Comportamento das celulas musculares lisas nos carcinomas da prostata humana : variações fenotipicas ultraestruturais

AUTOR(ES)

Eduardo Scortegagna

DATA DE PUBLICAÇÃO

2000

RESUMO

The smooth muscle cells of the human prostate were studied at the electron microscopy level from samples of radical prostatectomy in cases of prostate carcinomas. The smooth muscle cells are found in bundies, in which they are intimately associated to each other and with fused basement membrane. With the tumor progression, in the areas of glandular proliferation in the intermediary graded tumors, there is an accumulation of extra cellular matrix between the smooth muscle cells, which loose the homotypic contacts and acquire individualized basement membranes. With the stromal invasion by the epithelial cancer cells, the smooth muscle cells show three different phenotypes: atrophic, activated and degenerated cells. The atrophic cells show a diminished cytop1asmlnucleus ratio, with a marked loss of the contractile component and showing a reduced and frequently disrupted basement membrane. The activated phenotype shows an accumulation of vesicular material at the cell periphery and intense folding of the cell surface in regions of intimate contact with extracellular fibrillar components. Some cells had an increase in the amount of organelles such as the rough endoplasmic reticulum and Golgi while the cytoskeleton is diminished. The cells of the degenerated phenotype have a reduced cytoplasm, collapsed nuclei and expanded perinuclear spaces. The basement membrane around these cells is disrupted A series of conversions between these smooth muscle cell phenotypes is proposed. The modifications observed in this study seem to occur by the lack of a proper stimulation by the epithelium and or from the degradation of the basement membrane by proteolytic enzymes produced by the tumor cells

ASSUNTO(S)

prostata celulas musculares cancer

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