bluuebunny/crossref_metadata_2025 huggingface dataset:
Data from Mouse Homolog of the Human TP53 R337H Mutation Reveals Its Role in Tumorigenesis
Authors: Park Ji-Hoon , Li Jie , Starost Matthew F. , Liu Chengyu , Zhuang Jie , Chen Jichun , Achatz Maria I. , Kang Ju-Gyeong , Wang Ping-yuan , Savage Sharon A. , Hwang Paul M.
Published: March 2024

Abstract
Inheritance of germline mutations in the tumor suppressor gene TP53 causes Li-Fraumeni syndrome (LFS), a cancer predisposition disorder. The arginine to histidine substitution at amino acid position 337 of p53 (R337H) is a founder mutation highly prevalent in southern and southeastern Brazil and is considered an LFS mutation. Although this mutation is of significant clinical interest, its role in tumorigenesis using animal models has not been described. Here, we generate a knockin mouse model containing the homologous R337H mutation (mouse R334H). De novo tumorigenesis was not significantly increased in either heterozygous (p53334R/H) or homozygous (p53334H/H) p53 R334H knockin mice compared with wild-type mice. However, susceptibility to diethylnitrosamine (DEN)-induced liver carcinogenesis was increased in a mutant allele dose-dependent manner. In parallel, p53334H/H mice exposed to DEN exhibited increased DNA damage but decreased cell-cycle regulation in the liver. Oligomerization of p53, which is required for transactivation of target genes, was reduced in R334H liver, consistent with its decreased nuclear activity compared with wild-type. By modeling a TP53 mutation in mice that has relatively weak cancer penetrance, this study provides in vivo evidence that the human R337H mutation can compromise p53 activity and promote tumorigenesis.

Significance: A germline mutation in the oligomerization domain of p53 decreases its transactivation potential and renders mice susceptible to carcinogen-induced liver tumorigenesis. Cancer Res; 78(18); 5375–83. ©2018 AACR.
Data from Targeting USP7 Identifies a Metastasis-Competent State within Bone Marrow–Resident Melanoma CTCs
Authors: Vishnoi Monika , Boral Debasish , Liu Haowen , Sprouse Marc L. , Yin Wei , Goswami-Sewell Debalina , Tetzlaff Michael T. , Davies Michael A. , Oliva Isabella C. Glitza , Marchetti Dario
Published: March 2024

Abstract
Systemic metastasis is the major cause of death from melanoma, the most lethal form of skin cancer. Although most patients with melanoma exhibit a substantial gap between onset of primary and metastatic tumors, signaling mechanisms implicated in the period of metastatic latency remain unclear. We hypothesized that melanoma circulating tumor cells (CTC) home to and reside in the bone marrow during the asymptomatic phase of disease progression. Using a strategy to deplete normal cell lineages (Lin−), we isolated CTC-enriched cell populations from the blood of patients with metastatic melanoma, verified by the presence of putative CTCs characterized by melanoma-specific biomarkers and upregulated gene transcripts involved in cell survival and prodevelopment functions. Implantation of Lin− population in NSG mice (CTC-derived xenografts, i.e., CDX), and subsequent transcriptomic analysis of ex vivo bone marrow–resident tumor cells (BMRTC) versus CTC identified protein ubiquitination as a significant regulatory pathway of BMRTC signaling. Selective inhibition of USP7, a key deubiquinating enzyme, arrested BMRTCs in bone marrow locales and decreased systemic micrometastasis. This study provides first-time evidence that the asymptomatic progression of metastatic melanoma can be recapitulated in vivo using patient-isolated CTCs. Furthermore, these results suggest that USP7 inhibitors warrant further investigation as a strategy to prevent progression to overt clinical metastasis.

Significance: These findings provide insights into mechanism of melanoma recurrence and propose a novel approach to inhibit systematic metastatic disease by targeting bone marrow-resident tumor cells through pharmacological inhibition of USP7.

Graphical Abstract: http://cancerres.aacrjournals.org/content/canres/78/18/5349/F1.large.jpg. Cancer Res; 78(18); 5349–62. ©2018 AACR.
Data from Cholesterol Induces Epithelial-to-Mesenchymal Transition of Prostate Cancer Cells by Suppressing Degradation of EGFR through APMAP
Authors: Jiang Siyuan , Wang Xuetong , Song Dalong , Liu XiaoJun , Gu Yinmin , Xu Zhiyuan , Wang Xiaodong , Zhang Xiaolu , Ye Qinong , Tong Zhou , Yan BingXue , Yu Jie , Chen Yunzhao , Sun Minxuan , Wang Yang , Gao Shan
Published: March 2024

Abstract
Cholesterol increases the risk of aggressive prostate cancer and has emerged as a potential therapeutic target for prostate cancer. The functional roles of cholesterol in prostate cancer metastasis are not fully understood. Here, we found that cholesterol induces the epithelial-to-mesenchymal transition (EMT) through extracellular-regulated protein kinases 1/2 pathway activation, which is mediated by EGFR and adipocyte plasma membrane-associated protein (APMAP) accumulation in cholesterol-induced lipid rafts. Mechanistically, APMAP increases the interaction with EGFR substrate 15-related protein (EPS15R) to inhibit the endocytosis of EGFR by cholesterol, thus promoting cholesterol-induced EMT. Both the mRNA and protein levels of APMAP are upregulated in clinical prostate cancer samples. Together, these findings shed light onto an APMAP/EPS15R/EGFR axis that mediates cholesterol-induced EMT of prostate cancer cells.
Significance:
This study delineates the molecular mechanisms by which cholesterol increases prostate cancer progression and demonstrates that the binding of cholesterol-induced APMAP with EPS15R inhibits EGFR internalization and activates ERK1/2 to promote EMT.
Data from Single-Cell Transcriptome Analyses Reveal Endothelial Cell Heterogeneity in Tumors and Changes following Antiangiogenic Treatment
Authors: Zhao Qi , Eichten Alexandra , Parveen Asma , Adler Christina , Huang Ying , Wang Wei , Ding Yueming , Adler Alexander , Nevins Thomas , Ni Min , Wei Yi , Thurston Gavin
Published: March 2024

