bluuebunny/crossref_metadata_2025 huggingface dataset:
Abstract 4067: RNA primed SMAR-TTMcells against multiple driver mutations, all HLA's, designed for first line therapy
Authors: Muzaffar Farzonai , Ryan David , Barry Walter , Abera Abenezer , Slanetz Alfred E.
Published: April 2023

Immune checkpoint inhibitors, such as anti-PD1 antibodies, have revolutionized cancer immunotherapy. Their success demonstrates that a patient’s own T cells recognize and treat cancer. However, anti-PD1 therapy is most effective in the treatment of cancers with high mutational burden, ~5% of all malignancies. Therefore, an alternative strategy is necessary to target cancer with lower mutational burden (the other ~95%). Importantly, the efficacy of PD-1 blockade is associated with the recruitment of new T cells from the blood rather than the activation of pre-existing tumor infiltrating lymphocytes (Yost K.E., et al. Nat. Med. 2019). Our approach is to use RNA to prime and expand T cells from the blood to cancer-specific mutations ex vivo. We can generate T cell populations reactive to as few as 8 and as many as 40 cancer-specific mutant proteins in a single production run. In vitro, these T cells have mutation-specific cytotoxicity and do not kill the normal cells. These T cells express homing receptors that allow them to infiltrate the tumor and express high levels of TNFα and IFNγ, both of which are associated with effective tumor cytotoxicity and pro-inflammatory modification of the tumor microenvironment (TME). The predominant immunophenotype of these cells is consistent with central and effector memory, CD4+ and CD8+ T cells, with almost no regulatory or exhausted T cells. We believe these T cells can be used as a cellular therapy in conjunction with, or as an alternative to, immune checkpoint inhibitors to treat lower mutational burden cancers that comprise most patients’ tumors.

Citation Format: Farzonai Muzaffar, David Ryan, Walter Barry, Abenezer Abera, Alfred E. Slanetz. RNA primed SMAR-TTMcells against multiple driver mutations, all HLA's, designed for first line therapy. [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 4067.
Abstract 4072: Class I HLA-independent lysis of immunotherapy-resistant melanoma by CD8 T cells
Authors: Xie Hongyan , Jiang Aiping , Jenney Anne , Sun Yi , Sharova Tatyana , Sade-Feldman Moshe , Revach Or-yam , Cicerchia Angelina , Rasmussen Martin Q. , Hacohen Nir , Manguso Robert T. , Jenkins Russell W.
Published: April 2023

Cancer immunotherapy with immune checkpoint blockade (ICB) has transformed the treatment of melanoma, although intrinsic or acquired resistance develops in nearly half of patients. Tumor-infiltrating CD8+ T lymphocytes (TILs) are key determinants of anti-tumor immunity in melanoma and other cancers, and single-cell RNA-sequencing has identified T cell states associated with improved clinical response to ICB, as well as adoptive T cell therapy (ACT). Despite these advances, strategies to identify and analyze tumor-reactive TILs in ICB-resistant patients remain limited. Here, we demonstrate that TILs from ICB-resistant melanoma patients can recognize and eliminate autologous tumor cells independent of class I HLA-TCR interactions. TILs eliminated matched melanoma cells in a time and dose-dependent fashion associated with secretion of effector cytokines. Strikingly, the deletion of B2M (resulting in loss of class I HLA surface expression) did not alter the activity of these TILs. Immunophenotyping studies confirmed that TILs are largely (>95%) effector memory (Tem) CD8 T cells (CD45RA-CD45RO+CCR7-) and give rise to terminal effector cells after co-culture with matched melanoma cells. Further, the elimination of melanoma cells by TILs required intact JAK1/2 signaling, although interferon-gamma (IFNγ) was neither necessary nor sufficient for tumor cell elimination. Together, these findings demonstrate that expanded TILs from ICB-resistant melanoma patients are capable of eliminating melanoma cells via a novel, class I MHC-independent mechanism.

Citation Format: Hongyan Xie, Aiping Jiang, Anne Jenney, Yi Sun, Tatyana Sharova, Moshe Sade-Feldman, Or-yam Revach, Angelina Cicerchia, Martin Q. Rasmussen, Nir Hacohen, Robert T. Manguso, Russell W. Jenkins. Class I HLA-independent lysis of immunotherapy-resistant melanoma by CD8 T cells. [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 4072.
Abstract 4122: TIL-containing patient-derived explant cultures reveal role of metformin on antigen presenting cell activation
Authors: Turpin Rita J. , Liu Ruixian , Munne Pauliina , Peura Aino , Rannikko Jenna , Philips Gino , Salmelin Natasha , Hurskainen Elina , Suleymanova Ilida , Mutka Minna , Meretoja Tuomo , Mattson Johanna , Mustjoki Satu , Saavalainen Päivi , Lambrechts Diether , Pouwels Jeroen , Hollmén Maija , Klefström Juha
Published: April 2023

Globally, breast cancer is among the most diagnosed cancer types for women. Current and upcoming breast cancer therapies are being investigated in combination with compounds that stimulate an immune response, but whether the therapeutic agents themselves have unexpected immunomodulatory effects is often overlooked. Here, we have developed a method to grow 3D cultures of intact fragments of patient-derived tissue (Patient-Derived Explant Cultures; PDECs) to assess the preclinical potential of studying human tumor cells and immune cells simultaneously ex vivo

Single cell sequencing, flow cytometry, gene expression profiling and cytokine profiling data show that the tumor immunocontexture is conserved in PDECs and that these resident immune cells respond to distinct immune stimulus

We performed gene expression profiling, flow cytometry, and cytokine profiling of drug-treated human explants and found that metformin has antitumor potential through the activation of antigen presenting cells. We further validated in vitro that metformin-mediated APC activation is largely through mitochondrial respiration inhibition irrespective of the presence of tumor cells. Our PDEC platform highlights the preclinical potential of ex vivo explants by simultaneously offering information of tumor and immune cell toxicity and mechanism.

