tbuckley/cabot-search huggingface dataset:
Abstract 249: EGFR activation reverses gastrin suppression by MENIN by inducing its nuclear export
Authors: Uloma B. Elvis-Offiah, Suzann Duan, Sulaiman Sheriff, Juanita L. Merchant
Journal: Cancer Research (2025)

Abstract Introduction: Gastroenteropancreatic neuroendocrine tumors (GEP-NETs) are rapidly increasing malignancies in the US. They are strongly associated with loss-of-function mutations in the Multiple Endocrine Neoplasia type 1 (MEN1) gene which encodes the tumor suppressor MENIN. Gastrinomas secrete excess gastrin, representing the most malignant subtype of sporadic or hereditary GEP-NETs. Although MENIN epigenetically inhibits gastrin gene expression, ligand-receptor activation inducing GASTRIN removes MENIN suppression. However, the mechanism by which MENIN suppression is alleviated remains poorly defined. Exon 10 encodes all three nuclear localization signals (NLSs) of MENIN within its C-terminal domain. Moreover, NLS1 harbors a phosphorylation motif for protein kinase B, which mediates epidermal growth factor receptor (EGFR) signaling. Since MEN1-gastrinomas predominantly arise within the submucosal Brunner’s glands rich in pro-proliferative EGFR ligands like epiregulin (EREG), we hypothesized that EGFR activation induces GASTRIN by reducing nuclear MENIN. Methods: We subcloned wild-type (WT) MENIN cDNA and the sequential C-terminal deletions into pcDNA carrying the FLAG epitope and validated with sequencing. Regulation of endogenous GASTRIN mRNA was determined after transfection of MENIN vectors into two human gastric cancer cell lines—AGS and KATOIII. The effect of EGFR signaling on MENIN’s subcellular localization, stability, and repression of the gastrin gene was determined by immunoblotting, subcellular fractionation, immunofluorescent staining, and RT-qPCR. Results: WT MENIN and constructs retaining 2 or 3 nuclear localization signals (NLSs) suppressed 50% of GASTRIN expression under basal conditions. Moreover, deleting all three NLSs abolished MENIN suppression. EREG treatment induced GASTRIN in the absence of the presence of WT or MENIN without 1-2 NLS. However, no induction of GASTRIN was observed with all 3 NLSs deleted. Constructs lacking all 3 NLSs exhibited reduced protein expression, which was reversed by the proteasome inhibitor MG132, suggesting decreased protein stability. NLS-deficient MENIN was highly localized to the cytoplasm whereas WT MENIN and deletions with &amp;gt;1 NLSs were distributed between the nucleus and cytoplasm under basal conditions. However, EREG treatment induced their cytoplasmic translocation, suggesting that EGFR signaling blocks MENIN's nuclear localization. Conclusion: EGFR activation induces GASTRIN gene expression by preventing nuclear import which requires the C-terminal NLSs. Citation Format: Uloma B. Elvis-Offiah, Suzann Duan, Sulaiman Sheriff, Juanita L. Merchant. EGFR activation reverses gastrin suppression by MENIN by inducing its nuclear export [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2025; Part 1 (Regular Abstracts); 2025 Apr 25-30; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2025;85(8_Suppl_1):Abstract nr 249.
