bluuebunny/crossref_metadata_2025 huggingface dataset:
Abstract 4370: Functional characterisation of a novel mutation in PRKCA, a major driver of chordoid gliomas
Authors: Bellamy Charlotte , Tovell Hannah , Dingli Florent , Loew Damarys , Liva Stephane , Schwaighofer Selina , Stefan Eduard , Newton Alexandra , Sanson Marc , Bielle Franck
Published: March 2024

Chordoid gliomas (ChG) are a rare low-grade brain tumor, believed to be derived from tanycytes. An analysis by the team identified a novel mutation present in all ChGs: PRKCA p.D463H. This mutation involves a D463H substitution at the kinase domain of the Protein kinase C alpha (PKCα), it is not found in any other cancer, and represents the hallmark of ChG. The aim of the project is to identify novel and biologically relevant PKCαD463H signaling pathways, which will demonstrate the involvement and the role of this mutated kinase in cellular functions implicated in the development of ChGs. The D463H mutation affects a critical residue of the kinase domain of PKCα, suggesting that such a change modifies substrate affinity. Following the purification of PKCαD463H, we have shown its inactivation via in vitro kinase assays and peptide array. In cellulo fret-based activity reporter assays have shown that PKCαD463H has a dominant negative effect over PKCαWT. Through co-immunoprecipitation we have shown that the mutant protein can bind the WT form and also colocalizes in the cell. Our results also show that the mutation affects the tertiary structure of the protein, resulting in a more open, unstable protein compared to the WT. Phosphoproteomic analysis of HEK cells overexpressing PKC⍺D463H show a decrease of phosphorylation specifically on proteins involved with cell-cell adhesion, including functionally relevant phosphosites. This is in line with our Co-IP mass spectrometry data which shows a decrease in interaction of PKC⍺D463H with proteins involved in cell junctions. The cell of origin, tanycytes, are highly specialized cells that contain important cell-cell junctions and therefore their perturbation could be a potential route of tumorigenesis. By understanding these changes integrated with our snRNAseq and bulk RNAseq of ChGs, and exploration in cellular models, we hope to elucidate the mechanism by which the mutation leads to the development of Chordoid Glioma.

Citation Format: Charlotte Bellamy, Hannah Tovell, Florent Dingli, Damarys Loew, Stephane Liva, Selina Schwaighofer, Eduard Stefan, Alexandra Newton, Marc Sanson, Franck Bielle. Functional characterisation of a novel mutation in PRKCA, a major driver of chordoid gliomas [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 4370.
Abstract 441: Bioluminescent dehydrogenase assays: A novel approach for metabolic profiling and inhibitor screening in cancer biology
Authors: Haupt Kim , Karassina Natasha , Lauer Anthony , Sylvester Kayla , Vidugiriene Jolanta
Published: March 2024

Dehydrogenases play a pivotal role in cellular metabolism, acting as gatekeepers in key metabolic pathways. Their activity reflects the metabolic state of the cell, which is particularly relevant in the context of cancer and the immune response, where metabolic reprogramming is a hallmark of tumor progression and differentiation stages. Here, we present the development and application of novel bioluminescent dehydrogenase assays for direct measurement of metabolic activity in cell lysates. Our assays are highly sensitive, requiring as few as 100-500 cells, and have been successfully miniaturized to a 384-well plate format conducive to high-throughput screening. This technological advance allows for the precise monitoring of dehydrogenase activity across the pentose phosphate pathway, glycolysis, and the mitochondrial tricarboxylic acid (TCA) cycle. We demonstrate how shifts in dehydrogenase activity can serve as indicators of the metabolic status of cells, and their modulation during differentiation. Moreover, our bioluminescent assays provide a rapid screening platform for pathway-specific metabolic inhibitors, with potential applications in identifying new therapeutic targets within cancer metabolism. Our data reveal a dynamic landscape of metabolic activity during T cell maturation, underscoring the potential of dehydrogenase activity profiling in cancer immunobiology and the development of targeted cancer therapies.

Citation Format: Kim Haupt, Natasha Karassina, Anthony Lauer, Kayla Sylvester, Jolanta Vidugiriene. Bioluminescent dehydrogenase assays: A novel approach for metabolic profiling and inhibitor screening in cancer biology [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 441.
Abstract 4410: The CpG island methylator phenotype is closely associated with prognosis in patients with oral squamous cell carcinomas
Authors: Abe Masanobu , Yamashita Satoshi , Ushijima Toshikazu , Hoshi Kazuto
Published: March 2024

Few abnormalities are known to be closely associated with prognosis in OSCC cases. In this study, genomic abnormalities of cancer-related genes and epigenomic abnormalities of genes methylation-silenced in OSCCs were analyzed to identify abnormalities associated with prognosis. Thirty-nine OSCC cases and their surgical materials were analyzed for the presence of mutations using next-generation sequencing. Methylation status of promoter CpG islands of five genes was analyzed by methylation-specific PCR. Mutations in CRG, TP53 and PIK3CA were observed in 64.1%, 38.5%, and 33.3%, respectively, of the cases. However, no significant association between mutation status and overall survival (OS) was observed. Aberrant methylation of CMTM3, NKX2-3, RBP4, EGFLAM, and MAP6 were observed in 51.3%, 41.0%, 66.7%, 38.5%, and 41.0%, respectively. Methylation of NKX2-3, EGFLAM, and MAP6 were significantly associated with OS in OSCC cases (p=0.006, 0.006, and 0.012, respectively). Cases with methylation of CMTM3 and RBP4 showed a trend toward poor prognosis (p=0.052 and 0.059, respectively). Methylation profiles of the five genes indicated the presence of the CpG island methylator phenotype (CIMP), and the CIMP-positive cases showed poor prognosis (HR=20.5, p<0.001). In conclusion, CIMP was closely associated with the prognosis of OSCC cases.

