bluuebunny/crossref_metadata_2025 huggingface dataset:
Data from p53 Maintains Baseline Expression of Multiple Tumor Suppressor Genes
Authors: Pappas Kyrie , Xu Jia , Zairis Sakellarios , Resnick-Silverman Lois , Abate Francesco , Steinbach Nicole , Ozturk Sait , Saal Lao H. , Su Tao , Cheung Pamela , Schmidt Hank , Aaronson Stuart , Hibshoosh Hanina , Manfredi James , Rabadan Raul , Parsons Ramon
Published: March 2024

Abstract
TP53 is the most commonly mutated tumor suppressor gene and its mutation drives tumorigenesis. Using ChIP-seq for p53 in the absence of acute cell stress, we found that wild-type but not mutant p53 binds and activates numerous tumor suppressor genes, including PTEN, STK11(LKB1), miR-34a, KDM6A(UTX), FOXO1, PHLDA3, and TNFRSF10B through consensus binding sites in enhancers and promoters. Depletion of p53 reduced expression of these target genes, and analysis across 18 tumor types showed that mutation of TP53 associated with reduced expression of many of these genes. Regarding PTEN, p53 activated expression of a luciferase reporter gene containing the p53-consensus site in the PTEN enhancer, and homozygous deletion of this region in cells decreased PTEN expression and increased growth and transformation. These findings show that p53 maintains expression of a team of tumor suppressor genes that may together with the stress-induced targets mediate the ability of p53 to suppress cancer development. p53 mutations selected during tumor initiation and progression, thus, inactivate multiple tumor suppressor genes in parallel, which could account for the high frequency of p53 mutations in cancer.

Implications: In this study, we investigate the activities of p53 under normal low-stress conditions and discover that p53 is capable of maintaining the expression of a group of important tumor suppressor genes at baseline, many of which are haploinsufficient, which could contribute to p53-mediated tumor suppression. Mol Cancer Res; 15(8); 1051–62. ©2017 AACR.
Data from Normal and Cancerous Tissues Release Extrachromosomal Circular DNA (eccDNA) into the Circulation
Authors: Kumar Pankaj , Dillon Laura W. , Shibata Yoshiyuki , Jazaeri Amir A. , Jones David R. , Dutta Anindya
Published: March 2024

Abstract
Cell-free circulating linear DNA is being explored for noninvasive diagnosis and management of tumors and fetuses, the so-called liquid biopsy. Previously, we observed the presence of small extrachromosomal circular DNA (eccDNA), called microDNA, in the nuclei of mammalian tissues and cell lines. Now, we demonstrate that cell-free microDNA derived from uniquely mapping regions of the genome is detectable in plasma and serum from both mice and humans and that they are significantly longer (30%–60% >250 bases) than cell-free circulating linear DNA (∼150 bases). Tumor-derived human microDNA is detected in the mouse circulation in a mouse xenograft model of human ovarian cancer. Comparing the microDNA from paired tumor and normal lung tissue specimens reveals that the tumors contain longer microDNA. Consistent with human cancers releasing microDNA into the circulation, serum and plasma samples (12 lung and 11 ovarian cancer) collected prior to surgery are enriched for longer cell-free microDNA compared with samples from the same patient obtained several weeks after surgical resection of the tumor. Thus, circular DNA in the circulation is a previously unexplored pool of nucleic acids that could complement miRNAs and linear DNA for diagnosis and for intercellular communication.

Implications: eccDNA derived from chromosomal genomic sequence, first discovered in the nuclei of cells, are detected in the circulation, are longer than linear cell-free DNA, and are released from normal tissue and tumors into the circulation. Mol Cancer Res; 15(9); 1197–205. ©2017 AACR.
Data from Overexpression and Hypomethylation of Flap Endonuclease 1 Gene in Breast and Other Cancers
Authors: Singh Purnima , Yang Ming , Dai Huifang , Yu Dianke , Huang Qin , Tan Wen , Kernstine Kemp H. , Lin Dongxin , Shen Binghui
Published: March 2024

Abstract
Flap endonuclease 1 (FEN1) is a structure-specific nuclease best known for its critical roles in Okazaki fragment maturation, DNA repair, and apoptosis-induced DNA fragmentation. Functional deficiencies in FEN1, in the forms of somatic mutations and polymorphisms, have recently been shown to lead to autoimmunity, chronic inflammation, and predisposition to and progression of cancer. To explore how FEN1 contributes to cancer progression, we examined FEN1 expression using 241 matched pairs of cancer and corresponding normal tissues on a gene expression profiling array and validated differential expression by quantitative real-time PCR and immunohistochemistry. Furthermore, we defined the minimum promoter of human FEN1 and examined the methylation statuses of the 5′ region of the gene in paired breast cancer tissues. We show that FEN1 is significantly up-regulated in multiple cancers and the aberrant expression of FEN1 is associated with hypomethylation of the CpG island within the FEN1 promoter in tumor cells. The overexpression and promoter hypomethylation of FEN1 may serve as biomarkers for monitoring the progression of cancers. (Mol Cancer Res 2008;6(11):1710–7)
Data from SPINDLIN1 Promotes Cancer Cell Proliferation through Activation of WNT/TCF-4 Signaling
Authors: Wang Jing-Xue , Zeng Quan , Chen Lin , Du Ji-Chao , Yan Xin-Long , Yuan Hong-Feng , Zhai Chao , Zhou Jun-Nian , Jia Ya-Li , Yue Wen , Pei Xue-Tao
Published: March 2024

