bluuebunny/crossref_metadata_2025_split huggingface dataset:
The Retinoic Acid Synthesis GeneALDH1a2Is a Candidate Tumor Suppressor in Prostate Cancer
Authors: Kim Hanna , Lapointe Jacques , Kaygusuz Gulsah , Ong David E. , Li Chunde , van de Rijn Matt , Brooks James D. , Pollack Jonathan R. 
Published: September 2005

AbstractProstate cancer is the most common cancer among men in the United States, and aberrant DNA methylation is known to be an early molecular event in its development. Here, we have used expression profiling to identify novel hypermethylated genes whose expression is induced by treatment of prostate cancer cell lines with the DNA methyltransferase inhibitor 5-Aza-2′-deoxycytidine (5-aza-dC). Of the 271 genes that were induced by 5-aza-dC treatment, 25 also displayed reduced expression in primary prostate tumors compared with normal prostate tissue, and the decreased expression of only one gene, aldehyde dehydrogenase 1 family, member A2 (ALDH1a2), was also associated with shorter recurrence-free survival. ALDH1a2 encodes an enzyme responsible for synthesis of retinoic acid (RA), a compound with prodifferentiation properties. By immunohistochemistry, we observed that ALDH1a2 was expressed in epithelia from normal prostate but not prostate cancer. Using bisulfite sequencing, we determined that the ALDH1a2 promoter region was significantly hypermethylated in primary prostate tumors compared with normal prostate specimens (P = 0.01). Finally, transfection-mediated reexpression of wild-type ALDH1a2 (but not a presumptive catalytically dead mutant) in the prostate cancer cell line DU145 resulted in decreased colony growth (P &lt; 0.0001), comparable with treatment with either 5-aza-dC or RA. Taken together, our findings implicate ALDH1a2 as a candidate tumor suppressor gene in prostate cancer and further support a role of retinoids in the prevention or treatment of prostate cancer.
Intratumoral T-Cell Infiltrates and MHC Class I Expression in Patients with Stage IV Melanoma
Authors: Al-Batran Salah-Eddin , Rafiyan Mohammad-Reza , Atmaca Akin , Neumann Antje , Karbach Julia , Bender Armin , Weidmann Eckhart , Altmannsberger Hans-Michael , Knuth Alexander , Jäger Elke 
Published: September 2005

Abstract
The infiltration of tumors by T cells has been shown to correlate with prolonged patients' survival. However, it remains unclear why only some tumors are infiltrated with T cells. This study was designed to investigate possible correlations between intratumoral T-cell infiltrates and the expression of cancer-associated antigens and MHC class I and II molecules in patients with melanoma. Fresh frozen samples from 124 stage IV melanoma patients were analyzed by immunohistochemistry for the expression of Melan-A/MART-1, tyrosinase, gp100, NY-ESO-1, and MHC class I and II. Intratumoral T-cell and B-cell infiltrates were detected by staining with anti-CD4, anti-CD8, anti-CD3, and L26 antibodies. The NY-ESO-1 serum antibody status was assessed by Western blot analysis. Intratumoral CD8+ and CD4+ T cells were detected in 63.9% and 71.3% of patients, respectively. We observed a significant heterogeneity of the expression of the melanocyte differentiation antigens, NY-ESO-1, and MHC class I and II molecules. The only significant correlation was found between the expression of MHC class I and the presence of CD4+ and CD8+ T cells (P &lt; 0.0001). There was a strong association between these two variables with respect to the density and distribution of infiltrating T cells and the pattern of MHC class I expression (focal versus homogenous). Intratumoral T-cell infiltration is closely correlated with the MHC class I expression but not with the expression of differentiation antigens, cancer-associated antigens, or MHC class II molecules. These results may have implications for the definition of prognostic variables and for the identification of patients who may benefit from antigen-specific cancer immunotherapy.
Cloning and Characterization of the Novel Chimeric Gene TEL/PTPRR in Acute Myelogenous Leukemia with inv(12)(p13q13)
Authors: Nakamura Fumihiko , Nakamura Yuichi , Maki Kazuhiro , Sato Yuko , Mitani Kinuko 
Published: September 2005

