bluuebunny/crossref_metadata_2025 huggingface dataset:
Data from Cotargeting BCL-2 and PI3K Induces BAX-Dependent Mitochondrial Apoptosis in AML Cells
Authors: Rahmani Mohamed , Nkwocha Jewel , Hawkins Elisa , Pei Xinyan , Parker Rebecca E. , Kmieciak Maciej , Leverson Joel D. , Sampath Deepak , Ferreira-Gonzalez Andrea , Grant Steven
Published: March 2023

Abstract
Inhibitors targeting BCL-2 apoptotic proteins have significant potential for the treatment of acute myeloid leukemia (AML); however, complete responses are observed in only 20% of patients, suggesting that targeting BCL-2 alone is insufficient to yield durable responses. Here, we assessed the efficacy of coadministration of the PI3K/mTOR inhibitor GDC-0980 or the p110β-sparing PI3K inhibitor taselisib with the selective BCL-2 antagonist venetoclax in AML cells. Tetracycline-inducible downregulation of BCL-2 significantly sensitized MV4-11 and MOLM-13 AML cells to PI3K inhibition. Venetoclax/GDC-0980 coadministration induced rapid and pronounced BAX mitochondrial translocation, cytochrome c release, and apoptosis in various AML cell lines in association with AKT/mTOR inactivation and MCL-1 downregulation; ectopic expression of MCL-1 significantly protected cells from this regimen. Combined treatment was also effective against primary AML blasts from 17 patients, including those bearing various genetic abnormalities. Venetoclax/GDC-0980 markedly induced apoptosis in primitive CD34+/38−/123+ AML cell populations but not in normal hematopoietic progenitor CD34+ cells. The regimen was also active against AML cells displaying intrinsic or acquired venetoclax resistance or tumor microenvironment–associated resistance. Either combinatorial treatment markedly reduced AML growth and prolonged survival in a systemic AML xenograft mouse model and diminished AML growth in two patient-derived xenograft models. Venetoclax/GDC-0980 activity was partially diminished in BAK−/− cells and failed to induce apoptosis in BAX−/− and BAX−/−BAK−/− cells, whereas BIM−/− cells were fully sensitive. Similar results were observed with venetoclax alone in in vitro and in vivo systemic xenograft models. Collectively, these studies demonstrate that venetoclax/GDC-0980 exhibits potent anti-AML activity primarily through BAX and, to a lesser extent, BAK. These findings argue that dual BCL-2 and PI3K inhibition warrants further evaluation in AML.

Significance: Combined treatment with clinically relevant PI3K and BCL-2 inhibitors may prove effective in the treatment of acute myeloid leukemia. Cancer Res; 78(11); 3075–86. ©2018 AACR.
Data from YAP/TAZ Initiates Gastric Tumorigenesis via Upregulation of MYC
Authors: Choi Wonyoung , Kim Jeongsik , Park Jaeoh , Lee Da-Hye , Hwang Daehee , Kim Jeong-Hwan , Ashktorab Hassan , Smoot Duane , Kim Seon-Young , Choi Chan , Koh Gou Young , Lim Dae-Sik
Published: March 2023

Abstract
YAP and TAZ play oncogenic roles in various organs, but the role of YAP/TAZ in gastric cancer remains unclear. Here, we show that YAP/TAZ activation initiates gastric tumorigenesis in vivo and verify its significance in human gastric cancer. In mice, YAP/TAZ activation in the pyloric stem cell led to step-wise tumorigenesis. RNA sequencing identified MYC as a decisive target of YAP, which controls MYC at transcriptional and posttranscriptional levels. These mechanisms tightly regulated MYC in homeostatic conditions, but YAP activation altered this balance by impeding miRNA processing, causing a shift towards MYC upregulation. Pharmacologic inhibition of MYC suppressed YAP-dependent phenotypes in vitro and in vivo, verifying its functional role as a key mediator. Human gastric cancer samples also displayed a significant correlation between YAP and MYC. We reanalyzed human transcriptome data to verify enrichment of YAP signatures in a subpopulation of gastric cancers and found that our model closely reflected the molecular pattern of patients with high YAP activity. Overall, these results provide genetic evidence of YAP/TAZ as oncogenic initiators and drivers for gastric tumors with MYC as the key downstream mediator. These findings are also evident in human gastric cancer, emphasizing the significance of YAP/TAZ signaling in gastric carcinogenesis.

Significance: YAP/TAZ activation initiates gastric carcinogenesis with MYC as the key downstream mediator. Cancer Res; 78(12); 3306–20. ©2018 AACR.
Data from A Novel Mechanism for Activation of GLI1 by Nuclear SMO That Escapes Anti-SMO Inhibitors
Authors: Rahman Muhammad M. , Hazan Allon , Selway Joanne L. , Herath Dimalee S. , Harwood Catherine A. , Pirzado Muhammad S. , Atkar Ravinder , Kelsell David P. , Linton Kenneth J. , Philpott Mike P. , Neill Graham W.
Published: March 2023

Abstract
Small-molecule inhibitors of the Hedgehog (HH) pathway receptor Smoothened (SMO) have been effective in treating some patients with basal cell carcinoma (BCC), where the HH pathway is often activated, but many patients respond poorly. In this study, we report the results of investigations on PTCH1 signaling in the HH pathway that suggest why most patients with BCC respond poorly to SMO inhibitors. In immortalized human keratinocytes, PTCH1 silencing led to the generation of a compact, holoclone-like morphology with increased expression of SMO and the downstream HH pathway transcription factor GLI1. Notably, although siRNA silencing of SMO in PTCH1-silenced cells was sufficient to suppress GLI1 activity, this effect was not phenocopied by pharmacologic inhibition of SMO, suggesting the presence of a second undefined pathway through which SMO can induce GLI1. Consistent with this possibility, we observed increased nuclear localization of SMO in PTCH1-silenced cells as mediated by a putative SMO nuclear/nucleolar localization signal [N(o)LS]. Mutational inactivation of the N(o)LS ablated this increase and suppressed GLI1 induction. Immunohistologic analysis of human and mouse BCC confirmed evidence of nuclear SMO, although the pattern was heterogeneous between tumors. In PTCH1-silenced cells, >80% of the genes found to be differentially expressed were unaffected by SMO inhibitors, including the putative BCC driver gene CXCL11. Our results demonstrate how PTCH1 loss results in aberrant regulation of SMO-independent mechanisms important for BCC biology and highlights a novel nuclear mechanism of SMO-GLI1 signaling that is unresponsive to SMO inhibitors.

