bluuebunny/crossref_metadata_2025 huggingface dataset:
Impact of the COVID-19 Pandemic on Trends in Cardiothoracic Imaging
Authors: Capaccione Kathleen M. , Huang Sophia , Leb Jay S. , D’souza Belinda , Goldstein Jonathan , Salvatore Mary M.
Published: June 2022

Introduction. Here, we evaluate the effect of the COVID-19 pandemic on utilization of cardiothoracic imaging studies. Methods. We queried our radiology record system to retrospectively identify numbers of specific key cardiothoracic imaging studies for five years prior and during the COVID-19 pandemic. Statistical analysis was performed to evaluate changes in the number of exams in 2020 and 2021 compared to 2019. Results. Five-year retrospective analysis demonstrated progressive increases in nearly all cross-sectional studies. In 2020, daily chest radiograph utilization decreased with an overall number of daily radiographs of 406 (SD = 73.1) compared to 480 per day in 2019 (SD = 82.6) (

p

 < 0.0001). Portable radiograph utilization was increased in 2020 averaging 320 (SD = 68.2) films daily in 2020 compared to 266 (SD = 29.1) in 2019 (

p

 < 0.0001). Utilization of thoracic CT was decreased during the pandemic, with 21.8 (SD = 12.9) studies daily compared to 52.0 (SD = 21.4) (

p

 < 0.0001) studies daily in 2019. Cardiac imaging utilization was also substantially decreased in 2020 compared to 2019, averaging a total of 3.8 (SD = 3.2) versus 10.8 (SD = 6.6) studies daily and 0.88 (SD = 1.7) versus 2.5 (SD = 2.3) studies daily for CT and MRI, respectively. Evaluation of cardiothoracic imaging for the subsequent 18 months after New York’s entry to phase I recovery in June 2020 demonstrated that by one year after the emergence of COVID-19 imaging utilization had recovered to prepandemic levels. Cardiac imaging continued to increase throughout the chronic phase of the COVID-19 pandemic, reaching almost twice the prepandemic levels by the end of 2021. Conclusion. COVID-19 has had far-reaching effects on medicine and public health. Here, we demonstrate decreases in all cross-sectional cardiothoracic imaging studies, closely mirroring findings in other fields during the height of the pandemic, which have since rebounded.
Research on the Construction of English Autonomous Learning Model Based on Computer Network-Assisted Instruction
Authors: Tian Mijuan , Fu Rong , Tang Qianjun
Published: June 2022

As a supplement to traditional teaching methods, computer-assisted teaching methods can reflect modern educational concepts, such as creating student-led, teacher-led environments. The goal of college English education is to enable them to communicate effectively in English in their future academic, work, and social interactions, while also developing students’ self-learning skills. Chinese society improves overall cultural competence and adapts to the needs of international communication. Self-directed learning is not static and will increase or decrease with time, discipline, and conditions and is an evolving process. Understanding learning, taking responsibility for one’s own learning, and learning how to learn are all beneficial. Students abound in school life and even throughout their lives. In this paper, we try to propose a computer-based method for constructing an independent English learning model based on a practical study of computer network technology for the development of self-learning ability of non-English majors in a university. This paper uses comparative analysis techniques to compare traditional paper-and-pencil examinations and computer-based online evaluations and analyzes the effects of each. The survey showed that 81% of the students preferred the computer-based assessment. Therefore, the focus of this research is to strengthen the oral English training in college and create an authentic English learning environment for students to really feel the standard English pronunciation, intonation, and knowledge of grammar, listening, reading, writing, and translation.
Investigation of Statin Medication Use in Elderly Patients with Cardiovascular Disease on Regular Physical Examination and the Relationship with Glucolipid Metabolism and Adverse Cardiovascular Prognosis
Authors: Liu Chang , Ma Rui , Gao Daifeng , Hu Bin , Yin Xiaolei , Liu Zhipeng , Lin Hu , Zhang Zhenhua
Published: June 2022

Our purpose of this study was to investigate the use of statins in elderly patients with cardiovascular diseases during regular physical examination and to analyze the relationship between statins and glucose and lipid metabolism and adverse cardiovascular prognosis. From January 2019 to December 2021, 2121 elderly patients with cardiovascular disease underwent regular physical examination as the study subjects to investigate the use and intensity of statins. The patients were divided into the dosing group (

n
=
1848

) and the nondosing group (

n
=
273

) according to whether they were taking statins or not. The cardiac function, glucose and lipid metabolism indexes, and cardiovascular adverse events were compared between the two groups. Statin use in elderly patients with cardiovascular disease was 87.13% (1848/2121). The intensity of statin use decreased with age (

P
<
0.05

); the left ventricular ejection fraction (LVEF) was greater in the medicated group than in the nonmedicated group, and the left ventricular end-diastolic internal diameter (LVDd) and left ventricular end-systolic internal diameter (LVDs) were smaller than in the nonmedicated group (

P
<
0.05

). The total cholesterol (TC), triglyceride (TG), low-density lipoprotein cholesterol (LDL-C), and fasting blood glucose (FBG) levels were lower in the medicated group than in the nonmedicated group, the high-density lipoprotein cholesterol (HDL-C) levels were higher than in the nonmedicated group, and the glycated hemoglobin (HbA1c) values were lower than in the nonmedicated group (

P
<
0.05

). The overall incidence of cardiovascular adverse events in the medicated group was lower than that in the nonmedicated group (

P
<
0.05

). Statin use was higher in elderly patients with cardiovascular disease; the intensity of drug use decreased with age. The patients’ cardiac function, glucose metabolism, and prognosis were significantly improved after statin treatment.
miRNA‐Gene Interaction Network Construction Strategy to Discern Promising Traditional Chinese Medicine against Osteoporosis
Authors: Li Lubing , Ayiding Xiahatai , Han Ran
Published: June 2022

