bluuebunny/crossref_metadata_2025 huggingface dataset:
Abstract 2780: In vivo quantitative molecular imaging for receptor-specific contrast and image guided surgery of glioblastoma
Authors: Bano Shazia
Published: September 2020

Quantitative, noninvasive imaging utilizing the full potential of antibody targeted nanomedicines has recently emerged as a new paradigm in cancer therapeutics. However, the specificity of these nanomedicines to the molecular targets in in vivo is much controversial.

We have leveraged a molecular-specific approach for the simultaneous imaging and quantitation of in vivo EGFR expression levels, using NIR-activable cetuximab targeted nanomedicine. Using quantitative molecular imaging, the EGFR specificity of these targeted nanomedicines is measured, following i.v. administration in glioblastoma tumors bearing mice.

For the first time we demonstrate, that in vivo specificity of ligand targeted nanomedicines correlates positively with cellular expression levels of EGFR established by flow cytometry (Pearson's r = 0.93, p < 0.0003).Importantly, we show that the EGFR concentrations in glioblastoma (with varying expressions of EGFR) closely match with those previously derived from dual-reporter imaging using fluorescent conjugates.

This first demonstration of non-invasive quantitation of targeted nanomedicine binding introduces an unexplored approach to leverage targeted nanomedicines as a critical component in the design and validation process of cancer therapeutics. Such an informed methodology promises to expedite translation and minimize failures that often occur after substantial investment.

Citation Format: Shazia Bano. In vivo quantitative molecular imaging for receptor-specific contrast and image guided surgery of glioblastoma [abstract]. In: Proceedings of the Annual Meeting of the American Association for Cancer Research 2020; 2020 Apr 27-28 and Jun 22-24. Philadelphia (PA): AACR; Cancer Res 2020;80(16 Suppl):Abstract nr 2780.
Abstract 2784: Intratracheally delivered perflurocarbon nanoparticles to enhance radiotherapy against lung cancer
Authors: Wu Lina , Xie Jin
Published: September 2020

Radiotherapy (RT) is a major treatment modality for lung cancer. Despite of technological advances, the five-year survival rate remains low. There is an urgent need of new and effective approaches that can selectively sensitize lung cancer cells to radiation. In this proof-of-concept study, we tested whether intratracheally(IT) delivered perfluorocarbon nanoparticles (PFC NPs) can enhance radiotherapy against lung cancer. We hypothesize that the approach can capitalize on the oxygen-loading capacity of PFC NPs and solve the unfavorable delivery problem associated with systemically injected PFC NPs. Therapy studies were performed in mice bearing subcutaneously inoculated H460 tumors and in orthotopicVX2 tumor models established on New Zealand white rabbits. PET/CT, 19F-MRI, and DCE-MRI were employed to assess PFC NPs delivery and treatment outcomes. 1H-MRS was performed on tumors from different treatment groups and the results were compared with in vivo imaging. For both tumor models, animals were divided into four groups (n=3 for rabbits and 5 for mice): (1) control; (2) PFC NPs only; (3) radiotherapy only; and (4) RT+PFC NPs group. Tumor tissues were subjected to pathology analysis and the results were compared with imaging data. Urine samples were collected and analyzed by UPLC-Q-TOF-MS/MS to assess metastasis. Our results showed that combining IT delivered PFC NPs and radiotherapy led to significantly enhanced tumor growth inhibition. Specifically, 19F-MRI confirmed that PFC NPs can deliver O2 to tumors and increase the mean pO2. DCE-MRI showed distinct tumor blood perfusion behaviors in the RT+PFC NPs group (P<0.05).We also compared the 18F-FDG accumulation in lesions in the early dynamic perfusion phase with the standard static metabolic phase by analyzing the peak value of the SUV mean, time to peak value, and the rate of the SUVmean increase. We found significant difference between the two phases in the RT+PFCNPs group. 1H-MRS found a decreased Cho/Cr ratio in animals treated by RT+PFC, suggesting that the combination treatment improved tumor suppression. Meanwhile, urine glutamine content is elevated in the RT+PFCNPs group, indicating a tendency to return to normal after treatment. Overall, our studies suggest the potential of IT delivered PFCNPs to enhance lung cancer radiotherapy. The delivery of the particles can be image-guided for efficient and site-specific radiosensitization. The approach holds great promise in clinical translation.

Citation Format: Lina Wu, Jin Xie. Intratracheally delivered perflurocarbon nanoparticles to enhance radiotherapy against lung cancer [abstract]. In: Proceedings of the Annual Meeting of the American Association for Cancer Research 2020; 2020 Apr 27-28 and Jun 22-24. Philadelphia (PA): AACR; Cancer Res 2020;80(16 Suppl):Abstract nr 2784.
Abstract 2814: Establishment and optimization of a drug-resistant PDX-based platform using in vivo and in vitro approaches
Authors: Zhuang Xiaoying , Xie Nan , Jin Lei , Zeng Wengang , Zheng Yuhui , Zhang Chunling , Cai Liping , Sun Hanmei , Xu Jie , Gao Wenjie , Ji Qunsheng
Published: September 2020

Induced resistance after anticancer agent treatment is the main reason for cancer relapse and short median survival of patients. Here we employed in vivo and in vitro approaches to establish and optimize a drug-resistant platform based on patient-derived xenografts (PDXs). PDXs derived from lung cancer patients who acquired drug resistance reproduced the insensitivity to standard target therapies in mice. Alternatively, resistance was induced in established PDX by continuously exposing with dosage increasing, which demonstrated the induced response declining after the treatment of one second-line therapy drug (Irinotecan). These drug resistant models were additionally confirmed by the in vitro 3D cell based assay, which mimicked the precise histologic structure and cellular composition of the corresponding patient samples. These results from in vivo and in vitro studies displayed good correlation, suggesting that this platform of PDXs and 3D cell based assay can be applied to preclinical development, mechanism research and new drug screen to overcome treatment resistance and have the potential for application to personalized medicine programs.

