bluuebunny/crossref_metadata_2025 huggingface dataset:
Abstract 4400: Transcriptional dysregulation of chromosomes localized into the micronucleus
Authors: Norkunaite Danguole , Al-Rawi Duaa , Bakhoum Samuel
Published: March 2024

Chromosomal Instability (CIN) is a characteristic of the most aggressive and drug-resistant cancers. Chromosomally unstable cells form micronuclei (MN), a structure with an unstable nuclear membrane that spontaneously surrounds missegregating chromosomes upon mitotic exit. Several studies have demonstrated that CIN drives drug resistance and metastasis through the karyotypic diversity caused by copy number alterations. Beyond facilitating karyotypic diversity, CIN has recently been demonstrated to cause durable epigenetic alterations including reduction of the activating histone H3K27ac mark in chromosomes localized to micronuclei. This reduction in histone H3K27 acetylation persists after the relocalization of the missegregated chromosome to the primary nucleus (PN). Given the loss of transcription-associated epigenetic modifications, we hypothesized that MN would exhibit transcriptional impairment. Indeed, by using nascent RNA assays and immunofluorescence, we found that chromosomes localized into the MN are less transcriptionally active and exhibit lower levels of active RNA polymerase II (RNAP2). Transcriptional inhibitors targeting RNAP2 largely abrogate MN transcription. Conversely, class-specific histone deacetylase inhibitors (HDACi) cause increased hyperacetylation of the MN relative to the PN, which persists beyond MN reincorporation into the PN. We also hypothesized that transcription in MN depends on the manner of MN biogenesis. Preliminary data shows that MN formed from breakage-fusion-bridge (BFB) events may cause less transcriptionally active MN than ones generated from treatment with the MPS1 inhibitor, reversine. To better understand the mechanisms that regulate transcription in the MN, our ongoing work is focused on an unbiased investigation of the micronuclear transcriptome.

Citation Format: Danguole Norkunaite, Duaa Al-Rawi, Samuel Bakhoum. Transcriptional dysregulation of chromosomes localized into the micronucleus [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 4400.
Abstract 4412: Defining chromatin alterations in liver cancer at single cell resolution
Authors: Ramirez Miguel , Stephan Tabea , Schaeffer Daivd , Hoodless Pamela
Published: March 2024

Hepatocellular carcinoma (HCC) is the most common liver cancer and arises from the malignant transformation of hepatocytes. HCC tumors often express genes critical for hepatocyte development but the regulatory mechanisms driving aberrant expression remain unclear. Recent evidence indicates that epigenetic alterations contribute to HCC progression with nearly 50% of cases associated with mutations in chromatin modifiers. Thus, it is imperative to understand how chromatin is altered in HCC and identify the DNA regulatory sequences associated with HCC tumorigenesis. Our study aims to map the chromatin landscape and transcriptome in HCC tumors using a multiomic approach at single cell resolution. Single-cell ATAC- and RNA-seq will be conducted in HCC tumors, matched controls and normal livers to identify regulatory sequences and their target genes critical for HCC tumor progression. We will characterize these regulatory sequences in the context of liver development using genetic manipulation and epigenomic datasets generated from human pluripotent stem cells differentiated to hepatic lineages. Our goal is to elucidate how epigenetic alterations in HCC drive cancer progression and how they relate to a dedifferentiated state.

Citation Format: Miguel Ramirez, Tabea Stephan, Daivd Schaeffer, Pamela Hoodless. Defining chromatin alterations in liver cancer at single cell resolution [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 4412.
Abstract 4413: Identifying genome-wide histone profiles in patient derived models of AML for predictive biomarker development
Authors: Simmons Alysha , Oswald Eva , Kuales Georg , Keogh Michael , Kumary Vishnu U. , Brill Eva , Cowles Martis W. , Venters Bryan , Schueler Julia B.
Published: March 2024

Acute myeloid leukemia (AML) is a complex disease with highly individualized treatment plans for patients. Mostly these are based on genetic and phenotypic markers of the disease, but the patient’s overall condition is playing a significant role as well. To develop innovative drugs for a broad patient cohort, it is essential to understand the biological implications of these differences and to model them preclinically. In this study, we are assessing the utility of EpiCypher’s CUT&Tag-FFPE platform to characterize the epigenome of AML PDX samples. CUT&Tag-FFPE is an epigenome profiling assay that is compatible with Formalin-Fixed Paraffin-Embedded (FFPE) samples, enabling robust genome-wide profiling of histone modifications from limited clinical samples. We derived PDX model LEXFAM 2799 (NPM1 wt; FLT3 wt, t(8;21)) and LEXFAM 2966 (NPM1 mut; FLT3 wt) from treatment naïve patients and established in immunocompromised NSG mice. LEXFAM 2799 is a fast-growing model with passaging times of 33 days, whereas LEXFAM 2966 displays a passaging time of 140 days. We next treated with Standard of Care (SoC) agents Decitabine, Cytarabine and all-trans-retinoic acid (ATRA): LEXF 2966 was highly sensitive towards Decitabine leading to complete remission. Cytarabine induced a partial remission and ATRA had only minor effect on tumor growth. In contrast LEXFAM 2799 was resistant towards treatment with ATRA and showed only partial remission under treatment with Cytarabine or Decitabine. Using the CUT&Tag-FFPE platform we are analyzing FFPE slides from the above mentioned two AML PDX models to investigate differences in the genome-wide histone profile that relate to the different growth behavior as well as sensitivity towards SoC treatment. The goal of these studies is to identify tumor model specific profiles that correlated specifically with the sensitivity towards the hypomethylating agent Decitabine. In addition, we plan to analyze additional untreated as well as treated AML PD models to validate the identified signatures confirming them as predictive biomarkers for sensitivity towards current standard of care and prospectively as well innovative compounds.

