bluuebunny/crossref_metadata_2025 huggingface dataset:
Data from p53 Promotes Cell Survival due to the Reversibility of Its Cell-Cycle Checkpoints
Authors: Lukin Dana J. , Carvajal Luis A. , Liu Wen-jun , Resnick-Silverman Lois , Manfredi James J.
Published: April 2023

Abstract
The tumor suppressor p53 (TP53) has a well-studied role in triggering cell-cycle checkpoint in response to DNA damage. Previous studies have suggested that functional p53 enhances chemosensitivity. In contrast, data are presented to show that p53 can be required for cell survival following DNA damage due to activation of reversible cell-cycle checkpoints. The cellular outcome to DNA damage is determined by the duration and extent of the stimulus in a p53-dependent manner. In response to transient or low levels of DNA damage, p53 triggers a reversible G2 arrest, whereas a sustained p53-dependent cell-cycle arrest and senescence follows prolonged or high levels of DNA damage. Regardless of the length of treatment, p53-null cells arrest in G2, but ultimately adapt and proceed into mitosis. Interestingly, they fail to undergo cytokinesis, become multinucleated, and then die from apoptosis. Upon transient treatment with DNA-damaging agents, wild-type p53 cells reversibly arrest and repair the damage, whereas p53-null cells fail to do so and die. These data indicate that p53 can promote cell survival by inducing reversible cell-cycle arrest, thereby allowing for DNA repair. Thus, transient treatments may exploit differences between wild-type p53 and p53-null cells.

Implications: Although p53 status has been suggested as a clinical predictor of chemotherapeutic efficacy, studies to date have not always supported this. This study demonstrates that p53 is still an important determinant of cell fate in response to chemotherapy, under the appropriate treatment conditions. Mol Cancer Res; 13(1); 16–28. ©2014 AACR.
Data from JNK1 Inhibition Attenuates Hypoxia-Induced Autophagy and Sensitizes to Chemotherapy
Authors: Vasilevskaya Irina A. , Selvakumaran Muthu , Roberts David , O'Dwyer Peter J.
Published: April 2023

Abstract
Inhibition of hypoxia-induced stress signaling through JNK potentiates the effects of oxaliplatin. The JNK pathway plays a role in both autophagy and apoptosis; therefore, it was determined how much of the effect of JNK inhibition on oxaliplatin sensitivity is dependent on its effect on autophagy. We studied the impact of JNK isoform downregulation in the HT29 colon adenocarcinoma cell line on hypoxia- and oxaliplatin-induced responses. Electron microscopic analyses demonstrated that both oxaliplatin- and hypoxia-induced formations of autophagosomes were reduced significantly in HT29 cells treated with the JNK inhibitor SP600125. The role of specific JNK isoforms was defined using HT29-derived cell lines stably expressing dominant-negative constructs for JNK1 and JNK2 (HTJ1.3 and HTJ2.2, respectively). These cell lines demonstrated that functional JNK1 is required for hypoxia-induced autophagy and that JNK2 does not substitute for it. Inhibition of autophagy in HTJ1.3 cells also coincided with enhancement of intrinsic apoptosis. Analysis of Bcl2-family proteins revealed hyperphosphorylation of Bcl-XL in the HTJ1.3 cell line, but this did not lead to the expected dissociation from Beclin 1. Consistent with this, knockdown of Bcl-XL in HT29 cells did not significantly affect the induction of autophagy, but abrogated hypoxic resistance to oxaliplatin due to the faster and more robust activation of apoptosis.

Implications: These data suggest that balance between autophagy and apoptosis is shifted toward apoptosis by downregulation of JNK1, contributing to oxaliplatin sensitization. These findings further support the investigation of JNK inhibition in colorectal cancer treatment. Mol Cancer Res; 14(8); 753–63. ©2016 AACR.
Data from Nuclear Receptor CAR Suppresses GADD45B-p38 MAPK Signaling to Promote Phenobarbital-induced Proliferation in Mouse Liver
Authors: Hori Takeshi , Saito Kosuke , Moore Rick , Flake Gordon P. , Negishi Masahiko
Published: April 2023

Abstract
Phenobarbital, a nongenotoxic hepatocarcinogen, induces hepatic proliferation and promotes development of hepatocellular carcinoma (HCC) in rodents. Nuclear receptor constitutive active/androstane receptor (NR1I3/CAR) regulates the induction and promotion activities of phenobarbital. Here, it is demonstrated that phenobarbital treatment results in dephosphorylation of a tumor suppressor p38 MAPK in the liver of C57BL/6 and C3H/HeNCrlBR mice. The molecular mechanism entails CAR binding and inhibition of the growth arrest and DNA-damage-inducible 45 beta (GADD45B)-MAPK kinase 6 (MKK6) scaffold to repress phosphorylation of p38 MAPK. Phenobarbital-induced hepatocyte proliferation, as determined by BrdUrd incorporation, was significantly reduced in both male and female livers of GADD45B knockout (KO) mice compared with the wild-type mice. The phenobarbital-induced proliferation continued until 48 hours after phenobarbital injection in only the C57BL/6 males, but neither in males of GADD45B KO mice nor in females of C57BL/6 and GADD45B KO mice. Thus, these data reveal nuclear receptor CAR interacts with GADD45B to repress p38 MAPK signaling and elicit hepatocyte proliferation in male mice.

Implications: This GADD45B-regulated male-predominant proliferation can be expanded as a phenobarbital promotion signal of HCC development in future studies.

