bluuebunny/crossref_metadata_2025 huggingface dataset:
Data from EMT-Induced Gemcitabine Resistance in Pancreatic Cancer Involves the Functional Loss of Equilibrative Nucleoside Transporter 1
Authors: Weadick Brenna , Nayak Debasis , Persaud Avinash K. , Hung Sau Wai , Raj Radhika , Campbell Moray J. , Chen Wei , Li Junan , Williams Terence M. , Govindarajan Rajgopal
Published: April 2023

Abstract
Epithelial–mesenchymal transition (EMT) in cancer cells drives cancer chemoresistance, yet the molecular events of EMT that underpin the acquisition of chemoresistance are poorly understood. Here, we demonstrate a loss of gemcitabine chemosensitivity facilitated by human equilibrative nucleoside transporter 1 (ENT1) during EMT in pancreatic cancer and identify that cadherin switching from the epithelial (E) to neuronal (N) type, a hallmark of EMT, contributes to this loss. Our findings demonstrate that N-cadherin decreases ENT1 expression, membrane localization, and gemcitabine transport, while E-cadherin augments each of these. Besides E- and N-cadherin, another epithelial cell adhesion molecule, EpCAM, played a more prominent role in determining ENT1 membrane localization. Forced expression of EpCAM opposed cadherin switching with restored ENT1 expression, membrane localization, and gemcitabine transport in EMT-committed pancreatic cancer cells. In gemcitabine-treated mice, EpCAM-positive tumors had high ENT1 expression and reduced metastasis, whereas tumors with N-cadherin expression resisted gemcitabine treatment and formed extensive secondary metastatic nodules. Tissue microarray profiling and multiplexed IHC analysis of pancreatic cancer patient-derived primary tumors revealed EpCAM and ENT1 cell surface coexpression is favored, and ENT1 plasma membrane expression positively predicted median overall survival times in patients treated with adjuvant gemcitabine. Together, our findings identify ENT1 as an inadvertent target of EMT signaling mediated by cadherin switching and provide a mechanism by which mesenchymal pancreatic cancer cells evade gemcitabine therapy during EMT.
Data from Growth Inhibition and Induction of Innate Immune Signaling of Chondrosarcomas with Epigenetic Inhibitors
Authors: Sheikh Tahir N. , Chen Xiao , Xu Xinjing , McGuire John T. , Ingham Matthew , Lu Chao , Schwartz Gary K.
Published: April 2023

Abstract
Chondrosarcomas are inherently resistant to chemotherapy and radiotherapy, pointing to an unmet need for new treatment options. Immune checkpoint inhibitors, which have shown remarkable promise in multiple solid cancer types, have limited efficacy in chondrosarcomas. Mutations in IDH1/2 genes, which result in progressive increases in DNA and histone methylation, are observed in 50% of conventional chondrosarcomas, suggesting that epigenetic dysregulation represents a potential barrier for tumor progression and target for therapeutic intervention. Here, we demonstrated that combined treatment of FDA-approved inhibitors of DNA methyltransferases (DNMTs) 5-aza-2′-deoxycytidine (5-aza), and histone deacetylases (HDACs) suberanilohydroxamic acid (SAHA) impaired the proliferation of chondrosarcoma cell lines in vitro and in xenograft studies. Transcriptomic analysis reveals that chondrosarcoma cells treated with 5-aza and SAHA markedly elevated the expression of IFN-stimulated genes including PD-L1, indicating that these epigenetic drugs induced a potent innate immune response. We demonstrated that 5-aza and SAHA resulted in both genomic and epigenomic instability, as shown by elevated DNA damage response and derepression of retrotransposons, respectively, which in turn activated pattern recognition receptors (PRRs) and the downstream IFN signaling pathways. Importantly, the cytotoxic effects of 5-aza and SAHA can be rescued by depletion of PRRs such as cGAS and MAVS, and potentiated by depletion of the RNA-editing enzyme ADAR1. Together, our results demonstrate preclinical activity of combined DNMT and HDAC inhibition against chondrosarcomas and suggest that targeted epigenetic therapies could represent a new therapeutic approach in the treatment of chondrosarcomas, and this is being tested in an ongoing clinical trial (NCT04340843).
Data from A Benzenesulfonamide-Based Mitochondrial Uncoupler Induces Endoplasmic Reticulum Stress and Immunogenic Cell Death in Epithelial Ovarian Cancer
Authors: Bi Fangfang , Jiang Ziyan , Park Wonmin , Hartwich Tobias M.P. , Ge Zhiping , Chong Kay Y. , Yang Kevin , Morrison Madeline J. , Kim Dongin , Kim Jaeyeon , Zhang Wen , Kril Liliia M. , Watt David S. , Liu Chunming , Yang-Hartwich Yang
Published: April 2023

Abstract
Epithelial ovarian cancer (EOC) is the leading cause of death from gynecologic malignancies and requires new therapeutic strategies to improve clinical outcomes. EOC metastasizes in the abdominal cavity through dissemination in the peritoneal fluid and ascites, efficiently adapt to the nutrient-deprived microenvironment, and resist current chemotherapeutic agents. Accumulating evidence suggests that mitochondrial oxidative phosphorylation is critical for the adaptation of EOC cells to this otherwise hostile microenvironment. Although chemical mitochondrial uncouplers can impair mitochondrial functions and thereby target multiple, essential pathways for cancer cell proliferation, traditional mitochondria uncouplers often cause toxicity that precludes their clinical application. In this study, we demonstrated that a mitochondrial uncoupler, specifically 2,5-dichloro-N-(4-nitronaphthalen-1-yl)benzenesulfonamide, hereinafter named Y3, was an antineoplastic agent in ovarian cancer models. Y3 treatment activated AMP-activated protein kinase and resulted in the activation of endoplasmic reticulum stress sensors as well as growth inhibition and apoptosis in ovarian cancer cells in vitro. Y3 was well tolerated in vivo and effectively suppressed tumor progression in three mouse models of EOC, and Y3 also induced immunogenic cell death of cancer cells that involved the release of damage-associated molecular patterns and the activation of antitumor adaptive immune responses. These findings suggest that mitochondrial uncouplers hold promise in developing new anticancer therapies that delay tumor progression and protect patients with ovarian cancer against relapse.
Data from 3D Collagen Vascular Tumor-on-a-Chip Mimetics for Dynamic Combinatorial Drug Screening
Authors: Wan Li , Yin Jun , Skoko John , Schwartz Russell , Zhang Mei , LeDuc Philip R. , Neumann Carola A.
Published: April 2023

