bluuebunny/crossref_metadata_2025 huggingface dataset:
Data from Molecular Correlates of Metastasis by Systematic Pan-Cancer Analysis Across The Cancer Genome Atlas
Authors: Chen Fengju , Zhang Yiqun , Varambally Sooryanarayana , Creighton Chad J.
Published: April 2023

Abstract
Tumor metastasis is a major contributor to mortality of cancer patients, but the process remains poorly understood. Molecular comparisons between primary tumors and metastases can provide insights into the pathways and processes involved. Here, we systematically analyzed and cataloged molecular correlates of metastasis using The Cancer Genome Atlas (TCGA) datasets across 11 different cancer types, these data involving 4,473 primary tumor samples and 395 tumor metastasis samples (including 369 from melanoma). For each cancer type, widespread differences in gene transcription between primary and metastasis samples were observed. For several cancer types, metastasis-associated genes from TCGA comparisons were found to overlap extensively with external results from independent profiling datasets of metastatic tumors. Although some differential expression patterns associated with metastasis were found to be shared across multiple cancer types, by and large each cancer type showed a metastasis signature that was distinctive from those of the other cancer types. Functional categories of genes enriched in multiple cancer type–specific metastatic overexpression signatures included cellular response to stress, DNA repair, oxidation–reduction process, protein deubiquitination, and receptor activity. The TCGA-derived prostate cancer metastasis signature in particular could define a subset of aggressive primary prostate cancer. Transglutaminase 2 protein and mRNA were both elevated in metastases from breast and melanoma cancers. Alterations in miRNAs and in DNA methylation were also identified.
Implications:
Our findings suggest that there are different molecular pathways to metastasis involved in different cancers. Our catalog of alterations provides a resource for future studies investigating the role of specific genes in metastasis.
Data from Satellite RNA Increases DNA Damage and Accelerates Tumor Formation in Mouse Models of Pancreatic Cancer
Authors: Kishikawa Takahiro , Otsuka Motoyuki , Suzuki Tatsunori , Seimiya Takahiro , Sekiba Kazuma , Ishibashi Rei , Tanaka Eri , Ohno Motoko , Yamagami Mari , Koike Kazuhiko
Published: April 2023

Abstract
Highly repetitive tandem arrays such as satellite sequences in the centromeric and pericentromeric regions of chromosomes, which were previously considered to be silent, are actively transcribed in various biological processes, including cancers. In the pancreas, this aberrant expression occurs even in Kras-mutated pancreatic intraepithelial neoplasia (PanIN) tissues, which are precancerous lesions. To determine the biological role of satellite RNAs in carcinogenesis in vivo, we constructed mouse major satellite (MajSAT) RNA-expressing transgenic mice. However, these transgenic mice did not show spontaneous malignant tumor formation under normal breeding. Importantly, however, DNA damage was increased in pancreatic tissues induced by caerulein treatment or high-fat diet, which may be due to impaired nuclear localization of Y-Box Binding Protein 1 (YBX1), a component of the DNA damage repair machinery. In addition, when crossed with pancreas-specific Kras-mutant mice, MajSAT RNA expression resulted in an earlier increase in PanIN formation. These results suggest that aberrant MajSAT RNA expression accelerates oncogenesis by increasing the probability of a second driver mutation, thus accelerating cells to exit from the breakthrough phase to the expansion phase.

Implications: Aberrant expression of satellite RNAs accelerates oncogenesis through a mechanism involving increased DNA damage. Mol Cancer Res; 16(8); 1255–62. ©2018 AACR.
Data from Repurposing of mTOR Complex Inhibitors Attenuates MCL-1 and Sensitizes to PARP Inhibition
Authors: Mattoo Abid R. , Joun Alex , Jessup J. Milburn
Published: April 2023

Abstract
MCL-1, a member of the antiapoptotic BCL-2 family, is a prosurvival protein with an essential DNA repair function. This study aims to test whether inhibition of protein synthesis by mTOR complex (mTORC) inhibitors depletes MCL-1, suppresses homologous recombination (HR) repair, and sensitizes cancer cells to PARP inhibitors. Treatment with everolimus decreases MCL-1 in colorectal carcinomas and small cell lung cancer (SCLC) cells but not glioblastoma multiforme (GBM) cells with a PTEN mutational background. However, AZD2014, a dual mTORC inhibitor, depletes MCL-1 in GBMs. Further, we show that everolimus decreases 4EBP1 phosphorylation only in colorectal carcinoma, whereas AZD2014 decreases 4EBP1 phosphorylation in both colorectal carcinoma and GBM cells. Combination therapy using everolimus or AZD2014 with olaparib inhibits the growth of clone A and U87-MG xenografts in in vivo and decreases clonogenic survival in in vitro compared with monotherapy. Reintroduction of MCL-1 rescues the survival of cancer cells in response to combination of everolimus or AZD2014 with olaparib. Treatment of cells with mTORC inhibitors and olaparib increases γ-H2AX and 53BP1 foci, decreases BRCA1, RPA, and Rad51 foci, impairs phosphorylation of ATR/Chk1 kinases, and induces necroptosis. In summary, mTORC inhibitors deplete MCL-1 to suppress HR repair and increase sensitivity to olaparib both in in vitro and in xenografts.
Implications:
Targeting the DNA repair activity of MCL-1 in in vivo for cancer therapy has not been tested. This study demonstrates that depleting MCL-1 sensitizes cancer cells to PARP inhibitors besides eliciting necroptosis, which could stimulate antitumor immunity to improve the therapeutic intervention of cancers.
Data from Neoadjuvant Chemotherapy Shifts Breast Tumor Microbiota Populations to Regulate Drug Responsiveness and the Development of Metastasis
Authors: Chiba Akiko , Bawaneh Alaa , Velazquez Christine , Clear Kenysha Y.J. , Wilson Adam S. , Howard-McNatt Marissa , Levine Edward A. , Levi-Polyachenko Nicole , Yates-Alston Shaina A. , Diggle Stephen P. , Soto-Pantoja David R. , Cook Katherine L.
Published: April 2023