Citation Format: Masanobu Abe, Satoshi Yamashita, Toshikazu Ushijima, Kazuto Hoshi. The CpG island methylator phenotype is closely associated with prognosis in patients with oral squamous cell carcinomas [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 4410.
Abstract 4434: Cancer cell-derived adrenomedullin downregulates Zeb1 in adipocytes to induce adipolysis and promote breast cancer progression
Authors: Cao Lixia , Chen Xiao , Shi Yi , Yang Shuang
Published: March 2024

Background: Once breast carcinoma in situ breaks through the basement membrane, it preferentially invades the lipid-rich microenvironment around the mammary gland, which indicates a poor prognosis. However, the detailed mechanisms of this interaction remain elusive. Here, we describe bidirectional communication between breast cancer cells and cancer-associated adipocytes (CAAs). Different from the common hormone-driven mechanism of lipolysis of adipocytes, we found that CAAs perform a unique lipolysis program, and Zeb1 plays an important role in this lipolysis process.

Methods: Fabp4-cre;Zeb1-/- as adipose tissue-specific Zeb1 gene knockout homozygous mice and Fabp4-cre;Zeb1 tg as adipose tissue-specific Zeb1 gene overexpression mice were constructed to study mammary gland development and perform orthotopic tumor transplantation experiments. Tetracycline-induced Zeb1-overexpressing stable cells were constructed from mouse preadipocytes 3T3-L1 to study phenotypes of lipolysis. Single-cell sequencing, targeted lipidomics, and RNA sequencing analysis were used to investigate the interaction between cancer cells and adipocytes. Western blotting and immunohistochemical staining assays were used to detect the expression Zeb1 at the cellular level, in mouse models and in patient tissue samples.

Results: Our results indicated that breast cancer cell-derived adrenomedullin (ADM) significantly down-regulates Zeb1 expression in adipocytes, which drives downstream gene expression of Pnpla2/HSL/SCD1 and induces adipocyte lipolysis into CAA, a process that results in the release of excess palmitoleic acid. Consequently, we proved that palmitoleic acid could replace arachidonic acid (ARA) in the phospholipid sn-2 position of breast cell membrane, which enhances the fluidity and invasiveness of cancer cells. In addition, overexpression of Zeb1 in adipocytes reduces the ability of cancer cells to induce adipolysis and inhibits the malignant progression of cancer cells.

Conclusion: These results indicate that Zeb1 plays a pivotal role as core transcriptional factor in CAA lipolysis. The interaction between breast cancer cells and adipocytes leads to the reprogramming of metabolism within their tumor microenvironment, which may become a new target for breast cancer treatment.

Citation Format: Lixia Cao, Xiao Chen, Yi Shi, Shuang Yang. Cancer cell-derived adrenomedullin downregulates Zeb1 in adipocytes to induce adipolysis and promote breast cancer progression [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 4434.
Abstract 4483: New drug development opportunities for PARP1
Authors: Iglesias Pablo , Moreiras David , Porres-Ventin Laura , Gonzalez-Rendo Lara , Zumalave Jose A. , Arce Victor M. , Costoya Jose A.
Published: March 2024

Personalized therapies allow, not only the increase of its therapeutic efficiency, but also the reduction of the secondary effects associated to the treatment of cancer. Data obtained in our group suggest that PARP1 could play a key role in the cell cycle regulation through its interaction with E2F1 transcription factor. Considering that most oncogenic processes is associated with cell cycle deregulation, the disruption of this interaction would provide a new therapeutic target of great interest and wide spectrum of indications. Therefore, our goal was to find molecules that interfere its role in cell-cycle regulation without affecting its function on DNA repair. The identification of novel compounds disrupting the PARP1/E2F1 interaction was carried out by combining in silico and in vitro screening, using a rational drug design. The virtual screen was performed using a molecular library of several million compounds at the selected target site, using AtomNet® (Atomwise), the first deep learning neural network for structure-based drug design and discovery. Since there is no complete structural information of the PARP-1/E2F1 protein-protein interaction, a homologous structure of BRCT domain of BRCA1 complex with the phospho-peptide (PDBID: 1T2V) was utilized to identify the potential binding interface of BRCT domain of PARP-1 (PDBID: 2COK) and the E2F1 protein. Top scoring compounds were clustered and filtered to arrive at a final subset of 83 compounds, library that were incorporated to our in vitro screening, which included both transcriptional (E2F1 activity) and survival studies. Twelve compounds were finally selected, based upon their higher capacity of inhibiting E2F1 activity.This work was supported by Agencia Estatal de Investigación (AEl/10.13039/501100011033), Xunta de Galicia (GPC GI-1862, ED431B 2020/26; ED431G 2019/02) and European Regional Development Fund-ERDF. AIMS Awards Program - Project A19-513, Atomwise Inc.