Abstract
Angiogenesis involves dynamic interactions between specialized endothelial tip and stalk cells that are believed to be regulated in part by VEGF and Dll4-Notch signaling. However, our understanding of this process is hampered by limited knowledge of the heterogeneity of endothelial cells and the role of different signaling pathways in specifying endothelial phenotypes. Here, we characterized by single-cell transcriptomics the heterogeneity of mouse endothelial cells and other stromal cells during active angiogenesis in xenograft tumors as well as from adult normal heart, following pharmacologic inhibition of VEGF and Dll4-Notch signaling. We classified tumor endothelial cells into three subpopulations that appeared to correspond with tip-like, transition, and stalk-like cells. Previously identified markers for tip and stalk cells were confirmed and several novel ones discovered. Blockade of VEGF rapidly inhibited cell-cycle genes and strongly reduced the proportion of endothelial tip cells in tumors. In contrast, blockade of Dll4 promoted endothelial proliferation as well as tip cell markers; blockade of both pathways inhibited endothelial proliferation but preserved some tip cells. We also phenotypically classified other tumor stromal cells and found that tumor-associated fibroblasts responded to antiangiogenic drug treatments by upregulating hypoxia-associated genes and producing secreted factors involved in angiogenesis. Overall, our findings better define the heterogeneity of tumor endothelial and other stromal cells and reveal the roles of VEGF and Dll4-Notch in specifying tumor endothelial phenotype, highlighting the response of stromal cells to antiangiogenic therapies.

Significance: These findings provide a framework for defining subpopulations of endothelial cells and tumor-associated fibroblasts and their rapid changes in gene expression following antiangiogenic treatment. Cancer Res; 78(9); 2370–82. ©2018 AACR.
Data from Positron Emission Tomography Detects In Vivo Expression of Disialoganglioside GD2 in Mouse Models of Primary and Metastatic Osteosarcoma
Authors: Butch Elizabeth R. , Mead Paul E. , Amador Diaz Victor , Tillman Heather , Stewart Elizabeth , Mishra Jitendra K. , Kim Jieun , Bahrami Armita , Dearling Jason L.J. , Packard Alan B. , Stoddard Shana V. , Vāvere Amy L. , Han Yuanyuan , Shulkin Barry L. , Snyder Scott E.
Published: March 2024

Abstract
The cell membrane glycolipid GD2 is expressed by multiple solid tumors, including 88% of osteosarcomas and 98% of neuroblastomas. However, osteosarcomas are highly heterogeneous, with many tumors exhibiting GD2 expression on <50% of the individual cells, while some tumors are essentially GD2-negative. Anti-GD2 immunotherapy is the current standard of care for high-risk neuroblastoma, but its application to recurrent osteosarcomas, for which no effective therapies exist, has been extremely limited. This is, in part, because the standard assays to measure GD2 expression in these heterogeneous tumors are not quantitative and are subject to tissue availability and sampling bias. To address these limitations, we evaluated a novel, sensitive radiotracer [64Cu]Cu-Bn-NOTA-hu14.18K322A to detect GD2 expression in osteosarcomas (six patient-derived xenografts and one cell line) in vivo using positron emission tomography (PET). Tumor uptake of the radiolabeled, humanized anti-GD2 antibody [64Cu]Cu-Bn-NOTA-hu14.18K322A was 7-fold higher in modestly GD2-expressing osteosarcomas (32% GD2-positive cells) than in a GD2-negative tumor (9.8% vs. 1.3% of the injected dose per cc, respectively). This radiotracer also identified lesions as small as 29 mm3 in a 34% GD2-positive model of metastatic osteosarcoma of the lung. Radiolabeled antibody accumulation in patient-derived xenografts correlated with GD2 expression as measured by flow cytometry (Pearson r = 0.88, P = 0.01), distinguishing moderately GD2-expressing osteosarcomas (32%–69% GD2-positive cells) from high GD2 expressors (>99%, P < 0.05). These results support the utility of GD2 imaging with PET to measure GD2 expression in osteosarcoma and thus maximize the clinical impact of anti-GD2 immunotherapy.
Significance:
In situ assessment of all GD2-positive osteosarcoma sites with a novel PET radiotracer could significantly impact anti-GD2 immunotherapy patient selection and enable noninvasive probing of correlations between target expression and therapeutic response.
Data from The Cdk2–c-Myc–miR-571 Axis Regulates DNA Replication and Genomic Stability by Targeting Geminin
Authors: Zhang Yi , Li Zhuqing , Hao Qiang , Tan Wei , Sun Jing , Li Jing , Chen Chi-wei , Li Zongzhu , Meng Yunxiao , Zhou Yuan , Han Zhiyong , Pei Huadong , DePamphilis Melvin L. , Zhu Wenge
Published: March 2024

Abstract
DNA rereplication leads to genomic instability and has been implicated in the pathology of a variety of human cancers. Eukaryotic DNA replication is tightly controlled to ensure it occurs only once during each cell cycle. Geminin is a critical component of this control, it prevents DNA rereplication from occurring during S, G2, and early M phases by preventing MCM helicases from forming prereplication complexes. Geminin is targeted for degradation by the anaphase-promoting complex (APC/C) from anaphase through G1-phase, however, accumulating evidence indicates that Geminin is downregulated in late S-phase due to an unknown mechanism. Here, we used a high-throughput screen to identify miRNAs that can induce excess DNA replication and found that miR-571 could reduce the protein level of Geminin in late S-phase independent of the APC/C. Furthermore, miR-571 regulated efficient DNA replication and S-phase cell-cycle progression. Strikingly, c-Myc suppressed miR-571 expression by binding directly to the miR-571 promoter. At the beginning of S-phase, Cdk2 phosphorylated c-Myc at Serine 62, promoting its association with the miR-571 promoter region. Collectively, we identify miR-571 as the first miRNA that prevents aberrant DNA replication and the Cdk2–c-Myc–miR-571 axis as a new pathway for regulating DNA replication, cell cycle, and genomic stability in cancer cells.
Significance:
These findings identify a novel regulatory mechanism that is critical for maintaining genome integrity by regulating DNA replication and cell-cycle progression.
Data from Activation of PP2A and Inhibition of mTOR Synergistically Reduce MYC Signaling and Decrease Tumor Growth in Pancreatic Ductal Adenocarcinoma
Authors: Allen-Petersen Brittany L. , Risom Tyler , Feng Zipei , Wang Zhiping , Jenny Zina P. , Thoma Mary C. , Pelz Katherine R. , Morton Jennifer P. , Sansom Owen J. , Lopez Charles D. , Sheppard Brett , Christensen Dale J. , Ohlmeyer Michael , Narla Goutham , Sears Rosalie C.
Published: March 2024

