bluuebunny/crossref_metadata_2025 huggingface dataset:
Abstract 4598: Vitamin b1 derivative, benfotamine, prevents VEGF-induced angiogenesis
Authors: Allowitz Kieran V. , Plowman Trevor J. , Ramana Kota V.
Published: April 2023

Several studies have indicated that thiamine, and more specifically its lipid soluble derivative benfotiamine, exerts an anti-oxidative and anti-inflammatory effect on the body. However, its effect in preventing cancer cell proliferation, migration, invasion, and metastasis is not yet clearly understood. It is known that angiogenesis plays a significant role in the growth and spread of many cancers but the role of benfotiamine in neovascularization is not yet known. Therefore, in this study, we hypothesized that benfotiamine would prevent VEGF-induced angiogenesis in vitro and in vivo. To examine this, we have treated human umbilical vein endothelial cells (HUVECs) with VEGF (Vascular Endothelial Growth Factor; 10 ng/ml) in the absence and presence of benfotiamine (0-100 uM) in a time and dose-dependent manner. We then examined the cell viability by MTT assay and apoptosis by Annexin-V staining and found that benfotiamine alone had minimal effect on cell viability and it prevents VEGF-induced cell proliferation. In vitro angiogenesis assay indicates that benfotiamine prevented the VEGF -induced tube formation of HUVECs. Further, benfotiamine regulated the expression of VEGF-induced growth factors such as VEGF, PIGF, IGFBP-1, ECGF, FGF-1 and 2, anti-angiogenic enzymes such as Serpin E1, TIMP-1, MMP-8, TSP-1, PTX3 and uPA and cytokines such as IL-8, Prolactin, ET-1, Endostatin, and CCL3. We will next examine how benfotiamine prevents in vivo angiogenesis by utilizing a rat Matrigel plug model of angiogenesis in rats. The Matrigel sections will be stained with CD36, vWF, and other angiogenic markers to visualize the effect of benfotiamine on VEGF-induced angiogenesis. In conclusion, our current results indicate that benfotiamine has anti-angiogenic potential via inhibition of various pro-angiogenic growth factors and promoting anti-angiogenic factors in vitro and in vivo. Thus, our studies demonstrate that benfotiamine could be further developed as a novel therapeutic agent to prevent cancer growth and metastasis.

Citation Format: Kieran V. Allowitz, Trevor J. Plowman, Kota V. Ramana. Vitamin b1 derivative, benfotamine, prevents VEGF-induced angiogenesis. [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 4598.
Abstract 4668: In-vitro modeling of tumor-associated macrophages in glioblastoma
Authors: Alrefai Hasan , Beierle Andee M. , Schanel Taylor L. , Nassour Lauren C. , Anderson Joshua C. , Hicks Patricia H. , Willey Christopher D.
Published: April 2023

BACKGROUND: The Glioblastoma (GBM) tumor microenvironment (TME) is comprised of a plethora of cancerous and non-cancerous cells that contribute to GBM growth, invasion, and chemo- and radio-resistance. In-vitro models of GBM typically fail to incorporate multiple cell types. Some groups have addressed this problem by employing 3D bioprinting to incorporate macrophages, astrocytes, and other parenchymal cells in an extracellular matrix. However, these models also use serum-containing media, which has been shown to cause GBM brain-tumor initiating cells to lose their stem-like properties, and IL-4/13 polarized macrophages (M2), even though tumor-associated macrophages (TAMs) do not adhere to the traditional M2 phenotype. Taken together, these observations highlight a critical need to develop physiologically accurate in-vitro model systems for GBM.

METHODS: THP-1 monocytes were transitioned from serum-containing RPMI 1640 to serum-free CTS™ AIM V™ SFM and TheraPEAKTM X-VIVOTM-15 Serum-free Hematopoietic Cell Medium. Monocytes were stimulated towards a macrophage-like state with PMA and polarized by co-culturing them with GBM patient-derived xenograft (PDX) lines, using transwell inserts. dPCR, a cytokine array, and a phagocytosis assay were used to characterize macrophages polarized by this method relative to classically polarized resting (M0), pro-inflammatory (M1), and anti-inflammatory (M2) macrophages.

RESULTS: There was no significant difference in proliferation rates up to 48 hours for THP-1 monocytes grown in serum-free CTS AIM V or X-VIVO-15 media compared to serum-containing RPMI 1640. At 72 hours, both serum-free alternatives had slightly decreased proliferation relative to the serum-containing RPMI 1640; however, the X-VIVO-15 had higher proliferation relative to the CTS AIM V (p<0.0001). THP-1 macrophages polarized towards a tumor-supportive phenotype by the GBM PDX cell line, JX39P-RT, did not recapitulate the cytokine expression profile of any other polarization group. M2 macrophages had significantly higher phagocytic capacity (25%) of JX39P-RT relative to M0, M1, and TAMs (<15%, p<0.01).

CONCLUSIONS: We have demonstrated a serum-free method by which we can polarize macrophages towards a GBM-supportive phenotype. This high-fidelity method of modeling TAMs in GBM will aid in the development of innate immunomodulatory therapeutics that may one day enter the clinic in hopes of improving GBM outcomes.