Osteoporosis is a widespread bone disease that affects million cases annually. The underlying mechanisms behind the progress of osteoporosis remain enigmatic, which limits detections of biomarkers and therapeutic targets. Hence, this study was aimed at exploring hub molecules to better understand the mechanism of osteoporosis development and discover the traditional Chinese medicine potential drugs for osteoporosis. miRNA and gene expression profiles were downloaded from Gene Expression Omnibus (GEO). Weighted correlation network analysis (WGCNA) was used to identify the key modules for osteoporosis. DIANA Tools was applied to perform pathway enrichment. A miRNA‐gene interaction network was constructed, and hub miRNAs and genes were distinguished using Cytoscape software. Receiver operating characteristic (ROC) curves of hub miRNAs and genes were plotted, and correlations with hub genes and osteoporosis‐associated factors were evaluated. Potential drugs for osteoporosis in Traditional Chinese Medicine Systems Pharmacology Database and Analysis Platform (TCMSP) were screened, and molecular docking models between these drugs and target genes were showed by AutoDock tools. Two hub modules, 1 miRNA module and 1 gene module, were identified to be the most strongly correlated with osteoporosis by using WGCNA. Then, 3 KEGG pathways including focal adhesion, PI3K‐Akt signaling pathway, and gap junction were shared pathways enriched with the miRNAs and genes screened out by WGCNA and differential expression analyses. Finally, after constructing a miRNA‐gene interaction network, 6 hub miRNAs (hsa‐miR‐18b‐3p, hsa‐miR‐361‐3p, hsa‐miR‐484, hsa‐miR‐519e‐5p, hsa‐miR‐940, and hsa‐miR‐1275) and 6 hub genes (THBS1, IFNAR2, ARHGAP5, TUBB2B, FLNC, and NTF3) were detected. ROC curves showed good performances of miRNAs and genes for osteoporosis. Correlations with hub genes and osteoporosis‐associated factors suggested implicational roles of them for osteoporosis. Based on these hub genes, 3 natural compounds (kainic acid, uridine, and quercetin), which were the active ingredients of 192 herbs, were screened out, and a target‐compound‐herb network was extracted using TCMSP. Molecular docking models of kainic acid‐NTF3, uridine‐IFNAR2, and quercetin‐THBS1 were exhibited with AutoDock tools. Our study sheds light on the pathogenesis of osteoporosis and provides promising therapeutic targets and traditional Chinese medicine drugs for osteoporosis.
Cardiac Implications of COVID-19 in Deceased and Recovered Patients: A Systematic Review
Authors: Khanal Rajaram , Raj Bhattarai Shreeyash , Basnet Kriti , Shah Sangam , Dhital Roman , Kumar Sah Sanjit , Poudel Sujan , Frontela Odalys , Michel George , Marzban Sima , Rodriguez-Morales Alfonso J.
Published: June 2022

Background. Patients infected with coronavirus disease 2019 (COVID-19) present with various clinical presentations with majority of them developing pulmonary complications. This study focuses on cardiac implications of COVID-19 which are less discussed and thus will help to address cardiac implications of COVID-19. Methods. PubMed, PubMed Central, and Google Scholar were screened for articles which mentioned cardiac implications of COVID-19. NHLBI Study Quality Assessment Tools for the observational cohort and cross-sectional studies was used for assessing the risk of bias of our studies. Results. All 14 studies selected were good and had score of ≥9 by NHLBI Study Quality Assessment Tools. Cardiac complications of COVID-19 are common. They are associated with significant mortality. Also, people infected with COVID-19 with premorbid conditions such as cardiovascular diseases and diabetes mellitus have poor prognosis as compared to those without premorbid conditions. Cardiac biomarkers such as highly sensitive troponin I, creatinine, and creatinine kinase-MB on admission are good prognostic markers. Conclusions. Cardiac complications such as heart failure, myocardial injury, and arrhythmias are common among patients infected with COVID-19. Elevated cardiac markers and patients with cardiac complications require utmost care and continuous cardiac monitoring.
Hypolipidemic Effect of Hemp Seed Oil from the Northern Morocco Endemic Beldiya Ecotype in a Mice Model: Comparison with Fenofibrate Hypolipidemic Drugs
Authors: Mokhtari Imane , Taaifi Yassine , Harnafi Mohamed , Belhaj Kamal , Mansouri Farid , Melhaoui Reda , Addi Mohamed , Hano Christophe , Amrani Souliman , Harnafi Hicham , El Amrani Ahmed
Published: June 2022

Introduction. Cannabis sativa is a source of oil seeds for pharmaceutical, cosmetic, and food uses. Objective. The aim of this study is to evaluate the hypolipidemic effect of hemp seed oil (HSO) obtained from a local ecotype called “Beldiya.” Methods. The extraction of HSO was carried out by cold press method. Then, the fatty acid and tocopherol composition was analyzed, respectively, by GC-FID and HPLC. The hypolipidemic activity of HSO at a dose of 3.5 and 7 mg/kg body weight was evaluated in Triton WR-1339-induced hyperlipidemic mice by measuring plasma cholesterol (total lipid, HDL, and LDL), plasma triglycerides, and atherogenic index using enzymatic methods. Fenofibrate was used as a standard hypolipidemic drug at a dose of 3.5 mg/kg body weight. Results. Analyzed HSO shows a high unsaturated fatty acids’ content with the dominance of linoleic acid (48.85%), oleic acid (21.82%), as well as α- and γ-linolenic acid (14.72%). The result demonstrates that this typical vegetable oil contains a high concentration of γ-tocopherol (456 mg·kg−1 oil). Furthermore, the administration of HSO decreases plasma total cholesterol, triglycerides, and LDL-cholesterol while increases HDL-cholesterol. Consequently, the HSO reduces the atherogenic index and LDL/HDL ratio. The hypolipidemic effect of fenofibrate is relatively more marked comparatively to that of HSO especially concerning total cholesterol and its LDL fraction. Conclusions. The local ecotype HSO has an interesting effect on plasma lipid parameters and might be beneficial for the treatment of hyperlipidemia and prevention of atherosclerosis.
Potential Benefits of Music Therapy on Stroke Rehabilitation
Authors: Xu Chengyan , He Zixia , Shen Zhipeng , Huang Fei
Published: June 2022