Visual Overview: http://mcr.aacrjournals.org/content/molcanres/16/8/1309/F1.large.jpg. Mol Cancer Res; 16(8); 1309–18. ©2018 AACR.
Data from IL8 Expression Is Associated with Prostate Cancer Aggressiveness and Androgen Receptor Loss in Primary and Metastatic Prostate Cancer
Authors: Maynard Janielle P. , Ertunc Onur , Kulac Ibrahim , Baena-Del Valle Javier A. , De Marzo Angelo M. , Sfanos Karen S.
Published: April 2023

Abstract
Chronic inflammation and African ancestry are implicated in prostate cancer aggressiveness, and inflammation-related genes are more highly expressed in prostate cancer in African American men. IL8 secretion is also implicated in prostate cancer progression and castration resistance. We used RNA in situ hybridization to localize IL1β, IL6, IL8, and IL10 mRNA in low- and high-grade prostate cancer from African American and European American men. IL8 was the most abundantly expressed and the only interleukin detected in tumor cells. We further interrogated IL8 expression in primary and metastatic prostate cancer tissue microarrays and both androgen-dependent and castration-resistant patient-derived xenografts (PDX). IL8 was significantly increased in both tumor and benign regions of higher grade cases (ISUP Grade Group 4–5), but there was no difference between races. We determined that IL8 expression in prostate cancer cell lines, distant metastases, and PDX lines was associated with androgen receptor (AR) loss, but not castration resistance. Reciprocal IL8 and AR expression was also observed in high IL8-expressing atrophy lesions with simultaneous AR downregulation. Finally, we show that IL8 is likely repressed by AR binding to the IL8 promoter and is inducible in prostate cancer cells stimulated with lipopolysaccharide only in cells with AR loss. Likewise, AR knockdown in androgen-dependent cells induced IL8 expression, further demonstrating that AR represses IL8 expression. In conclusion, IL8 expression in the tumor microenvironment is associated with aggressive prostate cancer and with AR loss in metastatic disease.
Implications:
IL8 expression is repressed by AR and is associated with prostate cancer aggressiveness and AR loss in metastatic disease.
Data from Targeting IDH1 as a Prosenescent Therapy in High-grade Serous Ovarian Cancer
Authors: Dahl Erika S. , Buj Raquel , Leon Kelly E. , Newell Jordan M. , Imamura Yuka , Bitler Benjamin G. , Snyder Nathaniel W. , Aird Katherine M.
Published: April 2023

Abstract
Epithelial ovarian cancer (EOC) is the deadliest gynecologic cancer. High-grade serous carcinoma (HGSC) is the most frequently diagnosed and lethal histosubtype of EOC. A significant proportion of patients with HGSC relapse with chemoresistant disease. Therefore, there is an urgent need for novel therapeutic strategies for HGSC. Metabolic reprogramming is a hallmark of cancer cells, and targeting metabolism for cancer therapy may be beneficial. Here, we found that in comparison with normal fallopian tube epithelial cells, HGSC cells preferentially utilize glucose in the TCA cycle and not for aerobic glycolysis. This correlated with universally increased TCA cycle enzyme expression in HGSC cells under adherent conditions. HGSC disseminates as tumor cell spheroids within the peritoneal cavity. We found that wild-type isocitrate dehydrogenase I (IDH1) is the only TCA cycle enzyme upregulated in both adherent and spheroid conditions and is associated with reduced progression-free survival. IDH1 protein expression is also increased in patients with primary HGSC tumors. Pharmacologic inhibition or knockdown of IDH1 decreased proliferation of multiple HGSC cell lines by inducing senescence. Mechanistically, suppression of IDH1 increased the repressive histone mark H3K9me2 at multiple E2F target gene loci, which led to decreased expression of these genes. Altogether, these data suggest that increased IDH1 activity is an important metabolic adaptation in HGSC and that targeting wild-type IDH1 in HGSC alters the repressive histone epigenetic landscape to induce senescence.
Implications:
Inhibition of IDH1 may act as a novel therapeutic approach to alter both the metabolism and epigenetics of HGSC as a prosenescent therapy.
Data from Centrosome Linker–induced Tetraploid Segregation Errors Link Rhabdoid Phenotypes and Lethal Colorectal Cancers
Authors: Remo Andrea , Manfrin Erminia , Parcesepe Pietro , Ferrarini Alberto , Han Hye Seung , Mickys Ugnius , Laudanna Carmelo , Simbolo Michele , Malanga Donatella , Oliveira Duarte Mendes , Baritono Elisabetta , Colangelo Tommaso , Sabatino Lina , Giuliani Jacopo , Molinari Enrico , Garonzi Marianna , Xumerle Luciano , Delledonne Massimo , Giordano Guido , Ghimenton Claudio , Lonardo Fortunato , D'angelo Fulvio , Grillo Federica , Mastracci Luca , Viglietto Giuseppe , Ceccarelli Michele , Colantuoni Vittorio , Scarpa Aldo , Pancione Massimo
Published: April 2023

Abstract
Centrosome anomalies contribute to tumorigenesis, but it remains unclear how they are generated in lethal cancer phenotypes. Here, it is demonstrated that human microsatellite instable (MSI) and BRAFV600E-mutant colorectal cancers with a lethal rhabdoid phenotype are characterized by inactivation of centrosomal functions. A splice site mutation that causes an unbalanced dosage of rootletin (CROCC), a centrosome linker component required for centrosome cohesion and separation at the chromosome 1p36.13 locus, resulted in abnormally shaped centrosomes in rhabdoid cells from human colon tissues. Notably, deleterious deletions at 1p36.13 were recurrent in a subgroup of BRAFV600E-mutant and microsatellite stable (MSS) rhabdoid colorectal cancers, but not in classical colorectal cancer or pediatric rhabdoid tumors. Interfering with CROCC expression in near-diploid BRAFV600E-mutant/MSI colon cancer cells disrupts bipolar mitotic spindle architecture, promotes tetraploid segregation errors, resulting in a highly aggressive rhabdoid-like phenotype in vitro. Restoring near-wild-type levels of CROCC in a metastatic model harboring 1p36.13 deletion results in correction of centrosome segregation errors and cell death, revealing a mechanism of tolerance to mitotic errors and tetraploidization promoted by deleterious 1p36.13 loss. Accordingly, cancer cells lacking 1p36.13 display far greater sensitivity to centrosome spindle pole stabilizing agents in vitro. These data shed light on a previously unknown link between centrosome cohesion defects and lethal cancer phenotypes providing new insight into pathways underlying genome instability.

