Phorbol esters induce differentiation in human malignant T lymphoblasts

Phorbol Esters Induce Differentiation of Human

T-cell receptor and phorbol esters

The repertoire of novel and atypical protein kinase C (PKC) isotypes present in human T cells and their subcellular localization have not been fully characterized. We detected calciumindependent PKC activity in whole cell fractions from unstimulated peripheral blood lymphocytes (PBL). Towards an understanding of the role of PKC isoforms in lymphocyte activation we have studied the expression of...

Disappearance of terminal deoxynucleotidyltransferase in human malignant T-lymphoblasts treated with a human alpha interferon preparation.

Human T-lymphoblastoid cell lines RPMI 8402, MOLT-3, and CCRF-CEM were treated with interferon (IFN) to determine if the treatment would result in the disappearance of cellular terminaldeoxynucleotidyltransferase (TdT), a possible differentiation marker for T-lymphocytes. Incubation of RPMI 8402 cells in the presence of IFN preparation caused a decrease in the number of TdT-positive cells and i...

Epigenetics of Phorbol Esters, a Tumor Promoter and Differentiation Inducer

Epigenetics is the study of structurally and functionally relevant molecular changes to the genome that do not constitute a change in the nucleotide sequence such as DNA methylation and histone modifications. These changes are involved in the expression and repression of different genes in a particular cell type. Phorbol esters are diterpene compound known as phorbol 12-myristate 13-acetate (PM...

Tumor-promoting Phorbol Esters

The effect of tumor-promoting phorbol esters on the in vitro proliferation of mouse pluripotent hematopoietic stem cells (CFU-S) was examined using a short-term in vitro culture system and an 11-d spleen colony assay. Phorbol myristate acetate (PMA, 10-7 M), but not the inert compound phorbol, supported the in vitro survival of day 11 CFU-S for 72 h in a manner similar to IL 3. PMA also enhance...