bluuebunny/crossref_metadata_2025 huggingface dataset:
Data from Combination Immunotherapy with Cytotoxic T-Lymphocyte–Associated Antigen-4 and Programmed Death Protein-1 Inhibitors Prevents Postoperative Breast Tumor Recurrence and Metastasis
Authors: Sun Ting , Zhang Wenjia , Li Yuan , Jin Zhengyu , Du Yang , Tian Jie , Xue Huadan
Published: April 2023

Abstract
Postoperative tumor recurrence and metastasis remain an extreme challenge in breast cancer. Therapies that target cytotoxic T-lymphocyte–associated antigen 4 (CTLA-4) and programmed cell death protein 1 (PD-1) have provided unprecedented clinical benefits in various types of cancer. The aim of this study was to determine whether the combination of anti-CTLA-4 and anti-PD-1 could prevent postoperative breast tumor recurrence and metastasis in breast tumor–bearing mice. The results indicated that the combination of CTLA-4 and PD-1 inhibitors was more effective compared with single inhibitors for mammary tumor growth and prevention of postsurgical tumor recurrence and pulmonary metastasis (P < 0.05), which resulted in prolonged survival (P < 0.05). Analysis of the underlying mechanism revealed that anti-CTLA-4 and anti-PD-1 in combination synergistically promoted the infiltration of CD8+ and CD4+ T cells into tumors (P < 0.05 vs. single inhibitors), thus boosting the antitumor immune responses. In summary, our results revealed that combination immunotherapy with anti-CTLA-4 and anti-PD-1 may present a new, promising regimen to inhibit postoperative breast cancer relapse and lung metastasis and improve patient outcomes, which warrants further investigation in clinical settings.
Data from Menin-mediated Repression of Glycolysis in Combination with Autophagy Protects Colon Cancer Against Small-molecule EGFR Inhibitors
Authors: Katona Bryson W. , Hojnacki Taylor , Glynn Rebecca A. , Paulosky Kayla E. , Szigety Katherine M. , Cao Yan , Zhang Xuyao , Feng Zijie , He Xin , Ma Jian , Hua Xianxin
Published: April 2023

Abstract
Menin serves both tumor suppressor and promoter roles in a highly tumor-specific manner. In colorectal cancer, menin is overexpressed and plays a critical role in regulating transcription of SKP2, and combined treatment with a menin inhibitor and small-molecule EGFR inhibitor (EGFRi) leads to synergistic killing of colorectal cancer cells. However, the full spectrum of menin function in colorectal cancer remains uncertain. Herein, we demonstrate that menin inhibition increases glycolysis in colorectal cancer cells. This menin inhibitor–induced increase in glycolysis occurs in an mTOR-independent manner and enhances the sensitivity of colorectal cancer cells to EGFRis. In addition, we show that EGFRis induce autophagy in colorectal cancer cells, which is important for cell survival in the setting of combined treatment with an EGFRi and menin inhibitor. Inhibition of autophagy with chloroquine further sensitizes colorectal cancers to treatment with the combination of an EGFRi and menin inhibitor. Together, these findings uncover a novel role for menin in colorectal cancer as a repressor of glycolysis and demonstrate that menin inhibitor–induced increases in glycolysis sensitize colorectal cancer cells to EGFRis. In addition, these findings illustrate the importance of autophagy as a protective mechanism against EGFRis, especially in the presence of menin inhibition. Ultimately, these data open the possibility of using menin-mediated regulation of glycolysis to potentially improve treatment modalities for colorectal cancer.
Data from Survival Implications of the Relationship between Tissue versus Circulating Tumor DNA TP53 Mutations—A Perspective from a Real-World Precision Medicine Cohort
Authors: Rosenberg Shai , Okamura Ryosuke , Kato Shumei , Soussi Thierry , Kurzrock Razelle
Published: April 2023

Abstract
Interrogating the genomics of circulating tumor DNA (ctDNA; the liquid biopsy) has advantages in patients in whom tissue biopsy is difficult. However, the reported concordance between genomic analysis of tissue DNA and ctDNA is variable among studies. Herein, we characterized the clinical implications of the relationship between mutations in TP53 genes in tissue DNA versus ctDNA. The molecular profiles of both liquid (Guardant Health) and tissue (Foundation Medicine) biopsies from 433 patients were analyzed (pan-cancer setting). In 71/433 (16%) cases, all same TP53 mutations were detected in both tissue DNA and ctDNA; in 18/433 (4%), same mutation plus additional mutation/mutations; and in 27/433 (6%), different TP53 mutations were detected. In 99/433 (23%) cases, TP53 mutations were detected only in tissue DNA; in 43/433 (10%), only in ctDNA; and in 175/433 (40%), no TP53 mutations were detected in either test. When TP53 mutations were identical in tissue and ctDNA, the alterations were enriched for nonsense mutations, and survival was significantly shorter in multivariate analysis (as compared with different mutations in ctDNA vs. tissue or no mutations); this finding was independent of tumor type, time interval between tests, and the %ctDNA for TP53 mutations. In summary, in 16% of 433 patients with diverse cancers, TP53 mutations were identical in tissue DNA and ctDNA. In these individuals, the alterations were enriched for stop–gain (nonsense) mutations (results in a premature termination codon). Though unknown confounders cannot be ruled out, these patients fared significantly worse than those whose ctDNA and tissue DNA harbored different TP53 mutation portfolios or no TP53 mutations.
Data from Microparticle Encapsulation of a Prostate-targeted Biologic for the Treatment of Liver Metastases in a Preclinical Model of Castration-resistant Prostate Cancer
Authors: Rogers Oliver C. , Antony Lizamma , Levy Oren , Joshi Nitin , Simons Brian W. , Dalrymple Susan L. , Rosen D. Marc , Pickering Andrew , Lan Haoyue , Kuang Heidi , Ranganath Sudhir H. , Zheng Lei , Karp Jeffrey M. , Howard S. Peter , Denmeade Samuel R. , Isaacs John T. , Brennen W. Nathaniel
Published: April 2023

