bluuebunny/crossref_metadata_2025 huggingface dataset:
Data from TGFβ1 Protects Cells from γ-IR by Enhancing the Activity of the NHEJ Repair Pathway
Authors: Kim Mi-Ra , Lee Jeeyong , An You Sun , Jin Yeung Bae , Park In-Chul , Chung Eunkyung , Shin Incheol , Barcellos-Hoff Mary Helen , Yi Jae Youn
Published: March 2024

Abstract
Several groups have reported that TGFβ1 regulates cellular responses to γ-irradiation; however, the exact mechanism has not been fully elucidated. In the current study, the role of TGFβ1 in cellular responses to γ-irradiation was investigated in detail. The data indicate that TGFβ1 pretreatment decreased the aftermath of ionizing radiation (IR)-induced DNA damage in a SMAD-dependent manner. To determine the underlying mechanism for these effects, the extent of IR-induced DNA repair activity in the presence or absence of TGFβ1 was examined. Studies reveal that TGFβ1 upregulated DNA ligase IV (Lig4), augmented IR-induced nuclear retention of the DNA ligase, and enhanced nonhomologous end-joining (NHEJ) repair activity. In addition, knockdown of Lig4 reduced the TGFβ1-induced protection against IR. Overall, these data indicate that TGFβ1 facilitates the NHEJ repair process upon γ-irradiation and thereby enhances long-term survival.

Implications: These findings provide new insight and a possible approach to controlling genotoxic stress by the TGFβ signaling pathway. Mol Cancer Res; 13(2); 319–29. ©2014 AACR.
Data from Identification of Endogenous Adenomatous Polyposis Coli Interaction Partners and β-Catenin–Independent Targets by Proteomics
Authors: Popow Olesja , Paulo João A. , Tatham Michael H. , Volk Melanie S. , Rojas-Fernandez Alejandro , Loyer Nicolas , Newton Ian P. , Januschke Jens , Haigis Kevin M. , Näthke Inke
Published: March 2024

Abstract
Adenomatous Polyposis Coli (APC) is the most frequently mutated gene in colorectal cancer. APC negatively regulates the Wnt signaling pathway by promoting the degradation of β-catenin, but the extent to which APC exerts Wnt/β-catenin–independent tumor-suppressive activity is unclear. To identify interaction partners and β-catenin–independent targets of endogenous, full-length APC, we applied label-free and multiplexed tandem mass tag-based mass spectrometry. Affinity enrichment-mass spectrometry identified more than 150 previously unidentified APC interaction partners. Moreover, our global proteomic analysis revealed that roughly half of the protein expression changes that occur in response to APC loss are independent of β-catenin. Combining these two analyses, we identified Misshapen-like kinase 1 (MINK1) as a putative substrate of an APC-containing destruction complex. We validated the interaction between endogenous MINK1 and APC and further confirmed the negative, and β-catenin–independent, regulation of MINK1 by APC. Increased Mink1/Msn levels were also observed in mouse intestinal tissue and Drosophila follicular cells expressing mutant Apc/APC when compared with wild-type tissue/cells. Collectively, our results highlight the extent and importance of Wnt-independent APC functions in epithelial biology and disease.
Implications:
The tumor-suppressive function of APC, the most frequently mutated gene in colorectal cancer, is mainly attributed to its role in β-catenin/Wnt signaling. Our study substantially expands the list of APC interaction partners and reveals that approximately half of the changes in the cellular proteome induced by loss of APC function are mediated by β-catenin–independent mechanisms.
Data from O-GlcNAc Transferase Regulates Cancer Stem–like Potential of Breast Cancer Cells
Authors: Akella Neha M. , Le Minh Giang , Ciraku Lorela , Mukherjee Ayonika , Bacigalupa Zachary A. , Mukhopadhyay Dimpi , Sodi Valerie L. , Reginato Mauricio J.
Published: March 2024

Abstract
Breast tumors are heterogeneous and composed of different subpopulation of cells, each with dynamic roles that can change with stage, site, and microenvironment. Cellular heterogeneity is, in part, due to cancer stem–like cells (CSC) that share properties with stem cells and are associated with treatment resistance. CSCs rewire metabolism to meet energy demands of increased growth and biosynthesis. O-GlcNAc transferase enzyme (OGT) uses UDP-GlcNAc as a substrate for adding O-GlcNAc moieties to nuclear and cytoplasmic proteins. OGT/O-GlcNAc levels are elevated in multiple cancers and reducing OGT in cancer cells blocks tumor growth. Here, we report that breast CSCs enriched in mammosphere cultures contain elevated OGT/O-GlcNAcylation. Inhibition of OGT genetically or pharmacologically reduced mammosphere forming efficiency, the CD44H/CD24L, NANOG+, and ALDH+ CSC population in breast cancer cells. Conversely, breast cancer cells overexpressing OGT increased mammosphere formation, CSC populations in vitro, and also increased tumor initiation and CSC frequency in vivo. Furthermore, OGT regulates expression of a number of epithelial-to-mesenchymal transition and CSC markers including CD44, NANOG, and c-Myc. In addition, we identify Krüppel-like factor 8 (KLF8) as a novel regulator of breast cancer mammosphere formation and a critical target of OGT in regulating CSCs.
Implications:
These findings demonstrate that OGT plays a key role in the regulation of breast CSCs in vitro and tumor initiation in vivo, in part, via regulation of KLF8, and thus inhibition of OGT may serve as a therapeutic strategy to regulate tumor-initiating activity.
Data from Molecular Response to Neoadjuvant Chemotherapy in High-Grade Serous Ovarian Carcinoma
Authors: Arend Rebecca C. , Londoño Angelina I. , Montgomery Allison M. , Smith Haller J. , Dobbin Zachary C. , Katre Ashwini A. , Martinez Alba , Yang Eddy S. , Alvarez Ronald D. , Huh Warner K. , Bevis Kerri S. , Straughn J. Michael , Estes Jacob M. , Novak Lea , Crossman David K. , Cooper Sara J. , Landen Charles N. , Leath Charles A.
Published: March 2024