Citation Format: Hasan Alrefai, Andee M. Beierle, Taylor L. Schanel, Lauren C. Nassour, Joshua C. Anderson, Patricia H. Hicks, Christopher D. Willey. In-vitro modeling of tumor-associated macrophages in glioblastoma. [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 4668.
Abstract 4727: RAS and PP2A activities converge on phosphoregulation of epigenetic complexes in cancer
Authors: Sharma Mukund , Aakula Anna , Tabaro Francesco , Honkanen Henrik , Kamila Jesse , Schapira Matthieu , Arrowsmith Cheryl , Nykter Matti , Westermarck Jukka K.
Published: April 2023

RAS-mediated human cell transformation requires inhibition of the tumor suppressor Protein Phosphatase 2A (PP2A). Both RAS and PP2A mediate their effects by phosphoregulation, but phosphoprotein targets in which RAS and PP2A activities converge in human cancers have not been systematically analyzed. Here, based on mass spectrometry phosphoproteome data, we discover that phosphosites co-regulated by RAS and PP2A are enriched on proteins involved in epigenetic gene regulation. As examples, RAS and PP2A co-regulate the same phosphorylation sites on HDAC1/2, KDM1A, MTA1/2, RNF168 and TP53BP1. Mechanistically, we validate co-regulation of NuRD chromatin repressor complex by RAS and PP2A. Consistent with their known synergistic effects in cancer, RAS activation and PP2A inhibition resulted in epigenetic reporter de-repression and activation of oncogenic transcription. Notably, transcriptional de-repression by PP2A inhibition was associated with increased euchromatin and decrease in global DNA methylation. In RAS-driven cancers, PP2A activity is inhibited by nuclear PP2A inhibitor proteins PME-1 and SET. We further demonstrate that these PP2A inhibitors drive oncogenic transcription, but that their transcriptional targets are highly diversified. Whereas PME-1 controls RAS and MYC-driven transcription, SET controls TP53 targets and G2/M checkpoint genes. We further provide evidence that these nuclear PP2A inhibitors significantly differ in their roles in regulating DNA methylation. Collectively the results indicate that epigenetic protein complexes involved in oncogenic gene expression constitute a significant point of convergence for RAS hyperactivity and PP2A inhibition in cancer. Further, the results provide a rich source for future understanding of phosphorylation as a previously unappreciated layer of regulation of epigenetic gene regulation in cancer, and in other RAS/PP2A-regulated cellular processes.

Citation Format: Mukund Sharma, Anna Aakula, Francesco Tabaro, Henrik Honkanen, Jesse Kamila, Matthieu Schapira, Cheryl Arrowsmith, Matti Nykter, Jukka K. Westermarck. RAS and PP2A activities converge on phosphoregulation of epigenetic complexes in cancer. [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 4727.
Abstract 4772: β3-adrenoceptor minimize doxorubicin effect in Ewing sarcoma by UCP2 activation
Authors: Masi Claudia , Pasha Amada , Carrozzo Francesco , Rosati Martina , Pini Alessandro , Calvani Maura , Favre Claudio
Published: April 2023

The phenomenon of “Oxygen Paradox” arises when reactive oxygen species (ROS) overcome the cellular anti-oxidant defense system through either an escalation in ROS levels or a reduced capability of the cells to increase an antioxidant response. The deregulated redox signaling that stimulate an uncontrolled ROS increase, could induce both tumor initiation and progression, and cell death after chemotherapy treatment. In recent decades, the therapeutic choice for Ewing Sarcomas (ES) consisting of a multi-drug chemotherapy regimen combined with radiotherapy and surgery, has significantly improved the survival up to 70% in localized diseases. ES patients, often show resistance to multi chemotherapeutic agents since ES cells exhibit a high sensitivity to rapid changes in intracellular redox environment. In this context, an antioxidant-inhibiting strategy was evaluated in vitro to test chemotherapeutic efficacy used in the standard treatment of ES such as the anthracycline doxorubicin (DOX) that increases ROS generation and oxidative stress (OS) in mitochondria. DOX is a strong exogenous ROS generator but lacks target specificity thereby it also affects normal cells resulting in several side-effects. Literature shows that DOX ability to reduce tumor progression is due to a DOX-induced ROS overproduction that occurs in mitochondria, known to be the main site of constant ROS production, and this effect is mediated by the mitochondrial NADPH oxidase (NADPHox) activity. To investigate why DOX causes resistance in ES patients, experiments in vitro were conducted with A673 ES cell line. A673 cells express a high level of the β3-adrenergic receptor (β3-AR) and are high susceptible to OS. Recently, β3-AR has become highly attractive in cancer biology for its ability to reduce tumor growth, metastasis, and its antioxidant properties as main regulator of the cellular response to OS. β3-AR working as ROS sensor control the redox state of the cells, driving them to life or death through mitochondria bioenergetics function. In our experimental setting DOX induced β3-AR expression which influenced the uncoupling protein 2 (UCP2) expression. β3-AR/UCP2 axis strongly decreased the mitochondrial activity by reducing ATP synthesis and mitochondrial ROS content and this effect was reverted by β3-AR antagonist, SR59230A. In summary, the DOX chemotherapy promotes β3-AR expression that decreases ROS levels through β3-AR/UCP2 axis. Decreased ROS levels allow ES cells to survive chemotherapy.