Significance: This study describes novel noncanonical Hedgehog signaling, where SMO enters the nucleus to activate GLI1, a mode that is unaffected by SMO inhibitors, thus prompting re-evaluation of current BCC treatment as well as new potential therapies targeting nuclear SMO. Cancer Res; 78(10); 2577–88. ©2018 AACR.
Data from Inhibition of Nr4a Receptors Enhances Antitumor Immunity by Breaking Treg-Mediated Immune Tolerance
Authors: Hibino Sana , Chikuma Shunsuke , Kondo Taisuke , Ito Minako , Nakatsukasa Hiroko , Omata-Mise Setsuko , Yoshimura Akihiko
Published: March 2023

Abstract
Enhanced infiltration of regulatory T cells (Treg) into tumor tissue is detrimental to patients with cancer and is closely associated with poor prognosis as they create an immunosuppressive state that suppresses antitumor immune responses. Therefore, breaking Treg-mediated immune tolerance is important when considering cancer immunotherapy. Here, we show that the Nr4a nuclear receptors, key transcription factors maintaining Treg genetic programs, contribute to Treg-mediated suppression of antitumor immunity in the tumor microenvironment. Mice lacking Nr4a1 and Nr4a2 genes specifically in Tregs showed resistance to tumor growth in transplantation models without exhibiting any severe systemic autoimmunity. The chemotherapeutic agent camptothecin and a common cyclooxygenase-2 inhibitor were found to inhibit transcriptional activity and induction of Nr4a factors, and they synergistically exerted antitumor effects. Genetic inactivation or pharmacologic inhibition of Nr4a factors unleashed effector activities of CD8+ cytotoxic T cells and evoked potent antitumor immune responses. These findings demonstrate that inactivation of Nr4a in Tregs breaks immune tolerance toward cancer, and pharmacologic modulation of Nr4a activity may be a novel cancer treatment strategy targeting the immunosuppressive tumor microenvironment.

Significance: This study reveals the role of Nr4a transcription factors in Treg-mediated tolerance to antitumor immunity, with possible therapeutic implications for developing effective anticancer therapies. Cancer Res; 78(11); 3027–40. ©2018 AACR.
Data from Patient-Derived Xenograft Models Reveal Intratumor Heterogeneity and Temporal Stability in Neuroblastoma
Authors: Braekeveldt Noémie , von Stedingk Kristoffer , Fransson Susanne , Martinez-Monleon Angela , Lindgren David , Axelson Håkan , Levander Fredrik , Willforss Jakob , Hansson Karin , Øra Ingrid , Backman Torbjörn , Börjesson Anna , Beckman Siv , Esfandyari Javanshir , Berbegall Ana P. , Noguera Rosa , Karlsson Jenny , Koster Jan , Martinsson Tommy , Gisselsson David , Påhlman Sven , Bexell Daniel
Published: March 2023

Abstract
Patient-derived xenografts (PDX) and the Avatar, a single PDX mirroring an individual patient, are emerging tools in preclinical cancer research. However, the consequences of intratumor heterogeneity for PDX modeling of biomarkers, target identification, and treatment decisions remain underexplored. In this study, we undertook serial passaging and comprehensive molecular analysis of neuroblastoma orthotopic PDXs, which revealed strong intrinsic genetic, transcriptional, and phenotypic stability for more than 2 years. The PDXs showed preserved neuroblastoma-associated gene signatures that correlated with poor clinical outcome in a large cohort of patients with neuroblastoma. Furthermore, we captured spatial intratumor heterogeneity using ten PDXs from a single high-risk patient tumor. We observed diverse growth rates, transcriptional, proteomic, and phosphoproteomic profiles. PDX-derived transcriptional profiles were associated with diverse clinical characteristics in patients with high-risk neuroblastoma. These data suggest that high-risk neuroblastoma contains elements of both temporal stability and spatial intratumor heterogeneity, the latter of which complicates clinical translation of personalized PDX–Avatar studies into preclinical cancer research.

Significance: These findings underpin the complexity of PDX modeling as a means to advance translational applications against neuroblastoma. Cancer Res; 78(20); 5958–69. ©2018 AACR.
Data from The EGFR T790M Mutation Is Acquired through AICDA-Mediated Deamination of 5-Methylcytosine following TKI Treatment in Lung Cancer
Authors: El Kadi Najwa , Wang Luo , Davis April , Korkaya Hasan , Cooke Alexander , Vadnala Varun , Brown Noah A. , Betz Bryan L. , Cascalho Marilia , Kalemkerian Gregory P. , Hassan Khaled A.
Published: March 2023