Citation Format: Alysha Simmons, Eva Oswald, Georg Kuales, Michael Keogh, Vishnu U. Kumary, Eva Brill, Martis W. Cowles, Bryan Venters, Julia B. Schueler. Identifying genome-wide histone profiles in patient derived models of AML for predictive biomarker development [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 4413.
Abstract 4468: Elucidating the phosphoinositide-modulatory function of INPP5B in regulating cancer stemness and tumorigenesis in liver cancer
Authors: Liu Linglin , Wang Yifei , Xie Yunong , Tong Man
Published: March 2024

Hepatocellular carcinoma (HCC) represents a major global health challenge, characterized by its heterogeneity and aggressive nature. Solid evidence has now suggested that tumor growth is driven by subpopulations of tumor cells with less differentiated cell states, called cancer stem cells (CSCs), which govern therapeutic resistance and tumor recurrence. Therefore, characterization of CSCs and their associated oncogenic signaling pathways is crucial to the development of more specific and sensitive HCC prognostic markers and to the design of novel targeted therapies against CSCs for HCC treatment. In search of the altered genes and pathways that are tightly associated with cancer stemness trait in HCC, we exploited the stemness and oncogenic dedifferentiation signature to mine the HCC dataset of the Cancer Genome Atlas. Phosphoinositide signaling was identified to be enriched and downregulated in the transcriptomes of HCC patients with strong stemness and dedifferentiated signature. Subsequent clinical correlation analysis found inositol polyphosphate-5-phosphatase B (INPP5B) to be the top downregulated gene in phosphoinositide signaling with its expression correlated with poor survival in HCC patients. Functional studies showed that INPP5B overexpression reversed the oncogenic and stemness properties while INPP5B knockout promoted tumor growth in immunocompetent mice. Subsequent RNA sequencing and molecular assays revealed INPP5B deregulation to be associated with lipid metabolism remodeling. Collectively, our results suggest an intricate relationship between phosphoinositide signaling and lipid metabolism through the regulation of INPP5B in HCC. The findings may open new avenue for future research aimed at devising targeted therapies to interfere with liver CSCs and enhance the prognosis of HCC patients.

Citation Format: Linglin Liu, Yifei Wang, Yunong Xie, Man Tong. Elucidating the phosphoinositide-modulatory function of INPP5B in regulating cancer stemness and tumorigenesis in liver cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 4468.
Abstract 4477: The development of a small molecule dual inhibitor of CXCR4 and Mcl-1 to target bortezomib resistant and stem-like cells in multiple myeloma
Authors: Elbezanti Weam Othman , Al-Odat Omar S. , Jonnalagadda Subash C. , Budak-Alpdogan Tulin , Pandey Manoj K.
Published: March 2024

Multiple myeloma (MM) is a malignant plasma-cell illness defined by clonal growth of malignant plasma cells within the bone marrow (BM) microenvironment. Despite the availability of many therapeutic alternatives, MM remains consistently lethal, demanding the development of novel techniques. The intimate relationship between myeloma cells and the BM microenvironment is a distinguishing hallmark of MM. The chemokine stromal cell-derived factor-1 (SDF-1) and its receptor CXCR4 enhance the homing of MM cells to the BM, which has important functional implications. The BM microenvironment secretes a variety of hormones and cytokines that activate several signaling pathways, resulting in enhanced production of the anti-apoptotic Mcl-1 protein, boosting the proliferation, survival, and migration of MM cells and conferring resistance to standard chemotherapy. As a result, we created GA-A, a hybrid molecule in which we coupled an aralkyl carboxylic acid moiety, known to preferentially inhibit Mcl-1, to gambogic acid, which has previously been demonstrated to inhibit CXCR4 in MM. Our western blot has shown that this unique hybrid compound successfully suppressed CXCR4 and Mcl-1. Interestingly, using qPCR we found that CXCR4 was observed to be higher expressed in CD138- versus CD138+ cells, while GA-A inhibited CXCR4 in both subpopulations. In addition, using annexin-V flow cytometry staining we found that GA-A increased the apoptotic effect of bortezomib in MM stem-like cells while inhibiting the viability of bortezomib resistant cells. Using human cytokine array we found that GA-A activates some of proinflammatory cytokines that can activate the immune system such as GM-CSF, IFN gamma, IL-2 and IL-12. In summary, our findings indicate the successful creation of a novel dual CXCR4-Mcl1 inhibitor that demonstrates efficacy against the stem cell-like population and bortezomib resistant cells and enhances the effectiveness of bortezomib.