Citation Format: Claudia Masi, Amada Pasha, Francesco Carrozzo, Martina Rosati, Alessandro Pini, Maura Calvani, Claudio Favre. β3-adrenoceptor minimize doxorubicin effect in Ewing sarcoma by UCP2 activation. [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 4772.
Abstract 4773: DEAD Box 1 (DDX1) protects its RNA targets in cells exposed to oxidative stress
Authors: Garg Mansi , Godbout Roseline
Published: April 2023

DEAD box 1 (DDX1) belongs to the family of RNA helicases involved in all aspects of RNA metabolism, from transcription to transport, expression, and decay. DDX1 is overexpressed in a subset of retinoblastoma, neuroblastoma, and breast cancers. In breast cancer, the overexpression and cytoplasmic localization of DDX1 is correlated with poor prognosis. Cancer cells often exhibit high metabolic rates which can lead to genomic instability, oxidative stress, and endoplasmic stress. DDX1 is known to play a role in resolving genotoxic stress by participating in DNA double-strand break (DSB) repair. We propose that DDX1 also plays a key role as a stress response regulator in cells undergoing oxidative stress. When cells are exposed to oxidative stress, DDX1 is recruited to cytoplasmic stress granules (SGs). Although the exact function of SGs remains elusive, it is generally believed that tightly controlled SG assembly and disassembly are important for cell survival under stress. We found that while DDX1 is dispensable for SG assembly, depletion of DDX1 leads to impaired SG disassembly and hence, delayed stress recovery. Thus, DDX1 may play a role in stress resolution after the removal of stress conditions. To further understand the role of DDX1 in stress resolution, we performed RNA-immunoprecipitation followed by next-generation sequencing and identified DDX1-bound RNAs under normal and oxidative stress conditions. We found enhanced binding of DDX1 to its RNA targets in the presence of oxidative stress. Furthermore, we observed that DDX1 protects its target RNAs from degradation in the cytoplasm of cells undergoing oxidative stress. This RNA protection after stress exposure was more prominent in DDX1-overexpressing neuroblastoma cells, possibly explaining the faster stress recovery observed in these cells. Taken together, our results suggest that DDX1 plays a role in protecting cells from oxidative stress. This study may shed light on our understanding of cancer cell resistance to anticancer therapies.

Citation Format: Mansi Garg, Roseline Godbout. DEAD Box 1 (DDX1) protects its RNA targets in cells exposed to oxidative stress. [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 4773.
Abstract 4797: β3-AR blockade induces differentiation of malignant leukemia T cells in mature T lymphocytes
Authors: Carrozzo Francesco , Bruno Gennaro , Masi Claudia , Boaretto Alessia , Favre Claudio , Calvani Maura
Published: April 2023

Acute lymphoblastic leukemia (ALL) is a genetically heterogeneous cancer that arises from diverse genetic alterations during early lymphocyte development. About 10-15% of T-cell acute lymphoblastic leukemia (T-ALL) cases occur in childhood; despite having an event-free survival (EFS) rate of 85%, relapse is the main problem of this type of cancer. Mitochondria metabolic reprogramming plays a crucial role in the development of lymphocytes both in physiological and pathological processes such as differentiation and neoplastic transformation respectively. Mitochondria are the main actors of cellular homeostasis. They use glycolysis products exploiting them in the Krebs cycle and in oxidative phosphorylation to produce energy and plays key roles in reactive oxygen species (ROS) generation, Ca2+ signaling, cell death induction, and cellular differentiation. In particular, the increase of ROS is important to reduce tumor cell viability and at the same time is involved in induction of hematopoiesis. β3-adrenoreceptors (β3-Ars) is a class of receptors associated with pro-tumoral signaling in different tumors. In this study, we first have observed the expression of β3-Ars in leukemia T cells and then we studied how the modulation of this receptors affected tumor-related pathways. The treatment with an antagonist of β3-Ars (SR59230A) induced an increase of ROS leading to lymphoblastic cells differentiation, decrease of proliferation and enhanced induction of apoptosis signaling. Overall, these results suggest that β3-Ars could be a possible target for treatment of T-ALL.

Citation Format: Francesco Carrozzo, Gennaro Bruno, Claudia Masi, Alessia Boaretto, Claudio Favre, Maura Calvani. β3-AR blockade induces differentiation of malignant leukemia T cells in mature T lymphocytes. [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 4797.
Abstract 4807: BACH1 proline hydroxylation regulates the hypoxia response and metastasis in triple negative breast cancer
Authors: Nguyen Long Chi , Dann Christopher , Yang Dongbo , Shi Emily , Li Thomas , Wynne Joseph , Stock Letícia , Henn Madeline , Qiao Zeyu , Valdespino Andrea , Watson Raven , Liu Wenchao , Robinson-Mailman Lydia , Khramtsova Galina , Matsumoto Mitsuyo , Moellering Raymond , Olopade Olufunmilayo I. , Igarashi Kazuhiko , Rosner Marsha R.
Published: April 2023

Hypoxia is an important hallmark of aggressive solid tumors. Here we show that the pro-metastatic BTB and CNC homology 1 (BACH1) transcription factor is prolyl-hydroxylated by the HIF Prolyl Hydroxylase 1 (PHD1) in an oxygen-dependent manner. Using mass spectrometry, we identified two major prolyl hydroxylation sites in BACH1 and demonstrate that prolyl hydroxylation increased protein turnover in normoxia. Notably, a clinically relevant BACH1 mutant (BACH1M) resistant to hydroxylation displays enhanced BACH1 DNA binding capacity. Triple-negative breast cancer (TNBC) cells expressing BACH1M showed higher invasion in vitro and increased metastasis in vivo. Loss of BACH1 reduced the cellular transcriptional hypoxic response. Under hypoxia, BACH1 increases chromatin accessibility and gene expression through chromatin remodeling involving direct BACH1 binding and indirect epigenetic regulation. These results indicate that hypoxia stabilizes and enhances the pro-metastatic transcriptional activity of BACH1 through loss of prolyl hydoxylation in TNBC. Our findings identify BACH1 as an oxygen sensitive effector of the hypoxia response and a clinically relevant target for attenuating hypoxia induced, pro-metastatic signaling and therapeutic resistance in cancers.

