bluuebunny/crossref_metadata_2025_split huggingface dataset:
Abstract 6098: Genome wide CRISPR screen reveals genetic vulnerabilities of next generation PARP1 inhibitor AZD5305
Authors: Yin Ling , Chen Junjie 
Published: April 2023

Abstract
The first-generation PARP inhibitors (PARPi) olaparib, niraparib, talazoparib and rucaparib have been clinically approved for several cancers, like breast, ovarian and prostate, especially in BRCA-mutant tumors which are of homologous recombination repair (HRR)-deficiency. All PARPi both target PARP1 and PARP2, causing cancer cell deaths deficient in HRR. However, only inhibition of PARP1 is required for synthetic lethality in HRR-deficient cells. AZD5305 is a highly selective PARP1 inhibitor which has been used in clinical trials. In this study, we used the Toronto Knock Out Library version 3 (TKOv3), which contains 70948 gRNAs targeting 18,053 protein-coding genes to perform whole-genome CRISPR-Cas9 screens with three isogenic cell lines 293A, MCF10A, and Hela to uncover known and new high-confidence genes synthetic lethal interacted with AZD5305. MAGeCK and Drug Z were used to analyze the results and genes were ranked according to their drugZ scores. We identify that in all three cell lines, PARP1 was in the top hit in positive selection which proves the AZD5305 indeed a PARP1 inhibitor. Moreover, through a comprehensive and comparative analysis with the screen results of first generation PARPi olaparib, we reveal known and new essential genes which are proved to be a common mechanism for synthetic lethality. We identify the gene AUNIP (Aurora Kinase A and Ninein Interacting Protein), in the top hit from AZD5305 screen but not in olaparib screen, suggesting that AUNIP may be an additional target for synthetic lethality with PARP1 loss. Taken together, this screen reveals the potential molecular genes related with PARP1 inhibitor that can be further explored targeted and combined cancer therapy.
Citation Format: Ling Yin, Junjie Chen. Genome wide CRISPR screen reveals genetic vulnerabilities of next generation PARP1 inhibitor AZD5305 [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 6098.
Abstract 6154: Imipramine induces apoptosis and inhibits metastasis via suppression of EGFR signaling pathway in bladder cancer
Authors: Lo Tsai Lin , Tsai Jai-Jen , Hsu Fei-Ting , Chang Yuan 
Published: April 2023

Abstract
Bladder cancer (BC) is one of the most common malignant diseases of the urinary system, with poor prognosis and high recurrence and metastasis rate. Recent literatures suggested that BC patients have proportionately worse depression and mental health, as well as being at increased risk of suicidal death when compared to the general population, while relatively sane BC patients have a 2.2 times higher mortality rate, which means that depression can make BC worse. Imipramine is a tricyclic antidepressant, was used to treat neuropathic pain, nocturnal enuresis, and depression. Recently, imipramine has been reported to owns anti-tumor efficacy in various type of cancer. However, the effects and underlying mechanisms of imipramine on BC is remaining unclear. First, we indicated that imipramine may induce cytotoxicity of BC by MTT assay. Flow cytometry also showed that imipramine may trigger the loss of mitochondrial membrane potential, the accumulation of oxidative stress (ROS), and the activation of cleaved-caspase-3, -8 and -9. Our western blotting assay and immunofluorescence translocation staining also verified that imipramine markedly inhibited BC progression by inhibiting both EGFR/AKT/NFΚB and EGFR/ERK/NΚB signaling pathways. Furthermore, transwell and wound healing assay indicated that imipramine effectively reduced the metastatic ability of BC. In addition, the anti-tumor effect of imipramine was also validated by MB49 bearing animal model. Most importantly biochemistry level and pathology was not affected by imipramine. In conclusion, imipramine may not only suppressed BC progression by inactivation of EGFR/AKT/NFΚB and EGFR/ERK/NFΚB signaling pathways and induction of apoptosis pathways. These results suggested that imipramine has the opportunity to be a new therapeutic strategy for BC patients.
Citation Format: Tsai Lin Lo, Jai-Jen Tsai, Fei-Ting Hsu, Yuan Chang. Imipramine induces apoptosis and inhibits metastasis via suppression of EGFR signaling pathway in bladder cancer. [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 6154.
Abstract 6189: Targeting DNA damage responsive pathways in cancer therapy
Authors: Chen Junjie 
Published: April 2023

