bluuebunny/crossref_metadata_2025 huggingface dataset:
Abstract 922: Knockout of Sod2 accelerates formation of pancreatic atypical flat lesions which are a direct precursor to pancreatic ductal adenocarcinoma (PDA)
Authors: Martinez Alicia K. Fleming , Edenfield Brandy H. , Esposito Irene , Storz Peter
Published: June 2022

Manganese superoxide dismutase (MnSOD) is an important reactive oxygen species (ROS) scavenger which has largely been studied in pancreatic cancer cell lines, where it contributes to invasion but also decreases proliferation. In pancreatic cancer, it is unknown whether MnSOD contributes to or prevents lesion development. Therefore, we utilize a transgenic mouse model to study precancerous lesion development and progression. We here show that knockout of Sod2 in a p48Cre;LSL-KrasG12D (KC) mouse model accelerates formation of abnormal tissue area, increases abundance of DCLK1+ cancer stem cells (CSCs) and oxidative damage, and promotes formation of atypical flat lesions (AFLs) which are a direct precursor to pancreatic ductal adenocarcinoma (PDA). We further characterize AFLs as having fewer senescent cells and less oxidative damage than low grade PanIN lesions. Thus, MnSOD has a protective effect in early pancreatic lesion development and its deletion drives tumor development.

Citation Format: Alicia K. Fleming Martinez, Brandy H. Edenfield, Irene Esposito, Peter Storz. Knockout of Sod2 accelerates formation of pancreatic atypical flat lesions which are a direct precursor to pancreatic ductal adenocarcinoma (PDA) [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 922.
Abstract 925: A genetically engineered mouse model for carcinogenesis by the human enzyme APOBEC3B
Authors: Durfee Cameron C. , Argyris Prokopios P. , Jarvis Matthew C. , Levin-Klein Rena , Law Emily K. , Harris Reuben S.
Published: June 2022

Introduction: Advanced DNA sequencing technologies have revealed a substantial endogenous source of mutations in cancers, the human DNA-mutating enzyme APOBEC3B (A3B). This protein changes DNA cytosines into uracils (C-to-U), which can become “immortalized” in the genome as C-to-T or C-to-G mutations depending on how each uracil lesion is processed. However, mice lack analogous carcinogenic A3 enzymes, which makes a definitive cause-and-effect model of A3-induced carcinogenesis difficult to establish.

Results: Using C57BL/6 mice, we have generated a novel genetically engineered mouse model (GEMM) expressing the human protein A3B, where it is driven constitutively from the Rosa26 locus in combination with the strong synthetic CAG promoter. Importantly, tumor-free survival data suggest that CAG A3B mice develop tumors at an increased rate compared to wild-type mice. These CAG A3B mice develop predominantly lymphoid neoplasms including B- and T-cell lymphomas and marked splenomegaly, and less frequently lung and liver cancers. Using immunohistochemical and whole-genome sequencing techniques, we have further characterized the tumors arising in these novel GEMMs. The above analyses thus far have revealed that A3B is actively driving tumor formation, as seen by an enrichment of canonical APOBEC-related mutations in these cancers.

Conclusion: Overall, the CAG A3B mice are the first GEMMs demonstrating the potential for A3B to drive tumor formation in vivo, with a predilection towards blood malignancies. They will be an invaluable tool for characterizing A3B-driven mutational processes in an organism and testing novel therapeutic strategies against APOBEC-induced cancer initiation and progression.

Citation Format: Cameron C. Durfee, Prokopios P. Argyris, Matthew C. Jarvis, Rena Levin-Klein, Emily K. Law, Reuben S. Harris. A genetically engineered mouse model for carcinogenesis by the human enzyme APOBEC3B [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 925.
Abstract 930: Novel orthotopic pancreatic cancer cell lines derived from B6-KPC mice
Authors: Zhu Fang , Ju Cunxiang , Sun Hongyan , Yu Weiwei , Ju Chao , Li Shuai , Jiang Yunlong , Jia Dongjing , Smith Steve , Li Zhiying , Zhao Jing , Gao Xiang
Published: June 2022

Pancreatic ductal adenocarcinoma (PDAC) is one of the most lethal malignancies due to its late diagnosis and limited response to treatment. B6-KPC mice ( LSL-KrasG12D/+, LSL-Trp53R172H/+, Pdx1-Cre) generate spontaneous PDAC which could recapitulate the pathogenesis and genomic features of human PDAC. Although B6-KPC model is a wildly used for the exploration of the mechanisms of PDAC, some drawbacks of the model, such as long time for tumorigenesis, individual variation and difficulties in tumor observation, limit its application in cancer therapy. It is necessary to develop the pancreatic tumor cell lines from these models. In this study, we successfully established and well-characterized the luciferase-labled cell line mPAKPC-Luciferase. This cells carried the KrasG12D and Trp53R172H mutation. The orthotopic mPAKPC-Luciferase tumor model was well established by implanting tumor cell line into pancreas of B6 wild type mice and the tumor growth was traced by in vivo imaging. Moreover, Gemcitabine or combined with CD40 agonist presented significant tumor growth inhibition in B6 bearing mPAKPC-Luciferase orthotopic mouse models. While anti-PD1 or anti-OX40 had no anti-tumor effects in this model accordance with the low T cell infiltration of mPAKPC modle as a “cold” tumor. In addition, the immune profiling of this cell line showed highly expressed of potential therapeutic targets, including Claudin 18.2, CD47, CD73. Thus, mPAKPC-Luciferase cell lines are valuable models for the PDAC preclinical therapies.

