bluuebunny/crossref_metadata_2025 huggingface dataset:
Abstract 4662: Comparing 2D and 3D culture models for in vitro therapeutic screening of paclitaxel loaded micelles co-administered with iRGD peptide
Authors: Chowdhury Nayela N. , Das Nandita G. , Das Sudip K.
Published: August 2018

Clinical efficacy of paclitaxel, a potent chemotherapeutic agent, is limited by its nonspecificity that leads to toxic side effects. Polymeric micellar formulations of paclitaxel were designed with the long term goals of decreasing toxicity by tumor targeting, increasing circulation time, and enhancing permeability and retention in solid tumors. Biodegradable amphiphilic block copolymers that self assemble into micelles were used to entrap hydrophobic paclitaxel in the core. Traditional 2D cell culture models are standard for cytotoxicity assays. However, they lack the diffusion gradient and cell to cell interactions present in solid tumors which 3D multicellular tumor spheroids are capable of providing. We evaluated the in vitro cytotoxicity of polymeric micelles entrapping paclitaxel in 3D multicellular tumor spheroids of triple negative breast cancer cells and compared it with the standard 2D model. We added the cell penetrating iRGD peptide with the expectation that the iRGD peptide will increase the cellular uptake of the paclitaxel micelles. Particle uptake is enhanced due to the interaction of the iRGD peptide with the highly expressed integrin receptor on the cell surface, followed by neuropilin receptor binding which mediates an active transport system for deep tumor permeation. Paclitaxel loaded micelles were prepared and the drug content was analyzed. The cytotoxicity of the micellar paclitaxel nanocarrier system was studied in both the 2D and 3D cell culture models. Micellar paclitaxel induced cytotoxicity was significantly higher than free paclitaxel for the same concentrations of paclitaxel. Furthermore, a synergistic growth inhibitory response was observed upon coadministration of iRGD compared to treatment with the paclitaxel loaded nanocarriers on their own. Significantly higher concentration of the drug was needed in the 3D cultures to achieve comparable levels of cytotoxicity to the 2D cell culture models. This suggested that multicellular tumor spheroids exhibit higher resistance to anticancer drugs, supporting the fact that 3D culture is the better model to study in vitro cytotoxicity and likely to produce biorelevant data.

Citation Format: Nayela N. Chowdhury, Nandita G. Das, Sudip K. Das. Comparing 2D and 3D culture models for in vitro therapeutic screening of paclitaxel loaded micelles co-administered with iRGD peptide [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 4662.
Abstract 4674: IL-35 regulates anti-tumor immune response in pancreatic ductal adenocarcinoma
Authors: Mirlekar Bhalchandra , Searcy Ryan , Pylayeva-Gupta Yuliya
Published: August 2018

Despite advances in our understanding of the mutational landscape in pancreatic ductal adenocarcinoma (PDA), this devastating disease is now the third-leading cause of U.S. cancer-related deaths. While recent successes of cancer immunotherapy have generated considerable excitement, this form of treatment has been largely ineffective in patients with pancreatic cancer. A major barrier for immunotherapeutic approaches is marked immunosuppression within the PDA milieu. We have previously identified a novel role for IL-35 producing B regulatory cells in the pathogenesis of pancreatic cancer. However, little is known about the mechanisms behind IL-35 activity in cancer. The overarching goal of this project is to elucidate molecular and cellular mechanisms by which IL-35 facilitates the emergence of pancreatic cancer. Our results demonstrate that IL-35, but not IL-10, potentiates PDA growth. This correlates with induction of immunosuppressive T regulatory cells (Treg) and suppression of T effector cell (Teff) and cytotoxic CD8+ T cell activity, suggesting that IL-35 controls anti-tumor immune responses in PDA. Remarkably, while PDA is typically resistant to anti-PD1 immunotherapy, IL-35 deficiency converted PDA from immunologically ‘cold' to ‘hot' tumor, which allowed for a robust synergistic reduction in tumor growth in response to anti-PD-1 treatment. Insights gleaned from these and further mechanistic studies of IL-35 in PDA may be expeditiously translated into IL-35 targeted combination immunotherapy.

Citation Format: Bhalchandra Mirlekar, Ryan Searcy, Yuliya Pylayeva-Gupta. IL-35 regulates anti-tumor immune response in pancreatic ductal adenocarcinoma [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 4674.
Abstract 4679: Rectal cancer-infiltrating T cells show clonal expansion associated with spatially restricted tolerogenic phenotypes
Authors: Penter Livius , Dietze Kerstin , Aigner Felix , Bullinger Lars , Blankenstein Thomas , Hansmann Leo
Published: August 2018

T cell infiltration correlates with prognosis and outcome in colorectal cancer regardless of the tumor stage. However, data on clonal expansion, phenotypes, functions, and spatial distribution of tumor-infiltrating T cells (TILs) are limited.

We hypothesized that subsets of clonally expanded rectal cancer-associated T cells are specifically recruited into the tumor and show characteristic phenotypes and functions.