Abstract 485: Using the Celigo™ Image Cytometer for effectively screening rAAV gene delivery methods
Authors: Mackenzie Pierce, Yongyang Huang, Bo Lin
Journal: Cancer Research (2025)

Abstract To develop effective rAAV gene delivery vectors, scientists need to consider multiple elements, such as the promoter, insertion location, genetic target, and target gene to name a few. Green fluorescent protein (GFP), or other detection markers are often used to measure vector transduction and gene expression efficiency. Transduced GFP samples can be analyzed using fluorescent microscopy and flow cytometry, however, both methods can be quite time consuming, labor intensive, and lack high-throughput capabilities to kinetically monitor gene expression. In this work, we developed and employed the Celigo™ Image Cytometer to screen different gene delivery vectors by comparing GFP expression level in SupT1 cells at 24-, 48-, 72-, and 96-hours following transduction. Using the Celigo™ we were able to monitor transient and integrated GFP expression amongst multiple gene delivery vectors. For transient expression monitoring, SB-P-AA-101-07 displayed stronger expression levels at 24- and 48-hours. For integrated expression monitoring, both plasmid and rAAV with integration element exhibited over ∼90%+ GFP transduction efficiency by 96-hours. In summary, the Celigo™ may prove useful for researchers developing and screening gene delivery vectors in a high throughput manner. Note: SB-P-AA-101-07 (from Revvity Health Sciences, Inc.) is for research use only. Not for use in diagnostic procedures. Citation Format: Mackenzie Pierce, Yongyang Huang, Bo Lin. Using the Celigo™ Image Cytometer for effectively screening rAAV gene delivery methods [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2025; Part 1 (Regular Abstracts); 2025 Apr 25-30; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2025;85(8_Suppl_1):Abstract nr 485.
Abstract 375: Cancer cells may utilize centrosome amplification to promote survival as a response to chemotherapeutic stress
Authors: Madison M. Purkerson, Sarah R. Amend, Kenneth J. Pienta
Journal: Cancer Research (2025)

Abstract Therapy resistance is one of the most common underlying causes of poor prognosis in cancer patients, ultimately driving fatal outcome. We have previously demonstrated that following chemotherapeutic stress, a subset of cancer cells undergo a mitotic skip and enter an endocycle, causing whole-genome duplication without division. This endocycling cell state is resistant to cytotoxic therapies and thus is an actuator of therapy resistance. Cells in the endocycling state eventually undergo depolyploidization and repopulate the tumor, observed clinically as a recurrence. A common feature of cancers is centrosome amplification (CA) that includes aberrations in centrosome number (&amp;gt;2 centrosomes/cell), size, shape, and/or positioning. Our preliminary data has shown that endocycling cancer cells exhibit CA following treatment across multiple types of chemotherapies. Based upon this data, we hypothesize that studying centrosome dynamics and abnormalities presents a window into better understanding endocycle biology and this novel mechanism of therapy resistance.We have found that the population of prostate cancer and breast cancer cells possessing CA following treatment with LD50 dose of cisplatin or docetaxel increased as a function of recovery time to over 95% by day 10, with nearly all cells clustering extra centrosomes together. Of note, the number of mitotic skips an endocycling cell undergoes has not been found to be associated with the number of centrosomes the cell has. PLK4 is a kinase essential for centriole duplication and its overexpression causes CA. Immunofluorescence analysis has revealed that endocycling cancer cells exhibit an increase in PLK4 protein expression. Endocycling cancer cells also exhibit increased protein expression of KIFC1, a mediator of centrosome clustering. Both PLK4 and KIFC1 protein expression have been found to positively correlate with DNA content. We hypothesize that endocycling cells may use clustered, supernumerary centrosomes as platforms to locally concentrate signaling molecules, lowering the activation threshold for downstream effectors. Published data from bioID proteomics of centrosomal proteins has revealed an enormous unexplored protein landscape around these organelles. Because of this, CA may be a critical mechanism for endocycling cancer cells to survive and maintain this resistant cell state. Citation Format: Madison M. Purkerson, Sarah R. Amend, Kenneth J. Pienta. Cancer cells may utilize centrosome amplification to promote survival as a response to chemotherapeutic stress [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2025; Part 1 (Regular Abstracts); 2025 Apr 25-30; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2025;85(8_Suppl_1):Abstract nr 375.