Citation Format: Fang Zhu, Cunxiang Ju, Hongyan Sun, Weiwei Yu, Chao Ju, Shuai Li, Yunlong Jiang, Dongjing Jia, Steve Smith, Zhiying Li, Jing Zhao, Xiang Gao. Novel orthotopic pancreatic cancer cell lines derived from B6-KPC mice [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 930.
Abstract 936: Developing a sex-biased model for LKB1-mutant lung adenocarcinoma
Authors: Fan Yijian , Jin Rui , Liu Xiuju , Liu Yuan , Huang Chunzi , Gilbert-Ross Mellissa , Marcus Adam , Zhou Wei
Published: June 2022

Liver kinase B1 (LKB1) is the third most frequently mutated gene in lung adenocarcinoma (LUAD), and LKB1-mutant lung cancers are resistant to existing targeted therapy or immune checkpoint blockade therapy. In the TCGA-LUAD dataset, LKB1 was found to be more frequently mutated in males than in females even after correcting for potential confounders (male versus female: 22.8% versus 11.3%, p < 6.9x 10-4, FDR = 0.033). Similar trends can be found in all other large LUAD datasets. However, the mechanistic basis of this bias is unknown because the existing mouse models of lung cancers either did not exhibit sex bias or showed female mice being more susceptible to the development of lung cancers. Here, we demonstrate that our lentivirus-inducing Kras/LKB1-mutant genetically engineered mouse model (GEMM) and tail-vein injection syngeneic model exhibit sex bias against the tumor formation in the female host. In our KRASLSL-G12D/LKB1fl/fl/Rosa-Luc GEMM mice, the lung tumor formation was monitored by bioluminescence imaging (BLI) and validated by immunohistochemistry of tumor bearing-lung. The sex bias of time to lung adenocarcinoma formation in males and females was determined by the Kaplan-Meier method. 97% (31/32) male GEMM developed LUAD after the induction, whereas only 58% (15/26) female GEMM developed LUAD (p=0.0001, log-rank). The tail-vein injection method used the WRJ388-AD1 cell line, which was derived from WRJ388. Tumor growth in the chest area was monitored by BLI and evaluated by the mixed-effects model. Sex bias preference for developing lung tumors in the male host reached significance on day 14 post-injection (p=0.0037) and lasted during the study (day 21, p=0.0021). On day 21, with the cutoff as 1x106 p/sec/cm2/sr in lung region, 100% male GEMM formed lung tumor while only 36% female GEMM formed lung tumor after the injection. Collectively, this KRAS/LKB1-mutant lung adenocarcinoma exhibits sex-biased tumor formation and growth, which are consistent with clinical data among LUAD patients. This model will provide researchers with opportunities to understand the mechanistic basis of this sex bias and to develop novel personalized therapies.

Citation Format: Yijian Fan, Rui Jin, Xiuju Liu, Yuan Liu, Chunzi Huang, Mellissa Gilbert-Ross, Adam Marcus, Wei Zhou. Developing a sex-biased model for LKB1-mutant lung adenocarcinoma [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 936.
Abstract 937: Novel role of deubiquitylase USP13 in lineage plasticity and drug resistance of non-small cell lung cancer
Authors: Kwon Juntae , Han Cecil
Published: June 2022

Lineage plasticity, the ability of cells to transition from one defined cell type to another, has been proposed as a source of intertumoral heterogeneity and therapeutic resistance.However, molecular drivers and underlying mechanisms of lineage plasticity remain largely unknown. Here, we found a novel role of deubiquitylase USP13 in lineage transition of lung adenocarcinoma (ADC) to squamous cell carcinoma (SCC) using mouse model: Usp13-overexpressing (Usp13OE) ADC loses its characteristics while gaining SCC features are enhanced. Transcriptomic analysis showed that Usp13OE lung cancers were heterogeneous and epithelial-mesenchymal transition (EMT), hypoxia, and PI3K-Akt-mTOR signaling pathway were enriched. Furthermore, development disease pathways including neurological and gastrointestinal diseases were overrepresented in Usp13OE tumors. Notably, Usp13OE primary tumor cell lines showed higher drug resistance against first-line therapy. Collectively, our findings demonstrate the novel role of USP13 in lineage transition of lung cancer and suggest that targeting USP13 is a promising strategy for the further treatment of lung cancer patients.

Citation Format: Juntae Kwon, Cecil Han. Novel role of deubiquitylase USP13 in lineage plasticity and drug resistance of non-small cell lung cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 937.
Abstract 94: PRMT5 substrate recruitment as a therapeutic target in CDKN2A/MTAP null cancers
Authors: Mulvaney Kathleen M. , McMillan Brian , Blomquist Christa , Acharya Nischal , Ranaghan Matthew , Kesar Devishi , Ianari Alessandra , Sellers William
Published: June 2022

PRMT5 is an essential arginine methyltransferase and a therapeutic target in MTAP-null cancers. PRMT5 uses adaptor proteins for substrate recruitment through a previously undefined mechanism. Here, we identify an evolutionarily conserved peptide sequence shared among the three known substrate adaptors (CLNS1A, RIOK1, and COPR5) and show that it is necessary and sufficient for interaction with PRMT5. We demonstrate that PRMT5 uses modular adaptor proteins containing a common binding motif for substrate recruitment, comparable with other enzyme classes such as kinases and E3 ligases. We structurally resolve the interface with PRMT5 and show via genetic perturbation that it is required for methylation of adaptor-recruited substrates including the spliceosome, histones, and ribosomal complexes. Furthermore, disruption of this site affects Sm spliceosome activity, leading to intron retention. Genetic disruption of the PRMT5-substrate adaptor interface impairs growth of MTAP-null tumor cells and is thus a site for development of therapeutic inhibitors of PRMT5. Current efforts are focused on understanding whether PRMT5-substrate adaptor disruption synergizes with immune therapies or new classes of PRMT5 inhibitors in CDKN2A/MTAP null cancer.

