Intracellular versican expression in mesenchymal spindle cell tumors contrasts with extracellular expression in epithelial and other tumors--a tissue microarray-based study.

Versican is a large chondroitin sulfate proteoglycan that is an integral component of the extracellular matrix protein. It regulates cell proliferation, adhesion, and migration, and is expressed in a variety of normal tissues and tumors. We studied the pattern of versican expression in various epithelial, mesenchymal, neural, and hematopoietic tumors using immunohistochemistry on tissue microarrays. The primary antibody used was mouse monoclonal antibody to versican (clone 8S270, 1:4000, US Biological). Sections from 3 healing wounds were also included to demonstrate versican expression in reactive tissues. The extracellular matrix in all tissues including all tumors (epithelial and nonepithelial) was positive for versican. However, intracellular cytoplasmic expression of versican was seen only in spindle cells, for example, fibroblasts in healing wounds, 11 of 16 (69%) gastrointestinal stromal tumors and 12 of 42 (28%) smooth muscle tumors. Intracellular versican was not seen in any other tumor [0/344 carcinomas (64 breast, 63 prostate, 61 colorectal, 59 lung, 68 ovarian, and 29 thyroid), 0/22 glioblastoma multiforme, 0/46 lymphomas, and 0/21 melanomas]. As versican plays a role in cell proliferation, differentiation, adhesion, and migration, its differential expression in spindle cell tumors may be associated with the differentiation, progression, and spread of these tumors, which is different from epithelial tumors.