tbuckley/cabot-search huggingface dataset:
Abstract 574: <i>In vitro</i> TTFields enhance the response to temozolomide or radiation in GBM cells from a newly diagnosed patient
Authors: Sharon K. Michelhaugh, Sandeep Mittal
Journal: Cancer Research (2020)

Abstract Background: Tumor treating fields (TTFields) are FDA-approved for treatment of newly diagnosed and recurrent glioblastoma and are typically initiated after patients have undergone surgical resection, temozolomide, (TMZ) and radiotherapy. In this study, GBM cells generated from a tumor resected from a newly diagnosed glioblastoma patient were treated in vitro with TTFields ± TMZ or treated with in vitro TTFields followed by irradiation to determine if TTFields alter the response to the standard-of-care treatment modalities. Methods: Single-cell suspensions generated from tumor tissue obtained from a newly diagnosed patient were cultured in DMEM/F12 media with 10% fetal bovine serum and gentamicin. For the TMZ experiment, cells were plated on plastic coverslips (1 × 104cells/coverslip; n=4-6/group) and incubated overnight. TTFields (200 kHz; field intensity of ~1.6 V/cm). were applied with or without 50 µM TMZ for 5 days, followed by the XTT proliferation assay. For the radiation experiment, cells were plated on plastic coverslips (5 × 104cells/coverslip; n=3/group) and incubated overnight. TTFields (200 kHz; field intensity of ~1.6 V/cm). were applied for 3 days followed by irradiation with 0, 2, 4, or 6 Gy. Cells were harvested and plated to assess clonogenic potential. After 3 days, cells were stained with crystal violet and plates were scanned to determine cell counts. Data were analyzed by one-way ANOVA with Tukey's post-hoc test. Results: In the TTFields/TMZ experiment, control XTT values were 0.665 ± 0.052, TMZ only were 0.480±0.024, TTFields only were 0.550±0.080 and TTFields + TMZ were 0.164 ± 0.062 (mean ± SD; ANOVA p&amp;lt;0.0001). In the TTFields/radiation experiment, there was no statistical difference in cell counts across the radiation doses in the control cells. In the TTFields treated groups, the mean cell counts were 62146, 53324, 41070 and 28680 in the control, 2 Gy, 4Gy, and 6 Gy groups (ANOVA p=0.002). Conclusions: In GBM cells generated from a newly diagnosed patient's tumor. TTFields application in combination with TMZ reduced cell proliferation by 75%, compared to only 20-30% for either treatment alone. Also, TTFields application prior to radiation significantly reduced cell counts. These results suggest that newly diagnosed patients would benefit from TTFields therapy earlier in the course of treatment. Citation Format: Sharon K. Michelhaugh, Sandeep Mittal. In vitro TTFields enhance the response to temozolomide or radiation in GBM cells from a newly diagnosed patient [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 574.
Abstract 4670: TIP60 regulates alternative splicing of Integrin subunit alpha 6
Authors: Shreshtha Sailesh Bhatia, H. Phillip Koeffler, Sudhakar Jha
Journal: Cancer Research (2020)

Abstract Differences in RNA processing, specifically RNA splicing, contribute to enormous diversity that can be generated from the eukaryotic genome. Given the increasing evidence to show that splicing can occur co-transcriptionally, chromatin structure and histone modifications have been reported to affect the choice of a splice site. For instance, HDAC inhibitor treatment has been shown to affect alternative splicing. TIP60 is a haploinsufficient tumor suppressor gene that is frequently downregulated in cancers. TIP60 is a lysine acetyltransferase that acetylates histone and non-histone proteins. Since TIP60 is a writer of histone and non-histone modifications, we investigated TIP60's role in modulating alternative splicing. To understand TIP60's role in alternative splicing, RNA sequencing was performed in MCF10A cells that were (a) transiently depleted of TIP60 (b) stably overexpressing siRNA-resistant wild-type TIP60 (MCF10A*WT) and (c) stably overexpressing siRNA-resistant catalytically dead TIP60 (MCF10A*KD). Differential splicing analysis was performed using MISO program. We found 130 genes to be differentially spliced when TIP60 was depleted and 59 genes were differentially spliced in MCF10A*KD compared to MCF10A*WT. For both comparisons, the majority of the differential splicing events were skipped exon events. Upon overlapping the differential skipped exon events, we found significant exon 25 skipping of ITGA6, resulting in an isoform that has a shorter cytoplasmic domain. TIP60 depletion results in an increase in the ITGA6 isoform that lacks exon 25, which has been implicated to promote tumor initiation in breast cancer. To identify the splicing factor that regulates this event, we performed a siRNA screen of over 70 splicing factors and identified ESRP2 to regulate splicing of ITGA6 exon 25. The consequence and biological significance of TIP60-ESRP2 mediated alternative splicing will be discussed at the conference. Citation Format: Shreshtha Sailesh Bhatia, H. Phillip Koeffler, Sudhakar Jha. TIP60 regulates alternative splicing of Integrin subunit alpha 6 [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 4670.
Abstract 2525: Identification of mRNA targets associated with PIWIL1 protein complex in lung cancer cells
Authors: Yousef G. Amaar, Mark E. Reeves
Journal: Cancer Research (2020)