Abstract
Almost all patients with EGFR-driven lung cancer who are treated with EGFR tyrosine kinase inhibitors (TKI) develop resistance to treatment. A single base (c.2369C>T) transition mutation, EGFR T790M, is the most frequent resistance event after first-generation exposure to EGFR TKIs. Whether T790M mutation is acquired or is selected from a preexisting clone has been a matter of significant debate. In this study, we show that treatment with EGFR TKIs leads to activation of the NFκB pathway, which in turn induces expression of activation-induced cytidine deaminase (AICDA). In turn, AICDA causes deamination of 5-methylcytosine to thymine at position c.2369 to generate the T790M mutation. Pharmacologic inhibition of the NFκB pathway or knockout of AICDA decreased the frequency or prevented the development of T790M mutation, respectively. In addition, patients treated with first-line EGFR TKI displayed increased expression of AICDA and detection of the T790M mutation upon progression. These results identify the mechanism of T790M acquisition and present an opportunity to target the process to delay or prevent it.
Significance:
These findings identify the mechanism behind acquisition of a common resistance mutation to TKI treatment in lung cancer.
Data from Methylation of C/EBPα by PRMT1 Inhibits Its Tumor-Suppressive Function in Breast Cancer
Authors: Liu Li-Ming , Sun Wen-Zheng , Fan Xue-Zhe , Xu Ya-Li , Cheng Mo-Bin , Zhang Ye
Published: March 2023

Abstract
C/EBPα is an essential transcription factor involved in regulating the expression or function of certain cell-cycle regulators, including in breast cancer cells. Although protein arginine methyltransferases have been shown to play oncogenic roles in a variety of cancers, little is known about the role of arginine methylation in regulating the antiproliferation activity of C/EBPα. Here, we report that the protein arginine methyltransferase 1 (PRMT1) is overexpressed in human breast cancer and that elevated PRMT1 correlates with cancer malignancy. RNA-sequencing analysis revealed that knockdown of PRMT1 in breast cancer cells is accompanied by a decrease in the expression of pro-proliferative genes, including cyclin D1. Furthermore, tandem affinity purification followed by mass spectrometry identified PRMT1 as a component of the C/EBPα complex. C/EBPα associated with and was methylated by PRMT1 at three arginine residues (R35, R156, and R165). PRMT1-dependent methylation of C/EBPα promoted the expression of cyclin D1 by blocking the interaction between C/EBPα and its corepressor HDAC3, which resulted in rapid growth of tumor cells during the pathogenesis of breast cancer. Inhibition of PRMT1 significantly impeded the growth of cancer cells from patients with triple-negative breast cancer. This evidence that PRMT1 mediates C/EBPα methylation sheds light on a novel pathway and potential therapeutic target in breast cancer.
Significance:
This study provides novel mechanistic insight of the role of the arginine methyltransferase PRMT1 in breast cancer pathogenesis.
Data from Treatment-Induced Tumor Cell Apoptosis and Secondary Necrosis Drive Tumor Progression in the Residual Tumor Microenvironment through MerTK and IDO1
Authors: Werfel Thomas A. , Elion David L. , Rahman Bushra , Hicks Donna J. , Sanchez Violeta , Gonzales-Ericsson Paula I. , Nixon Mellissa J. , James Jamaal L. , Balko Justin M. , Scherle Peggy A. , Koblish Holly K. , Cook Rebecca S.
Published: March 2023

Abstract
Efferocytosis is the process by which apoptotic cells are cleared from tissue by phagocytic cells. The removal of apoptotic cells prevents them from undergoing secondary necrosis and releasing their inflammation-inducing intracellular contents. Efferocytosis also limits tissue damage by increasing immunosuppressive cytokines and leukocytes and maintains tissue homeostasis by promoting tolerance to antigens derived from apoptotic cells. Thus, tumor cell efferocytosis following cytotoxic cancer treatment could impart tolerance to tumor cells evading treatment-induced apoptosis with deleterious consequences in tumor residual disease. We report here that efferocytosis cleared apoptotic tumor cells in residual disease of lapatinib-treated HER2+ mammary tumors in MMTV-Neu mice, increased immunosuppressive cytokines, myeloid-derived suppressor cells (MDSC), and regulatory T cells (Treg). Blockade of efferocytosis induced secondary necrosis of apoptotic cells, but failed to prevent increased tumor MDSCs, Treg, and immunosuppressive cytokines. We found that efferocytosis stimulated expression of IFN-γ, which stimulated the expression of indoleamine-2,3-dioxegenase (IDO) 1, an immune regulator known for driving maternal-fetal antigen tolerance. Combined inhibition of efferocytosis and IDO1 in tumor residual disease decreased apoptotic cell- and necrotic cell-induced immunosuppressive phenotypes, blocked tumor metastasis, and caused tumor regression in 60% of MMTV-Neu mice. This suggests that apoptotic and necrotic tumor cells, via efferocytosis and IDO1, respectively, promote tumor ‘homeostasis’ and progression.
Significance:
These findings show in a model of HER2+ breast cancer that necrosis secondary to impaired efferocytosis activates IDO1 to drive immunosuppression and tumor progression.
Data from Single-Cell Analysis Reveals a Preexisting Drug-Resistant Subpopulation in the Luminal Breast Cancer Subtype
Authors: Prieto-Vila Marta , Usuba Wataru , Takahashi Ryou-u , Shimomura Iwao , Sasaki Hideo , Ochiya Takahiro , Yamamoto Yusuke
Published: March 2023

Abstract
Drug resistance is a major obstacle in the treatment of breast cancer. Surviving cells lead to tumor recurrence and metastasis, which remains the main cause of cancer-related mortality. Breast cancer is also highly heterogeneous, which hinders the identification of individual cells with the capacity to survive anticancer treatment. To address this, we performed extensive single-cell gene-expression profiling of the luminal-type breast cancer cell line MCF7 and its derivatives, including docetaxel-resistant cells. Upregulation of epithelial-to-mesenchymal transition and stemness-related genes and downregulation of cell-cycle–related genes, which were mainly regulated by LEF1, were observed in the drug-resistant cells. Interestingly, a small number of cells in the parental population exhibited a gene-expression profile similar to that of the drug-resistant cells, indicating that the untreated parental cells already contained a rare subpopulation of stem-like cells with an inherent predisposition toward docetaxel resistance. Our data suggest that during chemotherapy, this population may be positively selected, leading to treatment failure.
Significance:
This study highlights the role of breast cancer intratumor heterogeneity in drug resistance at a single-cell level.
Data from Thrombin Signaling Promotes Pancreatic Adenocarcinoma through PAR-1–Dependent Immune Evasion
Authors: Yang Yi , Stang Amanda , Schweickert Patrick G. , Lanman Nadia A. , Paul Erin N. , Monia Brett P. , Revenko Alexey S. , Palumbo Joseph S. , Mullins Eric S. , Elzey Bennett D. , Janssen Edith M. , Konieczny Stephen F. , Flick Matthew J.
Published: March 2023