Citation Format: Kathleen M. Mulvaney, Brian McMillan, Christa Blomquist, Nischal Acharya, Matthew Ranaghan, Devishi Kesar, Alessandra Ianari, William Sellers. PRMT5 substrate recruitment as a therapeutic target in CDKN2A/MTAP null cancers [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 94.
Abstract 943: Modeling and dissecting of esophageal squamous cell carcinoma initiation
Authors: Ko Kyung Pil , Zou Gengyi , Huang Yuanjian , Kim Bongjun , Zhang Jie , Jun Sohee , Park Jae-Il
Published: June 2022

Esophageal cancer is the 7th common cancer with the 6th highest cancer mortality rate worldwide. The 5-year survival rate of esophageal cancer is 10 ~ 25%. Esophageal cancer is mainly divided into esophageal squamous cell carcinoma (ESCC) and esophageal adenocarcinoma. ESCC accounts for 80% of all esophageal cancer cases and shows a poor prognosis due to a lack of symptoms at early stages. Given that early diagnosis of ESCC may lead to better outcomes, understanding the biology of ESCC initiation is imperative. To recapitulate the early events of ESCC, we employed the murine esophageal organoid (EO) system recently developed. Based on in silico analyses, we selected nine candidate genes (TP53, CDKN2A, NOTCH1, NOTCH3, KMT2D, KMT2C, FAT1, FAT4, and AJUBA) frequently mutated in ESCC patients. The EOs were then genetically manipulated with the combinatorial ablation of nine genes by CRISPR/Cas9 system. The EOs carrying PN (Trp53 and Notch1 KO), PC (Trp53 and Cdkn2a KO), and PCN (Trp53, Cdkn2a, and Notch1 KO) showed hyperplastic and neoplastic properties with impaired squamous cell differentiation and organoid integrity, compared to the wild-type (WT) EOs. Single-cell RNA-seq (scRNA-seq) analyses of WT, PC, PN, and PCN organoids showed the highest enrichment of ESCC cancer stem cell markers in PCN organoids. Unlike the cell lineage in WT EOs, neoplastic EOs (PC, PN, and PCN) exhibited distinct cell lineage along with multiple root cell clusters. While WT EOs failed to become neoplastic, PN, PC, and PCN EOs displayed the transforming activity in vitro and in vivo xenograft transplantation assays. Intriguingly, in allograft mouse models, while PN organoids-derived cells barely developed tumors, PC and PCN organoids-derived cells developed tumors with marked downregulation of genes related to antigen processing and presentation. These results suggest that combinatorial loss of P53, CDKN2A, and NOTCH1 play a pivotal role in ESCC neoplasia, stemness, and immune checkpoint, unveiling the biology of ESCC initiation.

Citation Format: Kyung Pil Ko, Gengyi Zou, Yuanjian Huang, Bongjun Kim, Jie Zhang, Sohee Jun, Jae-Il Park. Modeling and dissecting of esophageal squamous cell carcinoma initiation [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 943.
Abstract 963: Targeting epithelial-mesenchymal plasticity via ribosome biogenesis inhibition reduces chemoresistant metastasis of breast cancer
Authors: Ban Yi , Dong Wenjuan , Zou Yue , Lee Sharrell B. , Sheng Jianting , Cao Yuliang , Wong Stephen T.C. , Gao Dingcheng
Published: June 2022

Epithelial to mesenchymal transition (EMT) plays an important role in metastasis and chemoresistance. However, targeting EMT has been challenging due to the complex and redundant EMT signaling pathways. Moreover, EMT inhibition would unequivocally promote its reversed process, mesenchymal to epithelial transition (MET), which also favors malignancy progression. To solve this EMT targeting paradox, we proposed to target the ability of tumor cells to oscillate between epithelial and mesenchymal states, the epithelial to mesenchymal plasticity (EMP), which encompasses both EMT and MET. Using a SnailCre-ERT2 mediated EMT lineage-tracing model, we confirmed the involvement of EMP in chemoresistant metastasis of breast cancer. Single-cell transcriptome analyses of tumor cells in the transitioning phases of EMT or MET consistently revealed that ribosome biogenesis (RiBi) was specifically elevated regardless of their destined phenotypical fates. Further analyses delineated that the upregulation of RiBi and the subsequent nascent protein synthesis via the intensified ERK and mTOR signalings were vital for cancer cells to transit between epithelial and mesenchymal states. Importantly, inhibiting the excessive RiBi by either genetic or pharmacological means impaired EMP, as both EMT and MET processes were impeded, leading to significantly reduced metastatic outgrowth of chemoresistant tumor cells. Our studies revealed that elevated RiBi is required for tumor cells to “Ping Pong” between epithelial and mesenchymal states. Targeting the EMP via RiBi inhibition provides a feasible strategy to improve therapies for advanced breast cancers.