Abstract Introduction: In previous published work we have shown that RASSF1C promotes expression of PIWIL1 and PIWI interacting RNAs (piRNAs) in lung cancer cells, suggesting the hypothesis that that the RASSF1C-PIWI-piRNA pathway may promote lung cancer cell growth and progression. PIWIL1 protein-piRNA complexes have recently been shown to regulate mRNAs in mouse testes, suggesting that PIWIL1 plays an important role in mRNA cleavage to regulate specific targets involved in cellular growth. To investigate this hypothesis, we used a non-small cell lung cancer (NSCLC) cell model to identify candidate mRNAs targeted by the RASSF1C-PIWIL1-piRNA pathway through PIWIL1-protein complex co-immunoprecipitation and RNA sequencing. Methods: Cell lysates were prepared under non-denaturing conditions from the lung cancer cell line H1299 over-expressing RASSF1C (experimental sample) and H1299 over-expressing the vector backbone (control sample) using a co-immunoprecipitation kit (Pierce). The PIWIL1 2C12 monoclonal antibody (Wako Chemicals Inc., Richmond, VA) was used to pull down PIWIL1 protein using 1 mg of cell lysates from experimental and control samples. The RNA associated with the precipitated PIWIL1 protein complex was isolated using a total RNA isolation kit (Qiagen) and the isolated RNA was subjected to RNA deep sequencing and bioinformatic analysis. Results: Differential expression analysis based on read counts was carried out using a fold-change threshold of 2.0, maximum p-value of 0.05, and a minimum 1CPM, identified over 5505 genes that are differentially expressed when comparing read counts from H1299 cells over-expressing RASSF1C to H1299 cells over-expressing the vector back bone. Some of the genes identified with reduced mRNA levels correspond to tumor suppressors such as PTEN and p53 and apoptosis-inducing genes such as BAD and CASP3. Conclusions: Our study was designed to show that PIWIL-protein complexes can be pulled down from lung cancer cell lysates, and that PIWIL-protein complexes are likely to bind and regulate mRNA targets in lung cancer cells. We have identified interesting mRNAs that are potentially silenced by the PIWIL1-piRNA protein complex. Ongoing work is focused on validating some of the potential mRNA targets identified. This paves the way for conducting RNA-sequencing studies to identify specific piRNAs that associate with PIWIL1-protein complexes in the nucleus and cytoplasm. Citation Format: Yousef G. Amaar, Mark E. Reeves. Identification of mRNA targets associated with PIWIL1 protein complex in lung 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 2525.
Abstract 6331: Cloaking VEGF in small extracellular vesicles as a cause of adaptive resistance to anti-VEGF therapy
Authors: Shaolin Ma, Lingegowda S. Mangala, Wen Hu, Emine Bayaktar, Wei Hu, Nicholas B. Jennings, Robert L. Coleman, Gabriel Lopez-Berestein, Anil K. Sood
Journal: Cancer Research (2020)