Citation Format: Weam Othman Elbezanti, Omar S. Al-Odat, Subash C. Jonnalagadda, Tulin Budak-Alpdogan, Manoj K. Pandey. The development of a small molecule dual inhibitor of CXCR4 and Mcl-1 to target bortezomib resistant and stem-like cells in multiple myeloma [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 4477.
Abstract 4479: Design, synthesis, and evaluation of amino acid conjugated niclosamide prodrugs as a PepT1 substrate
Authors: McDonough Alaina C. , Cheng Jeffery Y. , Mohammed Shabber , Li Pui-Kai , Bhutia Yangzom
Published: March 2024

The anthelmintic drug, Niclosamide, has a multitude of promising anticancer properties including inhibition of key signaling pathways involved in tumorigenesis, disruption of mitochondrial function, degradation of the overexpressed androgen receptor, and more. However, a key limitation of the clinical use of Niclosamide in cancer treatment is its low solubility and cellular uptake, which result in poor pharmacokinetic properties and dose-limiting GI toxicities at concentrations lower than the therapeutic threshold of the drug. To overcome this, we hypothesized that we could use amino acid conjugated niclosamide prodrugs to improve cellular uptake by creating a substrate of the PepT1 transport protein. The overexpression of the PepT1 transport protein that is involved in many hormonal cancers is being used to our advantage. Our study involved first synthesizing a group of niclosamide and niclosamide analogs conjugated with polar or nonpolar amino acids. Next, we conducted a Glycine-Sarcosine assay measuring changes in the uptake of the dipeptide glycyl-sarcosine (Gly-Sar). Our initial step was to examine if our conjugates could disrupt the absorption of Gly-Sar. The active conjugate will be tested whether they are substrates or inhibitors of the transporter. For the future, we have plans to determine the half-maximal inhibitory concentration (IC50) of niclosamide conjugates in various cancer cell lines and to quantify cleavage of the prodrugs intracellularly.

Citation Format: Alaina C. McDonough, Jeffery Y. Cheng, Shabber Mohammed, Pui-Kai Li, Yangzom Bhutia. Design, synthesis, and evaluation of amino acid conjugated niclosamide prodrugs as a PepT1 substrate [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 4479.
Abstract 4500: A high-throughput approach to discover and characterize glueable ligase-target pairs
Authors: Sen Arpita , Burke Phil , Bansal Ruchi , Krayushkina Dasha , Noble David , McGowan Kerry , Murakowska Natasha Seelam , Reed Paxton , Barrett Juliana , Lopez Randolph
Published: March 2024

Targeted protein degradation can be induced with monovalent small molecules, termed molecular glues, that modify the substrate-binding interface of E3 ligases and reroute them to novel targets. Despite there being over 600 E3 ligases encoded in the human genome, most glues have focused on only a few. Expanding to additional ligases and targets is challenging due to the low probability of successful 'glueing.' Many have suggested that a weak basal interaction between a ligase and neo-substrate is an important prerequisite for the function of a molecular glue, but such weak interactions are challenging to discover. To address this need, we have harnessed AlphaSeq, a synthetic biology platform that measures protein-protein interactions at scale and with high sensitivity, to identify and characterize novel E3-target pairs. Our approach is twofold. First, we test for novel weak interactions (~100nM to 10uM) between a panel of E3 ligases and a library of disease relevant target proteins. Second, starting from a weakly interacting protein pair, we build mutational libraries of both proteins and measure their binding strengths. Mutations that strengthen binding serve to validate the weak interaction, provide structural insights into the nature of binding, and help to inform subsequent small molecule discovery. Here, we present our approach to discover and evaluate glueable ligase-target pairs using AlphaSeq, validation through proof-of-concept experiments involving a known interaction agonized by small molecules, and examples of novel glueable ligase-target pairs that we have recently discovered.

Citation Format: Arpita Sen, Phil Burke, Ruchi Bansal, Dasha Krayushkina, David Noble, Kerry McGowan, Natasha Seelam Murakowska, Paxton Reed, Juliana Barrett, Randolph Lopez. A high-throughput approach to discover and characterize glueable ligase-target pairs [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 4500.
Abstract 4508: Defining PIM kinase protein regulation and PROTAC for pre-clinical testing
Authors: Liou Hope , Brognard John , Swenson Rolf , Torres-Ayuso Pedro , Warfel Noel
Published: March 2024

The PIM kinase family are serine/threonine kinases known to be overexpressed in castration-resistant prostate cancer (CRPC). PIM1, an isoform of PIM, is known to regulate cell survival, migration, and proliferation. Uniquely, PIM kinases are constitutively active due to the lack of a regulatory domain. Therefore, PIM protein levels are reflected in PIM activity and are regulated by protein degradation and synthesis. PIM inhibitors have been developed, targeting the PIM kinase activity and inhibiting phosphorylation of downstream targets, but have had limited efficacy. Our lab and others demonstrate that PIM inhibitor treatment increases total PIM protein levels, suggesting that PIM kinases control protein stability via autophosphorylation. To elucidate the mechanism of autophosphorylation dependent regulation of PIM1, we used phospho-proteomics to identify potential autophosphorylation sites on PIM1. We have identified overexpression of deubiquitinase USP28 inhibiting degradation of PIM1, leading to the investigation of the role of F-box protein Fbw7 in regulating PIM1. Dominant-negative expression of Fbw7 results in increased PIM1 total protein. Additionally, coimmunoprecipitation of Fbw7 knockdown cells resulted in decreased PM1 ubiquitination compared to control. Therefore, we have identified Fbw7 as a putative E3 ligase responsible for PIM1 degradation. To address the limited efficacy of PIM inhibitors, we have developed the first PIM-PROTAC (PIMTAC) with our collaborators. Proteolysis targeting chimera (PROTAC) is a promising approach to eliminating the pro-tumorigenic effects of PIM. The PIMTAC selectively targets PIM kinases for degradation and we have demonstrated in vitro efficacy. PIMTAC successfully maintains degradation of all isoforms of PIM for over 72 hours. In vitro assessment of anti-tumor efficacy demonstrated increased apoptotic death with PIMTAC alone compared to PIM inhibitor or docetaxel. Furthermore, dual treatment of PIMTAC and docetaxel had more apoptotic death compared to PIM inhibitor with docetaxel. We aim to develop the PIMTAC for pre-clinical testing.

