bluuebunny/crossref_metadata_2025_split huggingface dataset:
Down-regulation of RAB6KIFL/KIF20A, a Kinesin Involved with Membrane Trafficking of Discs Large Homologue 5, Can Attenuate Growth of Pancreatic Cancer Cell
Authors: Taniuchi Keisuke , Nakagawa Hidewaki , Nakamura Toru , Eguchi Hidetoshi , Ohigashi Hiroaki , Ishikawa Osamu , Katagiri Toyomasa , Nakamura Yusuke 
Published: June 2022

Abstract
To identify novel molecular targets for treatment of pancreatic ductal adenocarcinoma (PDAC), we generated precise gene expression profiles of PDACs on a genome-wide cDNA microarray after populations of tumor cells were purified by laser microdissection. Through functional analysis of genes that were transactivated in PDACs, we identified RAB6KIFL as a candidate for development of drugs to treat PDACs at the molecular level. Knockdown of endogenous RAB6KIFL expression in PDAC cell lines by small interfering RNA drastically attenuated growth of those cells, suggesting an essential role for the gene product in maintaining viability of PDAC cells. RAB6KIFL belongs to the kinesin superfamily of motor proteins, which have critical functions in trafficking of molecules and organelles. Proteomics analyses using a polyclonal anti-RAB6KIFL antibody identified one of the cargoes transported by RAB6KIFL as discs, large homologue 5 (DLG5), a scaffolding protein that may link the vinexin-β-catenin complex at sites of cell-cell contact. Like RAB6KIFL, DLG5 was overexpressed in PDACs, and knockdown of endogenous DLG5 by small interfering RNA significantly suppressed the growth of PDAC cells as well. Decreased levels of endogenous RAB6KIFL in PDAC cells altered the subcellular localization of DLG5 from cytoplasmic membranes to cytoplasm. Our results imply that collaboration of RAB6KIFL and DLG5 is likely to be involved in pancreatic carcinogenesis. These molecules should be promising targets for development of new therapeutic strategies for PDACs.
Decreased Fidelity in Replicating CpG Methylation Patterns in Cancer Cells
Authors: Ushijima Toshikazu , Watanabe Naoko , Shimizu Kimiko , Miyamoto Kazuaki , Sugimura Takashi , Kaneda Atsushi 
Published: June 2022

Abstract
The unmethylated or methylated status of individual CpG sites is faithfully copied into daughter cells. Here, we analyzed the fidelity in replicating their methylation statuses in cancer cells. A single cell was clonally expanded, and methylation statuses of individual CpG sites were determined for an average of 12.5 DNA molecules obtained from the expanded population. By counting the deviation from the original methylation patterns inferred, the number of errors was measured. The analysis was done in four gastric cancer cell lines for five CpG islands (CGI), and repeated six times (total 1,495 clones sequenced). HSC39 and HSC57 showed error rates &lt;1.0 × 10−3 errors per site per generation (99.90-100% fidelity) for all the five CGIs. In contrast, AGS showed significantly elevated error rates, mainly due to increased de novo methylation, in three CGIs (1.6- to 3.2-fold), and KATOIII showed a significantly elevated error rate in one CGI (2.2-fold). By selective amplification of fully methylated DNA molecules by methylation-specific PCR, those were stochastically detected in KATOIII and AGS but never in HSC39 and HSC57. When methylation of entire CGIs was examined for eight additional CGIs, KATOIII and AGS had frequent methylation, whereas HSC39 and HSC57 had few. KATOIII and AGS had four and eight times, respectively, as high expression levels of DNMT3B as HSC39. These data showed that some cancer cells have decreased fidelity in replicating methylation patterns in some CGIs, and that the decrease could lead to methylation of the entire CGIs.
Thymosin β10 Inhibits Angiogenesis and Tumor Growth by Interfering with Ras Function
Authors: Lee Seung-Hoon , Son Myung Jin , Oh Sun-Hee , Rho Seung-Bae , Park Kyungsook , Kim Yung-Jin , Park Mi-Sun , Lee Je-Ho 
Published: June 2022

