1.Establishment and application of simple orthotopic kidney and bladder tumor models
Qi ZHANG ; Shanshan WANG ; Dexuan YANG ; Linna LI ; Jianghua LIU ; Pan KEVIN ; Shoujun YUAN
Military Medical Sciences 2015;(7):537-540,545
Objective To establish a simple and useful kidney or bladder orthotopic tumor model used in preclinical pharmacodynamic evaluation.Methods Mouse model of orthotopic renal cancer were established by subrenal capsule implantation.After aspirating urine and irrigating bladder with PBS,the bladder urothelium was slightly impaired to establish the orthotopic bladder tumor model.Then, B-Ultrasound and H&E staining were used to confirm the availability.Results Tumors could be seen 2 weeks after surgery, accompanied by body mass loss of the mice.H&E staining showed that the tumor cells acted as infiltrative growth.The growth of tumor was inhibited by NTX in vivo, the tumor mass inhibitory rate of the KCC-853 orthotopic tumor model was 57.5% of 60 mg/kg NTX treatment and 48.8% in the T24 orthotopic tumor model of 30 mg/kg NTX treatment.Conclusion Our methods for establishing the orthotopic kidney or bladder tumor model are simple and practical.The results indicate that nitroxoline has potential antitumor activity.
2.A transcription assay for EWS oncoproteins in Xenopus oocytes.
King Pan NG ; Felix CHEUNG ; Kevin A W LEE
Protein & Cell 2010;1(10):927-934
Aberrant chromosomal fusion of the Ewing's sarcoma oncogene (EWS) to several different cellular partners produces the Ewing's family of oncoproteins (EWS-fusion-proteins, EFPs) and associated tumors (EFTs). EFPs are potent transcriptional activators, dependent on the N-terminal region of EWS (the EWS-activation-domain, EAD) and this function is thought to be central to EFT oncogenesis and maintenance. Thus EFPs are promising therapeutic targets, but detailed molecular studies will be pivotal for exploring this potential. Such studies have so far largely been restricted to intact mammalian cells while recent evidence has indicated that a mammalian cell-free transcription system may not support bona fide EAD function. Therefore, the lack of manipulatable assays for the EAD presents a significant barrier to progress. Using Xenopus laevis oocytes we describe a plasmid-based micro-injection assay that supports efficient, bona fide EAD transcriptional activity and hence provides a new vehicle for molecular dissection of the EAD.
Animals
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Biological Assay
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Female
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Oncogene Proteins
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genetics
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Oncogenes
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genetics
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Oocytes
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metabolism
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pathology
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RNA-Binding Protein EWS
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genetics
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metabolism
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Sarcoma, Ewing
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genetics
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pathology
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Xenopus
3.The RNA Pol II sub-complex hsRpb4/7 is required for viability of multiple human cell lines.
Yang ZHAO ; Kim K C LI ; King Pan NG ; Chi Ho NG ; Kevin A W LEE
Protein & Cell 2012;3(11):846-854
The evolutionarily conserved RNA Polymerase II Rpb4/7 sub-complex has been thoroughly studied in yeast and impacts gene expression at multiple levels including transcription, mRNA processing and decay. In addition Rpb4/7 exerts differential effects on gene expression in yeast and Rpb4 is not obligatory for yeast (S. cerevisiae) survival. Specialised roles for human (hs) Rpb4/7 have not been extensively described and we have probed this question by depleting hsRpb4/7 in established human cell lines using RNA interference. We find that Rpb4/7 protein levels are inter-dependent and accordingly, the functional effects of depleting either protein are co-incident. hsRpb4/7 exhibits gene-specific effects and cells initially remain viable upon hsRpb4/7 depletion. However prolonged hsRpb4/7 depletion is cytotoxic in the range of cell lines tested. Protracted cell death occurs by an unknown mechanism and in some cases is accompanied by a pronounced elongated cell morphology. In conclusion we provide evidence for a gene-specific role of hsRpb4/7 in human cell viability.
Cell Line
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Cell Nucleus
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metabolism
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Cell Survival
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drug effects
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Gene Expression Profiling
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HeLa Cells
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Humans
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RNA Interference
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RNA Polymerase II
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antagonists & inhibitors
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genetics
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metabolism
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RNA, Small Interfering
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pharmacology