bluuebunny/crossref_metadata_2025 huggingface dataset:
Data from Targeting Phosphatidylserine with Calcium-Dependent Protein–Drug Conjugates for the Treatment of Cancer
Authors: Li Ran , Chiguru Srinivas , Li Li , Kim Dongyoung , Velmurugan Ramraj , Kim David , Devanaboyina Siva Charan , Tian Hong , Schroit Alan , Mason Ralph P. , Ober Raimund J. , Ward E. Sally
Published: April 2023

Abstract
In response to cellular stress, phosphatidylserine is exposed on the outer membrane leaflet of tumor blood vessels and cancer cells, motivating the development of phosphatidylserine-specific therapies. The generation of drug-conjugated phosphatidylserine-targeting agents represents an unexplored therapeutic approach, for which antitumor effects are critically dependent on efficient internalization and lysosomal delivery of the cytotoxic drug. In the current study, we have generated phosphatidylserine-targeting agents by fusing phosphatidylserine-binding domains to a human IgG1-derived Fc fragment. The tumor localization and pharmacokinetics of several phosphatidylserine-specific Fc fusions have been analyzed in mice and demonstrate that Fc-Syt1, a fusion containing the synaptotagmin 1 C2A domain, effectively targets tumor tissue. Conjugation of Fc-Syt1 to the cytotoxic drug monomethyl auristatin E results in a protein–drug conjugate (PDC) that is internalized into target cells and, due to the Ca2+ dependence of phosphatidylserine binding, dissociates from phosphatidylserine in early endosomes. The released PDC is efficiently delivered to lysosomes and has potent antitumor effects in mouse xenograft tumor models. Interestingly, although an engineered, tetravalent Fc-Syt1 fusion shows increased binding to target cells, this higher avidity variant demonstrates reduced persistence and therapeutic effects compared with bivalent Fc-Syt1. Collectively, these studies show that finely tuned, Ca2+-switched phosphatidylserine-targeting agents can be therapeutically efficacious. Mol Cancer Ther; 17(1); 169–82. ©2017 AACR.
Data from Tyrosine Threonine Kinase Inhibition Eliminates Lung Cancers by Augmenting Apoptosis and Polyploidy
Authors: Zheng Lin , Chen Zibo , Kawakami Masanori , Chen Yulong , Roszik Jason , Mustachio Lisa Maria , Kurie Jonathan M. , Villalobos Pamela , Lu Wei , Behrens Carmen , Mino Barbara , Solis Luisa M. , Silvester Jennifer , Thu Kelsie L. , Cescon David W , Rodriguez-Canales Jaime , Wistuba Ignacio I. , Mak Tak W. , Liu Xi , Dmitrovsky Ethan
Published: April 2023

Abstract
The spindle assembly checkpoint maintains genomic integrity. A key component is tyrosine threonine kinase (TTK, also known as Mps1). TTK antagonism is hypothesized to cause genomic instability and cell death. Interrogating The Cancer Genome Atlas revealed high TTK expression in lung adenocarcinomas and squamous cell cancers versus the normal lung (P < 0.001). This correlated with an unfavorable prognosis in examined lung adenocarcinoma cases (P = 0.007). TTK expression profiles in lung tumors were independently assessed by RNA in situ hybridization. CFI-402257 is a highly selective TTK inhibitor. Its potent antineoplastic effects are reported here against a panel of well-characterized murine and human lung cancer cell lines. Significant antitumorigenic activity followed independent treatments of athymic mice bearing human lung cancer xenografts (6.5 mg/kg, P < 0.05; 8.5 mg/kg, P < 0.01) and immunocompetent mice with syngeneic lung cancers (P < 0.001). CFI-402257 antineoplastic mechanisms were explored. CFI-402257 triggered aneuploidy and apoptotic death of lung cancer cells without changing centrosome number. Reverse phase protein arrays (RPPA) of vehicle versus CFI-402257–treated lung cancers were examined using more than 300 critical growth-regulatory proteins. RPPA bioinformatic analyses discovered CFI-402257 enhanced MAPK signaling, implicating MAPK antagonism in augmenting TTK inhibitory effects. This was independently confirmed using genetic and pharmacologic repression of MAPK that promoted CFI-402257 anticancer actions. TTK antagonism exerted marked antineoplastic effects against lung cancers and MAPK inhibition cooperated. Future work should determine whether CFI-402257 treatment alone or with a MAPK inhibitor is active in the lung cancer clinic.
Data from Concurrent HER or PI3K Inhibition Potentiates the Antitumor Effect of the ERK Inhibitor Ulixertinib in Preclinical Pancreatic Cancer Models
Authors: Jiang Hongmei , Xu Mai , Li Lin , Grierson Patrick , Dodhiawala Paarth , Highkin Maureen , Zhang Daoxiang , Li Qiong , Wang-Gillam Andrea , Lim Kian-Huat
Published: April 2023

Abstract
Effective treatment for pancreatic ductal adenocarcinoma (PDAC) is an urgent, unmet medical need. Targeting KRAS, the oncogene that is present in >95% of PDAC, is a heavily pursued strategy, but remains unsuccessful in the clinic. Therefore, targeting key effector cascades of KRAS oncoprotein, particularly the mitogenic RAF–MEK–ERK pathway, represents the next best strategy. However, RAF or MEK inhibitors have failed to show clinical efficacy in PDAC. Several studies have shown that cancer cells treated with RAF or MEK inhibitors adopt multiple mechanisms to reactivate ERK signaling. Therefore, development of ERK-specific inhibitors carries the promise to effectively abrogate this pathway. Ulixertinib (or BVD-523) is a first-in-class ERK-specific inhibitor that has demonstrated promising antitumor activity in a phase I clinical trial for advanced solid tumors with NRAS and BRAF mutations, providing a strong rationale to test this inhibitor in PDAC. In this study, we show that ulixertinib effectively inhibits in vitro growth of multiple PDAC lines and potentiates the cytotoxic effect of gemcitabine. Moreover, we found that PDAC cells treated with ulixertinib upregulates the parallel PI3K–AKT pathway through activating the HER/ErbB family proteins. Concurrent inhibition of PI3K or HER proteins synergizes with ulixertinib in suppressing PDAC cell growth in vitro and in vivo. Overall, our study provides the preclinical rationale for testing combinations of ulixertinib with chemotherapy or PI3K and HER inhibitors in PDAC patients. Mol Cancer Ther; 17(10); 2144–55. ©2018 AACR.
Data from Poly-ADP-Ribose Polymerase as a Therapeutic Target in Pediatric Diffuse Intrinsic Pontine Glioma and Pediatric High-Grade Astrocytoma
Authors: Chornenkyy Yevgen , Agnihotri Sameer , Yu Man , Buczkowicz Pawel , Rakopoulos Patricia , Golbourn Brian , Garzia Livia , Siddaway Robert , Leung Stephie , Rutka James T. , Taylor Michael D. , Dirks Peter B. , Hawkins Cynthia
Published: April 2023