Citation Format: Pablo Iglesias, David Moreiras, Laura Porres-Ventin, Lara Gonzalez-Rendo, Jose A. Zumalave, Victor M. Arce, Jose A. Costoya. New drug development opportunities for PARP1 [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 4483.
Abstract 4488: Newly developed organoiridium(III) complexes containing N,P-ligands possess antiproliferative activity in selected cancer cell lines
Authors: Hezova Renata , Hosek Jan , Strakova Nicol , Simeckova Pavlina , Masek Josef , Kajabova Simona , Starcha Pavel
Published: March 2024

In conventional cancer treatment, platinum-based cytostatics are considered as standard therapy; however, they possess severe side effects. This fact leads to a constant effort to develop new non-platinum metallodrugs with different mechanism of action (MoA). In our study we developed new half-sandwich organoiridium(III) complexes, of general formulas [Ir(η5-Cp*)Cl(LNP)]PF6 (1-3) and [Ir(η5-Cpph)Cl(LNP)]PF6 (4-6) involving three different N,P-donor phosphinoalkylamines (LNP), which we tested on 2D and 3D cancer models; HCp* = pentamethylcyclopentadiene, HCpph= (2,3,4,5-tetramethylcyclopenta-2,4-dien-1-yl)benzene. The most effective complexes 3 and 6 bearing 3-(diphenylphosphanyl)propan-1-amine had the highest cytotoxic effect against various cancer cell lines (THP-1, HeLa, SW982, A549, MOR) including a cisplatin-resistant lung carcinoma cell line (MOR/CPR) with IC50 values between 3.1 and 9.1 μM for specific cell lines. The cytotoxic effect was further demonstrated on 3D spheroids of lung cancer cells that revealed anti-cancer and anti-migration potential of complexes 3 and 6. Cell cycle and cell death analysis showed a different mechanism compared to the effect of cisplatin. Moreover, complex 3 did not decrease cell viability of non-cancerous cells (peripheral blood mononuclear cells and porcine chondrocytes) under 50% at a concentration of 20 µM. In addition, we report for the first time that organoiridium complexes showed high cytotoxic activity on cancer cell lines, including cisplatin-resistant cell line, with different MoA from cisplatin. They trigger expression of stress-related genes associated with oxidative stress, DNA damage, and endoplasmic reticulum stress and, moreover, complex 3 showed cytotoxic selectivity towards cancer cells. This work was supported by the Czech health research council of the Ministry of Health of the Czech Republic (AZV Project NU22-08-00236).

Citation Format: Renata Hezova, Jan Hosek, Nicol Strakova, Pavlina Simeckova, Josef Masek, Simona Kajabova, Pavel Starcha. Newly developed organoiridium(III) complexes containing N,P-ligands possess antiproliferative activity in selected cancer cell lines [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 4488.
Abstract 4502: Design, synthesis, and evaluation of next-generation EGFR degraders to overcome osimertinib-resistance
Authors: Baig Mohammad Hassan , Bok Juhan , Kim Dongmin , Nale Sagar Dattatraya , Jo Yun Sung , Kim Changjoong , Park Taehhwan , Dong Jaejune , Moon Byoung Gon
Published: March 2024

The occurrence of C797S mutation in epidermal growth factor receptor (EGFR) is a leading mechanism of clinically acquired resistance to third-generation EGFR inhibitors, including Osimertinib. L858R/T790M/C797S and del19/T790M/C797S are commonly observed tertiary EGFR mutants identified in Osimertinib-resistant tumors. As of now, no clinically approved treatment exists that specifically targets these mutants. Here, we report the design and synthesis of a series of highly effective next-generation EGFR degraders effectively degrading EGFR C797S-containing triple mutants. Most compounds demonstrated antiproliferation activity in the subnanomolar range when tested on Ba/F3L858R/T790M/C797S and del19/T790M/C797S cells. Not only C797S but our designed degraders also degraded a wide range of EGFR mutants, including Exon19Del and L858R/T790M (DC50 <100nM). One representative Compound, HDBNJ2812, strongly degrades L858R/T790M/C797S and del19/T790M/C797S with DC50 of 34 nM (Dmax 88.5%) and 14 nM (Dmax 99.7%), respectively. This compound potently inhibits the proliferation of Ba/F3L858R/T790M/C797S (GI50 64 nM) and del19/T790M/C797S (GI50 40 nM). HDBNJ2812 demonstrated high inhibitory potential on HCC827 (del19) and H1975 (L858R/T790M) cell lines (GI50 18.9 and 85 nM, respectively). Furthermore, this degrader demonstrates weak cytotoxicity on non-mutant EGFR-expressing cells, such as A431, WI-26 (human lung fibroblast cells), and CHO-K1 (Chinese hamster ovary cells). Additionally, the in vivo PK/PD findings complement this compound's potential to be considered further. HDBNJ2812 may serve as a lead compound to render the greater therapeutic window for treating resistant non-small cell lung cancer patients with EGFR C797S mutants.

Citation Format: Mohammad Hassan Baig, Juhan Bok, Dongmin Kim, Sagar Dattatraya Nale, Yun Sung Jo, Changjoong Kim, Taehhwan Park, Jaejune Dong, Byoung Gon Moon. Design, synthesis, and evaluation of next-generation EGFR degraders to overcome osimertinib-resistance [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 4502.
Abstract 4514: Discovery of potent and orally bioavailable degraders of HPK1 based on a novel HPK1 binder
Authors: Zhang Zhimin , Wu Mengqiang , Wang Ling , Yang Xi , Zhang Zhiping , Guo Liubin , Pan Hao , Zhao Mengting , Wang Linli , Liu Sirui , Dong Zhao , Jiang Chunhua , Zheng Haowen , Liu Dongzhou
Published: March 2024

Background: Proteolysis targeting chimeras (PROTACs) are novel structures designed to target a protein of interest (POI) for ubiquitination and degradation, leading to the selective reduction in the expression levels of the POI. Hematopoietic progenitor kinase 1 (HPK1) is considered a promising target for tumor immunotherapy. PROTAC-involved disruption of HPK1 protein activity enhanced the treatment efficacy of CAR-T-cell-based immunotherapies in different solid tumors and mouse models. Thus, targeting HPK1 by PROTAC to restore T-cell activity is an attractive approach to induce a greater immune responses in cancer.