Abstract
Disease models, including in vitro cell culture and animal models, have contributed significantly to developing diagnostics and treatments over the past several decades. The successes of traditional drug screening methods were generally hampered by not adequately mimicking critical in vivo features, such as a 3D microenvironment and dynamic drug diffusion through the extracellular matrix (ECM). To address these issues, we developed a 3D dynamic drug delivery system for cancer drug screening that mimicks drug dissemination through the tumor vasculature and the ECM by creating collagen-embedded microfluidic channels. Using this novel 3D ECM microsystem, we compared viability of tumor pieces with traditionally used 2D methods in response to three different drug combinations. Drug diffusion profiles were evaluated by simulation methods and tested in the 3D ECM microsystem and a 2D 96-well setup. Compared with the 2D control, the 3D ECM microsystem produced reliable data on viability, drug ratios, and combination indeces. This novel approach enables higher throughput and sets the stage for future applications utilizing drug sensitivity predicting algorithms based on dynamic diffusion profiles requiring only minimal patient tissue. Our findings moved drug sensitivity screening closer to clinical implications with a focus on testing combinatorial drug effects, an option often limited by the amount of available patient tissues.
Data from Intraperitoneal Pretargeted Radioimmunotherapy for Colorectal Peritoneal Carcinomatosis
Authors: Chandler Christopher S. , Bell Meghan M. , Chung Sebastian K. , Veach Darren R. , Fung Edward K. , Punzalan Blesida , Burnes Vargas Daniela , Patel Mitesh , Xu Hong , Guo Hong-fen , Santich Brian H. , Zanzonico Pat B. , Monette Sébastien , Nash Garrett M. , Cercek Andrea , Jungbluth Achim , Pandit-Taskar Neeta , Cheung Nai Kong V. , Larson Steven M. , Cheal Sarah M.
Published: April 2023

Abstract
Peritoneal carcinomatosis (PC) is considered incurable, and more effective therapies are needed. Herein we test the hypothesis that GPA33-directed intracompartmental pretargeted radioimmunotherapy (PRIT) can cure colorectal peritoneal carcinomatosis. Nude mice were implanted intraperitoneally with luciferase-transduced GPA33-expressing SW1222 cells for aggressive peritoneal carcinomatosis (e.g., resected tumor mass 0.369 ± 0.246 g; n = 17 on day 29). For GPA33-PRIT, we administered intraperitoneally a high-affinity anti-GPA33/anti-DOTA bispecific antibody (BsAb), followed by clearing agent (intravenous), and lutetium-177 (Lu-177) or yttrium-86 (Y-86) radiolabeled DOTA-radiohapten (intraperitoneal) for beta/gamma-emitter therapy and PET imaging, respectively. The DOTA-radiohaptens were prepared from S-2-(4-aminobenzyl)-1,4,7, 10-tetraazacyclododecane tetraacetic acid chelate (DOTA-Bn). Efficacy and toxicity of single- versus three-cycle therapy were evaluated in mice 26–27 days post-tumor implantation. Single-cycle treatment ([177Lu]LuDOTA-Bn 111 MBq; tumor dose: 4,992 cGy) significantly prolonged median survival (MS) approximately 2-fold to 84.5 days in comparison with controls (P = 0.007). With three-cycle therapy (once weekly, total 333 MBq; tumor dose: 14,975 cGy), 6/8 (75%) survived long-term (MS > 183 days). Furthermore, for these treated long-term survivors, 1 mouse was completely disease free (microscopic “cure”) at necropsy; the others showed stabilized disease, which was detectable during PET-CT using [86Y]DOTA-Bn. Treatment controls had MS ranging from 42–52.5 days (P < 0.001) and 19/20 mice succumbed to progressive intraperitoneal disease by 69 days. Multi-cycle GPA33 DOTA-PRIT significantly prolongs survival with reversible myelosuppression and no chronic marrow (929 cGy to blood) or kidney (982 cGy) radiotoxicity, with therapeutic indices of 12 for blood and 12 for kidneys. MTD was not reached.
Data from Obinutuzumab in Combination with Chemotherapy Enhances Direct Cell Death in CD20-Positive Obinutuzumab-resistant Non-Hodgkin Lymphoma Cells
Authors: Fujimura Takaaki , Yamashita-Kashima Yoriko , Kawasaki Natsumi , Yoshiura Shigeki , Harada Naoki , Yoshimura Yasushi
Published: April 2023

Abstract
Follicular lymphoma commonly recurs and is difficult to cure. Obinutuzumab is a humanized glycoengineered type II anti-CD20 antibody with a mode of action that includes induction of antibody-dependent cellular cytotoxicity, antibody-dependent cellular phagocytosis, and direct cell death. There is no evidence on the effectiveness of retreatment with obinutuzumab in patients with prior obinutuzumab treatment. Using obinutuzumab-induced direct-cell-death–resistant cells, we investigated the efficacy of obinutuzumab retreatment in combination with chemotherapeutic agents used in follicular lymphoma treatment. Human non-Hodgkin lymphoma SU-DHL-4 cells were sustainably exposed to obinutuzumab in vitro, and 17 resistant clones expressing CD20 and showing 100-fold higher IC50 of obinutuzumab than parental cells were established. The growth inhibition effect of obinutuzumab in combination with bendamustine, 4-hydroperoxy-cyclophosphamide, doxorubicin, vincristine, or prednisolone was estimated using an interaction index based on the Bliss independence model. For each clone, there were various combinations of obinutuzumab and chemotherapeutic agents that showed supra-additive effects. Obinutuzumab combined with doxorubicin enhanced caspase-dependent apoptosis and growth inhibition effect. Obinutuzumab combined with prednisolone enhanced DNA fragmentation and G0–G1 arrest. These combinations also had an antitumor effect in mouse xenograft models. Our results indicate that retreatment with obinutuzumab, when it is combined with chemotherapeutic agents, is effective in the CD20-positive obinutuzumab-induced direct-cell-death–resistant cells.
Data from Combined Inhibition of Rad51 and Wee1 Enhances Cell Killing in HNSCC Through Induction of Apoptosis Associated With Excessive DNA Damage and Replication Stress
Authors: Lindemann Antje , Patel Ameeta A. , Tang Lin , Tanaka Noriaki , Gleber-Netto Frederico O. , Bartels Mason D. , Wang Li , McGrail Daniel J. , Lin Shiaw-Yih , Frank Steven J. , Frederick Mitchell J. , Myers Jeffrey N. , Osman Abdullah A.
Published: April 2023