Abstract 73: Molecular characterization of senescence induced by PARPi in preclinical xenograft mouse models of ovarian cancer
Authors: Sarah Saoudaoui, Nicolas Malaquin, Isabelle Clément, Tibila Kientega, Erwan Goy, Kim Leclerc-Desaulniers, Anne Marie Mes-Masson, Francis Rodier
Journal: Cancer Research (2025)

Abstract Introduction: Ovarian cancer (OC) is amongst the most lethal cancers in Canada. High-grade serous ovarian cancer (HGSC) usually responds to initial therapy, however resistance to drugs often develops over time. We have described a new two-step OC combo-therapy: 1st, a PARP inhibitor is used to induce a senescence proliferation arrest in cancer cells followed by, 2nd, the induction of senolysis in senescent cancer cells using the Bcl-2 family inhibitor ABT263, which redirects senescent cells towards apoptosis. Our hypothesis is that therapy-induced senescence (TIS) could be beneficial in the clinic, but questions remain on its exact function in this context. Our objective is to characterize the spatiotemporal evolution of senescence during OC treatment using xenograft mouse models to define the senescence peak in tissues and optimize the targeting of senolysis approaches. Methods-results: We generate a tumor biobank consisting of OV1946, OV4453, TOV21G and MDAMB231 preclinical xenograft models treated with combinations of the PARP inhibitor Olaparib and ABT263. In all models, PARPi-ABT263 resulted in a significant reduction in tumor growth compared to each drug alone. To explore spatiotemporal cell fate decisions including senescence, a time course analysis was performed by gene expression analysis, SA-βgal staining and COMET multiplexing. COMET is an immunofluorescence technology that allows up to 40 molecular biomarkers (vasculature, epithelium, senescence phenotypes, DNA damage response) at single-cell resolution on paraffin embedded tumors. Conclusion: We propose that characterizing the cell fate decisions within the tumor including senescence can be used to improve drug administration patterns in combo therapies and reduce resistance. For example, this should refine targets and timing to improve chemotherapies that aim to manipulate senescence. Citation Format: Sarah Saoudaoui, Nicolas Malaquin, Isabelle Clément, Tibila Kientega, Erwan Goy, Kim Leclerc-Desaulniers, Anne Marie Mes-Masson, Francis Rodier. Molecular characterization of senescence induced by PARPi in preclinical xenograft mouse models of ovarian cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2025; Part 1 (Regular Abstracts); 2025 Apr 25-30; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2025;85(8_Suppl_1):Abstract nr 73.
Abstract 1999: Defining the distinct molecular landscapes of primary tumors and metastases in Merkel cell carcinoma
Authors: Yajie Yang, Sami Kilpinen, Harri Sihto, Libuse Janská, Xiaohao Wang, Catharina Larsson, Weng-Onn Lui
Journal: Cancer Research (2025)

Abstract Merkel cell carcinoma (MCC) is an aggressive skin cancer characterized by high metastatic potential and poor survival rates. Identifying biomarkers for early detection of metastatic MCC is crucial for improving clinical outcomes. In this study, we analyzed bulk RNA-sequencing data from the GEO dataset GSE235092, identifying 481 differentially expressed genes (DEGs) between primary tumors (n=43) and metastases (n=28) (fold change &amp;gt;2, adjusted p &amp;lt;0.01). Among these, 66 genes were upregulated and 415 were downregulated in metastases. Downregulated DEGs were enriched in processes and pathways associated with metastasis, such as cell-cell adhesion, focal adhesion, and epithelial-mesenchymal transition. To further investigate, we performed pseudobulk differential expression analysis on tumor cells from primary (n=13) and metastasis tumors (n=10) using single-cell RNA-sequencing (scRNA-seq) data (GSE235090). This analysis revealed 43 DEGs (fold change &amp;gt;1.5, adjusted p &amp;lt;0.05), with 3 overlapping with the bulk RNA-seq findings. Subsequent subdivision of scRNA-seq metastasis samples into regional and distant metastases