Abstract
Pancreatic ductal adenocarcinoma (PDAC) is associated with robust activity of the coagulation system. To determine mechanisms by which clotting factors influence PDAC tumor progression, we generated and characterized C57Bl/6-derived KPC (KRasG12D, TRP53R172H) cell lines. Tissue factor (TF) and protease-activated receptor-1 (PAR-1) were highly expressed in primary KPC pancreatic lesions and KPC cell lines similar to expression profiles observed in biopsies of patients with PDAC. In allograft studies, tumor growth and metastatic potential were significantly diminished by depletion of TF or Par-1 in cancer cells or by genetic or pharmacologic reduction of the coagulation zymogen prothrombin in mice. Notably, PAR-1–deleted KPC cells (KPC-Par-1KO) failed to generate sizable tumors, a phenotype completely rescued by restoration of Par-1 expression. Expression profiling of KPC and KPC-Par-1KO cells indicated that thrombin–PAR-1 signaling significantly altered immune regulation pathways. Accordingly, KPC-Par-1KO cells failed to form tumors in immune-competent mice but displayed robust tumor growth comparable to that observed with control KPC cells in immune-compromised NSG mice. Immune cell depletion studies indicated that CD8 T cells, but not CD4 cells or natural killer cells, mediated elimination of KPC-Par-1KO tumor cells in C57Bl/6 mice. These results demonstrate that PDAC is driven by activation of the coagulation system through tumor cell–derived TF, circulating prothrombin, and tumor cell–derived PAR-1 and further indicate that one key mechanism of thrombin/PAR-1–mediated tumor growth is suppression of antitumor immunity in the tumor microenvironment.
Significance:
The tissue factor–thrombin–PAR-1 signaling axis in tumor cells promotes PDAC growth and disease progression with one key mechanism being suppression of antitumor immunity in the microenvironment.
Data from Targeting BCR-ABL1 in Chronic Myeloid Leukemia by PROTAC-Mediated Targeted Protein Degradation
Authors: Burslem George M. , Schultz Anna Reister , Bondeson Daniel P. , Eide Christopher A. , Savage Stevens Samantha L. , Druker Brian J. , Crews Craig M.
Published: March 2023

Abstract
Although the use of ATP-competitive tyrosine kinase inhibitors of oncoprotein BCR-ABL1 has enabled durable responses in patients with chronic myeloid leukemia (CML), issues of drug resistance and residual leukemic stem cells remain. To test whether the degradation of BCR-ABL1 kinase could offer improved response, we developed a series of proteolysis-targeting chimera (PROTAC) that allosterically target BCR-ABL1 protein and recruit the E3 ligase Von Hippel-Lindau, resulting in ubiquitination and subsequent degradation of the oncogenic fusion protein. In both human CML K562 cells and murine Ba/F3 cells expressing BCR-ABL1, lead compound GMB-475 induced rapid proteasomal degradation and inhibition of downstream biomarkers, such as STAT5, and showed increased sensitivity compared with diastereomeric controls lacking degradation activity. Notably, GMB-475 inhibited the proliferation of certain clinically relevant BCR-ABL1 kinase domain point mutants and further sensitized Ba/F3 BCR-ABL1 cells to inhibition by imatinib, while demonstrating no toxicity toward Ba/F3 parental cells. Reverse phase protein array analysis suggested additional differences in levels of phosphorylated SHP2, GAB2, and SHC associated with BCR-ABL1 degradation. Importantly, GMB-475 reduced viability and increased apoptosis in primary CML CD34+ cells, with no effect on healthy CD34+ cells at identical concentrations. GMB-475 degraded BCR-ABL1 and reduced cell viability in primary CML stem cells. Together, these findings suggest that combined BCR-ABL1 kinase inhibition and protein degradation may represent a strategy to address BCR-ABL1–dependent drug resistance, and warrant further investigation into the eradication of persistent leukemic stem cells, which rely on neither the presence nor the activity of the BCR-ABL1 protein for survival.
Significance:
Small-molecule–induced degradation of BCR-ABL1 in CML provides an advantage over inhibition and provides insights into CML stem cell biology.
Data from Genetic Variants of VEGFA and FLT4 Are Determinants of Survival in Renal Cell Carcinoma Patients Treated with Sorafenib
Authors: Crona Daniel J. , Skol Andrew D. , Leppänen Veli-Matti , Glubb Dylan M. , Etheridge Amy S. , Hilliard Eleanor , Peña Carol E. , Peterson Yuri K. , Klauber-DeMore Nancy , Alitalo Kari K. , Innocenti Federico
Published: March 2023

Abstract
Molecular markers of sorafenib efficacy in patients with metastatic renal cell carcinoma (mRCC) are not available. The purpose of this study was to discover genetic markers of survival in patients with mRCC treated with sorafenib. Germline variants from 56 genes were genotyped in 295 patients with mRCC. Variant-overall survival (OS) associations were tested in multivariate regression models. Mechanistic studies were conducted to validate clinical associations. VEGFA rs1885657, ITGAV rs3816375, and WWOX rs8047917 (sorafenib arm), and FLT4 rs307826 and VEGFA rs3024987 (sorafenib and placebo arms combined) were associated with shorter OS. FLT4 rs307826 increased VEGFR-3 phosphorylation, membrane trafficking, and receptor activation. VEGFA rs1885657 and rs58159269 increased transcriptional activity of the constructs containing these variants in endothelial and RCC cell lines, and VEGFA rs58159269 increased endothelial cell proliferation and tube formation. FLT4 rs307826 and VEGFA rs58159269 led to reduced sorafenib cytotoxicity. Genetic variation in VEGFA and FLT4 could affect survival in sorafenib-treated patients with mRCC. These markers should be examined in additional malignancies treated with sorafenib and in other angiogenesis inhibitors used in mRCC.
Significance:
Clinical and mechanistic data identify germline genetic variants in VEGFA and FLT4 as markers of survival in patients with metastatic renal cell carcinoma.
Data from Posttraumatic Stress Disorder Is Associated with Increased Risk of Ovarian Cancer: A Prospective and Retrospective Longitudinal Cohort Study
Authors: Roberts Andrea L. , Huang Tianyi , Koenen Karestan C. , Kim Yongjoo , Kubzansky Laura D. , Tworoger Shelley S.
Published: March 2023

