changes on lysosomal compartment during pma induced differentiation of thp 1 monocytic cells influence of type i and type iv collagens

In this work, the influence of different substrate adhesion during phorbol-12-myristate-13-acetate (PMA)-induced differentiation of THP-1 monocytic cell line was studied. In particular, by morphocytochemical and cytometric approaches, the influence of type I and type IV collagens in an experimental model representative of three phases (initial, intermediate and terminal) of monocyte-macrophage transition was analyzed. The cells in these three phases of differentiation were obtained by using 6, 30 e 60 nM PMA. In this experimental model, referring to adhesion to glass as control, by using the azo-dye coupling method, we have considered the analysis of Acid Phosphatase (AcP) activity as a marker of differentiated status expression, in relation to the acquisition of macrophagic phenotype. Endosomal/lysosomal system was further characterized by taking into account the uptake of fluorescent probe LysoTracker Red. Fluorochromization in the various experimental conditions was analyzed morphologically (fluorescence microscopy) and quantitatively (static cytometry). Data related to lysosome compartment were integrated, from a cytokinetic point of view, by flow cytometry measurements of DNA/protein content. Our results have indicated that type I and type IV collagens were able to influence, with respect to glass adhesion, various differentiation phases. Type I collagen showed the higher effects in the condition of high differentiation (60 nM PMA), causing an increase in AcP activity and lysosomal system. Type IV collagen, besides determining effects on lysosomal compartment of intermediate and terminally differentiated cells, influenced mainly proliferative activity of cells with initial differentiation level (6 nM PMA)

Relationship between actin microfilaments and plasma membrane changes during apoptosis of neoplastic cell lines in different culture conditions

In this study we investigated the relationship between the reorganisation of actin cytoskeleton and the changes at cell surface level (i.e. PS exposure and blebbing) in two neoplastic cell lines during apoptosis: Chang liver cells (adherent culture) and promyelocytic HL-60 cells (suspension culture), treated with the podophyllotoxin derivative VP16. The morphological analysis, performed by means of conventional fluorescence microscopy and confocal laser scanning microscopy, on Chang cells showed that onset and progress of the two processes are synchronised. The initial disassembly of stress fibers was associated with the early PS exposure on the cell surface. Moreover, the accumulation of actin at cortical level appeared strongly associated with an intense labelling for Annexin V and, in some cases, especially in the areas of membrane blebbing. The double staining for actin and PS exposure, quantitatively analysed by flow cytometry in HL-60 cells after different treatment times, demonstrated that the decrease of Annexin V binding in the late stages of apoptosis is associated with the strong reduction of actin labelling probably also due to a proteolytic cleavage. These events were also partially related to variations of 255 the functional state of mitochondria, by analysing cytofluorometrically the dissipation of the inner membrane potential (DYm)

Effects of Cisplatin in Neuroblastoma Rat Cells: Damage to Cellular Organelles

Cisplatin (cisPt) is a chemotherapy agent used as a treatment for several types of cancer. The main cytotoxic effect of cisplatin is generally accepted to be DNA damage. Recently, the mechanism by which cisPt generates the cascade of events involved in the apoptotic process has been demonstrated. In particular it has been shown that some organelles are cisPt target and are involved in cell death. This paper aims to describe the morphological and functional changes of the Golgi apparatus and lysosomes during apoptosis induced in neuronal rat cells (B50) by cisplatin. The results obtained show that the cellular organelles are the target of cisPt, so their damage can induce cell death

Natural History of Malignant Bone Disease in Renal Cancer: Final Results of an Italian Bone Metastasis Survey

Abstract Background: Bone metastasis represents an increasing clinical problem in advanced renal cell carcinoma (RCC) as diseaserelated survival improves. There are few data on the natural history of bone disease in RCC