bluuebunny/crossref_metadata_2025 huggingface dataset:
Abstract 3854: TNIK inhibition as a novel therapeutic in cMyc high/TTF1 low SCLC
Authors: Tanimoto Azusa , Cardnell Robert J. , Morris Benjamin B. , Ramkumar Kavya , Li Shen , Wang Qi , Stewart Allison C. , Gay Carl Michael , Wang Jing , Averett Byers Lauren
Published: June 2023

Background: Small cell lung cancer (SCLC) is a highly lethal malignancy, with rapidly acquired chemotherapy resistance. Some studies have reported that Wnt signaling pathway activation promoted cell proliferation and was correlated with chemo-resistance in SCLC. None of the therapies targeting Wnt pathway components of the transmembrane and the cytoplasm have been successful in a clinical application due to toxicity and insufficient efficacy. However, targeting Wnt signaling inside the nucleus has been drawing increasing attention as cancer therapeutics. TRAF2 and NCK-interacting protein kinase (TNIK), which interacts with downstream effectors, TCF4/β-catenin transcriptional complex, is an essential activator of Wnt target genes. TNIK is highly expressed in several cancers for cell proliferation, thus TNIK is expected as a novel druggable target. On the other hand, the question remains whether TNIK is a critical target in SCLC. We hypothesize that a TNIK inhibitor has potent anti-tumor effects in SCLC and its promising biomarkers exist.

Methods: We used 29 SCLC cell lines including all four subtypes defined by differential expression of transcription factors ASCL1, NEUROD1, POU2F3, and inflamed gene signature (SCLC-A, N, P, and I, respectively) to evaluate the effect of a TNIK inhibitor, NCB-0846 in vitro. We correlated NCB-0846 IC50 values with proteomic profiling (Reverse Phase Protein Array, RPPA) data. Protein expression was examined by western blotting.

Results: NCB-0846 markedly reduced cell proliferation in SCLC-N and P cell lines. There was a strong positive correlation between cMyc and the efficacy of NCB-0846 (r=-0.484, P<0.01), while a negative correlation between TTF1 and the efficacy (r=0.569, P<0.01). Additionally, NCB0846 decreased the expression of cMyc in cMyc-high/TTF-1 low SCLC cells.

Conclusions: These findings indicate that TNIK inhibitors may be a new personalized molecular-targeted therapy in cMyc-high/TTF-1-low SCLC.

Citation Format: Azusa Tanimoto, Robert J. Cardnell, Benjamin B. Morris, Kavya Ramkumar, Shen Li, Qi Wang, Allison C. Stewart, Carl Michael Gay, Jing Wang, Lauren Averett Byers. TNIK inhibition as a novel therapeutic in cMyc high/TTF1 low SCLC. [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 3854.
Abstract 4885: APR-246 cytotoxic effects are TP53 independent in endometrial cancer cell lines
Authors: Yu Camilla , Petty Aaron , Vargas Roberto
Published: June 2023

Background: The majority (80%) of endometrial cancer (EC) related mortality is due to high-grade tumor histology, which harbor high rates of TP53 mutations. APR-246 is a small-molecule drug designed to restore WT p53 signaling in TP53-mutant cancers and has yet to be explored in EC. We aimed to test the cytotoxic potential for APR-246 in EC and its downstream impact.

Methods: Using 3 parental EC cell lines with differing TP53 statuses, JHUEM2 (WT), Hec108 (hetero P151H), and Hec1B (R248Q), we generated dose-response curves for APR-246. Cells were treated for 24 hours and viability assessed with CellTiter-Glo after 9 days. To assess for mutation specific effect, we generated dose-response curves using a WT non-targeting control (NTC), CRISPR/Cas9 KO of TP53, and five KO cell lines complemented with 5 common TP53 mutations (R248Q, R248W, R273C, R273H, Y220C). Western blot analysis was performed to assess for p53, p21, PUMA, GADD45, and NOXA using whole-cell lysates, after treatment with 20μM of APR-246 for 24 hours. To further evaluate for a time-dependent effect, 2 representative variants (R248Q and R273C) after 6 and 24 hours of incubation with 50μM APR-246 and 10μM of Nutlin-3.

Results: APR-246 demonstrated a negative, dose-dependent effect on cell viability in all EC cell lines. IC50s for JHUEM2, Hec108, and Hec1B were 2.5μM, 4.3μM, and 4.5μM respectively. For NTC, the IC50 was (1.7μM), while TP53-KO (7.5μM) demonstrated similar IC50 values to the variants (6.5-11.9μM). Two variants (Y220C and R248W), had significantly (<0.001 and <0.01 respectively) higher IC50 values (11.9 and 9.1 μM respectively). In Western blot analysis, no p53 downstream signaling via p21, GADD45, PUMA, and NOXA was observed for any variants.

Conclusions: Our results demonstrate that APR-246's cytotoxic effects in EC seem to be p53-independent. Potential mechanisms for the anti-neoplastic effects of APR-246 include activity targeting antioxidant pathways demonstrated in other solid tumors and provides an area for further investigation in TP53mut EC.