Paired TILs and T cells from adjacent unaffected mucosa were isolated from five treatment-naïve rectal cancer patients. Although T cell immune phenotypes were heterogeneous, the frequencies of CD38+, PD-1+, and TIM-3+ cells were significantly higher in CD8+ TILs when compared to T cells from unaffected mucosa (p < 0.05). To track clonal expansion and phenotypes at the single cell level, we combined 13-parameter FACS single cell index sorting with next generation T cell receptor (TCR) and phenotype sequencing. Paired TCRαβ sequences were obtained from 1237 TILs (on average 412 TILs per patient) and 1257 T cells infiltrating the unaffected mucosa (on average 419 T cells per patient) from three selected patients. Clonal T cell expansion was not restricted to TILs and occurred predominantly in CD8+ T cells (p < 0.05). Expanded TIL clones were more frequently TIM-3+, PD-1+, and CD38+ (p < 0.05) and occupied characteristic phenotype compartments when compared to T cells from unaffected mucosa with t-stochastic neighbor embedding (t-SNE) visualization. FOXP3 expression was enriched in non-expanded TILs (p < 0.05).

Only 11 out of 179 TIL clones were also detectable in unaffected mucosa of the same patients and these overlapping clones were exclusively PD-1- TIM-3-.

In conclusion, rectal cancer is infiltrated by oligoclonal T cells. Selected clones were exclusively detected in TILs suggesting their expansion and recruitment driven by tumor-associated cues. Tolerance was induced i) in an antigen-specific manner by the expression of immune checkpoint molecules predominantly on clonally expanded TILs, and ii) in an antigen-independent manner by infiltrating polyclonal FOXP3+ regulatory T cells.

Citation Format: Livius Penter, Kerstin Dietze, Felix Aigner, Lars Bullinger, Thomas Blankenstein, Leo Hansmann. Rectal cancer-infiltrating T cells show clonal expansion associated with spatially restricted tolerogenic phenotypes [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 4679.
Abstract 4685: Phenotypic difference of CD103+ tissue-resident memory T cells in various cancers
Authors: Park Hye Seon , Kim Young-Ae , Bang Won Seon , Lee Heejae , Lee Miseon , Park In Ah , Song In Hye , Heo Sun-Hee , Lee Hyeonjin , Lee Hee Jin , Gong Gyungyub
Published: August 2018

Background: The presence and clinical importance of tissue-resident memory T cells (TRM) have been recently described in human lung, liver, and bladder cancer. However, the frequency and phenotypic characteristics of TRM in other tumors are largely unknown.

Methods: We analyzed single-cell populations of renal cell carcinoma (n=20), breast (n=16), colorectal (n=20), and stomach cancer (n=15) by dissociation of tumor tissue with collagenase/hyaluronidase. We investigated population of memory T cells and TRM using anti-CD45RO or anti-CD103 antibodies by flow cytometry.

Results: Colorectal cancer had higher level of CD4+ T cells (70.1%) among CD3+ T cells than other tumors (stomach cancer, 59.6%; renal cell carcinoma, 49.4%; breast cancer, 49.0%; p=0.001). In CD4+ T cells, the percentage of CD45RO+ memory T cells was higher in renal cell carcinoma (75.7%) and breast cancer (85.4%) than colorectal (36.9%) and stomach cancer (38.1%, p<0.001). About 4% of CD4+ T cells in renal cell carcinoma, colorectal and stomach cancer were TRM, while 14.3% of CD4+ T cells were TRM in breast cancer (p<0.001). The percentage of CD45RO+ memory T cells among CD4+ TRM was about 60% in all tumors (p=0.164). In CD8+ T cells, the percentage of CD45RO+ memory T cells was higher in renal cell carcinoma (73.5%), breast (66.4%) and stomach cancer (54.4%) than colorectal cancer (33.0%, p<0.001). Stomach cancer had higher level of TRM (74.3%) among CD8+ T cells than other tumors (colorectal cancer, 19.6%; renal cell carcinoma, 20.1%; breast cancer, 30.6%; p<0.001). The percentage of CD45RO+ TRM in renal cell carcinoma (89.3%) and breast cancer (89.5%) was higher than colorectal (43.0%) and stomach cancer (51.5%, p<0.001).

Conclusions: The frequency and phenotypic characteristics of TRM in renal cell carcinoma, colorectal, stomach, and breast cancer were different. Further studies regarding functional difference and clinical significance of TRM in various tumors are warranted.Acknowledgement: This study was supported by Basic Science Research Programs through the National Research Foundation of Korea(NRF) funded by the Ministry of Science, ICT & Future Planning, Republic of Korea (NRF-2017R1D1A1B03033104).

Citation Format: Hye Seon Park, Young-Ae Kim, Won Seon Bang, Heejae Lee, Miseon Lee, In Ah Park, In Hye Song, Sun-Hee Heo, Hyeonjin Lee, Hee Jin Lee, Gyungyub Gong. Phenotypic difference of CD103+ tissue-resident memory T cells in various cancers [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 4685.
Abstract 4707: Pelareorep promotes the expression of a chemokine signature that predicts response to immunotherapy
Authors: Wilkinson Grey A. , Piar Aine , Cesarz Zoe , Tran Hue , Chakrabarty Romit , Gutierrez Andres , Coffey Matt
Published: August 2018

Introduction: It has been proposed that the presence of inflamed tumor phenotypes, characterized by the presence of infiltrating lymphocytes and the expression of specific chemokines and cytokines, can predict response to immunotherapy and result in better patient outcomes [1, 2]. We hypothesized that pelareorep, an immuno-oncolytic virus (IOV), may elicit predictive proinflammatory gene signatures in select cancer cell lines permissive to viral infection.