Citation Format: Hope Liou, John Brognard, Rolf Swenson, Pedro Torres-Ayuso, Noel Warfel. Defining PIM kinase protein regulation and PROTAC for pre-clinical testing [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 4508.
Abstract 4510: Potent and orally efficacious PROTAC degraders of estrogen receptor α (ERα)
Authors: Rej Rohan K. , Chen Zhixiang , Acharyya Ranjan K. , Wu Dimin , Hu Biao , Xu Guozhang , Nagilla Rakesh , Metwally Hoda , Wang Yu , Wen Bo , Sun Duxin , Bai Longchuan , Wang Shaomeng
Published: March 2024

The estrogen receptor α (ERα) plays a crucial role in hormonally driven breast cancer, making it a clinically validated oncology target. Over the past 30 years, SERMs, SERDs, and AIs have been the mainstay of endocrine therapy for ER+ breast cancer, but relapse and resistance remains a significant challenge for metastatic breast cancer, leading to cancer recurrences, metastasis, and mortality. We report the discovery and extensive evaluations of potent and orally efficacious ERα degraders using the PROTAC technology through extensive optimization of the cereblon ligands, the linker and ER ligands. Our lead compounds (UM-ERD-3111 and UM-ERD-4001) achieved sub-nanomlar DC50 values in ER degradation and demonstrate excellent oral bioavailability. Oral administration of these ER degraders effectively reduces the ER wild-type and ER mutated proteins in tumor tissues in mice. Both ERD-3111 and UM-ERD-4001 are capable of inducing tumor regression in vivo and are more efficacious than ARV-471, a PROTAC ER degrader currently in phase 3 clinical development. UM-ERD-3111 and UM-ERD-4001 are highly promising compounds for extensive evaluations as potential new therapies for the treatment of ER+ human breast cancer.

Citation Format: Rohan K. Rej, Zhixiang Chen, Ranjan K. Acharyya, Dimin Wu, Biao Hu, Guozhang Xu, Rakesh Nagilla, Hoda Metwally, Yu Wang, Bo Wen, Duxin Sun, Longchuan Bai, Shaomeng Wang. Potent and orally efficacious PROTAC degraders of estrogen receptor α (ERα) [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 4510.
Abstract 4511: Discovery of the first-in-class G9a/GLP PROTAC degrader
Authors: Velez Julia , Han Yulin , Park Kwang-Su , Kabir Md , Yang Peiyi , Xiong Yan , Kaniskan H. Umit , Jin Jian
Published: March 2024

G9a and GLP are lysine methyltransferases that catalyze dimethylation of histone H3 lysine 9 (H3K9me2), a transcriptionally repressive mark. Aberrantly expressed G9a/GLP has been implicated in numerous cancers, including prostate, lung, and leukemia. The oncogenic activity of G9a/GLP is attributed to both its catalytic and non-catalytic functions, such as forming co-activator complexes with p300, CARM1, GRIP1, and Mediator to positively regulate gene transcription. As such, current G9a/GLP enzymatic inhibitors display limited anti-cancer activity. As an alternative therapeutic strategy, PROTAC degraders harness the ubiquitin-proteasome system (UPS) to effectively eliminate oncoproteins and abrogate all catalytic and non-catalytic functions. Here, we present the first-in-class G9a/GLP PROTAC degrader, MS8709, which potently degrades G9a and GLP in a time-, concentration-, and UPS-dependent manner. Moreover, MS8709 induces superior cell growth inhibition compared to its parent inhibitor in prostate, lung, and leukemia cell lines. Overall, MS8709 is a useful chemical tool to investigate G9a/GLP biology and offers a novel approach for the treatment of G9a/GLP-dependent cancers.

Citation Format: Julia Velez, Yulin Han, Kwang-Su Park, Md Kabir, Peiyi Yang, Yan Xiong, H. Umit Kaniskan, Jian Jin. Discovery of the first-in-class G9a/GLP PROTAC degrader [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 4511.
Abstract 4519: Discovery of highly potent, selective and efficacious STAT3 PROTAC degraders capable of achieving complete tumor regression
Authors: Zhou Haibin , Wu Dimin , Bai Longchuan , Acharyya Ranjan K. , Metwally Hoda , McEachern Donna , Wen Bo , Sun Duxin , Wang Shaomeng
Published: March 2024

STAT3 (signal transducer and activator of transcription 3) is a transcription factor and a promising therapeutic targets for cancer and other human diseases. We have previously reported the discovery of SD-36 and SD-91 as potent, selective and highly efficacious STAT3 degraders. In the present study, we report the discovery and extensive evaluation of highly potent, selective and efficacious new STAT3 degraders designed using novel cereblon ligands and novel STAT3 ligands. Our most potent STAT3 degraders are >10-times more potent than SD-36 in inducing STAT3 degradation in cells and demonstrates >100-fold degradation selectivity over other STAT members. They achieve nanomolar IC50 values in leukemia and lymphoma cancer cell lines with activated STAT3. A single intravenous dose of these STAT3 degraders reduces the STAT3 protein for >48 hrs in xenograft tumor and native tissues, without reducing another other STAT members. Weekly administration of these STAT3 degraders is capable of achieving complete tumor regression in xenograft tumor models without any signs of toxicity. Taken together, these STAT3 degraders are promising lead compounds for extensive evaluation for the treatment of the treatment of human cancers and other human diseases in which STAT3 plays a key role.