Citation Format: Camilla Yu, Aaron Petty, Roberto Vargas. APR-246 cytotoxic effects are TP53 independent in endometrial cancer cell lines. [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 4885.
Abstract 5280: O-GlcNAcylation of progesterone receptor promotes mammary tumorigenesis
Authors: Saunders Harmony Ivanna , Holloran Sean M. , Trinca Gloria , Slawson Chad , Hagan Christy
Published: June 2023

The role of hormone receptors in breast cancer has been well established as a key contributor to breast cancer tumorigenesis. Estrogen receptor and progesterone receptors are present in nearly 70% of breast cancers. The role of estrogen receptor and estrogens in breast cancer has been extensively studied and targeted effectively through endocrine therapy, however the impact of progesterone and the progesterone receptor (PR) independent of estrogen is not well understood. We have previously demonstrated that PR promotes tumor growth and drives an immune suppressive environment, therefore understanding the biology of PR in breast cancer is critical. We have also demonstrated that PR attenuates type 1 interferon signaling via inhibition of STAT1 phosphorylation and increased degradation of STAT2. Post-translational modifications such as phosphorylation and SUMOylation can influence PR target gene promoter selectivity thereby altering its function. Our recent work indicates PR is modified by O-GlcNAc, a single N-acetyl-glucosamine sugar that cycles on and off and serine or threonine amino acids in nuclear, cytoplasmic and mitochondrial proteins. Levels of total O-GlcNAc staining are higher in breast cancer tissue compared to adjacent normal tissue. Active O-GlcNAcylation, as evidenced by immunohistochemistry staining of O-GlcNAc-transferase (OGT), is elevated in patients with PR+ tumors compared to PR-. Using T47D breast cancer cells (an ER/PR-positive tumor line), mass spectrometry analysis revealed an O-GlcNAc site at S499 on PR. We then used a naturally occurring PR-negative variant of T47D cells to introduce stable expression of a mutant PR with serine to alanine substitution at the O-GlcNAc site (S499A), thereby blocking O-GlcNAc flux, in addition to wt PR as a control. RNA-Seq analysis of these cells following treatment with progesterone revealed several significant differential gene expression patterns, including rescue of PR dependent interferon signaling attenuation. T47D-mutant PR cell lines implanted into immune deficient mice had significantly decreased growth as compared to WT-PR control tumors. In syngeneic mice harboring PR-positive and PR-negative tumors, loss of O-GlcNAc flux and increased O-GlcNac levels increased tumor growth only when tumors were expressing PR, corroborating the influence of O-GlcNAc in immunodeficient mice. Together these findings indicate O-GlcNAcylation of PR is potentially a mechanism of PR driven breast cancer tumorigenesis and immune evasion.

Citation Format: Harmony Ivanna Saunders, Sean M. Holloran, Gloria Trinca, Chad Slawson, Christy Hagan. O-GlcNAcylation of progesterone receptor promotes mammary tumorigenesis. [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 5280.
Abstract 5288: Single-cell multiomics reveal divergent transcriptional and epigenetic cell states in breast cancer
Authors: Ors Aysegul , Mohammed Hisham , Doe Aaron R. , Haverlack Syber , Handu Mithila , Mulqueen Ryan
Published: June 2023

Over the recent years, single-cell sequencing studies have been used to better describe the highly heterogeneous nature of breast cancers on transcriptional and genetic levels. It is also known that breast cancers are highly driven by estrogen receptor alpha (ER), a transcription factor that’s important for mammary tissue homeostasis. However, little is known about how estrogen signaling heterogeneity affects cancer progression and response to anti-estrogen therapy at a single-cell level. Leveraging single-omic and multi-omic single-cell sequencing technologies, we tracked estrogen response in breast cancer cell and organoid models. We developed TITAN, a topic-modeling based analysis tool to reveal signaling gradients in single-cell RNA-seq data. With this approach we showed that distinct cells prioritize distinct gene groups in response to estrogen. We defined two of these gene networks to be driven by either ER or FOXM1. These same networks exist not only in all the models used in the study but also in breast cancer patient datasets. FOXM1 is activated in estrogen treated cells and the FOXM1 driven gene signature correlates with more aggressive types of disease. Our combined scRNA and scATAC-seq experiments also highlighted distinct chromatin accessibility states associated with either cell group. Using scNMT-seq in patient samples we were able to describe DNA methylation and chromatin accessibility influence on hormone signaling patterns at the single-cell level. Together, our results provide insights into defining transcriptional and epigenetic cell states in ER positive breast cancer.

Citation Format: Aysegul Ors, Hisham Mohammed, Aaron R. Doe, Syber Haverlack, Mithila Handu, Ryan Mulqueen. Single-cell multiomics reveal divergent transcriptional and epigenetic cell states in 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 5288.
Abstract 5292: Characterization of androgen receptor properties and interactome in mediating transcriptional condensates in prostate cancer
Authors: Pinette Nicholas C. , Massah Shabnam , Kochkina Sofia , Zhang Fan , Biswas Maitree , Lee Joseph , Gsponer Jörg , Lallous Nada
Published: June 2023

In The United States of America 1 in 8 men will develop prostate cancer (PCa) in their lifetime. The assembly of phase-separated condensates containing players of the transcriptional machinery such as transcription factors, coactivators (e.g. MED1), and RNA polymerase II enhances the transcription of key oncogenes in various cancer including PCa. Many proteins undergoing phase-separation possess intrinsically disordered regions (IDR) that mediate multivalent intra- and inter-molecular interactions, essential for condensate formation. We recently demonstrated that full-length AR, the main oncogenic driver in PCa, is more prone to form nuclear transcriptional condensates upon androgen stimulation in PCa models than in benign epithelial prostate models. In this study, we investigated the effects of mutating or truncating key residues or regions involved in AR transcriptional activity on its ability to form nuclear condensates in LNCaP cells as visualized by confocal microscopy. We also used various bioinformatics tools to predict additional AR residues and sequences with high propensity for phase-separation. We thus made various truncations and mutations and evaluated their ability to form condensates in LNCaP cells. We also tested the effect MED1 phosphorylation and treatment with various inhibitors targeting different domains of the AR on the ability of full-length protein to form droplets in vitro. We hope by better understanding what drive AR condensates formation in PCa, to elucidate this new mechanism of transcriptional regulation and to identify new therapeutic avenues for patients with advanced forms of the disease.

