@article {223, title = {Analysis of lung tumor initiation and progression in transgenic mice for Cre-inducible overexpression of Cul4A gene.}, journal = {Thorac Cancer}, volume = {6}, year = {2015}, month = {2015 Jul}, pages = {480-7}, abstract = {

BACKGROUND: Lung cancer is the leading cause of morbidity and death worldwide. Although the available lung cancer animal models have been informative and further propel our understanding of human lung cancer, they still do not fully recapitulate the complexities of human lung cancer. The pathogenesis of lung cancer remains highly elusive because of its aggressive biologic nature and considerable heterogeneity, compared to other cancers. The association of Cul4A amplification with aggressive tumor growth and poor prognosis has been suggested. Our previous study suggested that Cul4A is oncogenic in vitro, but its oncogenic role in vivo has not been studied.

METHODS: Viral delivery approaches have been used extensively to model cancer in mouse models. In our experiments, we used Cre-recombinase induced overexpression of the Cul4A gene in transgenic mice to study the role of Cul4A on lung tumor initiation and progression and have developed a new model of lung tumor development in mice harboring a conditionally expressed allele of Cul4A.

RESULTS: Here we show that the use of a recombinant adenovirus expressing Cre-recombinase ("AdenoCre") to induce Cul4A overexpression in the lungs of mice allows controls of the timing and multiplicity of tumor initiation. Following our mouse models, we are able to study the potential role of Cul4A in the development and progression in pulmonary adenocarcinoma as well.

CONCLUSION: Our findings indicate that Cul4A is oncogenic in vivo, and this mouse model is a tool in understanding the mechanisms of Cul4A in human cancers and for testing experimental therapies targeting Cul4A.

}, issn = {1759-7706}, doi = {10.1111/1759-7714.12257}, author = {Wang, Yang and Xu, Zhidong and Jiang-Hua Mao and Hung, Ming-Szu and Hsieh, David and Au, Alfred and Jablons, David M and You, Liang} } @article {227, title = {Cul4A overexpression associated with Gli1 expression in malignant pleural mesothelioma.}, journal = {J Cell Mol Med}, volume = {19}, year = {2015}, month = {2015 Oct}, pages = {2385-96}, abstract = {

Malignant pleural mesothelioma (mesothelioma) is a highly aggressive cancer without an effective treatment. Cul4A, a scaffold protein that recruits substrates for degradation, is amplified in several human cancers, including mesothelioma. We have recently shown that Cul4A plays an oncogenic role in vitro and in a mouse model. In this study, we analysed clinical mesothelioma tumours and found moderate to strong expression of Cul4A in 70.9\% (51/72) of these tumours, as shown by immunohistochemistry. In 72.2\% mesothelioma tumours with increased Cul4A copy number identified by fluorescence in situ hybridization analysis, Cul4A protein expression was moderate to strong. Similarly, Cul4A was overexpressed and Cul4A copy number was increased in human mesothelioma cell lines. Because Gli1 is highly expressed in human mesothelioma cells, we compared Cul4A and Gli1 expression in mesothelioma tumours and found their expression associated (P < 0.05, chi-square). In mesothelioma cell lines, inhibiting Cul4A by siRNA decreased Gli1 expression, suggesting that Gli1 expression is, at least in part, regulated by Cul4A in mesothelioma cells. Our results suggest a linkage between Cul4A and Gli1 expression in human mesothelioma.

}, keywords = {Case-Control Studies, Cell Line, Tumor, Chi-Square Distribution, Cullin Proteins, Gene Dosage, Gene Expression Regulation, Neoplastic, Humans, Immunohistochemistry, Lung Neoplasms, Mesothelioma, Pleural Neoplasms, Real-Time Polymerase Chain Reaction, RNA, Messenger, Transcription Factors}, issn = {1582-4934}, doi = {10.1111/jcmm.12620}, author = {Yang, Yi-Lin and Ni, Jian and Hsu, Ping-Chih and Jiang-Hua Mao and Hsieh, David and Xu, Angela and Chan, Geraldine and Au, Alfred and Xu, Zhidong and Jablons, David M and You, Liang} } @article {221, title = {PR-Set7 is Degraded in a Conditional Cul4A Transgenic Mouse Model of Lung Cancer.}, journal = {Zhongguo Fei Ai Za Zhi}, volume = {18}, year = {2015}, month = {2015 Jun}, pages = {345-50}, abstract = {

BACKGROUND: Maintenance of genomic integrity is essential to ensure normal organismal development and to prevent diseases such as cancer. PR-Set7 (also known as Set8) is a cell cycle regulated enzyme that catalyses monomethylation of histone 4 at Lys20 (H4K20me1) to promote chromosome condensation and prevent DNA damage. Recent studies show that CRL4CDT2-mediated ubiquitylation of PR-Set7 leads to its degradation during S phase and after DNA damage. This might occur to ensure appropriate changes in chromosome structure during the cell cycle or to preserve genome integrity after DNA damage.