Citation Format: Yi Ban, Wenjuan Dong, Yue Zou, Sharrell B. Lee, Jianting Sheng, Yuliang Cao, Stephen T.C. Wong, Dingcheng Gao. Targeting epithelial-mesenchymal plasticity via ribosome biogenesis inhibition reduces chemoresistant metastasis of breast cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 963.
Abstract CT224: Multi-institutional randomized phase-3 trial comparing cancer stem cell-targeted vs physician-choice treatments in patients with recurrent high-grade gliomas (NCT03632135)
Authors: Ranjan Tulika , Sengupta Soma , Yu Alexander , Howard Candace M. , Chen Ricky , Chaudhary Rekha , Marko Nicholas , Aregawi Dawit , Glantz Michael , Glass Jon , Green Richard M. , Lu-Emerson Christine , Mammoser Aaron , Moulding Hugh , Jubelirer Steven , Schroeder Jason , Anderson Mark , Chow Frances , Lirette Seth , Denning Krista , Alberico Anthony , Valluri Jagan , Claudio Pier Paolo
Published: June 2022

Background: Clinical outcomes in patients with recurrent high-grade glioma (HGG) remain poor. Cancer stem cells (CSCs) have been implicated in metastasis, treatment resistance and recurrence of HHGs. We have shown in several clinical studies that anti-CSC-directed therapy provides benefits in many cancer types; however, this is the first report of a randomized clinical trial evaluating it for recurrent HGGs. Objective: Determine whether CSC-targeted cytotoxic agents selected by ChemoID assay-guided therapy improves survival in patients with recurrent HGG.

Design, Settings, and Participants: In this parallel-group, randomized, phase-3 clinical trial, patients at 13 clinical sites in the USA with grade-III/IV recurrent glioma (2016 WHO guidelines) were randomized 1:1 to either ChemoID assay-guided therapy or physician-choice therapy, and then treated and followed until unacceptable toxic effects, hospice, or death.

Main Outcomes and Measures: The primary endpoint was overall survival (OS).

Results: Combined median follow-up was 9 months. Median OS (mOS) was 12.5 months (95% CI, 10.2-14.7) in the ChemoID assay-guided group vs 9 months (95% CI, 4.2-13.8) in the physician-choice group (log-rank P = .010). Risk of death was significantly lower in the ChemoID assay group (HR = 0.44; 95% CI, 0.24-0.81; P = .008). Median progression free survival (PFS) was 10.1 vs 3.5 months (95% CI, 4.8-15.4 vs 1.9-5.1) (HR, 0.25; 95% CI, 0.14-0.44; P < .001).

Conclusions and Relevance: Primary endpoint was met in this randomized clinical trial. The mOS was 3.5 months longer in the ChemoID assay-guided group vs the physician-choice group demonstrating the clinical advantage of treating HGG patients using CSC personalized therapy.

Citation Format: Tulika Ranjan, Soma Sengupta, Alexander Yu, Candace M. Howard, Ricky Chen, Rekha Chaudhary, Nicholas Marko, Dawit Aregawi, Michael Glantz, Jon Glass, Richard M. Green, Christine Lu-Emerson, Aaron Mammoser, Hugh Moulding, Steven Jubelirer, Jason Schroeder, Mark Anderson, Frances Chow, Seth Lirette, Krista Denning, Anthony Alberico, Jagan Valluri, Pier Paolo Claudio. Multi-institutional randomized phase-3 trial comparing cancer stem cell-targeted vs physician-choice treatments in patients with recurrent high-grade gliomas (NCT03632135) [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr CT224.
Abstract CT502: Preliminary immunological monitoring of first-in-human immunotherapy-trio for advanced head and neck squamous cell carcinoma
Authors: Leidner Rom S. , Taylor Matthew H. , Moudgil Tarsem L. , Christie Tanisha L. , Koguchi Yoshinobu , Dowdell Alexa , Redmond William L. , Jensen Shawn M. , Ballesteros-Merino Carmen , Vancampen Jake A. , Rajamanickam Venkatesh , Bernard Brady M. , Paustian Christopher , Hilton Traci L. , Hu Hong-Ming , Bell Richard B. , Urba Walter J. , Bifulco Carlo B. , Piening Brian , Fox Bernard A.
Published: June 2022

Background: Preclinical studies document that complex cancer vaccines, combined with T cell agonists and anti-PD-1, can augment therapeutic efficacy. Here we report preliminary immunological analyses of patients enrolled in a first-in-human immunotherapy-trio study of multivalent autophagosome vaccine (DPV-001), with sequenced checkpoint inhibition (anti-PD-1; retifanlimab), with/without anti-GITR agonist (INCAGN-1949), in recurrent or metastatic HNSCC (NCT04470024).

Methods: Peripheral blood (PB) and sera are collected regularly and PB are evaluated by flow cytometry. Biopsies obtained at baseline, D15 and D45 are analyzed by multiplex IF and 10x Genomics scRNA-Seq. Sera are being analyzed by phage immunoprecipitation (PhIP) sequencing for reactivity against the human proteome.

Results: Preliminary results document increases in activated CD4 and CD8 effector memory T cells (TEM) with vaccine alone. Changes in tumor microenvironment (TEM) were also observed with increased infiltration of immune cells. Evaluation of changes to humoral immunity, T cell function and TCR analyses are ongoing.

Conclusions: We previously reported immunological monitoring of a phase I/II trial of an autophagosome cancer vaccine (DPV-001) containing more than 300 shared cancer antigens, as adjuvant therapy for NSCLC. Vaccination induced or augmented immune responses to more than 50 cancer antigens shared with head and neck squamous cell carcinoma (HNSCC). Preclinical studies combining this cancer vaccine with αGITR agonist and αPD-1 augmented therapeutic efficacy [PMID: 31747946], and provided the rationale for the current study. This is the first clinical trial to perform such a study with αGITR agonist (INCAGN-1949), in humans.

Support: Incyte, Providence Medical Foundation, The Harder Family, Nancy Lematta.