Results: We designed and synthesized a series of HPK1 degraders by tethering our previously discovered novel HPK1 inhibitor with CRBN binder through various linkage. The most potent PROTAC effectively degrades HPK1 proteins in the Ramous cell in a dose-dependent manner and achieves DC50 value <50 nM. The maximum degradation (D max ) values achieved are >90%. Our PROTAC showed EC50 value <100 nM for IL-2 and IFNγ production. PK studies revealed a low clearance, high plasma exposure and oral bioavailability in mice and rats. Furthermore, our PROTAC is shown to induce robust and statistically significant tumor growth inhibition in the MC38 and CT26 syngeneic model with increased T cell signatures observed within the tumor. The PROTAC in combination with anti-PD1 also resulted in robust anti-tumor activity with TGI > 90%. The 14 days DRF experiment shows that the compound has a great safety window(>200 folds).

Conclusion: We show here that a potent oral HPK1 degrader demonstrates strong immune cell activation and robust anti-tumor activity in mouse syngeneic tumor models, as a single agent and in combination with anti-PD1. Further evaluation of these potent degraders in additional in vivo studies will continue to build upon our mechanistic understanding of HPK1 degradation as a novel immunomodulatory approach for anti-tumor immunity.

Citation Format: Zhimin Zhang, Mengqiang Wu, Ling Wang, Xi Yang, Zhiping Zhang, Liubin Guo, Hao Pan, Mengting Zhao, Linli Wang, Sirui Liu, Zhao Dong, Chunhua Jiang, Haowen Zheng, Dongzhou Liu. Discovery of potent and orally bioavailable degraders of HPK1 based on a novel HPK1 binder [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 4514.
Abstract 455: Identification of hsa-miR-6794-3p as a key regulatory factor in human pancreatic cancer metastasis
Authors: Kim Ha Gyeong , Oh Eun-Taex , Cho Yunmi , Park Heon Joo
Published: March 2024

Metastasis is a major factor in treatment failure in patients with pancreatic cancer, but the underlying mechanisms remain unclear, and new, effective treatment strategies are needed. Here, we sought to identify novel microRNAs (miRNAs) with a key role in pancreatic cancer metastasis. Using a microarray analysis to evaluate miRNA expression in metastatic and non-metastatic pancreatic cancer, we found that expression of the miRNA, hsa-miR-6794-3p, was significantly lower in metastatic pancreatic cancer tissues than in non-metastatic pancreatic cancer tissues. Methylation-specific polymerase chain reaction analyses revealed that hsa-miR-6794-3p expression was downregulated in metastatic pancreatic cancer cells by hypermethylation of CpG islands within the hsa-miR-6794-3p promoter. Gain- and loss-of-function approaches using the human pancreatic cancer cell lines, MIA-PaCa-2 and HPAF-II, expressing low and high levels of hsa-miR-6794-3p, respectively, suggested a role for hsa-miR-6794-3p in decreasing cell invasion, migration, and epithelial-mesenchymal transition (EMT) signaling. Notably, we found that hsa-miR-6794-3p exerts its effects by inhibiting expression of the chromatin remodeling factor, RBBP4, through direct binding to the 3’-untranslated region of its mRNA. The resulting suppression of RBBP4 expression increases levels of the transcription factor GRHL2, which is involved in regulating invasion, migration, and EMT signaling in metastatic pancreatic cancer cells. Thus, lower levels of hsa-miR-6794-3p disrupt GRHL2-mediated regulation of these pathways by disinhibiting expression of the GRHL2 negative regulator, RBBP4. Consistent with these findings, an investigation of the relationship between hsa-miR-6794-3p and clinicopathological features in pancreatic cancer patients using publicly available datasets and immunohistochemistry showed that low levels of hsa-miR-6794-3p are correlated with a poorer prognosis in pancreatic cancer patients. Additional preclinical experiments in nude mice clearly demonstrated that hsa-miR-6794-3p is capable of suppressing pancreatic cancer cell metastasis. Taken together, these results suggest that hsa-miR-6794-3p suppresses tumor metastasis and thus represents a promising prognostic biomarker and therapeutic target in pancreatic cancer.

Citation Format: Ha Gyeong Kim, Eun-Taex Oh, Yunmi Cho, Heon Joo Park. Identification of hsa-miR-6794-3p as a key regulatory factor in human pancreatic cancer metastasis [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 455.
Abstract 4567: Dual targeting of HSP70 and AURKA improves treatment in neuroendocrine prostate cancer
Authors: Xu Pengfei , Yang Joy C. , Chen Bo , Ning Shu , Wang Leyi , Nip Christopher , Evans Christopher P. , Dall'Era Marc A. , Gao Allen C. , Gestwicki Jason , Liu Chengfei
Published: March 2024

Background: Neuroendocrine prostate cancer (NEPC) is the most aggressive type of prostate cancer with no effective treatments. Therefore, there is an urgent need to develop new treatment strategies. N-Myc plays a key role in driving NEPC progression, and Aurora kinase A (AURKA) prevents N-Myc degradation by interact with N-Myc and disallowing the intervention of ubiquitin ligases. The AURKA inhibitor Alisertib inhibits NEPC tumor growth by disrupting N-Myc signaling, but it is failed in a phase II clinical trial. In this study, we tested the synergy of novel HSP70 allosteric inhibitor JG231 and Alisertib in NEPC cells, organoids, and patient derived xenograft (PDX) models, which will provide new therapeutic strategies for the NEPC treatment.