Abstract
Ovarian cancer is the deadliest gynecologic cancer. Chronic stress accelerates tumor growth in animal models of ovarian cancer. We therefore postulated that posttraumatic stress disorder (PTSD) may be associated with increased risk of ovarian cancer. We used data from the Nurses' Health Study II, a longitudinal cohort study with 26 years of follow-up, conducted from 1989 to 2015 with 54,710 subjects. Lifetime PTSD symptoms were measured in 2008. Self-reported ovarian cancer was validated with medical records. Risk of ovarian cancer was estimated with Cox proportional hazards models and further adjusted for known ovarian cancer risk factors (e.g., hormonal factors) and health risk factors (e.g., smoking). Fully prospective secondary analyses examined incident ovarian cancer occurring after PTSD assessment in 2008. In addition, we examined associations by menopausal status. During follow-up, 110 ovarian cancers were identified. Women with high PTSD symptoms had 2-fold greater risk of ovarian cancer versus women with no trauma exposure [age-adjusted HR = 2.10; 95% confidence interval (CI), 1.12–3.95]. Adjustment for health and ovarian cancer risk factors moderately attenuated this association (HR = 1.86; 95% CI, 0.98–3.51). Associations were similar or moderately stronger in fully prospective analyses (age-adjusted HR = 2.38; 95% CI, 0.98–5.76, N cases = 50) and in premenopausal women (HR = 3.42; 95% CI, 1.08–10.85). In conclusion, we show that PTSD symptoms are associated with increased risk of ovarian cancer. Better understanding of the underlying molecular mechanisms could lead to interventions that reduce ovarian cancer risk in women with PTSD and other stress-related mental disorders.
Significance:
PTSD is associated with ovarian cancer risk, particularly in premenopausal women. Understanding the underlying molecular mechanisms will aid in formulating ways to reduce ovarian cancer risk associated with chronic stress.
Data from Collagen Prolyl Hydroxylation–Dependent Metabolic Perturbation Governs Epigenetic Remodeling and Mesenchymal Transition in Pluripotent and Cancer Cells
Authors: D'Aniello Cristina , Cermola Federica , Palamidessi Andrea , Wanderlingh Luca G. , Gagliardi Miriam , Migliaccio Agnese , Varrone Francesca , Casalino Laura , Matarazzo Maria R. , De Cesare Dario , Scita Giorgio , Patriarca Eduardo J. , Minchiotti Gabriella
Published: March 2023

Abstract
Collagen prolyl hydroxylation (CPH), which is catalyzed by prolyl 4-hydroxylase (P4H), is the most prevalent posttranslational modification in humans and requires vitamin C (VitC). Here, we demonstrate that CPH acts as an epigenetic modulator of cell plasticity. Increased CPH induced global DNA/histone methylation in pluripotent stem and tumor cells and promoted cell state transition (CST). Interfering with CPH by either genetic ablation of P4H subunit alpha-2 (P4HA2) or pharmacologic treatment reverted epigenetic changes and antagonized CST. Mechanistically, we suggest that CPH modifies the epigenetic landscape by reducing VitC for DNA and histone demethylases. Repurposed drugs targeting CPH-mediated metabolic perturbation, such as the antiasthmatic budesonide, blocked metastatic dissemination of breast cancer cells in vivo by preventing mesenchymal transition. Our study provides mechanistic insights into how metabolic cues and epigenetic factors integrate to control CST and paves the way for the development of novel antimetastatic strategies.
Significance:
A phenotype-based high-throughput screening reveals unforeseen metabolic control of cell plasticity and identifies budesonide as a drug candidate for metastatic cancer.
Data from Differential Activity of ATR and WEE1 Inhibitors in a Highly Sensitive Subpopulation of DLBCL Linked to Replication Stress
Authors: Young Lucy A. , O'Connor Lenka Oplustil , de Renty Christelle , Veldman-Jones Margaret H. , Dorval Thierry , Wilson Zena , Jones David R. , Lawson Deborah , Odedra Rajesh , Maya-Mendoza Apolinar , Reimer Corinne , Bartek Jiri , Lau Alan , O'Connor Mark J.
Published: March 2023