Abstract
We have cloned a novel TEL/protein tyrosine phosphatase receptor-type R (PTPRR) chimeric gene generated by inv(12)(p13q13). PTPRR is the first protein tyrosine phosphatase identified as a fusion partner of TEL. The chimeric gene fused exon 4 of the TEL gene with exon 7 of the PTPRR gene, and produced 10 isoforms through alternative splicing. Two isoforms that were expressed at the highest level in the leukemic cells could have been translated into COOH-terminally truncated TEL protein possessing the helix-loop-helix domain (tTEL) and TEL/PTPRR chimeric protein linking the helix-loop-helix domain of TEL to the catalytic domain of PTPRR. These two mutant proteins exerted a dominant-negative effect over transcriptional repression mediated by wild-type TEL, although they themselves did not show any transcriptional activity. Heterodimerization with wild-type TEL might be an underlying mechanism in this effect. TEL/PTPRR did not exhibit any tyrosine phosphatase activity. Importantly, overexpression of TEL/PTPRR in granulocyte macrophage colony-stimulating factor–dependent UT7/GM cells resulted in their factor-independent proliferation, whereas overexpression of tTEL did not. After cytokine depletion, phosphorylated signal transducers and activators of transcription 3 (STAT3) significantly declined in mock cells, but remained in both tTEL- and TEL/PTPRR-overexpressing cells. Loss of tumor suppressive function of wild-type TEL and maintenance of STAT3-mediated signal could at least partly contribute to the leukemogenesis caused by inv(12)(p13q13).
Differences in Glycosylation Patterns of Heat Shock Protein, gp96: Implications for Prostate Cancer Prevention
Authors: Suriano Robert , Ghosh Salil K. , Ashok Badithe T. , Mittelman Abraham , Chen Yuangen , Banerjee Asesh , Tiwari Raj K. 
Published: September 2005

Abstract
Heat shock protein gp96 induces a tumor-specific protective immunity in a variety of experimental tumor models. Because the primary sequences of the glycoprotein, gp96 are identical between tumor and normal tissues, the peptides associated with gp96 and/or the posttranslational modifications of gp96, determine its immunogenicity. Gp96-associated peptides constitute the antigenic repertoire of the source tissue; thus, purified gp96-peptide complexes have clinical significance as autologous cancer vaccines. However, the role of altered glycosylation and its contribution in the biological as well as immunologic activity of gp96 still remains uncharacterized. We examined the cancer-specific glycosylation patterns of gp96. To this end, monosaccharide compositions of gp96 were compared between normal rat prostate and two cancerous rat prostate tissues, nonmetastatic/androgen-dependent Dunning G and metastatic/androgen-independent MAT-LyLu, as well as two human nonmetastatic prostate cancer cell lines, androgen-dependent LnCaP and androgen-independent DU145. Marked differences were observed between the gp96 monosaccharide compositions of the normal and cancerous tissues. Furthermore, gp96 molecules from more aggressive cellular transformations were found to carry decreasing quantities of several monosaccharides as well as sum total content of neutral and amino sugars. We believe that the unique glycosylation patterns contribute to cellular phenotype and that the posttranslational modifications of gp96 may affect its functional attributes.
BRCA2 Suppresses Cell Proliferation via Stabilizing MAGE-D1
Authors: Tian Xin-xia , Rai Deepak , Li Jun , Zou Chaozhong , Bai Yujie , Wazer David , Band Vimla , Gao Qingshen 
Published: September 2005