Citation Format: Nicholas C. Pinette, Shabnam Massah, Sofia Kochkina, Fan Zhang, Maitree Biswas, Joseph Lee, Jörg Gsponer, Nada Lallous. Characterization of androgen receptor properties and interactome in mediating transcriptional condensates in prostate 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 5292.
Abstract 539: Furin predicts prognosis and promotes PTC progression and metastasis via MEK-ERK axis
Authors: Poyil Pratheeshkumar , Siraj Abdul K. , Padmaja Divya , Parvathareddy Sandeep Kumar , Diaz Roxanne , Thangavel Saravanan , Begum Rafia , Haqawi Wael , Alobaisi Khadija , Al-Mohanna Falah Hassan , Al-Sobhi Saif S. , Al-Dayel Fouad , Al-Kuraya Khawla S.
Published: June 2023

Furin belongs to the proprotein convertase family and its expression has been documented in various types of cancers, but its role in Thyroid cancer remains unclear. We investigated the expression of Furin in a large cohort of middle eastern PTC patient’s samples and explored its functional role and mechanism in PTC cell line in vitro and in vivo. Furin overexpression was observed in 44.6% of all PTC cases and it was significantly associated with aggressive clinicopathological parameters and poor outcome. We show that inactivation of Furin suppresses tumor growth, proliferation, migration, invasion, spheroid growth and progression of EMT in BRAF mutant cells, whereas its overexpression in BRAF wild-type PTC cell lines reversed the effect. Mechanistically, Furin inactivation caused MEK/ERK pathway suppression in BRAF mutant cells, while inhibition of MEK has no effect on Furin expression which suggest Furin is a functional upstream of MEK/ERK Pathway. Furthermore, study revealed the synergistic antitumor effect of Furin depletion and MEK inhibitor. These results indicate that Furin is an important prognostic marker and its inhibition can be a potential therapeutic target for aggressive PTC.

Citation Format: Pratheeshkumar Poyil, Abdul K. Siraj, Divya Padmaja, Sandeep Kumar Parvathareddy, Roxanne Diaz, Saravanan Thangavel, Rafia Begum, Wael Haqawi, Khadija Alobaisi, Falah Hassan Al-Mohanna, Saif S. Al-Sobhi, Fouad Al-Dayel, Khawla S. Al-Kuraya. Furin predicts prognosis and promotes PTC progression and metastasis via MEK-ERK axis [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 539.
Abstract 5526: State-of-the-art biobanking of gastroesophageal adenocarcinoma samples: Integrating non-viable biospecimens with 3D and 2D cell models and their characterization, validation, and utilization of cell models for precision oncology
Authors: Kong Mingyang Iris , Pal Sanjima , Berube Julie , Bourdeau France , Giannias Betty , Bertos Nicholas , Sangwan Veena , Ferri Lorenzo
Published: June 2023

Traditionally, biobanking platforms have collected and stored non-viable biological specimens such as serum, plasma, and fresh-frozen or formalin-fixed paraffin-embedded (FFPE) tissues. These constitute key resources for clinical and contemporary genomics, transcriptomics, and proteomics studies. However, such specimens cannot be used for studies involving drug testing, high throughput target validation, and implementation for personalized medicine. Next-generation biobanking strategies rectify this issue by combining the collection of non-viable samples from patients with the propagation of viable tissue fractions as in vitro 2D and 3D cell models or in vivo xenograft models. Such cutting-edge biobanking strategies enable downstream cell-based high-throughput functional assays promoting the discovery of therapeutic targets or assessing treatment responses and resistance to treatment. Here, we provide comprehensive details of our establishment of a state-of-the-art biobanking platform for gastroesophageal adenocarcinoma (GEA) samples (n=389). Our approach opens new directions for understanding disease biology and conducting translational cancer studies. Patient-derived 2D cells (n=376), organoids (PDOs) (n=185), and xenografts (PDXs) (n= 99) included in our pipeline retain crucial features of the original human tumors, serving as valuable tools for clinical and experimental analyses in the context of precision oncology. We also discuss the entire approach of next-generation biobanking and emphasize the importance of integrating the propagation of PDOs and PDXs simultaneously. In addition, we explain each protocol optimized to propagate patient tissue-derived cell models. We validate that these models recapitulate tissue heterogeneity and are relevant preclinical models. Taken together, we described each approach used to develop one of the largest next-level biobanks for GEA.