Abstract
Thymosin β10 is a monomeric actin sequestering protein that regulates actin dynamics. Previously, we and others have shown that thymosin β10 acts as an actin-mediated tumor suppressor. In this study, we show that thymosin β10 is not only a cytoskeletal regulator, but that it also acts as a potent inhibitor of angiogenesis and tumor growth by its interaction with Ras. We found that overexpressed thymosin β10 significantly inhibited vascular endothelial growth factor–induced endothelial cell proliferation, migration, invasion, and tube formation in vitro. Vessel sprouting was also inhibited ex vivo. We further show that thymosin β10 directly interacted with Ras. This interaction resulted in inhibition of the Ras downstream mitogen-activated protein kinase/extracellular signal-regulated kinase kinase signaling pathway, leading to decreased vascular endothelial growth factor production. Thymosin β10 injected into a xenograft model of human ovarian cancer in nude mice markedly inhibited tumor growth and reduced tumor vascularity. In contrast, a related thymosin family member, thymosin β4, did not bind to Ras and showed positive effects on angiogenesis. These findings show that the inhibition of Ras signal transduction by thymosin β10 results in antiangiogenic and antitumor effects, suggesting that thymosin β10 may be valuable in anticancer therapy.
Wavelet Transformations of Tumor Expression Profiles Reveals a Pervasive Genome-Wide Imprinting of Aneuploidy on the Cancer Transcriptome
Authors: Aggarwal Amit , Leong Siew Hong , Lee Cheryl , Kon Oi Lian , Tan Patrick 
Published: June 2022

Abstract
Aneuploidy is frequently observed in many human cancers, but its global effects on the cancer transcriptome are controversial. We did a systematic and unbiased genome-wide survey to determine the extent a tumor's abnormal karyotype (chromosomal amplifications and deletions) is detectably “imprinted” onto that tumor's gene expression profile. By using a novel methodology employing wavelet transform signal-processing algorithms to identify genomic regions of coordinated gene expression (wavelet variance scanning), we analyzed a series of gastric cancer cell lines and identified &gt;100 genomic regions exhibiting distinct patterns of subtle but significant coordinated transcription, ranging from tens to hundreds of genes. A large majority (80%) of these regions could be specifically localized to a site of detectable genomic amplification or deletion; reciprocally, up to 47% of the total aneuploidy in each of the individual cell lines could be directly inferred from the gene expression data. Genome-wide portraits of tumor aneuploidy can thus be successfully reconstructed solely from gene expression data, implying that the effects of aneuploidy must be pervasively and globally imprinted within the cancer transcriptome. Aneuploidy may contribute to tumor behavior not just by affecting the expression of a few key oncogenes and tumor suppressor genes but also by subtly altering the expression levels of hundreds of genes in the oncogenome.
Glioma Formation in Neurofibromatosis 1 Reflects Preferential Activation of K-RAS in Astrocytes
Authors: Dasgupta Biplab , Li Wen , Perry Arie , Gutmann David H. 
Published: June 2022

Abstract
Children with the tumor predisposition syndrome, neurofibromatosis 1 (NF1), develop optic pathway gliomas. The NF1 gene product, neurofibromin, functions as a negative regulator of RAS, such that NF1 inactivation results in RAS hyperactivation. Recent studies have highlighted the divergent biological and biochemical properties of the various RAS isoforms, which prompted us to examine the consequence of Nf1 inactivation in astrocytes on RAS isoform activation in vitro and in vivo. In this report, we show that only K-RAS is activated in Nf1−/− astrocytes and that activation of K-RAS, but not H-RAS, accounts for the proliferative advantage and abnormal actin cytoskeleton–mediated processes observed in Nf1−/− astrocytes in vitro. Moreover, dominant inhibitory K-RAS corrects these abnormalities in Nf1−/− astrocytes invitro. Lastly, we show that Nf1+/− mice with astrocyte-specific activated K-RAS expression in vivo develop optic pathway gliomas, similar to our previously reported Nf1+/− mice with astrocyte Nf1 inactivation. Collectively, our results show that K-RAS is the primary target for neurofibromin GTPase-activating protein activity in vitro and in vivo and that K-RAS activation in astrocytes recapitulates the biochemical, biological, and tumorigenic properties of neurofibromin loss.
Novel Prognostic Value of Nuclear Epidermal Growth Factor Receptor in Breast Cancer
Authors: Lo Hui-Wen , Xia Weiya , Wei Yongkun , Ali-Seyed Mohamed , Huang Shiu-Feng , Hung Mien-Chie 
Published: June 2022