Stroke is associated with a high rate of disability and mortality, and survivors are usually accompanied with dysphagia, aphasia, motor dysfunction, cognitive impairment, depression, and other complications. In the past decades, many studies have been conducted to reveal the pathogenesis and pathological mechanisms of stroke. Furthermore, treatment methods have been developed that contribute to the elevated survival rate of stroke patients. Early rehabilitation poststroke is starting to be recognized as important and has been receiving increasing attention in order to further improve the quality of life of the patients. As an emerging method of poststroke rehabilitation, music therapy can help attenuate dysphagia and aphasia, improve cognition and motor function, alleviate negative moods, and accelerate neurological recovery in stroke patients. This review helps summarize the recent progress that has been made using music therapy in stroke rehabilitation and is aimed at providing clinical evidence for the treatment of stroke patients.
SEMA6D, Negatively Regulated by miR-7, Contributes to C28/I2 chondrocyte’s Catabolic and Anabolic Activities via p38 Signaling Pathway
Authors: Yang Haoyu , Yang Zhicheng , Yu Zhentang , Xiong Chenwei , Zhang Yi , Zhang Junjie , Huang Yong , Zhou Xindie , Li Jin , Xu Nanwei
Published: June 2022

MiR-7 has been recognized as an osteoarthritis (OA-)-promoting factor, but the specific downstream pathway of miR-7 still remains unknown. Further investigation of the molecular regulatory mechanism of miR-7 might help develop a novel therapeutic method for OA. In this study, we revealed that Semaphorin 6D (SEMA6D) was a direct target gene of miR-7 and presented a negative regulatory relation with SEMA6D in vitro and in vivo. SEMA6D could improve OA in rat OA models, as indicated by H&E and Safranin O-Fast green staining, and also μCT analysis. Further evaluation of SEMA6D suggested that SEMA6D promotes the anabolism and reduces the catabolism of C28/I2 chondrocytes via inhibiting the activation of the p38 pathway. The present research illustrated that SEMA6D is a negatively regulatory factor of miR-7 and a pivotal mediator of catabolism and anabolism in C28/I2 chondrocytes. SEMA6D exerts its function via inhibiting the activation of the p38 pathway.
English Lexical Analysis System of Machine Translation Based on Simple Recurrent Neural Network
Authors: Zhu Jingyan
Published: June 2022

With the increasing communication between countries, machine translation has become an important way of communication between ethnic groups in different language systems. In order to further improve the coverage mechanism and vocabulary translation quality of the machine translation model of neural network, this paper will study the machine translation English lexical analysis system based on simple recurrent neural network. In order to improve the effect of word alignment, marking and attention mechanism are introduced into the English lexical analysis model. The experimental results show that the tagging of named entity words in the system can reduce the problem of unregistered words. Combined with the attention mechanism, it can significantly improve the effect of word alignment and label recall. It not only improves the controllability of translation but also has a positive impact on the quality of translation and its application effect in specific scenes. The evaluation of translation quality indicators shows that the system can effectively improve the accuracy and quality of Chinese-English translation.
Remote Sensing Image Water Body Recognition Algorithm Based on Deep Convolution Generating Network and Combined Features
Authors: Zhao Yan , Feng Caiying
Published: June 2022

The application of remote sensing images in water body recognition has become an effective method for ecological environment detection and evaluation, which has the disadvantages of low efficiency due to the existence of interpretation marks and rich interpretation experience in the current water body environment recognition, and overreliance on human experience. In this paper, the water body recognition method is applied to remote sensing images by combining the deep convolution generation network and the combined features, which has the advantage of high recognition accuracy. In the convolutional neural network, a five-layer convolutional neural network is used to construct a remote sensing water information extraction model, the transfer learning idea is introduced, and the densely connected feature fusion structure is added, so as to achieve the purposes of accelerating the convergence speed of the neural network, reducing the requirements of the neural network on the scale of training data, and reducing the loss of spatial hierarchical information and small object information. Compared with SVM, DBN, and CNN models, the experimental results show that the recognition accuracy of the proposed method is as high as 95. 69% under the constraint of scale window, which has a wide range of application scenarios and practical significance.
Down-Regulation of Overexpressed Sp1 Protein in Human Fibrosarcoma Cell Lines Inhibits Tumor Formation
Authors: Lou Zhenjun , O'Reilly Sandra , Liang Hongyan , Maher Veronica M. , Sleight Stuart D. , McCormick J. Justin
Published: June 2022

