bluuebunny/crossref_metadata_2025_split huggingface dataset:
Abstract 1808: Loss of BAP1/BRCA1 counteracts spindle assembly checkpoint activation by the anti-mesothelin antibody drug-conjugate anetumab ravtansine
Authors: Singh Anita , Luo Jin-li , Busacca Sara , Dawson Alan , Kolluri Krishna Kalyan , Janes Samuel , Fry Andrew , Sommer Anette , Fennell Dean 
Published: September 2020

Abstract
Mesothelioma is a rapidly lethal cancer with limited treatment options. Spindle poisons have demonstrated clinical usefulness in mesothelioma, however, predictive biomarkers are lacking. Anetumab ravtansine (ARav) is an antibody drug-conjugate (ADC) comprising a mesothelin targeting antibody coupled to the payload, DM4, a microtubule destabilizer. We have recently identified BRCA1 as a direct regulator of the spindle assembly checkpoint (SAC), which is activated by spindle poisons and mediates mitotic arrest. BAP1 is one of the most frequently inactivated tumor suppressors in mesothelioma and it interacts with and regulates expression of BRCA1. We therefore hypothesized that BAP1 inactivation may confer resistance to ARav, highlighting a potential opportunity to refine personalization with this ADC. Three primary cell lines were derived from mesotheliomas resected during pleurectomy decortication expressed mesothelin (MSLN) and further characterized via whole exome sequencing. Two of the three primary cell lines have BAP1 mutation (R417 frameshift (fs); E631fs) and show reduced BRCA1/MAD2 protein expression. MSLN expression was found to be independent of BAP1 inactivation status or BRCA1 expression level. BAP1 mutant primary cell lines exhibited resistance to ARav by overriding the mitotic arrest with continued cell cycle progression, indicating a defective SAC whereas the cell line with wt BAP1 underwent mitotic arrest followed by cell death. Increase in mitotic index was also observed in primary cell line with wt BAP1 following ARav treatment without any significant change in BAP1 mutant cell lines. Resistance to ARav in BAP1 deleted cell line NCI-H226 was reversed by stable expression of wildtype BAP1 in NCI-H226 indicating critical regulation of SAC by BAP1. Vinorelbine resistant cell line RVR with a defective SAC also exhibited resistance to ARav compared to the parental REN with no change in MSLN expression suggesting that an active SAC is required for prolonged mitotic arrest and subsequent cell death. Wildtype BAP1 and MSLN is critical for efficacy of ARav. Inactivation of BAP1 correlates with loss of BRCA1 expression and dysregulation of the SAC.
Citation Format: Anita Singh, Jin-li Luo, Sara Busacca, Alan Dawson, Krishna Kalyan Kolluri, Samuel Janes, Andrew Fry, Anette Sommer, Dean Fennell. Loss of BAP1/BRCA1 counteracts spindle assembly checkpoint activation by the anti-mesothelin antibody drug-conjugate anetumab ravtansine [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 1808.
Abstract 1821: Reversal of PD-L1-mediated chemoresistance by MCL-1/BCL-2 antagonism in colon cancer cells
Authors: Sun Lei , Patai Arpad , Qin Bo , Sinicrope Frank A. 
Published: September 2020

Abstract
Background: PD-L1 is an immune checkpoint protein that may display intrinsic, non-immune functions in human cancer cells. Previously, we discovered that PD-L1 is regulated by BRAFV600E via YAP and c-Jun, and whose deletion can confer chemoresistance due to a decrease in the BH3-only BIM protein in colorectal cancer (CRC) cells. Here, we hypothesize that release of pro-apoptotic BIM from its sequestration by MCL-1 or BCL-2 can overcomes drug resistance mediated by depletion of PD-L1.
Materials and Methods: Parental and PD-L1 knockout human (RKO) and murine (MC38) CRC cells with or without reconstituted PD-L1 were utilized. RKO cells with knockdown of MCL-1 or BCL-2 by shRNA were generated. Cells were treated with the MCL-1 selective inhibitor AZD5591 or the BCL-2/BCL-xL inhibitor ABT-263 alone or combined with the MEK inhibitor, cobimetinib. Apoptosis was measured by immunoblotting of cleaved caspase-3 and by Annexin V labeling using FACS. Clonogenic cell survival assay was performed. Protein/protein interaction was analyzed by immunoprecipitation assay.