identified 6 DEGs specific to regional metastases compared to primary tumors, 5 to distant metastases, and 1 common to both. Validation of these DEG candidates in our MCC cohort of 102 primary tumors, based on RNA sequencing, identified SLC4A7, CPVL, ENG, MYLIP, and MXRA8 as strong candidates linked to tumor metastasis, survival outcome, Merkel cell polyomavirus (MCPyV) status and other clinical characteristics. Additionally, scRNA-seq analysis highlighted distinct tumor microenvironment compositions among primary tumors, regional metastases, and distant metastases. Considering the role of MCPyV in MCC progression, we examined DEGs between primary and metastasis under MCPyV-positive and MCPyV-negative statuses using bulk RNA data. Gene set enrichment analysis uncovered 55 MYC-targeted genes and 52 E2F-targeted genes that were suppressed in MCPyV-positive patients but activated in MCPyV-negative patients. These findings provide new insights into MCC metastasis and highlight potential biomarkers for tumor progression and targeted therapies. Citation Format: Yajie Yang, Sami Kilpinen, Harri Sihto, Libuse Janská, Xiaohao Wang, Catharina Larsson, Weng-Onn Lui. Defining the distinct molecular landscapes of primary tumors and metastases in Merkel cell carcinoma [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2025; Part 1 (Regular Abstracts); 2025 Apr 25-30; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2025;85(8_Suppl_1):Abstract nr 1999.
Abstract 1552: Novel anti-CD3 heavy chain-only antibodies for use in T-cell engaging therapeutics
Authors: Paul Khalifé, Hannah C. Watkins, Elizabeth A. McGurk, Elizabeth R. Parker, Cameron M. Henkel, Todd M. Boland, Hailey M. Heston, Whitney E. Renaud, Christin R. Strong, Jingfu Zhou, Carissa Metzger, Michael E. Brown, Jessica P. Dawson, Andrew D. Avery, C Garrett Rappazzo, Beth H. Sharkey, Morgan B. Morrill, Cory L. Ahonen, Michael B. Battles, Noel T. Pauli
Journal: Cancer Research (2025)

Abstract T-cell engagers (TCEs) display increasing potential as an immunotherapeutic treatment for both hematologic and solid cancers. These multi-specific antibody-based therapeutics consist of a CD3-targeting arm and one or more tumor associated antigen (TAA) targeting arms. The multimeric nature of these therapeutics can present antibody engineering and manufacturing challenges. Developing an anti-CD3 heavy chain-only antibody (HCAb) reduces the design complexity of the final TCE therapeutic. Functional anti-CD3 HCAbs were discovered by combining llama immunization and a novel yeast-based HCAb presentation and discovery technology. Following several rounds of yeast-based HCAb selection, T-cell stimulating anti-CD3 HCAbs were identified that predominantly competed with UCHT1. Stimulating CD3-specific HCAbs were reformatted into CD3 X CD20 bispecifics, which displayed potent T-cell activation and Raji cell killing in a redirected T-cell cytotoxicity (RTCC) assay. This panel was further validated as a bispecific VHH-TCR fusion using a TCR specific for the gp100 peptide HLA complex; donor T-cell activation and target killing was observed against both SK-MEL-5 and MeWo cancer cell lines. The panel was subsequently humanized while maintaining functional activity and favorable drug developability profiles. These humanized anti-CD3 HCAbs are promising candidates for replacing conventional anti-CD3 IgG Fab arms in next-generation multispecific TCE antibodies. Citation Format: Paul Khalifé, Hannah C. Watkins, Elizabeth A. McGurk, Elizabeth R. Parker, Cameron M. Henkel, Todd M. Boland, Hailey M. Heston, Whitney E. Renaud, Christin R. Strong, Jingfu Zhou, Carissa Metzger, Michael E. Brown, Jessica P. Dawson, Andrew D. Avery, C Garrett Rappazzo, Beth H. Sharkey, Morgan B. Morrill, Cory L. Ahonen, Michael B. Battles, Noel T. Pauli. Novel anti-CD3 heavy chain-only antibodies for use in T-cell engaging therapeutics [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2025; Part 1 (Regular Abstracts); 2025 Apr 25-30; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2025;85(8_Suppl_1):Abstract nr 1552.