Citation Format: Xiaoying Zhuang, Nan Xie, Lei Jin, Wengang Zeng, Yuhui Zheng, Chunling Zhang, Liping Cai, Hanmei Sun, Jie Xu, Wenjie Gao, Qunsheng Ji. Establishment and optimization of a drug-resistant PDX-based platform using in vivo and in vitro approaches [abstract]. In: Proceedings of the Annual Meeting of the American Association for Cancer Research 2020; 2020 Apr 27-28 and Jun 22-24. Philadelphia (PA): AACR; Cancer Res 2020;80(16 Suppl):Abstract nr 2814.
Abstract 2835: Effector T-cell shape is a potential digital biomarker for assessing CD8 lymphocyte activation in colorectal cancer (CRC) tumors
Authors: Zwing Natalie , Li Xiao , Hibar Derrek , Failmezger Henrik , Nie Yao , Gaire Fabien , Korski Konstanty
Published: September 2020

With the recent advances in cancer immunotherapy it is critical to identify innovative biomarkers, reflecting the interaction between the tumor and its immune microenvironment. As a model system, CRC tumors are considered as non-immunogenic cancers with minor exception of microsatellite instable (MSI) cases that, in contrast to microsatellite stable (MSS) tumors, are characterized by a high tumor mutational burden (TMB) due to defects in mismatch repair (MMR) genes. These characteristics make MSI tumors more visible for the immune system, causing higher lymphocytic influx. When analyzing T cell kinetics, live cell imaging studies shown that T cells elongate while trafficking and are rounded while interacting or resting in the tissue. Based on these initial observations, we hypothesized that by assessing the density, distribution and shape of CD8 cytotoxic T cells in tumor areas, we could find a surrogate combined digital image-derived biomarker reflecting tumor immune microenvironment dynamics. To visualize this fundamental correlation, multiplexed immunohistochemistry was performed on 74 selected cases of primary CRC from our tissue bank collection with subsequent whole slide image analysis trained by machine learning. The CD8 T cell shape was assessed by nuclear eccentricity, along with PD1 and Ki67 activation status of the detected cell. Spatial plots revealed a haphazard T cell distribution in the overall tumor area, locating round and elongated CD8 T cells in both, tumor epithelium and tumor stroma compartments. Further discrimination of CD8 T cells according to PD1 and Ki67 positivity, showed higher activation / exhaustion in the round shaped T lymphocytes. In addition, we correlated the T cell shape with the MMR status and TMB assigned to the patient. Finally, integration of differential gene expression analysis provided insights into the role of the T cell shape in distinct tumor immune microenvironment conditions. With this novel approach, we discovered a new potential digital biomarker associated with the T effector cell function. Our results warrant further validation on bigger CRC patient cohorts, other tumor indications and through expanding the image analysis scope.

Citation Format: Natalie Zwing, Xiao Li, Derrek Hibar, Henrik Failmezger, Yao Nie, Fabien Gaire, Konstanty Korski. Effector T-cell shape is a potential digital biomarker for assessing CD8 lymphocyte activation in colorectal cancer (CRC) tumors [abstract]. In: Proceedings of the Annual Meeting of the American Association for Cancer Research 2020; 2020 Apr 27-28 and Jun 22-24. Philadelphia (PA): AACR; Cancer Res 2020;80(16 Suppl):Abstract nr 2835.
Abstract 2844: New breast cancer protein as a potential biomarker in liquid biopsies
Authors: Ibrahim Safaa A. , riehl Valerie , Beaman Kenneth D.
Published: September 2020

The decline in breast cancer mortality over the past 2 decades is primarily the result of advances in early detection and treatment. However, the five year relative survival rate of metastatic breast cancer (MBC) patients is only 27%. This requires the need of new biomarkers for early detection of MBC. Tumors secrete microvesicles (MV) in large quantities to blood circulation in order to communicate with distant cells such as immune cells and prepare the metastatic niche. Our recent studies showed that MV from metastatic breast cancer cells contain a specific peptide from the a2 isoform vacuolar ATPase (a2NTD). This a2NTD is undetectable in mammary epithelial cells MV but expressed abundantly by MV produced by breast tumor cells. We have previously shown that the MV containing a2NTD modulate immune cells, promotes tumor growth, metastasis and positively correlates with the invasiveness of breast cancer cells. Identifying the role of a2NTD in regulating immune cells in liquid biopsy will provide a new biomarker for breast cancer. Treatment of whole blood from healthy volunteers with MDA MB-231 MV or recombinant a2NTD drives the neutrophil transition from High density neutrophils (HDN) to Low density neutrophils (LDN). Flow cytometrical analysis showed that LDN possess the PMN-MDSCs markers CD11b+ CD15+ CD14- CD33- HLA-DR-. In addition a2NTD treatment was associated with decreased internal staining of Arg-1 in neutrophils that suggests the release of Arg-1. This data suggest that a2NTD can reprogram neutrophils to exert immunosuppressive phenotype. Further characterization of surface markers as well as functional assays demonstrate the exact phenotype of neutrophils. Together studying the impact of a2NTD present in MV on immune alteration during metastasis can be potential predictors of the growth and metastasis of breast cancer.