Abstract
While high-grade serous ovarian carcinoma (HGSOC) is the most common histologic subtype of ovarian cancer, significant tumor heterogeneity exists. In addition, chemotherapy induces changes in gene expression and alters the mutational profile. To evaluate the notion that patients with HGSOC could be better classified for optimal treatment based on gene expression, we compared genetic variants [by DNA next-generation sequencing (NGS) using a 50 gene Ion Torrent panel] and gene expression (using the NanoString PanCancer 770 gene Panel) in the tumor from 20 patients with HGSOC before and after neoadjuvant chemotherapy (NACT). NGS was performed on plasma cell free DNA (cfDNA) on a select group of patients (n = 14) to assess the utility of using cfDNA to monitor these changes. A total of 86 genes had significant changes in RNA expression after NACT. Thirty-eight genetic variants (including SNPs) from 6 genes were identified in tumors pre-NACT, while 59 variants from 19 genes were detected in the cfDNA. The number of DNA variants were similar after NACT. Of the 59 variants in the plasma pre-NACT, only 6 persisted, whereas 33 of 38 specific variants in the tumor DNA remained unchanged. Pathway analysis showed the most significant alterations in the cell cycle and DNA damage pathways.

Implications: Gene expression profiles at the time of interval debulking provide additional genetic information that could help impact treatment decisions after NACT; although, continued collection and analysis of matched tumor and cfDNA from multiple time points are needed to determine the role of cfDNA in the management of HGSOC. Mol Cancer Res; 16(5); 813–24. ©2018 AACR.
Data from T-Cell Deletion of MyD88 Connects IL17 and IκBζ to RAS Oncogenesis
Authors: Cataisson Christophe , Salcedo Rosalba , Michalowski Aleksandra M. , Klosterman Mary , Naik Shruti , Li Luowei , Pan Michelle J. , Sweet Amalia , Chen Jin-Qiu , Kostecka Laurie G. , Karwan Megan , Smith Loretta , Dai Ren-Ming , Stewart C. Andrew , Lyakh Lyudmila , Hsieh Wang-Ting , Khan Asra , Yang Howard , Lee Maxwell , Trinchieri Giorgio , Yuspa Stuart H.
Published: March 2024

Abstract
Cancer development requires a favorable tissue microenvironment. By deleting Myd88 in keratinocytes or specific bone marrow subpopulations in oncogenic RAS-mediated skin carcinogenesis, we show that IL17 from infiltrating T cells and IκBζ signaling in keratinocytes are essential to produce a permissive microenvironment and tumor formation. Both normal and RAS-transformed keratinocytes respond to tumor promoters by activating canonical NF-κB and IκBζ signaling, releasing specific cytokines and chemokines that attract Th17 cells through MyD88-dependent signaling in T cells. The release of IL17 into the microenvironment elevates IκBζ in normal and RAS-transformed keratinocytes. Activation of IκBζ signaling is required for the expression of specific promoting factors induced by IL17 in normal keratinocytes and constitutively expressed in RAS-initiated keratinocytes. Deletion of Nfkbiz in keratinocytes impairs RAS-mediated benign tumor formation. Transcriptional profiling and gene set enrichment analysis of IκBζ−deficient RAS-initiated keratinocytes indicate that IκBζ signaling is common for RAS transformation of multiple epithelial cancers. Probing The Cancer Genome Atlas datasets using this transcriptional profile indicates that reduction of IκBζ signaling during cancer progression associates with poor prognosis in RAS-driven human cancers.
Implications:
The paradox that elevation of IκBζ and stimulation of IκBζ signaling through tumor extrinsic factors is required for RAS-mediated benign tumor formation while relative IκBζ expression is reduced in advanced cancers with poor prognosis implies that tumor cells switch from microenvironmental dependency early in carcinogenesis to cell-autonomous pathways during cancer progression.
Data from Role of Rac1 Pathway in Epithelial-to-Mesenchymal Transition and Cancer Stem-like Cell Phenotypes in Gastric Adenocarcinoma
Authors: Yoon Changhwan , Cho Soo-Jeong , Chang Kevin K. , Park Do Joong , Ryeom Sandra W. , Yoon Sam S.
Published: March 2024

Abstract
Rac1, a Rho GTPase family member, is dysregulated in a variety of tumor types including gastric adenocarcinoma, but little is known about its role in cancer stem-like cells (CSCs). Therefore, Rac1 activity and inhibition were examined in gastric adenocarcinoma cells and mouse xenograft models for epithelial-to-mesenchymal transition (EMT) and CSC phenotypes. Rac1 activity was significantly higher in spheroid-forming or CD44+ gastric adenocarcinoma CSCs compared with unselected cells. Rac1 inhibition using Rac1 shRNA or a Rac1 inhibitor (NSC23766) decreased expression of the self-renewal transcription factor, Sox-2, decreased spheroid formation by 78%–81%, and prevented tumor initiation in immunodeficient mice. Gastric adenocarcinoma CSCs had increased expression of the EMT transcription factor Slug, 4.4- to 8.3-fold greater migration, and 4.2- to 12.6-fold greater invasion than unselected cells, and these increases could be blocked completely with Rac1 inhibition. Gastric adenocarcinoma spheroid cells were resistant to 5-fluorouracil and cisplatin chemotherapy, and this chemotherapy resistance could be reversed with Rac1 shRNA or NSC23766. The PI3K/Akt pathway may be upstream of Rac1, and JNK may be downstream of Rac1. In the MKN-45 xenograft model, cisplatin inhibited tumor growth by 50%, Rac1 inhibition by 35%, and the combination by 77%. Higher Rac1 activity, in clinical specimens from gastric adenocarcinoma patients who underwent potentially curative surgery, correlated with significantly worse survival (P = 0.017). In conclusion, Rac1 promotes the EMT program in gastric adenocarcinoma and the acquisition of a CSC state. Rac1 inhibition in gastric adenocarcinoma cells blocks EMT and CSC phenotypes, and thus may prevent metastasis and augment chemotherapy.

