Ultrastructural evidence of @entity6442 -induced differentiation of cultured XXXX @entity694 cells. Increased expression of desmosomes.

@entity1 @entity19 @entity9104 @entity5 @entity189 @entity6442 @entity35 @entity694 @entity420
@entity6442 ( @entity9104 ) induces differentiation of @entity1 @entity694 (DLD-1) cells in culture and reduces their tumorigenicity in @entity19 . The current investigation analyzed DLD-1 ( @entity35 ) cells for ultrastructural evidence of differentiation. Examination of treated and untreated confluent monolayers by transmission electron microscopy revealed an occasional intracytoplasmic lumen indicative of @entity420 . @entity9104 -treated cells showed no signs of a toxic reaction. Cytoplasmic organelles were essentially unchanged except for an increase in tonofilaments and associated desmosomes. The number of desmosomes per unit length of contiguous cell border increased almost sixfold in treated monolayers. No other type of cell junction was seen. The increased frequency of desmosomes in @entity9104 -treated cultures is significant because of the direct correlation known to exist between the number of desmosomes and degree of differentiation of some @entity1 @entity189 . Desmosomes serve as foci of cell adhesion and are reduced in number in some invasive @entity5 . Whether the supernumerary desmosomes in @entity9104 -treated cells contribute to the reduction in malignant behavior of these cells in vivo remains to be determined.
