Analysis of integrin mRNA in human and rodent tumor cells.

Several human and rodent tumor cell lines were examined for the presence of integrin mRNAs by dot- and Northern-blot analysis. All tumor cells tested expressed mRNAs for alpha 5, alpha IIb, beta 1 and beta 3. The mRNA of beta 2 integrin was not detectable and that of alpha V integrin was found only in certain cells. Northern blotting was carried out in three selected tumor cell lines: Clone A, HEL and B16a. An apparent difference in the mRNA species coding for the alpha IIb beta 3 integrin, but not for alpha 5 and beta 1, was found. Our result suggests that alternative splicing of integrin genes may be one of the important mechanisms in regulating alpha IIb beta 3 expression and function in different tumor cells.