bluuebunny/crossref_metadata_2025 huggingface dataset:
Data from Loss of MAP3K7 Sensitizes Prostate Cancer Cells to CDK1/2 Inhibition and DNA Damage by Disrupting Homologous Recombination
Authors: Washino Satoshi , Rider Leah C. , Romero Lina , Jillson Lauren K. , Affandi Trisiani , Ohm Angela M. , Lam Elaine T. , Reyland Mary E. , Costello James C. , Cramer Scott D.
Published: March 2024

Abstract
The combined loss of CHD1 and MAP3K7 promotes aggressive prostate cancer by unknown mechanisms. Because both of these genes are lost genetically in prostate cancer, they cannot be directly targeted. We applied an established computational systems pharmacology approach (TRAP) to identify altered signaling pathways and associated druggable targets. We compared gene expression profiles of prostate cancer with coloss of CHD1 and MAP3K7 with prostate cancer diploid for these genes using The Cancer Genome Atlas patient samples. This analysis prioritized druggable target genes that included CDK1 and CDK2. We validated that inhibitors of these druggable target genes, including the CDK1/CDK2 inhibitor dinaciclib, had antiproliferative and cytotoxic effects selectively on mouse prostate cells with knockdown of Chd1 and Map3k7. Dinaciclib had stronger effects on prostate cells with suppression of Map3k7 independent of Chd1 and also compared with cells without loss of Map3k7. Dinaciclib treatment reduced expression of homologous recombination (HR) repair genes such as ATM, ATR, BRCA2, and RAD51, blocked BRCA1 phosphorylation, reduced RAD51 foci formation, and increased γH2AX foci selectively in prostate cells with suppression of Map3k7, thus inhibiting HR repair of chromosomal double-strand breaks. Dinaciclib-induced HR disruption was also observed in human prostate cells with knockdown of MAP3K7. Cotreatment of dinaciclib with DNA-damaging agents or PARP inhibitor resulted in a stronger cytotoxic effect on prostate cells with suppression of MAP3K7 compared with those without loss of MAP3K7, or to each single agent.
Implications:
These findings demonstrate that loss of MAP3K7 is a main contributing factor to drug response through disruption of HR in prostate cancer.
Data from A Minimal DNA Methylation Signature in Oral Tongue Squamous Cell Carcinoma Links Altered Methylation with Tumor Attributes
Authors: Krishnan Neeraja M. , Dhas Kunal , Nair Jayalakshmi , Palve Vinayak , Bagwan Jamir , Siddappa Gangotri , Suresh Amritha , Kekatpure Vikram D. , Kuriakose Moni Abraham , Panda Binay
Published: March 2024

Abstract
Oral tongue squamous cell carcinomas (OTSCC) are a homogenous group of aggressive tumors in the head and neck region that spread early to lymph nodes and have a higher incidence of regional failure. In addition, there is a rising incidence of oral tongue cancer in younger populations. Studies on functional DNA methylation changes linked with altered gene expression are critical for understanding the mechanisms underlying tumor development and metastasis. Such studies also provide important insight into biomarkers linked with viral infection, tumor metastasis, and patient survival in OTSCC. Therefore, we performed genome-wide methylation analysis of tumors (N = 52) and correlated altered methylation with differential gene expression. The minimal tumor-specific DNA 5-methylcytosine signature identified genes near 16 different differentially methylated regions, which were validated using genomic data from The Cancer Genome Atlas cohort. In our cohort, hypermethylation of MIR10B was significantly associated with the differential expression of its target genes NR4A3 and BCL2L11 (P = 0.0125 and P = 0.014, respectively), which was inversely correlated with disease-free survival (P = 9E−15 and P = 2E−15, respectively) in patients. Finally, differential methylation in FUT3, TRIM5, TSPAN7, MAP3K8, RPS6KA2, SLC9A9, and NPAS3 genes was found to be predictive of certain clinical and epidemiologic parameters.

Implications: This study reveals a functional minimal methylation profile in oral tongue tumors with associated risk habits, clinical, and epidemiologic outcomes. In addition, NR4A3 downregulation and correlation with patient survival suggests a potential target for therapeutic intervention in oral tongue tumors. Data from the current study are deposited in the NCBI Geo database (accession number GSE75540). Mol Cancer Res; 14(9); 805–19. ©2016 AACR.
Data from Radiation-Induced Myofibroblasts Promote Tumor Growth via Mitochondrial ROS–Activated TGFβ Signaling
Authors: Shimura Tsutomu , Sasatani Megumi , Kawai Hidehiko , Kamiya Kenji , Kobayashi Junya , Komatsu Kenshi , Kunugita Naoki
Published: March 2024

Abstract
Fibroblasts are a key stromal cell in the tumor microenvironment (TME) and promote tumor growth via release of various growth factors. Stromal fibroblasts in cancer, called cancer-associated fibroblasts (CAF), are related to myofibroblasts, an activated form of fibroblast. While investigating the role of stroma fibroblasts on radiation-related carcinogenesis, it was observed following long-term fractionated radiation (FR) that the morphology of human diploid fibroblasts changed from smaller spindle shapes to larger flat shapes. These cells expressed smooth muscle actin (α-SMA) and platelet-derived growth factor receptors, markers of myofibroblasts and CAFs, respectively. Long-term FR induces progressive damage to the fibroblast nucleus and mitochondria via increases in mitochondrial reactive oxygen species (ROS) levels. Here, it is demonstrated that long-term FR-induced α-SMA–positive cells have decreased mitochondrial membrane potential and activated oxidative stress responses. Antioxidant N-acetyl cysteine suppressed radiation-induced mitochondrial damage and generation of myofibroblasts. These results indicate that mitochondrial ROS are associated with the acquisition of myofibroblasts after long-term FR. Mechanistically, mitochondrial ROS activated TGFβ signaling which in turn mediated the expression of α-SMA in radiation-induced myofibroblasts. Finally, in vivo tumor growth analysis in a human tumor xenograft model system revealed that long-term FR-induced myofibroblasts promote tumor growth by enhancing angiogenesis.