Results: BIM induction by cobimetinib was insufficient to overcome chemoresistance due to loss of PD-L1. Using a potent and selective inhibitor of MCL-1 (AZD-5591), we demonstrate that concurrent antagonism of MCL-1 and MEK can overcome apoptosis resistance in both human and murine PD-L1 knockout CRC cells. Specifically, inhibition of MCL-1 by AZD-5591 or gene knockdown combined with cobimetinib suppresses clonogenic cell survival and enhances apoptosis in cells with PD-L1 knockout, wild type or those with reconstituted PD-L1. Mechanistically, the interaction of BIM with MCL-1 is increased in PD-L1 knockout (versus wild-type cells) in the presence of cobimetinib, and enhanced binding of BIM to MCL-1 is associated with BIM phosphorylation at Thr116. Targeting MCL-1 using AZD-5591 or MCL-1 shRNA releases BIM from its sequestration by MCL-1 and results in enhanced apoptotic signaling induced by cobimetinib to an equivalent extent in wild type and PD-L1 knockout cells with or without reconstitution of PD-L1. Similarly, targeting BCL-2 by ABT-263 or by BCL-2 shRNA releases BIM from its binding to BCL-2, and enhances apoptosis induction by cobimetinib independent of PD-L1 status. Enhanced binding of BIM to BCL-2 was also associated with BIM phosphorylation at Thr116.
Conclusion: Chemoresistance mediated by loss of PD-L1 can be reversed by the use of BH3 mimetic drugs combined with MEK inhibition in CRC cells to exploit their apoptotic dependency on BIM expression.
Citation Format: Lei Sun, Arpad Patai, Bo Qin, Frank A. Sinicrope. Reversal of PD-L1-mediated chemoresistance by MCL-1/BCL-2 antagonism in colon 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 1821.
Abstract 1847: Phenotypic evaluation and discrimination of clinical JAK inhibitors for myeloproliferative disorders
Authors: Velichko Sharlene , Denker Sheryl P. , O'Mahony Alison 
Published: September 2020

Abstract
Small molecule inhibitors of Janus kinases (Jakinibs) represent a promising treatment for myeloproliferative disorders including polycythemia vera (PV), essential thrombocytosis (ET), and myelofibrosis (MF). Currently multiple JAK2 inhibitors (ruxolitinib, fedratinib, momelotinib, baricitinib) are either approved or in clinical development for the treatment of MF. The primary target of Jakinibs, the JAK-STAT pathway, plays a critical role in multiple cellular processes relevant for myelofibrosis, including survival, differentiation, and proliferation. However, all approved Jakinibs are reportedly promiscuous in that they inhibit kinases beyond the JAK family. Their overall clinical impact, therefore, reflects the sum of these target activities, as well as downstream secondary pharmacology relevant to both efficacy and safety. We evaluated these four Jakinibs using phenotypic profiling with the BioMAP® Diversity PLUS Panel to identify common versus differential activities. The BioMAP platform consists of human primary cell-based assay or systems designed to recapitulate key aspects of tissue and disease states. Distinct activity profiles were generated for each of the tested Jakinibs based on their impacts on 148 different biomarkers in 12 different model systems. Comparison of these profiles at concentrations relevant for clinical exposure levels revealed common activities including inhibition of T and B cell proliferation and decreased levels of inflammation and immune activation biomarkers. Together these activities represent a phenotypic signature related to shared primary JAK targets. In contrast, multiple differentiating activities were observed between the four drug profiles: baricitinib increased TNFα levels whereas momelotinib decreased TNFα in the LPS system modeling monocyte activation; fedratinib and momelotinib, but not ruxolitinib or baricitinib, inhibited endothelial cell proliferation; only momelotinib inhibited macrophage responses and decreased PGE2 levels. These data indicate that even within the specific JAK2 inhibitor drug class, individual entities have distinct modes of action relevant for clinical outcomes.
Citation Format: Sharlene Velichko, Sheryl P. Denker, Alison O'Mahony. Phenotypic evaluation and discrimination of clinical JAK inhibitors for myeloproliferative disorders [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 1847.
