Immunohistochemical demonstration of histone H10 in human breast carcinoma

Abstract

Histone H1(0) is a linker histone subvariant present in tissues of low proliferation rate. It is supposed to participate in the expression and maintenance of the terminal differentiation phenotype. The aim of this work was to study histone H1(0) distribution in human breast carcinoma and its relationship with the processes of proliferation and differentiation. Most of the cells in carcinomas of moderate and high level of differentiation expressed histone H1(0) including cells invading connective and adipose tissues. In low differentiated tumours, the number of H1(0) expressing cells was considerably lower. Staining of myoepithelial cells, when seen, and of stromal fibroblasts was variable. The metastatic malignant cells in the lymph nodes also accumulated H1(0) but lymphocytes were always negative. All immunopositive malignant cells exhibited signs of polymorphism. Double H1(0)/Ki-67 staining showed that the growth fraction in more differentiated tumours belonged to the H1(0)-positive cells, while in poorly differentiated carcinomas it also included a cell subpopulation not expressing H1(0). If expressed, p27Kip1 was always found in H1(0)-positive cells. These findings are inconsistent with the widespread view that histone H1(0) is expressed only in terminally differentiated cells. Rather, they suggest that the protein is expressed in cells in a prolonged intermitotic period irrespective of their level of differentiation. Double H1(0)/Ki-67 immunostaining could be a useful tool in studying the growth fraction in tumours.

Histone H1.5, a novel prostatic cancer marker: an immunohistochemical study

“…The latter results from alteration of chromatin structure [10], DNA methylation, or direct interaction with transcription factors [12,14,15]. Recently, specific histone subtypes have been implicated in tumorigenesis [18][19][20], which will be discussed later on.…”

Histone variant innovation in a rapidly evolving chordate lineage

“…The 5 OdH1 proteins contain comparatively short N- and C-terminal tails. The only linker histone type with similarly short C- and N-termini in vertebrates is H1.0, a replacement variant present mainly in terminally differentiated cells but also found in cells that have entered a prolonged inter-mitotic period [47]. OdH1.1 and the replacement variants OdH1.3 and OdH1.4 have the shortest C-termini and we found them to be the only H1 isoforms present in the endocycling stages of O. dioica , when the majority of cell fates are definitively determined and these cells no longer undergo mitosis.…”

Recent progress in histochemistry and cell biology: the state of the art 2005

“…On the basis of theses findings, the authors propose it as a target for antibody based therapy and its use in immunomagnetic tumor cell enrichment techniques. Kostova et al (2005) have studied the histone H1(0) distribution in human breast carcinoma and its relationship with the processes of proliferation and differentiation. Histone H1(0) is a linker histone subvariant present in tissues of low proliferation rate.…”