Abstract
SPINDLIN1, a new member of the SPIN/SSTY gene family, was first identified as a gene highly expressed in ovarian cancer cells. We have previously shown that it is involved in the process of spindle organization and chromosomal stability and plays a role in the development of cancer. Nevertheless, the mechanisms underlying its oncogenic role are still largely unknown. Here, we first showed that expression of SPINDLIN1 is upregulated in clinical tumors. Ectopic expression of SPINDLIN1 promoted cancer cell proliferation and activated WNT/T-cell factor (TCF)-4 signaling. The Ser84 and Ser99 amino acids within SPINDLIN1 were further identified as the key functional sites in WNT/TCF-4 signaling activation. Mutation of these two sites of SPINDLIN1 abolished its effects on promoting WNT/TCF-4 signaling and cancer cell proliferation. We further found that Aurora-A could interact with and phosphorylate SPINDLIN1 at its key functional sites, Ser84 and Ser99, suggesting that phosphorylation of SPINDLIN1 is involved in its oncogenic function. Collectively, these results suggest that SPINDLIN1, which may be a novel substrate of the Aurora-A kinase, promotes cancer cell growth through WNT/TCF-4 signaling activation. Mol Cancer Res; 10(3); 326–35. ©2012 AACR.
Data from TGF-β1 Induces Endothelial Cell Apoptosis by Shifting VEGF Activation of p38MAPK from the Prosurvival p38β to Proapoptotic p38α
Authors: Ferrari Giovanni , Terushkin Vitaly , Wolff Martin J. , Zhang Xiaodong , Valacca Cristina , Poggio Paolo , Pintucci Giuseppe , Mignatti Paolo
Published: March 2024

Abstract
TGF-β1 and VEGF, both angiogenesis inducers, have opposing effects on vascular endothelial cells. TGF-β1 induces apoptosis; VEGF induces survival. We have previously shown that TGF-β1 induces endothelial cell expression of VEGF, which mediates TGF-β1 induction of apoptosis through activation of p38 mitogen-activated protein kinase (MAPK). Because VEGF activates p38MAPK but protects the cells from apoptosis, this finding suggested that TGF-β1 converts p38MAPK signaling from prosurvival to proapoptotic. Four isoforms of p38MAPK —α, β, γ, and δ—have been identified. Therefore, we hypothesized that different p38MAPK isoforms control endothelial cell apoptosis or survival, and that TGF-β1 directs VEGF activation of p38MAPK from a prosurvival to a proapoptotic isoform. Here, we report that cultured endothelial cells express p38α, β, and γ. VEGF activates p38β, whereas TGF-β1 activates p38α. TGF-β1 treatment rapidly induces p38α activation and apoptosis. Subsequently, p38α activation is downregulated, p38β is activated, and the surviving cells become refractory to TGF-β1 induction of apoptosis and proliferate. Gene silencing of p38α blocks TGF-β1 induction of apoptosis, whereas downregulation of p38β or p38γ expression results in massive apoptosis. Thus, in endothelial cells p38α mediates apoptotic signaling, whereas p38β and p38γ transduce survival signaling. TGF-β1 activation of p38α is mediated by VEGF, which in the absence of TGF-β1 activates p38β. Therefore, these results show that TGF-β1 induces endothelial cell apoptosis by shifting VEGF signaling from the prosurvival p38β to the proapoptotic p38α. Mol Cancer Res; 10(5); 605–14. ©2012 AACR.
Data from Inhibition of the Nedd8 System Sensitizes Cells to DNA Interstrand Cross-linking Agents
Authors: Kee Younghoon , Huang Min , Chang Sophia , Moreau Lisa A. , Park Eunmi , Smith Peter G. , D'Andrea Alan D.
Published: March 2024

Abstract
The Fanconi anemia pathway is required for repair of DNA interstrand cross-links (ICL). Fanconi anemia pathway–deficient cells are hypersensitive to DNA ICL–inducing drugs such as cisplatin. Conversely, hyperactivation of the Fanconi anemia pathway is a mechanism that may underlie cellular resistance to DNA ICL agents. Modulating FANCD2 monoubiquitination, a key step in the Fanconi anemia pathway, may be an effective therapeutic approach to conferring cellular sensitivity to ICL agents. Here, we show that inhibition of the Nedd8 conjugation system increases cellular sensitivity to DNA ICL–inducing agents. Mechanistically, the Nedd8 inhibition, either by siRNA-mediated knockdown of Nedd8-conjugating enzymes or treatment with a Nedd8-activating enzyme inhibitor MLN4924, suppressed DNA damage–induced FANCD2 monoubiquitination and CHK1 phosphorylation. Our data indicate that inhibition of the Fanconi anemia pathway is largely responsible for the heightened cellular sensitivity to DNA ICLs upon Nedd8 inhibition. These results suggest that a combination of Nedd8 inhibition with ICL-inducing agents may be an effective strategy for sensitizing a subset of drug-resistant cancer cells. Mol Cancer Res; 10(3); 369–77. ©2012 AACR.
Data from Inhibition of Eg5 Acts Synergistically with Checkpoint Abrogation in Promoting Mitotic Catastrophe
Authors: Chen Yue , Chow Jeremy P.H. , Poon Randy Y.C.
Published: March 2024

Abstract
The G2 DNA damage checkpoint is activated by genotoxic agents and is particularly important for cancer therapies. Overriding the checkpoint can trigger precocious entry into mitosis, causing cells to undergo mitotic catastrophe. But some checkpoint-abrogated cells can remain viable and progress into G1 phase, which may contribute to further genome instability. Our previous studies reveal that the effectiveness of the spindle assembly checkpoint and the duration of mitosis are pivotal determinants of mitotic catastrophe after checkpoint abrogation. In this study, we tested the hypothesis whether mitotic catastrophe could be enhanced by combining genotoxic stress, checkpoint abrogation, and the inhibition of the mitotic kinesin protein Eg5. We found that mitotic catastrophe induced by ionizing radiation and a CHK1 inhibitor (UCN-01) was exacerbated after Eg5 was inhibited with either siRNAs or monastrol. The combination of DNA damage, UCN-01, and monastrol sensitized cancer cells that were normally resistant to checkpoint abrogation. Importantly, a relatively low concentration of monastrol, alone not sufficient in causing mitotic arrest, was already effective in promoting mitotic catastrophe. These experiments suggest that it is possible to use sublethal concentrations of Eg5 inhibitors in combination with G2 DNA damage checkpoint abrogation as an effective therapeutic approach. Mol Cancer Res; 10(5); 626–35. ©2012 AACR.
Data from Genome-Wide Association and Fine Mapping of Genetic Loci Predisposing to Colon Carcinogenesis in Mice
Authors: Liu Pengyuan , Lu Yan , Liu Hongbo , Wen Weidong , Jia Dongmei , Wang Yian , You Ming
Published: March 2024