METHODS: We developed a new model of lung tumor development in mice harboring a conditionally expressed allele of Cul4A. We have therefore used a mouse model to demonstrate for the first time that Cul4A is oncogenic in vivo. With this model, staining of PR-Set7 in the preneoplastic and tumor lesions in AdenoCre-induced mouse lungs was performed. Meanwhile we identified higher protein level changes of γ-tubulin and pericentrin by IHC.

RESULTS: The level of PR-Set7 down-regulated in the preneoplastic and adenocarcinomous lesions following over-expression of Cul4A. We also identified higher levels of the proteins pericentrin and γ-tubulin in Cul4A mouse lungs induced by AdenoCre.

CONCLUSIONS: PR-Set7 is a direct target of Cul4A for degradation and involved in the formation of lung tumors in the conditional Cul4A transgenic mouse model.

}, keywords = {Animals, Cell Cycle, Cullin Proteins, Disease Models, Animal, Down-Regulation, Histone-Lysine N-Methyltransferase, Histones, Humans, Lung, Lung Neoplasms, Mice, Mice, Transgenic, Proteolysis, Tubulin}, issn = {1999-6187}, doi = {10.3779/j.issn.1009-3419.2015.06.15}, author = {Wang, Yang and Xu, Zhidong and Jiang-Hua Mao and Hsieh, David and Au, Alfred and Jablons, David M and Li, Hui and You, Liang} } @article {208, title = {Lung tumourigenesis in a conditional Cul4A transgenic mouse model.}, journal = {J Pathol}, volume = {233}, year = {2014}, month = {2014 Jun}, pages = {113-23}, abstract = {

Cullin4A (Cul4A) is a scaffold protein that assembles cullin-RING ubiquitin ligase (E3) complexes and regulates many cellular events, including cell survival, development, growth and cell cycle control. Our previous study suggested that Cul4A is oncogenic in vitro, but its oncogenic role in vivo has not been studied. Here, we used a Cul4A transgenic mouse model to study the potential oncogenic role of Cul4A in lung tumour development. After Cul4A over-expression was induced in the lungs for 32 weeks, atypical epithelial cells were observed. After 40 weeks, lung tumours were visible and were characterized as grade I or II adenocarcinomas. Immunohistochemistry (IHC) revealed decreased levels of Cul4A-associated proteins p21(CIP1) and tumour suppressor p19(ARF) in the lung tumours, suggesting that Cul4A regulated their expression in these tumours. Increased levels of p27(KIP1) and p16(INK4a) were also detected in these tumours. Moreover, the protein level of DNA replication licensing factor CDT1 was decreased. Genomic instability in the lung tumours was further analysed by the results from pericentrin protein expression and array comparative genomic hybridization analysis. Furthermore, knocking down Cul4A expression in lung cancer H2170 cells increased their sensitivity to the chemotherapy drug cisplatin in vitro, suggesting that Cul4A over-expression is associated with cisplatin resistance in the cancer cells. Our findings indicate that Cul4A is oncogenic in vivo, and this Cul4A mouse model is a tool in understanding the mechanisms of Cul4A in human cancers and for testing experimental therapies targeting Cul4A.

}, keywords = {Adenocarcinoma, Animals, Antineoplastic Agents, Cell Cycle Proteins, Cell Line, Tumor, Cell Survival, Cell Transformation, Neoplastic, Cisplatin, Cullin Proteins, Cyclin-Dependent Kinase Inhibitor p16, Cyclin-Dependent Kinase Inhibitor p19, Cyclin-Dependent Kinase Inhibitor p21, Cyclin-Dependent Kinase Inhibitor p27, Disease Models, Animal, DNA-Binding Proteins, Dose-Response Relationship, Drug, Drug Resistance, Neoplasm, Gene Expression Regulation, Neoplastic, Genomic Instability, Humans, Lung, Lung Neoplasms, Mice, Mice, Transgenic, Neoplasm Grading, Proliferating Cell Nuclear Antigen, RNA Interference, Time Factors, Transfection, Up-Regulation}, issn = {1096-9896}, doi = {10.1002/path.4352}, author = {Yang, Yi-Lin and Hung, Ming-Szu and Wang, Yang and Ni, Jian and Jiang-Hua Mao and Hsieh, David and Au, Alfred and Kumar, Atul and Quigley, David and Fang, Li Tai and Yeh, Che-Chung and Xu, Zhidong and Jablons, David M and You, Liang} } @article {204, title = {Hematein, a casein kinase II inhibitor, inhibits lung cancer tumor growth in a murine xenograft model.}, journal = {Int J Oncol}, volume = {43}, year = {2013}, month = {2013 Nov}, pages = {1517-22}, abstract = {

