of a Sox2 targeting therapy for the treatment of lung squamous cell carcinoma
Authors: Ishida Naomasa , Fukazawa Takuya , Takaoka Munenori , Yamatsuji Tomoki , Morita Ichiro , Haisa Minoru , Takaoka Nagio , Naomoto Yoshio 
Published: August 2015

Abstract
Despite the recent development of several effective molecular targeted agents, lung cancer is the most common cause of cancer related deaths worldwide. Recently, molecular targeted therapies for pulmonary adenocarcinoma with mutant EGFR or ALK fusions have reduced non-tumor toxicity and have extended patient survival time compared to conventional chemotherapies. However, the development of molecular targeting drugs for NSCLC has made apparent the fact that histology is an important factor and molecularly targeted therapies have been more effective in pulmonary adenocarcinoma than in lung squamous cell carcinoma. Therefore, specific therapies that target lung squamous cell carcinoma are desperately needed.
Sox2 is a master pluripotency controller that was recently identified as a novel major oncogene, recurrently amplified and activated in lung squamous cell carcinoma. Immunohistochemistry shows that Sox2 expression is seen in approximately 55% of human pulmonary adenocarcinoma sections. On the other hand Sox2 expression is detected in more than 90% of lung squamous cell carcinoma sections. Inhibition of Sox2 by siRNA suppresses cell viability and colony formation of Sox2 expressing EBC2 and LK2 lung squamous cell carcinoma cells. Moreover, Sox2 siRNA inhibits lung squamous cell carcinoma growth in vivo in a xenograft mouse model derived from EBC2 cells. Flowcytometric analysis demonstrated that Annexin V positive and PI negative cell populations were not changed 48 hours after Sox2 silencing in EBC2 lung squamous cell carcinoma cells. Microarray analysis demonstrated that the expression of several cell cycle related genes were changed after Sox2 silencing in Sox2 expressing lung squamous cell carcinoma cells. Cell cycle analysis showed that Sox2 silencing significantly increased the G1 population in the cells. These results indicate that Sox2 silencing might produce an antitumor effect via G1 cell cycle arrest.
Citation Format: Naomasa Ishida, Takuya Fukazawa, Munenori Takaoka, Tomoki Yamatsuji, Ichiro Morita, Minoru Haisa, Nagio Takaoka, Yoshio Naomoto. Development of a Sox2 targeting therapy for the treatment of lung squamous cell carcinoma. [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 3616. doi:10.1158/1538-7445.AM2015-3616
Abstract 3618: SGKs survival signal via inhibition of pro-apoptotic Mixed Lineage Kinase 3 (MAP3K11) in cancer cells
Authors: Sondarva Gautam V. , Rangasamy Velusamy , Viswakarma Navin , Das Subhasis , Nair Rakesh Sathish , Rana Basabi , Rana Ajay 
Published: August 2015

Abstract
Survival of cancer cells requires activation of pro-survival and inhibition of pro-apoptotic pathways in concert. It is utmost important to understand the underlying molecular pathways that regulate cancer cell survival and death, so that specific inhibitor could be identified and used to target cancer cell death pathways. Dexamethasone (DEX) is routinely administered to cancer patients, in order to reduce allergic responses. It is reported that DEX use in certain cancer patients could lead to early cancer relapse and detrimental. Earlier, we reported that insulin regulated PI3K-AKT pathway down regulated pro-apoptotic Mixed Lineage Kinase 3 (MLK3) and this down regulation of kinase activity, favored cancer cell survival. Since SGK family members are also regulated by PI3K via Glucocorticoid Receptor (GR) in response to DEX, and SGK is reported to have similar function like AKT, we hypothesized that SGKs might also regulate pro-apoptotic function of MLK3, similar to AKT but probably via a non-redundant pathway.
Here we report that MLK3 is a direct target of SGK in cancer cells. Endogenous SGK physically associated with and phosphorylated MLK3 in HepG2 cells and this interaction was regulated by synthetic glucocorticoid, dexamethasone. JNK and MLK3 kinase activities were significantly inhibited either by over expression of SGK3 or by dexamethasone. The SGK3 and dexamethasone-mediated attenuation of MLK3, MKK7 and JNK kinase activities were blocked by PI3K inhibitor, LY294002, suggesting a link between PI3K-SGK and MLK3-JNK signaling pathways. SGK phosphorylated MLK3 both in vivo and in vitro. SGK1 and SGK2/3 phosphorylated MLK3 on Ser674 and Thr738, respectively. Furthermore, SGK3 inhibited MLK3-mediated cell death and JNK kinase activity in a manner, dependent on Thr738 phosphorylation of MLK3. Taken together, these data define the mechanisms of glucocorticoid-mediated inhibition of MLK3-JNK axis and cell death pathways. Furthermore, our data also identify MLK3 as an indirect target of glucocorticoids that might play a significant role in the pro-survival and anti-inflammatory actions of glucocorticoid in cancer cell. Therefore, it is conceivable that targetting MLK3 with its agonist, ceramide (by nano-ceramide particles) could possibly overcome DEX-induced cancer relapse.
This work is supported by VA Grant #: BX000312 and NIH, R01 CA 176846 to AR; and VA Grant #: BX000571to BR.
Citation Format: Gautam V. Sondarva, Velusamy Rangasamy, Navin Viswakarma, Subhasis Das, Rakesh Sathish Nair, Basabi Rana, Ajay Rana. SGKs survival signal via inhibition of pro-apoptotic Mixed Lineage Kinase 3 (MAP3K11) in cancer 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 3618. doi:10.1158/1538-7445.AM2015-3618
Abstract 3619: Arsenic trioxide downregulates NPM-ALK and inhibits the proliferation of ALK-positive anaplastic large cell lymphoma
Authors: Piao Wenying , Chau David HW , Yue Kevin LM , Kwong Yok Lam , Tse Eric WC 
Published: August 2015