Abstract
Germ line mutations in BRCA2 gene predispose women to early-onset familial breast and ovarian cancer. BRCA2 is a protein of multiple functions. In addition to its role in DNA double-strand break repair, BRCA2 also plays a role in stabilization of stalled DNA replication forks, cytokinesis, transcription regulation, mammalian gametogenesis, centrosome duplication, and suppression of cell proliferation. However, how BRCA2 mutations predispose women specifically to breast and ovarian cancer remains undefined. Here we found that BRCA2 binds and stabilizes MAGE-D1, a member of the MAGE gene family of proteins. Expression of BRCA2 and MAGE-D1 synergistically suppresses cell proliferation independently of the p53 pathway. Using two MAGE-D1 RNA interferences and two cell lines expressing low or undetectable levels of MAGE-D1, we further showed that the expression of MAGE-D1 is required for BRCA2-mediated suppression of cell proliferation, indicating that MAGE-D1 is a downstream target of BRCA2 and that BRCA2 suppresses cell proliferation via stabilizing MAGE-D1. Importantly, MAGE-D1 protein expression was reduced in 6 of 16 breast carcinoma cell lines tested as compared with untransformed immortal mammary epithelial cell lines, suggesting that suppression of MAGE-D1 expression may be involved in the tumorigenesis of a subset of sporadic breast cancers.
A Monoclonal Antibody that Binds Anionic Phospholipids on Tumor Blood Vessels Enhances the Antitumor Effect of Docetaxel on Human Breast Tumors in Mice
Authors: Huang Xianming , Bennett Mary , Thorpe Philip E. 
Published: September 2005

Abstract
Anionic phospholipids, principally phosphatidylserine, become exposed on the external surface of viable vascular endothelial cells in tumors, providing an excellent marker for tumor vascular targeting. We recently raised an IgG monoclonal antibody, 3G4, which binds to anionic phospholipids in a β2-glycoprotein I–dependent manner. It inhibited tumor growth in a variety of rodent tumor models by stimulating antibody-dependent cellular cytotoxicity toward tumor vessels. In the present study, we tested the hypothesis that docetaxel, which is known to have antivascular effects on tumors, might induce exposure of anionic phospholipids on tumor vasculature and, thus, enhance the antitumor activity of 3G4. Treatment of human umbilical vascular endothelial cells with subtoxic concentrations of docetaxel (20 pmol/L) in vitro caused anionic phospholipids to be externalized without inducing apoptosis. Docetaxel treatment of mice increased the percentage of tumor vessels that expose anionic phospholipids from 35% to 60%. No induction of phosphatidylserine was observed on vessels in normal tissues even after systemic treatment with docetaxel. Treatment of mice bearing orthotopic MDA-MB-435 human breast tumors with 3G4 plus docetaxel inhibited tumor growth by 93%. Treatment of mice bearing disseminated MDA-MB-435 tumors with 3G4 plus docetaxel reduced the average number of tumor colonies in the lungs by 93% and half the animals did not develop tumors. In both tumor models, the antitumor effect of the combination was statistically superior (P &lt; 0.01) to that of docetaxel or 3G4 alone. Combination therapy reduced the tumor vessel density and plasma volume in tumors to a greater extent than did the individual drugs. The combination therapy was no more toxic to the mice than was docetaxel alone. These results indicate that, as an adjuvant therapy, 3G4 could enhance the therapeutic efficacy of docetaxel in breast cancer patients.
The Ability of E1A to Rescue ras-Induced Premature Senescence and Confer Transformation Relies on Inactivation of Both p300/CBP and Rb Family Proteins
Authors: Deng Qingdong , Li Yilei , Tedesco Donato , Liao Rong , Fuhrmann Gerhard , Sun Peiqing 
Published: September 2005