Citation Format: Mingyang Iris Kong, Sanjima Pal, Julie Berube, France Bourdeau, Betty Giannias, Nicholas Bertos, Veena Sangwan, Lorenzo Ferri. State-of-the-art biobanking of gastroesophageal adenocarcinoma samples: Integrating non-viable biospecimens with 3D and 2D cell models and their characterization, validation, and utilization of cell models for precision oncology. [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 5526.
Abstract 5562: Prevalence and prognostic significance of malnutrition in patients with brain metastasis
Authors: Liu Zheran , Zhang Yu , Pei Yiyan , He Yan , Yu Jiayi , Zhang Renjie , Wang Jingjing , Chong Weelic , Hai Yang , Peng Xingchen , Fang Fang
Published: June 2023

Background: Malnutrition is a severe but modifiable risk factor for cancers. However, the relationship between malnutrition and the survival of patients with brain metastases has not been fully revealed. We aimed to evaluate the prevalence of malnutrition and assess its prognostic value on patients with brain metastases.

Method: We retrospectively recruited 2633 patients with brain metastases between January 2014 and September 2020. Three malnutrition scores were used to evaluate patients' malnutrition status at their first admission, including controlling nutritional status (CONUT), the nutritional risk index (NRI), and the prognostic nutritional index (PNI). The association between malnutrition and overall survival was estimated.

Results: A total of 1984 (75.4%) of patients were assessed as any degree malnourished and 963 (36.6%) of patients were assessed as moderate to severe malnutrition by at least one malnutrition score. The three malnutrition scores were associated with each other and with BMI. Malnutrition assessed by any of the three scores was significantly associated with poor overall survival (adjust hazard ratio [HR] and 95% confidence interval [CI] for CONUT: 1.12 [1.10-1.16]; for NRI: 0.97 [0.97-0.98]; for PNI: 0.96 [0.95-0.97], all p values <0.001). Furthermore, malnutrition was a better indicator than BMI, and adding malnutrition to the Graded Prognostic Assessment scoring system could significantly improve the accuracy of prognosis prediction.

Conclusion: Malnutrition was prevalent in patients with brain metastases and was significantly associated with overall survival. Malnutrition monitoring on patients' first admission could improve the survival prediction ability for brain metastasis.

Citation Format: Zheran Liu, Yu Zhang, Yiyan Pei, Yan He, Jiayi Yu, Renjie Zhang, Jingjing Wang, Weelic Chong, Yang Hai, Xingchen Peng, Fang Fang. Prevalence and prognostic significance of malnutrition in patients with brain metastasis. [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 5562.
Abstract 5564: SerpinE2: A potential biomarker for urological cancers
Authors: Kovanen Ruusu-Maaria , Koskinen Netta , Lehto Timo-Pekka , Rannikko Antti , Mirtti Tuomas , Koistinen Hannu
Published: June 2023

SerpinE2, also known as protease nexin-1, is an extracellular serine protease inhibitor modulating the activity of serine proteases such as thrombin, plasmin, urokinase-type plasminogen activator and trypsin. Dysregulation between extracellular serine proteases and their cognate inhibitors has been implicated in malignant progression, making serpins promising biomarkers for tumor progression and prognosis. SerpinE2 is upregulated in many cancers and promotes tumor invasion and metastasis. In this study, we analyzed serpinE2 expression by immunohistochemistry on tissue microarrays comprising of samples from prostate, bladder and kidney cancers. The studied samples were clinically hard-to-risk stratify and thus relevant for biomarker studies. We aimed to study the association of serpinE2 expression with survival and clinicopathological features in all three cancers, and evaluate its potential as an immunohistochemical biomarker. In the case of bladder cancer, association of serpinE2 expression with response to neoadjuvant chemotherapy was also assessed. We found that although the strong expression of serpinE2 was related to more aggressive prostate cancers (p = 0.017) and high grade bladder cancers (p = 0.034), it was not associated with relapse, treatment response or survival of prostate and bladder cancer patients. In renal cancer, on the contrary, serpinE2 expression was significantly lower in patients with tumor relapse (p = 0.048) and high expression predicted favorable disease-specific survival (p = 0.013). Our findings help understanding the functional role of serpinE2 in cancer progression and guide the prognostic biomarker research of serpinE2, particularly for prediction of renal cancer-specific survival.

Citation Format: Ruusu-Maaria Kovanen, Netta Koskinen, Timo-Pekka Lehto, Antti Rannikko, Tuomas Mirtti, Hannu Koistinen. SerpinE2: A potential biomarker for urological 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 5564.
Abstract 6264: NUV-868, a novel BD2-selective BET inhibitor, in combination with enzalutamide or olaparib, inhibits growth of solid tumor xenografts
Authors: Patel Hitisha , Hertzog Jennifer , Heller Laura , Vootukuri Spandana , Zhang Yan , Miller Chris , Hattersley Gary
Published: June 2023