Abstract
Despite advances in surgery, chemotherapy, and radiation, there are limited treatment options for advanced head and neck squamous cell carcinoma (HNSCC) and survival remains very poor. Therefore, effective therapies are desperately needed. Recently, selective exploitation of DNA damage and replication stress responses has become a novel approach for cancer treatment. Wee1 kinase and Rad51 recombinase are two proteins involved in regulating replication stress and homologous recombination repair in cancer cells. In this study, we investigated the combined effect of Rad51 inhibitor (B02) and Wee1 inhibitor (AZD1775) in vitro and in vivo in various HNSCC cell lines. Clonogenic survival assays demonstrated that B02 synergized with AZD1775 in vitro in all HNSCC cell lines tested. The synergy between these drugs was associated with forced CDK1 activation and reduced Chk1 phosphorylation leading to induction of excessive DNA damage and replication stress, culminating in aberrant mitosis and apoptosis. Our results showed that elevated Rad51 mRNA expression correlated with worse survival in HNSCC patients with HPV-positive tumors. The combination of B02 and AZD1775 significantly inhibited tumor growth in vivo in mice bearing HPV-positive HNSCC tumors as compared to HPV-negative HNSCC. This differential sensitivity appears to be linked to HPV-positive tumors having more in vivo endogenous replication stress owing to transformation by E6 and E7 oncogenes. Furthermore, addition of B02 radiosensitized the HPV-negative HNSCC tumors in vitro and in vivo. In conclusion, our data implicate that a novel rational combination with Rad51 and Wee1 inhibitors holds promise as synthetic lethal therapy, particularly in high-risk HPV-positive HNSCC.
Data from Novel Group C Oncolytic Adenoviruses Carrying a miRNA Inhibitor Demonstrate Enhanced Oncolytic Activity In Vitro and In Vivo
Authors: Doerner Johannes , Sallard Erwan , Zhang Wenli , Solanki Manish , Liu Jing , Ehrke-Schulz Eric , Zirngibl Hubert , Lieber André , Ehrhardt Anja
Published: April 2023

Abstract
Oncolytic adenoviruses (OAd) represent an attractive treatment option for cancer. Clinical efficacy of commonly utilized human adenovirus type 5 (Ad5)-based oncolytic viruses is limited by variable expression levels of the coxsackie- and adenovirus receptor (CAR) in tumor cells and high prevalence of neutralizing antibodies against human Ad5. However, previous studies have highlighted alternative human Ad types as promising candidates for oncolytic therapy. In this study, we generated novel OAds based on Ad1, -2, -5, and -6 derived from species C Ads. These OAds contain a 24-bp deletion in the early gene E1A for tumor selective replication and express the RNAi inhibitor P19. We examined these OAds for in vitro anticancer activity on various cancer cell lines derived from lung, colon, gynecologic, bone, and pancreatic carcinoma. In most surveyed cell lines, OAds based on Ad1, -2, and -6 demonstrated higher cell lysis capability compared with Ad5, suggesting enhanced oncolytic potential. Moreover, enhanced oncolytic activity was associated with P19 expression in a cell type–dependent manner. We further explored a A549 tumor xenograft mouse model to compare the novel OAds directly with Ad5 and H101, an oncolytic adenovirus used in clinical trials. These P19-containing OAds based on Ad1, -2, and -6 showed significantly decelerated tumor progression compared with H101, indicating better antitumor potency in vivo. Our studies provide a novel path for OAd development based on alternative Ad types with improved effectiveness by RNA interference suppression.
Data from Small-Molecule MMRi62 Induces Ferroptosis and Inhibits Metastasis in Pancreatic Cancer via Degradation of Ferritin Heavy Chain and Mutant p53
Authors: Li Junhui , Lama Rati , Galster Samuel L. , Inigo Joseph R. , Wu Jin , Chandra Dhyan , Chemler Sherry R. , Wang Xinjiang
Published: April 2023

Abstract
High frequency of KRAS and TP53 mutations is a unique genetic feature of pancreatic ductal adenocarcinoma (PDAC). TP53 mutation not only renders PDAC resistance to chemotherapies but also drives PDAC invasiveness. Therapies targeting activating mutant KRAS are not available and the outcomes of current PDAC treatment are extremely poor. Here, we report that MMRi62, initially identified as an MDM2-MDM4–targeting small molecule with p53-independent pro-apoptotic activity, shows anti-PDAC activity in vitro and in vivo. We show that MMRi62 inhibits proliferation, clonogenic, and spheroid growth of PDAC cells by induction of cell death. MMRi62-induced cell death in PDAC is characteristic of ferroptosis that is associated with increased autophagy, increased reactive oxygen species, and lysosomal degradation of NCOA4 and ferritin heavy chain (FTH1). In addition to induced degradation of FTH1, MMRi62 also induces proteasomal degradation of mutant p53. Interestingly, MMRi62-induced ferroptosis occurs in PDAC cell lines harboring either KRAS and TP53 double mutations or single TP53 mutation. In orthotopic xenograft PDAC mouse models, MMRi62 was capable of inhibiting tumor growth in mice associated with downregulation of NCOA4 and mutant p53 in vivo. Strikingly, MMRi62 completely abrogated metastasis of orthotopic tumors to distant organs, which is consistent with MMRi62's ability to inhibit cell migration and invasion in vitro. These findings identified MMRi62 as a novel ferroptosis inducer capable of suppressing PDAC growth and overcoming metastasis.
Data from Frondoside A Inhibits an MYC-Driven Medulloblastoma Model Derived from Human-Induced Pluripotent Stem Cells
Authors: Xue Yingchao , Fu Yi , Zhao Fenghong , Gui Gege , Li Yuguo , Rivero-Hinojosa Samuel , Liu Guanshu , Li Yunqing , Xia Shuli , Eberhart Charles G. , Ying Mingyao
Published: April 2023