Abstract Despite the wide use of anti-vascular endothelial growth factor (VEGF) therapy (AVT) for many solid cancers, most of them become resistant to such therapy, resulting in progressive disease. Therefore, new biomarkers and strategies for blocking adaptive resistance of cancer to AVT are needed. Small extracellular vesicles (small EVs, with a size of &amp;lt;200 nm) have been extensively studied as crucial intercellular messengers by delivering DNA, RNA, and proteins to recipient cells. We hypothesized that the packaging of angiogenic factors, especially VEGF, into small EVs could cause adaptive resistance to AVT by evading recognition by therapeutic antiboides. In this study, we carried out a series of in vitro (immunoblot analysis, flow cytometry, tube formation, and immunofluorescence staining) and in vivo (subcutaneous mouse models and Matrigel plug angiogenesis assay) experiments to determine the roles of small EVs in AVT resistance. We found that cancer-derived small EVs increasingly package VEGF and other factors in response to AVT. Further studies showed that bevacizumab cannot recognize the VEGF packaged inside small EVs (eVEGF) and eVEGF was protected from being neutralized by bevacizumab. Notably, eVEGF was transferred to endothelial cells, triggered intracrine signaling, and subsequently increased the number of tubes formed in an in vitro angiogenesis assay. In addition, VEGF was present at higher levels in serum small EVs in mouse models of adaptive resistance of ovarian cancer to bevacizumab than in models of sensitivity to it. Ovarian cancer cell-derived eVEGF increased tumor growth despite treatment with bevacizumab. Collectively, our data provide a new mechanism whereby eVEGF evades recognition by therapeutic antibodies and promotes tumor angiogenesis and progression. These findings have implications for biomarkers and new therapeutic strategies for ovarian cancer therapy. Citation Format: Shaolin Ma, Lingegowda S. Mangala, Wen Hu, Emine Bayaktar, Wei Hu, Nicholas B. Jennings, Robert L. Coleman, Gabriel Lopez-Berestein, Anil K. Sood. Cloaking VEGF in small extracellular vesicles as a cause of adaptive resistance to anti-VEGF therapy [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 6331.
Release of functional dexamethasone by intracellular enzymes: A modular peptide-based strategy for ocular drug delivery
Authors: Madhushree Bhattacharya, Amir Sadeghi, Sanjay Sarkhel, Marja Hagström, Sina Bahrpeyma, Elisa Toropainen, Seppo Auriola, Arto Urtti
Journal: Journal of Controlled Release (2020)

Tissue barriers limit drug delivery in the eye. Therefore, retinal diseases are treated with intravitreal injections. Delivery systems with reduced dosing frequency and/or cellular drug delivery properties are needed. We present here a modular peptide-based delivery system for cell targeted release of dexamethasone in the retinal pigment epithelial cells. The peptide-dexamethasone conjugates consist of cell penetrating peptide, enzyme cleavable linker and dexamethasone that is conjugated with hydrazone bond. The conjugates are chemically stable in the vitreous, internalize into the retinal pigment epithelial cells and release dexamethasone intracellularly by enzymatic action of cathepsin D. In vitro binding assay and molecular docking confirm binding of the released dexamethasone fragment to the human glucocorticoid receptor. In vivo rabbit studies show increased vitreal retention of dexamethasone with a peptide conjugate. Modular peptide conjugates are a promising approach for drug delivery into the retinal cells.
Abstract 2951: Knockdown of SCAMP3 suppresses the proliferation and emboli formation capacity of inflammatory breast cancer cells through EGFR signaling
Authors: Ivette J. Suarez-Arroyo, Jael Reyes-Chea, Michelle M. Martinez-Montemayor
Journal: Cancer Research (2020)

Abstract Inflammatory Breast Cancer (IBC) is one of the most lethal forms of breast cancer (BC), where patients have a 43% increased risk of death compared to women with non-IBC advanced BC. Approximately 30% of triple-negative (TN) IBC cases overexpress the Epidermal Growth Factor Receptor (EGFR). EGFR amplification is associated with a poor overall survival rate compared with EGFR-negative IBC cases. We previously identified increased expression of the secretory carrier membrane protein 3 (SCAMP3) in EGFR overexpressing TN SUM149 IBC cells, tissues and in the IBC metastasis promoting structure, the tumor emboli. SCAMP3 is an endosome-associated protein known to regulate the degradation of EGFR. Thus, we aim to elucidate the role of SCAMP3 in the regulation of EGFR signaling and IBC progression. To investigate how SCAMP3 contributes to the IBC cellular response, we knocked out (KO) the expression of SCAMP3 in IBC SUM149 cells using the CRISPR/Cas9 technique. Wild type (WT) and KO IBC cells treated with EGF for 30 min in serum-starved conditions were used to assess cell viability after 24, 48, 72, and 96h, colony, and emboli formation capacity. Our results demonstrate a reduction in the proliferation, colony, and emboli formation capacity of SCAMP3 KO cells in comparison with the WT. Taken together our results show that SCAMP3 plays a promoting role in the progression of IBC through EGFR signaling modulation. Citation Format: Ivette J. Suarez-Arroyo, Jael Reyes-Chea, Michelle M. Martinez-Montemayor. Knockdown of SCAMP3 suppresses the proliferation and emboli formation capacity of inflammatory breast cancer cells through EGFR signaling [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 2951.
Abstract 13492: Increasing Endothelial Insulin Sensitivity Rescues Vascular Function and Repair in Systemic Insulin Resistance by Restoring Nitric Oxide Bioavailability and Improving Endothelial Cell Migration
Authors: Anshuman Sengupta, Nadira Yuldasheva, Hema Viswambharan, Stacey Galloway, Romana Mughal, Ben Mercer, Noman Ali, Andrew Walker, Amir Aziz, Jessica Smith, Anna Skromna, Natallia Makava, Mark Kearney, Richard Cubbon
Journal: Circulation (2015)