Abstract
In cancer, kinases are often activated and phosphatases suppressed, leading to aberrant activation of signaling pathways driving cellular proliferation, survival, and therapeutic resistance. Although pancreatic ductal adenocarcinoma (PDA) has historically been refractory to kinase inhibition, therapeutic activation of phosphatases is emerging as a promising strategy to restore balance to these hyperactive signaling cascades. In this study, we hypothesized that phosphatase activation combined with kinase inhibition could deplete oncogenic survival signals to reduce tumor growth. We screened PDA cell lines for kinase inhibitors that could synergize with activation of protein phosphatase 2A (PP2A), a tumor suppressor phosphatase, and determined that activation of PP2A and inhibition of mTOR synergistically increase apoptosis and reduce oncogenic phenotypes in vitro and in vivo. This combination treatment resulted in suppression of AKT/mTOR signaling coupled with reduced expression of c-MYC, an oncoprotein implicated in tumor progression and therapeutic resistance. Forced expression of c-MYC or loss of PP2A B56α, the specific PP2A subunit shown to negatively regulate c-MYC, increased resistance to mTOR inhibition. Conversely, decreased c-MYC expression increased the sensitivity of PDA cells to mTOR inhibition. Together, these studies demonstrate that combined targeting of PP2A and mTOR suppresses proliferative signaling and induces cell death and implicates this combination as a promising therapeutic strategy for patients with PDA.
Significance:
These findings present a combinatorial strategy targeting serine/threonine protein phosphatase PP2A and mTOR in PDA, a cancer for which there are currently no targeted therapeutic options.
Data from PARPi Triggers the STING-Dependent Immune Response and Enhances the Therapeutic Efficacy of Immune Checkpoint Blockade Independent of BRCAness
Authors: Shen Jianfeng , Zhao Wei , Ju Zhenlin , Wang Lulu , Peng Yang , Labrie Marilyne , Yap Timothy A. , Mills Gordon B. , Peng Guang
Published: March 2024

Abstract
PARP inhibitors (PARPi) have shown remarkable therapeutic efficacy against BRCA1/2-mutant cancers through a synthetic lethal interaction. PARPi exert their therapeutic effects mainly through the blockade of ssDNA damage repair, which leads to the accumulation of toxic DNA double-strand breaks specifically in cancer cells with DNA repair deficiency (BCRAness), including those harboring BRCA1/2 mutations. Here we show that PARPi-mediated modulation of the immune response contributes to their therapeutic effects independently of BRCA1/2 mutations. PARPi promoted accumulation of cytosolic DNA fragments because of unresolved DNA lesions, which in turn activated the DNA-sensing cGAS–STING pathway and stimulated production of type I IFNs to induce antitumor immunity independent of BRCAness. These effects of PARPi were further enhanced by immune checkpoint blockade. Overall, these results provide a mechanistic rationale for using PARPi as immunomodulatory agents to harness the therapeutic efficacy of immune checkpoint blockade.
Significance:
This work uncovers the mechanism behind the clinical efficacy of PARPi in patients with both BRCA-wild-type and BRCA-mutant tumors and provides a rationale for combining PARPi with immunotherapy in patients with cancer.
Data from DIS3L2 Promotes Progression of Hepatocellular Carcinoma via hnRNP U-Mediated Alternative Splicing
Authors: Xing Songge , Li Zhaoyong , Ma Wenhao , He Xiaoping , Shen Shengqi , Wei Haoran , Li Shi-Ting , Shu Ying , Sun Linchong , Zhong Xiuying , Huangfu Yuhao , Su Lanhong , Feng Junru , Zhang Xiaozhang , Gao Ping , Jia Wei-Dong , Zhang Huafeng
Published: March 2024

Abstract
DIS3-like 3′-5′ exoribonuclease 2 (DIS3L2) degrades aberrant RNAs, however, its function in tumorigenesis remains largely unexplored. Here, aberrant DIS3L2 expression promoted human hepatocellular carcinoma (HCC) progression via heterogeneous nuclear ribonucleoproteins (hnRNP) U-mediated alternative splicing. DIS3L2 directly interacted with hnRNP U through its cold-shock domains and promoted inclusion of exon 3b during splicing of pre-Rac1 independent of its exonuclease activity, yielding an oncogenic splicing variant, Rac1b, which is known to stimulate cellular transformation and tumorigenesis. DIS3L2 regulated alternative splicing by recruiting hnRNP U to pre-Rac1. Rac1b was critical for DIS3L2 promotion of liver cancer development both in vitro and in vivo. Importantly, DIS3L2 and Rac1b expression highly correlated with HCC progression and patient survival. Taken together, our findings uncover an oncogenic role of DIS3L2, in which it promotes liver cancer progression through a previously unappreciated mechanism of regulating hnRNP U-mediated alterative splicing.
Significance:
These findings establish the role and mechanism of the 3′-5′ exoribonuclease DIS3L2 in hepatocellular carcinoma carcinogenesis.
Data from Modeling Cellular Response in Large-Scale Radiogenomic Databases to Advance Precision Radiotherapy
Authors: Manem Venkata SK. , Lambie Meghan , Smith Ian , Smirnov Petr , Kofia Victor , Freeman Mark , Koritzinsky Marianne , Abazeed Mohamed E. , Haibe-Kains Benjamin , Bratman Scott V.
Published: March 2024