AbstractEpidermal growth factor receptor (EGFR) has been detected in the nucleus of cancer cells and primary tumors for decades. While localized in the nucleus, EGFR functions as a transcriptional regulator resulting in the activation of the cyclin D1 gene. Despite nuclear accumulation of EGFR is linked to increased DNA synthesis and proliferative potential, the pathological significance of nuclear EGFR, however, remains uninvestigated. Furthermore, expression of EGFR has not provided a consistent predictive value for survival of breast cancer patients. Here, we analyzed 130 breast carcinomas via immunohistochemical analyses for the levels of nuclear and non-nuclear EGFR. We found 37.7% of the cohort immunostained positively for nuclear EGFR and 6.9% with high levels of expression. Importantly, Kaplan-Meier survival analysis and log-rank test revealed a significant inverse correlation between high nuclear EGFR and overall survival (P = 0.009). Expression of nuclear EGFR correlated positively with increased levels of cyclin D1 and Ki-67, both are indicators for cell proliferation. In contrast, expression of non-nuclear EGFR did not significantly correlate with those of cyclin D1 and Ki-67 or the overall survival rate. In addition, we analyzed 37 oral squamous carcinomas for EGFR expression and found 24.3% of the cases to contain moderate/high levels of nuclear EGFR. Taken together, our findings indicate pathological significance of nuclear EGFR and may have important clinical implication.
Expression in Hematological Malignancies of a Glucocorticoid Receptor Splice Variant That Augments Glucocorticoid Receptor-mediated Effects in Transfected Cells
Authors: de Lange Pieter , Segeren Christine M. , Koper Jan W. , Wiemer Erik , Sonneveld Pieter , Brinkmann Albert O. , White Anne , Brogan Iain J. , de Jong Frank H. , Lamberts Steven W. J. 
Published: June 2022

Abstract
Glucocorticoids play an important role in the treatment of a number of hematological malignancies, such as multiple myeloma. The effects of glucocorticoids are mediated through the glucocorticoid receptor α, the abundance of which can be modulated by alternative splicing of the glucocorticoid receptor mRNA. Two splice variants of the glucocorticoid receptor mRNA have been described: glucocorticoid receptor β, which reportedly has a dominant negative effect on the actions of the glucocorticoid receptor α, and glucocorticoid receptor P, of which the effects are unknown. In this study, we have investigated the expression levels of these two splice variants at the mRNA level in multiple myeloma cells and in a number of other hematological tumors. Although the glucocorticoid receptor β mRNA was, if at all, expressed at very low levels, considerable amounts (up to 50% of the total glucocorticoid receptor mRNA) glucocorticoid receptor P mRNA was present in most hematological malignancies. In transient transfection studies in several cell types and in multiple myeloma cell lines, the glucocorticoid receptor P increased the activity of the glucocorticoid receptor α. These results suggest that the relative levels of the glucocorticoid receptor α and the glucocorticoid receptor P may play a role in the occurrence of glucocorticoid resistance in tumor cells during the treatment of hematological malignancies with glucocorticoids.
Antiapoptotic Effect of Serum and Glucocorticoid-Inducible Protein Kinase Is Mediated by Novel Mechanism Activating IκB Kinase
Authors: Zhang Liping , Cui Ruwen , Cheng Xiaodong , Du Jie 
Published: June 2022

AbstractSerum and glucocorticoid inducible protein kinase (SGK) plays a crucial role in promoting cell survival, but the mechanisms for this response are not clear. We show that SGK is involved in the regulation of apoptosis in breast cancer cells by modulating the transcriptional activity of nuclear transcription factor κB (NF-κB). High levels of SGK expression were observed in human breast cancer samples. When SGK was reduced the apoptotic rate increased, and increased SGK activity prevents serum withdrawal–induced apoptosis. SGK-induced cell survival was abolished by a dominant-negative form of IκB kinase β (IKKβ, K44A) or a null mutation of IKKβ in mouse embryonic fibroblast cells indicating involvement of the NF-κB pathway. Serum-induced SGK or increased expression of SGK activated NF-κB transcriptional activity, whereas small interference RNA to SGK blocked NF-κB activity. Coexpression of SGK and IKKβ significantly increased the activation of NF-κB (versus expression of IKKβ alone). Expression of dominant-negative IKKβ K44A, IκBα AA, and kinase-dead SGK (127KM) blocked the ability of SGK to stimulate NF-κB activity, suggesting that IKKβ is a target of SGK. We also show that SGK enhances the ability of IKKβ to phosphorylate endogenous IκBα in cells or recombinant glutathione S-transferase-IκBα in vitro and increases IκBα degradation; SGK physically associates with and activates IKKβ in MDA231 cells via phosphorylation of Ser181 in IKKβ. Taken together, we conclude that SGK acts as an oncogene in breast cancer cells through activation of the IKK-NF-κB pathway, thereby preventing apoptosis. Blocking SGK expression/activity represents a potential therapeutic approach for breast cancer treatment.
The Serum Glycoprotein Fetuin-A Promotes Lewis Lung Carcinoma Tumorigenesis via Adhesive-Dependent and Adhesive-Independent Mechanisms
Authors: Kundranda Madappa N. , Henderson Melodie , Carter Kathy J. , Gorden Lee , Binhazim Awadh , Ray Sanhita , Baptiste Trevor , Shokrani Masih , Leite-Browning Maria L. , Jahnen-Dechent Willi , Matrisian Lynn M. , Ochieng Josiah 
Published: June 2022