Abstract 1980: Multiplex digital PCR combined with melting curve analysis for detecting KRAS and BRAF mutations
Authors: Tanaka Junko , Nakagawa Tatsuo , Shiratori Akiko , Harada Kunio , Uematsu Chihiro , Takai Erina , Yachida Shinichi 
Published: September 2020

Abstract
Background
Digital PCR (dPCR) is a promising method for liquid biopsies and is able to quantify nucleic acids more sensitively than real-time PCR. However, dPCR has a large fluctuation in the fluorescence intensity of the droplets or wells due to insufficient PCR in the small partitions, limiting the multiplexing capability of using the fluorescence intensity. In this study, we propose a new measurement method that combines dPCR with melting curve analysis for highly multiplexed genotyping.
Methods
A sample is digitized into a silicon chip with up to ~104 wells in which asymmetric PCR was performed to obtain more single-stranded amplicons that are complimentary to molecular beacon probes. Fluorescence images were captured while controlling the temperature of the chip, and melting curve was measured for each well. Then, genotyping was performed by using the fluorescence intensity, dye color of the probe, and melting temperature (Tm). Because the Tm of the PCR products does not considerably depend on the amplification efficiency of PCR, genotyping accuracy is improved by using Tm values, enabling highly multiplexed genotyping.
Results
The concept was confirmed by measuring four common KRAS mutations (G12D, G12V, G12R, and G13D) and one common BRAF mutation (V600E). G12D, G12V and G12R-mutant KRAS alleles were detected with FAM-labeled probes, G13D-mutant KRAS allele and wildtype KRAS allele were detected with HEX-labeled probes, and V600E-mutant BRAF allele and wildtype BRAF allele were detected with CAL Fluor Red 610-labeled probes. The results showed that the peaks of the Tm distributions of the DNA groups were separated by more than 2°C. By combining the fluorescence intensities and the Tm values, the wildtype and mutant groups were clearly identified and able to be quantified.
Conclusion
We have proposed a new measurement method that combines dPCR with melting curve analysis, and successfully performed the multiplexed genotyping assay. To our knowledge, this is the first demonstration of genotyping of seven DNA groups with a single mutation of cancer-related genes by combining dPCR with melting curve analysis.
Citation Format: Junko Tanaka, Tatsuo Nakagawa, Akiko Shiratori, Kunio Harada, Chihiro Uematsu, Erina Takai, Shinichi Yachida. Multiplex digital PCR combined with melting curve analysis for detecting KRAS and BRAF mutations [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 1980.
Abstract 2000: Systemic and tumor associated IL-8 correlates with resistance to PD-L1 blockade
Authors: Yuen Kobe , Liu Lifen , Li Congfen , Rishipathak Deepali , Williams Patrick , Kadel Edward , Koeppen Hartmut , Madireddi Shravan , Keerthivasan Shilpa , Chen Ying-Jun , Modrusen Zora , Banchereau Romain , Leng Ning , Hegde Priti , Huseni Mahrukh , Mariathasan Sanjeev 
Published: September 2020

Abstract
Elevated plasma interleukin-8 (IL-8) is a poor prognostic factor for many cancers. However, the association of IL-8 with clinical outcomes to checkpoint inhibition has not been comprehensively evaluated in randomized studies. Moreover, the source of IL-8 and the underlying biology that influences resistance to immune checkpoint inhibitors remain unknown. Here we analyzed circulating IL-8 protein in plasma, and IL8 gene expression in peripheral blood mononuclear cells (PBMC) and tumors of patients treated with atezolizumab (anti-PD-L1 mAb), from multiple randomized trials in metastatic urothelial carcinoma (mUC) and metastatic renal cell carcinoma (mRCC). High levels of IL-8 in plasma, PBMCs and tumors, were associated with decreased efficacy in mUC and mRCC patients treated with atezolizumab, even in tumors that were classically CD8+ T cell inflamed. mUC patients treated with atezolizumab, but not with chemotherapy, who experienced an on-treatment decrease in plasma IL-8, exhibited improved overall survival. IL-8 is primarily expressed in circulating and intratumoral myeloid cells, and high IL8 expression was associated with the downregulation of the antigen presentation machinery in myeloid cells. A better understanding of IL-8-mediated myeloid inflammation in curtailing responses to checkpoint inhibitors is essential for developing new therapies for patients.
