Differential Expression of TPX2 upon Differentiation of Human Embryonic Stem Cells

다국어 초록 (Multilingual Abstract)

Embryonic stem (ES) cells are known to have an infinite proliferation and pluripotency that are associated with complex processes. The objective of this study was to examine expression of genes differentially regulated during differentiation of human ES cells by suppression subtractive hybridization (SSH). Human ES cells were induced to differentiate into neural precursor cells via embryoid body. Neural precursor cells were isolated physically based on morphological criteria. Immunocytochemical analysis showed expression of pax6 in neural precursor cells, confirming that the isolated cells were neural precursor cells. Undifferentiated human ES cells and neural precursor cells were subject to the SSH. TPX2 (Targeting Protein for Xklp2 (Xenopus centrosomal kinesin-like protein 2)) was identified, cloned and analyzed during differentiation of human ES cells into neural lineages. Expression of TPX2 was gradually down-regulated in embryoid bodies and neural precursor cells relative to undifferentiated ES cells. Targeting Protein for Xklp2 has been shown to be involved in cell division by interaction with microtubule development in cancer cells. Taken together, result of this study suggests that TPX2 may be involved in proliferation and differentiation of human ES cells.

목차 (Table of Contents)

• ABSTRACT
• INTRODUCTION
• MATERIALS AND METHODS
• Culture of Human ES Cells
• Differentiation of Human ES Cells into Neural Precursor Cells
• Immunocytochemical Analysis
• Extraction of RNA
• Synthesis of cDNA by Reverse Transcription
• Suppression Subtractive Hybridization
• Analysis of Gene Expression by Semi-Quantitative RT-PCR
• RESULTS
• Identification of Differentially Expressed Genes by SSH
• Un-subtracted
• Down-Regulation of TPX2 Expression during Neural Differentiation
• DISCUSSION
• REFFRENCES

참고문헌 (Reference)

1 "hTPX2 is required for normal spindle morphology and centrosome integrity during vertebrate cell division" 12 : 2055-2059, 2002

2 "Totipotency, cell differentiation and reprogramming in humans" 13 : 551-557, 2006

3 "The future of human embryonic stem cell research: addressing ethical conflict with responsible scientific research" 10 : RA99-RA103, 2004

4 "The WHO analgesic ladder for cancer pain management. Stepping up the quality of its evaluation" 274 : 1870-1873, 1995

5 "Technical assessment of the first 20 years of research using mouse embryonic stem cell lines" 22 : 1168-1180, 2004

6 "TPX2 is required for postmitotic nuclear assembly in cell-free Xenopus laevis egg extracts" 173 : 685-694, 2006

7 "TPX2 expression and its significance in squamous cell carcinoma of lung" 35 : 540-544, 2006

8 "Stem cells-biology and therapeutic application" 58 : 202-208, 2004

9 "Self-renewal vs. differentiation of mouse embryonic stem cells" 71 : 1755-1765, 2004

10 "Molecular requirements for kinetochore-associated microtubule formation in mammalian cells" 16 : 536-541, 2006

11 "Modelling microtubule patterns" 8 : 1204-1211, 2006

12 "Microtubule nucleation: gamma-tubulin and beyond" 119 : 4143-4153, 2006

13 "Microfabricated embryonic stem cell divider for large-scale propagation of human embryonic stem cells" 7 : 513-515, 2007

14 "Localization of the kinesin-like protein Xklp2 to spindle poles requires a leucine zipper, a microtubule-associated protein, and dynein" 143 : 673-685, 1998

15 "Kinesin-1 and Dynein are the primary motors for fast transport of mitochondria in Drosophila motor axons" 17 : 2057-2068, 2006

16 Zhang SC, "In vitro differentiation of transplantable neural precursors from human embryonic stem cells" 19 : 1129-1133, 2001

17 "Importin alpha-regulated nucleation of microtubules by TPX2" 22 : 2060-2070, 2003

18 "Identification of differentially expressed genes in human gliomas by DNA microarray and tissue chip techniques" 60 : 6617-6622, 2000

19 "Human embryonic stem cells: an in vitro model to study mechanisms controlling pluripotency in early mammalian deve- lopment" 1 : 119-130, 2005

20 Zhu C, "Functional analysis of human microtubule-based motor proteins, the kinesins and dyneins, in mitosis/cytokinesis using RNA interference" 16 : 3187-3199, 2005

21 "Expression of targeting protein for xklp2 associated with both malignant transformation of respiratory epithelium and progression of squamous cell lung cancer" 12 : 1121-1127, 2006

22 "Establishment and maintenance of human embryonic stem cells on STO, a permanently growing cell line" 69 : 2007-2014, 2003

23 "Embryonic stem cell differentiation: a chromatin perspective" 1 : 100-, 2003

24 "Detection of differentially expressed genes in prostate cancer by combining suppression subtractive hybridization and cDNA library array" 193 : 73-79, 2001

25 "Derivation of neural precursor cells from human embryonic stem cells" 28 : 247-252, 2004

26 "Conversion of embryonic stem cells into neuroectodermal precursors in adherent monoculture" 21 : 183-186, 2003

27 "Comparison of the gene expression profile of undifferentiated human embryonic stem cell lines and differentiating embryoid bodies" 5 : 22-31, 2005

28 "Characterization of the TPX2 domains involved in microtubule nucleation and spindle assembly in Xenopus egg extracts" 15 : 5318-5328, 2004

29 "Bipolarization and poleward flux correlate during Xenopus extract spindle assembly" 15 : 5603-5615, 2004

30 "A profile of differentially expressed genes in primary colorectal cancer using suppression subtractive hybridization" 463 : 77-82, 1999