Abstract
Medulloblastoma (MB) is the most common malignant pediatric brain tumor. MYC-driven MBs, commonly found in the group 3 MB, are aggressive and metastatic with the worst prognosis. Modeling MYC-driven MB is the foundation of therapeutic development. Here, we applied a synthetic mRNA-driven strategy to generate neuronal precursors from human-induced pluripotent stem cells (iPSCs). These neuronal precursors were transformed by the MYC oncogene combined with p53 loss of function to establish an MYC-driven MB model recapitulating the histologic and transcriptomic hallmarks of group 3 MB. We further show that the marine compound Frondoside A (FA) effectively inhibits this MYC-driven MB model without affecting isogenic neuronal precursors with undetectable MYC expression. Consistent results from a panel of MB models support that MYC levels are positively correlated with FA's antitumor potency. Next, we show that FA suppresses MYC expression and its downstream gene targets in MB cells, suggesting a potential mechanism underlying FA's inhibitory effects on MYC-driven cancers. In orthotopic xenografts of MYC-driven MB, intratumoral FA administration potently induces cytotoxicity in tumor xenografts, significantly extends the survival of tumor-bearing animals, and enhances the recruitment of microglia/macrophages and cytotoxic T lymphocytes to tumors. Moreover, we show that MYC levels also predict FA potency in glioblastoma and non–small cell lung cancer cells. Taken together, this study provides an efficient human iPSC-based strategy for personalizable cancer modeling, widely applicable to mechanistic studies (e.g., genetic predisposition to cancer) and drug discovery. Our preclinical results justify the clinical translation of FA in treating MYC-driven MB and other human cancers.
Data from Macrophage Activation Status Rather than Repolarization Is Associated with Enhanced Checkpoint Activity in Combination with PI3Kγ Inhibition
Authors: Carnevalli Larissa S. , Taylor Molly A. , King Matthew , Coenen-Stass Anna M.L. , Hughes Adina M. , Bell Sigourney , Proia Theresa A. , Wang Yanjun , Ramos-Montoya Antonio , Wali Neha , Carroll Danielle , Singh Maneesh , Moschetta Michele , Gutierrez Pablo Morentin , Gardelli Cristina , Critchlow Susan E. , Klinowska Teresa , Fawell Stephen E. , Barry Simon T.
Published: April 2023

Abstract
Suppressive myeloid cells mediate resistance to immune checkpoint blockade. PI3Kγ inhibition can target suppressive macrophages, and enhance efficacy of immune checkpoint inhibitors. However, how PI3Kγ inhibitors function in different tumor microenvironments (TME) to activate specific immune cells is underexplored. The effect of the novel PI3Kγ inhibitor AZD3458 was assessed in preclinical models. AZD3458 enhanced antitumor activity of immune checkpoint inhibitors in 4T1, CT26, and MC38 syngeneic models, increasing CD8+ T-cell activation status. Immune and TME biomarker analysis of MC38 tumors revealed that AZD3458 monotherapy or combination treatment did not repolarize the phenotype of tumor-associated macrophage cells but induced gene signatures associated with LPS and type II INF activation. The activation biomarkers were present across tumor macrophages that appear phenotypically heterogenous. AZD3458 alone or in combination with PD-1–blocking antibodies promoted an increase in antigen-presenting (MHCII+) and cytotoxic (iNOS+)-activated macrophages, as well as dendritic cell activation. AZD3458 reduced IL-10 secretion and signaling in primary human macrophages and murine tumor-associated macrophages, but did not strongly regulate IL-12 as observed in other studies. Therefore, rather than polarizing tumor macrophages, PI3Kγ inhibition with AZD3458 promotes a cytotoxic switch of macrophages into antigen-presenting activated macrophages, resulting in CD8 T-cell–mediated antitumor activity with immune checkpoint inhibitors associated with tumor and peripheral immune activation.
Data from PP2A-activating Drugs Enhance FLT3 Inhibitor Efficacy through AKT Inhibition–Dependent GSK-3β–Mediated c-Myc and Pim-1 Proteasomal Degradation
Authors: Scarpa Mario , Singh Prerna , Bailey Christopher M. , Lee Jonelle K. , Kapoor Shivani , Lapidus Rena G. , Niyongere Sandrine , Sangodkar Jaya , Wang Yin , Perrotti Danilo , Narla Goutham , Baer Maria R.
Published: April 2023

Abstract
Fms-like tyrosine-like kinase 3 internal tandem duplication (FLT3-ITD) is present in acute myeloid leukemia (AML) in 30% of patients and is associated with short disease-free survival. FLT3 inhibitor efficacy is limited and transient but may be enhanced by multitargeting of FLT3-ITD signaling pathways. FLT3-ITD drives both STAT5-dependent transcription of oncogenic Pim-1 kinase and inactivation of the tumor-suppressor protein phosphatase 2A (PP2A), and FLT3-ITD, Pim-1, and PP2A all regulate the c-Myc oncogene. We studied mechanisms of action of cotreatment of FLT3-ITD–expressing cells with FLT3 inhibitors and PP2A-activating drugs (PADs), which are in development. PADs, including FTY720 and DT-061, enhanced FLT3 inhibitor growth suppression and apoptosis induction in FLT3-ITD–expressing cell lines and primary AML cells in vitro and MV4-11 growth suppression in vivo. PAD and FLT3 inhibitor cotreatment independently downregulated c-Myc and Pim-1 protein through enhanced proteasomal degradation. c-Myc and Pim-1 downregulation was preceded by AKT inactivation, did not occur in cells expressing myristoylated (constitutively active) AKT1, and could be induced by AKT inhibition. AKT inactivation resulted in activation of GSK-3β, and GSK-3β inhibition blocked downregulation of both c-Myc and Pim-1 by PAD and FLT3 inhibitor cotreatment. GSK-3β activation increased c-Myc proteasomal degradation through c-Myc phosphorylation on T58; infection with c-Myc with T58A substitution, preventing phosphorylation, blocked downregulation of c-Myc by PAD and FLT3 inhibitor cotreatment. GSK-3β also phosphorylated Pim-1L/Pim-1S on S95/S4. Thus, PADs enhance efficacy of FLT3 inhibitors in FLT3-ITD–expressing cells through a novel mechanism involving AKT inhibition–dependent GSK-3β–mediated increased c-Myc and Pim-1 proteasomal degradation.
Data from Reverse Translating Molecular Determinants of Anti–Programmed Death 1 Immunotherapy Response in Mouse Syngeneic Tumor Models
Authors: Georgiev Peter , Muise Eric S. , Linn Douglas E. , Hinton Marlene C. , Wang Yun , Cai Mingmei , Cadzow Louise , Wilson Douglas C. , Sukumar Selvakumar , Caniga Michael , Chen Lan , Xiao Hui , Yearley Jennifer H. , Sriram Venkataraman , Nebozhyn Michael , Sathe Manjiri , Blumenschein Wendy M. , Kerr Kimberly S. , Hirsch Heather A. , Javaid Sarah , Olow Aleksandra K. , Moy Lily Y. , Chiang Derek Y. , Loboda Andrey , Cristescu Razvan , Sadekova Svetlana , Long Brian J. , McClanahan Terrill K. , Pinheiro Elaine M.
Published: April 2023