Methods: RT-PCR, western blotting, or immunohistochemistry (IHC) were used to determine the expression of N-Myc, neuroendocrine maker (NSE, SYP, CHGA, etc) in different prostate cancer cell lines and PDX tumors. After the knockdown of HSP70 and AURKA by siRNA transfection, cell proliferation and N-Myc expression were assessed by using cell viability assay, RT-PCR and Western blotting respectively. The co-immunoprecipitation assay was performed to detect the N-Myc ubiquitination. RNA-sequencing, gene set enrichment analysis was employed to determine the changes of JG231 on gene programs. The effects of JG231 and Alisertib on the proliferation were examined in NEPC cell lines and PDX organoids models.

Results: We determined that PC3, CWR22Rv1, H660 cell lines, LuCaP49, and LuCaP93 PDX tumors had significantly increased the expression of N-Myc and neuroendocrine makers. Knockdown of HSP70 or using the HSP70 inhibitor, JG231, significantly inhibit the growth of H660 and CWR22Rv1 cells and leads to a synergistic effect with Alisertib (p<0.001). JG231 combined with Alisertib also inhibits growth and induces the death of LuCaP93 and H660 tumor derived organoids in a dose-dependent manner (p<0.001). Mechanistically, JG231 inhibits the protein expression of N-Myc through the ubiquitin-proteasome system and promote STUB1 to enter the nucleus to bind to N-Myc.

Conclusions: JG231, a novel HSP70 inhibitor, can improves the treatment efficacy of AURKA inhibitor Alisertib against NEPC through the regulation of N-Myc protein homeostasis.

Citation Format: Pengfei Xu, Joy C. Yang, Bo Chen, Shu Ning, Leyi Wang, Christopher Nip, Christopher P. Evans, Marc A. Dall'Era, Allen C. Gao, Jason Gestwicki, Chengfei Liu. Dual targeting of HSP70 and AURKA improves treatment in neuroendocrine 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 4567.
Abstract 4620: Exploring the role of GHRH antagonist MIA-602 in overcoming doxorubicin resistance in acute myeloid leukemia
Authors: Gaumond Simonetta I. , Costoya Joel , Schally Andrew V. , Jimenez Joaquin J.
Published: March 2024

Acute Myeloid Leukemia (AML) is characterized by the uncontrolled proliferation of immature hematopoietic progenitors, often associated with a poor prognosis. Conventional therapies involve chemotherapy and bone marrow stem cell transplantation. The growth hormone releasing hormone receptor (GHRH-R) antagonist MIA-602 has exhibited inhibitory effects on the growth of various human cancer cell lines, including AML cells. This study aimed to investigate the impact of MIA-602 alone and in combination with doxorubicin on three doxorubicin-resistant AML cell lines, K-562, U-937, and KG-1A. Initial examinations confirmed the presence of GHRH receptors in both wild-type and doxorubicin-resistant cell lines through western blot analysis. Doxorubicin was administered at concentrations of 0.005, 0.01, and 0.05 μg/ml, while MIA-602 was used at 5 μmol/L. Subsequent experiments involved culturing both wild-type and doxorubicin-resistant clones with MIA-602 at concentrations ranging from 0.05 μmol/L to 5 μmol/L for 24 and 48 hours. The results revealed a significant, dose- and time-dependent reduction in cell proliferation across all six cell lines. Both wild-type and doxorubicin-resistant clones exhibited a comparable decrease in cell proliferation when exposed to MIA-602 at concentrations greater than 0.05 μmol/L (p < 0.05) after 24 and 48 hours. In conclusion, our study demonstrates that these three AML cell lines and their doxorubicin-resistant clones remain susceptible to GHRH antagonist MIA-602. These findings may pave the way for the development of novel therapies or drug combinations using GHRH antagonists such as MIA-602 for treating AML. This is of particular interest for those who are resistant to conventional chemotherapy, further broadening the spectrum of treatment options available. Additional investigations are warranted to progress these findings to in vivo xenograft models.

Citation Format: Simonetta I. Gaumond, Joel Costoya, Andrew V. Schally, Joaquin J. Jimenez. Exploring the role of GHRH antagonist MIA-602 in overcoming doxorubicin resistance in acute myeloid leukemia [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 4620.
Abstract 4669: Differential preclinical activity of Bruton tyrosine kinase inhibitors (BTKis) against BTK resistance-associated mutations
Authors: Davids Matthew S. , Ahn Inhye E. , Riehm Jacob J. , Acar Melih , Girardi Vincent , Patel Sima , Gururaja Tarikere , Woyach Jennifer , Lam Lloyd T. , Szafer-Glusman Edith
Published: March 2024

Background: Differences in profiles of acquired mutations of resistance to BTKis might have implications for treatment sequencing. We evaluated preclinical activity of BTKis (ibrutinib [Ibr], acalabrutinib [Acala], zanubrutinib [Zanu], and pirtobrutinib [Pirto]) against multiple clinically relevant BTK mutations and report on the clinical impact of BTK C481S in patients (pts) treated with Ibr.