Abstract
Radiotherapy is integral to the care of a majority of patients with cancer. Despite differences in tumor responses to radiation (radioresponse), dose prescriptions are not currently tailored to individual patients. Recent large-scale cancer cell line databases hold the promise of unravelling the complex molecular arrangements underlying cellular response to radiation, which is critical for novel predictive biomarker discovery. Here, we present RadioGx, a computational platform for integrative analyses of radioresponse using radiogenomic databases. We fit the dose–response data within RadioGx to the linear-quadratic model. The imputed survival across a range of dose levels (AUC) was a robust radioresponse indicator that correlated with biological processes known to underpin the cellular response to radiation. Using AUC as a metric for further investigations, we found that radiation sensitivity was significantly associated with disruptive mutations in genes related to nonhomologous end joining. Next, by simulating the effects of different oxygen levels, we identified putative genes that may influence radioresponse specifically under hypoxic conditions. Furthermore, using transcriptomic data, we found evidence for tissue-specific determinants of radioresponse, suggesting that tumor type could influence the validity of putative predictive biomarkers of radioresponse. Finally, integrating radioresponse with drug response data, we found that drug classes impacting the cytoskeleton, DNA replication, and mitosis display similar therapeutic effects to ionizing radiation on cancer cell lines. In summary, RadioGx provides a unique computational toolbox for hypothesis generation to advance preclinical research for radiation oncology and precision medicine.
Significance:
The RadioGx computational platform enables integrative analyses of cellular response to radiation with drug responses and genome-wide molecular data.
Data from Hypermethylation of SHISA3 Promotes Nasopharyngeal Carcinoma Metastasis by Reducing SGSM1 Stability
Authors: Zhang Jian , Li Ying-Qin , Guo Rui , Wang Ya-Qin , Zhang Pan-Pan , Tang Xin-Ran , Wen Xin , Hong Xiao-Hong , Lei Yuan , He Qing-Mei , Yang Xiao-Jing , Sun Ying , Ma Jun , Liu Na
Published: March 2024

Abstract
Altered DNA methylation is a key feature of cancer, and aberrant methylation is important in nasopharyngeal carcinoma (NPC) development. However, the methylation mechanisms underlying metastasis of NPC remain unclear. Analyzing data from public databases and conducting our own experiments, we report here that promoter hypermethylation of SHISA3 is common and contributes to the downregulation of this gene in many types of tumors, including NPC. SHISA3 suppressed NPC cell invasion and metastasis in vitro and in vivo by impeding the E3 ubiquitin ligase tripartite motif containing 21 (TRIM21)–mediated ubiquitination and degradation small G protein signaling modulator 1 (SGSM1) and by inhibiting the MAPK pathway activation. Silencing SGSM1 abrogated the inhibitory effect of SHISA3 on NPC cell migration and invasion. This newly identified SHISA3–TRIM21–SGSM1 axis could be a novel therapeutic target in NPC.
Significance:
These findings highlight the mechanism by which a newly identified tumor suppressor SHISA3 suppresses invasion and metastasis of nasopharyngeal carcinoma.
Data from Mitochondrial NIX Promotes Tumor Survival in the Hypoxic Niche of Glioblastoma
Authors: Jung Jinkyu , Zhang Ying , Celiku Orieta , Zhang Wei , Song Hua , Williams Brian J. , Giles Amber J. , Rich Jeremy N. , Abounader Roger , Gilbert Mark R. , Park Deric M.
Published: March 2024

Abstract
Cancer cells rely on mitochondrial functions to regulate key survival and death signals. How cancer cells regulate mitochondrial autophagy (mitophagy) in the tumor microenvironment as well as utilize mitophagy as a survival signal is still not well understood. Here, we elucidate a key survival mechanism of mitochondrial NIX-mediated mitophagy within the hypoxic region of glioblastoma, the most malignant brain tumor. NIX was overexpressed in the pseudopalisading cells that envelop the hypoxic–necrotic regions, and mitochondrial NIX expression was robust in patient-derived glioblastoma tumor tissues and glioblastoma stem cells. NIX was required for hypoxia and oxidative stress–induced mitophagy through NFE2L2/NRF2 transactivation. Silencing NIX impaired mitochondrial reactive oxygen species clearance, cancer stem cell maintenance, and HIF/mTOR/RHEB signaling pathways under hypoxia, resulting in suppression of glioblastoma survival in vitro and in vivo. Clinical significance of these findings was validated by the compelling association between NIX expression and poor outcome for patients with glioblastoma. Taken together, our findings indicate that the NIX-mediated mitophagic pathway may represent a key therapeutic target for solid tumors, including glioblastoma.
Significance:
NIX-mediated mitophagy regulates tumor survival in the hypoxic niche of glioblastoma microenvironment, providing a potential therapeutic target for glioblastoma.
Data from Epigenomic Profiling Discovers Trans-lineage SOX2 Partnerships Driving Tumor Heterogeneity in Lung Squamous Cell Carcinoma
Authors: Sato Takashi , Yoo Seungyeul , Kong Ranran , Sinha Abhilasha , Chandramani-Shivalingappa Prashanth , Patel Ayushi , Fridrikh Maya , Nagano Osamu , Masuko Takashi , Beasley Mary Beth , Powell Charles A. , Zhu Jun , Watanabe Hideo
Published: March 2024