Sp1 is a transcription factor for many genes, including genes involved in tumorigenesis. We found that human fibroblast cells malignantly transformed in culture by a carcinogen or by stable transfection of an oncogene express Sp1 at 8-fold to 18-fold higher levels than their parental cells. These cell lines form fibrosarcomas in athymic mice with a very short latency, and the cells from the tumors express the same high levels of Sp1. Similar high levels of Sp1 were found in the patient-derived fibrosarcoma cell lines tested, and in the tumors formed in athymic mice by these cell lines. To investigate the role of overexpression of Sp1 in malignant transformation of human fibroblasts, we transfected an Sp1 U1snRNA/Ribozyme into two human cell lines, malignantly transformed in culture by a carcinogen or overexpression of an oncogene, and into a patient-derived fibrosarcoma cell line. The level of expression of Sp1 in these transfected cell lines was reduced to near normal. The cells regained the spindle-shaped morphology and exhibited increased apoptosis and decreased expression of several genes linked to cancer, i.e., epithelial growth factor receptor, urokinase plasminogen activator, urokinase plasminogen activator receptor, and vascular endothelial growth factor. When injected into athymic mice, these cell lines with near normal levels of Sp1 failed to form tumors or did so only at a greatly reduced frequency and with a much longer latency. These data indicate that overexpression of Sp1 plays a causal role in malignant transformation of human fibroblasts and suggest that for cancers in which it is overexpressed, Sp1 constitutes a target for therapy.
Aberrant Epidermal Growth Factor Receptor Signaling and Enhanced Sensitivity to EGFR Inhibitors in Lung Cancer
Authors: Amann Joseph , Kalyankrishna Shailaja , Massion Pierre P. , Ohm Joyce E. , Girard Luc , Shigematsu Hisayuki , Peyton Michael , Juroske Denise , Huang Yuhui , Stuart Salmon J. , Kim Young H. , Pollack Jonathan R. , Yanagisawa Kiyoshi , Gazdar Adi , Minna John D. , Kurie Jonathan M. , Carbone David P.
Published: June 2022

Epidermal growth factor receptor (EGFR) is occasionally amplified and/or mutated in non–small cell lung cancer (NSCLC) and can be coexpressed with other members of the HER receptor family to form functional heterodimers. We therefore investigated lung cancer cell lines for alterations in EGFR gene copy number, enhanced expression of EGFR and other HER family members, and EGFR coding sequence mutations and correlated these findings with response to treatment with the EGFR inhibitors and the kinetics of ligand-induced signaling. We show here that somatic deletions in the tyrosine kinase domain of EGFR were associated with increased EGFR gene copy number in NSCLC. Treatment with the specific EGFR tyrosine kinase inhibitors (TKI) gefitinib or erlotinib or the EGFR inhibitory antibody cetuximab induced apoptosis of HCC827, a NSCLC cell line with EGFR gene amplification and an exon 19 deletion. H1819, a NSCLC cell line that expresses high levels of EGFR, ErbB2, and ErbB3 but has wild-type EGFR, showed intermediate sensitivity to TKIs. In both cell lines, ligand-induced receptor tyrosine phosphorylation was delayed and prolonged and AKT was constitutively phosphorylated (but remained inhibitable by EGFR TKI). Thus, in addition to EGFR mutations, other factors in NSCLC cells, such as high expression of ErbB family members, may constitutively activate AKT and sensitize cells to EGFR inhibitors.
Gene Transfer–Mediated Pre-mRNA SegmentalTrans-splicing As a Strategy to Deliver Intracellular Toxins for Cancer Therapy
Authors: Nakayama Katsutoshi , Pergolizzi Robert G. , Crystal Ronald G.
Published: June 2022

Virus-mediated transfer of genes coding for intracellular toxins holds promise for cancer therapy, but the inherent toxicity of such vectors make them a risk to normal tissues and a challenge to produce due to the intrinsic dilemma that expression of toxin molecules kills producer cells. We employed pre-mRNA segmental trans-splicing (STS), in which two engineered DNA fragments coding for 5′ “donor” and 3′ “acceptor” segments of a toxin gene, respectively, are expressed by viral vectors. When co-delivered to target cells, the two vectors generate two toxin pre-mRNA fragments which are spliced by the target cell machinery to produce functional mRNA and toxin. To test this approach, we used an enzymatic fragment of Shigatoxin1A1 (STX1A1) known to provoke apoptotic cell death. Two adenovirus vectors, Shigatoxin1A1 donor (AdStx1A1Do) and Shigatoxin1A1 acceptor (AdStx1A1Ac), respectively, were used to deliver the Stx1A1 gene fragments. HeLa, HEp2, and A549 cells transfected with AdStx1A1Do and AdStx1A1Ac had a dose-dependent reduction in viability and inhibition of protein synthesis. Intratumoral injection of AdStx1A1Do and AdStx1A1Ac into preexisting HeLa, Hep2, and A549 tumors in immunodeficient mice revealed significant inhibition of tumor growth. There was no evidence of liver damage, suggesting that there was no leakage of vector or toxin from the site of injection following intratumoral injection of AdStx1A1Do and AdStx1A1Ac. These results suggest that the obstacles preventing gene transfer of intracellular toxins for local cancer therapy could be overcome by pre-mRNA segmental trans-splicing.
Rituximab (Chimeric Anti-CD20 Monoclonal Antibody) Inhibits the Constitutive Nuclear Factor-κB Signaling Pathway in Non-Hodgkin's Lymphoma B-Cell Lines: Role in Sensitization to Chemotherapeutic Drug-induced Apoptosis
Authors: Jazirehi Ali R. , Huerta-Yepez Sara , Cheng Genhong , Bonavida Benjamin
Published: June 2022