Abstract
To identify the genetic determinants of colon tumorigenesis, 268 male mice from 33 inbred strains derived from different genealogies were treated with azoxymethane (AOM; 10 mg/kg) once a week for six weeks to induce colon tumors. Tumors were localized exclusively within the distal colon in each of the strains examined. Inbred mouse strains exhibit a large variability in genetic susceptibility to AOM-induced colon tumorigenesis. The mean colon tumor multiplicity ranged from 0 to 38.6 (mean = 6.5 ± 8.6) and tumor volume ranged from 0 to 706.5 mm3 (mean = 87.4 ± 181.9) at 24 weeks after the first dose of AOM. AOM-induced colon tumor phenotypes are highly heritable in inbred mice, and 68.8% and 71.3% of total phenotypic variation in colon tumor multiplicity and tumor volume, respectively, are attributable to strain-dependent genetic background. Using 97,854 single-nucleotide polymorphisms, we carried out a genome-wide association study (GWAS) of AOM-induced colon tumorigenesis and identified a novel susceptibility locus on chromosome 15 (rs32359607, P = 6.31 × 10–6). Subsequent fine mapping confirmed five (Scc3, Scc2, Scc12, Scc8, and Ccs1) of 16 linkage regions previously found to be associated with colon tumor susceptibility. These five loci were refined to less than 1 Mb genomic regions of interest. Major candidates in these loci are Sema5a, Fmn2, Grem2, Fap, Gsg1l, Xpo6, Rabep2, Eif3c, Unc5d, and Gpr65. In particular, the refined Scc3 locus shows high concordance with the human GWAS locus that underlies hereditary mixed polyposis syndrome. These findings increase our understanding of the complex genetics of colon tumorigenesis, and provide important insights into the pathways of colorectal cancer development and might ultimately lead to more effective individually targeted cancer prevention strategies. Mol Cancer Res; 10(1); 66–74. ©2011 AACR.
Data from αB-Crystallin, an Effector of Unfolded Protein Response, Confers Anti-VEGF Resistance to Breast Cancer via Maintenance of Intracrine VEGF in Endothelial Cells
Authors: Ruan Qing , Han Song , Jiang Wen G. , Boulton Michael E. , Chen Zhi J. , Law Brian K. , Cai Jun
Published: March 2024

Abstract
Effective inhibition of angiogenesis targeting the tumor endothelial cells requires identification of key cellular and molecular mechanisms associated with survival of vasculatures within the tumor microenvironment. Intracellular autocrine (intracrine) VEGF production by endothelial cells plays a critical role on the vasculature homeostasis. In vitro breast cancer cell–stimulated activation of the unfolded protein response (UPR) of the endothelial cells contributes to maintenance of the intracrine VEGF levels in the endothelial cells through the upregulation of a previous undescribed downstream effector- αB-crystallin (CRYAB). siRNA-mediated knockdown of two major UPR proteins—inositol requiring kinase 1 and ATF6, led to attenuated CRYAB expression of the endothelial cells. Finally, inhibition of CRYAB blocked the breast cancer cell–stimulated increase in the endogenous VEGF levels of the endothelial cells. A VEGF limited proteolysis assay further revealed that CRYAB protected VEGF for proteolytic degradation. Here, we report that the molecular chaperone-CRYAB was significantly increased and colocalized with tumor vessels in a breast cancer xenograft. Specifically, neutralization of VEGF induced higher levels of CRYAB expression in the endothelial cells cocultured with MDA-MB-231 or the breast cancer xenograft with a significant survival benefit. However, knockdown of CRYAB had a greater inhibitory effect on endothelial survival. These findings underscore the importance of defining a role for intracrine VEGF signaling in sustaining aberrant tumor angiogenesis and strongly implicate UPR/CRYAB as dichotomous parts of a crucial regulation pathway for maintaining intracrine VEGF signaling. Mol Cancer Res; 9(12); 1632–43. ©2011 AACR.
Data from EWS-FLI1 and Menin Converge to Regulate ATF4 Activity in Ewing Sarcoma
Authors: Jiménez Jennifer A. , Apfelbaum April A. , Hawkins Allegra G. , Svoboda Laurie K. , Kumar Abhijay , Ruiz Ramon Ocadiz , Garcia Alessandra X. , Haarer Elena , Nwosu Zeribe C. , Bradin Joshua , Purohit Trupta , Chen Dong , Cierpicki Tomasz , Grembecka Jolanta , Lyssiotis Costas A. , Lawlor Elizabeth R.
Published: March 2024

Abstract
Ewing sarcomas are driven by EWS–ETS fusions, most commonly EWS-FLI1, which promotes widespread metabolic reprogramming, including activation of serine biosynthesis. We previously reported that serine biosynthesis is also activated in Ewing sarcoma by the scaffolding protein menin through as yet undefined mechanisms. Here, we investigated whether EWS-FLI1 and/or menin orchestrate serine biosynthesis via modulation of ATF4, a stress-response gene that acts as a master transcriptional regulator of serine biosynthesis in other tumors. Our results show that in Ewing sarcoma, ATF4 levels are high and that ATF4 modulates transcription of core serine synthesis pathway (SSP) genes. Inhibition of either EWS-FLI1 or menin leads to loss of ATF4, and this is associated with diminished expression of SSP transcripts and proteins. We identified and validated an EWS–FLI1 binding site at the ATF4 promoter, indicating that the fusion can directly activate ATF4 transcription. In contrast, our results suggest that menin-dependent regulation of ATF4 is mediated by transcriptional and post-transcriptional mechanisms. Importantly, our data also reveal that the downregulation of SSP genes that occurs in the context of EWS-FLI1 or menin loss is indicative of broader inhibition of ATF4-dependent transcription. Moreover, we find that menin inhibition similarly leads to loss of ATF4 and the ATF4-dependent transcriptional signature in MLL-rearranged B-cell acute lymphoblastic leukemia, extending our findings to another cancer in which menin serves an oncogenic role.
Implications:
These studies provide new insights into metabolic reprogramming in Ewing sarcoma and also uncover a previously undescribed role for menin in the regulation of ATF4.
Data from The PI3K/mTOR Inhibitor Ompalisib Suppresses Nonhomologous End Joining and Sensitizes Cancer Cells to Radio- and Chemotherapy
Authors: Du Jie , Chen Fuqiang , Yu Jiahua , Jiang Lijun , Zhou Meijuan
Published: March 2024