Methods: Cell lines derived from non-small cell lung cancer (NSCLC, H522), colorectal cancer (CRC, SW-620), and hepatocellular carcinoma (HCC, SNU 387) were infected at an multiplicity of infection equal to 50. We examined changes in gene expression and conducted cell viability assays at 6, 12, and 18 hours post pelareorep infection (including a non-infected control). To monitor changes in gene expression we employed a custom 780-gene Pan Cancer Immune panel developed by nanoString Technologies and specifically monitored for changes in the expression of key interferon and NF-κB signalling genes, immune checkpoint ligands, and a 12-gene chemokine signature predictive of a positive response to immunotherapy identified by Messina et al. [2].

Results: All cell lines examined were susceptible to pelareorep induced cytopathic effect. Strikingly, principal component analysis revealed that the changes in gene expression were unique and different for each cell line. Of the cell lines examined, only HCC cells infected with pelareorep promoted an inflammatory signature, similar to the one used to predict response to immunotherapy in melanoma [2].

Conclusions: This study demonstrates that pelareorep can prime or promote a predictive inflamed tumor phenotype in HCC, which correlates with the innate response recently described in HCC- animal models treated with pelareorep [3]. The role of pelareorep in the treatment of hepatocellular carcinoma deserves further investigation, particularly in combination with other immunotherapies.

References: [1] Gajewski, T.F., The Next Hurdle in Cancer Immunotherapy: Overcoming the Non-T-Cell-Inflamed Tumor Microenvironment. Semin Oncol, 2015. 42(4): p. 663-71. [2] Messina, J.L., et al., 12-Chemokine gene signature identifies lymph node-like structures in melanoma: potential for patient selection for immunotherapy? Sci Rep, 2012. 2: p. 765. [3] Samson, A., et al., Oncolytic reovirus as a combined antiviral and anti-tumour agent for the treatment of liver cancer. Gut, 2016.

Citation Format: Grey A. Wilkinson, Aine Piar, Zoe Cesarz, Hue Tran, Romit Chakrabarty, Andres Gutierrez, Matt Coffey. Pelareorep promotes the expression of a chemokine signature that predicts response to immunotherapy [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 4707.
Abstract 4738: IL-17 induces myeloid-related stimulating factors by stromal cells
Authors: Mucciolo Gianluca , Curto Roberta , Curcio Claudia , Roux Cecilia , Vannucci Luca , Novelli Francesco , Cappello Paola
Published: August 2018

Pancreatic ductal adenocarcinoma (PDA) is one of the most aggressive cancer with a 5-year survival rate of ∼ 8%. An hallmark of PDA is the massive desmoplasia and the complex stromal-tumor interaction, regulated by a pletory of secreted factors. The role of IL-17 and T-helper 17 in cancer progression or anti-tumour immunity remain controversial. To assess the role of this molecule, we crossed genetically engineered mice (GEM) characterized by a spontaneous PDA development, with IL-17 knockout mice (GEM/IL-17 KO). The absence of IL-17 correlated with an increased pancreatic fibrosis, evaluated by second harmonic generation approach. The transcripts and secretome of Cancer Associated Fibroblasts (CAFs), obtained from tumors arose in both WT and IL-17 KO GEM, have been evaluated. More than 60 genes were differently modulated in the CAFs from GEM/IL-17 KO mice. Among them, GM-CSF, G-CSF, M-CSF, CXCL1 and 2 where strongly up-regulated in GEM/WT compared to GEM/IL-17 KO mice and significantly inhibited by the addition of the recombinant cytokine. The absence of those factors paralleled an increased Th1-skewed cytokine pattern released by CAF that affected T cell infiltration and response. Taken together, these results suggest that IL-17 does affect the tumor progression by promoting a CAFs-mediated release of cytokines involved in myeloid cells recruitment and suppression of an anti-tumoral immune response. This feature defines IL-17 as a potential target to shape the tumor microenvironment and favour immunotherapy success.

Citation Format: Gianluca Mucciolo, Roberta Curto, Claudia Curcio, Cecilia Roux, Luca Vannucci, Francesco Novelli, Paola Cappello. IL-17 induces myeloid-related stimulating factors by stromal cells [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 4738.
Abstract 4786: WSD0922: A novel, oral bioavailable, brain penetrable and reversible EGFRm+ inhibitor for the treatment of primary and metastatic brain tumors
Authors: Zhong Wei , Zhang Jinqiang , Mu Zhihua , Sun Claire
Published: August 2018

Epidermal growth factor receptor (EGFR) is a cell surface protein that regulates normal cellular growth in tissues of epithelial origin. Des-regulated EGFR signaling (caused by mechanisms of overexpression, mutation, autocrine activation) contributes for oncogenesis by inducing cells proliferation and resisting apoptosis. In patients with NSCLC, activating mutants (EGFRm+) occur within exon 18-21 with increased EGFR activity. About 90% of these mutations (G719x, exon 19 deletions and exon 21 mutation) are sensitizing EGFRm+. EGFR TKIs have shown good performance in clinic for systemic NSCLC anchoring EGFRm+. However, up to 65% of NSCLC patients will develop brain metastasis (BM) ultimately. Current approved EGFR TKIs are not so effective for BM due to limited brain penetration as they are substrates of P-gp or BCRP, two main efflux transporters expressed on human BBB. In patients with GBM, the most common mutation is EGFRvIII (exon2-7 deletion) with an overall frequency of 25–64%. Current EGFR TKIs are ineffective in GBM treatment probably due to resistance caused by EGFRvIII as well as limited brain penetration. One-year survival of GBM patients is approximate 43%. Herein, we report a discovery of brain penetrable EGFR inhibitor WSD0922 for NSCLC BM and GBM with IC50 against EGFRm is <10nM. The ex-vivo antiproliferative GI50 in GBM tissues with EGFRvIII amplification is <100nM. WSD0922 is highly selective over other kinases. In-vitro MDCKII transfected cells and Caco-2 assays showed that WSD0922 is highly permeable and not a substrate of P-gp or BCRP. Preclinical CNS PK studies confirmed good brain penetration of WSD0922 with Kp,uu,brain close to unity. Treatment of mice bearing PC-9 (exon 19 del of NSCLC) in both subcutaneous (SC) and intracranial models with WSD0922 at 1-10mpk BID via PO resulted in dose dependent tumor growth inhibition (TGI) or regression with statistically significant survival benefit. Moreover, significant TGI for mice bearing GBM PDX model was achieved by treatment with