Abstract
PRX302 is a highly potent, mutant bacterial pore-forming biologic protoxin engineered for selective activation by PSA, a serine protease expressed by benign and malignant prostate epithelial cells. Although being developed as a local therapy for benign prostatic hyperplasia and localized prostate cancer, PRX302 cannot be administered systemically as a treatment for metastatic disease due to binding to ubiquitously expressed glycosylphosphatidylinositol (GPI)-anchored proteins, which leads to poor accumulation within the tumor microenvironment. To overcome this limitation, poly-lactic-co-glycolic acid (PLGA) microparticles encapsulating the protoxin were developed, which are known to accumulate in the liver, a major site of metastasis for prostate cancer and other solid tumors. A highly sensitive and reproducible sandwich ELISA to quantify PRX302 released from microparticles was developed. Utilizing this assay, PRX302 release from different microparticle formulations was assessed over multiple days. Hemolysis assays documented PSA-dependent pore formation and lytic potential (i.e., function) of the released protoxin. MTT assays demonstrated that conditioned supernatant from PRX302-loaded, but not blank (i.e., unloaded), PLGA microparticles was highly cytotoxic to PC3 and DU145 human prostate cancer cells in the presence of exogenous PSA. Microparticle encapsulation prevented PRX302 from immediately interacting with GPI-anchored proteins as demonstrated in a competition assay, which resulted in an increased therapeutic index and significant antitumor efficacy following a single dose of PRX302-loaded microparticles in a preclinical model of prostate cancer liver metastasis with no obvious toxicity. These results document that PRX302 released from PLGA microparticles demonstrate in vivo antitumor efficacy in a clinically relevant preclinical model of metastatic prostate cancer.
Data from On-Target Pharmacodynamic Activity of the PI3K Inhibitor Copanlisib in Paired Biopsies from Patients with Malignant Lymphoma and Advanced Solid Tumors
Authors: Morschhauser Franck , Machiels Jean-Pascal , Salles Gilles , Rottey Sylvie , Rule Simon A.J. , Cunningham David , Peyrade Frederic , Fruchart Christophe , Arkenau Hendrik-Tobias , Genvresse Isabelle , Liu Li , Köchert Karl , Shen Kui , Kneip Christoph , Peña Carol E. , Grevel Joachim , Zhang Jun , Cisternas Galia , Reschke Susanne , Granvil Camille , Awada Ahmad
Published: April 2023

Abstract
The PI3K inhibitor copanlisib has efficacy and manageable safety in patients with indolent lymphoma and solid tumors. Pharmacodynamic effects relative to copanlisib dose and plasma exposure were evaluated. Patients with lymphoma or solid tumors received copanlisib 0.4 or 0.8 mg/kg on days 1, 8, and 15 of a 28-day cycle. Primary variables were maximum changes in phosphorylated AKT (pAKT) levels in platelet-rich plasma (PRP) and plasma glucose. Other evaluations included PI3K signaling markers and T-lymphocytes in paired tumor biopsies, the relationship between estimated plasma exposure and pharmacodynamic markers, response, and safety. Sixty-three patients received copanlisib. PRP pAKT levels showed sustained reductions from baseline following copanlisib [median inhibition: 0.4 mg/kg, 73.8% (range −94.9 to 144.0); 0.8 mg/kg, 79.6% (range −96.0 to 408.0)]. Tumor pAKT was reduced versus baseline with copanlisib 0.8 mg/kg in paired biopsy samples (P < 0.05). Dose-related transient plasma glucose elevations were observed. Estimated copanlisib plasma exposure significantly correlated with changes in plasma pAKT and glucose metabolism markers. There were two complete responses and six partial responses; seven of eight responders received copanlisib 0.8 mg/kg. Adverse events (all grade) included hyperglycemia (52.4%), fatigue (46.0%), and hypertension (41.3%). Copanlisib demonstrated dose-dependent pharmacodynamic evidence of target engagement and PI3K pathway modulation/inhibition in tumor and immune cells. Results support the use of copanlisib 0.8 mg/kg (or flat-dose equivalent of 60 mg) in solid tumors and lymphoma, and provide a biomarker hypothesis for studies of copanlisib combined with immune checkpoint inhibitors (NCT03711058).
Data from Amivantamab (JNJ-61186372), an Fc Enhanced EGFR/cMet Bispecific Antibody, Induces Receptor Downmodulation and Antitumor Activity by Monocyte/Macrophage Trogocytosis
Authors: Vijayaraghavan Smruthi , Lipfert Lorraine , Chevalier Kristen , Bushey Barbara S. , Henley Benjamin , Lenhart Ryan , Sendecki Jocelyn , Beqiri Marilda , Millar Hillary J. , Packman Kathryn , Lorenzi Matthew V. , Laquerre Sylvie , Moores Sheri L.
Published: April 2023

Abstract
Small molecule inhibitors targeting mutant EGFR are standard of care in non–small cell lung cancer (NSCLC), but acquired resistance invariably develops through mutations in EGFR or through activation of compensatory pathways such as cMet. Amivantamab (JNJ-61186372) is an anti-EGFR and anti-cMet bispecific low fucose antibody with enhanced Fc function designed to treat tumors driven by activated EGFR and/or cMet signaling. Potent in vivo antitumor efficacy is observed upon amivantamab treatment of human tumor xenograft models driven by mutant activated EGFR, and this activity is associated with receptor downregulation. Despite these robust antitumor responses in vivo, limited antiproliferative effects and EGFR/cMet receptor downregulation by amivantamab were observed in vitro. Interestingly, in vitro addition of isolated human immune cells notably enhanced amivantamab-mediated EGFR and cMet downregulation, leading to antibody dose-dependent cancer cell killing. Through a comprehensive assessment of the Fc-mediated effector functions, we demonstrate that monocytes and/or macrophages, through trogocytosis, are necessary and sufficient for Fc interaction-mediated EGFR/cMet downmodulation and are required for in vivo antitumor efficacy. Collectively, our findings represent a novel Fc-dependent macrophage-mediated antitumor mechanism of amivantamab and highlight trogocytosis as an important mechanism of action to exploit in designing new antibody-based cancer therapies.
Data from An RNA-Binding Protein, Hu-antigen R, in Pancreatic Cancer Epithelial to Mesenchymal Transition, Metastasis, and Cancer Stem Cells
Authors: Dong Ruochen , Chen Ping , Polireddy Kishore , Wu Xiaoqing , Wang Tao , Ramesh Remya , Dixon Dan A. , Xu Liang , Aubé Jeffrey , Chen Qi
Published: April 2023