Methods: Inhibition of kinase activity by BTKis was evaluated in a cell-free kinase activity assay (Nanosyn). Cell-killing activity on CRISPR-generated BTK mutant knock-in TMD8 cells was assessed after 3 days of BTKi treatment. Time from first detection of C481S mutation to progressive disease (PD) was evaluated in pts treated with Ibr with previously untreated (n=247) or relapsed/refractory (R/R; n=172) CLL using pooled data from 5 clinical trials.

Results: In vitro kinase activity was highest for Ibr compared with Acala or Zanu against C481S (Ibr IC50: 26.3 nM; Zanu: 84.8 nM; Acala: 338 nM) and T474I (Ibr: 1.2 nM; Zanu: 4.4 nM; Acala: 43.6 nM). Ibr maintained cell-killing activity against all tested BTK mutants, whereas limited activity was seen with Acala against C481S and A428D; with Zanu against C481S, L528W, and A428D; and with Pirto against T474I, L528W, V416L, and A428D (Table). In pts treated with Ibr, C481S was detected prior to clinical PD in 3 previously untreated pts and in 26 pts with R/R CLL; median (range) time from first detection of C481S to PD in these pts was 17.0 mo (11.2-34.3) and 10.0 mo (2.6-35.7), respectively.

Conclusion: This study demonstrates activity of Ibr against all evaluated BTK variants, which are associated with resistance to covalent and noncovalent BTKis. Clinical data shows that pts who develop C481S mutations continue to derive benefit from Ibr for several months before PD. Together, these data suggest a role for Ibr in the treatment of pts with a broad spectrum of BTK variants.

Table. Cell-killing activity of BTKis against wild type and mutant BTK EC50 (nM) BTK Wild type C481S T474I L528W V416L A428D Ibr 0.6 414.0 1.9 181.4 0.5 205.3 Acala 3.9 2973.8 43.3 3.5 106.3 3000.0 Zanu 0.7 2322.0 11.7 3000.0 0.6 1726.0 Pirto 8.2 12.6 2727.5 3000.0 1898.0 3000.0

Citation Format: Matthew S. Davids, Inhye E. Ahn, Jacob J. Riehm, Melih Acar, Vincent Girardi, Sima Patel, Tarikere Gururaja, Jennifer Woyach, Lloyd T. Lam, Edith Szafer-Glusman. Differential preclinical activity of Bruton tyrosine kinase inhibitors (BTKis) against BTK resistance-associated mutations [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 4669.
Abstract 4703: Automated 42 PDX 3D in vitro tumor models of the TME screen immuno-oncology and targeted compounds and biologics for antitumor effects and MOA
Authors: Xue Bin , Harrod Christopher , Le Long , Schüler Julia , Hribar Kolin C.
Published: March 2024

High throughput screening has been widely utilized for its efficiency in testing novel therapeutic agents. However, the conventional screening using 2D culture of cancer cell lines lacks the biological complexity of the tumor microenvironment or the immune compartment which limits their application in testing immune-oncology therapies. Particularly with the passing of the FDA Modernization Act 2.0, it is critical to create more biologically relevant 3D in vitro models that can be used to reduce, refine and ultimately replace preclinical animal models. Here we have developed a highly automated 3D high throughput screening platform comprised of 42 patient-derived xenograft models in coculture with fibroblasts in engineered extracellular matrix hydrogels that resemble tumor stromal microenvironment. The PDX models cover a diverse range of tumor and histological types including NSCLC, CRC, gastric, TNBC, RCC, bladder, ovarian, melanoma, pancreatic, and others. Moreover, PBMCs or other immune cells can be incorporated into the system for evaluating immuno-oncology drugs. The panel has been tested against chemotherapy drug cisplatin and the immunotherapy biologic, Solitomab, an EpCAM/CD3 bispecific antibody. The endpoint analyses for antitumor effects include the dose response of tumor size and tumor cell death percentage based on high content imaging analysis. In addition, immune cells and supernatant in the IO assay can be recovered from the wells and used for flow cytometry profiling and cytokine assays. In summary, the novel 42-PDX panel described here offers a unique and powerful tool for rapidly generating preclinical data and a better understanding the drug activity at the pharmacology stages, opening the door for faster and more human relevant drug discovery for cancer patients.

Citation Format: Bin Xue, Christopher Harrod, Long Le, Julia Schüler, Kolin C. Hribar. Automated 42 PDX 3D in vitro tumor models of the TME screen immuno-oncology and targeted compounds and biologics for antitumor effects and MOA [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 4703.
Abstract 472: Long non-coding RNA MIR31HG-derived circRNA enhances the oncogenicity of oral carcinoma
Authors: Chou Chung-Hsien , Tu Hsi-Feng , Chang Kuo-Wei , Lin Shu-Chun
Published: March 2024

Introduction: Oral carcinoma (OC) represents a significant health challenge, with the role of non-coding RNAs, particularly microRNAs and long non-coding RNAs (LncRNAs), being well-established in its progression. However, the implications of circular RNAs (circRNAs) in this context are less well understood, presenting a notable gap in current research. Our study focuses on the MIR31HG LncRNA, identified as crucial in OC, particularly its role in producing circRNA, as evidenced by sequencing. This specific MIR31HG-derived circRNA, designated 31HGcircR, which contains a potential open reading frame (ORF), and may demonstrate phenotypic significances. Alterations to 31HGcircR, either through knockout or ORF mutation, result in remarkable phenotypic changes, highlighting its potential importance in the pathogenesis of OC.