Casein kinase II (CK2) inhibitors suppress cancer cell growth. In this study, we examined the inhibitory effects of a novel CK2 inhibitor, hematein, on tumor growth in a murine xenograft model. We found that in lung cancer cells, hematein inhibited cancer cell growth, Akt/PKB Ser129 phosphorylation, the Wnt/TCF pathway and increased apoptosis. In a murine xenograft model of lung cancer, hematein inhibited tumor growth without significant toxicity to the mice tested. Molecular docking showed that hematein binds to CK2α in durable binding sites. Collectively, our results suggest that hematein is an allosteric inhibitor of protein kinase CK2 and has antitumor activity to lung cancer.

}, keywords = {Animals, Apoptosis, Blotting, Western, Casein Kinase II, Enzyme Inhibitors, Female, Hematoxylin, Humans, Immunoenzyme Techniques, Lung Neoplasms, Mice, Mice, Inbred BALB C, Phosphorylation, Proto-Oncogene Proteins c-akt, T Cell Transcription Factor 1, Tumor Cells, Cultured, Wnt Proteins, Xenograft Model Antitumor Assays}, issn = {1791-2423}, doi = {10.3892/ijo.2013.2087}, author = {Hung, Ming-Szu and Xu, Zhidong and Chen, Yu and Smith, Emmanuel and Jiang-Hua Mao and Hsieh, David and Lin, Yu-Ching and Yang, Cheng-Ta and Jablons, David M and You, Liang} } @article {181, title = {Inhibition of CK2α down-regulates Hedgehog/Gli signaling leading to a reduction of a stem-like side population in human lung cancer cells.}, journal = {PLoS One}, volume = {7}, year = {2012}, month = {2012}, pages = {e38996}, abstract = {

Protein kinase CK2 is frequently elevated in a variety of human cancers. The Hedgehog (Hh) signaling pathway has been implicated in stem cell maintenance, and its aberrant activation has been indicated in several types of cancer, including lung cancer. In this study, we show that CK2 is positively involved in Hh/Gli signaling in lung cancer cell lines A549 and H1299. First, we found a correlation between CK2α and Gli1 mRNA levels in 100 primary lung cancer tissues. Down-regulation of Gli1 expression and transcriptional activity were demonstrated after the silencing of CK2α in lung cancer cells. In addition, CK2α siRNA down-regulated the expression of Hh target genes. Furthermore, two small-molecule CK2α inhibitors led to a dose-dependent inhibition of Gli1 expression and transcriptional activity in lung cancer cells. Reversely, forced over-expression of CK2α resulted in an increase both in Gli1 expression and transcriptional activity in A549 cells. Finally, the inhibition of Hh/Gli by CK2α siRNA led to a reduction of a cancer stem cell-like side population that shows higher ABCG2 expression level. Thus, we report that the inhibition of CK2α down-regulates Hh/Gli signaling and subsequently reduces stem-like side population in human lung cancer cells.

}, keywords = {ATP-Binding Cassette Transporters, Carcinoma, Non-Small-Cell Lung, Casein Kinase II, Cell Count, Cell Line, Tumor, Down-Regulation, Gene Expression Regulation, Neoplastic, Gene Knockdown Techniques, Gene Silencing, Humans, Lung Neoplasms, Neoplasm Proteins, Neoplastic Stem Cells, Protein Kinase Inhibitors, Proteolysis, Side-Population Cells, Signal Transduction, Small Molecule Libraries, Transcription Factors, Transcription, Genetic, Transcriptional Activation, Up-Regulation}, issn = {1932-6203}, doi = {10.1371/journal.pone.0038996}, author = {Zhang, Shulin and Wang, Yucheng and Jiang-Hua Mao and Hsieh, David and Kim, Il-Jin and Hu, Li-Min and Xu, Zhidong and Long, Hao and Jablons, David M and You, Liang} }