Citation Format: Safaa A. Ibrahim, Valerie riehl, Kenneth D. Beaman. New breast cancer protein as a potential biomarker in liquid biopsies [abstract]. In: Proceedings of the Annual Meeting of the American Association for Cancer Research 2020; 2020 Apr 27-28 and Jun 22-24. Philadelphia (PA): AACR; Cancer Res 2020;80(16 Suppl):Abstract nr 2844.
Abstract 2847: Multiplex bead array approach for quantitative profiling of 95 cancer-immunity biomarkers in breast cancer
Authors: Lie Wen-Rong , Davies Alexander , Pepin Danielle , Godeny Michael
Published: September 2020

Immune regulators, including immune checkpoint proteins and cytokines/chemokines, have an emerging role as both disease/treatment biomarkers and targeted agents in cancer therapies. To contribute to the understanding of the roles of these immune regulators in cancer, we have developed 3 new Luminex-based multiplex immunoassay panels, a 48-plex human cytokine/chemokine panel, a 17-plex human immune checkpoint protein panel, and a 30-plex human immune checkpoint protein panel, to simultaneously quantitate the expression levels of 95 key immune regulator proteins in biofluids or cell/tissue homogenates. Here we report the quantitative profiles of these 95 immune regulators in 4 types of breast cancer samples: cancer versus healthy control serum samples, the lysates from breast cancer tumor biopsies versus the adjacent normal tissues, the conditioned media and lysates from the established breast cancer cell lines, and breast cancer cell-derived exosomes. Analysis of the circulating immune protein signatures generated from this multiplex approach reveals an elevated level of IL-6, IL-27, M-CSF, MDC, MIG, sCD27, sTIM3, sCD40, Galectin-3, Galectin-1, FGL-1, BAFF and low level of EGF and sCD40L in breast cancer serum samples compared to the healthy serum controls. The expression profiling of tumor and adjacent normal tissues from 3 patients with metastatic breast cancer revealed differential expression of multiple protein markers including IL-6, IL-8, MIG, IL-1ra, IL-18, IP-10, MCP-1, MIP-1b, VEGF, BTLA, HVEM, CTLA-4, CD40, TLR-2, Siglec-9, CD25, Granzyme B, APRIL, BAFF, Nectin-2, Nectin-4, E-cadherin, and IDO-1 in the matched lysates. We performed similar analysis using cultured breast tumor cells. In these samples we identified markers with significantly altered expression in conditioned media, cell lysates, and tumor cell-derived exosomes from MCF10CA1d tumor cells versus MCF-10A non-tumorigenic mammary epithelial cells as well as triple negative HMT-3522 T4-2 and MDA-MB-231 breast cancer cells. Altogether, our results suggest Luminex-based profiling allows for sensitive and versatile multiplexed analysis of stimulating and inhibitory immune mediators in circulation, tissues, and cell lines which will assist in the discovery of biomarkers and therapeutic targets for cancer interventions.

Citation Format: Wen-Rong Lie, Alexander Davies, Danielle Pepin, Michael Godeny. Multiplex bead array approach for quantitative profiling of 95 cancer-immunity biomarkers in breast cancer [abstract]. In: Proceedings of the Annual Meeting of the American Association for Cancer Research 2020; 2020 Apr 27-28 and Jun 22-24. Philadelphia (PA): AACR; Cancer Res 2020;80(16 Suppl):Abstract nr 2847.
Abstract 2854: Multi-omic considerations: Exploring LBgard blood tubes for proteomic analysis
Authors: Vasquez Jacob M. , Desharnais Joel
Published: September 2020

Expanding the number of -omic (genomic, proteomic, etc.) analyte classes, a single blood draw will serve to increase the scientific value of that sample by affording additional multi-variant analyses. The detection and monitoring of many chronic diseases and cancers requires multi-factorial/multi-analyte measurement. Specialized blood collection tubes (e.g., liquid biopsy tubes) are routinely used in the development of minimally invasive methods to monitor key cancer biomarkers in blood. The suitability of plasma isolated from liquid biopsy blood tubes for quantitative proteomics studies needs further exploration. Herein we performed proteomic analyses of whole blood collected and stored in LBgard Blood Tubes.

In this study, matched blood samples from 3 healthy donors were collected in LBgard Blood Tubes and K3EDTA (EDTA) tubes, which is the standard blood collection tube used for plasma proteomic analyzes. Blood collected in LBgard Blood Tubes was stored for either 5 days or 7 days at ambient temperature. Following high-abundant plasma protein depletion, plasma proteins were analyzed in quantitative discovery proteomics by liquid chromatography tandem-mass spectrometry (TMT-LC-MS/MS). Over 800 unique proteins were identified by mass spectrometry in the plasma samples analyzed. Of those, >90% were found to be of similar abundance between EDTA Day 0 plasma samples and plasma isolated from whole blood collected in LBgard Blood Tubes. After storage of the LBgard Blood Tube samples for up to 7 days at ambient temperature, >85% of the proteins demonstrated similar abundance in both stored LBgard Blood samples and EDTA tube samples processed immediately after collection. Samples were also evaluated via ELISA to quantify the levels of proteins known to be cancer related. LBgard Blood Tubes prevented changes in the plasma concentrations of several protein biomarkers known to be sensitive to preanalytical variability in samples stored for 5 days at ambient temperature as compared to samples stored in EDTA tubes under the same conditions.

Utilizing tandem-mass tag spectrometry and immunoassay methodologies, we have determined the compatibility of LBgard Blood Tube for determining proteomic profiles of blood samples. Additionally, blood collected in LBgard Blood Tubes was shown to have consistent concentrations of protein after storing the collected blood sample for several days, with enhanced protein detection as compared to EDTA tubes.