The chimeric anti-CD20 antibody rituximab (Rituxan, IDEC-C2B8) is widely used in the clinical treatment of patients with non-Hodgkin's lymphoma (NHL). Rituximab sensitizes NHL B-cell lines to drug-induced apoptosis via down-regulation of Bcl-xL expression. We hypothesized that the mechanism by which rituximab down-regulates Bcl-xL may be, in part, due to inhibition of constitutive nuclear factor-κB (NF-κB) activity that regulates Bcl-xL expression. This hypothesis was tested in CD20+ drug-resistant Ramos (Bcl-2−/Bcl-xL+) and Daudi (Bcl-2+/Bcl-xL+) cell lines. Rituximab decreased the phosphorylation of NF-κB-inducing kinase, IκB kinase, and IκB-α, diminished IKK kinase activity, and decreased NF-κB DNA binding activity. These events occurred with similar kinetics and were observed 3 to 6 hours post-rituximab treatment. Rituximab significantly up-regulated Raf-1 kinase inhibitor protein expression, thus interrupting the NF-κB signaling pathway concomitant with Bcl-xL and Bfl-1/A1 down-regulation. The role of NF-κB in the regulation of Bcl-xL transcription was shown using promoter reporter assays in which deletion of the two-tandem NF-κB binding sites in the upstream promoter region significantly reduced the luciferase activity. This was further corroborated by using IκB superrepressor cells and by NF-κB–specific inhibitors. The direct role of Bcl-xL in drug resistance was assessed by using Bcl-xL–overexpressing cells, which exhibited higher drug resistance that was partially reversed by rituximab. Rituximab-mediated inhibition of the NF-κB signaling pathway and chemosensitization was corroborated by the use of specific inhibitors. These findings reveal a novel pathway mediated by rituximab through Raf-1 kinase inhibitor protein induction that negatively regulates the constitutive NF-κB pathway and chemosensitization of the NHL B-cells.
Attenuation of Proteasome-Induced Proteolysis in Skeletal Muscle by β-Hydroxy-β-Methylbutyrate in Cancer-Induced Muscle Loss
Authors: Smith Helen J. , Mukerji Pradip , Tisdale Michael J.
Published: June 2022

Loss of skeletal muscle is an important determinant of survival in patients with cancer-induced weight loss. The effect of the leucine metabolite β-hydroxy-β-methylbutyrate (HMB) on the reduction of body weight loss and protein degradation in the MAC16 model of cancer-induced weight loss has been compared with that of eicosapentaenoic acid (EPA), a recognized inhibitor of protein degradation. HMB was found to attenuate the development of weight loss at a dose greater than 0.125 g/kg accompanied by a small reduction in tumor growth rate. When EPA was used at a suboptimal dose level (0.6 g/kg) the combination with HMB seemed to enhance the anticachectic effect. Both treatments caused an increase in the wet weight of soleus muscle and a reduction in protein degradation, although there did not seem to be a synergistic effect of the combination. Proteasome activity, determined by the “chymotrypsin-like” enzyme activity, was attenuated by both HMB and EPA. Protein expression of the 20S α or β subunits was reduced by at least 50%, as were the ATPase subunits MSS1 and p42 of the 19S proteasome regulatory subunit. This was accompanied by a reduction in the expression of E214k ubiquitin-conjugating enzyme. The combination of EPA and HMB was at least as effective or more effective than either treatment alone. Attenuation of proteasome expression was reflected as a reduction in protein degradation in gastrocnemius muscle of cachectic mice treated with HMB. In addition, HMB produced a significant stimulation of protein synthesis in skeletal muscle. These results suggest that HMB preserves lean body mass and attenuates protein degradation through down-regulation of the increased expression of key regulatory components of the ubiquitin-proteasome proteolytic pathway, together with stimulation of protein synthesis.
Apolipoprotein E Is Required for Cell Proliferation and Survival in Ovarian Cancer
Authors: Chen Yu-Chi , Pohl Gudrun , Wang Tian-Li , Morin Patrice J. , Risberg Björn , Kristensen Gunnar B. , Yu Albert , Davidson Ben , Shih Ie-Ming
Published: June 2022

Apolipoprotein E (ApoE) has been recently identified as a potential tumor-associated marker in ovarian cancer by serial analysis of gene expression. ApoE has long been known to play a key role in lipid transport, and its specific isoforms may participate in atherosclerogenesis. However, its role in human cancer is not known. In this study, apoE expression was frequently detected in ovarian serous carcinomas, the most common and lethal type of ovarian cancer. It was not detected in serous borderline tumors and normal ovarian surface epithelium. Inhibition of apoE expression using an apoE-specific siRNA led to G2 cell cycle arrest and apoptosis in an apoE-expressing ovarian cancer cell line, OVCAR3, but not in apoE-negative cell lines. Furthermore, the phenotype of apoE siRNA–treated OVCAR3 cells was reversed by expressing engineered mutant apoE with introduced silent mutations in the siRNA target sequence. Expression of apoE in nuclei was significantly associated with a better survival in patients who presented peritoneal effusion at the time of diagnosis (5-year follow-up, P = 0.004). This study suggests a new role of apoE in cancer as apoE expression is important for the proliferation and survival in apoE-expressing ovarian cancer cells.
High-Density Single Nucleotide Polymorphism Array Defines Novel Stage and Location-Dependent Allelic Imbalances in Human Bladder Tumors
Authors: Koed Karen , Wiuf Carsten , Christensen Lise-Lotte , Wikman Friedrik P. , Zieger Karsten , Møller Klaus , von der Maase Hans , Ørntoft Torben F.
Published: June 2022

Bladder cancer is a common disease characterized by multiple recurrences and an invasive disease course in more than 10% of patients. It is of monoclonal or oligoclonal origin and genomic instability has been shown at certain loci. We used a 10,000 single nucleotide polymorphism (SNP) array with an average of 2,700 heterozygous SNPs to detect allelic imbalances (AI) in 37 microdissected bladder tumors from 17 patients. Eight tumors represented upstaging from Ta to T1, eight from T1 to T2+, and one from Ta to T2+. The AI was strongly stage-dependent as four chromosomal arms showed AI in > 50% of Ta samples, eight in T1, and twenty-two in T2+ samples. The tumors showed stage-dependent clonality as 61.3% of AIs were reconfirmed in later T1 tumors and 84.4% in muscle-invasive tumors. Novel unstable chromosomal areas were identified at chromosomes 6q, 10p, 16q, 20p, 20q, and 22q. The tumors separated into two distinct groups, highly stable tumors (all Ta tumors) and unstable tumors (2/3 muscle-invasive). All 11 unstable tumors had lost chromosome 17p areas and 90% chromosome 8 areas affecting Netrin-1/UNC5D/MAP2K4 genes as well as others. AI was present at the TP53 locus in 10 out of 11 unstable tumors, whereas 6 had homozygous TP53 mutations. Tumor distribution pattern reflected AI as seven out of eight patients with additional upper urinary tract tumors had genomic stable bladder tumors (P < 0.05). These data show the power of high-resolution SNP arrays for defining clinically relevant AIs.
Germ Line Fanconi Anemia Complementation Group C Mutations and Pancreatic Cancer
Authors: Couch Fergus J. , Johnson Michele R. , Rabe Kari , Boardman Lisa , McWilliams Robert , de Andrade Mariza , Petersen Gloria
Published: June 2022