Introduction: Insulin resistance is independently associated with vascular disease. Insulin receptor haploinsufficient (IRKO) mice are hypertensive and exhibit endothelial dysfunction and impaired vascular repair despite normal glucoregulation. We hypothesise that endothelial insulin signalling is crucial for vascular function and that selectively restoring endothelial cell (EC) insulin signalling may rescue these vascular derangements. Methods: Transgenic mice with Tie-2-driven human IR expression in the endothelium (HIRECO) were bred with IRKO, providing HIRECOxIRKO (HxI) offspring. Metabolic assessment included glucose and insulin tolerance tests, ELISA for plasma insulin concentration and non-invasive blood pressure measurement. Femoral artery injury was performed with angioplasty wires; repair was quantified in Evans Blue-perfused vessels at day 4. Circulating endothelial progenitor cells (EPC) were counted using FACS and cultured from blood. Explanted aortic rings were exposed to phenylephrine (PE) before and after incubation with the NOS inhibitor L-NMMA in organ baths to assess vasomotor function. Boyden chamber assays were used to assess migration of cultured lung ECs to VEGF. Data are expressed as mean(SE) and compared using t-tests;*=p&lt;0.05. Results: HxI and IRKO had similar glucocompetence and basal insulin [0.8(0.1)ng/mL vs 0.7(0.2);p=0.8]. Systolic BP was lower in HxI [97(2)mmHg vs 106(3)*]. Vascular repair was improved in HxI [57(4)% vs 46(2)%*]. There was no recovery in EPC numbers by FACS [99(10) vs 105(15);p=0.74], nor in culture [0.4(0.1)/HPF vs 0.4(0.2);p=0.99]. HxI aortic rings showed less PE-induced constriction than IRKO [EC50 8.9(0.8)x10 7 nM vs 6.3(0.9)x10 7 *], with greater NO bioavailability [Post-L-NMMA PE EC50 4.1(0.8)x10 7 nM vs IRKO 6.1(1.8)x10 7 *]. ECs from HxI showed greater net migration to VEGF [6.3(1.3) vs 1.9(1.2)*]. Conclusion: HIRECOxIRKO show rescue of vascular function despite global insulin resistance. This is not associated with improved glucoregulation or EPC abundance; rather, it may relate to increased NO availability and enhanced EC migration. Our data support endothelial insulin sensitisation as a potential therapeutic target for vascular dysfunction in insulin resistance.
Abstract LB-146: The impact of pancreatic cancer resection on long-term survival in the era of effective systemic treatment
Authors: Yaacov R. Lawrence, Alina Shtern, Ofer Margalit, Talia Golan, Zvi Symon
Journal: Cancer Research (2020)