WSD0922. No toxicity was observed in the animals during the treatment. Predicted human PK properties are very promising to offer sufficient target engagement in clinic. Taken together, our data provide a good rationale for WSD0922 to be developed toward clinic for the treatment of patients with BM of NSCLC or GBM harboring EGFRm+.

Citation Format: Wei Zhong, Jinqiang Zhang, Zhihua Mu, Claire Sun. WSD0922: A novel, oral bioavailable, brain penetrable and reversible EGFRm+ inhibitor for the treatment of primary and metastatic brain tumors [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 4786.
Abstract 4787: SKLB188 inhibits the growth of head and neck cancer cell growth by suppressing EGFR signaling
Authors: Huang Shile , Barzegar Mansoureh , Ma Shuang , Yang Shengyong
Published: August 2018

Overexpression of epidermal growth factor receptor (EGFR) occurs in approximately 90% of head and neck squamous cell carcinoma (HNSCC), and is correlated with poor prognosis. Thus, targeting EGFR is a promising strategy for treatment of HNSCC. So far, only Cetuximab, an anti-EGFR monoclonal antibody, has been approved for EGFR-target therapy in HNSCC. Here we show that SKLB188, a newly synthesized small molecule compound, inhibited cell proliferation and induced apoptosis of HNSCC cells in vitro and in vivo, by targeting EGFR signaling. SKLB188 induced cell cycle arrest in G1 phase, by downregulating the expression of Cdc25A, cyclins D1/A and cyclin dependent kinases (CDK2/4), and upregulating the expression of CDK inhibitors (p21Cip1 and p27Kip1), leading to decreased phosphorylation of Rb. SKLB188 also downregulated the expression of Mcl-1 and survivin, inducing caspase-dependent apoptosis. Molecular docking predicted that SKLB188 could bind to the kinase domain of EGFR through hydrogen bonds and hydrophobic interactions. In vitro kinase assay revealed that SKLB188 inhibited the activity of a recombinant human EGFR very potently (IC50 = 5 nM). Western blot analysis showed that SKLB188 inhibited the phosphorylation of EGFR and its downstream targets, extracellular signal-regulated protein kinases 1 and 2 (Erk1/2) and Akt in the cells. In addition, SKLB188 dose-dependently inhibited FaDu xenograft growth in nude mice, and concurrently inhibited the phosphorylation of Erk1/2 and Akt in the tumors. Taken together, our results support that SKLB188 inhibits the growth of HNSCC cells in vitro and in vivo by targeting EGFR signaling.

Citation Format: Shile Huang, Mansoureh Barzegar, Shuang Ma, Shengyong Yang. SKLB188 inhibits the growth of head and neck cancer cell growth by suppressing EGFR signaling [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 4787.
Abstract 4789: Clinical candidate DBPR112: A novel epidermal growth factor receptor inhibitor as a promising treatment for non-small cell lung cancer
Authors: Hsieh Hsing-Pang , Chang Jang-Yang , Kuo Ching-Chuan , Hsu John
Published: August 2018

Lung cancer is one of the chief causes of cancer death in the world; in addition, non-small cell lung cancer (NSCLC) accounts for 85% of the lung cancer deaths. The development of tyrosine kinase inhibitors (TKIs) targeting epidermal growth factor receptor (EGFR) have shown remarkable effects in patients but some acquired resistance after treatment. Therefore, the discovery of efficacious EGFR-TKIs poses an utmost priority. Our team at IBPR has designed and synthesized a series of compounds by high throughput parallel synthesis platform. In the subsequent structure-activity relationship study (SAR) and lead optimization, approximate 150 compounds were synthesized, which concluded that the presence of an N,N-dimethyl functional group on the Michael acceptor and the S-chirality of the phenylaminoethanol side chain were both essential. Consequently, DBPR112 was identified as a potent EGFR-TKI clinical candidate showing excellent inhibitory ability on EGFRL858R/T790M and EGFR exon 20 insertion. DBPR112 was orally effective against the growth of human lung H1975 tumors subcutaneously xenografted in nude mice. A dramatic reduction in tumor size was noted with DBPR112 treatment, while displaying negligible body weight loss in all dosing groups. Furthermore, DBPR112 was more tolerable than afatinib in mice. To date, all pre-clinical studies were completed, and the IND application of DBPR112 was approved by US FDA in 2016 and the Phase I clinical trial has been initiated since July 2017 in Taiwan.