Abstract
Pediatric high-grade astrocytomas (pHGA) and diffuse intrinsic pontine gliomas (DIPG) are devastating malignancies for which no effective therapies exist. We investigated the therapeutic potential of PARP1 inhibition in preclinical models of pHGA and DIPG. PARP1 levels were characterized in pHGA and DIPG patient samples and tumor-derived cell lines. The effects of PARP inhibitors veliparib, olaparib, and niraparib as monotherapy or as radiosensitizers on cell viability, DNA damage, and PARP1 activity were evaluated in a panel of pHGA and DIPG cell lines. Survival benefit of niraparib was examined in an orthotopic xenograft model of pHGA. About 85% of pHGAs and 76% of DIPG tissue microarray samples expressed PARP1. Six of 8 primary cell lines highly expressed PARP1. Interestingly, across multiple cell lines, some PARP1 protein expression was required for response to PARP inhibition; however, there was no correlation between protein level or PARP1 activity and sensitivity to PARP inhibitors. Niraparib was the most effective at reducing cell viability and proliferation (MTT and Ki67). Niraparib induced DNA damage (γH2AX foci) and induced growth arrest. Pretreatment of pHGA cells with a sublethal dose of niraparib (1 μmol/L) before 2 Gy of ionizing radiation (IR) decreased the rate of DNA damage repair, colony growth, and relative cell number. Niraparib (50 mg/kg) inhibited PARP1 activity in vivo and extended survival of mice with orthotopic pHGA xenografts, when administered before IR (20 Gy, fractionated), relative to control mice (40 vs. 25 days). Our data provide in vitro and in vivo evidence that niraparib may be an effective radiosensitizer for pHGA and DIPG. Mol Cancer Ther; 14(11); 2560–8. ©2015 AACR.
Data from LncRNA CCAT1 Promotes Prostate Cancer Cell Proliferation by Interacting with DDX5 and MIR-28-5P
Authors: You Zonghao , Liu Chunhui , Wang Can , Ling Zhixin , Wang Yiduo , Wang Yali , Zhang Minghao , Chen Shuqiu , Xu Bin , Guan Han , Chen Ming
Published: April 2023

Abstract
Accumulated evidence indicates that CCAT1 functions as an oncogene in the progression of a variety of tumors. However, little is known as to how CCAT1 impacts tumorigenesis in human prostate cancer. In this study, we found from The Cancer Genome Atlas and Memorial Sloan Kettering Cancer Center database that CCAT1 is highly upregulated in castration-resistant prostate cancer (CRPC) compared with androgen-dependent prostate cancer (ADPC). Higher level of CCAT1 leads to increased mortality in patients with CRPC. In vitro and in vivo studies show that CCAT1 promotes prostate cancer cell proliferation as well as the tumor growth of prostate cancer xenografts. Mechanistically, in cytoplasm, CCAT1 sponges MIR-28-5P to prevent the anticancer effect. In nucleus, CCAT1 acts as a scaffold for DDX5 (P68) and AR transcriptional complex to facilitate the expression of AR-regulated genes, thus stimulating CRPC progression. Our findings suggest that CCAT1 is an oncogenic factor in the progression of CRPC with different regulatory mechanisms in the nucleus and cytoplasm of cells.
Data from Identification of Pharmacodynamic Transcript Biomarkers in Response to FGFR Inhibition by AZD4547
Authors: Delpuech Oona , Rooney Claire , Mooney Lorraine , Baker Dawn , Shaw Robert , Dymond Michael , Wang Dennis , Zhang Pei , Cross Sarah , Veldman-Jones Margaret , Wilson Joanne , Davies Barry R. , Dry Jonathan R. , Kilgour Elaine , Smith Paul D.
Published: April 2023

Abstract
The challenge of developing effective pharmacodynamic biomarkers for preclinical and clinical testing of FGFR signaling inhibition is significant. Assays that rely on the measurement of phospho-protein epitopes can be limited by the availability of effective antibody detection reagents. Transcript profiling enables accurate quantification of many biomarkers and provides a broader representation of pathway modulation. To identify dynamic transcript biomarkers of FGFR signaling inhibition by AZD4547, a potent inhibitor of FGF receptors 1, 2, and 3, a gene expression profiling study was performed in FGFR2-amplified, drug-sensitive tumor cell lines. Consistent with known signaling pathways activated by FGFR, we identified transcript biomarkers downstream of the RAS-MAPK and PI3K/AKT pathways. Using different tumor cell lines in vitro and xenografts in vivo, we confirmed that some of these transcript biomarkers (DUSP6, ETV5, YPEL2) were modulated downstream of oncogenic FGFR1, 2, 3, whereas others showed selective modulation only by FGFR2 signaling (EGR1). These transcripts showed consistent time-dependent modulation, corresponding to the plasma exposure of AZD4547 and inhibition of phosphorylation of the downstream signaling molecules FRS2 or ERK. Combination of FGFR and AKT inhibition in an FGFR2-mutated endometrial cancer xenograft model enhanced modulation of transcript biomarkers from the PI3K/AKT pathway and tumor growth inhibition. These biomarkers were detected on the clinically validated nanoString platform. Taken together, these data identified novel dynamic transcript biomarkers of FGFR inhibition that were validated in a number of in vivo models, and which are more robustly modulated by FGFR inhibition than some conventional downstream signaling protein biomarkers. Mol Cancer Ther; 15(11); 2802–13. ©2016 AACR.
Data from Target Deconvolution of a Multikinase Inhibitor with Antimetastatic Properties Identifies TAOK3 as a Key Contributor to a Cancer Stem Cell–Like Phenotype
Authors: Bian Yansong , Teper Yaroslav , Mathews Griner Lesley A. , Aiken Taylor J. , Shukla Vivek , Guha Rajarshi , Shinn Paul , Xin Hong-Wu , Pflicke Holger , Powers Astin S. , Li Dandan , Jiang Jian-kang , Patel Paresma , Rogers Steven A. , Aubé Jeffrey , Ferrer Marc , Thomas Craig J. , Rudloff Udo
Published: April 2023