Implications: Mis-segregation of chromosomes is a prominent feature of chromosome instability and intratumoral heterogeneity recurrent in metastatic tumors for which the molecular basis is unknown. This study provides insight into the mechanism by which defects in rootletin, a centrosome linker component causes tetraploid segregation errors and phenotypic transition to a clinically devastating form of malignant rhabdoid tumor. Mol Cancer Res; 16(9); 1385–95. ©2018 AACR.
Data from β4-Integrin/PI3K Signaling Promotes Tumor Progression through the Galectin-3–N-Glycan Complex
Authors: Kariya Yukiko , Oyama Midori , Hashimoto Yasuhiro , Gu Jianguo , Kariya Yoshinobu
Published: April 2023

Abstract
Malignant transformation is associated with aberrant N-glycosylation, but the role of protein N-glycosylation in cancer progression remains poorly defined. β4-integrin is a major carrier of N-glycans and is associated with poor prognosis, tumorigenesis, and metastasis. Here, N-glycosylation of β4-integrin contributes to the activation of signaling pathways that promote β4-dependent tumor development and progression. Increased expression of β1,6GlcNAc-branched N-glycans was found to be colocalized with β4-integrin in human cutaneous squamous cell carcinoma tissues, and that the β1,6GlcNAc residue was abundant on β4-integrin in transformed keratinocytes. Interruption of β1,6GlcNAc-branching formation on β4-integrin with the introduction of bisecting GlcNAc by N-acetylglucosaminyltransferase III overexpression was correlated with suppression of cancer cell migration and tumorigenesis. N-Glycan deletion on β4-integrin impaired β4-dependent cancer cell migration, invasion, and growth in vitro and diminished tumorigenesis and proliferation in vivo. The reduced abilities of β4-integrin were accompanied with decreased phosphoinositol-3 kinase (PI3K)/Akt signals and were restored by the overexpression of the constitutively active p110 PI3K subunit. Binding of galectin-3 to β4-integrin via β1,6GlcNAc-branched N-glycans promoted β4-integrin–mediated cancer cell adhesion and migration. In contrast, a neutralizing antibody against galectin-3 attenuated β4-integrin N-glycan–mediated PI3K activation and inhibited the ability of β4-integrin to promote cell motility. Furthermore, galectin-3 knockdown by shRNA suppressed β4-integrin N-glycan–mediated tumorigenesis. These findings provide a novel role for N-glycosylation of β4-integrin in tumor development and progression, and the regulatory mechanism for β4-integrin/PI3K signaling via the galectin-3–N-glycan complex.

Implications: N-Glycosylation of β4-integrin plays a functional role in promoting tumor development and progression through PI3K activation via the galectin-3–N-glycan complex. Mol Cancer Res; 16(6); 1024–34. ©2018 AACR.
Data from Interaction Between MUC1 and STAT1 Drives IFITM1 Overexpression in Aromatase Inhibitor–Resistant Breast Cancer Cells and Mediates Estrogen-Induced Apoptosis
Authors: Escher Taylor E. , Lui Asona J. , Geanes Eric S. , Walter Katherine R. , Tawfik Ossama , Hagan Christy R. , Lewis-Wambi Joan
Published: April 2023

Abstract
The human oncoprotein, mucin 1 (MUC1), drives tumorigenesis in breast carcinomas by promoting epithelial-to-mesenchymal transition (EMT), epigenetic reprogramming, and evasion of immune response. MUC1 interacts with STAT1, through JAK/STAT signaling, and stimulates transcription of IFN-stimulated genes, specifically IFN-induced transmembrane protein 1 (IFITM1). Our laboratory has previously shown that IFITM1 overexpression in aromatase inhibitor (AI)-resistant breast cancer cells promotes aggressiveness. Here, we demonstrate that differential regulation of MUC1 in AI-sensitive (MCF-7 and T-47D) compared with AI-resistant (MCF-7:5C) cells is critical in mediating IFITM1 expression. A tumor microarray of 94 estrogen receptor–positive human breast tumors correlated coexpression of MUC1 and IFITM1 with poor recurrence-free survival, poor overall survival, and AI-resistance. In this study, we investigated the effects of MUC1/IFITM1 on cell survival and proliferation. We knocked down MUC1 levels with siRNA and pharmacologic inhibitors, which abrogated IFITM1 mRNA and protein expression and induced cell death in AI-resistant cells. In vivo, estrogen and ruxolitinib significantly reduced tumor size and decreased expression of MUC1, P-STAT1, and IFITM1.
Implications:
MUC1 and IFITM1 overexpression drives AI resistance and can be targeted with currently available therapies.

Visual Overview: http://mcr.aacrjournals.org/content/molcanres/17/5/1180/F1.large.jpg.
Data from The β2-Adrenergic Receptor Is a Molecular Switch for Neuroendocrine Transdifferentiation of Prostate Cancer Cells
Authors: Braadland Peder R. , Ramberg Håkon , Grytli Helene Hartvedt , Urbanucci Alfonso , Nielsen Heidi Kristin , Guldvik Ingrid Jenny , Engedal Andreas , Ketola Kirsi , Wang Wanzhong , Svindland Aud , Mills Ian G. , Bjartell Anders , Taskén Kristin Austlid
Published: April 2023

Abstract
The incidence of treatment-related neuroendocrine prostate cancer (t-NEPC) is rising as more potent drugs targeting the androgen signaling axis are clinically implemented. Neuroendocrine transdifferentiation (NEtD), an putative initial step in t-NEPC development, is induced by androgen-deprivation therapy (ADT) or anti-androgens, and by activation of the β2-adrenergic receptor (ADRB2) in prostate cancer cell lines. Thus, understanding whether ADRB2 is involved in ADT-initiated NEtD may assist in developing treatment strategies that can prevent or reverse t-NEPC emergence, thereby prolonging therapeutic responses. Here we found that in primary, treatment-naïve prostate cancers, ADRB2 mRNA was positively correlated with expression of luminal differentiation markers, and ADRB2 protein levels were inversely correlated with Gleason grade. ADRB2 mRNA was upregulated in metastatic prostate cancer, and progressively downregulated during ADT and t-NEPC emergence. In androgen-deprivated medium, high ADRB2 was required for LNCaP cells to undergo NEtD, measured as increased neurite outgrowth and expression of neuron differentiation and neuroendocrine genes. ADRB2 overexpression induced a neuroendocrine-like morphology in both androgen receptor (AR)-positive and -negative prostate cancer cell lines. ADRB2 downregulation in LNCaP cells increased canonical Wnt signaling, and GSK3α/β inhibition reduced the expression of neuron differentiation and neuroendocrine genes. In LNCaP xenografts, more pronounced castration-induced NEtD was observed in tumors derived from high than low ADRB2 cells. In conclusion, high ADRB2 expression is required for ADT-induced NEtD, characterized by ADRB2 downregulation and t-NEPC emergence.
Implications:
This data suggest a potential application of β-blockers to prevent cancer cells committed to a neuroendocrine lineage from evolving into t-NEPC.
Data from Aromatase Acetylation Patterns and Altered Activity in Response to Sirtuin Inhibition
Authors: Molehin Deborah , Castro-Piedras Isabel , Sharma Monica , Sennoune Souad R. , Arena Daphne , Manna Pulak R. , Pruitt Kevin
Published: April 2023