Biallelic mutations in Fanconi anemia complementation group genes disrupt DNA repair and result in the complex Fanconi anemia phenotype. In addition, germ line mutations in the BRCA2/FANCD1 Fanconi anemia complementation group gene have also been implicated in predisposition to a number of cancers including pancreatic cancer. The recent identification of FANCC and FANCG mutations in resected pancreatic tumors selected for loss of heterozygosity on chromosome 9, some of which were present in the germ line DNA, suggests that inactivation of these and other Fanconi complementation group genes may contribute to pancreatic cancer. To further assess the relevance of FANCC and FANCG mutations to pancreatic cancer we conducted a mutation screen of these genes in DNA from blood of 421 sequentially collected pancreatic cancer cases diagnosed at the Mayo Clinic. Two truncating FANCC mutations but no truncating FANCG mutations were identified in young onset (<55 years) pancreatic cancer cases with no family history of pancreatic cancer. Both mutations were associated with loss of heterozygosity of the wild-type allele in corresponding pancreatic tumors. In addition, no truncating mutations were identified in germ line DNA from blood of 658 control individuals undergoing routine colonoscopy. Taken together these data support the assertion that inherited mutations in FANCC can predispose to pancreatic cancer.
Functional Evaluation and Cancer Risk Assessment of BRCA2 Unclassified Variants
Authors: Wu Kangjian , Hinson Shannon R. , Ohashi Akihiro , Farrugia Daniel , Wendt Patricia , Tavtigian Sean V. , Deffenbaugh Amie , Goldgar David , Couch Fergus J.
Published: June 2022

The influence of germ line BRCA2 unclassified variants (UCV), including missense mutations and in-frame deletions and insertions on BRCA2 function and on cancer risk, has not been defined although these mutations account for 43% of all identified BRCA2 sequence alterations. To investigate the effects of UCVs on BRCA2 function, we compared mutant and wild-type forms of BRCA2 using assays of cellular survival and viability, homologous recombination repair, and genome instability. We confirm that the effects of known deleterious mutations can be distinguished from neutral polymorphisms and wild-type BRCA2 in these assays, and we characterize the influence of a series of UCVs on BRCA2 function. We also describe how the results from the assays can be combined with data from analysis of cosegregation of the UCVs with cancer, co-occurrence of the UCVs with other deleterious mutations, and interspecies sequence variation in a comprehensive framework in an effort to better distinguish between disease predisposing and neutral UCVs. This combined approach represents a useful means of addressing the functional significance and cancer relevance of UCVs in BRCA2.
E-Cadherin Phosphorylation by Protein Kinase D1/Protein Kinase Cμ is Associated with Altered Cellular Aggregation and Motility in Prostate Cancer
Authors: Jaggi Meena , Rao Prema S. , Smith David J. , Wheelock Margaret J. , Johnson Keith R. , Hemstreet George P. , Balaji K.C.
Published: June 2022

The cadherin family of transmembrane glycoproteins plays a critical role in cell-to-cell adhesion and cadherin dysregulation is strongly associated with cancer metastasis and progression. In this study, we report a novel interaction between protein kinase D1 [PKD1; formerly known as protein kinase C μ (PKCμ)] and E-cadherin. PKD1 is a serine/threonine-specific kinase known to play a role in multiple cellular processes including apoptosis, cytoskeleton remodeling, and invasion. Our study shows that PKD1 colocalizes with E-cadherin at cell junctions in LNCaP prostate cancer cells and coimmunoprecipitates with E-cadherin from lysates of LNCaP cells. In vitro kinase assays have shown that PKD1 phosphorylates E-cadherin. Inhibition of PKD1 activity by the selective inhibitor Gö6976 in LNCaP cells resulted in decreased cellular aggregation and overexpression of PKD1 in C4-2 prostate cancer cells increased cellular aggregation and decreased cellular motility. We also validated the PKD1 and E-cadherin colocalization in human prostate cancer tissue by confocal laser scanning microscopy. Our study has identified E-cadherin as a novel substrate of PKD1, and phosphorylation of E-cadherin by PKD1 is associated with increased cellular aggregation and decreased cellular motility in prostate cancer. Because both E-cadherin and PKD1 are known to be dysregulated in prostate cancer, our study identified an important protein-protein interaction influencing the signal transduction system associated with cell adhesion in prostate cancer.
Ultrasonic Imaging of Tumor Angiogenesis Using Contrast Microbubbles Targeted via the Tumor-Binding Peptide Arginine-Arginine-Leucine
Authors: Weller Gregory E.R. , Wong Michael K.K. , Modzelewski Ruth A. , Lu Erxiong , Klibanov Alexander L. , Wagner William R. , Villanueva Flordeliza S.
Published: June 2022