Abstract
Molecular characterization of lung squamous cell carcinoma (LUSC), one of the major subtypes of lung cancer, has not sufficiently improved its nonstratified treatment strategies over decades. Accumulating evidence suggests that lineage-specific transcriptional regulators control differentiation states during cancer evolution and underlie their distinct biological behaviors. In this study, by investigating the super-enhancer landscape of LUSC, we identified a previously undescribed “neural” subtype defined by Sox2 and a neural lineage factor Brn2, as well as the classical LUSC subtype defined by Sox2 and its classical squamous partner p63. Robust protein–protein interaction and genomic cooccupancy of Sox2 and Brn2, in place for p63 in the classical LUSC, indicated their transcriptional cooperation imparting this unique lineage state in the “neural” LUSC. Forced expression of p63 downregulated Brn2 in the “neural” LUSC cells and invoked the classical LUSC lineage with more squamous/epithelial features, which were accompanied by increased activities of ErbB/Akt and MAPK–ERK pathways, suggesting differential dependency. Collectively, our data demonstrate heterogeneous cell lineage states of LUSC featured by Sox2 cooperation with Brn2 or p63, for which distinct therapeutic approaches may be warranted.
Significance:
Epigenomic profiling reveals a novel subtype of lung squamous cell carcinoma with neural differentiation.
Data from Direct Targeting of MYCN Gene Amplification by Site-Specific DNA Alkylation in Neuroblastoma
Authors: Yoda Hiroyuki , Inoue Takahiro , Shinozaki Yoshinao , Lin Jason , Watanabe Takayoshi , Koshikawa Nobuko , Takatori Atsushi , Nagase Hiroki
Published: March 2024

Abstract
Amplification of MYCN plays a pivotal role in multiple types of tumors and correlates with poor prognosis in high-risk neuroblastoma. Despite recent advances in the treatment of neuroblastoma, no approaches directly target the master oncogene MYCN. Difficulties in targeting the MYCN protein inspired us to develop a new gene-level–inhibitory strategy using a sequence-specific gene regulator. Here, we generated a MYCN-targeting pyrrole-imidazole (PI) polyamide, MYCN-A3, which directly binds to and alkylates DNA at homing motifs within the MYCN transcript. Pharmacologic suppression of MYCN inhibited the proliferation of cancer cells harboring MYCN amplification compared with MYCN nonamplified cancer cells. In neuroblastoma xenograft mouse models, MYCN-A3 specifically downregulated MYCN expression and suppressed tumor progression with no detectable adverse effects and resulted in prolonged overall survival. Moreover, treatment with MYCN-A3, but not MYCN nontargeting PI polyamide, precipitated a copy number reduction of MYCN in neuroblastoma cells with MYCN amplification. These findings suggest that directly targeting MYCN with MYCN-A3 is a novel therapeutic approach to reduce copy number of the MYCN gene for MYCN-amplified neuroblastoma.
Significance:
This study presents a novel approach to drugging an amplified oncogene by showing that targeting gene amplification of MYCN suppresses MYCN expression and neuroblastoma growth.
Data from Disruption of the Rbm38-eIF4E Complex with a Synthetic Peptide Pep8 Increases p53 Expression
Authors: Lucchesi Christopher A. , Zhang Jin , Ma Buyong , Chen Mingyi , Chen Xinbin
Published: March 2024

Abstract
Rbm38 is a p53 target and an RNA-binding protein known to suppress p53 translation by preventing eukaryotic translation initiation factor 4E (eIF4E) from binding to p53 mRNA. In this study, we show that synthetic peptides corresponding to the binding interface between Rbm38 and eIF4E, including an 8 amino acid peptide (Pep8) derived from Rbm38, are effective in relieving Rbm38-mediated repression of p53. Molecular simulations showed that Ser-6 in Pep8 forms a hydrogen bond with Asp-202 in eIF4E. Substitution of Ser-6 with Lys, but not with Asp, enhanced the ability of Pep8 to inhibit the Rbm38-eIF4E complex. Importantly, Pep8 alone or together with a low dose of doxorubicin potently induced p53 expression and suppressed colony and tumor sphere formation and xenograft tumors in Rbm38- and p53-dependent manners. Together, we conclude that modulating the Rbm38-eIF4E complex may be explored as a therapeutic strategy for cancers that carry wild-type p53.
Significance:
Disruption of the Rbm38-eIF4E complex via synthetic peptides induces wild-type p53 expression, suppresses tumor growth and progression, and may serve as a novel cancer therapeutic strategy.
Data from MYC Regulates the HIF2α Stemness Pathway via Nanog and Sox2 to Maintain Self-Renewal in Cancer Stem Cells versus Non-Stem Cancer Cells
Authors: Das Bikul , Pal Bidisha , Bhuyan Rashmi , Li Hong , Sarma Anupam , Gayan Sukanya , Talukdar Joyeeta , Sandhya Sorra , Bhuyan Seema , Gogoi Gayatri , Gouw Arvin M. , Baishya Debabrat , Gotlib Jason R. , Kataki Amal C. , Felsher Dean W.
Published: March 2024

Abstract
Cancer stem cells (CSC) maintain both undifferentiated self-renewing CSCs and differentiated, non-self-renewing non-CSCs through cellular division. However, molecular mechanisms that maintain self-renewal in CSCs versus non-CSCs are not yet clear. Here, we report that in a transgenic mouse model of MYC-induced T-cell leukemia, MYC, maintains self-renewal in Sca1+ CSCs versus Sca-1− non-CSCs. MYC preferentially bound to the promoter and activated hypoxia-inducible factor-2α (HIF2α) in Sca-1+ cells only. Furthermore, the reprogramming factors, Nanog and Sox2, facilitated MYC regulation of HIF2α in Sca-1+ versus Sca-1− cells. Reduced expression of HIF2α inhibited the self-renewal of Sca-1+ cells; this effect was blocked through suppression of ROS by N-acetyl cysteine or the knockdown of p53, Nanog, or Sox2. Similar results were seen in ABCG2+ CSCs versus ABCG2− non-CSCs from primary human T-cell lymphoma. Thus, MYC maintains self-renewal exclusively in CSCs by selectively binding to the promoter and activating the HIF2α stemness pathway. Identification of this stemness pathway as a unique CSC determinant may have significant therapeutic implications.
Significance:
These findings show that the HIF2α stemness pathway maintains leukemic stem cells downstream of MYC in human and mouse T-cell leukemias.
Data from EN1 Is a Transcriptional Dependency in Triple-Negative Breast Cancer Associated with Brain Metastasis
Authors: Peluffo Guillermo , Subedee Ashim , Harper Nicholas W. , Kingston Natalie , Jovanović Bojana , Flores Felipe , Stevens Laura E. , Beca Francisco , Trinh Anne , Chilamakuri Chandra Sekhar Reddy , Papachristou Evangelia K. , Murphy Katherine , Su Ying , Marusyk Andriy , D'Santos Clive S. , Rueda Oscar M. , Beck Andrew H. , Caldas Carlos , Carroll Jason S. , Polyak Kornelia
Published: March 2024