Abstract
Breast tumors have their own specific microbiota, distinct from normal mammary gland tissue. Patients with breast cancer that present with locally advanced disease often undergo neoadjuvant chemotherapy to reduce tumor size prior to surgery to allow breast conservation or limit axillary lymph node dissection. The purpose of our study was to evaluate whether neoadjuvant chemotherapy modulates the tumor microbiome and the potential impact of microbes on breast cancer signaling. Using snap-frozen aseptically collected breast tumor tissue from women who underwent neoadjuvant chemotherapy (n = 15) or women with no prior therapy at time of surgery (n = 18), we performed 16S rRNA-sequencing to identify tumoral bacterial populations. We also stained breast tumor microarrays to confirm presence of identified microbiota. Using bacteria-conditioned media, we determined the effect of bacterial metabolites on breast cancer cell proliferation and doxorubicin therapy responsiveness. We show chemotherapy administration significantly increased breast tumor Pseudomonas spp. Primary breast tumors from patients who developed distant metastases displayed increased tumoral abundance of Brevundimonas and Staphylococcus. We confirmed presence of Pseudomonas in breast tumor tissue by IHC staining. Treatment of breast cancer cells with Pseudomonas aeruginosa conditioned media differentially effected proliferation in a dose-dependent manner and modulated doxorubicin-mediated cell death. Our results indicate chemotherapy shifts the breast tumor microbiome and specific microbes correlate with tumor recurrence. Further studies with a larger patient cohort may provide greater insights into the role of microbiota in therapeutic outcome and develop novel bacterial biomarkers that could predict distant metastases.
Implications:
Breast tumor microbiota are modified by therapy and affects molecular signaling.
Data from The Pluripotency Regulator PRDM14 Requires Hematopoietic Regulator CBFA2T3 to Initiate Leukemia in Mice
Authors: Tracey Lauren J. , Brooke-Bisschop Travis , Jansen Pascal W.T.C. , Campos Eric I. , Vermeulen Michiel , Justice Monica J.
Published: April 2023

Abstract
PR domain–containing 14 (Prdm14) is a pluripotency regulator central to embryonic stem cell identity and primordial germ cell specification. Genomic regions containing PRDM14 are often amplified leading to misexpression in human cancer. Prdm14 expression in mouse hematopoietic stem cells (HSC) leads to progenitor cell expansion prior to the development of T-cell acute lymphoblastic leukemia (T-ALL), consistent with PRDM14's role in cancer initiation. Here, we demonstrate mechanistic insight into PRDM14-driven leukemias in vivo. Mass spectrometry revealed novel PRDM14–protein interactions including histone H1, RNA-binding proteins, and the master hematopoietic regulator CBFA2T3. In mouse leukemic cells, CBFA2T3 and PRDM14 associate independently of the related ETO family member CBFA2T2, PRDM14's primary protein partner in pluripotent cells. CBFA2T3 plays crucial roles in HSC self-renewal and lineage commitment, and participates in oncogenic translocations in acute myeloid leukemia. These results suggest a model whereby PRDM14 recruits CBFA2T3 to DNA, leading to gene misregulation causing progenitor cell expansion and lineage perturbations preceding T-ALL development. Strikingly, Prdm14-induced T-ALL does not occur in mice deficient for Cbfa2t3, demonstrating that Cbfa2t3 is required for leukemogenesis. Moreover, T-ALL develops in Cbfa2t3 heterozygotes with a significantly longer latency, suggesting that PRDM14-associated T-ALL is sensitive to Cbfa2t3 levels. Our study highlights how an oncogenic protein uses a native protein in progenitor cells to initiate leukemia, providing insight into PRDM14-driven oncogenesis in other cell types.
Implications:
The pluripotency regulator PRDM14 requires the master hematopoietic regulator CBFA2T3 to initiate leukemia in progenitor cells, demonstrating an oncogenic role for CBFA2T3 and providing an avenue for targeting cancer-initiating cells.
Data from Exosomes Induce Fibroblast Differentiation into Cancer-Associated Fibroblasts through TGFβ Signaling
Authors: Ringuette Goulet Cassandra , Bernard Geneviève , Tremblay Sarah , Chabaud Stéphane , Bolduc Stéphane , Pouliot Frédéric
Published: April 2023

Abstract
A particularly important tumor microenvironment relationship exists between cancer cells and surrounding stromal cells. Fibroblasts, in response to cancer cells, become activated and exhibit myofibroblastic characteristics that favor invasive growth and metastasis. However, the mechanism by which cancer cells promote activation of healthy fibroblasts into cancer-associated fibroblasts (CAF) is still not well understood. Exosomes are nanometer-sized vesicles that shuttle proteins and nucleic acids between cells to establish intercellular communication. Here, bladder cancer–derived exosomes were investigated to determine their role in the activation of healthy primary vesical fibroblasts. Exosomes released by bladder cancer cells are internalized by fibroblasts and promoted the proliferation and expression of CAF markers. In addition, cancer cell–derived exosomes contain TGFβ and in exosome-induced CAFs SMAD-dependent signaling is activated. Furthermore, TGFβ inhibitors attenuated CAF marker expression in healthy fibroblasts. Therefore, these data demonstrate that bladder cancer cells trigger the differentiation of fibroblasts to CAFs by exosomes-mediated TGFβ transfer and SMAD pathway activation. Finally, exosomal TGFβ localized inside the vesicle and contributes 53.4% to 86.3% of the total TGFβ present in the cancer cell supernatant. This study highlights a new function for bladder cancer exosomes as novel modulators of stromal cell differentiation.

