An in vitro carcinogenesis model of human skin keratinocytes has been developed based on the spontaneously immortalized keratinocyte cell line HaCaT. Immortalization, the initial stage in human carcinogenesis in vitro, was induced by ultraviolet-type mutations in the p53 gene followed by further gen
Alterations of centromere positions in nuclei of immortalized and malignant mouse lymphocytes
โ Scribed by Rahul Sarkar; Amanda Guffei; Bart J. Vermolen; Yuval Garini; Sabine Mai
- Publisher
- John Wiley and Sons
- Year
- 2007
- Tongue
- English
- Weight
- 739 KB
- Volume
- 71A
- Category
- Article
- ISSN
- 0196-4763
No coin nor oath required. For personal study only.
โฆ Synopsis
Abstract
Background:
The threeโdimensional (3D) positions of centromeres have been studied in several cell systems. However, data on centromere positions during cellular transformation remain elusive. This study has focused on mouse lymphocytes and investigated the centromere positions in primary, immortalized, and tumor cells.
Methods:
Eightyโtoโninety zโslices of each mouse lymphocyte nucleus were acquired using a sampling distance of 107 nm in the xy plane and 200 nm along z for each zโstack, using an Axioplan 2 microscope, an AxioCam HR CCD, a 63ร/1.4 oil objective, and the Axiovision 3.1 software (Carl Zeiss, Canada). A constrained iterative algorithm (Schaefer et al., J Microsc 2001;204:99โ107) was used for deconvolution. Centromere positions in 3D images were analyzed using CentroView, a program we developed to measure nuclear centromere positions.
Results:
Using CentroView we determined the positions of centromeres in primary lymphocytes, immortalized and malignant mouse B cells. We show that centromeres exhibit altered nuclear positions in immortalized and malignant B cells. These changes are independent of previously described cell cycleโdependent centromere dynamics.
Conclusions:
The 3D positions of centromeres are altered during cellular transformation. In lymphocytes, centromeres are found in more central nuclear positions following immortalization and transformation. These nuclear changes reflect structural remodeling of mammalian nuclei during oncogenesis and may impact on the structural organization of chromosomes. How centromeric changes are linked to nuclear remodeling can now be quantitatively examined using the tools of this study. ยฉ 2007 International Society for Analytical Cytology
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