Implications: Radiation affects malignant cancer cells directly and indirectly via molecular alterations in stromal fibroblasts such as activation of TGFβ and angiogenic signaling pathways. Mol Cancer Res; 16(11); 1676–86. ©2018 AACR.
Data from ADAM12 Is a Novel Regulator of Tumor Angiogenesis via STAT3 Signaling
Authors: Roy Roopali , Dagher Adelle , Butterfield Catherine , Moses Marsha A.
Published: March 2024

Abstract
ADAM12, (A Disintegrin and metalloproteinase domain-containing protein 12), is upregulated in epithelial cancers and contributes to increased tumor proliferation, metastasis, and endocrine resistance. However, its role in tumor angiogenesis is unknown. Here, we report that ADAM12 is upregulated in the vessels of aggressive breast tumors and exerts key regulatory functions. ADAM12 significantly increases bFGF-mediated angiogenesis in vivo and ADAM12 levels are upregulated in tumors that have undergone a switch to the angiogenic phenotype. Importantly, ADAM12-overexpressing breast tumors display a higher microvessel density (MVD). Our goal was to identify the mechanisms by which tumor-associated ADAM12 promotes angiogenesis. ADAM12 expression in breast tumor cells correlated with a significant upregulation of proangiogenic factors such as VEGF and MMP-9 and downregulation of antiangiogenic factors such as Thrombospondin-1 (THBS1/TSP1) and Tissue Inhibitor of Metalloproteinases-2 (TIMP-2). Co-culture with ADAM12-expressing tumor cells promoted endothelial cell (EC) recruitment and capillary tube formation. Conversely, downregulation of endogenous ADAM12 in breast cancer cell lines resulted in reduction of pro-angiogenic factors and EC recruitment. These ADAM12-mediated effects are driven by the activation of EGFR, STAT3 and Akt signaling. Blockade of EGFR/STAT3 or silencing of ADAM12 reversed the proangiogenic tumor phenotype, significantly downregulated pro-angiogenic mitogens and reduced EC recruitment. In human breast cancer tissues, ADAM12 expression was significantly positively correlated with pro-angiogenic factors including VEGF and MMP-9 but negatively associated with TSP1.

Implications: These novel findings suggest that ADAM12 regulates EC function and facilitates a proangiogenic microenvironment in a STAT3-dependent manner. A combined approach of targeting ADAM12 and STAT3 signaling in breast cancer may represent a promising strategy to inhibit tumor neovascularization. Mol Cancer Res; 15(11); 1608–22. ©2017 AACR.
Data from Genomic Alterations Associated with Recurrence and TNBC Subtype in High-Risk Early Breast Cancers
Authors: Wilson Timothy R. , Udyavar Akshata R. , Chang Ching-Wei , Spoerke Jill M. , Aimi Junko , Savage Heidi M. , Daemen Anneleen , O'Shaughnessy Joyce A. , Bourgon Richard , Lackner Mark R.
Published: March 2024

Abstract
The identification of early breast cancer patients who may benefit from adjuvant chemotherapy has evolved to include assessment of clinicopathologic features such as tumor size and nodal status, as well as several gene-expression profiles for ER-positive, HER2-negative cancers. However, these tools do not reliably identify patients at the greatest risk of recurrence. The mutation and copy-number landscape of triple-negative breast cancer (TNBC) subtypes defined by gene expression is also largely unknown, and elucidation of this landscape may shed light on novel therapeutic opportunities. The USO01062 phase III clinical trial of standard chemotherapy (with or without capecitabine) enrolled a cohort of putatively high-risk patients based on clinical features, yet only observed a 5-year disease-free survival event rate of 11.6%. In order to uncover genomic aberrations associated with recurrence, a targeted next-generation sequencing panel was used to compare tumor specimens from patients who had a recurrence event with a matched set who did not. The somatic mutation and copy-number alteration landscapes of high-risk early breast cancer patients were characterized and alterations associated with relapse were identified. Tumor mutational burden was evaluated but was not prognostic in this study, nor did it correlate with PDL1 or CD8 gene expression. However, TNBC subtypes had substantial genomic heterogeneity with a distinct pattern of genomic alterations and putative underlying driver mutations.
Implications:
The present study uncovers a compendium of genomic alterations with utility to more precisely identify high-risk patients for adjuvant trials of novel therapeutic agents.
Data from Combining Homologous Recombination and Phosphopeptide-binding Data to Predict the Impact of BRCA1 BRCT Variants on Cancer Risk
Authors: Petitalot Ambre , Dardillac Elodie , Jacquet Eric , Nhiri Naima , Guirouilh-Barbat Josée , Julien Patrick , Bouazzaoui Isslam , Bonte Dorine , Feunteun Jean , Schnell Jeff A. , Lafitte Philippe , Aude Jean-Christophe , Noguès Catherine , Rouleau Etienne , Lidereau Rosette , Lopez Bernard S. , Zinn-Justin Sophie , Caputo Sandrine M.
Published: March 2024