Citation Format: Hsing-Pang Hsieh, Jang-Yang Chang, Ching-Chuan Kuo, John Hsu. Clinical candidate DBPR112: A novel epidermal growth factor receptor inhibitor as a promising treatment for non-small cell lung cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 4789.
Abstract 4793: WSD1227: A novel, oral bioavailable, brain penetrable and reversible VEGFR inhibitor for the treatment of primary and metastatic brain tumors
Authors: Zhang Jinqiang , Zhong Wei , Mu Zhihua , sun claire
Published: August 2018

Occurrence of brain metastases (BM) has been reported in ~10% cancer patients as a later manifestation of the disease with incidence depending on the type of primary tumors1: about 20~40% in NSCLC and BC2,3 and <5% in CRC4,5 and ovarian cancer (OC)6. The incidence of BM is increasing in part due to the earlier diagnosis by using brain imaging techniques and the improved survival offered by systemic therapies. Patients with BM have a very poor prognosis and the overall survival is only several months after diagnosis. Surgery and radiotherapy either as single treatment or in combination are the most common options for the management of BM since many anticancer drugs cannot cross the blood-brain barrier (BBB). VEGFR2, upregulated in many cancers7,8, plays an important role in tumor angiogenesis. Anti-angiogenesis has been proved to be a good strategy to shrink tumor in many cancer treatments, such as bevacizumab in GBM, NSCLC, mBC, cediranib in OC, etc. However, those clinical validated anti-VEGF agents cannot cross BBB effectively due to either large molecule weight or being substrate of BBB efflux transporters. Herein, using our advanced medicinal chemistry with deep knowledge in CNS area, a BBB penetrable, selective and potent VEGFR2 inhibitor WSD1227 is discovered with biochemical IC50 against VEGFR1/2/3 at 0.69/0.35/0.41nM versus against other targets such as PDGFRα IC50 22.9nM, PDGFRβ IC50 19.4nM, cKit IC50 383nM, FLT3 IC50 555 nM and CSF1R IC50 1062nM. In-vitro MDCKII transfected cell assays demonstrated WSD1227 is not a substrate of P-gp or BCRP, two main efflux transporters on human BBB. Preclinical CNS PK studies confirmed good brain penetration of WSD1227 with Kp,uu,brain close to unity. WSD1227 possessed superior PK profile with sufficient free PK exposure to achieve target engagement in mice. Treatment of mice bearing SW620, a CRC xenograft in both subcutaneous (SC) and intracranial models with WSD1227 after oral dosing resulted in

significant tumor growth inhibition (TGI). Similar TGI was observed in SKOV-3 bearing mice, an OC xenograft in both SC and intracranial models. No toxicity was observed in the animals during the treatment. Moreover, predicted human PK properties are very promising to offer sufficient target engagement at a pretty low dose in clinic. Taken together, our data provide a good rationale for WSD1227 to be developed toward clinic for the treatment of patients with BM whose primary tumors have already been controlled well by systemic therapies.

Citation Format: Jinqiang Zhang, Wei Zhong, Zhihua Mu, claire sun. WSD1227: A novel, oral bioavailable, brain penetrable and reversible VEGFR inhibitor for the treatment of primary and metastatic brain tumors [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 4793.
Abstract 4804: Multitargeted kinase inhibition (AEE788) alleviates mTOR inhibitor drug resistance in triple-negative breast cancer
Authors: He Jichao , McLaughlin Ronan P. , Noord Vera van der , Westen Gerard van , Zhang Yinghui , Water Bob van de
Published: August 2018

Triple negative breast cancer (TNBC), although accounting for 15-20% of breast cancer, is disproportionally responsible for female cancer death. Despite therapeutic strategies being advanced, the clinical outcome of mTOR-targeted chemotherapy remains poor in the past decades. Recent data have evidenced the interdependence of kinase signaling networks and their involvement in treatment refractory TNBC settings. Thus, a combinatorial therapy targeting multiple components of signaling cascade is urgently needed. We assessed drug response phenotype across 20 TNBC cell lines by profiling the effect of a kinase inhibitor library consisting of >350 different kinase inhibitors (KIs). A panel of TNBC cell lines clustered with resistance phenotype against rapalogues (rapamycin analogues). Rapamycin efficacy on TNBCs was detected by performing proliferation assays and calculating their IC50, respectively. Given the role of the mTOR pathway in translational control, the relationship between rapamycin responses (IC50) and translational factors expression in TNBC cell lines was studied by Pearson analysis. Notably, translation initiation factor EIF2B2, EIF2S3, EIF3S8 and EIF1AX positively correlated with rapamycin response, whereas EIF4EBP2 and EIF2AK2 displayed negative correlation. Next, a rapamycin combination KI library screen was performed to identify kinase inhibitors synergizing with mTOR inhibition. AEE788, a multiple kinase targeting inhibitor, synergistically enhanced inhibitory effect of rapamycin on TNBC cell proliferation. Moreover, AEE788 dose-dependently synergized with mTOR targeted therapy in several TNBC cell lines. The combination treatment significantly decreased phosphorylation level of mTOR and 4EBP1 as well as ERK, indicating downregulation of PI3K/AKT and MAPK pathways. ChEMBL-based cheminformatics analysis indicated that, besides VEGFR and EGFR, a number of other kinases were predicted as the targets of AEE788, including RPS6K1, AKT2 and CDK7. Altogether, our data reveals the essential role of rapamycin-associated translation factors in TNBC, and provides insight in the resistance of TNBC to rapamycin analogues as well as potential therapeutic approaches to alleviate rapamycin resistance.