Citation Format: Jacob M. Vasquez, Joel Desharnais. Multi-omic considerations: Exploring LBgard blood tubes for proteomic analysis [abstract]. In: Proceedings of the Annual Meeting of the American Association for Cancer Research 2020; 2020 Apr 27-28 and Jun 22-24. Philadelphia (PA): AACR; Cancer Res 2020;80(16 Suppl):Abstract nr 2854.
Abstract 2881: Injectable thermoresponsive hydrogel for the sustained delivery of triptolide in breast cancer treatment
Authors: Li Jingjing , Zhang Jinming , Leung George Pak-Heng
Published: September 2020

To avoid the narrow therapeutic window and take advantage of the anticancer efficacy of triptolide (TP), a major active component of Tripterygium wilfordii Hook.F., a novel thermo-responsive nano-micelle hydrogel was fabricated in present study for the sustained release of TP in breast tumor tissue. Briefly, the amphiphilic poloxamer 188-g-poly (N-isopropylacrylamide-co-acrylic acid) copolymer was synthesized by atomic transfer radical polymerization reaction and self-assembled into micelles in aqueous solution with CMC value of 2.6×10-3 mg/mL. TP encapsulated nanogel (TP/F68-g-(PNIPAAm-co-AAC)) exhibited the sol-gel phase transition at 32°C with a narrow size distribution (about 50.16 nm) and sustained drug release in vitro. And then, the TP-loaded nanogel significantly inhibited the cell proliferation against human breast cancer MDA-MB-231 and MCF-7 cells, as well as the induction of cell apoptosis and cell cycle arrest activity. Moreover, we also found the superior anti-angiogenic activities of TP nanogel in both HUVEC and rat aortic ring model when compared to free TP. As expected, mediated by the 4T1 mouse breast cancer model, we demonstrated that a single injection of the TP-loaded nanogel system resulted in the long detention time in tumor tissue due to its thermo-responsive capacity. Moreover, the novel nanogel remarkably enhanced anticancer efficacy and reduced the side effects, when compared with the multiple injections of free TP. Therefore, the injectable thermo-responsive nanogel provided a potential strategy for the efficient delivery of TP with a sustained release manner in breast cancer treatment.

Citation Format: Jingjing Li, Jinming Zhang, George Pak-Heng Leung. Injectable thermoresponsive hydrogel for the sustained delivery of triptolide in breast cancer treatment [abstract]. In: Proceedings of the Annual Meeting of the American Association for Cancer Research 2020; 2020 Apr 27-28 and Jun 22-24. Philadelphia (PA): AACR; Cancer Res 2020;80(16 Suppl):Abstract nr 2881.
Abstract 2883: A transformable delivery system for the effective treatment of pediatric central nervous system tumors
Authors: Lin Tzu-yin
Published: September 2020

Malignancies of the central nervous system (CNS) are the most common type of solid tumor affecting children and a leading cause of cancer-related death in children. With the deterioration of brain tumors, blood-brain barrier (BBB)/blood-brain tumor barrier (BBTB) with poor permeability, and relatively weak enhanced permeability and retention effect become major obstacles in delivering therapeutics to brain tumors. Vincristine (VCR) is a mainstay of treatment of a variety of cancers including brain tumors due to its well-defined mechanism of action and demonstrated anticancer activity. However, the clinical application of VCR in brain tumors was limited by its neurotoxicity and inability to penetrate BBB/BBTB resulting in unsatisfactory anti-cancer efficacy. In this project, we developed a transformable nanoparticle, named Ninja-nanoparticle, which is capable overcoming several important barriers for drug delivery to CNS tumors resulting in better efficacy and toxicity profile. Ninja-NP was stable during circulation due to crosslinking and could transpass BBB/BBTB through glucose receptor-mediated transcytosis. Ninja-NP could further transform into smaller nanoparticle upon encountering acidic microenvironment and revealed hidden moiety to target tumor surface overexpressed sialic acid. Ninja-NP employed a unique strategy which could sequentially target BBB/BBTB and brain tumor cells. Our study confirmed that VCR loaded Ninja-NP significantly accumulated at the orthotopic brain tumor sites, and exhibited superior anti-cancer efficacy in orthotopic diffuse intrinsic pontine glioma (DIPG), the most deadly pediatric CNS tumor, then free VCR or Liposomal VCR with limited systemic toxicity. Ninja-NP addresses multiple challenges for CNS tumor treatment and exhibits great potential to be translated into an effective theranostic nano-platform which could be seamlessly integrated into standard human brain tumor management (imaging-guided drug delivery) with reduced long term toxicity.

Citation Format: Tzu-yin Lin. A transformable delivery system for the effective treatment of pediatric central nervous system tumors [abstract]. In: Proceedings of the Annual Meeting of the American Association for Cancer Research 2020; 2020 Apr 27-28 and Jun 22-24. Philadelphia (PA): AACR; Cancer Res 2020;80(16 Suppl):Abstract nr 2883.
Abstract 2902: Antibody-drug conjugate targeting c-kit/CD117 suppresses imatinib resistant cancer cells
Authors: Kim Jin-Ock , Kim Kwang-Hyeok , Park Sang Gyu
Published: September 2020

c-Kit(CD117) is a type III receptor tyrosine kinase that mediates cell proliferation, survival, and differentiation. Gene amplification of c-kit is found in various cancers, including, glioblastoma (GBM) low grade glioma(LGG), gastrointestinal stromal tumor (GIST), sarcoma, melanoma, and small cell lung carcinoma (SCLC), leading to poor prognosis. In addition, the activation of c-kit as a cancer stem cell marker induces resistance of anti-cancer drug by increasing the expression of ABCG2. Imatinib is a first generation RTK inhibitor targeting BCR-ABL, c-kit, and PDGFR and currently using for the treatment of various cancers. Of note, the activating mutation of c-kit is found in various cancers, leading to resistance of imatinib. In this study, we have generated a human antibody targeting c-kit and developed antibody-drug conjugate using SMCC-DM1 to assess the therapeutic efficacy in vitro and in vivo.