Abstract
In primary cells, oncogenic ras induces a stable growth arrest known as premature senescence. Ras-induced premature senescence is considered as a tumor-suppressing defense response that needs to be bypassed before oncogenic potential ras can be revealed. To gain insights into the mechanism of senescence bypass during oncogenic transformation, we dissected the activities of an adenoviral oncoprotein E1A, which is capable of overcoming ras-induced senescence. Our results have indicated that the senescence bypassing activity resides in the NH2 terminus and requires both Rb-binding and p300/CBP-binding functions of E1A. Although interference with the p16INK4A/Rb pathway or inactivation of p300/CBP alone did not lead to senescence bypass, these two types of genetic alterations complemented the Rb-binding defective and the p300/CBP-binding defective mutants of E1A, respectively, to rescue premature senescence. Therefore, genetic alterations disrupting the p16INK4A/Rb pathway or the p300/CBP functions both contribute to the bypass of senescence. We further showed that p300/CBP were essential for ras-induced p53 activity, providing a potential mechanism underlying the important role of p300/CBP in senescence. Furthermore, p300/CBP inactivation led to cellular transformation in cooperation with the p300/CBP-binding defective E1A mutants, MDM2 and Ha-RasV12. These results have shown that p300 and CBP are integral components of the pathway that mediates ras-induced senescence. The critical role of p300 and CBP in the senescence response that limits the oncogenic potential of ras has provided a mechanistic basis for the tumor-suppressing function of these proteins.
1′-Acetoxychavicol Acetate Is a Novel Nuclear Factor κB Inhibitor with Significant Activity against Multiple Myeloma In vitro and In vivo
Authors: Ito Keisuke , Nakazato Tomonori , Xian Ming Ji , Yamada Taketo , Hozumi Nobumichi , Murakami Akira , Ohigashi Hajime , Ikeda Yasuo , Kizaki Masahiro 
Published: September 2005

Abstract
1′-Acetoxychavicol acetate (ACA) is a component of a traditional Asian condiment obtained from the rhizomes of the commonly used ethno-medicinal plant Languas galanga. Here, we show for the first time that ACA dramatically inhibits the cellular growth of human myeloma cells via the inhibition of nuclear factor κB (NF-κB) activity. In myeloma cells, cultivation with ACA induced G0-G1 phase cell cycle arrest, followed by apoptosis. Treatment with ACA induced caspase 3, 9, and 8 activities, suggesting that ACA-induced apoptosis in myeloma cells mediates both mitochondrial- and Fas-dependent pathways. Furthermore, we showed that ACA significantly inhibits the serine phosphorylation and degradation of IκBα. ACA rapidly decreased the nuclear expression of NF-κB, but increased the accumulation of cytosol NF-κB in RPMI8226 cells, indicating that ACA inhibits the translocation of NF-κB from the cytosol to the nucleus. To evaluate the effects of ACA in vivo, RPMI8226-transplanted NOD/SCID mice were treated with ACA. Tumor weight significantly decreased in the ACA-treated mice compared with the control mice. In conclusion, ACA has an inhibitory effect on NF-κB, and induces the apoptosis of myeloma cells in vitro and in vivo. ACA, therefore, provides a new biologically based therapy for the treatment of multiple myeloma patients as a novel NF-κB inhibitor.
Preclinical Antilymphoma Activity of a Humanized Anti-CD40 Monoclonal Antibody, SGN-40
Authors: Law Che-Leung , Gordon Kristine A. , Collier John , Klussman Kerry , McEarchern Julie A. , Cerveny Charles G. , Mixan Bruce J. , Lee Wyne P. , Lin Zhonghau , Valdez Patricia , Wahl Alan F. , Grewal Iqbal S. 
Published: September 2005

AbstractSGN-40 is a humanized IgG1 antihuman CD40 that is currently in a phase I clinical trial for the treatment of multiple myeloma. As surface CD40 expression on B-lineage cells is maintained from pro-B cells to plasma cells, SGN-40 may be applicable to treatment of other B-cell neoplasias, including non-Hodgkin's lymphoma. In this study, we examined potential in vitro and in vivo anti–B-lineage lymphoma activity of SGN-40. Recombinant SGN-40 was expressed and purified from Chinese hamster ovary cells and characterized based on binding affinity, specificity, and normal B-cell stimulation. The ability of SGN-40 to target neoplastic B cells was examined in vitro by proliferation inhibition, cytotoxicity, and antibody-dependent cell cytotoxicity assays and in vivo by human lymphoma xenograft models. Recombinant SGN-40 showed high affinity, Kd of ∼1 nmol/L, and specific binding to CD40. Whereas SGN-40 was a weak agonist in stimulating normal B-cell proliferation in the absence of IL-4 and CD40L, it delivered potent proliferation inhibitory and apoptotic signals to, and mediated antibody-dependent cytotoxicity against, a panel of high-grade B-lymphoma lines. These in vitro antilymphoma effects were extended to disseminated and s.c. xenograft CD40 tumor models. In these xenograft models, the antitumor activity of SGN-40 was comparable with that of rituximab. The preclinical in vitro and in vivo antilymphoma activity of SGN-40 observed in this study provides a rationale for the clinical testing of SGN-40 in the treatment of CD40+ B-lineage lymphomas.
Implication of Galectin-3 in Wnt Signaling
Authors: Shimura Tatsuo , Takenaka Yukinori , Fukumori Tomoharu , Tsutsumi Soichi , Okada Kohji , Hogan Victor , Kikuchi Akira , Kuwano Hiroyuki , Raz Avraham 
Published: September 2005