Abstract
Aromatase, a cytochrome P450 member, is a key enzyme involved in estrogen biosynthesis and is dysregulated in the majority of breast cancers. Studies have shown that lysine deacetylase inhibitors (KDI) decrease aromatase expression in cancer cells, yet many unknowns remain regarding the mechanism by which this occurs. However, advances have been made to clarify factors involved in the transcriptional regulation of the aromatase gene (CYP19A1). Yet, despite aromatase being a primary target for breast cancer therapy, its posttranslational regulation has been virtually unexplored. Acetylation is a posttranslational modification (PTM) known to alter the activity and stability of many oncoproteins, and given the role of KDIs in regulating aromatase expression, we postulate that aromatase acetylation acts as a novel posttranslational regulatory mechanism that impacts aromatase expression and/or activity in breast cancer. Liquid chromatography–tandem mass spectrometry (LC-MS/MS) analysis revealed that aromatase is basally acetylated on several lysine residues (108, 169, 242, 262, 334, 352, and 354) in MCF-7 cells, and treatment with a SIRT-1 inhibitor induced additional acetylation (376, 390, 440, and 448). These acetylated lysine residues are in regions critical for aromatase activity. Site-directed mutagenesis and overexpression studies demonstrated that K108R/Q or K440R/Q mutations significantly altered aromatase activity in breast cancer cells without altering its subcellular localization.

Implications: These findings demonstrate a novel posttranslational regulation of aromatase and uncover novel anticancer effects of deacetylase inhibitors, thus providing new insight for ongoing development of deacetylase inhibitors as cancer therapeutics. Mol Cancer Res; 16(10); 1530–42. ©2018 AACR.
Data from Inhibition of the ATR–CHK1 Pathway in Ewing Sarcoma Cells Causes DNA Damage and Apoptosis via the CDK2-Mediated Degradation of RRM2
Authors: Koppenhafer Stacia L. , Goss Kelli L. , Terry William W. , Gordon David J.
Published: April 2023

Abstract
Inhibition of ribonucleotide reductase (RNR), the rate-limiting enzyme in the synthesis of deoxyribonucleotides, causes DNA replication stress and activates the ataxia telangiectasia and rad3-related protein (ATR)-checkpoint kinase 1 (CHK1) pathway. Notably, a number of different cancers, including Ewing sarcoma tumors, are sensitive to the combination of RNR and ATR-CHK1 inhibitors. However, multiple, overlapping mechanisms are reported to underlie the toxicity of ATR-CHK1 inhibitors, both as single agents and in combination with RNR inhibitors, toward cancer cells. Here, we identified a feedback loop in Ewing sarcoma cells in which inhibition of the ATR–CHK1 pathway depletes RRM2, the small subunit of RNR, and exacerbates the DNA replication stress and DNA damage caused by RNR inhibitors. Mechanistically, we identified that the inhibition of ATR-CHK1 activates CDK2, which targets RRM2 for degradation via the proteasome. Similarly, activation of CDK2 by inhibition or knockdown of the WEE1 kinase also depletes RRM2 and causes DNA damage and apoptosis. Moreover, we show that the concurrent inhibition of ATR and WEE1 has a synergistic effect in Ewing sarcoma cells. Overall, our results provide novel insight into the response to DNA replication stress, as well as a rationale for targeting the ATR, CHK1, and WEE1 pathways, in Ewing sarcoma tumors.
Implications:
Targeting the ATR, CHK1, and WEE1 kinases in Ewing sarcoma cells activates CDK2 and increases DNA replication stress by promoting the proteasome-mediated degradation of RRM2.
Data from Efficacy of a Covalent ERK1/2 Inhibitor, CC-90003, in KRAS-Mutant Cancer Models Reveals Novel Mechanisms of Response and Resistance
Authors: Aronchik Ida , Dai Yumin , Labenski Matt , Barnes Carmen , Jones Terri , Qiao Lixin , Beebe Lisa , Malek Mehnaz , Elis Winfried , Shi Tao , Mavrommatis Konstantinos , Bray Gordon L. , Filvaroff Ellen H.
Published: April 2023

Abstract
As a critical signaling node, ERK1/2 are attractive drug targets, particularly in tumors driven by activation of the MAPK pathway. Utility of targeting the MAPK pathway has been demonstrated by clinical responses to inhibitors of MEK1/2 or RAF kinases in some mutant BRAF-activated malignancies. Unlike tumors with mutations in BRAF, those with mutations in KRAS (>30% of all cancers and >90% of certain cancer types) are generally not responsive to inhibitors of MEK1/2 or RAF. Here, a covalent ERK1/2 inhibitor, CC-90003, was characterized and shown to be active in preclinical models of KRAS-mutant tumors. A unique occupancy assay was used to understand the mechanism of resistance in a KRAS-mutant patient-derived xenograft (PDX) model of colorectal cancer. Finally, combination of CC-90003 with docetaxel achieved full tumor regression and prevented tumor regrowth after cessation of treatment in a PDX model of lung cancer. This effect corresponded to changes in a stemness gene network, revealing a potential effect on tumor stem cell reprograming.
Implications:
Here, a covalent ERK1/2 inhibitor (CC-90003) is demonstrated to have preclinical efficacy in models of KRAS-mutant tumors, which present a therapeutic challenge for currently available therapies.
Data from Pattern-Specific Transcriptomics Identifies ASGR2 as a Predictor of Hematogenous Recurrence of Gastric Cancer
Authors: Tanaka Haruyoshi , Kanda Mitsuro , Miwa Takashi , Tanaka Chie , Kobayashi Daisuke , Umeda Shinichi , Shibata Masahiro , Suenaga Masaya , Hattori Norifumi , Hayashi Masamichi , Iwata Naoki , Yamada Suguru , Nakayama Goro , Fujiwara Michitaka , Kodera Yasuhiro
Published: April 2023