Abstract
To define transcriptional dependencies of triple-negative breast cancer (TNBC), we identified transcription factors highly and specifically expressed in primary TNBCs and tested their requirement for cell growth in a panel of breast cancer cell lines. We found that EN1 (engrailed 1) is overexpressed in TNBCs and its downregulation preferentially and significantly reduced viability and tumorigenicity in TNBC cell lines. By integrating gene expression changes after EN1 downregulation with EN1 chromatin binding patterns, we identified genes involved in WNT and Hedgehog signaling, neurogenesis, and axonal guidance as direct EN1 transcriptional targets. Quantitative proteomic analyses of EN1-bound chromatin complexes revealed association with transcriptional repressors and coactivators including TLE3, TRIM24, TRIM28, and TRIM33. High expression of EN1 correlated with short overall survival and increased risk of developing brain metastases in patients with TNBC. Thus, EN1 is a prognostic marker and a potential therapeutic target in TNBC.
Significance:
These findings show that the EN1 transcription factor regulates neurogenesis-related genes and is associated with brain metastasis in triple-negative breast cancer.
Data from miR-221 Targets QKI to Enhance the Tumorigenic Capacity of Human Colorectal Cancer Stem Cells
Authors: Mukohyama Junko , Isobe Taichi , Hu Qingjiang , Hayashi Takanori , Watanabe Takashi , Maeda Masao , Yanagi Hisano , Qian Xin , Yamashita Kimihiro , Minami Hironobu , Mimori Koshi , Sahoo Debashis , Kakeji Yoshihiro , Suzuki Akira , Dalerba Piero , Shimono Yohei
Published: March 2024

Abstract
miRNAs are key players in the integrated regulation of cellular processes and shape many of the functional properties that define the “cancer stem cell” (CSC) phenotype. Little is known, however, about miRNAs that regulate such properties in human colorectal carcinoma. In this study, we compared the expression levels of 754 miRNAs between paired samples of EpCAM+/CD44+ cancer cells (enriched in CSCs) and EpCAM+/CD44neg cancer cells (with CSC depletion) sorted in parallel from human primary colorectal carcinomas and identified miR-221 as the miRNA that displayed the highest level of preferential expression in EpCAM+/CD44+ cancer cells. High levels of miR-221 expression were associated with Lgr5+ cells in mouse colon crypts and reduced survival in patients with colorectal carcinoma. Constitutive overexpression of miR-221 enhanced organoid-forming capacity of both conventional colorectal carcinoma cell lines and patient-derived xenografts (PDX) in vitro. Importantly, constitutive downregulation of miR-221 suppressed organoid-forming capacity in vitro and substantially reduced the tumorigenic capacity of CSC populations from PDX lines in vivo. Finally, the most abundant splicing isoform of the human Quaking (QKI) gene, QKI-5, was identified as a functional target of miR-221; overexpression of miR-221–reduced QKI-5 protein levels in human colorectal carcinoma cells. As expected, overexpression of QKI-5 suppressed organoid-forming capacity in vitro and tumorigenic capacity of colorectal carcinoma PDX cells in vivo. Our study reveals a mechanistic link between miR-221 and QKI and highlights their key role in regulating CSC properties in human colorectal cancer.
Significance:
These findings uncover molecular mechanisms underlying the maintenance of cancer stem cell properties in colon cancer.
Data from Melanoma Extracellular Vesicles Generate Immunosuppressive Myeloid Cells by Upregulating PD-L1 via TLR4 Signaling
Authors: Fleming Viktor , Hu Xiaoying , Weller Céline , Weber Rebekka , Groth Christopher , Riester Zeno , Hüser Laura , Sun Qian , Nagibin Vasyl , Kirschning Carsten , Bronte Vincenzo , Utikal Jochen , Altevogt Peter , Umansky Viktor
Published: March 2024

Abstract
Tumor cell–derived extracellular vesicles (EV) convert normal myeloid cells into myeloid-derived suppressor cells (MDSC), inhibiting antitumor immune responses. Here, we show that EV from Ret mouse melanoma cells upregulate the expression of programmed cell death ligand 1 (PD-L1) on mouse immature myeloid cells (IMC), leading to suppression of T-cell activation. PD-L1 expression and the immunosuppressive potential of EV-generated MDSC were dependent on the expression of Toll-like receptors (TLR). IMC from Tlr4−/− mice failed to increase T-cell PD-L1 expression and immunosuppression with Ret-EV treatment, and this effect was dependent on heat-shock protein 86 (HSP86) as HSP86-deficient Ret cells could not stimulate PD-L1 expression on normal IMC; IMC from Tlr2−/− and Tlr7−/− mice demonstrated similar results, although to a lesser extent. HSP86-deficient Ret cells slowed tumor progression in vivo associated with decreased frequency of tumor-infiltrating PD-L1+CD11b+Gr1+ MDSC. EV from human melanoma cells upregulated PD-L1 and immunosuppression of normal monocytes dependent on HSP86. These findings highlight a novel EV-mediated mechanism of MDSC generation from normal myeloid cells, suggesting the importance of EV targeting for tumor therapy.
Significance:
These findings validate the importance of TLR4 signaling in reprogramming normal myeloid cells into functional myeloid-derived suppressor cells.
Data from Precise Spatiotemporal Interruption of Regulatory T-cell–Mediated CD8+ T-cell Suppression Leads to Tumor Immunity
Authors: Zhou Xiaoyu , Zhao Shushu , He Yue , Geng Shuang , Shi Yan , Wang Bin
Published: March 2024