Abstract
Pancreatic cancer remains an incurable condition. Its progression is driven, in part, by subsets of cancer cells that evade the cytotoxic effects of conventional chemotherapies. These cells are often low-cycling, multidrug resistant, and adopt a stem cell–like phenotype consistent with the concept of cancer stem cells (CSC). To identify drugs impacting on tumor-promoting CSCs, we performed a differential high-throughput drug screen in pancreatic cancer cells cultured in traditional (2D) monolayers versus three-dimensional (3D) spheroids which replicate key elements of the CSC model. Among the agents capable of killing cells cultured in both formats was a 1H-benzo[d]imidazol-2-amine–based inhibitor of IL2-inducible T-cell kinase (ITK; NCGC00188382, inhibitor #1) that effectively mediated growth inhibition and induction of apoptosis in vitro, and suppressed cancer progression and metastasis formation in vivo. An examination of this agent's polypharmacology via in vitro and in situ phosphoproteomic profiling demonstrated an activity profile enriched for mediators involved in DNA damage repair. Included was a strong inhibitory potential versus the thousand-and-one amino acid kinase 3 (TAOK3), CDK7, and aurora B kinases. We found that cells grown under CSC-enriching spheroid conditions are selectively dependent on TAOK3 signaling. Loss of TAOK3 decreases colony formation, expression of stem cell markers, and sensitizes spheroids to the genotoxic effect of gemcitabine, whereas overexpression of TAOK3 increases stem cell traits including tumor initiation and metastasis formation. By inactivating multiple components of the cell-cycle machinery in concert with the downregulation of key CSC signatures, inhibitor #1 defines a distinctive strategy for targeting pancreatic cancer cell populations.
Data from AZD5153: A Novel Bivalent BET Bromodomain Inhibitor Highly Active against Hematologic Malignancies
Authors: Rhyasen Garrett W. , Hattersley Maureen M. , Yao Yi , Dulak Austin , Wang Wenxian , Petteruti Philip , Dale Ian L. , Boiko Scott , Cheung Tony , Zhang Jingwen , Wen Shenghua , Castriotta Lillian , Lawson Deborah , Collins Michael , Bao Larry , Ahdesmaki Miika J. , Walker Graeme , O'Connor Greg , Yeh Tammie C. , Rabow Alfred A. , Dry Jonathan R. , Reimer Corinne , Lyne Paul , Mills Gordon B. , Fawell Stephen E. , Waring Michael J. , Zinda Michael , Clark Edwin , Chen Huawei
Published: April 2023

Abstract
The bromodomain and extraterminal (BET) protein BRD4 regulates gene expression via recruitment of transcriptional regulatory complexes to acetylated chromatin. Pharmacological targeting of BRD4 bromodomains by small molecule inhibitors has proven to be an effective means to disrupt aberrant transcriptional programs critical for tumor growth and/or survival. Herein, we report AZD5153, a potent, selective, and orally available BET/BRD4 bromodomain inhibitor possessing a bivalent binding mode. Unlike previously described monovalent inhibitors, AZD5153 ligates two bromodomains in BRD4 simultaneously. The enhanced avidity afforded through bivalent binding translates into increased cellular and antitumor activity in preclinical hematologic tumor models. In vivo administration of AZD5153 led to tumor stasis or regression in multiple xenograft models of acute myeloid leukemia, multiple myeloma, and diffuse large B-cell lymphoma. The relationship between AZD5153 exposure and efficacy suggests that prolonged BRD4 target coverage is a primary efficacy driver. AZD5153 treatment markedly affects transcriptional programs of MYC, E2F, and mTOR. Of note, mTOR pathway modulation is associated with cell line sensitivity to AZD5153. Transcriptional modulation of MYC and HEXIM1 was confirmed in AZD5153-treated human whole blood, thus supporting their use as clinical pharmacodynamic biomarkers. This study establishes AZD5153 as a highly potent, orally available BET/BRD4 inhibitor and provides a rationale for clinical development in hematologic malignancies. Mol Cancer Ther; 15(11); 2563–74. ©2016 AACR.
Data from Dinaciclib Induces Anaphase Catastrophe in Lung Cancer Cells via Inhibition of Cyclin-Dependent Kinases 1 and 2
Authors: Danilov Alexey V. , Hu Shanhu , Orr Bernardo , Godek Kristina , Mustachio Lisa Maria , Sekula David , Liu Xi , Kawakami Masanori , Johnson Faye M. , Compton Duane A. , Freemantle Sarah J. , Dmitrovsky Ethan
Published: April 2023

