6533b871fe1ef96bd12d1be8
RESEARCH PRODUCT
Tumor dedifferentiation: an important step in tumor invasion.
Helmut E. GabbertRoland MollR. WagnerC. D. Gerharzsubject
MaleCancer ResearchCD30BiologyAdenocarcinomaMicrofilamentCell junctionIn vivoSurgical oncologyCell MovementmedicineAnimalsNeoplasm InvasivenessCytoskeletonBasement membraneDimethylhydrazinesRats Inbred StrainsGeneral MedicineDesmosomesCell biology12-DimethylhydrazineRatsIsolated Tumor CellsMicroscopy Electronmedicine.anatomical_structureCell Transformation NeoplasticOncologyMicroscopy FluorescenceCytoplasmColonic NeoplasmsImmunologic TechniquesMicroscopy Electron Scanningdescription
Tumor invasion in vivo was studied by light and electron microscopy as well as by immunofluorescence microscopy. Special regard was paid to the grade of tumor differentiation. Dimethylhydrazine-induced murine colonic carcinomas comprising a differentiated and an undifferentiated tumor type with low and high invasiveness respectively, were used. At the invasion front of both tumor types a striking dissociation of the organized tumor cell complexes into isolated tumor cells was found together with a loss of most of the cytological features of differentiation. It is supposed that this process mobilizes the tumor cells from the main tumor bulk enabling them to invade the host tissue by active locomotion. This view is strongly supported by the demonstration of morphological equivalents of active cell movement such as pseudopodia-like cytoplasmic extrusions, adaptive changes of the cell shape and microfilament bundles. Although the proposed mechanism of tumor invasion is essentially the same in both tumor types, the grade of differentiation is nevertheless critical, as in the undifferentiated carcinomas only subtle dedifferentiation steps (loss of basement membrane and cell junctions) are necessary to acquire an invasive status. This fact may explain the comparatively high invasiveness and poor prognosis of undifferentiated carcinomas.
year | journal | country | edition | language |
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1985-10-01 | Clinicalexperimental metastasis |