Citation Format: Long Chi Nguyen, Christopher Dann, Dongbo Yang, Emily Shi, Thomas Li, Joseph Wynne, Letícia Stock, Madeline Henn, Zeyu Qiao, Andrea Valdespino, Raven Watson, Wenchao Liu, Lydia Robinson-Mailman, Galina Khramtsova, Mitsuyo Matsumoto, Raymond Moellering, Olufunmilayo I. Olopade, Kazuhiko Igarashi, Marsha R. Rosner. BACH1 proline hydroxylation regulates the hypoxia response and metastasis in triple negative breast cancer. [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 4807.
Abstract 4864: ALK inhibitors downregulate the expression of death receptor 4 in ALK-mutant NSCLC cells via facilitating Fra-1 and c-Jun degradation and subsequent AP-1 suppression
Authors: Zhao Wen , Yu Danlei , Zhai Yifan , Sun Shi-Yong
Published: April 2023

The successful treatment of patients with advanced non-small cell lung cancer (NSCLC) harboring chromosomal rearrangements of anaplastic lymphoma kinase (ALK) with ALK tyrosine kinase inhibitors (ALK-TKIs) represents a promising targeted therapy. As a result, various ALK-TKIs have been rapidly developed, some of which were already approved while some are being tested in clinical trials. Death receptor 4 (DR4; also called TNFRSF10A or TRAIL-R1) is a cell surface protein, which is supposed to function as a pro-apoptotic protein that transduces TRAIL death signal to trigger apoptosis. Its expression is positively regulated by MEK/ERK signaling and thus can be downregulated by MEK/ERK inhibition. This study thus focused on determining the effects of AKL inhibition on DR4 expression and the underlying mechanisms. ALK-TKIs such as brigatinib and alectinib effectively and preferentially inhibited AKT/mTOR as well as MEK/ERK signaling and decreased cell survival in ALK-mutant (ALKm) NSCLC cells with induction of apoptosis. This was also true to DR4 downregulation, which occurred even at 2 h post treatment. These ALK-TKIs did not affect DR4 protein stability, rather potently decreased DR4 mRNA expression. In parallel, they promoted degradation and decreased the levels of Fra-1 and c-Jun, two critical components of AP-1, and suppressed AP-1 (Fra-1/c-Jun)-dependent transcription/expression of DR4. Hence, it appears that ALK-TKIs downregulate DR4 expression in ALKm NSCLC cells via facilitating Fra-1 and c-Jun degradation and subsequent AP-1 suppression. Our findings thus warrant further investigation on elucidating the biological significance of DR4 downregulation in ALK-targeted cancer therapy.

Citation Format: Wen Zhao, Danlei Yu, Yifan Zhai, Shi-Yong Sun. ALK inhibitors downregulate the expression of death receptor 4 in ALK-mutant NSCLC cells via facilitating Fra-1 and c-Jun degradation and subsequent AP-1 suppression. [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 4864.
Abstract 4865: Mechanisms of EGFR inhibitor sensitivity and resistance in chordoma
Authors: Punturi Nindo , Dolat Lee , Levy Joan , Sommer Josh , Freed Daniel M.
Published: April 2023

Target discovery studies have identified EGFR inhibition as a promising therapeutic strategy in chordoma, motivating ongoing clinical trials. Yet EGFR is not mutated in chordoma, leaving the mechanisms associated with EGFR inhibitor (EGFRi) sensitivity and resistance unclear. In this study, we profiled a panel of over 10 chordoma cell lines to categorize their sensitivity to afatinib, a second-generation EGFRi with potency against the wild-type receptor. Several cell lines, including U-CHCF365, UM-Chor1, MUG-Chor1, and U-CH1, were highly sensitive to afatinib in cell viability assays, with absolute IC50 values below 50 nanomolar. In contrast, other chordoma cell lines, including UM-Chor5C and U-CHCF359B, exhibited limited response to EGFRi at concentrations exceeding 1 micromolar. Among sensitive cell lines, we found that afatinib promoted cell death in some cases (e.g., U-CH1) whereas in others it induced a profound cell cycle arrest. Moreover, in U-CH1 cells, acute afatinib treatment enriched a population of drug-tolerant persister cells with a fusiform morphology, potentially indicative of an epithelial-mesenchymal transition. Ongoing studies are focused on understanding the mechanisms of afatinib-induced cell death, drug tolerance, and acquired resistance, with a view to designing rational combination strategies capable of enhancing the magnitude and duration of therapeutic response. In cell lines with matched xenograft models, in vitro responses to afatinib were consistent in vivo. In a panel of 12 chordoma patient-derived xenograft (PDX) models treated with afatinib or cetuximab, differential sensitivity to EGFRi was recapitulated - with EGFRi promoting complete or negligent tumor growth inhibition in sensitive or resistant models, respectively. Finally, we combined drug sensitivity profiling of chordoma cell lines and PDXs with whole-exome and whole-transcriptome sequencing to identify genomic and transcriptomic features associated with sensitivity and resistance to EGFRi in chordoma. Collectively, our data identify a striking degree of differential sensitivity to EGFRi in chordoma, and begin to shed light on factors associated with primary and acquired resistance. These results provide a framework for guiding patient selection and identifying potential combination therapy regimens to improve EGFRi efficacy and address resistance.