Implication: This study identifies exosomal TGFβ as new molecular mechanism involved in cancer-associated fibroblast activation. Mol Cancer Res; 16(7); 1196–204. ©2018 AACR.
Data from Metabolic Alterations in Lung Cancer–Associated Fibroblasts Correlated with Increased Glycolytic Metabolism of the Tumor
Authors: Chaudhri Virendra K. , Salzler Gregory G. , Dick Salihah A. , Buckman Melanie S. , Sordella Raffaella , Karoly Edward D. , Mohney Robert , Stiles Brendon M. , Elemento Olivier , Altorki Nasser K. , McGraw Timothy E.
Published: April 2023

Abstract
Cancer cells undergo a metabolic reprogramming but little is known about metabolic alterations of other cells within tumors. We use mass spectrometry–based profiling and a metabolic pathway–based systems analysis to compare 21 primary human lung cancer–associated fibroblast lines (CAF) to “normal” fibroblast lines (NF) generated from adjacent nonneoplastic lung tissue. CAFs are protumorigenic, although the mechanisms by which CAFs support tumors have not been elucidated. We have identified several pathways whose metabolite abundance globally distinguished CAFs from NFs, suggesting that metabolic alterations are not limited to cancer cells. In addition, we found metabolic differences between CAFs from high and low glycolytic tumors that might reflect distinct roles of CAFs related to the tumor's glycolytic capacity. One such change was an increase of dipeptides in CAFs. Dipeptides primarily arise from the breakdown of proteins. We found in CAFs an increase in basal macroautophagy which likely accounts for the increase in dipeptides. Furthermore, we show a difference between CAFs and NFs in the induction of autophagy promoted by reduced glucose. In sum, our data suggest that increased autophagy may account for metabolic differences between CAFs and NFs and may play additional as yet undetermined roles in lung cancer. Mol Cancer Res; 11(6); 579–92. ©2013 AACR.
Data from An Autocrine VEGF/VEGFR2 and p38 Signaling Loop Confers Resistance to 4-Hydroxytamoxifen in MCF-7 Breast Cancer Cells
Authors: Aesoy Reidun , Sanchez Betzabe Chavez , Norum Jens Henrik , Lewensohn Rolf , Viktorsson Kristina , Linderholm Barbro
Published: April 2023

Abstract
Tamoxifen, a partial estrogen receptor antagonist, is part of the standard treatment of both primary and advanced breast cancers. However, significant proportions of breast cancers are either de novo resistant or develop tamoxifen resistance during the course of treatment through mechanisms which have been only partly characterized. We have previously found that high vascular endothelial growth factor (VEGF) or VEGF receptor 2 (VEGFR2) expression and concomitant high p38 mitogen-activated protein kinase activity within breast cancers predict a poor outcome for tamoxifen-treated patients. Here, we have molecularly dissected how VEGF/VEGFR2 and p38 are linked, and contribute to tamoxifen resistance within breast cancer using a MCF-7 BC cell model with different 4-hydroxytamoxifen (4-OHT) responsiveness. We report that MCF-7 breast cancer cell lines with tamoxifen resistance have increased secretion of VEGF and increased signaling through VEGFR2 compared with parental MCF-7 cells. 4-OHT treatment caused the ablation of VEGF secretion in parental MCF-7 cells, whereas in the tamoxifen-resistant subline, a VEGF/VEGFR2 signaling loop was still evident upon treatment. Increased basal levels of total and phosphorylated p38 were observed in tamoxifen-resistant cells. Pharmacologic inhibition of p38 reduced the proliferation of both tamoxifen-responsive and tamoxifen-resistant cells and showed an additive growth-inhibitory effect in combination with 4-OHT. A connection between VEGF/VEGFR2 and p38 signaling was identified by VEGF and VEGFR2 knockdown, which equally reduced both the total and the active forms of p38 in tamoxifen-resistant cells. Taken together, our results suggest that decreased sensitivity to 4-OHT is caused by a death-protecting VEGF/VEGFR2 and p38 growth factor loop in breast cancer cells. Inhibition of these signaling pathways may be beneficial to overcome tamoxifen resistance. (Mol Cancer Res 2008;6(10):1630–8)
Data from CXCR4, but not CXCR7, Discriminates Metastatic Behavior in Non–Small Cell Lung Cancer Cells
Authors: Choi Young H. , Burdick Marie D. , Strieter Brett A. , Mehrad Borna , Strieter Robert M.
Published: April 2023

Abstract
Chemokines have been implicated as key contributors of non–small cell lung cancer (NSCLC) metastasis. However, the role of CXCR7, a recently discovered receptor for CXCL12 ligand, in the pathogenesis of NSCLC is unknown. To define the relative contribution of chemokine receptors to migration and metastasis, we generated human lung A549 and H157 cell lines with stable knockdown of CXCR4, CXCR7, or both. Cancer cells exhibited chemotaxis to CXCL12 that was enhanced under hypoxic conditions, associated with a parallel induction of CXCR4, but not CXCR7. Interestingly, neither knockdown cell line differed in the rate of proliferation, apoptosis, or cell adherence; however, in both cell lines, CXCL12-induced migration was abolished when CXCR4 signaling was abrogated. In contrast, inhibition of CXCR7 signaling did not alter cellular migration to CXCL12. In an in vivo heterotropic xenograft model using A549 cells, expression of CXCR4, but not CXCR7, on cancer cells was necessary for the development of metastases. In addition, cancer cells knocked down for CXCR4 (or both CXCR4 and CXCR7) produced larger and more vascular tumors as compared with wild-type or CXCR7 knockdown tumors, an effect that was attributable to cancer cell–derived CXCR4 out competing endothelial cells for available CXCL12 in the tumor microenvironment. These results indicate that CXCR4, not CXCR7, expression engages CXCL12 to mediate NSCLC metastatic behavior.