Methods: We implemented 31HGcircR overexpression in OC cell lines, utilizing the TetOff system for gene expression control. CRISPR/Cas9 was employed for gene knockout, and siRNA for gene knockdown. Gene expression was quantified using qPCR. Additionally, the BaseScope assay was used to label and detect the spatial expression of overexpressed 31HGcircR within the cells. Assays to assess cell proliferation, invasion, migration, anchorage-independent growth (AIG), and clonogenicity were conducted.

Results: The findings revealed specific junctions of 31HGcircR and varied expression levels across different OC cell lines. There was a significant correlation among the expression of 31HGcircR, MIR31HG and miR-31-5p. Notably, the knockdown of 31HGcircR led to pronounced inhibition of cell growth, migration, invasion, AIG, and clonogenic activity. Conversely, overexpression of 31HGcircR or its ORFs augmented invasion and clonogenic potential in certain cell lines. The TetOff system demonstrated that minimal concentrations of Doxycycline effectively suppressed 31HGcircR expression, with reversible effects upon removal. Knocking out 31HGcircR resulted in reduced invasion and clonogenic capabilities.

Conclusion: This study provides clues demonstrating the oncogenic roles of 31HGcircR in OC, which simulate the functions of MIR31HG or miR-31-5p. The changes in cell phenotypes following 31HGcircR manipulation suggest its potential as a therapeutic target or biomarker in OC. These findings offer valuable insights, contributing to the evolving understanding of circRNAs in cancer research and potential treatment avenues.

Citation Format: Chung-Hsien Chou, Hsi-Feng Tu, Kuo-Wei Chang, Shu-Chun Lin. Long non-coding RNA MIR31HG-derived circRNA enhances the oncogenicity of oral 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 472.
Abstract 4778: Development of self-amplifying RNA vaccines targeting prostate tissue-restricted and tumor-associated antigens
Authors: Shoemaker Robert H. , Erasmus Jesse H. , Berglund Peter , Marshall Jason D. , Koboziev Yuri , Beckman Bradley M. , Cholewa Brian D. , Reed Steven G.
Published: March 2024

Prostate cancer is the most frequent cancer type in men, with increasing incidence at advanced age. As this cancer is frequently slow growing, opportunities for cancer interception exist, particularly among men with low-grade tumors who frequently undergo active surveillance. A well-tolerated vaccine intervention would be ideal for this population. Self-amplifying RNA (saRNA) vaccines built on a replication-deficient alphavirus backbone such as VEEV, offer several advantages for vaccine development. Sequences for relatively large antigens can be encoded and efficiently expressed, at low vaccine doses. Practical and efficient delivery of the saRNA is possible with advanced nanoparticles such as cationic inorganic lipid nanoparticles (LION). Among candidate antigens for a prostate cancer interception vaccine, we selected prostein (SLC45A3), a protein whose natural expression is restricted to the prostate gland and prostate cancer and ERG, a member of the ETS family of transcription factors frequently involved in chromosomal translocations in prostate cancer. We generated saRNA constructs with several design strategies and demonstrated that upon in vitro transfection, both antigens are expressed as assessed by mass spectrometry and Western blot analysis. This was achieved using commercial transfection reagents and LION. Prostein expression was particularly notable in that this eleven-transmembrane protein could be detected in HEK-293 cells using flow-cytometry and cell-surface staining. Nearly 50% of the cell population stained positively. Immunogenicity of the vaccines was tested in mice. Following formulation with LION particles i.m. injection and boosting, saRNAs coding for prostein elicited strong cellular immunity as demonstrated by IFN-γ ELISPOT analysis. Detailed analysis of intracellular cytokine expression indicated a strong CD8 response. saRNAs coding for ERG also showed antigen-specific ELISPOTs. Using commercially available recombinant ERG protein, an ELISA was developed and a strong humoral response to the ERG saRNA vaccine was demonstrated. The saRNA vaccines will be further credentialled with additional preclinical studies including cancer preventive efficacy studies in genetically engineered mouse models of prostate cancer.

Citation Format: Robert H. Shoemaker, Jesse H. Erasmus, Peter Berglund, Jason D. Marshall, Yuri Koboziev, Bradley M. Beckman, Brian D. Cholewa, Steven G. Reed. Development of self-amplifying RNA vaccines targeting prostate tissue-restricted and tumor-associated antigens [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 4778.
Abstract 4795: Social capital and screening mammography rates in the United States
Authors: Huang Tracy , Ekenga Christine
Published: March 2024

Background: Social capital may play a role in screening mammogram utilization by influencing individuals' access to information and providing social support for healthy behaviors. However, few studies have examined associations between community-level social capital and screening mammography use. The purpose of this study was to examine the association between county-level social capital and screening mammography rates in the United States (U.S.).

Methods: We conducted a cross-sectional study of social capital and screening mammography rates across 2,613 U.S. counties for 2014. We obtained county-level data on (1) screening mammography rates for female Medicare enrollees aged 67-69 years and (2) social capital (Penn State Social Capital Index). Multivariable regression models were used to evaluate associations between social capital quartiles and mammography screening rates. Models were adjusted for county-level socioeconomic, demographic, and access to care factors.