Implications: In gastric adenocarcinoma, therapeutic targeting of the Rac1 pathway may prevent or reverse EMT and CSC phenotypes that drive tumor progression, metastasis, and chemotherapy resistance. Mol Cancer Res; 15(8); 1106–16. ©2017 AACR.
Data from Targeted Next-Generation Sequencing for Detecting MLL Gene Fusions in Leukemia
Authors: Afrin Sadia , Zhang Christine R.C. , Meyer Claus , Stinson Caedyn L. , Pham Thy , Bruxner Timothy J.C. , Venn Nicola C. , Trahair Toby N. , Sutton Rosemary , Marschalek Rolf , Fink J. Lynn , Moore Andrew S.
Published: March 2024

Abstract
Mixed lineage leukemia (MLL) gene rearrangements characterize approximately 70% of infant and 10% of adult and therapy-related leukemia. Conventional clinical diagnostics, including cytogenetics and fluorescence in situ hybridization (FISH) fail to detect MLL translocation partner genes (TPG) in many patients. Long-distance inverse (LDI)-PCR, the “gold standard” technique that is used to characterize MLL breakpoints, is laborious and requires a large input of genomic DNA (gDNA). To overcome the limitations of current techniques, a targeted next-generation sequencing (NGS) approach that requires low RNA input was tested. Anchored multiplex PCR-based enrichment (AMP-E) was used to rapidly identify a broad range of MLL fusions in patient specimens. Libraries generated using Archer FusionPlex Heme and Myeloid panels were sequenced using the Illumina platform. Diagnostic specimens (n = 39) from pediatric leukemia patients were tested with AMP-E and validated by LDI-PCR. In concordance with LDI-PCR, the AMP-E method successfully identified TPGs without prior knowledge. AMP-E identified 10 different MLL fusions in the 39 samples. Only two specimens were discordant; AMP-E successfully identified a MLL-MLLT1 fusion where LDI-PCR had failed to determine the breakpoint, whereas a MLL-MLLT3 fusion was not detected by AMP-E due to low expression of the fusion transcript. Sensitivity assays demonstrated that AMP-E can detect MLL-AFF1 in MV4-11 cell dilutions of 10−7 and transcripts down to 0.005 copies/ng.

Implications: This study demonstrates a NGS methodology with improved sensitivity compared with current diagnostic methods for MLL-rearranged leukemia. Furthermore, this assay rapidly and reliably identifies MLL partner genes and patient-specific fusion sequences that could be used for monitoring minimal residual disease. Mol Cancer Res; 16(2); 279–85. ©2017 AACR.
Data from Modulation of Mutant KrasG12D-Driven Lung Tumorigenesis In Vivo by Gain or Loss of PCDH7 Function
Authors: Zhou Xiaorong , Padanad Mahesh S. , Evers Bret M. , Smith Bethany , Novaresi Nicole , Suresh Shruthy , Richardson James A. , Stein Emily , Zhu Jingfei , Hammer Robert E. , O'Donnell Kathryn A.
Published: March 2024

Abstract
PROTOCADHERIN 7 (PCDH7), a transmembrane receptor and member of the Cadherin superfamily, is frequently overexpressed in lung adenocarcinoma and is associated with poor clinical outcome. Although PCDH7 was recently shown to promote transformation and facilitate brain metastasis in lung and breast cancers, decreased PCDH7 expression has also been documented in colorectal, gastric, and invasive bladder cancers. These data suggest context-dependent functions for PCDH7 in distinct tumor types. Given that PCDH7 is a potentially targetable molecule on the surface of cancer cells, further investigation of its role in tumorigenesis in vivo is needed to evaluate the therapeutic potential of its inhibition. Here, we report the analysis of novel PCDH7 gain- and loss-of-function mouse models and provide compelling evidence that this cell-surface protein acts as a potent lung cancer driver. Employing a Cre-inducible transgenic allele, we demonstrated that enforced PCDH7 expression significantly accelerates KrasG12D-driven lung tumorigenesis and potentiates MAPK pathway activation. Furthermore, we performed in vivo somatic genome editing with CRISPR/Cas9 in KrasLSL-G12D; Tp53fl/fl (KP) mice to assess the consequences of PCDH7 loss of function. Inactivation of PCDH7 in KP mice significantly reduced lung tumor development, prolonged survival, and diminished phospho-activation of ERK1/2. Together, these findings establish a critical oncogenic function for PCDH7 in vivo and highlight the therapeutic potential of PCDH7 inhibition for lung cancer. Moreover, given recent reports of elevated or reduced PCDH7 in distinct tumor types, the new inducible transgenic model described here provides a robust experimental system for broadly elucidating the effects of PCDH7 overexpression in vivo.
Implications:
In this study, we establish a critical oncogenic function for PCDH7 in vivo using novel mouse models and CRISPR/Cas9 genome editing, and we validate the therapeutic potential of PCDH7 inhibition for lung cancer.
Data from Intron 1–Mediated Regulation of EGFR Expression in EGFR-Dependent Malignancies Is Mediated by AP-1 and BET Proteins
Authors: Jameson Nathan M. , Ma Jianhui , Benitez Jorge , Izurieta Alejandro , Han Jee Yun , Mendez Robert , Parisian Alison , Furnari Frank
Published: March 2024