Implications: Targeting CXCR4-mediated migration and metastasis may be a viable therapeutic option in NSCLC. Mol Cancer Res; 12(1); 38–47. ©2013 AACR.
Data from MYC-Driven Tumorigenesis Is Inhibited by WRN Syndrome Gene Deficiency
Authors: Moser Russell , Toyoshima Masafumi , Robinson Kristin , Gurley Kay E. , Howie Heather L. , Davison Jerry , Morgan Martin , Kemp Christopher J. , Grandori Carla
Published: April 2023

Abstract
MYC-induced DNA damage is exacerbated in WRN-deficient cells, leading to replication stress and accelerated cellular senescence. To determine whether WRN deficiency impairs MYC-driven tumor development, we used both xenograft and autochthonous tumor models. Conditional silencing of WRN expression in c-MYC overexpressing non–small cell lung cancer xenografts impaired both tumor establishment and tumor growth. This inhibitory effect of WRN knockdown was accompanied by increased DNA damage, decreased proliferation, and tumor necrosis. In the Eμ-Myc mouse model of B-cell lymphoma, a germline mutation in the helicase domain of Wrn (WrnΔhel/Δhel) resulted in a significant delay in emergence of lethal lymphomas, extending tumor-free survival by more than 30%. Analysis of preneoplastic B cells from Eμ-Myc Wrn mutant mice revealed increased DNA damage, elevation of senescence markers, and decreased proliferation in comparison with cells from age-matched Eμ-Myc mice. Immunohistochemical and global gene expression analysis of overt Eμ-Myc WrnΔhel/Δhel lymphomas showed a marked increase in expression of the CDK inhibitor, p16Ink4a, as well as elevation of TAp63, a known mediator of senescence. Collectively, these studies show that in the context of Myc-associated tumorigenesis, loss of Wrn amplifies the DNA damage response, both in preneoplastic and neoplastic tissue, engaging activation of tumor suppressor pathways. This leads to inhibition of tumor growth and prolonged tumor-free survival. Targeting WRN or its enzymatic function could prove to be an effective strategy in the treatment of MYC-associated cancers. Mol Cancer Res; 10(4); 535–45. ©2012 AACR.
Data from Phosphoinositide 3-kinase/AKT/mTORC1/2 Signaling Determines Sensitivity of Burkitt's Lymphoma Cells to BH3 mimetics
Authors: Spender Lindsay C. , Inman Gareth J.
Published: April 2023

Abstract
Burkitt's lymphoma (BL), driven by translocation and overexpression of the c-MYC gene, is an aggressive, highly proliferative lymphoma, and novel therapeutic strategies are required to overcome drug resistance following conventional treatments. The importance of the prosurvival BCL-2 family member BCL-XL in BL cell survival suggests that antagonistic BH3-mimetic compounds may have therapeutic potential. Here, we show that treatment of BL cell lines with ABT-737 induces caspase-3/7 activation and apoptosis with varying potency. Using selective inhibitors, we identify phosphoinositide 3-kinase (PI3K) as a proproliferative/survival pathway in BL cells and investigate the potential of combined pharmacologic inhibition of both the BCL-2 family and PI3K signaling pathway. PI3K/AKT inhibition and ABT-737 treatment induced synergistic caspase activation, augmented BL cell apoptosis, and rendered chemoresistant cells sensitive. Targeting mTORC1/2 with PP242 was also effective, either as a monotherapy or, more generally, in combination with ABT-737. The combined use of a dual specificity PI3K/mTOR inhibitor (PI 103) with ABT-737 proved highly efficacious. PI 103 treatment of BL cells was associated with an increase in BIM/MCL-1 expression ratios and loss of c-MYC expression. Furthermore, blocking c-MYC function using the inhibitor 10058-F4 also induced apoptosis synergistically with ABT-737, suggesting that maintenance of expression of BCL-2 family members and/or c-MYC by the PI3K/AKT/mTOR pathway could contribute to BL cell survival and resistance to ABT-737. The combined use of BH3 mimetics and selective mTORC1/2 inhibitors may therefore be a useful novel therapeutic approach for the treatment of B-cell malignancy, including chemoresistant lymphomas. Mol Cancer Res; 10(3); 347–59. ©2012 AACR.
Data from Transforming Growth Factor-β Signaling–Deficient Fibroblasts Enhance Hepatocyte Growth Factor Signaling in Mammary Carcinoma Cells to Promote Scattering and Invasion
Authors: Cheng Nikki , Chytil Anna , Shyr Yu , Joly Alison , Moses Harold L.
Published: April 2023

Abstract
Fibroblasts are major cellular components of the tumor microenvironment, regulating tumor cell behavior in part through secretion of extracellular matrix proteins, growth factors, and angiogenic factors. In previous studies, conditional deletion of the type II transforming growth factor-β (TGF-β) receptor in fibroblasts (Tgfbr2FspKO) was shown to promote mammary tumor metastasis in fibroblast-epithelial cell cotransplantation studies in mice, correlating with increased expression of hepatocyte growth factor (HGF). Here, we advance our findings to show that Tgfbr2FspKO fibroblasts enhance HGF/c-Met and HGF/Ron signaling to promote scattering and invasion of mammary carcinoma cells. Blockade of c-Met and Ron by small interfering RNA silencing and pharmacologic inhibitors significantly reduced mammary carcinoma cell scattering and invasion caused by Tgfbr2FspKO fibroblasts. Moreover, neutralizing antibodies to c-Met and Ron significantly inhibited HGF-induced cell scattering and invasion, correlating with reduced Stat3 and p42/44MAPK phosphorylation. Investigation of the signal transducer and activator of transcription 3 (Stat3) and mitogen-activated protein kinase (MAPK) signaling pathways by pharmacologic inhibition and small interfering RNA silencing revealed a cooperative interaction between the two pathways to regulate HGF-induced invasion, scattering, and motility of mammary tumor cells. Furthermore, whereas c-Met was found to regulate both the Stat3 and MAPK signaling pathways, Ron was found to regulate Stat3 but not MAPK signaling in mammary carcinoma cells. These studies show a tumor-suppressive role for TGF-β signaling in fibroblasts, in part by suppressing HGF signaling between mammary fibroblasts and epithelial cells. These studies characterize complex functional roles for HGF and TGF-β signaling in mediating tumor-stromal interactions during mammary tumor cell scattering and invasion, with important implications in the metastatic process. (Mol Cancer Res 2008;6(10):1521–33)
Data from Dual Regulation of Histone Methylation by mTOR Complexes Controls Glioblastoma Tumor Cell Growth via EZH2 and SAM
Authors: Harachi Mio , Masui Kenta , Honda Hiroaki , Muragaki Yoshihiro , Kawamata Takakazu , Cavenee Webster K. , Mischel Paul S. , Shibata Noriyuki
Published: April 2023