Abstract
Despite advances in targeted therapy, lung cancer remains the most common cause of cancer-related mortality in the United States. Chromosomal instability is a prominent feature in lung cancer and, because it rarely occurs in normal cells, it represents a potential therapeutic target. Our prior work discovered that lung cancer cells undergo anaphase catastrophe in response to inhibition of cyclin-dependent kinase 2 (CDK2), followed by apoptosis and reduced growth. In this study, the effects and mechanisms of the multi-CDK inhibitor dinaciclib on lung cancer cells were investigated. We sought to determine the specificity of CDK-dependent induction of anaphase catastrophe. Live cell imaging provided direct evidence that dinaciclib caused multipolar cell divisions resulting in extensive chromosome missegregation. Genetic knockdown of dinaciclib CDK targets revealed that repression of CDK2 and CDK1, but not CDK5 or CDK9, triggered anaphase catastrophe in lung cancer cells. Overexpression of CP110, which is a mediator of CDK2 inhibitor–induced anaphase catastrophe (and a CDK1 and 2 phosphorylation substrate), antagonized anaphase catastrophe and apoptosis following dinaciclib treatment. Consistent with our previous findings, acquisition of activated KRAS sensitized lung cancer cells to dinaciclib-mediated anaphase catastrophe and cell death. Combining dinaciclib with the mitotic inhibitor taxol augmented anaphase catastrophe induction and reduced cell viability of lung cancer cells. Thus, the multi-CDK inhibitor dinaciclib causes anaphase catastrophe in lung cancer cells and should be investigated as a potential therapeutic for wild-type and KRAS-mutant lung cancer, individually or in combination with taxanes. Mol Cancer Ther; 15(11); 2758–66. ©2016 AACR.
Data from Anti–B-cell Maturation Antigen Chimeric Antigen Receptor T cell Function against Multiple Myeloma Is Enhanced in the Presence of Lenalidomide
Authors: Works Melissa , Soni Neha , Hauskins Collin , Sierra Catherine , Baturevych Alex , Jones Jon C. , Curtis Wendy , Carlson Patrick , Johnstone Timothy G. , Kugler David , Hause Ronald J. , Jiang Yue , Wimberly Lindsey , Clouser Christopher R. , Jessup Heidi K. , Sather Blythe , Salmon Ruth A. , Ports Michael O.
Published: April 2023

Abstract
Anti–B-cell maturation antigen (BCMA) chimeric antigen receptor (CAR) T cells have shown promising clinical responses in patients with relapsed/refractory multiple myeloma. Lenalidomide, an immunomodulatory drug, potentiates T cell functionality, drives antimyeloma activity, and alters the suppressive microenvironment; these properties may effectively combine with anti-BCMA CAR T cells to enhance function. Using an anti-BCMA CAR T, we demonstrated that lenalidomide enhances CAR T cell function in a concentration-dependent manner. Lenalidomide increased CAR T effector cytokine production, particularly under low CAR stimulation or in the presence of inhibitory ligand programmed cell death 1 ligand 1. Notably, lenalidomide also enhanced CAR T cytokine production, cytolytic activity, and activation profile relative to untreated CAR T cells in chronic stimulation assays. This unique potentiation of both short-term CAR T activity and long-term functionality during chronic stimulation prompted investigation of the molecular profile of lenalidomide-treated CAR T cells. Signatures from RNA sequencing and assay for transposase-accessible chromatin using sequencing indicated that pathways associated with T-helper 1 response, cytokine production, T cell activation, cell-cycle control, and cytoskeletal remodeling were altered with lenalidomide. Finally, study of lenalidomide and anti-BCMA CAR T cells in a murine, disseminated, multiple myeloma model indicated that lenalidomide increased CAR T cell counts in blood and significantly prolonged animal survival. In summary, preclinical studies demonstrated that lenalidomide potentiated CAR T activity in vivo in low-antigen or suppressive environments and delayed onset of functional exhaustion. These results support further investigation of lenalidomide and anti-BCMA CAR T cells in the clinic.
Data from A Novel Fully Human Antibody targeting Extracellular Domain of PSMA Inhibits Tumor Growth in Prostate Cancer
Authors: Wu Jieheng , Han Donghui , Shi Shengjia , Zhang Qiang , Zheng Guoxu , Wei Ming , Han Yueheng , Li Guodong , Yang Fa , Jiao Dian , Xie Pin , Zhang Lingling , Yang An-Gang , Zhao Aizhi , Qin Weijun , Wen Weihong
Published: April 2023

Abstract
Prostate cancer is the most commonly diagnosed malignancy in men and the second leading cause of cancer-related death. It is of vital importance to develop new strategies for prostate cancer therapy. PSMA (prostate-specific membrane antigen) is specifically expressed in prostate cancer and the neovasculature of certain cancer types, thus is considered to be an ideal target for cancer therapy. In our previous study, we have obtained a PSMA-specific single-chain variable fragment (scFv), named gy1, from a large yeast display naïve human scFv library. In this study, we reconstructed the PSMA scFv into a fully human antibody (named PSMAb) and evaluated its characterization both in vitro and in vivo. We showed that PSMAb can specifically bind with and internalize into PSMA+ cells. The binding affinity of PSMAb is measured to be at nanomolar level, and PSMAb has very good thermostability. In vivo study showed that near IR dye–labeled PSMAb can specifically localize at PSMA+ tumors, and the application of PSMAb in vivo significantly inhibited the growth of PSMA+ tumors, but not PSMA− tumors. At the studied doses, no obvious toxicity was observed when applied in vivo, as shown by the relative normal liver and kidney function and normal structure of important organs, shown by hematoxylin and eosin staining. In addition, PSMAb may inhibit tumor growth through antibody-dependent cell-mediated cytotoxicity and complement-dependent cytotoxicity mechanisms. Our results indicated that the novel fully human antibody, PSMAb, deserve further study for PSMA-targeted diagnosis and therapy for prostate cancer and other cancer types with vascular PSMA expression.
Data from The Discovery and Preclinical Development of ASG-5ME, an Antibody–Drug Conjugate Targeting SLC44A4-Positive Epithelial Tumors Including Pancreatic and Prostate Cancer
Authors: Mattie Michael , Raitano Arthur , Morrison Kendall , Morrison Karen , An Zili , Capo Linnette , Verlinsky Alla , Leavitt Monica , Ou Jimmy , Nadell Rossana , Aviña Hector , Guevara Claudia , Malik Faisal , Moser Ruth , Duniho Steven , Coleman Jeffrey , Li Ying , Pereira Daniel S. , Doñate Fernando , Joseph Ingrid B.J. , Challita-Eid Pia , Benjamin Dennis , Stover David R.
Published: April 2023