Citation Format: Kobe Yuen, Lifen Liu, Congfen Li, Deepali Rishipathak, Patrick Williams, Edward Kadel, Hartmut Koeppen, Shravan Madireddi, Shilpa Keerthivasan, Ying-Jun Chen, Zora Modrusen, Romain Banchereau, Ning Leng, Priti Hegde, Mahrukh Huseni, Sanjeev Mariathasan. Systemic and tumor associated IL-8 correlates with resistance to PD-L1 blockade [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 2000.
Abstract 2028: Recent trends in use of adjuvant chemotherapy in elderly stage II-III non-small cell lung cancer
Authors: Komiya Takefumi , Powell Emily , Guddati Achuta Kumar 
Published: September 2020

Abstract
Background: Although randomized trials demonstrated survival benefit of adjuvant chemotherapy, previous reports have suggested that its use in elderly populations for early stage non-small cell lung cancer (NSCLC) was infrequent. Oncologists often hesitate to offer adjuvant chemotherapy in resected early stage non-small cell lung cancer for elderly population. The status of adjuvant chemotherapy in this population is unknown for recent decades.
Materials and Methods: Using the Surveillance, Epidemiology, and End Results (SEER) database which represents about 28% of the US population, we examined the incidence of chemotherapy in resected stage II-III NSCLC between 2004 and 2015. Staging was determined according to the American Joint Committee on Cancer (AJCC) 6th version. Cases were grouped by age (20-69, 70-79, and 80+). Trends in use of chemotherapy by age group was assessed by univariate and multivariate analyses.
Results: A total of 35,009 were selected as surgically resected stage II-III NSCLC. Use of chemotherapy was 66.9%, 48.2%, 25.0% in age 20-69, 70-79, 80+, respectively. Multivariate analysis demonstrated that younger age (20-69) and recent year (2010-2015) of diagnosis were associated with increased use of chemotherapy. Chemotherapy use increased from 2004 to 2015 by 11.0%, 18.3%, and 11.3% in age 20-69, 70-79, 80+, respectively. In the age 70-79 group, increased use of chemotherapy was greater in stage II (24.3%) than stage III (14.1%). Five-year overall survival in age 70-79 group mildly increased by 7.6% from 2004 to 2011.
Conclusion: This study suggests that use of adjuvant chemotherapy in elderly population increased primarily in age 70-79. Few patients in age 80+ receive adjuvant chemotherapy even in recent years. This study not only informs oncologists of current status but also suggests further research on very elderly populations.
Citation Format: Takefumi Komiya, Emily Powell, Achuta Kumar Guddati. Recent trends in use of adjuvant chemotherapy in elderly stage II-III non-small cell 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 2028.
Abstract 2038: Overall survival of glioblastoma patients treated by standard therapy in comparison to standard therapy plus tumor treating fields
Authors: Rulseh Aaron , Derner Adam , Sroubek Jan , Klener Jan , Vymazal Josef 
Published: September 2020

Abstract
Introduction: Glioblastoma multiforme (GBM) is the most common malignant primary intracranial tumor and traditionally has a median survival of only 10 to 14 months, with only 3 to 5% of patients surviving more than three years. Recurrence is nearly universal, and further decreases the median survival to only 5 to 7 months with optimal therapy. Tumor treating fields (TTFields; Optune, Novocure, Haifa, Israel) therapy is a novel treatment technique that has recently shown significant prolonged survival in GBM patients. This therapy is approved for the treatment of newly diagnosed and recurrent GBM and is based on the principle that low intensity, intermediate frequency alternating electric fields (100 to 300 kHz) have an anti-mitotic effect in specific cell types. The applied fields disrupt the mitotic spindle, microtubule assembly and the segregation of intracellular organelles during cell division, leading to apoptosis or mitotic arrest. We aimed to compare overall survival between patients treated with standard therapy and standard therapy plus TTFields at our institution.