Abstract
DNA damage checkpoint kinases ATR and WEE1 are among key regulators of DNA damage response pathways protecting cells from replication stress, a hallmark of cancer that has potential to be exploited for therapeutic use. ATR and WEE1 inhibitors are in early clinical trials and success will require greater understanding of both their mechanism of action and biomarkers for patient selection. Here, we report selective antitumor activity of ATR and WEE1 inhibitors in a subset of non-germinal center B-cell (GCB) diffuse large B-cell lymphoma (DLBCL) cell lines, characterized by high MYC protein expression and CDKN2A/B deletion. Activity correlated with the induction of replication stress, indicated by increased origin firing and retardation of replication fork progression. However, ATR and WEE1 inhibitors caused different amounts of DNA damage and cell death in distinct phases of the cell cycle, underlying the increased potency observed with WEE1 inhibition. ATR inhibition caused DNA damage to manifest as 53BP1 nuclear bodies in daughter G1 cells leading to G1 arrest, whereas WEE1 inhibition caused DNA damage and arrest in S phase, leading to earlier onset apoptosis. In vivo xenograft DLBCL models confirmed differences in single-agent antitumor activity, but also showed potential for effective ATR inhibitor combinations. Importantly, insights into the different inhibitor mechanisms may guide differentiated clinical development strategies aimed at exploiting specific vulnerabilities of tumor cells while maximizing therapeutic index. Our data therefore highlight clinical development opportunities for both ATR and WEE1 inhibitors in non-GCB DLBCL subtypes that represent an area of unmet clinical need.
Significance:
ATR and WEE1 inhibitors demonstrate effective antitumor activity in preclinical models of DLBCL associated with replication stress, but new mechanistic insights and biomarkers of response support a differentiated clinical development strategy.
Data from Gene Editing of α6 Integrin Inhibits Muscle Invasive Networks and Increases Cell–Cell Biophysical Properties in Prostate Cancer
Authors: Rubenstein Cynthia S. , Gard Jaime M.C. , Wang Mengdie , McGrath Julie E. , Ingabire Nadia , Hinton James P. , Marr Kendra D. , Simpson Skyler J. , Nagle Raymond B. , Miranti Cindy K. , Warfel Noel A. , Garcia Joe G.N. , Arif-Tiwari Hina , Cress Anne E.
Published: March 2023

Abstract
Human prostate cancer confined to the gland is indolent (low-risk), but tumors outside the capsule are aggressive (high-risk). Extracapsular extension requires invasion within and through a smooth muscle-structured environment. Because integrins respond to biomechanical cues, we used a gene editing approach to determine if a specific region of laminin-binding α6β1 integrin was required for smooth muscle invasion both in vitro and in vivo. Human tissue specimens showed prostate cancer invasion through smooth muscle and tumor coexpression of α6 integrin and E-cadherin in a cell–cell location and α6 integrin in a cell–extracellular matrix (ECM) distribution. Prostate cancer cells expressing α6 integrin (DU145 α6WT) produced a 3D invasive network on laminin-containing Matrigel and invaded into smooth muscle both in vitro and in vivo. In contrast, cells without α6 integrin (DU145 α6KO) and cells expressing an integrin mutant (DU145 α6AA) did not produce invasive networks, could not invade muscle both in vitro and in vivo, and surprisingly formed 3D cohesive clusters. Using electric cell–substrate impedance testing, cohesive clusters had up to a 30-fold increase in normalized resistance at 400 Hz (cell–cell impedance) as compared with the DU145 α6WT cells. In contrast, measurements at 40,000 Hz (cell–ECM coverage) showed that DU145 α6AA cells were two-fold decreased in normalized resistance and were defective in restoring resistance after a 1 μmol/L S1P challenge as compared with the DU145 α6WT cells. The results suggest that gene editing of a specific α6 integrin extracellular region, not required for normal tissue function, can generate a new biophysical cancer phenotype unable to invade the muscle, presenting a new therapeutic strategy for metastasis prevention in prostate cancer.
Significance:
This study shows an innovative strategy to block prostate cancer metastasis and invasion in the muscle through gene editing of a specific α6 integrin extracellular region.
Data from HDAC8 Regulates a Stress Response Pathway in Melanoma to Mediate Escape from BRAF Inhibitor Therapy
Authors: Emmons Michael F. , Faião-Flores Fernanda , Sharma Ritin , Thapa Ram , Messina Jane L. , Becker Jurgen C. , Schadendorf Dirk , Seto Edward , Sondak Vernon K. , Koomen John M. , Chen Yian A. , Lau Eric K. , Wan Lixin , Licht Jonathan D. , Smalley Keiran S.M.
Published: March 2023

Abstract
Melanoma cells have the ability to switch to a dedifferentiated, invasive phenotype in response to multiple stimuli. Here, we show that exposure of melanomas to multiple stresses including BRAF–MEK inhibitor therapy, hypoxia, and UV irradiation leads to an increase in histone deacetylase 8 (HDAC8) activity and the adoption of a drug-resistant phenotype. Mass spectrometry–based phosphoproteomics implicated HDAC8 in the regulation of MAPK and AP-1 signaling. Introduction of HDAC8 into drug-naïve melanoma cells conveyed resistance both in vitro and in vivo. HDAC8-mediated BRAF inhibitor resistance was mediated via receptor tyrosine kinase activation, leading to MAPK signaling. Although HDACs function at the histone level, they also regulate nonhistone substrates, and introduction of HDAC8 decreased the acetylation of c-Jun, increasing its transcriptional activity and enriching for an AP-1 gene signature. Mutation of the putative c-Jun acetylation site at lysine 273 increased transcriptional activation of c-Jun in melanoma cells and conveyed resistance to BRAF inhibition. In vivo xenograft studies confirmed the key role of HDAC8 in therapeutic adaptation, with both nonselective and HDAC8-specific inhibitors enhancing the durability of BRAF inhibitor therapy. Our studies demonstrate that HDAC8-specific inhibitors limit the adaptation of melanoma cells to multiple stresses including BRAF–MEK inhibition.
Significance:
This study provides evidence that HDAC8 drives transcriptional plasticity in melanoma cells in response to a range of stresses through direct deacetylation of c-Jun.
Data from Epigenomic Reordering Induced by Polycomb Loss Drives Oncogenesis but Leads to Therapeutic Vulnerabilities in Malignant Peripheral Nerve Sheath Tumors
Authors: Wojcik John B. , Marchione Dylan M. , Sidoli Simone , Djedid Anissa , Lisby Amanda , Majewski Jacek , Garcia Benjamin A.
Published: March 2023