Abstract
The epidermal growth factor receptor (EGFR) is overexpressed in numerous solid tumors and is the subject of extensive therapeutic efforts. Much of the research on EGFR is focused on protein dynamics and downstream signaling; however, few studies have explored its transcriptional regulation. Here, we identified two enhancers (CE1 and CE2) present within the first intron of the EGFR gene in models of glioblastoma (GBM) and head and neck squamous cell carcinoma (HNSCC). CE1 and CE2 contain open chromatin and H3K27Ac histone marks, enhance transcription in reporter assays, and interact with the EGFR promoter. Enhancer genetic deletion by CRISPR/Cas9 significantly reduces EGFR transcript levels, with double deletion exercising an additive effect. Targeted repression of CE1 and CE2 by dCas9-KRAB demonstrates repression of transcription similar to that of genomic deletion. We identify AP-1 transcription factor family members in concert with BET bromodomain proteins as modulators of CE1 and CE2 activity in HNSCC and GBM through de novo motif identification and validate their presence. Genetic inhibition of AP-1 or pharmacologic disruption of BET/AP-1 binding results in downregulated EGFR protein and transcript levels, confirming a role for these factors in CE1 and CE2. Our results identify and characterize these novel enhancers, shedding light on the role that epigenetic mechanisms play in regulating EGFR transcription in EGFR-dependent cancers.
Implications:
We identify critical constituent enhancers present in the first intron of the EGFR gene, and provide a rationale for therapeutic targeting of EGFR intron 1 enhancers through perturbation of AP-1 and BET in EGFR-positive malignancies.
Data from The Role of Alcohol-Induced Golgi Fragmentation for Androgen Receptor Signaling in Prostate Cancer
Authors: Manca Sonia , Frisbie Cole P. , LaGrange Chad A. , Casey Carol A. , Riethoven Jean-Jack M. , Petrosyan Armen
Published: March 2024

Abstract
Multiple epidemiologic observations and meta-analysis clearly indicate the link between alcohol abuse and the incidence and progression of prostate cancer; however, the mechanism remains enigmatic. Recently, it was found that ethanol (EtOH) induces disorganization of the Golgi complex caused by impaired function of the largest Golgi matrix protein, giantin (GOLGB1), which, in turn, alters the Golgi docking of resident Golgi proteins. Here, it is determined that in normal prostate cells, histone deacetylase 6 (HDAC6), the known regulator of androgen receptor (AR) signaling, localizes in the cytoplasm and nucleus, while its kinase, glycogen synthase kinase β (GSK3β), primarily resides in the Golgi. Progression of prostate cancer is accompanied by Golgi scattering, translocation of GSK3β from the Golgi to the cytoplasm, and the cytoplasmic shift in HDAC6 localization. Alcohol dehydrogenase–generated metabolites induces Golgi disorganization in androgen-responsive LNCaP and 22Rv1 cells, facilitates tumor growth in a mouse xenograft model and activates anchorage-independent proliferation, migration, and cell adhesion. EtOH-treated cells demonstrate reduced giantin and subsequent cytoplasmic GSK3β; this phenomenon was validated in giantin-depleted cells. Redistribution of GSK3β to the cytoplasm results in phosphorylation of HDAC6 and its retention in the cytoplasm, which, in turn, stimulates deacetylation of HSP90, AR import into the nucleus, and secretion of prostate-specific antigen (PSA). Finally, the relationship between Golgi morphology, HDAC6 cytoplasmic content, and clinicopathologic features was assessed in human prostate cancer patient specimens with and without a history of alcohol dependence.
Implications:
This study demonstrates the importance of alcohol-induced Golgi fragmentation in the activation of AR-mediated proliferation.
Data from A Unique Morphological Phenotype in Chemoresistant Triple-Negative Breast Cancer Reveals Metabolic Reprogramming and PLIN4 Expression as a Molecular Vulnerability
Authors: Sirois Isabelle , Aguilar-Mahecha Adriana , Lafleur Josiane , Fowler Emma , Vu Viet , Scriver Michelle , Buchanan Marguerite , Chabot Catherine , Ramanathan Aparna , Balachandran Banujan , Légaré Stéphanie , Przybytkowski Ewa , Lan Cathy , Krzemien Urszula , Cavallone Luca , Aleynikova Olga , Ferrario Cristiano , Guilbert Marie-Christine , Benlimame Naciba , Saad Amine , Alaoui-Jamali Moulay , Saragovi Horace Uri , Josephy Sylvia , O'Flanagan Ciara , Hursting Stephen D. , Richard Vincent R. , Zahedi René P. , Borchers Christoph H. , Bareke Eric , Nabavi Sheida , Tonellato Peter , Roy Josée-Anne , Robidoux André , Marcus Elizabeth A. , Mihalcioiu Catalin , Majewski Jacek , Basik Mark
Published: March 2024

Abstract
The major obstacle in successfully treating triple-negative breast cancer (TNBC) is resistance to cytotoxic chemotherapy, the mainstay of treatment in this disease. Previous preclinical models of chemoresistance in TNBC have suffered from a lack of clinical relevance. Using a single high dose chemotherapy treatment, we developed a novel MDA-MB-436 cell-based model of chemoresistance characterized by a unique and complex morphologic phenotype, which consists of polyploid giant cancer cells giving rise to neuron-like mononuclear daughter cells filled with smaller but functional mitochondria and numerous lipid droplets. This resistant phenotype is associated with metabolic reprogramming with a shift to a greater dependence on fatty acids and oxidative phosphorylation. We validated both the molecular and histologic features of this model in a clinical cohort of primary chemoresistant TNBCs and identified several metabolic vulnerabilities including a dependence on PLIN4, a perilipin coating the observed lipid droplets, expressed both in the TNBC-resistant cells and clinical chemoresistant tumors treated with neoadjuvant doxorubicin-based chemotherapy. These findings thus reveal a novel mechanism of chemotherapy resistance that has therapeutic implications in the treatment of drug-resistant cancer.
Implications:
These findings underlie the importance of a novel morphologic–metabolic phenotype associated with chemotherapy resistance in TNBC, and bring to light novel therapeutic targets resulting from vulnerabilities in this phenotype, including the expression of PLIN4 essential for stabilizing lipid droplets in resistant cells.
Data from Aurora Kinase A Promotes AR Degradation via the E3 Ligase CHIP
Authors: Sarkar Sukumar , Brautigan David L. , Larner James M.
Published: March 2024