Abstract
DNA double strand breaks (DSBs) result in activation of several key DNA damage response (DDR) kinases including ATM, ATR, and DNA-PK. These protein kinases not only promote DNA damage-induced checkpoint control, but also facilitate DSB repair in humans. Thus, these DDR kinases have become promising drug targets for cancer therapy. However, the benefits of targeting DDR kinases remain to be realized, in part due to the lack of predictive biomarkers. By undertaking CRISPR screens with inhibitors targeting key DDR kinases, we obtained a global and unbiased view of genetic interactions with DDR inhibition. Additionally, we compared the synergistic effects of combining different DDR inhibitors and found that an ATM inhibitor plus a PARP inhibitor induced dramatic levels of cell death, probably through promoting apoptosis. Our results provide a better understanding of DDR pathways, which may facilitate the use of these DDR-targeting agents in cancer therapy. Moreover, To provide comprehensive and unbiased perspective of DDR signaling pathways, we performed 30 fluorescence-activated cell sorting-based genome-wide CRISPR screens with antibodies recognizing distinct endogenous DNA damage-signaling proteins to identify new regulators involved in DNA damage response (DDR). We discovered that proteasome-mediated processing is an early and prerequisite event for cells to trigger camptothecin- and etoposide-induced DDR signaling. Furthermore, we identified PRMT1 and PRMT5 as new modulators that regulate ATM protein level. Moreover, we discovered that GNB1L is a master regulator of DDR signaling via its role as a co-chaperone for PIKK proteins. Collectively, these screens offer a rich resource for further investigation of DDR, which may provide insight into strategies of targeting these DDR pathways to improve therapeutic outcomes.
Citation Format: Junjie Chen. Targeting DNA damage responsive pathways in cancer therapy [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 6189.
Abstract 6211: Development and validation of a novel sSTRIDE-MMR functional assay to study the efficiency of MMR inhibitors
Authors: Solarczyk Kamil , Uznańska Karolina , Wójcikowska Olga , Białecka Maja , Waligórska Agnieszka , Koman Szymon , Kordon-Kiszala Magdalena 
Published: April 2023

Abstract
Mismatch repair (MMR) is considered to be one of the fundamental pathways that guards genome stability and mutations in genes encoding for crucial MMR proteins have been shown to promote cancer initiation. On the other hand, inactivation of MMR components in cancer cells leads to increased neoantigen formation and in consequence, exposes the tumor to the immune system. Therapeutic strategies aiming at inhibiting MMR are thus under development, yet methods reporting on the status of MMR are lacking. We report here the development, optimization and validation of a first MMR-specific functional assay. The assay, which is based on the STRIDE platform technology, detects DNA nicks localized in close proximity to PMS2 protein and can thus be utilized as a direct reporter of inhibition of PSM2 itself or upstream acting proteins. The optimization phase of assay development was performed in U2OS cells. First, in untreated cells we have shown that the sSTRIDE-MMR signals constitute ca. 10-15% of total single-strand DNA breaks foci detected by the classic sSTRIDE assay variant. In a series of technical negative controls we have then shown that the number of false-positive foci never exceeds 10% of the total number of signals, with as little as 2% for the isotype controls. The assay was further validated in HAP1 wild-type and PMS2-KO isogenic cell line pair. As expected, the number of sSTRIDE-MMR foci in the PMS2-KO cell line was significantly lower than in wild-type cells and additionally, no response to the treatment with 6TG, a known inducer of MMR, was detected in PMS2 null cells. Finally, the assay was used to verify the efficiency of first-in-class small-molecule MMR inhibitors. After treatment with the compounds, the number of detected sSTRIDE-MMR foci was significantly lower when compared to the number of foci in untreated cells. In conclusion, we show here that sSTRIDE-MMR is an assay characterized by high specificity, low false positives rate and a high-dynamic range. We believe that sSTRIDE-MMR can prove to be a very useful cell-based solution to study the efficiency of MMR inhibitors.
Citation Format: Kamil Solarczyk, Karolina Uznańska, Olga Wójcikowska, Maja Białecka, Agnieszka Waligórska, Szymon Koman, Magdalena Kordon-Kiszala. Development and validation of a novel sSTRIDE-MMR functional assay to study the efficiency of MMR inhibitors. [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 6211.
Abstract 6212: Inhibition of ATM-dependent checkpoint control and DNA double-strand break repair enhances the efficacy of ATR inhibitors
Authors: Turchick Audrey , Zimmermann Astrid , Chiu Li-Ya , Dahmen Heike , Elenbaas Brian , Zenke Frank T. , Blaukat Andree , Vassilev Lyubomir T. 
Published: April 2023