Citation Format: Nindo Punturi, Lee Dolat, Joan Levy, Josh Sommer, Daniel M. Freed. Mechanisms of EGFR inhibitor sensitivity and resistance in chordoma. [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 4865.
Abstract 4909: Molecular analysis of small cell lung cancer provides insights into mechanism of action underlying the novel drug combination of lurbinectedin and TIC10/ONC201
Authors: Uruchurtu Ashley Sanchez Sevilla , Liguori Nicholas , Zhang Leiqing , Huntington Kelsey , Zhou Lanlan , Lee Young , Abbas Abbas E. , Azzoli Christopher G. , El-Deiry Wafik S.
Published: April 2023

We previously explored the combination of novel imipridone TIC10/ONC201 and small molecule RNA polymerase inhibitor lurbinectedin as a potentially effective treatment regimen for small cell lung cancer (SCLC). Data from cell viability experiments demonstrated synergistic killing of SCLC cells with minimal death of healthy control cells. Analysis of intracellular proteins via Western blot indicated that combinatorial treatment induces the integrated stress response, DNA damage/cell cycle checkpoint responses, and increased apoptosis of tumor cells. We have utilized the Luminex 200 platform to perform analyses of cytokine levels in SCLC cell lines with various genetic alterations before and after ONC201 and lurbinectedin treatment. Our results revealed significant changes in cytokine levels following treatment indicating potential immunomodulatory and angioregulatory effects of ONC201 and lurbinectedin. CCL3, known to recruit and activate granulocytes, was found to be elevated by treatment with lurbinectedin, ONC201 and combination versus control. Angiopoietin 1, which contributes to blood vessel maturation, and angiopoietin 2, which promotes neovascularisation, were elevated by all drug treatments in H1882 SCLC cells. Our ongoing studies are further analysing the importance of specific cytokines in tumor vascularity and in recruitment and killing of SCLC cells by immune cells. Results from these experiments are helping to elucidate the molecular mechanisms underlying SCLC, its immune landscape, and treatment response.

Citation Format: Ashley Sanchez Sevilla Uruchurtu, Nicholas Liguori, Leiqing Zhang, Kelsey Huntington, Lanlan Zhou, Young Lee, Abbas E. Abbas, Christopher G. Azzoli, Wafik S. El-Deiry. Molecular analysis of small cell lung cancer provides insights into mechanism of action underlying the novel drug combination of lurbinectedin and TIC10/ONC201. [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 4909.
Abstract 4929: ICX-101, a novel MYC inhibitor, shows antitumor activity in patient-derived cells of advanced lung cancer with high MYC expression
Authors: Choi Wonyoung , Jeong Kyung-Chae , Park Seog-Yun , Kim Sunshin , Kang Eun Hye , Hwang Mihwa , Han Ji-Youn
Published: April 2023

Background: MYC is an attractive therapeutic target in lung cancer. ICX-101 is a novel potent, selective small molecule that directly inhibits the binding of MYC/MAX dimers to the DNA binding sequence E-box. Here, we show that ICX-101 shows antitumor activity in patient-derived cells (PDC) of advanced lung cancer and that the drug responses are correlated with the MYC expression levels.

Methods: PDCs of lung cancer were treated with ICX-101, and the area under the dose-response curve (AUC) was measured as the readout for antitumor efficacy. MYC expression level of each PDC was measured with the fold expression of mRNA compared to the normal lung tissue. The patient’s clinical data and survival outcomes were analyzed to correlate with the drug responses of PDCs.

Results: We collected 100 PDCs from 82 lung cancer patients. The histologic types included adenocarcinoma (N = 82), squamous cell carcinoma (N = 10), non-small cell lung cancer (NSCLC) not otherwise specified (NOS) (N = 4), and small cell lung cancer (SCLC, N = 4). PDCs derived from SCLC showed higher MYC expression levels than NSCLC (P = 0.004). MYC was a prognostic factor, as the patient groups with the top and bottom 25 percentiles of MYC mRNA expression had an overall survival of 932.5 and 256 days, respectively (P = 0.029). However, MYC expression was predictive for the response to ICX-101, as the PDCs with the top 25 percentiles of MYC levels showed markedly lower AUC values than those with the bottom 25 percentile (P < 0.001). Additionally, the MYC mRNA levels and AUC values were inversely correlated with statistical significance (R = -0.46, P < 0.001).

Conclusion: ICX-101 is a potent MYC inhibitor that shows antitumor activity in lung cancer PDCs. Our results suggest the potential of ICX-101 as a possible therapeutic option in advanced lung cancer with high MYC expressions.

Citation Format: Wonyoung Choi, Kyung-Chae Jeong, Seog-Yun Park, Sunshin Kim, Eun Hye Kang, Mihwa Hwang, Ji-Youn Han. ICX-101, a novel MYC inhibitor, shows antitumor activity in patient-derived cells of advanced lung cancer with high MYC expression. [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 4929.
Abstract 494: BPI-452080: A potent and selective HIF-2α inhibitor for the treatment of clear cell renal cell carcinoma, von Hippel-Lindau disease, and other solid tumors
Authors: Wang Pingping , Yang Rongwen , Sun Yun , Ju Xuepeng , Zhao Jiayu , Liu Yanju , Liu Xiaoyun , Zou Zhengyao , Ren Jialin , Wang Min , Chen Haibo , Yi Xuegang , Zhang Jian , Ma Teng , Cheng Gaoliang , Liu Lijia , Guo Jing , Liu Xiangyong , Lan Hong , Ding Lieming , Wang Jiabing
Published: April 2023