Abstract
Reducing the levels of the androgen receptor (AR) is one of the most viable approaches to combat castration-resistant prostate cancer. Previously, we observed that proteasomal-dependent degradation of AR in response to 2-methoxyestradiol (2-ME) depends primarily on the E3 ligase C-terminus of HSP70-interacting protein (STUB1/CHIP). Here, 2-ME stimulation activates CHIP by phosphorylation via Aurora kinase A (AURKA). Aurora A kinase inhibitors and RNAi knockdown of Aurora A transcript selectively blocked CHIP phosphorylation and AR degradation. Aurora A kinase is activated by 2-ME in the S-phase as well as during mitosis, and phosphorylates CHIP at S273. Prostate cancer cells expressing an S273A mutant of CHIP have attenuated AR degradation upon 2-ME treatment compared with cells expressing wild-type CHIP, supporting the idea that CHIP phosphorylation by Aurora A activates its E3 ligase activity for the AR. These results reveal a novel 2-ME→Aurora A→CHIP→AR pathway that promotes AR degradation via the proteasome that may offer novel therapeutic opportunities for prostate cancer. Mol Cancer Res; 15(8); 1063–72. ©2017 AACR.
Data from Interferon-Stimulated Genes Are Transcriptionally Repressed by PR in Breast Cancer
Authors: Walter Katherine R. , Goodman Merit L. , Singhal Hari , Hall Jade A. , Li Tianbao , Holloran Sean M. , Trinca Gloria M. , Gibson Katelin A. , Jin Victor X. , Greene Geoffrey L. , Hagan Christy R.
Published: March 2024

Abstract
The progesterone receptor (PR) regulates transcriptional programs that drive proliferation, survival, and stem cell phenotypes. Although the role of native progesterone in the development of breast cancer remains controversial, PR clearly alters the transcriptome in breast tumors. This study identifies a class of genes, Interferon (IFN)-stimulated genes (ISGs), potently downregulated by ligand-activated PR which have not been previously shown to be regulated by PR. Progestin-dependent transcriptional repression of ISGs was observed in breast cancer cell line models and human breast tumors. Ligand-independent regulation of ISGs was also observed, as basal transcript levels were markedly higher in cells with PR knockdown. PR repressed ISG transcription in response to IFN treatment, the canonical mechanism through which these genes are activated. Liganded PR is robustly recruited to enhancer regions of ISGs, and ISG transcriptional repression is dependent upon PR's ability to bind DNA. In response to PR activation, key regulatory transcription factors that are required for IFN-activated ISG transcription, STAT2 and IRF9, exhibit impaired recruitment to ISG promoter regions, correlating with PR/ligand-dependent ISG transcriptional repression. IFN activation is a critical early step in nascent tumor recognition and destruction through immunosurveillance. As the large majority of breast tumors are PR positive at the time of diagnosis, PR-dependent downregulation of IFN signaling may be a mechanism through which early PR-positive breast tumors evade the immune system and develop into clinically relevant tumors.

Implications: This study highlights a novel transcriptional mechanism through which PR drives breast cancer development and potentially evades the immune system. Mol Cancer Res; 15(10); 1331–40. ©2017 AACR.
Data from Establishment and Genetic Landscape of Precancer Cell Model Systems from the Head and Neck Mucosal Lining
Authors: de Boer D. Vicky , Brink Arjen , Buijze Marijke , Stigter-van Walsum Marijke , Hunter Keith D. , Ylstra Bauke , Bloemena Elisabeth , Leemans C. René , Brakenhoff Ruud H.
Published: March 2024

Abstract
Head and neck squamous cell carcinomas (HNSCC) develop in fields of genetically altered cells. These fields are often dysplastic and a subset can be recognized as (erythro)leukoplakia, but most are macroscopically invisible. There is a lack of adequate treatment options to eradicate these fields, whereas they underlie the development of primary tumors as well as part of the local relapses. Unfortunately, there are almost no representative cellular models available to identify suitable treatment options. To this end, clinical biopsy specimens (n = 98) were cultured from normal appearing mucosa of the surgical margins of patients with primary HNSCCs (n = 32) to generate precancer cell culture models. This collection was extended with six previously established precancer cell cultures. Genetic analysis was performed on cultures with an extended life span (≥20 population doublings), the previously established cultures, and some randomly selected cultures. In total, cancer-associated changes were detected in 18 out of 34 (53%) cultures analyzed, which appeared to be independent of life span. A variety of genetic changes were identified, including somatic mutations as well as chromosomal copy-number aberrations (CNA). Loss of CDKN2A/p16Ink4A and mutations in TP53/p53 were most prominent. Remarkably, in some of these precancer cell cultures only chromosomal CNAs were detected, and none of the frequently occurring driver mutations.
Implications:
The precancer cell cultures, characterized herein, form a representative collection of field models that can be exploited to identify and validate new therapeutic strategies to prevent primary HNSCCs and local relapses.
Data from UNC-45A Is a Novel Microtubule-Associated Protein and Regulator of Paclitaxel Sensitivity in Ovarian Cancer Cells
Authors: Mooneyham Ashley , Iizuka Yoshie , Yang Qing , Coombes Courtney , McClellan Mark , Shridhar Vijayalakshmi , Emmings Edith , Shetty Mihir , Chen Liqiang , Ai Teng , Meints Joyce , Lee Michael K. , Gardner Melissa , Bazzaro Martina
Published: March 2024

Abstract
UNC-45A, a highly conserved member of the UCS (UNC45A/CRO1/SHE4P) protein family of cochaperones, plays an important role in regulating cytoskeletal-associated functions in invertebrates and mammalian cells, including cytokinesis, exocytosis, cell motility, and neuronal development. Here, for the first time, UNC-45A is demonstrated to function as a mitotic spindle-associated protein that destabilizes microtubules (MT) activity. Using in vitro biophysical reconstitution and total internal reflection fluorescence microscopy analysis, we reveal that UNC-45A directly binds to taxol-stabilized MTs in the absence of any additional cellular cofactors or other MT-associated proteins and acts as an ATP-independent MT destabilizer. In cells, UNC-45A binds to and destabilizes mitotic spindles, and its depletion causes severe defects in chromosome congression and segregation. UNC-45A is overexpressed in human clinical specimens from chemoresistant ovarian cancer and that UNC-45A–overexpressing cells resist chromosome missegregation and aneuploidy when treated with clinically relevant concentrations of paclitaxel. Lastly, UNC-45A depletion exacerbates paclitaxel-mediated stabilizing effects on mitotic spindles and restores sensitivity to paclitaxel.
Implications:
These findings reveal novel and significant roles for UNC-45A in regulation of cytoskeletal dynamics, broadening our understanding of the basic mechanisms regulating MT stability and human cancer susceptibility to paclitaxel, one of the most widely used chemotherapy agents for the treatment of human cancers.
Data from The Tissue-Reconstructing Ability of Colon CSCs Is Enhanced by FK506 and Suppressed by GSK3 Inhibition
Authors: Ishida Ryo , Koyanagi-Aoi Michiyo , Oshima Nobu , Kakeji Yoshihiro , Aoi Takashi
Published: March 2024