Citation Format: Haibin Zhou, Dimin Wu, Longchuan Bai, Ranjan K. Acharyya, Hoda Metwally, Donna McEachern, Bo Wen, Duxin Sun, Shaomeng Wang. Discovery of highly potent, selective and efficacious STAT3 PROTAC degraders capable of achieving complete tumor regression [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 4519.
Abstract 4538: Brigatinib induces synergy with PARP inhibitors through dual inhibition of FAK and EphA2 in high-grade serous ovarian carcinoma
Authors: Duffield Julie R. , Hou Xiaonan , McKeon-Makki Iman K. , Huehls Amelia M. , Wilson Benjamin W. , Prasad Anjali , Wu Xinyan , Kaufmann Scott H. , Karnitz Larry M. , Weroha John J. , Kanakkanthara Arun
Published: March 2024

PARP inhibitors (PARPis) have now become a standard of care for high-grade serous ovarian cancer (HGSOC), especially for those with defects in homologous recombination (HR) DNA repair. However, the innate and acquired PARPi resistance in HGSOC poses a significant concern, necessitating the exploration of novel treatment options and strategies. Here we investigated the potential of combining brigatinib—a second-generation anaplastic lymphoma kinase (ALK) inhibitor approved for treating lung cancer—with PARPis as way to enhance PARPi activity in HGSOC. Clonogenic cell survival assays revealed that brigatinib synergizes with PARPis in HR-proficient and -deficient HGSOC cell lines. In subsequent proteomics approaches and cell-based confirmatory studies, we found that brigatnib suppressed tyrosine kinases FAK and EphA2 with reduction in downstream signaling. Follow-up pharmacologic and gene-silencing techniques demonstrated that dual FAK and EphA2 inhibition additively reduces PI3K/Akt and MAPK/ERK cell survival signaling to levels conferring PARPi sensitivity. Additionally, the efficacy of this therapeutic approach on tumor size reduction was assessed in HGSOC patient-derived xenograft (PDX) models, with combination treatment inducing tumor regression more effectively than either agent alone. Overall, our studies unveil a beneficial ALK-independent effect of brigatinib that may offer new avenues for considering its repurposing as a HGSOC therapy.

Citation Format: Julie R. Duffield, Xiaonan Hou, Iman K. McKeon-Makki, Amelia M. Huehls, Benjamin W. Wilson, Anjali Prasad, Xinyan Wu, Scott H. Kaufmann, Larry M. Karnitz, John J. Weroha, Arun Kanakkanthara. Brigatinib induces synergy with PARP inhibitors through dual inhibition of FAK and EphA2 in high-grade serous ovarian carcinoma [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 4538.
Abstract 4563: Ferroptotic mechanism of drug induced toxicity of PARPi and AurKi in prostate cancer
Authors: John August , Luo Kuntian , Lou Zhenkun , Wang Liewei
Published: March 2024

BACKGROUND: Cancer is typically treated with a combination of drugs rather than monotherapy stratagems, but identification of synergistic drug combinations for the treatment of cancers is challenging. Here we present the combination of PARP and Aurora Kinase inhibitors synergize through induction of the ferroptosis pathway of cell death.

METHODS: We identified these drugs through an unbiased screen of enriched drug class response correlations. We then validated a synergistic cell killing effect of multiple drugs of each class by in vitro drug screening. Next, we performed reversal experiments using a ferroptosis inhibitor and lipid peroxide staining to confirm ferroptosis is a relevant cell death pathway. We performed Western immunoblot analysis in cells overexpressing putative Aurora Kinase phospho-substrates in the relevant pathway of interest, and performed site directed mutagenesis experiments to show the relevant amino acid altered by kinase activity. We also performed a series of qPCR and co-IP experiments to show PARPi effect on the antioxidant signaling pathway.

RESULTS: We validated and identified synergy in a prostate cancer specific context. Next, we found Talazoparib and Alisertib induced ferroptosis after synergy was reduced with a ferroptosis inhibitor and lipid peroxides increased accumulation. We found a novel mechanism action for Alisertib, wherein Aurora Kinase inhibitors can alter the phospho-status and activity of the iron reduction enzyme Steap3.We also found that PARP inhibitors can affect the Nrf2-driven antioxidant signaling pathway on a transcriptional level.

CONCLUSION: Aurora Kinase inhibitors and PARP inhibitors for the treatment of prostate cancer was identified and was validated as synergistic, which revealed new functional roles of both drugs in the context of cell killing. These findings represent a new clinical combination of drugs in prostate cancer and reveal a novel role for this drug class in ferroptosis.