The most observed alteration in clear cell renal cell carcinoma (ccRCC) is the inactivation of the tumor suppressor von Hippel-Lindau (VHL) E3 ligase due to genetic predisposition, somatic mutations, or methylation. Loss of VHL can lead to hypoxia-inducible factor 2α (HIF-2α) accumulation and elevated expression of HIF target genes, such as VEGFA, many of which facilitate angiogenesis, proliferation, and metastasis of ccRCC. Therefore, inhibiting HIF-2α has become a new strategy for the treatment of ccRCC. Here, we present the discovery of BPI-452080, a selective small molecule HIF-2α inhibitor. In VHL defective ccRCC cell lines, BPI-452080 potently and selectively blocked the heterodimerization of HIF-2α with HIF-1β, but not that of HIF-1α with HIF-1β. It inhibited the downstream hypoxia-responsive gene transcription and VEGFA protein secretion. In multiple xenograft mouse models, oral administration of BPI-452080 significantly inhibited tumor growth in a dose-dependent manner. BPI-452080 demonstrated good PK/PD correlation in the 786-O xenograft model after a single dosing, as shown by a concentration-dependent inhibition of VEGFA secretion in plasma and a reduction of the mRNA levels of VEGFA, CXCR4, CCND1, and GLUT1 genes in tumor tissue. Moreover, BPI-452080 exhibited good bioavailability in multiple pre-clinical species, favorable ADME properties, and good tolerance in toxicology studies. In conclusion, BPI-452080 is a potent, selective, and orally bioavailable HIF-2α inhibitor which presents a novel therapeutic option for ccRCC, von Hippel-Lindau disease, and other solid tumors. BPI-452080 is planned to enter Phase I clinical trial in China in early 2023.

Citation Format: Pingping Wang, Rongwen Yang, Yun Sun, Xuepeng Ju, Jiayu Zhao, Yanju Liu, Xiaoyun Liu, Zhengyao Zou, Jialin Ren, Min Wang, Haibo Chen, Xuegang Yi, Jian Zhang, Teng Ma, Gaoliang Cheng, Lijia Liu, Jing Guo, Xiangyong Liu, Hong Lan, Lieming Ding, Jiabing Wang. BPI-452080: A potent and selective HIF-2α inhibitor for the treatment of clear cell renal cell carcinoma, von Hippel-Lindau disease, and other solid tumors [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 494.
Abstract 4946: TOS-358, a first-in-class covalent PI3Kα inhibitor, demonstrates superior efficacy and does not induce significant hyperglycemia at efficacious doses in multiple animal models
Authors: MacDougall John R. , Bradley John , Mak Raymond , Dhawan Neil , Chen Wei
Published: April 2023

PI3Kα is frequently mutated in a variety of cancer types, and the PI3K-AKT signaling axis also plays a role in insulin signaling and glucose homeostasis. TOS-358 is a highly selective first-in-class covalent inhibitor of PI3Kα and is currently in clinical development in multiple solid malignancies. Interestingly, TOS-358 potently and specifically inhibits PI3Kα deeply and durably, but does not induce significant hyperglycemia in a variety of animal models. TOS-358 has consistently demonstrated superior efficacy comparing to reversible PI3Kα inhibitors (ATP-competitive and Allosteric) across 30+ different PDX and CDX mutant PI3Kα dependent cancer models. Detailed metabolic studies also revealed TOS-358 does not induce significant hyperglycemia effects in mice, rats and dogs at efficacious doses, which mirrors previous finding that show that PI3Kα knockout does not induce significant hyperglycemia. Furthermore, we elucidate that previous reversible PI3Kα inhibitors lead to dramatic hyperglycemia due to their potent inhibition of multiple PI3K isoforms at effective concentrations of the molecules in a cellular setting. This data reveals that highly specific and potent covalent inhibition of PI3Kα leads to dramatically superior efficacy and an improved safety profile.

Citation Format: John R. MacDougall, John Bradley, Raymond Mak, Neil Dhawan, Wei Chen. TOS-358, a first-in-class covalent PI3Kα inhibitor, demonstrates superior efficacy and does not induce significant hyperglycemia at efficacious doses in multiple animal models. [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 4946.
Abstract 4979: Evaluation of heme inhibitory therapy in combination with radiation of lung cancer
Authors: Salamat Narges , Wang Tianyuan , Berisha Eranda , Castro Maria Del Carmen Chacon , Ashrafi Adnin , Saha Debabrata , Mason Ralph P. , Liu Li , Zhang Li
Published: April 2023

Lung cancer is the leading cause of cancer-related death in the United States, with a 5-year survival rate of less than 25%. While most lung cancer patients receive radiation therapy, radioresistance severely impacts treatment outcomes. Thus, development of therapeutics to potentiate durable response to radiation therapy may be key to improving treatment outcomes. Research in our lab has previously implicated heme, a central biosynthetic molecule with important functions in diverse molecular and cellular processes, in lung cancer development and progression. To target heme, we designed heme-sequestering protein 2 (HeSP2) which displays potent anti-tumor activity in mouse tumor models. By decreasing tumor metabolic demand through heme sequestration, HeSP2 can significantly alleviate tumor hypoxia, a dominant radioresistance mechanism. Tumor hypoxia correlates with poor clinical outcomes by acting via multiple mechanisms such as inhibiting radiation-induced DNA damage and inducing the HIF-1 pathway that leads to antioxidant generation. Here, our preliminary data show that HeSP2 potentiates the antitumor efficacy of ionizing radiation. To see the effect of HeSP2 in combination with radiotherapy, in summary we subcutaneously implanted A549-luc, NSCLC cell lines with mutation in Kras and KLB1 in SCID mice. After 1-2 weeks mice were treated with saline (Control), HeSP2(25 mg/kg, i.v, twice a week), radiation (5 Gray, once per week at week 2 and 3), and HeSP2 combined with radiation (25 mg/kg, i.v, twice a week plus 5 Gray, once per week at week 2 and 3. Tumor tissues were harvested, processed and paraffin embedded for immunohistochemistry (IHC). Preliminary results indicate HeSP2 in combination with radiation reduce the levels of multiple angiogenic markers and vascular markers as well as microvessel density. These results indicate that heme sequestration in combination with radiation can be an effective strategy for suppressing lung tumors.