Abstract
Ataxia telangiectasia and Rad3 related (ATR) and ataxia telangiectasia mutated (ATM) protein kinases play key roles in the DNA damage response (DDR) by responding to replication stress and double-strand DNA breaks respectively to pause the cell cycle and promote DNA repair. ATR kinase inhibition in cancer cells disrupts cell cycle control and causes unrepaired DNA lesions and cytotoxicity. Accordingly, several ATR inhibitors (ATRi) are in clinical development as monotherapies and in combination with DNA damaging chemotherapies and poly(ADP-ribose) polymerase (PARP) inhibitors. Here we show that while treatment of cancer cells with an ATRi inhibits the ATR pathway, it simultaneously activates the ATM signaling pathway as shown by increased levels of p-ATM, p-CHK2, p-KAP1 and p-p53. In p53 wild-type cancer cells, ATR inhibition causes an ATM-mediated G1 cell cycle arrest which diminishes the DNA lesions and cytotoxic effects of ATR inhibition. Combination of an ATRi with a selective ATM inhibitor (ATMi) synergistically potentiated efficacy in cancer cells in vitro and increased efficacy in vivo at doses that did not show overt toxicities. In a panel of patient-derived xenograft (PDX) models of triple-negative breast cancer treated with an ATRi/ATMi combination, substantial improvement in efficacy was observed. Thus, activation of the ATM pathway by an ATRi acts as a compensatory resistance pathway for ATR inhibition. These results suggest a novel and efficacious combination approach for cancer therapy by dual inhibition of these two key DDR kinases.
Citation Format: Audrey Turchick, Astrid Zimmermann, Li-Ya Chiu, Heike Dahmen, Brian Elenbaas, Frank T. Zenke, Andree Blaukat, Lyubomir T. Vassilev. Inhibition of ATM-dependent checkpoint control and DNA double-strand break repair enhances the efficacy of ATR inhibitors. [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 6212.
Abstract 6251: High expression level of GSK3β in basal triple negative breast cancer: Effects of the HDAC inhibitor, vorinostat
Authors: Lyn-Cook Beverly D. , Emamzaden Fatemeh Nouri , Word Beverly , Hammons George 
Published: April 2023