Citation Format: August John, Kuntian Luo, Zhenkun Lou, Liewei Wang. Ferroptotic mechanism of drug induced toxicity of PARPi and AurKi in prostate cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 4563.
Abstract 4572: Ginsenoside Rh3 increases the susceptibility of regorafenib-mediated cancer cell death by inhibiting the JAK/STAT3 signaling pathway in hepatocellular carcinoma
Authors: Jeon Youngsic , Kwon Hyukjoon , Park Young Nyun , Woo Dong-Young , Kim Taejung , Ham Jungyeob , Kim Young-Joo
Published: March 2024

Ginsenosides, bioactive compounds derived from Panax ginseng, exhibit diverse pharmacological effects, including anti-cancer properties. Regorafenib, a potent multi-kinase inhibitor, is employed as a second-line therapy for advanced hepatocellular carcinoma (HCC). However, the modest survival benefits observed in treated patients may be attributed to drug resistance. In this study, we screened a panel of 40 ginsenosides for their activity in combination with regorafenib in HCC cell lines and investigated their underlying cellular mechanisms. Synergistic effects were evaluated using the WST-8 assay, and optimal drug concentrations were determined through synergy scoring. A phospho-kinase assay was conducted to elucidate the mechanism of action, and in vivo experiments validated our findings. Ginsenoside Rh3 emerged as a promising candidate, enhancing the sensitivity of HCC cells to regorafenib-induced anticancer effects by promoting apoptosis. The phospho-kinase array revealed that the combined treatment's apoptotic effect was associated with the inhibition of signal transducer and activator of transcription 3 (STAT3) activation through the Janus kinase pathway. In vivo results demonstrated the combination treatment's inhibitory effects on tumor growth. Our study proposes a novel treatment strategy, highlighting the potential efficacy of combining regorafenib and ginsenoside Rh3 for HCC treatment.

Citation Format: Youngsic Jeon, Hyukjoon Kwon, Young Nyun Park, Dong-Young Woo, Taejung Kim, Jungyeob Ham, Young-Joo Kim. Ginsenoside Rh3 increases the susceptibility of regorafenib-mediated cancer cell death by inhibiting the JAK/STAT3 signaling pathway in hepatocellular carcinoma [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 4572.
Abstract 4573: Pre-clinical evaluation of small molecule CHK2 inhibitor, ART446, pre-IND candidate that enhances the olaparib and irinotecan
Authors: Baik Taegon , Kang Young Woo , Lee Ha Young , Kim Jin Whan , Jeong A Hyeon , Kim Jong Oh , Kim Woo-Young
Published: March 2024

Background: Poly (ADP-ribose) polymerase (PARP) plays a pivotal role in DNA damage repair. Tumors with DNA Damage Response (DDR) defects exhibit increased susceptibility to drugs targeting PARP. The drugs induce DNA damage like Irinotecan (a Topoisomerase I inhibitor) are widely used in clinic as well. However, intrinsic resistance remains a significant obstacle, leading to frequent treatment failures. Chk2 is activated in response to these DNA damage inducing agents and hold the cell cycle. We developed pre-IND candidate ART446, with the aim of exploring its therapeutic potential in sensitizing DNA damage-targeting reagents.

Results: In the radiometric HopSpot Kinase Assay, ART446 demonstrated significant inhibition of Chk2 (IC50, 9 nM). In HT-29 colon adenocarcinomas, co-treatment with SN38 and ART446 exhibited a synergistic therapeutic effect in vitro, with a subsequent in vivo tumor growth assay demonstrating a remarkable combined effect (TGI; Irinotecan, 46%; ART446, 16%; combined, 83.4%). Further extending our investigation to triple-negative breast adenocarcinoma MDA-MB-436, characterized by a BRCA1 mutation, we explored the sensitization potential of ART446 to PARP inhibitors. Strikingly, the combination therapy with a PARP inhibitor, Olaparib surpassed monotherapy outcomes, resulting in complete tumor growth inhibition (TGI: Olaparib, 73%; ART446, 20%; combined, 102%). Mechanistic insights revealed an increase in gamma H2AX levels by ART446 and a decrease in active forms of Chk2 which were activated by Olaparib affirming that Olaparib-induced Chk2 inhibition contributed to the sensitization effect.

Conclusions: The pre-IND candidate ART446 exhibits promising potential in enhancing the therapeutic effects of Olaparib and Irinotecan. These findings provide a robust foundation for further clinical development, offering a strategic approach to overcome resistance in cancer treatment.

Citation Format: Taegon Baik, Young Woo Kang, Ha Young Lee, Jin Whan Kim, A Hyeon Jeong, Jong Oh Kim, Woo-Young Kim. Pre-clinical evaluation of small molecule CHK2 inhibitor, ART446, pre-IND candidate that enhances the olaparib and irinotecan [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 4573.
Abstract 4595: HSK41959-2: An oral MTA-cooperative PRMT5 inhibitor for MTAP deleted cancer
Authors: Yan Pangke , Wang Ju , Qian Meilin , Yu Xiaojuan , Li Yao , Zhang Haoliang , Tao Lihua , Kou Rui , Hu Teng , Tang Pingming , Dong Hongjiao , Wu Aipin , He Maotao
Published: March 2024