Abstract
Pancreatic cancer has poor prognosis and treatment outcomes due to its highly metastatic nature and resistance to current treatments. The RNA-binding protein (RBP) Hu-antigen R (HuR) is a central player in posttranscriptional regulation of cancer-related gene expression, and contributes to tumorigenesis, tumor growth, metastasis, and drug resistance. HuR has been suggested to regulate pancreatic cancer epithelial-to-mesenchymal transition (EMT), but the mechanism was not well understood. Here, we further elucidated the role HuR plays in pancreatic cancer cell EMT, and developed a novel inhibitor specifically interrupting HuR–RNA binding. The data showed that HuR binds to the 3′-UTR of the mRNA of the transcription factor Snail, resulting in stabilization of Snail mRNA and enhanced Snail protein expression, thus promoted EMT, metastasis, and formation of stem-like cancer cells (CSC) in pancreatic cancer cells. siRNA silencing or CRISPR/Cas9 gene deletion of HuR inhibited pancreatic cancer cell EMT, migration, invasion, and inhibited CSCs. HuR knockout cells had dampened tumorigenicity in immunocompromised mice. A novel compound KH-3 interrupted HuR–RNA binding, and KH-3 inhibited pancreatic cancer cell viability, EMT, migration/invasion in vitro. KH-3 showed HuR-dependent activity and inhibited HuR-positive tumor growth and metastasis in vivo.
Data from Targeting Histone Chaperone FACT Complex Overcomes 5-Fluorouracil Resistance in Colon Cancer
Authors: Song Heyu , Zeng Jiping , Roychoudhury Shrabasti , Biswas Pranjal , Mohapatra Bhopal , Ray Sutapa , Dowlatshahi Kayvon , Wang Jing , Band Vimla , Talmon Geoffrey , Bhakat Kishor K.
Published: April 2023

Abstract
Fluorouracil (5-FU) remains a first-line chemotherapeutic agent for colorectal cancer. However, a subset of colorectal cancer patients who have defective mismatch-repair (dMMR) pathway show resistance to 5-FU. Here, we demonstrate that the efficacy of 5-FU in dMMR colorectal cancer cells is largely dependent on the DNA base excision repair (BER) pathway. Downregulation of APE1, a key enzyme in the BER pathway, decreases IC50 of 5-FU in dMMR colorectal cancer cells by 10-fold. Furthermore, we discover that the facilitates chromatin transcription (FACT) complex facilitates 5-FU repair in DNA via promoting the recruitment and acetylation of APE1 (AcAPE1) to damage sites in chromatin. Downregulation of FACT affects 5-FU damage repair in DNA and sensitizes dMMR colorectal cancer cells to 5-FU. Targeting the FACT complex with curaxins, a class of small molecules, significantly improves the 5-FU efficacy in dMMR colorectal cancer in vitro (∼50-fold decrease in IC50) and in vivo xenograft models. We show that primary tumor tissues of colorectal cancer patients have higher FACT and AcAPE1 levels compared with adjacent nontumor tissues. Additionally, there is a strong clinical correlation of FACT and AcAPE1 levels with colorectal cancer patients' response to chemotherapy. Together, our study demonstrates that targeting FACT with curaxins is a promising strategy to overcome 5-FU resistance in dMMR colorectal cancer patients.
Data from The Glutaminase Inhibitor CB-839 (Telaglenastat) Enhances the Antimelanoma Activity of T-Cell–Mediated Immunotherapies
Authors: Varghese Sruthy , Pramanik Snigdha , Williams Leila J. , Hodges Hannah R. , Hudgens Courtney W. , Fischer Grant M. , Luo Catherine K. , Knighton Barbara , Tan Lin , Lorenzi Philip L. , Mackinnon Andrew L. , McQuade Jennifer L. , Hailemichael Yared , Roszik Jason , Peng Weiyi , Vashisht Gopal Y.N.
Published: April 2023

Abstract
Immune-checkpoint inhibitors and adoptive tumor-infiltrating lymphocyte (TIL) therapies have profoundly improved the survival of patients with melanoma. However, a majority of patients do not respond to these agents, and many responders experience disease relapse. Although numerous innovative treatments are being explored to offset the limitations of these agents, novel therapeutic combinations with immunotherapies have the potential to improve patient responses. In this study, we evaluated the antimelanoma activity of immunotherapy combinations with Telaglenastat (CB-839), a potent glutaminase inhibitor (GLSi) that has favorable systemic tolerance. In in vitro TIL:tumor coculture studies, CB-839 treatment improved the cytotoxic activity of autologous TILs on patient-derived melanoma cells. CB-839 treatment decreased the conversion of glutamine to alpha-ketoglutarate (αKGA) more potently in tumor cells versus TILs in these cocultures. These results suggest that CB-839 may improve immune function in a tumor microenvironment by differentially altering tumor and immune cell metabolism. In vivo CB-839 treatment activated melanoma antigen–specific T cells and improved their tumor killing activity in an immune-competent mouse model of adoptive T-cell therapy. Additionally, the combination of CB-839 with anti-PD1 or anti-CTLA4 antibodies increased tumor infiltration by effector T cells and improved the antitumor activity of these checkpoint inhibitors in a high mutation burden mouse melanoma model. Responsiveness to these treatments was also accompanied by an increase of interferon gamma (IFNγ)–associated gene expression in the tumors. Together, these results provide a strong rationale for combining CB-839 with immune therapies to improve efficacy of these treatments against melanoma.
Data from Preclinical Characterization of an Antibody–Drug Conjugate Targeting CS-1 and the Identification of Uncharacterized Populations of CS-1–Positive Cells
Authors: Chen Ruoyan , Rajan Saravanan , Overstreet Michael G. , Hurt Elaine M. , Thomas Suneetha B. , Muniz-Medina Vanessa , Ward Christopher , Sadowska Agnieszka , Fleming Ryan , Karanth Subramanya , Breen Shannon , Zheng Bo , Wu Yuling , Iverson William O. , Novick Steven , O'Day Terrence , Shah Dipesha P. , Dimasi Nazzareno , Tiberghien Arnaud C. , Osbourn Jane , Walker Jill
Published: April 2023