Abstract
Hematogenous recurrence is a challenging clinical finding that often leads to fatalities of patients with gastric cancer. Therefore, the identification of specific biomarkers and potential therapeutic target molecules for hematogenous recurrence is required to improve the outcomes of these patients. Here, transcriptome and bioinformatics analyses were conducted to uncover candidate molecules differentially expressed in patients with hematogenous recurrence of gastric cancer. One potential candidate identified was asialoglycoprotein receptor 2 (ASGR2), and siRNA experiments were conducted to determine the effect of manipulating ASGR2 expression has on cell phenotypes. ASGR2 mRNA expression analysis using quantitative real-time reverse-transcription PCR was conducted with stage II/III gastric cancer clinical specimens (n = 95). Transcript levels were increased in gastric cancer cells as compared with a control nontumorigenic epithelial cell line. Knockdown of ASGR2 decreased the adhesion and migration potential. Thus, although gastric cancer cell–invasive activity was significantly decreased by knockdown, forced expression of ASGR2 promoted invasive activity. Using a mouse hepatic metastasis model, knockdown of ASGR2 resulted in the absence of hepatic metastasis formation. High ASGR2 expression in primary gastric cancer tissues was an independent predictor of shorter disease-free and overall survival. Finally, patients with high ASGR2 expression were more likely to have a high cumulative rate of hematogenous recurrence but not peritoneal or nodal recurrence.

Implications: ASGR2 expression is associated with the malignant phenotypes in gastric cancer and represents a specific biomarker of hematogenous recurrences after curative resection for gastric cancer. Mol Cancer Res; 16(9); 1420–9. ©2018 AACR.
Data from An Integrated Stress Response Agent that Modulates DR5-Dependent TRAIL Synergy Reduces Patient-Derived Glioma Stem Cell Viability
Authors: Sheikh Saad , Saxena Deeksha , Tian Xiaobing , Amirshaghaghi Ahmad , Tsourkas Andrew , Brem Steven , Dorsey Jay F.
Published: April 2023

Abstract
The high incidence of glioblastoma recurrence necessitates additional therapeutic strategies. Heterogeneous populations of cells, including glioma stem cells (GSC) have been implicated in disease recurrence. GSCs are able to survive irradiation and temozolomide (TMZ) treatment due to upregulation of DNA damage pathways. One potential strategy to target treatment-resistant tumor populations may be via the integrated stress response (ISR). Modulation of the ISR pathway also allows for sensitization of treatment-resistant cells to TRAIL. We generated a novel cell-based death receptor assay to identify potent inducers of ISR-dependent DR5 expression. We used this assay to screen compounds from three commercially available libraries, and identified 1-benzyl-3-cetyl-2-methylimidazolium iodide (NH125) as a potent inducer of DR5 expression. NH125 engages the EIF2α–ATF4–CHOP axis culminating in DR5 expression at low micromolar doses. Expression of CHOP plays a critical role in NH125-mediated TRAIL synergy. Treatment of GSC with NH125 produces a marked reduction in viability when compared with other cell lines. NH125-treated GSC also synergize with lower doses of TRAIL when compared with all other cell lines tested. Transcriptional analysis of NH125-treated GSC uncovers a unique profile that involves activation of ISR and GADD45 pathways. Treatment of GSC xenografts with encapsulated PEG–PCL–NH125 leads to a sustained decrease in tumor volume.
Implications:
Taken together, these data suggest that engaging the ISR pathway represents a promising strategy to target treatment refractory GSC that have been implicated in glioblastoma recurrence.
Data from Pooled Genomic Screens Identify Anti-apoptotic Genes as Targetable Mediators of Chemotherapy Resistance in Ovarian Cancer
Authors: Stover Elizabeth H. , Baco Maria B. , Cohen Ofir , Li Yvonne Y. , Christie Elizabeth L. , Bagul Mukta , Goodale Amy , Lee Yenarae , Pantel Sasha , Rees Matthew G. , Wei Guo , Presser Adam G. , Gelbard Maya K. , Zhang Weiqun , Zervantonakis Ioannis K. , Bhola Patrick D. , Ryan Jeremy , Guerriero Jennifer L. , Montero Joan , Liang Felice J. , Cherniack Andrew D. , Piccioni Federica , Matulonis Ursula A. , Bowtell David D.L. , Sarosiek Kristopher A. , Letai Anthony , Garraway Levi A. , Johannessen Cory M. , Meyerson Matthew
Published: April 2023

Abstract
High-grade serous ovarian cancer (HGSOC) is often sensitive to initial treatment with platinum and taxane combination chemotherapy, but most patients relapse with chemotherapy-resistant disease. To systematically identify genes modulating chemotherapy response, we performed pooled functional genomic screens in HGSOC cell lines treated with cisplatin, paclitaxel, or cisplatin plus paclitaxel. Genes in the intrinsic pathway of apoptosis were among the top candidate resistance genes in both gain-of-function and loss-of-function screens. In an open reading frame overexpression screen, followed by a mini-pool secondary screen, anti-apoptotic genes including BCL2L1 (BCL-XL) and BCL2L2 (BCL-W) were associated with chemotherapy resistance. In a CRISPR-Cas9 knockout screen, loss of BCL2L1 decreased cell survival whereas loss of proapoptotic genes promoted resistance. To dissect the role of individual anti-apoptotic proteins in HGSOC chemotherapy response, we evaluated overexpression or inhibition of BCL-2, BCL-XL, BCL-W, and MCL1 in HGSOC cell lines. Overexpression of anti-apoptotic proteins decreased apoptosis and modestly increased cell viability upon cisplatin or paclitaxel treatment. Conversely, specific inhibitors of BCL-XL, MCL1, or BCL-XL/BCL-2, but not BCL-2 alone, enhanced cell death when combined with cisplatin or paclitaxel. Anti-apoptotic protein inhibitors also sensitized HGSOC cells to the poly (ADP-ribose) polymerase inhibitor olaparib. These unbiased screens highlight anti-apoptotic proteins as mediators of chemotherapy resistance in HGSOC, and support inhibition of BCL-XL and MCL1, alone or combined with chemotherapy or targeted agents, in treatment of primary and recurrent HGSOC.
Implications:
Anti-apoptotic proteins modulate drug resistance in ovarian cancer, and inhibitors of BCL-XL or MCL1 promote cell death in combination with chemotherapy.
Data from Inhibition of NR4A1 Promotes ROS Accumulation and IL24-Dependent Growth Arrest in Rhabdomyosarcoma
Authors: Hedrick Erik , Mohankumar Kumaravel , Lacey Alexandra , Safe Stephen
Published: April 2023