Abstract
Targeting the programmed death 1/programmed death ligand 1 (PD-1/PD-L1) pathway with immunotherapy has revolutionized the treatment of many cancers. Somatic tumor mutational burden (TMB) and T-cell–inflamed gene expression profile (GEP) are clinically validated pan-tumor genomic biomarkers that can predict responsiveness to anti-PD-1/PD-L1 monotherapy in many tumor types. We analyzed the association between these biomarkers and the efficacy of PD-1 inhibitor in 11 commonly used preclinical syngeneic tumor mouse models using murinized rat anti-mouse PD-1 DX400 antibody muDX400, a surrogate for pembrolizumab. Response to muDX400 treatment was broadly classified into three categories: highly responsive, partially responsive, and intrinsically resistant to therapy. Molecular and cellular profiling validated differences in immune cell infiltration and activation in the tumor microenvironment of muDX400-responsive tumors. Baseline and on-treatment genomic analysis showed an association between TMB, murine T-cell–inflamed gene expression profile (murine-GEP), and response to muDX400 treatment. We extended our analysis to investigate a canonical set of cancer and immune biology-related gene signatures, including signatures of angiogenesis, myeloid-derived suppressor cells, and stromal/epithelial-to-mesenchymal transition/TGFβ biology previously shown to be inversely associated with the clinical efficacy of immune checkpoint blockade. Finally, we evaluated the association between murine-GEP and preclinical efficacy with standard-of-care chemotherapy or antiangiogenic agents that previously demonstrated promising clinical activity, in combination with muDX400. Our profiling studies begin to elucidate the underlying biological mechanisms of response and resistance to PD-1/PD-L1 blockade represented by these models, thereby providing insight into which models are most appropriate for the evaluation of orthogonal combination strategies.
Data from Dolaflexin: A Novel Antibody–Drug Conjugate Platform Featuring High Drug Loading and a Controlled Bystander Effect
Authors: Yurkovetskiy Aleksandr V. , Bodyak Natalya D. , Yin Mao , Thomas Joshua D. , Clardy Susan M. , Conlon Patrick R. , Stevenson Cheri A. , Uttard Alex , Qin LiuLiang , Gumerov Dmitry R. , Ter-Ovanesyan Elena , Bu Charlie , Johnson Alex J. , Gurijala Venu R. , McGillicuddy Dennis , DeVit Michael J. , Poling Laura L. , Protopopova Marina , Xu Ling , Zhang Qingxiu , Park Peter U. , Bergstrom Donald A. , Lowinger Timothy B.
Published: April 2023

Abstract
After significant effort over the last 30 years, antibody–drug conjugates (ADC) have recently gained momentum as a therapeutic modality, and nine ADCs have been approved by the FDA to date, with additional ADCs in late stages of development. Here, we introduce dolaflexin, a novel ADC technology that overcomes key limitations of the most common ADC platforms with two key features: a higher drug-to-antibody ratio and a novel auristatin with a controlled bystander effect. The novel, cell permeable payload, auristatin F-hydroxypropylamide, undergoes metabolic conversion to the highly potent, but less cell permeable auristatin F to balance the bystander effect through drug trapping within target cells. We conducted studies in mice, rats, and cynomolgus monkeys to complement in vitro characterization and contrasted the performance of dolaflexin with regard to antitumor activity, pharmacokinetic properties, and safety in comparison with the ADC platform utilized in the approved ADC ado-trastuzumab emtansine (T-DM1). A HER2-targeted dolaflexin ADC was shown to have a much lower threshold of antigen expression for potent cell killing in vitro, was effective in vivo in tumors with low HER2 expression, and induced tumor regressions in a xenograft model that is resistant to T-DM1.
Data from The KRASG12C Inhibitor MRTX849 Reconditions the Tumor Immune Microenvironment and Sensitizes Tumors to Checkpoint Inhibitor Therapy
Authors: Briere David M. , Li Shuai , Calinisan Andrew , Sudhakar Niranjan , Aranda Ruth , Hargis Lauren , Peng David H. , Deng Jiehui , Engstrom Lars D. , Hallin Jill , Gatto Sole , Fernandez-Banet Julio , Pavlicek Adam , Wong Kwok-Kin , Christensen James G. , Olson Peter
Published: April 2023