Abstract
Fetuin-A is a serum glycoprotein in the cystatin family associated with the regulation of soft tissue calcification. We tested the role of systemic fetuin in tumor cell growth and metastasis by injecting Lewis lung carcinoma (LLC) cells into fetuin-A null and their wild-type (WT) littermate control C57BL/6 mice via the tail vein, s.c., and intrasplenic routes. In the experimental metastasis assay, the lungs of the WT mice were filled with metastatic nodules, whereas the lungs of the fetuin-A null mutant mice were virtually free of colonies at the end of 2 weeks. Lung colonization responded to the levels of serum fetuin-A in a dose-dependent manner, as observed by the formation of half as many colonies in mice heterozygous for the fetuin-A locus compared with homozygous WT mice and restoration of lung colonization by the administration of purified fetuin-A to fetuin-A-null mice. Serum fetuin-A also influenced the growth of LLC cells injected s.c.: fetuin-A-null mice developed small s.c. tumors only after a substantial delay. Similarly, intrasplenic injection of LLC cells resulted in rapid colonization of the liver with metastasis to the lungs within 2 weeks in the WT but not fetuin-A null mice. To examine the mechanism by which fetuin-A influences LLC colonization and growth, we showed that LLC tumor cells adhere to fetuin-A in a Ca2+-dependent fashion, resulting in growth of the tumor cells. These studies support the role of fetuin-A as a major growth promoter in serum that can influence tumor establishment and growth.
Induction of Ornithine Decarboxylase Activity Is a Necessary Step for Mitogen-Activated Protein Kinase Kinase–Induced Skin Tumorigenesis
Authors: Feith David J. , Bol David K. , Carboni Joan M. , Lynch Mark J. , Sass-Kuhn Suzanne , Shoop Paula L. , Shantz Lisa M. 
Published: June 2022

Abstract
A transgenic mouse line overexpressing a constitutively active mutant of MEK1, a downstream effector of Ras, driven by the keratin 14 (K14) promoter, has been used to test the hypothesis that ornithine decarboxylase (ODC) induction during tumor promotion following a single initiating event [i.e., the activation of the Raf/mitogen-activated protein kinase kinase/extracellular signal-regulated kinase (Raf/MEK/ERK) pathway], is a necessary step in skin carcinogenesis. K14-MEK mice exhibit moderate hyperplasia, with spontaneous skin tumor development within 5 weeks of birth. Analysis of epidermis and dermis showed induction of MEK protein and ERK1/ERK2 phosphorylation, but no change in Akt-1, suggesting that the PI 3-kinase pathway, another pathway downstream of ras, is not activated. Examination of tumors revealed high levels of ODC protein and activity, indicating that activation of signaling cascades dependent on MEK activity is a sufficient stimulus for ODC induction. When K14-MEK mice were given α-difluoromethylornithine (DFMO), a suicide inactivator of ODC, in the drinking water from birth, there was a dramatic delay in the onset of tumor growth (∼6 weeks), and only 25% of DFMO-treated mice developed tumors by 15 weeks of age. All untreated K14-MEK mice developed tumors by 6 weeks of age. Treatment of tumor-bearing mice with DFMO reduced both tumor size and tumor number within several weeks. Tumor regression was the result of both inhibition of proliferation and increased apoptosis in tumors. The results establish ODC activation as an important component of the Raf/MEK/ERK pathway, and identify K14-MEK mice as a valuable model with which to study the regulation of ODC in ras carcinogenesis.
Loss of Heterozygosity Analysis and DNA Copy Number Measurement on 8p in Bladder Cancer Reveals Two Mechanisms of Allelic Loss
Authors: Adams Jacqui , Williams Sarah V. , Aveyard Joanne S. , Knowles Margaret A. 
Published: June 2022