Abstract
Multiple myeloma is a hematologic cancer that disrupts normal bone marrow function and has multiple lines of therapeutic options, but is incurable as patients ultimately relapse. We developed a novel antibody–drug conjugate (ADC) targeting CS-1, a protein that is highly expressed on multiple myeloma tumor cells. The anti–CS-1 mAb specifically bound to cells expressing CS-1 and, when conjugated to a cytotoxic pyrrolobenzodiazepine payload, reduced the viability of multiple myeloma cell lines in vitro. In mouse models of multiple myeloma, a single administration of the CS-1 ADC caused durable regressions in disseminated models and complete regression in a subcutaneous model. In an exploratory study in cynomolgus monkeys, the CS-1 ADC demonstrated a half-life of 3 to 6 days; however, no highest nonseverely toxic dose was achieved, as bone marrow toxicity was dose limiting. Bone marrow from dosed monkeys showed reductions in progenitor cells as compared with normal marrow. In vitro cell killing assays demonstrated that the CS-1 ADC substantially reduced the number of progenitor cells in healthy bone marrow, leading us to identify previously unreported CS-1 expression on a small population of progenitor cells in the myeloid–erythroid lineage. This finding suggests that bone marrow toxicity is the result of both on-target and off-target killing by the ADC.
Data from Blockade of the Short Form of Prolactin Receptor Induces FOXO3a/EIF-4EBP1–Mediated Cell Death in Uterine Cancer
Authors: Wen Yunfei , Wang Ying , Chelariu-Raicu Anca , Stur Elaine , Liu Yuan , Corvigno Sara , Bartsch Faith , Redfern Lauren , Zand Behrouz , Kang Yu , Liu Jinsong , Baggerly Keith , Sood Anil K.
Published: April 2023

Abstract
Abnormal activity of human prolactin (PRL) and its membrane-associated receptor (PRLR) contributes to the progression of uterine carcinoma. However, the underlying mechanisms are not well understood, and current means of targeting the PRL/PRLR axis in uterine cancer are limited. Our integrated analyses using The Cancer Genome Atlas and Genotype-Tissue Expression (GTEx) databases demonstrated that a short form of PRLR (PRLR_SF) is the isoform predominantly expressed in human uterine cancers; expression of this PRLR_SF was elevated in uterine cancers in comparison with cancer-free uterine tissues. We hypothesized that the overexpression of PRLR_SF in uterine cancer cells contributes, in part, to the oncogenic activity of the PRL/PRLR axis. Next, we employed G129R, an antagonist of human PRL, to block the PRL/PRLR axis in both PTENwt and PTENmut orthotopic mouse models of uterine cancer. In comparison with control groups, treatment with G129R as monotherapy or in combination with paclitaxel resulted in a significant reduction of growth and progression of orthotopic uterine tumors. Results from protein profiling of uterine cancer cells and in vivo tumors revealed a set of new downstream targets for G129R. Our results showed that G129R induced sub-G0 population arrest, decreased nascent protein synthesis, and initiated FOXO3a/EIF-4EBP1–mediated cell death in both PTENwt and PTENmut uterine cancer cells. Collectively, our results show a unique pattern of PRLR_SF expression predominantly in uterine cancer. Moreover, FOXO3a and EIF-4EBP1 are important mediators of cell death following G129R treatment in uterine cancer models.
Data from Endogenous Retrovirus Transcript Levels Are Associated with Immunogenic Signatures in Multiple Metastatic Cancer Types
Authors: Topham James T. , Titmuss Emma , Pleasance Erin D. , Williamson Laura M. , Karasinska Joanna M. , Culibrk Luka , Lee Michael K.C. , Mendis Shehara , Denroche Robert E. , Jang Gun-Ho , Kalloger Steve E. , Wong Hui-Li , Moore Richard A. , Mungall Andrew J. , O'Kane Grainne M. , Knox Jennifer J. , Gallinger Steven , Loree Jonathan M. , Mager Dixie L. , Laskin Janessa , Marra Marco A. , Jones Steven J.M. , Schaeffer David F. , Renouf Daniel J.
Published: April 2023

Abstract
Next-generation sequencing of solid tumors has revealed variable signatures of immunogenicity across tumors, but underlying molecular characteristics driving such variation are not fully understood. Although expression of endogenous retrovirus (ERV)-containing transcripts can provide a source of tumor-specific neoantigen in some cancer models, associations between ERV levels and immunogenicity across different types of metastatic cancer are not well established. We performed bioinformatics analysis of genomic, transcriptomic, and clinical data across an integrated cohort of 199 patients with metastatic breast, colorectal, and pancreatic ductal adenocarcinoma tumors. Within each cancer type, we identified a subgroup of viral mimicry tumors in which increased ERV levels were coupled with transcriptional signatures of autonomous antiviral response and immunogenicity. In addition, viral mimicry colorectal and pancreatic tumors showed increased expression of DNA demethylation gene TET2. Taken together, these data demonstrate the existence of an ERV-associated viral mimicry phenotype across three distinct metastatic cancer types, while indicating links between ERV abundance, epigenetic dysregulation, and immunogenicity.
Data from Targeting the PI3K/AKT Pathway Overcomes Enzalutamide Resistance by Inhibiting Induction of the Glucocorticoid Receptor
Authors: Adelaiye-Ogala Remi , Gryder Berkley E. , Nguyen Yen Thi Minh , Alilin Aian Neil , Grayson Adlai R. , Bajwa Wardah , Jansson Keith H. , Beshiri Michael L. , Agarwal Supreet , Rodriguez-Nieves Jose Antonio , Capaldo Brian , Kelly Kathleen , VanderWeele David J.
Published: April 2023

