Attachment sites and biological functions of laminin isolated from murine EHS sarcoma have been well studied. Recently several variants of laminin including human placental laminin have been shown to be distinct from EHS-laminin. This study was undertaken to determine attachment, proliferation, and migration phenomena of human astrocytoma cell lines to human and murine sarcoma EHS-laminin. Using shortterm attachment assays human placental laminin was shown to be the better substrate for cell adhesion. EHS-laminin mediated approximately 30-50% of the effect observed on human laminin. The astrocytoma cells expressed PI, p3, and p4 subunit mRNA as determined by RT-PCR. Anti+, antibodies blocked adhesion to EHS-laminin, but antibodies against PI, p4, and a, subunits were all ineffective in blocking adhesion to human laminin. A migration assay showed that astrocytoma cells on human laminin dispersed from a central seeding area, while cells on EHS-laminin remained where they were seeded. The pattern of dispersion could not be accounted for by changes in growth rates of astrocytoma cells on the different proteins, since both cell lines grew equally well on the two laminins. We conclude that unique epitopes on human laminin are recognized by novel receptors on human astrocytoma cells which confer a migratory phenotype to the Cells. 0 1995 Wiley-Liss, Inc.