Abstract
Epigenetic regulation known for DNA methylation and histone modification is critical for securing proper gene expression and chromosomal function, and its aberration induces various pathologic conditions including cancer. Trimethylation of histone H3 on lysine 27 (H3K27me3) is known to suppress various genes related to cancer cell survival and the level of H3K27me3 may have an influence on tumor progression and malignancy. However, it remains unclear how histone methylation is regulated in response to genetic mutation and microenvironmental cues to facilitate the cancer cell survival. Here, we report a novel mechanism of the specific regulation of H3K27me3 by cooperatively two mTOR complexes, mTORC1 and mTORC2 in human glioblastoma (GBM). Integrated analyses revealed that mTORC1 upregulates the protein expression of enhancer of zeste homolog 2, a main component of polycomb repressive complex 2 which is known as H3K27-specific methyltransferase. The other mTOR complex, mTORC2, regulates production of S-adenosylmethionine, an essential substrate for histone methylation. This cooperative regulation causes H3K27 hypermethylation which subsequently promotes tumor cell survival both in vitro and in vivo xenografted mouse tumor model. These results indicate that activated mTORC1 and mTORC2 complexes cooperatively contribute to tumor progression through specific epigenetic regulation, nominating them as an exploitable therapeutic target against cancer.
Implications:
A dynamic regulation of histone methylation by mTOR complexes promotes tumor growth in human GBM, but at the same time could be exploitable as a novel therapeutic target against this deadly tumor.
Data from Autocrine Leukemia Inhibitory Factor Promotes Esophageal Squamous Cell Carcinoma Progression via Src Family Kinase-Dependent Yes-Associated Protein Activation
Authors: Kawazoe Tetsuro , Saeki Hiroshi , Oki Eiji , Oda Yoshinao , Maehara Yoshihiko , Mori Masaki , Taniguchi Koji
Published: April 2023

Abstract
The IL6 family of cytokines, including IL6 and leukemia-inhibitory factor (LIF), are induced during inflammation and are also expressed in many types of cancer where they play an important role in tumor development. IL6 family cytokines mainly activate the JAK–STAT3 pathway via the coreceptor, gp130, and IL6 is known to activate the Src family kinase (SFK)–Yes-associated protein (YAP) pathway. The current study investigated the role of autocrine LIF in human esophageal squamous cell carcinoma (ESCC) that highly expresses LIF. LIF knockdown had various effects on cancer cells, including profound changes in gene expression, suppression of cell proliferation, migration/invasion and sphere formation, and induction of apoptosis. Similar to IL6, LIF activated the SFK–YAP pathway as well as the JAK–STAT3 pathway. LIF-induced YAP activation was more important for cancer cell proliferation than LIF-induced STAT3 activation, and concomitant YAP and STAT3 activation completely compensated for the role of LIF in human ESCC growth. We also confirmed that SFK activation and LIF expression were correlated with YAP activation in human ESCC clinical samples. Furthermore, simultaneous inhibition of the SFK–YAP and JAK–STAT3 pathways in human ESCC cells was more effective at suppressing cell proliferation than single inhibition, and autocrine LIF signaling promoted human ESCC growth in vivo. Therefore, the LIF–SFK–YAP axis may represent a new therapeutic target for human ESCC.
Implications:
Autocrine LIF signaling promotes human ESCC progression via SFK-dependent YAP activation and is a new potential target of treatment for human ESCC.
Data from Profiling Human Androgen Receptor Mutations Reveals Treatment Effects in a Mouse Model of Prostate Cancer
Authors: O'Mahony Orla A. , Steinkamp Mara P. , Albertelli Megan A. , Brogley Michele , Rehman Haniya , Robins Diane M.
Published: April 2023

Abstract
Gain-of-function mutations in the androgen receptor (AR) are found in prostate cancer and are implicated in the failure of hormone therapy. Most studies have emphasized the ligand-binding domain (LBD) where mutations can create promiscuous receptors, but mutations in the NH2-terminal transactivation domain have also been found. To assess AR alteration as a mechanism of treatment resistance, a mouse model (h/mAR-TRAMP) was used in which the murine AR coding region is replaced by human sequence and prostate cancer initiated by a transgenic oncogene. Mice received either no treatment, androgen depletion by castration, or treatment with antiandrogens, and 20 AR transcripts were sequenced per end-stage tumor. All tumors expressed several mutant alleles, although most mutations were low frequency. Some mutations that occurred multiple times within the population were differentially located dependent on treatment. Mutations in castrated or antiandrogen-treated mice were widely dispersed but with a prominent cluster in the LBD (amino acids 736-771), whereas changes in intact mice centered near the NH2-terminal polymorphic glutamine tract. Functional characterization of selected LBD mutant alleles showed diverse effects on AR activity, with about half of the mutations reducing transactivation in vitro. One receptor, AR-R753Q, behaved in a cell- and promoter-dependent manner, although as a germ-line mutation it causes androgen insensitivity syndrome. This suggests that alleles that are loss of function during development may still activate a subset of AR targets to become gain of function in tumorigenesis. Mutant ARs may thus use multiple mechanisms to evade cancer treatment. (Mol Cancer Res 2008;6(11):1691–701)
Data from Lung Cancer in Mice Induced by the Jaagsiekte Sheep Retrovirus Envelope Protein Is Not Maintained by Rare Cancer Stem Cells, but Tumorigenicity Does Correlate with Wnt Pathway Activation
Authors: Vaughan Andrew E. , Halbert Christine L. , Wootton Sarah K. , Miller A. Dusty
Published: April 2023