Endothelial cells (EC) of angiogenic tumor vasculature are characterized by altered expression of molecular markers on their surface. Numerous peptides have been identified that specifically bind tumor angiogenic endothelium, including the tripeptide arginine-arginine-leucine (RRL). We hypothesized that ultrasound contrast microbubbles (MB) targeted via linkage with RRL would specifically adhere to tumor angiogenic endothelium versus normal myocardium, and that this selective adhesion could be detected ultrasonically. Microbubbles were conjugated to cyclic peptides containing either RRL (RRL-MB) or a glycine control sequence (control-MB). As measured in a parallel plate flow chamber, in vitro adhesion of RRL-MBs was three times greater to cultured tumor–derived ECs than to normal ECs (P < 0.01), demonstrating selective binding of RRL-MBs to tumor endothelium. Mice bearing s.c. Clone C or PC3 tumors were given i.v. injections of fluorescent RRL to show in vivo localization to tumor vasculature or were ultrasonically imaged following i.v. injections of targeted contrast MBs. Ultrasound images showed strong RRL-MB contrast enhancement within the tumors but not the control tissue myocardium. Control-MBs caused minimal enhancement in either tissue. Quantitative acoustic videointensity was significantly greater for the tumors than the hearts (5 ± 1 versus 0.5 ± 1 intensity units; P = 0.001). These data show that ultrasound contrast MBs targeted to tumor vasculature via RRL preferentially adhere to tumor versus normal vasculature and that this selective adherence can be detected with ultrasound. Targeted microbubbles may thus offer a noninvasive contrast-enhanced ultrasound imaging technique for the functional imaging of tumor neovascularization, and may have further implications for therapeutic tumor targeting.
Xenoestrogen Action in Prostate Cancer: Pleiotropic Effects Dependent on Androgen Receptor Status
Authors: Wetherill Yelena B. , Fisher Nicola L. , Staubach Ann , Danielsen Mark , de Vere White Ralph W. , Knudsen Karen E.
Published: June 2022

Androgen is critical for prostate development, growth, and survival. Therapies for advanced prostate cancer aim to block androgen receptor (AR) action. However, recurrent tumors ultimately arise, which harbor restored AR activity. One mechanism of such reactivation occurs through AR mutations, rendering the receptor responsive to noncanonical ligands. We have shown previously that a known xenoestrogen, bisphenol A (BPA), activates a tumor-derived AR mutant (T877A), leading to androgen-independent prostate cancer cell proliferation. Here, we show that BPA cooperates with androgen to activate AR-T877A as shown by both reporter assays and increased levels of prostate-specific antigen expression. Further investigations using both yeast and mammalian model systems revealed that multiple AR alleles are responsive to BPA, thus expanding the potential influence of xenoestrogens on prostate cancer. Moreover, in vitro radioligand binding assay revealed that BPA alters 5α-dihydrotestosterone binding to AR-T877A likely through noncompetitive inhibition. We also show that higher concentrations of BPA block proliferation of AR-positive, androgen-dependent prostate adenocarcinoma cells (LNCaP and LAPC-4), with a more modest inhibitory effect on androgen-independent cells (22Rv-1). By contrast, AR-negative prostate cancer cells failed to show growth inhibition after exposure to high BPA dose. Together, these data show that BPA can serve as a potential “hormone sensitizer” of the mutant ARs present in advanced prostate adenocarcinomas, thereby possibly contributing toward therapeutic relapse in advanced prostate cancer patients and supporting the notion that nonsteroidal environmental compounds can alter the function of nuclear receptor complexes.
A DNA Vaccine Targeting Survivin Combines Apoptosis with Suppression of Angiogenesis in Lung Tumor Eradication
Authors: Xiang Rong , Mizutani Noriko , Luo Yunping , Chiodoni Claudia , Zhou He , Mizutani Masato , Ba Yi , Becker Juergen C. , Reisfeld Ralph A.
Published: June 2022

A novel strategy achieved the eradication of lung tumor metastases by joint suppression of angiogenesis in the tumor neovasculature and induction of tumor cell apoptosis. This was accomplished by CTLs induced by a DNA vaccine encoding secretory chemokine CCL21 and the inhibitor of apoptosis protein survivin, overexpressed by both proliferating endothelial cells in the tumor vasculature and tumor cells. Oral delivery of this DNA vaccine by doubly attenuated Salmonella typhimurium (dam− and AroA−) to such secondary lymphoid organs as Peyer's patches in the small intestine, elicited marked activation of antigen-presenting dendritic cells, and an effective CD8+T cell immune response against the survivin self-antigen. This resulted in eradication or suppression of pulmonary metastases of non–small cell lung carcinoma in both prophylactic and therapeutic settings in C57BL/6J mice. Moreover, the suppression of angiogenesis induced by the vaccine did not impair wound healing or fertility of treated mice. It is anticipated that such novel DNA vaccines will aid in the rational design of future strategies for the prevention and treatment of cancer.
Eradication of Established Tumors by Vaccination With RecombinantBordetella pertussisAdenylate Cyclase Carrying the Human Papillomavirus 16 E7 Oncoprotein
Authors: Préville Xavier , Ladant Daniel , Timmerman Benedikt , Leclerc Claude
Published: June 2022