Citation Format: Rita J. Turpin, Ruixian Liu, Pauliina Munne, Aino Peura, Jenna Rannikko, Gino Philips, Natasha Salmelin, Elina Hurskainen, Ilida Suleymanova, Minna Mutka, Tuomo Meretoja, Johanna Mattson, Satu Mustjoki, Päivi Saavalainen, Diether Lambrechts, Jeroen Pouwels, Maija Hollmén, Juha Klefström. TIL-containing patient-derived explant cultures reveal role of metformin on antigen presenting cell 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 4122.
Abstract 4127: ANV600 is a potent, Cis-signaling, non-alpha IL-2 agonist which efficiently expands intratumoral stem-like CD8 T cells
Authors: Murer Patrizia , Salazar Ulisse , Egli Nicole , Petersen Laetitia , Neubert Pia , Richter Kirsten , Stocker Christian , Rau Alexander , Katopodis Andreas , Huber Christoph
Published: April 2023

Non-alpha IL-2-based therapeutic modalities with preferential signaling through the IL-2 beta(CD122)/gamma(CD132) receptor are in clinical development and have the potential to substantially increase the therapeutic index of recombinant IL-2 (aldesleukin) for cancer therapy. ANV600 is a novel bispecific compound, which features an anti-IL-2 antibody/IL-2 fusion protein and a proprietary hPD-1 binding moiety for specific delivery of the non-alpha IL-2 to tumor antigen experienced PD-1+ T cells. Compared to the untargeted control, ANV600 has increased potency to induce STAT5 phosphorylation in human PD-1+CD8 T cells in vitro. At the same time, stimulation with ANV600 results in markedly reduced STAT5 phosphorylation on Treg cells compared to aldesleukin. In activated human PBMCs, ANV600 induces PD-1 co-internalization with the CD122-CD132 complex, reducing detectable PD-1 on CD8 and CD4 T-cells. Surface PD-1 levels decrease is not observed on cells incubated with untargeted bispecific compound. In transgenic human PD-1 mice ANV600 treatment leads to marked tumor growth retardation in the B16F10 and MC38 subcutaneous tumor models compared to untargeted compound and vehicle. Immunophenotyping of the tumor infiltrating lymphocytes revealed a dose-dependent increase of intratumoral stem-like PD-1+T cells and cytotoxic GrzB+PD-1+T cells in mice treated with ANV600. ANV600 has potent and selective effects on antigen-experienced CD8 T cells both in human PBMCs and mouse syngeneic tumor models. This agent may be a promising anti-tumor therapeutic against poorly immunogenic tumors and warrants further pharmaceutical development.

Citation Format: Patrizia Murer, Ulisse Salazar, Nicole Egli, Laetitia Petersen, Pia Neubert, Kirsten Richter, Christian Stocker, Alexander Rau, Andreas Katopodis, Christoph Huber. ANV600 is a potent, Cis-signaling, non-alpha IL-2 agonist which efficiently expands intratumoral stem-like CD8 T cells. [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 4127.
Abstract 4144: Characterization of immune cell phenotypes in patient derived malignant pleural effusion treated with thiostrepton
Authors: Messier Terri , Guerra Roxana Del Rio , Naumov George , Cunniff Brian
Published: April 2023

Tumor cells generate elevated levels of reactive oxygen species (ROS) and therefore exhibit increased expression, activity, and reliance on critical ROS scavenging pathways, including the mitochondrial peroxiredoxin 3 (PRX3) system. PRX3 is a critical reactive oxygen species (ROS) scavenging enzyme localized to the mitochondrial matrix. Our group has characterized the mechanism of action of the PRX3 inhibitor and pro-oxidant therapeutic thiostrepton (TS). TS covalently crosslinks the peroxidatic and resolving cysteines of PRX3, leading to increased levels of mitochondrial ROS, resulting in tumor cell death. We have characterized the cellular and chemical composition of malignant pleural effusion (MPE) from patients with advanced cancer and evaluated cellular responses to TS. TS targets PRX3 in both adherent tumor cells and in non-adherent immune cell populations in a dose-dependent manner. We further characterized MPE-infiltrated immune cells and cytokines released following TS-treatment. Together, these data provide the first evidence for the activity of TS in MPE and resulting changes to immune cell profiles. TS is the active pharmaceutical ingredient of RSO-021, a new covalent inhibitor of PRX3 currently being tested in the MITOPE phase 1/2 clinical trial in patients with malignant pleural effusion (MPE) due to advanced solid tumors or malignant mesothelioma (NCT05278975).