The bromodomain and extraterminal domain (BET) family of proteins play a vital role in gene transcription, making it an attractive therapeutic target for cancer. BET inhibitors can also combine with many anticancer agents to enhance activity. The bromodomains of the BET protein, BD1 and BD2, have unique functions and inhibiting either domain can result in differential responses. To date, non-selective BET inhibitors have failed during early clinical development due to significant on-target toxicity and limited benefit; however, selectively targeting specific bromodomains may result in a more favorable benefit/risk profile. NUV-868 is a novel and highly selective BD2 inhibitor of the BET protein family with ~1500-fold selectivity for BRD4-BD2 relative to BRD4-BD1. Herein, we describe NUV-868 and its activity in multiple in vitro and in vivo solid tumor models. Target engagement, selectivity of bromodomain inhibition, and regulation of BET-mediated gene expression were examined. Additionally, the antitumor activity of NUV-868 in combination with enzalutamide or olaparib was studied in tumor xenograft models of prostate, breast, and pancreatic cancer. NUV-868 demonstrated high selectivity for BD2 and regulated expression of several BET target genes. NUV-868 in combination with enzalutamide inhibited growth of several prostate cancer cell line- and patient-derived xenografts. NUV-868 in combination with olaparib inhibited tumor growth in models of breast, ovarian and pancreatic cancer. Our preclinical data demonstrate that NUV-868, a BD2-selective BET inhibitor, inhibits growth of tumor xenografts in combination with enzalutamide or olaparib and provides rationale for examination of these combinations in the clinic. An ongoing, phase 1 clinical study (NCT05252390) is evaluating NUV-868 as a monotherapy and in combination with olaparib or enzalutamide in patients with advanced solid tumors.

Citation Format: Hitisha Patel, Jennifer Hertzog, Laura Heller, Spandana Vootukuri, Yan Zhang, Chris Miller, Gary Hattersley. NUV-868, a novel BD2-selective BET inhibitor, in combination with enzalutamide or olaparib, inhibits growth of solid tumor xenografts [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 6264.
Abstract 6290: Characterizing antitumor responses to EXS-74539, a novel, reversible LSD1 inhibitor with potential in small-cell lung cancer
Authors: Payne Andrew , Naik Manisha , Richards Simon , Perez Victor Sebastian , Dominguez Maria
Published: June 2023

Background: Lysine demethylase 1 (LSD1) is a potentially important target in oncology due to its role in demethylating histones and suppressing expression of genes required for cellular differentiation. In small-cell lung cancer (SCLC), high LSD1 expression is associated with suppressed differentiation pathways. Although selective LSD1 compounds are in clinical development, understanding of the molecular markers of tumor sensitivity to inhibition of LSD1 inhibition is incomplete. Methods: We report on the pharmacological characterization of EXS-74539, a potent, selective and reversible LSD1 inhibitor. We assessed EXS-74539 efficacy in in vitro and in vivo SCLC cell line models, encompassing the four molecular subtypes of SCLC tumor cells previously proposed (Rudin et al, 2019), based on differential expression of key transcription regulators, ASCL1, NEUROD1, POU2F3 and YAP1. Results: In vitro, EXS-74539 demonstrated similar anti-proliferative activity against both neuroendocrine (NCI-H1417 and NCI-H69, ASCL1 sub-type) and non-neuroendocrine (NCI-H526: POU2F3) SCLC cell lines, with IC50 values of 28, 12 and 11 nM, respectively. In vitro exposure of these cell lines to EXS-74539 led to concentration-dependent alterations in differentiation-associated genes. However, in vivo, significant differences in antitumor growth response upon LSD1 inhibition were observed between the cell lines; NCI-H69 tumor growth was unaffected following treatment with EXS-74539 and an irreversible LSD1 inhibitor at dose regimens which were efficacious in the NCI-H1417 and NCI-H5126 models. We describe in vitro and in vivo gene expression correlations associated with LSD1 sensitivity. Conclusions: The reversible LSD1 inhibitor, EXS-74539, is a potent inhibitor of SCLC cell line proliferation and shows in vivo efficacy. Characterizing SCLC cell line sensitivity in vitro and in vivo identified gene signatures that may have use as markers of sensitivity, which we are currently characterizing and validating in human SCLC patient samples. Rudin et al., Nat Rev Cancer, 2019

Citation Format: Andrew Payne, Manisha Naik, Simon Richards, Victor Sebastian Perez, Maria Dominguez. Characterizing antitumor responses to EXS-74539, a novel, reversible LSD1 inhibitor with potential in small-cell 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 6290.
Abstract 6309: Anti-tumor efficacy of SI-B001, a novel EGFR × HER3 bispecific antibody, against EGFR-driven epithelial tumors alone or in combination with paclitaxel and carboplatin
Authors: Renshaw Blair , Khalili Jahan Salar , Xiao Sa , Zhu Yi
Published: June 2023

EGFR is a member of the human epidermal growth factor receptor (ErbB) family with tyrosine kinase activity. Evidence indicates that EGFR is involved in the pathogenesis and progression of human carcinoma of different types. HER3 is a unique pseudokinase receptor of the ErbB family and known to mediate resistance to EGFR-targeting therapies. Therefore, we created SI-B001, an EGFR × HER3 bispecific antibody, which can bind EGFR × EGFR homodimers and EGFR × HER3 heterodimer to block their downstream pathways. We performed non-clinical studies to investigate in vitro and in vivo anti-tumor effects.

In vitro, the inhibition of tumor cell growth by SI-B001 was stronger than cetuximab and duligotuzumab in FaDu (mRNA expression levels of EGFRhigh/HER3high/NRG1medium). Importantly, testing with the cell line Oka-c-1 (mRNA expression levels of EGFRhigh/HER3high/NRG1low), showed that NRG1 supplementation did not change the potency of cetuximab. However, SI-B001 showed much stronger potency than cetuximab and duligotuzumab under conditions of NRG1 supplementation. This result indicates that the functionality of the bi-specific SI-B001 is competitive against a HER3 natural ligand and capable to act against cancer with HER3 ligand mediated resistance to cetuximab.

