Differential distribution of HP1 proteins after trichostatin a treatment influences chromosomal stability in HCT116 and WI-38 cells

Background:
Heterochromatin protein 1 (HP1) is important in the establishment, propagation, and maintenance of constitutive heterochromatin, especially at the pericentromeric region. HP1 might participate in recruiting and directing Mis12 to the centromere during interphase, and HP1 disruption or abrogation might lead to the loss of Mis12 incorporation into the kinetochore. Therefore, the centromere structure and kinetochore relaxation that are promoted in the absence of Mis12 could further induce chromosome instability (CIN) by reducing the capacity of the kinetochore to anchor microtubules. The aim of this study was to determine whether alterations in the localization of HP1 proteins induced by trichostatin A (TSA) modify Mis12 and Centromere Protein A (CENP-A) recruitment to the centromere and whether changes in the expression of HP1 proteins and H3K9 methylation at centromeric chromatin increase CIN in HCT116 and WI-38 cells.
Methods:
HCT116 and WI-38 cells were cultured and treated with TSA to evaluate CIN after 24 and 48?h of exposure. Immunofluorescence, Western blot, ChIP, and RT-PCR assays were performed in both cell lines to evaluate the localization and abundance of HP1?/?, Mis12, and CENP-A and to evaluate chromatin modifications during interphase and mitosis, as well as after 24 and 48?h of TSA treatment.
Results:
Our results show that the TSA-induced reduction in heterochromatic histone marks on centromeric chromatin reduced HP1 at the centromere in the non-tumo...

Source: Cell Division - December 30, 2014 Category: Cytology Authors: Rodrigo González-BarriosErnesto Soto-ReyesRicardo Quiroz-BaezEunice Fabián-MoralesJosé Díaz-ChávezVictor del CastilloJulia MendozaAlejandro López-SaavedraClementina CastroLuis Herrera Source Type: research