Citation Format: Terri Messier, Roxana Del Rio Guerra, George Naumov, Brian Cunniff. Characterization of immune cell phenotypes in patient derived malignant pleural effusion treated with thiostrepton. [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 4144.
Abstract 4151: Anti-CEACAM5 immune stimulant TLR7/8 agonist antibody drug conjugate is a potent myeloid cell activator for the treatment of CEACAM5-expressing tumors
Authors: Decary Stephanie , Blot Lydia , Lahoute Charlotte , Benoist Sandrine , Caron Anne , Graziano Francesca , Trombe Marc , Calvet Loreley , Ferrier Alexandra , Frederic Marc , Sidhu Sukhvinder , Brun Marie-Priscille , Chiron Marielle
Published: April 2023

Toll Like Receptor 7 and 8 (TLR7/8) agonists are a promising approach to treat tumors by harnessing the innate immune system to trigger anti-tumor innate and adaptive immunity. One of the main obstacles to the use of this class of low molecular weight molecules in cancer treatment is the toxicity associated with systemic immune activation after intravenous administration. We developed a novel immune stimulant ADC by conjugating the anti-CEACAM5 (carcinoembryonic antigen related cell adhesion molecule 5) tusamitamab antibody with a resiquimod (R848) TLR7/8 agonist payload. This tumor-targeted compound administered systemically and locally active, is expected to eradicate CEACAM5-positive (+) tumors by recruiting and activating immune cells in tumor microenvironment to promote anti-tumor immune response. Tusamitamab R848 ADC, evaluated in vitro, binds to CEACAM5+ tumor cells via its Fab moiety, and to myeloid cells via its Fc part at nanomolar (nM) concentrations. TLR7/8 pathway activation was evaluated on myeloid THP1 reporter cells. The conjugate elicits a potent and FcyR-dependent activity at low nM concentration. In co-culture of human blood cells and human CEACAM5+ gastric cancer cells, it was shown to induce phagocytosis activity, associated with increased activation/maturation of both monocytes and dendritic cells. Tusamitamab R848 ADC evaluated in vivo in CEACAM5+ pancreatic human tumor model, HPAFII, leads to robust antitumor activity with complete regressions (CR) after single administration at 5 mg/kg. In a pharmacodynamic study using lung tumor patient-derived xenograft mouse model, this ADC triggers murine cytokine inductions, innate immune cell enrollment at tumor site, and tumor necrosis in a dose-dependent manner. Based on preclinical in vitro and in vivo data, the tusamitamab R848 ADC is an innovative ADC approach with the potential to eradicate CEACAM5+ tumors in patients.

Citation Format: Stephanie Decary, Lydia Blot, Charlotte Lahoute, Sandrine Benoist, Anne Caron, Francesca Graziano, Marc Trombe, Loreley Calvet, Alexandra Ferrier, Marc Frederic, Sukhvinder Sidhu, Marie-Priscille Brun, Marielle Chiron. Anti-CEACAM5 immune stimulant TLR7/8 agonist antibody drug conjugate is a potent myeloid cell activator for the treatment of CEACAM5-expressing 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 4151.
Abstract 423: β-Escin eradicates cancer stem-like population in HER2-positive breast cancer with trastuzumab resistance
Authors: Park Soeun , Park Minsu , Ko Dongmi , Kim Seongjae , Seo Juyeon , Nam Kee Dal , Jung Eunsun , Kang Yong koo , Jang Seojin , Seock So Ra , Kim Yoon-Jae , Kim Ji Young , Seo Jae Hong , Park Jaeyoun
Published: April 2023

Purpose: Trastuzumab resistance is a multifactorial phenomenon arising from the steric effects of p95HER2, activation of HER2 downstream signaling pathways, and the existence of cancer stem cells. We sought to examine the capacity of β-escin, an anti-inflammatory drug, to address trastuzumab resistance in HER2-positive breast cancer cells.

Experimental designs: The effects of β-escin in trastuzumab-sensitive and -resistant cell lines were evaluated for apoptosis, HER2 expression, calpain activation and CSC-like properties. In vivo trastuzumab-resistant xenograft mice model was used to examine tumor growth, angiogenesis and organ toxicity of β-escin.

Results: β-escin induced mitochondrial-mediated apoptosis accompanied by reactive oxygen species (ROS) production and increased active p18Bax fragmentation, leading to caspase-3/-7 activation. β-escin downregulated p95HER2, HER2 and HER3 as well as their phosphorylation. β-escin-induced HER2 degradation appears to be mediated by calpain activation. We observed that treatment with β-escin induced cleavage of HER2 and p95HER2 (at 75, 50 and 42 kDa fragments) in HER2 overexpressing MDA-MB-231 cells. Attenuation of CSC-related features by β-escin challenge was accompanied by marked reductions in CD44high/CD24low stem-like cells and aldehyde dehydrogenase 1 (ALDH1) activity as well as hindrance of mammosphere formation. β-escin administration also significantly retarded tumor growth and angiogenesis in a trastuzumab-resistant JIMT-1 xenograft model via downregulation of CSC-associated markers and intracellular domain HER2. Importantly, β-escin selectively inhibited malignant cells and was less toxic to normal mammary cells, and no toxic effects were found in liver and kidney function in animals.