Abstract
Nuclear receptor 4A1 (NR4A1, Nur77) is overexpressed in rhabdomyosarcoma (RMS), and inactivation of NR4A1 (siNR4A1) or treatment with the NR4A1 antagonist 1,1-bis(3′-indoly)-1-(p-hydroxy-phenyl)methane (DIM-C-pPhOH) has antiproliferative and proapoptotic effects on RMS cells. However, the mechanism by which NR4A1 inhibition exerts these effects is poorly defined. Here, we report that NR4A1 silencing or inhibition resulted in accumulation of reactive oxygen species (ROS) and ROS-dependent induction of the tumor suppressor–like cytokine IL24 in RMS cells. Mechanistically, NR4A1 was found to regulate the expression of the proreductant genes thioredoxin domain-containing 5 (TXNDC5) and isocitrate dehydrogenase 1 (IDH1), which are downregulated in RMS cells following NR4A1 knockdown or inhibition. Silencing TXNDC5 and IDH1 also induced ROS accumulation and IL24 expression in RMS cells, suggesting that NR4A1 antagonists mediate their antiproliferative and apoptotic effects through modulation of proreductant gene expression. Finally, cotreatment with the antioxidant glutathione or IL24-blocking antibody reversed the effects of NR4A1 inhibition, demonstrating the importance of both ROS and IL24 in mediating the cellular responses.
Implications:
Overall, these data elucidate the mechanism by which NR4A1 inhibition functions to inhibit the proliferation, survival, and migration of RMS cells.
Data from CRISPR Knockout of the HuR Gene Causes a Xenograft Lethal Phenotype
Authors: Lal Shruti , Cheung Edwin C. , Zarei Mahsa , Preet Ranjan , Chand Saswati N. , Mambelli-Lisboa Nicole C. , Romeo Carmella , Stout Matthew C. , Londin Eric , Goetz Austin , Lowder Cinthya Y. , Nevler Avinoam , Yeo Charles J. , Campbell Paul M. , Winter Jordan M. , Dixon Dan A. , Brody Jonathan R.
Published: April 2023

Abstract
Pancreatic ductal adenocarcinoma (PDA) is the third leading cause of cancer-related deaths in the United States, whereas colorectal cancer is the third most common cancer. The RNA-binding protein HuR (ELAVL1) supports a pro-oncogenic network in gastrointestinal (GI) cancer cells through enhanced HuR expression. Using a publically available database, HuR expression levels were determined to be increased in primary PDA and colorectal cancer tumor cohorts as compared with normal pancreas and colon tissues, respectively. CRISPR/Cas9 technology was successfully used to delete the HuR gene in both PDA (MIA PaCa-2 and Hs 766T) and colorectal cancer (HCT116) cell lines. HuR deficiency has a mild phenotype, in vitro, as HuR-deficient MIA PaCa-2 (MIA.HuR-KO(−/−)) cells had increased apoptosis when compared with isogenic wild-type (MIA.HuR-WT(+/+)) cells. Using this isogenic system, mRNAs were identified that specifically bound to HuR and were required for transforming a two-dimensional culture into three dimensional (i.e., organoids). Importantly, HuR-deficient MIA PaCa-2 and Hs 766T cells were unable to engraft tumors in vivo compared with control HuR-proficient cells, demonstrating a unique xenograft lethal phenotype. Although not as a dramatic phenotype, CRISPR knockout HuR HCT116 colon cancer cells (HCT.HuR-KO(−/−)) showed significantly reduced in vivo tumor growth compared with controls (HCT.HuR-WT(+/+)). Finally, HuR deletion affects KRAS activity and controls a subset of pro-oncogenic genes.

Implications: The work reported here supports the notion that targeting HuR is a promising therapeutic strategy to treat GI malignancies. Mol Cancer Res; 15(6); 696–707. ©2017 AACR.
Data from LSD1 Inhibition Attenuates Tumor Growth by Disrupting PLK1 Mitotic Pathway
Authors: Dalvi Priya S. , Macheleidt Iris F. , Lim So-Young , Meemboor Sonja , Müller Marion , Eischeid-Scholz Hannah , Schaefer Stephan C. , Buettner Reinhard , Klein Sebastian , Odenthal Margarete
Published: April 2023

Abstract
Lysine-specific demethylase 1 (LSD1) is a histone modifier that is highly overexpressed in lung adenocarcinoma, which results in aggressive tumor biology. Tumor cell proliferation and migration analysis after LSD1 inhibition in the lung adenocarcinoma cell line PC9, using the LSD1 inhibitor HCI-2509 and siRNA, demonstrated that LSD1 activity was essential for proliferation and migration capacities of tumor cells. Moreover, reduced proliferation rates after LSD1 inhibition were shown to be associated with a cell-cycle arrest of the tumor cells in the G2–M-phase. Expression profiling followed by functional classification and pathway analysis indicated prominent repression of the polo-like kinase 1 (PLK1) pathway upon LSD1 inhibition. In contrast, transient overexpression of exogenous PLK1 plasmid rescued the LSD1 inhibition–mediated downregulation of PLK1 pathway genes. Mechanistically, LSD1 directly regulates expression of PLK1 by binding to its promoter region that subsequently affects expression of its downstream target genes. Notably, using lung adenocarcinoma TCGA datasets a significant correlation between LSD1 and PLK1 along with its downstream targets was observed. Furthermore, the LSD1/PLK1 linkage was confirmed by IHC analysis in a clinical lung adenocarcinoma cohort (n = 43). Conclusively, this is the first study showing a direct transcriptional link between LSD1 and PLK1.
Implications:
These findings point to a role of LSD1 in regulating PLK1 and thus efficient G2–M-transition–mediating proliferation of tumor cells and suggest targeting the LSD1/PLK1 axis as a novel therapeutic approach for lung adenocarcinoma treatment.
Data from Spindle Assembly Disruption and Cancer Cell Apoptosis with a CLTC-Binding Compound
Authors: Bond Michael J. , Bleiler Marina , Harrison Lauren E. , Scocchera Eric W. , Nakanishi Masako , G-Dayanan Narendran , Keshipeddy Santosh , Rosenberg Daniel W. , Wright Dennis L. , Giardina Charles
Published: April 2023