Abstract
Here, we report the development of an antibody–drug conjugate, ASG-5ME, which targets the solute carrier receptor SLC44A4. SLC44A4 is a member of a family of putative choline transporters that we show to be markedly upregulated in a variety of epithelial tumors, most notably prostate and pancreatic cancer. SLC44A4 is normally expressed on the apical surface of secretory epithelial cells, but in cancer we show expression is not restricted to the luminal surface in advanced and undifferentiated tumors. ASG-5ME consists of a human IgG2 anti-SLC44A4 antibody conjugated through a cleavable linker to the microtubule-disrupting agent monomethylauristatin E. It has potent antitumor activity in both cell line – and patient-derived xenograft models of pancreatic and prostate cancers. Combination studies with ASG-5ME and nab-paclitaxel demonstrated combination effect in both pancreatic and prostate tumor models. Altogether, the data presented here suggest that ASG-5ME may have the potential to offer a new therapeutic option for the treatment of pancreatic and prostate cancers. Mol Cancer Ther; 15(11); 2679–87. ©2016 AACR.
Data from Manipulation of Cell-Type Selective Antibody Internalization by a Guide-Effector Bispecific Design
Authors: Lee Nam-Kyung , Su Yang , Bidlingmaier Scott , Liu Bin
Published: April 2023

Abstract
Cell-type–specific intracellular payload delivery is desired for antibody-based–targeted therapy development. However, tumor-specific internalizing antigens are rare to find, and even rarer for those that are expressed at uniformly high levels. We constructed a bispecific antibody that is composed of a rapidly internalizing antibody binding to a tumor-associated antigen, ephrin receptor A2 (EphA2), and a noninternalizing antibody binding to a highly expressed tumor-associated antigen, activated leukocyte cell adhesion molecule (ALCAM). We found that the overall internalization property of the bispecific is profoundly impacted by the relative surface expression level (antigen density ratio) of EphA2 versus ALCAM. When the EphA2-to-ALCAM ratio is greater than a threshold level (1:5), the amount of the bispecific taken into the tumor cell exceeds what is achieved by either the monoclonal internalizing antibody or a mixture of the two antibodies, showing a bispecific-dependent amplification effect where a small amount of the internalizing antigen EphA2 induces internalization of a larger amount of the noninternalizing antigen ALCAM. When the ratio is below the threshold, EphA2 can be rendered noninternalizing by the presence of excess ALCAM on the same cell surface. We constructed a bispecific antibody–drug conjugate (ADC) based on the above bispecific design and found that the bispecific ADC is more potent than monospecific ADCs in tumor cell killing both in vitro and in vivo. Thus, the internalizing property of a cell surface antigen can be manipulated in either direction by a neighboring antigen, and this phenomenon can be exploited for therapeutic targeting.
Data from The Novel Small-Molecule SR18662 Efficiently Inhibits the Growth of Colorectal Cancer In Vitro and In Vivo
Authors: Kim Julie , Wang Chao , de Sabando Ainara Ruiz , Cole Hannah L. , Huang Timothy J. , Yang Jie , Bannister Thomas D. , Yang Vincent W. , Bialkowska Agnieszka B.
Published: April 2023

Abstract
Krüppel-like factor 5 (KLF5), a member of the SP/KLF family of zinc finger transcription factors, is overexpressed in human colorectal cancer specimens, and this overabundance is associated with aggressive cancer development and progression. We demonstrated that mice haploinsufficient for Klf5 had reduced intestinal tumor burden in the background of germline mutation in Apc, a gatekeeper of intestinal tumorigenesis. Based on a high-throughput screening strategy, we developed ML264, a small-molecule compound that inhibits KLF5, and showed that it inhibits growth of colorectal cancer in vitro and in vivo. Through optimization efforts based on the structure of ML264, we have now identified a new lead compound, SR18662. We find that treatment with SR18662 significantly reduces growth and proliferation of colorectal cancer cells as compared with treatment with vehicle control, ML264, or SR15006 (a less optimized analogue from SAR efforts leading to SR18662). SR18662 showed improved efficacy in reducing the viability of multiple colorectal cancer cell lines. Flow cytometry analysis following SR18662 treatment showed an increase in cells captured in either S or G2–M phases of the cell cycle and a significant increase in the number of apoptotic cells, the latter a unique property compared with ML264 or SR15006. SR18662 treatment also reduces the expression of cyclins and components of the MAPK and WNT signaling pathways. Importantly, we observed a significant dose-dependent inhibition of xenograft growth in mice following SR18662 treatment that exceeded the effect of ML264 at equivalent doses. These findings support further development of SR18662 and its analogues for colorectal cancer therapy.
Data from A Novel Eg5 Inhibitor (LY2523355) Causes Mitotic Arrest and Apoptosis in Cancer Cells and Shows Potent Antitumor Activity in Xenograft Tumor Models
Authors: Ye Xiang S. , Fan Li , Van Horn Robert D. , Nakai Ryuichiro , Ohta Yoshihisa , Akinaga Shiro , Murakata Chikara , Yamashita Yoshinori , Yin Tinggui , Credille Kelly M. , Donoho Gregory P. , Merzoug Farhana F. , Li Heng , Aggarwal Amit , Blanchard Kerry , Westin Eric H.
Published: April 2023