Abstract
The PI3K–AKT pathway has pleiotropic effects and its inhibition has long been of interest in the management of prostate cancer, where a compensatory increase in PI3K signaling has been reported following androgen receptor (AR) blockade. Prostate cancer cells can also bypass AR blockade through induction of other hormone receptors, in particular the glucocorticoid receptor (GR). Here we demonstrate that AKT inhibition significantly decreases cell proliferation through both cytostatic and cytotoxic effects. The cytotoxic effect is enhanced by AR inhibition and is most pronounced in models that induce compensatory GR expression. AKT inhibition increases canonical AR activity and remodels the chromatin landscape, decreasing enhancer interaction at the GR gene (NR3C1) locus. Importantly, it blocks induction of GR expression and activity following AR blockade. This is confirmed in multiple in vivo models, where AKT inhibition of established xenografts leads to increased canonical AR activity, decreased GR expression, and marked antitumor activity. Overall, our results demonstrate that inhibition of the PI3K/AKT pathway can block GR activity and overcome GR-mediated resistance to AR-targeted therapy. Ipatasertib is currently in clinical development, and GR induction may be a biomarker to identify responsive patients or a responsive disease state.
Data from Combinatorial Efficacy of Olaparib with Radiation and ATR Inhibitor Requires PARP1 Protein in Homologous Recombination–Proficient Pancreatic Cancer
Authors: Parsels Leslie A. , Engelke Carl G. , Parsels Joshua , Flanagan Sheryl A. , Zhang Qiang , Tanska Daria , Wahl Daniel R. , Canman Christine E. , Lawrence Theodore S. , Morgan Meredith A.
Published: April 2023

Abstract
PARP inhibitor monotherapy (olaparib) was recently FDA approved for the treatment of BRCA1/2-mutant, homologous recombination (HR) repair-deficient pancreatic cancer. Most pancreatic cancers, however, are HR proficient and thus resistant to PARP inhibitor monotherapy. We tested the hypothesis that combined therapy with radiation and ataxia telangiectasia and Rad3-related (ATR) inhibitor (AZD6738) would extend the therapeutic indication of olaparib to HR-proficient pancreatic cancers. We show that olaparib combined with AZD6738 significantly reduced radiation survival relative to either agent alone, regardless of HR status. Whereas catalytic inhibition of PARP with low concentrations of olaparib radiosensitized HR-deficient models, maximal sensitization in HR-proficient models required concentrations of olaparib that induce formation of PARP1–DNA complexes. Furthermore, CRISPR-Cas9–mediated PARP1 deletion failed to recapitulate the effects of olaparib on radiosensitivity and negated the combinatorial efficacy of olaparib and AZD6738 on radiosensitization, suggesting that PARP1–DNA complexes, rather than PARP catalytic inhibition, were responsible for radiosensitization. Mechanistically, therapeutic concentrations of olaparib in combination with radiation and AZD6738 increased DNA double-strand breaks. DNA fiber combing revealed that high concentrations of olaparib did not stall replication forks but instead accelerated replication fork progression in association with an ATR-mediated replication stress response that was antagonized by AZD6738. Finally, in HR-proficient tumor xenografts, the combination of olaparib, radiation, and AZD6738 significantly delayed tumor growth compared with all other treatments. These findings suggest that PARP1–DNA complexes are required for the therapeutic activity of olaparib combined with radiation and ATR inhibitor in HR-proficient pancreatic cancer and support the clinical development of this combination for tumors intrinsically resistant to PARP inhibitors.
Data from Elucidation of Pelareorep Pharmacodynamics in A Phase I Trial in Patients with KRAS-Mutated Colorectal Cancer
Authors: Goel Sanjay , Ocean Allyson J. , Parakrama Ruwan Y. , Ghalib Mohammad H. , Chaudhary Imran , Shah Umang , Viswanathan Sengottuvel , Kharkwal Himanshu , Coffey Matthew , Maitra Radhashree
Published: April 2023

Abstract
KRAS mutation is a negative predictive biomarker of anti-EGFR agents in patients with metastatic colorectal cancer (mCRC), and remains an elusive target. Pelareorep, a double-stranded RNA virus selectively replicates in KRAS-mutated cells, and is synergistic with irinotecan. A dose escalation trial of FOLFIRI/bevacizumab [irinotecan (150–180 mg/m2) and pelareorep (1 × 1010 TCID50–3 × 1010 TCID50)] was implemented in adult patients with oxaliplatin refractory/intolerant, KRAS-mutant mCRC. Pelareorep was administered intravenously over 1 hour on days 1–5 every 4 weeks. Additional studies included pharmacokinetics, tumor morphology, and immune responses. Among FOLFIRI-naïve patients, the highest dose of FOLFIRI/bevacizumab (180 mg/m2 irinotecan) and pelareorep (3 × 1010 TCID50) was well tolerated, without a dose-limiting toxicity. At the recommended phase II dose, 3 of 6 patients (50%) had a partial response; the median progression-free and overall survival (PFS, OS) were 65.6 weeks and 25.1 months, respectively. Toxicities included myelosuppression, fatigue, and diarrhea. Transmission electron microscopy revealed viral factories (viral collections forming vesicular structures), at various stages of development. Immunogold staining against viral capsid σ-1 protein demonstrated viral “homing” in the tumor cells. The nucleus displayed sufficient euchromatin regions suggestive of active transcription. Flow cytometry revealed rapid dendritic cell maturation (48 hours) with subsequent activation of cytotoxic T cells (7 days). The combination of pelareorep with FOLFIRI/bevacizumab is safe. The PFS and OS data are encouraging and deserve further exploration. Pelareorep leads to a clear recurrent immune stimulatory response with cytotoxic T-cell activation, and homes and replicates in the tumor.
Data from Isoform- and Phosphorylation-specific Multiplexed Quantitative Pharmacodynamics of Drugs Targeting PI3K and MAPK Signaling in Xenograft Models and Clinical Biopsies
Authors: Herrick William G. , Kilpatrick Casey L. , Hollingshead Melinda G. , Esposito Dominic , O'Sullivan Coyne Geraldine , Gross Andrea M. , Johnson Barry C. , Chen Alice P. , Widemann Brigitte C. , Doroshow James H. , Parchment Ralph E. , Srivastava Apurva K.
Published: April 2023