Citation Format: Jin-Ock Kim, Kwang-Hyeok Kim, Sang Gyu Park. Antibody-drug conjugate targeting c-kit/CD117 suppresses imatinib resistant cancer cells [abstract]. In: Proceedings of the Annual Meeting of the American Association for Cancer Research 2020; 2020 Apr 27-28 and Jun 22-24. Philadelphia (PA): AACR; Cancer Res 2020;80(16 Suppl):Abstract nr 2902.
Abstract 2927: Targeted combination treatment for B-cell acute lymphoblastic leukemia
Authors: Kane Shriya , Ding Yali , Gowda Chandrika , Payne Jonathon Lee , Iyer Soumya , Dhanyamraju Pavan K. , Song Chunhua , Desai Dhimant , Sharma Arati , Payne Kimberly J. , Dovat Sinisa
Published: September 2020

The CCND3 gene encodes Cyclin D3–a protein that is essential for G1/S cell cycle progression and proliferation of malignant cells. Targeting Cyclin D3 is used to treat B-cell acute lymphoblastic leukemia (B-ALL); however, the mechanisms that regulate expression of the CCND3 gene in B-ALL are largely unknown. Here, we present evidence that oncogenic Casein Kinase II (CK2) regulates expression of CCND3 and G1/S cell cycle progression via direct phosphorylation of Ikaros, a transcription regulator and tumor suppressor protein. Global genome-wide DNA-binding analysis using ChIP-seq, show that Ikaros binds the promoter of CCND3 in primary human B-ALL. The role of Ikaros in regulating CCND3 expression in B-ALL was tested using gain-of-function and loss-of-function experiments. Ikaros knock-down with shRNA results in increased transcription of CCND3 in B-ALL. Overexpression of Ikaros in human B-ALL was associated with reduced expression of CCND3. Since Ikaros activity in leukemia is regulated by pro-oncogenic Casein Kinase II (CK2), we tested whether CK2 regulates expression of CCND3 in B-ALL. Increased expression of CK2 in B-ALL results in increased expression of the CCND3 gene. This was associated with a loss of Ikaros binding to the promoter of the CCND3 gene. Inhibition of CK2 with shRNA, and/or a specific CK2 inhibitor, CX-4945, resulted in increased Ikaros binding to the CCND3 promoter and reduced expression of Cyclin D3 in B-ALL. Treatment with CX-4945 showed strong therapeutic activity in preclinical models of B-ALL. A combination treatment with CX-4945 and dexamethasone that targets G1/S cell cycle progression shows a strong synergistic effect on B-ALL cells. In conclusion, presented data show that CK2 and Ikaros regulate G1/S cell cycle progression via transcriptional regulation of the CCND3 gene in B-ALL and that CK2 inhibition represses CCND3 expression by enhancing Ikaros tumor suppressor function. Results demonstrate the synergistic efficacy of a combination treatment with CK2 inhibitor and dexamethasone and provide a rationale for the use of this combination treatment as a novel therapeutic approach for B-cell acute lymphoblastic leukemia.

Citation Format: Shriya Kane, Yali Ding, Chandrika Gowda, Jonathon Lee Payne, Soumya Iyer, Pavan K. Dhanyamraju, Chunhua Song, Dhimant Desai, Arati Sharma, Kimberly J. Payne, Sinisa Dovat. Targeted combination treatment for B-cell acute lymphoblastic leukemia [abstract]. In: Proceedings of the Annual Meeting of the American Association for Cancer Research 2020; 2020 Apr 27-28 and Jun 22-24. Philadelphia (PA): AACR; Cancer Res 2020;80(16 Suppl):Abstract nr 2927.
Abstract 294: Altered ARID1A expression in colorectal cancer
Authors: Erfani Mehran , Vahid Seyed , Mokhtari Maral , Zamani Mozhdeh , Tahmasebi Kamran , Alizadeh Mahvash , Taghavi Alireza , Carethers John , Koi Minoru , Brim Hassan , Mokarram Pooneh , Ashktorab Hassan
Published: September 2020

Background: ARID1A has been described as a tumor suppressor gene, participating in chromatin re-modeling, epithelial-mesenchymal-transition and many other cellular and molecular processes. It has been cited as a contribute in tumorigenesis. The role of ARID1A in CRC is not yet defined.

Aim: To investigate the role ARID1A methylation and CNV in its expression in CRC cell lines and to examine the relationship between ARID1A status with survival and clinicopathologic characteristics in patients with CRC.

Methods: We used RT-PCR to determine both CNV and expression of ARID1A from six CRC cell lines. And used MSP to evaluate methylation of ARID1A. We used (IHC) to ARID1A protein expression, and, evaluate both MSI and EMAST status in 18 paired CRC and adjacent normal tissues. Statistical analysis was performed to establish correlations between ARID1A expression and other parameters.

Results: Among the 18 CRC tumors studied, 7 (38.8 %) and 5 tumors (27.7%) showed no or low ARID1A expression, respectively. We observed no significant difference in ARID1A expression for overall patient survival, and no difference between clinicopathological parameters including MSI and EMAST. However, lymphatic invasion was more pronounced in the low/no ARID1A expression group when compared to moderate and high expression group (33% VS. 16.6% respectively. ARID1A promoter methylation was observed in 4/6 (66%) of cell lines and correlated with ARID1A mRNA expression level ranging from very low in SW48, to more pronounced in HCT116 and HT-29/219. Treatment with the methyltransferase inhibitor 5-Azacytidine (5-aza) resulted in a 25.4-fold and 6.1-fold increase in ARID1A mRNA expression in SW48 and SW742 cells, respectively, while there was no change in SW480 and LS180 cells. No ARID1A CNV was observed in the CRC cell lines.

Conclusion: ARID1A expression is downregulated in CRC tissues correlate with it being a tumor suppressor protein. This finding confirms ARID1A loss of expression in CRC development. Our in-vitro results suggest high methylation status associates with reduced ARID1A expression and contribute to CRC tumorigenesis. There was no significant association between the ARID1A loss of expression and clinicopathological characteristics. ARID1A might be a useful biomarker for colorectal cancer. Future in- vivo analysis is warranted to further established this role.