Abstract
Intervention of cancer cell mitosis by antitubulin drugs is among the most effective cancer chemotherapies. However, antitubulin drugs have dose-limiting side effects due to important functions of microtubules in resting normal cells and are often rendered ineffective by rapid emergence of resistance. Antimitotic agents with different mechanisms of action and improved safety profiles are needed as new treatment options. Mitosis-specific kinesin Eg5 represents an attractive anticancer target for discovering such new antimitotic agents, because Eg5 is essential only in mitotic progression and has no roles in resting, nondividing cells. Here, we show that a novel selective Eg5 inhibitor, LY2523355, has broad target-mediated anticancer activity in vitro and in vivo. LY2523355 arrests cancer cells at mitosis and causes rapid cell death that requires sustained spindle-assembly checkpoint (SAC) activation with a required threshold concentration. In vivo efficacy of LY2523355 is highly dose/schedule-dependent, achieving complete remission in a number of xenograft tumor models, including patient-derived xenograft (PDX) tumor models. We further establish that histone-H3 phosphorylation of tumor and proliferating skin cells is a promising pharmacodynamic biomarker for in vivo anticancer activity of LY2523355. Mol Cancer Ther; 14(11); 2463–72. ©2015 AACR.
Data from Amplification of the Mutation-Carrying BRCA2 Allele Promotes RAD51 Loading and PARP Inhibitor Resistance in the Absence of Reversion Mutations
Authors: Park Pyoung Hwa , Yamamoto Tomomi M. , Li Hua , Alcivar Allen L. , Xia Bing , Wang Yifan , Bernhardy Andrea J. , Turner Kristen M. , Kossenkov Andrew V. , Watson Zachary L. , Behbakht Kian , Casadei Silvia , Swisher Elizabeth M. , Mischel Paul S. , Johnson Neil , Bitler Benjamin G.
Published: April 2023

Abstract
Patients harboring germline breast cancer susceptibility genes 1 and 2 (BRCA1/2) mutations are predisposed to developing breast, pancreatic, and ovarian cancers. BRCA2 plays a critical role in homologous recombination (HR) DNA repair and deleterious mutations in BRCA2 confer sensitivity to PARP inhibition. Recently, the PARP inhibitors olaparib and rucaparib were FDA approved for the treatment of metastatic breast cancer and patients with recurrent ovarian cancer with mutations in BRCA1/2. Despite their initial antitumor activity, the development of resistance limits the clinical utility of PARP inhibitor therapy. Multiple resistance mechanisms have been described, including reversion mutations that restore the reading frame of the BRCA2 gene. In this study, we generated olaparib- and rucaparib-resistant BRCA2-mutant Capan1 cell lines. We did not detect secondary reversion mutations in the olaparib- or rucaparib-resistant clones. Several of the resistant clones had gene duplication and amplification of the mutant BRCA2 allele, with a corresponding increase in expression of a truncated BRCA2 protein. In addition, HR-mediated DNA repair was rescued, as evidenced by the restoration of RAD51 foci formation. Using mass spectrometry, we identified Disruptor Of Telomeric silencing 1-Like (DOT1L), as an interacting partner of truncated BRCA2. RNAi-mediated knockdown of BRCA2 or DOT1L was sufficient to resensitize cells to olaparib. The results demonstrate that independent of a BRCA2 reversion, mutation amplification of a mutant-carrying BRCA2 contributes to PARP inhibitor resistance.
Data from The DNA Endonuclease Mus81 Regulates ZEB1 Expression and Serves as a Target of BET4 Inhibitors in Gastric Cancer
Authors: Yin Yuping , Liu Weizhen , Shen Qian , Zhang Peng , Wang Lulu , Tao Ruikang , Li Hang , Ma Xianxiong , Zeng Xiangyu , Cheong Jae-Ho , Song Shumei , Ajani Jaffer A. , Mills Gordon B. , Tao Kaixiong , Peng Guang
Published: April 2023

Abstract
DNA replication and repair proteins play an important role in cancer initiation and progression by affecting genomic instability. The DNA endonuclease Mus81 is a DNA structure–specific endonuclease, which has been implicated in DNA replication and repair. In this study, we found that Mus81 promotes gastric metastasis by controlling the transcription of ZEB1, a master regulator of the epithelial–mesenchymal transition (EMT). Our results revealed that Mus81 is highly expressed in gastric cancer samples from patients and cell lines compared with their normal counterparts. Particularly, Mus81 expression positively correlated with ZEB1 expression and Mus81 overexpression was significantly associated with higher incidence of lymph node metastasis in patients. Furthermore, Mus81 promoted migration of gastric cancer cells both in vitro and in vivo. We conducted a drug screen using a collection of preclinical and FDA-approved drugs and found that the BRD4 inhibitor AZD5153 inhibited the expression of Mus81 and ZEB1 by regulating the epigenetic factor Sirt5. As expected, AZD5153 treatment significantly reduced the migration of gastric cancer cells overexpressing Mus81 in vitro and in vivo. Collectively, we show that Mus81 is a regulator of ZEB1 and promotes metastasis in gastric cancer. Importantly, we demonstrate that the BRD4 inhibitor AZD5153 can potentially be used as an effective antimetastasis drug because of its effect on Mus81.
Data from Photodynamic Therapy Using Indocyanine Green Loaded on Super Carbonate Apatite as Minimally Invasive Cancer Treatment
Authors: Tamai Koki , Mizushima Tsunekazu , Wu Xin , Inoue Akira , Ota Minori , Yokoyama Yuhki , Miyoshi Norikatsu , Haraguchi Naotsugu , Takahashi Hidekazu , Nishimura Junichi , Hata Taishi , Matsuda Chu , Doki Yuichiro , Mori Masaki , Yamamoto Hirofumi
Published: April 2023