Abstract
BRCA1 mutations have been identified that increase the risk of developing hereditary breast and ovarian cancers. Genetic screening is now offered to patients with a family history of cancer, to adapt their treatment and the management of their relatives. However, a large number of BRCA1 variants of uncertain significance (VUS) are detected. To better understand the significance of these variants, a high-throughput structural and functional analysis was performed on a large set of BRCA1 VUS. Information on both cellular localization and homology-directed DNA repair (HR) capacity was obtained for 78 BRCT missense variants in the UMD-BRCA1 database and measurement of the structural stability and phosphopeptide-binding capacities was performed for 42 mutated BRCT domains. This extensive and systematic analysis revealed that most characterized causal variants affect BRCT-domain solubility in bacteria and all impair BRCA1 HR activity in cells. Furthermore, binding to a set of 5 different phosphopeptides was tested: all causal variants showed phosphopeptide-binding defects and no neutral variant showed such defects. A classification is presented on the basis of mutated BRCT domain solubility, phosphopeptide-binding properties, and VUS HR capacity. These data suggest that HR-defective variants, which present, in addition, BRCT domains either insoluble in bacteria or defective for phosphopeptide binding, lead to an increased cancer risk. Furthermore, the data suggest that variants with a WT HR activity and whose BRCT domains bind with a WT affinity to the 5 phosphopeptides are neutral. The case of variants with WT HR activity and defective phosphopeptide binding should be further characterized, as this last functional defect might be sufficient per se to lead to tumorigenesis.
Implications:
The analysis of the current study on BRCA1 structural and functional defects on cancer risk and classification presented may improve clinical interpretation and therapeutic selection.
Data from Mitochondrial DNA Mutations are Associated with Ulcerative Colitis Preneoplasia but Tend to be Negatively Selected in Cancer
Authors: Baker Kathryn T. , Nachmanson Daniela , Kumar Shilpa , Emond Mary J. , Ussakli Cigdem , Brentnall Teresa A. , Kennedy Scott R. , Risques Rosa Ana
Published: March 2024

Abstract
The role of mitochondrial DNA (mtDNA) mutations in cancer remains controversial. Ulcerative colitis is an inflammatory bowel disease that increases the risk of colorectal cancer and involves mitochondrial dysfunction, making it an ideal model to study the role of mtDNA in tumorigenesis. Our goal was to comprehensively characterize mtDNA mutations in ulcerative colitis tumorigenesis using Duplex Sequencing, an ultra-accurate next-generation sequencing method. We analyzed 46 colon biopsies from non-ulcerative colitis control patients and ulcerative colitis patients with and without cancer, including biopsies at all stages of dysplastic progression. mtDNA was sequenced at a median depth of 1,364x. Mutations were classified by mutant allele frequency: clonal > 0.95, subclonal 0.01–0.95, and very low frequency (VLF) < 0.01. We identified 208 clonal and subclonal mutations and 56,764 VLF mutations. Mutations were randomly distributed across the mitochondrial genome. Clonal and subclonal mutations increased in number and pathogenicity in early dysplasia, but decreased in number and pathogenicity in cancer. Most clonal, subclonal, and VLF mutations were C>T transitions in the heavy strand of mtDNA, which likely arise from DNA replication errors. A subset of VLF mutations were C>A transversions, which are probably due to oxidative damage. VLF transitions and indels were less abundant in the non–D-loop region and decreased with progression. Our results indicate that mtDNA mutations are frequent in ulcerative colitis preneoplasia but negatively selected in cancers.
Implications:
While mtDNA mutations might contribute to early ulcerative colitis tumorigenesis, they appear to be selected against in cancer, suggesting that functional mitochondria might be required for malignant transformation in ulcerative colitis.
Data from IKKβ-Mediated Resistance to Skin Cancer Development Is Ink4a/Arf-Dependent
Authors: Page Angustias , Bravo Ana , Suarez-Cabrera Cristian , Alameda Josefa P. , Casanova M. Llanos , Lorz Corina , Segrelles Carmen , Segovia José C. , Paramio Jesús M. , Navarro Manuel , Ramirez Angel
Published: March 2024

Abstract
IKKβ (encoded by IKBKB) is a protein kinase that regulates the activity of numerous proteins important in several signaling pathways, such as the NF-κB pathway. IKKβ exerts a protumorigenic role in several animal models of lung, hepatic, intestinal, and oral cancer. In addition, genomic and proteomic studies of human tumors also indicate that IKBKB gene is amplified or overexpressed in multiple tumor types. Here, the relevance of IKKβ in skin cancer was determined by performing carcinogenesis studies in animal models overexpressing IKKβ in the basal skin layer. IKKβ overexpression resulted in a striking resistance to skin cancer development and an increased expression of several tumor suppressor proteins, such as p53, p16, and p19. Mechanistically, this skin tumor–protective role of IKKβ is independent of p53, but dependent on the activity of the Ink4a/Arf locus. Interestingly, in the absence of p16 and p19, IKKβ-increased expression favors the appearance of cutaneous spindle cell–like squamous cell carcinomas, which are highly aggressive tumors. These results reveal that IKKβ activity prevents skin tumor development, and shed light on the complex nature of IKKβ effects on cancer progression, as IKKβ can both promote and prevent carcinogenesis depending on the cell type or molecular context.

Implications: The ability of IKKβ to promote or prevent carcinogenesis suggests the need for further evaluation when targeting this protein. Mol Cancer Res; 15(9); 1255–64. ©2017 AACR.
Data from Potent EMT and CSC Phenotypes Are Induced By Oncostatin-M in Pancreatic Cancer
Authors: Smigiel Jacob M. , Parameswaran Neetha , Jackson Mark W.
Published: March 2024

Abstract
Pancreatic ductal adenocarcinoma (PDAC) is referred to as a silent killer due to the lack of clear symptoms, a lack of early detection methods, and a high frequency of metastasis at diagnosis. In addition, pancreatic cancer is remarkably resistant to chemotherapy, and clinical treatment options remain limited. The tumor microenvironment (TME) and associated factors are important determinants of metastatic capacity and drug resistance. Here, oncostatin M (OSM), an IL6 cytokine family member, was identified as an important driver of mesenchymal and cancer stem cell (CSC) phenotypes. Furthermore, the generation of cells that harbor mesenchymal/CSC properties following OSM exposure resulted in enhanced tumorigenicity, increased metastasis, and resistance to gemcitabine. OSM induced the expression of ZEB1, Snail (SNAI1), and OSM receptor (OSMR), engaging a positive feedback loop to potentiate the mesenchymal/CSC program. Suppression of JAK1/2 by ruxolitinib prevented STAT3-mediated transcription of ZEB1, SNAI1 and OSMR, as well as the emergence of a mesenchymal/CSC phenotype. Likewise, ZEB1 silencing, by shRNA-mediated knockdown, in OSM-driven mesenchymal/CSC reverted the phenotype back to an epithelial/non-CSC state. Importantly, the generation of cells with mesenchymal/CSC properties was unique to OSM, and not observed following IL6 exposure, implicating OSMR and downstream effector signaling as a distinct target in PDAC. Overall, these data demonstrate the capacity of OSM to regulate an epithelial–mesenchymal transition (EMT)/CSC plasticity program that promotes tumorigenic properties.