Conclusion: Herein, for the first time, we report the potent efficacy of β-escin, a drug repurposing candidate with an exceptional safety profile in addressing trastuzumab-resistant HER2-positive breast cancer.

Citation Format: Soeun Park, Minsu Park, Dongmi Ko, Seongjae Kim, Juyeon Seo, Kee Dal Nam, Eunsun Jung, Yong koo Kang, Seojin Jang, So Ra Seock, Yoon-Jae Kim, Ji Young Kim, Jae Hong Seo, Jaeyoun Park. β-Escin eradicates cancer stem-like population in HER2-positive breast cancer with trastuzumab resistance [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 423.
Abstract 4261: Genomic landscape of 2128 thyroid cancers from the aacr genie database: Implications for targeted therapies
Authors: Nelson Blessie Elizabeth , Gouda Mohammed , Roszik Jason , Hu Mimi L. , Cabanillas Maria , Subbiah Vivek
Published: April 2023

Background: Understanding molecular biology of thyroid cancer has revolutionized diagnosis, tumor classifications and identifying effective precision oncology therapies.

Methods: Using AACR GENIE database v.12, we cataloged genetic and co-occurring alterations in all thyroid cancers.

Results: We identified 2128 cases from 153,834 samples where tumor sub-histologies included Papillary Thyroid Cancer (PTC: 55%; 1162), Poorly Differentiated Thyroid Cancer (PDTC: 12%; 262); Medullary Thyroid Cancer (MTC: 12%; 244), Anaplastic Thyroid Cancer (ATC: 10%; 220); Follicular Thyroid Cancer (FTC: 5%; 111); Hurthle Cell Thyroid Cancer (HCTC: 5%; 95); and others (1; 34). Median age at sequencing was 59 years. Gender distribution was higher in female (54%; n=1104) compared to male (46%; n=933). Ethnicities included 73.2% (n=1,493) White, 8.9% (n=178) Asian, and others.Most frequent genomic mutational alterations overall were BRAF (40.8%; 868) [96% (n=845) V600E, 0.6% (n=5) G469A, 0.6% (n=5) V600_K601delinsE, 0.2% (n=2) K601E, 0.2% (n=2) A404Cfs*9, and 2.7% (n=24) others]; TERT (35%; 624); NRAS (11.6%; 247); TP53 (11.6%; 247) and RET (9.3%; 197) genes. There was variability in genomic alterations between sub-histologies (Table 1).

There was statistically significant co-occurrence between BRAF and TERT, TERT and TP53, TERT and NRAS alterations (p<0.001). Mutually exclusive alterations were BRAF and NRAS, BRAF and RET, TERT and RET, NRAS and RET, TP53 and RET, and BRAF and TP53 (p<0.001).Copy number alterations (CNA) were observed in 497 samples and were most frequent in CDKN2A, NKX2-1, CDKN2B, NF2, and CRKL genes (16.5%, 16%, 15.5%, 13.1%, and 13%). 362 oncogenic fusions were noted predominantly in CCDC6-RET, RET-NCOA4, ETV6-NTRK3, BRAF-Intragenic (20%, 7.2%, 3%, 1.6%).

Conclusion: Genomic profiling identified full breadth of BRAF, RET and NRAS alterations and co-occurring oncogenic driver alterations. This approach may refine use of targeted therapy in thyroid cancer.

Table 1. Histology Most frequent Alterations % n PTC BRAF 62.3% 724 TERT 32.7% 332 PDTC TERT 49% 117 NRAS 28.2% 74 MTC RET 71.3% 174 HRAS 7.8% 19 ATC TP53 58.2% 128 TERT 56.7% 106 FTC TERT 41% 27 NRAS 26.1% 29 HCTC TERT 41% 34 TP53 17.9% 17

Citation Format: Blessie Elizabeth Nelson, Mohammed Gouda, Jason Roszik, Mimi L. Hu, Maria Cabanillas, Vivek Subbiah. Genomic landscape of 2128 thyroid cancers from the aacr genie database: Implications for targeted therapies. [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 4261.
Abstract 4276: Recovering false negatives in CRISPR fitness screens with JLOE
Authors: Dede Merve , Hart Traver
Published: April 2023

It is widely accepted that pooled library CRISPR-Cas9 knockout screens offer greater sensitivity and specificity than prior technologies in detecting essential genes whose disruption leads to fitness defects, a critical step in identifying candidate cancer targets. However, the assumption that CRISPR screens are saturating has been largely untested and it is still poorly understood whether possible systematic biases in CRISPR screens affect our understanding of human cell-intrinsic gene essentiality. In the absence of a ground truth, the actual true positive, false positive and false negative rates of a typical genome-wide CRISPR-Cas9 knockout screen are still unknown.