Citation Format: Mehran Erfani, Seyed Vahid, Maral Mokhtari, Mozhdeh Zamani, Kamran Tahmasebi, Mahvash Alizadeh, Alireza Taghavi, John Carethers, Minoru Koi, Hassan Brim, Pooneh Mokarram, Hassan Ashktorab. Altered ARID1A expression in colorectal cancer [abstract]. In: Proceedings of the Annual Meeting of the American Association for Cancer Research 2020; 2020 Apr 27-28 and Jun 22-24. Philadelphia (PA): AACR; Cancer Res 2020;80(16 Suppl):Abstract nr 294.
Abstract 2948: Anti-tumor effect of C. orbiculata is modulated by alternative splicing
Authors: Makhafola Tshepiso , Bates David , Dlamini Zodwa
Published: September 2020

Recent research has revealed that alternative splice products can be linked to various genetic diseases and also play a role in carcinogenesis. It therefore appears that targeting splicing in cancer could offer novel effective cancer treatments. The aim of this study was to investigate the effects of a South African medicinal plant C. orbiculata on alternatively spliced genes in cancer cells. The effects of the crude extract on cell proliferation of colon (HCT116), esophageal (OE33 and KYSE70) and cervical (CASKI and C33A) cancer cell lines were evaluated using WST-1 assay. We also investigated the effects of this plant on splicing of hnRNPA2B1 and BCLx using RT-PCR and apoptosis induction via caspase-3-cleavage. Our data revealed that the crude C. orbiculata dose dependently decreased viability and also modulated splicing of hnRNPA2B1 and BCLx resulting in a decrease in hnRNPB1 splice variant and an increase in BCLxs splice variant in all 5 cancer cell lines. Additionally, the extract resulted in an increase in caspase-3-cleavage, an indication of apoptosis induction. We used siRNA knockdown of hnRNPB1 in HCT116 specifically to assess its functional role in cell proliferation and apoptosis. These cells had decreased viability and increased caspase-3-cleavage. We therefore concluded that in part, modulating hnRNPA2B1 splicing could be responsible for regulating the balance between pro/anti-apoptotic splice variants e.g. BCLxl/s resulting in apoptosis induction in colon cancer cells treated with C. orbiculata.

Citation Format: Tshepiso Makhafola, David Bates, Zodwa Dlamini. Anti-tumor effect of C. orbiculata is modulated by alternative splicing [abstract]. In: Proceedings of the Annual Meeting of the American Association for Cancer Research 2020; 2020 Apr 27-28 and Jun 22-24. Philadelphia (PA): AACR; Cancer Res 2020;80(16 Suppl):Abstract nr 2948.
Abstract 2960: Anti-cancer activity of NCTD: promotion of pro-apoptosis and anti-invasion in human oral cancer cells
Authors: Ahn Chi-Hyun , Hong Kyoung-Ok , Shin Ji-Ae , Hong Seong Doo , Cho Sung-Dae
Published: September 2020

Norcantharidin (NCTD), a demethylated analog of cantharidin isolated from blister beetles, has been used as a promising anticancer agent; however, the anti-tumor potentials of NCTD against human oral cancer has not been fully understood. Here, this study was aimed to investigate the pro-apoptotic and anti-invasive effect and its molecular targets of NCTD in human oral cancer cell lines. Trypan blue exclusion assay, live/dead assay, western blotting, 4-6-Diamidino-2-Phenylindole staining, flow cytometric analysis, Terminal Deoxynucleotidyl Transferase dUTP Nick end Labeling (TUNEL) assay, immunohistochemistry and tumor xenograft mice models were performed to investigate the pro-apoptotic effect of NCTD. Clonogenic, wound healing, invasion, zymography, western blotting and immunocytochemistry assays were performed to investigate the anti-invasive effect of NCTD. NCTD significantly inhibited cell growth and increased the number of dead cells in oral cancer cell lines. It induced the following apoptotic phenomena: (1) the cleavages of poly (ADP-ribose) polymerase and casepase-3; (2) increase in apoptotic morphological changes (nuclear condensation and fragmentation); (3) increase in annexin V-positive cells or sub-G1 population of cells. NCTD significantly activated the p38 mitogen-activated protein kinase (MAPK) pathway. A p38 MAPK inhibitor (SB203580) partially attenuated NCTD-induced apoptosis in oral cancer cell lines. NCTD strongly suppressed tumor growth in the tumor xenograft bearing HSC-3 cells, and the number of TUNEL-positive cells increased in NCTD-treated tumor tissues. Also, NCTD markedly suppressed the colony formation, migration, and invasion of YD-15 cells as well as the activities of MMP-2 and MMP-9. It disrupted F-actin reorganization through suppressing the FAK/Paxillin axis. Moreover, NCTD exhibited a powerful anti-invasive effect compared with that of PF-562271. Collectively, these results suggest that NCTD has a potential pro-apoptotic and anti-invasive activity against oral cancer cell lines. Therefore, these results suggest that NCTD could be a potential anticancer drug candidate for the treatment of human oral cancer. This work was supported by the Basic Science Research Program through the National Research Foundation of Korea (NRF) funded by the Ministry of Science, ICT, and future Planning [2017R1D1A1B03029317, 2018R1D1A1B07043080, and 2019R1A2C1085896].