Abstract
INTRODUCTION
Anaplastic Large Cell Lymphoma (ALCL) is a mature T-cell lymphoma. Depending on the presence or absence of chromosomal translocations involving the anaplastic lymphoma kinase ALK gene and hence the expression of ALK, ALCL is further subdivided into ALK positive (ALK+) or ALK negative (ALK-) types. NPM-ALK chimeric fusion oncogenic protein is found in around 80% of ALK+ ALCL, as a result of the chromosomal translocation t(2;5)(p23;q35). The current standard of treatment for ALK+ ALCL is combination chemotherapy. Crizotinib, an ALK tyrosine kinase inhibitor, is the only agent available to target NPM-ALK in ALCL. The identification of other targeting agents would potentially improve the treatment outcome of ALK+ ALCL especially for relapsed and/or refractory cases. In this study, we investigated the effect of arsenic trioxide (As2O3) on NPM-ALK in ALCL.
Methods
We treated ALK+ ALCL cell lines with various clinically achievable concentrations of As2O3 (0, 0.5, 1 and 2μM) for 24 hours and examined its effects on NPM-ALK mRNA expression by semi-quantitative RT-PCR and protein expression by Western immunoblotting. The downstream signaling pathway of NPM-ALK, phosphorylation of STAT3 on Tyr705, was also examined. Next, we analyzed apoptotic cell death and growth arrest induced by As2O3 in ALK+ and ALK- ALCL cell lines using Annexin V-7AAD staining and cell cycle analysis. The effect of As2O3 on cell viability was also measured with WST-1 assay.
RESULTS
Our data showed that As2O3 downregulated NPM-ALK at the protein level without affecting the transcription. It also inhibited the phosphorylation of STAT3 in all ALK+ ALCL cell lines. We also found that blocking protein degradation through proteasome with MG132 abrogated the effect of As2O3 on NPM-ALK. Furthermore, As2O3 induced apoptotic cell death, cell cycle arrest at G2/M phase and growth inhibition in ALK+ but not in ALK- ALCL cell lines, with a GI50 of less than 1μM, which was a level achievable with clinical use of As2O3.
CONCLUSIONS.
Our data demonstrated that As2O3 downregulated NPM-ALK by facilitating protein degradation through the proteasomal pathway, thereby inhibited cell proliferation and induced cell death in ALK+ ALCL. As2O3 may therefore represent a potential therapeutic agent for the treatment of ALK+ ALCL.
Citation Format: Wenying Piao, David HW Chau, Kevin LM Yue, Yok Lam Kwong, Eric WC Tse. Arsenic trioxide downregulates NPM-ALK and inhibits the proliferation of ALK-positive anaplastic large cell lymphoma. [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 3619. doi:10.1158/1538-7445.AM2015-3619
Abstract 3620: An oral procaspase activating drug, PAC-1, shows preclinical promise for glioblastoma therapy
Authors: Joshi Avadhut D. , Botham Rachel C. , Roth Howard S. , Fan Timothy M. , Tarasow Theodore M. , Hergenrother Paul J. , Riggins Gregory J. 
Published: August 2015

Abstract
PAC-1 is an oral administered procaspase-3 activating drug developed to overcome the malignant cell's barrier to apoptosis. The promising preclinical safety and efficacy of PAC-1 has led to its consideration for a first in human phase 1 clinical trial for recurrent and advanced malignancies. We have found that because PAC-1 is able to reach intracranial brain tumors in effective concentrations, that it is particularly useful for glioblastoma (GBM), an aggressive and invasive malignancy responsible for the most deaths due to brain cancer. In glioblastoma patients a worse prognosis was correlated with high expression of procaspase-3 mRNA, indicating that procaspase-3 activation may be involved in the pathology of the tumor progression. In preclinical testing of PAC-1, it showed significant survival benefit and low systemic toxicity, in orthotopic animal models of glioblastoma. An aqueous suspension of PAC-1 delivered orally to rats with intracranial 9L glioblastoma improved survival compared to untreated controls. Additionally, when PAC-1 was administered as an oral capsule to rats with 9L glioblastoma, median survival increased over three fold. Oral PAC-1 improved survival significantly also in a human xenograft model (p = 0.04) compared to controls. PAC-1 combined effectively with standard of care, and in some animals, either alone or in combination resulted in long term survival. PAC-1 has the ability to penetrate sufficiently within intracranial tumors and its ability to overcome resistance to apoptosis and activate widespread cell death specifically in the malignant cells makes it a promising small molecule for further preclinical and clinical development.
Citation Format: Avadhut D. Joshi, Rachel C. Botham, Howard S. Roth, Timothy M. Fan, Theodore M. Tarasow, Paul J. Hergenrother, Gregory J. Riggins. An oral procaspase activating drug, PAC-1, shows preclinical promise for glioblastoma therapy. [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 3620. doi:10.1158/1538-7445.AM2015-3620