Through integrated analysis of screen data in hundreds of cancer cell lines generated by the Cancer Dependency Map, we examine some of the biases characteristic of genome-wide CRISPR-Cas9 knockout screening. With our computational modeling approaches, we estimate the true positive rate, false positive rate and show that a typical CRISPR screen has a ~20% false negative rate, in addition to library-specific false negatives. Furthermore, replicability of essential gene hits falls sharply as gene expression decreases, while cancer subtype-specific genes within a tissue show distinct profiles compared to false negatives. With our cumulative analyses across tissues, we identified an improved new set of core essential genes, which, like the previous set, can be used as a metric for the quality control of genome-wide CRISPR-Cas9 knockout screens. Our results also suggest only a small number of lineage-specific essential genes, with the overwhelming majority of genes showing overlap between related tissues and are enriched for transcription factors that define pathways of tissue differentiation. To recover false negatives in these genome- wide CRISPR knockout screens, we introduce a method called Joint Log Odds of Essentiality (JLOE), which extends fundamental concepts from our Bayesian framework of BAGEL algorithm to improve analysis across multiple cell line screens. JLOE uses information derived from previous screens to update the probability of essentiality of each screen based on prior observations. We show that JLOE selectively rescues the false negatives without an increased false discovery rate and improves screen concordance with the Sanger dataset, reducing the number of background-specific essential genes. Overall, our methods offer a significantly improved analysis of genome-wide CRISPR-Cas9 knockout screens, detecting and correcting for the previously unidentified false negatives and enhancing our identification of cancer-specific vulnerabilities as therapeutic targets.

Citation Format: Merve Dede, Traver Hart. Recovering false negatives in CRISPR fitness screens with JLOE. [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 4276.
Abstract 43: Application of MiniPDX® in clinical indication identification and anti-tumor drug development
Authors: Long Yuan , Xie Bin , Chen Hongkui , Zhao Shizhu , Li Le , Xi Song , Wen Danyi
Published: April 2023

MiniPDX® represents a novel in vivo drug sensitivity test with fast turnaround (7-10 days), using either fresh patient tumor samples or tissues from established PDX models. We systematically evaluated and compared the response rates of MiniPDX® assays and PDX assays pair-wise in 26 PDX models across 3 types of cancers to 12 clinically relevant regimens for chemical and targeting drugs. The results showed a high correlation between drug responses of the two assays, with sensitivity and specificity of 80% and 93%, respectively. More studies of different tumor types showed that MiniPDX drug sensitivity test results were consistent with clinical responses in most patients, which indicated that MiniPDX® models have great potential in guiding personalized cancer therapy. LIDE has completed over 3,000 MiniPDX® tests for clinical precision medicine, covering more than 50 indications. MiniPDX® was used to rank clinically approved drugs or drug regimens to guide the selection of the best individualized treatment strategy. At the same time, screening other compounds facilitates selection of the best drug candidates for further R&D. Importantly, performing MiniPDX® Mouse Trial using fresh tumor samples generated from clinic is beneficial for determination of potential clinical indications. Only thousands of fresh cells leftover from MiniPDX® preparation are sufficient to get genomic and transcription data by OncoVee™ K-cell technology. The combination of MiniPDX® assay and omics data would be very useful for determination of potential bio-markers in order to distinguish responders and non-responders in population with certain indication(s) and leveraged for patient stratification and selection criteria in clinical trial design. Currently, we are developing a new version of MiniPDX® assay for immunotherapy (IO-FIVE, Immuno-Oncology Fast In Vivo Efficacy test) by using fresh patient cancer cells with autologous immune cells to maximally mimic human tumor microenvironment before seeding in immune-deficient mice. Total cell viability and cell phenotyping are tracked before and after drug treatment to evaluate its in vivo efficacy within two weeks. More than 60 samples have been tested and the IO-FIVE functional assay can effectively distinguish the non-responder from responders for immunotherapeutic drugs. Several Investigator Initiated Trials (II-T) are on-going to further validate the correlation of IO-FIVE result to clinic endpoint.

Citation Format: Yuan Long, Bin Xie, Hongkui Chen, Shizhu Zhao, Le Li, Song Xi, Danyi Wen. Application of MiniPDX® in clinical indication identification and anti-tumor drug development [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 43.
Abstract 4353: Utilizing scRNA sequencing to understand biomarkers of response and resistance to Sacitizumab Govetican in localized TNBC
Authors: Peiris Nicole , Cristea Simona , Zhang Mengran , Koh Siang , Coates James , Smidt Ilze , Bossuyt Veerle , Spring Laura , Bardia Aditya , Ellisen Leif
Published: April 2023

Triple-Negative Breast Cancer (TNBC) is an aggressive breast cancer subset, which lacks expression of estrogen receptors, progesterone receptors, and human epidermal growth factor receptor-2. This subset of breast cancer disproportionately affects Black and African American women and improving TNBC treatment options is vital to reducing breast cancer mortality. The novel antibody-drug conjugate, Sacitizumab Govetican (SG), which targets TROP2 at the cell surface, has shown promising clinical results from the NeoSTAR trial (NCT04230109), a phase II study evaluating neoadjuvant SG therapy in a localized TNBC setting. As part of the NeoSTAR clinical trial, we have collected and processed pre- and post- SG treatment patient samples, with the aim of understanding response to this monotherapy. Herein, we identify biomarkers of response and resistance to SG monotherapy through the use of single cell RNA sequencing of matched pre- and post-treatment patient biopsies combined with exome sequencing these patient samples. Pre-treatment core needle biopsy samples, and if applicable, post-treatment residual disease biopsies were dissociated into single cell suspensions and subjected to single cell RNA sequencing. Additionally, fixed patient tissue samples were processed accordingly for exome sequencing analyses. Overall, we analyzed over 144,000 cells from 37 total scRNA seq libraries with an average of 3800 cells per biopsy sample, demonstrating the feasibility of this method. From these analyses, we observed several cell-type differences between patients who achieved a pathological complete response (pCR) and patients who had residual disease (RD). Specifically, our data shows that tumor infiltrating lymphocytes are a potential prognostic biomarker of response to SG. Furthermore, we detected alterations in among stromal and immune cell subsets, among non-responders, indicating that these cell types maybe indicative of SG resistance. Taken together, we outline biomarkers of response to SG treatment for an improved understanding of resistance mechanisms in the neoadjuvant setting to improve TNBC outcomes among patients.