Abstract
High expression levels of glycogen synthases kinase 3 beta (GSK3β) have been correlated with poor prognosis in triple negative breast cancer (TNBC) patients. GSK3β is a multifaceted kinase and is a key regulator of a number of cellular processes. It is known to function as a positive regulator of epithelial-mesenchymal transition (EMT). Usually, cells that undergo EMT are known to acquire stem cell properties and these cells have properties that are known to be resistant to chemotherapies. Inhibition of GSK3β has been shown to decrease markers of EMT and reduce cancer stem cells. High levels of GSK3β were found in the basal-2 subtype of triple negative breast cancer cells, HCC1806. Histone deacetylases (HDACs) are expressed at high levels in some cancers, including TNBC. In this study, vorinostat, a histone deacetylase inhibitor, was shown to down regulate GSK3 expression in HCC1806 cells at both the gene and protein level using qPCR and western blots. Furthermore, cancer stem cells (CSC) cell markers CD44/CD24 using flow cytometry and immunostaining were significantly decreased. Previous studies published from our laboratory have shown vorinostat’s ability to decrease TNBC cells invasion compacity, as well as cell growth. This study suggests that targeting GSK3β may be a potential therapeutic target for certain subtypes of TNBC. Triple negative breast cancer remains one of the most aggressive breast cancers, often having a high mortality rate in younger women.
Citation Format: Beverly D. Lyn-Cook, Fatemeh Nouri Emamzaden, Beverly Word, George Hammons. High expression level of GSK3β in basal triple negative breast cancer: Effects of the HDAC inhibitor, vorinostat [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 6251.
Abstract 6258: The discovery and preclinical characterization of the potent covalent KRASG12C inhibitor UCT-001024
Authors: Rose Tristin E. , O'Boyle Brendan M. , Hilf Justin A. , Baker-Tripp Emma L. , Feng Zhengao , Yang Kevin , Bartberger Michael D. , Losón Oliver C. , O'Brien Neil A. , McDermott Martina S. , Kamranpour Naeimeh , Jia Weiping , Luo Tong , Ayala Raul , Glasby John , Stoltz Brian M. , Slamon Dennis J. 
Published: April 2023

Abstract
Small molecule inhibitors of KRASG12C have garnered substantial interest as a targeted therapy for lung, colon and pancreatic cancers bearing this mutation. Data from multiple clinical programs have shown strong efficacy in lung tumors but diminished and differential efficacy for other tumor sites including lung-derived brain metastases. We undertook a series of in vitro and in vivo studies to evaluate clinically staged KRASG12C inhibitors in an effort to elucidate pharmacological factors underlying these clinical differences and identified potency, permeability/efflux, and clearance as impediments to efficacy, particularly in the context of brain metastases. Adagrasib is reportedly efficacious in patients with brain metastases. Our preclinical experimentation suggests that distinguished potency and pharmacokinetics are critical to therapeutic benefit, particularly in the context of brain metastases. Using both structure- and ligand-based design approaches, we identified a development candidate UCT-001024, which is a covalent KRASG12C inhibitor that demonstrates superior target-engagement kinetics and cellular potency in vitro. UCT-001024 also demonstrates improved plasma and whole brain unbound clearance, and in vivo potency in ectopic xenograft models and a brain-tropic NSCLC metastasis model relative to adagrasib. Additionally, UCT-001024 shows a favorable DDI profile and ion channel safety in an in vitro iPSC-derived cardiomyocyte cardiac proarrhythmia assay.
Citation Format: Tristin E. Rose, Brendan M. O'Boyle, Justin A. Hilf, Emma L. Baker-Tripp, Zhengao Feng, Kevin Yang, Michael D. Bartberger, Oliver C. Losón, Neil A. O'Brien, Martina S. McDermott, Naeimeh Kamranpour, Weiping Jia, Tong Luo, Raul Ayala, John Glasby, Brian M. Stoltz, Dennis J. Slamon. The discovery and preclinical characterization of the potent covalent KRASG12C inhibitor UCT-001024 [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 6258.
Abstract 6401: HMGB1 release predicts chemotherapy combinatorial efficacy with TIM-3 blockade
Authors: Onimus Alexis , Mandula Jessica , Rodriguez Paulo , Ruffell Brian 
Published: April 2023

