Identification and validation of P311 as a glioblastoma invasion gene using laser capture microdissection

The mRNA expression profiles from glioblastoma cells residing at the tumor core and invasive rim of a human tumor resection mere compared. From a sing le tumor specimen, 20,000 single cells from each region were collected by l aser capture microdissection, Differential expression of 50-60 cDNA bands w as detected. One of the sequences overexpressed by the invasive cells showe d 99% homology to the P311 gene, the protein product of which is reported t o localize at focal adhesions. Relative overexpression of P311 by invading glioblastoma cells compared with tumor core was confirmed by quantitative r everse transcription-PCR of six glioblastoma specimens after laser capture microdissection collection of rim and core cells. In vitro studies using an tisense oligodeoxynucleotides and integrin activation confirmed the role of P311 in supporting migration of malignant glioma cells. Immunochemistry st udies confirmed the presence of the P311 protein in tumor cells, particular ly at the invasive edge of human glioblastoma specimens.