Lymphocytes prime activation is required for nicotine-induced calcium waves.

Lymphocytes are reported to express nicotinic acetylcholine receptors (nAChR). However, no data are available on the expression of these nAChR on activated lymphocyte relatively to resting lymphocytes. In this study, we examined nAChR subunits expression in PHA-stimulated versus un-stimulated lymphocytes, and four leukemic cell lines.

Nicotine induces chromatin changes and c-Jun up-regulation in HL-60 leukemia cells.

Although nicotine has been implicated as a potential factor in the pathogenesis of human cancer, its mechanisms of action regarding cancer development remain largely unknown. HL-60 cells were used to investigate the effects of a short-term treatment with nicotine at concentrations found in the blood of smokers. The findings show that nicotine induces chromatin decondensation, histone H3 acetylation and up-regulation of the c-Jun transcription factor mRNA.

Nuclear chromatin patterns in 3 glucocorticoid-resistant RPMI 8226 human myeloma cell sub-lines: correlations with cell growth and immunological phenotype.

Nuclear morphological alterations associated with glucocorticoid resistance in human myeloma were evaluated by image cytometry in three human myeloma RPMI 8226 cell sub-lines. Resistance was induced by drug selection using prednisone (8226p), methylprednisolone (8226m) and dexamethasone (8226d), respectively. All these three cell sub lines displayed significant glucocorticoid-resistance without cross-resistance to doxorubicin.

Effects of the histone deacetylase inhibitor trichostatin A on nuclear texture and c-jun gene expression in drug-sensitive and drug-resistant human H69 lung carcinoma cells.

Background: Texture analysis of chromatin patterns by image cytometry can be used in the development and refinement of diagnosis and prognosis of cancers and in the follow-up of therapies. However, little is known about the biological mechanisms underlying these patterns. Epigenetic mechanisms as histone posttranslational modifications and particularly histone acetylation could play a major role in the determination of these chromatin patterns and then influence nuclear texture measurements.