Citation Format: Nicole Peiris, Simona Cristea, Mengran Zhang, Siang Koh, James Coates, Ilze Smidt, Veerle Bossuyt, Laura Spring, Aditya Bardia, Leif Ellisen. Utilizing scRNA sequencing to understand biomarkers of response and resistance to Sacitizumab Govetican in localized TNBC. [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 4353.
Abstract 4387: Total toxicity burden of FDA approved immune checkpoint inhibitors in USA
Authors: Yang Fan , Shay Chloe , Qin Zhaohui , Saba Nabil , Teng Yong
Published: April 2023

Immune checkpoint inhibitors (ICIs) have revolutionized the treatment landscape for multiple cancers, demonstrating effective and durable responses and becoming the standard of care for a variety of malignancies. However, ICI-based treatment has resulted in the rise of unique immune-related adverse events (irAEs). To date, very little information is available on the frequency, significance, and management of single-organ or multiorgan irAEs in clinic. In this study, the irAEs associated with the treatment of seven FDA-approved ICIs, including three PD-1 inhibitors (cemiplimab, nivolumab and pembrolizumab), three PD-L1 inhibitors (atezolizumab, avelumab and durvalumab), and one CTLA4 inhibitor (ipilimumab), were analyzed based on the data of 149,303 report cases (January 1, 2015 - June 30, 2022) collected from FDA Adverse Events Reporting System (FAERS) public dashboard. Our data reveal that irAEs associated with the treatment of anti-PD-1 ICIs (e.g., pembrolizumab) require less hospital care resources compared with anti-PD-L1 and anti-CTLA4 ICIs. Tissue and organ toxicity of ICIs are age and gender specific. ‘Cardiac disorders’ is the main disorder caused by these ICIs in cancer patients aged 65-85, while ‘reproductive system and breast disease’ is the main disorder in cancer patients aged 18-64. There are risks of respiratory and urinary system toxicity in male patients and reproductive system toxicity in female patients when they receive the treatment of ICIs. Studies such as this one provide the statistical data for understanding patients at risk of developing irAEs, which will underscore the importance of further exploring research strategies to predict, detect, and mitigate toxicities from ICIs.

Citation Format: Fan Yang, Chloe Shay, Zhaohui Qin, Nabil Saba, Yong Teng. Total toxicity burden of FDA approved immune checkpoint inhibitors in USA. [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 4387.
Abstract 4672: In-vivo tumor implantation site exhibits differential immune response in solid tumors
Authors: Shrimali Rajeev , Borroel Jasmine , Sunico Carmen , Corcoran Bridget , Carapia Bianca , Prendergast Rowan , Sperry Jantzen , Nakashima Jonathan
Published: April 2023

Successful discovery and development of cancer targeted therapeutics depends on testing these agents in the clinically most relevant translational models. Emerging evidence highlights the importance of the local tumor microenvironment in evaluating the efficacy of new therapeutics, especially for immunotherapies. Historically, patient-derived xenograft (PDX) modeling involves subcutaneous implantation which minimally represents the actual human tumor site. Here, we use PBMC humanized PDX models to demonstrate differences in the tumor microenvironment, overall immune response, and the pharmacological outcome, between subcutaneous and orthotopic PDX models. These findings highlight the importance of testing cancer therapeutics in the most physiologically relevant setting for greater translation into clinical success.

Citation Format: Rajeev Shrimali, Jasmine Borroel, Carmen Sunico, Bridget Corcoran, Bianca Carapia, Rowan Prendergast, Jantzen Sperry, Jonathan Nakashima. In-vivo tumor implantation site exhibits differential immune response in 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 4672.
Abstract 4830: Uncoupling protein 2 (UCP2) loss of function mediates PDAC tumor suppression by mitochondrial fusion
Authors: Acevedo-Diaz Ariana Carolina , Caggiano Emily G. , Yu Meifang , Taniguchi Cullen
Published: April 2023

Background: Pancreatic ductal adenocarcinoma (PDAC) is a lethal cancer with a dependence on highly active mitochondria to grow and metastasize. We previously found that mitochondrial fusion suppressed PDAC growth and metastasis, leading to improved survival in a preclinical model. The tumor suppressive mechanisms of mitochondrial fusion remain unclear, and thus we explored the role of redox homeostasis through uncoupling protein 2 (UCP2).