Citation Format: Jichao He, Ronan P. McLaughlin, Vera van der Noord, Gerard van Westen, Yinghui Zhang, Bob van de Water. Multitargeted kinase inhibition (AEE788) alleviates mTOR inhibitor drug resistance in triple-negative breast cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 4804.
Abstract 4817: EP-100 sensitizes BRCA wild-type ovarian cancer cells to PARP inhibitor
Authors: Ma Shaolin , Pradeep Sunila , Wu Sherry , Kim Mark Seungwook , Hu Wei , Mangala Selanere , Coleman Robert L. , Sood Anil K.
Published: August 2018

EP-100 is a synthetic lytic peptide specific for targeting LHRH receptors on cancer cells that is being clinically tested for treatment of ovarian cancer. In this study, we aimed to identify combination approaches with EP-100 in ovarian cancer models. We carried out a series of in vitro (MTT assay, immunoblot analysis, Q-PCR, reverse phase protein array (RPPA), comet assay and immunofluorescence staining) and in vivo (orthotopic mouse model) experiments in ovarian cancer models to determine the biological effects of EP-100 alone and in combination with standard of care drugs. We first examined the cytotoxic effects of EP-100 alone on 8 ovarian cancer cell lines with variable expression level of LHRH receptors and the IC50 values ranged from 0.5 to 2.0 µM. We then tested the effect of combining EP-100 with standard drugs (e.g., cisplatin, paclitaxel, doxorubicin, topotecan, and olaparib) on ovarian cancer cells. Of those drugs, we found that combination of EP-100 and olaparib was highly synergistic in drug sensitive and multi-drug resistant ovarian cancer cell lines (HeyA8, HeyA8-MDR, A2780, and A2780CP20). The combination indices (CI) were < 0.9 at the ED50 level. Furthermore, the nuclear foci of γH2AX were significantly increased in combination group of EP100 and olaparib after 24 h incubation compared with control, EP-100 alone, or olaparib alone groups (p < 0.0001, ANOVA). In addition, there was increased DNA accumulation in tails using comet assay after treating cells with EP-100 and olaparib for 24 h (p < 0.001, ANOVA). RPPA results identified that PI3K/AKT pathway can be blocked significantly by the combination treatment. The study in HeyA8 xenograft mouse models showed that mice treated with EP-100 and olaparib had the lowest tumor weight (0.06 ± 0.05 g) compared with those treated with vehicle (1.19 ± 0.39 g, p < 0.008), EP-100 alone (0.62 ± 0.28 g, p < 0.008), and olaparib alone (0.50 ± 0.22 g, p < 0.01). EP-100 has efficacy in preclinical models of ovarian cancer, especially in combination with olaparib. Our findings suggested that combining EP-100 with olaparib could be a promising therapeutic strategy for ovarian cancer.

Citation Format: Shaolin Ma, Sunila Pradeep, Sherry Wu, Mark Seungwook Kim, Wei Hu, Selanere Mangala, Robert L. Coleman, Anil K. Sood. EP-100 sensitizes BRCA wild-type ovarian cancer cells to PARP inhibitor [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 4817.
Abstract 482: Epstein-Barr virus-encoded miRNAs target ATM-mediated response in nasopharyngeal carcinoma
Authors: Lung Raymond W. , Hau Po-Man , Tong Joanna H. , Lam Ka-Hei , Chan Anthony W. , Yip Kevin Y. , Tsao George S. , Lo Kwok-Wai , To Ka-Fai
Published: August 2018

Nasopharyngeal carcinoma (NPC) is a highly invasive epithelial malignancy that is prevalence in southern China and Southeast Asia. It is well-known to be associated with latent Epstein-Barr virus (EBV) infection. By using small RNA sequencing, we previously established a comprehensive miRNA profile in a panel of NPC samples and revealed that the EBV-encoded miRNAs derived from BamHI-A rightward transcripts (miR-BARTs) are abundantly expressed. The important roles of miR-BARTs in cancer development have been reported extensively. In the present study, we identified multiple putative binding sites of miR-BART5-5p, BART7-3p, BART9-3p and BART14-3p on the 3'-UTR of a critical DNA double-strand break (DSB) repair gene, Ataxia-Telangiectasia-Mutant (ATM). Notably, the expression of these 4 miR-BARTs represented more than 10% of all EBV-encoded miRNAs in NPC cells while downregulation of ATM expression was observed in our local primary NPC samples in both qRT-PCR and immunohistochemical (IHC) staining analysis. In addition, the abilities of miR-BARTs to downregulate ATM expression were demonstrated in the transient transfection experiments. By manipulating the miR-BARTs expression in epithelial cell lines, we further revealed that these four viral miRNAs could inhibit both ionizing radiation (IR)-induced ATM kinase activity and BZLF1-induced viral lytic reactivation. In conclusion, our findings suggest that miR-BART5-5p, BART7-3p, BART9-3p and BART14-3p work co-operatively to modulate DNA damage response and to maintain viral latency, contributing to the NPC tumorigenesis. Acknowledgement: Theme-based Research Scheme (T12-401/13-R) and GRF (14104415 and 14138016), Research Grant Council, Hong Kong.