Abstract
KRASG12C inhibitors, including MRTX849, are promising treatment options for KRAS-mutant non–small cell lung cancer (NSCLC). PD-1 inhibitors are approved in NSCLC; however, strategies to enhance checkpoint inhibitor therapy (CIT) are needed. KRASG12C mutations are smoking-associated transversion mutations associated with high tumor mutation burden, PD-L1 positivity, and an immunosuppressive tumor microenvironment. To evaluate the potential of MRTX849 to augment CIT, its impact on immune signaling and response to CIT was evaluated. In human tumor xenograft models, MRTX849 increased MHC class I protein expression and decreased RNA and/or plasma protein levels of immunosuppressive factors. In a KrasG12C-mutant CT26 syngeneic mouse model, MRTX849 decreased intratumoral myeloid-derived suppressor cells and increased M1-polarized macrophages, dendritic cells, CD4+, and CD8+ T cells. Similar results were observed in lung KrasG12C-mutant syngeneic and a genetically engineered mouse (GEM) model. In the CT26 KrasG12C model, MRTX849 demonstrated marked tumor regression when tumors were established in immune-competent BALB/c mice; however, the effect was diminished when tumors were grown in T-cell–deficient nu/nu mice. Tumors progressed following anti–PD-1 or MRTX849 single-agent treatment in immune-competent mice; however, combination treatment demonstrated durable, complete responses (CRs). Tumors did not reestablish in the same mice that exhibited durable CRs when rechallenged with tumor cell inoculum, demonstrating these mice developed adaptive antitumor immunity. In a GEM model, treatment with MRTX849 plus anti–PD-1 led to increased progression-free survival compared with either single agent alone. These data demonstrate KRAS inhibition reverses an immunosuppressive tumor microenvironment and sensitizes tumors to CIT through multiple mechanisms.
Data from Comprehensive Surfaceome Profiling to Identify and Validate Novel Cell-Surface Targets in Osteosarcoma
Authors: Wang Yifei , Tian Xiangjun , Zhang Wendong , Zhang Zhongting , Lazcano Rossana , Hingorani Pooja , Roth Michael E. , Gill Jonathan D. , Harrison Douglas J. , Xu Zhaohui , Jusu Sylvester , Kannan Sankaranarayanan , Wang Jing , Lazar Alexander J. , Earley Eric J. , Erickson Stephen W. , Gelb Tara , Huxley Philip , Lahdenranta Johanna , Mudd Gemma , Kurmasheva Raushan T. , Houghton Peter J. , Smith Malcolm A. , Kolb Edward A. , Gorlick Richard
Published: April 2023

Abstract
Immunoconjugates targeting cell-surface antigens have demonstrated clinical activity to enable regulatory approval in several solid and hematologic malignancies. We hypothesize that a rigorous and comprehensive surfaceome profiling approach to identify osteosarcoma-specific cell-surface antigens can similarly enable development of effective therapeutics in this disease. Herein, we describe an integrated proteomic and transcriptomic surfaceome profiling approach to identify cell-surface proteins that are highly expressed in osteosarcoma but minimally expressed on normal tissues. Using this approach, we identified targets that are highly expressed in osteosarcoma. Three targets, MT1-MMP, CD276, and MRC2, were validated as overexpressed in osteosarcoma. Furthermore, we tested BT1769, an MT1-MMP–targeted Bicycle toxin conjugate, in osteosarcoma patient-derived xenograft models. The results showed that BT1769 had encouraging antitumor activity, high affinity for its target, and a favorable pharmacokinetic profile. This confirms the hypothesis that our approach identifies novel targets with significant therapeutic potential in osteosarcoma.
Data from Suppression of Extracellular Vesicle VEGF-C–mediated Lymphangiogenesis and Pancreatic Cancer Early Dissemination By a Selective HDAC1/2 Inhibitor
Authors: Wang Chu-An , Li Chien-Feng , Huang Rho-Chi , Li Yo-Hua , Liou Jing-Ping , Tsai Shaw-Jenq
Published: April 2023

Abstract
Pancreatic ductal adenocarcinoma (PDAC) is a highly aggressive cancer characterized by early dissemination and poor drug response. Therefore, it is an unmet medical need to develop new strategies for treatment. As aberrant activation of ERK due to KRAS activating mutation is a driving force for PDAC, a brake system that can terminate ERK signaling represents an ideal druggable target. Herein, we demonstrate that forced expression of dual specificity phosphatase-2 (DUSP2), a specific ERK phosphatase, abrogated tumor formation and loss of Dusp2 facilitated Kras-driven PDAC progression. We report that a selective HDAC1/2 inhibitor (B390) has multifaceted therapeutic potential in PDAC by restoring the expression and function of DUSP2. In vitro study showed that treatment with B390 inhibited growth and migration abilities of PDAC cells, decreased extracellular vesicle-associated VEGF-C expression, and suppressed lymphatic endothelial cell proliferation. In vivo, B390 not only suppressed tumor growth by increasing tumor cell death, it also inhibited lymphangiogenesis and lymphovascular invasion. Taken together, our data demonstrate that B390 was able to alleviate loss of DUSP2-mediated pathologic processes, which provides the proof-of-concept evidence to demonstrate the potential of using selective HDAC1/2 inhibitors in PDAC treatment and suggests reinstating DUSP2 expression may be a strategy to subside PDAC progression.
Data from Tucatinib has Selective Activity in HER2-Positive Cancers and Significant Combined Activity with Approved and Novel Breast Cancer–Targeted Therapies
Authors: O'Brien Neil A. , Huang Holly K.T. , McDermott Martina S.J. , Madrid Athena M. , Luo Tong , Ayala Raul , Issakhanian Shawnt , Gong Ke Wei , Lu Ming , Zhang Jun , Slamon Dennis J.
Published: April 2023

Abstract
Pharmacologically targeting the HER2 oncoprotein with therapeutics such as the mAb, trastuzumab, provides clinical benefit for patients with HER2-positive (HER2+) cancers. However, a significant number of patients eventually progress on these therapies. Efforts to overcome therapeutic resistance through combination therapy with small-molecule inhibitors of HER2 have been limited by toxicities associated with off-target activity and/or limited efficacy. In this preclinical study, we explore single-agent and combined activity of tucatinib, a novel HER2-selective small-molecule inhibitor. Tucatinib demonstrated potent, selective activity in a panel of 456 human cancer cell lines, with activity restricted to cell lines (breast and non-breast) with HER2-amplification, including models of acquired resistance to trastuzumab. Within the HER2+ population, tucatinib response tracked strongly with HER2-driven signaling. Single-agent tucatinib induced tumor regressions in xenograft models of HER2+ breast cancer and combination with trastuzumab induced a complete and sustained blockade of HER2/PI3K/AKT signaling. Efficacy of the tucatinib/trastuzumab combination matched that induced by current standard-of-care trastuzumab/pertuzumab/docetaxel combination, with the exception that the chemotherapy-sparing tucatinib/trastuzumab combination did not require a dosing holiday to achieve the same efficacy. In xenograft models of HER2+ breast cancer that also express estrogen receptor (ER; HER2+/ER+), tucatinib showed combined efficacy with inhibitors of CDK4/6 and ER, indicating potential novel therapeutic strategies for difficult-to-treat subtypes of HER2+ breast cancer. These data support expanded clinical investigations of tucatinib as a combination partner for other novel and approved targeted therapies for HER2-driven malignancies.
Data from Exploitation of Sulfated Glycosaminoglycan Status for Precision Medicine of Triplatin in Triple-Negative Breast Cancer
Authors: Hampton James D. , Peterson Erica J. , Katner Samantha J. , Turner Tia H. , Alzubi Mohammad A. , Harrell J. Chuck , Dozmorov Mikhail G. , Turner Joseph B. McGee , Gigliotti Pam J. , Kraskauskiene Vita , Shende Mayuri , Idowu Michael O. , Puchalapalli Madhavi , Hu Bin , Litovchick Larisa , Katsuta Eriko , Takabe Kazuaki , Farrell Nicholas P. , Koblinski Jennifer E.
Published: April 2023