Abstract
Galectin-3 (gal-3), a member of the β-galactoside–binding proteins family, was identified as a binding partner of β-catenin. Analysis of the human gal-3 sequence reveled a structural similarity to β-catenin as it also contains the consensus sequence (S92XXXS96) for glycogen synthase kinase-3β (GSK-3β) phosphorylation and can serve as its substrate. In addition, Axin, a regulator protein of Wnt that complexes with β-catenin, also binds gal-3 using the same sequence motif identified here by a deletion mutant analysis. The data presented here give credence to the suggestion that gal-3 is a key regulator in the Wnt/β-catenin signaling pathway and highlight the functional similarities between gal-3 and β-catenin.
MicroRNA-21 Is an Antiapoptotic Factor in Human Glioblastoma Cells
Authors: Chan Jennifer A. , Krichevsky Anna M. , Kosik Kenneth S. 
Published: September 2005

Abstract
MicroRNAs (miRNAs) are small noncoding RNA molecules that regulate protein expression by targeting the mRNA of protein-coding genes for either cleavage or repression of translation. The roles of miRNAs in lineage determination and proliferation as well as the location of several miRNA genes at sites of translocation breakpoints or deletions has led to the speculation that miRNAs could be important factors in the development or maintenance of the neoplastic state. Here we show that the highly malignant human brain tumor, glioblastoma, strongly overexpresses a specific miRNA, miR-21. Our studies show markedly elevated miR-21 levels in human glioblastoma tumor tissues, early-passage glioblastoma cultures, and in six established glioblastoma cell lines (A172, U87, U373, LN229, LN428, and LN308) compared with nonneoplastic fetal and adult brain tissues and compared with cultured nonneoplastic glial cells. Knockdown of miR-21 in cultured glioblastoma cells triggers activation of caspases and leads to increased apoptotic cell death. Our data suggest that aberrantly expressed miR-21 may contribute to the malignant phenotype by blocking expression of critical apoptosis-related genes.
Pancreatic Cancer Cell Radiation Survival and Prenyltransferase Inhibition: The Role of K-Ras
Authors: Brunner Thomas B. , Cengel Keith A. , Hahn Stephen M. , Wu Junmin , Fraker Douglas L. , McKenna W. Gillies , Bernhard Eric J. 
Published: September 2005