Abstract
Minimally invasive treatment is getting more and more important in an aging society. The purpose of this study was to explore the possibility of ICG loaded on super carbonate apatite (sCA) nanoparticles as a novel photodynamic therapy (PDT) against cancers. Using colon cancer cells, ICG uptake and anti-tumor effects were examined between the treatments of ICG and sCA-ICG. Reactive oxygen species (ROS) production and temperature rise were also evaluated to explore the underlying mechanism. Atomic force microscopy revealed that the size of sCA-ICG ranged from 10 to 20 nm. In aqueous solution with 0.5% albumin, the temperature increase after laser irradiation was 27.1°C and 23.1°C in sCA-ICG and ICG, respectively (control DW: 5.7°C). A significant increase in ROS generation was noted in cell cultures treated with sCA-ICG plus irradiation compared with those treated with ICG plus irradiation (P < 0.01). Uptake of ICG in the tumor cells significantly increased in sCA-ICG compared with ICG in vitro and in vivo. The fluorescence signals of ICG in the tumor, liver, and kidney faded away in both treatments by 24 hours. Finally, the HT29 tumors treated with sCA-ICG followed by irradiation exhibited drastic tumor growth retardation (P < 0.01), whereas irradiation of tumors after injection of ICG did not inhibit tumor growth. This study shows that sCA is a useful vehicle for ICG-based PDT. Quick withdrawal of ICG from normal organs is unique to sCA-ICG and contrasts with the other nanoparticles remaining in normal organs for a long time. Mol Cancer Ther; 17(7); 1613–22. ©2018 AACR.
Data from Androgen Receptor Signaling Reduces Radiosensitivity in Bladder Cancer
Authors: Ide Hiroki , Inoue Satoshi , Mizushima Taichi , Jiang Guiyang , Chuang Kuang-Hsiang , Oya Mototsugu , Miyamoto Hiroshi
Published: April 2023

Abstract
Although radiotherapy often with chemotherapy has been shown to offer a survival benefit comparable with that of radical cystectomy in select patients with bladder cancer, the development of radiosensitization strategies may significantly enhance its application. Notably, emerging preclinical evidence has indicated the involvement of androgen receptor (AR) signaling in urothelial cancer progression. We here assessed whether AR signals could contribute to modulating radiosensitivity in bladder cancer cells. Ionizing radiation reduced the numbers of viable cells or colonies of AR-negative lines more significantly than those of AR-positive lines. Similarly, in AR-positive cells cultured in androgen-depleted conditions, dihydrotestosterone treatment lowered the effects of irradiation. Meanwhile, an antiandrogen hydroxyflutamide enhanced them in AR-positive cells cultured in the presence of androgens. AR knockdown or hydroxyflutamide treatment also resulted in a delay in DNA double-strand break repair 4–24 hours after irradiation. We then established “radiation-resistant” sublines and found considerable elevation of the expression of AR as well as DNA repair genes, such as ATR, CHEK1, and PARP-1, in these sublines, compared with respective controls. Furthermore, dihydrotestosterone induced the expression of these DNA repair genes in irradiated AR-positive cells, and hydroxyflutamide antagonized the androgen effects. Finally, in a mouse xenograft model, low-dose flutamide was found to enhance the inhibitory effects of irradiation, and its tumor size was similar to that of AR knockdown line with radiation alone. These findings suggest that AR activity inversely correlates with radiosensitivity in bladder cancer. Accordingly, antiandrogenic drugs may function as sensitizers of irradiation, especially in patients with AR-positive urothelial cancer. Mol Cancer Ther; 17(7); 1566–74. ©2018 AACR.
Data from CNDAC-Induced DNA Double-Strand Breaks Cause Aberrant Mitosis Prior to Cell Death
Authors: Liu Xiaojun , Jiang Yingjun , Takata Kei-ichi , Nowak Billie , Liu Chaomei , Wood Richard D. , Hittelman Walter N. , Plunkett William
Published: April 2023

Abstract
Incorporation of the clinically active deoxycytidine analogue 2′-C-cyano-2′-deoxy-1-β-D-arabino-pentofuranosyl-cytosine (CNDAC) into DNA generates single-strand breaks that are subsequently converted to double-strand breaks (DSB). Here, we investigated the cellular manifestations of these breaks that link these mechanisms to cell death, and we further tested the relevance of DNA repair pathways in protection of cells against CNDAC damage. The present investigations demonstrate that following exposure to CNDAC and a wash into drug-free medium, chromosomal aberrations, DNA strand breaks, and multinucleate cells arose. These portended loss of viability and were dependent upon exposure time, CNDAC concentration, and passage through mitosis. Following a pulse incubation with CNDAC, live cell imaging using GFP-tagged histone H2B as a marker demonstrated a normal rate of progression to mitosis, but a concentration-dependent delay in passage to a second mitosis. Progression through mitosis was also delayed and accompanied by formation of multinucleate cells. CNDAC-treated cells lacking XPF-ERCC1 nuclease function showed a 16-fold increase in chromosome aberrations. Chromosomal damage in Rad51D-mutant cells (homologous recombination repair deficient) were even more severely affected with extensive aberrations. Rodent or human Polq (POLQ) mutant cells, defective in Pol θ–mediated alternative end joining, did not show enhanced cellular sensitivity to CNDAC. These findings are consistent with formation of DSBs in the second S-phase following exposure, resulting in chromosome aberrations, aberrant mitoses, and subsequent apoptosis.
Data from Development of a RSK Inhibitor as a Novel Therapy for Triple-Negative Breast Cancer
Authors: Ludwik Katarzyna A. , Campbell J. Preston , Li Mingzong , Li Yu , Sandusky Zachary M. , Pasic Lejla , Sowder Miranda E. , Brenin David R. , Pietenpol Jennifer A. , O'Doherty George A. , Lannigan Deborah A.
Published: April 2023

Abstract
Metastatic breast cancer is an incurable disease and identification of novel therapeutic opportunities is vital. Triple-negative breast cancer (TNBC) frequently metastasizes and high levels of activated p90RSK (RSK), a downstream MEK-ERK1/2 effector, are found in TNBC. We demonstrate, using direct pharmacologic and genetic inhibition of RSK1/2, that these kinases contribute to the TNBC metastatic process in vivo. Kinase profiling showed that RSK1 and RSK2 are the predominant kinases targeted by the new inhibitor, which is based on the natural product SL0101. Further evidence for selectivity was provided by the observations that silencing RSK1 and RSK2 eliminated the ability of the analogue to further inhibit survival or proliferation of a TNBC cell line. In vivo, the new derivative was as effective as the FDA-approved MEK inhibitor trametinib in reducing the establishment of metastatic foci. Importantly, inhibition of RSK1/2 did not result in activation of AKT, which is known to limit the efficacy of MEK inhibitors in the clinic. Our results demonstrate that RSK is a major contributor to the TNBC metastatic program and provide preclinical proof-of-concept for the efficacy of the novel SL0101 analogue in vivo. Mol Cancer Ther; 15(11); 2598–608. ©2016 AACR.
Data from The Existence of MTH1-independent 8-oxodGTPase Activity in Cancer Cells as a Compensatory Mechanism against On-target Effects of MTH1 Inhibitors
Authors: Samaranayake Govindi J. , Troccoli Clara I. , Zhang Ling , Huynh Mai , Jayaraj Christina J. , Ji Debin , McPherson Lisa , Onishi Yoshiyuki , Nguyen Dao M. , Robbins David J. , Karbaschi Mahsa , Cooke Marcus S. , Barrientos Antonio , Kool Eric T. , Rai Priyamvada
Published: April 2023