Citation Format: Rom S. Leidner, Matthew H. Taylor, Tarsem L. Moudgil, Tanisha L. Christie, Yoshinobu Koguchi, Alexa Dowdell, William L. Redmond, Shawn M. Jensen, Carmen Ballesteros-Merino, Jake A. Vancampen, Venkatesh Rajamanickam, Brady M. Bernard, Christopher Paustian, Traci L. Hilton, Hong-Ming Hu, Richard B. Bell, Walter J. Urba, Carlo B. Bifulco, Brian Piening, Bernard A. Fox. Preliminary immunological monitoring of first-in-human immunotherapy-trio for advanced head and neck squamous cell carcinoma [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr CT502.
Abstract CT526: A Phase 1/2a Study of a PI3Kδγ dual inhibitor ZX-101A in patients with advanced solid tumors
Authors: Qin Xiaoli , Luo Lori , Ying-ying Li , Wang Yin , Sun Shuaijun , Hao Xiaolin , Yang Jinfu
Published: June 2022

ZX-101A is a next-generation PI3Kδ/γ dual inhibitor, exerting synergistic effects on PI3Kδ and PI3Kγ-mediated processes through multifaceted mechanisms of actions. Phase 1/2a study, ZX-101A-101 (NCT04504708) is ongoing to assess safety, pharmacokinetics, pharmacodynamics, and preliminary efficacy in patients with advanced hematologic malignancies. Furthermore, recent preclinical studies of ZX-101A showed that dual inhibition of PI3Kδ and PI3Kγ restored the immune surveillance to inhibit solid tumor growth. ZX-101A-201 is a phase 1/2a open-label, multiple-dose ascending study to investigate the safety, pharmacokinetics, pharmacodynamics, and preliminary antitumor activity of once daily oral ZX-101A in 28-day cycles in patients with advanced solid tumors.ZX-101A had minimal effects on solid tumor-derived CT26, 4T1 and A20 cells in in vitro cell proliferation assay. In contrast, ZX-101A inhibited tumor growth when CT26 cells were grafted to wild-type syngeneic mice, while only showed a limited tumor growth inhibition when CT26 tumors grew on T-cell deficient nude mice. Thus, in vivo tumor growth inhibition in wild-type mice was attributed to the enhanced anti-tumor immunity by ZX-101A treatment. Flow cytometry analysis on ex vivo tumor tissues from syngeneic mouse demonstrated that ZX-101A decreased regulatory T cells and increased M1/M2 macrophage polarization in the tumor microenvironment. In A20 syngeneic model, ZX-101A in combination of anti-PD1 antibody achieved 99.7% TGI after 18 days of treatment, while anti-PD1 antibody alone only had TGI at 11.7%. Synergistic inhibitory effect of ZX-101A and anti-PD1 antibody was also observed in LLC, CT26 and humanized MC38 syngeneic mouse models. Safety assessment on the mouse spleen, thymus and colon organs indicated minimal side effects by the treatment of the ZX-101A alone and in combination with anti-PD1. These results suggested ZX-101A as a potential immunotherapeutic agent to treat appropriate solid tumor types. ZX-101A-201 study consists of 2 parts, Dose Escalation and Dose Expansion. Part 1 dose escalation is designed to determine the safety, tolerability, and recommended phase 2 dose (RP2D) of ZX-101A monotherapy in patient with advanced solid tumors. Part 2 dose expansion will evaluate ZX-101A activity in up to three disease-specific cohorts. Inclusion of combination therapy is planned after obtaining the initial clinical assessment of ZX-101A on its safety, tolerability, pharmacokinetics, and pharmacodynamics in patients.

Citation Format: Xiaoli Qin, Lori Luo, Li Ying-ying, Yin Wang, Shuaijun Sun, Xiaolin Hao, Jinfu Yang. A Phase 1/2a Study of a PI3Kδγ dual inhibitor ZX-101A in patients with advanced solid tumors [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr CT526.
Abstract LB005: ATAK receptors, a new class of chimeric antigen receptors that harness innate immunity in myeloid cells to target cancer
Authors: Diwanji Neha , Kieffer-Kwon Kyong-Rim , Prod’homme Thomas , McCreedy Bruce , Wang Yuxiao , Getts Daniel
Published: June 2022

For the majority of patients with advanced solid tumors, sustained clinical benefit with immunotherapy has yet to be achieved. Myeloid cells, including monocytes and macrophages are the primary orchestrators of immune responses and are found to accumulate in tumors, in some cases contributing up to 75% of the tumor mass. Myeloid cells express a wide range of innate immune sensors such as Toll-like receptors, RIG-I and cGAS-STING as well as co-stimulatory molecules like CD40. The activation of these innate immune pathways in myeloid cells can associated with anti-tumor immune response. Notwithstanding the ability of the myeloid cells to infiltrate tumors and elicit broad immune responses, technologies capable of harnessing these cells to target cancer remains elusive. Here we designed and engineered a new class of chimeric antigen receptors that couple tumor recognition with multiple innate immune signal domains, referred to as Activate, Target, Attack & Kill (ATAK) receptors. By combining cancer recognition domains with intracellular signaling domains from innate immune receptors such as Fc, TLR and cytokine receptors, we show that myeloid cells can be controlled and programmed to recognize cancer and elicit a broad and tunable immune response. Critically, in mice with established, highly immunosuppressive B16 melanoma tumors, delivery of monocytes engineered to express ATAK receptors results in anti-tumor activity. Our data show the versatility of building ATAK receptors by harnessing innate immune pathways and support their clinical development in cell therapies.