Abstract
Cancer stem cells (CSC) are capable of reconstructing cancer tissues, are involved in both recurrence and metastasis, and contribute to therapeutic resistance. Therefore, elucidating the molecular mechanism in CSCs is important to successfully treat unresectable cancers. Previously, we observed that colon cancer stem-like cells can be induced from human colon cancer cell lines by retrovirally introducing OCT3/4, SOX2, and KLF4, and we have designated such cells as induced cancer stem cells (iCSC). In the current study, we used iCSCs to evaluate the molecular mechanism of colon CSCs and developed new methods to control them. The spheres that were derived in vitro from the iCSCs, but not those from parental cells, mimicked human colon cancer tissues in terms of their immunohistologic patterns; therefore, sphere-forming ability was assessed as a measure of the tissue-reconstructing ability of iCSCs. Interestingly, the calcineurin inhibitor FK506 enhanced the sphere-forming ability of iCSCs, whereas GSK3 inhibition by RNAi, CHIR99021, and valproic acid (VPA) impeded the sphere-forming ability and expansion of iCSCs. FK506 and GSK3 inhibition showed the opposite effect regarding the NFATc3 localization of iCSCs. These data reveal the crucial role that NFAT localization, as regulated by calcineurin and GSK3, plays in the tissue-reconstructing ability of colon cancer stem cells and the potential of GSK3 inhibitors, such as VPA, in colon cancer stem cell–targeting therapy.

Implications: This study identifies signaling pathways that contribute to the tissue-reconstructing capacity of colon CSCs and suggests that clinically used drugs could be repurposed to improve unresectable colon cancers. Mol Cancer Res; 15(10); 1455–66. ©2017 AACR.
Data from Mitogen-Activated Protein Kinase Kinase 4/c-Jun NH2-Terminal Kinase Kinase 1 Protein Expression Is Subject to Translational Regulation in Prostate Cancer Cell Lines
Authors: Robinson Victoria L. , Shalhav Ore , Otto Kristen , Kawai Tomoko , Gorospe Myriam , Rinker-Schaeffer Carrie W.
Published: March 2024

Abstract
Mitogen-activated protein kinase kinase 4/c-Jun NH2-terminal kinase kinase 1 (MKK4/JNKK1; hereafter referred to as MKK4) is a dual-specificity kinase with a critical role in regulating the activity of c-Jun NH2-terminal kinase and p38 kinases. We identified a novel biological function for MKK4 in the regulation of growth of ovarian and prostate cancer metastases. Clinical correlative studies showed that MKK4 protein levels were reduced in high-grade prostate cancer and prostate and ovarian cancer metastases compared with normal tissue, which prompted investigation into the mechanism(s) responsible for down-regulation of MKK4 in a panel of cancer cell lines. Initial studies found that low levels of MKK4 protein did not correlate with either exon deletion or decreased levels of MKK4 mRNA, suggesting that MKK4 protein levels were regulated posttranscriptionally by either reduced translation or reduced protein stability. Endogenous MKK4 was highly stable and not subject to altered proteolysis. Instead, MKK4 biosynthesis seemed to be regulated by altered translation. In support of this assertion, we found that cytosolic MKK4 mRNA was shifted toward active polysomes in cells with higher levels of MKK4 protein, suggesting that MKK4 mRNA was translated more efficiently in these cells. This study supports a novel mechanism for the regulation of MKK4 protein levels. Further, these findings have potential therapeutic implications for modulating the expression of a signaling kinase involved in the regulation of metastatic growth. (Mol Cancer Res 2008;6(3):501–8)
Data from Notch Signaling Modulates Hypoxia-Induced Neuroendocrine Differentiation of Human Prostate Cancer Cells
Authors: Danza Giovanna , Di Serio Claudia , Rosati Fabiana , Lonetto Giuseppe , Sturli Niccolò , Kacer Doreen , Pennella Antonio , Ventimiglia Giuseppina , Barucci Riccardo , Piscazzi Annamaria , Prudovsky Igor , Landriscina Matteo , Marchionni Niccolò , Tarantini Francesca
Published: March 2024

Abstract
Prostate carcinoma is among the most common causes of cancer-related death in men, representing 15% of all male malignancies in developed countries. Neuroendocrine differentiation (NED) has been associated with tumor progression, poor prognosis, and with the androgen-independent status. Currently, no successful therapy exists for advanced, castration-resistant disease. Because hypoxia has been linked to prostate cancer progression and unfavorable outcome, we sought to determine whether hypoxia would impact the degree of neuroendocrine differentiation of prostate cancer cells in vitro.

Results: Exposure of LNCaP cells to low oxygen tension induced a neuroendocrine phenotype, associated with an increased expression of the transcription factor neurogenin3 and neuroendocrine markers, such as neuron-specific enolase, chromogranin A, and β3-tubulin. Moreover, hypoxia triggered a significant decrease of Notch 1 and Notch 2 mRNA and protein expression, with subsequent downregulation of Notch-mediated signaling, as shown by reduced levels of the Notch target genes, Hes1 and Hey1. NED was promoted by attenuation of Hes1 transcription, as cells expressing a dominant-negative form of Hes1 displayed increased levels of neuroendocrine markers under normoxic conditions. Although hypoxia downregulated Notch 1 and Notch 2 mRNA transcription and receptor activation also in the androgen-independent cell lines, PC-3 and Du145, it did not change the extent of NED in these cultures, suggesting that androgen sensitivity may be required for transdifferentiation to occur.

