bluuebunny/crossref_metadata_2025_split huggingface dataset:
Prion Infection of Muscle Cells In Vitro
Authors: Dlakic Wendy M. , Grigg Eric , Bessen Richard A. 
Published: February 2007

ABSTRACTThe prion agent has been detected in skeletal muscle of humans and animals with prion diseases. Here we report scrapie infection of murine C2C12 myoblasts and myotubes in vitro following coculture with a scrapie-infected murine neuroblastoma (N2A) cell line but not following incubation with a scrapie-infected nonneuronal cell line or a scrapie brain homogenate. Terminal differentiation of scrapie-infected C2C12 myoblasts into myotubes resulted in an increase in the expression of the disease-specific prion protein, PrPSc. The amount of scrapie infectivity or PrPScin C2C12 myotubes was comparable to the levels found in scrapie-infected N2A cells, indicating that a high level of infection was established in muscle cells. Subclones of scrapie-infected C2C12 cells produced high levels of PrPScin myotubes, and the C-terminal C2 polypeptide fragment of PrPScwas found based on deglycosylation and PrPSc-specific immunoprecipitation of cell lysates. This is the first report of a stable prion infection in muscle cells in vitro and of a long-term prion infection in a nondividing, differentiated peripheral cell type in culture. These in vitro studies also suggest that in vivo prion infection of skeletal muscle requires contact with prion-infected neurons or, possibly, nerve terminals.
Primary Human Immunodeficiency Virus Type 1 Nef Alleles Show Major Differences in Pathogenicity in Transgenic Mice
Authors: Priceputu Elena , Hanna Zaher , Hu Chunyan , Simard Marie-Chantal , Vincent Patrick , Wildum Steffen , Schindler Michael , Kirchhoff Frank , Jolicoeur Paul 
Published: February 2007

ABSTRACT

We previously reported that the human immunodeficiency virus type 1 NL4-3 Nef is necessary and sufficient to induce a severe AIDS-like disease in transgenic (Tg) mice when the protein is expressed under the regulatory sequences of the human CD4 gene. We have now assayed additional Nef alleles (SF2, JR-CSF, YU10x, and NL4-3 [T71R] Nef alleles), including some from long-term nonprogressors (AD-93, 032an, and 039nm alleles) in the same Tg system and compared their pathogenicities. All these Nef alleles downregulated cell surface CD4 in human cells in vitro and also, with the exception of Nef
YU10x
, in Tg CD4
+
T cells. Depletion of double-positive and single-positive thymocytes occurred with all alleles but was less pronounced in Nef
YU10x
Tg mice. A loss of peripheral CD4
+
T cells was observed with all alleles but was minimal in Nef
YU10x
Tg mice. In Nef
032an
and Nef
SF2
Tg mice, T-cell loss was severe despite lower levels of Tg expression, suggesting a higher virulence of these alleles. All Nef alleles except the Nef
YU10x
and Nef
NL4-3(T71R)
alleles induced an enhanced activated memory (CD25
+
CD69
+
CD44
high
CD45RB
low
CD62L
low
) and apoptotic phenotype. Also, all could interact with and/or activate PAK2 except the Nef
JR-CSF
allele. Organ (lung and kidney) diseases were present in Nef
NL4-3(T71R)
, Nef
032an
, Nef
039nm
, and Nef
SF2
Tg mice, despite very low levels of Tg expression for the last strain. However, no organ disease or minimal organ disease developed in Nef
YU10x
and Nef
AD-93
Tg mice and Nef
JR-CSF
Tg mice, respectively, despite high levels of Tg expression. Our data show that important differences in the pathogenicities of various Nef alleles can be scored in Tg mice. Interestingly, our results also revealed that some phenotypes can segregate independently, such as CD4
+
T-cell depletion and activation, as well as severe depletion of thymic CD4
+
T cells and peripheral CD4
+
T cells. Therefore, expression of Nef alleles in Tg mice under the CD4C regulatory elements represents a novel assay for measuring their pathogenicity. Because of the very high similarity of this murine AIDS-like disease to human AIDS, this assay may have a predictive value regarding the behavior of Nef in infected humans.
Complement Contributes to Inflammatory Tissue Destruction in a Mouse Model of Ross River Virus-Induced Disease
Authors: Morrison Thomas E. , Fraser Robert J. , Smith Paul N. , Mahalingam Suresh , Heise Mark T. 
Published: February 2007