Abstract 201: Enhanced motility of cancer-associated fibroblasts is mediated by HIF-1α signaling in the lung tumor microenvironment
Authors: Jihye Park, Sieun Lee, Jonathan M. Kurie, Young-Ho Ahn
Journal: Cancer Research (2025)

Abstract Cancer-associated fibroblasts (CAFs) are key contributors to promote cancer progression in the lung tumor microenvironment via interactions with cancer cells and other cell types. In a 3-D culture system, we classified CAFs into two subgroups based on their motility, motile and static CAFs, and isolated these subgroups using the photoconvertible fluorescent protein Dendra2. RNA sequencing and subsequent analyses revealed the upregulation of hypoxia- and glycolysis-related genes in motile CAFs. Activation of HIF-1α increased CAF motility in both mono- and co-culture systems. Knockdown of HIF-1α downstream genes, ALDOA and LDHA, reduced CAF motility. Interestingly, HIF-1α activity and CAF motility were heightened when co-cultured with mesenchymal-like lung cancer cells. Mass spectrometry analysis identified ceruloplasmin (CP) as a secretory protein derived from mesenchymal-like lung cancer cells. Knockdown of CP in mesenchymal-like lung cancer cells attenuated CAF motility in co-culture systems and lung tumor metastasis in a mouse model. Collectively, these findings demonstrated that CAF motility is regulated by HIF-1α signaling, which is modulated by lung cancer cell-derived CP. Citation Format: Jihye Park, Sieun Lee, Jonathan M. Kurie, Young-Ho Ahn. Enhanced motility of cancer-associated fibroblasts is mediated by HIF-1α signaling in the lung tumor microenvironment. [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2025; Part 1 (Regular Abstracts); 2025 Apr 25-30; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2025;85(8_Suppl_1):Abstract nr 201.
Abstract 543: SF2523, a dual PI3K-BRD4 inhibitor, enhances KRAS (G12C) or EGFR (exon 19/21) mutant targeted inhibitors in non-small-cell lung cancer (NSCLC)
Authors: Baskaran Subramani, Patrick Joseph Conway, Kun Zhang, Guillermo A. Morales, Joseph R. Garlich, Daruka Mahadevan
Journal: Cancer Research (2025)

Abstract KRAS and EGFR mutations are common oncogenic drivers in NSCLC. Osimertinib is a first line therapy for EGFR exon 19 and 21 mutant NSCLC. Sotorasib and Adagrasib are a second line therapy for KRAS G12C mutant NSCLC. Single agent inhibitors targeting mutant EGFR or KRAS develop drug resistance leading to relapsed/refractory NSCLC. SF2523 is a dual PI3K-bromodomain-containing protein 4 (BRD4) small molecule inhibitor being evaluated to mitigate KRAS or EGFR inhibitor induced drug resistance. Co-inhibition of PI3K/BRD4 blocks MYC expression, activation and enhances MYC degradation leading to inhibition of cancer growth and metastasis. We investigated SF2523 in EGFR mutant (HCC2935 and HCC827) and KRAS mutant (NCI H2030 &amp; NCI H23) NSCLC cells lines with single agent or combination with Osimertinib or Sotorasib for anti-tumor activity, respectively. SF2523 IC50 in EGFR mutated NSCLC cells ranged from 90-230nM, while in KRAS mutated NSCLC cells ranged from 144-217nM versus Buparlisib plus JQ1 in the μM range. SF2523 plus Osimertinib decreased the IC50 to 1.2-1.4nM and SF2523 plus Sotorasib 1.6-13nM, respectively. In contrast, combinations of SF2523 plus Nindetinib (VEGFR inhibitor) or Rapamycin (mTOR inhibitor) were additive in potency with EGFR and KRAS mutant NSCLC cell lines. In KRAS mutant NSCLC treatment with SF2523 or Sotorasib increased PTEN mRNA expression and the combination therapy was additive. In EGFR mutant NSCLC