PRESENCE OF ATYPICAL LAMININ ON THE SURFACE OF MOUSE LEWIS-LUNG-CARCINOMA CELLS

We investigated the expression and distribution of laminin in Lewis lu ng carcinoma LL2-Lu3 cells. The microscopic immunofluorescence study o f the non-permeabilized cells and blotting assay after immunoprecipita tion with anti-laminin antibodies of biotinylated cell surface protein s demonstrated that LL2-Lu3 cells retained laminin on their cell surfa ces. This laminin was atypical in that it lacked A chain as revealed b y the immunoblot analysis. The results of the reverse transcription po lymerase chain reaction method indicated that LL2-Lu3 cells contained mRNA for B1 and B2 chains, but not A chain corresponding to those of t ypical laminin derived from murine Engelbreth-Holm-Swarm sarcoma. A pr ecursor form of 67 kDa laminin receptor protein was also shown to exis t on the surfaces of LL2-Lu3 cells. These findings suggest that the in teraction between atypical laminin and the precursor form of the 67 kD a laminin receptor protein or. the cell surfaces may function in regul ating cell activities such as metastasis of LL2-Lu3 cells.