Citation Format: Neha Diwanji, Kyong-Rim Kieffer-Kwon, Thomas Prod’homme, Bruce McCreedy, Yuxiao Wang, Daniel Getts. ATAK receptors, a new class of chimeric antigen receptors that harness innate immunity in myeloid cells to target cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr LB005.
Abstract LB014: Carbon monoxide induced PERK regulated autophagy reprograms anti-tumor T cells with robust immunometabolic phenotype
Authors: Chakraborty Paramita , Parikh Rasesh Y. , Choi Seungho , Mehrotra Meenal , Maldonado Eduardo N. , Wang Hongjun , Diehl J. Alan , Gangaraju Vamsi K. , Mehrotra Shikhar
Published: June 2022

Mitochondria and Endoplasmic reticulum (ER) share structural and functional networks to maintain cellular homeostasis and activate well-orchestrated signaling processes to shape cells' fate and function. While persistent ER stress (ERS) response leads to mitochondrial collapse, moderate ERS condition drives mitochondrial biogenesis and function. So far, various strategies have been tested to enhance the mitochondrial function in T cells to improve their anti-tumor potential. However, strategies targeting ER-Mitochondria crosstalk (by employing moderate ERS condition) to boost the anti-tumor T cell function have not been exploited yet. Thus, in the present study, we used carbon monoxide (CO), a short-lived gaseous molecule, to test if engaging moderate ERS conditions can improve T cells mitochondrial biogenesis, function, and anti-tumor therapeutic efficacy. Using melanoma antigen gp100 reactive T cells, we identify that CO induced transient activation of ERS sensor ‘protein kinase R-like endoplasmic reticulum kinase (PERK)’ dramatically increase anti-tumor T cell function. Furthermore, mechanistically we found that CO-induced PERK activation temporarily halts protein translation and induces protective autophagy (that includes mitophagy). To get further insight into how CO treatment kinetically regulates autophagic activity in T cells, we used LC3-GFP to differentiate between the cells that prepare themselves to undergo active autophagy (LC3-GFPpos) and those that fail to enter into the process (LC3-GFPneg). Using Ag-specific LC3-GFP expressing T cells, we demonstrate that LC3-GFPpos T cells show robust anti-tumor potential. Moreover, LC3-GFPneg shows a T regulatory-like phenotype, harbors dysfunctional mitochondria, and accumulates abnormal metabolite content. These anomalous ratios of metabolites render the cells with a hypermethylated state and distinct epigenetic profile limiting their anti-tumor activity. Overall, this preclinical data highlights that ERS-mediated activation of autophagy pathways modifies the mitochondrial function and epigenetically reprogram the T cells towards a superior anti-tumor phenotype and can be therapeutically translated to achieve robust tumor control in adoptive transfer therapies.

Citation Format: Paramita Chakraborty, Rasesh Y. Parikh, Seungho Choi, Meenal Mehrotra, Eduardo N. Maldonado, Hongjun Wang, J. Alan Diehl, Vamsi K. Gangaraju, Shikhar Mehrotra. Carbon monoxide induced PERK regulated autophagy reprograms anti-tumor T cells with robust immunometabolic phenotype [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr LB014.
Abstract LB032: CXCR7 drives prostate cancer growth through AURKA activation
Authors: Gritsina Galina , Lin Zhuoyuan , Fong Ka Wing , Lu Xiaodong , Zhao Changsheng , Yu Jindan
Published: June 2022

Prostate cancer (PCa) is the most commonly diagnosed cancer among males in the United States. The mainstay treatment for metastatic PCa patients is androgen-deprivation therapies, including high-affinity androgen receptor antagonists, such as enzalutamide. Unfortunately, most patients develop resistance and relapse with castration-resistant PCa (CRPC). We have previously reported up-regulation of CXCR7, an atypical chemokine receptor, in CRPC. CXCR7 interacts with beta-arrestin (ARRB2), a cytoplasmic scaffold protein, and translocates to the cytoplasm to induce signal transduction and PCa progression. However, much remains to be known regarding CXCR7-driven downstream signaling and its therapeutic targeting in advanced PCa. To unveil CXCR7-downstream signaling, we utilized RNA-seq to profile gene expression. Gene ontology analyses revealed remarkable enrichment of CXCR7-regulated genes in G2/M cell cycle progression. Comprehensive phospho-proteomics analysis of CXCR7-knockdown PCa cells showed markedly reduced phosphorylation of AURKA substrates. AURKA, a serine/threonine-protein kinase, is a key regulator of mitosis and G2/M progression and is frequently upregulated in CRPC and the late-stage neuroendocrine PCa (NEPC). Activated AURKA experiences autophosphorylation and phosphorylates downstream substrates, e.g., TACC3, that mediate proper cell division. Immunoblotting confirmed that CXCR7 depletion reduces phosphorylation of AURKA and TACC3. Co-immunoprecipitation revealed protein-protein interaction between CXCR7 and AURKA, which is mediated by ARRB2. Accordingly, ARRB2-knockdown similarly inhibits AURKA phosphorylation and arrests cell proliferation. Immunofluorescence coupled with confocal imaging demonstrated that CXCR7 is packed into clathrin-coated vesicles and locates in the plasma membrane, cytoplasm, and perinuclear Golgi complex, which surrounds the centrosomal AURKA and ARRB2. We found that CXCR7 translocates to the Golgi complex along microtubule-dependent trafficking. Finally, we found that pharmacological inhibitors of AURKA abolish CXCR7-driven PCa cell proliferation in vitro and tumor growth in vivo.

Conclusions: Our results describe for the first time that the CXCR7-ARRB2 complex interacts with AURKA and promotes its activation. Our data suggest that AURKA-targeting is a promising therapeutic strategy for CRPC and NEPC with CXCR7 up-regulation.