Abstract
Ras/Raf/MEK/ERK (MAPK) and PI3K/AKT signaling pathways influence several cell functions involved in oncogenesis, making them attractive drug targets. We describe a novel multiplex immunoassay to quantitate isoform-specific phosphorylation of proteins in the PI3K/AKT and MAPK pathways as a tool to assess pharmacodynamic changes. Isoform-specific assays measuring total protein and site-specific phosphorylation levels of ERK1/2, MEK1/2, AKT1/2/3, and rpS6 were developed on the Luminex platform with validated antibody reagents. The multiplex assay demonstrated satisfactory analytic performance. Fit-for-purpose validation was performed with xenograft models treated with selected agents. In PC3 and HCC70 xenograft tumors, the PI3Kβ inhibitor AZD8186 suppressed phosphorylation of AKT1, AKT2, and rpS6 for 4 to 7 hours post single dose, but levels returned to baseline by 24 hours. AKT3 phosphorylation was suppressed in PC3 xenografts at all doses tested, but only at the highest dose in HCC70. The AKT inhibitor MK-2206 reduced AKT1/2/3 phosphorylation in SW620 xenograft tumors 2 to 4 hours postdose, and the MEK inhibitor selumetinib reduced MEK1/2 and ERK1/2 phosphorylation by up to 50% and >90%, respectively. Clinical utility was demonstrated by analyzing biopsies from untreated patients with plexiform neurofibromas enrolled in a clinical trial of selumetinib (NCT02407405). These biopsies showed MEK and ERK phosphorylation levels sufficient for measuring up to 90% inhibition, and low AKT and rpS6 phosphorylation. This validated multiplex immunoassay demonstrates the degree and duration of phosphorylation modulation for three distinct classes of drugs targeting the PI3K/AKT and MAPK pathways.
Data from Selective and Potent CDK8/19 Inhibitors Enhance NK-Cell Activity and Promote Tumor Surveillance
Authors: Hofmann Marco H. , Mani Rajeswaran , Engelhardt Harald , Impagnatiello Maria A. , Carotta Sebastian , Kerenyi Marc , Lorenzo-Herrero Seila , Böttcher Jark , Scharn Dirk , Arnhof Heribert , Zoephel Andreas , Schnitzer Renate , Gerstberger Thomas , Sanderson Michael P. , Rajgolikar Girish , Goswami Swagata , Vasu Sumithira , Ettmayer Peter , Gonzalez Segundo , Pearson Mark , McConnell Darryl B. , Kraut Norbert , Muthusamy Natarajan , Moll Jürgen
Published: April 2023

Abstract
Natural killer (NK) cells play a pivotal role in controlling cancer. Multiple extracellular receptors and internal signaling nodes tightly regulate NK activation. Cyclin-dependent kinases of the mediator complex (CDK8 and CDK19) were described as a signaling intermediates in NK cells. Here, we report for the first time the development and use of CDK8/19 inhibitors to suppress phosphorylation of STAT1S727 in NK cells and to augment the production of the cytolytic molecules perforin and granzyme B (GZMB). Functionally, this resulted in enhanced NK-cell–mediated lysis of primary leukemia cells. Treatment with the CDK8/19 inhibitor BI-1347 increased the response rate and survival of mice bearing melanoma and breast cancer xenografts. In addition, CDK8/19 inhibition augmented the antitumoral activity of anti–PD-1 antibody and SMAC mimetic therapy, both agents that promote T-cell–mediated antitumor immunity. Treatment with the SMAC mimetic compound BI-8382 resulted in an increased number of NK cells infiltrating EMT6 tumors. Combination of the CDK8/19 inhibitor BI-1347, which augments the amount of degranulation enzymes, with the SMAC mimetic BI-8382 resulted in increased survival of mice carrying the EMT6 breast cancer model. The observed survival benefit was dependent on an intermittent treatment schedule of BI-1347, suggesting the importance of circumventing a hyporesponsive state of NK cells. These results suggest that CDK8/19 inhibitors can be combined with modulators of the adaptive immune system to inhibit the growth of solid tumors, independent of their activity on cancer cells, but rather through promoting NK-cell function.
Data from Pharmacologic Inhibitor of DNA-PK, M3814, Potentiates Radiotherapy and Regresses Human Tumors in Mouse Models
Authors: Zenke Frank T. , Zimmermann Astrid , Sirrenberg Christian , Dahmen Heike , Kirkin Vladimir , Pehl Ulrich , Grombacher Thomas , Wilm Claudia , Fuchss Thomas , Amendt Christiane , Vassilev Lyubomir T. , Blaukat Andree
Published: April 2023

Abstract
Physical and chemical DNA-damaging agents are used widely in the treatment of cancer. Double-strand break (DSB) lesions in DNA are the most deleterious form of damage and, if left unrepaired, can effectively kill cancer cells. DNA-dependent protein kinase (DNA-PK) is a critical component of nonhomologous end joining (NHEJ), one of the two major pathways for DSB repair. Although DNA-PK has been considered an attractive target for cancer therapy, the development of pharmacologic DNA-PK inhibitors for clinical use has been lagging. Here, we report the discovery and characterization of a potent, selective, and orally bioavailable DNA-PK inhibitor, M3814 (peposertib), and provide in vivo proof of principle for DNA-PK inhibition as a novel approach to combination radiotherapy. M3814 potently inhibits DNA-PK catalytic activity and sensitizes multiple cancer cell lines to ionizing radiation (IR) and DSB-inducing agents. Inhibition of DNA-PK autophosphorylation in cancer cells or xenograft tumors led to an increased number of persistent DSBs. Oral administration of M3814 to two xenograft models of human cancer, using a clinically established 6-week fractionated radiation schedule, strongly potentiated the antitumor activity of IR and led to complete tumor regression at nontoxic doses. Our results strongly support DNA-PK inhibition as a novel approach for the combination radiotherapy of cancer. M3814 is currently under investigation in combination with radiotherapy in clinical trials.
Data from Exosome Surface Display of IL12 Results in Tumor-Retained Pharmacology with Superior Potency and Limited Systemic Exposure Compared with Recombinant IL12
Authors: Lewis Nuruddeen D. , Sia Chang Ling , Kirwin Katherine , Haupt Sonya , Mahimkar Gauri , Zi Tong , Xu Ke , Dooley Kevin , Jang Su Chul , Choi Bryan , Boutin Adam , Grube Andrew , McCoy Christine , Sanchez-Salazar Jorge , Doherty Michael , Gaidukov Leonid , Estes Scott , Economides Kyriakos D. , Williams Douglas E. , Sathyanarayanan Sriram
Published: April 2023