Citation Format: Chi-Hyun Ahn, Kyoung-Ok Hong, Ji-Ae Shin, Seong Doo Hong, Sung-Dae Cho. Anti-cancer activity of NCTD: promotion of pro-apoptosis and anti-invasion in human oral cancer cells [abstract]. In: Proceedings of the Annual Meeting of the American Association for Cancer Research 2020; 2020 Apr 27-28 and Jun 22-24. Philadelphia (PA): AACR; Cancer Res 2020;80(16 Suppl):Abstract nr 2960.
Abstract 2961: Olaparib mediated DNA damage response and its resistant mechanism in cervical cancer cells
Authors: Tse Ka Yu , Liu Stephanie Si , Lee Horace Hok Yeung , Ip Philip Pun Ching , Chan Kin Tak
Published: September 2020

Cervical cancer is still the most common gynecologic cancer in developing countries. Olaparib is a poly-(ADR-ribose)-polymerase 1 (PARP1) inhibitor targeting at DNA strand break repair. However its efficacy in cervical cancer is unclear. This study aimed to evaluate the therapeutic potential of olaparib in cervical cancer. Olaparib remarkably reduced the PARylation activity and arrested cervical cancer cells at G2/M phase, and was associated with reduced level of a mitosis marker, phosphor-histone H3 as indicated by propidium iodide DNA staining and immunofluorescence. Cytotoxicity of olaparib against cervical cancer cells was determined by XTT assay with IC50 ranged from 35.49µM in C4I to 87.17µM in SiHa. The difference in olaparib sensitivity between C4I and SiHa was consistently demonstrated in annexin V based apoptotic assay, where a higher level of apoptotic response was found in C4I (21.12%) compared to SiHa (6.37%). Immunofluorescent staining and western blot for gH2AX clearly showed DNA double-strand break accumulation in both cell lines upon PARP1 blockade. Lower expression level of RAD51, a homologous recombination (HR) repair factor, was also observed in C4I, when compared to SiHa. Besides, gH2AX/RAD51 foci co-immunofluorescent line scan image analysis showed that there was reduced level of DNA damage recognition by RAD51 (26.80%), compared to SiHa (65.31%). These findings suggested that there was a reduced HR activity in C4I and might explain the higher sensitivity to olaparib compared to SiHa. We also demonstrated the therapeutic potential of olaparib in cervical cancer, and the rationale of using RAD51 as a predictive biomarker for olaparib sensitivity.

Citation Format: Ka Yu Tse, Stephanie Si Liu, Horace Hok Yeung Lee, Philip Pun Ching Ip, Kin Tak Chan. Olaparib mediated DNA damage response and its resistant mechanism in cervical cancer cells [abstract]. In: Proceedings of the Annual Meeting of the American Association for Cancer Research 2020; 2020 Apr 27-28 and Jun 22-24. Philadelphia (PA): AACR; Cancer Res 2020;80(16 Suppl):Abstract nr 2961.
Abstract 2968: BPM31510, a Coenzyme Q10 (CoQ10) containing lipid nanodispersion, enhances radiation effects to prolong survival in a rodent glioblastoma model
Authors: Sun Jiaxin , Merchant Milton , Diers Anne R. , Kazerounian Shiva , Gesta Stephane , Narain Niven R. , Sarangarajan Rangaprasad , Nagpal Seema , Recht Lawrence
Published: September 2020

BPM31510 is a Coenzyme Q10 (CoQ10)-containing lipid nanodispersion in clinical development for the treatment of glioblastoma. Prior results demonstrate that high doses of CoQ10 delivered via BPM31510 differentially increases oxidative stress in glioblastoma relative to non-tumor cells in vitro and extends long-term survival (LTS) in an in vivo glioblastoma model. Since a primary consequences of tumor irradiation is induction of oxidative stress, we hypothesized that BPM31510 treatment would result in an enhanced radiation response and influence survival outcomes.1 x 106 luciferase labeled C6 cells were implanted into the right striatum of Sprague Dawley rats. 4 days post-implantation, rats were randomized into one of four groups: (i) Saline injection ip bid; (ii) BPM31510 50 mg/kg ip bid to continue up to 35 days; (iii) 12 Gy radiotherapy (RT) to be administered on Day 8 post-implant with saline injection; and (iv) BPM31510 + RT. Tumor-bearing rats were monitored until death or Day 50. Log rank survival analysis indicated a marked enhancement of median survival with the addition of BPM31510 to RT. While neither RT nor BPM31510 enhanced median survival relative to saline, the combination was markedly more effective (median survival of 17, 19, 24 and >50 days for saline, BPM31510, RT and combination, respectively, p < 0.001). This was also reflected in increase in frequency of LTS, which was over 70% (11 of 14 rats) in the combination group (p < 0.01 compared to control). BPM31510 significantly enhanced the therapeutic efficacy of radiation in this model of glioblastoma. Effects on median survival and an enhancement of LTS with combination treatment were observed. While the mechanistic underpinnings are under investigation, the low toxicity profile of BPM31510 and its potential protective effects on normal cells may offer a unique strategy with which to enhance radiation.

Citation Format: Jiaxin Sun, Milton Merchant, Anne R. Diers, Shiva Kazerounian, Stephane Gesta, Niven R. Narain, Rangaprasad Sarangarajan, Seema Nagpal, Lawrence Recht. BPM31510, a Coenzyme Q10 (CoQ10) containing lipid nanodispersion, enhances radiation effects to prolong survival in a rodent glioblastoma model [abstract]. In: Proceedings of the Annual Meeting of the American Association for Cancer Research 2020; 2020 Apr 27-28 and Jun 22-24. Philadelphia (PA): AACR; Cancer Res 2020;80(16 Suppl):Abstract nr 2968.
Abstract 2969: Senescent stromal cells promote cancer resistance via Sirt1 loss-potentiated biogenesis of small extracellular vesicles
Authors: Han Liu , Long Qilai , Lam Eric , Sun Yu
Published: September 2020