High-risk human papillomaviruses (HPV) such as HPV16 are associated with the development of cervical cancer. The HPV16-E6 and HPV16-E7 oncoproteins are expressed throughout the replicative cycle of the virus and are necessary for the onset and maintenance of malignant transformation. Both these tumor-specific antigens are considered as potential targets for specific CTL-mediated immunotherapy. The adenylate cyclase (CyaA) of Bordetella pertussis is able to target dendritic cells through specific interaction with the αMβ2 integrin. It has been previously shown that this bacterial protein could be used to deliver CD4+ and CD8+ T cell epitopes to the MHC class II and class I presentation pathways to trigger specific Th and CTL responses in vivo, providing protection against subsequent viral or tumoral challenge. Here, we constructed recombinant CyaA containing either the full sequence or various subfragments from the HPV16-E7 protein. We show that, when injected to C57BL/6 mice in absence of any adjuvant, these HPV16-recombinant CyaAs are able to induce specific Th1 and CTL responses. Furthermore, when injected into mice grafted with HPV16-E7-expressing tumor cells (TC-1), one of these recombinant proteins was able to trigger complete tumor regression in 100% of the animals tested. This therapeutic efficacy compared favorably to that of strongly adjuvanted peptide and was marginally affected by prior immunity to CyaA protein. This study represents the first in vivo demonstration of the antitumoral therapeutic activity of recombinant CyaA proteins carrying human tumor–associated antigens and paves the way for the testing of this vector in clinical trials.
Pharmacology and Pharmacodynamics of Bevacizumab as Monotherapy or in Combination with Cytotoxic Therapy in Preclinical Studies
Authors: Gerber Hans-Peter , Ferrara Napoleone
Published: June 2022

Preclinical models have examined the pharmacologic and pharmacodynamic activities of an anti–vascular endothelial growth factor (VEGF) humanized, monoclonal antibody, bevacizumab, and/or its murine equivalent A4.6.1. These studies found that single-agent therapy with bevacizumab/A4.6.1 resulted in tumor growth inhibition of 20 different human tumor cell lines (13 tumor types) implanted into nude mice irrespective of the route of administration or tumor location. Several of these studies also observed significant inhibition of tumor metastases. Various studies have examined the feasibility of combining anti-VEGF therapy with cytotoxic or biological agents. Combining bevacizumab/A4.6.1 with doxorubicin, topotecan, paclitaxel, docetaxel, or radiotherapy resulted in additive or synergistic tumor growth inhibition. Changes in vascular functions were frequently reported, including decreased vessel diameter, density, and permeability in response to treatment. A reduction in interstitial fluid pressure was also observed. In some studies, these improvements resulted in an increase in intratumoral uptake of chemotherapy, implying that the most effective use of anti-VEGF therapy is in combination with chemotherapy. Alternatively, combination treatment with radiation increased tumor oxygenation and tumor growth inhibition. Interestingly, anti-VEGF therapy has also been reported to reduce the development of ascites in ovarian mouse models. Finally, safety pharmacology studies with bevacizumab in cynomolgus monkeys showed that this agent is generally well tolerated with no unexpected adverse events.
Novel Role of Prostate-Specific Membrane Antigen in Suppressing Prostate Cancer Invasiveness
Authors: Ghosh Arundhati , Wang Xinning , Klein Eric , Heston Warren D.W.
Published: June 2022

Prostate-specific membrane antigen (PSMA), a type II transmembrane glycoprotein, is overexpressed in prostate cancer. PSMA is a unique cell surface marker, negatively regulated by androgen and extensively used for imaging of hormone refractory carcinomas and metastatic foci. PSMA is a carboxypeptidase with two important enzymatic functions, namely, folate hydrolase and NAALADase. PSMA also exhibits an endocytic function, in which it spontaneously recycles through endocytic vesicles. PSMA is overexpressed at various stages of prostate cancer, including androgen-sensitive and -independent disease, increased in expression with early relapse after therapy. We have used in vitro invasion assays to explore the possible role of PSMA in the metastasis of prostate cancer cells. Androgen-dependent prostate cancer lines, which express PSMA endogenously (e.g., LNCaP, MDA PCa2b, and CWR22Rv1) are less invasive compared with androgen-independent PC3 or DU145 cells, neither of which expresses PSMA. Ectopic expression of PSMA in PC3 cells reduced the invasiveness of these cells, suggesting that this reduction in the invasion capability of PSMA-expressing cells is due to PSMA expression and not to intrinsic properties of different prostate cancer cell lines. Furthermore, knockdown of PSMA expression increased invasiveness of LNCaP cells by 5-fold. Finally, expression of PSMA mutants lacking carboxypeptidase activity reduced the impact of PSMA expression on invasiveness. Thus, it seems that the enzymatic activity is associated with the effect of PSMA on invasiveness.
A Novel Localization of the G-Protein-Coupled CysLT1 Receptor in the Nucleus of Colorectal Adenocarcinoma Cells
Authors: Nielsen Christian Kamp , Campbell Joan I.A. , Öhd John F. , Mörgelin Matthias , Riesbeck Kristian , Landberg Göran , Sjölander Anita
Published: June 2022

Searching for a link between inflammation and colon cancer, we have found that the inflammatory mediator leukotriene D4 (LTD4), via its receptor CysLT1, induces cyclooxygenase-2 expression, survival, and proliferation in intestinal epithelial cells. In conjunction with our previous observation that CysLT1 receptor expression is increased in colorectal adenocarcinomas, we here found an increased nuclear localization of the CysLT1 receptor in colorectal adenocarcinomas. This novel discovery of CysLT1 receptors in the nucleus was further analyzed. It was found to be located in the outer nuclear membrane in colon cancer cells and in the nontransformed epithelial cell line Int 407 cells by Western blot and electron microscopy. Cancer cells displayed higher amounts of the nuclear CysLT1 receptor, but prolonged LTD4 exposure induced its nuclear translocation in nontransformed cells. Truncation of a nuclear localization sequence abrogated this translocation as well as the LTD4-induced proliferative response. In accordance, nuclear CysLT1 receptors exhibited proliferative extracellular signal-regulated kinase 1/2 signaling. The significance of these experimental findings is supported by the observed correlation between the proliferative marker Ki-67 and nuclear CysLT1 receptor localization in colorectal adenocarcinomas. The present findings indicate that LTD4 cannot only be synthesized but also signal proliferation through nuclear CysLT1 receptors, stressing the importance of leukotrienes in inflammation-induced colon carcinogenesis.