Abstract
JSRV, a simple beta-retrovirus, is the etiologic agent of ovine pulmonary adenocarcinoma, a form of non–small cell lung cancer in sheep and goats. It has been shown that the envelope protein alone is sufficient to induce tumorigenesis in the lungs of mice when delivered via an adeno-associated viral vector. Here, we tested the hypothesis that JSRV envelope–induced tumors are maintained by a small population of tumor-initiating cells, termed cancer stem cells. To test this hypothesis, dissociated cancer cells were sorted from envelope-induced tumors in mouse lung based on the putative stem cell markers Sca-1, CD34, and CD133, the pluripotency-associated transcription factor Oct4, and the level of Wnt signaling. No association with increased tumor-initiating capacity was found with any of the cell-surface markers. In addition, we were unable to detect any evidence of Oct4 expression in tumor-bearing mouse lung. However, tumor cells possessing an active Wnt signaling pathway did show a significant correlation with increased tumor formation upon transplantation. Limiting dilution transplant analysis suggests the existence of a large fraction of cells with the ability to propagate tumor growth, with increasing tumor initiation potential correlating with activated Wnt signaling. Mol Cancer Res; 10(1); 86–95. ©2011 AACR.
Data from The Proteasome Activator PA200 Regulates Tumor Cell Responsiveness to Glutamine and Resistance to Ionizing Radiation
Authors: Blickwedehl Jennifer , Olejniczak Scott , Cummings Ryan , Sarvaiya Nilofar , Mantilla Ana , Chanan-Khan Asher , Pandita Tej K. , Schmidt Marion , Thompson Craig B. , Bangia Naveen
Published: April 2023

Abstract
The cellular response to ionizing radiation (IR) involves a variety of mechanisms to repair damage and maintain cell survival. We previously reported that the proteasome activator PA200 promotes long-term cell survival after IR exposure. The molecular function of PA200 is to enhance proteasome-mediated cleavage after glutamate; however, it is not known how this molecular function promotes survival after IR exposure. Here, we report that upon IR exposure, cellular demand for exogenous glutamine is increased. Cells containing PA200 are capable of surviving this IR-induced glutamine demand, whereas PA200-deficient cells show impaired long-term survival. Additional glutamine supplementation reverses the radiosensitivity of PA200-knockdown cells suggesting impaired glutamine homeostasis in these cells. Indeed, PA200-knockdown cells are unable to maintain intracellular glutamine levels. Furthermore, when extracellular glutamine is limiting, cells that contain PA200 respond by slowing growth, but PA200-knockdown cells and cells in which post-glutamyl proteasome activity is inhibited are nonresponsive and continue rapid growth. This cellular unresponsiveness to nutrient depletion is also reflected at the level of the mTOR substrate ribosomal S6 kinase (S6K). Thus, inability to restrict growth causes PA200-deficient cells to continue growing and eventually die due to lack of available glutamine. Together, these data indicate an important role for PA200 and post-glutamyl proteasome activity in maintaining glutamine homeostasis, which appears to be especially important for long-term survival of tumor cells after radiation exposure. Mol Cancer Res; 10(7); 937–44. ©2012 AACR.
Data from High-Throughput Hacking of the Methylation Patterns in Breast Cancer by In vitro Transcription and Thymidine-Specific Cleavage Mass Array on MALDI-TOF Silico-Chip
Authors: Radpour Ramin , Haghighi Mahdi Montazer , Fan Alex Xiu-Cheng , Torbati Peyman Mohammadi , Hahn Sinuhe , Holzgreve Wolfgang , Zhong Xiao Yan
Published: April 2023

Abstract
Over the last decade, the rapidly expanding interest in the involvement of DNA methylation in developmental mechanisms, human diseases, and malignancies has highlighted the need for an accurate, quantitative, and high-throughput assay. Existing methods are limited and are often too laborious for high-throughput analysis or inadequate for quantitative analysis of methylation. Recently, a MassCLEAVE assay has been developed using matrix-assisted laser desorption/ionization time-of-flight mass spectrometry to analyze base-specific methylation patterns after bisulfite conversion. To find an efficient and more cost-effective high-throughput method for analyzing the methylation profile in breast cancer, we developed a method that allows for the simultaneous detection of multiple target CpG residues by using thymidine-specific cleavage mass array on matrix-assisted laser desorption/ionization time-of-flight silicon chips. We used this novel quantitative approach for the analysis of DNA methylation patterns of four tumor suppressor genes in 96 breast tissue samples from 48 patients with breast cancer. Each individual contributed a breast cancer specimen and corresponding adjacent normal tissue. We evaluated the accuracy of the approach and implemented critical improvements in experimental design. (Mol Cancer Res 2008;6(11):1702–9)
Data from Fractalkine Receptor CX3CR1 Is Expressed in Epithelial Ovarian Carcinoma Cells and Required for Motility and Adhesion to Peritoneal Mesothelial Cells
Authors: Kim Mijung , Rooper Lisa , Xie Jia , Kajdacsy-Balla Andre A. , Barbolina Maria V.
Published: April 2023