Citation Format: Galina Gritsina, Zhuoyuan Lin, Ka Wing Fong, Xiaodong Lu, Changsheng Zhao, Jindan Yu. CXCR7 drives prostate cancer growth through AURKA activation [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr LB032.
Abstract LB054: Prometastatic effect of ATX derived from alveolar type II pneumocytes and B16F10 melanoma cells
Authors: Dacheux Melanie A. , Lee Sue Chin , Shin Yoojin , Norman Derek D. , Lin Kuan-Hung , Tigyi Gabor J.
Published: June 2022

Although metastasis is the principal cause of cancer-related deaths, the molecular aspects of the role of stromal cells in the establishment of the metastatic niche remain poorly understood. One of the most prevalent sites for cancer metastasis is the lungs. According to recent research, lung stromal cells such as bronchial epithelial cells and resident macrophages secrete autotaxin (ATX), an enzyme with lysophospholipase D activity that promotes cancer progression. In fact, several studies have shown that many cell types in the lung stroma could potentially provide a rich source of ATX in diseases. In the present study, we sought to determine whether ATX derived from alveolar type II epithelial (ATII) pneumocytes could modulate the progression of lung metastasis, which has not been evaluated previously. To accomplish this, we used the B16-F10 syngeneic melanoma model, which readily metastasize to the lungs when injected intravenously. Because B16-F10 cells express high levels of ATX, we used the CRISPR-Cas9 technology to knockout (KO) ATX in B16-F10 cells, eliminating the contribution of tumor-derived ATX in lung metastasis. Next, we used the inducible Cre/lox system (Sftpc-CreERT2/Enpp2fl/fl) to generate conditional KO mice in which ATX is specifically deleted in ATII cells (i.e. Sftpc-KO). Injection of ATX-KO B16-F10 cells into Sftpc-KO or Sftpc-WT control littermates allows us to investigate the specific contribution of ATII-derived ATX in lung metastasis. We found that targeted KO of ATX in ATII cells significantly reduced the metastatic burden of ATX-KO B16-F10 cells by 30% compared to Sftpc-WT mice (unpaired t-test, p=0.0283), suggesting that ATX derived from ATII cells could affect the metastatic progression. We detected upregulated levels of cytokines such as IFNγ (unpaired t-test, p<0.0001) and TNFα (unpaired t-test, p=0.0003), which could favor the increase in infiltrating CD8+-T cells observed in the tumor regions of Sftpc-KO mice. Taken together, our results highlight the contribution of host ATII cells as a stromal source of ATX in the progression of melanoma lung metastasis.

Citation Format: Melanie A. Dacheux, Sue Chin Lee, Yoojin Shin, Derek D. Norman, Kuan-Hung Lin, Gabor J. Tigyi. Prometastatic effect of ATX derived from alveolar type II pneumocytes and B16F10 melanoma cells [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr LB054.
Abstract LB082: Genome-wide CRISPR activation screen identifies PRRX2 as an enzalutamide resistance gene in prostate cancer
Authors: Rodriguez Yara R. , Unno Kenji , Truica Mihai , Chalmers Zachary R. , Yoo Young A , Vatapalli Rajita , Sagar Vinay , Yu Jindan , Lysy Barbara , Han Huiying , Abdulkadir Sarki A.
Published: June 2022

Androgen receptor pathway inhibitors are the mainstay treatment for advanced prostate cancer, but resistance is common. Here, we used a CRISPR activation screen to identify genes that promote enzalutamide resistance in the metastatic castration-sensitive prostate cancer cell line LNCaP. We found that activation of the TGF-β target gene, PRRX2, promoted enzalutamide resistance. PRRX2 expression is highest in double negative prostate cancer (DNPC) patients and a PRRX2-related gene signature identified a subset of DNPC patients with lower overall survival. PRRX2 expressing cells showed alterations in the CDK4/6/Rb/E2F and BCL2 pathways. Accordingly, CDK4/6 and BCL2 inhibitors sensitized PRRX2-expressing enzalutamide-resistant tumors to enzalutamide. High PRRX2 expression/signature in prostate cancer merit investigation as markers of enzalutamide resistance that could be reversed with CDK4/6 and BCL2 inhibitors.

Citation Format: Yara R. Rodriguez, Kenji Unno, Mihai Truica, Zachary R. Chalmers, Young A Yoo, Rajita Vatapalli, Vinay Sagar, Jindan Yu, Barbara Lysy, Huiying Han, Sarki A. Abdulkadir. Genome-wide CRISPR activation screen identifies PRRX2 as an enzalutamide resistance gene in prostate cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr LB082.
Abstract LB096: EGFR-dependent inflammation as a driver of breast cancer
Authors: Escoto Angelica
Published: June 2022

Triple Negative Breast Cancer (TNBC) is one of the most aggressive and metastatic subtypes of hormone receptor negative breast cancers. Evidence supports that most patients with TNBC overexpress the Epidermal Growth Factor Receptor (EGFR), yet its role in driving the disease remains unclear. Therapies have been developed to target EGFR, but EGFR-targeted antibodies and tyrosine kinase inhibitors fail to work effectively in breast cancer patients. A possible explanation is that in addition to its canonical function at the membrane, EGFR has a non-canonical function where it can undergo retrograde trafficking to the nucleus, making it resistant to antibody-based therapeutics. Once in the nucleus, EGFR is known to function as a transcriptional cofactor for STAT3, STAT5, and E2F1, thereby regulating the expression of genes that promote inflammation and cell proliferation. Via RNA-Seq analysis, we demonstrate that EGFR can regulate different subsets of genes depending on its canonical signaling activity or nuclear role. Our goal is to understand and distinguish this difference in regulation to assess how EGFR affects inflammation. We hypothesize that EGFR is modifying inflammation differently depending on its canonical or non-canonical role, thereby driving disease progression in multiple ways. We have found that canonical EGFR can induce interleukin 8 while nuclear EGFR can repress interleukin 6 through the use of either kinase inhibitors (IL8) or blocking nuclear translocation of EGFR (IL6). Correlated with these changes are alterations in growth and inflammatory profiles in both a triple negative inflammatory mouse model and an EGFR-driven breast cancer mouse model. We are now investigating the role of nuclear-EGFR-dependent inflammation in driving tumor progression. Understanding the different mechanisms by which EGFR modifies inflammation and the tumor microenvironment would allow us to develop more specific targets for patients with TNBC.