Materials and Methods: A total of 34 patients (22 male, 15 female) diagnosed with GBM and treated by standard therapy plus TTFields (STDTh-TTF) at our institution were included. Standard therapy (STDTh) consisted of surgical resection, followed by combined radiotherapy and chemotherapy (Temozolomide); in 2 cases biopsy was performed in place of resection. The date of resection or biopsy was considered the entry date and was used in calculating survival, and ranged from June 2015 to July 2019. A matching control group treated by STDTh alone at our institution was assembled from our database, based primarily on date of resection or biopsy, and secondarily by age (1 subject underwent biopsy in place of resection). When assembling the control group, the investigators were blinded to survival outcome.
Results: Significantly greater overall survival was observed for the group treated by TTFields in addition to standard therapy (p = 0.005; Hazard ratio [HR] 0.28; 95% confidence interval [CI] 0.11-0.69). The groups were identical with respect to sex, and no differences with respect to age (p=0.12; STDTh-TTF mean 50.54 years, SD 10.3; STDTh mean 54.39 years, SD 9.3) or inclusion date (p=0.3) were detected.
Conclusions: Our initial results appear promising with respect to overall survival in patients undergoing TTFields treatment in addition to standard therapy.
Citation Format: Aaron Rulseh, Adam Derner, Jan Sroubek, Jan Klener, Josef Vymazal. Overall survival of glioblastoma patients treated by standard therapy in comparison to standard therapy plus tumor treating fields [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 2038.
Abstract 2044: Chemotherapy induced neutropenia in rats following administration of eflapegrastim or pegfilgrastim on the same day at three different timepoints and at 24 hours post-chemotherapy
Authors: Kim Yu-Yon , Kim Eunjung , Han Hyesun , Baek Seungjae , Chawla Shanta , Kolli Prasad , Bhat Gajanan , Lebel Francois 
Published: September 2020

Abstract
Background: Eflapegrastim is a long-acting G-CSF that is comprised of a G-CSF analog and a recombinant IgG4 Fc fragment conjugated at their N-termini via a short polyethylene glycol linker. Currently, G-CSF products are administered 24 hours after chemotherapy. We compared the duration of neutropenia (DN) after treatment with eflapegrastim and pegfilgrastim given on the same-day, at three different timepoints, and after 24 hours in chemotherapy-induced neutropenic rats.
Method: Neutropenia was induced in rats via intraperitoneal administration of cyclophosphamide and docetaxel (TC) chemotherapy. Rats (5 animals per group) were assigned to dose groups of either vehicle or equivalent doses (based on human clinical doses) of pegfilgrastim (103.3 µg/kg) or eflapegrastim (61.8 µg/kg as G-CSF) on the same day as chemotherapy at 0, 2, and 5 hours or 24 hours after chemotherapy. The primary endpoint was the difference in DN after TC treatment and administration of eflapegrastim or pegfilgrastim at the specified timepoints.
Results: In the vehicle group, the TC regimen induced neutropenia in all animals with an ANC nadir occurring on approximately Day 4 and a mean DN of nearly 7 days. The mean DN values for treatment with eflapegrastim on the same day, at 0, 2, and 5 hours, and after 24 hours were similar and the mean DN values for eflapegrastim were significantly lower than for pegfilgrastim at all dosing timepoints (Table).
Time after Chemotherapy(hours)Mean Duration of Neutropenia (days)Difference (95% CI)Eflapegrastim Time vs 24 hoursDifference (95% CI)EflapegrastimPegfilgrastim00.62.2-1.6 (-3.067, -0.133)0.4 (-0.08, 1.28)20.21.8-1.6 (-2.84, -0.36)0 (-0.19, 0.59)50.01.2-1.2 (-1.20, -1.20)-0.2 (0, 0)240.21.8-1.6 (-2.84, -0.36)NA
Conclusions: The DN for same-day treatment with eflapegrastim at 0, 2, and 5 hours was similar to that of the treatment after 24-hours. However, the mean DN values were significantly lower for eflapegrastim than pegfilgrastim at all time points. Further exploration of the potential advantage of same-day dosing with eflapegrastim in patients undergoing chemotherapy is warranted.
Citation Format: Yu-Yon Kim, Eunjung Kim, Hyesun Han, Seungjae Baek, Shanta Chawla, Prasad Kolli, Gajanan Bhat, Francois Lebel. Chemotherapy induced neutropenia in rats following administration of eflapegrastim or pegfilgrastim on the same day at three different timepoints and at 24 hours post-chemotherapy [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 2044.