Implications: Therapeutic targeting the OSM/OSMR axis within the TME may prevent or reverse the aggressive mesenchymal and CSC phenotypes associated with poor outcomes in patients with PDAC. Mol Cancer Res; 15(4); 478–88. ©2017 AACR.
Data from De Novo Fatty Acid Synthesis-Driven Sphingolipid Metabolism Promotes Metastatic Potential of Colorectal Cancer
Authors: Jafari Naser , Drury James , Morris Andrew J. , Onono Fredrick O. , Stevens Payton D. , Gao Tianyan , Liu Jinpeng , Wang Chi , Lee Eun Y. , Weiss Heidi L. , Evers B. Mark , Zaytseva Yekaterina Y.
Published: March 2024

Abstract
Metastasis is the most common cause of death in colorectal cancer patients. Fatty acid synthase (FASN) and sphingosine kinase-1 and -2 (SPHK1 and 2) are overexpressed in many cancers, including colorectal cancer. However, the contribution of FASN-mediated upregulation of sphingolipid metabolism to colorectal cancer metastasis and the potential of these pathways as targets for therapeutic intervention remain unknown. This study determined that sphingosine kinases (SPHK) are overexpressed in colorectal cancer as compared with normal mucosa. FASN expression significantly correlated with SPHK2 expression in data sets from The Cancer Genome Atlas (TCGA) and a colorectal cancer tumor microarray. FASN, SPHK1, and SPHK2 colocalized within invadopodia of primary colorectal cancer cells. Moreover, FASN inhibition decreased SPHK2 expression and the levels of dihydrosphingosine 1-phosphate (DH-S1P) and sphingosine 1-phosphate (S1P) in colorectal cancer cells and tumor tissues. Inhibition of FASN using TVB-3664 and sphingolipid metabolism using FTY-720 significantly inhibited the ability of primary colorectal cancer cells to proliferate, migrate, form focal adhesions, and degrade gelatin. Inhibition of the FASN/SPHK/S1P axis was accompanied by decreased activation of p-MET, p-FAK, and p-PAX. S1P treatment rescued FASN-mediated inhibition of these proteins, suggesting that FASN promotes metastatic properties of colorectal cancer cells, in part, through an increased sphingolipid metabolism. These data demonstrate that upregulation of the FASN/SPHK/S1P axis promotes colorectal cancer progression by enhancing proliferation, adhesion, and migration.
Implications:
This study provides a strong rationale for further investigation of the interconnection of de novo lipogenesis and sphingolipid metabolism that could potentially lead to the identification of new therapeutic targets and strategies for colorectal cancer.
Data from Biomarker Assessment of HR Deficiency, Tumor BRCA1/2 Mutations, and CCNE1 Copy Number in Ovarian Cancer: Associations with Clinical Outcome Following Platinum Monotherapy
Authors: Stronach Euan A. , Paul James , Timms Kirsten M. , Hughes Elisha , Brown Krystal , Neff Christopher , Perry Michael , Gutin Alexander , El-Bahrawy Mona , Steel Jennifer H. , Liu Xinxue , Lewsley Liz-Anne , Siddiqui Nadeem , Gabra Hani , Lanchbury Jerry S. , Brown Robert
Published: March 2024

Abstract
The current study evaluated three biomarkers [homologous recombination deficiency (HRD), tumor BRCA1/2 (tBRCA) mutations, and CCNE1 copy-number variation (CNV)] in ovarian tumors from patients enrolled on the SCOTROC4 clinical trial for associations with outcome following carboplatin monotherapy. Ovarian tumors (n = 250), with high-grade serous (HGSOC) subgroup analysis (n = 179) were classified as HRD positive (HRD score ≥42 or tBRCA mutation) and as CCNE1 amplification positive (CCNE1 CNV score >2.4). Seventy-four (30%) tumors were HRD positive, including 34 (14%) with tBRCA mutations. Forty-seven (19%) were CCNE1 amplification positive, all of which were tBRCA wild-type. HRD and tBRCA, but not CCNE1 amplification, were significantly associated with CA125 complete response in the entire cohort (HRD, P = 0.00015; tBRCA P = 0.0096), and the HGSOC subgroup (HRD, P = 0.0016; tBRCA P = 0.032). HRD and lack of CCNE1 amplification were associated with improved progression-free survival (PFS) and overall survival (OS) in the full cohort and HGSOC subgroup (HRD, P = 0.00021; CCNE1 status P = 0.038). HRD remained significant for OS and PFS after adjusting for clinical factors, while CCNE1 status only remained significant for PFS. Patients with HRD-positive tumors had greater PFS and OS benefit from platinum dose intensification than HRD-negative tumors (P = 0.049 and P = 0.035, respectively). An alternative exploratory HRD score threshold (≥33 or tBRCA mutation) was also significantly associated with both PFS and OS in the HGSOC subset.