Abstract
Activating K-ras mutations are found in ∼90% of pancreatic carcinomas and may contribute to the poor prognosis of these tumors. Because radiotherapy is frequently used in pancreatic cancer treatment, we assessed the contribution of oncogenic K-ras signaling to pancreatic cancer radiosensitivity. Seven human pancreatic carcinoma lines with activated K-ras and two cell lines with wild-type ras were used to examine clonogenic cell survival after Ras inhibition. Ras inhibition was accomplished by small interfering RNA (siRNA) knockdown of K-ras expression and by blocking Ras processing using a panel of prenyltransferase inhibitors of differing specificity for the two prenyltransferases that modify K-Ras.
K-ras knockdown by siRNA or inhibition of prenyltransferase activity resulted in radiation sensitization in vitro and in vivo in tumors with oncogenic K-ras mutations. Inhibition of farnesyltransferase alone was sufficient to radiosensitize most K-ras mutant tumors, although K-Ras prenylation was not blocked. These results show that inhibition of activated K-Ras can promote radiation killing of pancreatic carcinoma in a superadditive manner. The finding that farnesyltransferase inhibition alone radiosensitizes tumors with K-ras mutations implies that a farnesyltransferase inhibitor–sensitive protein other than K-Ras may contribute to survival in the context of mutant K-ras. Farnesyltransferase inhibitors could therefore be of use as sensitizers for pancreatic carcinoma radiotherapy.
Silencing of Epidermal Growth Factor Receptor Suppresses Hypoxia-Inducible Factor-2–Driven VHL−/− Renal Cancer
Authors: Smith Karlene , Gunaratnam Lakshman , Morley Melissa , Franovic Aleksandra , Mekhail Karim , Lee Stephen 
Published: September 2005

Abstract
Inactivating mutations in the von Hippel-Lindau (VHL) tumor suppressor gene are associated with clear cell renal cell carcinoma (VHL−/− RCC), the most frequent malignancy of the human kidney. The VHL protein targets the α subunits of hypoxia-inducible factor (HIF) transcription factor for ubiquitination and degradation. VHL−/− RCC cells fail to degrade HIF resulting in the constitutive activation of its target genes, a process that is required for tumorigenesis. We recently reported that HIF activates the transforming growth factor-α/epidermal growth factor receptor (TGF-α/EGFR) pathway in VHL-defective RCC cells. Here, we show that short hairpin RNA (shRNA)–mediated inhibition of EGFR is sufficient to abolish HIF-dependent tumorigenesis in multiple VHL−/− RCC cell lines. The 2α form of HIF (HIF-2α), but not HIF-1α, drives in vitro and in vivo tumorigenesis of VHL−/− RCC cells by specifically activating the TGF-α/EGFR pathway. Transient incubation of VHL−/− RCC cell lines with small interfering RNA directed against EGFR prevents autonomous growth in two-dimensional culture as well as the ability of these cells to form dense spheroids in a three-dimensional in vitro tumor assay. Stable expression of shRNA against EGFR does not alter characteristics associated with VHL loss including constitutive production of HIF targets and defects in fibronectin deposition. In spite of this, silencing of EGFR efficiently abolishes in vivo tumor growth of VHL loss RCC cells. These data identify EGFR as a critical determinant of HIF-2α-dependent tumorigenesis and show at the molecular level that EGFR remains a credible target for therapeutic strategies against VHL−/− renal carcinoma.
Rho GDP Dissociation Inhibitor Protects Cancer Cells against Drug-Induced Apoptosis
Authors: Zhang Baolin , Zhang Yaqin , Dagher Marie-Claire , Shacter Emily 
Published: September 2005

Abstract
Rho GDP dissociation inhibitor (RhoGDI) plays an essential role in control of a variety of cellular functions through interactions with Rho family GTPases, including Rac1, Cdc42, and RhoA. RhoGDI is frequently overexpressed in human tumors and chemoresistant cancer cell lines, raising the possibility that RhoGDI might play a role in the development of drug resistance in cancer cells. We found that overexpression of RhoGDI increased resistance of cancer cells (MDA-MB-231 human breast cancer cells and JLP-119 lymphoma cells) to the induction of apoptosis by two chemotherapeutic agents: etoposide and doxorubicin. Conversely, silencing of RhoGDI expression by DNA vector–mediated RNA interference (small interfering RNA) sensitized MDA-MB-231 cells to drug-induced apoptosis. Resistance to apoptosis was restored by reintroduction of RhoGDI protein expression. The mechanism for the antiapoptotic activity of RhoGDI may derive from its ability to inhibit caspase-mediated cleavage of Rac1 GTPase, which is required for maximal apoptosis to occur in response to cytotoxic drugs. Taken together, the data show that RhoGDI is an antiapoptotic molecule that mediates cellular resistance to these chemotherapy agents.