Methods/Results: Murine pancreatic cancer cells (KPC) with enhanced mitochondrial fusion (sgDrp1) exhibited higher levels of mitochondrial ROS compared to controls targeting GFP (sgGFP), suggesting altered redox homeostasis. We performed RNAseq on these two cell lines and found that sgDRP1 cells exhibited reduced levels of UCP2. The UCP2 protein is known to have indirect antioxidant effects by reducing mitochondrial reactive oxygen species via uncoupling of ATP production from the electron transport chain. We found that abrogating UCP2 in KPC cells reduced its capacity for OXPHOS. Moreover, rescue of UCP2 in sgDrp1 cells restored their mitochondrial activity.

Conclusions: Mitochondrial fusion may suppress tumor growth and induce mitophagy by altering redox homeostasis. UCP2 may be a mediator of the tumor suppressive phenotype induced by mitochondrial fusion, thus linking mitochondrial dynamics and PDAC antioxidant strategies.

Future Work: These results will be explored for their translation in vivo and the effects of pharmacological inhibition of UCP2, both in vitro and in vivo, via the specific inhibitor Genipin, will be explored.

Citation Format: Ariana Carolina Acevedo-Diaz, Emily G. Caggiano, Meifang Yu, Cullen Taniguchi. Uncoupling protein 2 (UCP2) loss of function mediates PDAC tumor suppression by mitochondrial fusion. [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 4830.
Abstract 4840: Dysregulation of mitochondrial function by PLK1-mediated PDHA1 phosphorylation promotes Cr(VI)-associated lung cancer progression
Authors: Zhang Qiongsi , Li Zhiguo , Rao Xiongjian , Allison Derek B. , Qiao Qi , Zhang Zhuangzhuang , Kong Yifan , Wang Ruixin , Fan Teresa W. , Higashi Richard M. , Lane Andrew N. , Liu Xiaoqi
Published: April 2023

Hexavalent chromium (Cr(VI)), an class I environmental carcinogen, not only induces lung epithelial cell transformation but also promotes lung cancer progression by alterations of the cell cycle and cellular energy metabolism. Using Cr(VI)-transformed (CrT) bronchial epithelial cells (BEAS-2B) and parental BEAS-2B cells, we demonstrate that the level of polo-like kinase 1 (PLK1) is highly upregulated in CrT cells, which blocks mitochondrial function, and further promotes cell proliferation both in vitro and in vivo. Cells expressing a high level of PLK1 exhibited repressed mitochondrial activity due to defective modulation of pyruvate dehydrogenase E1 subunit alpha 1 (PDHA1), which facilitates the carbon influx to TCA cycle via catalyzing pyruvate/Acetyl-CoA conversion. Mechanistically, we show that PDHA1 can be directly phosphorylated by PLK1 at T57, which triggers collapse of E1 and PDHA1 degradation via activation of mitophagy. These defects resulted in the inhibition of oxidative phosphorylation and reduction of mitochondrial reactive oxygen species (ROS) generation, eventually inhibiting mitochondrial-mediated apoptotic response. Defining the role of PLK1 in metabolic reprogramming in Cr(VI)-associated cancer progression may give us a new perspective and a target to inhibit Cr(VI)-induced cancer development. In addition, PLK1 inhibitors may be used to increase the chemo-sensitivity of cancer cells by restoring the normal function of mitochondria, thus alleviating the drug resistance caused by dysfunction and hyperpolarization of mitochondria.

Citation Format: Qiongsi Zhang, Zhiguo Li, Xiongjian Rao, Derek B. Allison, Qi Qiao, Zhuangzhuang Zhang, Yifan Kong, Ruixin Wang, Teresa W. Fan, Richard M. Higashi, Andrew N. Lane, Xiaoqi Liu. Dysregulation of mitochondrial function by PLK1-mediated PDHA1 phosphorylation promotes Cr(VI)-associated lung cancer progression. [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 4840.
Abstract 4935: Cannabidiol and cannabis extract protect cells against platinum-based chemotherapy via cellular uptake
Authors: Buchtová Tereza , Beresova Lucie , Chroma Katarina , Mistrik Martin
Published: April 2023

Cannabinoids including cannabidiol belong between constituents of cannabis sp. (marijuana plant). Purified or as a part of cannabis products, the compounds are frequently used by cancer patients to attenuate chemotherapy-induced side effects such as pain, nausea, and vomiting. The presence of cannabis products on the public market expands each year while the illegality status weakens in an increasing number of countries. U.S. Food and Drug Administration has approved several cannabis-based drugs for seizures induced by Lennox-Gastaut syndrome, Dravet syndrome, or tuberous sclerosis complex, also for the lost appetite of AIDS patients, and chemotherapy-induced nausea and vomiting. Oncological patients are further and strongly motivated to take the drugs in combination with chemotherapy by numerous reports demonstrating the anticancer effects of cannabinoids. Nevertheless, here we present unsettling data that cannabis extract together with CBD negatively interferes with worldwide approved platinum-based drugs cisplatin, carboplatin, and oxaliplatin. The phenomenon is proven across three cellular models including primary cells. Even low concentrations of cannabidiol or cannabis extract reduced the toxicity of platinum-based drugs using long-term colony forming assay and/or short-term crystal violet assay. Increased resistance of cells was also accompanied by decreased cellular stress as evaluated by quantitative immunofluorescence microscopy and immunoblotting. Most importantly, concomitant cannabidiol and cisplatin exposure results in the decreased presence of cisplatin-modified DNA. Following the information, we determined platinum content in cells by ICP-MS. The experiment uncovered significantly decreased intracellular platinum content indicating an effect on cellular transport. Furthermore, the mechanism is translational independent as shown by the experiment with cycloheximide. This study offers crucial information that patients and physicians should take into account regarding possible interactions between platinum-based drugs and cannabis-based products. Furthermore, the study on the contradictory effects of cannabis products in cancer treatment may be motivated by this project.