Abstract
As the predominant pathway for the repair of DNA double-strand breaks (DSB), non-homologous end joining (NHEJ) attenuates the efficacy of cancer treatment which relies on the introduction of DSBs, such as radiotherapy and genotoxic drugs. Identifying novel NHEJ inhibitors is of great importance for improving the therapeutic efficiency of radio- or chemotherapy. Here we miniaturized our recently developed NHEJ detecting system into a 96-well plate-based format and interrogated an FDA approved drug library containing 1732 compounds. A collection of novel hits were considered to be potential DSB repair inhibitors at the noncytotoxic concentration. We identified omipalisib as an efficient sensitizer for DNA damage–induced cell death in vitro. Furthermore, in vitro analysis uncovered the repressive effect of omipalisib on the phosphorylation of DNA-dependent protein kinase catalytic subunit induced by ionizing radiation and doxorubicin, which led to the suppression of NHEJ pathway.
Implications:
In summary, our findings suggested the possibility for repurposing these candidates as radio- or chemosensitizers, which might extend their clinical application in cancer therapy.
Data from Aggressive B-cell Lymphoma with MYC/TP53 Dual Alterations Displays Distinct Clinicopathobiological Features and Response to Novel Targeted Agents
Authors: Deng Manman , Xu-Monette Zijun Y. , Pham Lan V. , Wang Xudong , Tzankov Alexandar , Fang Xiaosheng , Zhu Feng , Visco Carlo , Bhagat Govind , Dybkaer Karen , Chiu April , Tam Wayne , Zu Youli , Hsi Eric D. , You Hua , Huh Jooryung , Ponzoni Maurilio , Ferreri Andrés J.M. , Møller Michael B. , Parsons Benjamin M. , Hagemeister Fredrick , van Krieken J. Han , Piris Miguel A. , Winter Jane N. , Li Yong , Xu Bing , Liu Phillip , Young Ken H.
Published: March 2024

Abstract
Diffuse large B-cell lymphoma (DLBCL) is the major type of aggressive B-cell lymphoma. High-grade B-cell lymphoma (HGBCL) with MYC/BCL2 double-hit (DH) represents a distinct entity with dismal prognosis after standard immunochemotherapy in the current WHO lymphoma classification. However, whether TP53 mutation synergizes with MYC abnormalities (MYC rearrangement and/or Myc protein overexpression) contributing to HGBCL-like biology and prognosis is not well investigated. In this study, patients with DLBCL with MYC/TP53 abnormalities demonstrated poor clinical outcome, high-grade morphology, and distinct gene expression signatures. To identify more effective therapies for this distinctive DLBCL subset, novel MYC/TP53/BCL-2–targeted agents were investigated in DLBCL cells with MYC/TP53 dual alterations or HGBCL-MYC/BCL2-DH. A BET inhibitor INCB057643 effectively inhibited cell viability and induced apoptosis in DLBCL/HGBCL cells regardless of MYC/BCL2/TP53 status. Combining INCB057643 with a MDM2-p53 inhibitor DS3032b significantly enhanced the cytotoxic effects in HGBCL-DH without TP53 mutation, while combining with the BCL-2 inhibitor venetoclax displayed potent therapeutic synergy in DLBCL/HGBCL cells with and without concurrent TP53 mutation. Reverse-phase protein arrays revealed the synergistic molecular actions by INCB057643, DS3032b and venetoclax to induce cell-cycle arrest and apoptosis and to inhibit AKT/MEK/ERK/mTOR pathways, as well as potential drug resistance mechanisms mediated by upregulation of Mcl-1 and RAS/RAF/MEK/ERK pathways. In summary, these findings support subclassification of DLBCL/HGBCL with dual MYC/TP53 alterations, which demonstrates distinct pathobiologic features and dismal survival with standard therapy, therefore requiring additional targeted therapies.
Implications:
The clinical and pharmacologic studies suggest recognizing DLBCL with concomitant TP53 mutation and MYC abnormalities as a distinctive entity necessary for precision oncology practice.
Visual Overview:
http://mcr.aacrjournals.org/content/molcanres/19/2/249/F1.large.jpg.
Data from AXL Inhibition Induces DNA Damage and Replication Stress in Non–Small Cell Lung Cancer Cells and Promotes Sensitivity to ATR Inhibitors
Authors: Ramkumar Kavya , Stewart C. Allison , Cargill Kasey R. , Della Corte Carminia M. , Wang Qi , Shen Li , Diao Lixia , Cardnell Robert J. , Peng David H. , Rodriguez B. Leticia , Fan You-Hong , Heymach John V. , Wang Jing , Gay Carl M. , Gibbons Don L. , Byers Lauren A.
Published: March 2024

Abstract
AXL, a TAM (TYRO3, AXL, and MERTK) family receptor tyrosine kinase, is increasingly being recognized as a key determinant of resistance to targeted therapies, as well as chemotherapy and radiation in non–small cell lung cancer (NSCLC) and other cancers. We further show here that high levels of AXL and epithelial-to-mesenchymal transition were frequently expressed in subsets of both treatment-naïve and treatment-relapsed NSCLC. Previously, we and others have demonstrated a role for AXL in mediating DNA damage response (DDR), as well as resistance to inhibition of WEE1, a replication stress response kinase. Here, we show that BGB324 (bemcentinib), a selective small-molecule AXL inhibitor, caused DNA damage and induced replication stress, indicated by ATR/CHK1 phosphorylation, more significantly in TP53-deficient NSCLC cell lines. Similar effects were also observed in large-cell neuroendocrine carcinoma (LCNEC) cell lines. High AXL protein levels were also associated with resistance to ATR inhibition. Combined inhibition of AXL and ATR significantly decreased cell proliferation of NSCLC and LCNEC cell lines. Mechanistically, combined inhibition of AXL and ATR significantly increased RPA32 hyperphosphorylation and DNA double-strand breaks and induced markers of mitotic catastrophe. Notably, NSCLC cell lines with low levels of SLFN11, a known predictive biomarker for platinum and PARP inhibitor sensitivity, were more sensitive to AXL/ATR cotargeting. These findings demonstrate a novel and unexpected role for AXL in replication stress tolerance, with potential therapeutic implications.
Implications:
These findings demonstrate that the combination of AXL and ATR inhibitors could be a promising therapeutic combination for NSCLC, LCNEC, and other cancers.
Data from O-GlcNAc Transferase – An Auxiliary Factor or a Full-blown Oncogene?
Authors: Itkonen Harri M. , Loda Massimo , Mills Ian G.
Published: March 2024