Abstract
The promise of IL12 as a cancer treatment has yet to be fulfilled with multiple tested approaches being limited by unwanted systemic exposure and unpredictable pharmacology. To address these limitations, we generated exoIL12, a novel, engineered exosome therapeutic that displays functional IL12 on the surface of an exosome. IL12 exosomal surface expression was achieved via fusion to the abundant exosomal surface protein PTGFRN resulting in equivalent potency in vitro to recombinant IL12 (rIL12) as demonstrated by IFNγ production. Following intratumoral injection, exoIL12 exhibited prolonged tumor retention and greater antitumor activity than rIL12. Moreover, exoIL12 was significantly more potent than rIL12 in tumor growth inhibition. In the MC38 model, complete responses were observed in 63% of mice treated with exoIL12; in contrast, rIL12 resulted in 0% complete responses at an equivalent IL12 dose. This correlated with dose-dependent increases in tumor antigen–specific CD8+ T cells. Rechallenge studies of exoIL12 complete responder mice showed no tumor regrowth, and depletion of CD8+ T cells completely abrogated antitumor activity of exoIL12. Following intratumoral administration, exoIL12 exhibited 10-fold higher intratumoral exposure than rIL12 and prolonged IFNγ production up to 48 hours. Retained local pharmacology of exoIL12 was further confirmed using subcutaneous injections in nonhuman primates. This work demonstrates that tumor-restricted pharmacology of exoIL12 results in superior in vivo efficacy and immune memory without systemic IL12 exposure and related toxicity. ExoIL12 is a novel cancer therapeutic candidate that overcomes key limitations of rIL12 and thereby creates a therapeutic window for this potent cytokine.
Data from ABBV-085, Antibody–Drug Conjugate Targeting LRRC15, Is Effective in Osteosarcoma: A Report by the Pediatric Preclinical Testing Consortium
Authors: Hingorani Pooja , Roth Michael E. , Wang Yifei , Zhang Wendong , Gill Jonathan B. , Harrison Douglas J. , Teicher Beverly , Erickson Stephen , Gatto Gregory , Smith Malcolm A. , Kolb Edward A. , Gorlick Richard
Published: April 2023

Abstract
Membrane protein leucine–rich repeat containing 15 (LRRC15) is known to be expressed in several solid tumors including osteosarcoma. ABBV-085, an antibody–drug conjugate against LRRC15, conjugated to monomethyl auristatin E (MMAE), was studied in osteosarcoma patient-derived xenografts (PDXs) by the Pediatric Preclinical Testing Consortium (PPTC). LRRC15 expression data were obtained from PPTC RNA-sequencing data for the PDX models. The TARGET database was mined for LRRC15 expression in human osteosarcoma. Protein expression was confirmed via IHC in three PDX models. Seven osteosarcoma PDX models (OS1, OS9, OS33, OS34, OS42, OS55, and OS60) with varying LRRC15 gene expression were studied. ABBV-085 was administered at 3 mg/kg (OS33), 6 mg/kg (all seven PDXs), and 12 mg/kg (OS60) weekly for 4 consecutive weeks via intraperitoneal injection. Control cohorts included vehicle and an isotype MMAE-linked antibody. Tumor volumes and responses were reported using PPTC statistical analysis. OS1, OS33, OS42, OS55, and OS60 had high LRRC15 expression while OS9 and OS34 had low LRRC15 expression. ABBV-085 inhibited tumor growth in six of seven PDX models as compared with vehicle control and significantly improved event-free survival in five of seven models as compared with isotype controls. Two models showed maintained complete responses while all others showed progressive disease. Response correlated with LRRC15 expression. ABBV-085’s antitumor activity against osteosarcoma PDX suggests LRRC15 may be a rational target for pursuing clinical trials in patients with this disease.
Data from Selective Vulnerability to Pyrimidine Starvation in Hematologic Malignancies Revealed by AG-636, a Novel Clinical-Stage Inhibitor of Dihydroorotate Dehydrogenase
Authors: McDonald Gabrielle , Chubukov Victor , Coco John , Truskowski Kevin , Narayanaswamy Rohini , Choe Sung , Steadman Mya , Artin Erin , Padyana Anil K. , Jin Lei , Ronseaux Sebastien , Locuson Charles , Fan Zi-Peng , Erdmann Tabea , Mann Alan , Hayes Sebastian , Fletcher Mark , Nellore Kavitha , Rao Siva Sanjeeva , Subramanya Hosahalli , Reddy K. Satish , Panigrahi Sunil K. , Antony Thomas , Gopinath Sreevalsam , Sui Zhihua , Nagaraja Nelamangala , Dang Lenny , Lenz Georg , Hurov Jonathan , Biller Scott A. , Murtie Josh , Marks Kevin M. , Ulanet Danielle B.
Published: April 2023

Abstract
Agents targeting metabolic pathways form the backbone of standard oncology treatments, though a better understanding of differential metabolic dependencies could instruct more rationale-based therapeutic approaches. We performed a chemical biology screen that revealed a strong enrichment in sensitivity to a novel dihydroorotate dehydrogenase (DHODH) inhibitor, AG-636, in cancer cell lines of hematologic versus solid tumor origin. Differential AG-636 activity translated to the in vivo setting, with complete tumor regression observed in a lymphoma model. Dissection of the relationship between uridine availability and response to AG-636 revealed a divergent ability of lymphoma and solid tumor cell lines to survive and grow in the setting of depleted extracellular uridine and DHODH inhibition. Metabolic characterization paired with unbiased functional genomic and proteomic screens pointed to adaptive mechanisms to cope with nucleotide stress as contributing to response to AG-636. These findings support targeting of DHODH in lymphoma and other hematologic malignancies and suggest combination strategies aimed at interfering with DNA-damage response pathways.
Data from Targeting Oncogene mRNA Translation in B-Cell Malignancies with eFT226, a Potent and Selective Inhibitor of eIF4A
Authors: Thompson Peggy A. , Eam Boreth , Young Nathan P. , Fish Sarah , Chen Joan , Barrera Maria , Howard Haleigh , Sung Eric , Parra Ana , Staunton Jocelyn , Chiang Gary G. , Gerson-Gurwitz Adina , Wegerski Christopher J. , Nevarez Andres , Clarine Jeff , Sperry Samuel , Xiang Alan , Nilewski Christian , Packard Garrick K. , Michels Theodore , Tran Chinh , Sprengeler Paul A. , Ernst Justin T. , Reich Siegfried H. , Webster Kevin R.
Published: April 2023