Abstract
Epithelial ovarian carcinoma (EOC) is a deadly disease, and little is known about the mechanisms underlying its metastatic progression. Using human specimens and established cell lines, we determined that the G-protein–coupled seven-transmembrane fractalkine receptor (CX3CR1) is expressed in primary and metastatic ovarian carcinoma cells. Ovarian carcinoma cells robustly migrated toward CX3CL1, a specific ligand of CX3CR1, in a CX3CR1-dependent manner. Silencing of CX3CR1 reduced migration toward human ovarian carcinoma ascites fluid by approximately 70%. Importantly, adhesion of ovarian carcinoma cells to human peritoneal mesothelial cells was dependent on CX3CL1/CX3CR1 signaling. In addition, CX3CL1 was able to induce cellular proliferation. Together, our data suggest that the fractalkine network may function as a major contributor to the progression of EOC, and further attention to its role in the metastasis of this deadly malignancy is warranted. Mol Cancer Res; 10(1); 11–24. ©2011 AACR.
Data from Somatic Mutations in CCK2R Alter Receptor Activity that Promote Oncogenic Phenotypes
Authors: Willard Melinda D. , Lajiness Mary E. , Wulur Isabella H. , Feng Bo , Swearingen Michelle L. , Uhlik Mark T. , Kinzler Kenneth W. , Velculescu Victor E. , Sjöblom Tobias , Markowitz Sanford D. , Powell Steven M. , Vogelstein Bert , Barber Thomas D.
Published: April 2023

Abstract
The roles of cholecystokinin 2 receptor (CCK2R) in numerous physiologic processes in the gastrointestinal tract and central nervous system are well documented. There has been some evidence that CCK2R alterations play a role in cancers, but the functional significance of these alterations for tumorigenesis is unknown. We have identified six mutations in CCK2R among a panel of 140 colorectal cancers and 44 gastric cancers. We show that these mutations increase receptor activity, activate multiple downstream signaling pathways, increase cell migration, and promote angiogenesis. Our findings suggest that somatic mutations in CCK2R may promote tumorigenesis through deregulated receptor activity and highlight the importance of evaluating CCK2R inhibitors to block both the normal and mutant forms of the receptor. Mol Cancer Res; 10(6); 739–49. ©2012 AACR.
Data from The p38 MAPK–MK2 Axis Regulates E2F1 and FOXM1 Expression after Epirubicin Treatment
Authors: de Olano Natalia , Koo Chuay-Yeng , Monteiro Lara J. , Pinto Paola H. , Gomes Ana R. , Aligue Rosa , Lam Eric W.-F.
Published: April 2023

Abstract
E2F1 is responsible for the regulation of FOXM1 expression, which plays a key role in epirubicin resistance. Here, we examined the role and regulation of E2F1 in response to epirubicin in cancer cells. We first showed that E2F1 plays a key role in promoting FOXM1 expression, cell survival, and epirubicin resistance as its depletion by siRNA attenuated FOXM1 induction and cell viability in response to epirubicin. We also found that the p38–MAPK activity mirrors the expression patterns of E2F1 and FOXM1 in both epirubicin-sensitive and -resistant MCF-7 breast cancer cells, suggesting that p38 has a role in regulating E2F1 expression and epirubicin resistance. Consistently, studies using pharmacologic inhibitors, siRNA knockdown, and knockout mouse embryonic fibroblasts (MEF) revealed that p38 mediates the E2F1 induction by epirubicin and that the induction of E2F1 by p38 is, in turn, mediated through its downstream kinase MK2 [mitogen-activated protein kinase (MAPK)-activated protein kinase 2; MAPKAPK2]. In agreement, in vitro phosphorylation assays showed that MK2 can directly phosphorylate E2F1 at Ser-364. Transfection assays also showed that E2F1 phosphorylation at Ser-364 participates in its induction by epirubicin but also suggests that other phosphorylation events are also involved. In addition, the p38–MK2 axis can also limit c-jun-NH2-kinase (JNK) induction by epirubicin and, notably, JNK represses FOXM1 expression. Collectively, these findings underscore the importance of p38–MK2 signaling in the control of E2F1 and FOXM1 expression as well as epirubicin sensitivity. Mol Cancer Res; 10(9); 1189–202. ©2012 AACR.
Data from STEAP1 Is Associated with the Invasive and Oxidative Stress Phenotype of Ewing Tumors
Authors: Grunewald Thomas G.P. , Diebold Isabel , Esposito Irene , Plehm Stephanie , Hauer Kristina , Thiel Uwe , da Silva-Buttkus Patricia , Neff Frauke , Unland Rebekka , Müller-Tidow Carsten , Zobywalski Colette , Lohrig Katharina , Lewandrowski Urs , Sickmann Albert , da Costa Olivia Prazeres , Görlach Agnes , Cossarizza Andrea , Butt Elke , Richter Günther H.S. , Burdach Stefan
Published: April 2023