Implications: HRD, tumor BRCA1/2 mutations, and absence of CCNE1 amplification are associated with improved survival of ovarian cancer patients treated with platinum monotherapy and HRD-positive patients may benefit from platinum dose intensification. Mol Cancer Res; 16(7); 1103–11. ©2018 AACR.
Data from S-Nitrosylation of EGFR and Src Activates an Oncogenic Signaling Network in Human Basal-Like Breast Cancer
Authors: Switzer Christopher H. , Glynn Sharon A. , Cheng Robert Y.-S. , Ridnour Lisa A. , Green Jeffrey E. , Ambs Stefan , Wink David A.
Published: March 2024

Abstract
Increased inducible nitric oxide synthase (NOS2) expression in breast tumors is associated with decreased survival of estrogen receptor negative (ER−) breast cancer patients. We recently communicated the preliminary observation that nitric oxide (NO) signaling results in epidermal growth factor receptor (EGFR) tyrosine phosphorylation. To further define the role of NO in the pathogenesis of ER− breast cancer, we examined the mechanism of NO-induced EGFR activation in human ER− breast cancer. NO was found to activate EGFR and Src by a mechanism that includes S-nitrosylation. NO, at physiologically relevant concentrations, induced an EGFR/Src-mediated activation of oncogenic signal transduction pathways (including c-Myc, Akt, and β-catenin) and the loss of PP2A tumor suppressor activity. In addition, NO signaling increased cellular EMT, expression and activity of COX-2, and chemoresistance to adriamycin and paclitaxel. When connected into a network, these concerted events link NO to the development of a stem cell–like phenotype, resulting in the upregulation of CD44 and STAT3 phosphorylation. Our observations are also consistent with the finding that NOS2 is associated with a basal-like transcription pattern in human breast tumors. These results indicate that the inhibition of NOS2 activity or NO signaling networks may have beneficial effects in treating basal-like breast cancer patients. Mol Cancer Res; 10(9); 1203–15. ©2012 AACR.
Data from Induction of Antiproliferative Connective Tissue Growth Factor Expression in Wilms' Tumor Cells by Sphingosine-1-Phosphate Receptor 2
Authors: Li Mei-Hong , Sanchez Teresa , Pappalardo Anna , Lynch Kevin R. , Hla Timothy , Ferrer Fernando
Published: March 2024

Abstract
Connective tissue growth factor (CTGF), a member of the CCN family of secreted matricellular proteins, regulates fibrosis, angiogenesis, cell proliferation, apoptosis, tumor growth, and metastasis. However, the role of CTGF and its regulation mechanism in Wilms' tumor remains largely unknown. We found that the bioactive lipid sphingosine-1-phosphate (S1P) induced CTGF expression in a concentration- and time-dependent manner in a Wilms' tumor cell line (WiT49), whereas FTY720-phosphate, an S1P analogue that binds all S1P receptors except S1P2, did not. Further, the specific S1P2 antagonist JTE-013 completely inhibited S1P-induced CTGF expression, whereas the S1P1 antagonist VPC44116 did not, indicating that this effect was mediated by S1P2. This was confirmed by adenoviral transduction of S1P2 in WiT49 cells, which showed that overexpression of S1P2 increased the expression of CTGF. Induction of CTGF by S1P was sensitive to ROCK inhibitor Y-27632 and c-Jun NH2-terminal kinase inhibitor SP600125, suggesting the requirement of RhoA/ROCK and c-Jun NH2-terminal kinase pathways for S1P-induced CTGF expression. Interestingly, the expression levels of CTGF were decreased in 8 of 10 Wilms' tumor tissues compared with matched normal tissues by quantitative real-time PCR and Western blot analysis. In vitro, human recombinant CTGF significantly inhibited the proliferation of WiT49 cells. In addition, overexpression of CTGF resulted in significant inhibition of WiT49 cell growth. Taken together, these data suggest that CTGF protein induced by S1P2 might act as a growth inhibitor in Wilms' tumor. (Mol Cancer Res 2008;6(10):1649–56)
Data from The Signal Peptide of Mouse Mammary Tumor Virus-Env: A Phosphoprotein Tumor Modulator
Authors: Feldman Dafna , Roniger Maayan , Bar-Sinai Allan , Braitbard Ori , Natan Carmit , Love Dona C. , Hanover John A. , Hochman Jacob
Published: March 2024

Abstract
Mouse mammary tumor virus (MMTV) is associated primarily with mammary carcinomas and lymphomas. The signal peptide of the MMTV envelope precursor is uniquely targeted to nucleoli of cells that harbor the virus, where it can function as a nuclear export factor for intron-containing transcripts. Antibodies to this signal peptide, which we refer to as p14, were previously shown to label nucleoli in a subset of human breast cancers. To look for additional cellular functions of p14, different mutants were ectopically expressed in the MCF-7 human breast cancer cell line. This approach identified motifs responsible for its nucleolar targeting, nucleocytoplasmic shuttling, target protein (B23, nucleophosmin) binding, and phosphorylation at serine 18 and 65 both in situ and in vitro. To test the role of these phosphorylation sites, we carried out in vivo tumorigenesis studies in severe combined immunodeficient mice. The findings show that the p14-Ser65Ala mutation is associated with impaired tumorigenicity, whereas the p14-Ser18Ala mutation is associated with enhanced tumorigenicity. Microarray analysis suggests that phosphorylation at serine 18 or at serine 65 is associated with transcriptional regulation of the L5 nucleolar ribosomal protein (a p14 target) and the Erb-B signal transduction pathway. Taken together, these results show that the phosphorylation status of p14 determines whether it functions as a pro-oncogenic or antioncogenic modulator. Mol Cancer Res; 10(8); 1077–86. ©2012 AACR.
Data from Role of Neurofilament Light Polypeptide in Head and Neck Cancer Chemoresistance
Authors: Chen Baishen , Chen Ju , House Michael G. , Cullen Kevin J. , Nephew Kenneth P. , Guo Zhongmin
Published: March 2024