Abstract
The PI3K/AKT/mTOR pathway is often activated in lymphoma through alterations in PI3K, PTEN, and B-cell receptor signaling, leading to dysregulation of eIF4A (through its regulators, eIF4B, eIF4G, and PDCD4) and the eIF4F complex. Activation of eIF4F has a direct role in tumorigenesis due to increased synthesis of oncogenes that are dependent on enhanced eIF4A RNA helicase activity for translation. eFT226, which inhibits translation of specific mRNAs by promoting eIF4A1 binding to 5′-untranslated regions (UTR) containing polypurine and/or G-quadruplex recognition motifs, shows potent antiproliferative activity and significant in vivo efficacy against a panel of diffuse large B-cell lymphoma (DLBCL), and Burkitt lymphoma models with ≤1 mg/kg/week intravenous administration. Evaluation of predictive markers of sensitivity or resistance has shown that activation of eIF4A, mediated by mTOR signaling, correlated with eFT226 sensitivity in in vivo xenograft models. Mutation of PTEN is associated with reduced apoptosis in vitro and diminished efficacy in vivo in response to eFT226. In models evaluated with PTEN loss, AKT was stimulated without a corresponding increase in mTOR activation. AKT activation leads to the degradation of PDCD4, which can alter eIF4F complex formation. The association of eFT226 activity with PTEN/PI3K/mTOR pathway regulation of mRNA translation provides a means to identify patient subsets during clinical development.
Data from (+)-JJ-74–138 is a Novel Noncompetitive Androgen Receptor Antagonist
Authors: Cole Ryan N. , Chen Wei , Pascal Laura E. , Nelson Joel B. , Wipf Peter , Wang Zhou
Published: April 2023

Abstract
Identification of novel androgen receptor (AR) antagonists may lead to urgently needed new treatments for patients with prostate cancer resistant to current AR antagonists. AR is presently the main target for treating prostate cancer. Clinically approved AR antagonists compete with dihydrotestosterone (DHT) for binding to the ligand-binding domain (LBD) of AR, and patients eventually develop resistance to these treatments. One approach to overcoming resistance is to discover compounds that inhibit AR in alternative ways. Our lab previously identified a small molecule, JJ-450, that is capable of inhibiting AR lacking LBD. To optimize the efficacy of this class of inhibitors, we developed structural analogues of JJ-450 and identified (+)-JJ-74–138 as a promising candidate. Here, we show that (+)-JJ-74–138 is more potent than JJ-450 in the inhibition of androgen-independent AR activity in enzalutamide-resistant LN95 cells. Further studies showed (+)-JJ-74–138 inhibition of castration-resistant PSA expression in all tested castration-resistant prostate cancer (CRPC) cells. (+)-JJ-74–138 inhibited mRNA expression of AR and ARv7 target genes and reduced AR level in the nucleus in the absence of androgens. Also, this analogue noncompetitively inhibited androgen-stimulated AR activity in C4–2, LN95, and 22Rv1 CRPC cells. At low dosages, (+)-JJ-74–138 inhibited the proliferation of enzalutamide-resistant AR-positive LN95 and 22Rv1 cells, but not AR-negative PC3 and DU145 cells. A surface plasmon resonance assay detected (+)-JJ-74–138 binding to AR and a chromatin immunoprecipitation assay indicated (+)-JJ-74–138 inhibited AR binding to androgen response elements. In addition, (+)-JJ-74–138 inhibited 22Rv1 xenograft tumor growth. Our observations suggest that (+)-JJ-74–138 is a novel noncompetitive AR antagonist capable of inhibiting enzalutamide-resistant CRPC.
Data from PCA062, a P-cadherin Targeting Antibody–Drug Conjugate, Displays Potent Antitumor Activity Against P-cadherin–expressing Malignancies
Authors: Sheng Qing , D'Alessio Joseph A. , Menezes Daniel L. , Karim Christopher , Tang Yan , Tam Angela , Clark Suzanna , Ying Chi , Connor Anu , Mansfield Keith G. , Rondeau Jean-Michel , Ghoddusi Majid , Geyer Felipe C. , Gu Jane , McLaughlin Margaret E. , Newcombe Rick , Elliot GiNell , Tschantz William R. , Lehmann Sylvie , Fanton Christie P. , Miller Kathy , Huber Thomas , Rendahl Katherine G. , Jeffry Ursula , Pryer Nancy K. , Lees Emma , Kwon Paul , Abraham Judith A. , Damiano Jason S. , Abrams Tinya J.
Published: April 2023

Abstract
The cell surface glycoprotein P-cadherin is highly expressed in a number of malignancies, including those arising in the epithelium of the bladder, breast, esophagus, lung, and upper aerodigestive system. PCA062 is a P-cadherin specific antibody–drug conjugate that utilizes the clinically validated SMCC-DM1 linker payload to mediate potent cytotoxicity in cell lines expressing high levels of P-cadherin in vitro, while displaying no specific activity in P-cadherin–negative cell lines. High cell surface P-cadherin is necessary, but not sufficient, to mediate PCA062 cytotoxicity. In vivo, PCA062 demonstrated high serum stability and a potent ability to induce mitotic arrest. In addition, PCA062 was efficacious in clinically relevant models of P-cadherin–expressing cancers, including breast, esophageal, and head and neck. Preclinical non-human primate toxicology studies demonstrated a favorable safety profile that supports clinical development. Genome-wide CRISPR screens reveal that expression of the multidrug-resistant gene ABCC1 and the lysosomal transporter SLC46A3 differentially impact tumor cell sensitivity to PCA062. The preclinical data presented here suggest that PCA062 may have clinical value for treating patients with multiple cancer types including basal-like breast cancer.