Citation Format: Raymond W. Lung, Po-Man Hau, Joanna H. Tong, Ka-Hei Lam, Anthony W. Chan, Kevin Y. Yip, George S. Tsao, Kwok-Wai Lo, Ka-Fai To. Epstein-Barr virus-encoded miRNAs target ATM-mediated response in nasopharyngeal carcinoma [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 482.
Abstract 483: BRCA1 protein expression is downregulated by miR-185, miR-93 and miR-107 in breast cancer tumors
Authors: Zavala Valentina A. , Gajardo Patricia , Faundez Paola , Alvarez Carolina , Carvallo Pilar
Published: August 2018

BRCA1 is a tumor-suppressor gene whose mutations confer a high risk to breast cancer. Fifty percent of hereditary breast cancer tumors without germline mutation have impaired BRCA1 expression, as well as 30% of sporadic cases. Somatic events that silence BRCA1 expression have been described in breast cancer tumors, such as promoter hypermethylation and BRCA1 gene deletion; however, these mechanisms do not completely explain the loss of BRCA1 expression in breast tumors. Our aim is to identify miRNAs differentially expressed in tumors with negative or moderate BRCA1 protein, which could regulate BRCA1 expression. Total RNA from 50 fresh-frozen breast cancer tumors was isolated and miRNA profiling was performed using miRNA microarrays. Sixteen miRNAs were found exclusively upregulated in BRCA1-negative, and ten in BRCA1-moderate tumors. Among them, in silico analyses predicted eleven miRNAs that could regulate BRCA1 expression. The effect of five of these microRNAs was assessed using a luciferase reporter assay in HEK293T cells, where the complete BRCA1 3'UTR, or a segment of its coding region, was cloned within the 3' end of the Luciferase gene. Cells were co-transfected with each of the selected microRNAs. MiR-185, miR-93 and miR-107 significantly downregulated luciferase activity by binding to the 3'UTR. Also, we transfected these microRNAs into a nontumorigenic breast cell line (MCF10A), where miR-93 diminished endogenous BRCA1 expression in 48%, miR-185 in 39% and miR-107 in 38%, in relation to non-transfected cells. These results strongly support that these microRNAs are potential regulators of BRCA1 expression in breast cancer tumors.

FONDECYT1120200, CONICYT21120269.

Citation Format: Valentina A. Zavala, Patricia Gajardo, Paola Faundez, Carolina Alvarez, Pilar Carvallo. BRCA1 protein expression is downregulated by miR-185, miR-93 and miR-107 in breast cancer tumors [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 483.
Abstract 4838: R loop-driven genome instability by G-quadruplex binders in BRCA2-silenced human cancer cells
Authors: Magis Alessio De , Manzo Stefano Giustino , Russo Marco , Sordet Olivier , Morigi Rita , Capranico Giovanni
Published: August 2018

G-quadruplexes (G4s) and R-loops are non-B DNA structures that can regulate basic processes such as transcription and replication. Unscheduled formation of R-loops is regarded as highly deleterious to cells, as R loops can induce replicative stress and DNA damage leading to genome instability. G4s are formed by four guanine residues held together by Hoogsteen hydrogen bonds and stabilized by monovalent cations. R loops are triple-stranded structures that contain an RNA-DNA hybrid duplex and a displaced single-stranded DNA. We have recently shown that Topoisomerase I (Top1) can affect genome-wide levels of R loops in human cancer cells consistently with the knowledge that DNA superhelical tension is a main driving force allowing non-B DNA structure formation. As G4 ligands were suggested to synergize with Top1 inhibitors, we asked the question of whether G4 ligands can affect R loops. We have thus investigated by immunofluorescence microscopy the effects of two different G4 binders, Pyridostatin (PDS) and FG (compound 1 in Amato et al J Med Chem 2016), on R-loops in human cancer cells. These G4 binders can increase both G4s and R loops while an inactive derivative of FG cannot induce them. Interestingly, the induction of G4s and R loops well correlate to each other in time and intensity with PDS being more effective than FG. After 24 hours, G4 binders induce a cell cycle arrest at the G2/M phase associated to double-stranded DNA cleavage as detected by γH2AX and 53BP1 foci formation and to activation of checkpoint response as shown by ATM phosphorylation. Interestingly, overexpression of RNaseH1 reduces both R loops and γH2AX foci induced by G4 binders showing that the ligands induce DNA cleavage via an R loop-mediated mechanism. Then, we silenced the BRCA2 gene by RNAi in U2OS cells and the results show that BRCA2 depletion increased γH2AX foci induced by PDS while overexpression of RNaseH1 rescue DNA cleavage induction. We also determined genomic R loop maps by DRIP-seq, and bioinformatic analyses of the specific location of G4-stabilized R loops provided information consistent with a model in which a G4 opposite to a DNA:RNA hybrid can stabilize R loops. Our study establishes for the first time that G4 binders stabilize either G4s and R loops in human cancer cells, and that they induce genome instability with a mechanism dependent on R loop formation. Partially supported by AIRC, Milan.

Citation Format: Alessio De Magis, Stefano Giustino Manzo, Marco Russo, Olivier Sordet, Rita Morigi, Giovanni Capranico. R loop-driven genome instability by G-quadruplex binders in BRCA2-silenced human cancer cells [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 4838.
Abstract 4845: Preclinical evaluation of HWH340, a novel PARP inhibitor
Authors: Sun Wenjie , Yue Yang , Chen Hailiang , Tu Ronghua , Shen Jie , Li Gang , Ma Guoqiang , Zhang Zhixiang , Ding Charles Z. , Chen Shuhui
Published: August 2018

Objective: Poly-ADP-ribose polymerase (PARP) participates in DNA repair, replication and transcription, and is important to maintaining genome stability and integrity. PARP inhibitors have proven to be efficacious in the clinic to treat BRCA-deficient cancers. PARP inhibitors may also be used as sensitizing agent in combination with other antitumor agents. The purpose of this study is to investigate in preclinical models the antitumor activity of HWH340, a novel potent and selective PARP inhibitor currently undergoing clinical investigation.