Abstract
Ewing tumors comprise the second most common type of bone-associated cancer in children and are characterized by oncogenic EWS/FLI1 fusion proteins and early metastasis. Compelling evidence suggests that elevated levels of intracellular oxidative stress contribute to enhanced aggressiveness of numerous cancers, possibly including Ewing tumors. Using comprehensive microarray analyses and RNA interference, we identified the six-transmembrane epithelial antigen of the prostate 1 (STEAP1)—a membrane-bound mesenchymal stem cell marker of unknown function—as a highly expressed protein in Ewing tumors compared with benign tissues and show its regulation by EWS/FLI1. In addition, we show that STEAP1 knockdown reduces Ewing tumor proliferation, anchorage-independent colony formation as well as invasion in vitro and decreases growth and metastasis of Ewing tumor xenografts in vivo. Moreover, transcriptome and proteome analyses as well as functional studies revealed that STEAP1 expression correlates with oxidative stress responses and elevated levels of reactive oxygen species that in turn are able to regulate redox-sensitive and proinvasive genes. In synopsis, our data suggest that STEAP1 is associated with the invasive behavior and oxidative stress phenotype of Ewing tumors and point to a hitherto unanticipated oncogenic function of STEAP1. Mol Cancer Res; 10(1); 52–65. ©2011 AACR.
Data from α-Catulin Marks the Invasion Front of Squamous Cell Carcinoma and Is Important for Tumor Cell Metastasis
Authors: Cao Christine , Chen Yibu , Masood Rizwan , Sinha Uttam K. , Kobielak Agnieszka
Published: April 2023

Abstract
Squamous cell carcinomas (SCC) comprise the most common types of human epithelial cancers. One subtype, head and neck squamous cell carcinoma (HNSCC), is a particularly aggressive cancer with poor prognosis due to late diagnosis and lymph node metastasis. Of all the processes involved in carcinogenesis, local invasion and distant metastasis are clinically the most relevant, but are the least well understood on a molecular level. Here, we find that in vivo, the α-catenin homologue—α-catulin, a protein originally reported to interact with Lbc Rho guanine nucleotide exchange factor, is highly expressed at the tumor invasion front and in the metastatic streams of cells in both malignant hHNSCCs and a mouse model of oral SCC. Knockdown of α-catulin in hHNSCC cell lines dramatically decrease the migratory and invasive potential of those cells in vitro and metastatic potential in xenotransplants in vivo. Analysis of tumors deficient in α-catulin showed that the tumor cells are unable to invade the surrounding stroma. Accordingly, transcriptional profiling of those tumors revealed that α-catulin ablation is accompanied by changes in genes involved in cell migration and invasion. Interestingly enough, in vitro experiments show that an upregulation of α-catulin expression correlates with the transition of tumor cells from an epithelial to a mesenchymal morphology, as well as an upregulation of epithelial-to-mesenchymal transition (EMT) markers vimentin and snail. Overall, these results strongly indicate that α-catulin contributes to the invasive behavior of metastatic cells and may be used as a prognostic marker and future therapeutic target for patients with cancer. Mol Cancer Res; 10(7); 892–903. ©2012 AACR.
Data from Elevated Asparagine Biosynthesis Drives Brain Tumor Stem Cell Metabolic Plasticity and Resistance to Oxidative Stress
Authors: Thomas Tom M. , Miyaguchi Ken , Edwards Lincoln A. , Wang Hongqiang , Wollebo Hassen , Aiguo Li , Murali Ramachandran , Wang Yizhou , Braas Daniel , Michael Justin S. , Andres Allen M. , Zhang Miqin , Khalili Kamel , Gottlieb Roberta A. , Perez J. Manuel , Yu John S.
Published: April 2023

Abstract
Asparagine synthetase (ASNS) is a gene on the long arm of chromosome 7 that is copy-number amplified in the majority of glioblastomas. ASNS copy-number amplification is associated with a significantly decreased survival. Using patient-derived glioma stem cells (GSC), we showed that significant metabolic alterations occur in gliomas when perturbing the expression of ASNS, which is not merely restricted to amino acid homeostasis. ASNS-high GSCs maintained a slower basal metabolic profile yet readily shifted to a greatly increased capacity for glycolysis and oxidative phosphorylation when needed. This led ASNS-high cells to a greater ability to proliferate and spread into brain tissue. Finally, we demonstrate that these changes confer resistance to cellular stress, notably oxidative stress, through adaptive redox homeostasis that led to radiotherapy resistance. Furthermore, ASNS overexpression led to modifications of the one-carbon metabolism to promote a more antioxidant tumor environment revealing a metabolic vulnerability that may be therapeutically exploited.
Implications:
This study reveals a new role for ASNS in metabolic control and redox homeostasis in glioma stem cells and proposes a new treatment strategy that attempts to exploit one vulnerable metabolic node within the larger multilayered tumor network.
Data from Enhanced Expression of Rab27A Gene by Breast Cancer Cells Promoting Invasiveness and the Metastasis Potential by Secretion of Insulin-Like Growth Factor-II
Authors: Wang Jin-Song , Wang Fu-Bin , Zhang Qiang-Ge , Shen Zhen-Zhou , Shao Zhi-Ming
Published: April 2023

Abstract
In addition to the functions of transporting melanosome in melanocytes and releasing contents of lytic granules in CTLs, Rab27A was recently shown to be involved in exocytosis of insulin and chromaffin granules in endocrine cells; it was also reported to be expressed in an exceptionally broad range of specialized secretory cells. As autocrine and paracrine cytokines are essential for invasion and metastasis in some solid tumors, blocking them may be an effective strategy to prevent tumor dissemination. In the present study, we show that Rab27A is associated with invasive and metastatic potentials of human breast cancer cells. The overexpression of Rab27A protein redistributed the cell cycle and increased the invasive and metastatic abilities in breast cancer cells both in vitro and in vivo. We also certified that Rab27A conferred the invasive and metastatic phenotypes on breast cancer cells by promoting the secretion of insulin-like growth factor-II (IGF-II), which regulates the expression of p16, vascular endothelial growth factor, matrix metalloproteinase-9, cathepsin D, cyclin D1, and urokinase-type plasminogen activator. These data provide functional evidence that Rab27A acts as a novel mediator of invasion and metastasis promotion in human breast cancer cells, at least in part, through regulating the secretion of IGF-II, suggesting that synergistic suppression of Rab27A and IGF-II activities holds a promise for preventing breast cancer invasion and metastasis. (Mol Cancer Res 2008;6(3):372–82)