Abstract
Malignant peripheral nerve sheath tumor (MPNST) is an aggressive sarcoma with recurrent loss-of-function alterations in polycomb-repressive complex 2 (PRC2), a histone-modifying complex involved in transcriptional silencing. To understand the role of PRC2 loss in pathogenesis and identify therapeutic targets, we conducted parallel global epigenomic and proteomic analysis of archival formalin-fixed, paraffin-embedded (FFPE) human MPNST with and without PRC2 loss (MPNSTLOSS vs. MPNSTRET). Loss of PRC2 resulted in increased histone posttranslational modifications (PTM) associated with active transcription, most notably H3K27Ac and H3K36me2, whereas repressive H3K27 di- and trimethylation (H3K27me2/3) marks were globally lost without a compensatory gain in other repressive PTMs. Instead, DNA methylation globally increased in MPNSTLOSS. Epigenomic changes were associated with upregulation of proteins in growth pathways and reduction in IFN signaling and antigen presentation, suggesting a role for epigenomic changes in tumor progression and immune evasion, respectively. These changes also resulted in therapeutic vulnerabilities. Knockdown of NSD2, the methyltransferase responsible for H3K36me2, restored MHC expression and induced interferon pathway expression in a manner similar to PRC2 restoration. MPNSTLOSS were also highly sensitive to DNA methyltransferase and histone deacetylase (HDAC) inhibitors. Overall, these data suggest that global loss of PRC2-mediated repression renders MPNST differentially dependent on DNA methylation to maintain transcriptional integrity and makes them susceptible to therapeutics that promote aberrant transcription initiation.
Significance:
Global profiling of histone PTMs and protein expression in archival human MPNST illustrates how PRC2 loss promotes oncogenesis but renders tumors vulnerable to pharmacologic modulation of transcription.

See related commentary by Natarajan and Venneti, p. 3172
Data from KRAS Oncoprotein Expression Is Regulated by a Self-Governing eIF5A-PEAK1 Feed-Forward Regulatory Loop
Authors: Fujimura Ken , Wang Huawei , Watson Felicia , Klemke Richard L.
Published: March 2023

Abstract
There remains intense interest in tractable approaches to target or silence the KRAS oncoprotein as a rational therapeutic strategy to attack pancreatic ductal adenocarcinoma (PDAC) and other cancers that overexpress it. Here we provide evidence that accumulation of the KRAS oncoprotein is controlled by a self-regulating feed-forward regulatory loop that utilizes a unique hypusinated isoform of the translation elongation factor eIF5A and the tyrosine kinase PEAK1. Oncogenic activation of KRAS increased eIF5A–PEAK1 translational signaling, which in turn facilitated increased KRAS protein synthesis. Mechanistic investigations show that this feed-forward positive regulatory pathway was controlled by oncogenic KRAS-driven metabolic demands, operated independently of canonical mTOR signaling, and did not involve new KRAS gene transcription. Perturbing eIF5A–PEAK1 signaling, by genetic or pharmacologic strategies or by blocking glutamine synthesis, was sufficient to inhibit expression of KRAS, eIF5A, and PEAK1, to attenuate cancer cell growth and migration, and to block tumor formation in established preclinical mouse models of PDAC. Levels of KRAS, eIF5A, and PEAK1 protein increased during cancer progression with the highest levels of expression observed in metastatic cell populations. Combinatorial targeting of eIF5A hypusination and the RAS–ERK signaling pathway cooperated to attenuate KRAS expression and its downstream signaling along with cell growth in vitro and tumor formation in vivo. Collectively, our findings highlight a new mechanistic strategy to attenuate KRAS expression as a therapeutic strategy to target PDAC and other human cancers driven by KRAS activation.

Significance: These findings highlight a new mechanistic strategy to attenuate KRAS expression as a therapeutic strategy to target human cancers driven by KRAS activation. Cancer Res; 78(6); 1444–56. ©2018 AACR.
Data from A Human Organotypic Microfluidic Tumor Model Permits Investigation of the Interplay between Patient-Derived Fibroblasts and Breast Cancer Cells
Authors: Truong Danh D. , Kratz Alexander , Park Jin G. , Barrientos Eric S. , Saini Harpinder , Nguyen Toan , Pockaj Barbara , Mouneimne Ghassan , LaBaer Joshua , Nikkhah Mehdi
Published: March 2023

Abstract
Tumor–stroma interactions significantly influence cancer cell metastasis and disease progression. These interactions are partly comprised of the cross-talk between tumor and stromal fibroblasts, but the key molecular mechanisms within the cross-talk that govern cancer invasion are still unclear. Here, we adapted our previously developed microfluidic device as a 3D in vitro organotypic model to mechanistically study tumor–stroma interactions by mimicking the spatial organization of the tumor microenvironment on a chip. We cocultured breast cancer and patient-derived fibroblast cells in 3D tumor and stroma regions, respectively, and combined functional assessments, including cancer cell migration, with transcriptome profiling to unveil the molecular influence of tumor–stroma cross-talk on invasion. This led to the observation that cancer-associated fibroblasts (CAF) enhanced invasion in 3D by inducing expression of a novel gene of interest, glycoprotein nonmetastatic B (GPNMB), in breast cancer cells, resulting in increased migration speed. Importantly, knockdown of GPNMB blunted the influence of CAF on enhanced cancer invasion. Overall, these results demonstrate the ability of our model to recapitulate patient-specific tumor microenvironments to investigate the cellular and molecular consequences of tumor–stroma interactions.
Significance:
An organotypic model of tumor–stroma interactions on a microfluidic chip reveals that CAFs promote invasion by enhancing expression of GPNMB in breast cancer cells.
Data from Magnetic Resonance Imaging Is More Sensitive Than PET for Detecting Treatment-Induced Cell Death–Dependent Changes in Glycolysis
Authors: Hesketh Richard L. , Wang Jiazheng , Wright Alan J. , Lewis David Y. , Denton Alice E. , Grenfell Richard , Miller Jodi L. , Bielik Robert , Gehrung Marcel , Fala Maria , Ros Susana , Xie Bangwen , Hu De-en , Brindle Kevin M.
Published: March 2023