Abstract
Resistance to cisplatin-based chemotherapy is responsible for therapeutic failure of many common human cancers including cancer of head and neck (HNC). Mechanisms underlying cisplatin resistance remain unclear. In this study, we identified neurofilament light polypeptide (NEFL) as a novel hypermethylated gene associated with resistance to cisplatin-based chemotherapy in HNC. Analysis of 14 HNC cell lines revealed that downregulation of NEFL expression significantly correlated with increased resistance to cisplatin. Hypermethylation of NEFL promoter CpG islands was observed in cell lines as examined by bisulfite DNA sequencing and methylation-specific PCR (MSP) and tightly correlated with reduced NEFL mRNA and protein expression. Furthermore, in patient samples with HNC (n = 51) analyzed by quantitative MSP, NEFL promoter hypermethylation was associated with resistance to cisplatin-based chemotherapy [relative risk (RR), 3.045; 95% confidence interval (CI), 1.459–6.355; P = 0.007] and predicted diminished overall and disease-free survival for patients treated with cisplatin-based chemotherapy. Knockdown of NEFL by siRNA in the highly cisplatin-sensitive cell line PCI13 increased (P < 0.01) resistance to cisplatin. In cisplatin-resistant O11 and SCC25cp cells, restored expression of NEFL significantly increased sensitivity to the drug. Furthermore, NEFL physically associated with tuberous sclerosis complex 1 (TSC1), a known inhibitor of the mTOR pathway, and NEFL downregulation led to functional activation of mTOR pathway and consequentially conferred cisplatin resistance. This is the first study to show a role for NEFL in HNC chemoresistance. Our findings suggest that NEFL methylation is a novel mechanism for HNC chemoresistance and may represent a candidate biomarker predictive of chemotherapeutic response and survival in patients with HNC. Mol Cancer Res; 10(3); 305–15. ©2012 AACR.
Data from Akt Promotes Post-Irradiation Survival of Human Tumor Cells through Initiation, Progression, and Termination of DNA-PKcs–Dependent DNA Double-Strand Break Repair
Authors: Toulany Mahmoud , Lee Kyung-Jong , Fattah Kazi R. , Lin Yu-Fen , Fehrenbacher Brigit , Schaller Martin , Chen Benjamin P. , Chen David J. , Rodemann H. Peter
Published: March 2024

Abstract
Akt phosphorylation has previously been described to be involved in mediating DNA damage repair through the nonhomologous end-joining (NHEJ) repair pathway. Yet the mechanism how Akt stimulates DNA-protein kinase catalytic subunit (DNA-PKcs)-dependent DNA double-strand break (DNA-DSB) repair has not been described so far. In the present study, we investigated the mechanism by which Akt can interact with DNA-PKcs and promote its function during the NHEJ repair process. The results obtained indicate a prominent role of Akt, especially Akt1 in the regulation of NHEJ mechanism for DNA-DSB repair. As shown by pull-down assay of DNA-PKcs, Akt1 through its C-terminal domain interacts with DNA-PKcs. After exposure of cells to ionizing radiation (IR), Akt1 and DNA-PKcs form a functional complex in a first initiating step of DNA-DSB repair. Thereafter, Akt plays a pivotal role in the recruitment of AKT1/DNA-PKcs complex to DNA duplex ends marked by Ku dimers. Moreover, in the formed complex, Akt1 promotes DNA-PKcs kinase activity, which is the necessary step for progression of DNA-DSB repair. Akt1-dependent DNA-PKcs kinase activity stimulates autophosphorylation of DNA-PKcs at S2056 that is needed for efficient DNA-DSB repair and the release of DNA-PKcs from the damage site. Thus, targeting of Akt results in radiosensitization of DNA-PKcs and Ku80 expressing, but not of cells deficient for, either of these proteins. The data showed indicate for the first time that Akt through an immediate complex formation with DNA-PKcs can stimulate the accumulation of DNA-PKcs at DNA-DSBs and promote DNA-PKcs activity for efficient NHEJ DNA-DSB repair. Mol Cancer Res; 10(7); 945–57. ©2012 AACR.
Data from Analysis of mRNA Profiles after MEK1/2 Inhibition in Human Pancreatic Cancer Cell Lines Reveals Pathways Involved in Drug Sensitivity
Authors: Gysin Stephan , Paquette Jesse , McMahon Martin
Published: March 2024

Abstract
Mutationally activated KRAS, detected in approximately 90% of pancreatic ductal adenocarcinomas (PDA), has proven an intractable pharmacologic target to date. Consequently, efforts to treat KRAS-mutated cancers are focused on targeting RAS-regulated signaling pathways. In mouse models, expression of BRAFV600E combined with dominant-negative TP53 elicits PDA, and pharmacologic blockade of mitogen-activated protein/extracellular signal–regulated kinase (MEK) inhibits proliferation of human PDA-derived cell lines. To better understand the role of RAF→MEK→ERK signaling on PDA cell proliferation, we assessed the consequences of MEK inhibition on global patterns of mRNA expression and tumor cell proliferation in a panel of human PDA-derived cell lines. This analysis revealed that RAF→MEK→ERK signaling regulates mRNAs involved in cell-cycle control as well as regulators of the immune system. Linear regression analysis of relative drug sensitivity and mRNA expression revealed mRNAs and pathways correlating with relative drug sensitivity of the cell lines. Mice carrying orthotopically implanted pancreas tumors that were treated with MEK inhibitor displayed reduced tumor growth, concomitant with a reduction of cells in S phase. Furthermore, analysis of tumor mRNA expression revealed PDA cell lines to display similar baseline and MEK inhibitor mRNA expression profiles in vitro and in vivo. Among the proteins subject to downregulation following MEK inhibition, we identified c-MYC as a key driver of cell proliferation downstream of RAF→MEK→ERK signaling. Indeed, in some PDA cell lines, RNA interference–mediated silencing of c-MYC expression had antiproliferative effects similar to that of MEK inhibition, thereby highlighting the importance of c-MYC in key aspects of pancreatic cancer cell maintenance. Mol Cancer Res; 10(12); 1607–19. ©2012 AACR.
Data from A Novel Function of YWHAZ/β-Catenin Axis in Promoting Epithelial–Mesenchymal Transition and Lung Cancer Metastasis
Authors: Chen Ching-Hsien , Chuang Show-Mei , Yang Meng-Fang , Liao Jiunn-Wang , Yu Sung-Liang , Chen Jeremy J.W.
Published: March 2024

