In transfection protocols, the expression levels of the transgene is important to define, still is difficult to obtain in certain cell lines such as those derived from T-lymphoma cells. In this study we evaluate transgene expression kinetics in the presence and absence of two well known transcription activators such as phorbol-12-myristate13-acetate (PMA) and Ionomicin (IO). Three murine T lymphoma cell lines (LBC, EL4 and BW5147) were transfected by electroporation using green fluorescent protein (GFP) as a reporter gene and analyzed by flow cytometry. Addition of PMA/IO resulted in a significant increase of the Mean Fluorescence Intensity but not in GFP-positive cell percentages, either in transient or stable transfected LBC and EL4 cells. Remarkable, BW5147 cells showed low GFP induction with a significant increment only in stable transfected cells. Our results demonstrated that CMV promoter activity can be enhanced in transfected lymphoma cells by PMA/IO suggesting that transgene expression levels can be optimized by means of the use of transcription activators.

The TNF-family molecule, RANKL, is a key regulator of bone remodeling and essential for the development and activation of osteoclasis. Bone involvement signals diesease activity in non-Hodgkin's lymphoma and influences the progenesis. The molecular mechanism and soluble factors involved in osteoclastic activation in haematological malignancies remain unclear except for Multiple Myeloma and Adult T-cell Leukemia. The aim of this paper is to report the first case of Follicular Lymphoma with bone involvement displaying an aberrant expression of RANKL in malignant cells. The detection of RANKL in Follicullar Lymphoma may help to prevent bone lesion in patients by determining an appropriate treatment.