Method: HWH340 was evaluated for its PARP1/2 enzymatic activity in corresponding enzyme assays and its cellular PARylation inhibitory activity in HCC1937 cells. The anti-proliferative activity and the synergistic effect in combination with temozolamide (TMZ) were evaluated in vitro in a BRCA-deficient cell line MDA-MB-436 and BRCA proficient cell line MDA-MB-231. Antitumor activity was evaluated by daily oral administration of in xenograft tumor models. Synergistic effect in combination with TMZ was also determined. The animal models used were PARP highly expressed patient-derived xenograft (PDX) model of small cell lung cancer (SCLC) LU-01-0547 and BRCA1/2-deficient CDX models of breast cancer MDA-MB-436 and pancreatic cancer CAPAN-1.

Result: HWH340 displayed potent PARP1/2 enzymatic inhibitory activity with IC50 1.14 nM and 1.72 nM respectively. It also potently inhibited cellular PARylation in HCC1937 cell with IC50 2.77 nM. In BRCA proficient cell line MDA-MB-231, HWH340 showed no synergistic effect when combined with TMZ and a weak anti-proliferative activity with IC50 5.83 uM and 4.86 uM. In contrast, it displayed potent anti-proliferative activity and a synergistic effect in combination with TMZ with IC50 of 71 nM and 7 nM in the BRCA1/2-deficient MDA-MB-436 cells, respectively. HWH340 showed excellent in vivo antitumor efficacy in PARP overexpressed SCLC LU-01-0547 PDX model (TGI=81.69%@50mpk, QD). In BRCA-deficient breast cancer MDA-MB-436 CDX model, HWH340 showed potent antitumor efficacy as single agent (TGI=122% @12.5mpk, QD). In BRCA-deficient pancreatic cancer CAPAN-1 CDX model, it showed potent antitumor efficacy in combination with TMZ (TGI=79.61% @25mpk+ TMZ 30mpk, QD).

Conclusion: HWH340 is a potent PARP inhibitor. Its antitumor activity in the preclinical tumor models together with its excellent pharmaceutical properties provide confidence that HWH340 may have high potential in the clinic for treatment of BRCA deficient solid cancers.

Citation Format: Wenjie Sun, Yang Yue, Hailiang Chen, Ronghua Tu, Jie Shen, Gang Li, Guoqiang Ma, Zhixiang Zhang, Charles Z. Ding, Shuhui Chen. Preclinical evaluation of HWH340, a novel PARP inhibitor [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 4845.
Abstract 4854: Targeting ribonucleotide reductase M2 using didox causes inhibition of estrogen receptor-negative, inflammatory breast cancer cell proliferation and tumor emboli formation in culture
Authors: Patel Pranalee , Mirman Ben , Zhan Renzhi , Devi Gayathri R.
Published: August 2018

Ribonucleotide reductase (RR) catalyzes the conversion of ribonucleotides to deoxyribonucleotides during the rate-limiting step of DNA synthesis. Given its significant role in cell cycle regulation, RR and its catalytic subunits are significant molecular targets for inhibiting tumor cell growth and proliferation. Didox (3,4-dihydroxybenzohydroxamic acid) is a known inhibitor of the catalytic RR subunit of RRM2 and overall DNA synthesis. Previous meta-analyses have revealed that RRM2 is highly expressed in estrogen receptor-negative (ER-) breast cancer tumors. As ER negativity is frequent in inflammatory breast cancer (IBC), a distinct and the most aggressive breast cancer subtype, we proposed to evaluate efficacy of didox in IBC cell models. ER- inflammatory breast cancer (IBC) cell lines SUM149 (ER-, PR-, EGFR-activated), lapatinib-resistant SUM149 (rSUM149), and non-IBC BT474M1 metastatic subline of BT474 (ER+, PR+, HER2+) were compared for the cytotoxic and cytostatic effects of didox using cell viability (trypan blue exclusion) and proliferation (MTT) assays. Protein profiling was performed to evaluate changes in molecular expression of key proteins involved in cellular signaling pathways for apoptosis and proliferation. Only ER- cell lines exhibited decreased dose-dependent decrease in viability following didox treatment. In addition, didox inhibited tumor emboli formation in a novel ex vivo tumor emboli in culture assay that mimics the clinicopathologic hallmark of IBC disease in patients. Moreover, didox decreased proliferation in lapatinib-resistant rSUM149, suggesting that the drug may help circumvent lapatinib resistance. Studies are ongoing to evaluate the mechanism of didox in overcoming lapatinib resistance and evaluation in an in vivo IBC invasion model. IBC is rare but accounts for 10% of breast cancer deaths, and despite multimodal therapy the 5-yr survival is only 25-55%. Further, there is a need to identify new therapies that can inhibit IBC tumor emboli formation and migration. Didox has demonstrated minimal toxicity in human phase I/II cancer clinical trials and therefore is an attractive strategy for inflammatory breast cancer therapy.

Support in part from the Development funds (GRD) of the Duke Cancer Institute as part of the P30 Cancer Center Support Grant NIH CA014236 and Department of Defense Breakthrough Level 2 W81XWH-17-1-0297 (GRD).

Citation Format: Pranalee Patel, Ben Mirman, Renzhi Zhan, Gayathri R. Devi. Targeting ribonucleotide reductase M2 using didox causes inhibition of estrogen receptor-negative, inflammatory breast cancer cell proliferation and tumor emboli formation in culture [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 4854.