Abstract
Many epithelial tumors show deletion of the short arm of chromosome 8 that is related to aggressive disease or adverse prognosis. In undissected samples of urothelial cell carcinoma of the bladder, at least two regions of loss of heterozygosity (LOH) were identified previously within a small region of 8p11-p12. LOH analysis on a panel of pure tumor DNA samples confirmed this and identified tumors with allelic imbalance, some with clear breakpoints in 8p12. This suggests either that these samples contained genetically distinct subclones or that breakpoints in 8p12 may confer a selective advantage without LOH. To assess the mechanism of LOH and to map breakpoints precisely, a panel of bladder cancer cell lines was examined. Microsatellite analysis of 8p markers identified regions of contiguous homozygosity that coincided with regions of LOH in tumors. Fluorescence in situ hybridization analysis was carried out on seven cell lines predicted to have 8p LOH using a chromosome 8 paint, a chromosome 8 centromeric probe, and a series of single-copy genomic probes. This revealed overall underrepresentation of 8p and overrepresentation of 8q. Several breakpoints and one interstitial deletion were identified in 8p12. Two cell lines with extensive interstitial regions of homozygosity showed no reduction in DNA copy number by fluorescence in situ hybridization analysis, indicating that, in addition to large deletions and rearrangements of 8p, small regions of interstitial LOH on 8p12 may be generated by mitotic recombination. This implicates both major DNA double-strand break repair mechanisms in the generation of 8p alterations.
The Low Molecular Weight Cyclin E Isoforms Augment Angiogenesis and Metastasis of Human Melanoma Cells In vivo
Authors: Bales Elise , Mills Lisa , Milam Nancy , McGahren-Murray Mollianne , Bandyopadhyay Debdutta , Chen Dahu , Reed Jon A. , Timchenko Nikolai , van den Oord Joost J. , Bar-Eli Menashe , Keyomarsi Khandan , Medrano Estela E. 
Published: June 2022

Abstract
Immunohistochemical analysis has consistently shown that cyclin E is up-regulated in human malignant melanomas in vivo. Here we analyzed such expression in more detail and show that cyclin E is overexpressed and present in low molecular weight (LMW) isoforms in metastatic melanoma and in a subset of primary invasive melanoma tumor tissues, but not in benign nevi. Human metastatic melanoma cell lines, but not normal melanocytes, also expressed the LMW cyclin E forms. The biological significance of these findings was established by showing that overexpression of two LMW cyclin E forms named cyclin E truncated 1 [cyclinE(T1)] and cyclin E truncated 2 [cyclinE(T2)] in a low tumorigenic and non-metastatic primary cutaneous melanoma cell line generated angiogenic tumors with prominent perineural invasion compared with full-length cyclin E. In addition, cyclin E(T1)– and cyclin E(T2)–expressing melanoma cells displayed a dramatic increase in the incidence and number of metastases in an experimental lung metastasis assay. Together, these results indicate that the LMW cyclin E forms are functional and likely act as regulators of human melanoma tumor progression and invasion.
Metastasis Suppression by Breast Cancer Metastasis Suppressor 1 Involves Reduction of Phosphoinositide Signaling in MDA-MB-435 Breast Carcinoma Cells
Authors: DeWald Daryll B. , Torabinejad Javad , Samant Rajeev S. , Johnston Derrick , Erin Nuray , Shope Joseph C. , Xie Yi , Welch Danny R. 
Published: June 2022

Abstract
Several molecules that suppress metastasis without suppressing tumorigenicity have been identified, but their mechanisms of action have not yet been determined. Many block growth at the secondary site, suggesting involvement in how cells respond to signals from the extracellular milieu. Breast cancer metastasis suppressor 1 (BRMS1)–transfected MDA-MB-435 cells were examined for modifications of phosphoinositide signaling as a potential mechanism for metastasis suppression. 435/BRMS1 cells expressed &lt;10% of phosphatidylinositol-4, 5-bisphosphate compared with parental cells, whereas levels of the PtdIns(4)P and phosphatidylinositol-3-phosphate were unchanged. Inositol (1,4,5)-trisphosphate [Ins(1,4,5)P3] were decreased in 435/BRMS1 cells by ∼50%. Phosphatidylinositol-3,4,5-trisphosphate levels were undetectable in 435/BRMS1 cells, even when stimulated by exogenous insulin or platelet-derived growth factor. Immunofluorescence microscopy to examine cellular distribution confirmed that phosphatidylinositol-4,5-bisphosphate distribution with cells was unchanged but was uniformly decreased throughout the cell. Although the gross morphology of 435/BRMS1 cells is similar to the parent, filamentous actin was more readily apparent in 435/BRMS1. Intracellular calcium, measured using Fluo-3 and Fura-2 fluorescent calcium indicator dyes, was somewhat lower, but not statistically different in 435/BRMS1 compared with parental cell. However, when stimulated with platelet-derived growth factor, MDA-MB-435 cells, but not 435/BRMS1 cells mobilized intracellular calcium. Taken together, these results implicate signaling through phosphoinositides in the regulation of breast cancer metastasis, specifically metastasis that can be suppressed by BRMS1.