Abstract
Tumors can develop despite the presence of competent host immunity via a complex system of immune evasion. One of the most studied factors originating from the host is immune suppression by regulatory T cells (Treg). Ample laboratory and clinical evidence suggests that Treg ablation leads to robust antitumor immune activation. However, how Tregs specifically achieve their suppression in the context of tumor progression is not entirely clear, particularly with regard to the timing and location where Treg inhibition takes place. In this work, we report that Tregs migrate to tumor-draining lymph nodes (TDLN) and block expression of sphingosine-1-phosphate receptor 1 (S1P1) on CD8+ T cells. This event trapped the CD8+ T cells in the TDLN and served as a facilitating factor for tumor growth. Intriguingly, minimalistic depletion of Tregs in TDLN in a short window following tumor inoculation was sufficient to restore CD8+ T-cell activities, which resulted in significant tumor reduction. Similar treatments outside this time frame had no such effect. Our work therefore reveals a subtle feature in tumor biology whereby Tregs appear to be driven by newly established tumors for a programmed encounter with newly activated CD8+ T cells in TDLN. Our results suggest the possibility that clinical interception of this step can be tested as a new strategy of cancer therapy, with expected high efficacy and low systemic side effects.
Significance:
These findings reveal a strong tumor suppressive effect invoked by minimal blockade of tumor draining lymph node regulatory T cells during early versus late tumorigenesis.
Data from EZH2 Inhibitor GSK126 Suppresses Antitumor Immunity by Driving Production of Myeloid-Derived Suppressor Cells
Authors: Huang Shuo , Wang Zhongyu , Zhou Jie , Huang Jiani , Zhou Li , Luo Jing , Wan Yisong Y. , Long Haixia , Zhu Bo
Published: March 2024

Abstract
Enhancer of zeste homolog (EZH2) is a key epigenetic regulator of gene expression and is frequently overexpressed in various cancer types, suggesting a role in oncogenesis. The therapeutic potential of EZH2 inhibitors is currently being explored, but their effect on antitumor immunity is largely unknown. Here we report that suppressing EZH2 activity using EZH2 inhibitor GSK126 resulted in increased numbers of myeloid-derived suppressor cells (MDSC) and fewer CD4+ and IFNγ+CD8+ T cells, which are involved in antitumor immunity. Addition of a neutralizing antibody against the myeloid differentiation antigen GR-1 or gemcitabine/5-fluorouracil–depleted MDSCs alleviated MDSC-mediated immunosuppression and increased CD4+ and CD8+ T-cell tumor infiltration and GSK126 therapeutic efficacy. Mechanistically, we identified a novel pathway of MDSC production in cancer in which EZH2 inhibition directs myeloid differentiation from primitive hematopoietic progenitor cells. These findings suggest that modulating the tumor immune microenvironment may improve the efficacy of EZH2 inhibitors.
Significance:
This study uncovers a potential mechanism behind disappointing results of a phase I clinical trial of EZH2 inhibitor GSK126 and identifies a translatable combinational strategy to overcome it.
Data from RNF168-Mediated Ubiquitin Signaling Inhibits the Viability of BRCA1-Null Cancers
Authors: Krais John J. , Wang Yifan , Bernhardy Andrea J. , Clausen Emma , Miller Jessica A. , Cai Kathy Q. , Scott Clare L. , Johnson Neil
Published: March 2024

Abstract
BRCA1 gene mutations impair homologous recombination (HR) DNA repair, resulting in cellular senescence and embryonic lethality in mice. Therefore, BRCA1-deficient cancers require adaptations that prevent excessive genomic alterations from triggering cell death. RNF168-mediated ubiquitination of γH2AX at K13/15 (ub-H2AX) serves as a recruitment module for the localization of 53BP1 to DNA break sites. Here, we found multiple BRCA1-mutant cancer cell lines and primary tumors with low levels of RNF168 protein expression. Overexpression of ectopic RNF168 or a ub-H2AX fusion protein induced cell death and delayed BRCA1-mutant tumor formation. Cell death resulted from the recruitment of 53BP1 to DNA break sites and inhibition of DNA end resection. Strikingly, reintroduction of BRCA1 or 53BP1 depletion restored HR and rescued the ability of cells to maintain RNF168 and ub-H2AX overexpression. Thus, downregulation of RNF168 protein expression is a mechanism for providing BRCA1-null cancer cell lines with a residual level of HR that is essential for viability. Overall, our work identifies loss of RNF168 ubiquitin signaling as a proteomic alteration that supports BRCA1-mutant carcinogenesis. We propose that restoring RNF168-ub-H2AX signaling, potentially through inhibition of deubiquitinases, could represent a new therapeutic approach.
Significance:
This study explores the concept that homologous recombination DNA repair is not an all-or-nothing concept, but a spectrum, and that where a tumor stands on this spectrum may have therapeutic relevance.

See related commentary by Wang and Wulf, p. 2720
Data from A Genome-Wide Association Study Identifies Two Novel Susceptible Regions for Squamous Cell Carcinoma of the Head and Neck
Authors: Shete Sanjay , Liu Hongliang , Wang Jian , Yu Robert , Sturgis Erich M. , Li Guojun , Dahlstrom Kristina R. , Liu Zhensheng , Amos Christopher I. , Wei Qingyi
Published: March 2024