Abstract
YWHAZ, also known as 14-3-3zeta, has been reportedly elevated in many human tumors, including non–small cell lung carcinoma (NSCLC) but little is known about its specific contribution to lung cancer malignancy. Through a combined array-based comparative genomic hybridization and expression microarray analysis, we identified YWHAZ as a potential metastasis enhancer in lung cancer. Ectopic expression of YWHAZ on low invasive cancer cells showed enhanced cell invasion, migration in vitro, and both the tumorigenic and metastatic potentials in vivo. Gene array analysis has indicated these changes associated with an elevation of pathways relevant to epithelial–mesenchymal transition (EMT), with an increase of cell protrusions and branchings. Conversely, knockdown of YWHAZ levels with siRNA or short hairpin RNA (shRNA) in invasive cancer cells led to a reversal of EMT. We observed that high levels of YWHAZ protein are capable of activating β-catenin–mediated transcription by facilitating the accumulation of β-catenin in cytosol and nucleus. Coimmunoprecipitation assays showed a decrease of ubiquitinated β-catenin in presence of the interaction between YWHAZ and β-catenin. This interaction resulted in disassociating β-catenin from the binding of β-TrCP leading to increase β-catenin stability. Using enforced expression of dominant-negative and -positive β-catenin mutants, we confirmed that S552 phosphorylation of β-catenin increases the β-catenin/YWHAZ complex formation, which is important in promoting cell invasiveness and the suppression of ubiquitnated β-catenin. This is the first demonstration showing YWHAZ through its complex with β-catenin in mediating lung cancer malignancy and β-catenin protein stability. Mol Cancer Res; 10(10); 1319–31. ©2012 AACR.
Data from Kinetic Characterization of ASXL1/2-Mediated Allosteric Regulation of the BAP1 Deubiquitinase
Authors: Peng Hongzhuang , Cassel Joel , McCracken Daniel S. , Prokop Jeremy W. , Sementino Eleonora , Cheung Mitchell , Collop Paul R. , Polo Alexander , Joshi Surbhi , Mandell Jacob P. , Ayyanathan Kasirajan , Hinds David , Malkowicz S. Bruce , Harbour J. William , Bowcock Anne M. , Salvino Joseph , Kennedy Eileen J. , Testa Joseph R. , Rauscher Frank J.
Published: March 2024

Abstract
BAP1 is an ubiquitin hydrolase whose deubiquitinase activity is mediated by polycomb group-like protein ASXL2. Cancer-related BAP1 mutations/deletions lead to loss-of-function by targeting the catalytic ubiquitin C-terminal hydrolase (UCH) or UCH37-like domain (ULD) domains of BAP1, and the latter disrupts binding to ASXL2, an obligate partner for BAP1 enzymatic activity. However, the biochemical and biophysical properties of domains involved in forming the enzymatically active complex are unknown. Here, we report the molecular dynamics, kinetics, and stoichiometry of these interactions. We demonstrate that interactions between BAP1 and ASXL2 are direct, specific, and stable to biochemical and biophysical manipulations as detected by isothermal titration calorimetry (ITC), GST association, and optical biosensor assays. Association of the ASXL2-AB box greatly stimulates BAP1 activity. A stable ternary complex is formed, comprised of the BAP1-UCH, BAP1-ULD, and ASXL2-AB domains. Stoichiometric analysis revealed that one molecule of the ULD domain directly interacts with one molecule of the AB box. Real-time kinetic analysis of the ULD/AB protein complex to the BAP1-UCH domain, based on surface plasmon resonance, indicated that formation of the ULD/AB complex with the UCH domain is a single-step event with fast association and slow dissociation rates. In vitro experiments validated in cells that the ASXL-AB box directly regulates BAP1 activity.
Implications:
Collectively, these data elucidate molecular interactions between specific protein domains regulating BAP1 deubiquitinase activity, thus establishing a foundation for small-molecule approaches to reactivate latent wild-type BAP1 catalytic activity in BAP1-mutant cancers.
Data from Suberoylanilide Hydroxamic Acid as a Radiosensitizer through Modulation of RAD51 Protein and Inhibition of Homology-Directed Repair in Multiple Myeloma
Authors: Chen Xufeng , Wong Patty , Radany Eric H. , Stark Jeremy M. , Laulier Corentin , Wong Jeffrey Y.C.
Published: March 2024

Abstract
Histone deacetylase inhibitors (HDI) have shown promise as candidate radiosensitizers for many types of cancers. However, the mechanisms of action are not well understood, and whether they could sensitize multiple myeloma (MM) to radiation therapy is unclear. In this study, we show that suberoylanilide hydroxamic acid (SAHA) at low concentrations has minimal cytotoxic effects, yet can significantly increase radiosensitivity of MM cells. SAHA seems to block RAD51 protein response to ionizing radiation, consistent with an inhibitory effect on the formation of RAD51 focus in irradiated MM cells. These effects of SAHA on RAD51 focus are independent of cell-cycle distribution changes. Furthermore, we show that SAHA selectively inhibits the homology-directed repair (HDR) pathway. The results of this study suggest that SAHA, a recently approved HDI in clinical trials for malignancies, at lower concentrations may act as a radiosensitizer via disruption of the RAD51-dependent HDR pathway. Mol Cancer Res; 10(8); 1052–64. ©2012 AACR.
Data from EWS/FLI1 Regulates EYA3 in Ewing Sarcoma via Modulation of miRNA-708, Resulting in Increased Cell Survival and Chemoresistance
Authors: Robin Tyler P. , Smith Anna , McKinsey Erin , Reaves Lisa , Jedlicka Paul , Ford Heide L.
Published: March 2024