Abstract
The β-linked N-acetyl-d-glucosamine (GlcNAc) is a posttranslational modification of serine and threonine residues catalyzed by the enzyme O-GlcNAc transferase (OGT). Increased OGT expression is a feature of most human cancers and inhibition of OGT decreases cancer cell proliferation. Antiproliferative effects are attributed to posttranslational modifications of known regulators of cancer cell proliferation, such as MYC, FOXM1, and EZH2. In general, OGT amplifies cell-specific phenotype, for example, OGT overexpression enhances reprogramming efficiency of mouse embryonic fibroblasts into stem cells. Genome-wide screens suggest that certain cancers are particularly dependent on OGT, and understanding these addictions is important when considering OGT as a target for cancer therapy. The O-GlcNAc modification is involved in most cellular processes, which raises concerns of on-target undesirable effects of OGT-targeting therapy. Yet, emerging evidence suggest that, much like proteasome inhibitors, specific compounds targeting OGT elicit selective antiproliferative effects in cancer cells, and can prime malignant cells to other treatments. It is, therefore, essential to gain mechanistic insights on substrate specificity for OGT, develop reagents to more specifically enrich for O-GlcNAc–modified proteins, identify O-GlcNAc “readers,” and develop OGT small-molecule inhibitors. Here, we review the relevance of OGT in cancer progression and the potential targeting of this metabolic enzyme as a putative oncogene.
Data from Monoallelic IDH1 R132H Mutation Mediates Glioma Cell Response to Anticancer Therapies via Induction of Senescence
Authors: Zhan Daqian , Ma Ding , Wei Shuang , Lal Bachchu , Fu Yi , Eberhart Charles , Laterra John , Ying Mingyao , Li Yunqing , Meeker Alan , Lopez-Bertoni Hernando , Xia Shuli
Published: March 2024

Abstract
Heterozygous isocitrate dehydrogenase (IDH) R132H mutation (IDH1R132H/WT) is an early event during gliomagenesis. Clinically, patients with glioma carrying mutant IDH1 respond better to antitumor therapies. However, the mechanism by which IDH1 mutations contribute to gliomagenesis and therapeutic response remains elusive. Here we report that senescence is involved in the improved therapeutic responses of mutant IDH1 glioma cells. Knocking-in IDH1R132H/WT in glioma cells significantly enhanced gliomas cell senescence in response to temozolomide and radiation via a DNA-damage mediated mechanism. We further asked if senescence plays a role in IDH1R132H/WT-induced gliomagenesis. Together with ATRX knockout and p53/RB loss, IDH1R132H/WT transformed nonneoplastic human astroglial cells to form tumors in mouse brains. In-depth characterization revealed that a subset of these precancerous cells underwent senescence-like phenotypic changes, including flat and enlarged-cell morphology, increased senescence marker expression, decreased cell proliferation, and cell-cycle arrest at the G2–M phase. Mechanistic studies indicated that the combination of glioma driver genes (p53/RB/IDH1/ATRX) dramatically increased DNA damage and activated DNAdamage response (DDR) pathways ATR/ATR and Chk1/Chk2 in senescent cells. To determine how senescent cells drive tumor formation, we investigated non–cell-autonomous mechanisms such as senescence-associated secretory phenotype (SASP), a panel of proinflammatory and tissue-remodeling factors implicated in a tumor-permissive microenvironment. We found that astroglial cells carrying p53/RB/ATRX loss and IDH1R132H/WT upregulated key factors in SASP via an epigenetic-mediated mechanism. Our work suggests that drugs that specifically eliminate senescent cells could help kill precancerous cells and senescent tumor cells following antitumor therapies.
Implications:
The mechanisms by which IDH1 mutations contribute to gliomagenesis and therapeutic responses remain incompletely characterized; this work reveals senescence as a novel mechanism of IDH-mutant–mediated biological impact and describes new therapeutic opportunities concerning IDH1-mutant gliomas.
Data from Stromal-Derived Extracellular Vesicles Suppress Proliferation of Bone Metastatic Cancer Cells Mediated by ERK2
Authors: Shupp Alison B. , Neupane Manish , Agostini Lebaron C. , Ning Gang , Brody Jonathan R. , Bussard Karen M.
Published: March 2024

Abstract
Bone is a common site of cancer metastasis, including cancers such as breast, prostate, and multiple myeloma. Disseminated tumor cells (DTC) shed from a primary tumor may travel to bone and can survive undetected for years before proliferating to form overt metastatic lesions. This period of time can be defined as metastatic latency. Once in the metastatic microenvironment, DTCs engage in intercellular communication with surrounding stromal cells, which can influence cancer cell survival, proliferation, and ultimately disease progression. The role of the surrounding tumor microenvironment in regulating DTC fate is becoming increasingly recognized. We have previously shown that in the bone microenvironment, osteoblasts are “educated” by interactions with breast cancer cells, and these “educated” osteoblasts (EO) produce soluble factors that regulate cancer cell proliferation. In this study, we provide evidence indicating that EOs produce small extracellular vesicles (sEV) that suppress breast cancer proliferation, in part through regulation of ERK1/2 signaling. In addition, using EdU-incorporation assays and propidium iodide staining we demonstrate that exposure to EO-derived sEVs decreases breast cancer cell entry to S-phase of cell cycle. We also have evidence that particular microRNAs, including miR-148a-3p, are enriched in EO-derived sEVs, and that miR-148a-3p is capable of regulating breast cancer proliferation.
Implications:
These findings underscore the importance of sEV-mediated communication in the earlier stages of cancer progression, and suggest that EO-derived sEVs may be one mechanism by which the bone microenvironment suppresses breast cancer cell proliferation.
Data from Inhibition of O-GlcNAc Transferase Renders Prostate Cancer Cells Dependent on CDK9
Authors: Itkonen Harri M. , Poulose Ninu , Steele Rebecca E. , Martin Sara E.S. , Levine Zebulon G. , Duveau Damien Y. , Carelli Ryan , Singh Reema , Urbanucci Alfonso , Loda Massimo , Thomas Craig J. , Mills Ian G. , Walker Suzanne
Published: March 2024