treatment with SF2523 or Osimertinib or in combination decreased MYC, PIK3CA and AKT1, respectively. In a SCID H2030 KRAS G12C mouse xenograft model, SF2523 at a dose of 150 mg/kg was well tolerated without weight loss with tumor growth inhibition of &amp;gt;60% at 6 weeks. In conclusion, our results demonstrate SF2523 is active alone and is synergistic with Osimertinib or Sotorasib in inhibiting EGFR or KRAS mutant NSCLC cell lines and is active as a single agent in a KRAS G12C mutated H2030 CDX NSCLC mouse model. Citation Format: Baskaran Subramani, Patrick Joseph Conway, Kun Zhang, Guillermo A. Morales, Joseph R. Garlich, Daruka Mahadevan. SF2523, a dual PI3K-BRD4 inhibitor, enhances KRAS (G12C) or EGFR (exon 19/21) mutant targeted inhibitors in non-small-cell lung cancer (NSCLC) [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2025; Part 1 (Regular Abstracts); 2025 Apr 25-30; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2025;85(8_Suppl_1):Abstract nr 543.
Abstract 888: NKC and KIR humanized mice: a powerful tool to develop NK-targeting drugs
Authors: Qiurong Wang, Qi Zhang, Na Kang, Huizhen Zhao, Lili Liu, Jiawei Yao, Yanshuang Li
Journal: Cancer Research (2025)

Abstract Natural killer (NK) cells are leukocytes within the innate immune system, acting as a first line of defense against cancer and virally infected cells. NK cell responses—whether “killing” or “tolerant”—are regulated by interactions between activating and inhibitory receptors and their ligands. Currently, there remains a need for comprehensive in vivo models featuring humanized NK cell receptors, including key proteins encoded by the KIR and NKC gene clusters. Killer cell immunoglobulin-like receptors (KIR) form a highly polymorphic gene cluster expressed by NK and certain T cell subtypes, while the Natural Killer Gene Complex (NKC) encodes several C-type lectin-like receptors, such as the NKG2 family, found across various immune cells. To introduce a novel NK gene cluster-related in vivo model, Biocytogen has used advanced gene-editing technology to humanize ∼150,000 base pairs of KIR gene cluster DNA (B-hKIR mice) and 0.9 million base pairs of NKC gene cluster DNA (B-hNKC mice) on a C57BL/6 background. In this combined B-hNKC/hKIR mouse model, 29 functional genes have been modified.The immunophenotype of B-hNKC/hKIR mice is consistent with that of wild-type C57BL/6 mice. Human proteins NKG2A, NKG2C, CD94, NKG2D, and CD161 are detectable on NK cells, while human CLEC9A is observed on CD8a+ and CD103+ dendritic cells in the spleen. Human CLEC12A is expressed on T cells, macrophages, monocytes, and dendritic cells, and human LOX1 is present on activated macrophages, monocytes, and neutrophils in the bone marrow. Additionally, human CD69 is expressed on activated T cells, B cells, NK cells, macrophages, monocytes, neutrophils, and dendritic cells in the spleen. In B-hKIR mice, human KIR2DL1, KIR2DL3, and KIR3DL2 are detectable on NK cells, and mRNA for human KLRF2, CLEC2A, TMEM52B, CLEC1A, and CLEC2D is also expressed in B-hNKC/hKIR mice.This B-hNKC/hKIR mouse model provides an advanced platform for NK-targeted research and serves as a valuable in vivo system for preclinical studies. Citation Format: Qiurong Wang, Qi Zhang, Na Kang, Huizhen Zhao, Lili Liu, Jiawei Yao, Yanshuang Li. NKC and KIR humanized mice: a powerful tool to develop NK-targeting drugs [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2025; Part 1 (Regular Abstracts); 2025 Apr 25-30; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2025;85(8_Suppl_1):Abstract nr 888.