Conclusions: Hypoxia induces NED of LNCaP cells in vitro, which seems to be driven by the inhibition of Notch signaling with subsequent downregulation of Hes1 transcription. Mol Cancer Res; 10(2); 230–8. ©2011 AACR.
Data from Geldanamycin-Induced Down-Regulation of ErbB2 from the Plasma Membrane Is Clathrin Dependent but Proteasomal Activity Independent
Authors: Pedersen Nina Marie , Madshus Inger Helene , Haslekås Camilla , Stang Espen
Published: March 2024

Abstract
ErbB2, a member of the epidermal growth factor receptor family, is overexpressed in a number of human cancers. In contrast to the epidermal growth factor receptor, ErbB2 is normally endocytosis resistant. However, ErbB2 can be down-regulated by inhibitors of heat shock protein 90, such as geldanamycin. We now show that geldanamycin induces endocytosis and lysosomal degradation of full-length ErbB2. We further report that the endocytosis of ErbB2 is dynamin and clathrin dependent. When ErbB2 was retained at the plasma membrane due to knockdown of clathrin heavy chain, the intracellular part of ErbB2 was degraded in a proteasomal manner. However, our data strongly suggest that proteasomal activity is not required for geldanamycin-induced endocytosis of ErbB2 in SKBr3 cells. Interestingly, however, proteasomal inhibitors retarded degradation of ErbB2, and electron microscopy analysis strongly suggested that proteasomal activity is required to sort internalized ErbB2 to lysosomes. Because geldanamycin derivatives and inhibitors of proteasomal activity are both used in experimental cancer treatment, knowledge of molecular mechanisms involved in geldanamycin-induced down-regulation of ErbB2 is important for future design of cancer treatment. (Mol Cancer Res 2008;6(3):491–500)
Data from Cancer-Associated Fibroblasts Induce Matrix Metalloproteinase–Mediated Cetuximab Resistance in Head and Neck Squamous Cell Carcinoma Cells
Authors: Johansson Ann-Charlotte , Ansell Anna , Jerhammar Fredrik , Lindh Maja Bradic , Grénman Reidar , Munck-Wikland Eva , Östman Arne , Roberg Karin
Published: March 2024

Abstract
A growing body of evidence suggests that components of the tumor microenvironment, including cancer-associated fibroblasts (CAF), may modulate the treatment sensitivity of tumor cells. Here, we investigated the possible influence of CAFs on the sensitivity of head and neck squamous cell carcinoma (HNSCC) cell lines to cetuximab, an antagonistic epidermal growth factor receptor (EGFR) antibody. Cetuximab treatment caused a reduction in the proliferation rate of HNSCC cell lines, whereas the growth of HNSCC-derived CAF cultures was unaffected. When tumor cells were cocultured with CAFs in a transwell system, the cetuximab-induced growth inhibition was reduced, and a complete protection from growth inhibition was observed in one of the tumor cell lines investigated. Media that had been conditioned by CAFs offered protection from cetuximab treatment in a concentration-dependent manner, suggesting that the resistance to treatment was mediated by CAF-derived soluble factors. The coculture of HNSCC cell lines with CAFs resulted in an elevated expression of matrix metalloproteinase-1 (MMP-1) in both the tumor cells and CAFs. Moreover, the CAF-induced resistance was partly abolished by the presence of an MMP inhibitor. However, CAFs treated with siRNA targeting MMP-1 still protected tumor cells from cetuximab treatment, suggesting that several MMPs may cooperate to facilitate resistance or that the protective effect is mediated by another member of the MMP family. These results identify a novel CAF-dependent modulation of cetuximab sensitivity and suggest that inhibiting MMPs may improve the effects of EGFR-targeted therapy. Mol Cancer Res; 10(9); 1158–68. ©2012 AACR.
Data from Monochromosome Transfer and Microarray Analysis Identify a Critical Tumor-Suppressive Region Mapping to Chromosome 13q14 and THSD1 in Esophageal Carcinoma
Authors: Ko Josephine M.Y. , Chan Pui Ling , Yau Wing Lung , Chan Ho Kin , Chan King Chi , Yu Zhuo You , Kwong Fung Mei , Miller Lance D. , Liu Edison T. , Yang Li Chun , Lo Paulisally H.Y. , Stanbridge Eric J. , Tang Johnny C.O. , Srivastava Gopesh , Tsao Sai Wah , Law Simon , Lung Maria L.
Published: March 2024

Abstract
Loss of chromosome 13q regions in esophageal squamous cell carcinoma (ESCC) is a frequent event. Monochromosome transfer approaches provide direct functional evidence for tumor suppression by chromosome 13 in SLMT-1, an ESCC cell line, and identify critical regions at 13q12.3, 13q14.11, and 13q14.3. Differential gene expression profiles of three tumor-suppressing microcell hybrids (MCH) and their tumorigenic parental SLMT-1 cell line were revealed by competitive hybridization using 19k cDNA oligonucleotide microarrays. Nine candidate 13q14 tumor-suppressor genes (TSG), including RB1, showed down-regulation in SLMT-1, compared with NE1, an immortalized normal esophageal epithelial cell line; their average gene expression was restored in MCHs compared with SLMT-1. Reverse transcription-PCR validated gene expression levels in MCHs and a panel of ESCC cell lines. Results suggest that the tumor-suppressing effect is not attributed to RB1, but instead likely involves thrombospondin type I domain-containing 1 (THSD1), a novel candidate TSG mapping to 13q14. Quantitative reverse transcription-PCR detected down-regulation of THSD1 expression in 100% of ESCC and other cancer cell lines. Mechanisms for THSD1 silencing in ESCC involved loss of heterozygosity and promoter hypermethylation, as analyzed by methylation-specific PCR and clonal bisulfite sequencing. Transfection of wild-type THSD1 into SLMT-1 resulted in significant reduction of colony-forming ability, hence providing functional evidence for its growth-suppressive activity. These findings suggest that THSD1 is a good candidate TSG. (Mol Cancer Res 2008;6(4):592–603)
Data from A Vascular Model of Tsc1 Deficiency Accelerates Renal Tumor Formation with Accompanying Hemangiosarcomas
Authors: Leech Jarrett D. , Lammers Stephen H.T. , Goldman Sam , Auricchio Neil , Bronson Roderick T. , Kwiatkowski David J. , Sahin Mustafa
Published: March 2024