Citation Format: Angelica Escoto. EGFR-dependent inflammation as a driver of breast cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr LB096.
Abstract LB128: Oncolytic HSV-P10 and effects on metabolism as potential therapy for treatment of glioblastoma
Authors: Mullarkey Matthew P. , Sahu Upasana , Hong Bangxing , Kaur Balveen
Published: June 2022

Glioblastoma is an aggressive tumor of the central nervous system associated with a very poor prognosis even with surgery and chemoradiation. We have previously developed an oHSV that encodes for PTENα (HSV-P10) and stimulates anti-tumor immunity. This virus is currently licensed by and is being developed by Mesoblast to evaluate safety and efficacy in patients. To understand the effect of PTENα on tumor cell responses to oHSV therapy we performed RNA sequencing of primary GBM cells infected with control or oHSV-P10. We identified a dysregulation of glycolysis in cells infected with oHSV-P10 relative to control oHSV. Since cancer cells rely heavily on glycolysis for energy production (Warburg effect) the impact of PTENα on metabolic switch was significant. RNA sequencing PCR and western blot analysis showed a significant reduction in cellular Hexokinase II expression and downregulation of HIF-1α in HSV-P10 infected cells. Consistent with the function of HIF1 and hexokinase in driving glycolysis we also observed a significant reduction in glucose uptake and lactate release: implying a reduction in glycolysis in cells after being treated with oHSV-P10. Thus, cellular energetics of HSV-P10 infected cells was directed away from glycolysis relative to HSVQ infected cells. Consistent with this we observed increased, oxidative phosphorylation, production of reactive oxidative species and ATP production. Many cancers, including Glioblastoma are known to utilize the glutamine as a substrate for energy production through its entry into the TCA cycle. Blocking this shows a significant decrease in cell viability and ATP production when combined with HSV-P10. These results indicate that combination of HSV-P10 with radiation has a significant therapeutic potential and should be tested in patients for safety and efficacy.

Citation Format: Matthew P. Mullarkey, Upasana Sahu, Bangxing Hong, Balveen Kaur. Oncolytic HSV-P10 and effects on metabolism as potential therapy for treatment of glioblastoma [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr LB128.
Abstract LB129: Analysis of KRAS wildtype pancreatic ductal adenocarcinoma reveals mutation and expression-based similarities to cholangiocarcinoma
Authors: Topham James , Tsang Erica , Karasinska Joanna , Metcalfe Andrew , Ali Hassan , Kalloger Steve , Csizmok Veronika , Williamson Laura , Titmuss Emma , Wong Hui-Li , Moore Richard , Mungall Andrew , Loree Jonathan , Bathe Oliver , Tang Patricia , Goodwin Rachel , Laskin Janessa , Marra Marco , Jones Steven , Schaeffer David , Renouf Daniel
Published: June 2022

Introduction

Oncogenic KRAS mutations are absent in 10% of patients with pancreatic ductal adenocarcinoma (PDAC) and may represent a subgroup of PDAC with therapy options beyond standard-of-care chemotherapy. While distinct gene fusions have been implicated in KRAS wildtype (wt) PDAC, other traits unique to KRAS wt PDAC remain unexplored.

Methods

Patients with treatment-naive metastatic PDAC (n=63) received matched tumor/normal whole-genome and RNA sequencing and clinical follow-up as part of the PanGen trial (NCT02869802). Clinical data and mutation, gene fusion and copy alteration frequency was compared between KRAS wt (n=9) and mutant (n=54) groups. Metastatic colorectal adenocarcinoma and cholangiocarcinoma samples from the POG trial (NCT02155621) were incorporated for sequencing-based comparison.

Results

KRAS wt tumors showed lower frequency of TP53 SNV/indels (p=0.01) and distinct amplifications affecting chr1q genes NR5A2 (p=9.0e-4), MPC2 (p=0.002) and MCL1 (p=0.02) and chr8q gene SQLE (p=0.02). Oncogenic fusions involving NRG1, FGFR2, NTRK2 or BRAF were unique to KRAS wt tumors (67% of samples; p=1e-6). KRAS wt tumors showed expression patterns indicative of cholangiocytes and, when clustered alongside other tumor types, formed a distinct cluster with cholangiocarcinoma samples.

Conclusion

These data provide the first identification of distinct chr1q/chr8q amplification events unique to KRAS wt PDAC while highlighting novel and striking molecular similarities to cholangiocarcinoma. Taken together, results of the PanGen trial generate new hypotheses relevant to therapeutic targeting of KRAS wt PDAC and rationale towards incorporating KRAS mutation status as part of routine clinical testing in PDAC.

Citation Format: James Topham, Erica Tsang, Joanna Karasinska, Andrew Metcalfe, Hassan Ali, Steve Kalloger, Veronika Csizmok, Laura Williamson, Emma Titmuss, Hui-Li Wong, Richard Moore, Andrew Mungall, Jonathan Loree, Oliver Bathe, Patricia Tang, Rachel Goodwin, Janessa Laskin, Marco Marra, Steven Jones, David Schaeffer, Daniel Renouf. Analysis of KRAS wildtype pancreatic ductal adenocarcinoma reveals mutation and expression-based similarities to cholangiocarcinoma [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr LB129.