Abstract Background: Surgical resection is the only curative modality in pancreatic cancer, yet the vast majority of patients undergoing surgery succumb of their disease. No large randomized studies have been performed to assess the survival impact of the procedure. We hypothesized that in the era of effective systemic treatments the survival advantage of surgical resection would be lessened. Methods: A meta-analysis of published phase II and phase III clinical trials in pancreatic cancer in both the post resection adjuvant setting and the locally advanced / metastatic setting. Trials were included based upon a systemic literature search. Eligibility criteria included: at least 50 patients per arm, detailed overall survival rates reported. Exclusion criteria: patients from trial arms for which there were not complementary data sets with / without surgical resection, trials testing non-pharmacological modalities or neoadjuvant approaches. Data was stratified based upon the systemic agents used, and analysed using an indirect aggregate approach. Primary endpoint was 3 year overall survival (OS_3yr), comparing patients treated with systemic treatment alone vs. surgery followed by adjuvant systemic treatment. Results: 74 treatment arms from 56 prospective trials published between 1990 and 2018 were included in the analysis. Overall a total of 11,898 patients were included, of whom 3,600 underwent resection. Median follow-up was 29.8 months for studies were stated. OS_3yr was for systemic treatment alone was 0%, 0%, 0.5%, 2.5%, 0.16%, 1.2%, 3.8% for No chemo, 5FU, Gemcitabine, S-1, Gemcitabine + xeloda, Gemcitabine + S-1, and Folfirinox respectively, and 19.9%, 24.9%, 32.9%, 58.8%, 42.5%, 52%, and 62.5% for the same agents delivered in the adjuvant setting; the advantage in OS_3yr provided by resection was 19.9%, 24.9%, 32.4%, 56.3%, 42.3%, 50.8%, and 58.8% for these agents, respectively. The advantage in OS_3yr provided by resection correlated closely with reported response rates for each systemic agent, r=0.96 p&amp;lt;0.001. Conclusions: Within the limitations of this analysis, it appears that our hypothesis was incorrect, and that the opposite is true. The introduction of effective systemic therapies has greatly increased the impact of pancreatic surgery on long-term survival in pancreatic cancer. Furthermore, it appears that for pancreatic cancer, systemic agents are more active in the adjuvant than the metastatic setting. Consequently, every effort should be made to bring patients to curative resection. Citation Format: Yaacov R. Lawrence, Alina Shtern, Ofer Margalit, Talia Golan, Zvi Symon. The impact of pancreatic cancer resection on long-term survival in the era of effective systemic 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 LB-146.
Abstract 1411: Population level genetic differentiation at the PVT1 gene locus: Implications for prostate cancer
Authors: Gargi Pal, Lia Di, Akintunde Orunmuyi, E. Oluwabunmi Olapade-Olaopa, Weigang Qiu, Olorunseun O. Ogunwobi
Journal: Cancer Research (2020)

Abstract The incidence and mortality rate of prostate cancer (PCa) is highest in males of African ancestry. PCa is a multi-factorial, complex disease, but the exact mechanisms for its development and progression are unclear. Analysis of data from the one thousand genomes project revealed that a 26-kb region spanning PVT1 exons 4A and 4B shows a run of 75 SNPs with distinct allelic frequencies between African and non-African populations. The gene desert located on chromosome 8q24 is associated with aggressiveness of PCa in males of African ancestry. Interestingly, the non-protein coding gene locus Plasmacytoma Variant Translocation (PVT1) present at 8q24 is overexpressed in PCa. PVT1 gives rise to multiple transcripts with potentially different functions. To investigate if our observed population-level differences at the PVT1 gene locus have implications for PCa, we determined the expression of PVT1 exons 4A and 4B in histologically confirmed normal prostate (n=22), benign tumor prostate (n=35), and malignant tumor prostate tissue (n=28) samples obtained from males who had undergone prostatectomy or transrectal ultrasound-guided biopsy in Nigeria, a sub-Saharan Black African population. We have observed that PVT1 exons 4A and 4B are significantly overexpressed in PCa tissues in comparison to others. Transient and stable overexpression of PVT1 exons 4A and 4B significantly induce greater prostate epithelial cell migration and proliferation. We anticipate that further exploration of the role of PVT1 exons 4A and 4B may lead to the possibility of exploiting them for diagnosis, therapy, and other clinical applications in PCa. Citation Format: Gargi Pal, Lia Di, Akintunde Orunmuyi, E. Oluwabunmi Olapade-Olaopa, Weigang Qiu, Olorunseun O. Ogunwobi. Population level genetic differentiation at the PVT1 gene locus: Implications for prostate 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 1411.
TCT-516 Trans-catheter aortic valve replacement in the presence of mitral prosthesis or ring
Authors: David Biton, Yoni Grossman, Ariel Finkelstein, Yafim Brodov, Paul Fefer, Israel Barbash, Uri Landes, Yaron Arbel, Victor Guetta, Amit Segev
Journal: Journal of the American College of Cardiology (2017)