In vivo, single agent SI-B001 exhibited superior anti-tumor activity to cetuximab in the FaDu xenograft model. Meanwhile, SI-B001 in combination with paclitaxel and carboplatin led to a significant synergistic antitumor effect, which was stronger than the combination of cetuximab + paclitaxel + carboplatin. Compared to chemotherapy alone in this model, which could result in weight loss and treatment related mortality, no serious weight loss or deaths occurred in the single agent SI-B001 and the combination of SI-B001 with chemotherapy.

These results suggest that SI-B001 alone and in combination with chemotherapy can exhibit favorable safety and robust anti-tumor activity. Currently, 6 phase II clinical trials of SI-B001, either alone or in combination with chemotherapy, have been conducted in different epithelial carcinomas. These studies have shown a potential break-through activity in NSCLC and HNSCC with a very good safety profile.

Citation Format: Blair Renshaw, Jahan Salar Khalili, Sa Xiao, Yi Zhu. Anti-tumor efficacy of SI-B001, a novel EGFR × HER3 bispecific antibody, against EGFR-driven epithelial tumors alone or in combination with paclitaxel and carboplatin. [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 6309.
Abstract 6332: A humanized anti-cd40 antibody with anti-tumor pharmacological activity and cynomolgus monkey safety
Authors: Li Zhenyu , Zhao Lili , Zhang Guimin , Li Bin , Liu Zhong , Li Guangyan , Zhu Zhongsong
Published: June 2023

LNF1901 is a humanized CD40 agonistic antibody. LNF1901 can bind to CD40 protein of human(EC50=23.6ng/mL) and monkey(EC50=23.5ng/mL), but cannot bind to CD40 protein of rat and mouse. LNF1901 had strong activation effect on DC cells(EC50=0.04ug/mL) and had strong ADCC and CDC effects. AT a dose of 20mg/kg, the TGITW of LNF1901 was 59.9% in Female NPG mice were inoculated with Raji/CIK/DC subcutaneous transplanted tumor model. Following intravenous infusion of LNF1901 at doses of 6, 30, or 150 mg/kg to cynomolgus monkeys weekly for 4 weeks, the highest non-severely toxic dose (HNSTD) was considered to be 150 mg/kg.LNF1901 had demonstrated manageable safety and promising antitumor activity in vivo and in vitro tests.

Citation Format: Zhenyu Li, Lili Zhao, Guimin Zhang, Bin Li, Zhong Liu, Guangyan Li, Zhongsong Zhu. A humanized anti-cd40 antibody with anti-tumor pharmacological activity and cynomolgus monkey safety [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 6332.
Abstract 6360: In vivo antitumor efficacy evaluation of ASC63, an oral small molecule PD-L1 inhibitor, in a humanized mouse tumor model
Authors: Wu Jinzi J. , He Handan
Published: June 2023

Background: ASC63 is an oral small molecule programmed cell death-ligand 1 (PD-L1) inhibitor. After oral dosing, ASC63 is rapidly absorbed and converted to its pharmacologically active metabolite ASC63-A in vivo. In vitro studies showed that ASC63-A could activate PD-L1 dimerization and internalization from cell membrane, thus interfere PD-1/PD-L1 interaction and enhance T-cell activation. Here we report the in vivo antitumor efficacy of ASC63 in a humanized mouse tumor model.

Methods: 0.5×106 human PD-L1 knock in CT26 cells (CT26-hPD−L1) were implanted subcutaneously into BALB/c mice for tumor development. When the average tumor volume reached approximately 100 mm3, mice were randomly assigned (post-grouping, PG) and treated with vehicle, reference drug (10 mg/kg Atezolizumab intravenous injection twice a week [BIW]), 50 or 100 mg/kg ASC63 oral dosing twice a day (BID) for 18 days. Body weights and tumor volumes were measured regularly, and tumor growth inhibitions (TGI) of different groups were compared. TGI was calculated using the formula: TGI (%) =[1-(TRTV-1)/(CRTV-1)] ×100, where TRTV= mean relative tumor volume (RTV) of treatment group; CRTV= mean of control group.

Results: At PG-D18, the tumor volume of vehicle group reached 1548 mm3, and Atezolizumab, 50 and 100 mg/kg AS63 groups showed TGI values of 35.17, 17.12 and 36.87%, respectively. Atezolizumab 10 mg/kg BIW and ASC63 100 mg/kg BID produced similar antitumor activities. One mouse in 100 mg/kg ASC63 group had body weight loss more than 10% at PG-D6, and was back to normal at PG-D9 after extra nutrition was provided, while the rest of mice showed a gradually increase in body weight during the study. No significant difference of body weight or body weight change was found among different groups of mice.

Conclusion: Results of this study show that ASC63 is in general well tolerated in CT26-hPD−L1 humanized mouse tumor model, and ASC63 has comparable antitumor efficacy as the FDA-approved PD-L1 antibody, Atezolizumab. ASC63 is an oral small molecule PD-L1 inhibitor, and thus will have better patient compliance than injective PD-1/PD-L1 antibody. Results of this study support the continued investigation of ASC63.