Abstract
O-GlcNAc transferase (OGT) is a nutrient-sensitive glycosyltransferase that is overexpressed in prostate cancer, the most common cancer in males. We recently developed a specific and potent inhibitor targeting this enzyme, and here, we report a synthetic lethality screen using this compound. Our screen identified pan-cyclin-dependent kinase (CDK) inhibitor AT7519 as lethal in combination with OGT inhibition. Follow-up chemical and genetic approaches identified CDK9 as the major target for synthetic lethality with OGT inhibition in prostate cancer cells. OGT expression is regulated through retention of the fourth intron in the gene and CDK9 inhibition blunted this regulatory mechanism. CDK9 phosphorylates carboxy-terminal domain (CTD) of RNA Polymerase II to promote transcription elongation. We show that OGT inhibition augments effects of CDK9 inhibitors on CTD phosphorylation and general transcription. Finally, the combined inhibition of both OGT and CDK9 blocked growth of organoids derived from patients with metastatic prostate cancer, but had minimal effects on normal prostate spheroids. We report a novel synthetic lethal interaction between inhibitors of OGT and CDK9 that specifically kills prostate cancer cells, but not normal cells. Our study highlights the potential of combining OGT inhibitors with other treatments to exploit cancer-specific vulnerabilities.
Implications:
The primary contribution of OGT to cell proliferation is unknown, and in this study, we used a compound screen to indicate that OGT and CDK9 collaborate to sustain a cancer cell–specific pro-proliferative program. A better understanding of how OGT and CDK9 cross-talk will refine our understanding of this novel synthetic lethal interaction.
Data from L-Plastin Promotes Gastric Cancer Growth and Metastasis in a Helicobacter pylori cagA-ERK-SP1–Dependent Manner
Authors: Teng Yong-Sheng , Chen Wan-Yan , Yan Zong-Bao , Lv Yi-Pin , Liu Yu-Gang , Mao Fang-Yuan , Zhao Yong-Liang , Peng Liu-Sheng , Cheng Ping , Duan Mu-Bing , Chen Weisan , Wang Yu , Luo Ping , Zou Quan-Ming , Chen Jun , Zhuang Yuan
Published: March 2024

Abstract
Actin cytoskeleton dynamic rearrangement is required for tumor cell metastasis and is a key characteristic of Helicobacter pylori (H. pylori)-infected host cells. Actin cytoskeleton modulation is coordinated by multiple actin-binding proteins (ABP). Through Kyoto encyclopedia of gene and genomes database, GEPIA website, and real-time PCR data, we found that H. pylori infection significantly induced L-plastin, a key ABP, in gastric cancer cells. We further explored the regulation and function of L-plastin in H. pylori–associated gastric cancer and found that, mechanistically, H. pylori infection induced gastric cancer cells to express L-plastin via cagA-activated ERK signaling pathway to mediate SP1 binding to L-plastin promoter. Moreover, this increased L-plastin promoted gastric cancer cell proliferation and migration in vitro and facilitated the growth and metastasis of gastric cancer in vivo. Finally, we detected the expression pattern of L-plastin in gastric cancer tissues, and found that L-plastin was increased in gastric cancer tissues and that this increase of L-plastin positively correlated with cagA+ H. pylori infection status. Overall, our results elucidate a novel mechanism of L-plastin expression induced by H. pylori, and a new function of L-plastin–facilitated growth and metastasis of gastric cancer, and thereby implicating L-plastin as a potential therapeutic target against gastric cancer.
Implications:
Our results elucidate a novel mechanism of L-plastin expression induced by H. pylori in gastric cancer, and a new function of L-plastin–facilitated gastric cancer growth and metastasis, implicating L-plastin as a potential therapeutic target against gastric cancer.
Data from DNA-PK Inhibition and Radiation Promote Antitumoral Immunity through RNA Polymerase III in Pancreatic Cancer
Authors: Wang Weiwei , McMillan Matthew T. , Zhao Xinyi , Wang Zhuwen , Jiang Long , Karnak David , Lima Fatima , Parsels Joshua D. , Parsels Leslie A. , Lawrence Theodore S. , Frankel Timothy L. , Morgan Meredith A. , Green Michael D. , Zhang Qiang
Published: March 2024

Abstract
Targeting the DNA damage response in combination with radiation enhances type I interferon (T1IFN)-driven innate immune signaling. It is not understood, however, whether DNA-dependent protein kinase (DNA-PK), the kinase critical for repairing the majority of radiation-induced DNA double-strand breaks in cancer cells, is immunomodulatory. We show that combining radiation with DNA-PK inhibition increases cytosolic double-stranded DNA and tumoral T1IFN signaling in a cyclic GMP-AMP synthase (cGAS)- and stimulator of interferon genes (STING)-independent, but an RNA polymerase III (POL III), retinoic acid-inducible gene I (RIG-I), and antiviral-signaling protein (MAVS)-dependent manner. Although DNA-PK inhibition and radiation also promote programmed death-ligand 1 (PD-L1) expression, the use of anti–PD-L1 in combination with radiation and DNA-PK inhibitor potentiates antitumor immunity in pancreatic cancer models. Our findings demonstrate a novel mechanism for the antitumoral immune effects of DNA-PK inhibitor and radiation that leads to increased sensitivity to anti–PD-L1 in poorly immunogenic pancreatic cancers.
Implications:
Our work nominates a novel therapeutic strategy as well as its cellular mechanisms pertinent for future clinical trials combining M3814, radiation, and anti-PD-L1 antibody in patients with pancreatic cancer.
Data from Caspase 9b Drives Cellular Transformation, Lung Inflammation, and Lung Tumorigenesis
Authors: Kim Minjung , Vu Ngoc T. , Wang Xue , Bulut Gamze B. , Wang Min-Hsuan , Uram-Tuculescu Cora , Pillappa Raghavendra , Kim Sungjune , Chalfant Charles E.
Published: March 2024