Abstract
AK3 compounds are mitotic arrest agents that induce high levels of γH2AX during mitosis and apoptosis following release from arrest. We synthesized a potent AK3 derivative, AK306, that induced arrest and apoptosis of the HCT116 colon cancer cell line with an EC50 of approximately 50 nmol/L. AK306 was active on a broad spectrum of cancer cell lines with total growth inhibition values ranging from approximately 25 nmol/L to 25 μmol/L. Using biotin and BODIPY-linked derivatives of AK306, binding to clathrin heavy chain (CLTC/CHC) was observed, a protein with roles in endocytosis and mitosis. AK306 inhibited mitosis and endocytosis, while disrupting CHC cellular localization. Cells arrested in mitosis by AK306 showed the formation of multiple microtubule-organizing centers consisting of pericentrin, γ-tubulin, and Aurora A foci, without apparent centrosome amplification. Cells released from AK306 arrest were unable to form bipolar spindles, unlike nocodazole-released cells that reformed spindles and completed division. Like AK306, CHC siRNA knockdown disrupted spindle formation and activated p53. A short-term (3-day) treatment of tumor-bearing APC-mutant mice with AK306 increased apoptosis in tumors, but not normal mucosa. These findings indicate that targeting the mitotic CHC complex can selectively induce apoptosis and may have therapeutic value.

Implication: Disruption of clathrin with a small-molecule inhibitor, AK306, selectively induces apoptosis in cancer cells by disrupting bipolar spindle formation. Mol Cancer Res; 16(9); 1361–72. ©2018 AACR.
Data from Stemness Is Enhanced in Gastric Cancer by a SET/PP2A/E2F1 Axis
Authors: Enjoji Shuhei , Yabe Ryotaro , Tsuji Shunya , Yoshimura Kazuhiro , Kawasaki Hideyoshi , Sakurai Masashi , Sakai Yusuke , Takenouchi Hiroko , Yoshino Shigefumi , Hazama Shoichi , Nagano Hiroaki , Oshima Hiroko , Oshima Masanobu , Vitek Michael P. , Matsuura Tetsuya , Hippo Yoshitaka , Usui Tatsuya , Ohama Takashi , Sato Koichi
Published: April 2023

Abstract
Gastric cancer is the fifth most common malignancy and the third leading cause of cancer-related deaths worldwide. Chemotherapies against gastric cancer often fail, with cancer recurrence due potentially to the persistence of cancer stem cells. This unique subpopulation of cells in tumors possesses the ability to self-renew and dedifferentiate. These cancer stem cells are critical for initiation, maintenance, metastasis, and relapse of cancers; however, the molecular mechanisms supporting cancer stemness remain largely unknown. Increased kinase and decreased phosphatase activity are hallmarks of oncogenic signaling. Protein phosphatase 2A (PP2A) functions as a tumor-suppressor enzyme, and elevated levels of SET/I2PP2A, an endogenous PP2A protein inhibitor, are correlated with poor prognosis of several human cancers. Here, it was determined that SET expression was elevated in tumor tissue in a gastric cancer mouse model system, and SET expression was positively correlated with poor survival of human gastric cancer patients. Mechanistically, SET knockdown decreased E2F1 levels and suppressed the stemness of cancer cell lines. Immunoprecipitations show SET associated with the PP2A–B56 complex, and the B56 subunit interacted with the E2F1 transcription factor. Treatment of gastric cancer cells with the SET-targeting drug OP449 increased PP2A activity, decreased E2F1 protein levels, and suppressed stemness of cancer cells. These data indicate that a SET/PP2A/E2F1 axis regulates cancer cell stemness and is a potential target for gastric cancer therapy.

Implications: This study highlights the oncogenic role of SET/I2PP2A in gastric cancer and suggests that SET maintains cancer cell stemness by suppressing PP2A activity and stabilizing E2F1. Mol Cancer Res; 16(3); 554–63. ©2018 AACR.
Data from Network Inference Analysis Identifies SETDB1 as a Key Regulator for Reverting Colorectal Cancer Cells into Differentiated Normal-Like Cells
Authors: Lee Soobeom , Lee Chansu , Hwang Chae Young , Kim Dongsan , Han Younghyun , Hong Sung Noh , Kim Seok-Hyung , Cho Kwang-Hyun
Published: April 2023

Abstract
Cancer cells exhibit properties of cells in a less differentiated state than the adjacent normal cells in the tissue. We explored whether cancer cells can be converted to a differentiated normal-like state by restoring the gene regulatory network (GRN) of normal cells. Here, we report that colorectal cancer cells exhibit a range of developmental states from embryonic and intestinal stem-like cells to differentiated normal-like cells. To identify the transcription factors (TF) that commit stem-like colorectal cancer cells into a differentiated normal-like state, we reconstructed GRNs of normal colon mucosa and identified core TFs (CDX2, ELF3, HNF4G, PPARG, and VDR) that govern the cellular state. We further found that SET Domain Bifurcated 1 (SETDB1), a histone H3 lysine 9–specific methyltransferase, hinders the function of the identified TFs. SETDB1 depletion effectively converts stem-like colorectal cancer cells into postmitotic cells and restores normal morphology in patient-derived colorectal cancer organoids. RNA-sequencing analyses revealed that SETDB1 depletion recapitulates global gene expression profiles of normal differentiated cells by restoring the transcriptional activity of core TFs on their target genes.
Implications:
Our study provides insights into the molecular regulatory mechanism underlying the developmental hierarchy of colorectal cancer and suggests that induction of a postmitotic state may be a therapeutic alternative to destruction of cancer cells.
Data from Paracrine Interaction of Cancer Stem Cell Populations Is Regulated by the Senescence-Associated Secretory Phenotype (SASP)
Authors: Lagunas Angelica M. , Francis Marybeth , Maniar Nisha B. , Nikolova Gergana , Wu Jianchun , Crowe David L.
Published: April 2023