Citation Format: Jinzi J. Wu, Handan He. In vivo antitumor efficacy evaluation of ASC63, an oral small molecule PD-L1 inhibitor, in a humanized mouse tumor model [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 6360.
Abstract 6361: A preclinical model of acquired anti-PD-1 resistance is responsive to SEA-TGT, an effector-function enhanced anti-TIGIT monoclonal antibody
Authors: Gruber David R. , Zeng Weiping , Thurman Bob , O'Connor Brian P. , Gardai Shyra J. , Smith Alyson J.
Published: June 2023

Immune checkpoint inhibitors, including monoclonal antibodies targeting the PD-1/PD-L1 axis, induce robust antitumor immunity in a subset of patients with various cancers. Despite continued success of these therapies, some patients experience limited efficacy owing to clinically complex and unresolved mechanisms of primary and acquired immunotherapy resistance. To begin to understand the mechanisms of acquired resistance to anti-PD-1 blockade, we developed a syngeneic murine CT26 colorectal tumor model that is resistant to anti-PD-1 therapy. To achieve this, CT26 tumors were subjected to successive rounds of increasing levels of anti-PD-1 therapy. When tumors grew out, they were cultured in vitro and then re-implanted and re-treated for three rounds until PD-1 resistance was achieved. To characterize the underlying drivers of acquired resistance across the generation of the model, wild type and anti-PD-1 resistant tumors and cultured cell lines were evaluated by flow cytometric immunophenotyping and RNA-sequencing analysis. To assess how observed changes in the tumor microenvironment impact response to various therapeutics, the resistant tumors were treated with anti-PD-1 therapy or SEA-TGT, a nonfucosylated anti-TIGIT mAb with enhanced Fc-function that drives activity through multiple modes of action. As expected, treatment with anti-PD-1 monotherapy was ineffective, however, treatment with SEA-TGT demonstrated potent anti-tumor activity. These data are consistent with responsiveness to anti-TIGIT agents in other in vivo models of PD-1 resistance and/or PD-1 refractory response, indicating that the factors driving resistance to anti-PD-1 therapy can be different than those driving response to other known checkpoint molecules such as TIGIT. Thus, investigational agents such as SEA-TGT may have the potential to be efficacious in tumors that are primary or secondarily resistant to anti-PD-1 therapy. We have initiated a phase 1 study (NCT04254107) evaluating the safety, tolerability, and activity of SEA-TGT monotherapy and in combination with anti-PD-1 therapy in patients with advanced malignancies.

Citation Format: David R. Gruber, Weiping Zeng, Bob Thurman, Brian P. O'Connor, Shyra J. Gardai, Alyson J. Smith. A preclinical model of acquired anti-PD-1 resistance is responsive to SEA-TGT, an effector-function enhanced anti-TIGIT monoclonal antibody [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 6361.
Abstract 6450: Fatty acid intake as potential risk factor of colorectal cancer: A multicenter case control study in Iran
Authors: Seyyedsalehi Monireh Sadat , Boffetta Paolo , Zendehdel Kazem
Published: June 2023

A higher risk of colorectal cancer (CRC) has been associated with high animal fat intake, but not vegetable fat. To date, limited data provides the quantification of the effect exerted by fatty acids (FAs) on CRC overall and by anatomical sub-sites. This study aims to look at associations between some FAs intakes [cholesterol, total fat, total saturated fatty acids (SFAs), total monounsaturated fatty acids (MUFAs), total polyunsaturated fatty acids (PUFAs), total trans fatty acids (TFAs), oleic acid, myristic acid, total ruminant (rTFAs) and industrial fatty acids (iTFAs), eliadic acid (EA), conjugated linoleic acid (CLA), and CRC risk in a large case-control study (IROPICAN) in Iran . We analyzed 865 CRC cases (434 in colon, 404 in rectum, and 27 with unknown subsite) and 3,206 controls from seven provinces of Iran. Detailed information was collected by trained interviewers using validated lifestyle and food frequency questionnaires (FFQ). The different types of total and individual FAs intake were categorized into quartiles of intake. The odds ratios (OR) and 95% confidence intervals (CI) for the association between CRC them were calculated using multivariate logistic regression models by adjusting for the potential confounders. Furthermore, analyses were stratified by age (under and over 50) and also, we repeated the analyses for CRC subsites. There was a statistically significant positive association between CRC and high intake (quartile 4) compared to the low intake (quartile) of dietary total fat (OR=1.77, 95% CI=1.32-2.38), cholesterol (OR=1.58, 95% CI=1.22-2.05), total TFAs (OR=1.31, 95% CI=1.02-1.68), TFAs (OR=1.73, 95% CI=1.12-2.68), EA(OR=2.69, 95% CI=1.46-4.93), and SM (OR=1.45, 95% CI=1.00-2.09), as well as an inverse association with high intake of dietary rTFAs (OR=0.60, 95% CI=0.39-0.93), CLAs (OR=0.34, 95% CI=0.19- 0.60). Stratified analyses by age indicated that there was a statistically significant association between CRC and total fat intake [OR =1.30, 95% CI =1.16-1.46, p=0.006 for the interaction], cholesterol intake [OR =1.22, 95% CI=1.11-1.35, p=0.019 for the interaction], and iTFA intake [OR =1.31, 95% CI=1.06-1.62, p=0.02 for the interaction] after 50 years old. The results of our study indicate that decreasing fat consumption, particularly from industrial and animal sources, may reduce the risk of CRC.