ABSTRACTArthritogenic alphaviruses, including Ross River virus (RRV) and chikungunya virus, are mosquito-borne viruses that cause significant human disease worldwide, including explosive epidemics that can result in thousands to millions of infected individuals. Similar to infection of humans, infection of C57BL/6 mice with RRV results in severe monocytic inflammation of bone, joint, and skeletal muscle tissues. We demonstrate here that the complement system, an important component of the innate immune response, enhances the severity of RRV-induced disease in mice. Complement activation products were detected in the inflamed tissues and in the serum of RRV-infected wild-type mice. Furthermore, mice deficient in C3 (C3−/−), the central component of the complement system, developed much less severe disease signs than did wild-type mice. Complement-mediated chemotaxis is essential for many inflammatory arthritides; however, RRV-infected wild-type and C3−/−mice had similar numbers and composition of inflammatory infiltrates within hind limb skeletal muscle tissue. Despite similar inflammatory infiltrates, RRV-infected C3−/−mice exhibited far less severe destruction of skeletal muscle tissue. In addition to these studies, complement activation was also detected in synovial fluid from RRV-infected patients. Taken together, these findings indicate that complement activation occurs in the tissues of humans and mice infected with RRV and suggest that complement plays an essential role in the effector phase, but not the inductive phase, of RRV-induced arthritis and myositis.
Quantitative Detection of Micrometastases in Pelvic Lymph Nodes in Patients with Clinically Localized Prostate Cancer by Real-time Reverse Transcriptase-PCR
Authors: Miyake Hideaki , Hara Isao , Kurahashi Toshifumi , Inoue Taka-aki , Eto Hiroshi , Fujisawa Masato 
Published: February 2007

Abstract
Purpose: Routine pathologic examination can miss micrometastatic tumor foci in the lymph nodes of patients with prostate cancer, resulting in confusion during tumor staging and clinical decision-making. The objective of this study was to clarify the significance of micrometastases in pelvic lymph nodes in patients who underwent radical prostatectomy for prostate cancer.
Experimental Design: The expression of prostate-specific antigen (PSA) and prostate-specific membrane antigen (PSMA) in 2,215 lymph nodes isolated from 120 patients with clinically localized prostate cancer was assessed by a fully quantitative real-time reverse transcriptase-PCR. We regarded specimens in which either PSA or PSMA mRNAs were positive as proof of the “presence of micrometastasis.” Immunohistochemical staining of lymph node specimens with an antibody against PSA was also done.
Results: Pathologic examinations detected tumor cells in 29 lymph nodes from 11 patients, and real-time reverse transcriptase-PCR further identified micrometastasis in 143 lymph nodes from 32 patients with no pathologic evidence of lymph node involvement. The presence of micrometastatic cancer cells was confirmed by immunohistochemical staining in 61 lymph nodes from 17 patients with pathologically negative lymph nodes. The presence of micrometastases was significantly associated with other conventional prognostic variables, including serum PSA value, pathologic stage, Gleason score, and tumor volume. Biochemical recurrence was detected in 32 patients, 17 of whom were negative for lymph node metastasis by pathologic examination (including 4 patients with pathologically organ-confined disease), but were diagnosed as having micrometastasis. Biochemical recurrence–free survival rate in patients without micrometastasis was significantly higher than in those with micrometastasis irrespective of the presence of pathologically positive nodes. Furthermore, only the presence of micrometastasis was independently associated with biochemical recurrence regardless of other factors examined.
Conclusions: These findings suggest that ∼30% of clinically localized prostate cancers shed cancer cells to the pelvic lymph nodes, and that biochemical recurrence after radical prostatectomy could be explained, at least in part, by micrometastases in pelvic lymph nodes.
Gene Expression Profiling Reveals Potential Biomarkers of Human Hepatocellular Carcinoma
Authors: Jia Hu-Liang , Ye Qing-Hai , Qin Lun-Xiu , Budhu Anuradha , Forgues Marshonna , Chen Yidong , Liu Yin-Kun , Sun Hui-Chuan , Wang Lu , Lu Hong-Zhou , Shen Fang , Tang Zhao-You , Wang Xin Wei 
Published: February 2007