Abstract
Metabolic imaging has been widely used to measure the early responses of tumors to treatment. Here, we assess the abilities of PET measurement of [18F]FDG uptake and MRI measurement of hyperpolarized [1-13C]pyruvate metabolism to detect early changes in glycolysis following treatment-induced cell death in human colorectal (Colo205) and breast adenocarcinoma (MDA-MB-231) xenografts in mice. A TRAIL agonist that binds to human but not mouse cells induced tumor-selective cell death. Tumor glycolysis was assessed by injecting [1,6-13C2]glucose and measuring 13C-labeled metabolites in tumor extracts. Injection of hyperpolarized [1-13C]pyruvate induced rapid reduction in lactate labeling. This decrease, which correlated with an increase in histologic markers of cell death and preceded decrease in tumor volume, reflected reduced flux from glucose to lactate and decreased lactate concentration. However, [18F]FDG uptake and phosphorylation were maintained following treatment, which has been attributed previously to increased [18F]FDG uptake by infiltrating immune cells. Quantification of [18F]FDG uptake in flow-sorted tumor and immune cells from disaggregated tumors identified CD11b+/CD45+ macrophages as the most [18F]FDG-avid cell type present, yet they represented <5% of the cells present in the tumors and could not explain the failure of [18F]FDG-PET to detect treatment response. MRI measurement of hyperpolarized [1-13C]pyruvate metabolism is therefore a more sensitive marker of the early decreases in glycolytic flux that occur following cell death than PET measurements of [18F]FDG uptake.
Significance:
These findings demonstrate superior sensitivity of MRI measurement of hyperpolarized [1-13C]pyruvate metabolism versus PET measurement of 18F-FDG uptake for detecting early changes in glycolysis following treatment-induced tumor cell death.
Data from Radiolabeled Oligonucleotides Targeting the RNA Subunit of Telomerase Inhibit Telomerase and Induce DNA Damage in Telomerase-Positive Cancer Cells
Authors: Jackson Mark R. , Bavelaar Bas M. , Waghorn Philip A. , Gill Martin R. , El-Sagheer Afaf H. , Brown Tom , Tarsounas Madalena , Vallis Katherine A.
Published: March 2023

Abstract
Telomerase is expressed in the majority (>85%) of tumors, but has restricted expression in normal tissues. Long-term telomerase inhibition in malignant cells results in progressive telomere shortening and reduction in cell proliferation. Here we report the synthesis and characterization of radiolabeled oligonucleotides that target the RNA subunit of telomerase, hTR, simultaneously inhibiting enzymatic activity and delivering radiation intracellularly. Oligonucleotides complementary (Match) and noncomplementary (Scramble or Mismatch) to hTR were conjugated to diethylenetriaminepentaacetic dianhydride (DTPA), allowing radiolabeling with the Auger electron-emitting radionuclide indium-111 (111In). Match oligonucleotides inhibited telomerase activity with high potency, which was not observed with Scramble or Mismatch oligonucleotides. DTPA-conjugation and 111In-labeling did not change telomerase inhibition. In telomerase-positive cancer cells, unlabeled Match oligonucleotides had no effect on survival, however, 111In-labeled Match oligonucleotides significantly reduced clonogenic survival and upregulated the DNA damage marker γH2AX. Minimal radiotoxicity and DNA damage was observed in telomerase-negative cells exposed to 111In-Match oligonucleotides. Match oligonucleotides localized in close proximity to nuclear Cajal bodies in telomerase-positive cells. In comparison with Match oligonucleotides, 111In-Scramble or 111In-Mismatch oligonucleotides demonstrated reduced retention and negligible impact on cell survival. This study indicates the therapeutic activity of radiolabeled oligonucleotides that specifically target hTR through potent telomerase inhibition and DNA damage induction in telomerase-expressing cancer cells and paves the way for the development of novel oligonucleotide radiotherapeutics targeting telomerase-positive cancers.
Significance:
These findings present a novel radiolabeled oligonucleotide for targeting telomerase-positive cancer cells that exhibits dual activity by simultaneously inhibiting telomerase and promoting radiation-induced genomic DNA damage.
Data from Upregulation of Myt1 Promotes Acquired Resistance of Cancer Cells to Wee1 Inhibition
Authors: Lewis Cody W. , Bukhari Amirali B. , Xiao Edric J. , Choi Won-Shik , Smith Joanne D. , Homola Ellen , Mackey John R. , Campbell Shelagh D. , Gamper Armin M. , Chan Gordon K.
Published: March 2023

Abstract
Adavosertib (also known as AZD1775 or MK1775) is a small-molecule inhibitor of the protein kinase Wee1, with single-agent activity in multiple solid tumors, including sarcoma, glioblastoma, and head and neck cancer. Adavosertib also shows promising results in combination with genotoxic agents such as ionizing radiation or chemotherapy. Previous studies have investigated molecular mechanisms of primary resistance to Wee1 inhibition. Here, we investigated mechanisms of acquired resistance to Wee1 inhibition, focusing on the role of the Wee1-related kinase Myt1. Myt1 and Wee1 kinases were both capable of phosphorylating and inhibiting Cdk1/cyclin B, the key enzymatic complex required for mitosis, demonstrating their functional redundancy. Ectopic activation of Cdk1 induced aberrant mitosis and cell death by mitotic catastrophe. Cancer cells with intrinsic adavosertib resistance had higher levels of Myt1 compared with sensitive cells. Furthermore, cancer cells that acquired resistance following short-term adavosertib treatment had higher levels of Myt1 compared with mock-treated cells. Downregulating Myt1 enhanced ectopic Cdk1 activity and restored sensitivity to adavosertib. These data demonstrate that upregulating Myt1 is a mechanism by which cancer cells acquire resistance to adavosertib.
Significance:
Myt1 is a candidate predictive biomarker of acquired resistance to the Wee1 kinase inhibitor adavosertib.