Abstract
Ewing sarcoma is an aggressive pediatric cancer of the bone and soft tissue, in which patients whose tumors have a poor histologic response to initial chemotherapy have a poor overall prognosis. Therefore, it is important to identify molecules involved in resistance to chemotherapy. Herein, we show that the DNA repair protein and transcriptional cofactor, EYA3, is highly expressed in Ewing sarcoma tumor samples and cell lines compared with mesenchymal stem cells, the presumed cell-of-origin of Ewing sarcoma, and that it is regulated by the EWS/FLI1 fusion protein transcription factor. We further show that EWS/FLI1 mediates upregulation of EYA3 via repression of miR-708, a miRNA that targets the EYA3 3′-untranslated region, rather than by binding the EYA3 promoter directly. Importantly, we show that high levels of EYA3 significantly correlate with low levels of miR-708 in Ewing sarcoma samples, suggesting that this miR-mediated mechanism of EYA3 regulation holds true in human cancers. Because EYA proteins are important for cell survival during development, we examine, and show, that loss of EYA3 decreases survival of Ewing sarcoma cells. Most importantly, knockdown of EYA3 in Ewing sarcoma cells leads to sensitization to DNA-damaging chemotherapeutics used in the treatment of Ewing sarcoma, and as expected, after chemotherapeutic treatment, EYA3 knockdown cells repair DNA damage less effectively than their control counterparts. These studies identify EYA3 as a novel mediator of chemoresistance in Ewing sarcoma and define the molecular mechanisms of both EYA3 overexpression and of EYA3-mediated chemoresistance. Mol Cancer Res; 10(8); 1098–108. ©2012 AACR.
Data from Comprehensive Transcriptome and Mutational Profiling of Endemic Burkitt Lymphoma Reveals EBV Type–Specific Differences
Authors: Kaymaz Yasin , Oduor Cliff I. , Yu Hongbo , Otieno Juliana A. , Ong'echa John Michael , Moormann Ann M. , Bailey Jeffrey A.
Published: March 2024

Abstract
Endemic Burkitt lymphoma (eBL) is the most common pediatric cancer in malaria-endemic equatorial Africa and nearly always contains Epstein–Barr virus (EBV), unlike sporadic Burkitt lymphoma (sBL) that occurs with a lower incidence in developed countries. Given these differences and the variable clinical presentation and outcomes, we sought to further understand pathogenesis by investigating transcriptomes using RNA sequencing (RNAseq) from multiple primary eBL tumors compared with sBL tumors. Within eBL tumors, minimal expression differences were found based on: anatomical presentation site, in-hospital survival rates, and EBV genome type, suggesting that eBL tumors are homogeneous without marked subtypes. The outstanding difference detected using surrogate variable analysis was the significantly decreased expression of key genes in the immunoproteasome complex (PSMB9/β1i, PSMB10/β2i, PSMB8/β5i, and PSME2/PA28β) in eBL tumors carrying type 2 EBV compared with type 1 EBV. Second, in comparison with previously published pediatric sBL specimens, the majority of the expression and pathway differences was related to the PTEN/PI3K/mTOR signaling pathway and was correlated most strongly with EBV status rather than geographic designation. Third, common mutations were observed significantly less frequently in eBL tumors harboring EBV type 1, with mutation frequencies similar between tumors with EBV type 2 and without EBV. In addition to the previously reported genes, a set of new genes mutated in BL, including TFAP4, MSH6, PRRC2C, BCL7A, FOXO1, PLCG2, PRKDC, RAD50, and RPRD2, were identified. Overall, these data establish that EBV, particularly EBV type 1, supports BL oncogenesis, alleviating the need for certain driver mutations in the human genome.

Implications: Genomic and mutational analyses of Burkitt lymphoma tumors identify key differences based on viral content and clinical outcomes suggesting new avenues for the development of prognostic molecular biomarkers and therapeutic interventions. Mol Cancer Res; 15(5); 563–76. ©2017 AACR.
Data from Targeted Knockdown of SEPT9_v1 Inhibits Tumor Growth and Angiogenesis of Human Prostate Cancer Cells Concomitant with Disruption of Hypoxia-Inducible Factor-1 Pathway
Authors: Amir Sharon , Golan Maya , Mabjeesh Nicola J.
Published: March 2024

Abstract
Hypoxia-inducible factor-1 (HIF-1) is a key transcription factor in the hypoxic response pathway. We recently identified a novel interaction between HIF-1α and the mammalian septin family member, septin 9 protein, isoform 1 (SEPT9_i1), a protein product of septin 9 transcript variant 1 (SEPT9_v1). Septins are a highly conserved family of GTP-binding cytoskeletal proteins that are implicated in multiple cellular functions, including oncogenesis. SEPT9_i1 binds and stabilizes HIF-1α protein and stimulates HIF-1 transcriptional activity by preventing its RACK1-mediated ubiquitination and degradation. SEPT9_i1–HIF-1 activation promotes tumor growth and angiogenesis. The effect of SEPT9_v1 silencing in prostate cancer cells was studied. SEPT9_v1 stable knockdown was generated in PC-3 cells using a specific shRNA. SEPT9_v1 silencing reduced HIF-1α protein expression and inhibited HIF-1 transcriptional activity. SEPT9_v1 knockdown affected cell morphology, deregulated cell cycle, and decreased migration. The antiproliferative effect of shSEPT9_v1 was abolished in HIF-1α knockout colon cancer cells. In vivo, SEPT9_i1 depletion reduced HIF-1α protein expression, cellular proliferation, tumor growth, and angiogenesis. These results provide new insights and validation for applying SEPT9_v1 as a potential target for antitumor therapy by interrupting the HIF-1 pathway. Mol Cancer Res; 8(5); 643–52. ©2010 AACR.