Abstract
Purpose: Hepatocellular carcinoma (HCC), a common cancer worldwide, has a dismal outcome partly due to the poor identification of early-stage HCC. Currently, one third of HCC patients present with low serum α-fetoprotein (AFP) levels, the only clinically available diagnostic marker for HCC. The aim of this study was to identify new diagnostic molecular markers for HCC, especially for individuals with low serum AFP.
Experimental Design: We used the microarray technique to determine the expression profiles of 218 HCC specimens from patients with either high or low serum AFP. From the microarray study, we selected five candidate genes (i.e., GPC3, PEG10, MDK, SERPINI1, and QP-C), which were overexpressed in HCCs. Using quantitative real-time PCR analyses, we validated the expression of these five genes in 50 AFP-normal and 8 AFP-positive HCC specimens and 36 cirrhotic noncancerous hepatic specimens, which include 52 independent specimens not used in microarray analysis.
Results: A significant increase in the expression of the five candidate genes could be detected in most of the HCC samples, including those with normal serum AFP and small tumors. GPC3, MDK, and SERPINI1 encode known serum proteins. Consistently, a significant increase in serum midkine, encoded by MDK, was associated with HCC patients, including those with normal serum AFP. Using prediction analysis of microarray, we showed that a combined score of these five genes can accurately classify noncancerous hepatic tissues (100%) and HCC (71%).
Conclusions: We suggest that a diagnostic signature approach using a combined score of these five biomarkers rather than a single marker may improve the prediction accuracy of HCC patients, including those with normal serum AFP and smaller-sized tumors.
A Phase I Pharmacokinetic and Pharmacodynamic Study of Intravenous Calcitriol in Combination with Oral Gefitinib in Patients with Advanced Solid Tumors
Authors: Fakih Marwan G. , Trump Donald L. , Muindi Josephia R. , Black Jennifer D. , Bernardi Ronald J. , Creaven Patrick J. , Schwartz James , Brattain Michael G. , Hutson Alan , French Renee , Johnson Candace S. 
Published: February 2007

AbstractPurpose: In preclinical models, calcitriol and the tyrosine kinase inhibitor gefitinib are synergistic and modulate extracellular signal-regulated kinase (Erk) and Akt pathways. Therefore, we conducted a phase I study of calcitriol and gefitinib to determine the maximum tolerated dose (MTD) of this combination.Experimental Design: Calcitriol was given i.v. over 1 h on weeks 1, 3, and weekly thereafter. Gefitinib was given at a fixed oral daily dose of 250 mg starting at week 2 (day 8). Escalation occurred in cohorts of three patients until the MTD was defined. Pharmacokinetic studies were done for calcitriol and gefitinib. Serial skin biopsies were done to investigate epidermal growth factor receptor (EGFR) pathway pharmacodynamic interactions.Results: Thirty-two patients were treated. Dose-limiting hypercalcemia was noted in two of four patients receiving 96 μg/wk of calcitriol. One of seven patients developed dose-limiting hypercalcemia at the MTD 74 μg/wk calcitriol dose level. The relationship between calcitriol dose and peak serum calcitriol (Cmax) and systemic exposure (AUC) was linear. Mean (±SD) serum calcitriol Cmax at the MTD was 6.68 ± 1.42 ng/mL. Gefitinib treatment inhibited EGFR, Akt, and Erk phosphorylation in the skin. Calcitriol did not have consistent effects on skin EGFR or its downstream elements. The combination of gefitinib and calcitriol did not modulate tumor EGFR pathway in patients with serial tumor biopsies.Conclusions: High doses of weekly i.v. calcitriol can be administered safely in combination with gefitinib. Calcitriol concentrations achieved at the MTD 74 μg calcitriol exceed in vivo concentrations associated with antitumor activity in preclinical models.
DNA Mismatch Repair Initiates 6-Thioguanine–Induced Autophagy through p53 Activation in Human Tumor Cells
Authors: Zeng Xuehuo , Yan Tao , Schupp Jane E. , Seo Yuji , Kinsella Timothy J. 
Published: February 2007