Abstract
Caspase 9 undergoes alternative splicing to produce two opposing isoforms: proapoptotic Caspase 9a and pro-survival Caspase 9b (C9b). Previously, our laboratory reported that C9b is expressed in majority of non–small cell lung cancer tumors and directly activates the NF-κB pathway. In this study, the role of C9b in activation of the NF-κB pathway in vivo, lung inflammation and immune responses, and lung tumorigenesis were examined. Specifically, a transgenic mouse model expressing human C9b in the lung pneumocytes developed inflammatory lung lesions, which correlated with enhanced activation of the NF-κB pathway and increased influx of immunosuppressive myeloid-derived suppressor cells in contrast to wild-type mice. C9b mice presented with facial dermatitis, a thickened and disorganized dermis, enhanced collagen depth, and increased serum levels of IL6. C9b mice also developed spontaneous lung tumors, and C9b cooperated with oncogenic KRAS in lung tumorigenesis. C9b expression also cooperated with oncogenic KRAS and p53 downregulation to drive the full cell transformation of human bronchial epithelial cells (e.g., tumor formation).
Implications:
Our findings show that C9b can directly activate NF-κB pathway in vivo to modulate lung inflammation, immune cell influx, and peripheral immune responses, which demonstrates that C9b is key factor in driving cell transformation and lung tumorigenesis.
Data from O-GlcNAcylation of Blimp-1 in Lymphocytes Inhibits Its Transcriptional Function and Is Associated with Migration and Invasion of Breast Cancer Cells
Authors: Chen Yan-Fang , Shao Guang-Can , Li Jie , Yang An-Qi , Li Jing , Ye Xin-Shan
Published: March 2024

Abstract
Lymphocyte infiltration is an important feature of cancer. There is a complex network of chemokines that influence the degree and phenotype of lymphocyte infiltration, as well as the growth, survival, migration, and angiogenesis of tumor cells. High heterogeneity metastasis is a major obstacle to the treatment of breast cancer. Herein, we showed that O-GlcNAcylation of B lymphocyte–induced maturation protein-1 (Blimp-1) in lymphocytes inhibited the migration and invasion of breast cancer cells. It was found that Blimp-1 O-GlcNAcylation at Ser448 and Ser472 in lymphocytes promoted its nuclear localization, and blocked the bindings to three regions upstream of the ccl3l1 promoter to inhibit its expression. Decreased expression of CCL3L1 in lymphocytes not only decreased CCR5 expression in breast cancer cells, but also inhibited the membrane localization and activation of CCR5, thus blocking the migration and invasion of breast cancer cells in vitro. Therefore, O-GlcNAcylation of Blimp-1 in lymphocytes may serve as a new target for the treatment of metastatic breast cancer.
Implications:
This study reveals a new mechanism by which the lymphatic system promotes breast cancer cell metastasis.
Data from Liver Endothelium Promotes HER3-Mediated Cell Survival in Colorectal Cancer with Wild-Type and Mutant KRAS
Authors: Rathore Moeez , Zhang Wei , Wright Michel'le , Bhattacharya Rajat , Fan Fan , Vaziri-Gohar Ali , Winter Jordan , Wang Zhenghe , Markowitz Sanford D. , Willis Joseph , Ellis Lee M. , Wang Rui
Published: March 2024

Abstract
We previously identified that human epidermal growth factor receptor 3 (HER3, also known as ERBB3) is a key mediator in liver endothelial cell (EC) promoting colorectal cancer growth and chemoresistance, and suggested HER3-targeted therapy as a strategy for treating patients with metastatic colorectal cancer in the liver. Meanwhile, KRAS mutations occur in 40%–50% of metastatic colorectal cancer and render colorectal cancer resistant to therapies targeting the other HER family protein epidermal growth factor receptor (EGFR). It is necessary to elucidate the roles of KRAS mutation status in HER3-mediated cell survival and colorectal cancer response to HER3 inhibition. In the present study, we used primary ECs isolated from non-neoplastic liver tissues to recapitulate the liver EC microenvironment. We demonstrated that liver EC-secreted factors activated colorectal cancer-associated HER3, and increased colorectal cancer cell survival in vitro and promoted colorectal cancer patient-derived xenograft tumor growth in vivo. Moreover, we determined that blocking HER3, either by siRNA knockdown or the humanized antibody seribantumab, blocked EC-induced colorectal cancer survival in vitro in both KRAS wild-type and mutant colorectal cancer cells, and the HER3 antibody seribantumab significantly decreased colorectal cancer tumor growth and sensitized tumors to chemotherapy in an orthotopic xenograft model with colorectal cancer tumors developed in the liver. In summary, our findings demonstrated that blocking HER3 had significant effects on attenuating liver EC-induced colorectal cancer cell survival independent of the KRAS mutation status.
Implications:
This body of work highlighted a potential strategy of using HER3 antibodies in combination with standard chemotherapy agents for treating patients with either KRAS wild-type or KRAS mutant metastatic colorectal cancer.
Data from A Recurrent ADPRHL1 Germline Mutation Activates PARP1 and Confers Prostate Cancer Risk in African American Families
Authors: Zhang Guanyi , Wang Zemin , Bavarva Jasmin , Kuhns Katherine J. , Guo Jianhui , Ledet Elisa M. , Qian Chiping , Lin Yuan , Fang Zhide , Zabaleta Jovanny , Valle Luis Del , Hu Jennifer J. , Mandal Diptasri , Liu Wanguo
Published: March 2024