Methylthioadenosine phosphorylase (MTAP) homozygous deletion occurs in 10-15% of all human cancers. Loss of MTAP result in methylthioadenosine (MTA) accumulation. PRMT5, which is a type II arginine methyltransferase that regulates multiple essential cellular functions via symmetric dimethylation of arginine (SDMA) in target proteins, was identified as a synthetic lethal target for MTAP del cancers. MTA-cooperative PRMT5 inhibitors may exhibit better safety profiling compared to first generation PRMT5i (which observe limiting heme-related toxicities in clinical), which preferentially inhibiting PRMT5 in MTAP del cancer cells to normal cells. HSK41959-2 is a MTA-cooperative PRMT5 inhibitor, which could selectively inhibits PRMT5 in the present of MTA with IC50 was 0.80 nM. In HCT116 MTAP Deleted cell line, HSK41959-2 significantly inhibits the cell proliferation with GI50 of 19.89 nM, which was around 45-fold selectivity in HCT116 cell line. In SDMA assay, HSK41959-2 also showed high potency in HCT116 MTAP-del cell line with IC50 was 3.39 nM, and much weaker in HCT116 MTAP-WT cell line with IC50 was 499 nM, around 147-fold selectivity. In vitro CD34+ Hematopoietic stem cell cell proliferation assay was used for evaluate the heme-related toxicities. HSK41959-2 weakly inhibited the cell proliferation with IC50 of 544 nM while the first generation PRMT5i with IC50 was 35.39 nM. This results indicated HSK41959-2 may has lower heme-related toxicities compared with the first generation PRMT5i. In the HCT116 MTAP-del xenograft model, daily orally administrated with 25 mpk and 100 mpk HSK41959-2 showed significant tumor growth inhibition, with TGI were 62% and 88%, and PRMT5-dependent SDMA protein inhibition were 89% and 95%, respectively. Meanwhile in the HCT116 MTAP-WT xenograft model, HSK41959-2 did not show tumor growth inhibition at 100 mpk. In conclusion, HSK41959-2 is a promising oral MTA-cooperative PRMT5 inhibitor, it was nominated as a development candidate.

Citation Format: Pangke Yan, Ju Wang, Meilin Qian, Xiaojuan Yu, Yao Li, Haoliang Zhang, Lihua Tao, Rui Kou, Teng Hu, Pingming Tang, Hongjiao Dong, Aipin Wu, Maotao He. HSK41959-2: An oral MTA-cooperative PRMT5 inhibitor for MTAP deleted cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 4595.
Abstract 4617: Fisetin, a multi-kinase inhibitor enhances chemotherapeutic sensitivity in head and neck cancer
Authors: Tailor Dhanir , Mishra Deepali , Malhotra Sanjay V. , Singh Rana P.
Published: March 2024

Background: The limitations of chemotherapeutic applications are often imposed by dose-related toxicity and the emergence of therapeutic resistance. Fisetin, a naturally occurring flavonoid, has demonstrated anticancer properties in various cancer types. Despite its proven effectiveness against cancer, the molecular target of fisetin remains unknown.

Methods: Our study focused on understanding how fisetin and chemotherapy work together to inhibit the growth and survival of human HNC. We conducted in silico, in vitro and in vivo investigations. We employed target prediction, kinase profiling, transcriptome analysis and tumor xenograft to identify the chemosensitivity efficacy and mechanism of fisetin.

Results: In-silico target prediction suggested that fisetin might target multiple kinases. Based on this lead, we have screened fisetin for different kinase inhibition activities and found that it inhibits multiple CDKs including CDK1, 2, 4, 5 and 6 at nanomolar concentration. To test its cellular activity, we have selected the head and neck cancer (HNC) model and found that fisetin treatment strongly inhibited cell proliferation and arrested the HNC cells in G1 phase followed by apoptotic cell death. In tumor xenograft experiment, we found that oral fisetin treatment inhibited the FaDu and SAS tumor growth in the athymic mouse model. Transcriptome analysis on FaDu and SAS cell lines indicated that fisetin treatment significantly modulates pathways associated with cell cycle progression and regulation. These pathways include cellular assembly, DNA replication, cell death, and cell morphology. Pretreatment of HNC cells with fisetin improved the effectiveness of chemotherapy drugs including cisplatin, 5-fluorouracil, and docetaxel. Consistent with this, fisetin pre-treated cells showed elevated levels of cellular and mitochondrial ROS followed by the activation of caspases and apoptosis induction when compared with that in control cells after cisplatin, 5-FU, or docetaxel treatment.

Conclusion: These results imply that fisetin has the potential to be utilized as a multi-kinase inhibitor in cancer cells. The study revealed that fisetin has a strong potential for increasing the sensitivity of cancer cells to chemotherapy.

Citation Format: Dhanir Tailor, Deepali Mishra, Sanjay V. Malhotra, Rana P. Singh. Fisetin, a multi-kinase inhibitor enhances chemotherapeutic sensitivity in head and neck cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 4617.
Abstract 4630: Clinical and epidemiological profile of neuroendocrine differentiation- A hospital-based retrospective study
Authors: Wen Yaru , Shi Susheng
Published: March 2024

Background: Neuroendocrine differentiation (NED) in carcinomas is poorly studied globally, despite its distinct clinical features, disease progression, pathology, treatment outcomes, and poor prognosis. Therefore, it is imperative to conduct further analysis utilizing extensive clinical samples to unveil the clinical and epidemiological profile of NED.

Methods: A retrospective study was conducted to analyze the histopathological samples of patients diagnosed with malignant tumor using immunohistochemical techniques for NED markers, such as ChrA, Syno and CD56. The morbidity and prognosis of NED patient would be analyzed subsequently. Eligible patients must have pathologically confirmed gastric cancer, colorectal cancer, lung cancer, esophageal cancer and prostate cancer with no prior neoadjuvant chemotherapy or radiotherapy received before surgery. Patients aged 18-75 years with normal organ functions were enrolled.

Results: Between January 2017 and June 2018, over 450 cases were enrolled. Preliminary analysis focused on 36 esophageal cancer (EC) and 44 prostatic cancer (PC) samples. NED markers were expressed in 4 (11.1%) of 36 EC patients, including 4 cases positive for Syno, 1 case positive for ChrA, and 2 cases positive for CD56. Meanwhile, NED markers were expressed in 15 (34.1%) of 44 PC patients, including 10 cases positive for Syno, 15 cases positive for ChrA, and 2 cases positive for CD56.