Abstract
Purpose: We investigate the roles of DNA mismatch repair (MMR) and p53 in mediating the induction of autophagy in human tumor cells after exposure to 6-thioguanine (6-TG), a chemotherapy drug recognized by MMR. We also examine how activation of autophagy affects apoptosis (type I cell death) after MMR processing of 6-TG.
Experimental Design: Using isogenic pairs of MLH1−/MLH1+ human colorectal cancer cells (HCT116) and MSH2−/MSH2+ human endometrial cancer cells (HEC59), we initially measure activation of autophagy for up to 3 days after 6-TG treatment using LC3, a specific marker of autophagy. We then assess the role of p53 in autophagic signaling of 6-TG MMR processing using both pifithrin-α cotreatment to chemically inhibit p53 transcription and small hairpin RNA inhibition of p53 expression. Finally, we use Atg5 small hairpin RNA inhibition of autophagy to assess the effect on apoptosis after MMR processing of 6-TG.
Results: We find that MMR is required for mediating autophagy in response to 6-TG treatment in these human tumor cells. We also show that p53 plays an essential role in signaling from MMR to the autophagic pathway. Finally, our results indicate that 6-TG–induced autophagy inhibits apoptosis after MMR processing of 6-TG.
Conclusions: These data suggest a novel function of MMR in mediating autophagy after a chemical (6-TG) DNA mismatch damage through p53 activation. The resulting autophagy inhibits apoptosis after MMR processing of 6-TG.
Computational Modeling to Predict Effect of Treatment Schedule on Drug Delivery to Prostate in Humans
Authors: Hu Leijun , Au Jessie L-S. , Wientjes M. Guillaume 
Published: February 2007

AbstractPurpose: To evaluate a computational approach that incorporates experimental data in preclinical models to depict doxorubicin human tissue pharmacokinetics.Experimental Design: Beagle dogs were given 2 mg/kg doxorubicin as i.v. bolus, 4-h infusion, or 96-h infusion. Concentrations in plasma, prostate (target tissue), heart (toxicity), and major tissues for disposition were determined and modeled. Model parameters were obtained after the bolus injection with model validation based on the 4-h and 96-h infusion data. Clinical pharmacokinetic data and scale-up gave doxorubicin profiles in human prostate and heart.Results: In agreement with in vitro results, tissues were best modeled with two compartments, one rapidly and one slowly equilibrating. The developed tissue distribution model predicted concentrations for all three administration regimens well, with an average deviation of 34% (median, 29%). Interspecies scale-up to humans showed that the change from a bolus injection to a slow, 96-h infusion (a) had different effects on the drug partition and accumulation in heart and prostate, and (b) lowered the peak concentration in the plasma by ∼100-fold but had relatively little effect on maximal heart concentration (∼33% lower). The simulated drug exposure in a human prostate was above the exposure required to inhibit tumor proliferation but was 30 to 50 times below that needed for cell death.Conclusion: The present study shows a computation-based paradigm for translating in vitro and in vivo preclinical data and to estimate and compare the drug delivery and pharmacokinetics in target tissues after different treatment schedules.
A Susceptibility Gene Set for Early Onset Colorectal Cancer That Integrates Diverse Signaling Pathways: Implication for Tumorigenesis
Authors: Hong Yi , Ho Kok Sun , Eu Kong Weng , Cheah Peh Yean 
Published: February 2007

Abstract
Purpose: The causative genes for autosomal dominantly inherited familial adenomatous polyposis (FAP) and hereditary nonpolyposis colorectal cancer have been well characterized. There is, however, another 10% to 15% of early onset colorectal cancers (CRC) in which the genetic components are unclear. In this study, we used microarray technology to systematically search for differentially expressed genes in early onset CRC.
Experimental Design: Young patients with non–FAP or non–hereditary nonpolyposis colorectal cancer, and healthy controls were age- (≤50 years old), ethnicity- (Chinese), and tissue-matched. RNAs extracted from colonic mucosa specimens were analyzed using GeneChip U133-Plus 2.0 Array.
Results: Seven genes, CYR61, UCHL1, FOS, FOS B, EGR1, VIP, and KRT24, were consistently up-regulated in the mucosa of all six patients compared with the mucosa from four healthy controls. The overexpression of these genes was independently validated with a testing set of six patients and six healthy controls. Principal component analysis clustered the healthy control specimens separately from the patient specimens. Real-time PCR quantification with SYBR-Green on nine other patient specimens not previously used in microarray assays confirmed the up-regulation of these seven genes. These genes function in a multitude of biological processes ranging from transcription, angiogenesis, adhesion, and inflammatory regulation to protein catabolism in various cellular compartments, from extracellular to the nucleus. They integrate known tumorigenesis (Wnt, PI3K, MAP kinase, hypoxia, G protein–coupled receptor), neurologic, insulin-signaling, and NFAT-immune pathways into an intricate biological network.
Conclusions: The data suggest that the patient's mucosa is primed for tumorigenesis when cellular homeostasis is disrupted, and that the seven overexpressed genes could potentially predict early onset CRC.
Detection of Human Papillomavirus-16 in Fine-Needle Aspirates to Determine Tumor Origin in Patients with Metastatic Squamous Cell Carcinoma of the Head and Neck
Authors: Begum Shahnaz , Gillison Maura L. , Nicol Theresa L. , Westra William H. 
Published: February 2007