Abstract
To identify genetic variants for risk of squamous cell carcinoma of the head and neck (SCCHN), we conducted a two-phase genome-wide association study consisting of 7,858,089 SNPs in 2,171 cases and 4,493 controls of non-Hispanic white, of which, 434,839 typed and 7,423,250 imputed SNPs were used as the discovery. SNPs with P < 1 × 10−3 were further validated in the OncoArray study of oral and pharynx cancer (5,205 cases and 3,232 controls of European ancestry) from databases of Genotypes and Phenotypes. Meta-analysis of the discovery and replication studies identified one novel locus 6p22.1 (P = 2.96 × 10−9 for the leading rs259919) and two cancer susceptibility loci 6p21.32 (rs3135001, HLA-DQB1) and 6p21.33 (rs1265081, CCHCR1) associated with SCCHN risk. Further stratification by tumor site revealed four known cancer loci (5p15.33, 6p21.32, 6p21.33, and 2p23.1) associated with oral cavity cancer risk and oropharyngeal cancer risk, respectively. In addition, one novel locus 18q22.2 (P = 2.54 × 10−9 for the leading SNP rs142021700) was identified for hypopharynx and larynx cancer risk. For SNPs in those reported or novel loci, we also performed functional annotations by bioinformatics prediction and expression quantitative trait loci analysis. Collectively, our identification of four reported loci (2p23.1, 5p15.33, 6p21.32, and 6p21.33) and two novel loci (6p22.1 and 18q22.2) for SCCHN risk highlight the importance of human leukocyte antigen loci for oropharyngeal cancer risk, suggesting that immunologic mechanisms are implicated in the etiology of this subset of SCCHN.
Significance:
Two novel risk loci for SCCHN in non-Hispanic white individuals highlight the importance of immunologic mechanism in the disease etiology.
Data from HDAC10 Regulates Cancer Stem-Like Cell Properties in KRAS-Driven Lung Adenocarcinoma
Authors: Li Yixuan , Zhang Xiangyang , Zhu Shaoqi , Dejene Eden A. , Peng Weiqun , Sepulveda Antonia , Seto Edward
Published: March 2024

Abstract
Activation of oncogenic KRAS is the most common driving event in lung adenocarcinoma development. Despite the existing rationale for targeting activated KRAS and its downstream effectors, the failure of clinical trials to date indicates that the mechanism of KRAS-driven malignancy remains poorly understood. Here we report that histone deacetylase 10 (HDAC10) might function as a putative tumor suppressor in mice carrying a spontaneously activated oncogenic Kras allele. Hdac10 deletion accelerated KRAS-driven early-onset lung adenocarcinomas, increased macrophage infiltration in the tumor microenvironment, and shortened survival time in mice. Highly tumorigenic and stem-like lung adenocarcinoma cells were increased in Hdac10-deleted tumors compared with Hdac10 wild-type tumors. HDAC10 regulated the stem-like properties of KRAS-expressing tumor cells by targeting SOX9. Expression of SOX9 was significantly increased in Hdac10-deleted tumor cells and depletion of SOX9 in Hdac10 knockout (KO) lung adenocarcinoma cells inhibited growth of tumorspheres. The genes associated with TGFβ pathway were enriched in Hdac10 KO tumor cells, and activation of TGFβ signaling contributed to SOX9 induction in Hdac10 KO lung adenocarcinoma cells. Overall, our study evaluates the functions and mechanisms of action of HDAC10 in lung carcinogenesis that will inform the rationale for targeting its related regulatory signaling as an anticancer strategy.
Significance:
These findings linking HDAC10 and lung tumorigenesis identify potential novel strategies for targeting HDAC10 as a treatment for lung cancer.
Data from ZNF143-Mediated H3K9 Trimethylation Upregulates CDC6 by Activating MDIG in Hepatocellular Carcinoma
Authors: Zhang Lili , Huo Qi , Ge Chao , Zhao Fangyu , Zhou Qingqing , Chen Xiaoxia , Tian Hua , Chen Taoyang , Xie Haiyang , Cui Ying , Yao Ming , Li Hong , Li Jinjun
Published: March 2024

Abstract
Zinc finger protein 143 (ZNF143) belongs to the zinc finger protein family and possesses transcription factor activity by binding sequence-specific DNA. The exact biological role of ZNF143 in hepatocellular carcinoma (HCC) has not been investigated. Here we report that ZNF143 is overexpressed in HCC tissues and its overexpression correlates with poor prognosis. Gain- and loss-of-function experiments showed that ZNF143 promoted HCC cell proliferation, colony formation, and tumor growth in vitro and in vivo. ZNF143 accelerated HCC cell-cycle progression by activating cell division cycle 6 (CDC6). Mechanistically, ZNF143 promoted expression of CDC6 by directly activating transcription of histone demethylase mineral dust–induced gene (MDIG), which in turn reduced H3K9me3 enrichment in the CDC6 promoter region. Consistently, ZNF143 expression correlated significantly with MDIG and CDC6 expression in HCC. Collectively, we propose a model for a ZNF143–MDIG–CDC6 oncoprotein axis that provides novel insight into ZNF143, which may serve as a therapeutic target in HCC.
Significance:
These findings describe the mechanism by which ZNF143 promotes HCC proliferation and provide important clues for exploring new targets and strategies for clinical treatment of human liver cancer.
Data from Pomalidomide Alters Pancreatic Macrophage Populations to Generate an Immune-Responsive Environment at Precancerous and Cancerous Lesions
Authors: Bastea Ligia I. , Liou Geou-Yarh , Pandey Veethika , Fleming Alicia K. , von Roemeling Christina A. , Doeppler Heike , Li Zhimin , Qiu Yushi , Edenfield Brandy , Copland John A. , Tun Han W. , Storz Peter
Published: March 2024

Abstract
During development of pancreatic cancer, alternatively activated macrophages contribute to fibrogenesis, pancreatic intraepithelial neoplasia (PanIN) lesion growth, and generation of an immunosuppressive environment. Here, we show that the immunomodulatory agent pomalidomide depletes pancreatic lesion areas of alternatively activated macrophage populations. Pomalidomide treatment resulted in downregulation of interferon regulatory factor 4, a transcription factor for M2 macrophage polarization. Pomalidomide-induced absence of alternatively activated macrophages led to a decrease in fibrosis at PanIN lesions and in syngeneic tumors; this was due to generation of an inflammatory, immune-responsive environment with increased expression of IL1α and presence of activated (IFNγ-positive) CD4+ and CD8+ T-cell populations. Our results indicate that pomalidomide could be used to decrease fibrogenesis in pancreatic cancer and may be ideal as a combination treatment with chemotherapeutic drugs or other immunotherapies.
Significance:
These findings reveal new insights into how macrophage populations within the pancreatic cancer microenvironment can be modulated, providing the means to turn the microenvironment from immunosuppressive to immune-responsive.