Abstract
We have recently shown that TIM-3 blockade promotes response to paclitaxel chemotherapy in preclinical breast cancer models through its ability to suppress uptake of HMGB1-DNA complexes by dendritic cells. However, it remains unclear why paclitaxel is necessary for response to TIM-3 blockade. Here we demonstrate that the taxanes paclitaxel and docetaxel induce the loss of HMGB1 from breast cancer cells in vitro and in vivo. Interestingly, this does not occur through loss of cellular integrity, but rather through an active secretion process involving ADP-ribosylation of HMGB1 by PARP1. PARP1 was activated by docetaxel treatment, as measured by detection of its cleaved form in the cytoplasm, and HMGB1 release was prevented by the use of the PARP inhibitor niraparib. Both PARP1 activation and ADP-ribosylation of HMGB1 were dependent upon the activity of TLR4, a known receptor for paclitaxel, as demonstrated with CRISPR/Cas9-generated knockout cells and TLR4 inhibitors. However, TLR4 stimulation alone was insufficient to induce HMGB1 release. By understanding how taxanes promote the release of HMGB1 we may be able to develop biomarkers for the selection of patients most likely to respond to the combination of chemotherapy and immunotherapy with TIM-3 blocking antibodies.
Citation Format: Alexis Onimus, Jessica Mandula, Paulo Rodriguez, Brian Ruffell. HMGB1 release predicts chemotherapy combinatorial efficacy with TIM-3 blockade. [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 6401.
Abstract 6414: Concomitant anti-tumor immunity and checkpoint blockade responses are restored by depletion of CD62L expressing cells
Authors: Burke Brianna , Plaza-Rojas Lourdes , Perez Cynthia , Kostenko Elena , Austin Anna , Boucher Justin , Prajapati Kushal , Reyes Michael Delos , Chung Christine , Guevara-Patino Jose-Alejandro 
Published: April 2023

Abstract
Studies have shown the importance of CD62L in leukocyte trafficking. However, the significance of CD62L-expressing cells in concomitant anti-tumor immunity has not been investigated. Using a model of post-surgical tumor immunity, we show that in vivo depletion of CD62L-expressing cells before or immediately after surgical tumor resection enabled the development of anti-tumor concomitant responses against poorly immunogenic B16 (melanoma) or MTE-Ras (head & neck cancer) tumor cells. Anti-CD62L mAb administration depleted the cellular immune components that express CD62L, including NK, NKT, Mo, Ma, B, and T cells. Within the T cell compartment, naïve T cells (CD44lo CD62Lhi), effector (CD44hi CD62Llo), memory (CD44hi CD62Lhi) and regulatory T cells (Treg, CD4 CD25 Foxp3) were also depleted, while effector CD62L-negative T cells were spared in the TDLN. Tumor immunity did not occur in the absence of a primary tumor (sham surgery group) or after CD8 depletion. Whereas anti-CTLA-4 or anti-PD-1 mAbs failed as monotherapies, their administration during CD62L depletion restored their anti-tumor properties. The unified global gene expression analysis of the TDLN shows the significant enrichment of biological processes involved in the CD8 T cell effector phase, IL-2/IL-15, TNF-α, IFN-γ, IFN-α, IL-6, responses, mitotic cell division, glycolysis, and acetylation. Also, genes related to Treg responses were downregulated. These data point to a process in which depletion of CD62L cells in tumor-bearing hosts transforms the TDLN into a highly active immunological site in which tumor-reactive effector CD8 T cells (CD62L-negative) actively divide in the absence of Treg, accompanied by a cytokine response, glucose consumption, and acetylation of transcriptional factors and histones. These results identify an unrecognized role of CD62L-expressing cells in regulating concomitant anti-tumor immunity and restoring anti-tumor responses by checkpoint blockade inhibitors. Our study provides a new framework that could help understand how anti-tumor responses are limited.
Citation Format: Brianna Burke, Lourdes Plaza-Rojas, Cynthia Perez, Elena Kostenko, Anna Austin, Justin Boucher, Kushal Prajapati, Michael Delos Reyes, Christine Chung, Jose-Alejandro Guevara-Patino. Concomitant anti-tumor immunity and checkpoint blockade responses are restored by depletion of CD62L expressing cells [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 6414.