Abstract
Purpose: Patients with head and neck squamous cell carcinoma (HNSCC) often clinically present with metastases to regional lymph nodes. Fine-needle aspiration of neck masses is routinely used to establish the presence of metastatic carcinoma and in turn to initiate a subsequent workup to determine the site of tumor origin. Human papillomavirus (HPV) 16 is an important etiologic agent for HNSCCs that arise from the oropharynx but less so for tumors from non-oropharyngeal sites. HPV16 detection thus provides a strategy for localizing an important subset of HNSCCs, but this approach has not been applied to fine-needle aspiration specimens.
Experimental Design: We did in situ hybridization for HPV16 on 77 consecutive aspirated neck masses diagnosed as metastatic squamous cell carcinoma. P16 immunohistochemistry was also done because p16 overexpression may serve as a surrogate marker of HPV-associated HNSCC.
Results: HPV16 was detected in 13 of the 77 (17%) aspirates. By site of origin, HPV16 was detected in 10 of 19 metastases from the oropharynx but in none of 46 metastases from other sites (53% versus 0%; P &lt; 0.0001). HPV16 was not detected in 2 branchial cleft cysts misdiagnosed as metastatic squamous cell carcinoma, but it was detected in 3 of 10 metastases from occult primary tumors. P16 expression was associated with the presence of HPV16: 12 of 13 HPV16-positive metastases exhibited p16 expression, whereas only 4 of 62 HPV16-negative metastases were p16 positive (92% versus 6%; P &lt; 0.0001). P16 expression also correlated with site of tumor origin: 13 of 19 oropharyngeal metastases were p16 positive, whereas only 1 of 46 non-oropharyngeal metastases was p16 positive (68% versus 2%; P &lt; 0.0001).
Conclusions: HPV16 status can be determined in tumor cells aspirated from the necks of patients with metastatic HNSCC. Its presence is a reliable indicator of origin from the oropharynx.
Abrogation of MAPK and Akt Signaling by AEE788 Synergistically Potentiates Histone Deacetylase Inhibitor-Induced Apoptosis through Reactive Oxygen Species Generation
Authors: Yu Chunrong , Friday Bret B. , Lai Jin-Ping , McCollum Andrea , Atadja Peter , Roberts Lewis R. , Adjei Alex A. 
Published: February 2007

Abstract
Purpose: To evaluate the effects of combining the multiple receptor tyrosine kinase inhibitor AEE788 and histone deacetylase (HDAC) inhibitors on cytotoxicity in a broad spectrum of cancer cell lines, including cisplatin-resistant ovarian adenocarcinoma cells.
Experimental Design: Multiple cancer cell lines were treated in vitro using AEE788 and HDAC inhibitors (LBH589, LAQ824, and trichostatin A), either alone or in combination. Effects on cytotoxicity were determined by growth and morphologic assays. Effects of the combination on cell signaling pathways were determined by Western blotting, and the results were confirmed using pathway-specific inhibitors and transfection of constitutively active proteins.
Results: Cell treatment with AEE788 and HDAC inhibitors (LBH589, LAQ824, and trichostatin A) in combination resulted in synergistic induction of apoptosis in non–small cell lung cancer (MV522, A549), ovarian cancer (SKOV-3), and leukemia (K562, Jurkat, and ML-1) cells and in OV202hp cisplatin-resistant human ovarian cancer cells. AEE788 alone or in combination with LBH589 inactivated mitogen-activated protein kinase (MAPK) and Akt cascades. Inhibition of either MAPK and/or Akt enhanced LBH589-induced apoptosis. In contrast, constitutively active MAPK or Akt attenuated LBH589 or LBH589 + AEE788–induced apoptosis. Increased apoptosis was correlated with enhanced reactive oxygen species (ROS) generation. The free radical scavenger N-acetyl-l-cysteine not only substantially suppressed the ROS accumulation but also blocked the induction of apoptosis mediated by cotreatment with AEE788 and LBH589.
Conclusion: Collectively, these results show that MAPK and Akt inactivation along with ROS generation contribute to the synergistic cytotoxicity of the combination of AEE788 and HDAC inhibitors in a variety of human cancer cell types. This combination regimen warrants further preclinical and possible clinical study for a broad spectrum of cancers.