Abstract
Tuberous sclerosis complex (TSC) is an autosomal disease caused by inactivating mutations in either of the tumor suppressor genes TSC1 or TSC2. TSC-associated tumor growth is present in multiple tissues and organs including brain, kidney, liver, heart, lungs, and skin. In the kidney, TSC angiomyolipomas have aberrant vascular structures with abnormal endothelial cells, suggesting a role for endothelial mTORC1 function. In the current report, a genetically engineered mouse model (GEMM) with a conditional knockout allele of Tsc1 with a Darpp32-Cre allele displayed accelerated formation of both kidney cystadenomas and paw hemangiosarcomas. All mutant mice developed hemangiosarcomas on multiple paws by 6 weeks of age. By 16 weeks of age, the average mutant hind paw was 4.0 mm in diameter, nearly double the size of control mice. Furthermore, the hemangiosarcomas and kidney cystadenomas were responsive to intraperitoneal rapamycin treatment. Immunoblotting and immunostaining for phospho-S6 (pS6) and phospho-CAD showed that the effect of rapamycin on tumor size was through inhibition of the mTOR signaling pathway. Finally, elevated VEGF mRNA levels were also observed in hemangiosarcoma specimens. Because paw hemangiosarcomas are easily detectable and scorable for size and growth, this novel mouse model enables accelerated in vivo drug testing for therapies of TSC-related tumors.

Implications: These findings provide a strong rationale for simultaneous use of this conditional knockout mouse as an in vivo genetic model while seeking new cancer therapies for TSC-related tumors. Mol Cancer Res; 13(3); 548–55. ©2014 AACR.
Data from Ceramide Analogue SACLAC Modulates Sphingolipid Levels and MCL-1 Splicing to Induce Apoptosis in Acute Myeloid Leukemia
Authors: Pearson Jennifer M. , Tan Su-Fern , Sharma Arati , Annageldiyev Charyguly , Fox Todd E. , Abad Jose Luis , Fabrias Gemma , Desai Dhimant , Amin Shantu , Wang Hong-Gang , Cabot Myles C. , Claxton David F. , Kester Mark , Feith David J. , Loughran Thomas P.
Published: March 2024

Abstract
Acute myeloid leukemia (AML) is a disease characterized by uncontrolled proliferation of immature myeloid cells in the blood and bone marrow. The 5-year survival rate is approximately 25%, and recent therapeutic developments have yielded little survival benefit. Therefore, there is an urgent need to identify novel therapeutic targets. We previously demonstrated that acid ceramidase (ASAH1, referred to as AC) is upregulated in AML and high AC activity correlates with poor patient survival. Here, we characterized a novel AC inhibitor, SACLAC, that significantly reduced the viability of AML cells with an EC50 of approximately 3 μmol/L across 30 human AML cell lines. Treatment of AML cell lines with SACLAC effectively blocked AC activity and induced a decrease in sphingosine 1-phosphate and a 2.5-fold increase in total ceramide levels. Mechanistically, we showed that SACLAC treatment led to reduced levels of splicing factor SF3B1 and alternative MCL-1 mRNA splicing in multiple human AML cell lines. This increased proapoptotic MCL-1S levels and contributed to SACLAC-induced apoptosis in AML cells. The apoptotic effects of SACLAC were attenuated by SF3B1 or MCL-1 overexpression and by selective knockdown of MCL-1S. Furthermore, AC knockdown and exogenous C16-ceramide supplementation induced similar changes in SF3B1 level and MCL-1S/L ratio. Finally, we demonstrated that SACLAC treatment leads to a 37% to 75% reduction in leukemic burden in two human AML xenograft mouse models.
Implications:
These data further emphasize AC as a therapeutic target in AML and define SACLAC as a potent inhibitor to be further optimized for future clinical development.
Data from Protein Kinase Casein Kinase 2–Mediated Upregulation of N-Cadherin Confers Anoikis Resistance on Esophageal Carcinoma Cells
Authors: Ko Hyeonseok , Kim Seongrak , Jin Cheng-Hao , Lee Eunjung , Ham Sunyoung , Yook Jong In , Kim Kunhong
Published: March 2024

Abstract
Previously, we reported that high PKCK2 activity could protect cancer cells from death receptor–mediated apoptosis through phosphorylation of procaspase-2. Because anoikis is another form of apoptosis, we asked whether PKCK2 could similarly confer resistance to anoikis on cancer cells. Human esophageal squamous cancer cell lines with high PKCK2 activity (HCE4 and HCE7) were anoikis-resistant, whereas cell lines with low PKCK2 activity (TE2 and TE3) were anoikis-sensitive. Because the cells showed different sensitivity to anoikis, we compared the expression of cell adhesion molecules between anoikis-sensitive TE2 and anoikis-resistant HCE4 cells using cDNA microarray. We found that E-cadherin is expressed only in TE2 cells; whereas N-cadherin is expressed instead of E-cadherin in HCE4 cells. To examine whether PKCK2 activity could determine the type of cadherin expressed, we first increased intracellular PKCK2 activity in TE2 cells by overexpressing the PKCK2α catalytic subunit using lentivirus and found that high PKCK2 activity could switch cadherin expression from type E to N and confer anoikis resistance. Conversely, a decrease in PKCK2 activity in HCE4 cells by knockdown of PKCK2α catalytic subunit using shRNA induced N- to E-cadherin switching and the anoikis-resistant cells became sensitive. In addition, N-cadherin expression correlated with PKB/Akt activation and increased invasiveness. We conclude that high intracellular PKCK2 activity confers anoikis resistance on esophageal cancer cells by inducing E- to N-cadherin switching. Mol Cancer Res; 10(8); 1032–8. ©2012 AACR.