Citation Format: Narges Salamat, Tianyuan Wang, Eranda Berisha, Maria Del Carmen Chacon Castro, Adnin Ashrafi, Debabrata Saha, Ralph P. Mason, Li Liu, Li Zhang. Evaluation of heme inhibitory therapy in combination with radiation of lung cancer. [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 4979.
Abstract 4984: Integrated platform enables KRAS-targeted drugs discovery
Authors: Liu Beibei , Li an , Zuo Xiangyang , Yang Jie , Wang Ruifeng , Fan Feifei , Shi Wenting , Gu Qingyang
Published: April 2023

The Kirsten rat sarcoma viral oncogene homolog (KRAS) is mutated in approximately 25% of all human cancers and is known to be a major player promoting and maintaining tumorigenesis through the RAS-MAPK pathway. Activating mutations in KRAS increase the ability for GTP-loading, making it difficult to displace, thus constitutively activate downstream MAPK pathway and promote cancer formation. Fortunately, a revolutionary strategy to use covalent allosteric inhibitors that target a shallow pocket on the KRAS surface has provided new impetus for KRAS inhibitor development efforts. These inhibitors, such as AMG510 and MRTX849, show promising results in patients with tumors harboring KRAS G12C mutation. While the approval of AMG510 was a major breakthrough for those patients harboring KRAS G12C mutations, G12C only accounts for a fraction of those with KRAS mutations and eventual resistance to G12C inhibitors is unavoidable. Therefore, develop new drugs direct various KRAS mutants and combination strategies that target resistance mechanisms have become vital in the war against KRAS-mutant tumors.

To enable the discovery of novel KRAS inhibitors, we established a one-stop service platform, covering affinity detection of compounds to KRAS mutants, KRAS upstream and downstream protein-protein interaction detection, pathway activation detection, cell proliferation assay (2D/3D culture system), and in vivo efficacy evaluation in KRAS mutant xenograft models. Our platform provides assays on nearly all the current mainstream mutants of KRAS, such as G12C/G12D/G12R/G12S/G13D, and engineered Ba/F3 cell lines that harboring single or double KRAS mutation. In addition, we developed a panel of resistant models to KRAS G12C inhibitor that bringing a better understanding of the biological basis of drug resistance, and will serve as a new tool to optimize KRAS-G12C inhibitor regimens and combinatorial strategies. The comprehensive KRAS-targeted drug discovery platform is empowering new drug research and development.

Citation Format: Beibei Liu, an Li, Xiangyang Zuo, Jie Yang, Ruifeng Wang, Feifei Fan, Wenting Shi, Qingyang Gu. Integrated platform enables KRAS-targeted drugs discovery. [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 4984.
Abstract 4993: Development of abbapolin inhibitors of the PLK1 PBD as potential therapeutics for prostate and other challenging cancers
Authors: Stafford Jessy , Chapagai Danda , Merhej George , Pressley Justin , Nageswara-Rao Chintada , Wyatt Michael , Mcinnes Campbell
Published: April 2023

Polo-like kinase 1 (PLK1) has a plethora of roles within the cell of which mitotic regulation is the best characterized. This kinase is overexpressed and upregulated in cancer cells, making it an attractive target for therapeutics. Drug discovery efforts have mainly focused on the ATP binding site however have met with little clinical success to date. Targeting substrate recognition and subcellular localization through the Polo-Box domain represents an attractive alternative to generating PLK1 specific compounds and to avoid the tumor suppressor functions of PLK3. REplacement with Partial Ligand Alternatives through Computational Enrichment, REPLACE, is validated strategy used to convert peptide inhibitors of protein-protein interactions into more drug like compounds. Through the use of this methodology, we have discovered promising non-ATP competitive inhibitors based on a 2-(4-AlkylBenzamido) Benzoic Acid (ABBA) pharmacophore which bind to the polo-box domain of PLK1. These compounds, designated as abbapolins, engage PLK1 as evidenced by their ability to block phosphorylation of TCTP, a key substrate of PLK1, induce PLK1 degradation and are potently anti-proliferative in prostate cancer cell lines. Based on these observations, lead compounds were investigated further for their pharmacokinetic properties and in vivo efficacy and key compounds showed development potential based upon preliminary results. To further investigate their potential in other tumors, selected abbapolins were tested against the NCI-60 tumor cell panel and other cancers with poor prognosis. Results indicate that neuroblastoma, lung, colorectal and certain leukemias are the most sensitive cell lines and thus provide impetus to investigate the abbapolins for difficult to treat and resistant tumors. We present the further optimization of the abbapolins to determine their structure-activity relationship and identify compounds with novel structures and improved drug-like properties. This includes their ability to engage PLK1 and anti-proliferative activities against selected cell lines that represent therapeutically challenging cancers. Furthermore, these compounds serve as chemical biology probes to elucidate roles of the PBD in conformationally regulating PLK1 activity, through in vitro experiments and specifically in the abbapolin sensitive cell lines.