Abstract
Triple-negative breast cancer (TNBC) is a subtype of breast cancer lacking targetable biomarkers. TNBC is known to be most aggressive and when metastatic is often drug-resistant and uncurable. Biomarkers predicting response to therapy improve treatment decisions and allow personalized approaches for patients with TNBC. This study explores sulfated glycosaminoglycan (sGAG) levels as a predictor of TNBC response to platinum therapy. sGAG levels were quantified in three distinct TNBC tumor models, including cell line–derived, patient-derived xenograft (PDX) tumors, and isogenic models deficient in sGAG biosynthesis. The in vivo antitumor efficacy of Triplatin, a sGAG-directed platinum agent, was compared in these models with the clinical platinum agent, carboplatin. We determined that >40% of TNBC PDX tissue microarray samples have high levels of sGAGs. The in vivo accumulation of Triplatin in tumors as well as antitumor efficacy of Triplatin positively correlated with sGAG levels on tumor cells, whereas carboplatin followed the opposite trend. In carboplatin-resistant tumor models expressing high levels of sGAGs, Triplatin decreased primary tumor growth, reduced lung metastases, and inhibited metastatic growth in lungs, liver, and ovaries. sGAG levels served as a predictor of Triplatin sensitivity in TNBC. Triplatin may be particularly beneficial in treating patients with chemotherapy-resistant tumors who have evidence of residual disease after standard neoadjuvant chemotherapy. More effective neoadjuvant and adjuvant treatment will likely improve clinical outcome of TNBC.
Data from PhAc-ALGP-Dox, a Novel Anticancer Prodrug with Targeted Activation and Improved Therapeutic Index
Authors: Casazza Andrea , Van Helleputte Lawrence , Van Renterghem Britt , Pokreisz Peter , De Geest Natalie , De Petrini Marzia , Janssens Tom , Pellens Marijke , Diricx Marjan , Riera-Domingo Carla , Wozniak Agnieszka , Mazzone Massimiliano , Schöffski Patrick , Defert Olivier , Reyns Geert , Kindt Nele
Published: April 2023

Abstract
Clinical use of doxorubicin (Dox) is limited by cumulative myelo- and cardiotoxicity. This research focuses on the detailed characterization of PhAc-ALGP-Dox, a targeted tetrapeptide prodrug with a unique dual-step activation mechanism, designed to circumvent Dox-related toxicities and is ready for upcoming clinical investigation. Coupling Dox to a phosphonoacetyl (PhAc)-capped tetrapeptide forms the cell-impermeable, inactive compound, PhAc-ALGP-Dox. After extracellular cleavage by tumor-enriched thimet oligopeptidase-1 (THOP1), a cell-permeable but still biologically inactive dipeptide-conjugate is formed (GP-Dox), which is further processed intracellularly to Dox by fibroblast activation protein-alpha (FAPα) and/or dipeptidyl peptidase-4 (DPP4). In vitro, PhAc-ALGP-Dox is effective in various 2D- and 3D-cancer models, while showing improved safety toward normal epithelium, hematopoietic progenitors, and cardiomyocytes. In vivo, these results translate into a 10-fold higher tolerability and 5-fold greater retention of Dox in the tumor microenvironment compared with the parental drug. PhAc-ALGP-Dox demonstrates 63% to 96% tumor growth inhibition in preclinical models, an 8-fold improvement in efficacy in patient-derived xenograft (PDX) models, and reduced metastatic burden in a murine model of experimental lung metastasis, improving survival by 30%. The current findings highlight the potential clinical benefit of PhAc-ALGP-Dox, a targeted drug-conjugate with broad applicability, favorable tissue biodistribution, significantly improved tolerability, and tumor growth inhibition at primary and metastatic sites in numerous solid tumor models.
Data from Lurbinectedin Inhibits the EWS–WT1 Transcription Factor in Desmoplastic Small Round Cell Tumor
Authors: Gedminas Jenna M. , Kaufman Rebecca , Boguslawski Elissa A. , Gross Amy C. , Adams Marie , Beddows Ian , Kitchen-Goosen Susan M. , Roberts Ryan D. , Grohar Patrick J.
Published: April 2023

Abstract
Desmoplastic small round cell tumor (DSRCT) is a rare pediatric sarcoma with poor overall survival. This tumor is absolutely dependent on the continued expression and activity of its defining molecular lesion, the EWS–WT1 transcription factor. Unfortunately, the therapeutic targeting of transcription factors is challenging, and there is a critical need to identify compounds that inhibit EWS–WT1. Here we show that the compound lurbinectedin inhibits EWS–WT1 by redistributing the protein within the nucleus to the nucleolus. This nucleolar redistribution interferes with the activity of EWS–WT1 to reverse the expression of over 70% of the transcriptome. In addition, the compound blocks the expression of the EWS–WT1 fusion protein to inhibit cell proliferation at the lowest GI50 ever reported for this compound in any cell type. The effects occur at concentrations that are easily achievable in the clinic and translate to the in vivo setting to cause tumor regressions in multiple mice in a xenograft and PDX model of DSRCT. Importantly, this mechanism of nucleolar redistribution is also seen with wild-type EWSR1 and the related fusion protein EWS–FLI1. This provides evidence for a “class effect” for the more than 18 tumors driven by EWSR1 fusion proteins. More importantly, the data establish lurbinectedin as a promising clinical candidate for DSRCT.
Data from Opposite Effects of Src Family Kinases on YAP and ERK Activation in Pancreatic Cancer Cells: Implications for Targeted Therapy
Authors: Sinnett-Smith James , Anwar Tarique , Reed Elaine F. , Teper Yaroslav , Eibl Guido , Rozengurt Enrique
Published: April 2023