Abstract
Dyskeratosis congenita is a telomere DNA damage syndrome characterized by defective telomere maintenance, bone marrow failure, and increased head and neck cancer risk. The Pot1b−/−;Terc+/− mouse exhibits some features of dyskeratosis congenita, but head and neck cancer was not reported in this model. To model the head and neck cancer phenotype, we created unique Pot1b- and p53-null–mutant models which allow genetic lineage tracing of two distinct stem cell populations. Loss of Pot1b expression depleted stem cells via ATR/Chk1/p53 signaling. Tumorigenesis was inhibited in Pot1b−/−;p53+/+ mice due to cellular senescence. Pot1b−/−;p53−/− tumors also exhibited senescence, but proliferated and metastasized with expansion of Lgr6+ stem cells indicative of senescence-associated secretory phenotype. Selective depletion of the small K15+ stem cell fraction resulted in reduction of Lgr6+ cells and inhibition of tumorigenesis via senescence. Gene expression studies revealed that K15+ cancer stem cells regulate Lgr6+ cancer stem cell expansion via chemokine signaling. Genetic ablation of the chemokine receptor Cxcr2 inhibited cancer stem cell expansion and tumorigenesis via senescence. The effects of chemokines were primarily mediated by PI3K signaling, which is a therapeutic target in head and neck cancer.
Implications:
Paracrine interactions of cancer stem cell populations impact therapeutic options and patient outcomes.
Data from Imprecision and DNA Break Repair Biased towards Incompatible End Joining in Leukemia
Authors: Gassner Franz Josef , Schubert Maria , Rebhandl Stefan , Spandl Karina , Zaborsky Nadja , Catakovic Kemal , Blaimer Stephanie , Hebenstreit Daniel , Greil Richard , Geisberger Roland
Published: April 2023

Abstract
Cancer is a genetic disease caused by mutations and chromosomal abnormalities that contribute to uncontrolled cell growth. In addition, cancer cells can rapidly respond to conventional and targeted therapies by accumulating novel and often specific genetic lesions leading to acquired drug resistance and relapsing disease. In chronic lymphocytic leukemia (CLL), however, diverse chromosomal aberrations often occur. In many cases, improper repair of DNA double-strand breaks (DSB) is a major source for genomic abnormalities. Therefore, this study examined the repair of DNA DSBs by nonhomologous end joining (NHEJ) in CLL by performing plasmid-based repair assays in primary CLL cells and normal B cells, isolated from patients, as well as TALEN/Cas9–induced chromosomal deletions in the CLL cell line Mec1. It is demonstrated that DNA repair is aberrant in CLL cells, featuring perturbed DNA break structure preference with efficient joining of noncohesive ends and more deletions at repair junctions. In addition, increased microhomology-mediated end joining (MMEJ) of DNA substrates was observed in CLL together with increased expression of MMEJ-specific repair factors. In summary, these data identify major differences in DNA repair efficiency between CLL cells and normal B cells isolated from patients.

Implications: This study suggests inherently aberrant DNA DSB repair in the acquisition of subclonal genomic structural variations important for clonal evolution and treatment resistance in CLL. Mol Cancer Res; 16(3); 428–38. ©2017 AACR.
Data from Cigarette Smoke Induces Metabolic Reprogramming of the Tumor Stroma in Head and Neck Squamous Cell Carcinoma
Authors: Domingo-Vidal Marina , Whitaker-Menezes Diana , Martos-Rus Cristina , Tassone Patrick , Snyder Christopher M. , Tuluc Madalina , Philp Nancy , Curry Joseph , Martinez-Outschoorn Ubaldo
Published: April 2023

Abstract
Head and neck squamous cell carcinoma (HNSCC) is comprised of metabolically linked distinct compartments. Cancer-associated fibroblasts (CAF) and nonproliferative carcinoma cells display a glycolytic metabolism, while proliferative carcinoma cells rely on mitochondrial oxidative metabolism fueled by the catabolites provided by the adjacent CAFs. Metabolic coupling between these reprogrammed compartments contributes to HNSCC aggressiveness. In this study, we examined the effects of cigarette smoke–exposed CAFs on metabolic coupling and tumor aggressiveness of HNSCC. Cigarette smoke (CS) extract was generated by dissolving cigarette smoke in growth media. Fibroblasts were cultured in CS or control media. HNSCC cells were cocultured in vitro and coinjected in vivo with CS or control fibroblasts. We found that CS induced oxidative stress, glycolytic flux and MCT4 expression, and senescence in fibroblasts. MCT4 upregulation was critical for fibroblast viability under CS conditions. The effects of CS on fibroblasts were abrogated by antioxidant treatment. Coculture of carcinoma cells with CS fibroblasts induced metabolic coupling with upregulation of the marker of glycolysis MCT4 in fibroblasts and markers of mitochondrial metabolism MCT1 and TOMM20 in carcinoma cells. CS fibroblasts increased CCL2 expression and macrophage migration. Coculture with CS fibroblasts also increased two features of carcinoma cell aggressiveness: resistance to cell death and enhanced cell migration. Coinjection of carcinoma cells with CS fibroblasts generated larger tumors with reduced apoptosis than control coinjections, and upregulation of MCT4 by CS exposure was a driver of these effects. We demonstrate that a tumor microenvironment exposed to CS is sufficient to modulate metabolism and cancer aggressiveness in HNSCC.
Implications:
CS shifts cancer stroma toward glycolysis and induces head and neck cancer aggressiveness with a mitochondrial profile linked by catabolite transporters and oxidative stress.
Visual Overview:
http://mcr.aacrjournals.org/content/molcanres/17/9/1893/F1.large.jpg.