Citation Format: Jessy Stafford, Danda Chapagai, George Merhej, Justin Pressley, Chintada Nageswara-Rao, Michael Wyatt, Campbell Mcinnes. Development of abbapolin inhibitors of the PLK1 PBD as potential therapeutics for prostate and other challenging cancers. [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 4993.
Abstract 5004: DDR-targeting small molecule inhibitor as a novel therapeutic for treating pancreatic ductal adenocarcinoma
Authors: Do Trong Phat , Khan Sajid , Zhou Daohong , Hart Matthew , McHardy Stanton , Rao Manjeet
Published: April 2023

Background: Pancreatic ductal adenocarcinoma (PDAC) is the second most significant cause of cancer-related mortality, with a 5-year survival rate of just 11%. PDACs are one of the most difficult to treat cancers, mainly because of the desmoplastic tumor microenvironment enriched with tumor-supportive extracellular matrix (ECM) and stromal cells. Unfortunately, the efficacies of current pancreatic cancer therapies are limited partly by stroma-mediated drug resistance. We reason that Discoidin Domain Receptors, which belong to the receptor tyrosine kinase family and bind to fibrillar collagens present in the ECM, may be a critical promoter of PDAC growth and progression. Though several drugs targeting DDR proteins have been developed, no inhibitors specific to DDR proteins have been developed. Moreover, those drugs have not been approved for treating PDACs.

Methods. A high throughput screen using small molecule inhibitors was performed to identify bonafide inhibitors of DDR proteins. Structural and reported-based essays were done to determine the specificity. Functional assays were performed to test the potency of the candidate inhibitors. Mechanistic studies were done using RNA-seq, real-time PCR, and western blot.

Results: Using an unbiased screening approach, we identified inhibitors that specifically target DDR proteins. Our studies revealed that small molecule inhibitors blocked the short and long-term viability as well as migration/invasion of PDAC cells. In addition, they induced apoptosis and halted the cell cycle at the G1-S checkpoint. Mechanistic studies revealed that the pro-growth signaling cascade was significantly inhibited.

Conclusions: Our results showing specific DDR inhibitors blocking the growth and progression of PDAC cells without affecting the viability of normal cells suggest that these inhibitors may serve as a safe and potent regimen for treating pancreatic cancers.

Citation Format: Trong Phat Do, Sajid Khan, Daohong Zhou, Matthew Hart, Stanton McHardy, Manjeet Rao. DDR-targeting small molecule inhibitor as a novel therapeutic for treating pancreatic ductal adenocarcinoma. [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 5004.
Abstract 501: Discovery of BPI-460372, a potent and selective inhibitor of TEAD for the treatment of solid tumors harboring Hippo pathway aberrations
Authors: Shen Hongling , Xu Xiaofeng , Rong Hongfei , Song Xizhen , Gao Jinheng , Chen Jie , Zhu Di , Zhao Xiangdong , Tong Jun , Zou Zhengyao , Liu Xiaoyun , Guo Jin , Xu Yan , Li Yabin , Liu Xiangyong , Chen Hong , Zhao Jiayu , Liu Yanju , Ju Xuepeng , Chen Haibo , Lan Hong , Ding Lieming , Wang Jiabing
Published: April 2023

The Hippo signaling pathway is critical for the regulation of organ development, tissue homeostasis, and tumorigenesis by controlling the activation status of yes-associated protein (YAP) or its homolog PDZ-binding motif (TAZ). As a major downstream effector, the transcription factor TEAD is activated by forming a complex with YAP/TAZ. Hippo pathway aberrations, such as NF2-deficiency or LATS1/2 mutations leading to hyperactivation of YAP/TAZ and subsequent activation of TEAD, have been reported in many cancers, including mesothelioma, meningioma, soft tissue sarcoma and non-small cell lung cancer. Inhibiting TEAD auto-palmitoylation by directly blocking the palmitoylation pocket of TEAD is a potential therapeutic approach for cancer treatment. Here we present BPI-460372, a novel small molecule that directly blocks the TEAD auto-palmitoylation. BPI-460372 covalently and irreversibly binds to the cysteine residue in the TEAD palmitoylation pocket, preventing TEAD palmitoylation and inhibiting its biological function. BPI-460372 significantly inhibits the expression of a TEAD-responsive element reporter, as well as the mRNA of downstream target genes such as CTGF and CYR61 in NF2-deficient cells. At the cellular level, BPI-460372 strongly inhibited the proliferation of tumor cells harboring Hippo pathway aberrations. BPI-460372 also significantly suppressed tumor growth in NF2-deficient or LATS1/2 mutation xenograft models. In addition, BPI-460372 exhibited excellent oral bioavailability, high exposure across multiple species, and adequate ADME properties. In conclusion, BPI-460372 is a potent and selective TEAD palmitoylation inhibitor for the treatment of solid tumors harboring Hippo pathway aberrations. It is planned to enter Phase I clinical trial in China in early 2023.

Citation Format: Hongling Shen, Xiaofeng Xu, Hongfei Rong, Xizhen Song, Jinheng Gao, Jie Chen, Di Zhu, Xiangdong Zhao, Jun Tong, Zhengyao Zou, Xiaoyun Liu, Jin Guo, Yan Xu, Yabin Li, Xiangyong Liu, Hong Chen, Jiayu Zhao, Yanju Liu, Xuepeng Ju, Haibo Chen, Hong Lan, Lieming Ding, Jiabing Wang. Discovery of BPI-460372, a potent and selective inhibitor of TEAD for the treatment of solid tumors harboring Hippo pathway aberrations [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 501.