Cellular senescence is a potent tumor-suppressive program that prevents neoplastic events. Paradoxically, senescent cells develop an inflammatory secretome, termed the senescence-associated secretory phenotype (SASP) and implicated in age-related pathologies including cancer. Here we report that senescent cells actively synthesize and release small extracellular vesicles (sEVs) with a distinctive size distribution. Mechanistically, SIRT1 loss supports accelerated sEV production despite enhanced proteome-wide ubiquitination, a process correlated with ATP6V1A downregulation and defective lysosomal acidification. Senescent stromal cell-derived sEVs carry a special set of cargoes, including small RNA species such as microRNAs (miRNAs) whose spectrum markedly differ from that of proliferating cell-secreted sEVs. Once released, senescent stromal sEVs significantly alter the expression profile of recipient cancer cells and enhance their aggressiveness, specifically drug resistance mediated by expression of ATP binding cassette subfamily B member 4 (ABCB4). Targeting SIRT1 with an agonist SRT2104 prevents development of cancer resistance through restraining sEV production by senescent stromal cells. In clinical oncology, sEVs in peripheral blood of posttreatment cancer patients are readily detectable by routine biotechniques, presenting a novel biomarker to monitor therapeutic efficacy and predict long term outcome. Together, our study identifies a distinct mechanism supporting pathological activities of senescent cells, and provides a novel avenue to circumvent advanced human malignancies by co-targeting cancer cells and their surrounding microenvironment, which contributes to drug resistance via secretion of sEVs from senescent stromal cells.

Citation Format: Liu Han, Qilai Long, Eric Lam, Yu Sun. Senescent stromal cells promote cancer resistance via Sirt1 loss-potentiated biogenesis of small extracellular vesicles [abstract]. In: Proceedings of the Annual Meeting of the American Association for Cancer Research 2020; 2020 Apr 27-28 and Jun 22-24. Philadelphia (PA): AACR; Cancer Res 2020;80(16 Suppl):Abstract nr 2969.
Abstract 2975: Imipramine, an FDA approved anti-depressant, suppresses triple negative breast cancer growth and progression through inhibition of FOXM1 and DNA repair pathways
Authors: Timilsina Santosh , Rajamanickam Subapriya , Jatoi Ismail , Chen Yidong , Vadlamudi Ratna , Kaklamani Virginia , Rao Manjeet K.
Published: September 2020

Triple Negative Breast Cancer (TNBC) is an aggressive subtype of breast cancer that lacks effective targeted therapies with the main therapeutic option being cytotoxic chemotherapies, which have toxic side effects on patient's health. Less toxic alternatives that could target key pathways that are altered in TNBCs could lead to better outcomes for the patients. Important distinguishing traits of TNBCs is the high amounts of genomic instability and high number of alterations in key proteins in DNA repair and cell proliferation that helps the cancer grow, survive and progress. Previous findings from our lab indicate that Imipramine Blue, a derivative of anti-depressant imipramine, may be a potential inhibitor of proliferation and DNA repair pathways in TNBC. Therefore, we tested the therapeutic efficacy of Imipramine on TNBCs using various in vitro assays for viability, migration, invasion as well as in vivo xenograft assays for tumor growth. Our results demonstrate that Imipramine inhibits cancer cell viability and progression in vitro. Similarly, in vivo xenograft assays showed reduced tumor growth in pre-clinical models upon imipramine treatment. Importantly, at the molecular level, Imipramine treatment suppressed key players in both cell proliferation, and DNA repair pathways, including FOXM1; a proto-oncogene that is a master regulator of both cell proliferation and DNA Repair pathways. These findings suggest that Imipramine may be a potential therapeutic option for TNBC patients. A clinical trial is ongoing to test the efficacy of Imipramine in Triple Negative Breast Cancer patients.

Citation Format: Santosh Timilsina, Subapriya Rajamanickam, Ismail Jatoi, Yidong Chen, Ratna Vadlamudi, Virginia Kaklamani, Manjeet K. Rao. Imipramine, an FDA approved anti-depressant, suppresses triple negative breast cancer growth and progression through inhibition of FOXM1 and DNA repair pathways [abstract]. In: Proceedings of the Annual Meeting of the American Association for Cancer Research 2020; 2020 Apr 27-28 and Jun 22-24. Philadelphia (PA): AACR; Cancer Res 2020;80(16 Suppl):Abstract nr 2975.
Abstract 2988: PLAC8 confers the chemoresistance of placental site trophoblastic tumor and choriocarcinoma to etoposide in an autophagy-dependent manner
Authors: Feng Xuan , Yu Huandi , Tao Xiang , Du Yan , Wu Jing , Yu Yinhua , Xu Congjian , Zhao Hongbo
Published: September 2020

Chemotherapy is commonly used to treat gestational trophoblastic neoplasia (GTN), but placental site trophoblastic tumor (PSTT) and a small proportion of choriocarcinoma demonstrate chemotherapy resistance, which becomes the major obstacle for the treatment. However, the underlying mechanism remains elusive. In the present study, we found that PLAC8 expression in PSTT tissues was higher than that in placental site intermediate trophoblast cells. In addition, PLAC8 was also highly expressed in human choriocarcinoma tissues compared with normal placental villi. Over-expression of PLAC8 inhibited p53 protein stability and induced the autophagic flux in HTR-8 and JAR cells. PLAC8-induced autophagic activity could be partially recovered by p53 re-expression. Further, PLAC8 over-expression conferred chemoresistance of trophoblast cells to etoposide, which can be effectively abrogated by autophagic inhibitors 3-methyladenine (3-MA) or chloroquine (CQ). In conclusion, over-expression of PLAC8 in PSTT and choriocarcinoma tissues may endow the trophoblast cells with enhanced chemoresistance via inducing autophagy activity. Therefore, PLAC8 may serve as a potential therapeutic target for the treatment of PSTT and choriocarcinoma.

Citation Format: Xuan Feng, Huandi Yu, Xiang Tao, Yan Du, Jing Wu, Yinhua Yu, Congjian Xu, Hongbo Zhao. PLAC8 confers the chemoresistance of placental site trophoblastic tumor and choriocarcinoma to etoposide in an autophagy-dependent manner [abstract]. In: Proceedings of the Annual Meeting of the American Association for Cancer Research 2020; 2020 Apr 27-28 and Jun 22-24. Philadelphia (PA): AACR; Cancer Res 2020;80(16 Suppl):Abstract nr 2988.