Citation Format: Monireh Sadat Seyyedsalehi, Paolo Boffetta, Kazem Zendehdel. Fatty acid intake as potential risk factor of colorectal cancer: A multicenter case control study in Iran [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 6450.
Abstract 6633: T regulatory cell subsets in colorectal cancer: friends or foes
Authors: Elkord Eyad
Published: June 2023

T cells in the tumor microenvironment (TME) have diverse roles in anti-tumor immunity. Different T cell subsets may have opposing roles in tumor progression, especially in inflammatory cancers such as colorectal cancer (CRC). In different series of studies, we performed extensive characterization and critical analyses of T regulatory cell (Treg)-related markers and key inhibitory immune checkpoints (ICs) in CD4+ and CD8+ T cell subsets in the TME and periphery of CRC patients. We found a significant increase in levels of CD4+FoxP3+Helios+ T cells, which represent potentially highly immunosuppressive Tregs, in the TME. Additionally, tumor-infiltrating CD4+ T cells upregulated PD-1, CTLA-4, TIM-3 and LAG-3 immune checkpoints. CTLA-4, TIM-3, and LAG-3 were mainly co-expressed on FoxP3+Helios+ Tregs in the TME. Additionally, we found that FoxP3 expression and ICs including PD-1, CTLA-4, TIM-3, and LAG-3 were significantly upregulated in tumor-infiltrating CD8+ T cells. We then investigated associations between different tumor-infiltrating CD4+ and CD8+ T cell subpopulations and disease-free survival (DFS). Interestingly, a high frequency of circulating CD4+FoxP3+ Tregs was associated with poorer DFS, while higher frequency of these cells in the TME was associated with better DFS. Additionally, high frequencies of circulating CD4+FoxP3+Helios+ Tregs and tumor-infiltrating CD4+FoxP3-Helios- T cells were associated with poorer DFS. Moreover, a high frequency of CD4+FoxP3+Helios-PD-1+ Tregs in circulation was associated with worse DFS. In contrast, high frequencies of CD4+TIM-3+ T cells, FoxP3+Helios+TIM-3+ Tregs, and FoxP3-Helios+TIM-3+ CD4+ T cells in circulation were associated with longer DFS. Additionally, we found that high levels of certain circulating CD8+ T cell subsets (TIM-3+, FoxP3-Helios-TIM-3+ and FoxP3-Helios+TIM-3+ cells) were associated with longer DFS. In the TME, elevated levels of CD25+ and TIM-3+ CD8+ T cells, and FoxP3+Helios-TIM-3+ CD8+ Tregs were associated with better DFS. These data show that circulating and tumor-infiltrating immune checkpoint-expressing CD4+ and CD8+ Treg/T cell subsets play different roles in disease prognoses, and certain subsets could serve as independent predictive biomarkers in CRC patients.

Citation Format: Eyad Elkord. T regulatory cell subsets in colorectal cancer: friends or foes [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 6633.
Abstract 6634: Digital and spacial characterization of PD-L1 expression and IVD assay performance in the immune landscape of head and neck squamous cell carcinoma: A multimodal approach
Authors: Troccoli Clara , Matelski Lauren , Beharry Adam , Ly Vanessa , Wambaugh Morgan , Amen Melanie , Paces Will , Metcalf Geoffrey , Gianani Roberto , Turi Tom
Published: June 2023

The anti-PD-L1 antibody (22C3) is used as a companion diagnostic for successful checkpoint inhibitor therapy in head and neck squamous cell carcinoma. The positive predictive value of this assay, however, is less than ideal as a high PD-L1 score does not necessarily associate with a good response, and a good response may be seen with a low or negative PD-L1 score. In principle, this could be due to lack of accuracy and/or precision of the assay, as well as biological factors, such as variable expression across tumor cells and interacting immune cells. In this study, we describe a digital image analysis algorithm to address assay-related problems and improve both accuracy and precision, as well as improve identification of PD-L1 expression in differing cell populations of the tumor microenvironment. In addition, we propose a panel of assays that in aggregate might reveal inherent heterogeneity among cases with similar PD-L1 score and thus provide vital context underlying the efficacy of checkpoint inhibitors in the clinic. Here we show that applying novel machine-learning based digital image analysis to multiplex assays together with digital scoring of PD-L1 provides an accurate and precise assessment of the real-world tumor milieu that we hypothesize will help establish the immunophenotypes that inform therapeutic efficacy of checkpoint inhibitors. We have additionally interrogated whether expression of PD-L1 in these groups are consistent with known molecular patterns assayed using novel methodologies, such as high-plex digital spatial transcriptomics through the nanoString GeoMx Digital Spatial Profiler (DSP) platform and assessed the ability of the different digital platforms to provide concordant data relating to real-world expression patterns of PD-L1 and associated biomarkers. Thus, our results point to the importance of robust methodologies, used in combination, to evaluate complex tumor immune landscapes and the advantages of digital analyses to provide accurate and precise clinical contexts for better patient outcomes.

Citation Format: Clara Troccoli, Lauren Matelski, Adam Beharry, Vanessa Ly, Morgan Wambaugh, Melanie Amen, Will Paces, Geoffrey Metcalf, Roberto Gianani, Tom Turi. Digital and spacial characterization of PD-L1 expression and IVD assay performance in the immune landscape of head and neck squamous cell carcinoma: A multimodal approach [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 6634.