Abstract
Pancreatic ductal adenocarcinoma (PDAC) remains an aggressive disease that is expected to become the second cause of cancer fatalities during the next decade. As therapeutic options are limited, novel targets, and agents for therapeutic intervention are urgently needed. Previously, we identified potent positive crosstalk between insulin/IGF-1 receptors and G protein–coupled (GPCR) signaling systems leading to mitogenic signaling in PDAC cells. Here, we show that a combination of insulin and the GPCR agonist neurotensin induced rapid activation of Src family of tyrosine kinases (SFK) within PANC-1 cells, as shown by FAK phosphorylation at Tyr576/577 and Tyr861, sensitive biomarkers of SFK activity within intact cells and Src416 autophosphorylation. Crucially, SFKs promoted YAP nuclear localization and phosphorylation at Tyr357, as shown by using the SFK inhibitors dasatinib, saracatinib, the preferential YES1 inhibitor CH6953755, siRNA-mediated knockdown of YES1, and transfection of epitogue-tagged YAP mutants in PANC-1 and Mia PaCa-2 cancer cells, models of the aggressive squamous subtype of PDAC. Surprisingly, our results also demonstrate that exposure to SFK inhibitors, including dasatinib or knockdown of YES and Src induces ERK overactivation in PDAC cells. Dasatinib-induced ERK activation was completely abolished by exposure to the FDA-approved MEK inhibitor trametinib. A combination of dasatinib and trametinib potently and synergistically inhibited colony formation by PDAC cells and suppressed the growth of Mia PaCa-2 cells xenografted into the flank of nude mice. The results provide rationale for considering a combination(s) of FDA-approved SFK (dasatinib) and MEK (e.g., trametinib) inhibitors in prospective clinical trials for the treatment of PDAC.
Data from Genotype-Tailored ERK/MAPK Pathway and HDAC Inhibition Rewires the Apoptotic Rheostat to Trigger Colorectal Cancer Cell Death
Authors: Jenkins Laura J. , Luk Ian Y. , Fairlie W. Douglas , Lee Erinna F. , Palmieri Michelle , Schoffer Kael L. , Tan Tao , Ng Irvin , Vukelic Natalia , Tran Sharon , Tse Janson W.T. , Nightingale Rebecca , Alam Zakia , Chionh Fiona , Iatropoulos George , Ernst Matthias , Afshar-Sterle Shoukat , Desai Jayesh , Gibbs Peter , Sieber Oliver M. , Dhillon Amardeep S. , Tebbutt Niall C. , Mariadason John M.
Published: April 2023

Abstract
The EGFR/RAS/MEK/ERK signaling pathway (ERK/MAPK) is hyperactivated in most colorectal cancers. A current limitation of inhibitors of this pathway is that they primarily induce cytostatic effects in colorectal cancer cells. Nevertheless, these drugs do induce expression of proapoptotic factors, suggesting they may prime colorectal cancer cells to undergo apoptosis. As histone deacetylase inhibitors (HDACis) induce expression of multiple proapoptotic proteins, we examined whether they could synergize with ERK/MAPK inhibitors to trigger colorectal cancer cell apoptosis. Combined MEK/ERK and HDAC inhibition synergistically induced apoptosis in colorectal cancer cell lines and patient-derived tumor organoids in vitro, and attenuated Apc-initiated adenoma formation in vivo. Mechanistically, combined MAPK/HDAC inhibition enhanced expression of the BH3-only proapoptotic proteins BIM and BMF, and their knockdown significantly attenuated MAPK/HDAC inhibitor–induced apoptosis. Importantly, we demonstrate that the paradigm of combined MAPK/HDAC inhibitor treatment to induce apoptosis can be tailored to specific MAPK genotypes in colorectal cancers, by combining an HDAC inhibitor with either an EGFR, KRASG12C or BRAFV600 inhibitor in KRAS/BRAFWT; KRASG12C, BRAFV600E colorectal cancer cell lines, respectively. These findings identify a series of ERK/MAPK genotype-tailored treatment strategies that can readily undergo clinical testing for the treatment of colorectal cancer.
Supplementary Figure 6 from Small-Molecule Sigma1 Modulator Induces Autophagic Degradation of PD-L1
Authors: Maher Christina M. , Thomas Jeffrey D. , Haas Derick A. , Longen Charles G. , Oyer Halley M. , Tong Jane Y. , Kim Felix J.
Published: April 2023

Autophagic flux assay.
Supplementary Figure 5 from Small-Molecule Sigma1 Modulator Induces Autophagic Degradation of PD-L1
Authors: Maher Christina M. , Thomas Jeffrey D. , Haas Derick A. , Longen Charles G. , Oyer Halley M. , Tong Jane Y. , Kim Felix J.
Published: April 2023

ATG5 and ATG7 shRNA.
Supplementary Table S1 from A Human Genome-Wide RNAi Screen Reveals Diverse Modulators that Mediate IRE1α–XBP1 Activation
Authors: Yang Zhifen , Zhang Jing , Jiang Dadi , Khatri Purvesh , Solow-Cordero David E. , Toesca Diego A.S. , Koumenis Constantinos , Denko Nicholas C. , Giaccia Amato J. , Le Quynh-Thu , Koong Albert C.
Published: April 2023

227 candidate hits from primary screen.
Supplementary Figure S5 from A Human Genome-Wide RNAi Screen Reveals Diverse Modulators that Mediate IRE1α–XBP1 Activation
Authors: Yang Zhifen , Zhang Jing , Jiang Dadi , Khatri Purvesh , Solow-Cordero David E. , Toesca Diego A.S. , Koumenis Constantinos , Denko Nicholas C. , Giaccia Amato J. , Le Quynh-Thu , Koong Albert C.
Published: April 2023

Correlation of expression of screen hits with the XBP1 gene signature and XBP1s protein in human breast cancer.