Abstract
Investigations into the human 8-oxodGTPase, MutT Homolog 1 (MTH1), have risen sharply since the first-in-class MTH1 inhibitors were reported to be highly tumoricidal. However, MTH1 as a cancer therapeutic target is currently controversial because subsequently developed inhibitors did not exhibit similar cytotoxic effects. Here, we provide the first direct evidence for MTH1-independent 8-oxodGTPase function in human cancer cells and human tumors, using a novel ATP-releasing guanine-oxidized (ARGO) chemical probe. Our studies show that this functionally redundant 8-oxodGTPase activity is not decreased by five different published MTH1-targeting small molecules or by MTH1 depletion. Significantly, while only the two first-in-class inhibitors, TH588 and TH287, reduced cancer cell viability, all five inhibitors evaluated in our studies decreased 8-oxodGTPase activity to a similar extent. Thus, the reported efficacy of the first-in-class MTH1 inhibitors does not arise from their inhibition of MTH1-specific 8-oxodGTPase activity. Comparison of DNA strand breaks, genomic 8-oxoguanine incorporation, or alterations in cellular oxidative state by TH287 versus the noncytotoxic inhibitor, IACS-4759, contradict that the cytotoxicity of the former results solely from increased levels of oxidatively damaged genomic DNA. Thus, our findings indicate that mechanisms unrelated to oxidative stress or DNA damage likely underlie the reported efficacy of the first-in-class inhibitors. Our study suggests that MTH1 functional redundancy, existing to different extents in all cancer lines and human tumors evaluated in our study, is a thus far undefined factor which is likely to be critical in understanding the importance of MTH1 and its clinical targeting in cancer.
Data from Plk1 Inhibition Enhances the Efficacy of BET Epigenetic Reader Blockade in Castration-Resistant Prostate Cancer
Authors: Mao Fengyi , Li Jie , Luo Qian , Wang Ruixin , Kong Yifan , Carlock Colin , Liu Zian , Elzey Bennet D. , Liu Xiaoqi
Published: April 2023

Abstract
Polo-like kinase 1 (Plk1), a crucial regulator of cell-cycle progression, is overexpressed in multiple types of cancers and has been proven to be a potent and promising target for cancer treatment. In case of prostate cancer, we once showed that antineoplastic activity of Plk1 inhibitor is largely due to inhibition of androgen receptor (AR) signaling. However, we also discovered that Plk1 inhibition causes activation of the β-catenin pathway and increased expression of c-MYC, eventually resulting in resistance to Plk1 inhibition. JQ1, a selective small-molecule inhibitor targeting the amino-terminal bromodomains of BRD4, has been shown to dramatically inhibit c-MYC expression and AR signaling, exhibiting antiproliferative effects in a range of cancers. Because c-MYC and AR signaling are essential for prostate cancer initiation and progression, we aim to test whether targeting Plk1 and BRD4 at the same time is an effective approach to treat prostate cancer. Herein, we show that a combination of Plk1 inhibitor GSK461364A and BRD4 inhibitor JQ1 had a strong synergistic effect on castration-resistant prostate cancer (CRPC) cell lines, as well as in CRPC xenograft tumors. Mechanistically, the synergistic effect is likely due to two reasons: (i) Plk1 inhibition results in the accumulation of β-catenin in the nucleus, thus elevation of c-MYC expression, whereas JQ1 treatment directly suppresses c-MYC transcription; (ii) Plk1 and BRD4 dual inhibition acts synergistically in inhibition of AR signaling. Mol Cancer Ther; 17(7); 1554–65. ©2018 AACR.
Data from The Novel Glutamine Antagonist Prodrug JHU395 Has Antitumor Activity in Malignant Peripheral Nerve Sheath Tumor
Authors: Lemberg Kathryn M. , Zhao Liang , Wu Ying , Veeravalli Vijayabhaskar , Alt Jesse , Aguilar Joanna Marie H. , Dash Ranjeet P. , Lam Jenny , Tenora Lukáš , Rodriguez Chabely , Nedelcovych Michael T. , Brayton Cory , Majer Pavel , Blakeley Jaishri O. , Rais Rana , Slusher Barbara S.
Published: April 2023

Abstract
The carbon and nitrogen components of glutamine are used for multiple biosynthetic processes by tumors. Glutamine metabolism and the therapeutic potential of glutamine antagonists (GA), however, are incompletely understood in malignant peripheral nerve sheath tumor (MPNST), an aggressive soft tissue sarcoma observed in patients with neurofibromatosis type I. We investigated glutamine dependence of MPNST using JHU395, a novel orally bioavailable GA prodrug designed to circulate inert in plasma, but permeate and release active GA within target tissues. Human MPNST cells, compared with Schwann cells derived from healthy peripheral nerve, were selectively susceptible to both glutamine deprivation and GA dose-dependent growth inhibition. In vivo, orally administered JHU395 delivered active GA to tumors with over 2-fold higher tumor-to-plasma exposure, and significantly inhibited tumor growth in a murine flank MPNST model without observed toxicity. Global metabolomics studies and stable isotope–labeled flux analyses in tumors identified multiple glutamine-dependent metabolites affected, including prominent effects on purine synthesis. These data demonstrate that glutamine antagonism is a potential antitumor strategy for MPNST.