Citation Format: Tereza Buchtová, Lucie Beresova, Katarina Chroma, Martin Mistrik. Cannabidiol and cannabis extract protect cells against platinum-based chemotherapy via cellular uptake. [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 4935.
Abstract 4937: Immunoproteasome inhibitors for the treatment of t(4;11)-driven ALL
Authors: Kisselev Alexei F. , Jenkins Tyler W. , Fitzerald Elise , Maksimenko Andrey V. , Panizzi Peter , Fields Jennifer L. , Fiering Steven N. , Mitra Amit K.
Published: April 2023

The t(4;11)(q21;q23) chromosomal translocation that creates the MLL-AF4 fusion protein, confers a poor prognosis in infant acute lymphoblastic leukemia (ALL). This translocation also sensitizes cells to proteasome inhibitors bortezomib and carfilzomib, which are approved by the FDA for the treatment of multiple myeloma. Clinical activity of bortezomib in combination with standard chemotherapy has been documented in several clinical trials of ALL patients, and a case of a single-agent activity against relapsed leukemia driven by the MLL-AF4 translocation has been described. However, toxicities of bortezomib and carfilzomib may be unacceptable to pediatric patients. We found that the overwhelming majority of proteasomes in this subtype of ALL are lymphoid tissue specific immunoproteasomes. Cells with MLL-AF4 translocations were sensitive to pharmacologically relevant concentrations of specific immunoproteasome inhibitors ONX-0914 and M3258. Furthermore, both compounds dramatically delayed growth of orthotopic xenograft tumors in mice. Thus, immunoproteasomes are therapeutic targets in ALL and replacing bortezomib and carfilzomib with immunoproteasome inhibitors in ALL should reduce toxicities associated with inhibition of the proteasomes in non-lymphoid tissues.

Citation Format: Alexei F. Kisselev, Tyler W. Jenkins, Elise Fitzerald, Andrey V. Maksimenko, Peter Panizzi, Jennifer L. Fields, Steven N. Fiering, Amit K. Mitra. Immunoproteasome inhibitors for the treatment of t(4;11)-driven ALL. [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 4937.
Abstract 4939: Combinatorial approach using covalent menin inhibitor, BMF-219, and/or covalent FLT3 inhibitor, BMF-500, with MEK or BCL2 blockade potentiates therapeutic use in AML
Authors: Law Brian
Published: April 2023

Introduction:

Acute myeloid leukemia (AML) is a clinically and genetically heterogeneous disease characterized by a highly diverse genomic landscape. Despite recent advances in therapies, treatment outcome remains variable and largely defined by genomic abnormalities such as gene fusions, copy number alterations and point mutations. Mutations in epigenic modifiers, nucleophosmin (NPM1c), signaling and kinase pathway such as KMT2A-re-arrangements (KMT2A-r), internal tandem duplication (ITD) insertions in FLT3, and NRAS mutations are amongst the highest alterations in AML patients with a propensity towards poor response to treatment and overall disease outcome. Such limitations impact the ability to achieve long-lasting response to treatment and result in therapy-induced resistance eventually leading to relapse. Combinatorial strategies are required to combat resistance and maximize duration of antitumor activity.

BCL2 and MEK blockade in combination with menin and/or FLT3 inhibitors potentiates an improved therapeutic strategy to achieve increased antitumor activity and overcome AML resistance. Here we explored the use of our clinical-stage covalent menin inhibitor, BMF-219, and BMF-500, a covalent FLT3 inhibitor, in combination with each other and in combination with BCL2 and MEK inhibitors in MV-4-11 and MOLM-13 cell lines for 4-days, then viability was measured using CellTiter Glo.

Results:

BMF-219 and BMF-500 as single agents induce effective antitumor activity on MOLM-13 and MV-4-11 cells lines. When dosed in combination, BMF-219 and BMF-500 show beneficial effects affording higher cell killing at lower concentrations. Repeated experiments revealed patterns of increased cell killing is achieved when trametinib, MEK inhibitor, and venetoclax, BCL2 inhibitor, are combined with BMF-219 treatment.

Conclusions:

Collectively, our studies demonstrate the utility of combination strategies to achieve higher antileukemic cell killing with reduced concentrations of menin and FLT3 covalent inhibitors. Additionally, we show benefit of combinatorial approaches of menin and FLT3 covalent inhibitors with MEK and BCL2 blockade. These data provide initial pre-clinical evidence for combining pathway specific inhibitors as a promising therapeutic strategy for further investigation in acute leukemia.

Citation Format: Brian Law. Combinatorial approach using covalent menin inhibitor, BMF-219, and/or covalent FLT3 inhibitor, BMF-500, with MEK or BCL2 blockade potentiates therapeutic use in AML. [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 4939.