Abstract
African American (AA) families have the highest risk of prostate cancer. However, the genetic factors contributing to prostate cancer susceptibility in AA families remain poorly understood. We performed whole-exome sequencing of one affected and one unaffected brother in an AA family with hereditary prostate cancer. The novel non-synonymous variants discovered only in the affected individuals were further analyzed in all affected and unaffected men in 20 AA-PC families. Here, we report one rare recurrent ADPRHL1 germline mutation (c.A233T; p.D78V) in four of the 20 families affected by prostate cancer. The mutation co-segregates with prostate cancer in two families and presents in two affected men in the other two families, but was absent in 170 unrelated healthy AA men. Functional characterization of the mutation in benign prostate cells showed aberrant promotion of cell proliferation, whereas expression of the wild-type ADPRHL1 in prostate cancer cells suppressed cell proliferation and oncogenesis. Mechanistically, the ADPRHL1 mutant activates PARP1, leading to an increased H2O2 or cisplatin-induced DNA damage response for prostate cancer cell survival. Indeed, the PARP1 inhibitor, olaparib, suppresses prostate cancer cell survival induced by mutant ADPRHL1. Given that the expression levels of ADPRHL1 are significantly high in normal prostate tissues and reduce stepwise as Gleason scores increase in tumors, our findings provide genetic, biochemical, and clinicopathological evidence that ADPRHL1 is a tumor suppressor in prostate tissue. A loss of function mutation in ADPRHL1 induces prostate tumorigenesis and confers prostate cancer susceptibility in high-risk AA families.
Implications:
This study highlights a potential strategy for ADPRHL1 mutation detection in prostate cancer–risk assessment and a potential therapeutic application for individuals with prostate cancer in AA families.
Data from Chk1 Inhibition Potently Blocks STAT3 Tyrosine705 Phosphorylation, DNA-Binding Activity, and Activation of Downstream Targets in Human Multiple Myeloma Cells
Authors: Zhou Liang , Pei Xinyan , Zhang Yu , Ning Yanxia , Li Lin , Hu Xiaoyan , Chalasani Sri Lakshmi , Sharma Kanika , Nkwocha Jewel , Yu Jonathan , Bandyopadhyay Dipankar , Sebti Said M. , Grant Steven
Published: March 2024

Abstract
The relationship between the checkpoint kinase Chk1 and the STAT3 pathway was examined in multiple myeloma cells. Gene expression profiling of U266 cells exposed to low (nmol/L) Chk1 inhibitor [PF-477736 (PF)] concentrations revealed STAT3 pathway-related gene downregulation (e.g., BCL-XL, MCL-1, c-Myc), findings confirmed by RT-PCR. This was associated with marked inhibition of STAT3 Tyr705 (but not Ser727) phosphorylation, dimerization, nuclear localization, DNA binding, STAT3 promoter activity by chromatin immunoprecipitation assay, and downregulation of STAT-3-dependent proteins. Similar findings were obtained in other multiple myeloma cells and with alternative Chk1 inhibitors (e.g., prexasertib, CEP3891). While PF did not reduce GP130 expression or modify SOCS or PRL-3 phosphorylation, the phosphatase inhibitor pervanadate antagonized PF-mediated Tyr705 dephosphorylation. Significantly, PF attenuated Chk1-mediated STAT3 phosphorylation in in vitro assays. Surface plasmon resonance analysis suggested Chk1/STAT3 interactions and PF reduced Chk1/STAT3 co-immunoprecipitation. Chk1 CRISPR knockout or short hairpin RNA knockdown cells also displayed STAT3 inactivation and STAT3-dependent protein downregulation. Constitutively active STAT3 diminished PF-mediated STAT3 inactivation and downregulate STAT3-dependent proteins while significantly reducing PF-induced DNA damage (γH2A.X formation) and apoptosis. Exposure of cells with low basal phospho-STAT3 expression to IL6 or human stromal cell conditioned medium activated STAT3, an event attenuated by Chk1 inhibitors. PF also inactivated STAT3 in primary human CD138+ multiple myeloma cells and tumors extracted from an NSG multiple myeloma xenograft model while inhibiting tumor growth.
Implications:
These findings identify a heretofore unrecognized link between the Chk1 and STAT3 pathways and suggest that Chk1 pathway inhibitors warrant attention as novel and potent candidate STAT3 antagonists in myeloma.
Data from Enhanced Vulnerability of LKB1-Deficient NSCLC to Disruption of ATP Pools and Redox Homeostasis by 8-Cl-Ado
Authors: Galan-Cobo Ana , Stellrecht Christine M. , Yilmaz Emrullah , Yang Chao , Qian Yu , Qu Xiao , Akhter Ishita , Ayres Mary L. , Fan Youhong , Tong Pan , Diao Lixia , Ding Jie , Giri Uma , Gudikote Jayanthi , Nilsson Monique , Wierda William G. , Wang Jing , Skoulidis Ferdinandos , Minna John D. , Gandhi Varsha , Heymach John V.
Published: March 2024

Abstract
Loss-of-function somatic mutations of STK11, a tumor suppressor gene encoding LKB1 that contributes to the altered metabolic phenotype of cancer cells, is the second most common event in lung adenocarcinomas and often co-occurs with activating KRAS mutations. Tumor cells lacking LKB1 display an aggressive phenotype, with uncontrolled cell growth and higher energetic and redox stress due to its failure to balance ATP and NADPH levels in response to cellular stimulus. The identification of effective therapeutic regimens for patients with LKB1-deficient non–small cell lung cancer (NSCLC) remains a major clinical need. Here, we report that LKB1-deficient NSCLC tumor cells displayed reduced basal levels of ATP and to a lesser extent other nucleotides, and markedly enhanced sensitivity to 8-Cl-adenosine (8-Cl-Ado), an energy-depleting nucleoside analog. Treatment with 8-Cl-Ado depleted intracellular ATP levels, raised redox stress, and induced cell death leading to a compensatory suppression of mTOR signaling in LKB1-intact, but not LKB1-deficient, cells. Proteomic analysis revealed that the MAPK/MEK/ERK and PI3K/AKT pathways were activated in response to 8-Cl-Ado treatment and targeting these pathways enhanced the antitumor efficacy of 8-Cl-Ado.
Implications:
Together, our findings demonstrate that LKB1-deficient tumor cells are selectively sensitive to 8-Cl-Ado and suggest that therapeutic approaches targeting vulnerable energy stores combined with signaling pathway inhibitors merit further investigation for this patient population.