Results: Average county-level screening mammography rates were 60.5% ± 8.3% (range 26%-88%). Across all U.S. counties, social capital was associated with county-level mammography rates, after adjusting for covariates (p <0.001). This association did not vary by urban-rural classification. In analyses by region, associations between social capital and screening mammography rates were strongest in the West region (p<0.001).

Conclusions: In this nationwide study, social capital was significantly associated with screening mammography. Our findings suggest that there are regional variations in the association between social capital and mammography rates. The relationship between social capital and cancer screening behaviors warrants further investigation, particularly in the U.S. West.

Citation Format: Tracy Huang, Christine Ekenga. Social capital and screening mammography rates in the United States [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 4795.
Abstract 484: Enhancing therapeutic responses in NSCLC using iron-oxide nanoparticles combined with pharmacological ascorbate
Authors: Singhania Mekhla , Petronek Miachael S. , Pulliam Casey F. , Mapuskar Kranti A. , Zaher Amira , Spitz Douglas R.
Published: March 2024

High dose Vitamin C (pharmacological ascorbate; P-AscH‒ > 20 mM plasma levels) given intravenously (I.V.), has made a remarkable re-emergence as an adjuvant to combined modality approaches in cancer therapy. P-AscH‒ can be readily oxidized in the presence of redox active metals (i.e., P-AscH‒ serves as an iron reducing agent), which can result in increased fluxes of H2O2. This chemical phenomenon allows for the tumor-selective enhancement of chemo-radiation in NSCLC. We hypothesized that enhancing labile Fe2+ in cancer cells using iron-oxide nanoparticles (ferumoxytol, FMX) can increase the effectiveness of P-AscH‒ in enhancing cancer cell sensitivity to chemo-radiation in NSCLC by increasing H2O2 production. To test this hypothesis, we performed clonogenic cell survival assays in-vitro. To test the role of H2O2 in the combined effect of P-AscH‒ and FMX, we developed lentiviral-based doxycycline-inducible overexpression models for catalase, and to determine the changes in Fe, we used fluorescent probes that specifically detect changes in labile Fe2+. Results from these experiments showed FMX enhanced clonogenic cell killing in NSCLC. Furthermore, catalase overexpression inhibited this effect, suggesting that enhanced H2O2 production plays a central role in the additive effect of P-AscH- and FMX. Finally, staining the cells with the fluorescent iron probes showed that FMX enhanced labile Fe2+ in cells treated with P-AscH‒. These studies continue to support the hypothesis that H2O2 plays a significant role in P-AscH‒ toxicity in cancer cells that can be exacerbated using iron oxide nanoparticles. Future studies will test these findings in-vivo using preclinical xenograft models. (supported by P01 CA217797, P30 CA086862, T32 CA078586, and P01 CA244091).

Citation Format: Mekhla Singhania, Miachael S. Petronek, Casey F. Pulliam, Kranti A. Mapuskar, Amira Zaher, Douglas R. Spitz. Enhancing therapeutic responses in NSCLC using iron-oxide nanoparticles combined with pharmacological ascorbate [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 484.
Abstract 4919: AI-enabled hit selection of drug screening on human pancreatic cancer organoids
Authors: Tong Zhisong , Lim Angeline , Meyer Marine , Clapes Maria , Sirenko Oksana , Brandenberg Nathalie
Published: March 2024

Cancer remains one of the leading causes of death in the 21st century. Despite the latest advances in oncology, most cancer patients lack tailored therapeutic approaches with lasting benefit. Measuring the impact of anticancer compounds and their combinations is only possible on ex vivo assays. To this end, patient-derived organoids (PDOs) have been proposed as viable and efficient models for ex vivo testing. PDOs show long-term expansion potential while retaining tumor histopathology as well as cancer gene mutations. However, the translation of organoids in screening applications has so far been hampered by the lack of homogeneity and difficulties in handling and automation. Moreover, organoids are typically randomly distributed across the culture which complicates imaging and images analyses. To overcome these challenges, we set up a compound screening workflow with PDOs using Gri3D platform, comprising plates with micro-cavities suitable for high-throughput and reproducible organoid culture. Based on a standard 96 microtiter plate, each well contains a microwell array patterned in a cell repellent hydrogel. On Gri3D®, organoids are robustly generated in the microwells and are located in the same imaging plane. This greatly facilitates quantitative analyses in high content image-based screens. Furthermore, the pipetting port enables automation of cell seeding, media exchange and compound incubation with liquid-handlers, thus increasing assay reproducibility. In the presented work, we exposed human pancreatic cancer PDOs to a panel of anti-cancer compounds at different doses and followed their response to the drugs using viability dyes Calcein AM (live stain) and Ethidium Homodimer-1 (dead stain) with high-content confocal imaging. Using an AI-based approach, we efficiently detected each single organoid and extracted phenotypic features from all three channels (TL, live stain and dead stain) which correlate with cytotoxicity. The extracted features (more than 100) were first dimensionally reduced to 3 components using either PCA or UMAP, the treatments were then visualized in 3D scatter plots, ranked and clustered using machine learning. The data suggests that the compound treatment Palbociclib 50uM has significant cytotoxicity effects similar to the positive control, which is consistent with the traditional live/dead analysis. The AI approach demonstrates feasibility to perform drug screening in a robust and un-biased data analysis approach.

Citation Format: Zhisong Tong, Angeline Lim, Marine Meyer, Maria Clapes, Oksana Sirenko, Nathalie Brandenberg. AI-enabled hit selection of drug screening on human pancreatic cancer organoids [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 4919.