Conclusion: Neuroendocrine differentiation is obviously observed in EC and PC. The encouraging prevalence rate of NED may have clinical implications for individualized treatment. Further research is needed to explore this area in more detail.

Citation Format: Yaru Wen, Susheng Shi. Clinical and epidemiological profile of neuroendocrine differentiation- A hospital-based retrospective study [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 4630.
Abstract 464: Chromatin associated long non-coding RNAs involved in dormancy for late recurrence of ER-positive breast cancer
Authors: Saitoh Noriko , Palihati Maierdan , Tachiwana Hiroaki
Published: March 2024

Late recurrence is one of the major problems for hormone receptor-positive breast cancer patients. It is suggested that the risk of recurrence may be maintained by cancer cells that have been already disseminated in the body at surgery. They enter long-term dormancy, thus evade immune surveillance and become resistant to therapies. The detailed molecular mechanism for this process is largely unknown.Nuclear long noncoding RNAs, which are not translated to proteins, often function as epigenetic regulators and determine the phenotype of cells and individuals. We found that a cluster of long noncoding RNAs, ELEANORS, is specifically expressed in ER (estrogen receptor)-positive recurrent breast cancer cells, forms a molecular condensate (RNA cloud) in the nucleus, and activates the ESR1 gene that encodes ER. ELEANORS define a large chromatin domain, the 0.7 Mb topologically associated domain (TAD), which contains the ESR1 and three other breast-cancer-associated genes. ELEANORS also regulates the three-dimensional genome architecture. They mediate a long-range chromatin interaction of ESR1 and FOXO3 genes, which are 42.9 Mb apart, and contribute to their cooperatively activate transcription, equilibrating cell proliferation (ESR1) and apoptosis (FOXO3). Upon ELEANOR knockdown, the ELEANOR clouds are disappeared, and ESR1 gene transcription is repressed. Further, the two genes are dissociated and only the FOXO3 gene remains transcriptionally active, resulting in the induction of apoptosis.Further analysis of clinical specimens revealed that ELEANOR expression in primary tumors correlates with recurrences over 5 years after surgeries, suggesting that ELEANORs are involved in late recurrence. We also found that ELEANOR activates transcription of CD44, a breast cancer stem cell marker gene. Cancer stem cell maintenance and equilibration of proliferation and apoptosis by ELEANOR may be involved in long-term tumor dormancy in late recurrence. This study suggests the possibility of ELEANORS as a biomarker to predict late recurrence, as well as a therapeutic target for ER-positive breast cancer.

(References)Abdalla, MOA. et al., Nat. Commun, 10, 3778 (2019) Tomita, S. et al., Nat. Commun, 6, 6966 (2015)

Citation Format: Noriko Saitoh, Maierdan Palihati, Hiroaki Tachiwana. Chromatin associated long non-coding RNAs involved in dormancy for late recurrence of ER-positive breast cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 464.
Abstract 4653: Unraveling the vulnerabilities of targeted therapy-tolerant persister cells in NSCLC
Authors: Kim Donghwa , Kuchenov Dmitry , Zaman Aubhishek , Bennett Neal , Ramos Emilio , Nakamura Ken , Wiita Arun P. , Bandyopadhyay Sourav , Bivona Trever
Published: March 2024

Genetic profiling and the development of targeted therapy has improved survival of many cancer patients, but resistance to targeted therapy remains a major barrier to long-term patient survival. To develop more pro-active strategies to improve clinical outcomes, our research focuses on drug-tolerant persister cells that constitute a reservoir of cancer cells that survive and adapt during the initial stage of therapy. These cells typically display therapy resistance in a reversible manner and set the stage for the subsequent emergence of cells with full acquired resistance. We utilized quantitative proteomics to characterize persister cells generated from EGFRmut, KRASmut, and ALKmut non-small cell lung cancer (NSCLC) cell lines after treatment with osimertinib, sotorasib, and lorlatinib, respectively. Integrating proteomics data with network analysis revealed a decrease in the signaling network associated with cell cycle regulation and DNA replication. Meanwhile, persister cells exhibited an enrichment in proteins linked to lysosomes, amino acids, and fatty acid metabolism. The data revealed a consistent metabolic shift in persister cells, with an increased dependence on oxidative phosphorylation (OXPHOS) for ATP generation. Small-scale drug screening was performed based on findings from proteomics and confirmed that persister cells are vulnerable to inhibitors of OXPHOS mitochondrial complexes. Combination treatment of OXPHOS inhibitors and each targeted therapy delayed the emergence of resistance. One complex V inhibitor, Gboxin, selectively inhibited the growth of persister cells. The therapeutic potential of complex V was further validated by CRISPR-based genetic knockdown studies. The metabolic transition in drug tolerant persister cells may serve as a critical adaptive resistance mechanism to provide a survival advantage under targeted therapy-induced stress. Understanding this metabolic shift may lead to new treatments that aim to prevent or delay the onset of acquired resistance in NSCLC.

Citation Format: Donghwa Kim, Dmitry Kuchenov, Aubhishek Zaman, Neal Bennett, Emilio Ramos, Ken Nakamura, Arun P. Wiita, Sourav Bandyopadhyay, Trever Bivona. Unraveling the vulnerabilities of targeted therapy-tolerant persister cells in NSCLC [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 4653.